Quoting [EMAIL PROTECTED] ([EMAIL PROTECTED]):
> [PATCH 04/05]
>
> This patch uses the value written into the next_syscall_data proc file
> as a flag to change the way msgctl(IPC_SET), semctl(IPC_SET) and
> shmctl(IPC_SET) behave.
>
> When "LONG1 1" is echoed to this file, xxxctl(IPC_SET) will set the time
> fields and the pid fields according to what is specified in the input
> parameter (while currently only the permission fields are allowed to be set).
> The following syscalls are impacted:
> . msgctl(IPC_SET)
> . semctl(IPC_SET)
> . shmctl(IPC_SET)
>
> This makes it easy to restart an ipc object exactly is it was during the
> checkpoint phase.
>
> Signed-off-by: Nadia Derbey <[EMAIL PROTECTED]>
Acked-by: Serge Hallyn <[EMAIL PROTECTED]>
thanks,
-serge
> ---
> include/linux/next_syscall_data.h | 12 ++++++++++++
> ipc/msg.c | 19 ++++++++++++++++++-
> ipc/sem.c | 16 +++++++++++++++-
> ipc/shm.c | 19 ++++++++++++++++++-
> 4 files changed, 63 insertions(+), 3 deletions(-)
>
> Index: linux-2.6.26-rc8-mm1/include/linux/next_syscall_data.h
> ===================================================================
> --- linux-2.6.26-rc8-mm1.orig/include/linux/next_syscall_data.h
> 2008-07-08 12:22:47.000000000 +0200
> +++ linux-2.6.26-rc8-mm1/include/linux/next_syscall_data.h 2008-07-08
> 12:24:29.000000000 +0200
> @@ -6,6 +6,7 @@
> * . object creation with a predefined id
> * . for a sysv ipc object
> * . for a process
> + * . set more than the usual ipc_perm fields during and IPC_SET operation.
> */
>
> #ifndef _LINUX_NEXT_SYSCALL_DATA_H
> @@ -20,6 +21,10 @@
> * by next syscall. The following syscalls support this feature:
> * . msgget(), semget(), shmget()
> * . fork(), vfork(), clone()
> + *
> + * If it is set to a non null value before a call to:
> + * . msgctl(IPC_SET), semctl(IPC_SET), shmctl(IPC_SET),
> + * this means that we are going to set more than the usual ipc_perms fields.
> */
> struct next_syscall_data {
> int ndata;
> @@ -35,6 +40,13 @@ struct next_syscall_data {
>
> #define get_next_data(tsk) ((tsk)->nsd->data[0])
>
> +/*
> + * Returns true if next call to xxxctl(IPC_SET) should have a non-default
> + * behavior.
> + */
> +#define ipc_set_all(tsk) (next_data_set(tsk) ? get_next_data(tsk) : 0)
> +
> +
> extern ssize_t get_next_syscall_data(struct task_struct *, char *, size_t);
> extern int set_next_syscall_data(struct task_struct *, char *);
> extern void reset_next_syscall_data(struct task_struct *);
> Index: linux-2.6.26-rc8-mm1/ipc/msg.c
> ===================================================================
> --- linux-2.6.26-rc8-mm1.orig/ipc/msg.c 2008-07-08 12:12:36.000000000
> +0200
> +++ linux-2.6.26-rc8-mm1/ipc/msg.c 2008-07-08 12:26:03.000000000 +0200
> @@ -446,7 +446,24 @@ static int msgctl_down(struct ipc_namesp
> msq->q_qbytes = msqid64.msg_qbytes;
>
> ipc_update_perm(&msqid64.msg_perm, ipcp);
> - msq->q_ctime = get_seconds();
> + if (unlikely(ipc_set_all(current))) {
> + /*
> + * If this field is set in the task struct, this
> + * means that we want to set more than the usual
> + * fields. Particularly useful to restart a msgq
> + * in the same state as it was before being
> + * checkpointed.
> + */
> + msq->q_stime = msqid64.msg_stime;
> + msq->q_rtime = msqid64.msg_rtime;
> + msq->q_ctime = msqid64.msg_ctime;
> + msq->q_lspid = msqid64.msg_lspid;
> + msq->q_lrpid = msqid64.msg_lrpid;
> +
> + reset_next_syscall_data(current);
> + } else
> + msq->q_ctime = get_seconds();
> +
> /* sleeping receivers might be excluded by
> * stricter permissions.
> */
> Index: linux-2.6.26-rc8-mm1/ipc/sem.c
> ===================================================================
> --- linux-2.6.26-rc8-mm1.orig/ipc/sem.c 2008-07-08 12:12:36.000000000
> +0200
> +++ linux-2.6.26-rc8-mm1/ipc/sem.c 2008-07-08 12:27:06.000000000 +0200
> @@ -874,7 +874,21 @@ static int semctl_down(struct ipc_namesp
> goto out_up;
> case IPC_SET:
> ipc_update_perm(&semid64.sem_perm, ipcp);
> - sma->sem_ctime = get_seconds();
> +
> + if (unlikely(ipc_set_all(current))) {
> + /*
> + * If this field is set in the task struct, this
> + * means that we want to set more than the usual
> + * fields. Particularly useful to restart a semaphore
> + * in the same state as it was before being
> + * checkpointed.
> + */
> + sma->sem_ctime = semid64.sem_ctime;
> + sma->sem_otime = semid64.sem_otime;
> +
> + reset_next_syscall_data(current);
> + } else
> + sma->sem_ctime = get_seconds();
> break;
> default:
> err = -EINVAL;
> Index: linux-2.6.26-rc8-mm1/ipc/shm.c
> ===================================================================
> --- linux-2.6.26-rc8-mm1.orig/ipc/shm.c 2008-07-08 12:12:36.000000000
> +0200
> +++ linux-2.6.26-rc8-mm1/ipc/shm.c 2008-07-08 12:27:32.000000000 +0200
> @@ -609,7 +609,24 @@ static int shmctl_down(struct ipc_namesp
> goto out_up;
> case IPC_SET:
> ipc_update_perm(&shmid64.shm_perm, ipcp);
> - shp->shm_ctim = get_seconds();
> +
> + if (unlikely(ipc_set_all(current))) {
> + /*
> + * If this field is set in the task struct, this
> + * means that we want to set more than the usual
> + * fields. Particularly useful to restart a shm seg
> + * in the same state as it was before being
> + * checkpointed.
> + */
> + shp->shm_atim = shmid64.shm_atime;
> + shp->shm_dtim = shmid64.shm_dtime;
> + shp->shm_ctim = shmid64.shm_ctime;
> + shp->shm_cprid = shmid64.shm_cpid;
> + shp->shm_lprid = shmid64.shm_lpid;
> +
> + reset_next_syscall_data(current);
> + } else
> + shp->shm_ctim = get_seconds();
> break;
> default:
> err = -EINVAL;
>
> --
_______________________________________________
Containers mailing list
[EMAIL PROTECTED]
https://lists.linux-foundation.org/mailman/listinfo/containers
_______________________________________________
Devel mailing list
[email protected]
https://openvz.org/mailman/listinfo/devel
