ocfs2: further debugfs cleanups

There is no need to check return value of debugfs_create functions, but
the last sweep through ocfs missed a number of places where this was
happening.  There is also no need to save the individual dentries for the
debugfs files, as everything is can just be removed at once when the
directory is removed.

By getting rid of the file dentries for the debugfs entries, a bit of
local memory can be saved as well.

[colin.king@canonical.com: ensure ret is set to zero before returning]
  Link: http://lkml.kernel.org/r/20190807121929.28918-1-colin.king@canonical.com
Link: http://lkml.kernel.org/r/20190731132119.GA12603@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jia Guo <guojia12@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 20 insertions, 79 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 69a429b625cc..aaf24548b02a 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -142,7 +142,6 @@ struct dlm_ctxt
 	atomic_t res_tot_count;
 	atomic_t res_cur_count;
 
-	struct dlm_debug_ctxt *dlm_debug_ctxt;
 	struct dentry *dlm_debugfs_subroot;
 
 	/* NOTE: Next three are protected by dlm_domain_lock */
diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index a4b58ba99927..4d0b452012b2 100644
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -853,67 +853,34 @@ static const struct file_operations debug_state_fops = {
 /* files in subroot */
 void dlm_debug_init(struct dlm_ctxt *dlm)
 {
-	struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;
-
 	/* for dumping dlm_ctxt */
-	dc->debug_state_dentry = debugfs_create_file(DLM_DEBUGFS_DLM_STATE,
-						     S_IFREG|S_IRUSR,
-						     dlm->dlm_debugfs_subroot,
-						     dlm, &debug_state_fops);
+	debugfs_create_file(DLM_DEBUGFS_DLM_STATE, S_IFREG|S_IRUSR,
+			    dlm->dlm_debugfs_subroot, dlm, &debug_state_fops);
 
 	/* for dumping lockres */
-	dc->debug_lockres_dentry =
-			debugfs_create_file(DLM_DEBUGFS_LOCKING_STATE,
-					    S_IFREG|S_IRUSR,
-					    dlm->dlm_debugfs_subroot,
-					    dlm, &debug_lockres_fops);
+	debugfs_create_file(DLM_DEBUGFS_LOCKING_STATE, S_IFREG|S_IRUSR,
+			    dlm->dlm_debugfs_subroot, dlm, &debug_lockres_fops);
 
 	/* for dumping mles */
-	dc->debug_mle_dentry = debugfs_create_file(DLM_DEBUGFS_MLE_STATE,
-						   S_IFREG|S_IRUSR,
-						   dlm->dlm_debugfs_subroot,
-						   dlm, &debug_mle_fops);
+	debugfs_create_file(DLM_DEBUGFS_MLE_STATE, S_IFREG|S_IRUSR,
+			    dlm->dlm_debugfs_subroot, dlm, &debug_mle_fops);
 
 	/* for dumping lockres on the purge list */
-	dc->debug_purgelist_dentry =
-			debugfs_create_file(DLM_DEBUGFS_PURGE_LIST,
-					    S_IFREG|S_IRUSR,
-					    dlm->dlm_debugfs_subroot,
-					    dlm, &debug_purgelist_fops);
-}
-
-void dlm_debug_shutdown(struct dlm_ctxt *dlm)
-{
-	struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;
-
-	if (dc) {
-		debugfs_remove(dc->debug_purgelist_dentry);
-		debugfs_remove(dc->debug_mle_dentry);
-		debugfs_remove(dc->debug_lockres_dentry);
-		debugfs_remove(dc->debug_state_dentry);
-		kfree(dc);
-		dc = NULL;
-	}
+	debugfs_create_file(DLM_DEBUGFS_PURGE_LIST, S_IFREG|S_IRUSR,
+			    dlm->dlm_debugfs_subroot, dlm,
+			    &debug_purgelist_fops);
 }
 
 /* subroot - domain dir */
-int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
+void dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
 {
-	dlm->dlm_debug_ctxt = kzalloc(sizeof(struct dlm_debug_ctxt),
-				      GFP_KERNEL);
-	if (!dlm->dlm_debug_ctxt) {
-		mlog_errno(-ENOMEM);
-		return -ENOMEM;
-	}
-
 	dlm->dlm_debugfs_subroot = debugfs_create_dir(dlm->name,
 						      dlm_debugfs_root);
-	return 0;
 }
 
 void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
 {
-	debugfs_remove(dlm->dlm_debugfs_subroot);
+	debugfs_remove_recursive(dlm->dlm_debugfs_subroot);
 }
 
