This avoids fallbacks to explicit zeroing in (__)blkdev_issue_zeroout if the caller doesn't want them. Also clean up the convoluted check for the return condition that this new flag is added to. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> --- block/blk-lib.c | 5 ++++- include/linux/blkdev.h | 1 + 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index 2f6d2cb2e1a2..2f882e22890b 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -281,6 +281,9 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev, * * If a device is using logical block provisioning, the underlying space will * not be released if %flags contains BLKDEV_ZERO_NOUNMAP. + * + * If %flags contains BLKDEV_ZERO_NOFALLBACK, the function will return + * -EOPNOTSUPP if no explicit hardware offload for zeroing is provided. */ int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop, @@ -298,7 +301,7 @@ int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, ret = __blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask, biop, flags); - if (ret == 0 || (ret && ret != -EOPNOTSUPP)) + if (ret != -EOPNOTSUPP || (flags & BLKDEV_ZERO_NOFALLBACK)) goto out; ret = 0; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e7513ce3dbde..a5055d760661 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1351,6 +1351,7 @@ extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, struct bio **biop); #define BLKDEV_ZERO_NOUNMAP (1 << 0) /* do not free blocks */ +#define BLKDEV_ZERO_NOFALLBACK (1 << 1) /* don't write explicit zeroes */ extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop, -- 2.11.0 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
