The namespace is restored by creating each 'msq' object read from
the checkpoint image.
Message of a specific queue are first read and chained together on
a temporary list, and once done are attached atomically as a whole
to the newly created message queue ('msq').
Signed-off-by: Oren Laadan <orenl@xxxxxxxxxxxxxxx>
---
checkpoint/rstr_file.c | 1 -
checkpoint/util_ipc.c | 9 ++-
include/linux/checkpoint.h | 1 +
ipc/ckpt_msg.c | 210 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 219 insertions(+), 2 deletions(-)
diff --git a/checkpoint/rstr_file.c b/checkpoint/rstr_file.c
index cf3bece..845a5cd 100644
--- a/checkpoint/rstr_file.c
+++ b/checkpoint/rstr_file.c
@@ -399,7 +399,6 @@ int cr_read_fd_table(struct cr_ctx *ctx)
break;
}
- ret = 0;
out:
cr_hbuf_put(ctx, sizeof(*hh));
return ret;
diff --git a/checkpoint/util_ipc.c b/checkpoint/util_ipc.c
index 163a106..9a4e37d 100644
--- a/checkpoint/util_ipc.c
+++ b/checkpoint/util_ipc.c
@@ -27,7 +27,14 @@ int cr_write_ipcns(struct cr_ctx *ctx, struct ipc_namespace *ipc_ns)
int cr_read_ipcns(struct cr_ctx *ctx)
{
- return cr_read_ipc_shm(ctx);
+ int ret;
+
+ ret = cr_read_ipc_shm(ctx);
+ if (ret < 0)
+ return ret;
+ ret = cr_read_ipc_msg(ctx);
+
+ return ret;
}
void cr_fill_ipc_perms(struct cr_hdr_ipc_perms *hh, struct kern_ipc_perm *perm)
diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h
index 16dd96d..898176c 100644
--- a/include/linux/checkpoint.h
+++ b/include/linux/checkpoint.h
@@ -156,6 +156,7 @@ extern int cr_read_ipc_shm(struct cr_ctx *ctx);
extern int cr_ipc_shm_attach(struct file *file,
unsigned long addr, unsigned long flags);
extern int cr_write_ipc_msg(struct cr_ctx *ctx, struct ipc_namespace *ipcns);
+extern int cr_read_ipc_msg(struct cr_ctx *ctx);
#endif
diff --git a/ipc/ckpt_msg.c b/ipc/ckpt_msg.c
index 5e11253..eebbf06 100644
--- a/ipc/ckpt_msg.c
+++ b/ipc/ckpt_msg.c
@@ -202,3 +202,213 @@ int cr_write_ipc_msg(struct cr_ctx *ctx, struct ipc_namespace *ipcns)
up_read(&msg_ids->rw_mutex);
return ret;
}
+
+/************************************************************************
+ * ipc restart
+ */
+
+static int cr_load_ipc_msg_hdr(struct cr_ctx *ctx,
+ struct cr_hdr_ipc_msg *hh,
+ struct msg_queue *msq)
+{
+ int ret = 0;
+
+ ret = cr_load_ipc_perms(&hh->perms, &msq->q_perm);
+ if (ret < 0)
+ return ret;
+
+ cr_debug("msq: lspid %d lrpid %d qnum %lld qbytes %lld\n",
+ hh->q_lspid, hh->q_lrpid, hh->q_qnum, hh->q_qbytes);
+
+ if (hh->q_lspid < 0 || hh->q_lrpid < 0)
+ return -EINVAL;
+
+ msq->q_stime = hh->q_stime;
+ msq->q_rtime = hh->q_rtime;
+ msq->q_ctime = hh->q_ctime;
+ msq->q_lspid = hh->q_lspid;
+ msq->q_lrpid = hh->q_lrpid;
+
+ return 0;
+}
+
+static struct msg_msg *cr_read_msg_contents_one(struct cr_ctx *ctx)
+{
+ struct cr_hdr_ipc_msg_msg *hh;
+ struct msg_msg *msg = NULL;
+ struct msg_msgseg *seg, **pseg;
+ int total, len;
+ int ret;
+
+ hh = cr_hbuf_get(ctx, sizeof(*hh));
+ if (!hh)
+ return ERR_PTR(-ENOMEM);
+ ret = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_IPC_MSG_MSG);
+ if (ret < 0)
+ goto out;
+
+ ret = -EINVAL;
+ if (hh->m_type < 1)
+ goto out;
+ if (hh->m_ts > current->nsproxy->ipc_ns->msg_ctlmax)
+ goto out;
+
+ total = hh->m_ts;
+ len = min(total, (int) DATALEN_MSG);
+ ret = -ENOMEM;
+ msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
+ if (!msg)
+ goto out;
