Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the "big" driver core and debugfs changes for 5.3-rc1

  It's a lot of different patches, all across the tree due to some api
  changes and lots of debugfs cleanups.

  Other than the debugfs cleanups, in this set of changes we have:

   - bus iteration function cleanups

   - scripts/get_abi.pl tool to display and parse Documentation/ABI
     entries in a simple way

   - cleanups to Documenatation/ABI/ entries to make them parse easier
     due to typos and other minor things

   - default_attrs use for some ktype users

   - driver model documentation file conversions to .rst

   - compressed firmware file loading

   - deferred probe fixes

  All of these have been in linux-next for a while, with a bunch of
  merge issues that Stephen has been patient with me for"

* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
  debugfs: make error message a bit more verbose
  orangefs: fix build warning from debugfs cleanup patch
  ubifs: fix build warning after debugfs cleanup patch
  driver: core: Allow subsystems to continue deferring probe
  drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
  arch_topology: Remove error messages on out-of-memory conditions
  lib: notifier-error-inject: no need to check return value of debugfs_create functions
  swiotlb: no need to check return value of debugfs_create functions
  ceph: no need to check return value of debugfs_create functions
  sunrpc: no need to check return value of debugfs_create functions
  ubifs: no need to check return value of debugfs_create functions
  orangefs: no need to check return value of debugfs_create functions
  nfsd: no need to check return value of debugfs_create functions
  lib: 842: no need to check return value of debugfs_create functions
  debugfs: provide pr_fmt() macro
  debugfs: log errors when something goes wrong
  drivers: s390/cio: Fix compilation warning about const qualifiers
  drivers: Add generic helper to match by of_node
  driver_find_device: Unify the match function with class_find_device()
  bus_find_device: Unify the match callback with class_find_device
  ...

6 files changed, 17 insertions, 90 deletions

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 13f0cb080a4d..62fa5a82a065 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -696,29 +696,12 @@ bool is_swiotlb_active(void)
 
 static int __init swiotlb_create_debugfs(void)
 {
-	struct dentry *d_swiotlb_usage;
-	struct dentry *ent;
-
-	d_swiotlb_usage = debugfs_create_dir("swiotlb", NULL);
-
-	if (!d_swiotlb_usage)
-		return -ENOMEM;
-
-	ent = debugfs_create_ulong("io_tlb_nslabs", 0400,
-				   d_swiotlb_usage, &io_tlb_nslabs);
-	if (!ent)
-		goto fail;
-
-	ent = debugfs_create_ulong("io_tlb_used", 0400,
-				   d_swiotlb_usage, &io_tlb_used);
-	if (!ent)
-		goto fail;
+	struct dentry *root;
 
+	root = debugfs_create_dir("swiotlb", NULL);
+	debugfs_create_ulong("io_tlb_nslabs", 0400, root, &io_tlb_nslabs);
+	debugfs_create_ulong("io_tlb_used", 0400, root, &io_tlb_used);
 	return 0;
-
-fail:
-	debugfs_remove_recursive(d_swiotlb_usage);
-	return -ENOMEM;
 }
 
 late_initcall(swiotlb_create_debugfs);
diff --git a/kernel/fail_function.c b/kernel/fail_function.c
index feb80712b913..63b349168da7 100644
--- a/kernel/fail_function.c
+++ b/kernel/fail_function.c
@@ -152,20 +152,13 @@ static int fei_retval_get(void *data, u64 *val)
 DEFINE_DEBUGFS_ATTRIBUTE(fei_retval_ops, fei_retval_get, fei_retval_set,
 			 "%llx\n");
 
-static int fei_debugfs_add_attr(struct fei_attr *attr)
+static void fei_debugfs_add_attr(struct fei_attr *attr)
 {
 	struct dentry *dir;
 
 	dir = debugfs_create_dir(attr->kp.symbol_name, fei_debugfs_dir);
-	if (!dir)
-		return -ENOMEM;
-
-	if (!debugfs_create_file("retval", 0600, dir, attr, &fei_retval_ops)) {
-		debugfs_remove_recursive(dir);
-		return -ENOMEM;
-	}
 
-	return 0;
+	debugfs_create_file("retval", 0600, dir, attr, &fei_retval_ops);
 }
 
 static void fei_debugfs_remove_attr(struct fei_attr *attr)
@@ -306,7 +299,7 @@ static ssize_t fei_write(struct file *file, const char __user *buffer,
 
 	ret = register_kprobe(&attr->kp);
 	if (!ret)
-		ret = fei_debugfs_add_attr(attr);
+		fei_debugfs_add_attr(attr);
 	if (ret < 0)
 		fei_attr_remove(attr);
 	else {
@@ -337,19 +330,13 @@ static int __init fei_debugfs_init(void)
 		return PTR_ERR(dir);
 
 	/* injectable attribute is just a symlink of error_inject/list */
-	if (!debugfs_create_symlink("injectable", dir,
-				    "../error_injection/list"))
-		goto error;
+	debugfs_create_symlink("injectable", dir, "../error_injection/list");
 
