[CRIU] [PATCH 1/3] Process Migration using Sockets
Rodrigo Bruno
rbruno at gsd.inesc-id.pt
Wed Jan 11 09:16:10 PST 2017
criu/Makefile.crtools | 4 +
criu/cr-dump.c | 16 +++
criu/cr-restore.c | 6 +
criu/crtools.c | 20 +++-
criu/image-desc.c | 4 +-
criu/image.c | 51 +++++++-
criu/img-remote.c | 275
+++++++++++++++++++++++++++++++++++++++++++
criu/include/cr_options.h | 1 +
criu/include/image.h | 1 +
criu/include/img-remote.h | 83 +++++++++++++
criu/include/protobuf-desc.h | 4 +
criu/page-xfer.c | 25 +++-
criu/pagemap.c | 53 +++++++--
criu/protobuf-desc.c | 1 +
criu/sk-queue.c | 33 ++----
criu/util.c | 31 +++--
images/Makefile | 1 +
images/remote-image.proto | 20 ++++
18 files changed, 577 insertions(+), 52 deletions(-)
This patch introduces the --remote option and the necessary code
changes to
support it. This leaves user the option to decide if the checkpoint
data is to
be stored on disk or sent through the network (through the image-proxy).
The latter forwards the data to the destination node where image-cache
receives it.
The overall communication is performed as follows:
src_node CRIU dump -> (sends images through UNIX sockets) ->
image-proxy
|
V
dst_node: CRIU restore <- (receives images through UNIX sockets)<-
image-cache
Communication between image-proxy and image-cache is done through a
single
TCP connection.
Running criu with --remote option is like this:
dst_node# criu image-cache -d --port <port> -o /tmp/image-cache.log
--local-cache-path <local_cache_path> ...
dst_node# criu restore --remote -o /tmp/image-cache.log
--local-cache-path <local_cache_path> ...
src_node# criu image-proxy -d --port <port> --address <dst_node> -o
/tmp/image-proxy.log
--local-proxy-path <local_proxy_path> ...
src_node# criu dump -t <pid> --remote -o /tmp/dump.log
--local-proxy-path <local_proxy_path> ...
Signed-off-by: Rodrigo Bruno <rbruno at gsd.inesc-id.pt>
Signed-off-by: Katerina Koukiou <k.koukiou at gmail.com>
diff --git a/criu/Makefile.crtools b/criu/Makefile.crtools
index e740798..4d21199 100644
--- a/criu/Makefile.crtools
+++ b/criu/Makefile.crtools
@@ -26,6 +26,10 @@ obj-y += files-reg.o
obj-y += fsnotify.o
obj-y += image-desc.o
obj-y += image.o
+obj-y += img-remote.o
+obj-y += img-proxy.o
+obj-y += img-cache.o
+obj-y += img-remote-proto.o
obj-y += ipc_ns.o
obj-y += irmap.o
obj-y += kcmp-ids.o
diff --git a/criu/cr-dump.c b/criu/cr-dump.c
index 5e708a3..f7a4efb 100644
--- a/criu/cr-dump.c
+++ b/criu/cr-dump.c
@@ -83,6 +83,7 @@
#include "seize.h"
#include "fault-injection.h"
#include "dump.h"
+#include "img-remote.h"
static char loc_buf[PAGE_SIZE];
@@ -1497,6 +1498,11 @@ int cr_pre_dump_tasks(pid_t pid)
struct pstree_item *item;
int ret = -1;
+ if (opts.remote && push_snapshot_id() < 0) {
+ pr_err("Failed to push image namespace.\n");
+ goto err;
+ }
+
root_item = alloc_pstree_item();
if (!root_item)
goto err;
@@ -1632,6 +1638,11 @@ static int cr_dump_finish(int ret)
close_service_fd(CR_PROC_FD_OFF);
+ if (opts.remote && (finish_remote_dump() < 0)) {
+ pr_err("Finish remote dump failed.\n");
+ return post_dump_ret ? : 1;
+ }
+
if (ret) {
pr_err("Dumping FAILED.\n");
} else {
@@ -1652,6 +1663,11 @@ int cr_dump_tasks(pid_t pid)
pr_info("Dumping processes (pid: %d)\n", pid);
pr_info("========================================\n");
+ if (opts.remote && push_snapshot_id() < 0) {
+ pr_err("Failed to push image namespace.\n");
+ goto err;
+ }
+
root_item = alloc_pstree_item();
if (!root_item)
goto err;
