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1699 lines
48 KiB
1699 lines
48 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
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* linux/fs/ext2/inode.c |
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* |
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* Copyright (C) 1992, 1993, 1994, 1995 |
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* Remy Card ([email protected]) |
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* Laboratoire MASI - Institut Blaise Pascal |
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* Universite Pierre et Marie Curie (Paris VI) |
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* |
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* from |
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* |
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* linux/fs/minix/inode.c |
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* |
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* Copyright (C) 1991, 1992 Linus Torvalds |
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* |
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* Goal-directed block allocation by Stephen Tweedie |
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* ([email protected]), 1993, 1998 |
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* Big-endian to little-endian byte-swapping/bitmaps by |
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* David S. Miller ([email protected]), 1995 |
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* 64-bit file support on 64-bit platforms by Jakub Jelinek |
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* ([email protected]) |
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* |
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* Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000 |
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*/ |
|
|
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#include <linux/time.h> |
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#include <linux/highuid.h> |
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#include <linux/pagemap.h> |
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#include <linux/dax.h> |
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#include <linux/blkdev.h> |
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#include <linux/quotaops.h> |
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#include <linux/writeback.h> |
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#include <linux/buffer_head.h> |
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#include <linux/mpage.h> |
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#include <linux/fiemap.h> |
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#include <linux/iomap.h> |
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#include <linux/namei.h> |
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#include <linux/uio.h> |
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#include "ext2.h" |
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#include "acl.h" |
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#include "xattr.h" |
|
|
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static int __ext2_write_inode(struct inode *inode, int do_sync); |
|
|
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/* |
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* Test whether an inode is a fast symlink. |
|
*/ |
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static inline int ext2_inode_is_fast_symlink(struct inode *inode) |
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{ |
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int ea_blocks = EXT2_I(inode)->i_file_acl ? |
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(inode->i_sb->s_blocksize >> 9) : 0; |
|
|
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return (S_ISLNK(inode->i_mode) && |
|
inode->i_blocks - ea_blocks == 0); |
|
} |
|
|
|
static void ext2_truncate_blocks(struct inode *inode, loff_t offset); |
|
|
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static void ext2_write_failed(struct address_space *mapping, loff_t to) |
|
{ |
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struct inode *inode = mapping->host; |
|
|
|
if (to > inode->i_size) { |
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truncate_pagecache(inode, inode->i_size); |
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ext2_truncate_blocks(inode, inode->i_size); |
|
} |
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} |
|
|
|
/* |
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* Called at the last iput() if i_nlink is zero. |
|
*/ |
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void ext2_evict_inode(struct inode * inode) |
|
{ |
|
struct ext2_block_alloc_info *rsv; |
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int want_delete = 0; |
|
|
|
if (!inode->i_nlink && !is_bad_inode(inode)) { |
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want_delete = 1; |
|
dquot_initialize(inode); |
|
} else { |
|
dquot_drop(inode); |
|
} |
|
|
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truncate_inode_pages_final(&inode->i_data); |
|
|
|
if (want_delete) { |
|
sb_start_intwrite(inode->i_sb); |
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/* set dtime */ |
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EXT2_I(inode)->i_dtime = ktime_get_real_seconds(); |
|
mark_inode_dirty(inode); |
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__ext2_write_inode(inode, inode_needs_sync(inode)); |
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/* truncate to 0 */ |
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inode->i_size = 0; |
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if (inode->i_blocks) |
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ext2_truncate_blocks(inode, 0); |
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ext2_xattr_delete_inode(inode); |
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} |
|
|
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invalidate_inode_buffers(inode); |
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clear_inode(inode); |
|
|
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ext2_discard_reservation(inode); |
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rsv = EXT2_I(inode)->i_block_alloc_info; |
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EXT2_I(inode)->i_block_alloc_info = NULL; |
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if (unlikely(rsv)) |
|
kfree(rsv); |
|
|
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if (want_delete) { |
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ext2_free_inode(inode); |
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sb_end_intwrite(inode->i_sb); |
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} |
|
} |
|
|
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typedef struct { |
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__le32 *p; |
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__le32 key; |
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struct buffer_head *bh; |
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} Indirect; |
|
|
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static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) |
|
{ |
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p->key = *(p->p = v); |
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p->bh = bh; |
|
} |
|
|
