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4103 lines
102 KiB
4103 lines
102 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2009 Oracle. All rights reserved. |
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*/ |
|
|
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#include <linux/sched.h> |
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#include <linux/pagemap.h> |
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#include <linux/writeback.h> |
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#include <linux/blkdev.h> |
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#include <linux/rbtree.h> |
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#include <linux/slab.h> |
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#include <linux/error-injection.h> |
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#include "ctree.h" |
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#include "disk-io.h" |
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#include "transaction.h" |
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#include "volumes.h" |
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#include "locking.h" |
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#include "btrfs_inode.h" |
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#include "async-thread.h" |
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#include "free-space-cache.h" |
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#include "qgroup.h" |
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#include "print-tree.h" |
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#include "delalloc-space.h" |
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#include "block-group.h" |
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#include "backref.h" |
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#include "misc.h" |
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|
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/* |
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* Relocation overview |
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* |
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* [What does relocation do] |
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* |
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* The objective of relocation is to relocate all extents of the target block |
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* group to other block groups. |
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* This is utilized by resize (shrink only), profile converting, compacting |
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* space, or balance routine to spread chunks over devices. |
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* |
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* Before | After |
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* ------------------------------------------------------------------ |
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* BG A: 10 data extents | BG A: deleted |
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* BG B: 2 data extents | BG B: 10 data extents (2 old + 8 relocated) |
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* BG C: 1 extents | BG C: 3 data extents (1 old + 2 relocated) |
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* |
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* [How does relocation work] |
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* |
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* 1. Mark the target block group read-only |
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* New extents won't be allocated from the target block group. |
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* |
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* 2.1 Record each extent in the target block group |
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* To build a proper map of extents to be relocated. |
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* |
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* 2.2 Build data reloc tree and reloc trees |
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* Data reloc tree will contain an inode, recording all newly relocated |
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* data extents. |
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* There will be only one data reloc tree for one data block group. |
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* |
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* Reloc tree will be a special snapshot of its source tree, containing |
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* relocated tree blocks. |
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* Each tree referring to a tree block in target block group will get its |
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* reloc tree built. |
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* |
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* 2.3 Swap source tree with its corresponding reloc tree |
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* Each involved tree only refers to new extents after swap. |
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* |
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* 3. Cleanup reloc trees and data reloc tree. |
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* As old extents in the target block group are still referenced by reloc |
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* trees, we need to clean them up before really freeing the target block |
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* group. |
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* |
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* The main complexity is in steps 2.2 and 2.3. |
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* |
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* The entry point of relocation is relocate_block_group() function. |
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*/ |
|
|
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#define RELOCATION_RESERVED_NODES 256 |
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/* |
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* map address of tree root to tree |
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*/ |
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struct mapping_node { |
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struct { |
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struct rb_node rb_node; |
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u64 bytenr; |
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}; /* Use rb_simle_node for search/insert */ |
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void *data; |
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}; |
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|
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struct mapping_tree { |
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struct rb_root rb_root; |
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spinlock_t lock; |
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}; |
|
|
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/* |
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* present a tree block to process |
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*/ |
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struct tree_block { |
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struct { |
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struct rb_node rb_node; |
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u64 bytenr; |
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}; /* Use rb_simple_node for search/insert */ |
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u64 owner; |
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struct btrfs_key key; |
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unsigned int level:8; |
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unsigned int key_ready:1; |
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}; |
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|
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#define MAX_EXTENTS 128 |
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|
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struct file_extent_cluster { |
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u64 start; |
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u64 end; |
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u64 boundary[MAX_EXTENTS]; |
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unsigned int nr; |
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}; |
|
|
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struct reloc_control { |
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/* block group to relocate */ |
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struct btrfs_block_group *block_group; |
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/* extent tree */ |
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struct btrfs_root *extent_root; |
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/* inode for moving data */ |
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struct inode *data_inode; |
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|
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struct btrfs_block_rsv *block_rsv; |
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|
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struct btrfs_backref_cache backref_cache; |
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|
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struct file_extent_cluster cluster; |
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/* tree blocks have been processed */ |
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struct extent_io_tree processed_blocks; |
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/* map start of tree root to corresponding reloc tree */ |
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struct mapping_tree reloc_root_tree; |
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/* list of reloc trees */ |
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struct list_head reloc_roots; |
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/* list of subvolume trees that get relocated */ |
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struct list_head dirty_subvol_roots; |
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/* size of metadata reservation for merging reloc trees */ |
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u64 merging_rsv_size; |
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/* size of relocated tree nodes */ |
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u64 nodes_relocated; |
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/* reserved size for block group relocation*/ |
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u64 reserved_bytes; |
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|
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u64 search_start; |
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u64 extents_found; |
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|
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unsigned int stage:8; |
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unsigned int create_reloc_tree:1; |
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unsigned int merge_reloc_tree:1; |
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unsigned int found_file_extent:1; |
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}; |
|
|
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/* stages of data relocation */ |
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#define MOVE_DATA_EXTENTS 0 |
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#define UPDATE_DATA_PTRS 1 |
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|
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static void mark_block_processed(struct reloc_control *rc, |
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struct btrfs_backref_node *node) |
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{ |
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u32 blocksize; |
|
|
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if (node->level == 0 || |
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in_range(node->bytenr, rc->block_group->start, |
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rc->block_group->length)) { |
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blocksize = rc->extent_root->fs_info->nodesize; |
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set_extent_bits(&rc->processed_blocks, node->bytenr, |
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node->bytenr + blocksize - 1, EXTENT_DIRTY); |
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} |
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node->processed = 1; |
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} |
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|
|
|
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static void mapping_tree_init(struct mapping_tree *tree) |
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{ |
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tree->rb_root = RB_ROOT; |
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spin_lock_init(&tree->lock); |
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} |
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|
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/* |
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* walk up backref nodes until reach node presents tree root |
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*/ |
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static struct btrfs_backref_node *walk_up_backref( |
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struct btrfs_backref_node *node, |
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struct btrfs_backref_edge *edges[], int *index) |
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{ |
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struct btrfs_backref_edge *edge; |
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int idx = *index; |
|
|
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while (!list_empty(&node->upper)) { |
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edge = list_entry(node->upper.next, |
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struct btrfs_backref_edge, list[LOWER]); |
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edges[idx++] = edge; |
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node = edge->node[UPPER]; |
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} |
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BUG_ON(node->detached); |
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*index = idx; |
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return node; |
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} |
|
|
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/* |
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* walk down backref nodes to find start of next reference path |
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*/ |
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static struct btrfs_backref_node *walk_down_backref( |
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struct btrfs_backref_edge *edges[], int *index) |
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{ |
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struct btrfs_backref_edge *edge; |
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struct btrfs_backref_node *lower; |
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int idx = *index; |
|
|
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while (idx > 0) { |
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edge = edges[idx - 1]; |