diff --git a/criu/cr-restore.c b/criu/cr-restore.c
index dc7bef0..4c1b419 100644
--- a/criu/cr-restore.c
+++ b/criu/cr-restore.c
@@ -30,6 +30,7 @@
#include "cr_options.h"
#include "servicefd.h"
#include "image.h"
+#include "img-remote.h"
#include "util.h"
#include "util-pie.h"
#include "criu-log.h"
@@ -1954,6 +1955,11 @@ int cr_restore_tasks(void)
goto err;
ret = restore_root_task(root_item);
+
+ if (opts.remote && (finish_remote_restore() < 0)) {
+ pr_err("Finish remote restore failed.\n");
+ goto err;
+ }
err:
cr_plugin_fini(CR_PLUGIN_STAGE__RESTORE, ret);
return ret;
diff --git a/criu/crtools.c b/criu/crtools.c
index 1b5cbd1..622fc6c 100644
--- a/criu/crtools.c
+++ b/criu/crtools.c
@@ -52,6 +52,7 @@
#include "setproctitle.h"
#include "sysctl.h"
+#include "img-remote.h"
struct cr_options opts;
@@ -74,6 +75,8 @@ void init_opts(void)
opts.ghost_limit = DEFAULT_GHOST_LIMIT;
opts.timeout = DEFAULT_TIMEOUT;
opts.empty_ns = 0;
+ opts.addr = DEFAULT_CACHE_HOST;
+ opts.port = DEFAULT_CACHE_PORT;
}
static int parse_join_ns(const char *ptr)
@@ -280,6 +283,7 @@ int main(int argc, char *argv[], char *envp[])
{ "cgroup-dump-controller", required_argument, 0, 1082 },
{ SK_INFLIGHT_PARAM, no_argument, 0, 1083 },
{ "deprecated", no_argument, 0, 1084 },
+ { "remote", no_argument, 0, 1085 },
{ "display-stats", no_argument, 0, 1086 },
{ "weak-sysctls", no_argument, 0, 1087 },
{ },
@@ -594,6 +598,9 @@ int main(int argc, char *argv[], char *envp[])
pr_msg("Turn deprecated stuff ON\n");
opts.deprecated_ok = true;
break;
+ case 1085:
+ opts.remote = true;
+ break;
case 1086:
opts.display_stats = true;
break;
@@ -755,6 +762,12 @@ int main(int argc, char *argv[], char *envp[])
if (!strcmp(argv[optind], "page-server"))
return cr_page_server(opts.daemon_mode, -1) > 0 ? 0 : 1;
+ if (!strcmp(argv[optind], "image-cache"))
+ return image_cache(opts.daemon_mode, DEFAULT_CACHE_SOCKET, opts.port);
+
+ if (!strcmp(argv[optind], "image-proxy"))
+ return image_proxy(opts.daemon_mode, DEFAULT_PROXY_SOCKET, opts.addr,
opts.port);
+
if (!strcmp(argv[optind], "service"))
return cr_service(opts.daemon_mode);
@@ -781,6 +794,8 @@ usage:
" criu page-server\n"
" criu service [<options>]\n"
" criu dedup\n"
+" criu image-cache [<options>]\n"
+" criu image-proxy [<options>]\n"
"\n"
"Commands:\n"
" dump checkpoint a process/tree identified by pid\n"
@@ -793,6 +808,8 @@ usage:
" dedup remove duplicates in memory dump\n"
" cpuinfo dump writes cpu information into image file\n"
" cpuinfo check validates cpu information read from image file\n"
+" image-cache launch destination-side cache for images sent from the
source-side\n"
+" image-proxy launch source-side proxy to sent images to the
destination-side\n"
);
if (usage_error) {
@@ -836,6 +853,7 @@ usage:
" macvlan[IFNAME]:OUTNAME\n"
" mnt[COOKIE]:ROOT\n"
"\n"
+" --remote dump/restore images directly to/from remote node
using image-proxy/image-cache\n"
"* Special resources support:\n"
" --" SK_EST_PARAM " checkpoint/restore established TCP connections\n"
" --" SK_INFLIGHT_PARAM " skip (ignore) in-flight TCP connections\n"
@@ -922,7 +940,7 @@ usage:
"\n"
"Page/Service server options:\n"
" --address ADDR address of server or service\n"
-" --port PORT port of page server\n"
+" --port PORT port of page serve or service\n"
" -d|--daemon run in the background after creating socket\n"
"\n"
"Other options:\n"
diff --git a/criu/image-desc.c b/criu/image-desc.c
index bac7ca2..fffaf5a 100644
--- a/criu/image-desc.c
