1 files changed, 64 insertions, 114 deletions

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9ebf65379556..23d7f301a196 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -9,82 +9,46 @@
 
 #include "blk.h"
 
-struct bio_batch {
-	atomic_t		done;
-	int			error;
-	struct completion	*wait;
-};
-
-static void bio_batch_end_io(struct bio *bio)
+static struct bio *next_bio(struct bio *bio, int rw, unsigned int nr_pages,
+		gfp_t gfp)
 {
-	struct bio_batch *bb = bio->bi_private;
+	struct bio *new = bio_alloc(gfp, nr_pages);
+
+	if (bio) {
+		bio_chain(bio, new);
+		submit_bio(rw, bio);
+	}
 
-	if (bio->bi_error && bio->bi_error != -EOPNOTSUPP)
-		bb->error = bio->bi_error;
-	if (atomic_dec_and_test(&bb->done))
-		complete(bb->wait);
-	bio_put(bio);
+	return new;
 }
 
-/**
- * blkdev_issue_discard - queue a discard
- * @bdev:	blockdev to issue discard for
- * @sector:	start sector
- * @nr_sects:	number of sectors to discard
- * @gfp_mask:	memory allocation flags (for bio_alloc)
- * @flags:	BLKDEV_IFL_* flags to control behaviour
- *
- * Description:
- *    Issue a discard request for the sectors in question.
- */
-int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
-		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
+int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
+		sector_t nr_sects, gfp_t gfp_mask, int type, struct bio **biop)
 {
-	DECLARE_COMPLETION_ONSTACK(wait);
 	struct request_queue *q = bdev_get_queue(bdev);
-	int type = REQ_WRITE | REQ_DISCARD;
+	struct bio *bio = *biop;
 	unsigned int granularity;
 	int alignment;
-	struct bio_batch bb;
-	struct bio *bio;
-	int ret = 0;
-	struct blk_plug plug;
 
 	if (!q)
 		return -ENXIO;
-
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
+	if ((type & REQ_SECURE) && !blk_queue_secdiscard(q))
+		return -EOPNOTSUPP;
 
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
 
-	if (flags & BLKDEV_DISCARD_SECURE) {
-		if (!blk_queue_secdiscard(q))
-			return -EOPNOTSUPP;
-		type |= REQ_SECURE;
-	}
-
-	atomic_set(&bb.done, 1);
-	bb.error = 0;
-	bb.wait = &wait;
-
-	blk_start_plug(&plug);
 	while (nr_sects) {
 		unsigned int req_sects;
 		sector_t end_sect, tmp;
 
-		bio = bio_alloc(gfp_mask, 1);
-		if (!bio) {
-			ret = -ENOMEM;
-			break;
-		}
-
 		/* Make sure bi_size doesn't overflow */
 		req_sects = min_t(sector_t, nr_sects, UINT_MAX >> 9);
 
-		/*
+		/**
 		 * If splitting a request, and the next starting sector would be
 		 * misaligned, stop the discard at the previous aligned sector.
 		 */
@@ -98,18 +62,14 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 			req_sects = end_sect - sector;
 		}
 
+		bio = next_bio(bio, type, 1, gfp_mask);
 		bio->bi_iter.bi_sector = sector;
-		bio->bi_end_io = bio_batch_end_io;
 		bio->bi_bdev = bdev;
-		bio->bi_private = &bb;
 
 		bio->bi_iter.bi_size = req_sects << 9;
 		nr_sects -= req_sects;
 		sector = end_sect;
 
-		atomic_inc(&bb.done);
-		submit_bio(type, bio);
-
 		/*
 		 * We can loop for a long time in here, if someone does
 		 * full device discards (like mkfs). Be nice and allow
@@ -118,14 +78,44 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		 */
 		cond_resched();
 	}
-	blk_finish_plug(&plug);
 
