ztest: reduce gangblock creation

[zfs] / cmd / ztest / ztest.c

diff --git a/cmd/ztest/ztest.c b/cmd/ztest/ztest.c
index 47f3cdf126c17a20870c3cb1c8cace6a71dbf5b9..1ad87bb30cdf45d26dd9d1af59eeb5cf21cce723 100644 (file)
--- a/cmd/ztest/ztest.c
+++ b/cmd/ztest/ztest.c
@@ -128,7 +128,7 @@
 #include <sys/fs/zfs.h>
 #include <zfs_fletcher.h>
 #include <libnvpair.h>
-#include <libzfs.h>
+#include <libzutil.h>
 #include <sys/crypto/icp.h>
 #ifdef __GLIBC__
 #include <execinfo.h> /* for backtrace() */
@@ -178,6 +178,7 @@ typedef struct ztest_shared_opts {
        uint64_t zo_metaslab_force_ganging;
        int zo_mmp_test;
        int zo_special_vdevs;
+       int zo_dump_dbgmsg;
 } ztest_shared_opts_t;
 
 static const ztest_shared_opts_t ztest_opts_defaults = {
@@ -200,7 +201,7 @@ static const ztest_shared_opts_t ztest_opts_defaults = {
        .zo_init = 1,
        .zo_time = 300,                 /* 5 minutes */
        .zo_maxloops = 50,              /* max loops during spa_freeze() */
-       .zo_metaslab_force_ganging = 32 << 10,
+       .zo_metaslab_force_ganging = 64 << 10,
        .zo_special_vdevs = ZTEST_VDEV_CLASS_RND,
 };
 
@@ -484,7 +485,6 @@ static kmutex_t ztest_checkpoint_lock;
 static pthread_rwlock_t ztest_name_lock;
 
 static boolean_t ztest_dump_core = B_TRUE;
-static boolean_t ztest_dump_debug_buffer = B_FALSE;
 static boolean_t ztest_exiting;
 
 /* Global commit callback list */
@@ -533,10 +533,16 @@ _umem_logging_init(void)
 static void
 dump_debug_buffer(void)
 {
-       if (!ztest_dump_debug_buffer)
+       ssize_t ret __attribute__((unused));
+
+       if (!ztest_opts.zo_dump_dbgmsg)
                return;
 
-       (void) printf("\n");
+       /*
+        * We use write() instead of printf() so that this function
+        * is safe to call from a signal handler.
+        */
+       ret = write(STDOUT_FILENO, "\n", 1);
        zfs_dbgmsg_print("ztest");
 }
 
@@ -591,10 +597,11 @@ fatal(int do_perror, char *message, ...)
        (void) fprintf(stderr, "%s\n", buf);
        fatal_msg = buf;                        /* to ease debugging */
 
-       dump_debug_buffer();
-
        if (ztest_dump_core)
                abort();
+       else
+               dump_debug_buffer();
+
        exit(3);
 }
 
@@ -866,7 +873,7 @@ process_options(int argc, char **argv)
                                usage(B_FALSE);
                        break;
                case 'G':
-                       ztest_dump_debug_buffer = B_TRUE;
+                       zo->zo_dump_dbgmsg = 1;
                        break;
                case 'h':
                        usage(B_TRUE);
@@ -3542,6 +3549,15 @@ ztest_device_removal(ztest_ds_t *zd, uint64_t id)
                ztest_device_removal_active = B_TRUE;
                mutex_exit(&ztest_vdev_lock);
 
+               /*
+                * spa->spa_vdev_removal is created in a sync task that
+                * is initiated via dsl_sync_task_nowait(). Since the
+                * task may not run before spa_vdev_remove() returns, we
+                * must wait at least 1 txg to ensure that the removal
+                * struct has been created.
+                */
+               txg_wait_synced(spa_get_dsl(spa), 0);
+
                while (spa->spa_vdev_removal != NULL)
                        txg_wait_synced(spa_get_dsl(spa), 0);
        } else {
@@ -7049,7 +7065,6 @@ make_random_props(void)
 static void
 ztest_import(ztest_shared_t *zs)
 {
-       libzfs_handle_t *hdl;
        importargs_t args = { 0 };
        spa_t *spa;
        nvlist_t *cfg = NULL;
@@ -7064,14 +7079,14 @@ ztest_import(ztest_shared_t *zs)
        VERIFY0(pthread_rwlock_init(&ztest_name_lock, NULL));
 
        kernel_init(FREAD | FWRITE);
-       hdl = libzfs_init();
 
        searchdirs[0] = ztest_opts.zo_dir;
        args.paths = nsearch;
        args.path = searchdirs;
        args.can_be_active = B_FALSE;
 
-       error = zpool_tryimport(hdl, name, &cfg, &args);
+       error = zpool_find_config(NULL, name, &cfg, &args,
+           &libzpool_config_ops);
        if (error)
                (void) fatal(0, "No pools found\n");
 
@@ -7081,7 +7096,6 @@ ztest_import(ztest_shared_t *zs)
            1ULL << spa->spa_root_vdev->vdev_child[0]->vdev_ms_shift;
        spa_close(spa, FTAG);
 
-       libzfs_fini(hdl);
        kernel_fini();
 
        if (!ztest_opts.zo_mmp_test) {
@@ -7376,8 +7390,13 @@ main(int argc, char **argv)
         * Verify that even extensively damaged split blocks with many
         * segments can be reconstructed in a reasonable amount of time
         * when reconstruction is known to be possible.
+        *
+        * Note: the lower this value is, the more damage we inflict, and
+        * the more time ztest spends in recovering that damage. We chose
+        * to induce damage 1/100th of the time so recovery is tested but
+        * not so frequently that ztest doesn't get to test other code paths.
         */
-       zfs_reconstruct_indirect_damage_fraction = 4;
+       zfs_reconstruct_indirect_damage_fraction = 100;
 
        action.sa_handler = sig_handler;
        sigemptyset(&action.sa_mask);