+++ b/criu/image-desc.c
@@ -103,13 +103,13 @@ struct cr_fd_desc_tmpl imgset_template[CR_FD_MAX] = {
[CR_FD_STATS] = {
.fmt = "stats-%s",
.magic = STATS_MAGIC,
- .oflags = O_SERVICE,
+ .oflags = O_SERVICE | O_FORCE_LOCAL,
},
[CR_FD_IRMAP_CACHE] = {
.fmt = "irmap-cache",
.magic = IRMAP_CACHE_MAGIC,
- .oflags = O_SERVICE,
+ .oflags = O_SERVICE | O_FORCE_LOCAL,
},
[CR_FD_FILE_LOCKS_PID] = {
diff --git a/criu/image.c b/criu/image.c
index 11f1e7b..05c2652 100644
--- a/criu/image.c
+++ b/criu/image.c
@@ -16,6 +16,7 @@
#include "xmalloc.h"
#include "images/inventory.pb-c.h"
#include "images/pagemap.pb-c.h"
+#include "img-remote.h"
bool ns_per_id = false;
bool img_common_magic = true;
@@ -312,15 +313,55 @@ static int img_write_magic(struct cr_img *img, int
oflags, int type)
return write_img(img, &imgset_template[type].magic);
}
+int do_open_remote_image(int dfd, char *path, int flags)
+{
+ char *snapshot_id = NULL;
+ int ret;
+
+ /* When using namespaces, the current dir is changed so we need to
+ * change to previous working dir and back to correctly open the image
+ * proxy and cache sockets. */
+ int save = dirfd(opendir("."));
+ if (fchdir(dfd) < 0) {
+ pr_debug("fchdir to dfd failed!\n");
+ return -1;
+ }
+
+ snapshot_id = get_snapshot_id_from_idx(dfd);
+
+ if (snapshot_id == NULL)
+ ret = -1;
+ else if (flags == O_RDONLY) {
+ pr_debug("do_open_remote_image RDONLY path=%s snapshot_id=%s\n",
+ path, snapshot_id);
+ ret = read_remote_image_connection(snapshot_id, path);
+ } else {
+ pr_debug("do_open_remote_image WDONLY path=%s snapshot_id=%s\n",
+ path, snapshot_id);
+ ret = write_remote_image_connection(snapshot_id, path, O_WRONLY);
+ }
+
+ if (fchdir(save) < 0) {
+ pr_debug("fchdir to save failed!\n");
+ return -1;
+ }
+ close(save);
+
+ return ret;
+}
+
static int do_open_image(struct cr_img *img, int dfd, int type, unsigned
long oflags, char *path)
{
int ret, flags;
- flags = oflags & ~(O_NOBUF | O_SERVICE);
+ flags = oflags & ~(O_NOBUF | O_SERVICE | O_FORCE_LOCAL);
- ret = openat(dfd, path, flags, CR_FD_PERM);
+ if (opts.remote && !(oflags & O_FORCE_LOCAL))
+ ret = do_open_remote_image(dfd, path, flags);
+ else
+ ret = openat(dfd, path, flags, CR_FD_PERM);
if (ret < 0) {
- if (!(flags & O_CREAT) && (errno == ENOENT)) {
+ if (!(flags & O_CREAT) && (errno == ENOENT || ret == -ENOENT)) {
pr_info("No %s image\n", path);
img->_x.fd = EMPTY_IMG_FD;
goto skip_magic;
@@ -420,7 +461,9 @@ int open_image_dir(char *dir)
close(fd);
fd = ret;
- if (opts.img_parent) {
+ if (opts.remote) {
+ init_snapshot_id(dir);
+ } else if (opts.img_parent) {
ret = symlinkat(opts.img_parent, fd, CR_PARENT_LINK);
if (ret < 0 && errno != EEXIST) {
pr_perror("Can't link parent snapshot");
diff --git a/criu/img-remote.c b/criu/img-remote.c
new file mode 100644
index 0000000..337cb4a
--- /dev/null
+++ b/criu/img-remote.c
@@ -0,0 +1,275 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include "xmalloc.h"
+#include "criu-log.h"
+#include "img-remote.h"
+#include "img-remote-proto.h"
+#include "images/remote-image.pb-c.h"
+#include "protobuf-desc.h"
+#include <fcntl.h>
+#include "servicefd.h"
+#include "common/compiler.h"
+#include "cr_options.h"
+
+#define PB_LOCAL_IMAGE_SIZE PATHLEN
+
+static char *snapshot_id;
+bool restoring = true;
+
+LIST_HEAD(snapshot_head);
+
+/* A snapshot is a dump or pre-dump operation. Each snapshot is identified
by an
+ * ID which corresponds to the working directory specefied by the user.
