This is a note to let you know that I've just added the patch titled block: check virt boundary in bio_will_gap() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: block-check-virt-boundary-in-bio_will_gap.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e0af29171aa8912e1ca95023b75ef336cd70d661 Mon Sep 17 00:00:00 2001 From: Ming Lei <ming.lei@xxxxxxxxxxxxx> Date: Fri, 26 Feb 2016 23:40:51 +0800 Subject: block: check virt boundary in bio_will_gap() From: Ming Lei <ming.lei@xxxxxxxxxxxxx> commit e0af29171aa8912e1ca95023b75ef336cd70d661 upstream. 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. Reviewed-by: Sagi Grimberg <sagig@xxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/linux/blkdev.h | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1367,6 +1367,13 @@ static inline void put_dev_sector(Sector 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. @@ -1376,18 +1383,17 @@ static inline bool bvec_gap_to_prev(stru { 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], - next->bi_io_vec[0].bv_offset); + return __bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1], + next->bi_io_vec[0].bv_offset); } static inline bool req_gap_back_merge(struct request *req, struct bio *bio) Patches currently in stable-queue which might be from ming.lei@xxxxxxxxxxxxx are queue-4.4/block-bio-introduce-helpers-to-get-the-1st-and-last-bvec.patch queue-4.4/block-check-virt-boundary-in-bio_will_gap.patch queue-4.4/block-get-the-1st-and-last-bvec-via-helpers.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html