This is an attempt to fix the softlock on the delayed_work workqueue. As stated in 0002 patch: Function ceph_check_delayed_caps() is called from the mdsc->delayed_work workqueue and it can be kept looping for quite some time if caps keep being added back to the mdsc->cap_delay_list. This may result in the watchdog tainting the kernel with the softlockup flag. v2 of this fix modifies the approach by time-bounding the loop in this function, so that any caps added to the list *after* the loop starts will be postponed to the next wq run. An extra change in 0001 (suggested by Jeff) allows scheduling runs for periods smaller than the default (5 secs) period. This way, delayed_work() can have the next run scheduled for the next list element ci->i_hold_caps_max instead of 5 secs. This patchset should fix the issue reported here [1], although a quick search for "ceph_check_delayed_caps" in the tracker returns a few more bugs, possibly duplicates. [1] https://tracker.ceph.com/issues/46284 Luis Henriques (2): ceph: allow schedule_delayed() callers to set delay for workqueue ceph: reduce contention in ceph_check_delayed_caps() fs/ceph/caps.c | 17 ++++++++++++++++- fs/ceph/mds_client.c | 24 +++++++++++++++--------- fs/ceph/super.h | 2 +- 3 files changed, 32 insertions(+), 11 deletions(-)
