On 2022/6/5 19:49, Matthew Wilcox wrote:
> On Sun, Jun 05, 2022 at 11:55:55AM +0800, Chen Wandun wrote:
>> It will result in null pointer access if shmem_init_inodecache fail,
>> so check return value of shmem_init_inodecache
> You ignored my suggestion from v1. Here, let me write it out for you.
Hi Matthew,
I didn't ignore your suggestion, some explanation is needed, sorry for
that.
In V1, Kefeng point:
"kmem_cache_create return a pointer to the cache on success, NULL on
failure,
so error = -ENOMEM; is right :)"
so, I look some similar code such as init_inodecache in kinds of file
system, they all
return -ENOMEM on failure, so is it OK to return -ENOMEM on failure :)
Besides, kmem_cache_create return NULL on failure, maybe returning
error code
on failure is more proper, but it is another job.
>
> +static int shmem_init_inodecache(void)
> {
> shmem_inode_cachep = kmem_cache_create("shmem_inode_cache",
> sizeof(struct shmem_inode_info),
> 0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode);
> + if (!shmem_inode_cachep)
> + return -ENOMEM;
> + return 0;
> }
>
> ...
>
> + error = shmem_init_inodecache();
> + if (error)
> + goto out2;
>
>
> .
On Mon, Jun 06, 2022 at 09:34:13AM +0800, Chen Wandun wrote:
> On 2022/6/5 19:49, Matthew Wilcox wrote:
> > On Sun, Jun 05, 2022 at 11:55:55AM +0800, Chen Wandun wrote:
> > > It will result in null pointer access if shmem_init_inodecache fail,
> > > so check return value of shmem_init_inodecache
> > You ignored my suggestion from v1. Here, let me write it out for you.
> Hi Matthew,
> I didn't ignore your suggestion,? some explanation is needed, sorry for
> that.
>
> In V1, Kefeng point:
> "kmem_cache_create return a pointer to the cache on success, NULL on
> failure,
> so error = -ENOMEM; is right :)"
>
> so, I look some similar code such as init_inodecache in kinds of file
> system,? they all
> return -ENOMEM on failure, so is it OK to return -ENOMEM on failure :)
>
> Besides,? kmem_cache_create return NULL on failure, maybe returning error
> code
> on failure is more proper, but it is another job.
I literally wrote out what I think you should do instead. Stop arguing.
> > +static int shmem_init_inodecache(void)
> > {
> > shmem_inode_cachep = kmem_cache_create("shmem_inode_cache",
> > sizeof(struct shmem_inode_info),
> > 0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode);
> > + if (!shmem_inode_cachep)
> > + return -ENOMEM;
> > + return 0;
> > }
> >
> > ...
> >
> > + error = shmem_init_inodecache();
> > + if (error)
> > + goto out2;
> >
> >
> > .
>