From: Jeff Layton <jlayton@kernel.org>

Date: Mon, 1 Mar 2021 07:38:01 -0500

Subject: ceph: don't clobber i_snap_caps on non-I_NEW inode

Git-commit: d3c51ae1b8cce5bdaf91a1ce32b33cf5626075dc

Patch-mainline: v5.13-rc1

References: bsc#1186501

We want the snapdir to mirror the non-snapped directory's attributes for

most things, but i_snap_caps represents the caps granted on the snapshot

directory by the MDS itself. A misbehaving MDS could issue different

caps for the snapdir and we lose them here.

Only reset i_snap_caps when the inode is I_NEW. Also, move the setting

of i_op and i_fop inside the if block since they should never change

anyway.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Jeff Layton <jlayton@kernel.org>

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Acked-by: Luis Henriques <lhenriques@suse.com>

---

 fs/ceph/inode.c | 9 +++++----

 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c

index 4418d4be2907..2fd1c48ac5d7 100644

--- a/fs/ceph/inode.c

+++ b/fs/ceph/inode.c

@@ -87,14 +87,15 @@ struct inode *ceph_get_snapdir(struct inode *parent)

 	inode->i_mtime = parent->i_mtime;

 	inode->i_ctime = parent->i_ctime;

 	inode->i_atime = parent->i_atime;

-	inode->i_op = &ceph_snapdir_iops;

-	inode->i_fop = &ceph_snapdir_fops;

-	ci->i_snap_caps = CEPH_CAP_PIN; /* so we can open */

 	ci->i_rbytes = 0;

 	ci->i_btime = ceph_inode(parent)->i_btime;

-	if (inode->i_state & I_NEW)

+	if (inode->i_state & I_NEW) {

+		inode->i_op = &ceph_snapdir_iops;

+		inode->i_fop = &ceph_snapdir_fops;

+		ci->i_snap_caps = CEPH_CAP_PIN; /* so we can open */

 		unlock_new_inode(inode);

+	}

 	return inode;

 }