mir/criu
2
0
Fork 0
mirror of https://github.com/checkpoint-restore/criu synced 2025-08-30 22:05:36 +00:00
Code Issues Releases Wiki Activity

ipc/sysctl: c/r kernel.{msg_next_id,sem_next_id,shm_next_id}

Browse Source 
These are only three left in ipc_kern_table which we haven't
checkpointed yet, I'm not sure if somebody really uses them
except criu, but to be consistent, beter not to change them
while c/r.

v3: do one sysctl_op for all xxx_next_id(as sysctl_op is quiet slow)
v4: do only one sysctl_op in ipc_sysctl_req
v5: do msg*_default only if have /proc/sys/fs/mqueue same as other
ones from fs/mqueue

Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
This commit is contained in:
Pavel Tikhomirov
2016-07-19 13:42:00 +03:00
committed by Pavel Emelyanov
parent df81b884d4
commit f960e432f6
2 changed files with 39 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
criu/ipc_ns.c
View File

@@ -291,6 +291,8 @@ static void pr_info_ipc_shm(const IpcShmEntry *shm)
print_on_level(LOG_INFO, "size: %-10"PRIu64"\n", shm->size);
}
#define NR_MANDATORY_IPC_SYSCTLS 9
static int ipc_sysctl_req(IpcVarEntry *e, int op)
{
struct sysctl_req req[] = {
@@ -303,29 +305,37 @@ static int ipc_sysctl_req(IpcVarEntry *e, int op)
{ "kernel/shmall", &e->shm_ctlall, CTL_U64 },
{ "kernel/shmmni", &e->shm_ctlmni, CTL_U32 },
{ "kernel/shm_rmid_forced", &e->shm_rmid_forced, CTL_U32 },
};
struct sysctl_req req_mq[] = {
/* We have 9 mandatory sysctls above and 8 optional below */
{ "fs/mqueue/queues_max", &e->mq_queues_max, CTL_U32 },
{ "fs/mqueue/msg_max", &e->mq_msg_max, CTL_U32 },
{ "fs/mqueue/msgsize_max", &e->mq_msgsize_max, CTL_U32 },
{ "fs/mqueue/msg_default", &e->mq_msg_default, CTL_U32 },
{ "fs/mqueue/msgsize_default", &e->mq_msgsize_default, CTL_U32 },
{ "kernel/msg_next_id", &e->msg_next_id, CTL_U32 },
{ "kernel/sem_next_id", &e->sem_next_id, CTL_U32 },
{ "kernel/shm_next_id", &e->shm_next_id, CTL_U32 },
};
int ret;
int nr = NR_MANDATORY_IPC_SYSCTLS;
ret = sysctl_op(req, ARRAY_SIZE(req), op, CLONE_NEWIPC);
if (ret)
return ret;
if (access("/proc/sys/fs/mqueue", X_OK)) {
/* Skip sysctls which can't be set or haven't existed on dump */
if (access("/proc/sys/fs/mqueue", X_OK))
pr_info("Mqueue sysctls are missing\n");
return 0;
else {
nr += 3;
if (e->has_mq_msg_default) {
req[nr++] = req[12];
req[nr++] = req[13];
}
}
if (e->has_msg_next_id)
req[nr++] = req[14];
if (e->has_sem_next_id)
req[nr++] = req[15];
if (e->has_shm_next_id)
req[nr++] = req[16];
return sysctl_op(req_mq, ARRAY_SIZE(req_mq) - (e->has_mq_msg_default ? 0 : 2),
op, CLONE_NEWIPC);
return sysctl_op(req, nr, op, CLONE_NEWIPC);
}
/*
@@ -421,6 +431,9 @@ static int dump_ipc_var(struct cr_img *img)
goto err;
var.has_mq_msg_default = true;
var.has_mq_msgsize_default = true;
var.has_msg_next_id = true;
var.has_sem_next_id = true;
var.has_shm_next_id = true;
ret = ipc_sysctl_req(&var, CTL_READ);
if (ret < 0) {
@@ -428,6 +441,17 @@ static int dump_ipc_var(struct cr_img *img)
goto err;
}
/*
* One can not write to msg_next_xxx sysctls -1,
* which is their initial value
*/
if (var.msg_next_id == -1)
var.has_msg_next_id = false;
if (var.sem_next_id == -1)
var.has_sem_next_id = false;
if (var.shm_next_id == -1)
var.has_shm_next_id = false;
ret = pb_write_one(img, &var, PB_IPC_VAR);
if (ret < 0) {
pr_err("Failed to write IPC variables\n");

3
images/ipc-var.proto
View File

@@ -15,4 +15,7 @@ message ipc_var_entry {
required uint32 mq_msgsize_max = 12;
optional uint32 mq_msg_default = 13;
optional uint32 mq_msgsize_default = 14;
optional uint32 msg_next_id = 15;
optional uint32 sem_next_id = 16;
optional uint32 shm_next_id = 17;
}