The patch titled ext3: don't read inode block if the buffer has a write error has been added to the -mm tree. Its filename is ext3-dont-read-inode-block-if-the-buffer-has-a-write-error.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: ext3: don't read inode block if the buffer has a write error From: Hidehiro Kawai <hidehiro.kawai.ez@xxxxxxxxxxx> 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 __ext3_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 __ext3_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@xxxxxxxxxxx> Cc: sugita <yumiko.sugita.yf@xxxxxxxxxxx> Cc: Satoshi OSHIMA <satoshi.oshima.fk@xxxxxxxxxxx> Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx> Cc: Jan Kara <jack@xxxxxx> Cc: <linux-ext4@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ext3/inode.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff -puN fs/ext3/inode.c~ext3-dont-read-inode-block-if-the-buffer-has-a-write-error fs/ext3/inode.c --- a/fs/ext3/inode.c~ext3-dont-read-inode-block-if-the-buffer-has-a-write-error +++ a/fs/ext3/inode.c @@ -2525,6 +2525,16 @@ static int __ext3_get_inode_loc(struct i } 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); _ Patches currently in -mm which might be from hidehiro.kawai.ez@xxxxxxxxxxx are ext3-dont-read-inode-block-if-the-buffer-has-a-write-error.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html