module/zfs/zcp_get.c

   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 by Delphix. All rights reserved.
  18  */
  19
  20 #include <sys/lua/lua.h>
  21 #include <sys/lua/lualib.h>
  22 #include <sys/lua/lauxlib.h>
  23
  24 #include <zfs_prop.h>
  25
  26 #include <sys/dsl_prop.h>
  27 #include <sys/dsl_synctask.h>
  28 #include <sys/dsl_dataset.h>
  29 #include <sys/dsl_dir.h>
  30 #include <sys/dmu_objset.h>
  31 #include <sys/mntent.h>
  32 #include <sys/sunddi.h>
  33 #include <sys/zap.h>
  34 #include <sys/zcp.h>
  35 #include <sys/zcp_iter.h>
  36 #include <sys/zcp_global.h>
  37 #include <sys/zfs_ioctl.h>
  38 #include <sys/zfs_znode.h>
  39 #include <sys/zvol.h>
  40
  41 #ifdef _KERNEL
  42 #include <sys/zfs_vfsops.h>
  43 #endif
  44
  45 static int
  46 get_objset_type(dsl_dataset_t *ds, zfs_type_t *type)
  47 {
  48         int error;
  49         objset_t *os;
  50         error = dmu_objset_from_ds(ds, &os);
  51         if (error != 0)
  52                 return (error);
  53         if (ds->ds_is_snapshot) {
  54                 *type = ZFS_TYPE_SNAPSHOT;
  55         } else {
  56                 switch (os->os_phys->os_type) {
  57                 case DMU_OST_ZFS:
  58                         *type = ZFS_TYPE_FILESYSTEM;
  59                         break;
  60                 case DMU_OST_ZVOL:
  61                         *type = ZFS_TYPE_VOLUME;
  62                         break;
  63                 default:
  64                         return (EINVAL);
  65                 }
  66         }
  67         return (0);
  68 }
  69
  70 /*
  71  * Returns the string name of ds's type in str (a buffer which should be
  72  * at least 12 bytes long).
  73  */
  74 static int
  75 get_objset_type_name(dsl_dataset_t *ds, char *str)
  76 {
  77         int error;
  78         zfs_type_t type;
  79         error = get_objset_type(ds, &type);
  80         if (error != 0)
  81                 return (error);
  82         switch (type) {
  83         case ZFS_TYPE_SNAPSHOT:
  84                 (void) strcpy(str, "snapshot");
  85                 break;
  86         case ZFS_TYPE_FILESYSTEM:
  87                 (void) strcpy(str, "filesystem");
  88                 break;
  89         case ZFS_TYPE_VOLUME:
  90                 (void) strcpy(str, "volume");
  91                 break;
  92         default:
  93                 return (EINVAL);
  94         }
  95         return (0);
  96 }
  97
  98 /*
  99  * Determines the source of a property given its setpoint and
 100  * property type. It pushes the source to the lua stack.
 101  */
 102 static void
 103 get_prop_src(lua_State *state, const char *setpoint, zfs_prop_t prop)
 104 {
 105         if (zfs_prop_readonly(prop) || (prop == ZFS_PROP_VERSION)) {
 106                 lua_pushnil(state);
 107         } else {
 108                 const char *src;
 109                 if (strcmp("", setpoint) == 0) {
 110                         src = "default";
 111                 } else {
 112                         src = setpoint;
 113                 }
 114                 (void) lua_pushstring(state, src);
 115         }
 116 }
 117
 118 /*
 119  * Given an error encountered while getting properties, either longjmp's for
 120  * a fatal error or pushes nothing to the stack for a non fatal one.
 121  */
 122 static int
 123 zcp_handle_error(lua_State *state, const char *dataset_name,
 124     const char *property_name, int error)
 125 {
 126         ASSERT3S(error, !=, 0);
 127         if (error == ENOENT) {
 128                 return (0);
 129         } else if (error == EINVAL) {
 130                 return (luaL_error(state,
 131                     "property '%s' is not a valid property on dataset '%s'",
 132                     property_name, dataset_name));
 133         } else if (error == EIO) {
 134                 return (luaL_error(state,
 135                     "I/O error while retrieving property '%s' on dataset '%s'",
 136                     property_name, dataset_name));
 137         } else {
 138                 return (luaL_error(state, "unexpected error %d while "
 139                     "retrieving property '%s' on dataset '%s'",
 140                     error, property_name, dataset_name));
 141         }
 142 }
 143
 144 /*
 145  * Look up a user defined property in the zap object. If it exists, push it
 146  * and the setpoint onto the stack, otherwise don't push anything.
