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8132 lines
205 KiB
8132 lines
205 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2012 Alexander Block. All rights reserved. |
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*/ |
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|
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#include <linux/bsearch.h> |
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#include <linux/fs.h> |
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#include <linux/file.h> |
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#include <linux/sort.h> |
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#include <linux/mount.h> |
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#include <linux/xattr.h> |
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#include <linux/posix_acl_xattr.h> |
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#include <linux/radix-tree.h> |
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#include <linux/vmalloc.h> |
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#include <linux/string.h> |
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#include <linux/compat.h> |
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#include <linux/crc32c.h> |
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#include <linux/fsverity.h> |
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|
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#include "send.h" |
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#include "ctree.h" |
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#include "backref.h" |
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#include "locking.h" |
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#include "disk-io.h" |
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#include "btrfs_inode.h" |
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#include "transaction.h" |
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#include "compression.h" |
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#include "xattr.h" |
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#include "print-tree.h" |
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|
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/* |
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* Maximum number of references an extent can have in order for us to attempt to |
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* issue clone operations instead of write operations. This currently exists to |
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* avoid hitting limitations of the backreference walking code (taking a lot of |
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* time and using too much memory for extents with large number of references). |
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*/ |
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#define SEND_MAX_EXTENT_REFS 64 |
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|
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/* |
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* A fs_path is a helper to dynamically build path names with unknown size. |
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* It reallocates the internal buffer on demand. |
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* It allows fast adding of path elements on the right side (normal path) and |
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* fast adding to the left side (reversed path). A reversed path can also be |
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* unreversed if needed. |
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*/ |
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struct fs_path { |
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union { |
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struct { |
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char *start; |
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char *end; |
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|
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char *buf; |
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unsigned short buf_len:15; |
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unsigned short reversed:1; |
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char inline_buf[]; |
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}; |
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/* |
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* Average path length does not exceed 200 bytes, we'll have |
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* better packing in the slab and higher chance to satisfy |
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* a allocation later during send. |
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*/ |
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char pad[256]; |
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}; |
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}; |
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#define FS_PATH_INLINE_SIZE \ |
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(sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf)) |
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|
|
|
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/* reused for each extent */ |
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struct clone_root { |
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struct btrfs_root *root; |
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u64 ino; |
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u64 offset; |
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|
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u64 found_refs; |
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}; |
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|
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#define SEND_CTX_MAX_NAME_CACHE_SIZE 128 |
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#define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2) |
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|
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struct send_ctx { |
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struct file *send_filp; |
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loff_t send_off; |
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char *send_buf; |
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u32 send_size; |
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u32 send_max_size; |
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/* |
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* Whether BTRFS_SEND_A_DATA attribute was already added to current |
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* command (since protocol v2, data must be the last attribute). |
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*/ |
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bool put_data; |
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struct page **send_buf_pages; |
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u64 flags; /* 'flags' member of btrfs_ioctl_send_args is u64 */ |
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/* Protocol version compatibility requested */ |
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u32 proto; |
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|
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struct btrfs_root *send_root; |
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struct btrfs_root *parent_root; |
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struct clone_root *clone_roots; |
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int clone_roots_cnt; |
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|
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/* current state of the compare_tree call */ |
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struct btrfs_path *left_path; |
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struct btrfs_path *right_path; |
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struct btrfs_key *cmp_key; |
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|
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/* |
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* Keep track of the generation of the last transaction that was used |
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* for relocating a block group. This is periodically checked in order |
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* to detect if a relocation happened since the last check, so that we |
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* don't operate on stale extent buffers for nodes (level >= 1) or on |
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* stale disk_bytenr values of file extent items. |
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*/ |
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u64 last_reloc_trans; |
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|
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/* |
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* infos of the currently processed inode. In case of deleted inodes, |
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* these are the values from the deleted inode. |
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*/ |
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u64 cur_ino; |
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u64 cur_inode_gen; |
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u64 cur_inode_size; |
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u64 cur_inode_mode; |
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u64 cur_inode_rdev; |
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u64 cur_inode_last_extent; |
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u64 cur_inode_next_write_offset; |
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bool cur_inode_new; |
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bool cur_inode_new_gen; |
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bool cur_inode_deleted; |
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bool ignore_cur_inode; |
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bool cur_inode_needs_verity; |
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void *verity_descriptor; |
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|
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u64 send_progress; |
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|
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struct list_head new_refs; |
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struct list_head deleted_refs; |
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|
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struct radix_tree_root name_cache; |
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struct list_head name_cache_list; |
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int name_cache_size; |
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|
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/* |
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* The inode we are currently processing. It's not NULL only when we |
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* need to issue write commands for data extents from this inode. |
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*/ |
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struct inode *cur_inode; |
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struct file_ra_state ra; |
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u64 page_cache_clear_start; |
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bool clean_page_cache; |
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|
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/* |
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* We process inodes by their increasing order, so if before an |
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* incremental send we reverse the parent/child relationship of |
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* directories such that a directory with a lower inode number was |
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* the parent of a directory with a higher inode number, and the one |
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* becoming the new parent got renamed too, we can't rename/move the |
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* directory with lower inode number when we finish processing it - we |
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* must process the directory with higher inode number first, then |
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* rename/move it and then rename/move the directory with lower inode |
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* number. Example follows. |
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* |
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* Tree state when the first send was performed: |
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* |
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* . |
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* |-- a (ino 257) |
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* |-- b (ino 258) |
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* | |
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* | |
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* |-- c (ino 259) |
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* | |-- d (ino 260) |
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* | |
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* |-- c2 (ino 261) |
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* |
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* Tree state when the second (incremental) send is performed: |
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* |
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* . |
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* |-- a (ino 257) |
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* |-- b (ino 258) |
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* |-- c2 (ino 261) |
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* |-- d2 (ino 260) |
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* |-- cc (ino 259) |
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* |
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* The sequence of steps that lead to the second state was: |
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* |
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* mv /a/b/c/d /a/b/c2/d2 |
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* mv /a/b/c /a/b/c2/d2/cc |
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* |
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* "c" has lower inode number, but we can't move it (2nd mv operation) |
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* before we move "d", which has higher inode number. |
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* |
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* So we just memorize which move/rename operations must be performed |
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* later when their respective parent is processed and moved/renamed. |
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*/ |
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|
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/* Indexed by parent directory inode number. */ |
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struct rb_root pending_dir_moves; |
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|
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/* |
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* Reverse index, indexed by the inode number of a directory that |
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* is waiting for the move/rename of its immediate parent before its |
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* own move/rename can be performed. |
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*/ |
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struct rb_root waiting_dir_moves; |
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|
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/* |
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* A directory that is going to be rm'ed might have a child directory |
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* which is in the pending directory moves index above. In this case, |
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* the directory can only be removed after the move/rename of its child |
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* is performed. Example: |
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* |
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* Parent snapshot: |
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* |
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* . (ino 256) |
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* |-- a/ (ino 257) |
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* |-- b/ (ino 258) |
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* |-- c/ (ino 259) |
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* | |-- x/ (ino 260) |
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* | |
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* |-- y/ (ino 261) |
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* |
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* Send snapshot: |
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* |
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* . (ino 256) |
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* |-- a/ (ino 257) |
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* |-- b/ (ino 258) |
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* |-- YY/ (ino 261) |
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* |-- x/ (ino 260) |
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* |
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* Sequence of steps that lead to the send snapshot: |
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* rm -f /a/b/c/foo.txt |
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* mv /a/b/y /a/b/YY |
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* mv /a/b/c/x /a/b/YY |
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* rmdir /a/b/c |
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* |
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* When the child is processed, its move/rename is delayed until its |
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* parent is processed (as explained above), but all other operations |
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* like update utimes, chown, chgrp, etc, are performed and the paths |
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* that it uses for those operations must use the orphanized name of |
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* its parent (the directory we're going to rm later), so we need to |
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* memorize that name. |
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* |
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* Indexed by the inode number of the directory to be deleted. |
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*/ |
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struct rb_root orphan_dirs; |
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|
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struct rb_root rbtree_new_refs; |
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struct rb_root rbtree_deleted_refs; |
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}; |
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|
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struct pending_dir_move { |
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struct rb_node node; |
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struct list_head list; |
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u64 parent_ino; |
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u64 ino; |
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u64 gen; |
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struct list_head update_refs; |
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}; |
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|
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struct waiting_dir_move { |
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struct rb_node node; |
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u64 ino; |
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/* |
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* There might be some directory that could not be removed because it |
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* was waiting for this directory inode to be moved first. Therefore |
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* after this directory is moved, we can try to rmdir the ino rmdir_ino. |
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*/ |
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u64 rmdir_ino; |
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u64 rmdir_gen; |
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bool orphanized; |
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}; |
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|
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struct orphan_dir_info { |
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struct rb_node node; |
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u64 ino; |
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u64 gen; |
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u64 last_dir_index_offset; |
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}; |
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|
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struct name_cache_entry { |
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struct list_head list; |
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/* |
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* radix_tree has only 32bit entries but we need to handle 64bit inums. |
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* We use the lower 32bit of the 64bit inum to store it in the tree. If |
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* more then one inum would fall into the same entry, we use radix_list |
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* to store the additional entries. radix_list is also used to store |
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* entries where two entries have the same inum but different |
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* generations. |
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*/ |
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struct list_head radix_list; |
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u64 ino; |
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u64 gen; |
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u64 parent_ino; |
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u64 parent_gen; |
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int ret; |
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int need_later_update; |
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int name_len; |
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char name[]; |
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}; |
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|
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#define ADVANCE 1 |
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#define ADVANCE_ONLY_NEXT -1 |
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|
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enum btrfs_compare_tree_result { |
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BTRFS_COMPARE_TREE_NEW, |
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BTRFS_COMPARE_TREE_DELETED, |
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BTRFS_COMPARE_TREE_CHANGED, |
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BTRFS_COMPARE_TREE_SAME, |
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}; |
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|
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__cold |
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static void inconsistent_snapshot_error(struct send_ctx *sctx, |
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enum btrfs_compare_tree_result result, |
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const char *what) |
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{ |
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const char *result_string; |
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|
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switch (result) { |
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case BTRFS_COMPARE_TREE_NEW: |
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result_string = "new"; |
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break; |
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case BTRFS_COMPARE_TREE_DELETED: |
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result_string = "deleted"; |
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break; |
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case BTRFS_COMPARE_TREE_CHANGED: |
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result_string = "updated"; |
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break; |
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case BTRFS_COMPARE_TREE_SAME: |
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ASSERT(0); |
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result_string = "unchanged"; |
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break; |
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default: |
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ASSERT(0); |
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result_string = "unexpected"; |
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} |
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|
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btrfs_err(sctx->send_root->fs_info, |
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"Send: inconsistent snapshot, found %s %s for inode %llu without updated inode item, send root is %llu, parent root is %llu", |
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result_string, what, sctx->cmp_key->objectid, |
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sctx->send_root->root_key.objectid, |
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(sctx->parent_root ? |
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sctx->parent_root->root_key.objectid : 0)); |
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} |
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|
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__maybe_unused |
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static bool proto_cmd_ok(const struct send_ctx *sctx, int cmd) |
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{ |
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switch (sctx->proto) { |
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case 1: return cmd <= BTRFS_SEND_C_MAX_V1; |
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case 2: return cmd <= BTRFS_SEND_C_MAX_V2; |
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case 3: return cmd <= BTRFS_SEND_C_MAX_V3; |
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default: return false; |
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} |
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} |
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|
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static int is_waiting_for_move(struct send_ctx *sctx, u64 ino); |
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|
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static struct waiting_dir_move * |
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get_waiting_dir_move(struct send_ctx *sctx, u64 ino); |
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|
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static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino, u64 gen); |
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|
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static int need_send_hole(struct send_ctx *sctx) |
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{ |
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return (sctx->parent_root && !sctx->cur_inode_new && |
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!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted && |
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S_ISREG(sctx->cur_inode_mode)); |
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} |
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|
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static void fs_path_reset(struct fs_path *p) |
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{ |
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if (p->reversed) { |
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p->start = p->buf + p->buf_len - 1; |
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p->end = p->start; |
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*p->start = 0; |
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} else { |
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p->start = p->buf; |
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p->end = p->start; |
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*p->start = 0; |
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} |
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} |
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|
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static struct fs_path *fs_path_alloc(void) |
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{ |
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struct fs_path *p; |
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|
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p = kmalloc(sizeof(*p), GFP_KERNEL); |
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if (!p) |
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return NULL; |
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p->reversed = 0; |
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p->buf = p->inline_buf; |
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p->buf_len = FS_PATH_INLINE_SIZE; |
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fs_path_reset(p); |
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return p; |
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} |
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|
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static struct fs_path *fs_path_alloc_reversed(void) |
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{ |
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struct fs_path *p; |
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|
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p = fs_path_alloc(); |
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if (!p) |
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return NULL; |
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p->reversed = 1; |
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fs_path_reset(p); |
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return p; |
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} |
|
|
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static void fs_path_free(struct fs_path *p) |
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{ |
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if (!p) |
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return; |
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if (p->buf != p->inline_buf) |
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kfree(p->buf); |
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kfree(p); |
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} |
|
|
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static int fs_path_len(struct fs_path *p) |
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{ |
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return p->end - p->start; |
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} |
|
|
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static int fs_path_ensure_buf(struct fs_path *p, int len) |
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{ |
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char *tmp_buf; |
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int path_len; |
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int old_buf_len; |
|
|
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len++; |
|
|
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if (p->buf_len >= len) |
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return 0; |
|
|
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if (len > PATH_MAX) { |
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WARN_ON(1); |
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return -ENOMEM; |
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} |
|
|
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path_len = p->end - p->start; |
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old_buf_len = p->buf_len; |
|
|
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/* |
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* First time the inline_buf does not suffice |
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*/ |
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if (p->buf == p->inline_buf) { |
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tmp_buf = kmalloc(len, GFP_KERNEL); |
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if (tmp_buf) |
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memcpy(tmp_buf, p->buf, old_buf_len); |
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} else { |
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tmp_buf = krealloc(p->buf, len, GFP_KERNEL); |
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} |
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if (!tmp_buf) |
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return -ENOMEM; |
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p->buf = tmp_buf; |
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/* |
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* The real size of the buffer is bigger, this will let the fast path |
|
* happen most of the time |
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*/ |
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p->buf_len = ksize(p->buf); |
|
|
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if (p->reversed) { |
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tmp_buf = p->buf + old_buf_len - path_len - 1; |
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p->end = p->buf + p->buf_len - 1; |
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p->start = p->end - path_len; |
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memmove(p->start, tmp_buf, path_len + 1); |
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} else { |
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p->start = p->buf; |
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p->end = p->start + path_len; |
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} |
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return 0; |
|
} |
|
|
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static int fs_path_prepare_for_add(struct fs_path *p, int name_len, |
|
char **prepared) |
|
{ |
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int ret; |
|
int new_len; |
|
|
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new_len = p->end - p->start + name_len; |
|
if (p->start != p->end) |
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new_len++; |
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ret = fs_path_ensure_buf(p, new_len); |
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if (ret < 0) |
|
goto out; |
|
|
|
if (p->reversed) { |
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if (p->start != p->end) |
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*--p->start = '/'; |
|
p->start -= name_len; |
|
*prepared = p->start; |
|
} else { |
|
if (p->start != p->end) |
|
*p->end++ = '/'; |
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*prepared = p->end; |
|
p->end += name_len; |
|
*p->end = 0; |
|
} |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static int fs_path_add(struct fs_path *p, const char *name, int name_len) |
|
{ |
|
int ret; |
|
char *prepared; |
|
|
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ret = fs_path_prepare_for_add(p, name_len, &prepared); |
|
if (ret < 0) |
|
goto out; |
|
memcpy(prepared, name, name_len); |
|
|
|
out: |
|
return ret; |
|
} |
|
|
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static int fs_path_add_path(struct fs_path *p, struct fs_path *p2) |
|
{ |
|
int ret; |
|
char *prepared; |
|
|
|
ret = fs_path_prepare_for_add(p, p2->end - p2->start, &prepared); |
|
if (ret < 0) |
|
goto out; |
|
memcpy(prepared, p2->start, p2->end - p2->start); |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static int fs_path_add_from_extent_buffer(struct fs_path *p, |
|
struct extent_buffer *eb, |
|
unsigned long off, int len) |
|
{ |
|
int ret; |
|
char *prepared; |
|
|
|
ret = fs_path_prepare_for_add(p, len, &prepared); |
|
if (ret < 0) |
|
goto out; |
|
|
|
read_extent_buffer(eb, prepared, off, len); |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static int fs_path_copy(struct fs_path *p, struct fs_path *from) |
|
{ |
|
p->reversed = from->reversed; |
|
fs_path_reset(p); |
|
|
|
return fs_path_add_path(p, from); |
|
} |
|
|
|
static void fs_path_unreverse(struct fs_path *p) |
|
{ |
|
char *tmp; |
|
int len; |
|
|
|
if (!p->reversed) |
|
return; |
|
|
|
tmp = p->start; |
|
len = p->end - p->start; |
|
p->start = p->buf; |
|
p->end = p->start + len; |
|
memmove(p->start, tmp, len + 1); |
|
p->reversed = 0; |
|
} |
|
|
|
static struct btrfs_path *alloc_path_for_send(void) |
|
{ |
|
struct btrfs_path *path; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return NULL; |
|
path->search_commit_root = 1; |
|
path->skip_locking = 1; |
|
path->need_commit_sem = 1; |
|
return path; |
|
} |
|
|
|
static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off) |
|
{ |
|
int ret; |
|
u32 pos = 0; |
|
|
|
while (pos < len) { |
|
ret = kernel_write(filp, buf + pos, len - pos, off); |
|
if (ret < 0) |
|
return ret; |
|
if (ret == 0) |
|
return -EIO; |
|
pos += ret; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len) |
|
{ |
|
struct btrfs_tlv_header *hdr; |
|
int total_len = sizeof(*hdr) + len; |
|
int left = sctx->send_max_size - sctx->send_size; |
|
|
|
if (WARN_ON_ONCE(sctx->put_data)) |
|
return -EINVAL; |
|
|
|
if (unlikely(left < total_len)) |
|
return -EOVERFLOW; |
|
|
|
hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size); |
|
put_unaligned_le16(attr, &hdr->tlv_type); |
|
put_unaligned_le16(len, &hdr->tlv_len); |
|
memcpy(hdr + 1, data, len); |
|
sctx->send_size += total_len; |
|
|
|
return 0; |
|
} |
|
|
|
#define TLV_PUT_DEFINE_INT(bits) \ |
|
static int tlv_put_u##bits(struct send_ctx *sctx, \ |
|
u##bits attr, u##bits value) \ |
|
{ \ |
|
__le##bits __tmp = cpu_to_le##bits(value); \ |
|
return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \ |
|
} |
|
|
|
TLV_PUT_DEFINE_INT(8) |
|
TLV_PUT_DEFINE_INT(32) |
|
TLV_PUT_DEFINE_INT(64) |
|
|
|
static int tlv_put_string(struct send_ctx *sctx, u16 attr, |
|
const char *str, int len) |
|
{ |
|
if (len == -1) |
|
len = strlen(str); |
|
return tlv_put(sctx, attr, str, len); |
|
} |
|
|
|
static int tlv_put_uuid(struct send_ctx *sctx, u16 attr, |
|
const u8 *uuid) |
|
{ |
|
return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE); |
|
} |
|
|
|
static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr, |
|
struct extent_buffer *eb, |
|
struct btrfs_timespec *ts) |
|
{ |
|
struct btrfs_timespec bts; |
|
read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts)); |
|
return tlv_put(sctx, attr, &bts, sizeof(bts)); |
|
} |
|
|
|
|
|
#define TLV_PUT(sctx, attrtype, data, attrlen) \ |
|
do { \ |
|
ret = tlv_put(sctx, attrtype, data, attrlen); \ |
|
if (ret < 0) \ |
|
goto tlv_put_failure; \ |
|
} while (0) |
|
|
|
#define TLV_PUT_INT(sctx, attrtype, bits, value) \ |
|
do { \ |
|
ret = tlv_put_u##bits(sctx, attrtype, value); \ |
|
if (ret < 0) \ |
|
goto tlv_put_failure; \ |
|
} while (0) |
|
|
|
#define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data) |
|
#define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data) |
|
#define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data) |
|
#define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data) |
|
#define TLV_PUT_STRING(sctx, attrtype, str, len) \ |
|
do { \ |
|
ret = tlv_put_string(sctx, attrtype, str, len); \ |
|
if (ret < 0) \ |
|
goto tlv_put_failure; \ |
|
} while (0) |
|
#define TLV_PUT_PATH(sctx, attrtype, p) \ |
|
do { \ |
|
ret = tlv_put_string(sctx, attrtype, p->start, \ |
|
p->end - p->start); \ |
|
if (ret < 0) \ |
|
goto tlv_put_failure; \ |
|
} while(0) |
|
#define TLV_PUT_UUID(sctx, attrtype, uuid) \ |
|
do { \ |
|
ret = tlv_put_uuid(sctx, attrtype, uuid); \ |
|
if (ret < 0) \ |
|
goto tlv_put_failure; \ |
|
} while (0) |
|
#define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \ |
|
do { \ |
|
ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \ |
|
if (ret < 0) \ |
|
goto tlv_put_failure; \ |
|
} while (0) |
|
|
|
static int send_header(struct send_ctx *sctx) |
|
{ |
|
struct btrfs_stream_header hdr; |
|
|
|
strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC); |
|
hdr.version = cpu_to_le32(sctx->proto); |
|
return write_buf(sctx->send_filp, &hdr, sizeof(hdr), |
|
&sctx->send_off); |
|
} |
|
|
|
/* |
|
* For each command/item we want to send to userspace, we call this function. |
|
*/ |
|
static int begin_cmd(struct send_ctx *sctx, int cmd) |
|
{ |
|
struct btrfs_cmd_header *hdr; |
|
|
|
if (WARN_ON(!sctx->send_buf)) |
|
return -EINVAL; |
|
|
|
BUG_ON(sctx->send_size); |
|
|
|
sctx->send_size += sizeof(*hdr); |
|
hdr = (struct btrfs_cmd_header *)sctx->send_buf; |
|
put_unaligned_le16(cmd, &hdr->cmd); |
|
|
|
return 0; |
|
} |
|
|
|
static int send_cmd(struct send_ctx *sctx) |
|
{ |
|
int ret; |
|
struct btrfs_cmd_header *hdr; |
|
u32 crc; |
|
|
|
hdr = (struct btrfs_cmd_header *)sctx->send_buf; |
|
put_unaligned_le32(sctx->send_size - sizeof(*hdr), &hdr->len); |
|
put_unaligned_le32(0, &hdr->crc); |
|
|
|
crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size); |
|
put_unaligned_le32(crc, &hdr->crc); |
|
|
|
ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size, |
|
&sctx->send_off); |
|
|
|
sctx->send_size = 0; |
|
sctx->put_data = false; |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Sends a move instruction to user space |
|
*/ |
|
static int send_rename(struct send_ctx *sctx, |
|
struct fs_path *from, struct fs_path *to) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret; |
|
|
|
btrfs_debug(fs_info, "send_rename %s -> %s", from->start, to->start); |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from); |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Sends a link instruction to user space |
|
*/ |
|
static int send_link(struct send_ctx *sctx, |
|
struct fs_path *path, struct fs_path *lnk) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret; |
|
|
|
btrfs_debug(fs_info, "send_link %s -> %s", path->start, lnk->start); |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_LINK); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Sends an unlink instruction to user space |
|
*/ |
|
static int send_unlink(struct send_ctx *sctx, struct fs_path *path) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret; |
|
|
|
btrfs_debug(fs_info, "send_unlink %s", path->start); |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Sends a rmdir instruction to user space |
|
*/ |
|
static int send_rmdir(struct send_ctx *sctx, struct fs_path *path) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret; |
|
|
|
btrfs_debug(fs_info, "send_rmdir %s", path->start); |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
return ret; |
|
} |
|
|
|
struct btrfs_inode_info { |
|
u64 size; |
|
u64 gen; |
|
u64 mode; |
|
u64 uid; |
|
u64 gid; |
|
u64 rdev; |
|
u64 fileattr; |
|
u64 nlink; |
|
}; |
|
|
|
/* |
|
* Helper function to retrieve some fields from an inode item. |
|
*/ |
|
static int get_inode_info(struct btrfs_root *root, u64 ino, |
|
struct btrfs_inode_info *info) |
|
{ |
|
int ret; |
|
struct btrfs_path *path; |
|
struct btrfs_inode_item *ii; |
|
struct btrfs_key key; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
key.objectid = ino; |
|
key.type = BTRFS_INODE_ITEM_KEY; |
|
key.offset = 0; |
|
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
|
if (ret) { |
|
if (ret > 0) |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
|
|
if (!info) |
|
goto out; |
|
|
|
ii = btrfs_item_ptr(path->nodes[0], path->slots[0], |
|
struct btrfs_inode_item); |
|
info->size = btrfs_inode_size(path->nodes[0], ii); |
|
info->gen = btrfs_inode_generation(path->nodes[0], ii); |
|
info->mode = btrfs_inode_mode(path->nodes[0], ii); |
|
info->uid = btrfs_inode_uid(path->nodes[0], ii); |
|
info->gid = btrfs_inode_gid(path->nodes[0], ii); |
|
info->rdev = btrfs_inode_rdev(path->nodes[0], ii); |
|
info->nlink = btrfs_inode_nlink(path->nodes[0], ii); |
|
/* |
|
* Transfer the unchanged u64 value of btrfs_inode_item::flags, that's |
|
* otherwise logically split to 32/32 parts. |
|
*/ |
|
info->fileattr = btrfs_inode_flags(path->nodes[0], ii); |
|
|
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int get_inode_gen(struct btrfs_root *root, u64 ino, u64 *gen) |
|
{ |
|
int ret; |
|
struct btrfs_inode_info info; |
|
|
|
if (!gen) |
|
return -EPERM; |
|
|
|
ret = get_inode_info(root, ino, &info); |
|
if (!ret) |
|
*gen = info.gen; |
|
return ret; |
|
} |
|
|
|
typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index, |
|
struct fs_path *p, |
|
void *ctx); |
|
|
|
/* |
|
* Helper function to iterate the entries in ONE btrfs_inode_ref or |
|
* btrfs_inode_extref. |
|
* The iterate callback may return a non zero value to stop iteration. This can |
|
* be a negative value for error codes or 1 to simply stop it. |
|
* |
|
* path must point to the INODE_REF or INODE_EXTREF when called. |
|
*/ |
|
static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path, |
|
struct btrfs_key *found_key, int resolve, |
|
iterate_inode_ref_t iterate, void *ctx) |
|
{ |
|
struct extent_buffer *eb = path->nodes[0]; |
|
struct btrfs_inode_ref *iref; |
|
struct btrfs_inode_extref *extref; |
|
struct btrfs_path *tmp_path; |
|
struct fs_path *p; |
|
u32 cur = 0; |
|
u32 total; |
|
int slot = path->slots[0]; |
|
u32 name_len; |
|
char *start; |
|
int ret = 0; |
|
int num = 0; |
|
int index; |
|
u64 dir; |
|
unsigned long name_off; |
|
unsigned long elem_size; |
|
unsigned long ptr; |
|
|
|
p = fs_path_alloc_reversed(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
tmp_path = alloc_path_for_send(); |
|
if (!tmp_path) { |
|
fs_path_free(p); |
|
return -ENOMEM; |
|
} |
|
|
|
|
|
if (found_key->type == BTRFS_INODE_REF_KEY) { |
|
ptr = (unsigned long)btrfs_item_ptr(eb, slot, |
|
struct btrfs_inode_ref); |
|
total = btrfs_item_size(eb, slot); |
|
elem_size = sizeof(*iref); |
|
} else { |
|
ptr = btrfs_item_ptr_offset(eb, slot); |
|
total = btrfs_item_size(eb, slot); |
|
elem_size = sizeof(*extref); |
|
} |
|
|
|
while (cur < total) { |
|
fs_path_reset(p); |
|
|
|
if (found_key->type == BTRFS_INODE_REF_KEY) { |
|
iref = (struct btrfs_inode_ref *)(ptr + cur); |
|
name_len = btrfs_inode_ref_name_len(eb, iref); |
|
name_off = (unsigned long)(iref + 1); |
|
index = btrfs_inode_ref_index(eb, iref); |
|
dir = found_key->offset; |
|
} else { |
|
extref = (struct btrfs_inode_extref *)(ptr + cur); |
|
name_len = btrfs_inode_extref_name_len(eb, extref); |
|
name_off = (unsigned long)&extref->name; |
|
index = btrfs_inode_extref_index(eb, extref); |
|
dir = btrfs_inode_extref_parent(eb, extref); |
|
} |
|
|
|
if (resolve) { |
|
start = btrfs_ref_to_path(root, tmp_path, name_len, |
|
name_off, eb, dir, |
|
p->buf, p->buf_len); |
|
if (IS_ERR(start)) { |
|
ret = PTR_ERR(start); |
|
goto out; |
|
} |
|
if (start < p->buf) { |
|
/* overflow , try again with larger buffer */ |
|
ret = fs_path_ensure_buf(p, |
|
p->buf_len + p->buf - start); |
|
if (ret < 0) |
|
goto out; |
|
start = btrfs_ref_to_path(root, tmp_path, |
|
name_len, name_off, |
|
eb, dir, |
|
p->buf, p->buf_len); |
|
if (IS_ERR(start)) { |
|
ret = PTR_ERR(start); |
|
goto out; |
|
} |
|
BUG_ON(start < p->buf); |
|
} |
|
p->start = start; |
|
} else { |
|
ret = fs_path_add_from_extent_buffer(p, eb, name_off, |
|
name_len); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
cur += elem_size + name_len; |
|
ret = iterate(num, dir, index, p, ctx); |
|
if (ret) |
|
goto out; |
|
num++; |
|
} |
|
|
|
out: |
|
btrfs_free_path(tmp_path); |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key, |
|
const char *name, int name_len, |
|
const char *data, int data_len, |
|
void *ctx); |
|
|
|
/* |
|
* Helper function to iterate the entries in ONE btrfs_dir_item. |
|
* The iterate callback may return a non zero value to stop iteration. This can |
|
* be a negative value for error codes or 1 to simply stop it. |
|
* |
|
* path must point to the dir item when called. |
|
*/ |
|
static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path, |
|
iterate_dir_item_t iterate, void *ctx) |
|
{ |
|
int ret = 0; |
|
struct extent_buffer *eb; |
|
struct btrfs_dir_item *di; |
|
struct btrfs_key di_key; |
|
char *buf = NULL; |
|
int buf_len; |
|
u32 name_len; |
|
u32 data_len; |
|
u32 cur; |
|
u32 len; |
|
u32 total; |
|
int slot; |
|
int num; |
|
|
|
/* |
|
* Start with a small buffer (1 page). If later we end up needing more |
|
* space, which can happen for xattrs on a fs with a leaf size greater |
|
* then the page size, attempt to increase the buffer. Typically xattr |
|
* values are small. |
|
*/ |
|
buf_len = PATH_MAX; |
|
buf = kmalloc(buf_len, GFP_KERNEL); |
|
if (!buf) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
eb = path->nodes[0]; |
|
slot = path->slots[0]; |
|
di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item); |
|
cur = 0; |
|
len = 0; |
|
total = btrfs_item_size(eb, slot); |
|
|
|
num = 0; |
|
while (cur < total) { |
|
name_len = btrfs_dir_name_len(eb, di); |
|
data_len = btrfs_dir_data_len(eb, di); |
|
btrfs_dir_item_key_to_cpu(eb, di, &di_key); |
|
|
|
if (btrfs_dir_type(eb, di) == BTRFS_FT_XATTR) { |
|
if (name_len > XATTR_NAME_MAX) { |
|
ret = -ENAMETOOLONG; |
|
goto out; |
|
} |
|
if (name_len + data_len > |
|
BTRFS_MAX_XATTR_SIZE(root->fs_info)) { |
|
ret = -E2BIG; |
|
goto out; |
|
} |
|
} else { |
|
/* |
|
* Path too long |
|
*/ |
|
if (name_len + data_len > PATH_MAX) { |
|
ret = -ENAMETOOLONG; |
|
goto out; |
|
} |
|
} |
|
|
|
if (name_len + data_len > buf_len) { |
|
buf_len = name_len + data_len; |
|
if (is_vmalloc_addr(buf)) { |
|
vfree(buf); |
|
buf = NULL; |
|
} else { |
|
char *tmp = krealloc(buf, buf_len, |
|
GFP_KERNEL | __GFP_NOWARN); |
|
|
|
if (!tmp) |
|
kfree(buf); |
|
buf = tmp; |
|
} |
|
if (!buf) { |
|
buf = kvmalloc(buf_len, GFP_KERNEL); |
|
if (!buf) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
} |
|
} |
|
|
|
read_extent_buffer(eb, buf, (unsigned long)(di + 1), |
|
name_len + data_len); |
|
|
|
len = sizeof(*di) + name_len + data_len; |
|
di = (struct btrfs_dir_item *)((char *)di + len); |
|
cur += len; |
|
|
|
ret = iterate(num, &di_key, buf, name_len, buf + name_len, |
|
data_len, ctx); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
num++; |
|
} |
|
|
|
out: |
|
kvfree(buf); |
|
return ret; |
|
} |
|
|
|
static int __copy_first_ref(int num, u64 dir, int index, |
|
struct fs_path *p, void *ctx) |
|
{ |
|
int ret; |
|
struct fs_path *pt = ctx; |
|
|
|
ret = fs_path_copy(pt, p); |
|
if (ret < 0) |
|
return ret; |
|
|
|
/* we want the first only */ |
|
return 1; |
|
} |
|
|
|
/* |
|
* Retrieve the first path of an inode. If an inode has more then one |
|
* ref/hardlink, this is ignored. |
|
*/ |
|
static int get_inode_path(struct btrfs_root *root, |
|
u64 ino, struct fs_path *path) |
|
{ |
|
int ret; |
|
struct btrfs_key key, found_key; |
|
struct btrfs_path *p; |
|
|
|
p = alloc_path_for_send(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
fs_path_reset(path); |
|
|
|
key.objectid = ino; |
|
key.type = BTRFS_INODE_REF_KEY; |
|
key.offset = 0; |
|
|
|
ret = btrfs_search_slot_for_read(root, &key, p, 1, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = 1; |
|
goto out; |
|
} |
|
btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]); |
|
if (found_key.objectid != ino || |
|
(found_key.type != BTRFS_INODE_REF_KEY && |
|
found_key.type != BTRFS_INODE_EXTREF_KEY)) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
|
|
ret = iterate_inode_ref(root, p, &found_key, 1, |
|
__copy_first_ref, path); |
|
if (ret < 0) |
|
goto out; |
|
ret = 0; |
|
|
|
out: |
|
btrfs_free_path(p); |
|
return ret; |
|
} |
|
|
|
struct backref_ctx { |
|
struct send_ctx *sctx; |
|
|
|
/* number of total found references */ |
|
u64 found; |
|
|
|
/* |
|
* used for clones found in send_root. clones found behind cur_objectid |
|
* and cur_offset are not considered as allowed clones. |
|
*/ |
|
u64 cur_objectid; |
|
u64 cur_offset; |
|
|
|
/* may be truncated in case it's the last extent in a file */ |
|
u64 extent_len; |
|
|
|
/* Just to check for bugs in backref resolving */ |
|
int found_itself; |
|
}; |
|
|
|
static int __clone_root_cmp_bsearch(const void *key, const void *elt) |
|
{ |
|
u64 root = (u64)(uintptr_t)key; |
|
const struct clone_root *cr = elt; |
|
|
|
if (root < cr->root->root_key.objectid) |
|
return -1; |
|
if (root > cr->root->root_key.objectid) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
static int __clone_root_cmp_sort(const void *e1, const void *e2) |
|
{ |
|
const struct clone_root *cr1 = e1; |
|
const struct clone_root *cr2 = e2; |
|
|
|
if (cr1->root->root_key.objectid < cr2->root->root_key.objectid) |
|
return -1; |
|
if (cr1->root->root_key.objectid > cr2->root->root_key.objectid) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
/* |
|
* Called for every backref that is found for the current extent. |
|
* Results are collected in sctx->clone_roots->ino/offset/found_refs |
|
*/ |
|
static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_) |
|
{ |
|
struct backref_ctx *bctx = ctx_; |
|
struct clone_root *found; |
|
|
|
/* First check if the root is in the list of accepted clone sources */ |
|
found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots, |
|
bctx->sctx->clone_roots_cnt, |
|
sizeof(struct clone_root), |
|
__clone_root_cmp_bsearch); |
|
if (!found) |
|
return 0; |
|
|
|
if (found->root == bctx->sctx->send_root && |
|
ino == bctx->cur_objectid && |
|
offset == bctx->cur_offset) { |
|
bctx->found_itself = 1; |
|
} |
|
|
|
/* |
|
* Make sure we don't consider clones from send_root that are |
|
* behind the current inode/offset. |
|
*/ |
|
if (found->root == bctx->sctx->send_root) { |
|
/* |
|
* If the source inode was not yet processed we can't issue a |
|
* clone operation, as the source extent does not exist yet at |
|
* the destination of the stream. |
|
*/ |
|
if (ino > bctx->cur_objectid) |
|
return 0; |
|
/* |
|
* We clone from the inode currently being sent as long as the |
|
* source extent is already processed, otherwise we could try |
|
* to clone from an extent that does not exist yet at the |
|
* destination of the stream. |
|
*/ |
|
if (ino == bctx->cur_objectid && |
|
offset + bctx->extent_len > |
|
bctx->sctx->cur_inode_next_write_offset) |
|
return 0; |
|
} |
|
|
|
bctx->found++; |
|
found->found_refs++; |
|
if (ino < found->ino) { |
|
found->ino = ino; |
|
found->offset = offset; |
|
} else if (found->ino == ino) { |
|
/* |
|
* same extent found more then once in the same file. |
|
*/ |
|
if (found->offset > offset + bctx->extent_len) |
|
found->offset = offset; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Given an inode, offset and extent item, it finds a good clone for a clone |
|
* instruction. Returns -ENOENT when none could be found. The function makes |
|
* sure that the returned clone is usable at the point where sending is at the |
|
* moment. This means, that no clones are accepted which lie behind the current |
|
* inode+offset. |
|
* |
|
* path must point to the extent item when called. |
|
*/ |
|
static int find_extent_clone(struct send_ctx *sctx, |
|
struct btrfs_path *path, |
|
u64 ino, u64 data_offset, |
|
u64 ino_size, |
|
struct clone_root **found) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret; |
|
int extent_type; |
|
u64 logical; |
|
u64 disk_byte; |
|
u64 num_bytes; |
|
u64 extent_item_pos; |
|
u64 flags = 0; |
|
struct btrfs_file_extent_item *fi; |
|
struct extent_buffer *eb = path->nodes[0]; |
|
struct backref_ctx backref_ctx = {0}; |
|
struct clone_root *cur_clone_root; |
|
struct btrfs_key found_key; |
|
struct btrfs_path *tmp_path; |
|
struct btrfs_extent_item *ei; |
|
int compressed; |
|
u32 i; |
|
|
|
tmp_path = alloc_path_for_send(); |
|
if (!tmp_path) |
|
return -ENOMEM; |
|
|
|
/* We only use this path under the commit sem */ |
|
tmp_path->need_commit_sem = 0; |
|
|
|
if (data_offset >= ino_size) { |
|
/* |
|
* There may be extents that lie behind the file's size. |
|
* I at least had this in combination with snapshotting while |
|
* writing large files. |
|
*/ |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
fi = btrfs_item_ptr(eb, path->slots[0], |
|
struct btrfs_file_extent_item); |
|
extent_type = btrfs_file_extent_type(eb, fi); |
|
if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
compressed = btrfs_file_extent_compression(eb, fi); |
|
|
|
num_bytes = btrfs_file_extent_num_bytes(eb, fi); |
|
disk_byte = btrfs_file_extent_disk_bytenr(eb, fi); |
|
if (disk_byte == 0) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
logical = disk_byte + btrfs_file_extent_offset(eb, fi); |
|
|
|
down_read(&fs_info->commit_root_sem); |
|
ret = extent_from_logical(fs_info, disk_byte, tmp_path, |
|
&found_key, &flags); |
|
up_read(&fs_info->commit_root_sem); |
|
|
|
if (ret < 0) |
|
goto out; |
|
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
|
ret = -EIO; |
|
goto out; |
|
} |
|
|
|
ei = btrfs_item_ptr(tmp_path->nodes[0], tmp_path->slots[0], |
|
struct btrfs_extent_item); |
|
/* |
|
* Backreference walking (iterate_extent_inodes() below) is currently |
|
* too expensive when an extent has a large number of references, both |
|
* in time spent and used memory. So for now just fallback to write |
|
* operations instead of clone operations when an extent has more than |
|
* a certain amount of references. |
|
*/ |
|
if (btrfs_extent_refs(tmp_path->nodes[0], ei) > SEND_MAX_EXTENT_REFS) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
btrfs_release_path(tmp_path); |
|
|
|
/* |
|
* Setup the clone roots. |
|
*/ |
|
for (i = 0; i < sctx->clone_roots_cnt; i++) { |
|
cur_clone_root = sctx->clone_roots + i; |
|
cur_clone_root->ino = (u64)-1; |
|
cur_clone_root->offset = 0; |
|
cur_clone_root->found_refs = 0; |
|
} |
|
|
|
backref_ctx.sctx = sctx; |
|
backref_ctx.found = 0; |
|
backref_ctx.cur_objectid = ino; |
|
backref_ctx.cur_offset = data_offset; |
|
backref_ctx.found_itself = 0; |
|
backref_ctx.extent_len = num_bytes; |
|
|
|
/* |
|
* The last extent of a file may be too large due to page alignment. |
|
* We need to adjust extent_len in this case so that the checks in |
|
* __iterate_backrefs work. |
|
*/ |
|
if (data_offset + num_bytes >= ino_size) |
|
backref_ctx.extent_len = ino_size - data_offset; |
|
|
|
/* |
|
* Now collect all backrefs. |
|
*/ |
|
if (compressed == BTRFS_COMPRESS_NONE) |
|
extent_item_pos = logical - found_key.objectid; |
