Commit a1a50f60a6bf4f861eb94793420274bc1ccd409a
Committed by
Chris Mason
Chris Mason
1 parent
7fb18a0664
Exists in
ti-lsk-linux-4.1.y
and in
10 other branches
Btrfs: read inode size after acquiring the mutex when punching a hole
In a previous change, commit 12870f1c9b2de7d475d22e73fd7db1b418599725, I accidentally moved the roundup of inode->i_size to outside of the critical section delimited by the inode mutex, which is not atomic and not correct since the size can be changed by other task before we acquire the mutex. Therefore fix it. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
Showing 1 changed file with 2 additions and 1 deletions Side-by-side Diff
fs/btrfs/file.c
| ... | ... | @@ -2187,13 +2187,14 @@ |
| 2187 | 2187 | bool same_page = ((offset >> PAGE_CACHE_SHIFT) == |
| 2188 | 2188 | ((offset + len - 1) >> PAGE_CACHE_SHIFT)); |
| 2189 | 2189 | bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES); |
| 2190 | - u64 ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE); | |
| 2190 | + u64 ino_size; | |
| 2191 | 2191 | |
| 2192 | 2192 | ret = btrfs_wait_ordered_range(inode, offset, len); |
| 2193 | 2193 | if (ret) |
| 2194 | 2194 | return ret; |
| 2195 | 2195 | |
| 2196 | 2196 | mutex_lock(&inode->i_mutex); |
| 2197 | + ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE); | |
| 2197 | 2198 | /* |
| 2198 | 2199 | * We needn't truncate any page which is beyond the end of the file |
| 2199 | 2200 | * because we are sure there is no data there. |