Re: [PATCH] bcache:fix oops in cache_set_flush

[Coly Li]

> 2024年11月26日 23:38，Coly Li <colyli@xxxxxxx> 写道：
> 
> 
> 
>> 2024年11月19日 12:19，liequan che <liequanche@xxxxxxxxx> 写道：
>> 
> 
> [snipped]
> 
>>>> 7. Repartition again, triggering kernel panic again.
>>>> parted -s --align optimal /dev/nvme2n1 mkpart primary 2048s 1536GiB
>>>> The same operation was performed on the other two servers, and no
>>>> panic was triggered.
>> 
>>> I guess this is another undefine operation. I assume the cache device is still references somewhere. A reboot should follow the wipefs.
>> Your guess is correct. In addition, after erasing the superblock
>> information in CD rescue mode,
>> I rebooted into the system where the original panic kernel was located.
>> 
> 
> Please try latest upstream kernel and try whether you can see the issue.
> 
> c->root is allocated by __bch_btree_node_alloc(), it doesn’t return NULL pointer.

I need to withdraw the above inaccurate comments. It c->root cannot be NULL from __bch_btree_node_alloc(), but it can be NULL if previous lines failed and went to the error code path.

Thanks to commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations”). Could you please to compose a patch to partially revert it? The change is same, but change the commit log to mention that your change partially revert commit 028ddcac477b.


Thanks.

Coly Li