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lower = edge->node[LOWER]; |
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if (list_is_last(&edge->list[LOWER], &lower->upper)) { |
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idx--; |
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continue; |
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} |
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edge = list_entry(edge->list[LOWER].next, |
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struct btrfs_backref_edge, list[LOWER]); |
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edges[idx - 1] = edge; |
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*index = idx; |
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return edge->node[UPPER]; |
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} |
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*index = 0; |
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return NULL; |
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} |
|
|
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static void update_backref_node(struct btrfs_backref_cache *cache, |
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struct btrfs_backref_node *node, u64 bytenr) |
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{ |
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struct rb_node *rb_node; |
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rb_erase(&node->rb_node, &cache->rb_root); |
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node->bytenr = bytenr; |
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rb_node = rb_simple_insert(&cache->rb_root, node->bytenr, &node->rb_node); |
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if (rb_node) |
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btrfs_backref_panic(cache->fs_info, bytenr, -EEXIST); |
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} |
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|
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/* |
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* update backref cache after a transaction commit |
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*/ |
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static int update_backref_cache(struct btrfs_trans_handle *trans, |
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struct btrfs_backref_cache *cache) |
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{ |
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struct btrfs_backref_node *node; |
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int level = 0; |
|
|
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if (cache->last_trans == 0) { |
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cache->last_trans = trans->transid; |
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return 0; |
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} |
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|
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if (cache->last_trans == trans->transid) |
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return 0; |
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|
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/* |
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* detached nodes are used to avoid unnecessary backref |
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* lookup. transaction commit changes the extent tree. |
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* so the detached nodes are no longer useful. |
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*/ |
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while (!list_empty(&cache->detached)) { |
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node = list_entry(cache->detached.next, |
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struct btrfs_backref_node, list); |
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btrfs_backref_cleanup_node(cache, node); |
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} |
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|
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while (!list_empty(&cache->changed)) { |
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node = list_entry(cache->changed.next, |
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struct btrfs_backref_node, list); |
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list_del_init(&node->list); |
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BUG_ON(node->pending); |
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update_backref_node(cache, node, node->new_bytenr); |
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} |
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|
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/* |
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* some nodes can be left in the pending list if there were |
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* errors during processing the pending nodes. |
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*/ |
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for (level = 0; level < BTRFS_MAX_LEVEL; level++) { |
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list_for_each_entry(node, &cache->pending[level], list) { |
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BUG_ON(!node->pending); |
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if (node->bytenr == node->new_bytenr) |
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continue; |
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update_backref_node(cache, node, node->new_bytenr); |
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} |
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} |
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|
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cache->last_trans = 0; |
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return 1; |
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} |
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|
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static bool reloc_root_is_dead(struct btrfs_root *root) |
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{ |
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/* |
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* Pair with set_bit/clear_bit in clean_dirty_subvols and |
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* btrfs_update_reloc_root. We need to see the updated bit before |
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* trying to access reloc_root |
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*/ |
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smp_rmb(); |
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if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state)) |
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return true; |
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return false; |
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} |
|
|
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/* |
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* Check if this subvolume tree has valid reloc tree. |
|
* |
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* Reloc tree after swap is considered dead, thus not considered as valid. |
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* This is enough for most callers, as they don't distinguish dead reloc root |
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* from no reloc root. But btrfs_should_ignore_reloc_root() below is a |
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* special case. |
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*/ |
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static bool have_reloc_root(struct btrfs_root *root) |
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{ |
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if (reloc_root_is_dead(root)) |
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return false; |
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if (!root->reloc_root) |
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return false; |
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return true; |
|
} |
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|
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int btrfs_should_ignore_reloc_root(struct btrfs_root *root) |
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{ |
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struct btrfs_root *reloc_root; |
|
|
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if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) |
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return 0; |
|
|
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/* This root has been merged with its reloc tree, we can ignore it */ |
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if (reloc_root_is_dead(root)) |
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return 1; |
|
|
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reloc_root = root->reloc_root; |
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if (!reloc_root) |
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return 0; |
|
|
|
if (btrfs_header_generation(reloc_root->commit_root) == |
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root->fs_info->running_transaction->transid) |
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return 0; |
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/* |
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* if there is reloc tree and it was created in previous |
|
* transaction backref lookup can find the reloc tree, |
|
* so backref node for the fs tree root is useless for |
|
* relocation. |
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*/ |
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return 1; |
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} |
|
|
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/* |
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* find reloc tree by address of tree root |
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*/ |
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struct btrfs_root *find_reloc_root(struct btrfs_fs_info *fs_info, u64 bytenr) |
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{ |
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struct reloc_control *rc = fs_info->reloc_ctl; |
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struct rb_node *rb_node; |
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struct mapping_node *node; |
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struct btrfs_root *root = NULL; |
|
|
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ASSERT(rc); |
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spin_lock(&rc->reloc_root_tree.lock); |
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rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, bytenr); |
|
if (rb_node) { |
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node = rb_entry(rb_node, struct mapping_node, rb_node); |
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root = (struct btrfs_root *)node->data; |
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} |
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spin_unlock(&rc->reloc_root_tree.lock); |
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return btrfs_grab_root(root); |
|
} |
|
|
|
/* |
|
* For useless nodes, do two major clean ups: |
|
* |
|
* - Cleanup the children edges and nodes |
|
* If child node is also orphan (no parent) during cleanup, then the child |
|
* node will also be cleaned up. |
|
* |
|
* - Freeing up leaves (level 0), keeps nodes detached |
|
* For nodes, the node is still cached as "detached" |
|
* |
|
* Return false if @node is not in the @useless_nodes list. |
|
* Return true if @node is in the @useless_nodes list. |
|
*/ |
|
static bool handle_useless_nodes(struct reloc_control *rc, |
|
struct btrfs_backref_node *node) |
|
{ |
|
struct btrfs_backref_cache *cache = &rc->backref_cache; |
|
struct list_head *useless_node = &cache->useless_node; |
|
bool ret = false; |
|
|
|
while (!list_empty(useless_node)) { |
|
struct btrfs_backref_node *cur; |
|
|
|
cur = list_first_entry(useless_node, struct btrfs_backref_node, |
|
list); |
|
list_del_init(&cur->list); |
|
|
|
/* Only tree root nodes can be added to @useless_nodes */ |
|
ASSERT(list_empty(&cur->upper)); |
|
|
|
if (cur == node) |
|
ret = true; |
|
|
|
/* The node is the lowest node */ |
|
if (cur->lowest) { |
|
list_del_init(&cur->lower); |
|
cur->lowest = 0; |
|
} |
|
|
|
/* Cleanup the lower edges */ |
|
while (!list_empty(&cur->lower)) { |
|
struct btrfs_backref_edge *edge; |
|
struct btrfs_backref_node *lower; |
|
|
|
edge = list_entry(cur->lower.next, |
|
struct btrfs_backref_edge, list[UPPER]); |
|
list_del(&edge->list[UPPER]); |
|
list_del(&edge->list[LOWER]); |
|
lower = edge->node[LOWER]; |
|
btrfs_backref_free_edge(cache, edge); |
|
|
|
/* Child node is also orphan, queue for cleanup */ |
|
if (list_empty(&lower->upper)) |
|
list_add(&lower->list, useless_node); |
|
} |
|
/* Mark this block processed for relocation */ |
|
mark_block_processed(rc, cur); |
|
|
|
/* |
|
* Backref nodes for tree leaves are deleted from the cache. |
|
* Backref nodes for upper level tree blocks are left in the |
|
* cache to avoid unnecessary backref lookup. |
|
*/ |
|
if (cur->level > 0) { |
|
list_add(&cur->list, &cache->detached); |
|
cur->detached = 1; |
|
} else { |
|
rb_erase(&cur->rb_node, &cache->rb_root); |
|
btrfs_backref_free_node(cache, cur); |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
/* |
|
* Build backref tree for a given tree block. Root of the backref tree |
|
* corresponds the tree block, leaves of the backref tree correspond roots of |
|
* b-trees that reference the tree block. |
|
* |
|
* The basic idea of this function is check backrefs of a given block to find |
|
* upper level blocks that reference the block, and then check backrefs of |
|
* these upper level blocks recursively. The recursion stops when tree root is |
|
* reached or backrefs for the block is cached. |
|
* |
|
* NOTE: if we find that backrefs for a block are cached, we know backrefs for |
|
* all upper level blocks that directly/indirectly reference the block are also |
|
* cached. |
|
*/ |
|
static noinline_for_stack struct btrfs_backref_node *build_backref_tree( |
|
struct reloc_control *rc, struct btrfs_key *node_key, |
|
int level, u64 bytenr) |
|
{ |
|
struct btrfs_backref_iter *iter; |
|
struct btrfs_backref_cache *cache = &rc->backref_cache; |
|
/* For searching parent of TREE_BLOCK_REF */ |
|
struct btrfs_path *path; |
|
struct btrfs_backref_node *cur; |
|
struct btrfs_backref_node *node = NULL; |
|
struct btrfs_backref_edge *edge; |
|
int ret; |
|
int err = 0; |
|
|
|
iter = btrfs_backref_iter_alloc(rc->extent_root->fs_info, GFP_NOFS); |
|
if (!iter) |
|
return ERR_PTR(-ENOMEM); |
|
path = btrfs_alloc_path(); |
|
if (!path) { |
|
err = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
node = btrfs_backref_alloc_node(cache, bytenr, level); |
|
if (!node) { |
|
err = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
node->lowest = 1; |
|
cur = node; |
|
|
|
/* Breadth-first search to build backref cache */ |
|
do { |
|
ret = btrfs_backref_add_tree_node(cache, path, iter, node_key, |
|
cur); |
|
if (ret < 0) { |
|
err = ret; |
|
goto out; |
|
} |
|
edge = list_first_entry_or_null(&cache->pending_edge, |
|
struct btrfs_backref_edge, list[UPPER]); |
|
/* |
|
* The pending list isn't empty, take the first block to |
|
* process |
|
*/ |
|
if (edge) { |
|
list_del_init(&edge->list[UPPER]); |
|
cur = edge->node[UPPER]; |
|
} |
|
} while (edge); |
|
|
|
/* Finish the upper linkage of newly added edges/nodes */ |
|
ret = btrfs_backref_finish_upper_links(cache, node); |
|
if (ret < 0) { |
|
err = ret; |
|
goto out; |
|
} |
|
|
|
if (handle_useless_nodes(rc, node)) |
