Re: [ 068/103] SUNRPC: fix races on PipeFS UMOUNT notifications
On Tue, Jul 23, 2013 at 10:30:57PM +, Myklebust, Trond wrote: > On Tue, 2013-07-23 at 15:26 -0700, Greg Kroah-Hartman wrote: > > 3.10-stable review patch. If anyone has any objections, please let me know. > > > > Again, please drop this patch and 67/103 for now. We'll get back to > whether or not this should be stable material later. Ick, sorry, I thought I had dropped all of the patches you told me to already, sorry about this. Now really dropped :) greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[ 068/103] SUNRPC: fix races on PipeFS UMOUNT notifications
3.10-stable review patch. If anyone has any objections, please let me know.
--
From: Stanislav Kinsbursky
commit adb6fa7ffe9031857ec14b8aab75c9ab65556cbc upstream.
CPU#0 CPU#1
- -
rpc_kill_sb
sn->pipefs_sb = NULLrpc_release_client
(UMOUNT_EVENT) rpc_free_auth
rpc_pipefs_event
rpc_get_client_for_event
!atomic_inc_not_zero(cl_count)
atomic_inc(cl_count)
rpc_free_client
rpc_clnt_remove_pipedir
To fix this, this patch does the following:
1) Calls RPC_PIPEFS_UMOUNT notification with sn->pipefs_sb_lock being held.
2) Removes SUNRPC client from the list AFTER pipes destroying.
3) Doesn't hold RPC client on notification: if client in the list, then it
can't be destroyed while sn->pipefs_sb_lock in hold by notification caller.
Signed-off-by: Stanislav Kinsbursky
Signed-off-by: Trond Myklebust
Signed-off-by: Greg Kroah-Hartman
---
net/sunrpc/clnt.c |5 +
net/sunrpc/rpc_pipe.c |2 +-
2 files changed, 2 insertions(+), 5 deletions(-)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -236,8 +236,6 @@ static struct rpc_clnt *rpc_get_client_f
continue;
if (rpc_clnt_skip_event(clnt, event))
continue;
- if (atomic_inc_not_zero(>cl_count) == 0)
- continue;
spin_unlock(>rpc_client_lock);
return clnt;
}
@@ -254,7 +252,6 @@ static int rpc_pipefs_event(struct notif
while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
error = __rpc_pipefs_event(clnt, event, sb);
- rpc_release_client(clnt);
if (error)
break;
}
@@ -641,8 +638,8 @@ rpc_free_client(struct rpc_clnt *clnt)
rcu_dereference(clnt->cl_xprt)->servername);
if (clnt->cl_parent != clnt)
rpc_release_client(clnt->cl_parent);
- rpc_unregister_client(clnt);
rpc_clnt_remove_pipedir(clnt);
+ rpc_unregister_client(clnt);
rpc_free_iostats(clnt->cl_metrics);
kfree(clnt->cl_principal);
clnt->cl_metrics = NULL;
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -1165,12 +1165,12 @@ static void rpc_kill_sb(struct super_blo
goto out;
}
sn->pipefs_sb = NULL;
- mutex_unlock(>pipefs_sb_lock);
dprintk("RPC: sending pipefs UMOUNT notification for net %p%s\n",
net, NET_NAME(net));
blocking_notifier_call_chain(_pipefs_notifier_list,
RPC_PIPEFS_UMOUNT,
sb);
+ mutex_unlock(>pipefs_sb_lock);
put_net(net);
out:
kill_litter_super(sb);
--
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Re: [ 068/103] SUNRPC: fix races on PipeFS UMOUNT notifications
On Tue, 2013-07-23 at 15:26 -0700, Greg Kroah-Hartman wrote:
> 3.10-stable review patch. If anyone has any objections, please let me know.
>
Again, please drop this patch and 67/103 for now. We'll get back to
whether or not this should be stable material later.
--
Trond Myklebust
Linux NFS client maintainer
NetApp
trond.mykleb...@netapp.com
www.netapp.com
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Re: [ 068/103] SUNRPC: fix races on PipeFS UMOUNT notifications
On Tue, 2013-07-23 at 15:26 -0700, Greg Kroah-Hartman wrote:
3.10-stable review patch. If anyone has any objections, please let me know.