+ */
+struct snapshot {
+ char snapshot_id[PATHLEN];
+ struct list_head l;
+};
+
+struct snapshot *new_snapshot(char *snapshot_id)
+{
+ struct snapshot *s = malloc(sizeof(struct snapshot));
+
+ if (!s) {
+ pr_perror("Failed to allocate snapshot structure");
+ return NULL;
+ }
+ strncpy(s->snapshot_id, snapshot_id, PATHLEN);
+ return s;
+}
+
+void add_snapshot(struct snapshot *snapshot)
+{
+ list_add_tail(&(snapshot->l), &snapshot_head);
+}
+
+int read_remote_image_connection(char *snapshot_id, char *path)
+{
+ int error;
+ int sockfd = setup_UNIX_client_socket(restoring ? DEFAULT_CACHE_SOCKET:
DEFAULT_PROXY_SOCKET);
+
+ if (sockfd < 0) {
+ pr_perror("Error opening local connection for %s:%s", path, snapshot_id);
+ return -1;
+ }
+
+ if (write_header(sockfd, snapshot_id, path, O_RDONLY) < 0) {
+ pr_perror("Error writing header for %s:%s", path, snapshot_id);
+ return -1;
+ }
+
+ if (read_reply_header(sockfd, &error) < 0) {
+ pr_perror("Error reading reply header for %s:%s", path, snapshot_id);
+ return -1;
+ }
+ if (!error || !strncmp(path, RESTORE_FINISH, sizeof(RESTORE_FINISH)))
+ return sockfd;
+ else if (error == ENOENT) {
+ pr_info("Image does not exist (%s:%s)\n", path, snapshot_id);
+ close(sockfd);
+ return -ENOENT;
+ }
+ pr_perror("Unexpected error returned: %d (%s:%s)\n", error, path,
snapshot_id);
+ close(sockfd);
+ return -1;
+}
+
+int write_remote_image_connection(char *snapshot_id, char *path, int flags)
+{
+ int sockfd = setup_UNIX_client_socket(DEFAULT_PROXY_SOCKET);
+
+ if (sockfd < 0)
+ return -1;
+
+ if (write_header(sockfd, snapshot_id, path, flags) < 0) {
+ pr_perror("Error writing header for %s:%s", path, snapshot_id);
+ return -1;
+ }
+ return sockfd;
+}
+
+int finish_remote_dump(void)
+{
+ pr_info("Dump side is calling finish\n");
+ int fd = write_remote_image_connection(NULL_SNAPSHOT_ID, DUMP_FINISH,
O_WRONLY);
+
+ if (fd == -1) {
+ pr_perror("Unable to open finish dump connection");
+ return -1;
+ }
+
+ close(fd);
+ return 0;
+}
+
+int finish_remote_restore(void)
+{
+ pr_info("Restore side is calling finish\n");
+ int fd = read_remote_image_connection(NULL_SNAPSHOT_ID, RESTORE_FINISH);
+
+ if (fd == -1) {
+ pr_perror("Unable to open finish restore connection");
+ return -1;
+ }
+
+ close(fd);
+ return 0;
+}
+
+int skip_remote_bytes(int fd, unsigned long len)
+{
+ static char buf[4096];
+ int n = 0;
+ unsigned long curr = 0;
+
+ for (; curr < len; ) {
+ n = read(fd, buf, min(len - curr, (unsigned long)4096));
+ if (n == 0) {
+ pr_perror("Unexpected end of stream (skipping %lx/%lx bytes)",
+ curr, len);
+ return -1;
+ } else if (n > 0) {
+ curr += n;
+ } else {
+ pr_perror("Error while skipping bytes from stream (%lx/%lx)",
+ curr, len);
+ return -1;
+ }
+ }
+
+ if (curr != len) {
+ pr_perror("Unable to skip the current number of bytes: %lx instead of
%lx",
+ curr, len);
+ return -1;
+ }
+ return 0;
+}
+
+static int pull_snapshot_ids(void)
+{
+ int n, sockfd;
+ SnapshotIdEntry *ls;
+ struct snapshot *s = NULL;
+
+ sockfd = read_remote_image_connection(NULL_SNAPSHOT_ID, PARENT_IMG);
+
+ /* The connection was successful but there is not file. */
+ if (sockfd < 0 && errno == ENOENT)
+ return 0;
+ else if (sockfd < 0) {
+ pr_perror("Unable to open snapshot id read connection");
+ return -1;
+ }
+
+ while (1) {
+ n = pb_read_obj(sockfd, (void **)&ls, PB_SNAPSHOT_ID);
+ if (!n) {
+ close(sockfd);
+ return n;
+ } else if (n < 0) {
+ pr_perror("Unable to read remote snapshot ids");
+ close(sockfd);
+ return n;
+ }
+
+ s = new_snapshot(ls->snapshot_id);
+ if (!s) {
+ pr_perror("Unable create new snapshot structure");
+ close(sockfd);
+ return -1;
+ }
+ add_snapshot(s);
+ pr_info("[read_snapshot ids] parent = %s\n", ls->snapshot_id);
+ }
+ free(ls);
+ close(sockfd);
+ return n;
+}
+
+int push_snapshot_id(void)
+{
+ int n;
+ restoring = false;
+ SnapshotIdEntry rn = SNAPSHOT_ID_ENTRY__INIT;
+ int sockfd = write_remote_image_connection(NULL_SNAPSHOT_ID, PARENT_IMG,
O_APPEND);
+
+ if (sockfd < 0) {
+ pr_perror("Unable to open snapshot id push connection");
+ return -1;
+ }
+
+ rn.snapshot_id = xmalloc(sizeof(char) * PATHLEN);
+ if (!rn.snapshot_id) {
+ pr_perror("Unable to allocate snapshot id buffer");
+ close(sockfd);
+ return -1;
+ }
+ strncpy(rn.snapshot_id, snapshot_id, PATHLEN);
+
+ n = pb_write_obj(sockfd, &rn, PB_SNAPSHOT_ID);
+
+ xfree(rn.snapshot_id);
+ close(sockfd);
+ return n;
+}
+
+void init_snapshot_id(char *si)
+{
+ snapshot_id = si;
+}
+
+char *get_curr_snapshot_id(void)
+{
+ return snapshot_id;
+}
+
+int get_curr_snapshot_id_idx(void)
+{
+ struct snapshot *si;
+ int idx = 0;
+
+ if (list_empty(&snapshot_head))
+ pull_snapshot_ids();
+
+ list_for_each_entry(si, &snapshot_head, l) {
+ if (!strncmp(si->snapshot_id, snapshot_id, PATHLEN))
+ return idx;
+ idx++;
+ }
+
+ pr_perror("Error, could not find current snapshot id (%s) fd",
snapshot_id);
+ return -1;
+}
+
+char *get_snapshot_id_from_idx(int idx)
+{
+ struct snapshot *si;
+
+ if (list_empty(&snapshot_head))
+ pull_snapshot_ids();
+
+ /* Note: if idx is the service fd then we need the current
+ * snapshot_id idx. Else we need a parent snapshot_id idx.