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static inline int verify_chain(Indirect *from, Indirect *to) |
|
{ |
|
while (from <= to && from->key == *from->p) |
|
from++; |
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return (from > to); |
|
} |
|
|
|
/** |
|
* ext2_block_to_path - parse the block number into array of offsets |
|
* @inode: inode in question (we are only interested in its superblock) |
|
* @i_block: block number to be parsed |
|
* @offsets: array to store the offsets in |
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* @boundary: set this non-zero if the referred-to block is likely to be |
|
* followed (on disk) by an indirect block. |
|
* To store the locations of file's data ext2 uses a data structure common |
|
* for UNIX filesystems - tree of pointers anchored in the inode, with |
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* data blocks at leaves and indirect blocks in intermediate nodes. |
|
* This function translates the block number into path in that tree - |
|
* return value is the path length and @offsets[n] is the offset of |
|
* pointer to (n+1)th node in the nth one. If @block is out of range |
|
* (negative or too large) warning is printed and zero returned. |
|
* |
|
* Note: function doesn't find node addresses, so no IO is needed. All |
|
* we need to know is the capacity of indirect blocks (taken from the |
|
* inode->i_sb). |
|
*/ |
|
|
|
/* |
|
* Portability note: the last comparison (check that we fit into triple |
|
* indirect block) is spelled differently, because otherwise on an |
|
* architecture with 32-bit longs and 8Kb pages we might get into trouble |
|
* if our filesystem had 8Kb blocks. We might use long long, but that would |
|
* kill us on x86. Oh, well, at least the sign propagation does not matter - |
|
* i_block would have to be negative in the very beginning, so we would not |
|
* get there at all. |
|
*/ |
|
|
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static int ext2_block_to_path(struct inode *inode, |
|
long i_block, int offsets[4], int *boundary) |
|
{ |
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int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); |
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int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); |
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const long direct_blocks = EXT2_NDIR_BLOCKS, |
|
indirect_blocks = ptrs, |
|
double_blocks = (1 << (ptrs_bits * 2)); |
|
int n = 0; |
|
int final = 0; |
|
|
|
if (i_block < 0) { |
|
ext2_msg(inode->i_sb, KERN_WARNING, |
|
"warning: %s: block < 0", __func__); |
|
} else if (i_block < direct_blocks) { |
|
offsets[n++] = i_block; |
|
final = direct_blocks; |
|
} else if ( (i_block -= direct_blocks) < indirect_blocks) { |
|
offsets[n++] = EXT2_IND_BLOCK; |
|
offsets[n++] = i_block; |
|
final = ptrs; |
|
} else if ((i_block -= indirect_blocks) < double_blocks) { |
|
offsets[n++] = EXT2_DIND_BLOCK; |
|
offsets[n++] = i_block >> ptrs_bits; |
|
offsets[n++] = i_block & (ptrs - 1); |
|
final = ptrs; |
|
} else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { |
|
offsets[n++] = EXT2_TIND_BLOCK; |
|
offsets[n++] = i_block >> (ptrs_bits * 2); |
|
offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); |
|
offsets[n++] = i_block & (ptrs - 1); |
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final = ptrs; |
|
} else { |
|
ext2_msg(inode->i_sb, KERN_WARNING, |
|
"warning: %s: block is too big", __func__); |
|
} |
|
if (boundary) |
|
*boundary = final - 1 - (i_block & (ptrs - 1)); |
|
|
|
return n; |
|
} |
|
|
|
/** |
|
* ext2_get_branch - read the chain of indirect blocks leading to data |
|
* @inode: inode in question |
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* @depth: depth of the chain (1 - direct pointer, etc.) |
|
* @offsets: offsets of pointers in inode/indirect blocks |
|
* @chain: place to store the result |
|
* @err: here we store the error value |
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* |
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* Function fills the array of triples <key, p, bh> and returns %NULL |
|
* if everything went OK or the pointer to the last filled triple |
|
* (incomplete one) otherwise. Upon the return chain[i].key contains |
|
* the number of (i+1)-th block in the chain (as it is stored in memory, |
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* i.e. little-endian 32-bit), chain[i].p contains the address of that |
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* number (it points into struct inode for i==0 and into the bh->b_data |
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* for i>0) and chain[i].bh points to the buffer_head of i-th indirect |
|
* block for i>0 and NULL for i==0. In other words, it holds the block |
|
* numbers of the chain, addresses they were taken from (and where we can |
|
* verify that chain did not change) and buffer_heads hosting these |
|
* numbers. |
|
* |
|
* Function stops when it stumbles upon zero pointer (absent block) |
|
* (pointer to last triple returned, *@err == 0) |
|
* or when it gets an IO error reading an indirect block |
|
* (ditto, *@err == -EIO) |
|
* or when it notices that chain had been changed while it was reading |
|
* (ditto, *@err == -EAGAIN) |
|
* or when it reads all @depth-1 indirect blocks successfully and finds |
|
* the whole chain, all way to the data (returns %NULL, *err == 0). |
|
*/ |
|
static Indirect *ext2_get_branch(struct inode *inode, |
|
int depth, |
|
int *offsets, |
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Indirect chain[4], |
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int *err) |
|
{ |
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struct super_block *sb = inode->i_sb; |
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Indirect *p = chain; |
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struct buffer_head *bh; |
|
|
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*err = 0; |
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/* i_data is not going away, no lock needed */ |
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add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); |
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if (!p->key) |
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goto no_block; |
|
while (--depth) { |
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bh = sb_bread(sb, le32_to_cpu(p->key)); |
|
if (!bh) |
|
goto failure; |
|
read_lock(&EXT2_I(inode)->i_meta_lock); |
|
if (!verify_chain(chain, p)) |
|
goto changed; |
|
add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); |
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read_unlock(&EXT2_I(inode)->i_meta_lock); |
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if (!p->key) |
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goto no_block; |
|
} |
|
return NULL; |
|
|
|
changed: |
|
read_unlock(&EXT2_I(inode)->i_meta_lock); |
|
brelse(bh); |
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*err = -EAGAIN; |
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goto no_block; |
|
failure: |
|
*err = -EIO; |
|
no_block: |
|
return p; |
|
} |
|
|
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/** |
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* ext2_find_near - find a place for allocation with sufficient locality |
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* @inode: owner |
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* @ind: descriptor of indirect block. |
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* |
