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

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

1 files changed, 39 insertions, 22 deletions

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index adaaa04448b3..100186c2bf0a 100644
--- 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.