|
else |
|
extent_item_pos = 0; |
|
ret = iterate_extent_inodes(fs_info, found_key.objectid, |
|
extent_item_pos, 1, __iterate_backrefs, |
|
&backref_ctx, false); |
|
|
|
if (ret < 0) |
|
goto out; |
|
|
|
down_read(&fs_info->commit_root_sem); |
|
if (fs_info->last_reloc_trans > sctx->last_reloc_trans) { |
|
/* |
|
* A transaction commit for a transaction in which block group |
|
* relocation was done just happened. |
|
* The disk_bytenr of the file extent item we processed is |
|
* possibly stale, referring to the extent's location before |
|
* relocation. So act as if we haven't found any clone sources |
|
* and fallback to write commands, which will read the correct |
|
* data from the new extent location. Otherwise we will fail |
|
* below because we haven't found our own back reference or we |
|
* could be getting incorrect sources in case the old extent |
|
* was already reallocated after the relocation. |
|
*/ |
|
up_read(&fs_info->commit_root_sem); |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
up_read(&fs_info->commit_root_sem); |
|
|
|
if (!backref_ctx.found_itself) { |
|
/* found a bug in backref code? */ |
|
ret = -EIO; |
|
btrfs_err(fs_info, |
|
"did not find backref in send_root. inode=%llu, offset=%llu, disk_byte=%llu found extent=%llu", |
|
ino, data_offset, disk_byte, found_key.objectid); |
|
goto out; |
|
} |
|
|
|
btrfs_debug(fs_info, |
|
"find_extent_clone: data_offset=%llu, ino=%llu, num_bytes=%llu, logical=%llu", |
|
data_offset, ino, num_bytes, logical); |
|
|
|
if (!backref_ctx.found) |
|
btrfs_debug(fs_info, "no clones found"); |
|
|
|
cur_clone_root = NULL; |
|
for (i = 0; i < sctx->clone_roots_cnt; i++) { |
|
if (sctx->clone_roots[i].found_refs) { |
|
if (!cur_clone_root) |
|
cur_clone_root = sctx->clone_roots + i; |
|
else if (sctx->clone_roots[i].root == sctx->send_root) |
|
/* prefer clones from send_root over others */ |
|
cur_clone_root = sctx->clone_roots + i; |
|
} |
|
|
|
} |
|
|
|
if (cur_clone_root) { |
|
*found = cur_clone_root; |
|
ret = 0; |
|
} else { |
|
ret = -ENOENT; |
|
} |
|
|
|
out: |
|
btrfs_free_path(tmp_path); |
|
return ret; |
|
} |
|
|
|
static int read_symlink(struct btrfs_root *root, |
|
u64 ino, |
|
struct fs_path *dest) |
|
{ |
|
int ret; |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
struct btrfs_file_extent_item *ei; |
|
u8 type; |
|
u8 compression; |
|
unsigned long off; |
|
int len; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
key.objectid = ino; |
|
key.type = BTRFS_EXTENT_DATA_KEY; |
|
key.offset = 0; |
|
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
/* |
|
* An empty symlink inode. Can happen in rare error paths when |
|
* creating a symlink (transaction committed before the inode |
|
* eviction handler removed the symlink inode items and a crash |
|
* happened in between or the subvol was snapshoted in between). |
|
* Print an informative message to dmesg/syslog so that the user |
|
* can delete the symlink. |
|
*/ |
|
btrfs_err(root->fs_info, |
|
"Found empty symlink inode %llu at root %llu", |
|
ino, root->root_key.objectid); |
|
ret = -EIO; |
|
goto out; |
|
} |
|
|
|
ei = btrfs_item_ptr(path->nodes[0], path->slots[0], |
|
struct btrfs_file_extent_item); |
|
type = btrfs_file_extent_type(path->nodes[0], ei); |
|
compression = btrfs_file_extent_compression(path->nodes[0], ei); |
|
BUG_ON(type != BTRFS_FILE_EXTENT_INLINE); |
|
BUG_ON(compression); |
|
|
|
off = btrfs_file_extent_inline_start(ei); |
|
len = btrfs_file_extent_ram_bytes(path->nodes[0], ei); |
|
|
|
ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len); |
|
|
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Helper function to generate a file name that is unique in the root of |
|
* send_root and parent_root. This is used to generate names for orphan inodes. |
|
*/ |
|
static int gen_unique_name(struct send_ctx *sctx, |
|
u64 ino, u64 gen, |
|
struct fs_path *dest) |
|
{ |
|
int ret = 0; |
|
struct btrfs_path *path; |
|
struct btrfs_dir_item *di; |
|
char tmp[64]; |
|
int len; |
|
u64 idx = 0; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
while (1) { |
|
len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu", |
|
ino, gen, idx); |
|
ASSERT(len < sizeof(tmp)); |
|
|
|
di = btrfs_lookup_dir_item(NULL, sctx->send_root, |
|
path, BTRFS_FIRST_FREE_OBJECTID, |
|
tmp, strlen(tmp), 0); |
|
btrfs_release_path(path); |
|
if (IS_ERR(di)) { |
|
ret = PTR_ERR(di); |
|
goto out; |
|
} |
|
if (di) { |
|
/* not unique, try again */ |
|
idx++; |
|
continue; |
|
} |
|
|
|
if (!sctx->parent_root) { |
|
/* unique */ |
|
ret = 0; |
|
break; |
|
} |
|
|
|
di = btrfs_lookup_dir_item(NULL, sctx->parent_root, |
|
path, BTRFS_FIRST_FREE_OBJECTID, |
|
tmp, strlen(tmp), 0); |
|
btrfs_release_path(path); |
|
if (IS_ERR(di)) { |
|
ret = PTR_ERR(di); |
|
goto out; |
|
} |
|
if (di) { |
|
/* not unique, try again */ |
|
idx++; |
|
continue; |
|
} |
|
/* unique */ |
|
break; |
|
} |
|
|
|
ret = fs_path_add(dest, tmp, strlen(tmp)); |
|
|
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
enum inode_state { |
|
inode_state_no_change, |
|
inode_state_will_create, |
|
inode_state_did_create, |
|
inode_state_will_delete, |
|
inode_state_did_delete, |
|
}; |
|
|
|
static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen) |
|
{ |
|
int ret; |
|
int left_ret; |
|
int right_ret; |
|
u64 left_gen; |
|
u64 right_gen; |
|
struct btrfs_inode_info info; |
|
|
|
ret = get_inode_info(sctx->send_root, ino, &info); |
|
if (ret < 0 && ret != -ENOENT) |
|
goto out; |
|
left_ret = (info.nlink == 0) ? -ENOENT : ret; |
|
left_gen = info.gen; |
|
|
|
if (!sctx->parent_root) { |
|
right_ret = -ENOENT; |
|
} else { |
|
ret = get_inode_info(sctx->parent_root, ino, &info); |
|
if (ret < 0 && ret != -ENOENT) |
|
goto out; |
|
right_ret = (info.nlink == 0) ? -ENOENT : ret; |
|
right_gen = info.gen; |
|
} |
|
|
|
if (!left_ret && !right_ret) { |
|
if (left_gen == gen && right_gen == gen) { |
|
ret = inode_state_no_change; |
|
} else if (left_gen == gen) { |
|
if (ino < sctx->send_progress) |
|
ret = inode_state_did_create; |
|
else |
|
ret = inode_state_will_create; |
|
} else if (right_gen == gen) { |
|
if (ino < sctx->send_progress) |
|
ret = inode_state_did_delete; |
|
else |
|
ret = inode_state_will_delete; |
|
} else { |
|
ret = -ENOENT; |
|
} |
|
} else if (!left_ret) { |
|
if (left_gen == gen) { |
|
if (ino < sctx->send_progress) |
|
ret = inode_state_did_create; |
|
else |
|
ret = inode_state_will_create; |
|
} else { |
|
ret = -ENOENT; |
|
} |
|
} else if (!right_ret) { |
|
if (right_gen == gen) { |
|
if (ino < sctx->send_progress) |
|
ret = inode_state_did_delete; |
|
else |
|
ret = inode_state_will_delete; |
|
} else { |
|
ret = -ENOENT; |
|
} |
|
} else { |
|
ret = -ENOENT; |
|
} |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen) |
|
{ |
|
int ret; |
|
|
|
if (ino == BTRFS_FIRST_FREE_OBJECTID) |
|
return 1; |
|
|
|
ret = get_cur_inode_state(sctx, ino, gen); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (ret == inode_state_no_change || |
|
ret == inode_state_did_create || |
|
ret == inode_state_will_delete) |
|
ret = 1; |
|
else |
|
ret = 0; |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Helper function to lookup a dir item in a dir. |
|
*/ |
|
static int lookup_dir_item_inode(struct btrfs_root *root, |
|
u64 dir, const char *name, int name_len, |
|
u64 *found_inode) |
|
{ |
|
int ret = 0; |
|
struct btrfs_dir_item *di; |
|
struct btrfs_key key; |
|
struct btrfs_path *path; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
di = btrfs_lookup_dir_item(NULL, root, path, |
|
dir, name, name_len, 0); |
|
if (IS_ERR_OR_NULL(di)) { |
|
ret = di ? PTR_ERR(di) : -ENOENT; |
|
goto out; |
|
} |
|
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key); |
|
if (key.type == BTRFS_ROOT_ITEM_KEY) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
*found_inode = key.objectid; |
|
|
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir, |
|
* generation of the parent dir and the name of the dir entry. |
|
*/ |
|
static int get_first_ref(struct btrfs_root *root, u64 ino, |
|
u64 *dir, u64 *dir_gen, struct fs_path *name) |
|
{ |
|
int ret; |
|
struct btrfs_key key; |
|
struct btrfs_key found_key; |
|
struct btrfs_path *path; |
|
int len; |
|
u64 parent_dir; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
key.objectid = ino; |
|
key.type = BTRFS_INODE_REF_KEY; |
|
key.offset = 0; |
|
|
|
ret = btrfs_search_slot_for_read(root, &key, path, 1, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (!ret) |
|
btrfs_item_key_to_cpu(path->nodes[0], &found_key, |
|
path->slots[0]); |
|
if (ret || found_key.objectid != ino || |
|
(found_key.type != BTRFS_INODE_REF_KEY && |
|
found_key.type != BTRFS_INODE_EXTREF_KEY)) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
|
|
if (found_key.type == BTRFS_INODE_REF_KEY) { |
|
struct btrfs_inode_ref *iref; |
|
iref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
|
struct btrfs_inode_ref); |
|
len = btrfs_inode_ref_name_len(path->nodes[0], iref); |
|
ret = fs_path_add_from_extent_buffer(name, path->nodes[0], |
|
(unsigned long)(iref + 1), |
|
len); |
|
parent_dir = found_key.offset; |
|
} else { |
|
struct btrfs_inode_extref *extref; |
|
extref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
|
struct btrfs_inode_extref); |
|
len = btrfs_inode_extref_name_len(path->nodes[0], extref); |
|
ret = fs_path_add_from_extent_buffer(name, path->nodes[0], |
|
(unsigned long)&extref->name, len); |
|
parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref); |
|
} |
|
if (ret < 0) |
|
goto out; |
|
btrfs_release_path(path); |
|
|
|
if (dir_gen) { |
|
ret = get_inode_gen(root, parent_dir, dir_gen); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
*dir = parent_dir; |
|
|
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int is_first_ref(struct btrfs_root *root, |
|
u64 ino, u64 dir, |
|
const char *name, int name_len) |
|
{ |
|
int ret; |
|
struct fs_path *tmp_name; |
|
u64 tmp_dir; |
|
|
|
tmp_name = fs_path_alloc(); |
|
if (!tmp_name) |
|
return -ENOMEM; |
|
|
|
ret = get_first_ref(root, ino, &tmp_dir, NULL, tmp_name); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
ret = !memcmp(tmp_name->start, name, name_len); |
|
|
|
out: |
|
fs_path_free(tmp_name); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Used by process_recorded_refs to determine if a new ref would overwrite an |
|
* already existing ref. In case it detects an overwrite, it returns the |
|
* inode/gen in who_ino/who_gen. |
|
* When an overwrite is detected, process_recorded_refs does proper orphanizing |
|
* to make sure later references to the overwritten inode are possible. |
|
* Orphanizing is however only required for the first ref of an inode. |
|
* process_recorded_refs does an additional is_first_ref check to see if |
|
* orphanizing is really required. |
|
*/ |
|
static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen, |
|
const char *name, int name_len, |
|
u64 *who_ino, u64 *who_gen, u64 *who_mode) |
|
{ |
|
int ret = 0; |
|
u64 gen; |
|
u64 other_inode = 0; |
|
struct btrfs_inode_info info; |
|
|
|
if (!sctx->parent_root) |
|
goto out; |
|
|
|
ret = is_inode_existent(sctx, dir, dir_gen); |
|
if (ret <= 0) |
|
goto out; |
|
|
|
/* |
|
* If we have a parent root we need to verify that the parent dir was |
|
* not deleted and then re-created, if it was then we have no overwrite |
|
* and we can just unlink this entry. |
|
*/ |
|
if (sctx->parent_root && dir != BTRFS_FIRST_FREE_OBJECTID) { |
|
ret = get_inode_gen(sctx->parent_root, dir, &gen); |
|
if (ret < 0 && ret != -ENOENT) |
|
goto out; |
|
if (ret) { |
|
ret = 0; |
|
goto out; |
|
} |
|
if (gen != dir_gen) |
|
goto out; |
|
} |
|
|
|
ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len, |
|
&other_inode); |
|
if (ret < 0 && ret != -ENOENT) |
|
goto out; |
|
if (ret) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Check if the overwritten ref was already processed. If yes, the ref |
|
* was already unlinked/moved, so we can safely assume that we will not |
|
* overwrite anything at this point in time. |
|
*/ |
|
if (other_inode > sctx->send_progress || |
|
is_waiting_for_move(sctx, other_inode)) { |
|
ret = get_inode_info(sctx->parent_root, other_inode, &info); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = 1; |
|
*who_ino = other_inode; |
|
*who_gen = info.gen; |
|
*who_mode = info.mode; |
|
} else { |
|
ret = 0; |
|
} |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Checks if the ref was overwritten by an already processed inode. This is |
|
* used by __get_cur_name_and_parent to find out if the ref was orphanized and |
|
* thus the orphan name needs be used. |
|
* process_recorded_refs also uses it to avoid unlinking of refs that were |
|
* overwritten. |
|
*/ |
|
static int did_overwrite_ref(struct send_ctx *sctx, |
|
u64 dir, u64 dir_gen, |
|
u64 ino, u64 ino_gen, |
|
const char *name, int name_len) |
|
{ |
|
int ret = 0; |
|
u64 gen; |
|
u64 ow_inode; |
|
|
|
if (!sctx->parent_root) |
|
goto out; |
|
|
|
ret = is_inode_existent(sctx, dir, dir_gen); |
|
if (ret <= 0) |
|
goto out; |
|
|
|
if (dir != BTRFS_FIRST_FREE_OBJECTID) { |
|
ret = get_inode_gen(sctx->send_root, dir, &gen); |
|
if (ret < 0 && ret != -ENOENT) |
|
goto out; |
|
if (ret) { |
|
ret = 0; |
|
goto out; |
|
} |
|
if (gen != dir_gen) |
|
goto out; |
|
} |
|
|
|
/* check if the ref was overwritten by another ref */ |
|
ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len, |
|
&ow_inode); |
|
if (ret < 0 && ret != -ENOENT) |
|
goto out; |
|
if (ret) { |
|
/* was never and will never be overwritten */ |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
ret = get_inode_gen(sctx->send_root, ow_inode, &gen); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (ow_inode == ino && gen == ino_gen) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
/* |
|
* We know that it is or will be overwritten. Check this now. |
|
* The current inode being processed might have been the one that caused |
|
* inode 'ino' to be orphanized, therefore check if ow_inode matches |
|
* the current inode being processed. |
|
*/ |
|
if ((ow_inode < sctx->send_progress) || |
|
(ino != sctx->cur_ino && ow_inode == sctx->cur_ino && |
|
gen == sctx->cur_inode_gen)) |
|
ret = 1; |
|
else |
|
ret = 0; |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Same as did_overwrite_ref, but also checks if it is the first ref of an inode |
|
* that got overwritten. This is used by process_recorded_refs to determine |
|
* if it has to use the path as returned by get_cur_path or the orphan name. |
|
*/ |
|
static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen) |
|
{ |
|
int ret = 0; |
|
struct fs_path *name = NULL; |
|
u64 dir; |
|
u64 dir_gen; |
|
|
|
if (!sctx->parent_root) |
|
goto out; |
|
|
|
name = fs_path_alloc(); |
|
if (!name) |
|
return -ENOMEM; |
|
|
|
ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen, |
|
name->start, fs_path_len(name)); |
|
|
|
out: |
|
fs_path_free(name); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Insert a name cache entry. On 32bit kernels the radix tree index is 32bit, |
|
* so we need to do some special handling in case we have clashes. This function |
|
* takes care of this with the help of name_cache_entry::radix_list. |
|
* In case of error, nce is kfreed. |
|
*/ |
|
static int name_cache_insert(struct send_ctx *sctx, |
|
struct name_cache_entry *nce) |
|
{ |
|
int ret = 0; |
|
struct list_head *nce_head; |
|
|
|
nce_head = radix_tree_lookup(&sctx->name_cache, |
|
(unsigned long)nce->ino); |
|
if (!nce_head) { |
|
nce_head = kmalloc(sizeof(*nce_head), GFP_KERNEL); |
|
if (!nce_head) { |
|
kfree(nce); |
|
return -ENOMEM; |
|
} |
|
INIT_LIST_HEAD(nce_head); |
|
|
|
ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head); |
|
if (ret < 0) { |
|
kfree(nce_head); |
|
kfree(nce); |
|
return ret; |
|
} |
|
} |
|
list_add_tail(&nce->radix_list, nce_head); |
|
list_add_tail(&nce->list, &sctx->name_cache_list); |
|
sctx->name_cache_size++; |
|
|
|
return ret; |
|
} |
|
|
|
static void name_cache_delete(struct send_ctx *sctx, |
|
struct name_cache_entry *nce) |
|
{ |
|
struct list_head *nce_head; |
|
|
|
nce_head = radix_tree_lookup(&sctx->name_cache, |
|
(unsigned long)nce->ino); |
|
if (!nce_head) { |
|
btrfs_err(sctx->send_root->fs_info, |
|
"name_cache_delete lookup failed ino %llu cache size %d, leaking memory", |
|
nce->ino, sctx->name_cache_size); |
|
} |
|
|
|
list_del(&nce->radix_list); |
|
list_del(&nce->list); |
|
sctx->name_cache_size--; |
|
|
|
/* |
|
* We may not get to the final release of nce_head if the lookup fails |
|
*/ |
|
if (nce_head && list_empty(nce_head)) { |
|
radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino); |
|
kfree(nce_head); |
|
} |
|
} |
|
|
|
static struct name_cache_entry *name_cache_search(struct send_ctx *sctx, |
|
u64 ino, u64 gen) |
|
{ |
|
struct list_head *nce_head; |
|
struct name_cache_entry *cur; |
|
|
|
nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino); |
|
if (!nce_head) |
|
return NULL; |
|
|
|
list_for_each_entry(cur, nce_head, radix_list) { |
|
if (cur->ino == ino && cur->gen == gen) |
|
return cur; |
|
} |
|
return NULL; |
|
} |
|
|
|
/* |
|
* Remove some entries from the beginning of name_cache_list. |
|
*/ |
|
static void name_cache_clean_unused(struct send_ctx *sctx) |
|
{ |
|
struct name_cache_entry *nce; |
|
|
|
if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE) |
|
return; |
|
|
|
while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) { |
|
nce = list_entry(sctx->name_cache_list.next, |
|
struct name_cache_entry, list); |
|
name_cache_delete(sctx, nce); |
|
kfree(nce); |
|
} |
|
} |
|
|
|
static void name_cache_free(struct send_ctx *sctx) |
|
{ |
|
struct name_cache_entry *nce; |
|
|
|
while (!list_empty(&sctx->name_cache_list)) { |
|
nce = list_entry(sctx->name_cache_list.next, |
|
struct name_cache_entry, list); |
|
name_cache_delete(sctx, nce); |
|
kfree(nce); |
|
} |
|
} |
|
|
|
/* |
|
* Used by get_cur_path for each ref up to the root. |
|
* Returns 0 if it succeeded. |
|
* Returns 1 if the inode is not existent or got overwritten. In that case, the |
|
* name is an orphan name. This instructs get_cur_path to stop iterating. If 1 |
|
* is returned, parent_ino/parent_gen are not guaranteed to be valid. |
|
* Returns <0 in case of error. |
|
*/ |
|
static int __get_cur_name_and_parent(struct send_ctx *sctx, |
|
u64 ino, u64 gen, |
|
u64 *parent_ino, |
|
u64 *parent_gen, |
|
struct fs_path *dest) |
|
{ |
|
int ret; |
|
int nce_ret; |
|
struct name_cache_entry *nce = NULL; |
|
|
|
/* |
|
* First check if we already did a call to this function with the same |
|
* ino/gen. If yes, check if the cache entry is still up-to-date. If yes |
|
* return the cached result. |
|
*/ |
|
nce = name_cache_search(sctx, ino, gen); |
|
if (nce) { |
|
if (ino < sctx->send_progress && nce->need_later_update) { |
|
name_cache_delete(sctx, nce); |
|
kfree(nce); |
|
nce = NULL; |
|
} else { |
|
/* |
|
* Removes the entry from the list and adds it back to |
|
* the end. This marks the entry as recently used so |
|
* that name_cache_clean_unused does not remove it. |
|
*/ |
|
list_move_tail(&nce->list, &sctx->name_cache_list); |
|
|
|
*parent_ino = nce->parent_ino; |
|
*parent_gen = nce->parent_gen; |
|
ret = fs_path_add(dest, nce->name, nce->name_len); |
|
if (ret < 0) |
|
goto out; |
|
ret = nce->ret; |
|
goto out; |
|
} |
|
} |
|
|
|
/* |
|
* If the inode is not existent yet, add the orphan name and return 1. |
|
* This should only happen for the parent dir that we determine in |
|
* record_new_ref_if_needed(). |
|
*/ |
|
ret = is_inode_existent(sctx, ino, gen); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (!ret) { |
|
ret = gen_unique_name(sctx, ino, gen, dest); |
|
if (ret < 0) |
|
goto out; |
|
ret = 1; |
|
goto out_cache; |
|
} |
|
|
|
/* |
|
* Depending on whether the inode was already processed or not, use |
|
* send_root or parent_root for ref lookup. |
|
*/ |
|
if (ino < sctx->send_progress) |
|
ret = get_first_ref(sctx->send_root, ino, |
|
parent_ino, parent_gen, dest); |
|
else |
|
ret = get_first_ref(sctx->parent_root, ino, |
|
parent_ino, parent_gen, dest); |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* |
|
* Check if the ref was overwritten by an inode's ref that was processed |
|
* earlier. If yes, treat as orphan and return 1. |
|
*/ |
|
ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen, |
|
dest->start, dest->end - dest->start); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
fs_path_reset(dest); |
|
ret = gen_unique_name(sctx, ino, gen, dest); |
|
if (ret < 0) |
|
goto out; |
|
ret = 1; |
|
} |
|
|
|
out_cache: |
|
/* |
|
* Store the result of the lookup in the name cache. |
|
*/ |
|
nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_KERNEL); |
|
if (!nce) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
nce->ino = ino; |
|
nce->gen = gen; |
|
nce->parent_ino = *parent_ino; |
|
nce->parent_gen = *parent_gen; |
|
nce->name_len = fs_path_len(dest); |
|
nce->ret = ret; |
|
strcpy(nce->name, dest->start); |
|
|
|
if (ino < sctx->send_progress) |
|
nce->need_later_update = 0; |
|
else |
|
nce->need_later_update = 1; |
|
|
|
nce_ret = name_cache_insert(sctx, nce); |
|
if (nce_ret < 0) |
|
ret = nce_ret; |
|
name_cache_clean_unused(sctx); |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Magic happens here. This function returns the first ref to an inode as it |
|
* would look like while receiving the stream at this point in time. |
|
* We walk the path up to the root. For every inode in between, we check if it |
|
* was already processed/sent. If yes, we continue with the parent as found |
|
* in send_root. If not, we continue with the parent as found in parent_root. |
|
* If we encounter an inode that was deleted at this point in time, we use the |
|
* inodes "orphan" name instead of the real name and stop. Same with new inodes |
|
* that were not created yet and overwritten inodes/refs. |
|
* |
|
* When do we have orphan inodes: |
|
* 1. When an inode is freshly created and thus no valid refs are available yet |
|
* 2. When a directory lost all it's refs (deleted) but still has dir items |
|
* inside which were not processed yet (pending for move/delete). If anyone |
|
* tried to get the path to the dir items, it would get a path inside that |
|
* orphan directory. |
|
* 3. When an inode is moved around or gets new links, it may overwrite the ref |
|
* of an unprocessed inode. If in that case the first ref would be |
|
* overwritten, the overwritten inode gets "orphanized". Later when we |
|
* process this overwritten inode, it is restored at a new place by moving |
|
* the orphan inode. |
|
* |
|
* sctx->send_progress tells this function at which point in time receiving |
|
* would be. |
|
*/ |
|
static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen, |
|
struct fs_path *dest) |
|
{ |
|
int ret = 0; |
|
struct fs_path *name = NULL; |
|
u64 parent_inode = 0; |
|
u64 parent_gen = 0; |
|
int stop = 0; |
|
|
|
name = fs_path_alloc(); |
|
if (!name) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
dest->reversed = 1; |
|
fs_path_reset(dest); |
|
|
|
while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) { |
|
struct waiting_dir_move *wdm; |
|
|
|
fs_path_reset(name); |
|
|
|
if (is_waiting_for_rm(sctx, ino, gen)) { |
|
ret = gen_unique_name(sctx, ino, gen, name); |
|
if (ret < 0) |
|
goto out; |
|
ret = fs_path_add_path(dest, name); |
|
break; |
|
} |
|
|
|
wdm = get_waiting_dir_move(sctx, ino); |
|
if (wdm && wdm->orphanized) { |
|
ret = gen_unique_name(sctx, ino, gen, name); |
|
stop = 1; |
|
} else if (wdm) { |
|
ret = get_first_ref(sctx->parent_root, ino, |
|
&parent_inode, &parent_gen, name); |
|
} else { |
|
ret = __get_cur_name_and_parent(sctx, ino, gen, |
|
&parent_inode, |
|
&parent_gen, name); |
|
if (ret) |
|
stop = 1; |
|
} |
|
|
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = fs_path_add_path(dest, name); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ino = parent_inode; |
|
gen = parent_gen; |
|
} |
|
|
|
out: |
|
fs_path_free(name); |
|
if (!ret) |
|
fs_path_unreverse(dest); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Sends a BTRFS_SEND_C_SUBVOL command/item to userspace |
|
*/ |
|
static int send_subvol_begin(struct send_ctx *sctx) |
|
{ |
|
int ret; |
|
struct btrfs_root *send_root = sctx->send_root; |
|
struct btrfs_root *parent_root = sctx->parent_root; |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
struct btrfs_root_ref *ref; |
|
struct extent_buffer *leaf; |
|
char *name = NULL; |
|
int namelen; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_KERNEL); |
|
if (!name) { |
|
btrfs_free_path(path); |
|
return -ENOMEM; |
|
} |
|
|
|
key.objectid = send_root->root_key.objectid; |
|
key.type = BTRFS_ROOT_BACKREF_KEY; |
|
key.offset = 0; |
|
|
|
ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root, |
|
&key, path, 1, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
|
|
leaf = path->nodes[0]; |
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
|
if (key.type != BTRFS_ROOT_BACKREF_KEY || |
|
key.objectid != send_root->root_key.objectid) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); |
|
namelen = btrfs_root_ref_name_len(leaf, ref); |
|
read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen); |
|
btrfs_release_path(path); |
|
|
|
if (parent_root) { |
|
ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT); |
|
if (ret < 0) |
|
goto out; |
|
} else { |
|
ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen); |
|
|
|
if (!btrfs_is_empty_uuid(sctx->send_root->root_item.received_uuid)) |
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID, |
|
sctx->send_root->root_item.received_uuid); |
|
else |
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID, |
|
sctx->send_root->root_item.uuid); |
|
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID, |
|
btrfs_root_ctransid(&sctx->send_root->root_item)); |
|
if (parent_root) { |
|
if (!btrfs_is_empty_uuid(parent_root->root_item.received_uuid)) |
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, |
|
parent_root->root_item.received_uuid); |
|
else |
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, |
|
parent_root->root_item.uuid); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID, |
|
btrfs_root_ctransid(&sctx->parent_root->root_item)); |
|
} |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
btrfs_free_path(path); |
|
kfree(name); |
|
return ret; |
|
} |
|
|
|
static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret = 0; |
|
struct fs_path *p; |
|
|
|
btrfs_debug(fs_info, "send_truncate %llu size=%llu", ino, size); |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, ino, gen, p); |
|
if (ret < 0) |
|
goto out; |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret = 0; |
|
struct fs_path *p; |
|
|
|
btrfs_debug(fs_info, "send_chmod %llu mode=%llu", ino, mode); |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, ino, gen, p); |
|
if (ret < 0) |
|
goto out; |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
static int send_fileattr(struct send_ctx *sctx, u64 ino, u64 gen, u64 fileattr) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret = 0; |
|
struct fs_path *p; |
|
|
|
if (sctx->proto < 2) |
|
return 0; |
|
|
|
btrfs_debug(fs_info, "send_fileattr %llu fileattr=%llu", ino, fileattr); |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_FILEATTR); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, ino, gen, p); |
|
if (ret < 0) |
|
goto out; |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILEATTR, fileattr); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret = 0; |
|
struct fs_path *p; |
|
|
|
btrfs_debug(fs_info, "send_chown %llu uid=%llu, gid=%llu", |
|
ino, uid, gid); |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, ino, gen, p); |
|
if (ret < 0) |
|
goto out; |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret = 0; |
|
struct fs_path *p = NULL; |
|
struct btrfs_inode_item *ii; |
|
struct btrfs_path *path = NULL; |
|
struct extent_buffer *eb; |
|
struct btrfs_key key; |
|
int slot; |
|
|
|
btrfs_debug(fs_info, "send_utimes %llu", ino); |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
key.objectid = ino; |
|
key.type = BTRFS_INODE_ITEM_KEY; |
|
key.offset = 0; |
|
ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0); |
|
if (ret > 0) |
|
ret = -ENOENT; |
|
if (ret < 0) |
|
goto out; |
|
|
|
eb = path->nodes[0]; |
|
slot = path->slots[0]; |
|
ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item); |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, ino, gen, p); |
|
if (ret < 0) |
|
goto out; |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb, &ii->atime); |
|
TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb, &ii->mtime); |
|
TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb, &ii->ctime); |
|
if (sctx->proto >= 2) |
|
TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_OTIME, eb, &ii->otime); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have |
|
* a valid path yet because we did not process the refs yet. So, the inode |
|
* is created as orphan. |
|
*/ |
|
static int send_create_inode(struct send_ctx *sctx, u64 ino) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret = 0; |
|
struct fs_path *p; |
|
int cmd; |
|
struct btrfs_inode_info info; |
|
u64 gen; |
|
u64 mode; |
|
u64 rdev; |
|
|
|
btrfs_debug(fs_info, "send_create_inode %llu", ino); |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
if (ino != sctx->cur_ino) { |
|
ret = get_inode_info(sctx->send_root, ino, &info); |
|
if (ret < 0) |
|
goto out; |
|
gen = info.gen; |
|
mode = info.mode; |
|
rdev = info.rdev; |
|
} else { |
|
gen = sctx->cur_inode_gen; |
|
mode = sctx->cur_inode_mode; |
|
rdev = sctx->cur_inode_rdev; |
|
} |
|
|
|
if (S_ISREG(mode)) { |
|
cmd = BTRFS_SEND_C_MKFILE; |
|
} else if (S_ISDIR(mode)) { |
|
cmd = BTRFS_SEND_C_MKDIR; |
|
} else if (S_ISLNK(mode)) { |
|
cmd = BTRFS_SEND_C_SYMLINK; |
|
} else if (S_ISCHR(mode) || S_ISBLK(mode)) { |
|
cmd = BTRFS_SEND_C_MKNOD; |
|
} else if (S_ISFIFO(mode)) { |
|
cmd = BTRFS_SEND_C_MKFIFO; |
|
} else if (S_ISSOCK(mode)) { |
|
cmd = BTRFS_SEND_C_MKSOCK; |
|
} else { |
|
btrfs_warn(sctx->send_root->fs_info, "unexpected inode type %o", |
|
(int)(mode & S_IFMT)); |
|
ret = -EOPNOTSUPP; |
|
goto out; |
|
} |
|
|
|
