Illumos #3464

3464 zfs synctask code needs restructuring
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/3464
  illumos/illumos-gate@3b2aab1

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1495

Author: ahrens

cmd/zdb/zdb.c

@@ -1725,7 +1725,9 @@ dump_dir(objset_t *os)
 	int print_header = 1;
 	int i, error;
 
+	dsl_pool_config_enter(dmu_objset_pool(os), FTAG);
 	dmu_objset_fast_stat(os, &dds);
+	dsl_pool_config_exit(dmu_objset_pool(os), FTAG);
 
 	if (dds.dds_type < DMU_OST_NUMTYPES)
 		type = objset_types[dds.dds_type];
@@ -2171,7 +2173,6 @@ zdb_blkptr_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 
 		zio_nowait(zio_read(NULL, spa, bp, data, size,
 		    zdb_blkptr_done, zcb, ZIO_PRIORITY_ASYNC_READ, flags, zb));
-
 	}
 
 	zcb->zcb_readfails = 0;
@@ -2365,8 +2366,10 @@ dump_block_stats(spa_t *spa)
 	 */
 	(void) bpobj_iterate_nofree(&spa->spa_deferred_bpobj,
 	    count_block_cb, &zcb, NULL);
-	(void) bpobj_iterate_nofree(&spa->spa_dsl_pool->dp_free_bpobj,
-	    count_block_cb, &zcb, NULL);
+	if (spa_version(spa) >= SPA_VERSION_DEADLISTS) {
+		(void) bpobj_iterate_nofree(&spa->spa_dsl_pool->dp_free_bpobj,
+		    count_block_cb, &zcb, NULL);
+	}
 	if (spa_feature_is_active(spa,
 	    &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) {
 		VERIFY3U(0, ==, bptree_iterate(spa->spa_meta_objset,

cmd/zfs/zfs_main.c

@@ -892,6 +892,7 @@ typedef struct destroy_cbdata {
 	boolean_t	cb_parsable;
 	boolean_t	cb_dryrun;
 	nvlist_t	*cb_nvl;
+	nvlist_t	*cb_batchedsnaps;
 
 	/* first snap in contiguous run */
 	char		*cb_firstsnap;
@@ -988,9 +989,27 @@ destroy_callback(zfs_handle_t *zhp, void *data)
 		zfs_close(zhp);
 		return (0);
 	}
+	if (cb->cb_dryrun) {
+		zfs_close(zhp);
+		return (0);
+	}
+
+	/*
+	 * We batch up all contiguous snapshots (even of different
+	 * filesystems) and destroy them with one ioctl.  We can't
+	 * simply do all snap deletions and then all fs deletions,
+	 * because we must delete a clone before its origin.
+	 */
+	if (zfs_get_type(zhp) == ZFS_TYPE_SNAPSHOT) {
+		fnvlist_add_boolean(cb->cb_batchedsnaps, name);
+	} else {
+		int error = zfs_destroy_snaps_nvl(g_zfs,
+		    cb->cb_batchedsnaps, B_FALSE);
+		fnvlist_free(cb->cb_batchedsnaps);
+		cb->cb_batchedsnaps = fnvlist_alloc();
 
-	if (!cb->cb_dryrun) {
-		if (zfs_unmount(zhp, NULL, cb->cb_force ? MS_FORCE : 0) != 0 ||
+		if (error != 0 ||
+		    zfs_unmount(zhp, NULL, cb->cb_force ? MS_FORCE : 0) != 0 ||
 		    zfs_destroy(zhp, cb->cb_defer_destroy) != 0) {
 			zfs_close(zhp);
 			return (-1);
@@ -1146,8 +1165,10 @@ static int
 zfs_do_destroy(int argc, char **argv)
 {
 	destroy_cbdata_t cb = { 0 };
+	int rv = 0;
+	int err = 0;
 	int c;
-	zfs_handle_t *zhp;
+	zfs_handle_t *zhp = NULL;
 	char *at;
 	zfs_type_t type = ZFS_TYPE_DATASET;
 
@@ -1201,11 +1222,9 @@ zfs_do_destroy(int argc, char **argv)
 
 	at = strchr(argv[0], '@');
 	if (at != NULL) {
-		int err = 0;
 
 		/* Build the list of snaps to destroy in cb_nvl. */
-		if (nvlist_alloc(&cb.cb_nvl, NV_UNIQUE_NAME, 0) != 0)
-			nomem();
+		cb.cb_nvl = fnvlist_alloc();
 
