Re: [PATCH blktests v2 0/3] blktest: add unmap write zeroes tests

On 8/17/2025 2:14 PM, Shinichiro Kawasaki wrote:

On Aug 13, 2025 / 10:44, Zhang Yi wrote:

quoted

From: Zhang Yi <yi.zhang@huawei.com>

Change since v2:
 - Modify the sysfs interfaces according to the kernel implementation.
 - Determine whether the kernel supports it by directly checking the
   existence of the sysfs interface, instead of using device_requries(). 
 - Drop _short_dev() helper and directly use _real_dev() to acquire dm
   path.
 - Check the return value of setup_test_device().
 - Fix the '"make check'" errors.


The Linux kernel (since version 6.17)[1] supports FALLOC_FL_WRITE_ZEROES
in fallocate(2) and add max_{hw|user}_wzeroes_unmap_sectors parameters
to the block device queue limit. These tests test those block device
unmap write zeroes sysfs interface

        /sys/block/<disk>/queue/write_zeroes_max_bytes
        /sys/block/<disk>/queue/write_zeroes_unmap_max_hw_bytes

with various SCSI/NVMe/device-mapper devices.

The value of /sys/block//queue/write_zeroes_unmap_max_hw_bytes should be
equal to a nonzero value of /sys/block//queue/write_zeroes_max_bytes if
the block device supports the unmap write zeroes command; otherwise, it
should return 0. We can also disable unmap write zeroes command by
setting /sys/block/<disk>/queue/write_zeroes_max_bytes to 0.

 - scsi/010 test SCSI devices.
 - dm/003 test device mapper stacked devices.
 - nvme/065 test NVMe devices.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=278c7d9b5e0c

I applied this v2 series. Of note is that I amended the 2nd and 3rd patches to
fix the shellcheck warnings below. Anyway, thanks for the patches!

$ make check
shellcheck -x -e SC2119 -f gcc check common/* \
        tests/*/rc tests/*/[0-9]*[0-9] src/*.sh
common/rc:679:7: note: Double quote to prevent globbing and word splitting. [SC2086]
tests/nvme/065:44:7: warning: Quote this to prevent word splitting. [SC2046]
tests/nvme/065:44:7: note: Useless echo? Instead of 'echo $(cmd)', just use 'cmd'. [SC2005]
make: *** [Makefile:21: check] Error 1

Sorry for missing these warnings, and thank you for fixing them! :-)

Thanks.
Yi.