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| author | Alasdair G Kergon <agk@redhat.com> | 2009-04-09 00:27:14 +0100 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2009-04-09 00:27:14 +0100 |
| commit | 54d9a1b4513b96cbd835ca6866c6a604d194b2ae (patch) | |
| tree | 42813374e137f5ac6d9d7aedfae02a089b6443a6 /drivers/md | |
| parent | 1eb787ec183d1267cac95aae632e92dee05ed50a (diff) | |
| download | lwn-54d9a1b4513b96cbd835ca6866c6a604d194b2ae.tar.gz lwn-54d9a1b4513b96cbd835ca6866c6a604d194b2ae.zip | |
dm: simplify dm_request loop
Refactor the code in dm_request().
Require the new DMF_BLOCK_FOR_SUSPEND flag on readahead bios we will
discard so we don't drop such bios while processing a barrier.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm.c | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 7cac7220937f..bb97ec8d6644 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -929,7 +929,6 @@ out: */ static int dm_request(struct request_queue *q, struct bio *bio) { - int r = -EIO; int rw = bio_data_dir(bio); struct mapped_device *md = q->queuedata; int cpu; @@ -957,11 +956,14 @@ static int dm_request(struct request_queue *q, struct bio *bio) while (test_bit(DMF_QUEUE_IO_TO_THREAD, &md->flags)) { up_read(&md->io_lock); - if (bio_rw(bio) != READA) - r = queue_io(md, bio); + if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) && + bio_rw(bio) == READA) { + bio_io_error(bio); + return 0; + } - if (r <= 0) - goto out_req; + if (!queue_io(md, bio)) + return 0; /* * We're in a while loop, because someone could suspend @@ -973,12 +975,6 @@ static int dm_request(struct request_queue *q, struct bio *bio) __split_and_process_bio(md, bio); up_read(&md->io_lock); return 0; - -out_req: - if (r < 0) - bio_io_error(bio); - - return 0; } static void dm_unplug_all(struct request_queue *q) |