From: yan yan <clouds.yan@gmail.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] proc: return -ENOMEM when inode allocation failed
Date: Wed, 5 Sep 2012 15:57:54 +0800 [thread overview]
Message-ID: <CAH+=+MGaevMRUoF9CKi+YoS4ais3UFJNbQkqRfFBtgjhyWPaeQ@mail.gmail.com> (raw)
In-Reply-To: <5046FC22.3050509@gmail.com>
2012/9/5 Cong Wang <xiyou.wangcong@gmail.com>:
>>> 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);
>
>
Change so many lines to save a assignment to 'error' ...
That's a stye issue. I prefer a simple change, though your
change seems OK to me.
Thanks
next prev parent reply other threads:[~2012-09-05 7:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-03 14:14 [PATCH 0/3] Trivial code clean for procfs yan
2012-09-03 14:14 ` [PATCH 1/3] proc: return -ENOMEM when inode allocation failed yan
2012-09-04 0:38 ` Ryan Mallon
2012-09-04 3:02 ` Cong Wang
2012-09-04 9:22 ` yan yan
2012-09-04 22:41 ` Andrew Morton
2012-09-05 7:15 ` Cong Wang
2012-09-05 7:57 ` yan yan [this message]
2012-09-03 14:14 ` [PATCH 2/3] proc : no need to initialize proc_inode->fd in proc_get_inode yan
2012-09-04 22:49 ` Andrew Morton
2012-09-03 14:14 ` [PATCH 3/3] proc: use kzalloc instead of kmalloc and memset yan
2012-09-04 0:44 ` Ryan Mallon
2012-09-04 9:10 ` yan yan
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