1 files changed, 24 insertions, 90 deletions

diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 9f0bf13291e..80ef38c73e5 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -12,7 +12,6 @@
 #include <linux/file.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
-#include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/mount.h>
@@ -25,15 +24,6 @@
 
 static struct vfsmount *anon_inode_mnt __read_mostly;
 static struct inode *anon_inode_inode;
-static const struct file_operations anon_inode_fops;
-
-static int anon_inodefs_get_sb(struct file_system_type *fs_type, int flags,
-			       const char *dev_name, void *data,
-			       struct vfsmount *mnt)
-{
-	return get_sb_pseudo(fs_type, "anon_inode:", NULL, ANON_INODE_FS_MAGIC,
-			     mnt);
-}
 
 /*
  * anon_inodefs_dname() is called from d_path().
@@ -44,32 +34,27 @@ static char *anon_inodefs_dname(struct dentry *dentry, char *buffer, int buflen)
 				dentry->d_name.name);
 }
 
-static struct file_system_type anon_inode_fs_type = {
-	.name		= "anon_inodefs",
-	.get_sb		= anon_inodefs_get_sb,
-	.kill_sb	= kill_anon_super,
-};
 static const struct dentry_operations anon_inodefs_dentry_operations = {
 	.d_dname	= anon_inodefs_dname,
 };
 
-/*
- * nop .set_page_dirty method so that people can use .page_mkwrite on
- * anon inodes.
- */
-static int anon_set_page_dirty(struct page *page)
+static struct dentry *anon_inodefs_mount(struct file_system_type *fs_type,
+				int flags, const char *dev_name, void *data)
 {
-	return 0;
-};
+	return mount_pseudo(fs_type, "anon_inode:", NULL,
+			&anon_inodefs_dentry_operations, ANON_INODE_FS_MAGIC);
+}
 
-static const struct address_space_operations anon_aops = {
-	.set_page_dirty = anon_set_page_dirty,
+static struct file_system_type anon_inode_fs_type = {
+	.name		= "anon_inodefs",
+	.mount		= anon_inodefs_mount,
+	.kill_sb	= kill_anon_super,
 };
 
 /**
- * anon_inode_getfd - creates a new file instance by hooking it up to an
- *                    anonymous inode, and a dentry that describe the "class"
- *                    of the file
+ * anon_inode_getfile - creates a new file instance by hooking it up to an
+ *                      anonymous inode, and a dentry that describe the "class"
+ *                      of the file
  *
  * @name:    [in]    name of the "class" of the new file
  * @fops:    [in]    file operations for the new file
@@ -89,7 +74,6 @@ struct file *anon_inode_getfile(const char *name,
 	struct qstr this;
 	struct path path;
 	struct file *file;
-	int error;
 
 	if (IS_ERR(anon_inode_inode))
 		return ERR_PTR(-ENODEV);
@@ -101,34 +85,29 @@ struct file *anon_inode_getfile(const char *name,
 	 * Link the inode to a directory entry by creating a unique name
 	 * using the inode sequence number.
 	 */
-	error = -ENOMEM;
+	file = ERR_PTR(-ENOMEM);
 	this.name = name;
 	this.len = strlen(name);
 	this.hash = 0;
-	path.dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this);
+	path.dentry = d_alloc_pseudo(anon_inode_mnt->mnt_sb, &this);
 	if (!path.dentry)
 		goto err_module;
 
 	path.mnt = mntget(anon_inode_mnt);
 	/*
 	 * We know the anon_inode inode count is always greater than zero,
-	 * so we can avoid doing an igrab() and we can use an open-coded
-	 * atomic_inc().
+	 * so ihold() is safe.
 	 */
-	atomic_inc(&anon_inode_inode->i_count);
+	ihold(anon_inode_inode);
 
-	path.dentry->d_op = &anon_inodefs_dentry_operations;
 	d_instantiate(path.dentry, anon_inode_inode);
 
-	error = -ENFILE;
 	file = alloc_file(&path, OPEN_FMODE(flags), fops);
-	if (!file)
+	if (IS_ERR(file))
 		goto err_dput;
 	file->f_mapping = anon_inode_inode->i_mapping;
 
-	file->f_pos = 0;
 	file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
-	file->f_version = 0;
 	file->private_data = priv;
 
 	return file;
@@ -137,7 +116,7 @@ err_dput:
 	path_put(&path);
 err_module:
 	module_put(fops->owner);
-	return ERR_PTR(error);
+	return file;
 }
 EXPORT_SYMBOL_GPL(anon_inode_getfile);
 
@@ -183,62 +162,17 @@ err_put_unused_fd:
 }
 EXPORT_SYMBOL_GPL(anon_inode_getfd);
 
-/*
- * A single inode exists for all anon_inode files. Contrary to pipes,
- * anon_inode inodes have no associated per-instance data, so we need
- * only allocate one of them.
- */
-static struct inode *anon_inode_mkinode(void)
-{
-	struct inode *inode = new_inode(anon_inode_mnt->mnt_sb);
-
-	if (!inode)
-		return ERR_PTR(-ENOMEM);
-
-	inode->i_fop = &anon_inode_fops;
-
-	inode->i_mapping->a_ops = &anon_aops;
-
-	/*
-	 * Mark the inode dirty from the very beginning,
-	 * that way it will never be moved to the dirty
-	 * list because mark_inode_dirty() will think
-	 * that it already _is_ on the dirty list.
-	 */
-	inode->i_state = I_DIRTY;
-	inode->i_mode = S_IRUSR | S_IWUSR;
-	inode->i_uid = current_fsuid();
-	inode->i_gid = current_fsgid();
-	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-	return inode;
-}
-
 static int __init anon_inode_init(void)
 {
-	int error;
-
-	error = register_filesystem(&anon_inode_fs_type);
-	if (error)
-		goto err_exit;
 	anon_inode_mnt = kern_mount(&anon_inode_fs_type);
-	if (IS_ERR(anon_inode_mnt)) {
-		error = PTR_ERR(anon_inode_mnt);
-		goto err_unregister_filesystem;
-	}
-	anon_inode_inode = anon_inode_mkinode();
-	if (IS_ERR(anon_inode_inode)) {
-		error = PTR_ERR(anon_inode_inode);
-		goto err_mntput;
-	}
+	if (IS_ERR(anon_inode_mnt))
+		panic("anon_inode_init() kernel mount failed (%ld)\n", PTR_ERR(anon_inode_mnt));
 
-	return 0;
+	anon_inode_inode = alloc_anon_inode(anon_inode_mnt->mnt_sb);
+	if (IS_ERR(anon_inode_inode))
+		panic("anon_inode_init() inode allocation failed (%ld)\n", PTR_ERR(anon_inode_inode));
 
-err_mntput:
-	mntput(anon_inode_mnt);
-err_unregister_filesystem:
-	unregister_filesystem(&anon_inode_fs_type);
-err_exit:
-	panic(KERN_ERR "anon_inode_init() failed (%d)\n", error);
+	return 0;
 }
 
 fs_initcall(anon_inode_init);