LOCKD: Don't call utsname()->nodename from nlmclnt_setlockargs

Firstly, nlmclnt_setlockargs can be called from a reclaimer thread, in which case we're in entirely the wrong namespace. Secondly, commit 8aac627 (move exit_task_namespaces() outside of exit_notify()) now means that exit_task_work() is called after exit_task_namespaces(), which triggers an Oops when we're freeing up the locks. Fix this by ensuring that we initialise the nlm_host's rpc_client at mount time, so that the cl_nodename field is initialised to the value of utsname()->nodename that the net namespace uses. Then replace the lockd callers of utsname()->nodename. Signed-off-by: Trond Myklebust <[email protected]> Cc: Toralf Förster <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Nix <[email protected]> Cc: Jeff Layton <[email protected]> Cc: [email protected] # 3.10.x
fracktal · Aug 5, 2013 · 9a1b6bf · 9a1b6bf
1 parent c095ba7
commit 9a1b6bf
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Showing 2 changed files with 12 additions and 6 deletions.
diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
@@ -64,12 +64,17 @@ struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
 				   nlm_init->protocol, nlm_version,
 				   nlm_init->hostname, nlm_init->noresvport,
 				   nlm_init->net);
-	if (host == NULL) {
-		lockd_down(nlm_init->net);
-		return ERR_PTR(-ENOLCK);
-	}
+	if (host == NULL)
+		goto out_nohost;
+	if (host->h_rpcclnt == NULL && nlm_bind_host(host) == NULL)
+		goto out_nobind;
 
 	return host;
+out_nobind:
+	nlmclnt_release_host(host);
+out_nohost:
+	lockd_down(nlm_init->net);
+	return ERR_PTR(-ENOLCK);
 }
 EXPORT_SYMBOL_GPL(nlmclnt_init);
 

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
@@ -125,14 +125,15 @@ static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
 {
 	struct nlm_args	*argp = &req->a_args;
 	struct nlm_lock	*lock = &argp->lock;
+	char *nodename = req->a_host->h_rpcclnt->cl_nodename;
 
 	nlmclnt_next_cookie(&argp->cookie);
 	memcpy(&lock->fh, NFS_FH(file_inode(fl->fl_file)), sizeof(struct nfs_fh));
-	lock->caller  = utsname()->nodename;
+	lock->caller  = nodename;
 	lock->oh.data = req->a_owner;
 	lock->oh.len  = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
 				(unsigned int)fl->fl_u.nfs_fl.owner->pid,
-				utsname()->nodename);
+				nodename);
 	lock->svid = fl->fl_u.nfs_fl.owner->pid;
 	lock->fl.fl_start = fl->fl_start;
 	lock->fl.fl_end = fl->fl_end;