Merge tag 'for-5.13/block-2021-04-27' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Pretty quiet round this time, which is nice. In detail:

   - Series revamping bounce buffer support (Christoph)

   - Dead code removal (Christoph, Bart)

   - Partition iteration revamp, now using xarray (Christoph)

   - Passthrough request scheduler improvements (Lin)

   - Series of BFQ improvements (Paolo)

   - Fix ioprio task iteration (Peter)

   - Various little tweaks and fixes (Tejun, Saravanan, Bhaskar, Max,
     Nikolay)"

* tag 'for-5.13/block-2021-04-27' of git://git.kernel.dk/linux-block: (41 commits)
  blk-iocost: don't ignore vrate_min on QD contention
  blk-mq: Fix spurious debugfs directory creation during initialization
  bfq/mq-deadline: remove redundant check for passthrough request
  blk-mq: bypass IO scheduler's limit_depth for passthrough request
  block: Remove an obsolete comment from sg_io()
  block: move bio_list_copy_data to pktcdvd
  block: remove zero_fill_bio_iter
  block: add queue_to_disk() to get gendisk from request_queue
  block: remove an incorrect check from blk_rq_append_bio
  block: initialize ret in bdev_disk_changed
  block: Fix sys_ioprio_set(.which=IOPRIO_WHO_PGRP) task iteration
  block: remove disk_part_iter
  block: simplify diskstats_show
  block: simplify show_partition
  block: simplify printk_all_partitions
  block: simplify partition_overlaps
  block: simplify partition removal
  block: take bd_mutex around delete_partitions in del_gendisk
  block: refactor blk_drop_partitions
  block: move more syncing and invalidation to delete_partition
  ...

1 files changed, 29 insertions, 90 deletions

diff --git a/block/blk-map.c b/block/blk-map.c
index 1ffef782fcf2..3743158ddaeb 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -123,7 +123,6 @@ static int bio_uncopy_user(struct bio *bio)
 			bio_free_pages(bio);
 	}
 	kfree(bmd);
-	bio_put(bio);
 	return ret;
 }
 
@@ -132,7 +131,7 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,
 {
 	struct bio_map_data *bmd;
 	struct page *page;
-	struct bio *bio, *bounce_bio;
+	struct bio *bio;
 	int i = 0, ret;
 	int nr_pages;
 	unsigned int len = iter->count;
@@ -181,7 +180,7 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,
 
 			i++;
 		} else {
-			page = alloc_page(rq->q->bounce_gfp | gfp_mask);
+			page = alloc_page(GFP_NOIO | gfp_mask);
 			if (!page) {
 				ret = -ENOMEM;
 				goto cleanup;
@@ -218,16 +217,9 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,
 
 	bio->bi_private = bmd;
 
-	bounce_bio = bio;
-	ret = blk_rq_append_bio(rq, &bounce_bio);
+	ret = blk_rq_append_bio(rq, bio);
 	if (ret)
 		goto cleanup;
-
-	/*
-	 * We link the bounce buffer in and could have to traverse it later, so
-	 * we have to get a ref to prevent it from being freed
-	 */
-	bio_get(bounce_bio);
 	return 0;
 cleanup:
 	if (!map_data)
@@ -242,7 +234,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
 		gfp_t gfp_mask)
 {
 	unsigned int max_sectors = queue_max_hw_sectors(rq->q);
-	struct bio *bio, *bounce_bio;
+	struct bio *bio;
 	int ret;
 	int j;
 
@@ -304,49 +296,17 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
 			break;
 	}
 
-	/*
-	 * Subtle: if we end up needing to bounce a bio, it would normally
-	 * disappear when its bi_end_io is run.  However, we need the original
-	 * bio for the unmap, so grab an extra reference to it
-	 */
-	bio_get(bio);
-
-	bounce_bio = bio;
-	ret = blk_rq_append_bio(rq, &bounce_bio);
+	ret = blk_rq_append_bio(rq, bio);
 	if (ret)
-		goto out_put_orig;
-
-	/*
-	 * We link the bounce buffer in and could have to traverse it
-	 * later, so we have to get a ref to prevent it from being freed
-	 */
-	bio_get(bounce_bio);
+		goto out_unmap;
 	return 0;
 
- out_put_orig:
-	bio_put(bio);
  out_unmap:
 	bio_release_pages(bio, false);
 	bio_put(bio);
 	return ret;
 }
 
-/**
- *	bio_unmap_user	-	unmap a bio
- *	@bio:		the bio being unmapped
- *
- *	Unmap a bio previously mapped by bio_map_user_iov(). Must be called from
- *	process context.
- *
- *	bio_unmap_user() may sleep.
- */
-static void bio_unmap_user(struct bio *bio)
-{
-	bio_release_pages(bio, bio_data_dir(bio) == READ);
-	bio_put(bio);
-	bio_put(bio);
-}
-
 static void bio_invalidate_vmalloc_pages(struct bio *bio)
 {
 #ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
@@ -486,7 +446,7 @@ static struct bio *bio_copy_kern(struct request_queue *q, void *data,
 		if (bytes > len)
 			bytes = len;
 
