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From: Christoph Hellwig <hch@lst.de>
To: axboe@kernel.dk
Cc: linux-block@vger.kernel.org, dm-devel@redhat.com,
	linux-btrfs@vger.kernel.org
Subject: [PATCH 04/13] dm: fix REQ_RAHEAD handling
Date: Sat,  3 Jun 2017 09:37:57 +0200	[thread overview]
Message-ID: <20170603073806.2046-5-hch@lst.de> (raw)
In-Reply-To: <20170603073806.2046-1-hch@lst.de>

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>
---
 drivers/md/dm-raid1.c  | 4 ++--
 drivers/md/dm-stripe.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

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)
-- 
2.11.0


  parent reply	other threads:[~2017-06-03  7:38 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-03  7:37 dedicated error codes for the block layer V3 Christoph Hellwig
2017-06-03  7:37 ` [PATCH 01/13] nvme-lightnvm: use blk_execute_rq in nvme_nvm_submit_user_cmd Christoph Hellwig
2017-06-03  7:37 ` [PATCH 02/13] scsi/osd: don't save block errors into req_results Christoph Hellwig
2017-06-03  7:37 ` [PATCH 03/13] gfs2: remove the unused sd_log_error field Christoph Hellwig
2017-06-03  7:37 ` Christoph Hellwig [this message]
2017-06-03  7:37 ` [PATCH 05/13] fs: remove the unused error argument to dio_end_io() Christoph Hellwig
2017-06-03  7:37 ` [PATCH 06/13] fs: simplify dio_bio_complete Christoph Hellwig
2017-06-03  7:38 ` [PATCH 07/13] block_dev: propagate bio_iov_iter_get_pages error in __blkdev_direct_IO Christoph Hellwig
2017-06-03  7:38 ` [PATCH 08/13] dm mpath: merge do_end_io_bio into multipath_end_io_bio Christoph Hellwig
2017-06-03  7:38 ` [PATCH 09/13] dm: don't return errnos from ->map Christoph Hellwig
2017-06-03  7:38 ` [PATCH 10/13] dm: change ->end_io calling convention Christoph Hellwig
2017-06-03  7:38 ` [PATCH 12/13] blk-mq: switch ->queue_rq return value to blk_status_t Christoph Hellwig
2017-06-08 15:42 ` dedicated error codes for the block layer V3 Jens Axboe
2017-06-08 16:00   ` Mike Snitzer
2017-06-09 15:18   ` Mike Snitzer
2017-06-09 15:28     ` Jens Axboe
2017-06-09 15:29 ` Jens Axboe
  -- strict thread matches above, loose matches on Subject: below --
2017-05-26  8:56 dedicated error codes for the block layer V2 Christoph Hellwig
2017-05-26  8:56 ` [PATCH 04/13] dm: fix REQ_RAHEAD handling Christoph Hellwig

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