Re: [PATCH] hugetlbfs: add err code in initializing module

Andrew Morton
2012-03-12T23:58:30Z

On Mon, 12 Mar 2012 20:01:43 +0800
Hillf Danton <dhillf@gmail.com> wrote:

> On Mon, Mar 12, 2012 at 4:25 AM, David Rientjes <rientjes@google.com> wrote:
> >
> > The patch looks good, however, we typically do things like
> >
> > __ __ __ __error = -ENOMEM;
> > __ __ __ __hugetlbfs_inode_cachep = kmem_cache_create(...);
> > __ __ __ __if (!hugetlbfs_inode_cachep)
> > __ __ __ __ __ __ __ __...
> >
> > instead. __Sometimes people grep to see if a call a function that can fail,
> > such as kmem_cache_create(), is followed up by a check for NULL and this
> > would otherwise fail.
> >
> >
> It is updated, thanks David.
>
> -hd
> ===cut here===
> From: Hillf Danton <dhillf@gmail.com>
> Subject: [PATCH] hugetlbfs: add err code in initilizing module
>
> Error code is added if fail to create inode kmem cache, and newly registered
> hugetlb FS is unregistered if fail to mount, both for unlikely corner cases.
>
> Signed-off-by: Hillf Danton <dhillf@gmail.com>
> ---
>
> --- a/fs/hugetlbfs/inode.c Sun Mar 11 12:46:38 2012
> +++ b/fs/hugetlbfs/inode.c Mon Mar 12 19:52:16 2012
> @@ -997,6 +997,7 @@ static int __init init_hugetlbfs_fs(void
> if (error)
> return error;
>
> + error = -ENOMEM;
> hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
> sizeof(struct hugetlbfs_inode_info),
> 0, 0, init_once);
> @@ -1015,6 +1016,7 @@ static int __init init_hugetlbfs_fs(void
> }
>
> error = PTR_ERR(vfsmount);
> + unregister_filesystem(&hugetlbfs_fs_type);
>
> out:
> if (error)

And this, yes?

remove unneeded test of `error'

--- a/fs/hugetlbfs/inode.c~hugetlbfs-return-error-code-when-initializing-module-fix
+++ a/fs/hugetlbfs/inode.c
@@ -1035,8 +1035,7 @@ static int __init init_hugetlbfs_fs(void
unregister_filesystem(&hugetlbfs_fs_type);

out:
- if (error)
- kmem_cache_destroy(hugetlbfs_inode_cachep);
+ kmem_cache_destroy(hugetlbfs_inode_cachep);
out2:
bdi_destroy(&hugetlbfs_backing_dev_info);
return error;
_