+ */
+ if (idx == get_service_fd(IMG_FD_OFF))
+ idx = get_curr_snapshot_id_idx();
+
+ list_for_each_entry(si, &snapshot_head, l) {
+ if (!idx)
+ return si->snapshot_id;
+ idx--;
+ }
+
+ pr_perror("Error, could not find snapshot id for idx %d", idx);
+ return NULL;
+}
+
+int get_curr_parent_snapshot_id_idx(void)
+{
+ return get_curr_snapshot_id_idx() - 1;
+}
diff --git a/criu/include/cr_options.h b/criu/include/cr_options.h
index c2f4b10..16e9243 100644
--- a/criu/include/cr_options.h
+++ b/criu/include/cr_options.h
@@ -115,6 +115,7 @@ struct cr_options {
* to turn one ON while the code is in.
*/
bool deprecated_ok;
+ bool remote;
bool display_stats;
bool weak_sysctls;
};
diff --git a/criu/include/image.h b/criu/include/image.h
index 1c22a4f..c2b612e 100644
--- a/criu/include/image.h
+++ b/criu/include/image.h
@@ -105,6 +105,7 @@ extern bool img_common_magic;
#define O_DUMP (O_WRONLY | O_CREAT | O_TRUNC)
#define O_SHOW (O_RDONLY | O_NOBUF)
#define O_RSTR (O_RDONLY)
+#define O_FORCE_LOCAL (O_SYNC)
struct cr_img {
union {
diff --git a/criu/include/img-remote.h b/criu/include/img-remote.h
new file mode 100644
index 0000000..6ffc429
--- /dev/null
+++ b/criu/include/img-remote.h
@@ -0,0 +1,83 @@
+#include <limits.h>
+#include <stdbool.h>
+
+#ifndef IMAGE_REMOTE_H
+#define IMAGE_REMOTE_H
+
+#define PATHLEN PATH_MAX
+#define DUMP_FINISH "DUMP_FINISH"
+#define RESTORE_FINISH "RESTORE_FINISH"
+#define PARENT_IMG "parent"
+#define NULL_SNAPSHOT_ID "null"
+#define DEFAULT_CACHE_SOCKET "img-cache.sock"
+#define DEFAULT_PROXY_SOCKET "img-proxy.sock"
+#define DEFAULT_CACHE_PORT 9996
+#define DEFAULT_CACHE_HOST "localhost"
+
+/* Called by restore to get the fd correspondent to a particular path.
This call
+ * will block until the connection is received.
+ */
+int read_remote_image_connection(char *snapshot_id, char *path);
+
+/* Called by dump to create a socket connection to the restore side. The
socket
+ * fd is returned for further writing operations.
+ */
+int write_remote_image_connection(char *snapshot_id, char *path, int
flags);
+
+/* Called by dump/restore when everything is dumped/restored. This
function
+ * creates a new connection with a special control name. The receiver side
uses
+ * it to ack that no more files are coming.
+ */
+int finish_remote_dump();
+int finish_remote_restore();
+
+/* Starts an image proxy daemon (dump side). It receives image files
through
+ * socket connections and forwards them to the image cache (restore side).
+ */
+int image_proxy(bool background, char *local_proxy_path, char *cache_host,
unsigned short cache_port);
+
+/* Starts an image cache daemon (restore side). It receives image files
through
+ * socket connections and caches them until they are requested by the
restore
+ * process.
