dm: fix REQ_RAHEAD handling
authorChristoph Hellwig <hch@lst.de>
Sat, 3 Jun 2017 07:37:57 +0000 (09:37 +0200)
committerJens Axboe <axboe@fb.com>
Fri, 9 Jun 2017 15:27:32 +0000 (09:27 -0600)
commit9966afaf91b37e8c3d106379eeae0afa91c68aa8
treea5d06e2c647e3e74c2238f20270512e7bdd50ec6
parentf729b66fca43d850d564b264c2033980c00a14b0
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 <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
drivers/md/dm-raid1.c
drivers/md/dm-stripe.c