ceph: check if mds create snaprealm when setting quota

If mds does not, return -EOPNOTSUPP.

Link: http://tracker.ceph.com/issues/23491
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 25 insertions, 3 deletions

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 7e72348639e4..315f7e63e7cc 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -228,7 +228,15 @@ static size_t ceph_vxattrcb_dir_rctime(struct ceph_inode_info *ci, char *val,
 
 static bool ceph_vxattrcb_quota_exists(struct ceph_inode_info *ci)
 {
-        return (ci->i_max_files || ci->i_max_bytes);
+        bool ret = false;
+        spin_lock(&ci->i_ceph_lock);
+        if ((ci->i_max_files || ci->i_max_bytes) &&
+            ci->i_vino.snap == CEPH_NOSNAP &&
+            ci->i_snap_realm &&
+            ci->i_snap_realm->ino == ci->i_vino.ino)
+                ret = true;
+        spin_unlock(&ci->i_ceph_lock);
+        return ret;
 }
 
 static size_t ceph_vxattrcb_quota(struct ceph_inode_info *ci, char *val,
@@ -1008,14 +1016,19 @@ int __ceph_setxattr(struct inode *inode, const char *name,
         char *newval = NULL;
         struct ceph_inode_xattr *xattr = NULL;
         int required_blob_size;
+        bool check_realm = false;
         bool lock_snap_rwsem = false;
 
         if (ceph_snap(inode) != CEPH_NOSNAP)
                 return -EROFS;
 
         vxattr = ceph_match_vxattr(inode, name);
-        if (vxattr && vxattr->readonly)
-                return -EOPNOTSUPP;
+        if (vxattr) {
+                if (vxattr->readonly)
+                        return -EOPNOTSUPP;
+                if (value && !strncmp(vxattr->name, "ceph.quota", 10))
+                        check_realm = true;
+        }
 
         /* pass any unhandled ceph.* xattrs through to the MDS */
         if (!strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN))
@@ -1109,6 +1122,15 @@ do_sync_unlocked:
                 err = -EBUSY;
         } else {
                 err = ceph_sync_setxattr(inode, name, value, size, flags);
+                if (err >= 0 && check_realm) {
+                        /* check if snaprealm was created for quota inode */
+                        spin_lock(&ci->i_ceph_lock);
+                        if ((ci->i_max_files || ci->i_max_bytes) &&
+                            !(ci->i_snap_realm &&
+                              ci->i_snap_realm->ino == ci->i_vino.ino))
+                                err = -EOPNOTSUPP;
+                        spin_unlock(&ci->i_ceph_lock);
+                }
         }
 out:
         ceph_free_cap_flush(prealloc_cf);