ret = begin_cmd(sctx, cmd); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = gen_unique_name(sctx, ino, gen, p); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino); |
|
|
|
if (S_ISLNK(mode)) { |
|
fs_path_reset(p); |
|
ret = read_symlink(sctx->send_root, ino, p); |
|
if (ret < 0) |
|
goto out; |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p); |
|
} else if (S_ISCHR(mode) || S_ISBLK(mode) || |
|
S_ISFIFO(mode) || S_ISSOCK(mode)) { |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev)); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode); |
|
} |
|
|
|
ret = send_cmd(sctx); |
|
if (ret < 0) |
|
goto out; |
|
|
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
/* |
|
* We need some special handling for inodes that get processed before the parent |
|
* directory got created. See process_recorded_refs for details. |
|
* This function does the check if we already created the dir out of order. |
|
*/ |
|
static int did_create_dir(struct send_ctx *sctx, u64 dir) |
|
{ |
|
int ret = 0; |
|
int iter_ret = 0; |
|
struct btrfs_path *path = NULL; |
|
struct btrfs_key key; |
|
struct btrfs_key found_key; |
|
struct btrfs_key di_key; |
|
struct btrfs_dir_item *di; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
key.objectid = dir; |
|
key.type = BTRFS_DIR_INDEX_KEY; |
|
key.offset = 0; |
|
|
|
btrfs_for_each_slot(sctx->send_root, &key, &found_key, path, iter_ret) { |
|
struct extent_buffer *eb = path->nodes[0]; |
|
|
|
if (found_key.objectid != key.objectid || |
|
found_key.type != key.type) { |
|
ret = 0; |
|
break; |
|
} |
|
|
|
di = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dir_item); |
|
btrfs_dir_item_key_to_cpu(eb, di, &di_key); |
|
|
|
if (di_key.type != BTRFS_ROOT_ITEM_KEY && |
|
di_key.objectid < sctx->send_progress) { |
|
ret = 1; |
|
break; |
|
} |
|
} |
|
/* Catch error found during iteration */ |
|
if (iter_ret < 0) |
|
ret = iter_ret; |
|
|
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Only creates the inode if it is: |
|
* 1. Not a directory |
|
* 2. Or a directory which was not created already due to out of order |
|
* directories. See did_create_dir and process_recorded_refs for details. |
|
*/ |
|
static int send_create_inode_if_needed(struct send_ctx *sctx) |
|
{ |
|
int ret; |
|
|
|
if (S_ISDIR(sctx->cur_inode_mode)) { |
|
ret = did_create_dir(sctx, sctx->cur_ino); |
|
if (ret < 0) |
|
return ret; |
|
else if (ret > 0) |
|
return 0; |
|
} |
|
|
|
return send_create_inode(sctx, sctx->cur_ino); |
|
} |
|
|
|
struct recorded_ref { |
|
struct list_head list; |
|
char *name; |
|
struct fs_path *full_path; |
|
u64 dir; |
|
u64 dir_gen; |
|
int name_len; |
|
struct rb_node node; |
|
struct rb_root *root; |
|
}; |
|
|
|
static struct recorded_ref *recorded_ref_alloc(void) |
|
{ |
|
struct recorded_ref *ref; |
|
|
|
ref = kzalloc(sizeof(*ref), GFP_KERNEL); |
|
if (!ref) |
|
return NULL; |
|
RB_CLEAR_NODE(&ref->node); |
|
INIT_LIST_HEAD(&ref->list); |
|
return ref; |
|
} |
|
|
|
static void recorded_ref_free(struct recorded_ref *ref) |
|
{ |
|
if (!ref) |
|
return; |
|
if (!RB_EMPTY_NODE(&ref->node)) |
|
rb_erase(&ref->node, ref->root); |
|
list_del(&ref->list); |
|
fs_path_free(ref->full_path); |
|
kfree(ref); |
|
} |
|
|
|
static void set_ref_path(struct recorded_ref *ref, struct fs_path *path) |
|
{ |
|
ref->full_path = path; |
|
ref->name = (char *)kbasename(ref->full_path->start); |
|
ref->name_len = ref->full_path->end - ref->name; |
|
} |
|
|
|
static int dup_ref(struct recorded_ref *ref, struct list_head *list) |
|
{ |
|
struct recorded_ref *new; |
|
|
|
new = recorded_ref_alloc(); |
|
if (!new) |
|
return -ENOMEM; |
|
|
|
new->dir = ref->dir; |
|
new->dir_gen = ref->dir_gen; |
|
list_add_tail(&new->list, list); |
|
return 0; |
|
} |
|
|
|
static void __free_recorded_refs(struct list_head *head) |
|
{ |
|
struct recorded_ref *cur; |
|
|
|
while (!list_empty(head)) { |
|
cur = list_entry(head->next, struct recorded_ref, list); |
|
recorded_ref_free(cur); |
|
} |
|
} |
|
|
|
static void free_recorded_refs(struct send_ctx *sctx) |
|
{ |
|
__free_recorded_refs(&sctx->new_refs); |
|
__free_recorded_refs(&sctx->deleted_refs); |
|
} |
|
|
|
/* |
|
* Renames/moves a file/dir to its orphan name. Used when the first |
|
* ref of an unprocessed inode gets overwritten and for all non empty |
|
* directories. |
|
*/ |
|
static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen, |
|
struct fs_path *path) |
|
{ |
|
int ret; |
|
struct fs_path *orphan; |
|
|
|
orphan = fs_path_alloc(); |
|
if (!orphan) |
|
return -ENOMEM; |
|
|
|
ret = gen_unique_name(sctx, ino, gen, orphan); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = send_rename(sctx, path, orphan); |
|
|
|
out: |
|
fs_path_free(orphan); |
|
return ret; |
|
} |
|
|
|
static struct orphan_dir_info *add_orphan_dir_info(struct send_ctx *sctx, |
|
u64 dir_ino, u64 dir_gen) |
|
{ |
|
struct rb_node **p = &sctx->orphan_dirs.rb_node; |
|
struct rb_node *parent = NULL; |
|
struct orphan_dir_info *entry, *odi; |
|
|
|
while (*p) { |
|
parent = *p; |
|
entry = rb_entry(parent, struct orphan_dir_info, node); |
|
if (dir_ino < entry->ino) |
|
p = &(*p)->rb_left; |
|
else if (dir_ino > entry->ino) |
|
p = &(*p)->rb_right; |
|
else if (dir_gen < entry->gen) |
|
p = &(*p)->rb_left; |
|
else if (dir_gen > entry->gen) |
|
p = &(*p)->rb_right; |
|
else |
|
return entry; |
|
} |
|
|
|
odi = kmalloc(sizeof(*odi), GFP_KERNEL); |
|
if (!odi) |
|
return ERR_PTR(-ENOMEM); |
|
odi->ino = dir_ino; |
|
odi->gen = dir_gen; |
|
odi->last_dir_index_offset = 0; |
|
|
|
rb_link_node(&odi->node, parent, p); |
|
rb_insert_color(&odi->node, &sctx->orphan_dirs); |
|
return odi; |
|
} |
|
|
|
static struct orphan_dir_info *get_orphan_dir_info(struct send_ctx *sctx, |
|
u64 dir_ino, u64 gen) |
|
{ |
|
struct rb_node *n = sctx->orphan_dirs.rb_node; |
|
struct orphan_dir_info *entry; |
|
|
|
while (n) { |
|
entry = rb_entry(n, struct orphan_dir_info, node); |
|
if (dir_ino < entry->ino) |
|
n = n->rb_left; |
|
else if (dir_ino > entry->ino) |
|
n = n->rb_right; |
|
else if (gen < entry->gen) |
|
n = n->rb_left; |
|
else if (gen > entry->gen) |
|
n = n->rb_right; |
|
else |
|
return entry; |
|
} |
|
return NULL; |
|
} |
|
|
|
static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino, u64 gen) |
|
{ |
|
struct orphan_dir_info *odi = get_orphan_dir_info(sctx, dir_ino, gen); |
|
|
|
return odi != NULL; |
|
} |
|
|
|
static void free_orphan_dir_info(struct send_ctx *sctx, |
|
struct orphan_dir_info *odi) |
|
{ |
|
if (!odi) |
|
return; |
|
rb_erase(&odi->node, &sctx->orphan_dirs); |
|
kfree(odi); |
|
} |
|
|
|
/* |
|
* Returns 1 if a directory can be removed at this point in time. |
|
* We check this by iterating all dir items and checking if the inode behind |
|
* the dir item was already processed. |
|
*/ |
|
static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen, |
|
u64 send_progress) |
|
{ |
|
int ret = 0; |
|
int iter_ret = 0; |
|
struct btrfs_root *root = sctx->parent_root; |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
struct btrfs_key found_key; |
|
struct btrfs_key loc; |
|
struct btrfs_dir_item *di; |
|
struct orphan_dir_info *odi = NULL; |
|
|
|
/* |
|
* Don't try to rmdir the top/root subvolume dir. |
|
*/ |
|
if (dir == BTRFS_FIRST_FREE_OBJECTID) |
|
return 0; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
key.objectid = dir; |
|
key.type = BTRFS_DIR_INDEX_KEY; |
|
key.offset = 0; |
|
|
|
odi = get_orphan_dir_info(sctx, dir, dir_gen); |
|
if (odi) |
|
key.offset = odi->last_dir_index_offset; |
|
|
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) { |
|
struct waiting_dir_move *dm; |
|
|
|
if (found_key.objectid != key.objectid || |
|
found_key.type != key.type) |
|
break; |
|
|
|
di = btrfs_item_ptr(path->nodes[0], path->slots[0], |
|
struct btrfs_dir_item); |
|
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc); |
|
|
|
dm = get_waiting_dir_move(sctx, loc.objectid); |
|
if (dm) { |
|
odi = add_orphan_dir_info(sctx, dir, dir_gen); |
|
if (IS_ERR(odi)) { |
|
ret = PTR_ERR(odi); |
|
goto out; |
|
} |
|
odi->gen = dir_gen; |
|
odi->last_dir_index_offset = found_key.offset; |
|
dm->rmdir_ino = dir; |
|
dm->rmdir_gen = dir_gen; |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
if (loc.objectid > send_progress) { |
|
odi = add_orphan_dir_info(sctx, dir, dir_gen); |
|
if (IS_ERR(odi)) { |
|
ret = PTR_ERR(odi); |
|
goto out; |
|
} |
|
odi->gen = dir_gen; |
|
odi->last_dir_index_offset = found_key.offset; |
|
ret = 0; |
|
goto out; |
|
} |
|
} |
|
if (iter_ret < 0) { |
|
ret = iter_ret; |
|
goto out; |
|
} |
|
free_orphan_dir_info(sctx, odi); |
|
|
|
ret = 1; |
|
|
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int is_waiting_for_move(struct send_ctx *sctx, u64 ino) |
|
{ |
|
struct waiting_dir_move *entry = get_waiting_dir_move(sctx, ino); |
|
|
|
return entry != NULL; |
|
} |
|
|
|
static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino, bool orphanized) |
|
{ |
|
struct rb_node **p = &sctx->waiting_dir_moves.rb_node; |
|
struct rb_node *parent = NULL; |
|
struct waiting_dir_move *entry, *dm; |
|
|
|
dm = kmalloc(sizeof(*dm), GFP_KERNEL); |
|
if (!dm) |
|
return -ENOMEM; |
|
dm->ino = ino; |
|
dm->rmdir_ino = 0; |
|
dm->rmdir_gen = 0; |
|
dm->orphanized = orphanized; |
|
|
|
while (*p) { |
|
parent = *p; |
|
entry = rb_entry(parent, struct waiting_dir_move, node); |
|
if (ino < entry->ino) { |
|
p = &(*p)->rb_left; |
|
} else if (ino > entry->ino) { |
|
p = &(*p)->rb_right; |
|
} else { |
|
kfree(dm); |
|
return -EEXIST; |
|
} |
|
} |
|
|
|
rb_link_node(&dm->node, parent, p); |
|
rb_insert_color(&dm->node, &sctx->waiting_dir_moves); |
|
return 0; |
|
} |
|
|
|
static struct waiting_dir_move * |
|
get_waiting_dir_move(struct send_ctx *sctx, u64 ino) |
|
{ |
|
struct rb_node *n = sctx->waiting_dir_moves.rb_node; |
|
struct waiting_dir_move *entry; |
|
|
|
while (n) { |
|
entry = rb_entry(n, struct waiting_dir_move, node); |
|
if (ino < entry->ino) |
|
n = n->rb_left; |
|
else if (ino > entry->ino) |
|
n = n->rb_right; |
|
else |
|
return entry; |
|
} |
|
return NULL; |
|
} |
|
|
|
static void free_waiting_dir_move(struct send_ctx *sctx, |
|
struct waiting_dir_move *dm) |
|
{ |
|
if (!dm) |
|
return; |
|
rb_erase(&dm->node, &sctx->waiting_dir_moves); |
|
kfree(dm); |
|
} |
|
|
|
static int add_pending_dir_move(struct send_ctx *sctx, |
|
u64 ino, |
|
u64 ino_gen, |
|
u64 parent_ino, |
|
struct list_head *new_refs, |
|
struct list_head *deleted_refs, |
|
const bool is_orphan) |
|
{ |
|
struct rb_node **p = &sctx->pending_dir_moves.rb_node; |
|
struct rb_node *parent = NULL; |
|
struct pending_dir_move *entry = NULL, *pm; |
|
struct recorded_ref *cur; |
|
int exists = 0; |
|
int ret; |
|
|
|
pm = kmalloc(sizeof(*pm), GFP_KERNEL); |
|
if (!pm) |
|
return -ENOMEM; |
|
pm->parent_ino = parent_ino; |
|
pm->ino = ino; |
|
pm->gen = ino_gen; |
|
INIT_LIST_HEAD(&pm->list); |
|
INIT_LIST_HEAD(&pm->update_refs); |
|
RB_CLEAR_NODE(&pm->node); |
|
|
|
while (*p) { |
|
parent = *p; |
|
entry = rb_entry(parent, struct pending_dir_move, node); |
|
if (parent_ino < entry->parent_ino) { |
|
p = &(*p)->rb_left; |
|
} else if (parent_ino > entry->parent_ino) { |
|
p = &(*p)->rb_right; |
|
} else { |
|
exists = 1; |
|
break; |
|
} |
|
} |
|
|
|
list_for_each_entry(cur, deleted_refs, list) { |
|
ret = dup_ref(cur, &pm->update_refs); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
list_for_each_entry(cur, new_refs, list) { |
|
ret = dup_ref(cur, &pm->update_refs); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
ret = add_waiting_dir_move(sctx, pm->ino, is_orphan); |
|
if (ret) |
|
goto out; |
|
|
|
if (exists) { |
|
list_add_tail(&pm->list, &entry->list); |
|
} else { |
|
rb_link_node(&pm->node, parent, p); |
|
rb_insert_color(&pm->node, &sctx->pending_dir_moves); |
|
} |
|
ret = 0; |
|
out: |
|
if (ret) { |
|
__free_recorded_refs(&pm->update_refs); |
|
kfree(pm); |
|
} |
|
return ret; |
|
} |
|
|
|
static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx, |
|
u64 parent_ino) |
|
{ |
|
struct rb_node *n = sctx->pending_dir_moves.rb_node; |
|
struct pending_dir_move *entry; |
|
|
|
while (n) { |
|
entry = rb_entry(n, struct pending_dir_move, node); |
|
if (parent_ino < entry->parent_ino) |
|
n = n->rb_left; |
|
else if (parent_ino > entry->parent_ino) |
|
n = n->rb_right; |
|
else |
|
return entry; |
|
} |
|
return NULL; |
|
} |
|
|
|
static int path_loop(struct send_ctx *sctx, struct fs_path *name, |
|
u64 ino, u64 gen, u64 *ancestor_ino) |
|
{ |
|
int ret = 0; |
|
u64 parent_inode = 0; |
|
u64 parent_gen = 0; |
|
u64 start_ino = ino; |
|
|
|
*ancestor_ino = 0; |
|
while (ino != BTRFS_FIRST_FREE_OBJECTID) { |
|
fs_path_reset(name); |
|
|
|
if (is_waiting_for_rm(sctx, ino, gen)) |
|
break; |
|
if (is_waiting_for_move(sctx, ino)) { |
|
if (*ancestor_ino == 0) |
|
*ancestor_ino = ino; |
|
ret = get_first_ref(sctx->parent_root, ino, |
|
&parent_inode, &parent_gen, name); |
|
} else { |
|
ret = __get_cur_name_and_parent(sctx, ino, gen, |
|
&parent_inode, |
|
&parent_gen, name); |
|
if (ret > 0) { |
|
ret = 0; |
|
break; |
|
} |
|
} |
|
if (ret < 0) |
|
break; |
|
if (parent_inode == start_ino) { |
|
ret = 1; |
|
if (*ancestor_ino == 0) |
|
*ancestor_ino = ino; |
|
break; |
|
} |
|
ino = parent_inode; |
|
gen = parent_gen; |
|
} |
|
return ret; |
|
} |
|
|
|
static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm) |
|
{ |
|
struct fs_path *from_path = NULL; |
|
struct fs_path *to_path = NULL; |
|
struct fs_path *name = NULL; |
|
u64 orig_progress = sctx->send_progress; |
|
struct recorded_ref *cur; |
|
u64 parent_ino, parent_gen; |
|
struct waiting_dir_move *dm = NULL; |
|
u64 rmdir_ino = 0; |
|
u64 rmdir_gen; |
|
u64 ancestor; |
|
bool is_orphan; |
|
int ret; |
|
|
|
name = fs_path_alloc(); |
|
from_path = fs_path_alloc(); |
|
if (!name || !from_path) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
dm = get_waiting_dir_move(sctx, pm->ino); |
|
ASSERT(dm); |
|
rmdir_ino = dm->rmdir_ino; |
|
rmdir_gen = dm->rmdir_gen; |
|
is_orphan = dm->orphanized; |
|
free_waiting_dir_move(sctx, dm); |
|
|
|
if (is_orphan) { |
|
ret = gen_unique_name(sctx, pm->ino, |
|
pm->gen, from_path); |
|
} else { |
|
ret = get_first_ref(sctx->parent_root, pm->ino, |
|
&parent_ino, &parent_gen, name); |
|
if (ret < 0) |
|
goto out; |
|
ret = get_cur_path(sctx, parent_ino, parent_gen, |
|
from_path); |
|
if (ret < 0) |
|
goto out; |
|
ret = fs_path_add_path(from_path, name); |
|
} |
|
if (ret < 0) |
|
goto out; |
|
|
|
sctx->send_progress = sctx->cur_ino + 1; |
|
ret = path_loop(sctx, name, pm->ino, pm->gen, &ancestor); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
LIST_HEAD(deleted_refs); |
|
ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID); |
|
ret = add_pending_dir_move(sctx, pm->ino, pm->gen, ancestor, |
|
&pm->update_refs, &deleted_refs, |
|
is_orphan); |
|
if (ret < 0) |
|
goto out; |
|
if (rmdir_ino) { |
|
dm = get_waiting_dir_move(sctx, pm->ino); |
|
ASSERT(dm); |
|
dm->rmdir_ino = rmdir_ino; |
|
dm->rmdir_gen = rmdir_gen; |
|
} |
|
goto out; |
|
} |
|
fs_path_reset(name); |
|
to_path = name; |
|
name = NULL; |
|
ret = get_cur_path(sctx, pm->ino, pm->gen, to_path); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = send_rename(sctx, from_path, to_path); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (rmdir_ino) { |
|
struct orphan_dir_info *odi; |
|
u64 gen; |
|
|
|
odi = get_orphan_dir_info(sctx, rmdir_ino, rmdir_gen); |
|
if (!odi) { |
|
/* already deleted */ |
|
goto finish; |
|
} |
|
gen = odi->gen; |
|
|
|
ret = can_rmdir(sctx, rmdir_ino, gen, sctx->cur_ino); |
|
if (ret < 0) |
|
goto out; |
|
if (!ret) |
|
goto finish; |
|
|
|
name = fs_path_alloc(); |
|
if (!name) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
ret = get_cur_path(sctx, rmdir_ino, gen, name); |
|
if (ret < 0) |
|
goto out; |
|
ret = send_rmdir(sctx, name); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
finish: |
|
ret = send_utimes(sctx, pm->ino, pm->gen); |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* |
|
* After rename/move, need to update the utimes of both new parent(s) |
|
* and old parent(s). |
|
*/ |
|
list_for_each_entry(cur, &pm->update_refs, list) { |
|
/* |
|
* The parent inode might have been deleted in the send snapshot |
|
*/ |
|
ret = get_inode_info(sctx->send_root, cur->dir, NULL); |
|
if (ret == -ENOENT) { |
|
ret = 0; |
|
continue; |
|
} |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = send_utimes(sctx, cur->dir, cur->dir_gen); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
out: |
|
fs_path_free(name); |
|
fs_path_free(from_path); |
|
fs_path_free(to_path); |
|
sctx->send_progress = orig_progress; |
|
|
|
return ret; |
|
} |
|
|
|
static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m) |
|
{ |
|
if (!list_empty(&m->list)) |
|
list_del(&m->list); |
|
if (!RB_EMPTY_NODE(&m->node)) |
|
rb_erase(&m->node, &sctx->pending_dir_moves); |
|
__free_recorded_refs(&m->update_refs); |
|
kfree(m); |
|
} |
|
|
|
static void tail_append_pending_moves(struct send_ctx *sctx, |
|
struct pending_dir_move *moves, |
|
struct list_head *stack) |
|
{ |
|
if (list_empty(&moves->list)) { |
|
list_add_tail(&moves->list, stack); |
|
} else { |
|
LIST_HEAD(list); |
|
list_splice_init(&moves->list, &list); |
|
list_add_tail(&moves->list, stack); |
|
list_splice_tail(&list, stack); |
|
} |
|
if (!RB_EMPTY_NODE(&moves->node)) { |
|
rb_erase(&moves->node, &sctx->pending_dir_moves); |
|
RB_CLEAR_NODE(&moves->node); |
|
} |
|
} |
|
|
|
static int apply_children_dir_moves(struct send_ctx *sctx) |
|
{ |
|
struct pending_dir_move *pm; |
|
struct list_head stack; |
|
u64 parent_ino = sctx->cur_ino; |
|
int ret = 0; |
|
|
|
pm = get_pending_dir_moves(sctx, parent_ino); |
|
if (!pm) |
|
return 0; |
|
|
|
INIT_LIST_HEAD(&stack); |
|
tail_append_pending_moves(sctx, pm, &stack); |
|
|
|
while (!list_empty(&stack)) { |
|
pm = list_first_entry(&stack, struct pending_dir_move, list); |
|
parent_ino = pm->ino; |
|
ret = apply_dir_move(sctx, pm); |
|
free_pending_move(sctx, pm); |
|
if (ret) |
|
goto out; |
|
pm = get_pending_dir_moves(sctx, parent_ino); |
|
if (pm) |
|
tail_append_pending_moves(sctx, pm, &stack); |
|
} |
|
return 0; |
|
|
|
out: |
|
while (!list_empty(&stack)) { |
|
pm = list_first_entry(&stack, struct pending_dir_move, list); |
|
free_pending_move(sctx, pm); |
|
} |
|
return ret; |
|
} |
|
|
|
/* |
|
* We might need to delay a directory rename even when no ancestor directory |
|
* (in the send root) with a higher inode number than ours (sctx->cur_ino) was |
|
* renamed. This happens when we rename a directory to the old name (the name |
|
* in the parent root) of some other unrelated directory that got its rename |
|
* delayed due to some ancestor with higher number that got renamed. |
|
* |
|
* Example: |
|
* |
|
* Parent snapshot: |
|
* . (ino 256) |
|
* |---- a/ (ino 257) |
|
* | |---- file (ino 260) |
|
* | |
|
* |---- b/ (ino 258) |
|
* |---- c/ (ino 259) |
|
* |
|
* Send snapshot: |
|
* . (ino 256) |
|
* |---- a/ (ino 258) |
|
* |---- x/ (ino 259) |
|
* |---- y/ (ino 257) |
|
* |----- file (ino 260) |
|
* |
|
* Here we can not rename 258 from 'b' to 'a' without the rename of inode 257 |
|
* from 'a' to 'x/y' happening first, which in turn depends on the rename of |
|
* inode 259 from 'c' to 'x'. So the order of rename commands the send stream |
|
* must issue is: |
|
* |
|
* 1 - rename 259 from 'c' to 'x' |
|
* 2 - rename 257 from 'a' to 'x/y' |
|
* 3 - rename 258 from 'b' to 'a' |
|
* |
|
* Returns 1 if the rename of sctx->cur_ino needs to be delayed, 0 if it can |
|
* be done right away and < 0 on error. |
|
*/ |
|
static int wait_for_dest_dir_move(struct send_ctx *sctx, |
|
struct recorded_ref *parent_ref, |
|
const bool is_orphan) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->parent_root->fs_info; |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
struct btrfs_key di_key; |
|
struct btrfs_dir_item *di; |
|
u64 left_gen; |
|
u64 right_gen; |
|
int ret = 0; |
|
struct waiting_dir_move *wdm; |
|
|
|
if (RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) |
|
return 0; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
key.objectid = parent_ref->dir; |
|
key.type = BTRFS_DIR_ITEM_KEY; |
|
key.offset = btrfs_name_hash(parent_ref->name, parent_ref->name_len); |
|
|
|
ret = btrfs_search_slot(NULL, sctx->parent_root, &key, path, 0, 0); |
|
if (ret < 0) { |
|
goto out; |
|
} else if (ret > 0) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
di = btrfs_match_dir_item_name(fs_info, path, parent_ref->name, |
|
parent_ref->name_len); |
|
if (!di) { |
|
ret = 0; |
|
goto out; |
|
} |
|
/* |
|
* di_key.objectid has the number of the inode that has a dentry in the |
|
* parent directory with the same name that sctx->cur_ino is being |
|
* renamed to. We need to check if that inode is in the send root as |
|
* well and if it is currently marked as an inode with a pending rename, |
|
* if it is, we need to delay the rename of sctx->cur_ino as well, so |
|
* that it happens after that other inode is renamed. |
|
*/ |
|
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &di_key); |
|
if (di_key.type != BTRFS_INODE_ITEM_KEY) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
ret = get_inode_gen(sctx->parent_root, di_key.objectid, &left_gen); |
|
if (ret < 0) |
|
goto out; |
|
ret = get_inode_gen(sctx->send_root, di_key.objectid, &right_gen); |
|
if (ret < 0) { |
|
if (ret == -ENOENT) |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
/* Different inode, no need to delay the rename of sctx->cur_ino */ |
|
if (right_gen != left_gen) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
wdm = get_waiting_dir_move(sctx, di_key.objectid); |
|
if (wdm && !wdm->orphanized) { |
|
ret = add_pending_dir_move(sctx, |
|
sctx->cur_ino, |
|
sctx->cur_inode_gen, |
|
di_key.objectid, |
|
&sctx->new_refs, |
|
&sctx->deleted_refs, |
|
is_orphan); |
|
if (!ret) |
|
ret = 1; |
|
} |
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Check if inode ino2, or any of its ancestors, is inode ino1. |
|
* Return 1 if true, 0 if false and < 0 on error. |
|
*/ |
|
static int check_ino_in_path(struct btrfs_root *root, |
|
const u64 ino1, |
|
const u64 ino1_gen, |
|
const u64 ino2, |
|
const u64 ino2_gen, |
|
struct fs_path *fs_path) |
|
{ |
|
u64 ino = ino2; |
|
|
|
if (ino1 == ino2) |
|
return ino1_gen == ino2_gen; |
|
|
|
while (ino > BTRFS_FIRST_FREE_OBJECTID) { |
|
u64 parent; |
|
u64 parent_gen; |
|
int ret; |
|
|
|
fs_path_reset(fs_path); |
|
ret = get_first_ref(root, ino, &parent, &parent_gen, fs_path); |
|
if (ret < 0) |
|
return ret; |
|
if (parent == ino1) |
|
return parent_gen == ino1_gen; |
|
ino = parent; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* Check if inode ino1 is an ancestor of inode ino2 in the given root for any |
|
* possible path (in case ino2 is not a directory and has multiple hard links). |
|
* Return 1 if true, 0 if false and < 0 on error. |
|
*/ |
|
static int is_ancestor(struct btrfs_root *root, |
|
const u64 ino1, |
|
const u64 ino1_gen, |
|
const u64 ino2, |
|
struct fs_path *fs_path) |
|
{ |
|
bool free_fs_path = false; |
|
int ret = 0; |
|
int iter_ret = 0; |
|
struct btrfs_path *path = NULL; |
|
struct btrfs_key key; |
|
|
|
if (!fs_path) { |
|
fs_path = fs_path_alloc(); |
|
if (!fs_path) |
|
return -ENOMEM; |
|
free_fs_path = true; |
|
} |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
key.objectid = ino2; |
|
key.type = BTRFS_INODE_REF_KEY; |
|
key.offset = 0; |
|
|
|
btrfs_for_each_slot(root, &key, &key, path, iter_ret) { |
|
struct extent_buffer *leaf = path->nodes[0]; |
|
int slot = path->slots[0]; |
|
u32 cur_offset = 0; |
|
u32 item_size; |
|
|
|
if (key.objectid != ino2) |
|
break; |
|
if (key.type != BTRFS_INODE_REF_KEY && |
|
key.type != BTRFS_INODE_EXTREF_KEY) |
|
break; |
|
|
|
item_size = btrfs_item_size(leaf, slot); |
|
while (cur_offset < item_size) { |
|
u64 parent; |
|
u64 parent_gen; |
|
|
|
if (key.type == BTRFS_INODE_EXTREF_KEY) { |
|
unsigned long ptr; |
|
struct btrfs_inode_extref *extref; |
|
|
|
ptr = btrfs_item_ptr_offset(leaf, slot); |
|
extref = (struct btrfs_inode_extref *) |
|
(ptr + cur_offset); |
|
parent = btrfs_inode_extref_parent(leaf, |
|
extref); |
|
cur_offset += sizeof(*extref); |
|
cur_offset += btrfs_inode_extref_name_len(leaf, |
|
extref); |
|
} else { |
|
parent = key.offset; |
|
cur_offset = item_size; |
|
} |
|
|
|
ret = get_inode_gen(root, parent, &parent_gen); |
|
if (ret < 0) |
|
goto out; |
|
ret = check_ino_in_path(root, ino1, ino1_gen, |
|
parent, parent_gen, fs_path); |
|
if (ret) |
|
goto out; |
|
} |
|
} |
|
ret = 0; |
|
if (iter_ret < 0) |
|
ret = iter_ret; |
|
|
|
out: |
|
btrfs_free_path(path); |
|
if (free_fs_path) |
|
fs_path_free(fs_path); |
|
return ret; |
|
} |
|
|
|
static int wait_for_parent_move(struct send_ctx *sctx, |
|
struct recorded_ref *parent_ref, |
|
const bool is_orphan) |
|
{ |
|
int ret = 0; |
|
u64 ino = parent_ref->dir; |
|
u64 ino_gen = parent_ref->dir_gen; |
|
u64 parent_ino_before, parent_ino_after; |
|
struct fs_path *path_before = NULL; |
|
struct fs_path *path_after = NULL; |
|
int len1, len2; |
|
|
|
path_after = fs_path_alloc(); |
|
path_before = fs_path_alloc(); |
|
if (!path_after || !path_before) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Our current directory inode may not yet be renamed/moved because some |
|
* ancestor (immediate or not) has to be renamed/moved first. So find if |
|
* such ancestor exists and make sure our own rename/move happens after |
|
* that ancestor is processed to avoid path build infinite loops (done |
|
* at get_cur_path()). |
|
*/ |
|
while (ino > BTRFS_FIRST_FREE_OBJECTID) { |
|
u64 parent_ino_after_gen; |
|
|
|
if (is_waiting_for_move(sctx, ino)) { |
|
/* |
|
* If the current inode is an ancestor of ino in the |
|
* parent root, we need to delay the rename of the |
|
* current inode, otherwise don't delayed the rename |
|
* because we can end up with a circular dependency |
|
* of renames, resulting in some directories never |
|
* getting the respective rename operations issued in |
|
* the send stream or getting into infinite path build |
|
* loops. |
|
*/ |
|
ret = is_ancestor(sctx->parent_root, |
|
sctx->cur_ino, sctx->cur_inode_gen, |
|
ino, path_before); |
|
if (ret) |
|
break; |
|
} |
|
|
|
fs_path_reset(path_before); |
|
fs_path_reset(path_after); |
|
|
|
ret = get_first_ref(sctx->send_root, ino, &parent_ino_after, |
|
&parent_ino_after_gen, path_after); |
|
if (ret < 0) |
|
goto out; |
|
ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before, |
|
NULL, path_before); |
|
if (ret < 0 && ret != -ENOENT) { |
|
goto out; |
|
} else if (ret == -ENOENT) { |
|
ret = 0; |
|
break; |
|
} |
|
|
|
len1 = fs_path_len(path_before); |
|
len2 = fs_path_len(path_after); |
|
if (ino > sctx->cur_ino && |
|
(parent_ino_before != parent_ino_after || len1 != len2 || |
|
memcmp(path_before->start, path_after->start, len1))) { |
|
u64 parent_ino_gen; |
|
|
|
ret = get_inode_gen(sctx->parent_root, ino, &parent_ino_gen); |
|
if (ret < 0) |
|
goto out; |
|
if (ino_gen == parent_ino_gen) { |
|
ret = 1; |
|
break; |
|
} |
|
} |
|
ino = parent_ino_after; |
|
ino_gen = parent_ino_after_gen; |
|
} |
|
|
|
out: |
|
fs_path_free(path_before); |
|
fs_path_free(path_after); |
|
|
|
if (ret == 1) { |
|
ret = add_pending_dir_move(sctx, |
|
sctx->cur_ino, |
|
sctx->cur_inode_gen, |
|
ino, |
|
&sctx->new_refs, |
|
&sctx->deleted_refs, |
|
is_orphan); |
|
if (!ret) |
|
ret = 1; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int update_ref_path(struct send_ctx *sctx, struct recorded_ref *ref) |
|
{ |
|
int ret; |
|
struct fs_path *new_path; |
|
|
|
/* |
|
* Our reference's name member points to its full_path member string, so |
|
* we use here a new path. |
|
*/ |
|
new_path = fs_path_alloc(); |
|
if (!new_path) |
|
return -ENOMEM; |
|
|
|
ret = get_cur_path(sctx, ref->dir, ref->dir_gen, new_path); |
|
if (ret < 0) { |
|
fs_path_free(new_path); |
|
return ret; |
|
} |
|
ret = fs_path_add(new_path, ref->name, ref->name_len); |
|
if (ret < 0) { |
|
fs_path_free(new_path); |
|
return ret; |
|
} |
|
|
|
fs_path_free(ref->full_path); |
|
set_ref_path(ref, new_path); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* When processing the new references for an inode we may orphanize an existing |
|
* directory inode because its old name conflicts with one of the new references |
|
* of the current inode. Later, when processing another new reference of our |
|
* inode, we might need to orphanize another inode, but the path we have in the |
|
* reference reflects the pre-orphanization name of the directory we previously |
|
* orphanized. For example: |
|
* |
|
* parent snapshot looks like: |
|
* |
|
* . (ino 256) |
|
* |----- f1 (ino 257) |
|
* |----- f2 (ino 258) |
|
* |----- d1/ (ino 259) |
|
* |----- d2/ (ino 260) |
|
* |
|
* send snapshot looks like: |
|
* |
|
* . (ino 256) |
|
* |----- d1 (ino 258) |
|
* |----- f2/ (ino 259) |
|
* |----- f2_link/ (ino 260) |
|
* | |----- f1 (ino 257) |
|
* | |
|
* |----- d2 (ino 258) |
|
* |
|
* When processing inode 257 we compute the name for inode 259 as "d1", and we |
|
* cache it in the name cache. Later when we start processing inode 258, when |
|
* collecting all its new references we set a full path of "d1/d2" for its new |
|
* reference with name "d2". When we start processing the new references we |
|
* start by processing the new reference with name "d1", and this results in |
|
* orphanizing inode 259, since its old reference causes a conflict. Then we |
|
* move on the next new reference, with name "d2", and we find out we must |
|
* orphanize inode 260, as its old reference conflicts with ours - but for the |
|
* orphanization we use a source path corresponding to the path we stored in the |
|
* new reference, which is "d1/d2" and not "o259-6-0/d2" - this makes the |
|
* receiver fail since the path component "d1/" no longer exists, it was renamed |
|
* to "o259-6-0/" when processing the previous new reference. So in this case we |
|
* must recompute the path in the new reference and use it for the new |
|
* orphanization operation. |
|
*/ |
|
static int refresh_ref_path(struct send_ctx *sctx, struct recorded_ref *ref) |
|
{ |
|
char *name; |
|
int ret; |
|
|
|
name = kmemdup(ref->name, ref->name_len, GFP_KERNEL); |
|
if (!name) |
|
return -ENOMEM; |
|
|
|
fs_path_reset(ref->full_path); |
|
