Quoting Nadia.Derbey@xxxxxxxx (Nadia.Derbey@xxxxxxxx): > [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 <Nadia.Derbey@xxxxxxxx> Acked-by: Serge Hallyn <serue@xxxxxxxxxx> 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 Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers