1/*
2 * CDDL HEADER START
3 *
4 * This file and its contents are supplied under the terms of the
5 * Common Development and Distribution License ("CDDL"), version 1.0.
6 * You may only use this file in accordance with the terms of version
7 * 1.0 of the CDDL.
8 *
9 * A full copy of the text of the CDDL should have accompanied this
10 * source.  A copy of the CDDL is also available via the Internet at
11 * http://www.illumos.org/license/CDDL.
12 *
13 * CDDL HEADER END
14 */
15
16/*
17 * Copyright (c) 2016, 2017 by Delphix. All rights reserved.
18 * Copyright 2020 Joyent, Inc.
19 */
20
21#include "lua.h"
22#include "lauxlib.h"
23
24#include <sys/zcp.h>
25#include <sys/dsl_dir.h>
26#include <sys/dsl_pool.h>
27#include <sys/dsl_prop.h>
28#include <sys/dsl_synctask.h>
29#include <sys/dsl_dataset.h>
30#include <sys/dsl_bookmark.h>
31#include <sys/dsl_destroy.h>
32#include <sys/dmu_objset.h>
33#include <sys/zfs_znode.h>
34#include <sys/zfeature.h>
35#include <sys/metaslab.h>
36
37#define	DST_AVG_BLKSHIFT 14
38
39typedef struct zcp_inherit_prop_arg {
40	lua_State		*zipa_state;
41	const char		*zipa_prop;
42	dsl_props_set_arg_t	zipa_dpsa;
43} zcp_inherit_prop_arg_t;
44
45typedef int (zcp_synctask_func_t)(lua_State *, boolean_t, nvlist_t *);
46typedef struct zcp_synctask_info {
47	const char *name;
48	zcp_synctask_func_t *func;
49	const zcp_arg_t pargs[4];
50	const zcp_arg_t kwargs[2];
51	zfs_space_check_t space_check;
52	int blocks_modified;
53} zcp_synctask_info_t;
54
55/*
56 * Generic synctask interface for channel program syncfuncs.
57 *
58 * To perform some action in syncing context, we'd generally call
59 * dsl_sync_task(), but since the Lua script is already running inside a
60 * synctask we need to leave out some actions (such as acquiring the config
61 * rwlock and performing space checks).
62 *
63 * If 'sync' is false, executes a dry run and returns the error code.
64 *
65 * If we are not running in syncing context and we are not doing a dry run
66 * (meaning we are running a zfs.sync function in open-context) then we
67 * return a Lua error.
68 *
69 * This function also handles common fatal error cases for channel program
70 * library functions. If a fatal error occurs, err_dsname will be the dataset
71 * name reported in error messages, if supplied.
72 */
73static int
74zcp_sync_task(lua_State *state, dsl_checkfunc_t *checkfunc,
75    dsl_syncfunc_t *syncfunc, void *arg, boolean_t sync, const char *err_dsname)
76{
77	int err;
78	zcp_run_info_t *ri = zcp_run_info(state);
79
80	err = checkfunc(arg, ri->zri_tx);
81	if (!sync)
82		return (err);
83
84	if (!ri->zri_sync) {
85		return (luaL_error(state, "running functions from the zfs.sync "
86		    "submodule requires passing sync=TRUE to "
87		    "lzc_channel_program() (i.e. do not specify the \"-n\" "
88		    "command line argument)"));
89	}
90
91	if (err == 0) {
92		syncfunc(arg, ri->zri_tx);
93	} else if (err == EIO) {
94		if (err_dsname != NULL) {
95			return (luaL_error(state,
96			    "I/O error while accessing dataset '%s'",
97			    err_dsname));
98		} else {
99			return (luaL_error(state,
100			    "I/O error while accessing dataset."));
101		}
102	}
103
104	return (err);
105}
106
107
108static int zcp_synctask_destroy(lua_State *, boolean_t, nvlist_t *);
109static zcp_synctask_info_t zcp_synctask_destroy_info = {
110	.name = "destroy",
111	.func = zcp_synctask_destroy,
112	.pargs = {
113	    {.za_name = "filesystem | snapshot", .za_lua_type = LUA_TSTRING},
114	    {NULL, 0}
115	},
116	.kwargs = {
117	    {.za_name = "defer", .za_lua_type = LUA_TBOOLEAN},
118	    {NULL, 0}
119	},
120	.space_check = ZFS_SPACE_CHECK_DESTROY,
121	.blocks_modified = 0
122};
123
124/* ARGSUSED */
125static int