 147  */
 148 static int
 149 zcp_get_user_prop(lua_State *state, dsl_pool_t *dp, const char *dataset_name,
 150     const char *property_name)
 151 {
 152         int error;
 153         char *buf;
 154         char setpoint[ZFS_MAX_DATASET_NAME_LEN];
 155         /*
 156          * zcp_dataset_hold will either successfully return the requested
 157          * dataset or throw a lua error and longjmp out of the zfs.get_prop call
 158          * without returning.
 159          */
 160         dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
 161         if (ds == NULL)
 162                 return (1); /* not reached; zcp_dataset_hold() longjmp'd */
 163
 164         buf = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
 165         error = dsl_prop_get_ds(ds, property_name, 1, ZAP_MAXVALUELEN,
 166             buf, setpoint);
 167         dsl_dataset_rele(ds, FTAG);
 168
 169         if (error != 0) {
 170                 kmem_free(buf, ZAP_MAXVALUELEN);
 171                 return (zcp_handle_error(state, dataset_name, property_name,
 172                     error));
 173         }
 174         (void) lua_pushstring(state, buf);
 175         (void) lua_pushstring(state, setpoint);
 176         kmem_free(buf, ZAP_MAXVALUELEN);
 177         return (2);
 178 }
 179
 180 /*
 181  * Check if the property we're looking for is stored in the ds_dir. If so,
 182  * return it in the 'val' argument. Return 0 on success and ENOENT and if
 183  * the property is not present.
 184  */
 185 static int
 186 get_dsl_dir_prop(dsl_dataset_t *ds, zfs_prop_t zfs_prop,
 187     uint64_t *val)
 188 {
 189         dsl_dir_t *dd = ds->ds_dir;
 190         mutex_enter(&dd->dd_lock);
 191         switch (zfs_prop) {
 192         case ZFS_PROP_USEDSNAP:
 193                 *val = dsl_dir_get_usedsnap(dd);
 194                 break;
 195         case ZFS_PROP_USEDCHILD:
 196                 *val = dsl_dir_get_usedchild(dd);
 197                 break;
 198         case ZFS_PROP_USEDDS:
 199                 *val = dsl_dir_get_usedds(dd);
 200                 break;
 201         case ZFS_PROP_USEDREFRESERV:
 202                 *val = dsl_dir_get_usedrefreserv(dd);
 203                 break;
 204         case ZFS_PROP_LOGICALUSED:
 205                 *val = dsl_dir_get_logicalused(dd);
 206                 break;
 207         default:
 208                 mutex_exit(&dd->dd_lock);
 209                 return (ENOENT);
 210         }
 211         mutex_exit(&dd->dd_lock);
 212         return (0);
 213 }
 214
 215 /*
 216  * Takes a dataset, a property, a value and that value's setpoint as
 217  * found in the ZAP. Checks if the property has been changed in the vfs.
 218  * If so, val and setpoint will be overwritten with updated content.
 219  * Otherwise, they are left unchanged.
 220  */
 221 static int
 222 get_temporary_prop(dsl_dataset_t *ds, zfs_prop_t zfs_prop, uint64_t *val,
 223     char *setpoint)
 224 {
 225 #if     !defined(_KERNEL)
 226         return (0);
 227 #else
 228         int error;
 229         zfsvfs_t *zfvp;
 230         vfs_t *vfsp;
 231         objset_t *os;
 232         uint64_t tmp = *val;
 233
 234         error = dmu_objset_from_ds(ds, &os);
 235         if (error != 0)
 236                 return (error);
 237
 238         if (dmu_objset_type(os) != DMU_OST_ZFS)
 239                 return (EINVAL);
 240
 241         mutex_enter(&os->os_user_ptr_lock);
 242         zfvp = dmu_objset_get_user(os);
 243         mutex_exit(&os->os_user_ptr_lock);
 244         if (zfvp == NULL)
 245                 return (ESRCH);
 246
 247         vfsp = zfvp->z_vfs;
 248
 249         switch (zfs_prop) {
 250         case ZFS_PROP_ATIME:
 251                 if (vfsp->vfs_do_atime)
 252                         tmp = vfsp->vfs_atime;
 253                 break;
 254         case ZFS_PROP_RELATIME:
 255                 if (vfsp->vfs_do_relatime)
 256                         tmp = vfsp->vfs_relatime;
 257                 break;
 258         case ZFS_PROP_DEVICES:
 259                 if (vfsp->vfs_do_devices)
 260                         tmp = vfsp->vfs_devices;
 261                 break;
 262         case ZFS_PROP_EXEC:
 263                 if (vfsp->vfs_do_exec)
 264                         tmp = vfsp->vfs_exec;
 265                 break;
 266         case ZFS_PROP_SETUID:
 267                 if (vfsp->vfs_do_setuid)
 268                         tmp = vfsp->vfs_setuid;
 269                 break;
 270         case ZFS_PROP_READONLY:
 271                 if (vfsp->vfs_do_readonly)
 272                         tmp = vfsp->vfs_readonly;
 273                 break;
 274         case ZFS_PROP_XATTR:
 275                 if (vfsp->vfs_do_xattr)
 276                         tmp = vfsp->vfs_xattr;
 277                 break;
 278         case ZFS_PROP_NBMAND:
 279                 if (vfsp->vfs_do_nbmand)
 280                         tmp = vfsp->vfs_nbmand;
 281                 break;
 282         default:
 283                 return (ENOENT);
 284         }
 285
 286         if (tmp != *val) {
 287                 (void) strcpy(setpoint, "temporary");
 288                 *val = tmp;
 289         }
 290         return (0);
 291 #endif
 292 }
 293
 294 /*
 295  * Check if the property we're looking for is stored at the dsl_dataset or
 296  * dsl_dir level. If so, push the property value and source onto the lua stack
 297  * and return 0. If it is not present or a failure occurs in lookup, return a
 298  * non-zero error value.
