Check l2cache vdevs pending list inside the vdev_inuse()

The l2cache device could be added twice because vdev_inuse() does not
check spa_l2cache for added devices. Make l2cache vdevs inuse checking
logic more closer to spare vdevs.

Reviewed-by: George Amanakis <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Fedor Uporov <[email protected]>
Closes #9153 
Closes #12689 

2 files changed, 35 insertions, 9 deletions

diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index 1083b5a90..7546e3e41 100644
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -9451,12 +9451,11 @@ spa_upgrade(spa_t *spa, uint64_t version)
 	txg_wait_synced(spa_get_dsl(spa), 0);
 }
 
-boolean_t
-spa_has_spare(spa_t *spa, uint64_t guid)
+static boolean_t
+spa_has_aux_vdev(spa_t *spa, uint64_t guid, spa_aux_vdev_t *sav)
 {
 	int i;
-	uint64_t spareguid;
-	spa_aux_vdev_t *sav = &spa->spa_spares;
+	uint64_t vdev_guid;
 
 	for (i = 0; i < sav->sav_count; i++)
 		if (sav->sav_vdevs[i]->vdev_guid == guid)
@@ -9464,13 +9463,25 @@ spa_has_spare(spa_t *spa, uint64_t guid)
 
 	for (i = 0; i < sav->sav_npending; i++) {
 		if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
-		    &spareguid) == 0 && spareguid == guid)
+		    &vdev_guid) == 0 && vdev_guid == guid)
 			return (B_TRUE);
 	}
 
 	return (B_FALSE);
 }
 
+boolean_t
+spa_has_l2cache(spa_t *spa, uint64_t guid)
+{
+	return (spa_has_aux_vdev(spa, guid, &spa->spa_l2cache));
+}
+
+boolean_t
+spa_has_spare(spa_t *spa, uint64_t guid)
+{
+	return (spa_has_aux_vdev(spa, guid, &spa->spa_spares));
+}
+
 /*
  * Check if a pool has an active shared spare device.
  * Note: reference count of an active spare is 2, as a spare and as a replace
diff --git a/module/zfs/vdev_label.c b/module/zfs/vdev_label.c
index f03ae0873..daf53f0a0 100644
--- a/module/zfs/vdev_label.c
+++ b/module/zfs/vdev_label.c
@@ -933,7 +933,7 @@ vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason,
 	/*
 	 * Check to see if this is a spare device.  We do an explicit check for
 	 * spa_has_spare() here because it may be on our pending list of spares
-	 * to add.  We also check if it is an l2cache device.
+	 * to add.
 	 */
 	if (spa_spare_exists(device_guid, &spare_pool, NULL) ||
 	    spa_has_spare(spa, device_guid)) {
@@ -942,7 +942,6 @@ vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason,
 
 		switch (reason) {
 		case VDEV_LABEL_CREATE:
-		case VDEV_LABEL_L2CACHE:
 			return (B_TRUE);
 
 		case VDEV_LABEL_REPLACE:
@@ -959,8 +958,24 @@ vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason,
 	/*
 	 * Check to see if this is an l2cache device.
 	 */
-	if (spa_l2cache_exists(device_guid, NULL))
-		return (B_TRUE);
+	if (spa_l2cache_exists(device_guid, NULL) ||
+	    spa_has_l2cache(spa, device_guid)) {
+		if (l2cache_guid)
+			*l2cache_guid = device_guid;
+
+		switch (reason) {
+		case VDEV_LABEL_CREATE:
+			return (B_TRUE);
+
+		case VDEV_LABEL_REPLACE:
+			return (!spa_has_l2cache(spa, device_guid));
+
+		case VDEV_LABEL_L2CACHE:
+			return (spa_has_l2cache(spa, device_guid));
+		default:
+			break;
+		}
+	}
 
 	/*
 	 * We can't rely on a pool's state if it's been imported