2013-01-26 01:31:37

by Tejun Heo

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

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 <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: [email protected]
---
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



2013-01-30 02:18:08

by Myklebust, Trond

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

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 <[email protected]>

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 <[email protected]>
> > Cc: "J. Bruce Fields" <[email protected]>
> > Cc: [email protected]
> > ---
> > 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
[email protected]
http://www.netapp.com

2013-01-29 22:58:51

by J. Bruce Fields

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

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 <[email protected]>
> Cc: "J. Bruce Fields" <[email protected]>
> Cc: [email protected]
> ---
> 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
>

2013-02-01 00:08:23

by Tejun Heo

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

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