From 887f6099e6f6b662df356e7d26102ff84aa0c901 Mon Sep 17 00:00:00 2001

From: David Teigland <teigland@redhat.com>

Date: Wed, 16 Jan 2019 10:41:43 -0600

Subject: [PATCH 4/5] lvmlockd: make lockstart wait for existing start

If there are two independent scripts doing:

  vgchange --lockstart vg

  lvchange -ay vg/lv

The first vgchange to do the lockstart will wait for

the lockstart to complete before returning.

The second vgchange to do the lockstart will see that

the start is already in progress (from the first) and

will do nothing.  This means the second does not wait

for any lockstart to complete, and moves on to the

lvchange which may find the lockspace still starting

and fail.

To fix this, make the vgchange lockstart command

wait for any lockstart's in progress to complete.

---

 daemons/lvmlockd/lvmlockd-core.c |  9 ++++++---

 lib/locking/lvmlockd.c           | 12 +++++++++---

 lib/locking/lvmlockd.h           |  2 +-

 tools/vgchange.c                 |  5 ++++-

 tools/vgcreate.c                 |  2 +-

 5 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/daemons/lvmlockd/lvmlockd-core.c b/daemons/lvmlockd/lvmlockd-core.c

index a9ce6fc..e2d4595 100644

--- a/daemons/lvmlockd/lvmlockd-core.c

+++ b/daemons/lvmlockd/lvmlockd-core.c

@@ -2742,6 +2742,9 @@ static int add_lockspace_thread(const char *ls_name,

 		if (ls2->thread_stop) {

 			log_debug("add_lockspace_thread %s exists and stopping", ls->name);

 			rv = -EAGAIN;

+		} else if (!ls2->create_fail && !ls2->create_done) {

+			log_debug("add_lockspace_thread %s exists and starting", ls->name);

+			rv = -ESTARTING;

 		} else {

 			log_debug("add_lockspace_thread %s exists", ls->name);

 			rv = -EEXIST;

@@ -2983,7 +2986,7 @@ static int count_lockspace_starting(uint32_t client_id)

 	pthread_mutex_lock(&lockspaces_mutex);

 	list_for_each_entry(ls, &lockspaces, list) {

-		if (ls->start_client_id != client_id)

+		if (client_id && (ls->start_client_id != client_id))

 			continue;

 		if (!ls->create_done && !ls->create_fail) {

@@ -3384,7 +3387,7 @@ static void *worker_thread_main(void *arg_in)

 			add_client_result(act);

 		} else if (act->op == LD_OP_START_WAIT) {

-			act->result = count_lockspace_starting(act->client_id);

+			act->result = count_lockspace_starting(0);

 			if (!act->result)

 				add_client_result(act);

 			else

@@ -3418,7 +3421,7 @@ static void *worker_thread_main(void *arg_in)

 		list_for_each_entry_safe(act, safe, &delayed_list, list) {

 			if (act->op == LD_OP_START_WAIT) {

 				log_debug("work delayed start_wait for client %u", act->client_id);

-				act->result = count_lockspace_starting(act->client_id);

+				act->result = count_lockspace_starting(0);

 				if (!act->result) {

 					list_del(&act->list);

 					add_client_result(act);

diff --git a/lib/locking/lvmlockd.c b/lib/locking/lvmlockd.c

index 969a7fe..6168630 100644

--- a/lib/locking/lvmlockd.c

+++ b/lib/locking/lvmlockd.c

@@ -1077,7 +1077,7 @@ void lockd_free_vg_final(struct cmd_context *cmd, struct volume_group *vg)

  * that the VG lockspace being started is new.

