2 files changed, 65 insertions, 47 deletions

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index c5ca6ae5a30c..63146295153b 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 4888cb3fdef7..c7c83ff0f752 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);