From: "Yan, Zheng" <zyan@redhat.com>
Date: Fri, 22 Sep 2017 11:41:06 +0800
Subject: ceph: fix __choose_mds() for LSSNAP request
Git-commit: 38f340ccdf9ed5f1350505b46c5689d015967057
Patch-mainline: v4.14-rc4
References: FATE#324714
previous commit 5d37ca14 "ceph: send LSSNAP request to auth mds
of directory inode" is buggy. It makes __choose_mds() choose mds
base on hash of '.snap' dentry.
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/mds_client.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 84edfc60d87a..f23c820daaed 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -734,12 +734,13 @@ static int __choose_mds(struct ceph_mds_client *mdsc,
inode = req->r_inode;
ihold(inode);
} else {
- /* req->r_dentry is non-null for LSSNAP request.
- * fall-thru */
- WARN_ON_ONCE(!req->r_dentry);
+ /* req->r_dentry is non-null for LSSNAP request */
+ rcu_read_lock();
+ inode = get_nonsnap_parent(req->r_dentry);
+ rcu_read_unlock();
+ dout("__choose_mds using snapdir's parent %p\n", inode);
}
- }
- if (!inode && req->r_dentry) {
+ } else if (req->r_dentry) {
/* ignore race with rename; old or new d_parent is okay */
struct dentry *parent;
struct inode *dir;