From: Liu Bo bo.li.liu@oracle.com
[ Upstream commit e3d37faba2eb19a1d459917bbf54ac1c65711510 ]
With raid1 profile, dio read isn't tolerating IO errors if read length is less than the stripe length (64K).
Our bio didn't get split in btrfs_submit_direct_hook() if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) is true and that happens when the read length is less than 64k. In this case, if the underlying device returns error somehow, bio->bi_error has recorded that error.
If we could recover the correct data from another copy in profile raid1/10/5/6, with btrfs_subio_endio_read() returning 0, bio would have the correct data in its vector, but bio->bi_error is not updated accordingly so that the following dio_end_io(dio_bio, bio->bi_error) makes directIO think this read has failed.
This fixes the problem by setting bio's error to 0 if a good copy has been found.
Signed-off-by: Liu Bo bo.li.liu@oracle.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- fs/btrfs/inode.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 81b5a461d94e..d56520e52dce 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8029,8 +8029,11 @@ static void btrfs_endio_direct_read(struct bio *bio) struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); int err = bio->bi_error;
- if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) + if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) { err = btrfs_subio_endio_read(inode, io_bio, err); + if (!err) + bio->bi_error = 0; + }
unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, dip->logical_offset + dip->bytes - 1);