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* This function returns the preferred place for block allocation. |
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* It is used when heuristic for sequential allocation fails. |
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* Rules are: |
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* + if there is a block to the left of our position - allocate near it. |
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* + if pointer will live in indirect block - allocate near that block. |
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* + if pointer will live in inode - allocate in the same cylinder group. |
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* |
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* In the latter case we colour the starting block by the callers PID to |
|
* prevent it from clashing with concurrent allocations for a different inode |
|
* in the same block group. The PID is used here so that functionally related |
|
* files will be close-by on-disk. |
|
* |
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* Caller must make sure that @ind is valid and will stay that way. |
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*/ |
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|
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static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind) |
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{ |
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struct ext2_inode_info *ei = EXT2_I(inode); |
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__le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; |
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__le32 *p; |
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ext2_fsblk_t bg_start; |
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ext2_fsblk_t colour; |
|
|
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/* Try to find previous block */ |
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for (p = ind->p - 1; p >= start; p--) |
|
if (*p) |
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return le32_to_cpu(*p); |
|
|
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/* No such thing, so let's try location of indirect block */ |
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if (ind->bh) |
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return ind->bh->b_blocknr; |
|
|
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/* |
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* It is going to be referred from inode itself? OK, just put it into |
|
* the same cylinder group then. |
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*/ |
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bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group); |
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colour = (current->pid % 16) * |
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(EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); |
|
return bg_start + colour; |
|
} |
|
|
|
/** |
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* ext2_find_goal - find a preferred place for allocation. |
|
* @inode: owner |
|
* @block: block we want |
|
* @partial: pointer to the last triple within a chain |
|
* |
|
* Returns preferred place for a block (the goal). |
|
*/ |
|
|
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static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block, |
|
Indirect *partial) |
|
{ |
|
struct ext2_block_alloc_info *block_i; |
|
|
|
block_i = EXT2_I(inode)->i_block_alloc_info; |
|
|
|
/* |
|
* try the heuristic for sequential allocation, |
|
* failing that at least try to get decent locality. |
|
*/ |
|
if (block_i && (block == block_i->last_alloc_logical_block + 1) |
|
&& (block_i->last_alloc_physical_block != 0)) { |
|
return block_i->last_alloc_physical_block + 1; |
|
} |
|
|
|
return ext2_find_near(inode, partial); |
|
} |
|
|
|
/** |
|
* ext2_blks_to_allocate: Look up the block map and count the number |
|
* of direct blocks need to be allocated for the given branch. |
|
* |
|
* @branch: chain of indirect blocks |
|
* @k: number of blocks need for indirect blocks |
|
* @blks: number of data blocks to be mapped. |
|
* @blocks_to_boundary: the offset in the indirect block |
|
* |
|
* return the number of direct blocks to allocate. |
|
*/ |
|
static int |
|
ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, |
|
int blocks_to_boundary) |
|
{ |
|
unsigned long count = 0; |
|
|
|
/* |
|
* Simple case, [t,d]Indirect block(s) has not allocated yet |
|
* then it's clear blocks on that path have not allocated |
|
*/ |
|
if (k > 0) { |
|
/* right now don't hanel cross boundary allocation */ |
|
if (blks < blocks_to_boundary + 1) |
|
count += blks; |
|
else |
|
count += blocks_to_boundary + 1; |
|
return count; |
|
} |
|
|
|
count++; |
|
while (count < blks && count <= blocks_to_boundary |
|
&& le32_to_cpu(*(branch[0].p + count)) == 0) { |
|
count++; |
|
} |
|
return count; |
|
} |
|
|
|
/** |
|
* ext2_alloc_blocks: multiple allocate blocks needed for a branch |
|
* @indirect_blks: the number of blocks need to allocate for indirect |
|
* blocks |
|
* @blks: the number of blocks need to allocate for direct blocks |
|
* @new_blocks: on return it will store the new block numbers for |
|
* the indirect blocks(if needed) and the first direct block, |
|
*/ |
|
static int ext2_alloc_blocks(struct inode *inode, |
|
ext2_fsblk_t goal, int indirect_blks, int blks, |
|
ext2_fsblk_t new_blocks[4], int *err) |
|
{ |
|
int target, i; |
|
unsigned long count = 0; |
|
int index = 0; |
|
ext2_fsblk_t current_block = 0; |
|
int ret = 0; |
|
|
|
/* |
|
* Here we try to allocate the requested multiple blocks at once, |
|
* on a best-effort basis. |
|
* To build a branch, we should allocate blocks for |
|
* the indirect blocks(if not allocated yet), and at least |
|
* the first direct block of this branch. That's the |
|
* minimum number of blocks need to allocate(required) |
|
*/ |
|
target = blks + indirect_blks; |
|
|
|
while (1) { |
|
count = target; |
|
/* allocating blocks for indirect blocks and direct blocks */ |
|
current_block = ext2_new_blocks(inode,goal,&count,err); |
|
if (*err) |
|
goto failed_out; |
|
|
|
target -= count; |
|
/* allocate blocks for indirect blocks */ |
|
while (index < indirect_blks && count) { |
|
new_blocks[index++] = current_block++; |
|
count--; |
|
} |
|
|
|
if (count > 0) |
|
break; |
|
} |
|
|
|
/* save the new block number for the first direct block */ |
|
new_blocks[index] = current_block; |
|
|
|
/* total number of blocks allocated for direct blocks */ |
|
ret = count; |
|
*err = 0; |
|
return ret; |
|
failed_out: |
|
for (i = 0; i <index; i++) |
|
ext2_free_blocks(inode, new_blocks[i], 1); |
|
if (index) |
|
mark_inode_dirty(inode); |
|
return ret; |
|
} |
|
|
|
/** |
|
* ext2_alloc_branch - allocate and set up a chain of blocks. |
|
* @inode: owner |
|
* @indirect_blks: depth of the chain (number of blocks to allocate) |
|
* @blks: number of allocated direct blocks |
|
* @goal: preferred place for allocation |
|
* @offsets: offsets (in the blocks) to store the pointers to next. |
|
* @branch: place to store the chain in. |
|
* |
|
* This function allocates @num blocks, zeroes out all but the last one, |
|
* links them into chain and (if we are synchronous) writes them to disk. |
|
* In other words, it prepares a branch that can be spliced onto the |
|
* inode. It stores the information about that chain in the branch[], in |
|
* the same format as ext2_get_branch() would do. We are calling it after |