 		*at = '\0';
 		zhp = zfs_open(g_zfs, argv[0],
@@ -1216,17 +1235,15 @@ zfs_do_destroy(int argc, char **argv)
 		cb.cb_snapspec = at + 1;
 		if (gather_snapshots(zfs_handle_dup(zhp), &cb) != 0 ||
 		    cb.cb_error) {
-			zfs_close(zhp);
-			nvlist_free(cb.cb_nvl);
-			return (1);
+			rv = 1;
+			goto out;
 		}
 
 		if (nvlist_empty(cb.cb_nvl)) {
 			(void) fprintf(stderr, gettext("could not find any "
 			    "snapshots to destroy; check snapshot names.\n"));
-			zfs_close(zhp);
-			nvlist_free(cb.cb_nvl);
-			return (1);
+			rv = 1;
+			goto out;
 		}
 
 		if (cb.cb_verbose) {
@@ -1245,18 +1262,26 @@ zfs_do_destroy(int argc, char **argv)
 		}
 
 		if (!cb.cb_dryrun) {
-			if (cb.cb_doclones)
+			if (cb.cb_doclones) {
+				cb.cb_batchedsnaps = fnvlist_alloc();
 				err = destroy_clones(&cb);
+				if (err == 0) {
+					err = zfs_destroy_snaps_nvl(g_zfs,
+					    cb.cb_batchedsnaps, B_FALSE);
+				}
+				if (err != 0) {
+					rv = 1;
+					goto out;
+				}
+			}
 			if (err == 0) {
-				err = zfs_destroy_snaps_nvl(zhp, cb.cb_nvl,
+				err = zfs_destroy_snaps_nvl(g_zfs, cb.cb_nvl,
 				    cb.cb_defer_destroy);
 			}
 		}
 
-		zfs_close(zhp);
-		nvlist_free(cb.cb_nvl);
 		if (err != 0)
-			return (1);
+			rv = 1;
 	} else {
 		/* Open the given dataset */
 		if ((zhp = zfs_open(g_zfs, argv[0], type)) == NULL)
@@ -1277,8 +1302,8 @@ zfs_do_destroy(int argc, char **argv)
 			    zfs_get_name(zhp));
 			(void) fprintf(stderr, gettext("use 'zpool destroy %s' "
 			    "to destroy the pool itself\n"), zfs_get_name(zhp));
-			zfs_close(zhp);
-			return (1);
+			rv = 1;
+			goto out;
 		}
 
 		/*
@@ -1288,30 +1313,42 @@ zfs_do_destroy(int argc, char **argv)
 		if (!cb.cb_doclones &&
 		    zfs_iter_dependents(zhp, B_TRUE, destroy_check_dependent,
 		    &cb) != 0) {
-			zfs_close(zhp);
-			return (1);
+			rv = 1;
+			goto out;
 		}
 
 		if (cb.cb_error) {
-			zfs_close(zhp);
-			return (1);
+			rv = 1;
+			goto out;
 		}
 
+		cb.cb_batchedsnaps = fnvlist_alloc();
 		if (zfs_iter_dependents(zhp, B_FALSE, destroy_callback,
 		    &cb) != 0) {
-			zfs_close(zhp);
-			return (1);
+			rv = 1;
+			goto out;
 		}
 
 		/*
 		 * Do the real thing.  The callback will close the
 		 * handle regardless of whether it succeeds or not.
 		 */
-		if (destroy_callback(zhp, &cb) != 0)
-			return (1);
+		err = destroy_callback(zhp, &cb);
+		zhp = NULL;
+		if (err == 0) {
+			err = zfs_destroy_snaps_nvl(g_zfs,
+			    cb.cb_batchedsnaps, cb.cb_defer_destroy);
+		}
+		if (err != 0)
+			rv = 1;
 	}
 
-	return (0);
+out:
+	fnvlist_free(cb.cb_batchedsnaps);
+	fnvlist_free(cb.cb_nvl);
+	if (zhp != NULL)
+		zfs_close(zhp);
+	return (rv);
 }
 
 static boolean_t
@@ -5081,28 +5118,12 @@ zfs_do_allow_unallow_impl(int argc, char **argv, boolean_t un)
 	return (error);
 }
 
-/*
- * zfs allow [-r] [-t] <tag> <snap> ...
- *
- *	-r	Recursively hold
- *	-t	Temporary hold (hidden option)
- *
- * Apply a user-hold with the given tag to the list of snapshots.
- */
 static int
 zfs_do_allow(int argc, char **argv)
 {
 	return (zfs_do_allow_unallow_impl(argc, argv, B_FALSE));
 }
 
-/*
- * zfs unallow [-r] [-t] <tag> <snap> ...
- *
- *	-r	Recursively hold
- *	-t	Temporary hold (hidden option)
- *
- * Apply a user-hold with the given tag to the list of snapshots.
- */
 static int
 zfs_do_unallow(int argc, char **argv)
 {
@@ -5116,7 +5137,6 @@ zfs_do_hold_rele_impl(int argc, char **argv, boolean_t holding)
 	int i;
 	const char *tag;
 	boolean_t recursive = B_FALSE;
-	boolean_t temphold = B_FALSE;
 	const char *opts = holding ? "rt" : "r";
 	int c;
 
