3 files changed, 72 insertions, 15 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 2f436d4f1d6..50ed691098b 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -142,7 +142,7 @@ static int init_dir(struct inode * inode)
 	return 0;
 }
 
-static int init_file(struct inode * inode)
+static int configfs_init_file(struct inode * inode)
 {
 	inode->i_size = PAGE_SIZE;
 	inode->i_fop = &configfs_file_operations;
@@ -283,7 +283,8 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
 
 	dentry->d_fsdata = configfs_get(sd);
 	sd->s_dentry = dentry;
-	error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, init_file);
+	error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
+				configfs_init_file);
 	if (error) {
 		configfs_put(sd);
 		return error;
diff --git a/fs/file_table.c b/fs/file_table.c
index ce3f39a4798..3176fefc92e 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -137,6 +137,66 @@ fail:
 
 EXPORT_SYMBOL(get_empty_filp);
 
+/**
+ * alloc_file - allocate and initialize a 'struct file'
+ * @mnt: the vfsmount on which the file will reside
+ * @dentry: the dentry representing the new file
+ * @mode: the mode with which the new file will be opened
+ * @fop: the 'struct file_operations' for the new file
+ *
+ * Use this instead of get_empty_filp() to get a new
+ * 'struct file'.  Do so because of the same initialization
+ * pitfalls reasons listed for init_file().  This is a
+ * preferred interface to using init_file().
+ *
+ * If all the callers of init_file() are eliminated, its
+ * code should be moved into this function.
+ */
+struct file *alloc_file(struct vfsmount *mnt, struct dentry *dentry,
+		mode_t mode, const struct file_operations *fop)
+{
+	struct file *file;
+	struct path;
+
+	file = get_empty_filp();
+	if (!file)
+		return NULL;
+
+	init_file(file, mnt, dentry, mode, fop);
+	return file;
+}
+EXPORT_SYMBOL(alloc_file);
+
+/**
+ * init_file - initialize a 'struct file'
+ * @file: the already allocated 'struct file' to initialized
+ * @mnt: the vfsmount on which the file resides
+ * @dentry: the dentry representing this file
+ * @mode: the mode the file is opened with
+ * @fop: the 'struct file_operations' for this file
+ *
+ * Use this instead of setting the members directly.  Doing so
+ * avoids making mistakes like forgetting the mntget() or
+ * forgetting to take a write on the mnt.
+ *
+ * Note: This is a crappy interface.  It is here to make
+ * merging with the existing users of get_empty_filp()
+ * who have complex failure logic easier.  All users
+ * of this should be moving to alloc_file().
+ */
+int init_file(struct file *file, struct vfsmount *mnt, struct dentry *dentry,
+	   mode_t mode, const struct file_operations *fop)
+{
+	int error = 0;
+	file->f_path.dentry = dentry;
+	file->f_path.mnt = mntget(mnt);
+	file->f_mapping = dentry->d_inode->i_mapping;
+	file->f_mode = mode;
+	file->f_op = fop;
+	return error;
+}
+EXPORT_SYMBOL(init_file);
+
 void fastcall fput(struct file *file)
 {
 	if (atomic_dec_and_test(&file->f_count))
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 0f5df73dbb7..12aca8ed605 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -933,16 +933,11 @@ struct file *hugetlb_file_setup(const char *name, size_t size)
 	if (!dentry)
 		goto out_shm_unlock;
 
-	error = -ENFILE;
-	file = get_empty_filp();
-	if (!file)
-		goto out_dentry;
-
 	error = -ENOSPC;
 	inode = hugetlbfs_get_inode(root->d_sb, current->fsuid,
 				current->fsgid, S_IFREG | S_IRWXUGO, 0);
 	if (!inode)
-		goto out_file;
+		goto out_dentry;
 
 	error = -ENOMEM;
 	if (hugetlb_reserve_pages(inode, 0, size >> HPAGE_SHIFT))
@@ -951,17 +946,18 @@ struct file *hugetlb_file_setup(const char *name, size_t size)
 	d_instantiate(dentry, inode);
 	inode->i_size = size;
 	inode->i_nlink = 0;
-	file->f_path.mnt = mntget(hugetlbfs_vfsmount);
-	file->f_path.dentry = dentry;
-	file->f_mapping = inode->i_mapping;
-	file->f_op = &hugetlbfs_file_operations;
-	file->f_mode = FMODE_WRITE | FMODE_READ;
+
+	error = -ENFILE;
+	file = alloc_file(hugetlbfs_vfsmount, dentry,
+			FMODE_WRITE | FMODE_READ,
+			&hugetlbfs_file_operations);
+	if (!file)
+		goto out_inode;
+
 	return file;
 
 out_inode:
 	iput(inode);
-out_file:
-	put_filp(file);
 out_dentry:
 	dput(dentry);
 out_shm_unlock: