debugfs: split the beginning and the end of __create_file() off

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index adaaa04..100186c 100644 (file)
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -305,11 +305,9 @@ static struct file_system_type debug_fs_type = {
 };
 MODULE_ALIAS_FS("debugfs");
 
-static struct dentry *__create_file(const char *name, umode_t mode,
-                                   struct dentry *parent, void *data,
-                                   const struct file_operations *fops)
+static struct dentry *start_creating(const char *name, struct dentry *parent)
 {
-       struct dentry *dentry = NULL;
+       struct dentry *dentry;
        int error;
 
        pr_debug("debugfs: creating file '%s'\n",name);
@@ -317,7 +315,7 @@ static struct dentry *__create_file(const char *name, umode_t mode,
        error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
                              &debugfs_mount_count);
        if (error)
-               goto exit;
+               return ERR_PTR(error);
 
        /* If the parent is not specified, we create it in the root.
         * We need the root dentry to do this, which is in the super
@@ -329,32 +327,51 @@ static struct dentry *__create_file(const char *name, umode_t mode,
 
        mutex_lock(&parent->d_inode->i_mutex);
        dentry = lookup_one_len(name, parent, strlen(name));
-       if (!IS_ERR(dentry)) {
-               switch (mode & S_IFMT) {
-               case S_IFDIR:
-                       error = debugfs_mkdir(dentry, mode);
-
-                       break;
-               case S_IFLNK:
-                       error = debugfs_link(dentry, mode, data);
-                       break;
-               default:
-                       error = debugfs_create(dentry, mode, data, fops);
-                       break;
-               }
+       if (!IS_ERR(dentry) && dentry->d_inode) {
                dput(dentry);
-       } else
-               error = PTR_ERR(dentry);
-       mutex_unlock(&parent->d_inode->i_mutex);
+               dentry = ERR_PTR(-EEXIST);
+       }
+       if (IS_ERR(dentry))
+               mutex_unlock(&parent->d_inode->i_mutex);
+       return dentry;
+}
+
+static struct dentry *end_creating(struct dentry *dentry, int error)
+{
+       mutex_unlock(&dentry->d_parent->d_inode->i_mutex);
+       dput(dentry);
 
        if (error) {
                dentry = NULL;
                simple_release_fs(&debugfs_mount, &debugfs_mount_count);
        }
-exit:
        return dentry;
 }
 
+static struct dentry *__create_file(const char *name, umode_t mode,
+                                   struct dentry *parent, void *data,
+                                   const struct file_operations *fops)
+{
+       struct dentry *dentry = start_creating(name, parent);
+       int error;
+
+       if (IS_ERR(dentry))
+               return NULL;
+
+       switch (mode & S_IFMT) {
+       case S_IFDIR:
+               error = debugfs_mkdir(dentry, mode);
+               break;
+       case S_IFLNK:
+               error = debugfs_link(dentry, mode, data);
+               break;
+       default:
+               error = debugfs_create(dentry, mode, data, fops);
+               break;
+       }
+       return end_creating(dentry, error);
+}
+
 /**
  * debugfs_create_file - create a file in the debugfs filesystem
  * @name: a pointer to a string containing the name of the file to create.