From 37659182bff1eeaaeadcfc8f853c6d2b6dbc3f47 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 18 Apr 2019 11:24:57 +0800 Subject: [PATCH] ceph: fix ci->i_head_snapc leak We missed two places that i_wrbuffer_ref_head, i_wr_ref, i_dirty_caps and i_flushing_caps may change. When they are all zeros, we should free i_head_snapc. Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/38224 Reported-and-tested-by: Luis Henriques Signed-off-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov --- fs/ceph/mds_client.c | 9 +++++++++ fs/ceph/snap.c | 7 ++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index bc5d70d6bfe6..9049c2a3e972 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1414,6 +1414,15 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove); ci->i_prealloc_cap_flush = NULL; } + + if (drop && + ci->i_wrbuffer_ref_head == 0 && + ci->i_wr_ref == 0 && + ci->i_dirty_caps == 0 && + ci->i_flushing_caps == 0) { + ceph_put_snap_context(ci->i_head_snapc); + ci->i_head_snapc = NULL; + } } spin_unlock(&ci->i_ceph_lock); while (!list_empty(&to_remove)) { diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 89aa37fa0f84..b26e12cd8ec3 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -572,7 +572,12 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci) old_snapc = NULL; update_snapc: - if (ci->i_head_snapc) { + if (ci->i_wrbuffer_ref_head == 0 && + ci->i_wr_ref == 0 && + ci->i_dirty_caps == 0 && + ci->i_flushing_caps == 0) { + ci->i_head_snapc = NULL; + } else { ci->i_head_snapc = ceph_get_snap_context(new_snapc); dout(" new snapc is %p\n", new_snapc); }