mirror of https://gitee.com/openkylin/linux.git
block: stop calling blk_queue_bounce for passthrough requests
Instead of overloading the passthrough fast path with the deprecated block layer bounce buffering let the users that combine an old undermaintained driver with a highmem system pay the price by always falling back to copies in that case. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210331073001.46776-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig
Jens Axboe
parent
9bb33f24ab
commit
393bb12e00
116
block/blk-map.c
116
block/blk-map.c
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@ -123,7 +123,6 @@ static int bio_uncopy_user(struct bio *bio)
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bio_free_pages(bio);
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}
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kfree(bmd);
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bio_put(bio);
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return ret;
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}
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@ -132,7 +131,7 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,
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{
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struct bio_map_data *bmd;
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struct page *page;
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struct bio *bio, *bounce_bio;
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struct bio *bio;
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int i = 0, ret;
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int nr_pages;
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unsigned int len = iter->count;
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@ -218,16 +217,9 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,
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bio->bi_private = bmd;
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bounce_bio = bio;
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ret = blk_rq_append_bio(rq, &bounce_bio);
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ret = blk_rq_append_bio(rq, bio);
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if (ret)
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goto cleanup;
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/*
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* We link the bounce buffer in and could have to traverse it later, so
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* we have to get a ref to prevent it from being freed
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*/
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bio_get(bounce_bio);
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return 0;
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cleanup:
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if (!map_data)
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@ -242,7 +234,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
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gfp_t gfp_mask)
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{
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unsigned int max_sectors = queue_max_hw_sectors(rq->q);
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struct bio *bio, *bounce_bio;
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struct bio *bio;
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int ret;
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int j;
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@ -304,49 +296,17 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
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break;
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}
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/*
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* Subtle: if we end up needing to bounce a bio, it would normally
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* disappear when its bi_end_io is run. However, we need the original
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* bio for the unmap, so grab an extra reference to it
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*/
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bio_get(bio);
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bounce_bio = bio;
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ret = blk_rq_append_bio(rq, &bounce_bio);
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ret = blk_rq_append_bio(rq, bio);
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if (ret)
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goto out_put_orig;
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/*
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* We link the bounce buffer in and could have to traverse it
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* later, so we have to get a ref to prevent it from being freed
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*/
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bio_get(bounce_bio);
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goto out_unmap;
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return 0;
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out_put_orig:
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bio_put(bio);
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out_unmap:
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bio_release_pages(bio, false);
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bio_put(bio);
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return ret;
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}
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/**
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* bio_unmap_user - unmap a bio
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* @bio: the bio being unmapped
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*
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* Unmap a bio previously mapped by bio_map_user_iov(). Must be called from
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* process context.
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*
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* bio_unmap_user() may sleep.
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*/
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static void bio_unmap_user(struct bio *bio)
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{
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bio_release_pages(bio, bio_data_dir(bio) == READ);
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bio_put(bio);
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bio_put(bio);
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}
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static void bio_invalidate_vmalloc_pages(struct bio *bio)
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{
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#ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
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@ -519,33 +479,27 @@ static struct bio *bio_copy_kern(struct request_queue *q, void *data,
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* Append a bio to a passthrough request. Only works if the bio can be merged
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* into the request based on the driver constraints.
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*/
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int blk_rq_append_bio(struct request *rq, struct bio **bio)
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int blk_rq_append_bio(struct request *rq, struct bio *bio)
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{
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struct bio *orig_bio = *bio;
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struct bvec_iter iter;
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struct bio_vec bv;
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unsigned int nr_segs = 0;
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blk_queue_bounce(rq->q, bio);
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if (WARN_ON_ONCE(rq->q->limits.bounce != BLK_BOUNCE_NONE))
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return -EINVAL;
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bio_for_each_bvec(bv, *bio, iter)
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bio_for_each_bvec(bv, bio, iter)
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nr_segs++;
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if (!rq->bio) {
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blk_rq_bio_prep(rq, *bio, nr_segs);
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blk_rq_bio_prep(rq, bio, nr_segs);
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} else {
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if (!ll_back_merge_fn(rq, *bio, nr_segs)) {
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if (orig_bio != *bio) {
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bio_put(*bio);
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*bio = orig_bio;
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}
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if (!ll_back_merge_fn(rq, bio, nr_segs))
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return -EINVAL;
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}
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rq->biotail->bi_next = *bio;
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rq->biotail = *bio;
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rq->__data_len += (*bio)->bi_iter.bi_size;
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bio_crypt_free_ctx(*bio);
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rq->biotail->bi_next = bio;
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rq->biotail = bio;
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rq->__data_len += (bio)->bi_iter.bi_size;
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bio_crypt_free_ctx(bio);
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}
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return 0;
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@ -566,12 +520,6 @@ EXPORT_SYMBOL(blk_rq_append_bio);
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*
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* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
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* still in process context.
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*
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* Note: The mapped bio may need to be bounced through blk_queue_bounce()
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* before being submitted to the device, as pages mapped may be out of
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* reach. It's the callers responsibility to make sure this happens. The
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* original bio must be passed back in to blk_rq_unmap_user() for proper
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* unmapping.