+ */
+int image_cache(bool background, char *local_cache_path, unsigned short
cache_port);
+
+/* Reads (discards) 'len' bytes from fd. This is used to emulate the
function
+ * lseek, which is used to advance the file needle.
+ */
+int skip_remote_bytes(int fd, unsigned long len);
+
+/* To support iterative migration, the concept of snapshot_id is introduced
+ * (only when remote migration is enabled). Each image is tagged with one
+ * snapshot_id. The snapshot_id is the image directory used for the
operation
+ * that creates the image (either predump or dump). Images stored in memory
+ * (both in Image Proxy and Image Cache) are identified by their name and
+ * snapshot_id. Snapshot_ids are ordered so that we can find parent
pagemaps
+ * (that will be used when restoring the process).
+ */
+
+/* Sets the current snapshot_id */
+void init_snapshot_id(char *ns);
+
+/* Returns the current snapshot_id. */
+char *get_curr_snapshot_id();
+
+/* Returns the snapshot_id index representing the current snapshot_id. This
+ * index represents the hierarchy position. For example: images tagged with
+ * the snapshot_id with index 1 are more recent than the images tagged with
+ * the snapshot_id with index 0.
+ */
+int get_curr_snapshot_id_idx();
+
+/* Returns the snapshot_id associated with the snapshot_id index. */
+char *get_snapshot_id_from_idx(int idx);
+
+/* Pushes the current snapshot_id into the snapshot_id hierarchy (into the
Image
+ * Proxy and Image Cache).
+ */
+int push_snapshot_id();
+
+/* Returns the snapshot id index that preceeds the current snapshot_id. */
+int get_curr_parent_snapshot_id_idx();
+
+#endif
diff --git a/criu/include/protobuf-desc.h b/criu/include/protobuf-desc.h
index 6c76b49..43ac534 100644
--- a/criu/include/protobuf-desc.h
+++ b/criu/include/protobuf-desc.h
@@ -59,6 +59,10 @@ enum {
PB_BINFMT_MISC, /* 50 */
PB_TTY_DATA,
PB_AUTOFS,
+ PB_REMOTE_IMAGE, /* Header for images sent from proxy to cache.*/
+ PB_LOCAL_IMAGE, /* Header for reading/writing images from/to
proxy or cache. */
+ PB_LOCAL_IMAGE_REPLY, /* Header for reading/writing images reply. */
+ PB_SNAPSHOT_ID, /* Contains a single id. Used for reading/writing
ids from proxy or cache. */
/* PB_AUTOGEN_STOP */
diff --git a/criu/page-xfer.c b/criu/page-xfer.c
index 4def13a..d933bb7 100644
--- a/criu/page-xfer.c
+++ b/criu/page-xfer.c
@@ -17,6 +17,7 @@
#include "protobuf.h"
#include "images/pagemap.pb-c.h"
#include "fcntl.h"
+#include "img-remote.h"
static int page_server_sk = -1;
@@ -294,7 +295,8 @@ static int open_page_local_xfer(struct page_xfer *xfer,
int fd_type, long id)
xfer->parent = xmalloc(sizeof(*xfer->parent));
if (!xfer->parent) {
- close(pfd);
+ if (!opts.remote)
+ close(pfd);
return -1;
}
@@ -303,10 +305,12 @@ static int open_page_local_xfer(struct page_xfer
*xfer, int fd_type, long id)
pr_perror("No parent image found, though parent directory is set");
xfree(xfer->parent);
xfer->parent = NULL;
- close(pfd);
+ if (!opts.remote)
+ close(pfd);
goto out;
}
- close(pfd);
+ if (!opts.remote)
+ close(pfd);
}
out:
@@ -411,9 +415,16 @@ int check_parent_local_xfer(int fd_type, int id)
struct stat st;
int ret, pfd;
- pfd = openat(get_service_fd(IMG_FD_OFF), CR_PARENT_LINK, O_RDONLY);
- if (pfd < 0 && errno == ENOENT)
- return 0;
+ if (opts.remote) {
+ pfd = get_curr_parent_snapshot_id_idx();
+ pr_err("Unable to get parent snapsgot id");
+ if (pfd == -1)
+ return -1;
+ } else {
+ pfd = openat(get_service_fd(IMG_FD_OFF), CR_PARENT_LINK, O_RDONLY);
+ if (pfd < 0 && errno == ENOENT)
+ return 0;
+ }
snprintf(path, sizeof(path), imgset_template[fd_type].fmt, id);
ret = fstatat(pfd, path, &st, 0);
@@ -475,6 +486,8 @@ int check_parent_page_xfer(int fd_type, long id)
{
if (opts.use_page_server)
return check_parent_server_xfer(fd_type, id);
+ else if (opts.remote)
+ return get_curr_parent_snapshot_id_idx() == -1 ? 0 : 1;
else
return check_parent_local_xfer(fd_type, id);
}
diff --git a/criu/pagemap.c b/criu/pagemap.c
index 8e854c9..be5b144 100644
--- a/criu/pagemap.c
