From e125fbeb538e5e35a00c6c8150a5361bef34814c Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Mon, 1 Mar 2021 17:05:09 -0500 Subject: fs: dlm: fix mark setting deadlock This patch fixes an deadlock issue when dlm_lowcomms_close() is called. When dlm_lowcomms_close() is called the clusters_root.subsys.su_mutex is held to remove configfs items. At this time we flushing (e.g. cancel_work_sync()) the workers of send and recv workqueue. Due the fact that we accessing configfs items (mark values), these workers will lock clusters_root.subsys.su_mutex as well which are already hold by dlm_lowcomms_close() and ends in a deadlock situation. [67170.703046] ====================================================== [67170.703965] WARNING: possible circular locking dependency detected [67170.704758] 5.11.0-rc4+ #22 Tainted: G W [67170.705433] ------------------------------------------------------ [67170.706228] dlm_controld/280 is trying to acquire lock: [67170.706915] ffff9f2f475a6948 ((wq_completion)dlm_recv){+.+.}-{0:0}, at: __flush_work+0x203/0x4c0 [67170.708026] but task is already holding lock: [67170.708758] ffffffffa132f878 (&clusters_root.subsys.su_mutex){+.+.}-{3:3}, at: configfs_rmdir+0x29b/0x310 [67170.710016] which lock already depends on the new lock. The new behaviour adds the mark value to the node address configuration which doesn't require to held the clusters_root.subsys.su_mutex by accessing mark values in a separate datastructure. However the mark values can be set now only after a node address was set which is the case when the user is using dlm_controld. Signed-off-by: Alexander Aring Signed-off-by: David Teigland --- fs/dlm/lowcomms.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/dlm/lowcomms.h') diff --git a/fs/dlm/lowcomms.h b/fs/dlm/lowcomms.h index 0918f9376489..790d6703b17e 100644 --- a/fs/dlm/lowcomms.h +++ b/fs/dlm/lowcomms.h @@ -21,6 +21,7 @@ int dlm_lowcomms_close(int nodeid); void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc); void dlm_lowcomms_commit_buffer(void *mh); int dlm_lowcomms_connect_node(int nodeid); +int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark); int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len); #endif /* __LOWCOMMS_DOT_H__ */ -- cgit v1.2.3-59-g8ed1b