Commit 8e948c36 authored by Jeff Layton's avatar Jeff Layton Committed by Chuck Lever
Browse files

nfsd: fix oops when reading pool_stats before server is started 



Sourbh reported an oops that is triggerable by trying to read the
pool_stats procfile before nfsd had been started. Move the check for a
NULL serv in svc_pool_stats_start above the mutex acquisition, and fix
the stop routine not to unlock the mutex if there is no serv yet.

Fixes: 7b207ccd ("svc: don't hold reference for poolstats, only mutex.")
Reported-by: default avatarSourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Tested-by: default avatarSourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 4a77c3de

net/sunrpc/svc_xprt.c

+5 −3
Original line number Diff line number Diff line
@@ -1421,12 +1421,13 @@ static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos) 


	dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);



	if (!si->serv)

		return NULL;



	mutex_lock(si->mutex);



	if (!pidx)

		return SEQ_START_TOKEN;

	if (!si->serv)

		return NULL;

	return pidx > si->serv->sv_nrpools ? NULL

		: &si->serv->sv_pools[pidx - 1];

}
@@ -1458,6 +1459,7 @@ static void svc_pool_stats_stop(struct seq_file *m, void *p) 
{

	struct svc_info *si = m->private;



	if (si->serv)

		mutex_unlock(si->mutex);

}