ret = get_cur_path(sctx, ref->dir, ref->dir_gen, ref->full_path); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = fs_path_add(ref->full_path, name, ref->name_len); |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* Update the reference's base name pointer. */ |
|
set_ref_path(ref, ref->full_path); |
|
out: |
|
kfree(name); |
|
return ret; |
|
} |
|
|
|
/* |
|
* This does all the move/link/unlink/rmdir magic. |
|
*/ |
|
static int process_recorded_refs(struct send_ctx *sctx, int *pending_move) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret = 0; |
|
struct recorded_ref *cur; |
|
struct recorded_ref *cur2; |
|
struct list_head check_dirs; |
|
struct fs_path *valid_path = NULL; |
|
u64 ow_inode = 0; |
|
u64 ow_gen; |
|
u64 ow_mode; |
|
int did_overwrite = 0; |
|
int is_orphan = 0; |
|
u64 last_dir_ino_rm = 0; |
|
bool can_rename = true; |
|
bool orphanized_dir = false; |
|
bool orphanized_ancestor = false; |
|
|
|
btrfs_debug(fs_info, "process_recorded_refs %llu", sctx->cur_ino); |
|
|
|
/* |
|
* This should never happen as the root dir always has the same ref |
|
* which is always '..' |
|
*/ |
|
BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID); |
|
INIT_LIST_HEAD(&check_dirs); |
|
|
|
valid_path = fs_path_alloc(); |
|
if (!valid_path) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
/* |
|
* First, check if the first ref of the current inode was overwritten |
|
* before. If yes, we know that the current inode was already orphanized |
|
* and thus use the orphan name. If not, we can use get_cur_path to |
|
* get the path of the first ref as it would like while receiving at |
|
* this point in time. |
|
* New inodes are always orphan at the beginning, so force to use the |
|
* orphan name in this case. |
|
* The first ref is stored in valid_path and will be updated if it |
|
* gets moved around. |
|
*/ |
|
if (!sctx->cur_inode_new) { |
|
ret = did_overwrite_first_ref(sctx, sctx->cur_ino, |
|
sctx->cur_inode_gen); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) |
|
did_overwrite = 1; |
|
} |
|
if (sctx->cur_inode_new || did_overwrite) { |
|
ret = gen_unique_name(sctx, sctx->cur_ino, |
|
sctx->cur_inode_gen, valid_path); |
|
if (ret < 0) |
|
goto out; |
|
is_orphan = 1; |
|
} else { |
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, |
|
valid_path); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
/* |
|
* Before doing any rename and link operations, do a first pass on the |
|
* new references to orphanize any unprocessed inodes that may have a |
|
* reference that conflicts with one of the new references of the current |
|
* inode. This needs to happen first because a new reference may conflict |
|
* with the old reference of a parent directory, so we must make sure |
|
* that the path used for link and rename commands don't use an |
|
* orphanized name when an ancestor was not yet orphanized. |
|
* |
|
* Example: |
|
* |
|
* Parent snapshot: |
|
* |
|
* . (ino 256) |
|
* |----- testdir/ (ino 259) |
|
* | |----- a (ino 257) |
|
* | |
|
* |----- b (ino 258) |
|
* |
|
* Send snapshot: |
|
* |
|
* . (ino 256) |
|
* |----- testdir_2/ (ino 259) |
|
* | |----- a (ino 260) |
|
* | |
|
* |----- testdir (ino 257) |
|
* |----- b (ino 257) |
|
* |----- b2 (ino 258) |
|
* |
|
* Processing the new reference for inode 257 with name "b" may happen |
|
* before processing the new reference with name "testdir". If so, we |
|
* must make sure that by the time we send a link command to create the |
|
* hard link "b", inode 259 was already orphanized, since the generated |
|
* path in "valid_path" already contains the orphanized name for 259. |
|
* We are processing inode 257, so only later when processing 259 we do |
|
* the rename operation to change its temporary (orphanized) name to |
|
* "testdir_2". |
|
*/ |
|
list_for_each_entry(cur, &sctx->new_refs, list) { |
|
ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen); |
|
if (ret < 0) |
|
goto out; |
|
if (ret == inode_state_will_create) |
|
continue; |
|
|
|
/* |
|
* Check if this new ref would overwrite the first ref of another |
|
* unprocessed inode. If yes, orphanize the overwritten inode. |
|
* If we find an overwritten ref that is not the first ref, |
|
* simply unlink it. |
|
*/ |
|
ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen, |
|
cur->name, cur->name_len, |
|
&ow_inode, &ow_gen, &ow_mode); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = is_first_ref(sctx->parent_root, |
|
ow_inode, cur->dir, cur->name, |
|
cur->name_len); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
struct name_cache_entry *nce; |
|
struct waiting_dir_move *wdm; |
|
|
|
if (orphanized_dir) { |
|
ret = refresh_ref_path(sctx, cur); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
ret = orphanize_inode(sctx, ow_inode, ow_gen, |
|
cur->full_path); |
|
if (ret < 0) |
|
goto out; |
|
if (S_ISDIR(ow_mode)) |
|
orphanized_dir = true; |
|
|
|
/* |
|
* If ow_inode has its rename operation delayed |
|
* make sure that its orphanized name is used in |
|
* the source path when performing its rename |
|
* operation. |
|
*/ |
|
if (is_waiting_for_move(sctx, ow_inode)) { |
|
wdm = get_waiting_dir_move(sctx, |
|
ow_inode); |
|
ASSERT(wdm); |
|
wdm->orphanized = true; |
|
} |
|
|
|
/* |
|
* Make sure we clear our orphanized inode's |
|
* name from the name cache. This is because the |
|
* inode ow_inode might be an ancestor of some |
|
* other inode that will be orphanized as well |
|
* later and has an inode number greater than |
|
* sctx->send_progress. We need to prevent |
|
* future name lookups from using the old name |
|
* and get instead the orphan name. |
|
*/ |
|
nce = name_cache_search(sctx, ow_inode, ow_gen); |
|
if (nce) { |
|
name_cache_delete(sctx, nce); |
|
kfree(nce); |
|
} |
|
|
|
/* |
|
* ow_inode might currently be an ancestor of |
|
* cur_ino, therefore compute valid_path (the |
|
* current path of cur_ino) again because it |
|
* might contain the pre-orphanization name of |
|
* ow_inode, which is no longer valid. |
|
*/ |
|
ret = is_ancestor(sctx->parent_root, |
|
ow_inode, ow_gen, |
|
sctx->cur_ino, NULL); |
|
if (ret > 0) { |
|
orphanized_ancestor = true; |
|
fs_path_reset(valid_path); |
|
ret = get_cur_path(sctx, sctx->cur_ino, |
|
sctx->cur_inode_gen, |
|
valid_path); |
|
} |
|
if (ret < 0) |
|
goto out; |
|
} else { |
|
/* |
|
* If we previously orphanized a directory that |
|
* collided with a new reference that we already |
|
* processed, recompute the current path because |
|
* that directory may be part of the path. |
|
*/ |
|
if (orphanized_dir) { |
|
ret = refresh_ref_path(sctx, cur); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
ret = send_unlink(sctx, cur->full_path); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
} |
|
|
|
} |
|
|
|
list_for_each_entry(cur, &sctx->new_refs, list) { |
|
/* |
|
* We may have refs where the parent directory does not exist |
|
* yet. This happens if the parent directories inum is higher |
|
* than the current inum. To handle this case, we create the |
|
* parent directory out of order. But we need to check if this |
|
* did already happen before due to other refs in the same dir. |
|
*/ |
|
ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen); |
|
if (ret < 0) |
|
goto out; |
|
if (ret == inode_state_will_create) { |
|
ret = 0; |
|
/* |
|
* First check if any of the current inodes refs did |
|
* already create the dir. |
|
*/ |
|
list_for_each_entry(cur2, &sctx->new_refs, list) { |
|
if (cur == cur2) |
|
break; |
|
if (cur2->dir == cur->dir) { |
|
ret = 1; |
|
break; |
|
} |
|
} |
|
|
|
/* |
|
* If that did not happen, check if a previous inode |
|
* did already create the dir. |
|
*/ |
|
if (!ret) |
|
ret = did_create_dir(sctx, cur->dir); |
|
if (ret < 0) |
|
goto out; |
|
if (!ret) { |
|
ret = send_create_inode(sctx, cur->dir); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
} |
|
|
|
if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root) { |
|
ret = wait_for_dest_dir_move(sctx, cur, is_orphan); |
|
if (ret < 0) |
|
goto out; |
|
if (ret == 1) { |
|
can_rename = false; |
|
*pending_move = 1; |
|
} |
|
} |
|
|
|
if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root && |
|
can_rename) { |
|
ret = wait_for_parent_move(sctx, cur, is_orphan); |
|
if (ret < 0) |
|
goto out; |
|
if (ret == 1) { |
|
can_rename = false; |
|
*pending_move = 1; |
|
} |
|
} |
|
|
|
/* |
|
* link/move the ref to the new place. If we have an orphan |
|
* inode, move it and update valid_path. If not, link or move |
|
* it depending on the inode mode. |
|
*/ |
|
if (is_orphan && can_rename) { |
|
ret = send_rename(sctx, valid_path, cur->full_path); |
|
if (ret < 0) |
|
goto out; |
|
is_orphan = 0; |
|
ret = fs_path_copy(valid_path, cur->full_path); |
|
if (ret < 0) |
|
goto out; |
|
} else if (can_rename) { |
|
if (S_ISDIR(sctx->cur_inode_mode)) { |
|
/* |
|
* Dirs can't be linked, so move it. For moved |
|
* dirs, we always have one new and one deleted |
|
* ref. The deleted ref is ignored later. |
|
*/ |
|
ret = send_rename(sctx, valid_path, |
|
cur->full_path); |
|
if (!ret) |
|
ret = fs_path_copy(valid_path, |
|
cur->full_path); |
|
if (ret < 0) |
|
goto out; |
|
} else { |
|
/* |
|
* We might have previously orphanized an inode |
|
* which is an ancestor of our current inode, |
|
* so our reference's full path, which was |
|
* computed before any such orphanizations, must |
|
* be updated. |
|
*/ |
|
if (orphanized_dir) { |
|
ret = update_ref_path(sctx, cur); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
ret = send_link(sctx, cur->full_path, |
|
valid_path); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
} |
|
ret = dup_ref(cur, &check_dirs); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) { |
|
/* |
|
* Check if we can already rmdir the directory. If not, |
|
* orphanize it. For every dir item inside that gets deleted |
|
* later, we do this check again and rmdir it then if possible. |
|
* See the use of check_dirs for more details. |
|
*/ |
|
ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen, |
|
sctx->cur_ino); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = send_rmdir(sctx, valid_path); |
|
if (ret < 0) |
|
goto out; |
|
} else if (!is_orphan) { |
|
ret = orphanize_inode(sctx, sctx->cur_ino, |
|
sctx->cur_inode_gen, valid_path); |
|
if (ret < 0) |
|
goto out; |
|
is_orphan = 1; |
|
} |
|
|
|
list_for_each_entry(cur, &sctx->deleted_refs, list) { |
|
ret = dup_ref(cur, &check_dirs); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
} else if (S_ISDIR(sctx->cur_inode_mode) && |
|
!list_empty(&sctx->deleted_refs)) { |
|
/* |
|
* We have a moved dir. Add the old parent to check_dirs |
|
*/ |
|
cur = list_entry(sctx->deleted_refs.next, struct recorded_ref, |
|
list); |
|
ret = dup_ref(cur, &check_dirs); |
|
if (ret < 0) |
|
goto out; |
|
} else if (!S_ISDIR(sctx->cur_inode_mode)) { |
|
/* |
|
* We have a non dir inode. Go through all deleted refs and |
|
* unlink them if they were not already overwritten by other |
|
* inodes. |
|
*/ |
|
list_for_each_entry(cur, &sctx->deleted_refs, list) { |
|
ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen, |
|
sctx->cur_ino, sctx->cur_inode_gen, |
|
cur->name, cur->name_len); |
|
if (ret < 0) |
|
goto out; |
|
if (!ret) { |
|
/* |
|
* If we orphanized any ancestor before, we need |
|
* to recompute the full path for deleted names, |
|
* since any such path was computed before we |
|
* processed any references and orphanized any |
|
* ancestor inode. |
|
*/ |
|
if (orphanized_ancestor) { |
|
ret = update_ref_path(sctx, cur); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
ret = send_unlink(sctx, cur->full_path); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
ret = dup_ref(cur, &check_dirs); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
/* |
|
* If the inode is still orphan, unlink the orphan. This may |
|
* happen when a previous inode did overwrite the first ref |
|
* of this inode and no new refs were added for the current |
|
* inode. Unlinking does not mean that the inode is deleted in |
|
* all cases. There may still be links to this inode in other |
|
* places. |
|
*/ |
|
if (is_orphan) { |
|
ret = send_unlink(sctx, valid_path); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
} |
|
|
|
/* |
|
* We did collect all parent dirs where cur_inode was once located. We |
|
* now go through all these dirs and check if they are pending for |
|
* deletion and if it's finally possible to perform the rmdir now. |
|
* We also update the inode stats of the parent dirs here. |
|
*/ |
|
list_for_each_entry(cur, &check_dirs, list) { |
|
/* |
|
* In case we had refs into dirs that were not processed yet, |
|
* we don't need to do the utime and rmdir logic for these dirs. |
|
* The dir will be processed later. |
|
*/ |
|
if (cur->dir > sctx->cur_ino) |
|
continue; |
|
|
|
ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (ret == inode_state_did_create || |
|
ret == inode_state_no_change) { |
|
/* TODO delayed utimes */ |
|
ret = send_utimes(sctx, cur->dir, cur->dir_gen); |
|
if (ret < 0) |
|
goto out; |
|
} else if (ret == inode_state_did_delete && |
|
cur->dir != last_dir_ino_rm) { |
|
ret = can_rmdir(sctx, cur->dir, cur->dir_gen, |
|
sctx->cur_ino); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = get_cur_path(sctx, cur->dir, |
|
cur->dir_gen, valid_path); |
|
if (ret < 0) |
|
goto out; |
|
ret = send_rmdir(sctx, valid_path); |
|
if (ret < 0) |
|
goto out; |
|
last_dir_ino_rm = cur->dir; |
|
} |
|
} |
|
} |
|
|
|
ret = 0; |
|
|
|
out: |
|
__free_recorded_refs(&check_dirs); |
|
free_recorded_refs(sctx); |
|
fs_path_free(valid_path); |
|
return ret; |
|
} |
|
|
|
static int rbtree_ref_comp(const void *k, const struct rb_node *node) |
|
{ |
|
const struct recorded_ref *data = k; |
|
const struct recorded_ref *ref = rb_entry(node, struct recorded_ref, node); |
|
int result; |
|
|
|
if (data->dir > ref->dir) |
|
return 1; |
|
if (data->dir < ref->dir) |
|
return -1; |
|
if (data->dir_gen > ref->dir_gen) |
|
return 1; |
|
if (data->dir_gen < ref->dir_gen) |
|
return -1; |
|
if (data->name_len > ref->name_len) |
|
return 1; |
|
if (data->name_len < ref->name_len) |
|
return -1; |
|
result = strcmp(data->name, ref->name); |
|
if (result > 0) |
|
return 1; |
|
if (result < 0) |
|
return -1; |
|
return 0; |
|
} |
|
|
|
static bool rbtree_ref_less(struct rb_node *node, const struct rb_node *parent) |
|
{ |
|
const struct recorded_ref *entry = rb_entry(node, struct recorded_ref, node); |
|
|
|
return rbtree_ref_comp(entry, parent) < 0; |
|
} |
|
|
|
static int record_ref_in_tree(struct rb_root *root, struct list_head *refs, |
|
struct fs_path *name, u64 dir, u64 dir_gen, |
|
struct send_ctx *sctx) |
|
{ |
|
int ret = 0; |
|
struct fs_path *path = NULL; |
|
struct recorded_ref *ref = NULL; |
|
|
|
path = fs_path_alloc(); |
|
if (!path) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ref = recorded_ref_alloc(); |
|
if (!ref) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ret = get_cur_path(sctx, dir, dir_gen, path); |
|
if (ret < 0) |
|
goto out; |
|
ret = fs_path_add_path(path, name); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ref->dir = dir; |
|
ref->dir_gen = dir_gen; |
|
set_ref_path(ref, path); |
|
list_add_tail(&ref->list, refs); |
|
rb_add(&ref->node, root, rbtree_ref_less); |
|
ref->root = root; |
|
out: |
|
if (ret) { |
|
if (path && (!ref || !ref->full_path)) |
|
fs_path_free(path); |
|
recorded_ref_free(ref); |
|
} |
|
return ret; |
|
} |
|
|
|
static int record_new_ref_if_needed(int num, u64 dir, int index, |
|
struct fs_path *name, void *ctx) |
|
{ |
|
int ret = 0; |
|
struct send_ctx *sctx = ctx; |
|
struct rb_node *node = NULL; |
|
struct recorded_ref data; |
|
struct recorded_ref *ref; |
|
u64 dir_gen; |
|
|
|
ret = get_inode_gen(sctx->send_root, dir, &dir_gen); |
|
if (ret < 0) |
|
goto out; |
|
|
|
data.dir = dir; |
|
data.dir_gen = dir_gen; |
|
set_ref_path(&data, name); |
|
node = rb_find(&data, &sctx->rbtree_deleted_refs, rbtree_ref_comp); |
|
if (node) { |
|
ref = rb_entry(node, struct recorded_ref, node); |
|
recorded_ref_free(ref); |
|
} else { |
|
ret = record_ref_in_tree(&sctx->rbtree_new_refs, |
|
&sctx->new_refs, name, dir, dir_gen, |
|
sctx); |
|
} |
|
out: |
|
return ret; |
|
} |
|
|
|
static int record_deleted_ref_if_needed(int num, u64 dir, int index, |
|
struct fs_path *name, void *ctx) |
|
{ |
|
int ret = 0; |
|
struct send_ctx *sctx = ctx; |
|
struct rb_node *node = NULL; |
|
struct recorded_ref data; |
|
struct recorded_ref *ref; |
|
u64 dir_gen; |
|
|
|
ret = get_inode_gen(sctx->parent_root, dir, &dir_gen); |
|
if (ret < 0) |
|
goto out; |
|
|
|
data.dir = dir; |
|
data.dir_gen = dir_gen; |
|
set_ref_path(&data, name); |
|
node = rb_find(&data, &sctx->rbtree_new_refs, rbtree_ref_comp); |
|
if (node) { |
|
ref = rb_entry(node, struct recorded_ref, node); |
|
recorded_ref_free(ref); |
|
} else { |
|
ret = record_ref_in_tree(&sctx->rbtree_deleted_refs, |
|
&sctx->deleted_refs, name, dir, |
|
dir_gen, sctx); |
|
} |
|
out: |
|
return ret; |
|
} |
|
|
|
static int record_new_ref(struct send_ctx *sctx) |
|
{ |
|
int ret; |
|
|
|
ret = iterate_inode_ref(sctx->send_root, sctx->left_path, |
|
sctx->cmp_key, 0, record_new_ref_if_needed, sctx); |
|
if (ret < 0) |
|
goto out; |
|
ret = 0; |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static int record_deleted_ref(struct send_ctx *sctx) |
|
{ |
|
int ret; |
|
|
|
ret = iterate_inode_ref(sctx->parent_root, sctx->right_path, |
|
sctx->cmp_key, 0, record_deleted_ref_if_needed, |
|
sctx); |
|
if (ret < 0) |
|
goto out; |
|
ret = 0; |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static int record_changed_ref(struct send_ctx *sctx) |
|
{ |
|
int ret = 0; |
|
|
|
ret = iterate_inode_ref(sctx->send_root, sctx->left_path, |
|
sctx->cmp_key, 0, record_new_ref_if_needed, sctx); |
|
if (ret < 0) |
|
goto out; |
|
ret = iterate_inode_ref(sctx->parent_root, sctx->right_path, |
|
sctx->cmp_key, 0, record_deleted_ref_if_needed, sctx); |
|
if (ret < 0) |
|
goto out; |
|
ret = 0; |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Record and process all refs at once. Needed when an inode changes the |
|
* generation number, which means that it was deleted and recreated. |
|
*/ |
|
static int process_all_refs(struct send_ctx *sctx, |
|
enum btrfs_compare_tree_result cmd) |
|
{ |
|
int ret = 0; |
|
int iter_ret = 0; |
|
struct btrfs_root *root; |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
struct btrfs_key found_key; |
|
iterate_inode_ref_t cb; |
|
int pending_move = 0; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
if (cmd == BTRFS_COMPARE_TREE_NEW) { |
|
root = sctx->send_root; |
|
cb = record_new_ref_if_needed; |
|
} else if (cmd == BTRFS_COMPARE_TREE_DELETED) { |
|
root = sctx->parent_root; |
|
cb = record_deleted_ref_if_needed; |
|
} else { |
|
btrfs_err(sctx->send_root->fs_info, |
|
"Wrong command %d in process_all_refs", cmd); |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
key.objectid = sctx->cmp_key->objectid; |
|
key.type = BTRFS_INODE_REF_KEY; |
|
key.offset = 0; |
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) { |
|
if (found_key.objectid != key.objectid || |
|
(found_key.type != BTRFS_INODE_REF_KEY && |
|
found_key.type != BTRFS_INODE_EXTREF_KEY)) |
|
break; |
|
|
|
ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
/* Catch error found during iteration */ |
|
if (iter_ret < 0) { |
|
ret = iter_ret; |
|
goto out; |
|
} |
|
btrfs_release_path(path); |
|
|
|
/* |
|
* We don't actually care about pending_move as we are simply |
|
* re-creating this inode and will be rename'ing it into place once we |
|
* rename the parent directory. |
|
*/ |
|
ret = process_recorded_refs(sctx, &pending_move); |
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int send_set_xattr(struct send_ctx *sctx, |
|
struct fs_path *path, |
|
const char *name, int name_len, |
|
const char *data, int data_len) |
|
{ |
|
int ret = 0; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); |
|
TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len); |
|
TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
return ret; |
|
} |
|
|
|
static int send_remove_xattr(struct send_ctx *sctx, |
|
struct fs_path *path, |
|
const char *name, int name_len) |
|
{ |
|
int ret = 0; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); |
|
TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
return ret; |
|
} |
|
|
|
static int __process_new_xattr(int num, struct btrfs_key *di_key, |
|
const char *name, int name_len, const char *data, |
|
int data_len, void *ctx) |
|
{ |
|
int ret; |
|
struct send_ctx *sctx = ctx; |
|
struct fs_path *p; |
|
struct posix_acl_xattr_header dummy_acl; |
|
|
|
/* Capabilities are emitted by finish_inode_if_needed */ |
|
if (!strncmp(name, XATTR_NAME_CAPS, name_len)) |
|
return 0; |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
/* |
|
* This hack is needed because empty acls are stored as zero byte |
|
* data in xattrs. Problem with that is, that receiving these zero byte |
|
* acls will fail later. To fix this, we send a dummy acl list that |
|
* only contains the version number and no entries. |
|
*/ |
|
if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) || |
|
!strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) { |
|
if (data_len == 0) { |
|
dummy_acl.a_version = |
|
cpu_to_le32(POSIX_ACL_XATTR_VERSION); |
|
data = (char *)&dummy_acl; |
|
data_len = sizeof(dummy_acl); |
|
} |
|
} |
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = send_set_xattr(sctx, p, name, name_len, data, data_len); |
|
|
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
static int __process_deleted_xattr(int num, struct btrfs_key *di_key, |
|
const char *name, int name_len, |
|
const char *data, int data_len, void *ctx) |
|
{ |
|
int ret; |
|
struct send_ctx *sctx = ctx; |
|
struct fs_path *p; |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = send_remove_xattr(sctx, p, name, name_len); |
|
|
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
static int process_new_xattr(struct send_ctx *sctx) |
|
{ |
|
int ret = 0; |
|
|
|
ret = iterate_dir_item(sctx->send_root, sctx->left_path, |
|
__process_new_xattr, sctx); |
|
|
|
return ret; |
|
} |
|
|
|
static int process_deleted_xattr(struct send_ctx *sctx) |
|
{ |
|
return iterate_dir_item(sctx->parent_root, sctx->right_path, |
|
__process_deleted_xattr, sctx); |
|
} |
|
|
|
struct find_xattr_ctx { |
|
const char *name; |
|
int name_len; |
|
int found_idx; |
|
char *found_data; |
|
int found_data_len; |
|
}; |
|
|
|
static int __find_xattr(int num, struct btrfs_key *di_key, const char *name, |
|
int name_len, const char *data, int data_len, void *vctx) |
|
{ |
|
struct find_xattr_ctx *ctx = vctx; |
|
|
|
if (name_len == ctx->name_len && |
|
strncmp(name, ctx->name, name_len) == 0) { |
|
ctx->found_idx = num; |
|
ctx->found_data_len = data_len; |
|
ctx->found_data = kmemdup(data, data_len, GFP_KERNEL); |
|
if (!ctx->found_data) |
|
return -ENOMEM; |
|
return 1; |
|
} |
|
return 0; |
|
} |
|
|
|
static int find_xattr(struct btrfs_root *root, |
|
struct btrfs_path *path, |
|
struct btrfs_key *key, |
|
const char *name, int name_len, |
|
char **data, int *data_len) |
|
{ |
|
int ret; |
|
struct find_xattr_ctx ctx; |
|
|
|
ctx.name = name; |
|
ctx.name_len = name_len; |
|
ctx.found_idx = -1; |
|
ctx.found_data = NULL; |
|
ctx.found_data_len = 0; |
|
|
|
ret = iterate_dir_item(root, path, __find_xattr, &ctx); |
|
if (ret < 0) |
|
return ret; |
|
|
|
if (ctx.found_idx == -1) |
|
return -ENOENT; |
|
if (data) { |
|
*data = ctx.found_data; |
|
*data_len = ctx.found_data_len; |
|
} else { |
|
kfree(ctx.found_data); |
|
} |
|
return ctx.found_idx; |
|
} |
|
|
|
|
|
static int __process_changed_new_xattr(int num, struct btrfs_key *di_key, |
|
const char *name, int name_len, |
|
const char *data, int data_len, |
|
void *ctx) |
|
{ |
|
int ret; |
|
struct send_ctx *sctx = ctx; |
|
char *found_data = NULL; |
|
int found_data_len = 0; |
|
|
|
ret = find_xattr(sctx->parent_root, sctx->right_path, |
|
sctx->cmp_key, name, name_len, &found_data, |
|
&found_data_len); |
|
if (ret == -ENOENT) { |
|
ret = __process_new_xattr(num, di_key, name, name_len, data, |
|
data_len, ctx); |
|
} else if (ret >= 0) { |
|
if (data_len != found_data_len || |
|
memcmp(data, found_data, data_len)) { |
|
ret = __process_new_xattr(num, di_key, name, name_len, |
|
data, data_len, ctx); |
|
} else { |
|
ret = 0; |
|
} |
|
} |
|
|
|
kfree(found_data); |
|
return ret; |
|
} |
|
|
|
static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key, |
|
const char *name, int name_len, |
|
const char *data, int data_len, |
|
void *ctx) |
|
{ |
|
int ret; |
|
struct send_ctx *sctx = ctx; |
|
|
|
ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key, |
|
name, name_len, NULL, NULL); |
|
if (ret == -ENOENT) |
|
ret = __process_deleted_xattr(num, di_key, name, name_len, data, |
|
data_len, ctx); |
|
else if (ret >= 0) |
|
ret = 0; |
|
|
|
return ret; |
|
} |
|
|
|
static int process_changed_xattr(struct send_ctx *sctx) |
|
{ |
|
int ret = 0; |
|
|
|
ret = iterate_dir_item(sctx->send_root, sctx->left_path, |
|
__process_changed_new_xattr, sctx); |
|
if (ret < 0) |
|
goto out; |
|
ret = iterate_dir_item(sctx->parent_root, sctx->right_path, |
|
__process_changed_deleted_xattr, sctx); |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static int process_all_new_xattrs(struct send_ctx *sctx) |
|
{ |
|
int ret = 0; |
|
int iter_ret = 0; |
|
struct btrfs_root *root; |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
struct btrfs_key found_key; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
root = sctx->send_root; |
|
|
|
key.objectid = sctx->cmp_key->objectid; |
|
key.type = BTRFS_XATTR_ITEM_KEY; |
|
key.offset = 0; |
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) { |
|
if (found_key.objectid != key.objectid || |
|
found_key.type != key.type) { |
|
ret = 0; |
|
break; |
|
} |
|
|
|
ret = iterate_dir_item(root, path, __process_new_xattr, sctx); |
|
if (ret < 0) |
|
break; |
|
} |
|
/* Catch error found during iteration */ |
|
if (iter_ret < 0) |
|
ret = iter_ret; |
|
|
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int send_verity(struct send_ctx *sctx, struct fs_path *path, |
|
struct fsverity_descriptor *desc) |
|
{ |
|
int ret; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_ENABLE_VERITY); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); |
|
TLV_PUT_U8(sctx, BTRFS_SEND_A_VERITY_ALGORITHM, |
|
le8_to_cpu(desc->hash_algorithm)); |
|
TLV_PUT_U32(sctx, BTRFS_SEND_A_VERITY_BLOCK_SIZE, |
|
1U << le8_to_cpu(desc->log_blocksize)); |
|
TLV_PUT(sctx, BTRFS_SEND_A_VERITY_SALT_DATA, desc->salt, |
|
le8_to_cpu(desc->salt_size)); |
|
TLV_PUT(sctx, BTRFS_SEND_A_VERITY_SIG_DATA, desc->signature, |
|
le32_to_cpu(desc->sig_size)); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
return ret; |
|
} |
|
|
|
static int process_verity(struct send_ctx *sctx) |
|
{ |
|
int ret = 0; |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
struct inode *inode; |
|
struct fs_path *p; |
|
|
|
inode = btrfs_iget(fs_info->sb, sctx->cur_ino, sctx->send_root); |
|
if (IS_ERR(inode)) |
|
return PTR_ERR(inode); |
|
|
|
ret = btrfs_get_verity_descriptor(inode, NULL, 0); |
|
if (ret < 0) |
|
goto iput; |
|
|
|
if (ret > FS_VERITY_MAX_DESCRIPTOR_SIZE) { |
|
ret = -EMSGSIZE; |
|
goto iput; |
|
} |
|
if (!sctx->verity_descriptor) { |
|
sctx->verity_descriptor = kvmalloc(FS_VERITY_MAX_DESCRIPTOR_SIZE, |
|
GFP_KERNEL); |
|
if (!sctx->verity_descriptor) { |
|
ret = -ENOMEM; |
|
goto iput; |
|
} |
|
} |
|
|
|
ret = btrfs_get_verity_descriptor(inode, sctx->verity_descriptor, ret); |
|
if (ret < 0) |
|
goto iput; |
|
|
|
p = fs_path_alloc(); |
|
if (!p) { |
|
ret = -ENOMEM; |
|
goto iput; |
|
} |
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); |
|
if (ret < 0) |
|
goto free_path; |
|
|
|
ret = send_verity(sctx, p, sctx->verity_descriptor); |
|
if (ret < 0) |
|
goto free_path; |
|
|
|
free_path: |
|
fs_path_free(p); |
|
iput: |
|
iput(inode); |
|
return ret; |
|
} |
|
|
|
static inline u64 max_send_read_size(const struct send_ctx *sctx) |
|
{ |
|
return sctx->send_max_size - SZ_16K; |
|
} |
|
|
|
static int put_data_header(struct send_ctx *sctx, u32 len) |
|
{ |
|
if (WARN_ON_ONCE(sctx->put_data)) |
|
return -EINVAL; |
|
sctx->put_data = true; |
|
if (sctx->proto >= 2) { |
|
/* |
|
* Since v2, the data attribute header doesn't include a length, |
|
* it is implicitly to the end of the command. |
|
*/ |
|
if (sctx->send_max_size - sctx->send_size < sizeof(__le16) + len) |
|
return -EOVERFLOW; |
|
put_unaligned_le16(BTRFS_SEND_A_DATA, sctx->send_buf + sctx->send_size); |
|
sctx->send_size += sizeof(__le16); |
|
} else { |
|
struct btrfs_tlv_header *hdr; |
|
|
|
if (sctx->send_max_size - sctx->send_size < sizeof(*hdr) + len) |
|
return -EOVERFLOW; |
|
hdr = (struct btrfs_tlv_header *)(sctx->send_buf + sctx->send_size); |
|
put_unaligned_le16(BTRFS_SEND_A_DATA, &hdr->tlv_type); |
|
put_unaligned_le16(len, &hdr->tlv_len); |
|
sctx->send_size += sizeof(*hdr); |
|
} |
|
return 0; |
|
} |
|
|
|
static int put_file_data(struct send_ctx *sctx, u64 offset, u32 len) |
|
{ |
|
struct btrfs_root *root = sctx->send_root; |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct page *page; |
|
pgoff_t index = offset >> PAGE_SHIFT; |
|
pgoff_t last_index; |
|
unsigned pg_offset = offset_in_page(offset); |
|
int ret; |
|
|
|
ret = put_data_header(sctx, len); |
|
if (ret) |
|
return ret; |
|
|
|
last_index = (offset + len - 1) >> PAGE_SHIFT; |
|
|
|
while (index <= last_index) { |
|
unsigned cur_len = min_t(unsigned, len, |
|
PAGE_SIZE - pg_offset); |
|
|
|
page = find_lock_page(sctx->cur_inode->i_mapping, index); |
|
if (!page) { |
|
page_cache_sync_readahead(sctx->cur_inode->i_mapping, |
|
&sctx->ra, NULL, index, |
|
last_index + 1 - index); |
|
|
|
page = find_or_create_page(sctx->cur_inode->i_mapping, |
|
index, GFP_KERNEL); |
|
if (!page) { |
|
ret = -ENOMEM; |
|
break; |
|
} |
|
} |
|
|
|
if (PageReadahead(page)) |
|
page_cache_async_readahead(sctx->cur_inode->i_mapping, |
|
&sctx->ra, NULL, page_folio(page), |
|
index, last_index + 1 - index); |
|
|
|
if (!PageUptodate(page)) { |
|
btrfs_read_folio(NULL, page_folio(page)); |
|
lock_page(page); |
|
if (!PageUptodate(page)) { |
|
unlock_page(page); |
|
btrfs_err(fs_info, |
|
