From: Christoph Hellwig Date: Sat, 3 Jun 2017 07:37:57 +0000 (+0200) Subject: dm: fix REQ_RAHEAD handling X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=9966afaf91b37e8c3d106379eeae0afa91c68aa8;p=openwrt%2Fstaging%2Fblogic.git dm: fix REQ_RAHEAD handling A few (but not all) dm targets use a special EWOULDBLOCK error code for failing REQ_RAHEAD requests that fail due to a lack of available resources. But no one else knows about this magic code, and lower level drivers also don't generate it when failing read-ahead requests for similar reasons. So remove this special casing and ignore all additional error handling for REQ_RAHEAD - if this was a real underlying error we'd get a normal read once the real read comes in. Signed-off-by: Christoph Hellwig Reviewed-by: Bart Van Assche Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe --- diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index a95cbb80fb34..5e30b08b91d9 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -1214,7 +1214,7 @@ static int mirror_map(struct dm_target *ti, struct bio *bio) */ if (!r || (r == -EWOULDBLOCK)) { if (bio->bi_opf & REQ_RAHEAD) - return -EWOULDBLOCK; + return -EIO; queue_bio(ms, bio, rw); return DM_MAPIO_SUBMITTED; @@ -1258,7 +1258,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error) if (error == -EOPNOTSUPP) return error; - if ((error == -EWOULDBLOCK) && (bio->bi_opf & REQ_RAHEAD)) + if (bio->bi_opf & REQ_RAHEAD) return error; if (unlikely(error)) { diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index 75152482f3ad..780e95889a7c 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -384,7 +384,7 @@ static int stripe_end_io(struct dm_target *ti, struct bio *bio, int error) if (!error) return 0; /* I/O complete */ - if ((error == -EWOULDBLOCK) && (bio->bi_opf & REQ_RAHEAD)) + if (bio->bi_opf & REQ_RAHEAD) return error; if (error == -EOPNOTSUPP)