[CRIU] [PATCH 1/4] IPC: dump message queue

Kinsbursky Stanislav skinsbursky at openvz.org
Wed Feb 8 12:30:39 EST 2012



Signed-off-by: Stanislav Kinsbursky <skinsbursky at parallels.com>

---
 crtools.c         |    6 ++
 include/crtools.h |    5 ++
 include/image.h   |   14 ++++++
 ipc_ns.c          |  128 ++++++++++++++++++++++++++++++++++++++++++++---------
 4 files changed, 131 insertions(+), 22 deletions(-)

diff --git a/crtools.c b/crtools.c
index c43eeab..fee18ef 100644
--- a/crtools.c
+++ b/crtools.c
@@ -122,6 +122,12 @@ struct cr_fd_desc_tmpl fdset_template[CR_FD_MAX] = {
 		.fmt	= FMT_FNAME_IPCNS_SHM,
 		.magic	= IPCNS_SHM_MAGIC,
 	},
+
+	/* IPC namespace message queues */
+	[CR_FD_IPCNS_MSG] = {
+		.fmt	= FMT_FNAME_IPCNS_MSG,
+		.magic	= IPCNS_MSG_MAGIC,
+	},
 };
 
 static struct cr_fdset *alloc_cr_fdset(void)
diff --git a/include/crtools.h b/include/crtools.h
index cf7a46b..32c84ed 100644
--- a/include/crtools.h
+++ b/include/crtools.h
@@ -39,6 +39,7 @@ enum {
 	CR_FD_UTSNS,
 	CR_FD_IPCNS_VAR,
 	CR_FD_IPCNS_SHM,
+	CR_FD_IPCNS_MSG,
 
 	CR_FD_MAX
 };
@@ -82,6 +83,7 @@ extern struct cr_fd_desc_tmpl fdset_template[CR_FD_MAX];
 #define FMT_FNAME_UTSNS		"utsns-%d.img"
 #define FMT_FNAME_IPCNS_VAR	"ipcns-var-%d.img"
 #define FMT_FNAME_IPCNS_SHM	"ipcns-shm-%d.img"
+#define FMT_FNAME_IPCNS_MSG	"ipcns-msg-%d.img"
 
 extern int get_image_path(char *path, int size, const char *fmt, int pid);
 
@@ -114,7 +116,8 @@ struct cr_fdset {
 #define CR_FD_DESC_NS				(\
 	CR_FD_DESC_USE(CR_FD_UTSNS)		|\
 	CR_FD_DESC_USE(CR_FD_IPCNS_VAR)		|\
-	CR_FD_DESC_USE(CR_FD_IPCNS_SHM)		)
+	CR_FD_DESC_USE(CR_FD_IPCNS_SHM)		|\
+	CR_FD_DESC_USE(CR_FD_IPCNS_MSG)		)
 #define CR_FD_DESC_NONE			(0)
 
 int cr_dump_tasks(pid_t pid, struct cr_options *opts);
diff --git a/include/image.h b/include/image.h
index 01a3b86..ef176f3 100644
--- a/include/image.h
+++ b/include/image.h
@@ -23,6 +23,7 @@
 #define CREDS_MAGIC	0x54023547 /* Kozelsk */
 #define IPCNS_VAR_MAGIC	0x53115007 /* Samara */
 #define IPCNS_SHM_MAGIC	0x46283044 /* Odessa */
+#define IPCNS_MSG_MAGIC	0x55453737 /* Moscow */
 
 #define PIPEFS_MAGIC	0x50495045
 
@@ -142,6 +143,19 @@ struct ipc_shm_entry {
 	u64	size;
 } __packed;
 
+struct ipc_msg {
+	u64	mtype;
+	u16	size;
+	u8	pad[6];
+} __packed;
+
+struct ipc_msg_entry {
+	struct ipc_seg seg;
+	u16	qbytes;
+	u16	qnum;
+	u8	pad[4];
+} __packed;
+
 #define VMA_AREA_NONE		(0 <<  0)
 #define VMA_AREA_REGULAR	(1 <<  0)	/* Dumpable area */
 #define VMA_AREA_STACK		(1 <<  1)
diff --git a/ipc_ns.c b/ipc_ns.c
index 5c4d27f..c958e63 100644
--- a/ipc_ns.c
+++ b/ipc_ns.c
@@ -21,6 +21,10 @@
 #define SHM_SET			15
 #endif
 
+#ifndef MSGMAX
+#define MSGMAX			8192
+#endif
+
 static void print_ipc_seg(const struct ipc_seg *seg)
 {
 	pr_info("id: %-10d key: 0x%08x ", seg->id, seg->key);
@@ -45,6 +49,108 @@ static void fill_ipc_seg(int id, struct ipc_seg *seg, const struct ipc_perm *ipc
 	seg->mode = ipcp->mode;
 }
 
