[Ocfs2-devel] [PATCH 1/1] OCFS2: unhash all dentries on a inode.
wengang wang
wen.gang.wang at oracle.com
Mon Sep 22 22:27:26 PDT 2008
Sunil Mushran wrote:
> If so, won't that be a bug?
>
If you meant my patch is bug, why?
unhashing dentry from dentry cache only leads to a mis-match in that
cache when a new request comes.
when the dentry is not found in cache, before creating a new dentry, a
validation check should be done on the inode in inode cache or by
ocfs2_lookup().
so I think there is no problem.
without unhashing the dentries, dput() won't call dentry_iput(). thus
the stale inode will be kept in memory for ever. --this is a problem.
thanks,
wengang.
> wengang wang wrote:
>> Sunil,
>>
>> d_prune_aliases() unhashes dentries that has 0 reference count,
>> dentries with non-zero ref count won't be unhashed.
>> My code unhashes all no matter there reference counts are 0 or not.
>>
>> regards,
>> wengang.
>>
>> Sunil Mushran wrote:
>>> NAK.
>>>
>>> I fail to understand your logic. The code you've added is pretty
>>> much what d_prune_aliases() does (the call you have deleted).
>>>
>>> wangang wang wrote:
>>>> In ocfs2_process_delete_request(), we should unhash all dentries on
>>>> the inode.
>>>> --not only the ones with 0 referrence count. so that it's possible
>>>> for dput()
>>>> to drop the stale inode.
>>>>
>>>> the patch is against 1.2 svn.
>>>>
>>>> Signed-off-by: Wengang wang <wen.gang.wang at oracle.com>
>>>> --
>>>>
>>>> Index: fs/ocfs2/vote.c
>>>> ===================================================================
>>>> --- fs/ocfs2/vote.c (revision 3101)
>>>> +++ fs/ocfs2/vote.c (working copy)
>>>> @@ -176,6 +176,7 @@
>>>> int deleting_node)
>>>> {
>>>> int response = OCFS2_RESPONSE_BUSY;
>>>> + struct list_head *tmp, *head;
>>>>
>>>> mlog(0, "DELETE vote on inode %lu, read lnk_cnt = %u, slot =
>>>> %d\n",
>>>> inode->i_ino, inode->i_nlink, *orphaned_slot);
>>>> @@ -253,9 +254,19 @@
>>>> ocfs2_mark_inode_remotely_deleted(inode, deleting_node);
>>>> spin_unlock(&OCFS2_I(inode)->ip_lock);
>>>>
>>>> - /* Not sure this is necessary anymore. */
>>>> - d_prune_aliases(inode);
>>>> + /* unhash all dentries on this inode */
>>>> + spin_lock(&dcache_lock);
>>>> + head = &inode->i_dentry;
>>>> + tmp = head;
>>>>
>>>> + while ((tmp = tmp->next) != head) {
>>>> + struct dentry *dentry = list_entry(tmp, struct dentry,
>>>> d_alias);
>>>> + spin_lock(&dentry->d_lock);
>>>> + __d_drop(dentry);
>>>> + spin_unlock(&dentry->d_lock);
>>>> + }
>>>> + spin_unlock(&dcache_lock);
>>>> +
>>>> /* If we get here, then we're voting 'yes', so commit the
>>>> * delete on our side. */
>>>> response = OCFS2_RESPONSE_OK;
>>>>
>>>> _______________________________________________
>>>> Ocfs2-devel mailing list
>>>> Ocfs2-devel at oss.oracle.com
>>>> http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>>>>
>>>
>>
>
--
Wengang Wang
Member of Technical Staff
Oracle Asia R&D Center
Open Source Technologies Development
Tel: +86 10 8278 6265
Mobile: +86 13381078925
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