From 55708698c5f153f4e390175cdfc395333b2eafbd Mon Sep 17 00:00:00 2001 From: Gu Zheng Date: Tue, 16 Jul 2013 17:56:12 +0800 Subject: fs/anon_inode: Introduce a new lib function anon_inode_getfile_private() Introduce a new lib function anon_inode_getfile_private(), it creates a new file instance by hooking it up to an anonymous inode, and a dentry that describe the "class" of the file, similar to anon_inode_getfile(), but each file holds a single inode. Furthermore, anyone who wants to create a private anon file will benefit from this change. Signed-off-by: Gu Zheng Signed-off-by: Benjamin LaHaise --- fs/anon_inodes.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) (limited to 'fs') diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 47a65df8c871..85c961849953 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -108,6 +108,72 @@ 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" -- cgit v1.2.3