@@ -5126,9 +5146,6 @@ zfs_do_hold_rele_impl(int argc, char **argv, boolean_t holding)
 		case 'r':
 			recursive = B_TRUE;
 			break;
-		case 't':
-			temphold = B_TRUE;
-			break;
 		case '?':
 			(void) fprintf(stderr, gettext("invalid option '%c'\n"),
 			    optopt);
@@ -5177,7 +5194,7 @@ zfs_do_hold_rele_impl(int argc, char **argv, boolean_t holding)
 		}
 		if (holding) {
 			if (zfs_hold(zhp, delim+1, tag, recursive,
-			    temphold, B_FALSE, -1, 0, 0) != 0)
+			    B_FALSE, -1) != 0)
 				++errors;
 		} else {
 			if (zfs_release(zhp, delim+1, tag, recursive) != 0)
@@ -5193,7 +5210,6 @@ zfs_do_hold_rele_impl(int argc, char **argv, boolean_t holding)
  * zfs hold [-r] [-t] <tag> <snap> ...
  *
  *	-r	Recursively hold
- *	-t	Temporary hold (hidden option)
  *
  * Apply a user-hold with the given tag to the list of snapshots.
  */

cmd/zhack/zhack.c

@@ -46,6 +46,7 @@
 #include <sys/zio_checksum.h>
 #include <sys/zio_compress.h>
 #include <sys/zfeature.h>
+#include <sys/dmu_tx.h>
 #undef ZFS_MAXNAMELEN
 #include <libzfs.h>
 
@@ -123,7 +124,7 @@ import_pool(const char *target, boolean_t readonly)
 	spa_t *spa;
 	nvpair_t *elem;
 	nvlist_t *props;
-	const char *name;
+	char *name;
 
 	kernel_init(readonly ? FREAD : (FREAD | FWRITE));
 	g_zfs = libzfs_init();
@@ -273,10 +274,10 @@ zhack_do_feature_stat(int argc, char **argv)
 }
 
 static void
-feature_enable_sync(void *arg1, void *arg2, dmu_tx_t *tx)
+feature_enable_sync(void *arg, dmu_tx_t *tx)
 {
-	spa_t *spa = arg1;
-	zfeature_info_t *feature = arg2;
+	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
+	zfeature_info_t *feature = arg;
 
 	spa_feature_enable(spa, feature, tx);
 	spa_history_log_internal(spa, "zhack enable feature", tx,
@@ -344,30 +345,30 @@ zhack_do_feature_enable(int argc, char **argv)
 	if (0 == zap_contains(mos, spa->spa_feat_desc_obj, feature.fi_guid))
 		fatal("feature already enabled: %s", feature.fi_guid);
 
-	VERIFY3U(0, ==, dsl_sync_task_do(spa->spa_dsl_pool, NULL,
-	    feature_enable_sync, spa, &feature, 5));
+	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
+	    feature_enable_sync, &feature, 5));
 
 	spa_close(spa, FTAG);
 
 	free(desc);
 }
 
 static void
-feature_incr_sync(void *arg1, void *arg2, dmu_tx_t *tx)
+feature_incr_sync(void *arg, dmu_tx_t *tx)
 {
-	spa_t *spa = arg1;
-	zfeature_info_t *feature = arg2;
+	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
+	zfeature_info_t *feature = arg;
 
 	spa_feature_incr(spa, feature, tx);
 	spa_history_log_internal(spa, "zhack feature incr", tx,
 	    "name=%s", feature->fi_guid);
 }
 
 static void
-feature_decr_sync(void *arg1, void *arg2, dmu_tx_t *tx)
+feature_decr_sync(void *arg, dmu_tx_t *tx)
 {
-	spa_t *spa = arg1;
-	zfeature_info_t *feature = arg2;
+	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
+	zfeature_info_t *feature = arg;
 
 	spa_feature_decr(spa, feature, tx);
 	spa_history_log_internal(spa, "zhack feature decr", tx,
@@ -442,8 +443,8 @@ zhack_do_feature_ref(int argc, char **argv)
 	if (decr && !spa_feature_is_active(spa, &feature))
 		fatal("feature refcount already 0: %s", feature.fi_guid);
 
-	VERIFY3U(0, ==, dsl_sync_task_do(spa->spa_dsl_pool, NULL,
-	    decr ? feature_decr_sync : feature_incr_sync, spa, &feature, 5));
+	VERIFY0(dsl_sync_task(spa_name(spa), NULL,
+	    decr ? feature_decr_sync : feature_incr_sync, &feature, 5));
 
 	spa_close(spa, FTAG);
 }