This is a note to let you know that I've just added the patch titled

    svcrpc: make svc_age_temp_xprts enqueue under sv_lock

to the 3.0-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     svcrpc-make-svc_age_temp_xprts-enqueue-under-sv_lock.patch
and it can be found in the queue-3.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From e75bafbff2270993926abcc31358361db74a9bc2 Mon Sep 17 00:00:00 2001
From: "J. Bruce Fields" <bfie...@redhat.com>
Date: Sun, 10 Feb 2013 11:33:48 -0500
Subject: svcrpc: make svc_age_temp_xprts enqueue under sv_lock

From: "J. Bruce Fields" <bfie...@redhat.com>

commit e75bafbff2270993926abcc31358361db74a9bc2 upstream.

svc_age_temp_xprts expires xprts in a two-step process: first it takes
the sv_lock and moves the xprts to expire off their server-wide list
(sv_tempsocks or sv_permsocks) to a local list.  Then it drops the
sv_lock and enqueues and puts each one.

I see no reason for this: svc_xprt_enqueue() will take sp_lock, but the
sv_lock and sp_lock are not otherwise nested anywhere (and documentation
at the top of this file claims it's correct to nest these with sp_lock
inside.)

Tested-by: Jason Tibbitts <ti...@math.uh.edu>
Tested-by: Paweł Sikora <pawel.sik...@agmk.net>
Signed-off-by: J. Bruce Fields <bfie...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 net/sunrpc/svc_xprt.c |   15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -824,7 +824,6 @@ static void svc_age_temp_xprts(unsigned
        struct svc_serv *serv = (struct svc_serv *)closure;
        struct svc_xprt *xprt;
        struct list_head *le, *next;
-       LIST_HEAD(to_be_aged);
 
        dprintk("svc_age_temp_xprts\n");
 
@@ -845,25 +844,15 @@ static void svc_age_temp_xprts(unsigned
                if (atomic_read(&xprt->xpt_ref.refcount) > 1 ||
                    test_bit(XPT_BUSY, &xprt->xpt_flags))
                        continue;
-               svc_xprt_get(xprt);
-               list_move(le, &to_be_aged);
+               list_del_init(le);
                set_bit(XPT_CLOSE, &xprt->xpt_flags);
                set_bit(XPT_DETACHED, &xprt->xpt_flags);
-       }
-       spin_unlock_bh(&serv->sv_lock);
-
-       while (!list_empty(&to_be_aged)) {
-               le = to_be_aged.next;
-               /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
-               list_del_init(le);
-               xprt = list_entry(le, struct svc_xprt, xpt_list);
-
                dprintk("queuing xprt %p for closing\n", xprt);
 
                /* a thread will dequeue and close it soon */
                svc_xprt_enqueue(xprt);
-               svc_xprt_put(xprt);
        }
+       spin_unlock_bh(&serv->sv_lock);
 
        mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
 }


Patches currently in stable-queue which might be from bfie...@redhat.com are

queue-3.0/svcrpc-make-svc_age_temp_xprts-enqueue-under-sv_lock.patch
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