[CRIU] [PATCH RFC 7/8] criu: uffd: add --lazy-addr option

Pavel Emelyanov xemul at virtuozzo.com
Thu Jun 16 08:45:20 PDT 2016


On 06/15/2016 08:36 AM, Mike Rapoport wrote:
> On Fri, May 27, 2016 at 10:33 PM, Pavel Emelyanov <xemul at virtuozzo.com> wrote:
>> On 05/21/2016 01:49 PM, Mike Rapoport wrote:
>>> to distinguish between UNIX socket address for passing uffd and the address
>>> of the remote dump
>>
>> Would you show when the --addredd and --lazy-addr confusion may occur?
> 
> Well, we can skip --lazy-addr if we will fork() lazy-pages from
> cr-restore. Then the unix socket will be created in cr-restore and
> inherited by lazy-pages daemon.

Yup, that should be the default behavior for migration.

> Another possibility is to make lazy-pages daemon a variation of the
> page-server that does not depend on existing checkpoint directory,
> like Adrian suggested a while ago.

For lazy restore from previously collected images. Yes.

> Then it will get the required information via the unix socket. For
> instance, in addition to pid and uffd, lazy-pages daemon will receive
> the path to relevant checkpoint directory.

Hm, what if we put the lazy socket into the images directory?
Or, more exactly, into __working__ directory (which coincides with
the images one if not specified separately).

>>> Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
>>> ---
>>>  criu/crtools.c            |  4 ++++
>>>  criu/include/cr_options.h |  1 +
>>>  criu/uffd.c               | 26 +++++++++++++-------------
>>>  3 files changed, 18 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/criu/crtools.c b/criu/crtools.c
>>> index b35a4b0..b3962e5 100644
>>> --- a/criu/crtools.c
>>> +++ b/criu/crtools.c
>>> @@ -322,6 +322,7 @@ int main(int argc, char *argv[], char *envp[])
>>>               { "all",                        no_argument,            0, 1079 },
>>>               { "cgroup-props",               required_argument,      0, 1080 },
>>>               { "cgroup-props-file",          required_argument,      0, 1081 },
>>> +             { "lazy-addr",                  required_argument,      0, 1082 },
>>>               { },
>>>       };
>>>
>>> @@ -627,6 +628,9 @@ int main(int argc, char *argv[], char *envp[])
>>>               case 1081:
>>>                       opts.cgroup_props_file = optarg;
>>>                       break;
>>> +             case 1082:
>>> +                     opts.lazy_addr = optarg;
>>> +                     break;
>>>               case 'V':
>>>                       pr_msg("Version: %s\n", CRIU_VERSION);
>>>                       if (strcmp(CRIU_GITID, "0"))
>>> diff --git a/criu/include/cr_options.h b/criu/include/cr_options.h
>>> index e36c362..641f0e5 100644
>>> --- a/criu/include/cr_options.h
>>> +++ b/criu/include/cr_options.h
>>> @@ -111,6 +111,7 @@ struct cr_options {
>>>       unsigned int            timeout;
>>>       unsigned int            empty_ns;
>>>       bool                    lazy_pages;
>>> +     char                    *lazy_addr;
>>>  };
>>>
>>>  extern struct cr_options opts;
>>> diff --git a/criu/uffd.c b/criu/uffd.c
>>> index 1dadc23..ef1ff89 100644
>>> --- a/criu/uffd.c
>>> +++ b/criu/uffd.c
>>> @@ -115,18 +115,18 @@ static int send_uffd(int sendfd, int pid)
>>>       int ret = -1;
>>>       struct sockaddr_un sun;
>>>
>>> -     if (!opts.addr) {
>>> +     if (!opts.lazy_addr) {
>>>               pr_info("Please specify a file name for the unix domain socket\n");
>>>               pr_info("used to communicate between the lazy-pages server\n");
>>> -             pr_info("and the restore process. Use the --address option like\n");
>>> -             pr_info("criu restore --lazy-pages --address /tmp/userfault.socket\n");
>>> +             pr_info("and the restore process. Use the --lazy-addr option like\n");
>>> +             pr_info("criu restore --lazy-pages --lazy-addr /tmp/uffd.sock\n");
>>>               return -1;
>>>       }
>>>
>>>       if (sendfd < 0)
>>>               return -1;
>>>
>>> -     if (strlen(opts.addr) >= sizeof(sun.sun_path)) {
>>> +     if (strlen(opts.lazy_addr) >= sizeof(sun.sun_path)) {
>>>               return -1;
>>>       }
>>>
>>> @@ -135,10 +135,10 @@ static int send_uffd(int sendfd, int pid)
>>>
>>>       memset(&sun, 0, sizeof(sun));
>>>       sun.sun_family = AF_UNIX;
>>> -     strcpy(sun.sun_path, opts.addr);
>>> -     len = offsetof(struct sockaddr_un, sun_path) + strlen(opts.addr);
>>> +     strcpy(sun.sun_path, opts.lazy_addr);
>>> +     len = offsetof(struct sockaddr_un, sun_path) + strlen(opts.lazy_addr);
>>>       if (connect(fd, (struct sockaddr *) &sun, len) < 0) {
>>> -             pr_perror("connect to %s failed", opts.addr);
>>> +             pr_perror("connect to %s failed", opts.lazy_addr);
>>>               goto out;
>>>       }
>>>
>>> @@ -225,19 +225,19 @@ static int server_listen(struct sockaddr_un *saddr)
>>>       int fd;
>>>       int len;
>>>
>>> -     if (strlen(opts.addr) >= sizeof(saddr->sun_path)) {
>>> +     if (strlen(opts.lazy_addr) >= sizeof(saddr->sun_path)) {
>>>               return -1;
>>>       }
>>>
>>>       if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
>>>               return -1;
>>>
>>> -     unlink(opts.addr);
>>> +     unlink(opts.lazy_addr);
>>>
>>>       memset(saddr, 0, sizeof(struct sockaddr_un));
>>>       saddr->sun_family = AF_UNIX;
>>> -     strcpy(saddr->sun_path, opts.addr);
>>> -     len = offsetof(struct sockaddr_un, sun_path) + strlen(opts.addr);
>>> +     strcpy(saddr->sun_path, opts.lazy_addr);
>>> +     len = offsetof(struct sockaddr_un, sun_path) + strlen(opts.lazy_addr);
>>>
>>>       if (bind(fd, (struct sockaddr *) saddr, len) < 0) {
>>>               goto out;
>>> @@ -808,7 +808,7 @@ static int prepare_uffds(int epollfd)
>>>       int listen;
>>>       struct sockaddr_un saddr;
>>>
>>> -     pr_debug("Waiting for incoming connections on %s\n", opts.addr);
>>> +     pr_debug("Waiting for incoming connections on %s\n", opts.lazy_addr);
>>>       if ((listen = server_listen(&saddr)) < 0) {
>>>               pr_perror("server_listen error");
>>>               return -1;
>>> @@ -841,7 +841,7 @@ int cr_lazy_pages()
>>>       if (check_for_uffd())
>>>               return -1;
>>>
>>> -     if (!opts.addr) {
>>> +     if (!opts.lazy_addr) {
>>>               pr_info("Please specify a file name for the unix domain socket\n");
>>>               pr_info("used to communicate between the lazy-pages server\n");
>>>               pr_info("and the restore process. Use the --address option like\n");
>>>
>>
> 
> 
> 



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