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| author | Jens Axboe <jens.axboe@oracle.com> | 2007-09-27 13:01:25 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2007-10-16 11:03:56 +0200 |
| commit | bf2de6f5a4faf0197268f18d08969b003b87b6e8 (patch) | |
| tree | 16830a15a7effea352445a7aba5dbb433314d3eb /mm/bounce.c | |
| parent | c07e2b41291853b19fff11ceee3657df252a4e42 (diff) | |
| download | linux-bf2de6f5a4faf0197268f18d08969b003b87b6e8.tar.bz2 | |
block: Initial support for data-less (or empty) barrier support
This implements functionality to pass down or insert a barrier
in a queue, without having data attached to it. The ->prepare_flush_fn()
infrastructure from data barriers are reused to provide this
functionality.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'mm/bounce.c')
| -rw-r--r-- | mm/bounce.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/mm/bounce.c b/mm/bounce.c index 3b549bf31f7d..b6d2d0f1019b 100644 --- a/mm/bounce.c +++ b/mm/bounce.c @@ -265,6 +265,12 @@ void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) mempool_t *pool; /* + * Data-less bio, nothing to bounce + */ + if (bio_empty_barrier(*bio_orig)) + return; + + /* * for non-isa bounce case, just check if the bounce pfn is equal * to or bigger than the highest pfn in the system -- in that case, * don't waste time iterating over bio segments |