ceph: break the check delayed cap loop every 5s

In some cases this may take a long time and will block renewing
the caps to MDS.

[ idryomov: massage comment ]

Link: https://tracker.ceph.com/issues/50223#note-21
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 7fb4aae97412464c54b42037f75016085d214bd3..55051ad09c19197e9b12d5d17068d20b04d6d3e6 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -4634,6 +4634,14 @@ unsigned long ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
                        iput(inode);
                        spin_lock(&mdsc->cap_delay_lock);
                }
+
+               /*
+                * Make sure too many dirty caps or general
+                * slowness doesn't block mdsc delayed work,
+                * preventing send_renew_caps() from running.
+                */
+               if (jiffies - loop_start >= 5 * HZ)
+                       break;
        }
        spin_unlock(&mdsc->cap_delay_lock);
        doutc(cl, "done\n");