|
* we had read the existing part of chain and partial points to the last |
|
* triple of that (one with zero ->key). Upon the exit we have the same |
|
* picture as after the successful ext2_get_block(), except that in one |
|
* place chain is disconnected - *branch->p is still zero (we did not |
|
* set the last link), but branch->key contains the number that should |
|
* be placed into *branch->p to fill that gap. |
|
* |
|
* If allocation fails we free all blocks we've allocated (and forget |
|
* their buffer_heads) and return the error value the from failed |
|
* ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain |
|
* as described above and return 0. |
|
*/ |
|
|
|
static int ext2_alloc_branch(struct inode *inode, |
|
int indirect_blks, int *blks, ext2_fsblk_t goal, |
|
int *offsets, Indirect *branch) |
|
{ |
|
int blocksize = inode->i_sb->s_blocksize; |
|
int i, n = 0; |
|
int err = 0; |
|
struct buffer_head *bh; |
|
int num; |
|
ext2_fsblk_t new_blocks[4]; |
|
ext2_fsblk_t current_block; |
|
|
|
num = ext2_alloc_blocks(inode, goal, indirect_blks, |
|
*blks, new_blocks, &err); |
|
if (err) |
|
return err; |
|
|
|
branch[0].key = cpu_to_le32(new_blocks[0]); |
|
/* |
|
* metadata blocks and data blocks are allocated. |
|
*/ |
|
for (n = 1; n <= indirect_blks; n++) { |
|
/* |
|
* Get buffer_head for parent block, zero it out |
|
* and set the pointer to new one, then send |
|
* parent to disk. |
|
*/ |
|
bh = sb_getblk(inode->i_sb, new_blocks[n-1]); |
|
if (unlikely(!bh)) { |
|
err = -ENOMEM; |
|
goto failed; |
|
} |
|
branch[n].bh = bh; |
|
lock_buffer(bh); |
|
memset(bh->b_data, 0, blocksize); |
|
branch[n].p = (__le32 *) bh->b_data + offsets[n]; |
|
branch[n].key = cpu_to_le32(new_blocks[n]); |
|
*branch[n].p = branch[n].key; |
|
if ( n == indirect_blks) { |
|
current_block = new_blocks[n]; |
|
/* |
|
* End of chain, update the last new metablock of |
|
* the chain to point to the new allocated |
|
* data blocks numbers |
|
*/ |
|
for (i=1; i < num; i++) |
|
*(branch[n].p + i) = cpu_to_le32(++current_block); |
|
} |
|
set_buffer_uptodate(bh); |
|
unlock_buffer(bh); |
|
mark_buffer_dirty_inode(bh, inode); |
|
/* We used to sync bh here if IS_SYNC(inode). |
|
* But we now rely upon generic_write_sync() |
|
* and b_inode_buffers. But not for directories. |
|
*/ |
|
if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) |
|
sync_dirty_buffer(bh); |
|
} |
|
*blks = num; |
|
return err; |
|
|
|
failed: |
|
for (i = 1; i < n; i++) |
|
bforget(branch[i].bh); |
|
for (i = 0; i < indirect_blks; i++) |
|
ext2_free_blocks(inode, new_blocks[i], 1); |
|
ext2_free_blocks(inode, new_blocks[i], num); |
|
return err; |
|
} |
|
|
|
/** |
|
* ext2_splice_branch - splice the allocated branch onto inode. |
|
* @inode: owner |
|
* @block: (logical) number of block we are adding |
|
* @where: location of missing link |
|
* @num: number of indirect blocks we are adding |
|
* @blks: number of direct blocks we are adding |
|
* |
|
* This function fills the missing link and does all housekeeping needed in |
|
* inode (->i_blocks, etc.). In case of success we end up with the full |
|
* chain to new block and return 0. |
|
*/ |
|
static void ext2_splice_branch(struct inode *inode, |
|
long block, Indirect *where, int num, int blks) |
|
{ |
|
int i; |
|
struct ext2_block_alloc_info *block_i; |
|
ext2_fsblk_t current_block; |
|
|
|
block_i = EXT2_I(inode)->i_block_alloc_info; |
|
|
|
/* XXX LOCKING probably should have i_meta_lock ?*/ |
|
/* That's it */ |
|
|
|
*where->p = where->key; |
|
|
|
/* |
|
* Update the host buffer_head or inode to point to more just allocated |
|
* direct blocks blocks |
|
*/ |
|
if (num == 0 && blks > 1) { |
|
current_block = le32_to_cpu(where->key) + 1; |
|
for (i = 1; i < blks; i++) |
|
*(where->p + i ) = cpu_to_le32(current_block++); |
|
} |
|
|
|
/* |
|
* update the most recently allocated logical & physical block |
|
* in i_block_alloc_info, to assist find the proper goal block for next |
|
* allocation |
|
*/ |
|
if (block_i) { |
|
block_i->last_alloc_logical_block = block + blks - 1; |
|
block_i->last_alloc_physical_block = |
|
le32_to_cpu(where[num].key) + blks - 1; |
|
} |
|
|
|
/* We are done with atomic stuff, now do the rest of housekeeping */ |
|
|
|
/* had we spliced it onto indirect block? */ |
|
if (where->bh) |
|
mark_buffer_dirty_inode(where->bh, inode); |
|
|
|
inode->i_ctime = current_time(inode); |
|
mark_inode_dirty(inode); |
|
} |
|
|
|
/* |
|
* Allocation strategy is simple: if we have to allocate something, we will |
|
* have to go the whole way to leaf. So let's do it before attaching anything |
|
* to tree, set linkage between the newborn blocks, write them if sync is |
|
* required, recheck the path, free and repeat if check fails, otherwise |
|
* set the last missing link (that will protect us from any truncate-generated |
|
* removals - all blocks on the path are immune now) and possibly force the |
|
* write on the parent block. |
|
* That has a nice additional property: no special recovery from the failed |
|
* allocations is needed - we simply release blocks and do not touch anything |
|
* reachable from inode. |
|
* |
|
* `handle' can be NULL if create == 0. |
|
* |
|
* return > 0, # of blocks mapped or allocated. |
|
* return = 0, if plain lookup failed. |
|
* return < 0, error case. |
|
*/ |
|
static int ext2_get_blocks(struct inode *inode, |
|
sector_t iblock, unsigned long maxblocks, |
|
u32 *bno, bool *new, bool *boundary, |
|
int create) |
|
{ |
|
int err; |
|
int offsets[4]; |
|
Indirect chain[4]; |
|
Indirect *partial; |
|
ext2_fsblk_t goal; |
|
int indirect_blks; |
|
int blocks_to_boundary = 0; |
|
int depth; |
|
struct ext2_inode_info *ei = EXT2_I(inode); |
|
int count = 0; |
|
ext2_fsblk_t first_block = 0; |
|
|
|
BUG_ON(maxblocks == 0); |
|
|
|
depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); |
|
|
|
if (depth == 0) |
|
return -EIO; |
|
|
|
partial = ext2_get_branch(inode, depth, offsets, chain, &err); |
|
/* Simplest case - block found, no allocation needed */ |
|
if (!partial) { |
|
first_block = le32_to_cpu(chain[depth - 1].key); |
|
count++; |
|
/*map more blocks*/ |
|
while (count < maxblocks && count <= blocks_to_boundary) { |
|
ext2_fsblk_t blk; |
|
|
|
if (!verify_chain(chain, chain + depth - 1)) { |
|
/* |
|
* Indirect block might be removed by |
|
* truncate while we were reading it. |
|
* Handling of that case: forget what we've |
|
* got now, go to reread. |
|
*/ |
|
err = -EAGAIN; |
|
count = 0; |
|
partial = chain + depth - 1; |
|
break; |
|
} |
|
blk = le32_to_cpu(*(chain[depth-1].p + count)); |
|
if (blk == first_block + count) |
|
count++; |
|
else |
|
break; |
|
} |
|
if (err != -EAGAIN) |
|
goto got_it; |
|
} |
|
|
|
/* Next simple case - plain lookup or failed read of indirect block */ |
|
if (!create || err == -EIO) |
|
goto cleanup; |
|
|
|
mutex_lock(&ei->truncate_mutex); |
|
/* |
|
* If the indirect block is missing while we are reading |
|
* the chain(ext2_get_branch() returns -EAGAIN err), or |
|
* if the chain has been changed after we grab the semaphore, |
|
* (either because another process truncated this branch, or |
|
* another get_block allocated this branch) re-grab the chain to see if |
|
* the request block has been allocated or not. |
|
* |
|
* Since we already block the truncate/other get_block |
|
* at this point, we will have the current copy of the chain when we |
|
* splice the branch into the tree. |
|
*/ |
|
if (err == -EAGAIN || !verify_chain(chain, partial)) { |
|
while (partial > chain) { |
|
brelse(partial->bh); |
|
partial--; |