 /* debugfs root */
diff --git a/fs/ocfs2/dlm/dlmdebug.h b/fs/ocfs2/dlm/dlmdebug.h
index 7d0c7c9013ce..f8fd8680a4b6 100644
--- a/fs/ocfs2/dlm/dlmdebug.h
+++ b/fs/ocfs2/dlm/dlmdebug.h
@@ -14,13 +14,6 @@ void dlm_print_one_mle(struct dlm_master_list_entry *mle);
 
 #ifdef CONFIG_DEBUG_FS
 
-struct dlm_debug_ctxt {
-	struct dentry *debug_state_dentry;
-	struct dentry *debug_lockres_dentry;
-	struct dentry *debug_mle_dentry;
-	struct dentry *debug_purgelist_dentry;
-};
-
 struct debug_lockres {
 	int dl_len;
 	char *dl_buf;
@@ -29,9 +22,8 @@ struct debug_lockres {
 };
 
 void dlm_debug_init(struct dlm_ctxt *dlm);
-void dlm_debug_shutdown(struct dlm_ctxt *dlm);
 
-int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm);
+void dlm_create_debugfs_subroot(struct dlm_ctxt *dlm);
 void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm);
 
 void dlm_create_debugfs_root(void);
@@ -42,12 +34,8 @@ void dlm_destroy_debugfs_root(void);
 static inline void dlm_debug_init(struct dlm_ctxt *dlm)
 {
 }
-static inline void dlm_debug_shutdown(struct dlm_ctxt *dlm)
-{
-}
-static inline int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
+static inline void dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
 {
-	return 0;
 }
 static inline void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
 {
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 7338b5d4647c..ee6f459f9770 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -387,7 +387,6 @@ static void dlm_destroy_dlm_worker(struct dlm_ctxt *dlm)
 static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm)
 {
 	dlm_unregister_domain_handlers(dlm);
-	dlm_debug_shutdown(dlm);
 	dlm_complete_thread(dlm);
 	dlm_complete_recovery_thread(dlm);
 	dlm_destroy_dlm_worker(dlm);
@@ -1938,7 +1937,6 @@ bail:
 
 	if (status) {
 		dlm_unregister_domain_handlers(dlm);
-		dlm_debug_shutdown(dlm);
 		dlm_complete_thread(dlm);
 		dlm_complete_recovery_thread(dlm);
 		dlm_destroy_dlm_worker(dlm);
@@ -1992,9 +1990,7 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
 	dlm->key = key;
 	dlm->node_num = o2nm_this_node();
 
-	ret = dlm_create_debugfs_subroot(dlm);
-	if (ret < 0)
-		goto leave;
+	dlm_create_debugfs_subroot(dlm);
 
 	spin_lock_init(&dlm->spinlock);
 	spin_lock_init(&dlm->master_lock);
@@ -2056,6 +2052,7 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
 	mlog(0, "context init: refcount %u\n",
 		  kref_read(&dlm->dlm_refs));
 
+	ret = 0;
 leave:
 	if (ret < 0 && dlm) {
 		if (dlm->master_hash)
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 14207234fa3d..ad594fef2ab0 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -3012,8 +3012,6 @@ struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
 
 	kref_init(&dlm_debug->d_refcnt);
 	INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
-	dlm_debug->d_locking_state = NULL;
-	dlm_debug->d_locking_filter = NULL;
 	dlm_debug->d_filter_secs = 0;
 out:
 	return dlm_debug;
@@ -3282,27 +3280,19 @@ static void ocfs2_dlm_init_debug(struct ocfs2_super *osb)
 {
 	struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
 
-	dlm_debug->d_locking_state = debugfs_create_file("locking_state",
-							 S_IFREG|S_IRUSR,
-							 osb->osb_debug_root,
-							 osb,
-							 &ocfs2_dlm_debug_fops);
+	debugfs_create_file("locking_state", S_IFREG|S_IRUSR,
+			    osb->osb_debug_root, osb, &ocfs2_dlm_debug_fops);
 
-	dlm_debug->d_locking_filter = debugfs_create_u32("locking_filter",
-						0600,
-						osb->osb_debug_root,
-						&dlm_debug->d_filter_secs);
+	debugfs_create_u32("locking_filter", 0600, osb->osb_debug_root,
+			   &dlm_debug->d_filter_secs);
 }
 
 static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
 {
 	struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
 
-	if (dlm_debug) {
-		debugfs_remove(dlm_debug->d_locking_state);
-		debugfs_remove(dlm_debug->d_locking_filter);
+	if (dlm_debug)
 		ocfs2_put_dlm_debug(dlm_debug);
-	}
 }
 
 int ocfs2_dlm_init(struct ocfs2_super *osb)