"send: IO error at offset %llu for inode %llu root %llu", |
|
page_offset(page), sctx->cur_ino, |
|
sctx->send_root->root_key.objectid); |
|
put_page(page); |
|
ret = -EIO; |
|
break; |
|
} |
|
} |
|
|
|
memcpy_from_page(sctx->send_buf + sctx->send_size, page, |
|
pg_offset, cur_len); |
|
unlock_page(page); |
|
put_page(page); |
|
index++; |
|
pg_offset = 0; |
|
len -= cur_len; |
|
sctx->send_size += cur_len; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Read some bytes from the current inode/file and send a write command to |
|
* user space. |
|
*/ |
|
static int send_write(struct send_ctx *sctx, u64 offset, u32 len) |
|
{ |
|
struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; |
|
int ret = 0; |
|
struct fs_path *p; |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
btrfs_debug(fs_info, "send_write offset=%llu, len=%d", offset, len); |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); |
|
ret = put_file_data(sctx, offset, len); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Send a clone command to user space. |
|
*/ |
|
static int send_clone(struct send_ctx *sctx, |
|
u64 offset, u32 len, |
|
struct clone_root *clone_root) |
|
{ |
|
int ret = 0; |
|
struct fs_path *p; |
|
u64 gen; |
|
|
|
btrfs_debug(sctx->send_root->fs_info, |
|
"send_clone offset=%llu, len=%d, clone_root=%llu, clone_inode=%llu, clone_offset=%llu", |
|
offset, len, clone_root->root->root_key.objectid, |
|
clone_root->ino, clone_root->offset); |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len); |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
|
|
if (clone_root->root == sctx->send_root) { |
|
ret = get_inode_gen(sctx->send_root, clone_root->ino, &gen); |
|
if (ret < 0) |
|
goto out; |
|
ret = get_cur_path(sctx, clone_root->ino, gen, p); |
|
} else { |
|
ret = get_inode_path(clone_root->root, clone_root->ino, p); |
|
} |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* |
|
* If the parent we're using has a received_uuid set then use that as |
|
* our clone source as that is what we will look for when doing a |
|
* receive. |
|
* |
|
* This covers the case that we create a snapshot off of a received |
|
* subvolume and then use that as the parent and try to receive on a |
|
* different host. |
|
*/ |
|
if (!btrfs_is_empty_uuid(clone_root->root->root_item.received_uuid)) |
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, |
|
clone_root->root->root_item.received_uuid); |
|
else |
|
TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID, |
|
clone_root->root->root_item.uuid); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID, |
|
btrfs_root_ctransid(&clone_root->root->root_item)); |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET, |
|
clone_root->offset); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Send an update extent command to user space. |
|
*/ |
|
static int send_update_extent(struct send_ctx *sctx, |
|
u64 offset, u32 len) |
|
{ |
|
int ret = 0; |
|
struct fs_path *p; |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); |
|
if (ret < 0) |
|
goto out; |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len); |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
static int send_hole(struct send_ctx *sctx, u64 end) |
|
{ |
|
struct fs_path *p = NULL; |
|
u64 read_size = max_send_read_size(sctx); |
|
u64 offset = sctx->cur_inode_last_extent; |
|
int ret = 0; |
|
|
|
/* |
|
* A hole that starts at EOF or beyond it. Since we do not yet support |
|
* fallocate (for extent preallocation and hole punching), sending a |
|
* write of zeroes starting at EOF or beyond would later require issuing |
|
* a truncate operation which would undo the write and achieve nothing. |
|
*/ |
|
if (offset >= sctx->cur_inode_size) |
|
return 0; |
|
|
|
/* |
|
* Don't go beyond the inode's i_size due to prealloc extents that start |
|
* after the i_size. |
|
*/ |
|
end = min_t(u64, end, sctx->cur_inode_size); |
|
|
|
if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) |
|
return send_update_extent(sctx, offset, end - offset); |
|
|
|
p = fs_path_alloc(); |
|
if (!p) |
|
return -ENOMEM; |
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); |
|
if (ret < 0) |
|
goto tlv_put_failure; |
|
while (offset < end) { |
|
u64 len = min(end - offset, read_size); |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE); |
|
if (ret < 0) |
|
break; |
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); |
|
ret = put_data_header(sctx, len); |
|
if (ret < 0) |
|
break; |
|
memset(sctx->send_buf + sctx->send_size, 0, len); |
|
sctx->send_size += len; |
|
ret = send_cmd(sctx); |
|
if (ret < 0) |
|
break; |
|
offset += len; |
|
} |
|
sctx->cur_inode_next_write_offset = offset; |
|
tlv_put_failure: |
|
fs_path_free(p); |
|
return ret; |
|
} |
|
|
|
static int send_encoded_inline_extent(struct send_ctx *sctx, |
|
struct btrfs_path *path, u64 offset, |
|
u64 len) |
|
{ |
|
struct btrfs_root *root = sctx->send_root; |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct inode *inode; |
|
struct fs_path *fspath; |
|
struct extent_buffer *leaf = path->nodes[0]; |
|
struct btrfs_key key; |
|
struct btrfs_file_extent_item *ei; |
|
u64 ram_bytes; |
|
size_t inline_size; |
|
int ret; |
|
|
|
inode = btrfs_iget(fs_info->sb, sctx->cur_ino, root); |
|
if (IS_ERR(inode)) |
|
return PTR_ERR(inode); |
|
|
|
fspath = fs_path_alloc(); |
|
if (!fspath) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_ENCODED_WRITE); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, fspath); |
|
if (ret < 0) |
|
goto out; |
|
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
|
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); |
|
ram_bytes = btrfs_file_extent_ram_bytes(leaf, ei); |
|
inline_size = btrfs_file_extent_inline_item_len(leaf, path->slots[0]); |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, fspath); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_FILE_LEN, |
|
min(key.offset + ram_bytes - offset, len)); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_LEN, ram_bytes); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_OFFSET, offset - key.offset); |
|
ret = btrfs_encoded_io_compression_from_extent(fs_info, |
|
btrfs_file_extent_compression(leaf, ei)); |
|
if (ret < 0) |
|
goto out; |
|
TLV_PUT_U32(sctx, BTRFS_SEND_A_COMPRESSION, ret); |
|
|
|
ret = put_data_header(sctx, inline_size); |
|
if (ret < 0) |
|
goto out; |
|
read_extent_buffer(leaf, sctx->send_buf + sctx->send_size, |
|
btrfs_file_extent_inline_start(ei), inline_size); |
|
sctx->send_size += inline_size; |
|
|
|
ret = send_cmd(sctx); |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(fspath); |
|
iput(inode); |
|
return ret; |
|
} |
|
|
|
static int send_encoded_extent(struct send_ctx *sctx, struct btrfs_path *path, |
|
u64 offset, u64 len) |
|
{ |
|
struct btrfs_root *root = sctx->send_root; |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct inode *inode; |
|
struct fs_path *fspath; |
|
struct extent_buffer *leaf = path->nodes[0]; |
|
struct btrfs_key key; |
|
struct btrfs_file_extent_item *ei; |
|
u64 disk_bytenr, disk_num_bytes; |
|
u32 data_offset; |
|
struct btrfs_cmd_header *hdr; |
|
u32 crc; |
|
int ret; |
|
|
|
inode = btrfs_iget(fs_info->sb, sctx->cur_ino, root); |
|
if (IS_ERR(inode)) |
|
return PTR_ERR(inode); |
|
|
|
fspath = fs_path_alloc(); |
|
if (!fspath) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ret = begin_cmd(sctx, BTRFS_SEND_C_ENCODED_WRITE); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, fspath); |
|
if (ret < 0) |
|
goto out; |
|
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
|
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); |
|
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei); |
|
disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, ei); |
|
|
|
TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, fspath); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_FILE_LEN, |
|
min(key.offset + btrfs_file_extent_num_bytes(leaf, ei) - offset, |
|
len)); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_LEN, |
|
btrfs_file_extent_ram_bytes(leaf, ei)); |
|
TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_OFFSET, |
|
offset - key.offset + btrfs_file_extent_offset(leaf, ei)); |
|
ret = btrfs_encoded_io_compression_from_extent(fs_info, |
|
btrfs_file_extent_compression(leaf, ei)); |
|
if (ret < 0) |
|
goto out; |
|
TLV_PUT_U32(sctx, BTRFS_SEND_A_COMPRESSION, ret); |
|
TLV_PUT_U32(sctx, BTRFS_SEND_A_ENCRYPTION, 0); |
|
|
|
ret = put_data_header(sctx, disk_num_bytes); |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* |
|
* We want to do I/O directly into the send buffer, so get the next page |
|
* boundary in the send buffer. This means that there may be a gap |
|
* between the beginning of the command and the file data. |
|
*/ |
|
data_offset = ALIGN(sctx->send_size, PAGE_SIZE); |
|
if (data_offset > sctx->send_max_size || |
|
sctx->send_max_size - data_offset < disk_num_bytes) { |
|
ret = -EOVERFLOW; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Note that send_buf is a mapping of send_buf_pages, so this is really |
|
* reading into send_buf. |
|
*/ |
|
ret = btrfs_encoded_read_regular_fill_pages(BTRFS_I(inode), offset, |
|
disk_bytenr, disk_num_bytes, |
|
sctx->send_buf_pages + |
|
(data_offset >> PAGE_SHIFT)); |
|
if (ret) |
|
goto out; |
|
|
|
hdr = (struct btrfs_cmd_header *)sctx->send_buf; |
|
hdr->len = cpu_to_le32(sctx->send_size + disk_num_bytes - sizeof(*hdr)); |
|
hdr->crc = 0; |
|
crc = btrfs_crc32c(0, sctx->send_buf, sctx->send_size); |
|
crc = btrfs_crc32c(crc, sctx->send_buf + data_offset, disk_num_bytes); |
|
hdr->crc = cpu_to_le32(crc); |
|
|
|
ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size, |
|
&sctx->send_off); |
|
if (!ret) { |
|
ret = write_buf(sctx->send_filp, sctx->send_buf + data_offset, |
|
disk_num_bytes, &sctx->send_off); |
|
} |
|
sctx->send_size = 0; |
|
sctx->put_data = false; |
|
|
|
tlv_put_failure: |
|
out: |
|
fs_path_free(fspath); |
|
iput(inode); |
|
return ret; |
|
} |
|
|
|
static int send_extent_data(struct send_ctx *sctx, struct btrfs_path *path, |
|
const u64 offset, const u64 len) |
|
{ |
|
const u64 end = offset + len; |
|
struct extent_buffer *leaf = path->nodes[0]; |
|
struct btrfs_file_extent_item *ei; |
|
u64 read_size = max_send_read_size(sctx); |
|
u64 sent = 0; |
|
|
|
if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) |
|
return send_update_extent(sctx, offset, len); |
|
|
|
ei = btrfs_item_ptr(leaf, path->slots[0], |
|
struct btrfs_file_extent_item); |
|
if ((sctx->flags & BTRFS_SEND_FLAG_COMPRESSED) && |
|
btrfs_file_extent_compression(leaf, ei) != BTRFS_COMPRESS_NONE) { |
|
bool is_inline = (btrfs_file_extent_type(leaf, ei) == |
|
BTRFS_FILE_EXTENT_INLINE); |
|
|
|
/* |
|
* Send the compressed extent unless the compressed data is |
|
* larger than the decompressed data. This can happen if we're |
|
* not sending the entire extent, either because it has been |
|
* partially overwritten/truncated or because this is a part of |
|
* the extent that we couldn't clone in clone_range(). |
|
*/ |
|
if (is_inline && |
|
btrfs_file_extent_inline_item_len(leaf, |
|
path->slots[0]) <= len) { |
|
return send_encoded_inline_extent(sctx, path, offset, |
|
len); |
|
} else if (!is_inline && |
|
btrfs_file_extent_disk_num_bytes(leaf, ei) <= len) { |
|
return send_encoded_extent(sctx, path, offset, len); |
|
} |
|
} |
|
|
|
if (sctx->cur_inode == NULL) { |
|
struct btrfs_root *root = sctx->send_root; |
|
|
|
sctx->cur_inode = btrfs_iget(root->fs_info->sb, sctx->cur_ino, root); |
|
if (IS_ERR(sctx->cur_inode)) { |
|
int err = PTR_ERR(sctx->cur_inode); |
|
|
|
sctx->cur_inode = NULL; |
|
return err; |
|
} |
|
memset(&sctx->ra, 0, sizeof(struct file_ra_state)); |
|
file_ra_state_init(&sctx->ra, sctx->cur_inode->i_mapping); |
|
|
|
/* |
|
* It's very likely there are no pages from this inode in the page |
|
* cache, so after reading extents and sending their data, we clean |
|
* the page cache to avoid trashing the page cache (adding pressure |
|
* to the page cache and forcing eviction of other data more useful |
|
* for applications). |
|
* |
|
* We decide if we should clean the page cache simply by checking |
|
* if the inode's mapping nrpages is 0 when we first open it, and |
|
* not by using something like filemap_range_has_page() before |
|
* reading an extent because when we ask the readahead code to |
|
* read a given file range, it may (and almost always does) read |
|
* pages from beyond that range (see the documentation for |
|
* page_cache_sync_readahead()), so it would not be reliable, |
|
* because after reading the first extent future calls to |
|
* filemap_range_has_page() would return true because the readahead |
|
* on the previous extent resulted in reading pages of the current |
|
* extent as well. |
|
*/ |
|
sctx->clean_page_cache = (sctx->cur_inode->i_mapping->nrpages == 0); |
|
sctx->page_cache_clear_start = round_down(offset, PAGE_SIZE); |
|
} |
|
|
|
while (sent < len) { |
|
u64 size = min(len - sent, read_size); |
|
int ret; |
|
|
|
ret = send_write(sctx, offset + sent, size); |
|
if (ret < 0) |
|
return ret; |
|
sent += size; |
|
} |
|
|
|
if (sctx->clean_page_cache && IS_ALIGNED(end, PAGE_SIZE)) { |
|
/* |
|
* Always operate only on ranges that are a multiple of the page |
|
* size. This is not only to prevent zeroing parts of a page in |
|
* the case of subpage sector size, but also to guarantee we evict |
|
* pages, as passing a range that is smaller than page size does |
|
* not evict the respective page (only zeroes part of its content). |
|
* |
|
* Always start from the end offset of the last range cleared. |
|
* This is because the readahead code may (and very often does) |
|
* reads pages beyond the range we request for readahead. So if |
|
* we have an extent layout like this: |
|
* |
|
* [ extent A ] [ extent B ] [ extent C ] |
|
* |
|
* When we ask page_cache_sync_readahead() to read extent A, it |
|
* may also trigger reads for pages of extent B. If we are doing |
|
* an incremental send and extent B has not changed between the |
|
* parent and send snapshots, some or all of its pages may end |
|
* up being read and placed in the page cache. So when truncating |
|
* the page cache we always start from the end offset of the |
|
* previously processed extent up to the end of the current |
|
* extent. |
|
*/ |
|
truncate_inode_pages_range(&sctx->cur_inode->i_data, |
|
sctx->page_cache_clear_start, |
|
end - 1); |
|
sctx->page_cache_clear_start = end; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Search for a capability xattr related to sctx->cur_ino. If the capability is |
|
* found, call send_set_xattr function to emit it. |
|
* |
|
* Return 0 if there isn't a capability, or when the capability was emitted |
|
* successfully, or < 0 if an error occurred. |
|
*/ |
|
static int send_capabilities(struct send_ctx *sctx) |
|
{ |
|
struct fs_path *fspath = NULL; |
|
struct btrfs_path *path; |
|
struct btrfs_dir_item *di; |
|
struct extent_buffer *leaf; |
|
unsigned long data_ptr; |
|
char *buf = NULL; |
|
int buf_len; |
|
int ret = 0; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
di = btrfs_lookup_xattr(NULL, sctx->send_root, path, sctx->cur_ino, |
|
XATTR_NAME_CAPS, strlen(XATTR_NAME_CAPS), 0); |
|
if (!di) { |
|
/* There is no xattr for this inode */ |
|
goto out; |
|
} else if (IS_ERR(di)) { |
|
ret = PTR_ERR(di); |
|
goto out; |
|
} |
|
|
|
leaf = path->nodes[0]; |
|
buf_len = btrfs_dir_data_len(leaf, di); |
|
|
|
fspath = fs_path_alloc(); |
|
buf = kmalloc(buf_len, GFP_KERNEL); |
|
if (!fspath || !buf) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, fspath); |
|
if (ret < 0) |
|
goto out; |
|
|
|
data_ptr = (unsigned long)(di + 1) + btrfs_dir_name_len(leaf, di); |
|
read_extent_buffer(leaf, buf, data_ptr, buf_len); |
|
|
|
ret = send_set_xattr(sctx, fspath, XATTR_NAME_CAPS, |
|
strlen(XATTR_NAME_CAPS), buf, buf_len); |
|
out: |
|
kfree(buf); |
|
fs_path_free(fspath); |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int clone_range(struct send_ctx *sctx, struct btrfs_path *dst_path, |
|
struct clone_root *clone_root, const u64 disk_byte, |
|
u64 data_offset, u64 offset, u64 len) |
|
{ |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
int ret; |
|
struct btrfs_inode_info info; |
|
u64 clone_src_i_size = 0; |
|
|
|
/* |
|
* Prevent cloning from a zero offset with a length matching the sector |
|
* size because in some scenarios this will make the receiver fail. |
|
* |
|
* For example, if in the source filesystem the extent at offset 0 |
|
* has a length of sectorsize and it was written using direct IO, then |
|
* it can never be an inline extent (even if compression is enabled). |
|
* Then this extent can be cloned in the original filesystem to a non |
|
* zero file offset, but it may not be possible to clone in the |
|
* destination filesystem because it can be inlined due to compression |
|
* on the destination filesystem (as the receiver's write operations are |
|
* always done using buffered IO). The same happens when the original |
|
* filesystem does not have compression enabled but the destination |
|
* filesystem has. |
|
*/ |
|
if (clone_root->offset == 0 && |
|
len == sctx->send_root->fs_info->sectorsize) |
|
return send_extent_data(sctx, dst_path, offset, len); |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
/* |
|
* There are inodes that have extents that lie behind its i_size. Don't |
|
* accept clones from these extents. |
|
*/ |
|
ret = get_inode_info(clone_root->root, clone_root->ino, &info); |
|
btrfs_release_path(path); |
|
if (ret < 0) |
|
goto out; |
|
clone_src_i_size = info.size; |
|
|
|
/* |
|
* We can't send a clone operation for the entire range if we find |
|
* extent items in the respective range in the source file that |
|
* refer to different extents or if we find holes. |
|
* So check for that and do a mix of clone and regular write/copy |
|
* operations if needed. |
|
* |
|
* Example: |
|
* |
|
* mkfs.btrfs -f /dev/sda |
|
* mount /dev/sda /mnt |
|
* xfs_io -f -c "pwrite -S 0xaa 0K 100K" /mnt/foo |
|
* cp --reflink=always /mnt/foo /mnt/bar |
|
* xfs_io -c "pwrite -S 0xbb 50K 50K" /mnt/foo |
|
* btrfs subvolume snapshot -r /mnt /mnt/snap |
|
* |
|
* If when we send the snapshot and we are processing file bar (which |
|
* has a higher inode number than foo) we blindly send a clone operation |
|
* for the [0, 100K[ range from foo to bar, the receiver ends up getting |
|
* a file bar that matches the content of file foo - iow, doesn't match |
|
* the content from bar in the original filesystem. |
|
*/ |
|
key.objectid = clone_root->ino; |
|
key.type = BTRFS_EXTENT_DATA_KEY; |
|
key.offset = clone_root->offset; |
|
ret = btrfs_search_slot(NULL, clone_root->root, &key, path, 0, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (ret > 0 && path->slots[0] > 0) { |
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1); |
|
if (key.objectid == clone_root->ino && |
|
key.type == BTRFS_EXTENT_DATA_KEY) |
|
path->slots[0]--; |
|
} |
|
|
|
while (true) { |
|
struct extent_buffer *leaf = path->nodes[0]; |
|
int slot = path->slots[0]; |
|
struct btrfs_file_extent_item *ei; |
|
u8 type; |
|
u64 ext_len; |
|
u64 clone_len; |
|
u64 clone_data_offset; |
|
bool crossed_src_i_size = false; |
|
|
|
if (slot >= btrfs_header_nritems(leaf)) { |
|
ret = btrfs_next_leaf(clone_root->root, path); |
|
if (ret < 0) |
|
goto out; |
|
else if (ret > 0) |
|
break; |
|
continue; |
|
} |
|
|
|
btrfs_item_key_to_cpu(leaf, &key, slot); |
|
|
|
/* |
|
* We might have an implicit trailing hole (NO_HOLES feature |
|
* enabled). We deal with it after leaving this loop. |
|
*/ |
|
if (key.objectid != clone_root->ino || |
|
key.type != BTRFS_EXTENT_DATA_KEY) |
|
break; |
|
|
|
ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
|
type = btrfs_file_extent_type(leaf, ei); |
|
if (type == BTRFS_FILE_EXTENT_INLINE) { |
|
ext_len = btrfs_file_extent_ram_bytes(leaf, ei); |
|
ext_len = PAGE_ALIGN(ext_len); |
|
} else { |
|
ext_len = btrfs_file_extent_num_bytes(leaf, ei); |
|
} |
|
|
|
if (key.offset + ext_len <= clone_root->offset) |
|
goto next; |
|
|
|
if (key.offset > clone_root->offset) { |
|
/* Implicit hole, NO_HOLES feature enabled. */ |
|
u64 hole_len = key.offset - clone_root->offset; |
|
|
|
if (hole_len > len) |
|
hole_len = len; |
|
ret = send_extent_data(sctx, dst_path, offset, |
|
hole_len); |
|
if (ret < 0) |
|
goto out; |
|
|
|
len -= hole_len; |
|
if (len == 0) |
|
break; |
|
offset += hole_len; |
|
clone_root->offset += hole_len; |
|
data_offset += hole_len; |
|
} |
|
|
|
if (key.offset >= clone_root->offset + len) |
|
break; |
|
|
|
if (key.offset >= clone_src_i_size) |
|
break; |
|
|
|
if (key.offset + ext_len > clone_src_i_size) { |
|
ext_len = clone_src_i_size - key.offset; |
|
crossed_src_i_size = true; |
|
} |
|
|
|
clone_data_offset = btrfs_file_extent_offset(leaf, ei); |
|
if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte) { |
|
clone_root->offset = key.offset; |
|
if (clone_data_offset < data_offset && |
|
clone_data_offset + ext_len > data_offset) { |
|
u64 extent_offset; |
|
|
|
extent_offset = data_offset - clone_data_offset; |
|
ext_len -= extent_offset; |
|
clone_data_offset += extent_offset; |
|
clone_root->offset += extent_offset; |
|
} |
|
} |
|
|
|
clone_len = min_t(u64, ext_len, len); |
|
|
|
if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte && |
|
clone_data_offset == data_offset) { |
|
const u64 src_end = clone_root->offset + clone_len; |
|
const u64 sectorsize = SZ_64K; |
|
|
|
/* |
|
* We can't clone the last block, when its size is not |
|
* sector size aligned, into the middle of a file. If we |
|
* do so, the receiver will get a failure (-EINVAL) when |
|
* trying to clone or will silently corrupt the data in |
|
* the destination file if it's on a kernel without the |
|
* fix introduced by commit ac765f83f1397646 |
|
* ("Btrfs: fix data corruption due to cloning of eof |
|
* block). |
|
* |
|
* So issue a clone of the aligned down range plus a |
|
* regular write for the eof block, if we hit that case. |
|
* |
|
* Also, we use the maximum possible sector size, 64K, |
|
* because we don't know what's the sector size of the |
|
* filesystem that receives the stream, so we have to |
|
* assume the largest possible sector size. |
|
*/ |
|
if (src_end == clone_src_i_size && |
|
!IS_ALIGNED(src_end, sectorsize) && |
|
offset + clone_len < sctx->cur_inode_size) { |
|
u64 slen; |
|
|
|
slen = ALIGN_DOWN(src_end - clone_root->offset, |
|
sectorsize); |
|
if (slen > 0) { |
|
ret = send_clone(sctx, offset, slen, |
|
clone_root); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
ret = send_extent_data(sctx, dst_path, |
|
offset + slen, |
|
clone_len - slen); |
|
} else { |
|
ret = send_clone(sctx, offset, clone_len, |
|
clone_root); |
|
} |
|
} else if (crossed_src_i_size && clone_len < len) { |
|
/* |
|
* If we are at i_size of the clone source inode and we |
|
* can not clone from it, terminate the loop. This is |
|
* to avoid sending two write operations, one with a |
|
* length matching clone_len and the final one after |
|
* this loop with a length of len - clone_len. |
|
* |
|
* When using encoded writes (BTRFS_SEND_FLAG_COMPRESSED |
|
* was passed to the send ioctl), this helps avoid |
|
* sending an encoded write for an offset that is not |
|
* sector size aligned, in case the i_size of the source |
|
* inode is not sector size aligned. That will make the |
|
* receiver fallback to decompression of the data and |
|
* writing it using regular buffered IO, therefore while |
|
* not incorrect, it's not optimal due decompression and |
|
* possible re-compression at the receiver. |
|
*/ |
|
break; |
|
} else { |
|
ret = send_extent_data(sctx, dst_path, offset, |
|
clone_len); |
|
} |
|
|
|
if (ret < 0) |
|
goto out; |
|
|
|
len -= clone_len; |
|
if (len == 0) |
|
break; |
|
offset += clone_len; |
|
clone_root->offset += clone_len; |
|
|
|
/* |
|
* If we are cloning from the file we are currently processing, |
|
* and using the send root as the clone root, we must stop once |
|
* the current clone offset reaches the current eof of the file |
|
* at the receiver, otherwise we would issue an invalid clone |
|
* operation (source range going beyond eof) and cause the |
|
* receiver to fail. So if we reach the current eof, bail out |
|
* and fallback to a regular write. |
|
*/ |
|
if (clone_root->root == sctx->send_root && |
|
clone_root->ino == sctx->cur_ino && |
|
clone_root->offset >= sctx->cur_inode_next_write_offset) |
|
break; |
|
|
|
data_offset += clone_len; |
|
next: |
|
path->slots[0]++; |
|
} |
|
|
|
if (len > 0) |
|
ret = send_extent_data(sctx, dst_path, offset, len); |
|
else |
|
ret = 0; |
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int send_write_or_clone(struct send_ctx *sctx, |
|
struct btrfs_path *path, |
|
struct btrfs_key *key, |
|
struct clone_root *clone_root) |
|
{ |
|
int ret = 0; |
|
u64 offset = key->offset; |
|
u64 end; |
|
u64 bs = sctx->send_root->fs_info->sb->s_blocksize; |
|
|
|
end = min_t(u64, btrfs_file_extent_end(path), sctx->cur_inode_size); |
|
if (offset >= end) |
|
return 0; |
|
|
|
if (clone_root && IS_ALIGNED(end, bs)) { |
|
struct btrfs_file_extent_item *ei; |
|
u64 disk_byte; |
|
u64 data_offset; |
|
|
|
ei = btrfs_item_ptr(path->nodes[0], path->slots[0], |
|
struct btrfs_file_extent_item); |
|
disk_byte = btrfs_file_extent_disk_bytenr(path->nodes[0], ei); |
|
data_offset = btrfs_file_extent_offset(path->nodes[0], ei); |
|
ret = clone_range(sctx, path, clone_root, disk_byte, |
|
data_offset, offset, end - offset); |
|
} else { |
|
ret = send_extent_data(sctx, path, offset, end - offset); |
|
} |
|
sctx->cur_inode_next_write_offset = end; |
|
return ret; |
|
} |
|
|
|
static int is_extent_unchanged(struct send_ctx *sctx, |
|
struct btrfs_path *left_path, |
|
struct btrfs_key *ekey) |
|
{ |
|
int ret = 0; |
|
struct btrfs_key key; |
|
struct btrfs_path *path = NULL; |
|
struct extent_buffer *eb; |
|
int slot; |
|
struct btrfs_key found_key; |
|
struct btrfs_file_extent_item *ei; |
|
u64 left_disknr; |
|
u64 right_disknr; |
|
u64 left_offset; |
|
u64 right_offset; |
|
u64 left_offset_fixed; |
|
u64 left_len; |
|
u64 right_len; |
|
u64 left_gen; |
|
u64 right_gen; |
|
u8 left_type; |
|
u8 right_type; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
eb = left_path->nodes[0]; |
|
slot = left_path->slots[0]; |
|
ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); |
|
left_type = btrfs_file_extent_type(eb, ei); |
|
|
|
if (left_type != BTRFS_FILE_EXTENT_REG) { |
|
ret = 0; |
|
goto out; |
|
} |
|
left_disknr = btrfs_file_extent_disk_bytenr(eb, ei); |
|
left_len = btrfs_file_extent_num_bytes(eb, ei); |
|
left_offset = btrfs_file_extent_offset(eb, ei); |
|
left_gen = btrfs_file_extent_generation(eb, ei); |
|
|
|
/* |
|
* Following comments will refer to these graphics. L is the left |
|
* extents which we are checking at the moment. 1-8 are the right |
|
* extents that we iterate. |
|
* |
|
* |-----L-----| |
|
* |-1-|-2a-|-3-|-4-|-5-|-6-| |
|
* |
|
* |-----L-----| |
|
* |--1--|-2b-|...(same as above) |
|
* |
|
* Alternative situation. Happens on files where extents got split. |
|
* |-----L-----| |
|
* |-----------7-----------|-6-| |
|
* |
|
* Alternative situation. Happens on files which got larger. |
|
* |-----L-----| |
|
* |-8-| |
|
* Nothing follows after 8. |
|
*/ |
|
|
|
key.objectid = ekey->objectid; |
|
key.type = BTRFS_EXTENT_DATA_KEY; |
|
key.offset = ekey->offset; |
|
ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Handle special case where the right side has no extents at all. |
|
*/ |
|
eb = path->nodes[0]; |
|
slot = path->slots[0]; |
|
btrfs_item_key_to_cpu(eb, &found_key, slot); |
|
if (found_key.objectid != key.objectid || |
|
found_key.type != key.type) { |
|
/* If we're a hole then just pretend nothing changed */ |
|
ret = (left_disknr) ? 0 : 1; |
|
goto out; |
|
} |
|
|
|
/* |
|
* We're now on 2a, 2b or 7. |
|
*/ |
|
key = found_key; |
|
while (key.offset < ekey->offset + left_len) { |
|
ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); |
|
right_type = btrfs_file_extent_type(eb, ei); |
|
if (right_type != BTRFS_FILE_EXTENT_REG && |
|
right_type != BTRFS_FILE_EXTENT_INLINE) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
if (right_type == BTRFS_FILE_EXTENT_INLINE) { |
|
right_len = btrfs_file_extent_ram_bytes(eb, ei); |
|
right_len = PAGE_ALIGN(right_len); |
|
} else { |
|
right_len = btrfs_file_extent_num_bytes(eb, ei); |
|
} |
|
|
|
/* |
|
* Are we at extent 8? If yes, we know the extent is changed. |
|
* This may only happen on the first iteration. |
|
*/ |
|
if (found_key.offset + right_len <= ekey->offset) { |
|
/* If we're a hole just pretend nothing changed */ |
|
ret = (left_disknr) ? 0 : 1; |
|
goto out; |
|
} |
|
|
|
/* |
|
* We just wanted to see if when we have an inline extent, what |
|
* follows it is a regular extent (wanted to check the above |
|
* condition for inline extents too). This should normally not |
|
* happen but it's possible for example when we have an inline |
|
* compressed extent representing data with a size matching |
|
* the page size (currently the same as sector size). |
|
*/ |
|
if (right_type == BTRFS_FILE_EXTENT_INLINE) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
right_disknr = btrfs_file_extent_disk_bytenr(eb, ei); |
|
right_offset = btrfs_file_extent_offset(eb, ei); |
|
right_gen = btrfs_file_extent_generation(eb, ei); |
|
|
|
left_offset_fixed = left_offset; |
|
if (key.offset < ekey->offset) { |
|
/* Fix the right offset for 2a and 7. */ |
|
right_offset += ekey->offset - key.offset; |
|
} else { |
|
/* Fix the left offset for all behind 2a and 2b */ |
|
left_offset_fixed += key.offset - ekey->offset; |
|
} |
|
|
|
/* |
|
* Check if we have the same extent. |
|
*/ |
|
if (left_disknr != right_disknr || |
|
left_offset_fixed != right_offset || |
|
left_gen != right_gen) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Go to the next extent. |
|
*/ |
|
ret = btrfs_next_item(sctx->parent_root, path); |
|
if (ret < 0) |
|
goto out; |
|
if (!ret) { |
|
eb = path->nodes[0]; |
|
slot = path->slots[0]; |
|
btrfs_item_key_to_cpu(eb, &found_key, slot); |
|
} |
|
if (ret || found_key.objectid != key.objectid || |
|
found_key.type != key.type) { |
|
key.offset += right_len; |
|
break; |
|
} |
|
if (found_key.offset != key.offset + right_len) { |
