From 950eec8126001c63ec6055d22d370d8ab833ed4f Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
Date: Thu, 18 Apr 2019 11:24:57 +0800
Subject: [PATCH] ceph: fix ci->i_head_snapc leak
commit 37659182bff1eeaaeadcfc8f853c6d2b6dbc3f47 upstream.
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 <lhenriques@suse.com>
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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 d87ca0bd1bcd..bfcf11c70bfa 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1290,6 +1290,15 @@ 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 f74193da0e09..1f46b02f7314 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -568,7 +568,12 @@ 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);
}
--
2.30.9