Messages in this thread Patch in this message | | | From | Ming Lei <> | Subject | [PATCH v1 2/4] block: check virt boundary in bio_will_gap() | Date | Fri, 19 Feb 2016 11:20:20 +0800 |
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In the following patch, the way for figuring out the last bvec will be changed with a bit cost introduced, so return immediately if the queue doesn't have virt boundary limit. Actually most of devices have not this limit.
Cc: Sagi Grimberg <sagig@dev.mellanox.co.il> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> --- include/linux/blkdev.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 4571ef1..5023401 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1372,6 +1372,13 @@ static inline void put_dev_sector(Sector p) page_cache_release(p.v); } +static inline bool __bvec_gap_to_prev(struct request_queue *q, + struct bio_vec *bprv, unsigned int offset) +{ + return offset || + ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); +} + /* * Check if adding a bio_vec after bprv with offset would create a gap in * the SG list. Most drivers don't care about this, but some do. @@ -1381,14 +1388,13 @@ static inline bool bvec_gap_to_prev(struct request_queue *q, { if (!queue_virt_boundary(q)) return false; - return offset || - ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); + return __bvec_gap_to_prev(q, bprv, offset); } static inline bool bio_will_gap(struct request_queue *q, struct bio *prev, struct bio *next) { - if (!bio_has_data(prev)) + if (!bio_has_data(prev) || !queue_virt_boundary(q)) return false; return bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1], -- 1.9.1
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