OpenZFS 8592 - ZFS channel programs - rollback

Authored by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Chris Williamson <chris.williamson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Don Brady <don.brady@delphix.com>

ZFS channel programs should be able to perform a rollback.

OpenZFS-issue: https://www.illumos.org/issues/8592
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d46b5ed6

include/sys/dsl_dataset.h

@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  */
@@ -245,6 +245,13 @@ typedef struct dsl_dataset_promote_arg {
 	cred_t *cr;
 } dsl_dataset_promote_arg_t;
 
+typedef struct dsl_dataset_rollback_arg {
+	const char *ddra_fsname;
+	const char *ddra_tosnap;
+	void *ddra_owner;
+	nvlist_t *ddra_result;
+} dsl_dataset_rollback_arg_t;
+
 /*
  * The max length of a temporary tag prefix is the number of hex digits
  * required to express UINT64_MAX plus one for the hyphen.
@@ -394,6 +401,9 @@ void dsl_dataset_set_refreservation_sync_impl(dsl_dataset_t *ds,
 void dsl_dataset_zapify(dsl_dataset_t *ds, dmu_tx_t *tx);
 boolean_t dsl_dataset_is_zapified(dsl_dataset_t *ds);
 boolean_t dsl_dataset_has_resume_receive_state(dsl_dataset_t *ds);
+
+int dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx);
+void dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx);
 int dsl_dataset_rollback(const char *fsname, const char *tosnap, void *owner,
     nvlist_t *result);
 

man/man8/zfs-program.8

@@ -8,7 +8,7 @@
 .\" http://www.illumos.org/license/CDDL.
 .\"
 .\"
-.\" Copyright (c) 2016 by Delphix. All Rights Reserved.
+.\" Copyright (c) 2016, 2017 by Delphix. All Rights Reserved.
 .\"
 .Dd January 21, 2016
 .Dt ZFS-PROGRAM 8
@@ -361,6 +361,17 @@ dataset (string)
 .Bd -ragged -compact -offset "xxxx"
 Clone to be promoted.
 .Ed
+.It Em zfs.sync.rollback(filesystem)
+Rollback to the previous snapshot for a dataset.
+Returns 0 on successful rollback, or a nonzero error code otherwise.
+Rollbacks can be performed on filesystems or zvols, but not on snapshots
+or mounted datasets.
+EBUSY is returned in the case where the filesystem is mounted.
+.Pp
+filesystem (string)
+.Bd -ragged -compact -offset "xxxx"
+Filesystem to rollback.
+.Ed
 .El
 .It Sy zfs.check submodule
 For each function in the zfs.sync submodule, there is a corresponding zfs.check
@@ -380,6 +391,7 @@ The available zfs.check functions are:
 .Bl -tag -width "xx"
 .It Em zfs.check.destroy(dataset, [defer=true|false])
 .It Em zfs.check.promote(dataset)
+.It Em zfs.check.rollback(filesystem)
 .El
 .It Sy zfs.list submodule
 The zfs.list submodule provides functions for iterating over datasets and

module/zfs/dsl_dataset.c

@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
  * Copyright (c) 2014, Joyent, Inc. All rights reserved.
  * Copyright (c) 2014 RackTop Systems.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
@@ -2526,14 +2526,7 @@ dsl_dataset_handoff_check(dsl_dataset_t *ds, void *owner, dmu_tx_t *tx)
 	return (0);
 }
 
-typedef struct dsl_dataset_rollback_arg {
-	const char *ddra_fsname;
-	const char *ddra_tosnap;
-	void *ddra_owner;
-	nvlist_t *ddra_result;
-} dsl_dataset_rollback_arg_t;
-
-static int
+int
 dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx)
 {
 	dsl_dataset_rollback_arg_t *ddra = arg;
@@ -2641,7 +2634,7 @@ dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx)
 	return (0);
 }
 
-static void
+void
 dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx)
 {
 	dsl_dataset_rollback_arg_t *ddra = arg;

module/zfs/zcp_synctask.c

@@ -14,7 +14,7 @@
  */
 
 /*
- * Copyright (c) 2016 by Delphix. All rights reserved.
+ * Copyright (c) 2016, 2017 by Delphix. All rights reserved.
  */
 
 #include <sys/lua/lua.h>
@@ -177,6 +177,37 @@ zcp_synctask_promote(lua_State *state, boolean_t sync, nvlist_t *err_details)
 	return (err);
 }
 
