An inflight async io could keep the filesystem busy and cause umount
-EBUSY errors after process exit. When the async io process is killed
forcibly with SIGKILL, it doesn't get a chance to wait for ios to
complete.
With this patch, instead of killing the children processes, we let them
exit on their own after the timeout expires.
Signed-off-by: Tahsin Erdogan <tahsin@xxxxxxxxxx>
---
src/aio-dio-regress/aio-dio-invalidate-failure.c | 89 ++++++++++++++----------
1 file changed, 54 insertions(+), 35 deletions(-)
diff --git a/src/aio-dio-regress/aio-dio-invalidate-failure.c b/src/aio-dio-regress/aio-dio-invalidate-failure.c
index 24f3e3c..474a83c 100644
--- a/src/aio-dio-regress/aio-dio-invalidate-failure.c
+++ b/src/aio-dio-regress/aio-dio-invalidate-failure.c
@@ -62,6 +62,26 @@ static unsigned char buf[GINORMOUS] __attribute((aligned (4096)));
exit(1); \
} while (0)
+
+volatile int timeout_reached = 0;
+
+static void alarm_handler(int signum)
+{
+ timeout_reached = 1;
+}
+
+void set_timeout(unsigned int seconds)
+{
+ struct sigaction sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = alarm_handler;
+ sigemptyset(&sa.sa_mask);
+ if (sigaction(SIGALRM, &sa, NULL) == -1)
+ fail("sigaction: %d\n", errno);
+
+ alarm(seconds);
+}
+
void spin_dio(int fd)
{
io_context_t ctx;
@@ -70,18 +90,28 @@ void spin_dio(int fd)
struct io_event event;
int ret;
+ set_timeout(SECONDS);
+
io_prep_pwrite(&iocb, fd, buf, GINORMOUS, 0);
ret = io_queue_init(1, &ctx);
if (ret)
fail("io_queue_init returned %d", ret);
- while (1) {
+ while (!timeout_reached) {
ret = io_submit(ctx, 1, iocbs);
if (ret != 1)
fail("io_submit returned %d instead of 1", ret);
- ret = io_getevents(ctx, 1, 1, &event, NULL);
+ /*
+ * Retry io_getevents() if it gets interrupted by alarm signal.
+ * We don't want to leave behind uncompleted async io requests
+ * that could cause umount -EBUSY errors.
+ */
+ do {
+ ret = io_getevents(ctx, 1, 1, &event, NULL);
+ } while (ret == -EINTR && timeout_reached);
+
if (ret != 1)
fail("io_getevents returned %d instead of 1", ret);
@@ -99,17 +129,15 @@ void spin_buffered(int fd)
{
int ret;
- while (1) {
+ set_timeout(SECONDS);
+
+ while (!timeout_reached) {
ret = pwrite(fd, buf, GINORMOUS, 0);
if (ret != GINORMOUS)
fail("buffered write returned %d", ret);
}
}
-static void alarm_handler(int signum)
-{
-}
-
int main(int argc, char **argv)
{
pid_t buffered_pid;
@@ -118,7 +146,8 @@ int main(int argc, char **argv)
int fd;
int fd2;
int status;
- struct sigaction sa;
+ int dio_exit;
+ int buffered_exit;
if (argc != 2)
fail("only arg should be file name");
@@ -152,38 +181,28 @@ int main(int argc, char **argv)
exit(0);
}
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = alarm_handler;
- sigemptyset(&sa.sa_mask);
- if (sigaction(SIGALRM, &sa, NULL) == -1)
- fail("sigaction: %d\n", errno);
- alarm(SECONDS);
+ /* Child processes will exit on their own when timeout expires. */
+ pid = waitpid(dio_pid, &status, 0);
+ printf("dio_pid %d, pid %d, status %#x\n", dio_pid, pid, status);
- pid = wait(&status);
- if (pid < 0 && errno == EINTR) {
- /* if we timed out then we're done */
- kill(buffered_pid, SIGKILL);
- kill(dio_pid, SIGKILL);
+ dio_exit = (pid == dio_pid && WIFEXITED(status)) ?
+ WEXITSTATUS(status) : 1;
- waitpid(buffered_pid, NULL, 0);
- waitpid(dio_pid, NULL, 0);
+ pid = waitpid(buffered_pid, &status, 0);
+ printf("buffered_pid %d, pid %d, status %#x\n", buffered_pid, pid, status);
- printf("ran for %d seconds without error, passing\n", SECONDS);
- exit(0);
- }
+ buffered_exit = (pid == buffered_pid && WIFEXITED(status)) ?
+ WEXITSTATUS(status) : 1;
- if (pid == dio_pid) {
- kill(buffered_pid, SIGKILL);
- waitpid(buffered_pid, NULL, 0);
- } else {
- kill(dio_pid, SIGKILL);
- waitpid(dio_pid, NULL, 0);
+ if (dio_exit || buffered_exit) {
+ /*
+ * pass on the child's pass/fail return code or fail if the
+ * child didn't exit cleanly.
+ */
+ exit(dio_exit || buffered_exit);
}
- /*
- * pass on the child's pass/fail return code or fail if the child
- * didn't exit cleanly.
- */
- exit(WIFEXITED(status) ? WEXITSTATUS(status) : 1);
+ printf("ran for %d seconds without error, passing\n", SECONDS);
+ exit(0);
}
--
2.8.0.rc3.226.g39d4020
--
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