-	if (!debugfs_create_file("inject", 0600, dir, NULL, &fei_ops))
-		goto error;
+	debugfs_create_file("inject", 0600, dir, NULL, &fei_ops);
 
 	fei_debugfs_dir = dir;
 
 	return 0;
-error:
-	debugfs_remove_recursive(dir);
-	return -ENOMEM;
 }
 
 late_initcall(fei_debugfs_init);
diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c
index 6e40ff6be083..e5eb5ea7ea59 100644
--- a/kernel/gcov/fs.c
+++ b/kernel/gcov/fs.c
@@ -64,7 +64,6 @@ struct gcov_node {
 static const char objtree[] = OBJTREE;
 static const char srctree[] = SRCTREE;
 static struct gcov_node root_node;
-static struct dentry *reset_dentry;
 static LIST_HEAD(all_head);
 static DEFINE_MUTEX(node_lock);
 
@@ -387,8 +386,6 @@ static void add_links(struct gcov_node *node, struct dentry *parent)
 			goto out_err;
 		node->links[i] = debugfs_create_symlink(deskew(basename),
 							parent,	target);
-		if (!node->links[i])
-			goto out_err;
 		kfree(target);
 	}
 
@@ -450,11 +447,6 @@ static struct gcov_node *new_node(struct gcov_node *parent,
 					parent->dentry, node, &gcov_data_fops);
 	} else
 		node->dentry = debugfs_create_dir(node->name, parent->dentry);
-	if (!node->dentry) {
-		pr_warn("could not create file\n");
-		kfree(node);
-		return NULL;
-	}
 	if (info)
 		add_links(node, parent->dentry);
 	list_add(&node->list, &parent->children);
@@ -761,32 +753,20 @@ void gcov_event(enum gcov_action action, struct gcov_info *info)
 /* Create debugfs entries. */
 static __init int gcov_fs_init(void)
 {
-	int rc = -EIO;
-
 	init_node(&root_node, NULL, NULL, NULL);
 	/*
 	 * /sys/kernel/debug/gcov will be parent for the reset control file
 	 * and all profiling files.
 	 */
 	root_node.dentry = debugfs_create_dir("gcov", NULL);
-	if (!root_node.dentry)
-		goto err_remove;
 	/*
 	 * Create reset file which resets all profiling counts when written
 	 * to.
 	 */
-	reset_dentry = debugfs_create_file("reset", 0600, root_node.dentry,
-					   NULL, &gcov_reset_fops);
-	if (!reset_dentry)
-		goto err_remove;
+	debugfs_create_file("reset", 0600, root_node.dentry, NULL,
+			    &gcov_reset_fops);
 	/* Replay previous events to get our fs hierarchy up-to-date. */
 	gcov_enable_events();
 	return 0;
-
-err_remove:
-	pr_err("init failed\n");
-	debugfs_remove(root_node.dentry);
-
-	return rc;
 }
 device_initcall(gcov_fs_init);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 445337c107e0..9f5433a52488 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2570,33 +2570,20 @@ static const struct file_operations fops_kp = {
 
 static int __init debugfs_kprobe_init(void)
 {
-	struct dentry *dir, *file;
+	struct dentry *dir;
 	unsigned int value = 1;
 
 	dir = debugfs_create_dir("kprobes", NULL);
-	if (!dir)
-		return -ENOMEM;
 
-	file = debugfs_create_file("list", 0400, dir, NULL,
-				&debugfs_kprobes_operations);
-	if (!file)
-		goto error;
+	debugfs_create_file("list", 0400, dir, NULL,
+			    &debugfs_kprobes_operations);
 
-	file = debugfs_create_file("enabled", 0600, dir,
-					&value, &fops_kp);
-	if (!file)
-		goto error;
+	debugfs_create_file("enabled", 0600, dir, &value, &fops_kp);
 
-	file = debugfs_create_file("blacklist", 0400, dir, NULL,
-				&debugfs_kprobe_blacklist_ops);
-	if (!file)
-		goto error;
+	debugfs_create_file("blacklist", 0400, dir, NULL,
+			    &debugfs_kprobe_blacklist_ops);
 
 	return 0;
-
-error:
-	debugfs_remove(dir);
-	return -ENOMEM;
 }
 
 late_initcall(debugfs_kprobe_init);
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index e1c6d79fb4cc..2d6e93ab0478 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -512,8 +512,6 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 	dir = debugfs_lookup(buts->name, blk_debugfs_root);
 	if (!dir)
 		bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
-	if (!dir)
-		goto err;
 
 	bt->dev = dev;
 	atomic_set(&bt->dropped, 0);
@@ -522,12 +520,8 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 	ret = -EIO;
 	bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt,
 					       &blk_dropped_fops);
-	if (!bt->dropped_file)
-		goto err;
 
 	bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops);
-	if (!bt->msg_file)
-		goto err;
 
 	bt->rchan = relay_open("trace", dir, buts->buf_size,
 				buts->buf_nr, &blk_relay_callbacks, bt);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c3aabb576fe5..c90c687cf950 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8618,10 +8618,6 @@ struct dentry *tracing_init_dentry(void)
 	 */
 	tr->dir = debugfs_create_automount("tracing", NULL,
 					   trace_automount, NULL);
-	if (!tr->dir) {
-		pr_warn_once("Could not create debugfs directory 'tracing'\n");
-		return ERR_PTR(-ENOMEM);
-	}
 
 	return NULL;
 }