  */

-int lockd_start_vg(struct cmd_context *cmd, struct volume_group *vg, int start_init)

+int lockd_start_vg(struct cmd_context *cmd, struct volume_group *vg, int start_init, int *exists)

 {

 	char uuid[64] __attribute__((aligned(8)));

 	daemon_reply reply;

@@ -1152,6 +1152,12 @@ int lockd_start_vg(struct cmd_context *cmd, struct volume_group *vg, int start_i

 		log_debug("VG %s start error: already started", vg->name);

 		ret = 1;

 		break;

+	case -ESTARTING:

+		log_debug("VG %s start error: already starting", vg->name);

+		if (exists)

+			*exists = 1;

+		ret = 1;

+		break;

 	case -EARGS:

 		log_error("VG %s start failed: invalid parameters for %s", vg->name, vg->lock_type);

 		break;

@@ -2673,7 +2679,7 @@ int lockd_rename_vg_final(struct cmd_context *cmd, struct volume_group *vg, int

 		 * Depending on the problem that caused the rename to

 		 * fail, it may make sense to not restart the VG here.

 		 */

-		if (!lockd_start_vg(cmd, vg, 0))

+		if (!lockd_start_vg(cmd, vg, 0, NULL))

 			log_error("Failed to restart VG %s lockspace.", vg->name);

 		return 1;

 	}

@@ -2713,7 +2719,7 @@ int lockd_rename_vg_final(struct cmd_context *cmd, struct volume_group *vg, int

 		}

 	}

-	if (!lockd_start_vg(cmd, vg, 1))

+	if (!lockd_start_vg(cmd, vg, 1, NULL))

 		log_error("Failed to start VG %s lockspace.", vg->name);

 	return 1;

diff --git a/lib/locking/lvmlockd.h b/lib/locking/lvmlockd.h

index 0a6ea96..1fbf765 100644

--- a/lib/locking/lvmlockd.h

+++ b/lib/locking/lvmlockd.h

@@ -63,7 +63,7 @@ int lockd_rename_vg_final(struct cmd_context *cmd, struct volume_group *vg, int

 /* start and stop the lockspace for a vg */

-int lockd_start_vg(struct cmd_context *cmd, struct volume_group *vg, int start_init);

+int lockd_start_vg(struct cmd_context *cmd, struct volume_group *vg, int start_init, int *exists);

 int lockd_stop_vg(struct cmd_context *cmd, struct volume_group *vg);

 int lockd_start_wait(struct cmd_context *cmd);

diff --git a/tools/vgchange.c b/tools/vgchange.c

index 0f9241c..f3d535c 100644

--- a/tools/vgchange.c

+++ b/tools/vgchange.c

@@ -560,6 +560,7 @@ static int _vgchange_lock_start(struct cmd_context *cmd, struct volume_group *vg

 {

 	const char *start_opt = arg_str_value(cmd, lockopt_ARG, NULL);

 	int auto_opt = 0;

+	int exists = 0;

 	int r;

 	if (!vg_is_shared(vg))

@@ -586,10 +587,12 @@ static int _vgchange_lock_start(struct cmd_context *cmd, struct volume_group *vg

 	}

 do_start:

-	r = lockd_start_vg(cmd, vg, 0);

+	r = lockd_start_vg(cmd, vg, 0, &exists;;

 	if (r)

 		vp->lock_start_count++;

+	else if (exists)

+		vp->lock_start_count++;

 	if (!strcmp(vg->lock_type, "sanlock"))

 		vp->lock_start_sanlock = 1;

diff --git a/tools/vgcreate.c b/tools/vgcreate.c

index 2a40bc7..b595349 100644

--- a/tools/vgcreate.c

+++ b/tools/vgcreate.c

@@ -202,7 +202,7 @@ int vgcreate(struct cmd_context *cmd, int argc, char **argv)

 	if (vg_is_shared(vg)) {

 		const char *start_opt = arg_str_value(cmd, lockopt_ARG, NULL);

-		if (!lockd_start_vg(cmd, vg, 1)) {

+		if (!lockd_start_vg(cmd, vg, 1, NULL)) {

 			log_error("Failed to start locking");

 			goto out;

 		}

-- 

1.8.3.1