2 files changed, 65 insertions, 47 deletions

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index c5ca6ae5a30..63146295153 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -21,6 +21,7 @@
 #include <linux/debugfs.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/atomic.h>
 
 static ssize_t default_read_file(struct file *file, char __user *buf,
 				 size_t count, loff_t *ppos)
@@ -403,6 +404,47 @@ struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_size_t);
 
+static int debugfs_atomic_t_set(void *data, u64 val)
+{
+	atomic_set((atomic_t *)data, val);
+	return 0;
+}
+static int debugfs_atomic_t_get(void *data, u64 *val)
+{
+	*val = atomic_read((atomic_t *)data);
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
+			debugfs_atomic_t_set, "%lld\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n");
+DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n");
+
+/**
+ * debugfs_create_atomic_t - create a debugfs file that is used to read and
+ * write an atomic_t value
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this parameter is %NULL, then the
+ *          file will be created in the root of the debugfs filesystem.
+ * @value: a pointer to the variable that the file should read to and write
+ *         from.
+ */
+struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
+				 struct dentry *parent, atomic_t *value)
+{
+	/* if there are no write bits set, make read only */
+	if (!(mode & S_IWUGO))
+		return debugfs_create_file(name, mode, parent, value,
+					&fops_atomic_t_ro);
+	/* if there are no read bits set, make write only */
+	if (!(mode & S_IRUGO))
+		return debugfs_create_file(name, mode, parent, value,
+					&fops_atomic_t_wo);
+
+	return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
 
 static ssize_t read_file_bool(struct file *file, char __user *user_buf,
 			      size_t count, loff_t *ppos)
@@ -431,6 +473,7 @@ static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
 	if (copy_from_user(buf, user_buf, buf_size))
 		return -EFAULT;
 
+	buf[buf_size] = '\0';
 	if (strtobool(buf, &bv) == 0)
 		*val = bv;
 
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 4888cb3fdef..c7c83ff0f75 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -533,8 +533,7 @@ EXPORT_SYMBOL_GPL(debugfs_remove);
  */
 void debugfs_remove_recursive(struct dentry *dentry)
 {
-	struct dentry *child;
-	struct dentry *parent;
+	struct dentry *child, *next, *parent;
 
 	if (IS_ERR_OR_NULL(dentry))
 		return;
@@ -544,61 +543,37 @@ void debugfs_remove_recursive(struct dentry *dentry)
 		return;
 
 	parent = dentry;
+ down:
 	mutex_lock(&parent->d_inode->i_mutex);
+	list_for_each_entry_safe(child, next, &parent->d_subdirs, d_u.d_child) {
+		if (!debugfs_positive(child))
+			continue;
 
-	while (1) {
-		/*
-		 * When all dentries under "parent" has been removed,
-		 * walk up the tree until we reach our starting point.
-		 */
-		if (list_empty(&parent->d_subdirs)) {
-			mutex_unlock(&parent->d_inode->i_mutex);
-			if (parent == dentry)
-				break;
-			parent = parent->d_parent;
-			mutex_lock(&parent->d_inode->i_mutex);
-		}
-		child = list_entry(parent->d_subdirs.next, struct dentry,
-				d_u.d_child);
- next_sibling:
-
-		/*
-		 * If "child" isn't empty, walk down the tree and
-		 * remove all its descendants first.
-		 */
+		/* perhaps simple_empty(child) makes more sense */
 		if (!list_empty(&child->d_subdirs)) {
 			mutex_unlock(&parent->d_inode->i_mutex);
 			parent = child;
-			mutex_lock(&parent->d_inode->i_mutex);
-			continue;
+			goto down;
 		}
-		__debugfs_remove(child, parent);
-		if (parent->d_subdirs.next == &child->d_u.d_child) {
-			/*
-			 * Try the next sibling.
-			 */
-			if (child->d_u.d_child.next != &parent->d_subdirs) {
-				child = list_entry(child->d_u.d_child.next,
-						   struct dentry,
-						   d_u.d_child);
-				goto next_sibling;
-			}
-
-			/*
-			 * Avoid infinite loop if we fail to remove
-			 * one dentry.
-			 */
-			mutex_unlock(&parent->d_inode->i_mutex);
-			break;
-		}
-		simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+ up:
+		if (!__debugfs_remove(child, parent))
+			simple_release_fs(&debugfs_mount, &debugfs_mount_count);
 	}
 
-	parent = dentry->d_parent;
+	mutex_unlock(&parent->d_inode->i_mutex);
+	child = parent;
+	parent = parent->d_parent;
 	mutex_lock(&parent->d_inode->i_mutex);
-	__debugfs_remove(dentry, parent);
+
+	if (child != dentry) {
+		next = list_entry(child->d_u.d_child.next, struct dentry,
+					d_u.d_child);
+		goto up;
+	}
+
+	if (!__debugfs_remove(child, parent))
+		simple_release_fs(&debugfs_mount, &debugfs_mount_count);
 	mutex_unlock(&parent->d_inode->i_mutex);
-	simple_release_fs(&debugfs_mount, &debugfs_mount_count);
 }
 EXPORT_SYMBOL_GPL(debugfs_remove_recursive);