2013-09-10 21:02:50

by Dave Jones

Subject: lock held returning to user space (i_mutex_dir_key)

================================================
[ BUG: lock held when returning to user space! ]
3.11.0+ #64 Not tainted
------------------------------------------------
trinity-child2/8333 is leaving the kernel with locks still held!
1 lock held by trinity-child2/8333:
#0: (&type->i_mutex_dir_key#3){+.+.+.}, at: [<ffffffff811c7fce>] mountpoint_last+0x4e/0x1a0

2013-09-10 21:04:34

by Dave Jones

Subject: Re: lock held returning to user space (i_mutex_dir_key)

On Tue, Sep 10, 2013 at 05:02:37PM -0400, Dave Jones wrote:
> ================================================
> [ BUG: lock held when returning to user space! ]
> 3.11.0+ #64 Not tainted
> ------------------------------------------------
> trinity-child2/8333 is leaving the kernel with locks still held!
> 1 lock held by trinity-child2/8333:
> #0: (&type->i_mutex_dir_key#3){+.+.+.}, at: [<ffffffff811c7fce>] mountpoint_last+0x4e/0x1a0

This perhaps ?


--

Add missing unlocks to error paths of mountpoint_last.

Signed-off-by: Dave Jones <[email protected]>

diff --git a/fs/namei.c b/fs/namei.c
index 409a441..5a91474 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2271,12 +2271,15 @@ mountpoint_last(struct nameidata *nd, struct path *path)
dentry = d_alloc(dir, &nd->last);
if (!dentry) {
error = -ENOMEM;
+ mutex_unlock(&dir->d_inode->i_mutex);
goto out;
}
dentry = lookup_real(dir->d_inode, dentry, nd->flags);
error = PTR_ERR(dentry);
- if (IS_ERR(dentry))
+ if (IS_ERR(dentry)) {
+ mutex_unlock(&dir->d_inode->i_mutex);
goto out;
+ }
}
mutex_unlock(&dir->d_inode->i_mutex);

2013-09-10 21:09:31

by Al Viro

Subject: Re: lock held returning to user space (i_mutex_dir_key)

On Tue, Sep 10, 2013 at 05:04:25PM -0400, Dave Jones wrote:
> On Tue, Sep 10, 2013 at 05:02:37PM -0400, Dave Jones wrote:
> > ================================================
> > [ BUG: lock held when returning to user space! ]
> > 3.11.0+ #64 Not tainted
> > ------------------------------------------------
> > trinity-child2/8333 is leaving the kernel with locks still held!
> > 1 lock held by trinity-child2/8333:
> > #0: (&type->i_mutex_dir_key#3){+.+.+.}, at: [<ffffffff811c7fce>] mountpoint_last+0x4e/0x1a0
>
> This perhaps ?

Applied

2013-09-12 16:45:37

by Jeff Layton

Subject: Re: lock held returning to user space (i_mutex_dir_key)

On Tue, 10 Sep 2013 17:04:25 -0400
Dave Jones <[email protected]> wrote:

> On Tue, Sep 10, 2013 at 05:02:37PM -0400, Dave Jones wrote:
> > ================================================
> > [ BUG: lock held when returning to user space! ]
> > 3.11.0+ #64 Not tainted
> > ------------------------------------------------
> > trinity-child2/8333 is leaving the kernel with locks still held!
> > 1 lock held by trinity-child2/8333:
> > #0: (&type->i_mutex_dir_key#3){+.+.+.}, at: [<ffffffff811c7fce>] mountpoint_last+0x4e/0x1a0
>
> This perhaps ?
>
>
> --
>
> Add missing unlocks to error paths of mountpoint_last.
>
> Signed-off-by: Dave Jones <[email protected]>
>
> diff --git a/fs/namei.c b/fs/namei.c
> index 409a441..5a91474 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -2271,12 +2271,15 @@ mountpoint_last(struct nameidata *nd, struct path *path)
> dentry = d_alloc(dir, &nd->last);
> if (!dentry) {
> error = -ENOMEM;
> + mutex_unlock(&dir->d_inode->i_mutex);
> goto out;
> }
> dentry = lookup_real(dir->d_inode, dentry, nd->flags);
> error = PTR_ERR(dentry);
> - if (IS_ERR(dentry))
> + if (IS_ERR(dentry)) {
> + mutex_unlock(&dir->d_inode->i_mutex);
> goto out;
> + }
> }
> mutex_unlock(&dir->d_inode->i_mutex);
>

Well spotted.

Reviewed-by: Jeff Layton <[email protected]>