Re: LTP test df01.sh detected different size of loop device in v5.19

[Petr Vorel <pvorel@suse.cz>]

> Hi all,

> LTP test df01.sh found different size of loop device in v5.19.
> Test uses loop device formatted on various file systems, only XFS fails.
> It randomly fails during verifying that loop size usage changes:

> grep ${TST_DEVICE} output | grep -q "${total}.*${used}" [1]

> How to reproduce:
> # PATH="/opt/ltp/testcases/bin:$PATH" df01.sh -f xfs # it needs several tries to hit

> df saved output:
> Filesystem     1024-blocks    Used Available Capacity Mounted on
> ...
> /dev/loop0          256672   16208    240464       7% /tmp/LTP_df01.1kRwoUCCR7/mntpoint
> df output:
> Filesystem     1024-blocks    Used Available Capacity Mounted on
> ...
> tmpfs               201780       0    201780       0% /run/user/0
> /dev/loop0          256672   15160    241512       6% /tmp/LTP_df01.1kRwoUCCR7/mntpoint
> => different size
> df01 4 TFAIL: 'df -k -P' failed, not expected.

> Also 'df -T -P' fails.

> It might be a false positive / bug in the test, but it's at least a changed behavior.
> I was able to reproduce it on v5.19 distro kernels (openSUSE, Debian).
> I haven't bisected (yet), nor checked Jens' git tree (maybe it has been fixed).

Forget to note dmesg "operation not supported error" warning on *each* run (even
successful) on affected v5.19:
[ 5097.594021] loop0: detected capacity change from 0 to 524288
[ 5097.658201] operation not supported error, dev loop0, sector 262192 op 0x9:(WRITE_ZEROES) flags 0x8000800 phys_seg 0 prio class 0
[ 5097.675670] XFS (loop0): Mounting V5 Filesystem
[ 5097.681668] XFS (loop0): Ending clean mount
[ 5097.956445] XFS (loop0): Unmounting Filesystem

Kind regards,
Petr

> Kind regards,
> Petr

> [1] https://github.com/linux-test-project/ltp/blob/f42f6f3b4671f447b743afe8612917ba4362b8a6/testcases/commands/df/df01.sh#L103-L110