|
ret = 0; |
|
goto out; |
|
} |
|
key = found_key; |
|
} |
|
|
|
/* |
|
* We're now behind the left extent (treat as unchanged) or at the end |
|
* of the right side (treat as changed). |
|
*/ |
|
if (key.offset >= ekey->offset + left_len) |
|
ret = 1; |
|
else |
|
ret = 0; |
|
|
|
|
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int get_last_extent(struct send_ctx *sctx, u64 offset) |
|
{ |
|
struct btrfs_path *path; |
|
struct btrfs_root *root = sctx->send_root; |
|
struct btrfs_key key; |
|
int ret; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
sctx->cur_inode_last_extent = 0; |
|
|
|
key.objectid = sctx->cur_ino; |
|
key.type = BTRFS_EXTENT_DATA_KEY; |
|
key.offset = offset; |
|
ret = btrfs_search_slot_for_read(root, &key, path, 0, 1); |
|
if (ret < 0) |
|
goto out; |
|
ret = 0; |
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); |
|
if (key.objectid != sctx->cur_ino || key.type != BTRFS_EXTENT_DATA_KEY) |
|
goto out; |
|
|
|
sctx->cur_inode_last_extent = btrfs_file_extent_end(path); |
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int range_is_hole_in_parent(struct send_ctx *sctx, |
|
const u64 start, |
|
const u64 end) |
|
{ |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
struct btrfs_root *root = sctx->parent_root; |
|
u64 search_start = start; |
|
int ret; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
key.objectid = sctx->cur_ino; |
|
key.type = BTRFS_EXTENT_DATA_KEY; |
|
key.offset = search_start; |
|
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (ret > 0 && path->slots[0] > 0) |
|
path->slots[0]--; |
|
|
|
while (search_start < end) { |
|
struct extent_buffer *leaf = path->nodes[0]; |
|
int slot = path->slots[0]; |
|
struct btrfs_file_extent_item *fi; |
|
u64 extent_end; |
|
|
|
if (slot >= btrfs_header_nritems(leaf)) { |
|
ret = btrfs_next_leaf(root, path); |
|
if (ret < 0) |
|
goto out; |
|
else if (ret > 0) |
|
break; |
|
continue; |
|
} |
|
|
|
btrfs_item_key_to_cpu(leaf, &key, slot); |
|
if (key.objectid < sctx->cur_ino || |
|
key.type < BTRFS_EXTENT_DATA_KEY) |
|
goto next; |
|
if (key.objectid > sctx->cur_ino || |
|
key.type > BTRFS_EXTENT_DATA_KEY || |
|
key.offset >= end) |
|
break; |
|
|
|
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
|
extent_end = btrfs_file_extent_end(path); |
|
if (extent_end <= start) |
|
goto next; |
|
if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0) { |
|
search_start = extent_end; |
|
goto next; |
|
} |
|
ret = 0; |
|
goto out; |
|
next: |
|
path->slots[0]++; |
|
} |
|
ret = 1; |
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path, |
|
struct btrfs_key *key) |
|
{ |
|
int ret = 0; |
|
|
|
if (sctx->cur_ino != key->objectid || !need_send_hole(sctx)) |
|
return 0; |
|
|
|
if (sctx->cur_inode_last_extent == (u64)-1) { |
|
ret = get_last_extent(sctx, key->offset - 1); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
if (path->slots[0] == 0 && |
|
sctx->cur_inode_last_extent < key->offset) { |
|
/* |
|
* We might have skipped entire leafs that contained only |
|
* file extent items for our current inode. These leafs have |
|
* a generation number smaller (older) than the one in the |
|
* current leaf and the leaf our last extent came from, and |
|
* are located between these 2 leafs. |
|
*/ |
|
ret = get_last_extent(sctx, key->offset - 1); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
if (sctx->cur_inode_last_extent < key->offset) { |
|
ret = range_is_hole_in_parent(sctx, |
|
sctx->cur_inode_last_extent, |
|
key->offset); |
|
if (ret < 0) |
|
return ret; |
|
else if (ret == 0) |
|
ret = send_hole(sctx, key->offset); |
|
else |
|
ret = 0; |
|
} |
|
sctx->cur_inode_last_extent = btrfs_file_extent_end(path); |
|
return ret; |
|
} |
|
|
|
static int process_extent(struct send_ctx *sctx, |
|
struct btrfs_path *path, |
|
struct btrfs_key *key) |
|
{ |
|
struct clone_root *found_clone = NULL; |
|
int ret = 0; |
|
|
|
if (S_ISLNK(sctx->cur_inode_mode)) |
|
return 0; |
|
|
|
if (sctx->parent_root && !sctx->cur_inode_new) { |
|
ret = is_extent_unchanged(sctx, path, key); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = 0; |
|
goto out_hole; |
|
} |
|
} else { |
|
struct btrfs_file_extent_item *ei; |
|
u8 type; |
|
|
|
ei = btrfs_item_ptr(path->nodes[0], path->slots[0], |
|
struct btrfs_file_extent_item); |
|
type = btrfs_file_extent_type(path->nodes[0], ei); |
|
if (type == BTRFS_FILE_EXTENT_PREALLOC || |
|
type == BTRFS_FILE_EXTENT_REG) { |
|
/* |
|
* The send spec does not have a prealloc command yet, |
|
* so just leave a hole for prealloc'ed extents until |
|
* we have enough commands queued up to justify rev'ing |
|
* the send spec. |
|
*/ |
|
if (type == BTRFS_FILE_EXTENT_PREALLOC) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
/* Have a hole, just skip it. */ |
|
if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) { |
|
ret = 0; |
|
goto out; |
|
} |
|
} |
|
} |
|
|
|
ret = find_extent_clone(sctx, path, key->objectid, key->offset, |
|
sctx->cur_inode_size, &found_clone); |
|
if (ret != -ENOENT && ret < 0) |
|
goto out; |
|
|
|
ret = send_write_or_clone(sctx, path, key, found_clone); |
|
if (ret) |
|
goto out; |
|
out_hole: |
|
ret = maybe_send_hole(sctx, path, key); |
|
out: |
|
return ret; |
|
} |
|
|
|
static int process_all_extents(struct send_ctx *sctx) |
|
{ |
|
int ret = 0; |
|
int iter_ret = 0; |
|
struct btrfs_root *root; |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
struct btrfs_key found_key; |
|
|
|
root = sctx->send_root; |
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
key.objectid = sctx->cmp_key->objectid; |
|
key.type = BTRFS_EXTENT_DATA_KEY; |
|
key.offset = 0; |
|
btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) { |
|
if (found_key.objectid != key.objectid || |
|
found_key.type != key.type) { |
|
ret = 0; |
|
break; |
|
} |
|
|
|
ret = process_extent(sctx, path, &found_key); |
|
if (ret < 0) |
|
break; |
|
} |
|
/* Catch error found during iteration */ |
|
if (iter_ret < 0) |
|
ret = iter_ret; |
|
|
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end, |
|
int *pending_move, |
|
int *refs_processed) |
|
{ |
|
int ret = 0; |
|
|
|
if (sctx->cur_ino == 0) |
|
goto out; |
|
if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid && |
|
sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY) |
|
goto out; |
|
if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs)) |
|
goto out; |
|
|
|
ret = process_recorded_refs(sctx, pending_move); |
|
if (ret < 0) |
|
goto out; |
|
|
|
*refs_processed = 1; |
|
out: |
|
return ret; |
|
} |
|
|
|
static int finish_inode_if_needed(struct send_ctx *sctx, int at_end) |
|
{ |
|
int ret = 0; |
|
struct btrfs_inode_info info; |
|
u64 left_mode; |
|
u64 left_uid; |
|
u64 left_gid; |
|
u64 left_fileattr; |
|
u64 right_mode; |
|
u64 right_uid; |
|
u64 right_gid; |
|
u64 right_fileattr; |
|
int need_chmod = 0; |
|
int need_chown = 0; |
|
bool need_fileattr = false; |
|
int need_truncate = 1; |
|
int pending_move = 0; |
|
int refs_processed = 0; |
|
|
|
if (sctx->ignore_cur_inode) |
|
return 0; |
|
|
|
ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move, |
|
&refs_processed); |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* |
|
* We have processed the refs and thus need to advance send_progress. |
|
* Now, calls to get_cur_xxx will take the updated refs of the current |
|
* inode into account. |
|
* |
|
* On the other hand, if our current inode is a directory and couldn't |
|
* be moved/renamed because its parent was renamed/moved too and it has |
|
* a higher inode number, we can only move/rename our current inode |
|
* after we moved/renamed its parent. Therefore in this case operate on |
|
* the old path (pre move/rename) of our current inode, and the |
|
* move/rename will be performed later. |
|
*/ |
|
if (refs_processed && !pending_move) |
|
sctx->send_progress = sctx->cur_ino + 1; |
|
|
|
if (sctx->cur_ino == 0 || sctx->cur_inode_deleted) |
|
goto out; |
|
if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino) |
|
goto out; |
|
ret = get_inode_info(sctx->send_root, sctx->cur_ino, &info); |
|
if (ret < 0) |
|
goto out; |
|
left_mode = info.mode; |
|
left_uid = info.uid; |
|
left_gid = info.gid; |
|
left_fileattr = info.fileattr; |
|
|
|
if (!sctx->parent_root || sctx->cur_inode_new) { |
|
need_chown = 1; |
|
if (!S_ISLNK(sctx->cur_inode_mode)) |
|
need_chmod = 1; |
|
if (sctx->cur_inode_next_write_offset == sctx->cur_inode_size) |
|
need_truncate = 0; |
|
} else { |
|
u64 old_size; |
|
|
|
ret = get_inode_info(sctx->parent_root, sctx->cur_ino, &info); |
|
if (ret < 0) |
|
goto out; |
|
old_size = info.size; |
|
right_mode = info.mode; |
|
right_uid = info.uid; |
|
right_gid = info.gid; |
|
right_fileattr = info.fileattr; |
|
|
|
if (left_uid != right_uid || left_gid != right_gid) |
|
need_chown = 1; |
|
if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode) |
|
need_chmod = 1; |
|
if (!S_ISLNK(sctx->cur_inode_mode) && left_fileattr != right_fileattr) |
|
need_fileattr = true; |
|
if ((old_size == sctx->cur_inode_size) || |
|
(sctx->cur_inode_size > old_size && |
|
sctx->cur_inode_next_write_offset == sctx->cur_inode_size)) |
|
need_truncate = 0; |
|
} |
|
|
|
if (S_ISREG(sctx->cur_inode_mode)) { |
|
if (need_send_hole(sctx)) { |
|
if (sctx->cur_inode_last_extent == (u64)-1 || |
|
sctx->cur_inode_last_extent < |
|
sctx->cur_inode_size) { |
|
ret = get_last_extent(sctx, (u64)-1); |
|
if (ret) |
|
goto out; |
|
} |
|
if (sctx->cur_inode_last_extent < |
|
sctx->cur_inode_size) { |
|
ret = send_hole(sctx, sctx->cur_inode_size); |
|
if (ret) |
|
goto out; |
|
} |
|
} |
|
if (need_truncate) { |
|
ret = send_truncate(sctx, sctx->cur_ino, |
|
sctx->cur_inode_gen, |
|
sctx->cur_inode_size); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
} |
|
|
|
if (need_chown) { |
|
ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen, |
|
left_uid, left_gid); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
if (need_chmod) { |
|
ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen, |
|
left_mode); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
if (need_fileattr) { |
|
ret = send_fileattr(sctx, sctx->cur_ino, sctx->cur_inode_gen, |
|
left_fileattr); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
if (proto_cmd_ok(sctx, BTRFS_SEND_C_ENABLE_VERITY) |
|
&& sctx->cur_inode_needs_verity) { |
|
ret = process_verity(sctx); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
ret = send_capabilities(sctx); |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* |
|
* If other directory inodes depended on our current directory |
|
* inode's move/rename, now do their move/rename operations. |
|
*/ |
|
if (!is_waiting_for_move(sctx, sctx->cur_ino)) { |
|
ret = apply_children_dir_moves(sctx); |
|
if (ret) |
|
goto out; |
|
/* |
|
* Need to send that every time, no matter if it actually |
|
* changed between the two trees as we have done changes to |
|
* the inode before. If our inode is a directory and it's |
|
* waiting to be moved/renamed, we will send its utimes when |
|
* it's moved/renamed, therefore we don't need to do it here. |
|
*/ |
|
sctx->send_progress = sctx->cur_ino + 1; |
|
ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static void close_current_inode(struct send_ctx *sctx) |
|
{ |
|
u64 i_size; |
|
|
|
if (sctx->cur_inode == NULL) |
|
return; |
|
|
|
i_size = i_size_read(sctx->cur_inode); |
|
|
|
/* |
|
* If we are doing an incremental send, we may have extents between the |
|
* last processed extent and the i_size that have not been processed |
|
* because they haven't changed but we may have read some of their pages |
|
* through readahead, see the comments at send_extent_data(). |
|
*/ |
|
if (sctx->clean_page_cache && sctx->page_cache_clear_start < i_size) |
|
truncate_inode_pages_range(&sctx->cur_inode->i_data, |
|
sctx->page_cache_clear_start, |
|
round_up(i_size, PAGE_SIZE) - 1); |
|
|
|
iput(sctx->cur_inode); |
|
sctx->cur_inode = NULL; |
|
} |
|
|
|
static int changed_inode(struct send_ctx *sctx, |
|
enum btrfs_compare_tree_result result) |
|
{ |
|
int ret = 0; |
|
struct btrfs_key *key = sctx->cmp_key; |
|
struct btrfs_inode_item *left_ii = NULL; |
|
struct btrfs_inode_item *right_ii = NULL; |
|
u64 left_gen = 0; |
|
u64 right_gen = 0; |
|
|
|
close_current_inode(sctx); |
|
|
|
sctx->cur_ino = key->objectid; |
|
sctx->cur_inode_new_gen = false; |
|
sctx->cur_inode_last_extent = (u64)-1; |
|
sctx->cur_inode_next_write_offset = 0; |
|
sctx->ignore_cur_inode = false; |
|
|
|
/* |
|
* Set send_progress to current inode. This will tell all get_cur_xxx |
|
* functions that the current inode's refs are not updated yet. Later, |
|
* when process_recorded_refs is finished, it is set to cur_ino + 1. |
|
*/ |
|
sctx->send_progress = sctx->cur_ino; |
|
|
|
if (result == BTRFS_COMPARE_TREE_NEW || |
|
result == BTRFS_COMPARE_TREE_CHANGED) { |
|
left_ii = btrfs_item_ptr(sctx->left_path->nodes[0], |
|
sctx->left_path->slots[0], |
|
struct btrfs_inode_item); |
|
left_gen = btrfs_inode_generation(sctx->left_path->nodes[0], |
|
left_ii); |
|
} else { |
|
right_ii = btrfs_item_ptr(sctx->right_path->nodes[0], |
|
sctx->right_path->slots[0], |
|
struct btrfs_inode_item); |
|
right_gen = btrfs_inode_generation(sctx->right_path->nodes[0], |
|
right_ii); |
|
} |
|
if (result == BTRFS_COMPARE_TREE_CHANGED) { |
|
right_ii = btrfs_item_ptr(sctx->right_path->nodes[0], |
|
sctx->right_path->slots[0], |
|
struct btrfs_inode_item); |
|
|
|
right_gen = btrfs_inode_generation(sctx->right_path->nodes[0], |
|
right_ii); |
|
|
|
/* |
|
* The cur_ino = root dir case is special here. We can't treat |
|
* the inode as deleted+reused because it would generate a |
|
* stream that tries to delete/mkdir the root dir. |
|
*/ |
|
if (left_gen != right_gen && |
|
sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) |
|
sctx->cur_inode_new_gen = true; |
|
} |
|
|
|
/* |
|
* Normally we do not find inodes with a link count of zero (orphans) |
|
* because the most common case is to create a snapshot and use it |
|
* for a send operation. However other less common use cases involve |
|
* using a subvolume and send it after turning it to RO mode just |
|
* after deleting all hard links of a file while holding an open |
|
* file descriptor against it or turning a RO snapshot into RW mode, |
|
* keep an open file descriptor against a file, delete it and then |
|
* turn the snapshot back to RO mode before using it for a send |
|
* operation. The former is what the receiver operation does. |
|
* Therefore, if we want to send these snapshots soon after they're |
|
* received, we need to handle orphan inodes as well. Moreover, orphans |
|
* can appear not only in the send snapshot but also in the parent |
|
* snapshot. Here are several cases: |
|
* |
|
* Case 1: BTRFS_COMPARE_TREE_NEW |
|
* | send snapshot | action |
|
* -------------------------------- |
|
* nlink | 0 | ignore |
|
* |
|
* Case 2: BTRFS_COMPARE_TREE_DELETED |
|
* | parent snapshot | action |
|
* ---------------------------------- |
|
* nlink | 0 | as usual |
|
* Note: No unlinks will be sent because there're no paths for it. |
|
* |
|
* Case 3: BTRFS_COMPARE_TREE_CHANGED |
|
* | | parent snapshot | send snapshot | action |
|
* ----------------------------------------------------------------------- |
|
* subcase 1 | nlink | 0 | 0 | ignore |
|
* subcase 2 | nlink | >0 | 0 | new_gen(deletion) |
|
* subcase 3 | nlink | 0 | >0 | new_gen(creation) |
|
* |
|
*/ |
|
if (result == BTRFS_COMPARE_TREE_NEW) { |
|
if (btrfs_inode_nlink(sctx->left_path->nodes[0], left_ii) == 0) { |
|
sctx->ignore_cur_inode = true; |
|
goto out; |
|
} |
|
sctx->cur_inode_gen = left_gen; |
|
sctx->cur_inode_new = true; |
|
sctx->cur_inode_deleted = false; |
|
sctx->cur_inode_size = btrfs_inode_size( |
|
sctx->left_path->nodes[0], left_ii); |
|
sctx->cur_inode_mode = btrfs_inode_mode( |
|
sctx->left_path->nodes[0], left_ii); |
|
sctx->cur_inode_rdev = btrfs_inode_rdev( |
|
sctx->left_path->nodes[0], left_ii); |
|
if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) |
|
ret = send_create_inode_if_needed(sctx); |
|
} else if (result == BTRFS_COMPARE_TREE_DELETED) { |
|
sctx->cur_inode_gen = right_gen; |
|
sctx->cur_inode_new = false; |
|
sctx->cur_inode_deleted = true; |
|
sctx->cur_inode_size = btrfs_inode_size( |
|
sctx->right_path->nodes[0], right_ii); |
|
sctx->cur_inode_mode = btrfs_inode_mode( |
|
sctx->right_path->nodes[0], right_ii); |
|
} else if (result == BTRFS_COMPARE_TREE_CHANGED) { |
|
u32 new_nlinks, old_nlinks; |
|
|
|
new_nlinks = btrfs_inode_nlink(sctx->left_path->nodes[0], left_ii); |
|
old_nlinks = btrfs_inode_nlink(sctx->right_path->nodes[0], right_ii); |
|
if (new_nlinks == 0 && old_nlinks == 0) { |
|
sctx->ignore_cur_inode = true; |
|
goto out; |
|
} else if (new_nlinks == 0 || old_nlinks == 0) { |
|
sctx->cur_inode_new_gen = 1; |
|
} |
|
/* |
|
* We need to do some special handling in case the inode was |
|
* reported as changed with a changed generation number. This |
|
* means that the original inode was deleted and new inode |
|
* reused the same inum. So we have to treat the old inode as |
|
* deleted and the new one as new. |
|
*/ |
|
if (sctx->cur_inode_new_gen) { |
|
/* |
|
* First, process the inode as if it was deleted. |
|
*/ |
|
if (old_nlinks > 0) { |
|
sctx->cur_inode_gen = right_gen; |
|
sctx->cur_inode_new = false; |
|
sctx->cur_inode_deleted = true; |
|
sctx->cur_inode_size = btrfs_inode_size( |
|
sctx->right_path->nodes[0], right_ii); |
|
sctx->cur_inode_mode = btrfs_inode_mode( |
|
sctx->right_path->nodes[0], right_ii); |
|
ret = process_all_refs(sctx, |
|
BTRFS_COMPARE_TREE_DELETED); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
/* |
|
* Now process the inode as if it was new. |
|
*/ |
|
if (new_nlinks > 0) { |
|
sctx->cur_inode_gen = left_gen; |
|
sctx->cur_inode_new = true; |
|
sctx->cur_inode_deleted = false; |
|
sctx->cur_inode_size = btrfs_inode_size( |
|
sctx->left_path->nodes[0], |
|
left_ii); |
|
sctx->cur_inode_mode = btrfs_inode_mode( |
|
sctx->left_path->nodes[0], |
|
left_ii); |
|
sctx->cur_inode_rdev = btrfs_inode_rdev( |
|
sctx->left_path->nodes[0], |
|
left_ii); |
|
ret = send_create_inode_if_needed(sctx); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW); |
|
if (ret < 0) |
|
goto out; |
|
/* |
|
* Advance send_progress now as we did not get |
|
* into process_recorded_refs_if_needed in the |
|
* new_gen case. |
|
*/ |
|
sctx->send_progress = sctx->cur_ino + 1; |
|
|
|
/* |
|
* Now process all extents and xattrs of the |
|
* inode as if they were all new. |
|
*/ |
|
ret = process_all_extents(sctx); |
|
if (ret < 0) |
|
goto out; |
|
ret = process_all_new_xattrs(sctx); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
} else { |
|
sctx->cur_inode_gen = left_gen; |
|
sctx->cur_inode_new = false; |
|
sctx->cur_inode_new_gen = false; |
|
sctx->cur_inode_deleted = false; |
|
sctx->cur_inode_size = btrfs_inode_size( |
|
sctx->left_path->nodes[0], left_ii); |
|
sctx->cur_inode_mode = btrfs_inode_mode( |
|
sctx->left_path->nodes[0], left_ii); |
|
} |
|
} |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* We have to process new refs before deleted refs, but compare_trees gives us |
|
* the new and deleted refs mixed. To fix this, we record the new/deleted refs |
|
* first and later process them in process_recorded_refs. |
|
* For the cur_inode_new_gen case, we skip recording completely because |
|
* changed_inode did already initiate processing of refs. The reason for this is |
|
* that in this case, compare_tree actually compares the refs of 2 different |
|
* inodes. To fix this, process_all_refs is used in changed_inode to handle all |
|
* refs of the right tree as deleted and all refs of the left tree as new. |
|
*/ |
|
static int changed_ref(struct send_ctx *sctx, |
|
enum btrfs_compare_tree_result result) |
|
{ |
|
int ret = 0; |
|
|
|
if (sctx->cur_ino != sctx->cmp_key->objectid) { |
|
inconsistent_snapshot_error(sctx, result, "reference"); |
|
return -EIO; |
|
} |
|
|
|
if (!sctx->cur_inode_new_gen && |
|
sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) { |
|
if (result == BTRFS_COMPARE_TREE_NEW) |
|
ret = record_new_ref(sctx); |
|
else if (result == BTRFS_COMPARE_TREE_DELETED) |
|
ret = record_deleted_ref(sctx); |
|
else if (result == BTRFS_COMPARE_TREE_CHANGED) |
|
ret = record_changed_ref(sctx); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Process new/deleted/changed xattrs. We skip processing in the |
|
* cur_inode_new_gen case because changed_inode did already initiate processing |
|
* of xattrs. The reason is the same as in changed_ref |
|
*/ |
|
static int changed_xattr(struct send_ctx *sctx, |
|
enum btrfs_compare_tree_result result) |
|
{ |
|
int ret = 0; |
|
|
|
if (sctx->cur_ino != sctx->cmp_key->objectid) { |
|
inconsistent_snapshot_error(sctx, result, "xattr"); |
|
return -EIO; |
|
} |
|
|
|
if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) { |
|
if (result == BTRFS_COMPARE_TREE_NEW) |
|
ret = process_new_xattr(sctx); |
|
else if (result == BTRFS_COMPARE_TREE_DELETED) |
|
ret = process_deleted_xattr(sctx); |
|
else if (result == BTRFS_COMPARE_TREE_CHANGED) |
|
ret = process_changed_xattr(sctx); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Process new/deleted/changed extents. We skip processing in the |
|
* cur_inode_new_gen case because changed_inode did already initiate processing |
|
* of extents. The reason is the same as in changed_ref |
|
*/ |
|
static int changed_extent(struct send_ctx *sctx, |
|
enum btrfs_compare_tree_result result) |
|
{ |
|
int ret = 0; |
|
|
|
/* |
|
* We have found an extent item that changed without the inode item |
|
* having changed. This can happen either after relocation (where the |
|
* disk_bytenr of an extent item is replaced at |
|
* relocation.c:replace_file_extents()) or after deduplication into a |
|
* file in both the parent and send snapshots (where an extent item can |
|
* get modified or replaced with a new one). Note that deduplication |
|
* updates the inode item, but it only changes the iversion (sequence |
|
* field in the inode item) of the inode, so if a file is deduplicated |
|
* the same amount of times in both the parent and send snapshots, its |
|
* iversion becomes the same in both snapshots, whence the inode item is |
|
* the same on both snapshots. |
|
*/ |
|
if (sctx->cur_ino != sctx->cmp_key->objectid) |
|
return 0; |
|
|
|
if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) { |
|
if (result != BTRFS_COMPARE_TREE_DELETED) |
|
ret = process_extent(sctx, sctx->left_path, |
|
sctx->cmp_key); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int changed_verity(struct send_ctx *sctx, enum btrfs_compare_tree_result result) |
|
{ |
|
int ret = 0; |
|
|
|
if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) { |
|
if (result == BTRFS_COMPARE_TREE_NEW) |
|
sctx->cur_inode_needs_verity = true; |
|
} |
|
return ret; |
|
} |
|
|
|
static int dir_changed(struct send_ctx *sctx, u64 dir) |
|
{ |
|
u64 orig_gen, new_gen; |
|
int ret; |
|
|
|
ret = get_inode_gen(sctx->send_root, dir, &new_gen); |
|
if (ret) |
|
return ret; |
|
|
|
ret = get_inode_gen(sctx->parent_root, dir, &orig_gen); |
|
if (ret) |
|
return ret; |
|
|
|
return (orig_gen != new_gen) ? 1 : 0; |
|
} |
|
|
|
static int compare_refs(struct send_ctx *sctx, struct btrfs_path *path, |
|
struct btrfs_key *key) |
|
{ |
|
struct btrfs_inode_extref *extref; |
|
struct extent_buffer *leaf; |
|
u64 dirid = 0, last_dirid = 0; |
|
unsigned long ptr; |
|
u32 item_size; |
|
u32 cur_offset = 0; |
|
int ref_name_len; |
|
int ret = 0; |
|
|
|
/* Easy case, just check this one dirid */ |
|
if (key->type == BTRFS_INODE_REF_KEY) { |
|
dirid = key->offset; |
|
|
|
ret = dir_changed(sctx, dirid); |
|
goto out; |
|
} |
|
|
|
leaf = path->nodes[0]; |
|
item_size = btrfs_item_size(leaf, path->slots[0]); |
|
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
|
while (cur_offset < item_size) { |
|
extref = (struct btrfs_inode_extref *)(ptr + |
|
cur_offset); |
|
dirid = btrfs_inode_extref_parent(leaf, extref); |
|
ref_name_len = btrfs_inode_extref_name_len(leaf, extref); |
|
cur_offset += ref_name_len + sizeof(*extref); |
|
if (dirid == last_dirid) |
|
continue; |
|
ret = dir_changed(sctx, dirid); |
|
if (ret) |
|
break; |
|
last_dirid = dirid; |
|
} |
|
out: |
|
return ret; |
|
} |
|
|
|
/* |
|
* Updates compare related fields in sctx and simply forwards to the actual |
|
* changed_xxx functions. |
|
*/ |
|
static int changed_cb(struct btrfs_path *left_path, |
|
struct btrfs_path *right_path, |
|
struct btrfs_key *key, |
|
enum btrfs_compare_tree_result result, |
|
struct send_ctx *sctx) |
|
{ |
|
int ret = 0; |
|
|
|
/* |
|
* We can not hold the commit root semaphore here. This is because in |
|
* the case of sending and receiving to the same filesystem, using a |
|
* pipe, could result in a deadlock: |
|
* |
|
* 1) The task running send blocks on the pipe because it's full; |
|
* |
|
* 2) The task running receive, which is the only consumer of the pipe, |
|
* is waiting for a transaction commit (for example due to a space |
|
* reservation when doing a write or triggering a transaction commit |
|
* when creating a subvolume); |
|
* |
|
* 3) The transaction is waiting to write lock the commit root semaphore, |
|
* but can not acquire it since it's being held at 1). |
|
* |
|
* Down this call chain we write to the pipe through kernel_write(). |
|
* The same type of problem can also happen when sending to a file that |
|
* is stored in the same filesystem - when reserving space for a write |
|
* into the file, we can trigger a transaction commit. |
|
* |
|
* Our caller has supplied us with clones of leaves from the send and |
|
* parent roots, so we're safe here from a concurrent relocation and |
|
* further reallocation of metadata extents while we are here. Below we |
|
* also assert that the leaves are clones. |
|
*/ |
|
lockdep_assert_not_held(&sctx->send_root->fs_info->commit_root_sem); |
|
|
|
/* |
|
* We always have a send root, so left_path is never NULL. We will not |
|
* have a leaf when we have reached the end of the send root but have |
|
* not yet reached the end of the parent root. |
|
*/ |
|
if (left_path->nodes[0]) |
|
ASSERT(test_bit(EXTENT_BUFFER_UNMAPPED, |
|
&left_path->nodes[0]->bflags)); |
|
/* |
|
* When doing a full send we don't have a parent root, so right_path is |
|
* NULL. When doing an incremental send, we may have reached the end of |
|
* the parent root already, so we don't have a leaf at right_path. |
|
*/ |
|
if (right_path && right_path->nodes[0]) |
|
ASSERT(test_bit(EXTENT_BUFFER_UNMAPPED, |
|
&right_path->nodes[0]->bflags)); |
|
|
|
if (result == BTRFS_COMPARE_TREE_SAME) { |
|
if (key->type == BTRFS_INODE_REF_KEY || |
|
key->type == BTRFS_INODE_EXTREF_KEY) { |
|
ret = compare_refs(sctx, left_path, key); |
|
if (!ret) |
|
return 0; |
|
if (ret < 0) |
|
return ret; |
|
} else if (key->type == BTRFS_EXTENT_DATA_KEY) { |
|
return maybe_send_hole(sctx, left_path, key); |
|
} else { |
|
return 0; |
|
} |
|
result = BTRFS_COMPARE_TREE_CHANGED; |
|
ret = 0; |
|
} |
|
|
|
sctx->left_path = left_path; |
|
sctx->right_path = right_path; |
|
sctx->cmp_key = key; |
|
|
|
ret = finish_inode_if_needed(sctx, 0); |
|
if (ret < 0) |
|
goto out; |
|
|
|
/* Ignore non-FS objects */ |
|
if (key->objectid == BTRFS_FREE_INO_OBJECTID || |
|
key->objectid == BTRFS_FREE_SPACE_OBJECTID) |
|
goto out; |
|
|
|
if (key->type == BTRFS_INODE_ITEM_KEY) { |
|
ret = changed_inode(sctx, result); |
|
} else if (!sctx->ignore_cur_inode) { |
|
if (key->type == BTRFS_INODE_REF_KEY || |
|
key->type == BTRFS_INODE_EXTREF_KEY) |
|
ret = changed_ref(sctx, result); |
|
else if (key->type == BTRFS_XATTR_ITEM_KEY) |
|
ret = changed_xattr(sctx, result); |
|
else if (key->type == BTRFS_EXTENT_DATA_KEY) |
|
ret = changed_extent(sctx, result); |
|
else if (key->type == BTRFS_VERITY_DESC_ITEM_KEY && |
|
key->offset == 0) |
|
ret = changed_verity(sctx, result); |
|
} |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
static int search_key_again(const struct send_ctx *sctx, |
|
struct btrfs_root *root, |
|
struct btrfs_path *path, |
|
const struct btrfs_key *key) |
|
{ |
|
int ret; |
|
|
|
if (!path->need_commit_sem) |
|
lockdep_assert_held_read(&root->fs_info->commit_root_sem); |
|
|
|
/* |
|
* Roots used for send operations are readonly and no one can add, |
|
* update or remove keys from them, so we should be able to find our |
|
* key again. The only exception is deduplication, which can operate on |
|
* readonly roots and add, update or remove keys to/from them - but at |
|
* the moment we don't allow it to run in parallel with send. |
|
*/ |
|
ret = btrfs_search_slot(NULL, root, key, path, 0, 0); |
|
ASSERT(ret <= 0); |
|
if (ret > 0) { |
|
btrfs_print_tree(path->nodes[path->lowest_level], false); |
|
btrfs_err(root->fs_info, |
|
"send: key (%llu %u %llu) not found in %s root %llu, lowest_level %d, slot %d", |
|
key->objectid, key->type, key->offset, |
|
(root == sctx->parent_root ? "parent" : "send"), |
|
root->root_key.objectid, path->lowest_level, |
|
path->slots[path->lowest_level]); |
|
return -EUCLEAN; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int full_send_tree(struct send_ctx *sctx) |
|
{ |
|
int ret; |
|
struct btrfs_root *send_root = sctx->send_root; |
|
struct btrfs_key key; |
|
struct btrfs_fs_info *fs_info = send_root->fs_info; |
|
struct btrfs_path *path; |
|
|
|
path = alloc_path_for_send(); |
|
if (!path) |
|
return -ENOMEM; |
|
path->reada = READA_FORWARD_ALWAYS; |
|
|
|
key.objectid = BTRFS_FIRST_FREE_OBJECTID; |
|
key.type = BTRFS_INODE_ITEM_KEY; |
|
key.offset = 0; |
|
|
|
down_read(&fs_info->commit_root_sem); |
|
sctx->last_reloc_trans = fs_info->last_reloc_trans; |
|
up_read(&fs_info->commit_root_sem); |
|
|
|
ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) |
|
goto out_finish; |
|
|
|
while (1) { |
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); |
|
|
|
ret = changed_cb(path, NULL, &key, |
|
BTRFS_COMPARE_TREE_NEW, sctx); |
|
if (ret < 0) |
|
goto out; |
|
|
|
down_read(&fs_info->commit_root_sem); |
|
if (fs_info->last_reloc_trans > sctx->last_reloc_trans) { |
|
sctx->last_reloc_trans = fs_info->last_reloc_trans; |
|
up_read(&fs_info->commit_root_sem); |
|
/* |
|
* A transaction used for relocating a block group was |
|
* committed or is about to finish its commit. Release |
