[CRIU] [PATCH] ns: Implement setns_from_fdstore() for repeating code
Andrei Vagin
avagin at virtuozzo.com
Sat Jul 22 06:38:48 MSK 2017
Applied, thanks
On Tue, Jul 11, 2017 at 12:47:37PM +0300, Kirill Tkhai wrote:
> Introduce a helper and use it instead of repeating code.
> Use file and line of caller in error message printing
> to allow the caller do not use additional print.
>
> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
> ---
> criu/cr-restore.c | 31 ++++---------------------------
> criu/include/namespaces.h | 5 +++++
> criu/mount.c | 23 +----------------------
> criu/namespaces.c | 40 ++++++++++++++++++++++++++++------------
> criu/net.c | 28 ++++------------------------
> criu/sockets.c | 12 +++---------
> 6 files changed, 45 insertions(+), 94 deletions(-)
>
> diff --git a/criu/cr-restore.c b/criu/cr-restore.c
> index e14fa0694..a9dacce8f 100644
> --- a/criu/cr-restore.c
> +++ b/criu/cr-restore.c
> @@ -431,8 +431,6 @@ static void wait_pid_ns_helper_prepared(struct ns_id *pid_ns, struct pid *pid)
>
> static int set_pid_for_children_ns(struct ns_id *pid_ns)
> {
> - int fd, ret = 0;
> -
> if (!(root_ns_mask & CLONE_NEWPID))
> return 0;
>
> @@ -441,21 +439,11 @@ static int set_pid_for_children_ns(struct ns_id *pid_ns)
> if (current->pid_for_children_ns == pid_ns)
> return 0;
>
> - fd = fdstore_get(pid_ns->pid.nsfd_id);
> - if (fd < 0) {
> - pr_err("Can't get pid_ns fd\n");
> + if (setns_from_fdstore(pid_ns->pid.nsfd_id, CLONE_NEWPID) < 0)
> return -1;
> - }
>
> - if (setns(fd, CLONE_NEWPID) < 0) {
> - pr_perror("Can't set pid ns");
> - ret = -1;
> - } else {
> - current->pid_for_children_ns = pid_ns;
> - }
> -
> - close(fd);
> - return ret;
> + current->pid_for_children_ns = pid_ns;
> + return 0;
> }
>
> static int restore_task_pfc_before_user_ns(void)
> @@ -1310,7 +1298,6 @@ static int call_clone_fn(void *arg)
> struct cr_clone_arg *ca = arg;
> struct ns_id *pid_ns;
> pid_t pid;
> - int fd;
>
> pid_ns = lookup_ns_by_id(ca->item->ids->pid_ns_id, &pid_ns_desc);
> BUG_ON(!pid_ns);
> @@ -1320,18 +1307,8 @@ static int call_clone_fn(void *arg)
> return -1;
> }
>
> - fd = fdstore_get(pid_ns->user_ns->user.nsfd_id);
> - if (fd < 0) {
> - pr_err("Can't get ns fd\n");
> + if (setns_from_fdstore(pid_ns->user_ns->user.nsfd_id, CLONE_NEWUSER))
> return -1;
> - }
> -
> - if (setns(fd, CLONE_NEWUSER) < 0) {
> - pr_perror("Can't set user ns");
> - close(fd);
> - return -1;
> - }
> - close(fd);
>
> close_pid_proc();
> pid = clone_noasan(restore_task_with_children, ca->clone_flags | CLONE_PARENT | SIGCHLD, ca);
> diff --git a/criu/include/namespaces.h b/criu/include/namespaces.h
> index 44520a81a..bc7372c22 100644
> --- a/criu/include/namespaces.h
> +++ b/criu/include/namespaces.h
> @@ -264,6 +264,11 @@ extern int __userns_call(const char *func_name, uns_call_t call, int flags,
> __userns_call(__stringify(__call), __call, __flags, \
> __arg, __arg_size, __fd)
>
> +extern int __setns_from_fdstore(int fd_id, int nstype, const char *, int);
> +
> +#define setns_from_fdstore(fd_id, nstype) \
> + __setns_from_fdstore(fd_id, nstype, __FILE__, __LINE__)
> +
> extern int add_ns_shared_cb(int (*actor)(void *data), void *data);
>
> extern struct ns_id *get_socket_ns(int lfd);
> diff --git a/criu/mount.c b/criu/mount.c
> index 83915b7b2..b825b7086 100644
> --- a/criu/mount.c
> +++ b/criu/mount.c
> @@ -2713,24 +2713,6 @@ int mntns_maybe_create_roots(void)
> return create_mnt_roots();
> }
>
> -static int do_restore_task_mnt_ns(struct ns_id *nsid, struct pstree_item *current)
> -{
> - int fd;
> -
> - fd = fdstore_get(nsid->mnt.nsfd_id);
> - if (fd < 0)
> - return -1;
> -
> - if (setns(fd, CLONE_NEWNS)) {
> - pr_perror("Can't restore mntns");
> - close(fd);
> - return -1;
> - }
> - close(fd);
> -
> - return 0;
> -}
> -
> int restore_task_mnt_ns(struct pstree_item *current)
> {
> unsigned int id = current->ids->mnt_ns_id;