Again, please drop this patch and 67/103 for now. We'll get back to
whether or not this should be stable material later.
--
Trond Myklebust
Linux NFS client maintainer
NetApp
trond.mykleb...@netapp.com
www.netapp.com
N�r��yb�X��ǧv�^�){.n�+{zX����ܨ}���Ơz�j:+v���zZ+��+zf���h���~i���z� �w���?��)ߢf��^jǫy�m��@A�a���
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[ 068/103] SUNRPC: fix races on PipeFS UMOUNT notifications
3.10-stable review patch. If anyone has any objections, please let me know.
--
From: Stanislav Kinsbursky skinsbur...@parallels.com
commit adb6fa7ffe9031857ec14b8aab75c9ab65556cbc upstream.
CPU#0 CPU#1
- -
rpc_kill_sb
sn-pipefs_sb = NULLrpc_release_client
(UMOUNT_EVENT) rpc_free_auth
rpc_pipefs_event
rpc_get_client_for_event
!atomic_inc_not_zero(cl_count)
skip the client
atomic_inc(cl_count)
rpc_free_client
rpc_clnt_remove_pipedir
skip client dir removing
To fix this, this patch does the following:
1) Calls RPC_PIPEFS_UMOUNT notification with sn-pipefs_sb_lock being held.
2) Removes SUNRPC client from the list AFTER pipes destroying.
3) Doesn't hold RPC client on notification: if client in the list, then it
can't be destroyed while sn-pipefs_sb_lock in hold by notification caller.
Signed-off-by: Stanislav Kinsbursky skinsbur...@parallels.com
Signed-off-by: Trond Myklebust trond.mykleb...@netapp.com
Signed-off-by: Greg Kroah-Hartman gre...@linuxfoundation.org
---
net/sunrpc/clnt.c |5 +
net/sunrpc/rpc_pipe.c |2 +-
2 files changed, 2 insertions(+), 5 deletions(-)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -236,8 +236,6 @@ static struct rpc_clnt *rpc_get_client_f
continue;
if (rpc_clnt_skip_event(clnt, event))
continue;
- if (atomic_inc_not_zero(clnt-cl_count) == 0)
- continue;
spin_unlock(sn-rpc_client_lock);
return clnt;
}
@@ -254,7 +252,6 @@ static int rpc_pipefs_event(struct notif
while ((clnt = rpc_get_client_for_event(sb-s_fs_info, event))) {
error = __rpc_pipefs_event(clnt, event, sb);
- rpc_release_client(clnt);
if (error)
break;
}
@@ -641,8 +638,8 @@ rpc_free_client(struct rpc_clnt *clnt)
rcu_dereference(clnt-cl_xprt)-servername);
if (clnt-cl_parent != clnt)
rpc_release_client(clnt-cl_parent);
- rpc_unregister_client(clnt);
rpc_clnt_remove_pipedir(clnt);
+ rpc_unregister_client(clnt);
rpc_free_iostats(clnt-cl_metrics);
kfree(clnt-cl_principal);
clnt-cl_metrics = NULL;
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -1165,12 +1165,12 @@ static void rpc_kill_sb(struct super_blo
goto out;
}
sn-pipefs_sb = NULL;
- mutex_unlock(sn-pipefs_sb_lock);
dprintk(RPC: sending pipefs UMOUNT notification for net %p%s\n,
net, NET_NAME(net));
blocking_notifier_call_chain(rpc_pipefs_notifier_list,
RPC_PIPEFS_UMOUNT,
sb);
+ mutex_unlock(sn-pipefs_sb_lock);
put_net(net);
out:
kill_litter_super(sb);
--
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the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [ 068/103] SUNRPC: fix races on PipeFS UMOUNT notifications
On Tue, Jul 23, 2013 at 10:30:57PM +, Myklebust, Trond wrote: On Tue, 2013-07-23 at 15:26 -0700, Greg Kroah-Hartman wrote: 3.10-stable review patch. If anyone has any objections, please let me know. Again, please drop this patch and 67/103 for now. We'll get back to whether or not this should be stable material later. Ick, sorry, I thought I had dropped all of the patches you told me to already, sorry about this. Now really dropped :) greg k-h -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
