From: Sage Weil <sage@inktank.com>
Date: Tue, 21 Aug 2012 22:55:25 +0000 (-0700)
Subject: ceph: tolerate (and warn on) extraneous dentry from mds
X-Git-Tag: firefly_0821_release~3680^2~2171^2~2
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=6c5e50fa614fea5325a2973be06f7ec6f1055316;p=firefly-linux-kernel-4.4.55.git

ceph: tolerate (and warn on) extraneous dentry from mds

If the MDS gives us a dentry and we weren't prepared to handle it,
WARN_ON_ONCE instead of crashing.

Reported-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
---

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 9fff9f3b17e4..4b5762ef7c2b 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -992,11 +992,15 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
 	if (rinfo->head->is_dentry) {
 		struct inode *dir = req->r_locked_dir;
 
-		err = fill_inode(dir, &rinfo->diri, rinfo->dirfrag,
-				 session, req->r_request_started, -1,
-				 &req->r_caps_reservation);
-		if (err < 0)
-			return err;
+		if (dir) {
+			err = fill_inode(dir, &rinfo->diri, rinfo->dirfrag,
+					 session, req->r_request_started, -1,
+					 &req->r_caps_reservation);
+			if (err < 0)
+				return err;
+		} else {
+			WARN_ON_ONCE(1);
+		}
 	}
 
 	/*
@@ -1004,6 +1008,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
 	 * will have trouble splicing in the virtual snapdir later
 	 */
 	if (rinfo->head->is_dentry && !req->r_aborted &&
+	    req->r_locked_dir &&
 	    (rinfo->head->is_target || strncmp(req->r_dentry->d_name.name,
 					       fsc->mount_options->snapdir_name,
 					       req->r_dentry->d_name.len))) {