[PATCH 3.13.y-ckt 048/103] LOCKD: Fix a race when initialising nlmsvc_timeout

From: Kamal Mostafa
Date: Wed Feb 18 2015 - 19:52:41 EST

3.13.11-ckt16 -stable review patch. If anyone has any objections, please let me know.


From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

commit 06bed7d18c2c07b3e3eeadf4bd357f6e806618cc upstream.

This commit fixes a race whereby nlmclnt_init() first starts the lockd
daemon, and then calls nlm_bind_host() with the expectation that
nlmsvc_timeout has already been initialised. Unfortunately, there is no
no synchronisation between lockd() and lockd_up() to guarantee that this
is the case.

Fix is to move the initialisation of nlmsvc_timeout into lockd_create_svc

Fixes: 9a1b6bf818e74 ("LOCKD: Don't call utsname()->nodename...")
Cc: Bruce Fields <bfields@xxxxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
fs/lockd/svc.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 223e1cb..59a53f6 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -137,10 +137,6 @@ lockd(void *vrqstp)

dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");

- if (!nlm_timeout)
- nlm_timeout = LOCKD_DFLT_TIMEO;
- nlmsvc_timeout = nlm_timeout * HZ;
* The main request loop. We don't terminate until the last
* NFS mount or NFS daemon has gone away.
@@ -346,6 +342,10 @@ static struct svc_serv *lockd_create_svc(void)
"lockd_up: no pid, %d users??\n", nlmsvc_users);

+ if (!nlm_timeout)
+ nlm_timeout = LOCKD_DFLT_TIMEO;
+ nlmsvc_timeout = nlm_timeout * HZ;
serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL);
if (!serv) {
printk(KERN_WARNING "lockd_up: create service failed\n");

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