+static int zcp_synctask_rollback(lua_State *, boolean_t, nvlist_t *err_details);
+static zcp_synctask_info_t zcp_synctask_rollback_info = {
+	.name = "rollback",
+	.func = zcp_synctask_rollback,
+	.space_check = ZFS_SPACE_CHECK_RESERVED,
+	.blocks_modified = 1,
+	.pargs = {
+	    {.za_name = "filesystem", .za_lua_type = LUA_TSTRING},
+	    {0, 0}
+	},
+	.kwargs = {
+	    {0, 0}
+	}
+};
+
+static int
+zcp_synctask_rollback(lua_State *state, boolean_t sync, nvlist_t *err_details)
+{
+	int err;
+	const char *dsname = lua_tostring(state, 1);
+	dsl_dataset_rollback_arg_t ddra = { 0 };
+
+	ddra.ddra_fsname = dsname;
+	ddra.ddra_result = err_details;
+
+	err = zcp_sync_task(state, dsl_dataset_rollback_check,
+	    dsl_dataset_rollback_sync, &ddra, sync, dsname);
+
+	return (err);
+}
+
 void
 zcp_synctask_wrapper_cleanup(void *arg)
 {
@@ -247,6 +278,7 @@ zcp_load_synctask_lib(lua_State *state, boolean_t sync)
 	zcp_synctask_info_t *zcp_synctask_funcs[] = {
 		&zcp_synctask_destroy_info,
 		&zcp_synctask_promote_info,
+		&zcp_synctask_rollback_info,
 		NULL
 	};
 

tests/runfiles/linux.run

@@ -77,8 +77,8 @@ tests = ['tst.destroy_fs', 'tst.destroy_snap', 'tst.get_count_and_limit',
     'tst.get_number_props', 'tst.get_string_props', 'tst.get_type',
     'tst.get_userquota', 'tst.get_written', 'tst.list_children',
     'tst.list_clones', 'tst.list_snapshots', 'tst.list_system_props',
-    'tst.parse_args_neg','tst.promote_conflict', 'tst.promote_multiple',
-    'tst.promote_simple']
+    'tst.parse_args_neg', 'tst.promote_conflict', 'tst.promote_multiple',
+    'tst.promote_simple', 'tst.rollback_mult', 'tst.rollback_one']
 tags = ['functional', 'channel_program', 'synctask_core']
 
 [tests/functional/chattr]

tests/zfs-tests/tests/functional/channel_program/synctask_core/Makefile.am

@@ -27,4 +27,6 @@ dist_pkgdata_SCRIPTS = \
 	tst.promote_conflict.ksh \
 	tst.promote_conflict.zcp \
 	tst.promote_multiple.ksh \
-	tst.promote_simple.ksh
+	tst.promote_simple.ksh \
+	tst.rollback_mult.ksh \
+	tst.rollback_one.ksh

tests/zfs-tests/tests/functional/channel_program/synctask_core/tst.rollback_mult.ksh

@@ -0,0 +1,61 @@
+#!/bin/ksh -p
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2016, 2017 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/tests/functional/channel_program/channel_common.kshlib
+
+verify_runnable "global"
+snap1=$TESTPOOL/$TESTFS@$TESTSNAP1
+snap2=$TESTPOOL/$TESTFS@$TESTSNAP2
+fs=$TESTPOOL/$TESTFS
+file=$TESTDIR/$TESTFILE0
+
+function cleanup
+{
+	datasetexists $snap1 && log_must zfs destroy $snap1 && \
+	    log_must rm $file
+}
+
+log_onexit cleanup
+
+log_must mkfile 128b $file
+create_snapshot $TESTPOOL/$TESTFS $TESTSNAP1
+log_must rm $file
+create_snapshot $TESTPOOL/$TESTFS $TESTSNAP2
+
+log_must snapexists $snap1
+log_must snapexists $snap2
+log_must zfs unmount $fs
+
+log_must_program $TESTPOOL - $fs $snap2 <<-EOF
+	arg = ...
+	fs = arg["argv"][1]
+	snap = arg["argv"][2]
+	err = zfs.sync.rollback(fs)
+	if err == 0 then
+		err = zfs.sync.destroy(snap)
+	end
+	if err == 0 then
+		err = zfs.sync.rollback(fs)
+	end
+	msg = "rolling back " .. fs .. " err=" .. err
+	return msg
+EOF
+
+log_must zfs mount $fs
+log_must [ -f $file ]
+log_mustnot snapexists $snap2
+
+log_pass "Rolling back snapshot with channel program works."

tests/zfs-tests/tests/functional/channel_program/synctask_core/tst.rollback_one.ksh

@@ -0,0 +1,51 @@
+#!/bin/ksh -p
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2016, 2017 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/tests/functional/channel_program/channel_common.kshlib
+
+verify_runnable "global"
+snap=$TESTPOOL/$TESTFS@$TESTSNAP
+fs=$TESTPOOL/$TESTFS
+file=$TESTDIR/$TESTFILE0
+
+function cleanup
+{
+	datasetexists $snap && log_must zfs destroy $snap && \
+	    log_must rm $file
+
+}
+
+log_onexit cleanup
+
+log_must mkfile 128b $file
+create_snapshot $TESTPOOL/$TESTFS $TESTSNAP
+log_must rm $file
+
+log_must snapexists $snap
+log_must zfs unmount $fs
+
+log_must_program $TESTPOOL - $fs <<-EOF
+	arg = ...
+	fs = arg["argv"][1]
+	err = zfs.sync.rollback(fs)
+	msg = "rolling back " .. fs .. " err=" .. err
+	return msg
+EOF
+
+log_must zfs mount $fs
+log_must [ -f $file ]
+
+log_pass "Rolling back snapshot with channel program works."