126zcp_synctask_destroy(lua_State *state, boolean_t sync, nvlist_t *err_details)
127{
128	int err;
129	const char *dsname = lua_tostring(state, 1);
130
131	boolean_t issnap = (strchr(dsname, '@') != NULL);
132
133	if (!issnap && !lua_isnil(state, 2)) {
134		return (luaL_error(state,
135		    "'deferred' kwarg only supported for snapshots: %s",
136		    dsname));
137	}
138
139	if (issnap) {
140		dsl_destroy_snapshot_arg_t ddsa = { 0 };
141		ddsa.ddsa_name = dsname;
142		if (!lua_isnil(state, 2)) {
143			ddsa.ddsa_defer = lua_toboolean(state, 2);
144		} else {
145			ddsa.ddsa_defer = B_FALSE;
146		}
147
148		err = zcp_sync_task(state, dsl_destroy_snapshot_check,
149		    dsl_destroy_snapshot_sync, &ddsa, sync, dsname);
150	} else {
151		dsl_destroy_head_arg_t ddha = { 0 };
152		ddha.ddha_name = dsname;
153
154		err = zcp_sync_task(state, dsl_destroy_head_check,
155		    dsl_destroy_head_sync, &ddha, sync, dsname);
156	}
157
158	return (err);
159}
160
161static int zcp_synctask_promote(lua_State *, boolean_t, nvlist_t *);
162static zcp_synctask_info_t zcp_synctask_promote_info = {
163	.name = "promote",
164	.func = zcp_synctask_promote,
165	.pargs = {
166	    {.za_name = "clone", .za_lua_type = LUA_TSTRING},
167	    {NULL, 0}
168	},
169	.kwargs = {
170	    {NULL, 0}
171	},
172	.space_check = ZFS_SPACE_CHECK_RESERVED,
173	.blocks_modified = 3
174};
175
176static int
177zcp_synctask_promote(lua_State *state, boolean_t sync, nvlist_t *err_details)
178{
179	int err;
180	dsl_dataset_promote_arg_t ddpa = { 0 };
181	const char *dsname = lua_tostring(state, 1);
182	zcp_run_info_t *ri = zcp_run_info(state);
183
184	ddpa.ddpa_clonename = dsname;
185	ddpa.err_ds = err_details;
186	ddpa.cr = ri->zri_cred;
187
188	/*
189	 * If there was a snapshot name conflict, then err_ds will be filled
190	 * with a list of conflicting snapshot names.
191	 */
192	err = zcp_sync_task(state, dsl_dataset_promote_check,
193	    dsl_dataset_promote_sync, &ddpa, sync, dsname);
194
195	return (err);
196}
197
198static int zcp_synctask_rollback(lua_State *, boolean_t, nvlist_t *err_details);
199static zcp_synctask_info_t zcp_synctask_rollback_info = {
200	.name = "rollback",
201	.func = zcp_synctask_rollback,
202	.space_check = ZFS_SPACE_CHECK_RESERVED,
203	.blocks_modified = 1,
204	.pargs = {
205	    {.za_name = "filesystem", .za_lua_type = LUA_TSTRING},
206	    {NULL, 0}
207	},
208	.kwargs = {
209	    {NULL, 0}
210	}
211};
212
213static int
214zcp_synctask_rollback(lua_State *state, boolean_t sync, nvlist_t *err_details)
215{
216	int err;
217	const char *dsname = lua_tostring(state, 1);
218	dsl_dataset_rollback_arg_t ddra = { 0 };
219
220	ddra.ddra_fsname = dsname;
221	ddra.ddra_result = err_details;
222
223	err = zcp_sync_task(state, dsl_dataset_rollback_check,
224	    dsl_dataset_rollback_sync, &ddra, sync, dsname);
225
226	return (err);
227}
228
229static int zcp_synctask_snapshot(lua_State *, boolean_t, nvlist_t *);
230static zcp_synctask_info_t zcp_synctask_snapshot_info = {
231	.name = "snapshot",
232	.func = zcp_synctask_snapshot,
233	.pargs = {
234	    {.za_name = "filesystem@snapname | volume@snapname",
235	    .za_lua_type = LUA_TSTRING},
236	    {NULL, 0}
237	},
238	.kwargs = {
239	    {NULL, 0}
240	},
241	.space_check = ZFS_SPACE_CHECK_NORMAL,
242	.blocks_modified = 3
243};
244
245/* ARGSUSED */
246static int
247zcp_synctask_snapshot(lua_State *state, boolean_t sync, nvlist_t *err_details)
248{
249	int err;
250	dsl_dataset_snapshot_arg_t ddsa = { 0 };
251	const char *dsname = lua_tostring(state, 1);
252	zcp_run_info_t *ri = zcp_run_info(state);
253
254	/*
255	 * On old pools, the ZIL must not be active when a snapshot is created,
256	 * but we can't suspend the ZIL because we're already in syncing
257	 * context.
