Fix ztest deadlock in spa_vdev_remove()

[mirror_zfs.git] / module / zfs / vdev_removal.c

diff --git a/module/zfs/vdev_removal.c b/module/zfs/vdev_removal.c
index 5952a5d8fc68fa9fe42cb4a81169215f1f94e2df..a706bc2a425a186d50dbd3dcc2e6dc9c8f61b3c9 100644 (file)
--- a/module/zfs/vdev_removal.c
+++ b/module/zfs/vdev_removal.c
@@ -1894,10 +1894,6 @@ spa_vdev_remove_log(vdev_t *vd, uint64_t *txg)
        vdev_dirty_leaves(vd, VDD_DTL, *txg);
        vdev_config_dirty(vd);
 
-       spa_history_log_internal(spa, "vdev remove", NULL,
-           "%s vdev %llu (log) %s", spa_name(spa), vd->vdev_id,
-           (vd->vdev_path != NULL) ? vd->vdev_path : "-");
-
        spa_vdev_config_exit(spa, NULL, *txg, 0, FTAG);
 
        *txg = spa_vdev_config_enter(spa);
@@ -2122,6 +2118,7 @@ spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
        int error = 0;
        boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
        sysevent_t *ev = NULL;
+       char *vd_type = NULL, *vd_path = NULL;
 
        ASSERT(spa_writeable(spa));
 
@@ -2155,11 +2152,8 @@ spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
                        ev = spa_event_create(spa, vd, NULL,
                            ESC_ZFS_VDEV_REMOVE_AUX);
 
-                       char *nvstr = fnvlist_lookup_string(nv,
-                           ZPOOL_CONFIG_PATH);
-                       spa_history_log_internal(spa, "vdev remove", NULL,
-                           "%s vdev (%s) %s", spa_name(spa),
-                           VDEV_TYPE_SPARE, nvstr);
+                       vd_type = VDEV_TYPE_SPARE;
+                       vd_path = fnvlist_lookup_string(nv, ZPOOL_CONFIG_PATH);
                        spa_vdev_remove_aux(spa->spa_spares.sav_config,
                            ZPOOL_CONFIG_SPARES, spares, nspares, nv);
                        spa_load_spares(spa);
@@ -2171,9 +2165,8 @@ spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
            nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
            ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
            (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
-               char *nvstr = fnvlist_lookup_string(nv, ZPOOL_CONFIG_PATH);
-               spa_history_log_internal(spa, "vdev remove", NULL,
-                   "%s vdev (%s) %s", spa_name(spa), VDEV_TYPE_L2CACHE, nvstr);
+               vd_type = VDEV_TYPE_L2CACHE;
+               vd_path = fnvlist_lookup_string(nv, ZPOOL_CONFIG_PATH);
                /*
                 * Cache devices can always be removed.
                 */
@@ -2185,6 +2178,8 @@ spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
                spa->spa_l2cache.sav_sync = B_TRUE;
        } else if (vd != NULL && vd->vdev_islog) {
                ASSERT(!locked);
+               vd_type = "log";
+               vd_path = (vd->vdev_path != NULL) ? vd->vdev_path : "-";
                error = spa_vdev_remove_log(vd, &txg);
        } else if (vd != NULL) {
                ASSERT(!locked);
@@ -2199,6 +2194,18 @@ spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
        if (!locked)
                error = spa_vdev_exit(spa, NULL, txg, error);
 
+       /*
+        * Logging must be done outside the spa config lock. Otherwise,
+        * this code path could end up holding the spa config lock while
+        * waiting for a txg_sync so it can write to the internal log.
+        * Doing that would prevent the txg sync from actually happening,
+        * causing a deadlock.
+        */
+       if (error == 0 && vd_type != NULL && vd_path != NULL) {
+               spa_history_log_internal(spa, "vdev remove", NULL,
+                   "%s vdev (%s) %s", spa_name(spa), vd_type, vd_path);
+       }
+
        if (ev != NULL)
                spa_event_post(ev);