mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 10:29:37 +00:00
ext4: don't read inode block if the buffer has a write error
A transient I/O error can corrupt inode data. Here is the scenario: (1) update inode_A at the block_B (2) pdflush writes out new inode_A to the filesystem, but it results in write I/O error, at this point, BH_Uptodate flag of the buffer for block_B is cleared and BH_Write_EIO is set (3) create new inode_C which located at block_B, and __ext4_get_inode_loc() tries to read on-disk block_B because the buffer is not uptodate (4) if it can read on-disk block_B successfully, inode_A is overwritten by old data This patch makes __ext4_get_inode_loc() not read the inode block if the buffer has BH_Write_EIO flag. In this case, the buffer should have the latest information, so setting the uptodate flag to the buffer (this avoids WARN_ON_ONCE() in mark_buffer_dirty().) According to this change, we would need to test BH_Write_EIO flag for the error checking. Currently nobody checks write I/O errors on metadata buffers, but it will be done in other patches I'm working on. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: sugita <yumiko.sugita.yf@hitachi.com> Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Jan Kara <jack@ucw.cz> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
parent
6be2ded1d7
commit
9c83a923c6
1 changed files with 10 additions and 0 deletions
|
@ -3590,6 +3590,16 @@ static int __ext4_get_inode_loc(struct inode *inode,
|
|||
}
|
||||
if (!buffer_uptodate(bh)) {
|
||||
lock_buffer(bh);
|
||||
|
||||
/*
|
||||
* If the buffer has the write error flag, we have failed
|
||||
* to write out another inode in the same block. In this
|
||||
* case, we don't have to read the block because we may
|
||||
* read the old inode data successfully.
|
||||
*/
|
||||
if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
|
||||
set_buffer_uptodate(bh);
|
||||
|
||||
if (buffer_uptodate(bh)) {
|
||||
/* someone brought it uptodate while we waited */
|
||||
unlock_buffer(bh);
|
||||
|
|
Loading…
Reference in a new issue