From 9030f0c1de632879d56149a6d3a1f392fce79035 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Mon, 23 Mar 2015 20:12:20 +0800 Subject: [PATCH 1/2] 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 --- fs/ceph/caps.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index cefca66..020650a 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -897,6 +897,18 @@ int ceph_is_any_caps(struct inode *inode) 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. * @@ -947,15 +959,13 @@ void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release) 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); } @@ -2247,6 +2257,9 @@ void ceph_put_cap_refs(struct ceph_inode_info *ci, int had) 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); -- 1.9.3