[PATCH 1/5] block: add async variant of blkdev_issue_zeroout
Chaitanya Kulkarni
ckulkarnilinux at gmail.com
Tue Nov 15 22:50:35 PST 2016
Similar to __blkdev_issue_discard this variant allows submitting
the final bio asynchronously and chaining multiple ranges
into a single completion.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at hgst.com>
---
block/blk-lib.c | 115 ++++++++++++++++++++++++++++++++++---------------
include/linux/blkdev.h | 3 ++
2 files changed, 84 insertions(+), 34 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 18abda8..bfb28b0 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -137,24 +137,24 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
EXPORT_SYMBOL(blkdev_issue_discard);
/**
- * blkdev_issue_write_same - queue a write same operation
+ * __blkdev_issue_write_same - generate number of bios with same page
* @bdev: target blockdev
* @sector: start sector
* @nr_sects: number of sectors to write
* @gfp_mask: memory allocation flags (for bio_alloc)
* @page: page containing data to write
+ * @biop: pointer to anchor bio
*
* Description:
- * Issue a write same request for the sectors in question.
+ * Generate and issue number of bios(REQ_OP_WRITE_SAME) with same page.
*/
-int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
- sector_t nr_sects, gfp_t gfp_mask,
- struct page *page)
+static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, struct page *page,
+ struct bio **biop)
{
struct request_queue *q = bdev_get_queue(bdev);
unsigned int max_write_same_sectors;
- struct bio *bio = NULL;
- int ret = 0;
+ struct bio *bio = *biop;
sector_t bs_mask;
if (!q)
@@ -164,6 +164,9 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
if ((sector | nr_sects) & bs_mask)
return -EINVAL;
+ if (!bdev_write_same(bdev))
+ return -EOPNOTSUPP;
+
/* Ensure that max_write_same_sectors doesn't overflow bi_size */
max_write_same_sectors = UINT_MAX >> 9;
@@ -185,32 +188,63 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
bio->bi_iter.bi_size = nr_sects << 9;
nr_sects = 0;
}
+ cond_resched();
}
- if (bio) {
+ *biop = bio;
+ return 0;
+}
+
+/**
+ * blkdev_issue_write_same - queue a write same operation
+ * @bdev: target blockdev
+ * @sector: start sector
+ * @nr_sects: number of sectors to write
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ * @page: page containing data
+ *
+ * Description:
+ * Issue a write same request for the sectors in question.
+ */
+int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask,
+ struct page *page)
+{
+ struct bio *bio = NULL;
+ struct blk_plug plug;
+ int ret;
+
+ blk_start_plug(&plug);
+ ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask, page,
+ &bio);
+ if (ret == 0 && bio) {
ret = submit_bio_wait(bio);
bio_put(bio);
}
+ blk_finish_plug(&plug);
return ret;
}
EXPORT_SYMBOL(blkdev_issue_write_same);
/**
- * blkdev_issue_zeroout - generate number of zero filed write bios
+ * __blkdev_issue_zeroout - generate number of zero filed write bios
* @bdev: blockdev to issue
* @sector: start sector
* @nr_sects: number of sectors to write
* @gfp_mask: memory allocation flags (for bio_alloc)
+ * @biop: pointer to anchor bio
+ * @discard: discard flag
*
* Description:
* Generate and issue number of bios with zerofiled pages.
*/
-
-static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
- sector_t nr_sects, gfp_t gfp_mask)
+int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
+ bool discard)
{
int ret;
- struct bio *bio = NULL;
+ int bi_size = 0;
+ struct bio *bio = *biop;
unsigned int sz;
sector_t bs_mask;
@@ -218,6 +252,19 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
if ((sector | nr_sects) & bs_mask)
return -EINVAL;
+ if (discard) {
+ ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
+ BLKDEV_DISCARD_ZERO, biop);
+ if (ret == 0 || (ret && ret != -EOPNOTSUPP))
+ goto out;
+ }
+
+ ret = __blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
+ ZERO_PAGE(0), biop);
+ if (ret == 0 || (ret && ret != -EOPNOTSUPP))
+ goto out;
+
+ ret = 0;
while (nr_sects != 0) {
bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),
gfp_mask);
@@ -227,21 +274,20 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
while (nr_sects != 0) {
sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects);
- ret = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
- nr_sects -= ret >> 9;
- sector += ret >> 9;
- if (ret < (sz << 9))
+ bi_size = bio_add_page(bio, ZERO_PAGE(0), sz << 9, 0);
+ nr_sects -= bi_size >> 9;
+ sector += bi_size >> 9;
+ if (bi_size < (sz << 9))
break;
}
+ cond_resched();
}
- if (bio) {
- ret = submit_bio_wait(bio);
- bio_put(bio);
- return ret;
- }
- return 0;
+ *biop = bio;
+out:
+ return ret;
}
+EXPORT_SYMBOL(__blkdev_issue_zeroout);
/**
* blkdev_issue_zeroout - zero-fill a block range
@@ -263,21 +309,22 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
* clearing the block range. Otherwise the zeroing will be performed
* using regular WRITE calls.
*/
-
int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, bool discard)
{
- if (discard) {
- if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
- BLKDEV_DISCARD_ZERO))
- return 0;
- }
+ int ret;
+ struct bio *bio = NULL;
+ struct blk_plug plug;
- if (bdev_write_same(bdev) &&
- blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
- ZERO_PAGE(0)) == 0)
- return 0;
+ blk_start_plug(&plug);
+ ret = __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask,
+ &bio, discard);
+ if (ret == 0 && bio) {
+ ret = submit_bio_wait(bio);
+ bio_put(bio);
+ }
+ blk_finish_plug(&plug);
- return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask);
+ return ret;
}
EXPORT_SYMBOL(blkdev_issue_zeroout);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index bab18ee..13b2f2a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1268,6 +1268,9 @@ extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
struct bio **biop);
extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, struct page *page);
+extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask, struct bio **biop,
+ bool discard);
extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask, bool discard);
static inline int sb_issue_discard(struct super_block *sb, sector_t block,
--
1.8.3.1
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