Re: [PATCH] scsi: virtio_scsi: Remove unnecessary condition checks

From: Markus Elfring
Date: Fri Jul 10 2020 - 02:33:05 EST


>>> + mempool_destroy(virtscsi_cmd_pool);
>>> + virtscsi_cmd_pool = NULL;
>>> + kmem_cache_destroy(virtscsi_cmd_cache);
>>> + virtscsi_cmd_cache = NULL;
>>> return ret;
>>> }
>>
>> How do you think about to add a jump target so that the execution
>> of a few statements can be avoided according to a previous
>> null pointer check?
>
> The point of the patch is precisely to simplify the code,

I suggest to reconsider also Linux coding style aspects
for the implementation of the function âinitâ.
https://elixir.bootlin.com/linux/v5.8-rc4/source/drivers/scsi/virtio_scsi.c#L980
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/scsi/virtio_scsi.c?id=42f82040ee66db13525dc6f14b8559890b2f4c1c#n980

if (!virtscsi_cmd_cache) {
pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
- goto error;
+ return -ENOMEM;
}


See also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=42f82040ee66db13525dc6f14b8559890b2f4c1c#n461


> executing a couple more instruction is not an issue.

With which update steps would like to achieve such a code variant?

destroy_pool:
mempool_destroy(virtscsi_cmd_pool);
virtscsi_cmd_pool = NULL;
destroy_cache:
kmem_cache_destroy(virtscsi_cmd_cache);
virtscsi_cmd_cache = NULL;
return ret;


Regards,
Markus