|
} |
|
partial = ext2_get_branch(inode, depth, offsets, chain, &err); |
|
if (!partial) { |
|
count++; |
|
mutex_unlock(&ei->truncate_mutex); |
|
goto got_it; |
|
} |
|
|
|
if (err) { |
|
mutex_unlock(&ei->truncate_mutex); |
|
goto cleanup; |
|
} |
|
} |
|
|
|
/* |
|
* Okay, we need to do block allocation. Lazily initialize the block |
|
* allocation info here if necessary |
|
*/ |
|
if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) |
|
ext2_init_block_alloc_info(inode); |
|
|
|
goal = ext2_find_goal(inode, iblock, partial); |
|
|
|
/* the number of blocks need to allocate for [d,t]indirect blocks */ |
|
indirect_blks = (chain + depth) - partial - 1; |
|
/* |
|
* Next look up the indirect map to count the total number of |
|
* direct blocks to allocate for this branch. |
|
*/ |
|
count = ext2_blks_to_allocate(partial, indirect_blks, |
|
maxblocks, blocks_to_boundary); |
|
/* |
|
* XXX ???? Block out ext2_truncate while we alter the tree |
|
*/ |
|
err = ext2_alloc_branch(inode, indirect_blks, &count, goal, |
|
offsets + (partial - chain), partial); |
|
|
|
if (err) { |
|
mutex_unlock(&ei->truncate_mutex); |
|
goto cleanup; |
|
} |
|
|
|
if (IS_DAX(inode)) { |
|
/* |
|
* We must unmap blocks before zeroing so that writeback cannot |
|
* overwrite zeros with stale data from block device page cache. |
|
*/ |
|
clean_bdev_aliases(inode->i_sb->s_bdev, |
|
le32_to_cpu(chain[depth-1].key), |
|
count); |
|
/* |
|
* block must be initialised before we put it in the tree |
|
* so that it's not found by another thread before it's |
|
* initialised |
|
*/ |
|
err = sb_issue_zeroout(inode->i_sb, |
|
le32_to_cpu(chain[depth-1].key), count, |
|
GFP_NOFS); |
|
if (err) { |
|
mutex_unlock(&ei->truncate_mutex); |
|
goto cleanup; |
|
} |
|
} |
|
*new = true; |
|
|
|
ext2_splice_branch(inode, iblock, partial, indirect_blks, count); |
|
mutex_unlock(&ei->truncate_mutex); |
|
got_it: |
|
if (count > blocks_to_boundary) |
|
*boundary = true; |
|
err = count; |
|
/* Clean up and exit */ |
|
partial = chain + depth - 1; /* the whole chain */ |
|
cleanup: |
|
while (partial > chain) { |
|
brelse(partial->bh); |
|
partial--; |
|
} |
|
if (err > 0) |
|
*bno = le32_to_cpu(chain[depth-1].key); |
|
return err; |
|
} |
|
|
|
int ext2_get_block(struct inode *inode, sector_t iblock, |
|
struct buffer_head *bh_result, int create) |
|
{ |
|
unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; |
|
bool new = false, boundary = false; |
|
u32 bno; |
|
int ret; |
|
|
|
ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary, |
|
create); |
|
if (ret <= 0) |
|
return ret; |
|
|
|
map_bh(bh_result, inode->i_sb, bno); |
|
bh_result->b_size = (ret << inode->i_blkbits); |
|
if (new) |
|
set_buffer_new(bh_result); |
|
if (boundary) |
|
set_buffer_boundary(bh_result); |
|
return 0; |
|
|
|
} |
|
|
|
#ifdef CONFIG_FS_DAX |
|
static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, |
|
unsigned flags, struct iomap *iomap, struct iomap *srcmap) |
|
{ |
|
unsigned int blkbits = inode->i_blkbits; |
|
unsigned long first_block = offset >> blkbits; |
|
unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; |
|
struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb); |
|
bool new = false, boundary = false; |
|
u32 bno; |
|
int ret; |
|
|
|
ret = ext2_get_blocks(inode, first_block, max_blocks, |
|
&bno, &new, &boundary, flags & IOMAP_WRITE); |
|
if (ret < 0) |
|
return ret; |
|
|
|
iomap->flags = 0; |
|
iomap->bdev = inode->i_sb->s_bdev; |
|
iomap->offset = (u64)first_block << blkbits; |
|
iomap->dax_dev = sbi->s_daxdev; |
|
|
|
if (ret == 0) { |
|
iomap->type = IOMAP_HOLE; |
|
iomap->addr = IOMAP_NULL_ADDR; |
|
iomap->length = 1 << blkbits; |
|
} else { |
|
iomap->type = IOMAP_MAPPED; |
|
iomap->addr = (u64)bno << blkbits; |
|
iomap->length = (u64)ret << blkbits; |
|
iomap->flags |= IOMAP_F_MERGED; |
|
} |
|
|
|
if (new) |
|
iomap->flags |= IOMAP_F_NEW; |
|
return 0; |
|
} |
|
|
|
static int |
|
ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length, |
|
ssize_t written, unsigned flags, struct iomap *iomap) |
|
{ |
|
if (iomap->type == IOMAP_MAPPED && |
|
written < length && |
|
(flags & IOMAP_WRITE)) |
|
ext2_write_failed(inode->i_mapping, offset + length); |
|
return 0; |
|
} |
|
|
|
const struct iomap_ops ext2_iomap_ops = { |
|
.iomap_begin = ext2_iomap_begin, |
|
.iomap_end = ext2_iomap_end, |
|
}; |
|
#else |
|
/* Define empty ops for !CONFIG_FS_DAX case to avoid ugly ifdefs */ |
|
const struct iomap_ops ext2_iomap_ops; |
|
#endif /* CONFIG_FS_DAX */ |
|
|
|
int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |
|
u64 start, u64 len) |
|
{ |
|
return generic_block_fiemap(inode, fieinfo, start, len, |
|
ext2_get_block); |
|
} |
|
|
|
static int ext2_writepage(struct page *page, struct writeback_control *wbc) |
|
{ |
|
return block_write_full_page(page, ext2_get_block, wbc); |
|
} |
|
|
|
static int ext2_readpage(struct file *file, struct page *page) |
|
{ |
|
return mpage_readpage(page, ext2_get_block); |
|
} |
|
|
|
static void ext2_readahead(struct readahead_control *rac) |
|
{ |
|
mpage_readahead(rac, ext2_get_block); |
|
} |
|
|
|
static int |
|
ext2_write_begin(struct file *file, struct address_space *mapping, |
|
loff_t pos, unsigned len, unsigned flags, |
|
struct page **pagep, void **fsdata) |
|
{ |
|
int ret; |
|
|
|
ret = block_write_begin(mapping, pos, len, flags, pagep, |
|
ext2_get_block); |
|
if (ret < 0) |
|
ext2_write_failed(mapping, pos + len); |
|
return ret; |
|
} |
|
|
|
static int ext2_write_end(struct file *file, struct address_space *mapping, |
|
loff_t pos, unsigned len, unsigned copied, |
|
struct page *page, void *fsdata) |
|
{ |
|
int ret; |
|
|
|
ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); |
|
if (ret < len) |
|
ext2_write_failed(mapping, pos + len); |
|
return ret; |
|
} |
|
|
|
static int |
|
ext2_nobh_write_begin(struct file *file, struct address_space *mapping, |
|
loff_t pos, unsigned len, unsigned flags, |
|
struct page **pagep, void **fsdata) |
|
{ |
|
int ret; |
|
|
|
ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata, |
|
ext2_get_block); |
|
if (ret < 0) |
|
ext2_write_failed(mapping, pos + len); |
|
return ret; |
|
} |
|
|
|
static int ext2_nobh_writepage(struct page *page, |
|
struct writeback_control *wbc) |
|
{ |
|
return nobh_writepage(page, ext2_get_block, wbc); |
|
} |
|
|
|
static sector_t ext2_bmap(struct address_space *mapping, sector_t block) |
|
{ |
|
return generic_block_bmap(mapping,block,ext2_get_block); |
|
} |
|
|
|
static ssize_t |
|
ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
|
{ |
|
struct file *file = iocb->ki_filp; |
|
struct address_space *mapping = file->f_mapping; |
|
struct inode *inode = mapping->host; |
|
size_t count = iov_iter_count(iter); |
|
loff_t offset = iocb->ki_pos; |
|
ssize_t ret; |
|
|
|
ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); |
|
if (ret < 0 && iov_iter_rw(iter) == WRITE) |
|
ext2_write_failed(mapping, offset + count); |
|
return ret; |
|
} |
|
|
|
static int |
|
ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) |
|
{ |
|
return mpage_writepages(mapping, wbc, ext2_get_block); |
|
} |
|
|
|
static int |
|
ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) |
|
{ |
|
struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb); |
|
|
|
return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); |
|
} |
|
|
|
const struct address_space_operations ext2_aops = { |
|
.readpage = ext2_readpage, |
|
.readahead = ext2_readahead, |
|
.writepage = ext2_writepage, |
|
.write_begin = ext2_write_begin, |
|
.write_end = ext2_write_end, |
|
.bmap = ext2_bmap, |
|
