From: Xiubo Li xiubli@redhat.com
commit 257e6172ab36ebbe295a6c9ee9a9dd0fe54c1dc2 upstream.
If a client sends out a cap update dropping caps with the prior 'seq' just before an incoming cap revoke request, then the client may drop the revoke because it believes it's already released the requested capabilities.
This causes the MDS to wait indefinitely for the client to respond to the revoke. It's therefore always a good idea to ack the cap revoke request with the bumped up 'seq'.
Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/61782 Signed-off-by: Xiubo Li xiubli@redhat.com Reviewed-by: Milind Changire mchangir@redhat.com Reviewed-by: Patrick Donnelly pdonnell@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ceph/caps.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -3574,6 +3574,15 @@ static void handle_cap_grant(struct inod } BUG_ON(cap->issued & ~cap->implemented);
+ /* don't let check_caps skip sending a response to MDS for revoke msgs */ + if (le32_to_cpu(grant->op) == CEPH_CAP_OP_REVOKE) { + cap->mds_wanted = 0; + if (cap == ci->i_auth_cap) + check_caps = 1; /* check auth cap only */ + else + check_caps = 2; /* check all caps */ + } + if (extra_info->inline_version > 0 && extra_info->inline_version >= ci->i_inline_version) { ci->i_inline_version = extra_info->inline_version;