Patch looks good to me. Sorry I must nitpick the commit message wording:
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'.
On Tue, Jun 27, 2023 at 7:59 PM xiubli@redhat.com wrote:
From: Xiubo Li xiubli@redhat.com
If a client sends out a cap-update request with the old 'seq' just before a pending cap revoke request, then the MDS might miscalculate the 'seqs' and caps. It's therefore always a good idea to ack the cap revoke request with the bumped up 'seq'.
Cc: stable@vger.kernel.org Cc: Patrick Donnelly pdonnell@redhat.com URL: https://tracker.ceph.com/issues/61782 Signed-off-by: Xiubo Li xiubli@redhat.com
V2:
- Rephrased the commit comment for better understanding from Milind
fs/ceph/caps.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 1052885025b3..eee2fbca3430 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -3737,6 +3737,15 @@ 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 */elsecheck_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;-- 2.40.1