.direct_IO = ext2_direct_IO, |
|
.writepages = ext2_writepages, |
|
.migratepage = buffer_migrate_page, |
|
.is_partially_uptodate = block_is_partially_uptodate, |
|
.error_remove_page = generic_error_remove_page, |
|
}; |
|
|
|
const struct address_space_operations ext2_nobh_aops = { |
|
.readpage = ext2_readpage, |
|
.readahead = ext2_readahead, |
|
.writepage = ext2_nobh_writepage, |
|
.write_begin = ext2_nobh_write_begin, |
|
.write_end = nobh_write_end, |
|
.bmap = ext2_bmap, |
|
.direct_IO = ext2_direct_IO, |
|
.writepages = ext2_writepages, |
|
.migratepage = buffer_migrate_page, |
|
.error_remove_page = generic_error_remove_page, |
|
}; |
|
|
|
static const struct address_space_operations ext2_dax_aops = { |
|
.writepages = ext2_dax_writepages, |
|
.direct_IO = noop_direct_IO, |
|
.set_page_dirty = noop_set_page_dirty, |
|
.invalidatepage = noop_invalidatepage, |
|
}; |
|
|
|
/* |
|
* Probably it should be a library function... search for first non-zero word |
|
* or memcmp with zero_page, whatever is better for particular architecture. |
|
* Linus? |
|
*/ |
|
static inline int all_zeroes(__le32 *p, __le32 *q) |
|
{ |
|
while (p < q) |
|
if (*p++) |
|
return 0; |
|
return 1; |
|
} |
|
|
|
/** |
|
* ext2_find_shared - find the indirect blocks for partial truncation. |
|
* @inode: inode in question |
|
* @depth: depth of the affected branch |
|
* @offsets: offsets of pointers in that branch (see ext2_block_to_path) |
|
* @chain: place to store the pointers to partial indirect blocks |
|
* @top: place to the (detached) top of branch |
|
* |
|
* This is a helper function used by ext2_truncate(). |
|
* |
|
* When we do truncate() we may have to clean the ends of several indirect |
|
* blocks but leave the blocks themselves alive. Block is partially |
|
* truncated if some data below the new i_size is referred from it (and |
|
* it is on the path to the first completely truncated data block, indeed). |
|
* We have to free the top of that path along with everything to the right |
|
* of the path. Since no allocation past the truncation point is possible |
|
* until ext2_truncate() finishes, we may safely do the latter, but top |
|
* of branch may require special attention - pageout below the truncation |
|
* point might try to populate it. |
|
* |
|
* We atomically detach the top of branch from the tree, store the block |
|
* number of its root in *@top, pointers to buffer_heads of partially |
|
* truncated blocks - in @chain[].bh and pointers to their last elements |
|
* that should not be removed - in @chain[].p. Return value is the pointer |
|
* to last filled element of @chain. |
|
* |
|
* The work left to caller to do the actual freeing of subtrees: |
|
* a) free the subtree starting from *@top |
|
* b) free the subtrees whose roots are stored in |
|
* (@chain[i].p+1 .. end of @chain[i].bh->b_data) |
|
* c) free the subtrees growing from the inode past the @chain[0].p |
|
* (no partially truncated stuff there). |
|
*/ |
|
|
|
static Indirect *ext2_find_shared(struct inode *inode, |
|
int depth, |
|
int offsets[4], |
|
Indirect chain[4], |
|
__le32 *top) |
|
{ |
|
Indirect *partial, *p; |
|
int k, err; |
|
|
|
*top = 0; |
|
for (k = depth; k > 1 && !offsets[k-1]; k--) |
|
; |
|
partial = ext2_get_branch(inode, k, offsets, chain, &err); |
|
if (!partial) |
|
partial = chain + k-1; |
|
/* |
|
* If the branch acquired continuation since we've looked at it - |
|
* fine, it should all survive and (new) top doesn't belong to us. |
|
*/ |
|
write_lock(&EXT2_I(inode)->i_meta_lock); |
|
if (!partial->key && *partial->p) { |
|
write_unlock(&EXT2_I(inode)->i_meta_lock); |
|
goto no_top; |
|
} |
|
for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) |
|
; |
|
/* |
|
* OK, we've found the last block that must survive. The rest of our |
|
* branch should be detached before unlocking. However, if that rest |
|
* of branch is all ours and does not grow immediately from the inode |
|
* it's easier to cheat and just decrement partial->p. |
|
*/ |
|
if (p == chain + k - 1 && p > chain) { |
|
p->p--; |
|
} else { |
|
*top = *p->p; |
|
*p->p = 0; |
|
} |
|
write_unlock(&EXT2_I(inode)->i_meta_lock); |
|
|
|
while(partial > p) |
|
{ |
|
brelse(partial->bh); |
|
partial--; |
|
} |
|
no_top: |
|
return partial; |
|
} |
|
|
|
/** |
|
* ext2_free_data - free a list of data blocks |
|
* @inode: inode we are dealing with |
|
* @p: array of block numbers |
|
* @q: points immediately past the end of array |
|
* |
|
* We are freeing all blocks referred from that array (numbers are |
|
* stored as little-endian 32-bit) and updating @inode->i_blocks |
|
* appropriately. |
|
*/ |
|
static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) |
|
{ |
|
unsigned long block_to_free = 0, count = 0; |
|
unsigned long nr; |
|
|
|
for ( ; p < q ; p++) { |
|
nr = le32_to_cpu(*p); |
|
if (nr) { |
|
*p = 0; |
|
/* accumulate blocks to free if they're contiguous */ |
|
if (count == 0) |
|
goto free_this; |
|
else if (block_to_free == nr - count) |
|
count++; |
|
else { |
|
ext2_free_blocks (inode, block_to_free, count); |
|
mark_inode_dirty(inode); |
|
free_this: |
|
block_to_free = nr; |
|
count = 1; |
|
} |
|
} |
|
} |
|
if (count > 0) { |
|
ext2_free_blocks (inode, block_to_free, count); |
|
mark_inode_dirty(inode); |
|
} |
|
} |
|
|
|
/** |
|
* ext2_free_branches - free an array of branches |
|
* @inode: inode we are dealing with |
|
* @p: array of block numbers |
|
* @q: pointer immediately past the end of array |
|
* @depth: depth of the branches to free |
|
* |
|
* We are freeing all blocks referred from these branches (numbers are |
|
* stored as little-endian 32-bit) and updating @inode->i_blocks |
|
* appropriately. |
|
*/ |
|
static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) |
|
{ |
|
struct buffer_head * bh; |
|
unsigned long nr; |
|
|
|
if (depth--) { |
|
int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); |
|
for ( ; p < q ; p++) { |
|
nr = le32_to_cpu(*p); |
|
if (!nr) |
|
continue; |
|
*p = 0; |
|
bh = sb_bread(inode->i_sb, nr); |
|
/* |
|
* A read failure? Report error and clear slot |
|
* (should be rare). |
|
*/ |
|
if (!bh) { |
|
ext2_error(inode->i_sb, "ext2_free_branches", |
|
"Read failure, inode=%ld, block=%ld", |
|
inode->i_ino, nr); |
|
continue; |
|
} |
|
ext2_free_branches(inode, |
|
(__le32*)bh->b_data, |
|
(__le32*)bh->b_data + addr_per_block, |
|
depth); |
|
bforget(bh); |
|
ext2_free_blocks(inode, nr, 1); |
|
mark_inode_dirty(inode); |
|
} |
|
} else |
|
ext2_free_data(inode, p, q); |
|
} |
|
|
|
/* dax_sem must be held when calling this function */ |
|
static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) |
|
{ |
|
__le32 *i_data = EXT2_I(inode)->i_data; |
|
struct ext2_inode_info *ei = EXT2_I(inode); |
|
int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); |
|
int offsets[4]; |
|
Indirect chain[4]; |
|
Indirect *partial; |
|
__le32 nr = 0; |
|
int n; |
|
long iblock; |
|
unsigned blocksize; |
|
blocksize = inode->i_sb->s_blocksize; |
|
iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); |
|
|
|
#ifdef CONFIG_FS_DAX |
|
WARN_ON(!rwsem_is_locked(&ei->dax_sem)); |
|
#endif |
|
|
|
n = ext2_block_to_path(inode, iblock, offsets, NULL); |
|
if (n == 0) |
|
return; |
|
|
|
/* |
|
* From here we block out all ext2_get_block() callers who want to |
|
* modify the block allocation tree. |
|
*/ |
|
mutex_lock(&ei->truncate_mutex); |
|
|
|
if (n == 1) { |
|
ext2_free_data(inode, i_data+offsets[0], |
|
i_data + EXT2_NDIR_BLOCKS); |
|
goto do_indirects; |
|
} |
|
|
|
partial = ext2_find_shared(inode, n, offsets, chain, &nr); |
|
