1 files changed, 51 insertions, 67 deletions

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index d17c20fd74e..8c41b52da35 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -28,7 +28,7 @@
 #include <linux/magic.h>
 #include <linux/slab.h>
 
-#define DEBUGFS_DEFAULT_MODE	0755
+#define DEBUGFS_DEFAULT_MODE	0700
 
 static struct vfsmount *debugfs_mount;
 static int debugfs_mount_count;
@@ -59,7 +59,6 @@ static struct inode *debugfs_get_inode(struct super_block *sb, umode_t mode, dev
 		case S_IFDIR:
 			inode->i_op = &simple_dir_inode_operations;
 			inode->i_fop = &simple_dir_operations;
-			inode->i_private = NULL;
 
 			/* directory inodes start off with i_nlink == 2
 			 * (for "." entry) */
@@ -128,8 +127,8 @@ static inline int debugfs_positive(struct dentry *dentry)
 }
 
 struct debugfs_mount_opts {
-	uid_t uid;
-	gid_t gid;
+	kuid_t uid;
+	kgid_t gid;
 	umode_t mode;
 };
 
@@ -156,6 +155,8 @@ static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts)
 	substring_t args[MAX_OPT_ARGS];
 	int option;
 	int token;
+	kuid_t uid;
+	kgid_t gid;
 	char *p;
 
 	opts->mode = DEBUGFS_DEFAULT_MODE;
@@ -169,12 +170,18 @@ static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts)
 		case Opt_uid:
 			if (match_int(&args[0], &option))
 				return -EINVAL;
-			opts->uid = option;
+			uid = make_kuid(current_user_ns(), option);
+			if (!uid_valid(uid))
+				return -EINVAL;
+			opts->uid = uid;
 			break;
 		case Opt_gid:
-			if (match_octal(&args[0], &option))
+			if (match_int(&args[0], &option))
+				return -EINVAL;
+			gid = make_kgid(current_user_ns(), option);
+			if (!gid_valid(gid))
 				return -EINVAL;
-			opts->gid = option;
+			opts->gid = gid;
 			break;
 		case Opt_mode:
 			if (match_octal(&args[0], &option))
@@ -211,6 +218,7 @@ static int debugfs_remount(struct super_block *sb, int *flags, char *data)
 	int err;
 	struct debugfs_fs_info *fsi = sb->s_fs_info;
 
+	sync_filesystem(sb);
 	err = debugfs_parse_options(data, &fsi->mount_opts);
 	if (err)
 		goto fail;
@@ -226,10 +234,12 @@ static int debugfs_show_options(struct seq_file *m, struct dentry *root)
 	struct debugfs_fs_info *fsi = root->d_sb->s_fs_info;
 	struct debugfs_mount_opts *opts = &fsi->mount_opts;
 
-	if (opts->uid != 0)
-		seq_printf(m, ",uid=%u", opts->uid);
-	if (opts->gid != 0)
-		seq_printf(m, ",gid=%u", opts->gid);
+	if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
+		seq_printf(m, ",uid=%u",
+			   from_kuid_munged(&init_user_ns, opts->uid));
+	if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
+		seq_printf(m, ",gid=%u",
+			   from_kgid_munged(&init_user_ns, opts->gid));
 	if (opts->mode != DEBUGFS_DEFAULT_MODE)
 		seq_printf(m, ",mode=%o", opts->mode);
 
@@ -290,10 +300,11 @@ static struct file_system_type debug_fs_type = {
 	.mount =	debug_mount,
 	.kill_sb =	kill_litter_super,
 };
+MODULE_ALIAS_FS("debugfs");
 
-struct dentry *__create_file(const char *name, umode_t mode,
-				   struct dentry *parent, void *data,
-				   const struct file_operations *fops)
+static struct dentry *__create_file(const char *name, umode_t mode,
+				    struct dentry *parent, void *data,
+				    const struct file_operations *fops)
 {
 	struct dentry *dentry = NULL;
 	int error;
@@ -313,7 +324,6 @@ struct dentry *__create_file(const char *name, umode_t mode,
 	if (!parent)
 		parent = debugfs_mount->mnt_root;
 
-	dentry = NULL;
 	mutex_lock(&parent->d_inode->i_mutex);
 	dentry = lookup_one_len(name, parent, strlen(name));
 	if (!IS_ERR(dentry)) {
@@ -349,7 +359,7 @@ exit:
  * @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 paramater is NULL, then the
+ *          directory dentry if set.  If this parameter is NULL, then the
  *          file will be created in the root of the debugfs filesystem.
  * @data: a pointer to something that the caller will want to get to later
  *        on.  The inode.i_private pointer will point to this value on
@@ -391,7 +401,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_file);
  * @name: a pointer to a string containing the name of the directory to
  *        create.
  * @parent: a pointer to the parent dentry for this file.  This should be a
- *          directory dentry if set.  If this paramater is NULL, then the
+ *          directory dentry if set.  If this parameter is NULL, then the
  *          directory will be created in the root of the debugfs filesystem.
  *
  * This function creates a directory in debugfs with the given name.
@@ -416,7 +426,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_dir);
  * @name: a pointer to a string containing the name of the symbolic link to
  *        create.
  * @parent: a pointer to the parent dentry for this symbolic link.  This
- *          should be a directory dentry if set.  If this paramater is NULL,
+ *          should be a directory dentry if set.  If this parameter is NULL,
  *          then the symbolic link will be created in the root of the debugfs
  *          filesystem.
  * @target: a pointer to a string containing the path to the target of the
@@ -495,7 +505,7 @@ void debugfs_remove(struct dentry *dentry)
 	struct dentry *parent;
 	int ret;
 
-	if (!dentry)
+	if (IS_ERR_OR_NULL(dentry))
 		return;
 
 	parent = dentry->d_parent;
@@ -524,10 +534,9 @@ EXPORT_SYMBOL_GPL(debugfs_remove);
  */
 void debugfs_remove_recursive(struct dentry *dentry)
 {
-	struct dentry *child;
-	struct dentry *parent;
+	struct dentry *child, *next, *parent;
 
-	if (!dentry)
+	if (IS_ERR_OR_NULL(dentry))
 		return;
 
 	parent = dentry->d_parent;
@@ -535,61 +544,36 @@ 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;
-		}
-		__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;
+			goto down;
 		}
-		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_next_entry(child, 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);