Illumos #3129, #3130

illumos/illumos-gate@d6afdce20f8481c95471dd821bc8ec0dbde66213
Illumos changeset: 13794:7c5e0e746b2c

3129 'zpool reopen' restarts resilvers
3130 ztest failure: Assertion failed:
     0 == dmu_objset_destroy(name, B_FALSE) (0x0 == 0x10)

Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  https://www.illumos.org/issues/3129
  https://www.illumos.org/issues/3130

Ported by: Etienne Dechamps <etienne.dechamps@ovh.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #994

diff --git a/module/zfs/dsl_dir.c b/module/zfs/dsl_dir.c
index d615832..97b38d2 100644 (file)
--- a/module/zfs/dsl_dir.c
+++ b/module/zfs/dsl_dir.c
@@ -460,12 +460,14 @@ dsl_dir_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
        /*
         * There should be exactly two holds, both from
         * dsl_dataset_destroy: one on the dd directory, and one on its
-        * head ds.  Otherwise, someone is trying to lookup something
-        * inside this dir while we want to destroy it.  The
-        * config_rwlock ensures that nobody else opens it after we
-        * check.
+        * head ds.  If there are more holds, then a concurrent thread is
+        * performing a lookup inside this dir while we're trying to destroy
+        * it.  To minimize this possibility, we perform this check only
+        * in syncing context and fail the operation if we encounter
+        * additional holds.  The dp_config_rwlock ensures that nobody else
+        * opens it after we check.
         */
-       if (dmu_buf_refcount(dd->dd_dbuf) > 2)
+       if (dmu_tx_is_syncing(tx) && dmu_buf_refcount(dd->dd_dbuf) > 2)
                return (EBUSY);
 
        err = zap_count(mos, dd->dd_phys->dd_child_dir_zapobj, &count);

diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index aeac014..c609203 100644 (file)
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -4094,7 +4094,17 @@ zfs_ioc_pool_reopen(zfs_cmd_t *zc)
                return (error);
 
        spa_vdev_state_enter(spa, SCL_NONE);
+
+       /*
+        * If a resilver is already in progress then set the
+        * spa_scrub_reopen flag to B_TRUE so that we don't restart
+        * the scan as a side effect of the reopen. Otherwise, let
+        * vdev_open() decided if a resilver is required.
+        */
+       spa->spa_scrub_reopen = dsl_scan_resilvering(spa->spa_dsl_pool);
        vdev_reopen(spa->spa_root_vdev);
+       spa->spa_scrub_reopen = B_FALSE;
+
        (void) spa_vdev_state_exit(spa, NULL, 0);
        spa_close(spa, FTAG);
        return (0);