diff options
| author | Christoph Hellwig <hch@lst.de> | 2010-06-17 09:54:32 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-06-17 10:10:53 +0200 |
| commit | fbbf055692aeb25c54c49d9ca84532de836fbba0 (patch) | |
| tree | df058ee803db2b5c8362fd2f2e8f60eacbd9138a /block/blk-core.c | |
| parent | cciss: set SCSI max cmd len to 16, as default is wrong (diff) | |
| download | linux-fbbf055692aeb25c54c49d9ca84532de836fbba0.tar.xz linux-fbbf055692aeb25c54c49d9ca84532de836fbba0.zip | |
block: fix DISCARD_BARRIER requests
Filesystems assume that DISCARD_BARRIER are full barriers, so that they
don't have to track in-progress discard operation when submitting new I/O.
But currently we only treat them as elevator barriers, which don't
actually do the nessecary queue drains.
Also remove the unlikely around both the DISCARD and BARRIER requests -
the happen far too often for a static mispredict.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/blk-core.c')
| -rw-r--r-- | block/blk-core.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index f84cce42fc58..3deca77e0254 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1149,13 +1149,10 @@ void init_request_from_bio(struct request *req, struct bio *bio) else req->cmd_flags |= bio->bi_rw & REQ_FAILFAST_MASK; - if (unlikely(bio_rw_flagged(bio, BIO_RW_DISCARD))) { + if (bio_rw_flagged(bio, BIO_RW_DISCARD)) req->cmd_flags |= REQ_DISCARD; - if (bio_rw_flagged(bio, BIO_RW_BARRIER)) - req->cmd_flags |= REQ_SOFTBARRIER; - } else if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) + if (bio_rw_flagged(bio, BIO_RW_BARRIER)) req->cmd_flags |= REQ_HARDBARRIER; - if (bio_rw_flagged(bio, BIO_RW_SYNCIO)) req->cmd_flags |= REQ_RW_SYNC; if (bio_rw_flagged(bio, BIO_RW_META)) |