|
node = NULL; |
|
out: |
|
btrfs_backref_iter_free(iter); |
|
btrfs_free_path(path); |
|
if (err) { |
|
btrfs_backref_error_cleanup(cache, node); |
|
return ERR_PTR(err); |
|
} |
|
ASSERT(!node || !node->detached); |
|
ASSERT(list_empty(&cache->useless_node) && |
|
list_empty(&cache->pending_edge)); |
|
return node; |
|
} |
|
|
|
/* |
|
* helper to add backref node for the newly created snapshot. |
|
* the backref node is created by cloning backref node that |
|
* corresponds to root of source tree |
|
*/ |
|
static int clone_backref_node(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_root *src, |
|
struct btrfs_root *dest) |
|
{ |
|
struct btrfs_root *reloc_root = src->reloc_root; |
|
struct btrfs_backref_cache *cache = &rc->backref_cache; |
|
struct btrfs_backref_node *node = NULL; |
|
struct btrfs_backref_node *new_node; |
|
struct btrfs_backref_edge *edge; |
|
struct btrfs_backref_edge *new_edge; |
|
struct rb_node *rb_node; |
|
|
|
if (cache->last_trans > 0) |
|
update_backref_cache(trans, cache); |
|
|
|
rb_node = rb_simple_search(&cache->rb_root, src->commit_root->start); |
|
if (rb_node) { |
|
node = rb_entry(rb_node, struct btrfs_backref_node, rb_node); |
|
if (node->detached) |
|
node = NULL; |
|
else |
|
BUG_ON(node->new_bytenr != reloc_root->node->start); |
|
} |
|
|
|
if (!node) { |
|
rb_node = rb_simple_search(&cache->rb_root, |
|
reloc_root->commit_root->start); |
|
if (rb_node) { |
|
node = rb_entry(rb_node, struct btrfs_backref_node, |
|
rb_node); |
|
BUG_ON(node->detached); |
|
} |
|
} |
|
|
|
if (!node) |
|
return 0; |
|
|
|
new_node = btrfs_backref_alloc_node(cache, dest->node->start, |
|
node->level); |
|
if (!new_node) |
|
return -ENOMEM; |
|
|
|
new_node->lowest = node->lowest; |
|
new_node->checked = 1; |
|
new_node->root = btrfs_grab_root(dest); |
|
ASSERT(new_node->root); |
|
|
|
if (!node->lowest) { |
|
list_for_each_entry(edge, &node->lower, list[UPPER]) { |
|
new_edge = btrfs_backref_alloc_edge(cache); |
|
if (!new_edge) |
|
goto fail; |
|
|
|
btrfs_backref_link_edge(new_edge, edge->node[LOWER], |
|
new_node, LINK_UPPER); |
|
} |
|
} else { |
|
list_add_tail(&new_node->lower, &cache->leaves); |
|
} |
|
|
|
rb_node = rb_simple_insert(&cache->rb_root, new_node->bytenr, |
|
&new_node->rb_node); |
|
if (rb_node) |
|
btrfs_backref_panic(trans->fs_info, new_node->bytenr, -EEXIST); |
|
|
|
if (!new_node->lowest) { |
|
list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) { |
|
list_add_tail(&new_edge->list[LOWER], |
|
&new_edge->node[LOWER]->upper); |
|
} |
|
} |
|
return 0; |
|
fail: |
|
while (!list_empty(&new_node->lower)) { |
|
new_edge = list_entry(new_node->lower.next, |
|
struct btrfs_backref_edge, list[UPPER]); |
|
list_del(&new_edge->list[UPPER]); |
|
btrfs_backref_free_edge(cache, new_edge); |
|
} |
|
btrfs_backref_free_node(cache, new_node); |
|
return -ENOMEM; |
|
} |
|
|
|
/* |
|
* helper to add 'address of tree root -> reloc tree' mapping |
|
*/ |
|
static int __must_check __add_reloc_root(struct btrfs_root *root) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct rb_node *rb_node; |
|
struct mapping_node *node; |
|
struct reloc_control *rc = fs_info->reloc_ctl; |
|
|
|
node = kmalloc(sizeof(*node), GFP_NOFS); |
|
if (!node) |
|
return -ENOMEM; |
|
|
|
node->bytenr = root->commit_root->start; |
|
node->data = root; |
|
|
|
spin_lock(&rc->reloc_root_tree.lock); |
|
rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root, |
|
node->bytenr, &node->rb_node); |
|
spin_unlock(&rc->reloc_root_tree.lock); |
|
if (rb_node) { |
|
btrfs_panic(fs_info, -EEXIST, |
|
"Duplicate root found for start=%llu while inserting into relocation tree", |
|
node->bytenr); |
|
} |
|
|
|
list_add_tail(&root->root_list, &rc->reloc_roots); |
|
return 0; |
|
} |
|
|
|
/* |
|
* helper to delete the 'address of tree root -> reloc tree' |
|
* mapping |
|
*/ |
|
static void __del_reloc_root(struct btrfs_root *root) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct rb_node *rb_node; |
|
struct mapping_node *node = NULL; |
|
struct reloc_control *rc = fs_info->reloc_ctl; |
|
bool put_ref = false; |
|
|
|
if (rc && root->node) { |
|
spin_lock(&rc->reloc_root_tree.lock); |
|
rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, |
|
root->commit_root->start); |
|
if (rb_node) { |
|
node = rb_entry(rb_node, struct mapping_node, rb_node); |
|
rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); |
|
RB_CLEAR_NODE(&node->rb_node); |
|
} |
|
spin_unlock(&rc->reloc_root_tree.lock); |
|
ASSERT(!node || (struct btrfs_root *)node->data == root); |
|
} |
|
|
|
/* |
|
* We only put the reloc root here if it's on the list. There's a lot |
|
* of places where the pattern is to splice the rc->reloc_roots, process |
|
* the reloc roots, and then add the reloc root back onto |
|
* rc->reloc_roots. If we call __del_reloc_root while it's off of the |
|
* list we don't want the reference being dropped, because the guy |
|
* messing with the list is in charge of the reference. |
|
*/ |
|
spin_lock(&fs_info->trans_lock); |
|
if (!list_empty(&root->root_list)) { |
|
put_ref = true; |
|
list_del_init(&root->root_list); |
|
} |
|
spin_unlock(&fs_info->trans_lock); |
|
if (put_ref) |
|
btrfs_put_root(root); |
|
kfree(node); |
|
} |
|
|
|
/* |
|
* helper to update the 'address of tree root -> reloc tree' |
|
* mapping |
|
*/ |
|
static int __update_reloc_root(struct btrfs_root *root) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct rb_node *rb_node; |
|
struct mapping_node *node = NULL; |
|
struct reloc_control *rc = fs_info->reloc_ctl; |
|
|
|
spin_lock(&rc->reloc_root_tree.lock); |
|
rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, |
|
root->commit_root->start); |
|
if (rb_node) { |
|
node = rb_entry(rb_node, struct mapping_node, rb_node); |
|
rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); |
|
} |
|
spin_unlock(&rc->reloc_root_tree.lock); |
|
|
|
if (!node) |
|
return 0; |
|
BUG_ON((struct btrfs_root *)node->data != root); |
|
|
|
spin_lock(&rc->reloc_root_tree.lock); |
|
node->bytenr = root->node->start; |
|
rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root, |
|
node->bytenr, &node->rb_node); |
|
spin_unlock(&rc->reloc_root_tree.lock); |
|
if (rb_node) |
|
btrfs_backref_panic(fs_info, node->bytenr, -EEXIST); |
|
return 0; |
|
} |
|
|
|
static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans, |
|
struct btrfs_root *root, u64 objectid) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct btrfs_root *reloc_root; |
|
struct extent_buffer *eb; |
|
struct btrfs_root_item *root_item; |
|
struct btrfs_key root_key; |
|
int ret = 0; |
|
bool must_abort = false; |
|
|
|
root_item = kmalloc(sizeof(*root_item), GFP_NOFS); |
|
if (!root_item) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; |
|
root_key.type = BTRFS_ROOT_ITEM_KEY; |
|
root_key.offset = objectid; |
|
|
|
if (root->root_key.objectid == objectid) { |
|
u64 commit_root_gen; |
|
|
|
/* called by btrfs_init_reloc_root */ |
|
ret = btrfs_copy_root(trans, root, root->commit_root, &eb, |
|
BTRFS_TREE_RELOC_OBJECTID); |
|
if (ret) |
|
goto fail; |
|
|
|
/* |
|
* Set the last_snapshot field to the generation of the commit |
|
* root - like this ctree.c:btrfs_block_can_be_shared() behaves |
|
* correctly (returns true) when the relocation root is created |
|
* either inside the critical section of a transaction commit |
|
* (through transaction.c:qgroup_account_snapshot()) and when |
|
* it's created before the transaction commit is started. |
|
*/ |
|
commit_root_gen = btrfs_header_generation(root->commit_root); |
|
btrfs_set_root_last_snapshot(&root->root_item, commit_root_gen); |
|
} else { |
|
/* |
|
* called by btrfs_reloc_post_snapshot_hook. |
|
* the source tree is a reloc tree, all tree blocks |
|
* modified after it was created have RELOC flag |
|
* set in their headers. so it's OK to not update |
|
* the 'last_snapshot'. |
|
*/ |
|
ret = btrfs_copy_root(trans, root, root->node, &eb, |
|
BTRFS_TREE_RELOC_OBJECTID); |
|
if (ret) |
|
goto fail; |
|
} |
|
|
|
/* |
|
* We have changed references at this point, we must abort the |
|
* transaction if anything fails. |
|
*/ |
|
must_abort = true; |
|
|
|
memcpy(root_item, &root->root_item, sizeof(*root_item)); |
|
btrfs_set_root_bytenr(root_item, eb->start); |
|
btrfs_set_root_level(root_item, btrfs_header_level(eb)); |
|
btrfs_set_root_generation(root_item, trans->transid); |
|
|
|
if (root->root_key.objectid == objectid) { |
|
btrfs_set_root_refs(root_item, 0); |
|
memset(&root_item->drop_progress, 0, |
|
sizeof(struct btrfs_disk_key)); |
|
btrfs_set_root_drop_level(root_item, 0); |
|
} |
|
|
|
btrfs_tree_unlock(eb); |
|
free_extent_buffer(eb); |
|
|
|
ret = btrfs_insert_root(trans, fs_info->tree_root, |
|
&root_key, root_item); |
|
if (ret) |
|
goto fail; |
|
|
|
kfree(root_item); |
|
|
|
reloc_root = btrfs_read_tree_root(fs_info->tree_root, &root_key); |
|
if (IS_ERR(reloc_root)) { |
|
ret = PTR_ERR(reloc_root); |
|
goto abort; |
|
} |
|
set_bit(BTRFS_ROOT_SHAREABLE, &reloc_root->state); |
|
reloc_root->last_trans = trans->transid; |
|
return reloc_root; |
|
fail: |
|
kfree(root_item); |
|
abort: |
|
if (must_abort) |
|
btrfs_abort_transaction(trans, ret); |
|
return ERR_PTR(ret); |
|
} |
|
|
|
/* |
|
* create reloc tree for a given fs tree. reloc tree is just a |
|
* snapshot of the fs tree with special root objectid. |
|
* |
|
* The reloc_root comes out of here with two references, one for |
|
* root->reloc_root, and another for being on the rc->reloc_roots list. |
|
*/ |
|
int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, |
|
struct btrfs_root *root) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct btrfs_root *reloc_root; |
|
struct reloc_control *rc = fs_info->reloc_ctl; |
|
struct btrfs_block_rsv *rsv; |
|
int clear_rsv = 0; |
|
int ret; |
|
|
|
if (!rc) |
|
return 0; |
|
|
|
/* |
|
* The subvolume has reloc tree but the swap is finished, no need to |
|
* create/update the dead reloc tree |
|
*/ |
|
if (reloc_root_is_dead(root)) |
|
return 0; |
|
|
|
/* |
|
* This is subtle but important. We do not do |
|
* record_root_in_transaction for reloc roots, instead we record their |
|
* corresponding fs root, and then here we update the last trans for the |
|
* reloc root. This means that we have to do this for the entire life |
|
* of the reloc root, regardless of which stage of the relocation we are |
|
* in. |
|
*/ |
|
if (root->reloc_root) { |
|
reloc_root = root->reloc_root; |
|
reloc_root->last_trans = trans->transid; |
|
return 0; |
|
} |
|
|
|
/* |
|
* We are merging reloc roots, we do not need new reloc trees. Also |
|
* reloc trees never need their own reloc tree. |
|
*/ |
|
if (!rc->create_reloc_tree || |
|
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
|
return 0; |
|
|
|
if (!trans->reloc_reserved) { |
|
rsv = trans->block_rsv; |
|
trans->block_rsv = rc->block_rsv; |
|
clear_rsv = 1; |
|
} |
|
reloc_root = create_reloc_root(trans, root, root->root_key.objectid); |
|
if (clear_rsv) |
|
trans->block_rsv = rsv; |
|
|
|
ret = __add_reloc_root(reloc_root); |
|
BUG_ON(ret < 0); |
|
root->reloc_root = btrfs_grab_root(reloc_root); |
|
return 0; |
|
} |
|
|
|
/* |
|
* update root item of reloc tree |
|
*/ |
|
int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, |
|
struct btrfs_root *root) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct btrfs_root *reloc_root; |
|
struct btrfs_root_item *root_item; |
|
int ret; |
|
|
|
if (!have_reloc_root(root)) |
|
return 0; |
|
|
|
reloc_root = root->reloc_root; |
|
root_item = &reloc_root->root_item; |
|
|
|
/* |
|
* We are probably ok here, but __del_reloc_root() will drop its ref of |
|
* the root. We have the ref for root->reloc_root, but just in case |
|
* hold it while we update the reloc root. |
|
*/ |
|
btrfs_grab_root(reloc_root); |
|
|
|
/* root->reloc_root will stay until current relocation finished */ |
|
if (fs_info->reloc_ctl->merge_reloc_tree && |
|
btrfs_root_refs(root_item) == 0) { |
|
set_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state); |
|
/* |
|
* Mark the tree as dead before we change reloc_root so |
|
* have_reloc_root will not touch it from now on. |
|
*/ |
|
smp_wmb(); |
|
__del_reloc_root(reloc_root); |
|
} |
|
|
|
if (reloc_root->commit_root != reloc_root->node) { |
|
__update_reloc_root(reloc_root); |
|
btrfs_set_root_node(root_item, reloc_root->node); |
|
free_extent_buffer(reloc_root->commit_root); |
|
reloc_root->commit_root = btrfs_root_node(reloc_root); |
|
} |
|
|
|
ret = btrfs_update_root(trans, fs_info->tree_root, |
|
&reloc_root->root_key, root_item); |
|
btrfs_put_root(reloc_root); |
|
return ret; |
|
} |
|
|
|
/* |
|
* helper to find first cached inode with inode number >= objectid |
|
* in a subvolume |
|
*/ |
|
static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid) |
|
{ |
|
struct rb_node *node; |
|
struct rb_node *prev; |
|
struct btrfs_inode *entry; |
|
struct inode *inode; |
|
|
|
spin_lock(&root->inode_lock); |
|
again: |
|
node = root->inode_tree.rb_node; |
|
prev = NULL; |
|
while (node) { |
|
prev = node; |
|
entry = rb_entry(node, struct btrfs_inode, rb_node); |
|
|
|
if (objectid < btrfs_ino(entry)) |
|
node = node->rb_left; |
|
else if (objectid > btrfs_ino(entry)) |
|
node = node->rb_right; |
|
else |
|
break; |
|
} |
|
if (!node) { |
|
while (prev) { |
|
entry = rb_entry(prev, struct btrfs_inode, rb_node); |
|
if (objectid <= btrfs_ino(entry)) { |
|
node = prev; |
|
break; |
|
} |
|
prev = rb_next(prev); |
|
} |
|
} |
|
while (node) { |
|
entry = rb_entry(node, struct btrfs_inode, rb_node); |
|
inode = igrab(&entry->vfs_inode); |
|
if (inode) { |
|
spin_unlock(&root->inode_lock); |
|
return inode; |
|
} |
|
|
|
objectid = btrfs_ino(entry) + 1; |
|
if (cond_resched_lock(&root->inode_lock)) |
|
goto again; |
|
|
|
node = rb_next(node); |
|
} |
|
spin_unlock(&root->inode_lock); |
|
return NULL; |
|
} |
|
|
|
/* |
|
* get new location of data |
|
*/ |
|
static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr, |
|
u64 bytenr, u64 num_bytes) |
|
{ |
|
struct btrfs_root *root = BTRFS_I(reloc_inode)->root; |
|
struct btrfs_path *path; |
|
struct btrfs_file_extent_item *fi; |
|
struct extent_buffer *leaf; |
|
int ret; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
bytenr -= BTRFS_I(reloc_inode)->index_cnt; |
|
ret = btrfs_lookup_file_extent(NULL, root, path, |
|
btrfs_ino(BTRFS_I(reloc_inode)), bytenr, 0); |
|
if (ret < 0) |
|
goto out; |
|
if (ret > 0) { |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
|
|
leaf = path->nodes[0]; |
|
fi = btrfs_item_ptr(leaf, path->slots[0], |
|
struct btrfs_file_extent_item); |
|
|
|
BUG_ON(btrfs_file_extent_offset(leaf, fi) || |
|
btrfs_file_extent_compression(leaf, fi) || |
|
btrfs_file_extent_encryption(leaf, fi) || |
|
btrfs_file_extent_other_encoding(leaf, fi)); |
|
|
|
if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
*new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
|
ret = 0; |
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
/* |
|
* update file extent items in the tree leaf to point to |
|
* the new locations. |
|
*/ |
|
static noinline_for_stack |
|
int replace_file_extents(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_root *root, |
|
struct extent_buffer *leaf) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct btrfs_key key; |
|
struct btrfs_file_extent_item *fi; |
|
struct inode *inode = NULL; |
|
u64 parent; |
|
u64 bytenr; |
|
u64 new_bytenr = 0; |
|
u64 num_bytes; |
|
u64 end; |
|
u32 nritems; |
|
u32 i; |
|
int ret = 0; |
|
int first = 1; |
|
int dirty = 0; |
|
|
|
if (rc->stage != UPDATE_DATA_PTRS) |
|
return 0; |
|
|
|
/* reloc trees always use full backref */ |
|
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
|
parent = leaf->start; |
|
else |
|
parent = 0; |
|
|
|
nritems = btrfs_header_nritems(leaf); |
|
for (i = 0; i < nritems; i++) { |
|
struct btrfs_ref ref = { 0 }; |
|
|
|
cond_resched(); |
|
btrfs_item_key_to_cpu(leaf, &key, i); |
|
if (key.type != BTRFS_EXTENT_DATA_KEY) |
|
continue; |
|
fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); |
|
if (btrfs_file_extent_type(leaf, fi) == |
|
BTRFS_FILE_EXTENT_INLINE) |
|
