diff mbox series

[01/27] target: remove an incorrect unmap zeroes data deduction

Message ID 20220415045258.199825-2-hch@lst.de (mailing list archive)
State Not Applicable, archived
Delegated to: Mike Snitzer
Headers show
Series [01/27] target: remove an incorrect unmap zeroes data deduction | expand

Commit Message

Christoph Hellwig April 15, 2022, 4:52 a.m. UTC 
For block devices, the SCSI target drivers implements UNMAP as calls to
blkdev_issue_discard, which does not guarantee zeroing just because
Write Zeroes is supported.

Note that this does not affect the file backed path which uses
fallocate to punch holes.

Fixes: 2237498f0b5c ("target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
---
 drivers/target/target_core_device.c | 1 -
 1 file changed, 1 deletion(-)

Comments

Chaitanya Kulkarni April 15, 2022, 5:36 a.m. UTC | #1 
On 4/14/22 21:52, Christoph Hellwig wrote:
> For block devices, the SCSI target drivers implements UNMAP as calls to
> blkdev_issue_discard, which does not guarantee zeroing just because
> Write Zeroes is supported.
> 
> Note that this does not affect the file backed path which uses
> fallocate to punch holes.
> 
> Fixes: 2237498f0b5c ("target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout")
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

Not a good assumption to have for sure.

Looks good.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

-ck


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diff mbox series

Patch

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 44bb380e7390c..fa866acef5bb2 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -850,7 +850,6 @@  bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,
 	attrib->unmap_granularity = q->limits.discard_granularity / block_size;
 	attrib->unmap_granularity_alignment = q->limits.discard_alignment /
 								block_size;
-	attrib->unmap_zeroes_data = !!(q->limits.max_write_zeroes_sectors);
 	return true;
 }
 EXPORT_SYMBOL(target_configure_unmap_from_queue);