+static void print_ipc_msg(int nr, const struct ipc_msg *msg)
+{
+	pr_info("  %-5d: type: %-20ld size: %-10d\n",
+		nr++, msg->mtype, msg->size);
+}
+
+static void print_ipc_msg_entry(const struct ipc_msg_entry *msg)
+{
+	print_ipc_seg(&msg->seg);
+	pr_info ("qbytes: %-10d qnum: %-10d\n", msg->qbytes, msg->qnum);
+}
+
+static int dump_ipc_msg_pages(int fd, const struct ipc_msg_entry *entry)
+{
+	int msg_nr = 0;
+
+	while (msg_nr < entry->qnum) {
+		struct msgbuf {
+			long mtype;
+			char mtext[MSGMAX];
+		} data;
+		struct ipc_msg msg;
+		int ret;
+
+		ret = msgrcv(entry->seg.id, &data, sizeof(data), 0, IPC_NOWAIT);
+		if (ret < 0) {
+			pr_err("Failed to receive IPC message: %d\n", -errno);
+			return -1;
+		}
+		msg.size = ret;
+		msg.mtype = data.mtype;
+
+		print_ipc_msg(msg_nr, &msg);
+
+		ret = write_img(fd, &msg);
+		if (ret < 0) {
+			pr_err("Failed to write IPC message header\n");
+			return ret;
+		}
+		ret = write_img_buf(fd, data.mtext, round_up(msg.size, sizeof(u64)));
+		if (ret < 0) {
+			pr_err("Failed to write IPC message data\n");
+			return ret;
+		}
+		msg_nr++;
+	}
+	return 0;
+}
+
+static int dump_ipc_msg_seg(int fd, int id, const struct msqid_ds *ds)
+{
+	struct ipc_msg_entry msg;
+	int ret;
+
+	fill_ipc_seg(id, &msg.seg, &ds->msg_perm);
+	msg.qbytes = ds->msg_qbytes;
+	msg.qnum = ds->msg_qnum;
+	print_ipc_msg_entry(&msg);
+
+	ret = write_img(fd, &msg);
+	if (ret < 0) {
+		pr_err("Failed to write IPC message queue segment\n");
+		return ret;
+	}
+	return dump_ipc_msg_pages(fd, &msg);
+}
+
+static int dump_ipc_msg(int fd)
+{
+	int i, maxid;
+	struct msginfo info;
+	int err, slot;
+
+	maxid = msgctl(0, MSG_INFO, (struct msqid_ds *)&info);
+	if (maxid < 0) {
+		pr_perror("msgctl failed");
+		return maxid;
+	}
+
+	pr_info("IPC message queues: %d\n", info.msgpool);
+	for (i = 0, slot = 0; i <= maxid; i++) {
+		struct msqid_ds ds;
+		int id, ret;
+
+		id = msgctl(i, MSG_STAT, &ds);
+		if (id < 0) {
+			if (errno == EINVAL)
+				continue;
+			pr_perror("Failed to get stats for IPC message queue\n");
+			break;
+		}
+		ret = dump_ipc_msg_seg(fd, id, &ds);
+		if (!ret)
+			slot++;
+	}
+	if (slot != info.msgpool) {
+		pr_err("Failed to collect %d (only %d succeeded)\n", info.msgpool, slot);
+		return -EFAULT;
+	}
+	return info.msgpool;
+}
+
 static void print_ipc_shm(const struct ipc_shm_entry *shm)
 {
 	print_ipc_seg(&shm->seg);
@@ -72,26 +178,6 @@ static int ipc_sysctl_req(struct ipc_var_entry *e, int op)
 	return sysctl_op(req, op);
 }
 
-static int dump_ipc_msg(void *data)
-{
-	struct msginfo info;
-	int ret;
-	int fd;
-
-	ret = msgctl(0, MSG_INFO, (struct msqid_ds *)&info);
-	if (ret < 0) {
-		pr_perror("msgctl failed");
-		return ret;
-	}
-
-	if (ret) {
-		pr_err("IPC messages migration is not supported yet\n");
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 static int dump_ipc_sem(void *data)
 {
 	int ret;
@@ -216,7 +302,7 @@ static int dump_ipc_data(const struct cr_fdset *fdset)
 	ret = dump_ipc_shm(fdset->fds[CR_FD_IPCNS_SHM]);
 	if (ret < 0)
 		return ret;
-	ret = dump_ipc_msg(0);
+	ret = dump_ipc_msg(fdset->fds[CR_FD_IPCNS_MSG]);
 	if (ret < 0)
 		return ret;
 	ret = dump_ipc_sem(0);



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