1 files changed, 90 insertions, 109 deletions

diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index f42be069e08..80ef38c73e5 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -8,9 +8,10 @@
  *
  */
 
+#include <linux/cred.h>
 #include <linux/file.h>
 #include <linux/poll.h>
-#include <linux/slab.h>
+#include <linux/sched.h>
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/mount.h>
@@ -23,175 +24,155 @@
 
 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)
+/*
+ * anon_inodefs_dname() is called from d_path().
+ */
+static char *anon_inodefs_dname(struct dentry *dentry, char *buffer, int buflen)
 {
-	return get_sb_pseudo(fs_type, "anon_inode:", NULL, ANON_INODE_FS_MAGIC,
-			     mnt);
+	return dynamic_dname(dentry, buffer, buflen, "anon_inode:%s",
+				dentry->d_name.name);
 }
 
-static int anon_inodefs_delete_dentry(struct dentry *dentry)
+static const struct dentry_operations anon_inodefs_dentry_operations = {
+	.d_dname	= anon_inodefs_dname,
+};
+
+static struct dentry *anon_inodefs_mount(struct file_system_type *fs_type,
+				int flags, const char *dev_name, void *data)
 {
-	/*
-	 * We faked vfs to believe the dentry was hashed when we created it.
-	 * Now we restore the flag so that dput() will work correctly.
-	 */
-	dentry->d_flags |= DCACHE_UNHASHED;
-	return 1;
+	return mount_pseudo(fs_type, "anon_inode:", NULL,
+			&anon_inodefs_dentry_operations, ANON_INODE_FS_MAGIC);
 }
 
 static struct file_system_type anon_inode_fs_type = {
 	.name		= "anon_inodefs",
-	.get_sb		= anon_inodefs_get_sb,
+	.mount		= anon_inodefs_mount,
 	.kill_sb	= kill_anon_super,
 };
-static struct dentry_operations anon_inodefs_dentry_operations = {
-	.d_delete	= anon_inodefs_delete_dentry,
-};
 
 /**
- * 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
  *
- * @pfd:     [out]   pointer to the file descriptor
- * @dpinode: [out]   pointer to the inode
- * @pfile:   [out]   pointer to the file struct
  * @name:    [in]    name of the "class" of the new file
- * @fops     [in]    file operations for the new file
- * @priv     [in]    private data for the new file (will be file's private_data)
+ * @fops:    [in]    file operations for the new file
+ * @priv:    [in]    private data for the new file (will be file's private_data)
+ * @flags:   [in]    flags
  *
  * Creates a new file by hooking it on a single inode. This is useful for files
  * that do not need to have a full-fledged inode in order to operate correctly.
- * All the files created with anon_inode_getfd() will share a single inode,
+ * All the files created with anon_inode_getfile() will share a single inode,
  * hence saving memory and avoiding code duplication for the file/inode/dentry
- * setup.
+ * setup.  Returns the newly created file* or an error pointer.
  */
-int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile,
-		     const char *name, const struct file_operations *fops,
-		     void *priv)
+struct file *anon_inode_getfile(const char *name,
+				const struct file_operations *fops,
+				void *priv, int flags)
 {
 	struct qstr this;
-	struct dentry *dentry;
+	struct path path;
 	struct file *file;
-	int error, fd;
 
 	if (IS_ERR(anon_inode_inode))
-		return -ENODEV;
+		return ERR_PTR(-ENODEV);
 
-	error = get_unused_fd();
-	if (error < 0)
-		return error;
-	fd = error;
+	if (fops->owner && !try_module_get(fops->owner))
+		return ERR_PTR(-ENOENT);
 
 	/*
 	 * 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;
-	dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this);
-	if (!dentry)
-		goto err_put_unused_fd;
+	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);
 
-	dentry->d_op = &anon_inodefs_dentry_operations;
-	/* Do not publish this dentry inside the global dentry hash table */
-	dentry->d_flags &= ~DCACHE_UNHASHED;
-	d_instantiate(dentry, anon_inode_inode);
+	d_instantiate(path.dentry, anon_inode_inode);
 
-	error = -ENFILE;
-	file = alloc_file(anon_inode_mnt, dentry,
-			  FMODE_READ | FMODE_WRITE, fops);
-	if (!file)
+	file = alloc_file(&path, OPEN_FMODE(flags), fops);
+	if (IS_ERR(file))
 		goto err_dput;
 	file->f_mapping = anon_inode_inode->i_mapping;
 
-	file->f_pos = 0;
-	file->f_flags = O_RDWR;
-	file->f_version = 0;
+	file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
 	file->private_data = priv;
 
-	fd_install(fd, file);
-
-	*pfd = fd;
-	*pinode = anon_inode_inode;
-	*pfile = file;
-	return 0;
+	return file;
 
 err_dput:
-	dput(dentry);
-err_put_unused_fd:
-	put_unused_fd(fd);
-	return error;
+	path_put(&path);
+err_module:
+	module_put(fops->owner);
+	return file;
 }
-EXPORT_SYMBOL_GPL(anon_inode_getfd);
+EXPORT_SYMBOL_GPL(anon_inode_getfile);
 
-/*
- * 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.
+/**
+ * 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
+ *
+ * @name:    [in]    name of the "class" of the new file
+ * @fops:    [in]    file operations for the new file
+ * @priv:    [in]    private data for the new file (will be file's private_data)
+ * @flags:   [in]    flags
+ *
+ * Creates a new file by hooking it on a single inode. This is useful for files
+ * that do not need to have a full-fledged inode in order to operate correctly.
+ * All the files created with anon_inode_getfd() will share a single inode,
+ * hence saving memory and avoiding code duplication for the file/inode/dentry
+ * setup.  Returns new descriptor or an error code.
  */
-static struct inode *anon_inode_mkinode(void)
+int anon_inode_getfd(const char *name, const struct file_operations *fops,
+		     void *priv, int flags)
 {
-	struct inode *inode = new_inode(anon_inode_mnt->mnt_sb);
+	int error, fd;
+	struct file *file;
 
-	if (!inode)
-		return ERR_PTR(-ENOMEM);
+	error = get_unused_fd_flags(flags);
+	if (error < 0)
+		return error;
+	fd = error;
+
+	file = anon_inode_getfile(name, fops, priv, flags);
+	if (IS_ERR(file)) {
+		error = PTR_ERR(file);
+		goto err_put_unused_fd;
+	}
+	fd_install(fd, file);
 
-	inode->i_fop = &anon_inode_fops;
+	return fd;
 
-	/*
-	 * 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;
+err_put_unused_fd:
+	put_unused_fd(fd);
+	return error;
 }
+EXPORT_SYMBOL_GPL(anon_inode_getfd);
 
 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);