ceph: keep i_snap_realm while there are writers
when reconnecting to MDS is denied, we remove session caps
forcibly. But it's possible there are ongoing write, the
write code needs to reference i_snap_realm. So if there are
ongoing write, we keep i_snap_realm.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 8172775..4ddadc1 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -896,6 +896,18 @@
return ret;
}
+static void drop_inode_snap_realm(struct ceph_inode_info *ci)
+{
+ struct ceph_snap_realm *realm = ci->i_snap_realm;
+ spin_lock(&realm->inodes_with_caps_lock);
+ list_del_init(&ci->i_snap_realm_item);
+ ci->i_snap_realm_counter++;
+ ci->i_snap_realm = NULL;
+ spin_unlock(&realm->inodes_with_caps_lock);
+ ceph_put_snap_realm(ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc,
+ realm);
+}
+
/*
* Remove a cap. Take steps to deal with a racing iterate_session_caps.
*
@@ -946,15 +958,13 @@
if (removed)
ceph_put_cap(mdsc, cap);
- if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) {
- struct ceph_snap_realm *realm = ci->i_snap_realm;
- spin_lock(&realm->inodes_with_caps_lock);
- list_del_init(&ci->i_snap_realm_item);
- ci->i_snap_realm_counter++;
- ci->i_snap_realm = NULL;
- spin_unlock(&realm->inodes_with_caps_lock);
- ceph_put_snap_realm(mdsc, realm);
- }
+ /* when reconnect denied, we remove session caps forcibly,
+ * i_wr_ref can be non-zero. If there are ongoing write,
+ * keep i_snap_realm.
+ */
+ if (!__ceph_is_any_caps(ci) && ci->i_wr_ref == 0 && ci->i_snap_realm)
+ drop_inode_snap_realm(ci);
+
if (!__ceph_is_any_real_caps(ci))
__cap_delay_cancel(mdsc, ci);
}
@@ -2309,6 +2319,9 @@
wake = 1;
}
}
+ /* see comment in __ceph_remove_cap() */
+ if (!__ceph_is_any_caps(ci) && ci->i_snap_realm)
+ drop_inode_snap_realm(ci);
}
spin_unlock(&ci->i_ceph_lock);