[PATCH 11/14] nfs: idr_destroy() no longer needs idr_remove_all()

[PATCH 11/14] nfs: idr_destroy() no longer needs idr_remove_all()

[Tejun Heo]

idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop reference to idr_remove_all().  Note that the code
wasn't completely correct before because idr_remove() on all entries
doesn't necessarily release all idr_layers which could lead to memory
leak.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: linux-nfs@vger.kernel.org
---
This patch depends on an earlier idr patch and given the trivial
nature of the patch, I think it would be best to route these together
through -mm.  Please holler if there's any objection.

Thanks.

 fs/nfs/client.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 9f3c664..84d8eae 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -197,7 +197,6 @@ error_0:
 EXPORT_SYMBOL_GPL(nfs_alloc_client);
 
 #if IS_ENABLED(CONFIG_NFS_V4)
-/* idr_remove_all is not needed as all id's are removed by nfs_put_client */
 void nfs_cleanup_cb_ident_idr(struct net *net)
 {
 	struct nfs_net *nn = net_generic(net, nfs_net_id);
-- 
1.8.1

Re: [PATCH 11/14] nfs: idr_destroy() no longer needs idr_remove_all()

[J. Bruce Fields]

On Fri, Jan 25, 2013 at 05:31:09PM -0800, Tejun Heo wrote:
> idr_destroy() can destroy idr by itself and idr_remove_all() is being
> deprecated.  Drop reference to idr_remove_all().  Note that the code
> wasn't completely correct before because idr_remove() on all entries
> doesn't necessarily release all idr_layers which could lead to memory
> leak.

Seems fine, but actually this is client-side so I think you meant the cc
to be to Trond.

--b.

> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: "J. Bruce Fields" <bfields@fieldses.org>
> Cc: linux-nfs@vger.kernel.org
> ---
> This patch depends on an earlier idr patch and given the trivial
> nature of the patch, I think it would be best to route these together
> through -mm.  Please holler if there's any objection.
> 
> Thanks.
> 
>  fs/nfs/client.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/fs/nfs/client.c b/fs/nfs/client.c
> index 9f3c664..84d8eae 100644
> --- a/fs/nfs/client.c
> +++ b/fs/nfs/client.c
> @@ -197,7 +197,6 @@ error_0:
>  EXPORT_SYMBOL_GPL(nfs_alloc_client);
>  
>  #if IS_ENABLED(CONFIG_NFS_V4)
> -/* idr_remove_all is not needed as all id's are removed by nfs_put_client */
>  void nfs_cleanup_cb_ident_idr(struct net *net)
>  {
>  	struct nfs_net *nn = net_generic(net, nfs_net_id);
> -- 
> 1.8.1
> 

Re: [PATCH 11/14] nfs: idr_destroy() no longer needs idr_remove_all()

[Myklebust, Trond]

On Tue, 2013-01-29 at 17:58 -0500, J. Bruce Fields wrote:
> On Fri, Jan 25, 2013 at 05:31:09PM -0800, Tejun Heo wrote:
> > idr_destroy() can destroy idr by itself and idr_remove_all() is being
> > deprecated.  Drop reference to idr_remove_all().  Note that the code
> > wasn't completely correct before because idr_remove() on all entries
> > doesn't necessarily release all idr_layers which could lead to memory
> > leak.
> 
> Seems fine, but actually this is client-side so I think you meant the cc
> to be to Trond.

Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>

No problems whatsoever with removing a comment. :-)

My worry is more about Tejun's comment that we did actually need a call
to idr_remove_all() in the original code. Do we need to queue up a fix
for the 3.8 and existing stable kernels?

Cheers
  Trond

> > Signed-off-by: Tejun Heo <tj@kernel.org>
> > Cc: "J. Bruce Fields" <bfields@fieldses.org>
> > Cc: linux-nfs@vger.kernel.org
> > ---
> > This patch depends on an earlier idr patch and given the trivial
> > nature of the patch, I think it would be best to route these together
> > through -mm.  Please holler if there's any objection.
> > 
> > Thanks.
> > 
> >  fs/nfs/client.c | 1 -
> >  1 file changed, 1 deletion(-)
> > 
> > diff --git a/fs/nfs/client.c b/fs/nfs/client.c
> > index 9f3c664..84d8eae 100644
> > --- a/fs/nfs/client.c
> > +++ b/fs/nfs/client.c
> > @@ -197,7 +197,6 @@ error_0:
> >  EXPORT_SYMBOL_GPL(nfs_alloc_client);
> >  
> >  #if IS_ENABLED(CONFIG_NFS_V4)
> > -/* idr_remove_all is not needed as all id's are removed by nfs_put_client */
> >  void nfs_cleanup_cb_ident_idr(struct net *net)
> >  {
> >  	struct nfs_net *nn = net_generic(net, nfs_net_id);
> > -- 
> > 1.8.1
> > 

-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com
www.netapp.com

Re: [PATCH 11/14] nfs: idr_destroy() no longer needs idr_remove_all()

[Tejun Heo]

Hello, Trond.

On Wed, Jan 30, 2013 at 02:18:06AM +0000, Myklebust, Trond wrote:
> My worry is more about Tejun's comment that we did actually need a call
> to idr_remove_all() in the original code. Do we need to queue up a fix
> for the 3.8 and existing stable kernels?

IIUC, the only case where idr_layer is left around after idr_remove()
on all elems is when the deletions lead to multi-level left-most
collapse.  Not sure whether the current code can actually hit that.
No harm in adding idr_remove_all(), I guess.

Thanks.

-- 
tejun