> @@ -2758,10 +2740,7 @@ int restore_task_mnt_ns(struct pstree_item *current)
>
> BUG_ON(nsid->type == NS_CRIU);
>
> - if (do_restore_task_mnt_ns(nsid, current))
> - return -1;
> -
> - return 0;
> + return setns_from_fdstore(nsid->mnt.nsfd_id, CLONE_NEWNS);
> }
>
> void fini_restore_mntns(void)
> diff --git a/criu/namespaces.c b/criu/namespaces.c
> index 100a631e9..127a202d6 100644
> --- a/criu/namespaces.c
> +++ b/criu/namespaces.c
> @@ -2553,26 +2553,16 @@ int prepare_namespace_before_tasks(void)
>
> int __set_user_ns(struct ns_id *ns)
> {
> - int fd;
> -
> if (!(root_ns_mask & CLONE_NEWUSER))
> return 0;
>
> if (current->user_ns && current->user_ns->id == ns->id)
> return 0;
>
> - fd = fdstore_get(ns->user.nsfd_id);
> - if (fd < 0) {
> - pr_err("Can't get ns fd\n");
> + if (setns_from_fdstore(ns->user.nsfd_id, CLONE_NEWUSER))
> return -1;
> - }
> - if (setns(fd, CLONE_NEWUSER) < 0) {
> - pr_perror("Can't setns");
> - close(fd);
> - return -1;
> - }
> +
> current->user_ns = ns;
> - close(fd);
>
> if (prepare_userns_creds() < 0) {
> pr_err("Can't set creds\n");
> @@ -2834,5 +2824,31 @@ int destroy_pid_ns_helpers(void)
> return 0;
> }
>
> +int __setns_from_fdstore(int fd_id, int nstype, const char *file, int line)
> +{
> + int fd, saved_errno, ret;
> +
> + fd = fdstore_get(fd_id);
> + if (fd < 0)
> + goto err;
> +
> + ret = setns(fd, nstype);
> + saved_errno = errno;
> + close(fd);
> + if (ret) {
> + errno = saved_errno;
> + pr_perror("Can't set user ns");
> + goto err;
> + }
> +
> + return 0;
> +err:
> + pr_err("Can't set %s_ns from fdstore (called from %s: %d)\n",
> + ns_to_string(nstype), file, line);
> + return -1;
> +}
> +
> +
> +
> struct ns_desc pid_ns_desc = NS_DESC_ENTRY(CLONE_NEWPID, "pid", "pid_for_children");
> struct ns_desc user_ns_desc = NS_DESC_ENTRY(CLONE_NEWUSER, "user", NULL);
> diff --git a/criu/net.c b/criu/net.c
> index 15aae2be4..99a78ee14 100644
> --- a/criu/net.c
> +++ b/criu/net.c
> @@ -2060,23 +2060,16 @@ static int do_create_net_ns(struct ns_id *ns)
> static int create_net_ns(void *arg)
> {
> struct ns_id *uns, *ns = arg;
> - int ufd, ret;
> + int ret;
>
> uns = ns->user_ns;
> - ufd = fdstore_get(uns->user.nsfd_id);
> - if (ufd < 0) {
> - pr_err("Can't get user ns\n");
> + if (setns_from_fdstore(uns->user.nsfd_id, CLONE_NEWUSER))
> exit(1);
> - }
> - if (setns(ufd, CLONE_NEWUSER) < 0) {
> - pr_perror("Can't set user ns");
> - exit(2);
> - }
> +
> if (prepare_userns_creds() < 0) {
> pr_err("Can't prepare creds\n");
> exit(3);
> }
> - close(ufd);
> ret = do_create_net_ns(ns) ? 3 : 0;
> exit(ret);
> }
> @@ -2160,23 +2153,10 @@ int prepare_net_namespaces(void)
>
> static int do_restore_task_net_ns(struct ns_id *nsid, struct pstree_item *current)
> {
> - int fd;
> -
> if (!(root_ns_mask & CLONE_NEWNET))
> return 0;
>
> - fd = fdstore_get(nsid->net.nsfd_id);
> - if (fd < 0)
> - return -1;
> -
> - if (setns(fd, CLONE_NEWNET)) {
> - pr_perror("Can't restore netns");
> - close(fd);
> - return -1;
> - }
> - close(fd);
> -
> - return 0;
> + return setns_from_fdstore(nsid->net.nsfd_id, CLONE_NEWNET);
> }
>
> int restore_task_net_ns(struct pstree_item *current)
> diff --git a/criu/sockets.c b/criu/sockets.c
> index 9b0c4df99..fd6f525a0 100644
> --- a/criu/sockets.c
> +++ b/criu/sockets.c
> @@ -750,7 +750,6 @@ static uint32_t last_ns_id = 0;
> int set_netns(uint32_t ns_id)
> {
> struct ns_id *ns;
> - int nsfd;
>
> if (!(root_ns_mask & CLONE_NEWNET))
> return 0;
> @@ -763,16 +762,11 @@ int set_netns(uint32_t ns_id)
> pr_err("Unable to find a network namespace\n");
> return -1;
> }
> - nsfd = fdstore_get(ns->net.nsfd_id);
> - if (nsfd < 0)
> - return -1;
> - if (setns(nsfd, CLONE_NEWNET)) {
> - pr_perror("Unable to switch a network namespace");
> - close(nsfd);
> +
> + if (setns_from_fdstore(ns->net.nsfd_id, CLONE_NEWNET))
> return -1;
> - }
> +
> last_ns_id = ns_id;
> - close(nsfd);
>
> close_pid_proc();
>
>
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