Re: [PATCH] btrfs: fix race between balance and cancel/pause

[xiaoshoukui]

I think this patch does not fully fix the issue.

This patch just fix assertion panic, but in the race situation, the ioctl pause 
request still returns an incorrect value 0 to the user which mislead the user the
pause request finished successfully. In fact, the balance request has not been paused.

Test results and analysis are as follows:
https://lore.kernel.org/linux-btrfs/20230726030617.109018-1-xiaoshoukui@xxxxxxxxx/T/#me125d17fa59e9e671149cc76d410ced747f488b1