Messages in this thread Patch in this message | | | Date | Wed, 05 Sep 2012 15:15:46 +0800 | From | Cong Wang <> | Subject | Re: [PATCH 1/3] proc: return -ENOMEM when inode allocation failed |
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On 09/04/2012 05:22 PM, yan yan wrote: > 2012/9/4 Cong Wang <xiyou.wangcong@gmail.com>: >> On 09/03/2012 10:14 PM, yan wrote: >>> >>> Signed-off-by: yan <clouds.yan@gmail.com> >> >> >> Please provide a changelog to explain why we need this patch. > > I think the title is self explained. > > >>> --- >>> fs/proc/generic.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/fs/proc/generic.c b/fs/proc/generic.c >>> index b3647fe..9e8f631 100644 >>> --- a/fs/proc/generic.c >>> +++ b/fs/proc/generic.c >>> @@ -427,7 +427,7 @@ struct dentry *proc_lookup_de(struct proc_dir_entry >>> *de, struct inode *dir, >>> if (!memcmp(dentry->d_name.name, de->name, de->namelen)) { >>> pde_get(de); >>> spin_unlock(&proc_subdir_lock); >>> - error = -EINVAL; >>> + error = -ENOMEM; >> >> >> Why the !memcmp() case is related with ENOMEM ?? > > We are presetting 'error' here. The following proc_get_inode() will try > to get an inode, either from inode cache or allocate a new one (and fill it). > > If we get a NULL inode, that means allocation failed. That's how > ENOMEM involved.
Then the following patch is probably better than yours:
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index b3647fe..6b22913 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -427,12 +427,16 @@ struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir, if (!memcmp(dentry->d_name.name, de->name, de->namelen)) { pde_get(de); spin_unlock(&proc_subdir_lock); - error = -EINVAL; inode = proc_get_inode(dir->i_sb, de); + if (!inode) { + error = -ENOMEM; + goto out_put; + } goto out_unlock; } } spin_unlock(&proc_subdir_lock); + out_unlock:
if (inode) { @@ -440,6 +444,8 @@ out_unlock: d_add(dentry, inode); return NULL; } +out_put: + if (de) pde_put(de); return ERR_PTR(error);
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