continue; |
|
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
|
num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
|
if (bytenr == 0) |
|
continue; |
|
if (!in_range(bytenr, rc->block_group->start, |
|
rc->block_group->length)) |
|
continue; |
|
|
|
/* |
|
* if we are modifying block in fs tree, wait for readpage |
|
* to complete and drop the extent cache |
|
*/ |
|
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { |
|
if (first) { |
|
inode = find_next_inode(root, key.objectid); |
|
first = 0; |
|
} else if (inode && btrfs_ino(BTRFS_I(inode)) < key.objectid) { |
|
btrfs_add_delayed_iput(inode); |
|
inode = find_next_inode(root, key.objectid); |
|
} |
|
if (inode && btrfs_ino(BTRFS_I(inode)) == key.objectid) { |
|
end = key.offset + |
|
btrfs_file_extent_num_bytes(leaf, fi); |
|
WARN_ON(!IS_ALIGNED(key.offset, |
|
fs_info->sectorsize)); |
|
WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize)); |
|
end--; |
|
ret = try_lock_extent(&BTRFS_I(inode)->io_tree, |
|
key.offset, end); |
|
if (!ret) |
|
continue; |
|
|
|
btrfs_drop_extent_cache(BTRFS_I(inode), |
|
key.offset, end, 1); |
|
unlock_extent(&BTRFS_I(inode)->io_tree, |
|
key.offset, end); |
|
} |
|
} |
|
|
|
ret = get_new_location(rc->data_inode, &new_bytenr, |
|
bytenr, num_bytes); |
|
if (ret) { |
|
/* |
|
* Don't have to abort since we've not changed anything |
|
* in the file extent yet. |
|
*/ |
|
break; |
|
} |
|
|
|
btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr); |
|
dirty = 1; |
|
|
|
key.offset -= btrfs_file_extent_offset(leaf, fi); |
|
btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr, |
|
num_bytes, parent); |
|
ref.real_root = root->root_key.objectid; |
|
btrfs_init_data_ref(&ref, btrfs_header_owner(leaf), |
|
key.objectid, key.offset); |
|
ret = btrfs_inc_extent_ref(trans, &ref); |
|
if (ret) { |
|
btrfs_abort_transaction(trans, ret); |
|
break; |
|
} |
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr, |
|
num_bytes, parent); |
|
ref.real_root = root->root_key.objectid; |
|
btrfs_init_data_ref(&ref, btrfs_header_owner(leaf), |
|
key.objectid, key.offset); |
|
ret = btrfs_free_extent(trans, &ref); |
|
if (ret) { |
|
btrfs_abort_transaction(trans, ret); |
|
break; |
|
} |
|
} |
|
if (dirty) |
|
btrfs_mark_buffer_dirty(leaf); |
|
if (inode) |
|
btrfs_add_delayed_iput(inode); |
|
return ret; |
|
} |
|
|
|
static noinline_for_stack |
|
int memcmp_node_keys(struct extent_buffer *eb, int slot, |
|
struct btrfs_path *path, int level) |
|
{ |
|
struct btrfs_disk_key key1; |
|
struct btrfs_disk_key key2; |
|
btrfs_node_key(eb, &key1, slot); |
|
btrfs_node_key(path->nodes[level], &key2, path->slots[level]); |
|
return memcmp(&key1, &key2, sizeof(key1)); |
|
} |
|
|
|
/* |
|
* try to replace tree blocks in fs tree with the new blocks |
|
* in reloc tree. tree blocks haven't been modified since the |
|
* reloc tree was create can be replaced. |
|
* |
|
* if a block was replaced, level of the block + 1 is returned. |
|
* if no block got replaced, 0 is returned. if there are other |
|
* errors, a negative error number is returned. |
|
*/ |
|
static noinline_for_stack |
|
int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc, |
|
struct btrfs_root *dest, struct btrfs_root *src, |
|
struct btrfs_path *path, struct btrfs_key *next_key, |
|
int lowest_level, int max_level) |
|
{ |
|
struct btrfs_fs_info *fs_info = dest->fs_info; |
|
struct extent_buffer *eb; |
|
struct extent_buffer *parent; |
|
struct btrfs_ref ref = { 0 }; |
|
struct btrfs_key key; |
|
u64 old_bytenr; |
|
u64 new_bytenr; |
|
u64 old_ptr_gen; |
|
u64 new_ptr_gen; |
|
u64 last_snapshot; |
|
u32 blocksize; |
|
int cow = 0; |
|
int level; |
|
int ret; |
|
int slot; |
|
|
|
ASSERT(src->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID); |
|
ASSERT(dest->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); |
|
|
|
last_snapshot = btrfs_root_last_snapshot(&src->root_item); |
|
again: |
|
slot = path->slots[lowest_level]; |
|
btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot); |
|
|
|
eb = btrfs_lock_root_node(dest); |
|
level = btrfs_header_level(eb); |
|
|
|
if (level < lowest_level) { |
|
btrfs_tree_unlock(eb); |
|
free_extent_buffer(eb); |
|
return 0; |
|
} |
|
|
|
if (cow) { |
|
ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb, |
|
BTRFS_NESTING_COW); |
|
BUG_ON(ret); |
|
} |
|
|
|
if (next_key) { |
|
next_key->objectid = (u64)-1; |
|
next_key->type = (u8)-1; |
|
next_key->offset = (u64)-1; |
|
} |
|
|
|
parent = eb; |
|
while (1) { |
|
level = btrfs_header_level(parent); |
|
ASSERT(level >= lowest_level); |
|
|
|
ret = btrfs_bin_search(parent, &key, &slot); |
|
if (ret < 0) |
|
break; |
|
if (ret && slot > 0) |
|
slot--; |
|
|
|
if (next_key && slot + 1 < btrfs_header_nritems(parent)) |
|
btrfs_node_key_to_cpu(parent, next_key, slot + 1); |
|
|
|
old_bytenr = btrfs_node_blockptr(parent, slot); |
|
blocksize = fs_info->nodesize; |
|
old_ptr_gen = btrfs_node_ptr_generation(parent, slot); |
|
|
|
if (level <= max_level) { |
|
eb = path->nodes[level]; |
|
new_bytenr = btrfs_node_blockptr(eb, |
|
path->slots[level]); |
|
new_ptr_gen = btrfs_node_ptr_generation(eb, |
|
path->slots[level]); |
|
} else { |
|
new_bytenr = 0; |
|
new_ptr_gen = 0; |
|
} |
|
|
|
if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) { |
|
ret = level; |
|
break; |
|
} |
|
|
|
if (new_bytenr == 0 || old_ptr_gen > last_snapshot || |
|
memcmp_node_keys(parent, slot, path, level)) { |
|
if (level <= lowest_level) { |
|
ret = 0; |
|
break; |
|
} |
|
|
|
eb = btrfs_read_node_slot(parent, slot); |
|
if (IS_ERR(eb)) { |
|
ret = PTR_ERR(eb); |
|
break; |
|
} |
|
btrfs_tree_lock(eb); |
|
if (cow) { |
|
ret = btrfs_cow_block(trans, dest, eb, parent, |
|
slot, &eb, |
|
BTRFS_NESTING_COW); |
|
BUG_ON(ret); |
|
} |
|
|
|
btrfs_tree_unlock(parent); |
|
free_extent_buffer(parent); |
|
|
|
parent = eb; |
|
continue; |
|
} |
|
|
|
if (!cow) { |
|
btrfs_tree_unlock(parent); |
|
free_extent_buffer(parent); |
|
cow = 1; |
|
goto again; |
|
} |
|
|
|
btrfs_node_key_to_cpu(path->nodes[level], &key, |
|
path->slots[level]); |
|
btrfs_release_path(path); |
|
|
|
path->lowest_level = level; |
|
ret = btrfs_search_slot(trans, src, &key, path, 0, 1); |
|
path->lowest_level = 0; |
|
BUG_ON(ret); |
|
|
|
/* |
|
* Info qgroup to trace both subtrees. |
|
* |
|
* We must trace both trees. |
|
* 1) Tree reloc subtree |
|
* If not traced, we will leak data numbers |
|
* 2) Fs subtree |
|
* If not traced, we will double count old data |
|
* |
|
* We don't scan the subtree right now, but only record |
|
* the swapped tree blocks. |
|
* The real subtree rescan is delayed until we have new |
|
* CoW on the subtree root node before transaction commit. |
|
*/ |
|
ret = btrfs_qgroup_add_swapped_blocks(trans, dest, |
|
rc->block_group, parent, slot, |
|
path->nodes[level], path->slots[level], |
|
last_snapshot); |
|
if (ret < 0) |
|
break; |
|
/* |
|
* swap blocks in fs tree and reloc tree. |
|
*/ |
|
btrfs_set_node_blockptr(parent, slot, new_bytenr); |
|
btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen); |
|
btrfs_mark_buffer_dirty(parent); |
|
|
|
btrfs_set_node_blockptr(path->nodes[level], |
|
path->slots[level], old_bytenr); |
|
btrfs_set_node_ptr_generation(path->nodes[level], |
|
path->slots[level], old_ptr_gen); |
|
btrfs_mark_buffer_dirty(path->nodes[level]); |
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, old_bytenr, |
|
blocksize, path->nodes[level]->start); |
|
ref.skip_qgroup = true; |
|
btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid); |
|
ret = btrfs_inc_extent_ref(trans, &ref); |
|
BUG_ON(ret); |
|
btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr, |
|
blocksize, 0); |
|
ref.skip_qgroup = true; |
|
btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid); |
|
ret = btrfs_inc_extent_ref(trans, &ref); |
|
BUG_ON(ret); |
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, new_bytenr, |
|
blocksize, path->nodes[level]->start); |
|
btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid); |
|
ref.skip_qgroup = true; |
|
ret = btrfs_free_extent(trans, &ref); |
|
BUG_ON(ret); |
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, old_bytenr, |
|
blocksize, 0); |
|
btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid); |
|
ref.skip_qgroup = true; |
|
ret = btrfs_free_extent(trans, &ref); |
|
BUG_ON(ret); |
|
|
|
btrfs_unlock_up_safe(path, 0); |
|
|
|
ret = level; |
|
break; |
|
} |
|
btrfs_tree_unlock(parent); |
|
free_extent_buffer(parent); |
|
return ret; |
|
} |
|
|
|
/* |
|
* helper to find next relocated block in reloc tree |
|
*/ |
|
static noinline_for_stack |
|
int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, |
|
int *level) |
|
{ |
|
struct extent_buffer *eb; |
|
int i; |
|
u64 last_snapshot; |
|
u32 nritems; |
|
|
|
last_snapshot = btrfs_root_last_snapshot(&root->root_item); |
|
|
|
for (i = 0; i < *level; i++) { |
|
free_extent_buffer(path->nodes[i]); |
|
path->nodes[i] = NULL; |
|
} |
|
|
|
for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) { |
|
eb = path->nodes[i]; |
|
nritems = btrfs_header_nritems(eb); |
|
while (path->slots[i] + 1 < nritems) { |
|
path->slots[i]++; |
|
if (btrfs_node_ptr_generation(eb, path->slots[i]) <= |
|
last_snapshot) |
|
continue; |
|
|
|
*level = i; |
|
return 0; |
|
} |
|
free_extent_buffer(path->nodes[i]); |
|
path->nodes[i] = NULL; |
|
} |
|
return 1; |
|
} |
|
|
|
/* |
|
* walk down reloc tree to find relocated block of lowest level |
|
*/ |
|
static noinline_for_stack |
|
int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, |
|
int *level) |
|
{ |
|
struct extent_buffer *eb = NULL; |
|
int i; |
|
u64 ptr_gen = 0; |
|
u64 last_snapshot; |
|
u32 nritems; |
|
|
|
last_snapshot = btrfs_root_last_snapshot(&root->root_item); |
|
|
|
for (i = *level; i > 0; i--) { |
|
eb = path->nodes[i]; |
|
nritems = btrfs_header_nritems(eb); |
|
while (path->slots[i] < nritems) { |
|
ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]); |
|
if (ptr_gen > last_snapshot) |
|
break; |
|
path->slots[i]++; |
|
} |
|
if (path->slots[i] >= nritems) { |
|
if (i == *level) |
|
break; |
|
*level = i + 1; |
|
return 0; |
|
} |
|
if (i == 1) { |
|
*level = i; |
|
return 0; |
|
} |
|
|
|
eb = btrfs_read_node_slot(eb, path->slots[i]); |
|
if (IS_ERR(eb)) |
|
return PTR_ERR(eb); |
|
BUG_ON(btrfs_header_level(eb) != i - 1); |
|
path->nodes[i - 1] = eb; |
|
path->slots[i - 1] = 0; |
|
} |
|
return 1; |
|
} |
|
|
|
/* |
|
* invalidate extent cache for file extents whose key in range of |
|
* [min_key, max_key) |
|
*/ |
|
static int invalidate_extent_cache(struct btrfs_root *root, |
|
struct btrfs_key *min_key, |
|
struct btrfs_key *max_key) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct inode *inode = NULL; |
|
u64 objectid; |
|
u64 start, end; |
|
u64 ino; |
|
|
|
objectid = min_key->objectid; |
|
while (1) { |
|
cond_resched(); |
|
iput(inode); |
|
|
|
if (objectid > max_key->objectid) |
|
break; |
|
|
|
inode = find_next_inode(root, objectid); |
|
if (!inode) |
|
break; |
|
ino = btrfs_ino(BTRFS_I(inode)); |
|
|
|
if (ino > max_key->objectid) { |
|
iput(inode); |
|
break; |
|
} |
|
|
|
objectid = ino + 1; |
|
if (!S_ISREG(inode->i_mode)) |
|
continue; |
|
|
|
if (unlikely(min_key->objectid == ino)) { |
|
if (min_key->type > BTRFS_EXTENT_DATA_KEY) |
|
continue; |
|
if (min_key->type < BTRFS_EXTENT_DATA_KEY) |
|
start = 0; |
|
else { |
|
start = min_key->offset; |
|
WARN_ON(!IS_ALIGNED(start, fs_info->sectorsize)); |
|
} |
|
} else { |
|
start = 0; |
|
} |
|
|
|
if (unlikely(max_key->objectid == ino)) { |
|
if (max_key->type < BTRFS_EXTENT_DATA_KEY) |
|
continue; |
|
if (max_key->type > BTRFS_EXTENT_DATA_KEY) { |
|
end = (u64)-1; |
|
} else { |
|
if (max_key->offset == 0) |
|
continue; |
|
end = max_key->offset; |
|
WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize)); |
|
end--; |
|
} |
|
} else { |
|
end = (u64)-1; |
|
} |
|
|
|
/* the lock_extent waits for readpage to complete */ |
|
lock_extent(&BTRFS_I(inode)->io_tree, start, end); |
|
btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 1); |
|
unlock_extent(&BTRFS_I(inode)->io_tree, start, end); |
|
} |
|
return 0; |
|
} |
|
|
|
static int find_next_key(struct btrfs_path *path, int level, |
|
struct btrfs_key *key) |
|
|
|
{ |
|
while (level < BTRFS_MAX_LEVEL) { |
|
if (!path->nodes[level]) |
|
break; |
|
if (path->slots[level] + 1 < |
|
btrfs_header_nritems(path->nodes[level])) { |
|
btrfs_node_key_to_cpu(path->nodes[level], key, |
|
path->slots[level] + 1); |
|
return 0; |
|
} |
|
level++; |
|
} |
|
return 1; |
|
} |
|
|
|
/* |
|
* Insert current subvolume into reloc_control::dirty_subvol_roots |
|
*/ |
|
static void insert_dirty_subvol(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_root *root) |
|
{ |
|
struct btrfs_root *reloc_root = root->reloc_root; |
|
struct btrfs_root_item *reloc_root_item; |
|
|
|
/* @root must be a subvolume tree root with a valid reloc tree */ |
|
ASSERT(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); |
|
ASSERT(reloc_root); |
|
|
|
reloc_root_item = &reloc_root->root_item; |
|
memset(&reloc_root_item->drop_progress, 0, |
|
sizeof(reloc_root_item->drop_progress)); |
|
btrfs_set_root_drop_level(reloc_root_item, 0); |
|
btrfs_set_root_refs(reloc_root_item, 0); |
|
btrfs_update_reloc_root(trans, root); |
|
|
|
if (list_empty(&root->reloc_dirty_list)) { |
|
btrfs_grab_root(root); |
|
list_add_tail(&root->reloc_dirty_list, &rc->dirty_subvol_roots); |
|
} |
|
} |
|
|
|
static int clean_dirty_subvols(struct reloc_control *rc) |
|
{ |
|
struct btrfs_root *root; |
|
struct btrfs_root *next; |
|
int ret = 0; |
|
int ret2; |
|
|
|
list_for_each_entry_safe(root, next, &rc->dirty_subvol_roots, |
|
reloc_dirty_list) { |
|
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { |
|
/* Merged subvolume, cleanup its reloc root */ |
|
struct btrfs_root *reloc_root = root->reloc_root; |
|
|
|
list_del_init(&root->reloc_dirty_list); |
|
root->reloc_root = NULL; |
|
/* |
|
* Need barrier to ensure clear_bit() only happens after |
|
* root->reloc_root = NULL. Pairs with have_reloc_root. |
|
*/ |
|
smp_wmb(); |
|
clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state); |
|
if (reloc_root) { |
|
/* |
|
* btrfs_drop_snapshot drops our ref we hold for |
|
* ->reloc_root. If it fails however we must |
|
* drop the ref ourselves. |
|
*/ |
|
ret2 = btrfs_drop_snapshot(reloc_root, 0, 1); |
|
if (ret2 < 0) { |
|
btrfs_put_root(reloc_root); |
|
if (!ret) |
|
ret = ret2; |
|
} |
|
} |
|
btrfs_put_root(root); |
|
} else { |
|
/* Orphan reloc tree, just clean it up */ |
|
ret2 = btrfs_drop_snapshot(root, 0, 1); |
|
if (ret2 < 0) { |
|
btrfs_put_root(root); |
|
if (!ret) |
|
ret = ret2; |
|
} |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
/* |
|
* merge the relocated tree blocks in reloc tree with corresponding |
|
* fs tree. |
|
*/ |
|
static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, |
|
struct btrfs_root *root) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
struct btrfs_key key; |
|
struct btrfs_key next_key; |
|
struct btrfs_trans_handle *trans = NULL; |
|
struct btrfs_root *reloc_root; |
|
struct btrfs_root_item *root_item; |
|
struct btrfs_path *path; |
|
struct extent_buffer *leaf; |
|
int reserve_level; |
|
int level; |
|
int max_level; |
|
int replaced = 0; |
|
int ret = 0; |
|
u32 min_reserved; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return -ENOMEM; |
|
path->reada = READA_FORWARD; |
|
|
|
reloc_root = root->reloc_root; |
|
root_item = &reloc_root->root_item; |
|
|
|
if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { |
|
level = btrfs_root_level(root_item); |
|
atomic_inc(&reloc_root->node->refs); |
|
path->nodes[level] = reloc_root->node; |
|
path->slots[level] = 0; |
|
} else { |
|
btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); |
|
|
|
level = btrfs_root_drop_level(root_item); |
|
BUG_ON(level == 0); |
|
path->lowest_level = level; |
|
ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0); |
|
path->lowest_level = 0; |
|
if (ret < 0) { |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
btrfs_node_key_to_cpu(path->nodes[level], &next_key, |
|
path->slots[level]); |
