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 <h...@lst.de>
---
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 a59bb54ac7c7..33c5bf373b7f 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
* only be release if %flags contains BLKDEV_ZERO_UNMAP.
+ *
+ * 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 19209416225d..1bddcfc631a4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1347,6 +1347,7 @@ extern int __blkdev_issue_discard(struct block_device
*bdev, sector_t sector,
struct bio **biop);
#define BLKDEV_ZERO_UNMAP (1 << 0) /* free unused 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
--
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