+++ b/criu/pagemap.c
@@ -14,6 +14,7 @@
#include "xmalloc.h"
#include "protobuf.h"
#include "images/pagemap.pb-c.h"
+#include "img-remote.h"
#ifndef SEEK_DATA
#define SEEK_DATA 3
@@ -137,6 +138,9 @@ static void skip_pagemap_pages(struct page_read *pr,
unsigned long len)
return;
if (!pr->pe->in_parent)
+ if (opts.remote)
+ if (! skip_remote_bytes(img_raw_fd(pr->pi), len))
+ pr_perror("Error skipping remote bytes");
pr->pi_off += len;
pr->cvaddr += len;
}
@@ -248,6 +252,7 @@ static int read_local_page(struct page_read *pr,
unsigned long vaddr,
{
int fd = img_raw_fd(pr->pi);
int ret;
+ size_t curr = 0;
/*
* Flush any pending async requests if any not to break the
@@ -257,10 +262,15 @@ static int read_local_page(struct page_read *pr,
unsigned long vaddr,
return -1;
pr_debug("\tpr%u Read page from self %lx/%"PRIx64"\n", pr->id,
pr->cvaddr, pr->pi_off);
- ret = pread(fd, buf, len, pr->pi_off);
- if (ret != len) {
- pr_perror("Can't read mapping page %d", ret);
- return -1;
+ while (1) {
+ ret = read(fd, buf + curr, len - curr);
+ if (ret < 1) {
+ pr_perror("Can't read mapping page %d", ret);
+ return -1;
+ }
+ curr += ret;
+ if (curr == len)
+ break;
}
if (opts.auto_dedup) {
@@ -358,7 +368,7 @@ static int maybe_read_page(struct page_read *pr,
unsigned long vaddr,
int ret;
unsigned long len = nr * PAGE_SIZE;
- if (flags & PR_ASYNC)
+ if (flags & PR_ASYNC && !opts.remote)
ret = enqueue_async_page(pr, vaddr, len, buf);
else
ret = read_local_page(pr, vaddr, len, buf);
@@ -459,9 +469,24 @@ static int try_open_parent(int dfd, int pid, struct
page_read *pr, int pr_flags)
int pfd, ret;
struct page_read *parent = NULL;
- pfd = openat(dfd, CR_PARENT_LINK, O_RDONLY);
- if (pfd < 0 && errno == ENOENT)
- goto out;
+ if (opts.remote) {
+ /* Note: we are replacing a real directory FD for a snapshot_id
+ * index. Since we need the parent of the current snapshot_id,
+ * we want the current snapshot_id index minus one. It is
+ * possible that dfd is already a snapshot_id index. We test it
+ * by comparing it to the service FD. When opening an image (see
+ * do_open_image) we convert the snapshot_id index into a real
+ * snapshot_id.
+ */
+ pfd = dfd == get_service_fd(IMG_FD_OFF) ?
+ get_curr_snapshot_id_idx() - 1 : dfd - 1;
+ if (pfd < 0)
+ goto out;
+ } else {
+ pfd = openat(dfd, CR_PARENT_LINK, O_RDONLY);
+ if (pfd < 0 && errno == ENOENT)
+ goto out;
+ }
parent = xmalloc(sizeof(*parent));
if (!parent)
@@ -476,7 +501,8 @@ static int try_open_parent(int dfd, int pid, struct
page_read *pr, int pr_flags)
parent = NULL;
}
- close(pfd);
+ if (!opts.remote)
+ close(pfd);
out:
pr->parent = parent;
return 0;
@@ -484,7 +510,8 @@ out:
err_free:
xfree(parent);
err_cl:
- close(pfd);
+ if (!opts.remote)
+ close(pfd);
return -1;
}
@@ -501,7 +528,11 @@ static int init_pagemaps(struct page_read *pr)
off_t fsize;
int nr_pmes, nr_realloc;
- fsize = img_raw_size(pr->pmi);
+ if (!opts.remote)
+ fsize = img_raw_size(pr->pmi);
+ else
+ fsize = 1024; /*FIXME*/
+
if (fsize < 0)
return -1;
diff --git a/criu/protobuf-desc.c b/criu/protobuf-desc.c
index 41c2080..bfe00c5 100644
--- a/criu/protobuf-desc.c
+++ b/criu/protobuf-desc.c
@@ -62,6 +62,7 @@
#include "images/seccomp.pb-c.h"
#include "images/binfmt-misc.pb-c.h"
#include "images/autofs.pb-c.h"
+#include "images/remote-image.pb-c.h"
struct cr_pb_message_desc cr_pb_descs[PB_MAX];
diff --git a/criu/sk-queue.c b/criu/sk-queue.c
index 7b1da2d..f92d020 100644
--- a/criu/sk-queue.c
+++ b/criu/sk-queue.c
@@ -27,7 +27,7 @@
struct sk_packet {
struct list_head list;
SkPacketEntry *entry;
- off_t img_off;
+ char *data;
};
static LIST_HEAD(packets_list);
@@ -37,14 +37,20 @@ static int collect_one_packet(void *obj,
ProtobufCMessage *msg, struct cr_img *i
struct sk_packet *pkt = obj;
pkt->entry = pb_msg(msg, SkPacketEntry);
- pkt->img_off = lseek(img_raw_fd(img), 0, SEEK_CUR);
+
+ pkt->data = xmalloc(pkt->entry->length);
+ if (pkt->data ==NULL)
+ return -1;
+
/*
* NOTE: packet must be added to the tail. Otherwise sequence
* will be broken.