|
WARN_ON(memcmp(&key, &next_key, sizeof(key))); |
|
|
|
btrfs_unlock_up_safe(path, 0); |
|
} |
|
|
|
/* |
|
* In merge_reloc_root(), we modify the upper level pointer to swap the |
|
* tree blocks between reloc tree and subvolume tree. Thus for tree |
|
* block COW, we COW at most from level 1 to root level for each tree. |
|
* |
|
* Thus the needed metadata size is at most root_level * nodesize, |
|
* and * 2 since we have two trees to COW. |
|
*/ |
|
reserve_level = max_t(int, 1, btrfs_root_level(root_item)); |
|
min_reserved = fs_info->nodesize * reserve_level * 2; |
|
memset(&next_key, 0, sizeof(next_key)); |
|
|
|
while (1) { |
|
ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved, |
|
BTRFS_RESERVE_FLUSH_LIMIT); |
|
if (ret) |
|
goto out; |
|
trans = btrfs_start_transaction(root, 0); |
|
if (IS_ERR(trans)) { |
|
ret = PTR_ERR(trans); |
|
trans = NULL; |
|
goto out; |
|
} |
|
|
|
/* |
|
* At this point we no longer have a reloc_control, so we can't |
|
* depend on btrfs_init_reloc_root to update our last_trans. |
|
* |
|
* But that's ok, we started the trans handle on our |
|
* corresponding fs_root, which means it's been added to the |
|
* dirty list. At commit time we'll still call |
|
* btrfs_update_reloc_root() and update our root item |
|
* appropriately. |
|
*/ |
|
reloc_root->last_trans = trans->transid; |
|
trans->block_rsv = rc->block_rsv; |
|
|
|
replaced = 0; |
|
max_level = level; |
|
|
|
ret = walk_down_reloc_tree(reloc_root, path, &level); |
|
if (ret < 0) |
|
goto out; |
|
if (ret > 0) |
|
break; |
|
|
|
if (!find_next_key(path, level, &key) && |
|
btrfs_comp_cpu_keys(&next_key, &key) >= 0) { |
|
ret = 0; |
|
} else { |
|
ret = replace_path(trans, rc, root, reloc_root, path, |
|
&next_key, level, max_level); |
|
} |
|
if (ret < 0) |
|
goto out; |
|
if (ret > 0) { |
|
level = ret; |
|
btrfs_node_key_to_cpu(path->nodes[level], &key, |
|
path->slots[level]); |
|
replaced = 1; |
|
} |
|
|
|
ret = walk_up_reloc_tree(reloc_root, path, &level); |
|
if (ret > 0) |
|
break; |
|
|
|
BUG_ON(level == 0); |
|
/* |
|
* save the merging progress in the drop_progress. |
|
* this is OK since root refs == 1 in this case. |
|
*/ |
|
btrfs_node_key(path->nodes[level], &root_item->drop_progress, |
|
path->slots[level]); |
|
btrfs_set_root_drop_level(root_item, level); |
|
|
|
btrfs_end_transaction_throttle(trans); |
|
trans = NULL; |
|
|
|
btrfs_btree_balance_dirty(fs_info); |
|
|
|
if (replaced && rc->stage == UPDATE_DATA_PTRS) |
|
invalidate_extent_cache(root, &key, &next_key); |
|
} |
|
|
|
/* |
|
* handle the case only one block in the fs tree need to be |
|
* relocated and the block is tree root. |
|
*/ |
|
leaf = btrfs_lock_root_node(root); |
|
ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf, |
|
BTRFS_NESTING_COW); |
|
btrfs_tree_unlock(leaf); |
|
free_extent_buffer(leaf); |
|
out: |
|
btrfs_free_path(path); |
|
|
|
if (ret == 0) |
|
insert_dirty_subvol(trans, rc, root); |
|
|
|
if (trans) |
|
btrfs_end_transaction_throttle(trans); |
|
|
|
btrfs_btree_balance_dirty(fs_info); |
|
|
|
if (replaced && rc->stage == UPDATE_DATA_PTRS) |
|
invalidate_extent_cache(root, &key, &next_key); |
|
|
|
return ret; |
|
} |
|
|
|
static noinline_for_stack |
|
int prepare_to_merge(struct reloc_control *rc, int err) |
|
{ |
|
struct btrfs_root *root = rc->extent_root; |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct btrfs_root *reloc_root; |
|
struct btrfs_trans_handle *trans; |
|
LIST_HEAD(reloc_roots); |
|
u64 num_bytes = 0; |
|
int ret; |
|
|
|
mutex_lock(&fs_info->reloc_mutex); |
|
rc->merging_rsv_size += fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; |
|
rc->merging_rsv_size += rc->nodes_relocated * 2; |
|
mutex_unlock(&fs_info->reloc_mutex); |
|
|
|
again: |
|
if (!err) { |
|
num_bytes = rc->merging_rsv_size; |
|
ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes, |
|
BTRFS_RESERVE_FLUSH_ALL); |
|
if (ret) |
|
err = ret; |
|
} |
|
|
|
trans = btrfs_join_transaction(rc->extent_root); |
|
if (IS_ERR(trans)) { |
|
if (!err) |
|
btrfs_block_rsv_release(fs_info, rc->block_rsv, |
|
num_bytes, NULL); |
|
return PTR_ERR(trans); |
|
} |
|
|
|
if (!err) { |
|
if (num_bytes != rc->merging_rsv_size) { |
|
btrfs_end_transaction(trans); |
|
btrfs_block_rsv_release(fs_info, rc->block_rsv, |
|
num_bytes, NULL); |
|
goto again; |
|
} |
|
} |
|
|
|
rc->merge_reloc_tree = 1; |
|
|
|
while (!list_empty(&rc->reloc_roots)) { |
|
reloc_root = list_entry(rc->reloc_roots.next, |
|
struct btrfs_root, root_list); |
|
list_del_init(&reloc_root->root_list); |
|
|
|
root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, |
|
false); |
|
BUG_ON(IS_ERR(root)); |
|
BUG_ON(root->reloc_root != reloc_root); |
|
|
|
/* |
|
* set reference count to 1, so btrfs_recover_relocation |
|
* knows it should resumes merging |
|
*/ |
|
if (!err) |
|
btrfs_set_root_refs(&reloc_root->root_item, 1); |
|
btrfs_update_reloc_root(trans, root); |
|
|
|
list_add(&reloc_root->root_list, &reloc_roots); |
|
btrfs_put_root(root); |
|
} |
|
|
|
list_splice(&reloc_roots, &rc->reloc_roots); |
|
|
|
if (!err) |
|
btrfs_commit_transaction(trans); |
|
else |
|
btrfs_end_transaction(trans); |
|
return err; |
|
} |
|
|
|
static noinline_for_stack |
|
void free_reloc_roots(struct list_head *list) |
|
{ |
|
struct btrfs_root *reloc_root, *tmp; |
|
|
|
list_for_each_entry_safe(reloc_root, tmp, list, root_list) |
|
__del_reloc_root(reloc_root); |
|
} |
|
|
|
static noinline_for_stack |
|
void merge_reloc_roots(struct reloc_control *rc) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
struct btrfs_root *root; |
|
struct btrfs_root *reloc_root; |
|
LIST_HEAD(reloc_roots); |
|
int found = 0; |
|
int ret = 0; |
|
again: |
|
root = rc->extent_root; |
|
|
|
/* |
|
* this serializes us with btrfs_record_root_in_transaction, |
|
* we have to make sure nobody is in the middle of |
|
* adding their roots to the list while we are |
|
* doing this splice |
|
*/ |
|
mutex_lock(&fs_info->reloc_mutex); |
|
list_splice_init(&rc->reloc_roots, &reloc_roots); |
|
mutex_unlock(&fs_info->reloc_mutex); |
|
|
|
while (!list_empty(&reloc_roots)) { |
|
found = 1; |
|
reloc_root = list_entry(reloc_roots.next, |
|
struct btrfs_root, root_list); |
|
|
|
root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, |
|
false); |
|
if (btrfs_root_refs(&reloc_root->root_item) > 0) { |
|
BUG_ON(IS_ERR(root)); |
|
BUG_ON(root->reloc_root != reloc_root); |
|
ret = merge_reloc_root(rc, root); |
|
btrfs_put_root(root); |
|
if (ret) { |
|
if (list_empty(&reloc_root->root_list)) |
|
list_add_tail(&reloc_root->root_list, |
|
&reloc_roots); |
|
goto out; |
|
} |
|
} else { |
|
if (!IS_ERR(root)) { |
|
if (root->reloc_root == reloc_root) { |
|
root->reloc_root = NULL; |
|
btrfs_put_root(reloc_root); |
|
} |
|
clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, |
|
&root->state); |
|
btrfs_put_root(root); |
|
} |
|
|
|
list_del_init(&reloc_root->root_list); |
|
/* Don't forget to queue this reloc root for cleanup */ |
|
list_add_tail(&reloc_root->reloc_dirty_list, |
|
&rc->dirty_subvol_roots); |
|
} |
|
} |
|
|
|
if (found) { |
|
found = 0; |
|
goto again; |
|
} |
|
out: |
|
if (ret) { |
|
btrfs_handle_fs_error(fs_info, ret, NULL); |
|
free_reloc_roots(&reloc_roots); |
|
|
|
/* new reloc root may be added */ |
|
mutex_lock(&fs_info->reloc_mutex); |
|
list_splice_init(&rc->reloc_roots, &reloc_roots); |
|
mutex_unlock(&fs_info->reloc_mutex); |
|
free_reloc_roots(&reloc_roots); |
|
} |
|
|
|
/* |
|
* We used to have |
|
* |
|
* BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root)); |
|
* |
|
* here, but it's wrong. If we fail to start the transaction in |
|
* prepare_to_merge() we will have only 0 ref reloc roots, none of which |
|
* have actually been removed from the reloc_root_tree rb tree. This is |
|
* fine because we're bailing here, and we hold a reference on the root |
|
* for the list that holds it, so these roots will be cleaned up when we |
|
* do the reloc_dirty_list afterwards. Meanwhile the root->reloc_root |
|
* will be cleaned up on unmount. |
|
* |
|
* The remaining nodes will be cleaned up by free_reloc_control. |
|
*/ |
|
} |
|
|
|
static void free_block_list(struct rb_root *blocks) |
|
{ |
|
struct tree_block *block; |
|
struct rb_node *rb_node; |
|
while ((rb_node = rb_first(blocks))) { |
|
block = rb_entry(rb_node, struct tree_block, rb_node); |
|
rb_erase(rb_node, blocks); |
|
kfree(block); |
|
} |
|
} |
|
|
|
static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans, |
|
struct btrfs_root *reloc_root) |
|
{ |
|
struct btrfs_fs_info *fs_info = reloc_root->fs_info; |
|
struct btrfs_root *root; |
|
int ret; |
|
|
|
if (reloc_root->last_trans == trans->transid) |
|
return 0; |
|
|
|
root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, false); |
|
BUG_ON(IS_ERR(root)); |
|
BUG_ON(root->reloc_root != reloc_root); |
|
ret = btrfs_record_root_in_trans(trans, root); |
|
btrfs_put_root(root); |
|
|
|
return ret; |
|
} |
|
|
|
static noinline_for_stack |
|
struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_backref_node *node, |
|
struct btrfs_backref_edge *edges[]) |
|
{ |
|
struct btrfs_backref_node *next; |
|
struct btrfs_root *root; |
|
int index = 0; |
|
|
|
next = node; |
|
while (1) { |
|
cond_resched(); |
|
next = walk_up_backref(next, edges, &index); |
|
root = next->root; |
|
BUG_ON(!root); |
|
BUG_ON(!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)); |
|
|
|
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { |
|
record_reloc_root_in_trans(trans, root); |
|
break; |
|
} |
|
|
|
btrfs_record_root_in_trans(trans, root); |
|
root = root->reloc_root; |
|
|
|
if (next->new_bytenr != root->node->start) { |
|
BUG_ON(next->new_bytenr); |
|
BUG_ON(!list_empty(&next->list)); |
|
next->new_bytenr = root->node->start; |
|
btrfs_put_root(next->root); |
|
next->root = btrfs_grab_root(root); |
|
ASSERT(next->root); |
|
list_add_tail(&next->list, |
|
&rc->backref_cache.changed); |
|
mark_block_processed(rc, next); |
|
break; |
|
} |
|
|
|
WARN_ON(1); |
|
root = NULL; |
|
next = walk_down_backref(edges, &index); |
|
if (!next || next->level <= node->level) |
|
break; |
|
} |
|
if (!root) |
|
return NULL; |
|
|
|
next = node; |
|
/* setup backref node path for btrfs_reloc_cow_block */ |
|
while (1) { |
|
rc->backref_cache.path[next->level] = next; |
|
if (--index < 0) |
|
break; |
|
next = edges[index]->node[UPPER]; |
|
} |
|
return root; |
|
} |
|
|
|
/* |
|
* Select a tree root for relocation. |
|
* |
|
* Return NULL if the block is not shareable. We should use do_relocation() in |
|
* this case. |
|
* |
|
* Return a tree root pointer if the block is shareable. |
|
* Return -ENOENT if the block is root of reloc tree. |
|
*/ |
|
static noinline_for_stack |
|
struct btrfs_root *select_one_root(struct btrfs_backref_node *node) |
|
{ |
|
struct btrfs_backref_node *next; |
|
struct btrfs_root *root; |
|
struct btrfs_root *fs_root = NULL; |
|
struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
|
int index = 0; |
|
|
|
next = node; |
|
while (1) { |
|
cond_resched(); |
|
next = walk_up_backref(next, edges, &index); |
|
root = next->root; |
|
BUG_ON(!root); |
|
|
|
/* No other choice for non-shareable tree */ |
|
if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) |
|
return root; |
|
|
|
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) |
|
fs_root = root; |
|
|
|
if (next != node) |
|
return NULL; |
|
|
|
next = walk_down_backref(edges, &index); |
|
if (!next || next->level <= node->level) |
|
break; |
|
} |
|
|
|
if (!fs_root) |
|
return ERR_PTR(-ENOENT); |
|
return fs_root; |
|
} |
|
|
|
static noinline_for_stack |
|
u64 calcu_metadata_size(struct reloc_control *rc, |
|
struct btrfs_backref_node *node, int reserve) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
struct btrfs_backref_node *next = node; |
|
struct btrfs_backref_edge *edge; |
|
struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
|
u64 num_bytes = 0; |
|
int index = 0; |
|
|
|
BUG_ON(reserve && node->processed); |
|
|
|
while (next) { |
|
cond_resched(); |
|
while (1) { |
|
if (next->processed && (reserve || next != node)) |
|
break; |
|
|
|
num_bytes += fs_info->nodesize; |
|
|
|
if (list_empty(&next->upper)) |
|
break; |
|
|
|
edge = list_entry(next->upper.next, |
|
struct btrfs_backref_edge, list[LOWER]); |
|
edges[index++] = edge; |
|
next = edge->node[UPPER]; |
|
} |
|
next = walk_down_backref(edges, &index); |
|
} |
|
return num_bytes; |
|
} |
|
|
|
static int reserve_metadata_space(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_backref_node *node) |
|
{ |
|
struct btrfs_root *root = rc->extent_root; |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
u64 num_bytes; |
|
int ret; |
|
u64 tmp; |
|
|
|
num_bytes = calcu_metadata_size(rc, node, 1) * 2; |
|
|
|
trans->block_rsv = rc->block_rsv; |
|
rc->reserved_bytes += num_bytes; |
|
|
|
/* |
|
* We are under a transaction here so we can only do limited flushing. |
|
* If we get an enospc just kick back -EAGAIN so we know to drop the |
|
* transaction and try to refill when we can flush all the things. |
|
*/ |
|
ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes, |
|
BTRFS_RESERVE_FLUSH_LIMIT); |
|
if (ret) { |
|
tmp = fs_info->nodesize * RELOCATION_RESERVED_NODES; |
|
while (tmp <= rc->reserved_bytes) |
|
tmp <<= 1; |
|
/* |
|
* only one thread can access block_rsv at this point, |
|
* so we don't need hold lock to protect block_rsv. |
|
* we expand more reservation size here to allow enough |
|
* space for relocation and we will return earlier in |
|
* enospc case. |
|
*/ |
|
rc->block_rsv->size = tmp + fs_info->nodesize * |
|
RELOCATION_RESERVED_NODES; |
|
return -EAGAIN; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* relocate a block tree, and then update pointers in upper level |
|
* blocks that reference the block to point to the new location. |
|
* |
|
* if called by link_to_upper, the block has already been relocated. |
|
* in that case this function just updates pointers. |
|
*/ |
|
static int do_relocation(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_backref_node *node, |
|
struct btrfs_key *key, |
|
struct btrfs_path *path, int lowest) |
|
{ |
|
struct btrfs_backref_node *upper; |
|
struct btrfs_backref_edge *edge; |
|
struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
|
struct btrfs_root *root; |
|
struct extent_buffer *eb; |
|
u32 blocksize; |
|
u64 bytenr; |
|
int slot; |
|
int ret = 0; |
|
|
|
BUG_ON(lowest && node->eb); |
|
|
|
path->lowest_level = node->level + 1; |
|
rc->backref_cache.path[node->level] = node; |
|
list_for_each_entry(edge, &node->upper, list[LOWER]) { |
|
struct btrfs_ref ref = { 0 }; |
|
|
|
cond_resched(); |
|
|
|
upper = edge->node[UPPER]; |
|
root = select_reloc_root(trans, rc, upper, edges); |
|
BUG_ON(!root); |
|
|
|
if (upper->eb && !upper->locked) { |
|
if (!lowest) { |
|
ret = btrfs_bin_search(upper->eb, key, &slot); |
|
if (ret < 0) |
|
goto next; |
|
BUG_ON(ret); |
|
bytenr = btrfs_node_blockptr(upper->eb, slot); |
|
if (node->eb->start == bytenr) |
|
goto next; |
|
} |
|
btrfs_backref_drop_node_buffer(upper); |
|
} |
|
|
|
if (!upper->eb) { |
|
ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
|
if (ret) { |
|
if (ret > 0) |
|
ret = -ENOENT; |
|
|
|
btrfs_release_path(path); |
|
break; |
|
} |
|
|
|
if (!upper->eb) { |
|
upper->eb = path->nodes[upper->level]; |
|
path->nodes[upper->level] = NULL; |
|
} else { |
|
BUG_ON(upper->eb != path->nodes[upper->level]); |
|
} |
|
|
|
upper->locked = 1; |
|
path->locks[upper->level] = 0; |
|
|
|
slot = path->slots[upper->level]; |
|
btrfs_release_path(path); |
|
} else { |
|
ret = btrfs_bin_search(upper->eb, key, &slot); |
|
if (ret < 0) |
|
goto next; |
|
BUG_ON(ret); |
|
} |
|
|
|
bytenr = btrfs_node_blockptr(upper->eb, slot); |
|
if (lowest) { |
|
if (bytenr != node->bytenr) { |
|
btrfs_err(root->fs_info, |
|
"lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu", |
|
bytenr, node->bytenr, slot, |
|
upper->eb->start); |
|
ret = -EIO; |
|
goto next; |
|
} |
|
} else { |
|
if (node->eb->start == bytenr) |
|
goto next; |
|
} |
|
|
|
blocksize = root->fs_info->nodesize; |
|
