Commit 257e6172 authored by Xiubo Li's avatar Xiubo Li Committed by Ilya Dryomov
Browse files

ceph: don't let check_caps skip sending responses for revoke msgs 

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: default avatarXiubo Li <xiubli@redhat.com>
Reviewed-by: default avatarMilind Changire <mchangir@redhat.com>
Reviewed-by: default avatarPatrick Donnelly <pdonnell@redhat.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent ce72d4e0

fs/ceph/caps.c

+9 −0
Original line number Diff line number Diff line
@@ -3566,6 +3566,15 @@ static void handle_cap_grant(struct inode *inode, 
	}

	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;