258	 */
259	if (spa_version(ri->zri_pool->dp_spa) < SPA_VERSION_FAST_SNAP) {
260		return (ENOTSUP);
261	}
262
263	/*
264	 * We only allow for a single snapshot rather than a list, so the
265	 * error list output is unnecessary.
266	 */
267	ddsa.ddsa_errors = NULL;
268	ddsa.ddsa_props = NULL;
269	ddsa.ddsa_cr = ri->zri_cred;
270	ddsa.ddsa_snaps = fnvlist_alloc();
271	fnvlist_add_boolean(ddsa.ddsa_snaps, dsname);
272
273	zcp_cleanup_handler_t *zch = zcp_register_cleanup(state,
274	    (zcp_cleanup_t *)&fnvlist_free, ddsa.ddsa_snaps);
275
276	err = zcp_sync_task(state, dsl_dataset_snapshot_check,
277	    dsl_dataset_snapshot_sync, &ddsa, sync, dsname);
278
279	zcp_deregister_cleanup(state, zch);
280	fnvlist_free(ddsa.ddsa_snaps);
281
282	return (err);
283}
284
285static int zcp_synctask_inherit_prop(lua_State *, boolean_t,
286    nvlist_t *err_details);
287static zcp_synctask_info_t zcp_synctask_inherit_prop_info = {
288	.name = "inherit",
289	.func = zcp_synctask_inherit_prop,
290	.space_check = ZFS_SPACE_CHECK_RESERVED,
291	.blocks_modified = 2, /* 2 * numprops */
292	.pargs = {
293		{ .za_name = "dataset", .za_lua_type = LUA_TSTRING },
294		{ .za_name = "property", .za_lua_type = LUA_TSTRING },
295		{ NULL, 0 }
296	},
297	.kwargs = {
298		{ NULL, 0 }
299	},
300};
301
302static int
303zcp_synctask_inherit_prop_check(void *arg, dmu_tx_t *tx)
304{
305	zcp_inherit_prop_arg_t *args = arg;
306	zfs_prop_t prop = zfs_name_to_prop(args->zipa_prop);
307
308	if (prop == ZPROP_INVAL) {
309		if (zfs_prop_user(args->zipa_prop))
310			return (0);
311
312		return (EINVAL);
313	}
314
315	if (zfs_prop_readonly(prop))
316		return (EINVAL);
317
318	if (!zfs_prop_inheritable(prop))
319		return (EINVAL);
320
321	return (dsl_props_set_check(&args->zipa_dpsa, tx));
322}
323
324static void
325zcp_synctask_inherit_prop_sync(void *arg, dmu_tx_t *tx)
326{
327	zcp_inherit_prop_arg_t *args = arg;
328	dsl_props_set_arg_t *dpsa = &args->zipa_dpsa;
329
330	dsl_props_set_sync(dpsa, tx);
331}
332
333static int
334zcp_synctask_inherit_prop(lua_State *state, boolean_t sync,
335    nvlist_t *err_details)
336{
337	int err;
338	zcp_inherit_prop_arg_t zipa = { 0 };
339	dsl_props_set_arg_t *dpsa = &zipa.zipa_dpsa;
340
341	const char *dsname = lua_tostring(state, 1);
342	const char *prop = lua_tostring(state, 2);
343
344	zipa.zipa_state = state;
345	zipa.zipa_prop = prop;
346	dpsa->dpsa_dsname = dsname;
347	dpsa->dpsa_source = ZPROP_SRC_INHERITED;
348	dpsa->dpsa_props = fnvlist_alloc();
349	fnvlist_add_boolean(dpsa->dpsa_props, prop);
350
351	zcp_cleanup_handler_t *zch = zcp_register_cleanup(state,