eb = btrfs_read_node_slot(upper->eb, slot); |
|
if (IS_ERR(eb)) { |
|
ret = PTR_ERR(eb); |
|
goto next; |
|
} |
|
btrfs_tree_lock(eb); |
|
|
|
if (!node->eb) { |
|
ret = btrfs_cow_block(trans, root, eb, upper->eb, |
|
slot, &eb, BTRFS_NESTING_COW); |
|
btrfs_tree_unlock(eb); |
|
free_extent_buffer(eb); |
|
if (ret < 0) |
|
goto next; |
|
BUG_ON(node->eb != eb); |
|
} else { |
|
btrfs_set_node_blockptr(upper->eb, slot, |
|
node->eb->start); |
|
btrfs_set_node_ptr_generation(upper->eb, slot, |
|
trans->transid); |
|
btrfs_mark_buffer_dirty(upper->eb); |
|
|
|
btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, |
|
node->eb->start, blocksize, |
|
upper->eb->start); |
|
ref.real_root = root->root_key.objectid; |
|
btrfs_init_tree_ref(&ref, node->level, |
|
btrfs_header_owner(upper->eb)); |
|
ret = btrfs_inc_extent_ref(trans, &ref); |
|
BUG_ON(ret); |
|
|
|
ret = btrfs_drop_subtree(trans, root, eb, upper->eb); |
|
BUG_ON(ret); |
|
} |
|
next: |
|
if (!upper->pending) |
|
btrfs_backref_drop_node_buffer(upper); |
|
else |
|
btrfs_backref_unlock_node_buffer(upper); |
|
if (ret) |
|
break; |
|
} |
|
|
|
if (!ret && node->pending) { |
|
btrfs_backref_drop_node_buffer(node); |
|
list_move_tail(&node->list, &rc->backref_cache.changed); |
|
node->pending = 0; |
|
} |
|
|
|
path->lowest_level = 0; |
|
BUG_ON(ret == -ENOSPC); |
|
return ret; |
|
} |
|
|
|
static int link_to_upper(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_backref_node *node, |
|
struct btrfs_path *path) |
|
{ |
|
struct btrfs_key key; |
|
|
|
btrfs_node_key_to_cpu(node->eb, &key, 0); |
|
return do_relocation(trans, rc, node, &key, path, 0); |
|
} |
|
|
|
static int finish_pending_nodes(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_path *path, int err) |
|
{ |
|
LIST_HEAD(list); |
|
struct btrfs_backref_cache *cache = &rc->backref_cache; |
|
struct btrfs_backref_node *node; |
|
int level; |
|
int ret; |
|
|
|
for (level = 0; level < BTRFS_MAX_LEVEL; level++) { |
|
while (!list_empty(&cache->pending[level])) { |
|
node = list_entry(cache->pending[level].next, |
|
struct btrfs_backref_node, list); |
|
list_move_tail(&node->list, &list); |
|
BUG_ON(!node->pending); |
|
|
|
if (!err) { |
|
ret = link_to_upper(trans, rc, node, path); |
|
if (ret < 0) |
|
err = ret; |
|
} |
|
} |
|
list_splice_init(&list, &cache->pending[level]); |
|
} |
|
return err; |
|
} |
|
|
|
/* |
|
* mark a block and all blocks directly/indirectly reference the block |
|
* as processed. |
|
*/ |
|
static void update_processed_blocks(struct reloc_control *rc, |
|
struct btrfs_backref_node *node) |
|
{ |
|
struct btrfs_backref_node *next = node; |
|
struct btrfs_backref_edge *edge; |
|
struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1]; |
|
int index = 0; |
|
|
|
while (next) { |
|
cond_resched(); |
|
while (1) { |
|
if (next->processed) |
|
break; |
|
|
|
mark_block_processed(rc, next); |
|
|
|
if (list_empty(&next->upper)) |
|
break; |
|
|
|
edge = list_entry(next->upper.next, |
|
struct btrfs_backref_edge, list[LOWER]); |
|
edges[index++] = edge; |
|
next = edge->node[UPPER]; |
|
} |
|
next = walk_down_backref(edges, &index); |
|
} |
|
} |
|
|
|
static int tree_block_processed(u64 bytenr, struct reloc_control *rc) |
|
{ |
|
u32 blocksize = rc->extent_root->fs_info->nodesize; |
|
|
|
if (test_range_bit(&rc->processed_blocks, bytenr, |
|
bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL)) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
static int get_tree_block_key(struct btrfs_fs_info *fs_info, |
|
struct tree_block *block) |
|
{ |
|
struct extent_buffer *eb; |
|
|
|
eb = read_tree_block(fs_info, block->bytenr, block->owner, |
|
block->key.offset, block->level, NULL); |
|
if (IS_ERR(eb)) { |
|
return PTR_ERR(eb); |
|
} else if (!extent_buffer_uptodate(eb)) { |
|
free_extent_buffer(eb); |
|
return -EIO; |
|
} |
|
if (block->level == 0) |
|
btrfs_item_key_to_cpu(eb, &block->key, 0); |
|
else |
|
btrfs_node_key_to_cpu(eb, &block->key, 0); |
|
free_extent_buffer(eb); |
|
block->key_ready = 1; |
|
return 0; |
|
} |
|
|
|
/* |
|
* helper function to relocate a tree block |
|
*/ |
|
static int relocate_tree_block(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, |
|
struct btrfs_backref_node *node, |
|
struct btrfs_key *key, |
|
struct btrfs_path *path) |
|
{ |
|
struct btrfs_root *root; |
|
int ret = 0; |
|
|
|
if (!node) |
|
return 0; |
|
|
|
/* |
|
* If we fail here we want to drop our backref_node because we are going |
|
* to start over and regenerate the tree for it. |
|
*/ |
|
ret = reserve_metadata_space(trans, rc, node); |
|
if (ret) |
|
goto out; |
|
|
|
BUG_ON(node->processed); |
|
root = select_one_root(node); |
|
if (root == ERR_PTR(-ENOENT)) { |
|
update_processed_blocks(rc, node); |
|
goto out; |
|
} |
|
|
|
if (root) { |
|
if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { |
|
BUG_ON(node->new_bytenr); |
|
BUG_ON(!list_empty(&node->list)); |
|
btrfs_record_root_in_trans(trans, root); |
|
root = root->reloc_root; |
|
node->new_bytenr = root->node->start; |
|
btrfs_put_root(node->root); |
|
node->root = btrfs_grab_root(root); |
|
ASSERT(node->root); |
|
list_add_tail(&node->list, &rc->backref_cache.changed); |
|
} else { |
|
path->lowest_level = node->level; |
|
ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
|
btrfs_release_path(path); |
|
if (ret > 0) |
|
ret = 0; |
|
} |
|
if (!ret) |
|
update_processed_blocks(rc, node); |
|
} else { |
|
ret = do_relocation(trans, rc, node, key, path, 1); |
|
} |
|
out: |
|
if (ret || node->level == 0 || node->cowonly) |
|
btrfs_backref_cleanup_node(&rc->backref_cache, node); |
|
return ret; |
|
} |
|
|
|
/* |
|
* relocate a list of blocks |
|
*/ |
|
static noinline_for_stack |
|
int relocate_tree_blocks(struct btrfs_trans_handle *trans, |
|
struct reloc_control *rc, struct rb_root *blocks) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
struct btrfs_backref_node *node; |
|
struct btrfs_path *path; |
|
struct tree_block *block; |
|
struct tree_block *next; |
|
int ret; |
|
int err = 0; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) { |
|
err = -ENOMEM; |
|
goto out_free_blocks; |
|
} |
|
|
|
/* Kick in readahead for tree blocks with missing keys */ |
|
rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) { |
|
if (!block->key_ready) |
|
btrfs_readahead_tree_block(fs_info, block->bytenr, |
|
block->owner, 0, |
|
block->level); |
|
} |
|
|
|
/* Get first keys */ |
|
rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) { |
|
if (!block->key_ready) { |
|
err = get_tree_block_key(fs_info, block); |
|
if (err) |
|
goto out_free_path; |
|
} |
|
} |
|
|
|
/* Do tree relocation */ |
|
rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) { |
|
node = build_backref_tree(rc, &block->key, |
|
block->level, block->bytenr); |
|
if (IS_ERR(node)) { |
|
err = PTR_ERR(node); |
|
goto out; |
|
} |
|
|
|
ret = relocate_tree_block(trans, rc, node, &block->key, |
|
path); |
|
if (ret < 0) { |
|
err = ret; |
|
break; |
|
} |
|
} |
|
out: |
|
err = finish_pending_nodes(trans, rc, path, err); |
|
|
|
out_free_path: |
|
btrfs_free_path(path); |
|
out_free_blocks: |
|
free_block_list(blocks); |
|
return err; |
|
} |
|
|
|
static noinline_for_stack int prealloc_file_extent_cluster( |
|
struct btrfs_inode *inode, |
|
struct file_extent_cluster *cluster) |
|
{ |
|
u64 alloc_hint = 0; |
|
u64 start; |
|
u64 end; |
|
u64 offset = inode->index_cnt; |
|
u64 num_bytes; |
|
int nr; |
|
int ret = 0; |
|
u64 prealloc_start = cluster->start - offset; |
|
u64 prealloc_end = cluster->end - offset; |
|
u64 cur_offset = prealloc_start; |
|
|
|
BUG_ON(cluster->start != cluster->boundary[0]); |
|
ret = btrfs_alloc_data_chunk_ondemand(inode, |
|
prealloc_end + 1 - prealloc_start); |
|
if (ret) |
|
return ret; |
|
|
|
/* |
|
* On a zoned filesystem, we cannot preallocate the file region. |
|
* Instead, we dirty and fiemap_write the region. |
|
*/ |
|
if (btrfs_is_zoned(inode->root->fs_info)) { |
|
struct btrfs_root *root = inode->root; |
|
struct btrfs_trans_handle *trans; |
|
|
|
end = cluster->end - offset + 1; |
|
trans = btrfs_start_transaction(root, 1); |
|
if (IS_ERR(trans)) |
|
return PTR_ERR(trans); |
|
|
|
inode->vfs_inode.i_ctime = current_time(&inode->vfs_inode); |
|
i_size_write(&inode->vfs_inode, end); |
|
ret = btrfs_update_inode(trans, root, inode); |
|
if (ret) { |
|
btrfs_abort_transaction(trans, ret); |
|
btrfs_end_transaction(trans); |
|
return ret; |
|
} |
|
|
|
return btrfs_end_transaction(trans); |
|
} |
|
|
|
btrfs_inode_lock(&inode->vfs_inode, 0); |
|
for (nr = 0; nr < cluster->nr; nr++) { |
|
start = cluster->boundary[nr] - offset; |
|
if (nr + 1 < cluster->nr) |
|
end = cluster->boundary[nr + 1] - 1 - offset; |
|
else |
|
end = cluster->end - offset; |
|
|
|
lock_extent(&inode->io_tree, start, end); |
|
num_bytes = end + 1 - start; |
|
ret = btrfs_prealloc_file_range(&inode->vfs_inode, 0, start, |
|
num_bytes, num_bytes, |
|
end + 1, &alloc_hint); |
|
cur_offset = end + 1; |
|
unlock_extent(&inode->io_tree, start, end); |
|
if (ret) |
|
break; |
|
} |
|
btrfs_inode_unlock(&inode->vfs_inode, 0); |
|
|
|
if (cur_offset < prealloc_end) |
|
btrfs_free_reserved_data_space_noquota(inode->root->fs_info, |
|
prealloc_end + 1 - cur_offset); |
|
return ret; |
|
} |
|
|
|
static noinline_for_stack |
|
int setup_extent_mapping(struct inode *inode, u64 start, u64 end, |
|
u64 block_start) |
|
{ |
|
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
|
struct extent_map *em; |
|
int ret = 0; |
|
|
|
em = alloc_extent_map(); |
|
if (!em) |
|
return -ENOMEM; |
|
|
|
em->start = start; |
|
em->len = end + 1 - start; |
|
em->block_len = em->len; |
|
em->block_start = block_start; |
|
set_bit(EXTENT_FLAG_PINNED, &em->flags); |
|
|
|
lock_extent(&BTRFS_I(inode)->io_tree, start, end); |
|
while (1) { |
|
write_lock(&em_tree->lock); |
|
ret = add_extent_mapping(em_tree, em, 0); |
|
write_unlock(&em_tree->lock); |
|
if (ret != -EEXIST) { |
|
free_extent_map(em); |
|
break; |
|
} |
|
btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0); |
|
} |
|
unlock_extent(&BTRFS_I(inode)->io_tree, start, end); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Allow error injection to test balance cancellation |
|
*/ |
|
noinline int btrfs_should_cancel_balance(struct btrfs_fs_info *fs_info) |
|
{ |
|
return atomic_read(&fs_info->balance_cancel_req) || |
|
fatal_signal_pending(current); |
|
} |
|
ALLOW_ERROR_INJECTION(btrfs_should_cancel_balance, TRUE); |
|
|
|
static int relocate_file_extent_cluster(struct inode *inode, |
|
struct file_extent_cluster *cluster) |
|
{ |
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
|
u64 page_start; |
|
u64 page_end; |
|
u64 offset = BTRFS_I(inode)->index_cnt; |
|
unsigned long index; |
|
unsigned long last_index; |
|
struct page *page; |
|
struct file_ra_state *ra; |
|
gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); |
|
int nr = 0; |
|
int ret = 0; |
|
|
|
if (!cluster->nr) |
|
return 0; |
|
|
|
ra = kzalloc(sizeof(*ra), GFP_NOFS); |
|
if (!ra) |
|
return -ENOMEM; |
|
|
|
ret = prealloc_file_extent_cluster(BTRFS_I(inode), cluster); |
|
if (ret) |
|
goto out; |
|
|
|
file_ra_state_init(ra, inode->i_mapping); |
|
|
|
ret = setup_extent_mapping(inode, cluster->start - offset, |
|
cluster->end - offset, cluster->start); |
|
if (ret) |
|
goto out; |
|
|
|
index = (cluster->start - offset) >> PAGE_SHIFT; |
|
last_index = (cluster->end - offset) >> PAGE_SHIFT; |
|
while (index <= last_index) { |
|
ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), |
|
PAGE_SIZE); |
|
if (ret) |
|
goto out; |
|
|
|
page = find_lock_page(inode->i_mapping, index); |
|
if (!page) { |
|
page_cache_sync_readahead(inode->i_mapping, |
|
ra, NULL, index, |
|
last_index + 1 - index); |
|
page = find_or_create_page(inode->i_mapping, index, |
|
mask); |
|
if (!page) { |
|
btrfs_delalloc_release_metadata(BTRFS_I(inode), |
|
PAGE_SIZE, true); |
|
btrfs_delalloc_release_extents(BTRFS_I(inode), |
|
PAGE_SIZE); |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
} |
|
ret = set_page_extent_mapped(page); |
|
if (ret < 0) { |
|
btrfs_delalloc_release_metadata(BTRFS_I(inode), |
|
PAGE_SIZE, true); |
|
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); |
|
unlock_page(page); |
|
put_page(page); |
|
goto out; |
|
} |
|
|
|
if (PageReadahead(page)) { |
|
page_cache_async_readahead(inode->i_mapping, |
|
ra, NULL, page, index, |
|
last_index + 1 - index); |
|
} |
|
|
|
if (!PageUptodate(page)) { |
|
btrfs_readpage(NULL, page); |
|
lock_page(page); |
|
if (!PageUptodate(page)) { |
|
unlock_page(page); |
|
put_page(page); |
|
btrfs_delalloc_release_metadata(BTRFS_I(inode), |
|
PAGE_SIZE, true); |
|
btrfs_delalloc_release_extents(BTRFS_I(inode), |
|
PAGE_SIZE); |
|
ret = -EIO; |
|
goto out; |
|
} |
|
} |
|
|
|
page_start = page_offset(page); |
|
page_end = page_start + PAGE_SIZE - 1; |
|
|
|
lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end); |
|
|
|
if (nr < cluster->nr && |
|
page_start + offset == cluster->boundary[nr]) { |
|
set_extent_bits(&BTRFS_I(inode)->io_tree, |
|
page_start, page_end, |
|
EXTENT_BOUNDARY); |
|
nr++; |
|
} |
|
|
|
ret = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, |
|
page_end, 0, NULL); |
|
if (ret) { |
|
unlock_page(page); |
|
put_page(page); |
|
btrfs_delalloc_release_metadata(BTRFS_I(inode), |
|
PAGE_SIZE, true); |
|
btrfs_delalloc_release_extents(BTRFS_I(inode), |
|
PAGE_SIZE); |
|
|
|
clear_extent_bits(&BTRFS_I(inode)->io_tree, |
|
page_start, page_end, |
|
EXTENT_LOCKED | EXTENT_BOUNDARY); |
|
goto out; |
|
|
|
} |
|
set_page_dirty(page); |
|
|
|
unlock_extent(&BTRFS_I(inode)->io_tree, |
|
page_start, page_end); |
|
unlock_page(page); |
|
put_page(page); |
|
|
|
index++; |
|
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); |
|
balance_dirty_pages_ratelimited(inode->i_mapping); |
|
btrfs_throttle(fs_info); |
|
if (btrfs_should_cancel_balance(fs_info)) { |
|
ret = -ECANCELED; |
|
goto out; |
|
} |
|
} |
|
WARN_ON(nr != cluster->nr); |
|
if (btrfs_is_zoned(fs_info) && !ret) |
|
ret = btrfs_wait_ordered_range(inode, 0, (u64)-1); |
|
out: |
|
kfree(ra); |
|
return ret; |
|
} |
|
|
|
static noinline_for_stack |
|
int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key, |
|
struct file_extent_cluster *cluster) |
|
{ |
|
int ret; |
|
|
|
if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) { |
|
ret = relocate_file_extent_cluster(inode, cluster); |
|
if (ret) |
|
return ret; |
|
cluster->nr = 0; |
|
} |
|
|
|
if (!cluster->nr) |
|
cluster->start = extent_key->objectid; |
|
else |
|
BUG_ON(cluster->nr >= MAX_EXTENTS); |
|
cluster->end = extent_key->objectid + extent_key->offset - 1; |
|
cluster->boundary[cluster->nr] = extent_key->objectid; |
|
cluster->nr++; |
|
|
|
if (cluster->nr >= MAX_EXTENTS) { |
|
ret = relocate_file_extent_cluster(inode, cluster); |
|
if (ret) |
|
return ret; |
|
cluster->nr = 0; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* helper to add a tree block to the list. |
|
* the major work is getting the generation and level of the block |
|
*/ |
|
static int add_tree_block(struct reloc_control *rc, |
|
struct btrfs_key *extent_key, |
|
struct btrfs_path *path, |
|
struct rb_root *blocks) |
|
{ |
|
struct extent_buffer *eb; |
|
struct btrfs_extent_item *ei; |
|
struct btrfs_tree_block_info *bi; |
|
struct tree_block *block; |
|
struct rb_node *rb_node; |
|
u32 item_size; |
|
int level = -1; |
|
u64 generation; |
|
u64 owner = 0; |
|
|
|
eb = path->nodes[0]; |
|
item_size = btrfs_item_size_nr(eb, path->slots[0]); |
|
|
|
if (extent_key->type == BTRFS_METADATA_ITEM_KEY || |
|
item_size >= sizeof(*ei) + sizeof(*bi)) { |
|
unsigned long ptr = 0, end; |
|
|
|
ei = btrfs_item_ptr(eb, path->slots[0], |
|
struct btrfs_extent_item); |
|
end = (unsigned long)ei + item_size; |
|
if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) { |
|
bi = (struct btrfs_tree_block_info *)(ei + 1); |
|
level = btrfs_tree_block_level(eb, bi); |
|
ptr = (unsigned long)(bi + 1); |
|
} else { |
|
level = (int)extent_key->offset; |
|
ptr = (unsigned long)(ei + 1); |
|
} |
|
generation = btrfs_extent_generation(eb, ei); |
|
|
|
/* |
|
* We're reading random blocks without knowing their owner ahead |
