From: "Yan, Zheng" <zyan@redhat.com>
Date: Wed, 26 Jul 2017 12:48:08 +0800
Subject: ceph: send LSSNAP request to auth mds of directory inode
Git-commit: 5d37ca1480a70f437e4c425ee5723c760cf6afac
Patch-mainline: v4.14-rc1
References: FATE#324714

Snapdir inode has no capability. __choose_mds() should choose mds
base on capabilities of snapdir's parent inode.

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
 fs/ceph/dir.c        |  6 ++++--
 fs/ceph/mds_client.c | 13 ++++++++++---
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index ef7240ace576..019c2036d36f 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -377,8 +377,10 @@ static int ceph_readdir(struct file *file, struct dir_context *ctx)
 		}
 		/* hints to request -> mds selection code */
 		req->r_direct_mode = USE_AUTH_MDS;
-		req->r_direct_hash = ceph_frag_value(frag);
-		__set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
+		if (op == CEPH_MDS_OP_READDIR) {
+			req->r_direct_hash = ceph_frag_value(frag);
+			__set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
+		}
 		if (fi->last_name) {
 			req->r_path2 = kstrdup(fi->last_name, GFP_KERNEL);
 			if (!req->r_path2) {
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 666a9f274832..86ff74424df4 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -731,9 +731,16 @@ static int __choose_mds(struct ceph_mds_client *mdsc,
 
 	inode = NULL;
 	if (req->r_inode) {
-		inode = req->r_inode;
-		ihold(inode);
-	} else if (req->r_dentry) {
+		if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
+			inode = req->r_inode;
+			ihold(inode);
+		} else {
+			/* req->r_dentry is non-null for LSSNAP request.
+			 * fall-thru */
+			WARN_ON_ONCE(!req->r_dentry);
+		}
+	}
+	if (!inode && req->r_dentry) {
 		/* ignore race with rename; old or new d_parent is okay */
 		struct dentry *parent;
 		struct inode *dir;