[CRIU] [PATCH v2 0/9] epoll: Add support for duped targets

[Andrey Vagin]

This test doesn't pass my 5-minutes test

[root at fc24 criu]# python test/zdtm.py run -t zdtm/static/eventfs00
=== Run 1/1 ================ zdtm/static/eventfs00
======================== Run zdtm/static/eventfs00 in h ========================
Start test
./eventfs00 --pidfile=eventfs00.pid --outfile=eventfs00.out
Run criu dump
Run criu restore
=[log]=> dump/zdtm/static/eventfs00/36/1/restore.log
------------------------ grep Error ------------------------
(00.165038)     36: 		Create fd for 405
(00.165060)     36: epoll: Restore eventpoll-tfd: id 00000000 tfd 0x000052 events 0x00001d data 0xffffffffffffffff
(00.165106)     36: epoll: Restore eventpoll-tfd: id 00000000 tfd 0x000054 events 0x00001d data 0xffffffffffffffff
(00.165184)     36: epoll: Restore eventpoll-tfd: id 00000000 tfd 0x000054 events 0x00001d data 0xffffffffffffffff
(00.165232)     36: Error (criu/eventpoll.c:263): epoll: Can't add event on 0x000007: File exists
(00.165250)     36: Error (criu/files.c:1245): Unable to open fd=4 id=0x7
(00.165391) Error (criu/cr-restore.c:2395): Failed to wait inprogress tasks
(00.165493) Error (criu/cr-restore.c:2572): Restoring FAILED.
------------------------ ERROR OVER ------------------------
############### Test zdtm/static/eventfs00 FAIL at CRIU restore ################
##################################### FAIL #####################################



On Wed, Jun 20, 2018 at 08:01:38PM +0300, Cyrill Gorcunov wrote:
> We need to support a case where file has been added into
> epoll, then duped into some other number, and finally
> the former one is closed. So that epoll fdinfo will
> print no longer existing fd number (in this series
> we will find which new file is matching the target).
> 
> v2:
>  - fix scm unix on the fly (we dont support them yet)
> 
> Cyrill Gorcunov (9):
>   kcmp: Cleanup sources
>   kcmp: Beautify kcmp-ids.h
>   kcmp: Drop empty line at EOF
>   kcmp: Add epoll definitions
>   epoll: kdat -- Check if we have KCMP_EPOLL_TFD support
>   epoll: Pass drained fds to dump_one_file
>   epoll: Use real file transferred for target fds check
>   epoll: Use kcmp to find proper target file
>   test: eventfs00 -- Extend to test duped fd
> 
>  criu/eventpoll.c             | 119 +++++++++++++++++++++++++++++++++++++++++--
>  criu/files.c                 |   8 +--
>  criu/include/files.h         |   2 +
>  criu/include/kcmp-ids.h      |  29 ++++++-----
>  criu/include/kcmp.h          |  10 ++++
>  criu/include/kerndat.h       |   1 +
>  criu/kcmp-ids.c              |  14 +++--
>  criu/kerndat.c               |  48 +++++++++++++++++
>  test/zdtm/static/eventfs00.c |  23 +++++++--
>  9 files changed, 224 insertions(+), 30 deletions(-)
> 
> -- 
> 2.14.4
> 
-------------- next part --------------
diff --git a/test/zdtm/static/eventfs00.c b/test/zdtm/static/eventfs00.c
index 61d26e90b..7261050db 100644
--- a/test/zdtm/static/eventfs00.c
+++ b/test/zdtm/static/eventfs00.c
@@ -37,6 +37,7 @@ int main(int argc, char *argv[])
 	int efd, ret, epollfd, fd;
 	uint64_t v = EVENTFD_INITIAL;
 	struct epoll_event ev;
+	int i;
 
 	test_init(argc, argv);
 
@@ -55,33 +56,36 @@ int main(int argc, char *argv[])
 	memset(&ev, 0xff, sizeof(ev));
 	ev.events = EPOLLIN | EPOLLOUT;
 
-	if (pipe(pipefd1) || pipe(pipefd2)) {
-		fail("pipe");
-		exit(1);
-	}
-
-	test_msg("epoll %d add %d native\n", epollfd, pipefd1[0]);
-	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, pipefd1[0], &ev)) {
-		fail("epoll_ctl");
-		exit(1);
+	for (i = 0; i < 100; i++) {
+		if (pipe(pipefd1) || pipe(pipefd2)) {
+			fail("pipe");
+			exit(1);
+		}
+
+		test_msg("epoll %d add %d native\n", epollfd, pipefd1[0]);
+		if (epoll_ctl(epollfd, EPOLL_CTL_ADD, pipefd1[0], &ev)) {
+			fail("epoll_ctl");
+			exit(1);
+		}
+
+		fd = dup2(pipefd2[0], 999);
+		if (fd < 0) {
+			fail(" dup on pipe");
+			exit(1);
+		}
+
+		test_msg("epoll %d add %d dup'ed from %d\n", epollfd, fd, pipefd2[0]);
+		if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev)) {
+			fail("epoll_ctl on duped pipe");
+			exit(1);
+		}
+		close(fd);
+		test_msg("epoll source %d closed\n", fd);
+
+
+		test_msg("created eventfd with %"PRIu64"\n", v);
 	}
 
-	fd = dup2(pipefd2[0], 64);
-	if (fd < 0) {
-		fail(" dup on pipe");
-		exit(1);
-	}
-
-	test_msg("epoll %d add %d dup'ed from %d\n", epollfd, fd, pipefd2[0]);
-	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev)) {
-		fail("epoll_ctl on duped pipe");
-		exit(1);
-	}
-	close(fd);
-	test_msg("epoll source %d closed\n", fd);
-
-	test_msg("created eventfd with %"PRIu64"\n", v);
-
 	ret = write(efd, &v, sizeof(v));
 	if (ret != sizeof(v)) {
 		fail("write");