|
* our path (leaf) and restart the search, so that we |
|
* avoid operating on any file extent items that are |
|
* stale, with a disk_bytenr that reflects a pre |
|
* relocation value. This way we avoid as much as |
|
* possible to fallback to regular writes when checking |
|
* if we can clone file ranges. |
|
*/ |
|
btrfs_release_path(path); |
|
ret = search_key_again(sctx, send_root, path, &key); |
|
if (ret < 0) |
|
goto out; |
|
} else { |
|
up_read(&fs_info->commit_root_sem); |
|
} |
|
|
|
ret = btrfs_next_item(send_root, path); |
|
if (ret < 0) |
|
goto out; |
|
if (ret) { |
|
ret = 0; |
|
break; |
|
} |
|
} |
|
|
|
out_finish: |
|
ret = finish_inode_if_needed(sctx, 1); |
|
|
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int replace_node_with_clone(struct btrfs_path *path, int level) |
|
{ |
|
struct extent_buffer *clone; |
|
|
|
clone = btrfs_clone_extent_buffer(path->nodes[level]); |
|
if (!clone) |
|
return -ENOMEM; |
|
|
|
free_extent_buffer(path->nodes[level]); |
|
path->nodes[level] = clone; |
|
|
|
return 0; |
|
} |
|
|
|
static int tree_move_down(struct btrfs_path *path, int *level, u64 reada_min_gen) |
|
{ |
|
struct extent_buffer *eb; |
|
struct extent_buffer *parent = path->nodes[*level]; |
|
int slot = path->slots[*level]; |
|
const int nritems = btrfs_header_nritems(parent); |
|
u64 reada_max; |
|
u64 reada_done = 0; |
|
|
|
lockdep_assert_held_read(&parent->fs_info->commit_root_sem); |
|
|
|
BUG_ON(*level == 0); |
|
eb = btrfs_read_node_slot(parent, slot); |
|
if (IS_ERR(eb)) |
|
return PTR_ERR(eb); |
|
|
|
/* |
|
* Trigger readahead for the next leaves we will process, so that it is |
|
* very likely that when we need them they are already in memory and we |
|
* will not block on disk IO. For nodes we only do readahead for one, |
|
* since the time window between processing nodes is typically larger. |
|
*/ |
|
reada_max = (*level == 1 ? SZ_128K : eb->fs_info->nodesize); |
|
|
|
for (slot++; slot < nritems && reada_done < reada_max; slot++) { |
|
if (btrfs_node_ptr_generation(parent, slot) > reada_min_gen) { |
|
btrfs_readahead_node_child(parent, slot); |
|
reada_done += eb->fs_info->nodesize; |
|
} |
|
} |
|
|
|
path->nodes[*level - 1] = eb; |
|
path->slots[*level - 1] = 0; |
|
(*level)--; |
|
|
|
if (*level == 0) |
|
return replace_node_with_clone(path, 0); |
|
|
|
return 0; |
|
} |
|
|
|
static int tree_move_next_or_upnext(struct btrfs_path *path, |
|
int *level, int root_level) |
|
{ |
|
int ret = 0; |
|
int nritems; |
|
nritems = btrfs_header_nritems(path->nodes[*level]); |
|
|
|
path->slots[*level]++; |
|
|
|
while (path->slots[*level] >= nritems) { |
|
if (*level == root_level) { |
|
path->slots[*level] = nritems - 1; |
|
return -1; |
|
} |
|
|
|
/* move upnext */ |
|
path->slots[*level] = 0; |
|
free_extent_buffer(path->nodes[*level]); |
|
path->nodes[*level] = NULL; |
|
(*level)++; |
|
path->slots[*level]++; |
|
|
|
nritems = btrfs_header_nritems(path->nodes[*level]); |
|
ret = 1; |
|
} |
|
return ret; |
|
} |
|
|
|
/* |
|
* Returns 1 if it had to move up and next. 0 is returned if it moved only next |
|
* or down. |
|
*/ |
|
static int tree_advance(struct btrfs_path *path, |
|
int *level, int root_level, |
|
int allow_down, |
|
struct btrfs_key *key, |
|
u64 reada_min_gen) |
|
{ |
|
int ret; |
|
|
|
if (*level == 0 || !allow_down) { |
|
ret = tree_move_next_or_upnext(path, level, root_level); |
|
} else { |
|
ret = tree_move_down(path, level, reada_min_gen); |
|
} |
|
|
|
/* |
|
* Even if we have reached the end of a tree, ret is -1, update the key |
|
* anyway, so that in case we need to restart due to a block group |
|
* relocation, we can assert that the last key of the root node still |
|
* exists in the tree. |
|
*/ |
|
if (*level == 0) |
|
btrfs_item_key_to_cpu(path->nodes[*level], key, |
|
path->slots[*level]); |
|
else |
|
btrfs_node_key_to_cpu(path->nodes[*level], key, |
|
path->slots[*level]); |
|
|
|
return ret; |
|
} |
|
|
|
static int tree_compare_item(struct btrfs_path *left_path, |
|
struct btrfs_path *right_path, |
|
char *tmp_buf) |
|
{ |
|
int cmp; |
|
int len1, len2; |
|
unsigned long off1, off2; |
|
|
|
len1 = btrfs_item_size(left_path->nodes[0], left_path->slots[0]); |
|
len2 = btrfs_item_size(right_path->nodes[0], right_path->slots[0]); |
|
if (len1 != len2) |
|
return 1; |
|
|
|
off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]); |
|
off2 = btrfs_item_ptr_offset(right_path->nodes[0], |
|
right_path->slots[0]); |
|
|
|
read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1); |
|
|
|
cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1); |
|
if (cmp) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
/* |
|
* A transaction used for relocating a block group was committed or is about to |
|
* finish its commit. Release our paths and restart the search, so that we are |
|
* not using stale extent buffers: |
|
* |
|
* 1) For levels > 0, we are only holding references of extent buffers, without |
|
* any locks on them, which does not prevent them from having been relocated |
|
* and reallocated after the last time we released the commit root semaphore. |
|
* The exception are the root nodes, for which we always have a clone, see |
|
* the comment at btrfs_compare_trees(); |
|
* |
|
* 2) For leaves, level 0, we are holding copies (clones) of extent buffers, so |
|
* we are safe from the concurrent relocation and reallocation. However they |
|
* can have file extent items with a pre relocation disk_bytenr value, so we |
|
* restart the start from the current commit roots and clone the new leaves so |
|
* that we get the post relocation disk_bytenr values. Not doing so, could |
|
* make us clone the wrong data in case there are new extents using the old |
|
* disk_bytenr that happen to be shared. |
|
*/ |
|
static int restart_after_relocation(struct btrfs_path *left_path, |
|
struct btrfs_path *right_path, |
|
const struct btrfs_key *left_key, |
|
const struct btrfs_key *right_key, |
|
int left_level, |
|
int right_level, |
|
const struct send_ctx *sctx) |
|
{ |
|
int root_level; |
|
int ret; |
|
|
|
lockdep_assert_held_read(&sctx->send_root->fs_info->commit_root_sem); |
|
|
|
btrfs_release_path(left_path); |
|
btrfs_release_path(right_path); |
|
|
|
/* |
|
* Since keys can not be added or removed to/from our roots because they |
|
* are readonly and we do not allow deduplication to run in parallel |
|
* (which can add, remove or change keys), the layout of the trees should |
|
* not change. |
|
*/ |
|
left_path->lowest_level = left_level; |
|
ret = search_key_again(sctx, sctx->send_root, left_path, left_key); |
|
if (ret < 0) |
|
return ret; |
|
|
|
right_path->lowest_level = right_level; |
|
ret = search_key_again(sctx, sctx->parent_root, right_path, right_key); |
|
if (ret < 0) |
|
return ret; |
|
|
|
/* |
|
* If the lowest level nodes are leaves, clone them so that they can be |
|
* safely used by changed_cb() while not under the protection of the |
|
* commit root semaphore, even if relocation and reallocation happens in |
|
* parallel. |
|
*/ |
|
if (left_level == 0) { |
|
ret = replace_node_with_clone(left_path, 0); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
if (right_level == 0) { |
|
ret = replace_node_with_clone(right_path, 0); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
/* |
|
* Now clone the root nodes (unless they happen to be the leaves we have |
|
* already cloned). This is to protect against concurrent snapshotting of |
|
* the send and parent roots (see the comment at btrfs_compare_trees()). |
|
*/ |
|
root_level = btrfs_header_level(sctx->send_root->commit_root); |
|
if (root_level > 0) { |
|
ret = replace_node_with_clone(left_path, root_level); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
root_level = btrfs_header_level(sctx->parent_root->commit_root); |
|
if (root_level > 0) { |
|
ret = replace_node_with_clone(right_path, root_level); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* This function compares two trees and calls the provided callback for |
|
* every changed/new/deleted item it finds. |
|
* If shared tree blocks are encountered, whole subtrees are skipped, making |
|
* the compare pretty fast on snapshotted subvolumes. |
|
* |
|
* This currently works on commit roots only. As commit roots are read only, |
|
* we don't do any locking. The commit roots are protected with transactions. |
|
* Transactions are ended and rejoined when a commit is tried in between. |
|
* |
|
* This function checks for modifications done to the trees while comparing. |
|
* If it detects a change, it aborts immediately. |
|
*/ |
|
static int btrfs_compare_trees(struct btrfs_root *left_root, |
|
struct btrfs_root *right_root, struct send_ctx *sctx) |
|
{ |
|
struct btrfs_fs_info *fs_info = left_root->fs_info; |
|
int ret; |
|
int cmp; |
|
struct btrfs_path *left_path = NULL; |
|
struct btrfs_path *right_path = NULL; |
|
struct btrfs_key left_key; |
|
struct btrfs_key right_key; |
|
char *tmp_buf = NULL; |
|
int left_root_level; |
|
int right_root_level; |
|
int left_level; |
|
int right_level; |
|
int left_end_reached = 0; |
|
int right_end_reached = 0; |
|
int advance_left = 0; |
|
int advance_right = 0; |
|
u64 left_blockptr; |
|
u64 right_blockptr; |
|
u64 left_gen; |
|
u64 right_gen; |
|
u64 reada_min_gen; |
|
|
|
left_path = btrfs_alloc_path(); |
|
if (!left_path) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
right_path = btrfs_alloc_path(); |
|
if (!right_path) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
tmp_buf = kvmalloc(fs_info->nodesize, GFP_KERNEL); |
|
if (!tmp_buf) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
left_path->search_commit_root = 1; |
|
left_path->skip_locking = 1; |
|
right_path->search_commit_root = 1; |
|
right_path->skip_locking = 1; |
|
|
|
/* |
|
* Strategy: Go to the first items of both trees. Then do |
|
* |
|
* If both trees are at level 0 |
|
* Compare keys of current items |
|
* If left < right treat left item as new, advance left tree |
|
* and repeat |
|
* If left > right treat right item as deleted, advance right tree |
|
* and repeat |
|
* If left == right do deep compare of items, treat as changed if |
|
* needed, advance both trees and repeat |
|
* If both trees are at the same level but not at level 0 |
|
* Compare keys of current nodes/leafs |
|
* If left < right advance left tree and repeat |
|
* If left > right advance right tree and repeat |
|
* If left == right compare blockptrs of the next nodes/leafs |
|
* If they match advance both trees but stay at the same level |
|
* and repeat |
|
* If they don't match advance both trees while allowing to go |
|
* deeper and repeat |
|
* If tree levels are different |
|
* Advance the tree that needs it and repeat |
|
* |
|
* Advancing a tree means: |
|
* If we are at level 0, try to go to the next slot. If that's not |
|
* possible, go one level up and repeat. Stop when we found a level |
|
* where we could go to the next slot. We may at this point be on a |
|
* node or a leaf. |
|
* |
|
* If we are not at level 0 and not on shared tree blocks, go one |
|
* level deeper. |
|
* |
|
* If we are not at level 0 and on shared tree blocks, go one slot to |
|
* the right if possible or go up and right. |
|
*/ |
|
|
|
down_read(&fs_info->commit_root_sem); |
|
left_level = btrfs_header_level(left_root->commit_root); |
|
left_root_level = left_level; |
|
/* |
|
* We clone the root node of the send and parent roots to prevent races |
|
* with snapshot creation of these roots. Snapshot creation COWs the |
|
* root node of a tree, so after the transaction is committed the old |
|
* extent can be reallocated while this send operation is still ongoing. |
|
* So we clone them, under the commit root semaphore, to be race free. |
|
*/ |
|
left_path->nodes[left_level] = |
|
btrfs_clone_extent_buffer(left_root->commit_root); |
|
if (!left_path->nodes[left_level]) { |
|
ret = -ENOMEM; |
|
goto out_unlock; |
|
} |
|
|
|
right_level = btrfs_header_level(right_root->commit_root); |
|
right_root_level = right_level; |
|
right_path->nodes[right_level] = |
|
btrfs_clone_extent_buffer(right_root->commit_root); |
|
if (!right_path->nodes[right_level]) { |
|
ret = -ENOMEM; |
|
goto out_unlock; |
|
} |
|
/* |
|
* Our right root is the parent root, while the left root is the "send" |
|
* root. We know that all new nodes/leaves in the left root must have |
|
* a generation greater than the right root's generation, so we trigger |
|
* readahead for those nodes and leaves of the left root, as we know we |
|
* will need to read them at some point. |
|
*/ |
|
reada_min_gen = btrfs_header_generation(right_root->commit_root); |
|
|
|
if (left_level == 0) |
|
btrfs_item_key_to_cpu(left_path->nodes[left_level], |
|
&left_key, left_path->slots[left_level]); |
|
else |
|
btrfs_node_key_to_cpu(left_path->nodes[left_level], |
|
&left_key, left_path->slots[left_level]); |
|
if (right_level == 0) |
|
btrfs_item_key_to_cpu(right_path->nodes[right_level], |
|
&right_key, right_path->slots[right_level]); |
|
else |
|
btrfs_node_key_to_cpu(right_path->nodes[right_level], |
|
&right_key, right_path->slots[right_level]); |
|
|
|
sctx->last_reloc_trans = fs_info->last_reloc_trans; |
|
|
|
while (1) { |
|
if (need_resched() || |
|
rwsem_is_contended(&fs_info->commit_root_sem)) { |
|
up_read(&fs_info->commit_root_sem); |
|
cond_resched(); |
|
down_read(&fs_info->commit_root_sem); |
|
} |
|
|
|
if (fs_info->last_reloc_trans > sctx->last_reloc_trans) { |
|
ret = restart_after_relocation(left_path, right_path, |
|
&left_key, &right_key, |
|
left_level, right_level, |
|
sctx); |
|
if (ret < 0) |
|
goto out_unlock; |
|
sctx->last_reloc_trans = fs_info->last_reloc_trans; |
|
} |
|
|
|
if (advance_left && !left_end_reached) { |
|
ret = tree_advance(left_path, &left_level, |
|
left_root_level, |
|
advance_left != ADVANCE_ONLY_NEXT, |
|
&left_key, reada_min_gen); |
|
if (ret == -1) |
|
left_end_reached = ADVANCE; |
|
else if (ret < 0) |
|
goto out_unlock; |
|
advance_left = 0; |
|
} |
|
if (advance_right && !right_end_reached) { |
|
ret = tree_advance(right_path, &right_level, |
|
right_root_level, |
|
advance_right != ADVANCE_ONLY_NEXT, |
|
&right_key, reada_min_gen); |
|
if (ret == -1) |
|
right_end_reached = ADVANCE; |
|
else if (ret < 0) |
|
goto out_unlock; |
|
advance_right = 0; |
|
} |
|
|
|
if (left_end_reached && right_end_reached) { |
|
ret = 0; |
|
goto out_unlock; |
|
} else if (left_end_reached) { |
|
if (right_level == 0) { |
|
up_read(&fs_info->commit_root_sem); |
|
ret = changed_cb(left_path, right_path, |
|
&right_key, |
|
BTRFS_COMPARE_TREE_DELETED, |
|
sctx); |
|
if (ret < 0) |
|
goto out; |
|
down_read(&fs_info->commit_root_sem); |
|
} |
|
advance_right = ADVANCE; |
|
continue; |
|
} else if (right_end_reached) { |
|
if (left_level == 0) { |
|
up_read(&fs_info->commit_root_sem); |
|
ret = changed_cb(left_path, right_path, |
|
&left_key, |
|
BTRFS_COMPARE_TREE_NEW, |
|
sctx); |
|
if (ret < 0) |
|
goto out; |
|
down_read(&fs_info->commit_root_sem); |
|
} |
|
advance_left = ADVANCE; |
|
continue; |
|
} |
|
|
|
if (left_level == 0 && right_level == 0) { |
|
up_read(&fs_info->commit_root_sem); |
|
cmp = btrfs_comp_cpu_keys(&left_key, &right_key); |
|
if (cmp < 0) { |
|
ret = changed_cb(left_path, right_path, |
|
&left_key, |
|
BTRFS_COMPARE_TREE_NEW, |
|
sctx); |
|
advance_left = ADVANCE; |
|
} else if (cmp > 0) { |
|
ret = changed_cb(left_path, right_path, |
|
&right_key, |
|
BTRFS_COMPARE_TREE_DELETED, |
|
sctx); |
|
advance_right = ADVANCE; |
|
} else { |
|
enum btrfs_compare_tree_result result; |
|
|
|
WARN_ON(!extent_buffer_uptodate(left_path->nodes[0])); |
|
ret = tree_compare_item(left_path, right_path, |
|
tmp_buf); |
|
if (ret) |
|
result = BTRFS_COMPARE_TREE_CHANGED; |
|
else |
|
result = BTRFS_COMPARE_TREE_SAME; |
|
ret = changed_cb(left_path, right_path, |
|
&left_key, result, sctx); |
|
advance_left = ADVANCE; |
|
advance_right = ADVANCE; |
|
} |
|
|
|
if (ret < 0) |
|
goto out; |
|
down_read(&fs_info->commit_root_sem); |
|
} else if (left_level == right_level) { |
|
cmp = btrfs_comp_cpu_keys(&left_key, &right_key); |
|
if (cmp < 0) { |
|
advance_left = ADVANCE; |
|
} else if (cmp > 0) { |
|
advance_right = ADVANCE; |
|
} else { |
|
left_blockptr = btrfs_node_blockptr( |
|
left_path->nodes[left_level], |
|
left_path->slots[left_level]); |
|
right_blockptr = btrfs_node_blockptr( |
|
right_path->nodes[right_level], |
|
right_path->slots[right_level]); |
|
left_gen = btrfs_node_ptr_generation( |
|
left_path->nodes[left_level], |
|
left_path->slots[left_level]); |
|
right_gen = btrfs_node_ptr_generation( |
|
right_path->nodes[right_level], |
|
right_path->slots[right_level]); |
|
if (left_blockptr == right_blockptr && |
|
left_gen == right_gen) { |
|
/* |
|
* As we're on a shared block, don't |
|
* allow to go deeper. |
|
*/ |
|
advance_left = ADVANCE_ONLY_NEXT; |
|
advance_right = ADVANCE_ONLY_NEXT; |
|
} else { |
|
advance_left = ADVANCE; |
|
advance_right = ADVANCE; |
|
} |
|
} |
|
} else if (left_level < right_level) { |
|
advance_right = ADVANCE; |
|
} else { |
|
advance_left = ADVANCE; |
|
} |
|
} |
|
|
|
out_unlock: |
|
up_read(&fs_info->commit_root_sem); |
|
out: |
|
btrfs_free_path(left_path); |
|
btrfs_free_path(right_path); |
|
kvfree(tmp_buf); |
|
return ret; |
|
} |
|
|
|
static int send_subvol(struct send_ctx *sctx) |
|
{ |
|
int ret; |
|
|
|
if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) { |
|
ret = send_header(sctx); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
ret = send_subvol_begin(sctx); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (sctx->parent_root) { |
|
ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root, sctx); |
|
if (ret < 0) |
|
goto out; |
|
ret = finish_inode_if_needed(sctx, 1); |
|
if (ret < 0) |
|
goto out; |
|
} else { |
|
ret = full_send_tree(sctx); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
out: |
|
free_recorded_refs(sctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* If orphan cleanup did remove any orphans from a root, it means the tree |
|
* was modified and therefore the commit root is not the same as the current |
|
* root anymore. This is a problem, because send uses the commit root and |
|
* therefore can see inode items that don't exist in the current root anymore, |
|
* and for example make calls to btrfs_iget, which will do tree lookups based |
|
* on the current root and not on the commit root. Those lookups will fail, |
|
* returning a -ESTALE error, and making send fail with that error. So make |
|
* sure a send does not see any orphans we have just removed, and that it will |
|
* see the same inodes regardless of whether a transaction commit happened |
|
* before it started (meaning that the commit root will be the same as the |
|
* current root) or not. |
|
*/ |
|
static int ensure_commit_roots_uptodate(struct send_ctx *sctx) |
|
{ |
|
int i; |
|
struct btrfs_trans_handle *trans = NULL; |
|
|
|
again: |
|
if (sctx->parent_root && |
|
sctx->parent_root->node != sctx->parent_root->commit_root) |
|
goto commit_trans; |
|
|
|
for (i = 0; i < sctx->clone_roots_cnt; i++) |
|
if (sctx->clone_roots[i].root->node != |
|
sctx->clone_roots[i].root->commit_root) |
|
goto commit_trans; |
|
|
|
if (trans) |
|
return btrfs_end_transaction(trans); |
|
|
|
return 0; |
|
|
|
commit_trans: |
|
/* Use any root, all fs roots will get their commit roots updated. */ |
|
if (!trans) { |
|
trans = btrfs_join_transaction(sctx->send_root); |
|
if (IS_ERR(trans)) |
|
return PTR_ERR(trans); |
|
goto again; |
|
} |
|
|
|
return btrfs_commit_transaction(trans); |
|
} |
|
|
|
/* |
|
* Make sure any existing dellaloc is flushed for any root used by a send |
|
* operation so that we do not miss any data and we do not race with writeback |
|
* finishing and changing a tree while send is using the tree. This could |
|
* happen if a subvolume is in RW mode, has delalloc, is turned to RO mode and |
|
* a send operation then uses the subvolume. |
|
* After flushing delalloc ensure_commit_roots_uptodate() must be called. |
|
*/ |
|
static int flush_delalloc_roots(struct send_ctx *sctx) |
|
{ |
|
struct btrfs_root *root = sctx->parent_root; |
|
int ret; |
|
int i; |
|
|
|
if (root) { |
|
ret = btrfs_start_delalloc_snapshot(root, false); |
|
if (ret) |
|
return ret; |
|
btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX); |
|
} |
|
|
|
for (i = 0; i < sctx->clone_roots_cnt; i++) { |
|
root = sctx->clone_roots[i].root; |
|
ret = btrfs_start_delalloc_snapshot(root, false); |
|
if (ret) |
|
return ret; |
|
btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void btrfs_root_dec_send_in_progress(struct btrfs_root* root) |
|
{ |
|
spin_lock(&root->root_item_lock); |
|
root->send_in_progress--; |
|
/* |
|
* Not much left to do, we don't know why it's unbalanced and |
|
* can't blindly reset it to 0. |
|
*/ |
|
if (root->send_in_progress < 0) |
|
btrfs_err(root->fs_info, |
|
"send_in_progress unbalanced %d root %llu", |
|
root->send_in_progress, root->root_key.objectid); |
|
spin_unlock(&root->root_item_lock); |
|
} |
|
|
|
static void dedupe_in_progress_warn(const struct btrfs_root *root) |
|
{ |
|
btrfs_warn_rl(root->fs_info, |
|
"cannot use root %llu for send while deduplications on it are in progress (%d in progress)", |
|
root->root_key.objectid, root->dedupe_in_progress); |
|
} |
|
|
|
long btrfs_ioctl_send(struct inode *inode, struct btrfs_ioctl_send_args *arg) |
|
{ |
|
int ret = 0; |
|
struct btrfs_root *send_root = BTRFS_I(inode)->root; |
|
struct btrfs_fs_info *fs_info = send_root->fs_info; |
|
struct btrfs_root *clone_root; |
|
struct send_ctx *sctx = NULL; |
|
u32 i; |
|
u64 *clone_sources_tmp = NULL; |
|
int clone_sources_to_rollback = 0; |
|
size_t alloc_size; |
|
int sort_clone_roots = 0; |
|
|
|
if (!capable(CAP_SYS_ADMIN)) |
|
return -EPERM; |
|
|
|
/* |
|
* The subvolume must remain read-only during send, protect against |
|
* making it RW. This also protects against deletion. |
|
*/ |
|
spin_lock(&send_root->root_item_lock); |
|
if (btrfs_root_readonly(send_root) && send_root->dedupe_in_progress) { |
|
dedupe_in_progress_warn(send_root); |
|
spin_unlock(&send_root->root_item_lock); |
|
return -EAGAIN; |
|
} |
|
send_root->send_in_progress++; |
|
spin_unlock(&send_root->root_item_lock); |
|
|
|
/* |
|
* Userspace tools do the checks and warn the user if it's |
|
* not RO. |
|
*/ |
|
if (!btrfs_root_readonly(send_root)) { |
|
ret = -EPERM; |
|
goto out; |
|
} |
|
|
|
/* |
|
* Check that we don't overflow at later allocations, we request |
|
* clone_sources_count + 1 items, and compare to unsigned long inside |
|
* access_ok. |
|
*/ |
|
if (arg->clone_sources_count > |
|
ULONG_MAX / sizeof(struct clone_root) - 1) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (arg->flags & ~BTRFS_SEND_FLAG_MASK) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
sctx = kzalloc(sizeof(struct send_ctx), GFP_KERNEL); |
|
if (!sctx) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
INIT_LIST_HEAD(&sctx->new_refs); |
|
INIT_LIST_HEAD(&sctx->deleted_refs); |
|
INIT_RADIX_TREE(&sctx->name_cache, GFP_KERNEL); |
|
INIT_LIST_HEAD(&sctx->name_cache_list); |
|
|
|
sctx->flags = arg->flags; |
|
|
|
if (arg->flags & BTRFS_SEND_FLAG_VERSION) { |
|
if (arg->version > BTRFS_SEND_STREAM_VERSION) { |
|
ret = -EPROTO; |
|
goto out; |
|
} |
|
/* Zero means "use the highest version" */ |
|
sctx->proto = arg->version ?: BTRFS_SEND_STREAM_VERSION; |
|
} else { |
|
sctx->proto = 1; |
|
} |
|
if ((arg->flags & BTRFS_SEND_FLAG_COMPRESSED) && sctx->proto < 2) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
sctx->send_filp = fget(arg->send_fd); |
|
if (!sctx->send_filp) { |
|
ret = -EBADF; |
|
goto out; |
|
} |
|
|
|
sctx->send_root = send_root; |
|
/* |
|
* Unlikely but possible, if the subvolume is marked for deletion but |
|
* is slow to remove the directory entry, send can still be started |
|
*/ |
|
if (btrfs_root_dead(sctx->send_root)) { |
|
ret = -EPERM; |
|
goto out; |
|
} |
|
|
|
sctx->clone_roots_cnt = arg->clone_sources_count; |
|
|
|
if (sctx->proto >= 2) { |
|
u32 send_buf_num_pages; |
|
|
|
sctx->send_max_size = ALIGN(SZ_16K + BTRFS_MAX_COMPRESSED, PAGE_SIZE); |
|
sctx->send_buf = vmalloc(sctx->send_max_size); |
|
if (!sctx->send_buf) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
send_buf_num_pages = sctx->send_max_size >> PAGE_SHIFT; |
|
sctx->send_buf_pages = kcalloc(send_buf_num_pages, |
|
sizeof(*sctx->send_buf_pages), |
|
GFP_KERNEL); |
|
if (!sctx->send_buf_pages) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
for (i = 0; i < send_buf_num_pages; i++) { |
|
sctx->send_buf_pages[i] = |
|
vmalloc_to_page(sctx->send_buf + (i << PAGE_SHIFT)); |
|
} |
|
} else { |
|
sctx->send_max_size = BTRFS_SEND_BUF_SIZE_V1; |
|
sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL); |
|
} |
|
if (!sctx->send_buf) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
sctx->pending_dir_moves = RB_ROOT; |
|
sctx->waiting_dir_moves = RB_ROOT; |
|
sctx->orphan_dirs = RB_ROOT; |
|
sctx->rbtree_new_refs = RB_ROOT; |
|
sctx->rbtree_deleted_refs = RB_ROOT; |
|
|
|
sctx->clone_roots = kvcalloc(sizeof(*sctx->clone_roots), |
|
arg->clone_sources_count + 1, |
|
GFP_KERNEL); |
|
if (!sctx->clone_roots) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
alloc_size = array_size(sizeof(*arg->clone_sources), |
|
arg->clone_sources_count); |
|
|
|
if (arg->clone_sources_count) { |
|
clone_sources_tmp = kvmalloc(alloc_size, GFP_KERNEL); |
|
if (!clone_sources_tmp) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ret = copy_from_user(clone_sources_tmp, arg->clone_sources, |
|
alloc_size); |
|
if (ret) { |
|
ret = -EFAULT; |
|
goto out; |
|
} |
|
|
|
for (i = 0; i < arg->clone_sources_count; i++) { |
|
clone_root = btrfs_get_fs_root(fs_info, |
|
clone_sources_tmp[i], true); |
|
if (IS_ERR(clone_root)) { |
|
ret = PTR_ERR(clone_root); |
|
goto out; |
|
} |
|
spin_lock(&clone_root->root_item_lock); |
|
if (!btrfs_root_readonly(clone_root) || |
|
btrfs_root_dead(clone_root)) { |
|
spin_unlock(&clone_root->root_item_lock); |
|
btrfs_put_root(clone_root); |
|
ret = -EPERM; |
|
goto out; |
|
} |
|
if (clone_root->dedupe_in_progress) { |
|
dedupe_in_progress_warn(clone_root); |
|
spin_unlock(&clone_root->root_item_lock); |
|
btrfs_put_root(clone_root); |
|
ret = -EAGAIN; |
|
goto out; |
|
} |
|
clone_root->send_in_progress++; |
|
spin_unlock(&clone_root->root_item_lock); |
|
|
|
sctx->clone_roots[i].root = clone_root; |
|
clone_sources_to_rollback = i + 1; |
|
} |
|
kvfree(clone_sources_tmp); |
|
clone_sources_tmp = NULL; |
|
} |
|
|
|
if (arg->parent_root) { |
|
sctx->parent_root = btrfs_get_fs_root(fs_info, arg->parent_root, |
|
true); |
|
if (IS_ERR(sctx->parent_root)) { |
|
ret = PTR_ERR(sctx->parent_root); |
|
goto out; |
|
} |
|
|
|
spin_lock(&sctx->parent_root->root_item_lock); |
|
sctx->parent_root->send_in_progress++; |
|
if (!btrfs_root_readonly(sctx->parent_root) || |
|
btrfs_root_dead(sctx->parent_root)) { |
|
spin_unlock(&sctx->parent_root->root_item_lock); |
|
ret = -EPERM; |
|
goto out; |
|
} |
|
if (sctx->parent_root->dedupe_in_progress) { |
|
dedupe_in_progress_warn(sctx->parent_root); |
|
spin_unlock(&sctx->parent_root->root_item_lock); |
|
ret = -EAGAIN; |
|
goto out; |
|
} |
|
spin_unlock(&sctx->parent_root->root_item_lock); |
|
} |
|
|
|
/* |
|
* Clones from send_root are allowed, but only if the clone source |
|
* is behind the current send position. This is checked while searching |
|
* for possible clone sources. |
|
*/ |
|
sctx->clone_roots[sctx->clone_roots_cnt++].root = |
|
btrfs_grab_root(sctx->send_root); |
|
|
|
/* We do a bsearch later */ |
|
sort(sctx->clone_roots, sctx->clone_roots_cnt, |
|
sizeof(*sctx->clone_roots), __clone_root_cmp_sort, |
|
NULL); |
|
sort_clone_roots = 1; |
|
|
|
ret = flush_delalloc_roots(sctx); |
|
if (ret) |
|
goto out; |
|
|
|
ret = ensure_commit_roots_uptodate(sctx); |
|
if (ret) |
|
goto out; |
|
|
|
ret = send_subvol(sctx); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_END_CMD)) { |
|
ret = begin_cmd(sctx, BTRFS_SEND_C_END); |
|
if (ret < 0) |
|
goto out; |
|
ret = send_cmd(sctx); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
out: |
|
WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)); |
|
while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) { |
|
struct rb_node *n; |
|
struct pending_dir_move *pm; |
|
|
|
n = rb_first(&sctx->pending_dir_moves); |
|
pm = rb_entry(n, struct pending_dir_move, node); |
|
while (!list_empty(&pm->list)) { |
|
struct pending_dir_move *pm2; |
|
|
|
pm2 = list_first_entry(&pm->list, |
|
struct pending_dir_move, list); |
|
free_pending_move(sctx, pm2); |
|
} |
|
free_pending_move(sctx, pm); |
|
} |
|
|
|
WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)); |
|
while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) { |
|
struct rb_node *n; |
|
struct waiting_dir_move *dm; |
|
|
|
n = rb_first(&sctx->waiting_dir_moves); |
|
dm = rb_entry(n, struct waiting_dir_move, node); |
|
rb_erase(&dm->node, &sctx->waiting_dir_moves); |
|
kfree(dm); |
|
} |
|
|
|
WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->orphan_dirs)); |
|
while (sctx && !RB_EMPTY_ROOT(&sctx->orphan_dirs)) { |
|
struct rb_node *n; |
|
struct orphan_dir_info *odi; |
|
|
|
n = rb_first(&sctx->orphan_dirs); |
|
odi = rb_entry(n, struct orphan_dir_info, node); |
|
free_orphan_dir_info(sctx, odi); |
|
} |
|
|
|
if (sort_clone_roots) { |
|
for (i = 0; i < sctx->clone_roots_cnt; i++) { |
|
btrfs_root_dec_send_in_progress( |
|
sctx->clone_roots[i].root); |
|
btrfs_put_root(sctx->clone_roots[i].root); |
|
} |
|
} else { |
|
for (i = 0; sctx && i < clone_sources_to_rollback; i++) { |
|
btrfs_root_dec_send_in_progress( |
|
sctx->clone_roots[i].root); |
|
btrfs_put_root(sctx->clone_roots[i].root); |
|
} |
|
|
|
btrfs_root_dec_send_in_progress(send_root); |
|
} |
|
if (sctx && !IS_ERR_OR_NULL(sctx->parent_root)) { |
|
btrfs_root_dec_send_in_progress(sctx->parent_root); |
|
btrfs_put_root(sctx->parent_root); |
|
} |
|
|
|
kvfree(clone_sources_tmp); |
|
|
|
if (sctx) { |
|
if (sctx->send_filp) |
|
fput(sctx->send_filp); |
|
|
|
kvfree(sctx->clone_roots); |
|
kfree(sctx->send_buf_pages); |
|
kvfree(sctx->send_buf); |
|
kvfree(sctx->verity_descriptor); |
|
|
|
name_cache_free(sctx); |
|
|
|
close_current_inode(sctx); |
|
|
|
kfree(sctx); |
|
} |
|
|
|
return ret; |
|
}
|
|
|