Now that we have REQ_OP_WRITE_ZEROES implemented for all devices that
support efficient zeroing, we can remove the call to blkdev_issue_discard.
This means we only have two ways of zeroing left and can simplify the
code.
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 | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 2f882e22890b..b0c6c4bcf441 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -279,6 +279,12 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev,
* Zero-fill a block range, either using hardware offload or by explicitly
* writing zeroes to the device.
*
+ * Note that this function may fail with -EOPNOTSUPP if the driver signals
+ * zeroing offload support, but the device fails to process the command (for
+ * some devices there is no non-destructive way to verify whether this
+ * operation is actually supported). In this case the caller should call
+ * retry the call to blkdev_issue_zeroout() and the fallback path will be used.
+ *
* If a device is using logical block provisioning, the underlying space will
* not be released if %flags contains BLKDEV_ZERO_NOUNMAP.
*
@@ -349,12 +355,6 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
struct bio *bio = NULL;
struct blk_plug plug;
- if (!(flags & BLKDEV_ZERO_NOUNMAP)) {
- if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
- BLKDEV_DISCARD_ZERO))
- return 0;
- }
-
blk_start_plug(&plug);
ret = __blkdev_issue_zeroout(bdev, sector, nr_sects, gfp_mask,
&bio, flags);
--
2.11.0
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
