On Thu, Sep 23, 2021 at 03:16:17PM +0000, Raphael Norwitz wrote: > In the vhost-user-blk-test, as of now there is nothing stoping > vhost-user-blk in QEMU writing to the socket right after forking off the > storage daemon before it has a chance to come up properly, leaving the > test hanging forever. This intermittently hanging test has caused QEMU > automation failures reported multiple times on the mailing list [1]. > > This change makes the storage-daemon notify the vhost-user-blk-test > that it is fully initialized and ready to handle client connections by > creating a pidfile on initialiation. This ensures that the storage-daemon > backend won't miss vhost-user messages and thereby resolves the hang. > > [1] > https://lore.kernel.org/qemu-devel/CAFEAcA8kYpz9LiPNxnWJAPSjc=nv532bedyfynabemeohqb...@mail.gmail.com/ > > Signed-off-by: Raphael Norwitz <raphael.norw...@nutanix.com> > --- > Accidentally left a raw free() in v3. Converted it to g_free() here. > > tests/qtest/vhost-user-blk-test.c | 27 ++++++++++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff --git a/tests/qtest/vhost-user-blk-test.c > b/tests/qtest/vhost-user-blk-test.c > index 6f108a1b62..6898f55f11 100644 > --- a/tests/qtest/vhost-user-blk-test.c > +++ b/tests/qtest/vhost-user-blk-test.c > @@ -24,6 +24,7 @@ > #define TEST_IMAGE_SIZE (64 * 1024 * 1024) > #define QVIRTIO_BLK_TIMEOUT_US (30 * 1000 * 1000) > #define PCI_SLOT_HP 0x06 > +#define PIDFILE_RETRIES 5 > > typedef struct { > pid_t pid; > @@ -885,7 +886,8 @@ static void start_vhost_user_blk(GString *cmd_line, int > vus_instances, > int num_queues) > { > const char *vhost_user_blk_bin = qtest_qemu_storage_daemon_binary(); > - int i; > + int i, retries; > + char *daemon_pidfile_path; > gchar *img_path; > GString *storage_daemon_command = g_string_new(NULL); > QemuStorageDaemonState *qsd; > @@ -898,6 +900,9 @@ static void start_vhost_user_blk(GString *cmd_line, int > vus_instances, > " -object memory-backend-memfd,id=mem,size=256M,share=on " > " -M memory-backend=mem -m 256M "); > > + daemon_pidfile_path = g_strdup_printf("/tmp/daemon-%d", getpid()); > + g_assert_cmpint((uintptr_t) daemon_pidfile_path, !=, (uintptr_t) NULL);
Feels verbose compared to: g_assert(daemon_pidfile_path) For that matter, can g_strdup_printf() ever return NULL? On memory error, it exit()s rather than returning. So this assert feels like overkill. Otherwise, Reviewed-by: Eric Blake <ebl...@redhat.com> -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