*/
list_add_tail(&pkt->list, &packets_list);
- if (lseek(img_raw_fd(img), pkt->entry->length, SEEK_CUR) < 0) {
- pr_perror("Unable to change an image offset");
+
+ if (read_img_buf(img, pkt->data, pkt->entry->length) != 1) {
+ xfree(pkt->data);
+ pr_perror("Unable to read packet data");
return -1;
}
@@ -208,7 +214,6 @@ int restore_sk_queue(int fd, unsigned int peer_id)
list_for_each_entry_safe(pkt, tmp, &packets_list, list) {
SkPacketEntry *entry = pkt->entry;
- char *buf;
if (entry->id_for != peer_id)
continue;
@@ -224,22 +229,8 @@ int restore_sk_queue(int fd, unsigned int peer_id)
* boundaries messages should be saved.
*/
- buf = xmalloc(entry->length);
- if (buf ==NULL)
- goto err;
-
- if (lseek(img_raw_fd(img), pkt->img_off, SEEK_SET) == -1) {
- pr_perror("lseek() failed");
- xfree(buf);
- goto err;
- }
- if (read_img_buf(img, buf, entry->length) != 1) {
- xfree(buf);
- goto err;
- }
-
- ret = write(fd, buf, entry->length);
- xfree(buf);
+ ret = write(fd, pkt->data, entry->length);
+ xfree(pkt->data);
if (ret < 0) {
pr_perror("Failed to send packet");
goto err;
diff --git a/criu/util.c b/criu/util.c
index 4b0bcfd..d826732 100644
--- a/criu/util.c
+++ b/criu/util.c
@@ -516,29 +516,46 @@ int copy_file(int fd_in, int fd_out, size_t bytes)
{
ssize_t written = 0;
size_t chunk = bytes ? bytes : 4096;
+ char *buffer = (char*) malloc(chunk);
+ ssize_t ret;
while (1) {
- ssize_t ret;
-
- ret = sendfile(fd_out, fd_in, NULL, chunk);
+ if (opts.remote) {
+ ret = read(fd_in, buffer, chunk);
+ if (ret < 0) {
+ pr_perror("Can't read from fd_in\n");
+ ret = -1;
+ goto err;
+ }
+ if (write(fd_out, buffer, ret) != ret) {
+ pr_perror("Couldn't write all read bytes\n");
+ ret = -1;
+ goto err;
+ }
+ }
+ else
+ ret = sendfile(fd_out, fd_in, NULL, chunk);
if (ret < 0) {
pr_perror("Can't send data to ghost file");
- return -1;
+ ret = -1;
+ goto err;
}
if (ret == 0) {
if (bytes && (written != bytes)) {
pr_err("Ghost file size mismatch %zu/%zu\n",
written, bytes);
- return -1;
+ ret = -1;
+ goto err;
}
break;
}
written += ret;
}
-
- return 0;
+err:
+ free(buffer);
+ return ret;
}
int read_fd_link(int lfd, char *buf, size_t size)
diff --git a/images/Makefile b/images/Makefile
index eb18526..5b60948 100644
--- a/images/Makefile
+++ b/images/Makefile
@@ -61,6 +61,7 @@ proto-obj-y += time.o
proto-obj-y += sysctl.o
proto-obj-y += autofs.o
proto-obj-y += macvlan.o
+proto-obj-y += remote-image.o
CFLAGS += -iquote $(obj)/
diff --git a/images/remote-image.proto b/images/remote-image.proto
new file mode 100644
index 0000000..1212627
--- /dev/null
+++ b/images/remote-image.proto
@@ -0,0 +1,20 @@
+message local_image_entry {
+ required string name = 1;
+ required string snapshot_id = 2;
+ required uint32 open_mode = 3;
+}
+
+message remote_image_entry {
+ required string name = 1;
+ required string snapshot_id = 2;
+ required uint32 open_mode = 3;
+ required uint64 size = 4;
+}
+
+message local_image_reply_entry {
+ required uint32 error = 1;
+}
+
+message snapshot_id_entry {
+ required string snapshot_id = 1;
+}
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