/* Kill the top of shared branch (already detached) */ |
|
if (nr) { |
|
if (partial == chain) |
|
mark_inode_dirty(inode); |
|
else |
|
mark_buffer_dirty_inode(partial->bh, inode); |
|
ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); |
|
} |
|
/* Clear the ends of indirect blocks on the shared branch */ |
|
while (partial > chain) { |
|
ext2_free_branches(inode, |
|
partial->p + 1, |
|
(__le32*)partial->bh->b_data+addr_per_block, |
|
(chain+n-1) - partial); |
|
mark_buffer_dirty_inode(partial->bh, inode); |
|
brelse (partial->bh); |
|
partial--; |
|
} |
|
do_indirects: |
|
/* Kill the remaining (whole) subtrees */ |
|
switch (offsets[0]) { |
|
default: |
|
nr = i_data[EXT2_IND_BLOCK]; |
|
if (nr) { |
|
i_data[EXT2_IND_BLOCK] = 0; |
|
mark_inode_dirty(inode); |
|
ext2_free_branches(inode, &nr, &nr+1, 1); |
|
} |
|
fallthrough; |
|
case EXT2_IND_BLOCK: |
|
nr = i_data[EXT2_DIND_BLOCK]; |
|
if (nr) { |
|
i_data[EXT2_DIND_BLOCK] = 0; |
|
mark_inode_dirty(inode); |
|
ext2_free_branches(inode, &nr, &nr+1, 2); |
|
} |
|
fallthrough; |
|
case EXT2_DIND_BLOCK: |
|
nr = i_data[EXT2_TIND_BLOCK]; |
|
if (nr) { |
|
i_data[EXT2_TIND_BLOCK] = 0; |
|
mark_inode_dirty(inode); |
|
ext2_free_branches(inode, &nr, &nr+1, 3); |
|
} |
|
break; |
|
case EXT2_TIND_BLOCK: |
|
; |
|
} |
|
|
|
ext2_discard_reservation(inode); |
|
|
|
mutex_unlock(&ei->truncate_mutex); |
|
} |
|
|
|
static void ext2_truncate_blocks(struct inode *inode, loff_t offset) |
|
{ |
|
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || |
|
S_ISLNK(inode->i_mode))) |
|
return; |
|
if (ext2_inode_is_fast_symlink(inode)) |
|
return; |
|
|
|
dax_sem_down_write(EXT2_I(inode)); |
|
__ext2_truncate_blocks(inode, offset); |
|
dax_sem_up_write(EXT2_I(inode)); |
|
} |
|
|
|
static int ext2_setsize(struct inode *inode, loff_t newsize) |
|
{ |
|
int error; |
|
|
|
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || |
|
S_ISLNK(inode->i_mode))) |
|
return -EINVAL; |
|
if (ext2_inode_is_fast_symlink(inode)) |
|
return -EINVAL; |
|
if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) |
|
return -EPERM; |
|
|
|
inode_dio_wait(inode); |
|
|
|
if (IS_DAX(inode)) { |
|
error = iomap_zero_range(inode, newsize, |
|
PAGE_ALIGN(newsize) - newsize, NULL, |
|
&ext2_iomap_ops); |
|
} else if (test_opt(inode->i_sb, NOBH)) |
|
error = nobh_truncate_page(inode->i_mapping, |
|
newsize, ext2_get_block); |
|
else |
|
error = block_truncate_page(inode->i_mapping, |
|
newsize, ext2_get_block); |
|
if (error) |
|
return error; |
|
|
|
dax_sem_down_write(EXT2_I(inode)); |
|
truncate_setsize(inode, newsize); |
|
__ext2_truncate_blocks(inode, newsize); |
|
dax_sem_up_write(EXT2_I(inode)); |
|
|
|
inode->i_mtime = inode->i_ctime = current_time(inode); |
|
if (inode_needs_sync(inode)) { |
|
sync_mapping_buffers(inode->i_mapping); |
|
sync_inode_metadata(inode, 1); |
|
} else { |
|
mark_inode_dirty(inode); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, |
|
struct buffer_head **p) |
|
{ |
|
struct buffer_head * bh; |
|
unsigned long block_group; |
|
unsigned long block; |
|
unsigned long offset; |
|
struct ext2_group_desc * gdp; |
|
|
|
*p = NULL; |
|
if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || |
|
ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) |
|
goto Einval; |
|
|
|
block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); |
|
gdp = ext2_get_group_desc(sb, block_group, NULL); |
|
if (!gdp) |
|
goto Egdp; |
|
/* |
|
* Figure out the offset within the block group inode table |
|
*/ |
|
offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); |
|
block = le32_to_cpu(gdp->bg_inode_table) + |
|
(offset >> EXT2_BLOCK_SIZE_BITS(sb)); |
|
if (!(bh = sb_bread(sb, block))) |
|
goto Eio; |
|
|
|
*p = bh; |
|
offset &= (EXT2_BLOCK_SIZE(sb) - 1); |
|
return (struct ext2_inode *) (bh->b_data + offset); |
|
|
|
Einval: |
|
ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", |
|
(unsigned long) ino); |
|
return ERR_PTR(-EINVAL); |
|
Eio: |
|
ext2_error(sb, "ext2_get_inode", |
|
"unable to read inode block - inode=%lu, block=%lu", |
|
(unsigned long) ino, block); |
|
Egdp: |
|
return ERR_PTR(-EIO); |
|
} |
|
|
|
void ext2_set_inode_flags(struct inode *inode) |
|
{ |
|
unsigned int flags = EXT2_I(inode)->i_flags; |
|
|
|
inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | |
|
S_DIRSYNC | S_DAX); |
|
if (flags & EXT2_SYNC_FL) |
|
inode->i_flags |= S_SYNC; |
|
if (flags & EXT2_APPEND_FL) |
|
inode->i_flags |= S_APPEND; |
|
if (flags & EXT2_IMMUTABLE_FL) |
|
inode->i_flags |= S_IMMUTABLE; |
|
if (flags & EXT2_NOATIME_FL) |
|
inode->i_flags |= S_NOATIME; |
|
if (flags & EXT2_DIRSYNC_FL) |
|
inode->i_flags |= S_DIRSYNC; |
|
if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) |
|
inode->i_flags |= S_DAX; |
|
} |
|
|
|
void ext2_set_file_ops(struct inode *inode) |
|
{ |
|
inode->i_op = &ext2_file_inode_operations; |
|
inode->i_fop = &ext2_file_operations; |
|
if (IS_DAX(inode)) |
|
inode->i_mapping->a_ops = &ext2_dax_aops; |
|
else if (test_opt(inode->i_sb, NOBH)) |
|
inode->i_mapping->a_ops = &ext2_nobh_aops; |
|
else |
|
inode->i_mapping->a_ops = &ext2_aops; |
|
} |
|
|
|
struct inode *ext2_iget (struct super_block *sb, unsigned long ino) |
|
{ |
|
struct ext2_inode_info *ei; |
|
struct buffer_head * bh = NULL; |
|
struct ext2_inode *raw_inode; |
|
struct inode *inode; |
|
long ret = -EIO; |
|
int n; |
|
uid_t i_uid; |
|
gid_t i_gid; |
|
|
|
inode = iget_locked(sb, ino); |
|
if (!inode) |
|
return ERR_PTR(-ENOMEM); |
|
if (!(inode->i_state & I_NEW)) |
|
return inode; |
|
|
|
ei = EXT2_I(inode); |
|
ei->i_block_alloc_info = NULL; |
|
|
|
raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); |
|
if (IS_ERR(raw_inode)) { |
|
ret = PTR_ERR(raw_inode); |
|
goto bad_inode; |
|
} |
|
|
|
inode->i_mode = le16_to_cpu(raw_inode->i_mode); |
|
i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); |
|
i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); |
|
if (!(test_opt (inode->i_sb, NO_UID32))) { |
|
i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; |
|
i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; |
|
} |
|
i_uid_write(inode, i_uid); |
|
i_gid_write(inode, i_gid); |
|
set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); |
|
inode->i_size = le32_to_cpu(raw_inode->i_size); |
|
inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); |
|
inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); |
|
inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); |
|
inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; |
|
ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); |
|
/* We now have enough fields to check if the inode was active or not. |
|
* This is needed because nfsd might try to access dead inodes |
|
* the test is that same one that e2fsck uses |
|
* NeilBrown 1999oct15 |
|
*/ |
|
if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { |
|
/* this inode is deleted */ |
|
ret = -ESTALE; |
|
goto bad_inode; |
|
} |
|
inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); |
|
ei->i_flags = le32_to_cpu(raw_inode->i_flags); |
|
ext2_set_inode_flags(inode); |
|
ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); |
|
ei->i_frag_no = raw_inode->i_frag; |
|
ei->i_frag_size = raw_inode->i_fsize; |
|
ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); |
|
ei->i_dir_acl = 0; |
|
|
|
if (ei->i_file_acl && |
|
!ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) { |
|
ext2_error(sb, "ext2_iget", "bad extended attribute block %u", |
|
ei->i_file_acl); |
|
ret = -EFSCORRUPTED; |
|
goto bad_inode; |
|
} |
|
|
|
if (S_ISREG(inode->i_mode)) |
|
inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; |
