[v3,08/11] block: Improve zone reset execution

Commit Message

Damien Le Moal Oct. 12, 2018, 2:30 a.m. UTC

There is no need to synchronously execute all REQ_OP_ZONE_RESET BIOs
necessary to reset a range of zones. Similarly to what is done for
discard BIOs in blk-lib.c, all zone reset BIOs can be chained and
executed asynchronously and a synchronous call done only for the last
BIO of the chain.

Modify blkdev_reset_zones() to operate similarly to
blkdev_issue_discard() using the next_bio() helper for chaining BIOs. To
avoid code duplication of that function in blk_zoned.c, rename
next_bio() into blk_next_bio() and declare it as a block internal
function in blk.h.

Signed-off-by: Damien Le Moal <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
---
 block/blk-lib.c   | 13 ++++++-------
 block/blk-zoned.c | 29 ++++++++++++++++-------------
 block/blk.h       |  2 ++
 3 files changed, 24 insertions(+), 20 deletions(-)

Comments

Hannes Reinecke Oct. 12, 2018, 7:39 a.m. UTC | #1

On 10/12/18 4:30 AM, Damien Le Moal wrote:
> There is no need to synchronously execute all REQ_OP_ZONE_RESET BIOs
> necessary to reset a range of zones. Similarly to what is done for
> discard BIOs in blk-lib.c, all zone reset BIOs can be chained and
> executed asynchronously and a synchronous call done only for the last
> BIO of the chain.
> 
> Modify blkdev_reset_zones() to operate similarly to
> blkdev_issue_discard() using the next_bio() helper for chaining BIOs. To
> avoid code duplication of that function in blk_zoned.c, rename
> next_bio() into blk_next_bio() and declare it as a block internal
> function in blk.h.
> 
> Signed-off-by: Damien Le Moal <[e-mail]>
> Reviewed-by: Christoph Hellwig <[e-mail]>
> ---
>   block/blk-lib.c   | 13 ++++++-------
>   block/blk-zoned.c | 29 ++++++++++++++++-------------
>   block/blk.h       |  2 ++
>   3 files changed, 24 insertions(+), 20 deletions(-)
> 
Neat.

Reviewed-by: Hannes Reinecke <[e-mail]>

Cheers,

Hannes

Patch

diff --git a/block/blk-lib.c b/block/blk-lib.c
index d1b9dd03da25..d7bedee5f9ba 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -10,8 +10,7 @@ 
 
 #include "blk.h"
 
-static struct bio *next_bio(struct bio *bio, unsigned int nr_pages,
-		gfp_t gfp)
+struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp)
 {
 	struct bio *new = bio_alloc(gfp, nr_pages);
 
@@ -87,7 +86,7 @@  int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 			req_sects = end_sect - sector;
 		}
 
-		bio = next_bio(bio, 0, gfp_mask);
+		bio = blk_next_bio(bio, 0, gfp_mask);
 		bio->bi_iter.bi_sector = sector;
 		bio_set_dev(bio, bdev);
 		bio_set_op_attrs(bio, op, 0);
@@ -189,7 +188,7 @@  static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	max_write_same_sectors = UINT_MAX >> 9;
 
 	while (nr_sects) {
-		bio = next_bio(bio, 1, gfp_mask);
+		bio = blk_next_bio(bio, 1, gfp_mask);
 		bio->bi_iter.bi_sector = sector;
 		bio_set_dev(bio, bdev);
 		bio->bi_vcnt = 1;
@@ -265,7 +264,7 @@  static int __blkdev_issue_write_zeroes(struct block_device *bdev,
 		return -EOPNOTSUPP;
 
 	while (nr_sects) {
-		bio = next_bio(bio, 0, gfp_mask);
+		bio = blk_next_bio(bio, 0, gfp_mask);
 		bio->bi_iter.bi_sector = sector;
 		bio_set_dev(bio, bdev);
 		bio->bi_opf = REQ_OP_WRITE_ZEROES;
@@ -316,8 +315,8 @@  static int __blkdev_issue_zero_pages(struct block_device *bdev,
 		return -EPERM;
 
 	while (nr_sects != 0) {
-		bio = next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
-			       gfp_mask);
+		bio = blk_next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects),
+				   gfp_mask);
 		bio->bi_iter.bi_sector = sector;
 		bio_set_dev(bio, bdev);
 		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index bb4ed69f917f..5d967fd39fbd 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -13,6 +13,8 @@ 
 #include <linux/rbtree.h>
 #include <linux/blkdev.h>
 
+#include "blk.h"
+
 static inline sector_t blk_zone_start(struct request_queue *q,
 				      sector_t sector)
 {
@@ -277,16 +279,17 @@  int blkdev_reset_zones(struct block_device *bdev,
 	struct request_queue *q = bdev_get_queue(bdev);
 	sector_t zone_sectors;
 	sector_t end_sector = sector + nr_sectors;
-	struct bio *bio;
+	struct bio *bio = NULL;
+	struct blk_plug plug;
 	int ret;
 
-	if (!q)
-		return -ENXIO;
-
 	if (!blk_queue_is_zoned(q))
 		return -EOPNOTSUPP;
 
-	if (end_sector > bdev->bd_part->nr_sects)
+	if (bdev_read_only(bdev))
+		return -EPERM;
+
+	if (!nr_sectors || end_sector > bdev->bd_part->nr_sects)
 		/* Out of range */
 		return -EINVAL;
 
@@ -299,19 +302,14 @@  int blkdev_reset_zones(struct block_device *bdev,
 	    end_sector != bdev->bd_part->nr_sects)
 		return -EINVAL;
 
+	blk_start_plug(&plug);
 	while (sector < end_sector) {
 
-		bio = bio_alloc(gfp_mask, 0);
+		bio = blk_next_bio(bio, 0, gfp_mask);
 		bio->bi_iter.bi_sector = sector;
 		bio_set_dev(bio, bdev);
 		bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
 
-		ret = submit_bio_wait(bio);
-		bio_put(bio);
-
-		if (ret)
-			return ret;
-
 		sector += zone_sectors;
 
 		/* This may take a while, so be nice to others */
@@ -319,7 +317,12 @@  int blkdev_reset_zones(struct block_device *bdev,
 
 	}
 
-	return 0;
+	ret = submit_bio_wait(bio);
+	bio_put(bio);
+
+	blk_finish_plug(&plug);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(blkdev_reset_zones);
 
diff --git a/block/blk.h b/block/blk.h
index 9db4e389582c..3d67844676fb 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -421,4 +421,6 @@  extern int blk_iolatency_init(struct request_queue *q);
 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
 #endif
 
+struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
+
 #endif /* BLK_INTERNAL_H */