From 1636d1d77ef4e01e57f706a4cae3371463896136 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Mon, 15 Feb 2016 16:20:26 +0000 Subject: [PATCH] Btrfs: fix direct IO requests not reporting IO error to user space If a bio for a direct IO request fails, we were not setting the error in the parent bio (the main DIO bio), making us not return the error to user space in btrfs_direct_IO(), that is, it made __blockdev_direct_IO() return the number of bytes issued for IO and not the error a bio created and submitted by btrfs_submit_direct() got from the block layer. This essentially happens because when we call: dio_end_io(dio_bio, bio->bi_error); It does not set dio_bio->bi_error to the value of the second argument. So just add this missing assignment in endio callbacks, just as we do in the error path at btrfs_submit_direct() when we fail to clone the dio bio or allocate its private object. This follows the convention of what is done with other similar APIs such as bio_endio() where the caller is responsible for setting the bi_error field in the bio it passes as an argument to bio_endio(). This was detected by the new generic test cases in xfstests: 271, 272, 276 and 278. Which essentially setup a dm error target, then load the error table, do a direct IO write and unload the error table. They expect the write to fail with -EIO, which was not getting reported when testing against btrfs. Cc: stable@vger.kernel.org # 4.3+ Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio") Signed-off-by: Filipe Manana --- fs/btrfs/inode.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 600bf0d9ceaf..e0ad8b2c2a36 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7985,6 +7985,7 @@ static void btrfs_endio_direct_read(struct bio *bio) kfree(dip); + dio_bio->bi_error = bio->bi_error; dio_end_io(dio_bio, bio->bi_error); if (io_bio->end_io) @@ -8039,6 +8040,7 @@ static void btrfs_endio_direct_write(struct bio *bio) kfree(dip); + dio_bio->bi_error = bio->bi_error; dio_end_io(dio_bio, bio->bi_error); bio_put(bio); } -- 2.20.1