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*/
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int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
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struct rq_map_data *map_data,
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@ -588,6 +536,8 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
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if (map_data)
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copy = true;
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else if (blk_queue_may_bounce(q))
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copy = true;
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else if (iov_iter_alignment(iter) & align)
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copy = true;
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else if (queue_virt_boundary(q))
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@ -641,25 +591,21 @@ EXPORT_SYMBOL(blk_rq_map_user);
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*/
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int blk_rq_unmap_user(struct bio *bio)
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{
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struct bio *mapped_bio;
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struct bio *next_bio;
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int ret = 0, ret2;
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while (bio) {
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mapped_bio = bio;
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if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
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mapped_bio = bio->bi_private;
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if (bio->bi_private) {
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ret2 = bio_uncopy_user(mapped_bio);
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ret2 = bio_uncopy_user(bio);
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if (ret2 && !ret)
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ret = ret2;
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} else {
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bio_unmap_user(mapped_bio);
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bio_release_pages(bio, bio_data_dir(bio) == READ);
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}
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mapped_bio = bio;
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next_bio = bio;
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bio = bio->bi_next;
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bio_put(mapped_bio);
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bio_put(next_bio);
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}
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return ret;
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@ -684,7 +630,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
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{
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int reading = rq_data_dir(rq) == READ;
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unsigned long addr = (unsigned long) kbuf;
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struct bio *bio, *orig_bio;
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struct bio *bio;
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int ret;
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if (len > (queue_max_hw_sectors(q) << 9))
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@ -692,7 +638,8 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
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if (!len || !kbuf)
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return -EINVAL;
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if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf))
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if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf) ||
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blk_queue_may_bounce(q))
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bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
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else
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bio = bio_map_kern(q, kbuf, len, gfp_mask);
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@ -703,14 +650,9 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
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bio->bi_opf &= ~REQ_OP_MASK;
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bio->bi_opf |= req_op(rq);
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orig_bio = bio;
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ret = blk_rq_append_bio(rq, &bio);
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if (unlikely(ret)) {
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/* request is too big */
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bio_put(orig_bio);
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return ret;
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}
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return 0;
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ret = blk_rq_append_bio(rq, bio);
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if (unlikely(ret))
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bio_put(bio);
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return ret;
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}
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EXPORT_SYMBOL(blk_rq_map_kern);
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@ -180,12 +180,8 @@ static struct bio *bounce_clone_bio(struct bio *bio_src)
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* asking for trouble and would force extra work on
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* __bio_clone_fast() anyways.
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*/
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if (bio_is_passthrough(bio_src))
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bio = bio_kmalloc(GFP_NOIO | __GFP_NOFAIL,
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bio_segments(bio_src));
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else
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bio = bio_alloc_bioset(GFP_NOIO, bio_segments(bio_src),
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&bounce_bio_set);
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bio = bio_alloc_bioset(GFP_NOIO, bio_segments(bio_src),
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&bounce_bio_set);
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bio->bi_bdev = bio_src->bi_bdev;
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if (bio_flagged(bio_src, BIO_REMAPPED))
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bio_set_flag(bio, BIO_REMAPPED);
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@ -245,8 +241,7 @@ void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
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if (!bounce)
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return;
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if (!bio_is_passthrough(*bio_orig) &&
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sectors < bio_sectors(*bio_orig)) {
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if (sectors < bio_sectors(*bio_orig)) {
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bio = bio_split(*bio_orig, sectors, GFP_NOIO, &bounce_bio_split);
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bio_chain(bio, *bio_orig);
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submit_bio_noacct(*bio_orig);
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@ -660,7 +660,7 @@ static struct request *nvme_nvm_alloc_request(struct request_queue *q,
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rq->cmd_flags &= ~REQ_FAILFAST_DRIVER;
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if (rqd->bio)
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blk_rq_append_bio(rq, &rqd->bio);
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blk_rq_append_bio(rq, rqd->bio);
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else
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rq->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM);
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@ -911,7 +911,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
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" %d i: %d bio: %p, allocating another"
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" bio\n", bio->bi_vcnt, i, bio);
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rc = blk_rq_append_bio(req, &bio);
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rc = blk_rq_append_bio(req, bio);
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if (rc) {
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pr_err("pSCSI: failed to append bio\n");
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goto fail;
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@ -930,7 +930,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
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}
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if (bio) {
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rc = blk_rq_append_bio(req, &bio);
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rc = blk_rq_append_bio(req, bio);
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if (rc) {
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pr_err("pSCSI: failed to append bio\n");
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goto fail;
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@ -909,7 +909,7 @@ extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
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extern void blk_rq_unprep_clone(struct request *rq);
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extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
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struct request *rq);
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extern int blk_rq_append_bio(struct request *rq, struct bio **bio);
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int blk_rq_append_bio(struct request *rq, struct bio *bio);
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extern void blk_queue_split(struct bio **);
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extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
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extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t,
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