From 460695a294e63de4e4f30ad1679ffddeec932bb8 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 27 Jun 2024 16:11:41 +0200 Subject: nsfs: add open_namespace() and call it from open_related_ns(). Link: https://lore.kernel.org/r/20240627-work-pidfs-v1-3-7e9ab6cc3bb1@kernel.org Reviewed-by: Jeff Layton Reviewed-by: Josef Bacik Reviewed-by: Alexander Mikhalitsyn Signed-off-by: Christian Brauner --- fs/nsfs.c | 55 +++++++++++++++++++++++++++++++------------------------ 1 file changed, 31 insertions(+), 24 deletions(-) (limited to 'fs/nsfs.c') diff --git a/fs/nsfs.c b/fs/nsfs.c index 07e22a15ef02..4c4dbdce7601 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -82,40 +82,47 @@ int ns_get_path(struct path *path, struct task_struct *task, return ns_get_path_cb(path, ns_get_path_task, &args); } -int open_related_ns(struct ns_common *ns, - struct ns_common *(*get_ns)(struct ns_common *ns)) +/** + * open_namespace - open a namespace + * @ns: the namespace to open + * + * This will consume a reference to @ns indendent of success or failure. + * + * Return: A file descriptor on success or a negative error code on failure. + */ +int open_namespace(struct ns_common *ns) { - struct path path = {}; - struct ns_common *relative; + struct path path __free(path_put) = {}; struct file *f; int err; - int fd; - fd = get_unused_fd_flags(O_CLOEXEC); + /* call first to consume reference */ + err = path_from_stashed(&ns->stashed, nsfs_mnt, ns, &path); + if (err < 0) + return err; + + CLASS(get_unused_fd, fd)(O_CLOEXEC); if (fd < 0) return fd; + f = dentry_open(&path, O_RDONLY, current_cred()); + if (IS_ERR(f)) + return PTR_ERR(f); + + fd_install(fd, f); + return take_fd(fd); +} + +int open_related_ns(struct ns_common *ns, + struct ns_common *(*get_ns)(struct ns_common *ns)) +{ + struct ns_common *relative; + relative = get_ns(ns); - if (IS_ERR(relative)) { - put_unused_fd(fd); + if (IS_ERR(relative)) return PTR_ERR(relative); - } - err = path_from_stashed(&relative->stashed, nsfs_mnt, relative, &path); - if (err < 0) { - put_unused_fd(fd); - return err; - } - - f = dentry_open(&path, O_RDONLY, current_cred()); - path_put(&path); - if (IS_ERR(f)) { - put_unused_fd(fd); - fd = PTR_ERR(f); - } else - fd_install(fd, f); - - return fd; + return open_namespace(relative); } EXPORT_SYMBOL_GPL(open_related_ns); -- cgit v1.2.3