libceph: don't consume a ref on pagelist in ceph_msg_data_add_pagelist()

Because send_mds_reconnect() wants to send a message with a pagelist
and pass the ownership to the messenger, ceph_msg_data_add_pagelist()
consumes a ref which is then put in ceph_msg_data_destroy().  This
makes managing pagelists in the OSD client (where they are wrapped in
ceph_osd_data) unnecessarily hard because the handoff only happens in
ceph_osdc_start_request() instead of when the pagelist is passed to
ceph_osd_data_pagelist_init().  I counted several memory leaks on
various error paths.

Fix up ceph_msg_data_add_pagelist() and carry a pagelist ref in
ceph_osd_data.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 580a79b9a91f..97de674ea377 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2136,7 +2136,6 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
 
         if (req->r_pagelist) {
                 struct ceph_pagelist *pagelist = req->r_pagelist;
-                refcount_inc(&pagelist->refcnt);
                 ceph_msg_data_add_pagelist(msg, pagelist);
                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
         } else {
@@ -3240,6 +3239,7 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc,
         mutex_unlock(&mdsc->mutex);
 
         up_read(&mdsc->snap_rwsem);
+        ceph_pagelist_release(pagelist);
         return;
 
 fail: