[Drbd-dev] [PATCH 01/27] target: remove an incorrect unmap zeroes data deduction

Christoph Hellwig hch at lst.de
Sat Apr 9 06:50:17 CEST 2022

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 at lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen at oracle.com>
 drivers/target/target_core_device.c | 1 -
 1 file changed, 1 deletion(-)

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 /
-	attrib->unmap_zeroes_data = !!(q->limits.max_write_zeroes_sectors);
 	return true;

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