|
else |
|
ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); |
|
if (i_size_read(inode) < 0) { |
|
ret = -EFSCORRUPTED; |
|
goto bad_inode; |
|
} |
|
ei->i_dtime = 0; |
|
inode->i_generation = le32_to_cpu(raw_inode->i_generation); |
|
ei->i_state = 0; |
|
ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); |
|
ei->i_dir_start_lookup = 0; |
|
|
|
/* |
|
* NOTE! The in-memory inode i_data array is in little-endian order |
|
* even on big-endian machines: we do NOT byteswap the block numbers! |
|
*/ |
|
for (n = 0; n < EXT2_N_BLOCKS; n++) |
|
ei->i_data[n] = raw_inode->i_block[n]; |
|
|
|
if (S_ISREG(inode->i_mode)) { |
|
ext2_set_file_ops(inode); |
|
} else if (S_ISDIR(inode->i_mode)) { |
|
inode->i_op = &ext2_dir_inode_operations; |
|
inode->i_fop = &ext2_dir_operations; |
|
if (test_opt(inode->i_sb, NOBH)) |
|
inode->i_mapping->a_ops = &ext2_nobh_aops; |
|
else |
|
inode->i_mapping->a_ops = &ext2_aops; |
|
} else if (S_ISLNK(inode->i_mode)) { |
|
if (ext2_inode_is_fast_symlink(inode)) { |
|
inode->i_link = (char *)ei->i_data; |
|
inode->i_op = &ext2_fast_symlink_inode_operations; |
|
nd_terminate_link(ei->i_data, inode->i_size, |
|
sizeof(ei->i_data) - 1); |
|
} else { |
|
inode->i_op = &ext2_symlink_inode_operations; |
|
inode_nohighmem(inode); |
|
if (test_opt(inode->i_sb, NOBH)) |
|
inode->i_mapping->a_ops = &ext2_nobh_aops; |
|
else |
|
inode->i_mapping->a_ops = &ext2_aops; |
|
} |
|
} else { |
|
inode->i_op = &ext2_special_inode_operations; |
|
if (raw_inode->i_block[0]) |
|
init_special_inode(inode, inode->i_mode, |
|
old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); |
|
else |
|
init_special_inode(inode, inode->i_mode, |
|
new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); |
|
} |
|
brelse (bh); |
|
unlock_new_inode(inode); |
|
return inode; |
|
|
|
bad_inode: |
|
brelse(bh); |
|
iget_failed(inode); |
|
return ERR_PTR(ret); |
|
} |
|
|
|
static int __ext2_write_inode(struct inode *inode, int do_sync) |
|
{ |
|
struct ext2_inode_info *ei = EXT2_I(inode); |
|
struct super_block *sb = inode->i_sb; |
|
ino_t ino = inode->i_ino; |
|
uid_t uid = i_uid_read(inode); |
|
gid_t gid = i_gid_read(inode); |
|
struct buffer_head * bh; |
|
struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); |
|
int n; |
|
int err = 0; |
|
|
|
if (IS_ERR(raw_inode)) |
|
return -EIO; |
|
|
|
/* For fields not not tracking in the in-memory inode, |
|
* initialise them to zero for new inodes. */ |
|
if (ei->i_state & EXT2_STATE_NEW) |
|
memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); |
|
|
|
raw_inode->i_mode = cpu_to_le16(inode->i_mode); |
|
if (!(test_opt(sb, NO_UID32))) { |
|
raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); |
|
raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); |
|
/* |
|
* Fix up interoperability with old kernels. Otherwise, old inodes get |
|
* re-used with the upper 16 bits of the uid/gid intact |
|
*/ |
|
if (!ei->i_dtime) { |
|
raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); |
|
raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); |
|
} else { |
|
raw_inode->i_uid_high = 0; |
|
raw_inode->i_gid_high = 0; |
|
} |
|
} else { |
|
raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); |
|
raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); |
|
raw_inode->i_uid_high = 0; |
|
raw_inode->i_gid_high = 0; |
|
} |
|
raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); |
|
raw_inode->i_size = cpu_to_le32(inode->i_size); |
|
raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); |
|
raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); |
|
raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); |
|
|
|
raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); |
|
raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); |
|
raw_inode->i_flags = cpu_to_le32(ei->i_flags); |
|
raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); |
|
raw_inode->i_frag = ei->i_frag_no; |
|
raw_inode->i_fsize = ei->i_frag_size; |
|
raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); |
|
if (!S_ISREG(inode->i_mode)) |
|
raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); |
|
else { |
|
raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); |
|
if (inode->i_size > 0x7fffffffULL) { |
|
if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, |
|
EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || |
|
EXT2_SB(sb)->s_es->s_rev_level == |
|
cpu_to_le32(EXT2_GOOD_OLD_REV)) { |
|
/* If this is the first large file |
|
* created, add a flag to the superblock. |
|
*/ |
|
spin_lock(&EXT2_SB(sb)->s_lock); |
|
ext2_update_dynamic_rev(sb); |
|
EXT2_SET_RO_COMPAT_FEATURE(sb, |
|
EXT2_FEATURE_RO_COMPAT_LARGE_FILE); |
|
spin_unlock(&EXT2_SB(sb)->s_lock); |
|
ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1); |
|
} |
|
} |
|
} |
|
|
|
raw_inode->i_generation = cpu_to_le32(inode->i_generation); |
|
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { |
|
if (old_valid_dev(inode->i_rdev)) { |
|
raw_inode->i_block[0] = |
|
cpu_to_le32(old_encode_dev(inode->i_rdev)); |
|
raw_inode->i_block[1] = 0; |
|
} else { |
|
raw_inode->i_block[0] = 0; |
|
raw_inode->i_block[1] = |
|
cpu_to_le32(new_encode_dev(inode->i_rdev)); |
|
raw_inode->i_block[2] = 0; |
|
} |
|
} else for (n = 0; n < EXT2_N_BLOCKS; n++) |
|
raw_inode->i_block[n] = ei->i_data[n]; |
|
mark_buffer_dirty(bh); |
|
if (do_sync) { |
|
sync_dirty_buffer(bh); |
|
if (buffer_req(bh) && !buffer_uptodate(bh)) { |
|
printk ("IO error syncing ext2 inode [%s:%08lx]\n", |
|
sb->s_id, (unsigned long) ino); |
|
err = -EIO; |
|
} |
|
} |
|
ei->i_state &= ~EXT2_STATE_NEW; |
|
brelse (bh); |
|
return err; |
|
} |
|
|
|
int ext2_write_inode(struct inode *inode, struct writeback_control *wbc) |
|
{ |
|
return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); |
|
} |
|
|
|
int ext2_getattr(struct user_namespace *mnt_userns, const struct path *path, |
|
struct kstat *stat, u32 request_mask, unsigned int query_flags) |
|
{ |
|
struct inode *inode = d_inode(path->dentry); |
|
struct ext2_inode_info *ei = EXT2_I(inode); |
|
unsigned int flags; |
|
|
|
flags = ei->i_flags & EXT2_FL_USER_VISIBLE; |
|
if (flags & EXT2_APPEND_FL) |
|
stat->attributes |= STATX_ATTR_APPEND; |
|
if (flags & EXT2_COMPR_FL) |
|
stat->attributes |= STATX_ATTR_COMPRESSED; |
|
if (flags & EXT2_IMMUTABLE_FL) |
|
stat->attributes |= STATX_ATTR_IMMUTABLE; |
|
if (flags & EXT2_NODUMP_FL) |
|
stat->attributes |= STATX_ATTR_NODUMP; |
|
stat->attributes_mask |= (STATX_ATTR_APPEND | |
|
STATX_ATTR_COMPRESSED | |
|
STATX_ATTR_ENCRYPTED | |
|
STATX_ATTR_IMMUTABLE | |
|
STATX_ATTR_NODUMP); |
|
|
|
generic_fillattr(&init_user_ns, inode, stat); |
|
return 0; |
|
} |
|
|
|
int ext2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, |
|
struct iattr *iattr) |
|
{ |
|
struct inode *inode = d_inode(dentry); |
|
int error; |
|
|
|
error = setattr_prepare(&init_user_ns, dentry, iattr); |
|
if (error) |
|
return error; |
|
|
|
if (is_quota_modification(inode, iattr)) { |
|
error = dquot_initialize(inode); |
|
if (error) |
|
return error; |
|
} |
|
if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) || |
|
(iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) { |
|
error = dquot_transfer(inode, iattr); |
|
if (error) |
|
return error; |
|
} |
|
if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) { |
|
error = ext2_setsize(inode, iattr->ia_size); |
|
if (error) |
|
return error; |
|
} |
|
setattr_copy(&init_user_ns, inode, iattr); |
|
if (iattr->ia_valid & ATTR_MODE) |
|
error = posix_acl_chmod(&init_user_ns, inode, inode->i_mode); |
|
mark_inode_dirty(inode); |
|
|
|
return error; |
|
}
|
|
|