[PATCH] ceph: fix cap ref leak via netfs init_request

[Patrick Donnelly <batrick@batbytes.com>]

From: Patrick Donnelly <pdonnell@redhat.com>

Log recovered from a user's cluster:

    <7>[ 5413.970692] ceph:  get_cap_refs 00000000958c114b ret 1 got Fr
    <7>[ 5413.970695] ceph:  start_read 00000000958c114b, no cache cap
    ...
    <7>[ 5473.934609] ceph:   my wanted = Fr, used = Fr, dirty -
    <7>[ 5473.934616] ceph:  revocation: pAsLsXsFr -> pAsLsXs (revoking Fr)
    <7>[ 5473.934632] ceph:  __ceph_caps_issued 00000000958c114b cap 00000000f7784259 issued pAsLsXs
    <7>[ 5473.934638] ceph:  check_caps 10000000e68.fffffffffffffffe file_want - used Fr dirty - flushing - issued pAsLsXs revoking Fr retain pAsLsXsFsr  AUTHONLY NOINVAL FLUSH_FORCE

The MDS subsequently complains that the kernel client is late releasing caps.

Closes: https://tracker.ceph.com/issues/67008
Fixes: 2504470854f8 ("ceph: Make ceph_init_request() check caps on readahead")
Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>
Cc: stable@vger.kernel.org
---
 fs/ceph/addr.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 53fef258c2bc..702c6a730b70 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -489,8 +489,11 @@ static int ceph_init_request(struct netfs_io_request *rreq, struct file *file)
 	rreq->io_streams[0].sreq_max_len = fsc->mount_options->rsize;
 
 out:
-	if (ret < 0)
+	if (ret < 0) {
+		if (got)
+			ceph_put_cap_refs(ceph_inode(inode), got);
 		kfree(priv);
+	}
 
 	return ret;
 }

base-commit: e32cde8d2bd7d251a8f9b434143977ddf13dcec6
-- 
Patrick Donnelly, Ph.D.
He / Him / His
Red Hat Partner Engineer
IBM, Inc.
GPG: 19F28A586F808C2402351B93C3301A3E258DD79D