static struct vfsmount *anon_inode_mnt __read_mostly;
static struct inode *anon_inode_inode;
-static const struct file_operations anon_inode_fops;
/*
* anon_inodefs_dname() is called from d_path().
.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)
-{
- return 0;
-};
-
-static const struct address_space_operations anon_aops = {
- .set_page_dirty = anon_set_page_dirty,
-};
-
-/*
- * 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(struct super_block *s)
-{
- struct inode *inode = new_inode_pseudo(s);
-
- if (!inode)
- return ERR_PTR(-ENOMEM);
-
- inode->i_ino = get_next_ino();
- 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_flags |= S_PRIVATE;
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
- return inode;
-}
-
static struct dentry *anon_inodefs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- struct dentry *root;
- root = mount_pseudo(fs_type, "anon_inode:", NULL,
+ return mount_pseudo(fs_type, "anon_inode:", NULL,
&anon_inodefs_dentry_operations, ANON_INODE_FS_MAGIC);
- if (!IS_ERR(root)) {
- struct super_block *s = root->d_sb;
- anon_inode_inode = anon_inode_mkinode(s);
- if (IS_ERR(anon_inode_inode)) {
- dput(root);
- deactivate_locked_super(s);
- root = ERR_CAST(anon_inode_inode);
- }
- }
- return root;
}
static struct file_system_type anon_inode_fs_type = {
.kill_sb = kill_anon_super,
};
-/**
- * anon_inode_getfile_private - 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
- *
- *
- * Similar to anon_inode_getfile, but each file holds a single inode.
- *
- */
-struct file *anon_inode_getfile_private(const char *name,
- const struct file_operations *fops,
- void *priv, int flags)
-{
- struct qstr this;
- struct path path;
- struct file *file;
- struct inode *inode;
-
- if (fops->owner && !try_module_get(fops->owner))
- return ERR_PTR(-ENOENT);
-
- inode = anon_inode_mkinode(anon_inode_mnt->mnt_sb);
- if (IS_ERR(inode)) {
- file = ERR_PTR(-ENOMEM);
- goto err_module;
- }
-
- /*
- * Link the inode to a directory entry by creating a unique name
- * using the inode sequence number.
- */
- file = ERR_PTR(-ENOMEM);
- this.name = name;
- this.len = strlen(name);
- this.hash = 0;
- path.dentry = d_alloc_pseudo(anon_inode_mnt->mnt_sb, &this);
- if (!path.dentry)
- goto err_module;
-
- path.mnt = mntget(anon_inode_mnt);
-
- d_instantiate(path.dentry, inode);
-
- file = alloc_file(&path, OPEN_FMODE(flags), fops);
- if (IS_ERR(file))
- goto err_dput;
-
- file->f_mapping = inode->i_mapping;
- file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
- file->private_data = priv;
-
- return file;
-
-err_dput:
- path_put(&path);
-err_module:
- module_put(fops->owner);
- return file;
-}
-EXPORT_SYMBOL_GPL(anon_inode_getfile_private);
-
/**
* anon_inode_getfile - creates a new file instance by hooking it up to an
* anonymous inode, and a dentry that describe the "class"
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;
- }
- return 0;
+ if (IS_ERR(anon_inode_mnt))
+ panic("anon_inode_init() kernel mount failed (%ld)\n", PTR_ERR(anon_inode_mnt));
-err_unregister_filesystem:
- unregister_filesystem(&anon_inode_fs_type);
-err_exit:
- panic(KERN_ERR "anon_inode_init() failed (%d)\n", error);
+ 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));
+
+ return 0;
}
fs_initcall(anon_inode_init);
projects / ~andy / linux / blobdiff