+ msg->next = NULL;
+ pseg = &msg->next;
+
+ ret = cr_read_buffer_len(ctx, (msg + 1), len);
+ if (ret < 0)
+ goto out;
+
+ total -= len;
+ while (total) {
+ len = min(total, (int) DATALEN_SEG);
+ ret = -ENOMEM;
+ seg = kmalloc(sizeof(*seg) + len, GFP_KERNEL);
+ if (!seg)
+ goto out;
+ seg->next = NULL;
+ *pseg = seg;
+ pseg = &seg->next;
+
+ ret = cr_read_buffer_len(ctx, (seg + 1), len);
+ if (ret < 0)
+ goto out;
+ }
+
+ msg->m_type = hh->m_type;
+ msg->m_ts = hh->m_ts;
+ return msg;
+
+ out:
+ if (msg)
+ free_msg(msg);
+ return ERR_PTR(ret);
+}
+
+static int cr_read_msg_contents(struct cr_ctx *ctx,
+ struct list_head *queue, unsigned long qnum)
+{
+ struct msg_msg *msg, *tmp;
+ int ret = 0;
+
+ INIT_LIST_HEAD(queue);
+
+ while (qnum--) {
+ msg = cr_read_msg_contents_one(ctx);
+ if (IS_ERR(msg))
+ goto fail;
+ list_add_tail(&msg->m_list, queue);
+ }
+
+ return 0;
+
+ fail:
+ ret = PTR_ERR(msg);
+ list_for_each_entry_safe(msg, tmp, queue, m_list)
+ free_msg(msg);
+ return ret;
+}
+
+static int cr_do_read_ipc_msg(struct cr_ctx *ctx)
+{
+ struct cr_hdr_ipc_msg *hh;
+ struct kern_ipc_perm *perms;
+ struct msg_queue *msq;
+ struct ipc_ids *msg_ids = ¤t->nsproxy->ipc_ns->ids[IPC_MSG_IDS];
+ struct list_head messages;
+ int msgflag;
+ int ret;
+
+ hh = cr_hbuf_get(ctx, sizeof(*hh));
+ if (!hh)
+ return -ENOMEM;
+ ret = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_IPC_MSG);
+ if (ret < 0)
+ goto out;
+ ret = -EINVAL;
+ if (hh->perms.id < 0)
+ goto out;
+
+ /* read queued messages into temporary queue */
+ ret = cr_read_msg_contents(ctx, &messages, hh->q_qnum);
+ if (ret < 0)
+ goto out;
+
+ /* restore the message queue now */
+ msgflag = hh->perms.mode | IPC_CREAT | IPC_EXCL;
+ cr_debug("msg: do_msgget key %d flag %#x id %d\n",
+ hh->perms.key, msgflag, hh->perms.id);
+ ret = do_msgget(hh->perms.key, msgflag, hh->perms.id);
+ cr_debug("shm: do_msgget ret %d\n", ret);
+ if (ret < 0)
+ goto out;
+
+ down_write(&msg_ids->rw_mutex);
+ ret = -EIDRM;
+ perms = ipc_lock(msg_ids, hh->perms.id);
+ if (IS_ERR(perms)) { /* this should not happen .. but be safe */
+ up_write(&msg_ids->rw_mutex);
+ ret = PTR_ERR(perms);
+ goto out;
+ }
+
+ msq = container_of(perms, struct msg_queue, q_perm);
+ ret = cr_load_ipc_msg_hdr(ctx, hh, msq);
+ if (ret < 0) {
+ cr_debug("msq: need to remove (%d)\n", ret);
+ freeque(current->nsproxy->ipc_ns, perms);
+ up_write(&msg_ids->rw_mutex);
+ goto out;
+ }
+
+ /* attach queued messages we read before */
+ if (list_empty(&msq->q_messages))
+ list_splice_init(&messages, &msq->q_messages);
+ else
+ ret = -EBUSY;
+
+ ipc_unlock(perms);
+ up_write(&msg_ids->rw_mutex);
+ out:
+ cr_hbuf_put(ctx, sizeof(*hh));
+ return ret;
+}
+
+int cr_read_ipc_msg(struct cr_ctx *ctx)
+{
+ struct cr_hdr_ipc *hh;
+ int n, ret;
+
+ hh = cr_hbuf_get(ctx, sizeof(*hh));
+ if (!hh)
+ return -ENOMEM;
+
+ ret = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_IPC);
+ if (ret < 0)
+ goto out;
+
+ cr_debug("msg: count %d\n", hh->ipc_count);
+
+ ret = -EINVAL;
+ if (hh->ipc_type != CR_HDR_IPC_MSG)
+ goto out;
+
+ ret = 0;
+ for (n = 0; n < hh->ipc_count; n++) {
+ ret = cr_do_read_ipc_msg(ctx);
+ if (ret < 0)
+ goto out;
+ }
+
+ out:
+ cr_debug("msg: ret %d\n", ret);
+ cr_hbuf_put(ctx, sizeof(*hh));
+ return ret;
+}
--
1.5.4.3
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