| From e75bafbff2270993926abcc31358361db74a9bc2 Mon Sep 17 00:00:00 2001 |
| From: "J. Bruce Fields" <bfields@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" <bfields@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 <tibbs@math.uh.edu> |
| Tested-by: Paweł Sikora <pawel.sikora@agmk.net> |
| Signed-off-by: J. Bruce Fields <bfields@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@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 |
| @@ -817,7 +817,6 @@ 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"); |
| |
| @@ -838,25 +837,15 @@ 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); |
| } |