|
* of time. This is ok most of the time, as all reloc roots and |
|
* fs roots have the same lock type. However normal trees do |
|
* not, and the only way to know ahead of time is to read the |
|
* inline ref offset. We know it's an fs root if |
|
* |
|
* 1. There's more than one ref. |
|
* 2. There's a SHARED_DATA_REF_KEY set. |
|
* 3. FULL_BACKREF is set on the flags. |
|
* |
|
* Otherwise it's safe to assume that the ref offset == the |
|
* owner of this block, so we can use that when calling |
|
* read_tree_block. |
|
*/ |
|
if (btrfs_extent_refs(eb, ei) == 1 && |
|
!(btrfs_extent_flags(eb, ei) & |
|
BTRFS_BLOCK_FLAG_FULL_BACKREF) && |
|
ptr < end) { |
|
struct btrfs_extent_inline_ref *iref; |
|
int type; |
|
|
|
iref = (struct btrfs_extent_inline_ref *)ptr; |
|
type = btrfs_get_extent_inline_ref_type(eb, iref, |
|
BTRFS_REF_TYPE_BLOCK); |
|
if (type == BTRFS_REF_TYPE_INVALID) |
|
return -EINVAL; |
|
if (type == BTRFS_TREE_BLOCK_REF_KEY) |
|
owner = btrfs_extent_inline_ref_offset(eb, iref); |
|
} |
|
} else if (unlikely(item_size == sizeof(struct btrfs_extent_item_v0))) { |
|
btrfs_print_v0_err(eb->fs_info); |
|
btrfs_handle_fs_error(eb->fs_info, -EINVAL, NULL); |
|
return -EINVAL; |
|
} else { |
|
BUG(); |
|
} |
|
|
|
btrfs_release_path(path); |
|
|
|
BUG_ON(level == -1); |
|
|
|
block = kmalloc(sizeof(*block), GFP_NOFS); |
|
if (!block) |
|
return -ENOMEM; |
|
|
|
block->bytenr = extent_key->objectid; |
|
block->key.objectid = rc->extent_root->fs_info->nodesize; |
|
block->key.offset = generation; |
|
block->level = level; |
|
block->key_ready = 0; |
|
block->owner = owner; |
|
|
|
rb_node = rb_simple_insert(blocks, block->bytenr, &block->rb_node); |
|
if (rb_node) |
|
btrfs_backref_panic(rc->extent_root->fs_info, block->bytenr, |
|
-EEXIST); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY |
|
*/ |
|
static int __add_tree_block(struct reloc_control *rc, |
|
u64 bytenr, u32 blocksize, |
|
struct rb_root *blocks) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
struct btrfs_path *path; |
|
struct btrfs_key key; |
|
int ret; |
|
bool skinny = btrfs_fs_incompat(fs_info, SKINNY_METADATA); |
|
|
|
if (tree_block_processed(bytenr, rc)) |
|
return 0; |
|
|
|
if (rb_simple_search(blocks, bytenr)) |
|
return 0; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return -ENOMEM; |
|
again: |
|
key.objectid = bytenr; |
|
if (skinny) { |
|
key.type = BTRFS_METADATA_ITEM_KEY; |
|
key.offset = (u64)-1; |
|
} else { |
|
key.type = BTRFS_EXTENT_ITEM_KEY; |
|
key.offset = blocksize; |
|
} |
|
|
|
path->search_commit_root = 1; |
|
path->skip_locking = 1; |
|
ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (ret > 0 && skinny) { |
|
if (path->slots[0]) { |
|
path->slots[0]--; |
|
btrfs_item_key_to_cpu(path->nodes[0], &key, |
|
path->slots[0]); |
|
if (key.objectid == bytenr && |
|
(key.type == BTRFS_METADATA_ITEM_KEY || |
|
(key.type == BTRFS_EXTENT_ITEM_KEY && |
|
key.offset == blocksize))) |
|
ret = 0; |
|
} |
|
|
|
if (ret) { |
|
skinny = false; |
|
btrfs_release_path(path); |
|
goto again; |
|
} |
|
} |
|
if (ret) { |
|
ASSERT(ret == 1); |
|
btrfs_print_leaf(path->nodes[0]); |
|
btrfs_err(fs_info, |
|
"tree block extent item (%llu) is not found in extent tree", |
|
bytenr); |
|
WARN_ON(1); |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
ret = add_tree_block(rc, &key, path, blocks); |
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
static int delete_block_group_cache(struct btrfs_fs_info *fs_info, |
|
struct btrfs_block_group *block_group, |
|
struct inode *inode, |
|
u64 ino) |
|
{ |
|
struct btrfs_root *root = fs_info->tree_root; |
|
struct btrfs_trans_handle *trans; |
|
int ret = 0; |
|
|
|
if (inode) |
|
goto truncate; |
|
|
|
inode = btrfs_iget(fs_info->sb, ino, root); |
|
if (IS_ERR(inode)) |
|
return -ENOENT; |
|
|
|
truncate: |
|
ret = btrfs_check_trunc_cache_free_space(fs_info, |
|
&fs_info->global_block_rsv); |
|
if (ret) |
|
goto out; |
|
|
|
trans = btrfs_join_transaction(root); |
|
if (IS_ERR(trans)) { |
|
ret = PTR_ERR(trans); |
|
goto out; |
|
} |
|
|
|
ret = btrfs_truncate_free_space_cache(trans, block_group, inode); |
|
|
|
btrfs_end_transaction(trans); |
|
btrfs_btree_balance_dirty(fs_info); |
|
out: |
|
iput(inode); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Locate the free space cache EXTENT_DATA in root tree leaf and delete the |
|
* cache inode, to avoid free space cache data extent blocking data relocation. |
|
*/ |
|
static int delete_v1_space_cache(struct extent_buffer *leaf, |
|
struct btrfs_block_group *block_group, |
|
u64 data_bytenr) |
|
{ |
|
u64 space_cache_ino; |
|
struct btrfs_file_extent_item *ei; |
|
struct btrfs_key key; |
|
bool found = false; |
|
int i; |
|
int ret; |
|
|
|
if (btrfs_header_owner(leaf) != BTRFS_ROOT_TREE_OBJECTID) |
|
return 0; |
|
|
|
for (i = 0; i < btrfs_header_nritems(leaf); i++) { |
|
u8 type; |
|
|
|
btrfs_item_key_to_cpu(leaf, &key, i); |
|
if (key.type != BTRFS_EXTENT_DATA_KEY) |
|
continue; |
|
ei = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); |
|
type = btrfs_file_extent_type(leaf, ei); |
|
|
|
if ((type == BTRFS_FILE_EXTENT_REG || |
|
type == BTRFS_FILE_EXTENT_PREALLOC) && |
|
btrfs_file_extent_disk_bytenr(leaf, ei) == data_bytenr) { |
|
found = true; |
|
space_cache_ino = key.objectid; |
|
break; |
|
} |
|
} |
|
if (!found) |
|
return -ENOENT; |
|
ret = delete_block_group_cache(leaf->fs_info, block_group, NULL, |
|
space_cache_ino); |
|
return ret; |
|
} |
|
|
|
/* |
|
* helper to find all tree blocks that reference a given data extent |
|
*/ |
|
static noinline_for_stack |
|
int add_data_references(struct reloc_control *rc, |
|
struct btrfs_key *extent_key, |
|
struct btrfs_path *path, |
|
struct rb_root *blocks) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
struct ulist *leaves = NULL; |
|
struct ulist_iterator leaf_uiter; |
|
struct ulist_node *ref_node = NULL; |
|
const u32 blocksize = fs_info->nodesize; |
|
int ret = 0; |
|
|
|
btrfs_release_path(path); |
|
ret = btrfs_find_all_leafs(NULL, fs_info, extent_key->objectid, |
|
0, &leaves, NULL, true); |
|
if (ret < 0) |
|
return ret; |
|
|
|
ULIST_ITER_INIT(&leaf_uiter); |
|
while ((ref_node = ulist_next(leaves, &leaf_uiter))) { |
|
struct extent_buffer *eb; |
|
|
|
eb = read_tree_block(fs_info, ref_node->val, 0, 0, 0, NULL); |
|
if (IS_ERR(eb)) { |
|
ret = PTR_ERR(eb); |
|
break; |
|
} |
|
ret = delete_v1_space_cache(eb, rc->block_group, |
|
extent_key->objectid); |
|
free_extent_buffer(eb); |
|
if (ret < 0) |
|
break; |
|
ret = __add_tree_block(rc, ref_node->val, blocksize, blocks); |
|
if (ret < 0) |
|
break; |
|
} |
|
if (ret < 0) |
|
free_block_list(blocks); |
|
ulist_free(leaves); |
|
return ret; |
|
} |
|
|
|
/* |
|
* helper to find next unprocessed extent |
|
*/ |
|
static noinline_for_stack |
|
int find_next_extent(struct reloc_control *rc, struct btrfs_path *path, |
|
struct btrfs_key *extent_key) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
struct btrfs_key key; |
|
struct extent_buffer *leaf; |
|
u64 start, end, last; |
|
int ret; |
|
|
|
last = rc->block_group->start + rc->block_group->length; |
|
while (1) { |
|
cond_resched(); |
|
if (rc->search_start >= last) { |
|
ret = 1; |
|
break; |
|
} |
|
|
|
key.objectid = rc->search_start; |
|
key.type = BTRFS_EXTENT_ITEM_KEY; |
|
key.offset = 0; |
|
|
|
path->search_commit_root = 1; |
|
path->skip_locking = 1; |
|
ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, |
|
0, 0); |
|
if (ret < 0) |
|
break; |
|
next: |
|
leaf = path->nodes[0]; |
|
if (path->slots[0] >= btrfs_header_nritems(leaf)) { |
|
ret = btrfs_next_leaf(rc->extent_root, path); |
|
if (ret != 0) |
|
break; |
|
leaf = path->nodes[0]; |
|
} |
|
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
|
if (key.objectid >= last) { |
|
ret = 1; |
|
break; |
|
} |
|
|
|
if (key.type != BTRFS_EXTENT_ITEM_KEY && |
|
key.type != BTRFS_METADATA_ITEM_KEY) { |
|
path->slots[0]++; |
|
goto next; |
|
} |
|
|
|
if (key.type == BTRFS_EXTENT_ITEM_KEY && |
|
key.objectid + key.offset <= rc->search_start) { |
|
path->slots[0]++; |
|
goto next; |
|
} |
|
|
|
if (key.type == BTRFS_METADATA_ITEM_KEY && |
|
key.objectid + fs_info->nodesize <= |
|
rc->search_start) { |
|
path->slots[0]++; |
|
goto next; |
|
} |
|
|
|
ret = find_first_extent_bit(&rc->processed_blocks, |
|
key.objectid, &start, &end, |
|
EXTENT_DIRTY, NULL); |
|
|
|
if (ret == 0 && start <= key.objectid) { |
|
btrfs_release_path(path); |
|
rc->search_start = end + 1; |
|
} else { |
|
if (key.type == BTRFS_EXTENT_ITEM_KEY) |
|
rc->search_start = key.objectid + key.offset; |
|
else |
|
rc->search_start = key.objectid + |
|
fs_info->nodesize; |
|
memcpy(extent_key, &key, sizeof(key)); |
|
return 0; |
|
} |
|
} |
|
btrfs_release_path(path); |
|
return ret; |
|
} |
|
|
|
static void set_reloc_control(struct reloc_control *rc) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
|
|
mutex_lock(&fs_info->reloc_mutex); |
|
fs_info->reloc_ctl = rc; |
|
mutex_unlock(&fs_info->reloc_mutex); |
|
} |
|
|
|
static void unset_reloc_control(struct reloc_control *rc) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
|
|
mutex_lock(&fs_info->reloc_mutex); |
|
fs_info->reloc_ctl = NULL; |
|
mutex_unlock(&fs_info->reloc_mutex); |
|
} |
|
|
|
static int check_extent_flags(u64 flags) |
|
{ |
|
if ((flags & BTRFS_EXTENT_FLAG_DATA) && |
|
(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) |
|
return 1; |
|
if (!(flags & BTRFS_EXTENT_FLAG_DATA) && |
|
!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) |
|
return 1; |
|
if ((flags & BTRFS_EXTENT_FLAG_DATA) && |
|
(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
static noinline_for_stack |
|
int prepare_to_relocate(struct reloc_control *rc) |
|
{ |
|
struct btrfs_trans_handle *trans; |
|
int ret; |
|
|
|
rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root->fs_info, |
|
BTRFS_BLOCK_RSV_TEMP); |
|
if (!rc->block_rsv) |
|
return -ENOMEM; |
|
|
|
memset(&rc->cluster, 0, sizeof(rc->cluster)); |
|
rc->search_start = rc->block_group->start; |
|
rc->extents_found = 0; |
|
rc->nodes_relocated = 0; |
|
rc->merging_rsv_size = 0; |
|
rc->reserved_bytes = 0; |
|
rc->block_rsv->size = rc->extent_root->fs_info->nodesize * |
|
RELOCATION_RESERVED_NODES; |
|
ret = btrfs_block_rsv_refill(rc->extent_root, |
|
rc->block_rsv, rc->block_rsv->size, |
|
BTRFS_RESERVE_FLUSH_ALL); |
|
if (ret) |
|
return ret; |
|
|
|
rc->create_reloc_tree = 1; |
|
set_reloc_control(rc); |
|
|
|
trans = btrfs_join_transaction(rc->extent_root); |
|
if (IS_ERR(trans)) { |
|
unset_reloc_control(rc); |
|
/* |
|
* extent tree is not a ref_cow tree and has no reloc_root to |
|
* cleanup. And callers are responsible to free the above |
|
* block rsv. |
|
*/ |
|
return PTR_ERR(trans); |
|
} |
|
btrfs_commit_transaction(trans); |
|
return 0; |
|
} |
|
|
|
static noinline_for_stack int relocate_block_group(struct reloc_control *rc) |
|
{ |
|
struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; |
|
struct rb_root blocks = RB_ROOT; |
|
struct btrfs_key key; |
|
struct btrfs_trans_handle *trans = NULL; |
|
struct btrfs_path *path; |
|
struct btrfs_extent_item *ei; |
|
u64 flags; |
|
u32 item_size; |
|
int ret; |
|
int err = 0; |
|
int progress = 0; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return -ENOMEM; |
|
path->reada = READA_FORWARD; |
|
|
|
ret = prepare_to_relocate(rc); |
|
if (ret) { |
|
err = ret; |
|
goto out_free; |
|
} |
|
|
|
while (1) { |
|
rc->reserved_bytes = 0; |
|
ret = btrfs_block_rsv_refill(rc->extent_root, |
|
rc->block_rsv, rc->block_rsv->size, |
|
BTRFS_RESERVE_FLUSH_ALL); |
|
if (ret) { |
|
err = ret; |
|
break; |
|
} |
|
progress++; |
|
trans = btrfs_start_transaction(rc->extent_root, 0); |
|
if (IS_ERR(trans)) { |
|
err = PTR_ERR(trans); |
|
trans = NULL; |
|
break; |
|
} |
|
restart: |
|
if (update_backref_cache(trans, &rc->backref_cache)) { |
|
btrfs_end_transaction(trans); |
|
trans = NULL; |
|
continue; |
|
} |
|
|
|
ret = find_next_extent(rc, path, &key); |
|
if (ret < 0) |
|
err = ret; |
|
if (ret != 0) |
|
break; |
|
|
|
rc->extents_found++; |
|
|
|
ei = btrfs_item_ptr(path->nodes[0], path->slots[0], |
|
struct btrfs_extent_item); |
|
item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); |
|
if (item_size >= sizeof(*ei)) { |
|
flags = btrfs_extent_flags(path->nodes[0], ei); |
|
ret = check_extent_flags(flags); |
|
BUG_ON(ret); |
|
} else if (unlikely(item_size == sizeof(struct btrfs_extent_item_v0))) { |
|
err = -EINVAL; |
|
btrfs_print_v0_err(trans->fs_info); |
|
btrfs_abort_transaction(trans, err); |
|
break; |
|
} else { |
|
BUG(); |
|
} |
|
|
|
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { |
|
ret = add_tree_block(rc, &key, path, &blocks); |
|
} else if (rc->stage == UPDATE_DATA_PTRS && |
|
(flags & BTRFS_EXTENT_FLAG_DATA)) { |
|
ret = add_data_references(rc, &key, path, &blocks); |
|
} else { |
|
btrfs_release_path(path); |
|
ret = 0; |
|
} |
|
if (ret < 0) { |
|
err = ret; |
|
break; |
|
} |
|
|
|
if (!RB_EMPTY_ROOT(&blocks)) { |
|
ret = relocate_tree_blocks(trans, rc, &blocks); |
|
if (ret < 0) { |
|
if (ret != -EAGAIN) { |
|
err = ret; |
|
break; |
|
} |
|
rc->extents_found--; |
|
rc->search_start = key.objectid; |
|
} |
|
} |
|
|
|
btrfs_end_transaction_throttle(trans); |
|
btrfs_btree_balance_dirty(fs_info); |
|
trans = NULL; |
|
|
|
if (rc->stage == MOVE_DATA_EXTENTS && |
|
(flags & BTRFS_EXTENT_FLAG_DATA)) { |
|
rc->found_file_extent = 1; |
|
ret = relocate_data_extent(rc->data_inode, |
|
&key, &rc->cluster); |
|
if (ret < 0) { |
|
err = ret; |
|
break; |
|
} |
|
} |
|
if (btrfs_should_cancel_balance(fs_info)) { |
|
err = -ECANCELED; |
|
break; |
|
} |
|
} |
|
if (trans && progress && err == -ENOSPC) { |
|
ret = btrfs_force_chunk_alloc(trans, rc->block_group->flags); |
|
if (ret == 1) { |
|
err = 0; |
|
progress = 0; |
|
goto restart; |
|
} |
|
} |
|
|
|
btrfs_release_path(path); |
|
clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY); |
|
|
|
if (trans) { |
|
btrfs_end_transaction_throttle(trans); |
|
btrfs_btree_balance_dirty(fs_info); |
|
} |
|
|
|
if (!err) { |
|
ret = relocate_file_extent_cluster(rc->data_inode, |
|
&rc->cluster); |
|
if (ret < 0) |
|
err = ret; |
|
} |
|
|
|
rc->create_reloc_tree = 0; |
|
set_reloc_control(rc); |
|
|
|
btrfs_backref_release_cache(&rc->backref_cache); |
|
btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1, NULL); |
|
|
|
/* |
|
* Even in the case when the relocation is cancelled, we should all go |
|
* through prepare_to_merge() and merge_reloc_roots(). |
|
* |
|
* For error (including cancelled balance), prepare_to_merge() will |
|
* mark all reloc trees orphan, then queue them for cleanup in |
|
* merge_reloc_roots() |
|
*/ |
|
err = prepare_to_merge(rc, err); |
|
|
|
merge_reloc_roots(rc); |
|
|
|
rc->merge_reloc_tree = 0; |
|
unset_reloc_control(rc); |
|
btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1, NULL); |
|
|
|
/* get rid of pinned extents */ |
|
trans = btrfs_join_transaction(rc->extent_root); |
|
if (IS_ERR(trans)) { |
|
err = PTR_ERR(trans); |
|
goto out_free; |
|
} |
|
btrfs_commit_transaction(trans); |
|
out_free: |
|
ret = clean_dirty_subvols(rc); |
|
if (ret < 0 && !err) |
|
err = ret; |
|
btrfs_free_block_rsv(fs_info, rc->block_rsv); |
|
btrfs_free_path(path); |
|
return err; |
|
} |
|
|
|
static int __insert_orphan_inode(struct btrfs_trans_handle *trans, |
|
struct btrfs_root *root, u64 objectid) |
|
{ |
|
struct btrfs_path *path; |
|
struct btrfs_inode_item *item; |
|
struct extent_buffer *leaf; |
|
u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC; |
|
int ret; |
|
|
|
if (btrfs_is_zoned(trans->fs_info)) |
|
flags &= ~BTRFS_INODE_PREALLOC; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return -ENOMEM; |
|
|
|
ret = btrfs_insert_empty_inode(trans, root, path, objectid); |
|
if (ret) |
|
goto out; |
|
|
|
leaf = path->nodes[0]; |
|
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); |
|
memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item)); |
|
btrfs_set_inode_generation(leaf, item, 1); |
|
btrfs_set_inode_size(leaf, item, 0); |
|
btrfs_set_inode_mode(leaf, item, S_IFREG | 0600); |
|