-	/* Wait for bios in-flight */
-	if (!atomic_dec_and_test(&bb.done))
-		wait_for_completion_io(&wait);
+	*biop = bio;
+	return 0;
+}
+EXPORT_SYMBOL(__blkdev_issue_discard);
+
+/**
+ * blkdev_issue_discard - queue a discard
+ * @bdev:	blockdev to issue discard for
+ * @sector:	start sector
+ * @nr_sects:	number of sectors to discard
+ * @gfp_mask:	memory allocation flags (for bio_alloc)
+ * @flags:	BLKDEV_IFL_* flags to control behaviour
+ *
+ * Description:
+ *    Issue a discard request for the sectors in question.
+ */
+int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
+		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
+{
+	int type = REQ_WRITE | REQ_DISCARD;
+	struct bio *bio = NULL;
+	struct blk_plug plug;
+	int ret;
+
+	if (flags & BLKDEV_DISCARD_SECURE)
+		type |= REQ_SECURE;
+
+	blk_start_plug(&plug);
+	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, type,
+			&bio);
+	if (!ret && bio) {
+		ret = submit_bio_wait(type, bio);
+		if (ret == -EOPNOTSUPP)
+			ret = 0;
+	}
+	blk_finish_plug(&plug);
 
-	if (bb.error)
-		return bb.error;
 	return ret;
 }
 EXPORT_SYMBOL(blkdev_issue_discard);
@@ -145,11 +135,9 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 			    sector_t nr_sects, gfp_t gfp_mask,
 			    struct page *page)
 {
-	DECLARE_COMPLETION_ONSTACK(wait);
 	struct request_queue *q = bdev_get_queue(bdev);
 	unsigned int max_write_same_sectors;
-	struct bio_batch bb;
-	struct bio *bio;
+	struct bio *bio = NULL;
 	int ret = 0;
 
 	if (!q)
@@ -158,21 +146,10 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
-	atomic_set(&bb.done, 1);
-	bb.error = 0;
-	bb.wait = &wait;
-
 	while (nr_sects) {
-		bio = bio_alloc(gfp_mask, 1);
-		if (!bio) {
-			ret = -ENOMEM;
-			break;
-		}
-
+		bio = next_bio(bio, REQ_WRITE | REQ_WRITE_SAME, 1, gfp_mask);
 		bio->bi_iter.bi_sector = sector;
-		bio->bi_end_io = bio_batch_end_io;
 		bio->bi_bdev = bdev;
-		bio->bi_private = &bb;
 		bio->bi_vcnt = 1;
 		bio->bi_io_vec->bv_page = page;
 		bio->bi_io_vec->bv_offset = 0;
@@ -186,18 +163,11 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 			bio->bi_iter.bi_size = nr_sects << 9;
 			nr_sects = 0;
 		}
-
-		atomic_inc(&bb.done);
-		submit_bio(REQ_WRITE | REQ_WRITE_SAME, bio);
 	}
 
-	/* Wait for bios in-flight */
-	if (!atomic_dec_and_test(&bb.done))
-		wait_for_completion_io(&wait);
-
-	if (bb.error)
-		return bb.error;
-	return ret;
+	if (bio)
+		ret = submit_bio_wait(REQ_WRITE | REQ_WRITE_SAME, bio);
+	return ret != -EOPNOTSUPP ? ret : 0;
 }
 EXPORT_SYMBOL(blkdev_issue_write_same);
 
@@ -216,28 +186,15 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 				  sector_t nr_sects, gfp_t gfp_mask)
 {
 	int ret;
-	struct bio *bio;
-	struct bio_batch bb;
+	struct bio *bio = NULL;
 	unsigned int sz;
-	DECLARE_COMPLETION_ONSTACK(wait);
-
-	atomic_set(&bb.done, 1);
-	bb.error = 0;
-	bb.wait = &wait;
 
-	ret = 0;
 	while (nr_sects != 0) {
-		bio = bio_alloc(gfp_mask,
-				min(nr_sects, (sector_t)BIO_MAX_PAGES));
-		if (!bio) {
-			ret = -ENOMEM;
-			break;
-		}
-
+		bio = next_bio(bio, WRITE,
+				min(nr_sects, (sector_t)BIO_MAX_PAGES),
+				gfp_mask);
 		bio->bi_iter.bi_sector = sector;
 		bio->bi_bdev   = bdev;
-		bio->bi_end_io = bio_batch_end_io;
-		bio->bi_private = &bb;
 
 		while (nr_sects != 0) {
 			sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
@@ -247,18 +204,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 			if (ret < (sz << 9))
 				break;
 		}
-		ret = 0;
-		atomic_inc(&bb.done);
-		submit_bio(WRITE, bio);
 	}
 
-	/* Wait for bios in-flight */
-	if (!atomic_dec_and_test(&bb.done))
-		wait_for_completion_io(&wait);
-
-	if (bb.error)
-		return bb.error;
-	return ret;
+	if (bio)
+		return submit_bio_wait(WRITE, bio);
+	return 0;
 }
 
 /**