352	    (zcp_cleanup_t *)&fnvlist_free, dpsa->dpsa_props);
353
354	err = zcp_sync_task(state, zcp_synctask_inherit_prop_check,
355	    zcp_synctask_inherit_prop_sync, &zipa, sync, dsname);
356
357	zcp_deregister_cleanup(state, zch);
358	fnvlist_free(dpsa->dpsa_props);
359
360	return (err);
361}
362
363static int
364zcp_synctask_wrapper(lua_State *state)
365{
366	int err;
367	zcp_cleanup_handler_t *zch;
368	int num_ret = 1;
369	nvlist_t *err_details = fnvlist_alloc();
370
371	/*
372	 * Make sure err_details is properly freed, even if a fatal error is
373	 * thrown during the synctask.
374	 */
375	zch = zcp_register_cleanup(state,
376	    (zcp_cleanup_t *)&fnvlist_free, err_details);
377
378	zcp_synctask_info_t *info = lua_touserdata(state, lua_upvalueindex(1));
379	boolean_t sync = lua_toboolean(state, lua_upvalueindex(2));
380
381	zcp_run_info_t *ri = zcp_run_info(state);
382	dsl_pool_t *dp = ri->zri_pool;
383
384	/* MOS space is triple-dittoed, so we multiply by 3. */
385	uint64_t funcspace = (info->blocks_modified << DST_AVG_BLKSHIFT) * 3;
386
387	zcp_parse_args(state, info->name, info->pargs, info->kwargs);
388
389	err = 0;
390	if (info->space_check != ZFS_SPACE_CHECK_NONE) {
391		uint64_t quota = dsl_pool_unreserved_space(dp,
392		    info->space_check);
393		uint64_t used = dsl_dir_phys(dp->dp_root_dir)->dd_used_bytes +
394		    ri->zri_space_used;
395
396		if (used + funcspace > quota) {
397			err = SET_ERROR(ENOSPC);
398		}
399	}
400
401	if (err == 0) {
402		err = info->func(state, sync, err_details);
403	}
404
405	if (err == 0) {
406		ri->zri_space_used += funcspace;
407	}
408
409	lua_pushnumber(state, (lua_Number)err);
410	if (fnvlist_num_pairs(err_details) > 0) {
411		(void) zcp_nvlist_to_lua(state, err_details, NULL, 0);
412		num_ret++;
413	}
414
415	zcp_deregister_cleanup(state, zch);
416	fnvlist_free(err_details);
417
418	return (num_ret);
419}
420
421int
422zcp_load_synctask_lib(lua_State *state, boolean_t sync)
423{
424	int i;
425	zcp_synctask_info_t *zcp_synctask_funcs[] = {
426		&zcp_synctask_destroy_info,
427		&zcp_synctask_promote_info,
428		&zcp_synctask_rollback_info,
429		&zcp_synctask_snapshot_info,
430		&zcp_synctask_inherit_prop_info,
431		NULL
432	};
433
434	lua_newtable(state);
435
436	for (i = 0; zcp_synctask_funcs[i] != NULL; i++) {
437		zcp_synctask_info_t *info = zcp_synctask_funcs[i];
438		lua_pushlightuserdata(state, info);
439		lua_pushboolean(state, sync);
440		lua_pushcclosure(state, &zcp_synctask_wrapper, 2);
441		lua_setfield(state, -2, info->name);
442		info++;
443	}
444
445	return (1);
446}
447