[PATCH 11/41] block: filter flush bio's in __generic_make_request()
From: Tejun Heo <tj@kernel.org>
Date: 2010-09-03 10:29:26
Also in:
dm-devel, linux-fsdevel, linux-ide, linux-scsi, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
There are a number of make_request based drivers which don't support cache flushes. Filter out flush bio's in __generic_make_request() so that they don't have to worry about them. All FLUSH/FUA requests with data are converted to regular IO requests and empty ones are completed immediately. Signed-off-by: Tejun Heo <tj@kernel.org> --- block/blk-core.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 18455c4..495bdc4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c@@ -1509,6 +1509,19 @@ static inline void __generic_make_request(struct bio *bio) if (bio_check_eod(bio, nr_sectors)) goto end_io; + /* + * Filter flush bio's early so that make_request based + * drivers without flush support don't have to worry + * about them. + */ + if ((bio->bi_rw & (REQ_FLUSH | REQ_FUA)) && !q->flush_flags) { + bio->bi_rw &= ~(REQ_FLUSH | REQ_FUA); + if (!nr_sectors) { + err = 0; + goto end_io; + } + } + if ((bio->bi_rw & REQ_DISCARD) && (!blk_queue_discard(q) || ((bio->bi_rw & REQ_SECURE) &&
--
1.7.1