Re: [PATCH] ocfs2: cluster: don't sleep while holding o2hb_live_lock in o2hb_region_pin()
Joseph Qi <[email protected]> Wed, 22 Jul 2026 10:29:53 +0800
| Newsgroups | dev.linux.lists.ocfs2-devel,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On 7/22/26 1:56 AM, Andrew Morton wrote: > On Tue, 21 Jul 2026 19:49:16 +0800 Joseph Qi <[email protected]> wrote: > >> o2hb_region_pin() is always called with the o2hb_live_lock spinlock held >> (from o2hb_region_inc_user() and o2hb_heartbeat_group_drop_item()), but it >> calls o2nm_depend_item() -> configfs_depend_item(), which sleeps: it pins >> the configfs filesystem and takes the configfs root inode rwsem. Under >> CONFIG_DEBUG_ATOMIC_SLEEP this triggers: >> >> BUG: sleeping function called from invalid context at kernel/locking/rwsem.c >> in_atomic(): 1, ... name: mount.ocfs2 >> down_write >> configfs_depend_item >> o2hb_region_pin >> o2hb_region_inc_user >> o2hb_register_callback >> dlm_register_domain_handlers >> ... >> ocfs2_dlm_init >> ocfs2_mount_volume >> ocfs2_fill_super >> >> Rework o2hb_region_pin() to pin one region at a time with the lock >> dropped across the sleeping call: under o2hb_live_lock find the next >> eligible region and take a config_item reference to keep it alive, drop >> the lock, call o2nm_depend_item(), then retake the lock and record the >> pin. The config_item_put() is done with the lock released as well, since >> o2hb_region_release() also acquires o2hb_live_lock and can sleep. The >> region list may change while unlocked, so the scan restarts from the >> top after each pin. Local heartbeat still pins only the matching region; >> global heartbeat pins all eligible regions. > > Thanks, I'll add cc:stable to this. > > Sashiko might have a found a couple of pre-existing issues in there: > > https://sashiko.dev/#/patchset/[email protected] Thanks, the two comments seems real pre-existing issues. I'll look into them later. Thanks, Joseph