From ccda9910d8490f4fb067131598e4b2e986faa5a0 Mon Sep 17 00:00:00 2001 From: Patrick Donnelly Date: Wed, 2 Oct 2024 21:05:12 -0400 Subject: [PATCH] ceph: fix cap ref leak via netfs init_request 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. Approximately, a series of changes to this code by commits 49870056005c ("ceph: convert ceph_readpages to ceph_readahead"), 2de160417315 ("netfs: Change ->init_request() to return an error code") and a5c9dc445139 ("ceph: Make ceph_init_request() check caps on readahead") resulted in subtle resource cleanup to be missed. The main culprit is the change in error handling in 2de160417315 which meant that a failure in init_request() would no longer cause cleanup to be called. That would prevent the ceph_put_cap_refs() call which would cleanup the leaked cap ref. Cc: stable@vger.kernel.org Fixes: a5c9dc445139 ("ceph: Make ceph_init_request() check caps on readahead") Link: https://tracker.ceph.com/issues/67008 Signed-off-by: Patrick Donnelly Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov --- 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 1d97a53d1b29..c2a9e2cc03de 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; } -- 2.25.1