btrfs_set_inode_flags(leaf, item, flags); |
|
btrfs_mark_buffer_dirty(leaf); |
|
out: |
|
btrfs_free_path(path); |
|
return ret; |
|
} |
|
|
|
/* |
|
* helper to create inode for data relocation. |
|
* the inode is in data relocation tree and its link count is 0 |
|
*/ |
|
static noinline_for_stack |
|
struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info, |
|
struct btrfs_block_group *group) |
|
{ |
|
struct inode *inode = NULL; |
|
struct btrfs_trans_handle *trans; |
|
struct btrfs_root *root; |
|
u64 objectid; |
|
int err = 0; |
|
|
|
root = btrfs_grab_root(fs_info->data_reloc_root); |
|
trans = btrfs_start_transaction(root, 6); |
|
if (IS_ERR(trans)) { |
|
btrfs_put_root(root); |
|
return ERR_CAST(trans); |
|
} |
|
|
|
err = btrfs_get_free_objectid(root, &objectid); |
|
if (err) |
|
goto out; |
|
|
|
err = __insert_orphan_inode(trans, root, objectid); |
|
BUG_ON(err); |
|
|
|
inode = btrfs_iget(fs_info->sb, objectid, root); |
|
BUG_ON(IS_ERR(inode)); |
|
BTRFS_I(inode)->index_cnt = group->start; |
|
|
|
err = btrfs_orphan_add(trans, BTRFS_I(inode)); |
|
out: |
|
btrfs_put_root(root); |
|
btrfs_end_transaction(trans); |
|
btrfs_btree_balance_dirty(fs_info); |
|
if (err) { |
|
if (inode) |
|
iput(inode); |
|
inode = ERR_PTR(err); |
|
} |
|
return inode; |
|
} |
|
|
|
static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info) |
|
{ |
|
struct reloc_control *rc; |
|
|
|
rc = kzalloc(sizeof(*rc), GFP_NOFS); |
|
if (!rc) |
|
return NULL; |
|
|
|
INIT_LIST_HEAD(&rc->reloc_roots); |
|
INIT_LIST_HEAD(&rc->dirty_subvol_roots); |
|
btrfs_backref_init_cache(fs_info, &rc->backref_cache, 1); |
|
mapping_tree_init(&rc->reloc_root_tree); |
|
extent_io_tree_init(fs_info, &rc->processed_blocks, |
|
IO_TREE_RELOC_BLOCKS, NULL); |
|
return rc; |
|
} |
|
|
|
static void free_reloc_control(struct reloc_control *rc) |
|
{ |
|
struct mapping_node *node, *tmp; |
|
|
|
free_reloc_roots(&rc->reloc_roots); |
|
rbtree_postorder_for_each_entry_safe(node, tmp, |
|
&rc->reloc_root_tree.rb_root, rb_node) |
|
kfree(node); |
|
|
|
kfree(rc); |
|
} |
|
|
|
/* |
|
* Print the block group being relocated |
|
*/ |
|
static void describe_relocation(struct btrfs_fs_info *fs_info, |
|
struct btrfs_block_group *block_group) |
|
{ |
|
char buf[128] = {'\0'}; |
|
|
|
btrfs_describe_block_groups(block_group->flags, buf, sizeof(buf)); |
|
|
|
btrfs_info(fs_info, |
|
"relocating block group %llu flags %s", |
|
block_group->start, buf); |
|
} |
|
|
|
static const char *stage_to_string(int stage) |
|
{ |
|
if (stage == MOVE_DATA_EXTENTS) |
|
return "move data extents"; |
|
if (stage == UPDATE_DATA_PTRS) |
|
return "update data pointers"; |
|
return "unknown"; |
|
} |
|
|
|
/* |
|
* function to relocate all extents in a block group. |
|
*/ |
|
int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start) |
|
{ |
|
struct btrfs_block_group *bg; |
|
struct btrfs_root *extent_root = fs_info->extent_root; |
|
struct reloc_control *rc; |
|
struct inode *inode; |
|
struct btrfs_path *path; |
|
int ret; |
|
int rw = 0; |
|
int err = 0; |
|
|
|
bg = btrfs_lookup_block_group(fs_info, group_start); |
|
if (!bg) |
|
return -ENOENT; |
|
|
|
if (btrfs_pinned_by_swapfile(fs_info, bg)) { |
|
btrfs_put_block_group(bg); |
|
return -ETXTBSY; |
|
} |
|
|
|
rc = alloc_reloc_control(fs_info); |
|
if (!rc) { |
|
btrfs_put_block_group(bg); |
|
return -ENOMEM; |
|
} |
|
|
|
rc->extent_root = extent_root; |
|
rc->block_group = bg; |
|
|
|
ret = btrfs_inc_block_group_ro(rc->block_group, true); |
|
if (ret) { |
|
err = ret; |
|
goto out; |
|
} |
|
rw = 1; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) { |
|
err = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
inode = lookup_free_space_inode(rc->block_group, path); |
|
btrfs_free_path(path); |
|
|
|
if (!IS_ERR(inode)) |
|
ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0); |
|
else |
|
ret = PTR_ERR(inode); |
|
|
|
if (ret && ret != -ENOENT) { |
|
err = ret; |
|
goto out; |
|
} |
|
|
|
rc->data_inode = create_reloc_inode(fs_info, rc->block_group); |
|
if (IS_ERR(rc->data_inode)) { |
|
err = PTR_ERR(rc->data_inode); |
|
rc->data_inode = NULL; |
|
goto out; |
|
} |
|
|
|
describe_relocation(fs_info, rc->block_group); |
|
|
|
btrfs_wait_block_group_reservations(rc->block_group); |
|
btrfs_wait_nocow_writers(rc->block_group); |
|
btrfs_wait_ordered_roots(fs_info, U64_MAX, |
|
rc->block_group->start, |
|
rc->block_group->length); |
|
|
|
while (1) { |
|
int finishes_stage; |
|
|
|
mutex_lock(&fs_info->cleaner_mutex); |
|
ret = relocate_block_group(rc); |
|
mutex_unlock(&fs_info->cleaner_mutex); |
|
if (ret < 0) |
|
err = ret; |
|
|
|
finishes_stage = rc->stage; |
|
/* |
|
* We may have gotten ENOSPC after we already dirtied some |
|
* extents. If writeout happens while we're relocating a |
|
* different block group we could end up hitting the |
|
* BUG_ON(rc->stage == UPDATE_DATA_PTRS) in |
|
* btrfs_reloc_cow_block. Make sure we write everything out |
|
* properly so we don't trip over this problem, and then break |
|
* out of the loop if we hit an error. |
|
*/ |
|
if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) { |
|
ret = btrfs_wait_ordered_range(rc->data_inode, 0, |
|
(u64)-1); |
|
if (ret) |
|
err = ret; |
|
invalidate_mapping_pages(rc->data_inode->i_mapping, |
|
0, -1); |
|
rc->stage = UPDATE_DATA_PTRS; |
|
} |
|
|
|
if (err < 0) |
|
goto out; |
|
|
|
if (rc->extents_found == 0) |
|
break; |
|
|
|
btrfs_info(fs_info, "found %llu extents, stage: %s", |
|
rc->extents_found, stage_to_string(finishes_stage)); |
|
} |
|
|
|
WARN_ON(rc->block_group->pinned > 0); |
|
WARN_ON(rc->block_group->reserved > 0); |
|
WARN_ON(rc->block_group->used > 0); |
|
out: |
|
if (err && rw) |
|
btrfs_dec_block_group_ro(rc->block_group); |
|
iput(rc->data_inode); |
|
btrfs_put_block_group(rc->block_group); |
|
free_reloc_control(rc); |
|
return err; |
|
} |
|
|
|
static noinline_for_stack int mark_garbage_root(struct btrfs_root *root) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct btrfs_trans_handle *trans; |
|
int ret, err; |
|
|
|
trans = btrfs_start_transaction(fs_info->tree_root, 0); |
|
if (IS_ERR(trans)) |
|
return PTR_ERR(trans); |
|
|
|
memset(&root->root_item.drop_progress, 0, |
|
sizeof(root->root_item.drop_progress)); |
|
btrfs_set_root_drop_level(&root->root_item, 0); |
|
btrfs_set_root_refs(&root->root_item, 0); |
|
ret = btrfs_update_root(trans, fs_info->tree_root, |
|
&root->root_key, &root->root_item); |
|
|
|
err = btrfs_end_transaction(trans); |
|
if (err) |
|
return err; |
|
return ret; |
|
} |
|
|
|
/* |
|
* recover relocation interrupted by system crash. |
|
* |
|
* this function resumes merging reloc trees with corresponding fs trees. |
|
* this is important for keeping the sharing of tree blocks |
|
*/ |
|
int btrfs_recover_relocation(struct btrfs_root *root) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
LIST_HEAD(reloc_roots); |
|
struct btrfs_key key; |
|
struct btrfs_root *fs_root; |
|
struct btrfs_root *reloc_root; |
|
struct btrfs_path *path; |
|
struct extent_buffer *leaf; |
|
struct reloc_control *rc = NULL; |
|
struct btrfs_trans_handle *trans; |
|
int ret; |
|
int err = 0; |
|
|
|
path = btrfs_alloc_path(); |
|
if (!path) |
|
return -ENOMEM; |
|
path->reada = READA_BACK; |
|
|
|
key.objectid = BTRFS_TREE_RELOC_OBJECTID; |
|
key.type = BTRFS_ROOT_ITEM_KEY; |
|
key.offset = (u64)-1; |
|
|
|
while (1) { |
|
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, |
|
path, 0, 0); |
|
if (ret < 0) { |
|
err = ret; |
|
goto out; |
|
} |
|
if (ret > 0) { |
|
if (path->slots[0] == 0) |
|
break; |
|
path->slots[0]--; |
|
} |
|
leaf = path->nodes[0]; |
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
|
btrfs_release_path(path); |
|
|
|
if (key.objectid != BTRFS_TREE_RELOC_OBJECTID || |
|
key.type != BTRFS_ROOT_ITEM_KEY) |
|
break; |
|
|
|
reloc_root = btrfs_read_tree_root(root, &key); |
|
if (IS_ERR(reloc_root)) { |
|
err = PTR_ERR(reloc_root); |
|
goto out; |
|
} |
|
|
|
set_bit(BTRFS_ROOT_SHAREABLE, &reloc_root->state); |
|
list_add(&reloc_root->root_list, &reloc_roots); |
|
|
|
if (btrfs_root_refs(&reloc_root->root_item) > 0) { |
|
fs_root = btrfs_get_fs_root(fs_info, |
|
reloc_root->root_key.offset, false); |
|
if (IS_ERR(fs_root)) { |
|
ret = PTR_ERR(fs_root); |
|
if (ret != -ENOENT) { |
|
err = ret; |
|
goto out; |
|
} |
|
ret = mark_garbage_root(reloc_root); |
|
if (ret < 0) { |
|
err = ret; |
|
goto out; |
|
} |
|
} else { |
|
btrfs_put_root(fs_root); |
|
} |
|
} |
|
|
|
if (key.offset == 0) |
|
break; |
|
|
|
key.offset--; |
|
} |
|
btrfs_release_path(path); |
|
|
|
if (list_empty(&reloc_roots)) |
|
goto out; |
|
|
|
rc = alloc_reloc_control(fs_info); |
|
if (!rc) { |
|
err = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
rc->extent_root = fs_info->extent_root; |
|
|
|
set_reloc_control(rc); |
|
|
|
trans = btrfs_join_transaction(rc->extent_root); |
|
if (IS_ERR(trans)) { |
|
err = PTR_ERR(trans); |
|
goto out_unset; |
|
} |
|
|
|
rc->merge_reloc_tree = 1; |
|
|
|
while (!list_empty(&reloc_roots)) { |
|
reloc_root = list_entry(reloc_roots.next, |
|
struct btrfs_root, root_list); |
|
list_del(&reloc_root->root_list); |
|
|
|
if (btrfs_root_refs(&reloc_root->root_item) == 0) { |
|
list_add_tail(&reloc_root->root_list, |
|
&rc->reloc_roots); |
|
continue; |
|
} |
|
|
|
fs_root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, |
|
false); |
|
if (IS_ERR(fs_root)) { |
|
err = PTR_ERR(fs_root); |
|
list_add_tail(&reloc_root->root_list, &reloc_roots); |
|
btrfs_end_transaction(trans); |
|
goto out_unset; |
|
} |
|
|
|
err = __add_reloc_root(reloc_root); |
|
BUG_ON(err < 0); /* -ENOMEM or logic error */ |
|
fs_root->reloc_root = btrfs_grab_root(reloc_root); |
|
btrfs_put_root(fs_root); |
|
} |
|
|
|
err = btrfs_commit_transaction(trans); |
|
if (err) |
|
goto out_unset; |
|
|
|
merge_reloc_roots(rc); |
|
|
|
unset_reloc_control(rc); |
|
|
|
trans = btrfs_join_transaction(rc->extent_root); |
|
if (IS_ERR(trans)) { |
|
err = PTR_ERR(trans); |
|
goto out_clean; |
|
} |
|
err = btrfs_commit_transaction(trans); |
|
out_clean: |
|
ret = clean_dirty_subvols(rc); |
|
if (ret < 0 && !err) |
|
err = ret; |
|
out_unset: |
|
unset_reloc_control(rc); |
|
free_reloc_control(rc); |
|
out: |
|
free_reloc_roots(&reloc_roots); |
|
|
|
btrfs_free_path(path); |
|
|
|
if (err == 0) { |
|
/* cleanup orphan inode in data relocation tree */ |
|
fs_root = btrfs_grab_root(fs_info->data_reloc_root); |
|
ASSERT(fs_root); |
|
err = btrfs_orphan_cleanup(fs_root); |
|
btrfs_put_root(fs_root); |
|
} |
|
return err; |
|
} |
|
|
|
/* |
|
* helper to add ordered checksum for data relocation. |
|
* |
|
* cloning checksum properly handles the nodatasum extents. |
|
* it also saves CPU time to re-calculate the checksum. |
|
*/ |
|
int btrfs_reloc_clone_csums(struct btrfs_inode *inode, u64 file_pos, u64 len) |
|
{ |
|
struct btrfs_fs_info *fs_info = inode->root->fs_info; |
|
struct btrfs_ordered_sum *sums; |
|
struct btrfs_ordered_extent *ordered; |
|
int ret; |
|
u64 disk_bytenr; |
|
u64 new_bytenr; |
|
LIST_HEAD(list); |
|
|
|
ordered = btrfs_lookup_ordered_extent(inode, file_pos); |
|
BUG_ON(ordered->file_offset != file_pos || ordered->num_bytes != len); |
|
|
|
disk_bytenr = file_pos + inode->index_cnt; |
|
ret = btrfs_lookup_csums_range(fs_info->csum_root, disk_bytenr, |
|
disk_bytenr + len - 1, &list, 0); |
|
if (ret) |
|
goto out; |
|
|
|
while (!list_empty(&list)) { |
|
sums = list_entry(list.next, struct btrfs_ordered_sum, list); |
|
list_del_init(&sums->list); |
|
|
|
/* |
|
* We need to offset the new_bytenr based on where the csum is. |
|
* We need to do this because we will read in entire prealloc |
|
* extents but we may have written to say the middle of the |
|
* prealloc extent, so we need to make sure the csum goes with |
|
* the right disk offset. |
|
* |
|
* We can do this because the data reloc inode refers strictly |
|
* to the on disk bytes, so we don't have to worry about |
|
* disk_len vs real len like with real inodes since it's all |
|
* disk length. |
|
*/ |
|
new_bytenr = ordered->disk_bytenr + sums->bytenr - disk_bytenr; |
|
sums->bytenr = new_bytenr; |
|
|
|
btrfs_add_ordered_sum(ordered, sums); |
|
} |
|
out: |
|
btrfs_put_ordered_extent(ordered); |
|
return ret; |
|
} |
|
|
|
int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, |
|
struct btrfs_root *root, struct extent_buffer *buf, |
|
struct extent_buffer *cow) |
|
{ |
|
struct btrfs_fs_info *fs_info = root->fs_info; |
|
struct reloc_control *rc; |
|
struct btrfs_backref_node *node; |
|
int first_cow = 0; |
|
int level; |
|
int ret = 0; |
|
|
|
rc = fs_info->reloc_ctl; |
|
if (!rc) |
|
return 0; |
|
|
|
BUG_ON(rc->stage == UPDATE_DATA_PTRS && |
|
root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID); |
|
|
|
level = btrfs_header_level(buf); |
|
if (btrfs_header_generation(buf) <= |
|
btrfs_root_last_snapshot(&root->root_item)) |
|
first_cow = 1; |
|
|
|
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID && |
|
rc->create_reloc_tree) { |
|
WARN_ON(!first_cow && level == 0); |
|
|
|
node = rc->backref_cache.path[level]; |
|
BUG_ON(node->bytenr != buf->start && |
|
node->new_bytenr != buf->start); |
|
|
|
btrfs_backref_drop_node_buffer(node); |
|
atomic_inc(&cow->refs); |
|
node->eb = cow; |
|
node->new_bytenr = cow->start; |
|
|
|
if (!node->pending) { |
|
list_move_tail(&node->list, |
|
&rc->backref_cache.pending[level]); |
|
node->pending = 1; |
|
} |
|
|
|
if (first_cow) |
|
mark_block_processed(rc, node); |
|
|
|
if (first_cow && level > 0) |
|
rc->nodes_relocated += buf->len; |
|
} |
|
|
|
if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) |
|
ret = replace_file_extents(trans, rc, root, cow); |
|
return ret; |
|
} |
|
|
|
/* |
|
* called before creating snapshot. it calculates metadata reservation |
|
* required for relocating tree blocks in the snapshot |
|
*/ |
|
void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending, |
|
u64 *bytes_to_reserve) |
|
{ |
|
struct btrfs_root *root = pending->root; |
|
struct reloc_control *rc = root->fs_info->reloc_ctl; |
|
|
|
if (!rc || !have_reloc_root(root)) |
|
return; |
|
|
|
if (!rc->merge_reloc_tree) |
|
return; |
|
|
|
root = root->reloc_root; |
|
BUG_ON(btrfs_root_refs(&root->root_item) == 0); |
|
/* |
|
* relocation is in the stage of merging trees. the space |
|
* used by merging a reloc tree is twice the size of |
|
* relocated tree nodes in the worst case. half for cowing |
|
* the reloc tree, half for cowing the fs tree. the space |
|
* used by cowing the reloc tree will be freed after the |
|
* tree is dropped. if we create snapshot, cowing the fs |
|
* tree may use more space than it frees. so we need |
|
* reserve extra space. |
|
*/ |
|
*bytes_to_reserve += rc->nodes_relocated; |
|
} |
|
|
|
/* |
|
* called after snapshot is created. migrate block reservation |
|
* and create reloc root for the newly created snapshot |
|
* |
|
* This is similar to btrfs_init_reloc_root(), we come out of here with two |
|
* references held on the reloc_root, one for root->reloc_root and one for |
|
* rc->reloc_roots. |
|
*/ |
|
int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans, |
|
struct btrfs_pending_snapshot *pending) |
|
{ |
|
struct btrfs_root *root = pending->root; |
|
struct btrfs_root *reloc_root; |
|
struct btrfs_root *new_root; |
|
struct reloc_control *rc = root->fs_info->reloc_ctl; |
|
int ret; |
|
|
|
if (!rc || !have_reloc_root(root)) |
|
return 0; |
|
|
|
rc = root->fs_info->reloc_ctl; |
|
rc->merging_rsv_size += rc->nodes_relocated; |
|
|
|
if (rc->merge_reloc_tree) { |
|
ret = btrfs_block_rsv_migrate(&pending->block_rsv, |
|
rc->block_rsv, |
|
rc->nodes_relocated, true); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
new_root = pending->snap; |
|
reloc_root = create_reloc_root(trans, root->reloc_root, |
|
new_root->root_key.objectid); |
|
if (IS_ERR(reloc_root)) |
|
return PTR_ERR(reloc_root); |
|
|
|
ret = __add_reloc_root(reloc_root); |
|
BUG_ON(ret < 0); |
|
new_root->reloc_root = btrfs_grab_root(reloc_root); |
|
|
|
if (rc->create_reloc_tree) |
|
ret = clone_backref_node(trans, rc, root, reloc_root); |
|
return ret; |
|
}
|
|
|