From b355516f450703c9015316e429b66a93dfff0e6f Mon Sep 17 00:00:00 2001 From: David Windsor Date: Tue, 2 Apr 2019 08:37:10 -0400 Subject: [PATCH 1/2] dlm: check if workqueues are NULL before flushing/destroying If the DLM lowcomms stack is shut down before any DLM traffic can be generated, flush_workqueue() and destroy_workqueue() can be called on empty send and/or recv workqueues. Insert guard conditionals to only call flush_workqueue() and destroy_workqueue() on workqueues that are not NULL. Signed-off-by: David Windsor Signed-off-by: David Teigland --- fs/dlm/lowcomms.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 114ebfe30929..3951d39b9b75 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -1628,8 +1628,10 @@ static void clean_writequeues(void) static void work_stop(void) { - destroy_workqueue(recv_workqueue); - destroy_workqueue(send_workqueue); + if (recv_workqueue) + destroy_workqueue(recv_workqueue); + if (send_workqueue) + destroy_workqueue(send_workqueue); } static int work_start(void) @@ -1689,13 +1691,17 @@ static void work_flush(void) struct hlist_node *n; struct connection *con; - flush_workqueue(recv_workqueue); - flush_workqueue(send_workqueue); + if (recv_workqueue) + flush_workqueue(recv_workqueue); + if (send_workqueue) + flush_workqueue(send_workqueue); do { ok = 1; foreach_conn(stop_conn); - flush_workqueue(recv_workqueue); - flush_workqueue(send_workqueue); + if (recv_workqueue) + flush_workqueue(recv_workqueue); + if (send_workqueue) + flush_workqueue(send_workqueue); for (i = 0; i < CONN_HASH_SIZE && ok; i++) { hlist_for_each_entry_safe(con, n, &connection_hash[i], list) { From a48f9721e6db74dfbeb8d4a2cd616b20017f4b78 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 12 Jun 2019 17:25:36 +0200 Subject: [PATCH 2/2] dlm: no need to check return value of debugfs_create functions When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman Signed-off-by: David Teigland --- fs/dlm/debug_fs.c | 21 ++------------------- fs/dlm/dlm_internal.h | 8 ++++---- fs/dlm/main.c | 5 +---- 3 files changed, 7 insertions(+), 27 deletions(-) diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c index 0e941d42e3e9..d6bbccb0ed15 100644 --- a/fs/dlm/debug_fs.c +++ b/fs/dlm/debug_fs.c @@ -737,7 +737,7 @@ void dlm_delete_debug_file(struct dlm_ls *ls) debugfs_remove(ls->ls_debug_toss_dentry); } -int dlm_create_debug_file(struct dlm_ls *ls) +void dlm_create_debug_file(struct dlm_ls *ls) { char name[DLM_LOCKSPACE_LEN + 8]; @@ -748,8 +748,6 @@ int dlm_create_debug_file(struct dlm_ls *ls) dlm_root, ls, &format1_fops); - if (!ls->ls_debug_rsb_dentry) - goto fail; /* format 2 */ @@ -761,8 +759,6 @@ int dlm_create_debug_file(struct dlm_ls *ls) dlm_root, ls, &format2_fops); - if (!ls->ls_debug_locks_dentry) - goto fail; /* format 3 */ @@ -774,8 +770,6 @@ int dlm_create_debug_file(struct dlm_ls *ls) dlm_root, ls, &format3_fops); - if (!ls->ls_debug_all_dentry) - goto fail; /* format 4 */ @@ -787,8 +781,6 @@ int dlm_create_debug_file(struct dlm_ls *ls) dlm_root, ls, &format4_fops); - if (!ls->ls_debug_toss_dentry) - goto fail; memset(name, 0, sizeof(name)); snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_waiters", ls->ls_name); @@ -798,21 +790,12 @@ int dlm_create_debug_file(struct dlm_ls *ls) dlm_root, ls, &waiters_fops); - if (!ls->ls_debug_waiters_dentry) - goto fail; - - return 0; - - fail: - dlm_delete_debug_file(ls); - return -ENOMEM; } -int __init dlm_register_debugfs(void) +void __init dlm_register_debugfs(void) { mutex_init(&debug_buf_lock); dlm_root = debugfs_create_dir("dlm", NULL); - return dlm_root ? 0 : -ENOMEM; } void dlm_unregister_debugfs(void) diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h index da1173a0b274..416d9de35679 100644 --- a/fs/dlm/dlm_internal.h +++ b/fs/dlm/dlm_internal.h @@ -719,14 +719,14 @@ int dlm_plock_init(void); void dlm_plock_exit(void); #ifdef CONFIG_DLM_DEBUG -int dlm_register_debugfs(void); +void dlm_register_debugfs(void); void dlm_unregister_debugfs(void); -int dlm_create_debug_file(struct dlm_ls *ls); +void dlm_create_debug_file(struct dlm_ls *ls); void dlm_delete_debug_file(struct dlm_ls *ls); #else -static inline int dlm_register_debugfs(void) { return 0; } +static inline void dlm_register_debugfs(void) { } static inline void dlm_unregister_debugfs(void) { } -static inline int dlm_create_debug_file(struct dlm_ls *ls) { return 0; } +static inline void dlm_create_debug_file(struct dlm_ls *ls) { } static inline void dlm_delete_debug_file(struct dlm_ls *ls) { } #endif diff --git a/fs/dlm/main.c b/fs/dlm/main.c index 39579927ed84..afc66a1346d3 100644 --- a/fs/dlm/main.c +++ b/fs/dlm/main.c @@ -35,9 +35,7 @@ static int __init init_dlm(void) if (error) goto out_lockspace; - error = dlm_register_debugfs(); - if (error) - goto out_config; + dlm_register_debugfs(); error = dlm_user_init(); if (error) @@ -61,7 +59,6 @@ static int __init init_dlm(void) dlm_user_exit(); out_debug: dlm_unregister_debugfs(); - out_config: dlm_config_exit(); out_lockspace: dlm_lockspace_exit();