This is a note to let you know that I've just added the patch titled xfs: return errors from partial I/O failures to files to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: xfs-return-errors-from-partial-i-o-failures-to-files.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c9eb256eda4420c06bb10f5e8fbdbe1a34bc98e0 Mon Sep 17 00:00:00 2001 From: David Jeffery <djeffery@xxxxxxxxxx> Date: Fri, 28 Aug 2015 14:50:45 +1000 Subject: xfs: return errors from partial I/O failures to files From: David Jeffery <djeffery@xxxxxxxxxx> commit c9eb256eda4420c06bb10f5e8fbdbe1a34bc98e0 upstream. There is an issue with xfs's error reporting in some cases of I/O partially failing and partially succeeding. Calls like fsync() can report success even though not all I/O was successful in partial-failure cases such as one disk of a RAID0 array being offline. The issue can occur when there are more than one bio per xfs_ioend struct. Each call to xfs_end_bio() for a bio completing will write a value to ioend->io_error. If a successful bio completes after any failed bio, no error is reported do to it writing 0 over the error code set by any failed bio. The I/O error information is now lost and when the ioend is completed only success is reported back up the filesystem stack. xfs_end_bio() should only set ioend->io_error in the case of BIO_UPTODATE being clear. ioend->io_error is initialized to 0 at allocation so only needs to be updated by a failed bio. Also check that ioend->io_error is 0 so that the first error reported will be the error code returned. Signed-off-by: David Jeffery <djeffery@xxxxxxxxxx> Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/xfs/xfs_aops.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -356,7 +356,8 @@ xfs_end_bio( { xfs_ioend_t *ioend = bio->bi_private; - ioend->io_error = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : error; + if (!ioend->io_error && !test_bit(BIO_UPTODATE, &bio->bi_flags)) + ioend->io_error = error; /* Toss bio and pass work off to an xfsdatad thread */ bio->bi_private = NULL; Patches currently in stable-queue which might be from djeffery@xxxxxxxxxx are queue-4.2/xfs-return-errors-from-partial-i-o-failures-to-files.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html