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authorMartin K. Petersen <martin.petersen@oracle.com>2012-09-18 12:19:28 -0400
committerJens Axboe <axboe@kernel.dk>2012-09-20 14:31:49 +0200
commit579e8f3c7b2ecf7db91398d942d76457a3ddba21 (patch)
treef41d7d469cb427550656f1d1d2c3b5215a9ea0aa /block
parent4363ac7c13a9a4b763c6e8d9fdbfc2468f3b8ca4 (diff)
downloadvexpress-lsk-579e8f3c7b2ecf7db91398d942d76457a3ddba21.tar.gz
block: Make blkdev_issue_zeroout use WRITE SAME
If the device supports WRITE SAME, use that to optimize zeroing of blocks. If the device does not support WRITE SAME or if the operation fails, fall back to writing zeroes the old-fashioned way. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-lib.c30
1 files changed, 29 insertions, 1 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c
index a062543c58a..9373b58dfab 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -214,7 +214,7 @@ EXPORT_SYMBOL(blkdev_issue_write_same);
* Generate and issue number of bios with zerofiled pages.
*/
-int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
+int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
sector_t nr_sects, gfp_t gfp_mask)
{
int ret;
@@ -264,4 +264,32 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
return ret;
}
+
+/**
+ * blkdev_issue_zeroout - zero-fill a block range
+ * @bdev: blockdev to write
+ * @sector: start sector
+ * @nr_sects: number of sectors to write
+ * @gfp_mask: memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ * Generate and issue number of bios with zerofiled pages.
+ */
+
+int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
+ sector_t nr_sects, gfp_t gfp_mask)
+{
+ if (bdev_write_same(bdev)) {
+ unsigned char bdn[BDEVNAME_SIZE];
+
+ if (!blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
+ ZERO_PAGE(0)))
+ return 0;
+
+ bdevname(bdev, bdn);
+ pr_err("%s: WRITE SAME failed. Manually zeroing.\n", bdn);
+ }
+
+ return __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask);
+}
EXPORT_SYMBOL(blkdev_issue_zeroout);