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 <[email protected]> Signed-off-by: Benjamin LaHaise <[email protected]> --- fs/anon_inodes.c | 66 +++++++++++++++++++++++++++++++++++++++++++ include/linux/anon_inodes.h | 3 ++ 2 files changed, 69 insertions(+), 0 deletions(-) diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 47a65df..85c9618 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -109,6 +109,72 @@ static struct file_system_type anon_inode_fs_type = { }; /** + * 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" * of the file diff --git a/include/linux/anon_inodes.h b/include/linux/anon_inodes.h index 8013a45..cf573c2 100644 --- a/include/linux/anon_inodes.h +++ b/include/linux/anon_inodes.h @@ -13,6 +13,9 @@ struct file_operations; struct file *anon_inode_getfile(const char *name, const struct file_operations *fops, void *priv, int flags); +struct file *anon_inode_getfile_private(const char *name, + const struct file_operations *fops, + void *priv, int flags); int anon_inode_getfd(const char *name, const struct file_operations *fops, void *priv, int flags); -- 1.7.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