-		page = alloc_page(q->bounce_gfp | gfp_mask);
+		page = alloc_page(GFP_NOIO | gfp_mask);
 		if (!page)
 			goto cleanup;
 
@@ -519,33 +479,24 @@ cleanup:
  * Append a bio to a passthrough request.  Only works if the bio can be merged
  * into the request based on the driver constraints.
  */
-int blk_rq_append_bio(struct request *rq, struct bio **bio)
+int blk_rq_append_bio(struct request *rq, struct bio *bio)
 {
-	struct bio *orig_bio = *bio;
 	struct bvec_iter iter;
 	struct bio_vec bv;
 	unsigned int nr_segs = 0;
 
-	blk_queue_bounce(rq->q, bio);
-
-	bio_for_each_bvec(bv, *bio, iter)
+	bio_for_each_bvec(bv, bio, iter)
 		nr_segs++;
 
 	if (!rq->bio) {
-		blk_rq_bio_prep(rq, *bio, nr_segs);
+		blk_rq_bio_prep(rq, bio, nr_segs);
 	} else {
-		if (!ll_back_merge_fn(rq, *bio, nr_segs)) {
-			if (orig_bio != *bio) {
-				bio_put(*bio);
-				*bio = orig_bio;
-			}
+		if (!ll_back_merge_fn(rq, bio, nr_segs))
 			return -EINVAL;
-		}
-
-		rq->biotail->bi_next = *bio;
-		rq->biotail = *bio;
-		rq->__data_len += (*bio)->bi_iter.bi_size;
-		bio_crypt_free_ctx(*bio);
+		rq->biotail->bi_next = bio;
+		rq->biotail = bio;
+		rq->__data_len += (bio)->bi_iter.bi_size;
+		bio_crypt_free_ctx(bio);
 	}
 
 	return 0;
@@ -566,12 +517,6 @@ EXPORT_SYMBOL(blk_rq_append_bio);
  *
  *    A matching blk_rq_unmap_user() must be issued at the end of I/O, while
  *    still in process context.
- *
- *    Note: The mapped bio may need to be bounced through blk_queue_bounce()
- *    before being submitted to the device, as pages mapped may be out of
- *    reach. It's the callers responsibility to make sure this happens. The
- *    original bio must be passed back in to blk_rq_unmap_user() for proper
- *    unmapping.
  */
 int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 			struct rq_map_data *map_data,
@@ -588,6 +533,8 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 
 	if (map_data)
 		copy = true;
+	else if (blk_queue_may_bounce(q))
+		copy = true;
 	else if (iov_iter_alignment(iter) & align)
 		copy = true;
 	else if (queue_virt_boundary(q))
@@ -641,25 +588,21 @@ EXPORT_SYMBOL(blk_rq_map_user);
  */
 int blk_rq_unmap_user(struct bio *bio)
 {
-	struct bio *mapped_bio;
+	struct bio *next_bio;
 	int ret = 0, ret2;
 
 	while (bio) {
-		mapped_bio = bio;
-		if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
-			mapped_bio = bio->bi_private;
-
 		if (bio->bi_private) {
-			ret2 = bio_uncopy_user(mapped_bio);
+			ret2 = bio_uncopy_user(bio);
 			if (ret2 && !ret)
 				ret = ret2;
 		} else {
-			bio_unmap_user(mapped_bio);
+			bio_release_pages(bio, bio_data_dir(bio) == READ);
 		}
 
-		mapped_bio = bio;
+		next_bio = bio;
 		bio = bio->bi_next;
-		bio_put(mapped_bio);
+		bio_put(next_bio);
 	}
 
 	return ret;
@@ -684,7 +627,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 {
 	int reading = rq_data_dir(rq) == READ;
 	unsigned long addr = (unsigned long) kbuf;
-	struct bio *bio, *orig_bio;
+	struct bio *bio;
 	int ret;
 
 	if (len > (queue_max_hw_sectors(q) << 9))
@@ -692,7 +635,8 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	if (!len || !kbuf)
 		return -EINVAL;
 
-	if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf))
+	if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf) ||
+	    blk_queue_may_bounce(q))
 		bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
 	else
 		bio = bio_map_kern(q, kbuf, len, gfp_mask);
@@ -703,14 +647,9 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	bio->bi_opf &= ~REQ_OP_MASK;
 	bio->bi_opf |= req_op(rq);
 
-	orig_bio = bio;
-	ret = blk_rq_append_bio(rq, &bio);
-	if (unlikely(ret)) {
-		/* request is too big */
-		bio_put(orig_bio);
-		return ret;
-	}
-
-	return 0;
+	ret = blk_rq_append_bio(rq, bio);
+	if (unlikely(ret))
+		bio_put(bio);
+	return ret;
 }
 EXPORT_SYMBOL(blk_rq_map_kern);