 299  */
 300 static int
 301 get_special_prop(lua_State *state, dsl_dataset_t *ds, const char *dsname,
 302     zfs_prop_t zfs_prop)
 303 {
 304         int error = 0;
 305         objset_t *os;
 306         uint64_t numval = 0;
 307         char *strval = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
 308         char setpoint[ZFS_MAX_DATASET_NAME_LEN] =
 309             "Internal error - setpoint not determined";
 310         zfs_type_t ds_type;
 311         zprop_type_t prop_type = zfs_prop_get_type(zfs_prop);
 312         (void) get_objset_type(ds, &ds_type);
 313
 314         switch (zfs_prop) {
 315         case ZFS_PROP_REFRATIO:
 316                 numval = dsl_get_refratio(ds);
 317                 break;
 318         case ZFS_PROP_USED:
 319                 numval = dsl_get_used(ds);
 320                 break;
 321         case ZFS_PROP_CLONES: {
 322                 nvlist_t *clones = fnvlist_alloc();
 323                 error = get_clones_stat_impl(ds, clones);
 324                 if (error == 0) {
 325                         /* push list to lua stack */
 326                         VERIFY0(zcp_nvlist_to_lua(state, clones, NULL, 0ULL));
 327                         /* source */
 328                         (void) lua_pushnil(state);
 329                 }
 330                 nvlist_free(clones);
 331                 kmem_free(strval, ZAP_MAXVALUELEN);
 332                 return (error);
 333         }
 334         case ZFS_PROP_COMPRESSRATIO:
 335                 numval = dsl_get_compressratio(ds);
 336                 break;
 337         case ZFS_PROP_CREATION:
 338                 numval = dsl_get_creation(ds);
 339                 break;
 340         case ZFS_PROP_REFERENCED:
 341                 numval = dsl_get_referenced(ds);
 342                 break;
 343         case ZFS_PROP_AVAILABLE:
 344                 numval = dsl_get_available(ds);
 345                 break;
 346         case ZFS_PROP_LOGICALREFERENCED:
 347                 numval = dsl_get_logicalreferenced(ds);
 348                 break;
 349         case ZFS_PROP_CREATETXG:
 350                 numval = dsl_get_creationtxg(ds);
 351                 break;
 352         case ZFS_PROP_GUID:
 353                 numval = dsl_get_guid(ds);
 354                 break;
 355         case ZFS_PROP_UNIQUE:
 356                 numval = dsl_get_unique(ds);
 357                 break;
 358         case ZFS_PROP_OBJSETID:
 359                 numval = dsl_get_objsetid(ds);
 360                 break;
 361         case ZFS_PROP_ORIGIN:
 362                 dsl_dir_get_origin(ds->ds_dir, strval);
 363                 break;
 364         case ZFS_PROP_USERACCOUNTING:
 365                 error = dmu_objset_from_ds(ds, &os);
 366                 if (error == 0)
 367                         numval = dmu_objset_userspace_present(os);
 368                 break;
 369         case ZFS_PROP_WRITTEN:
 370                 error = dsl_get_written(ds, &numval);
 371                 break;
 372         case ZFS_PROP_TYPE:
 373                 error = get_objset_type_name(ds, strval);
 374                 break;
 375         case ZFS_PROP_PREV_SNAP:
 376                 error = dsl_get_prev_snap(ds, strval);
 377                 break;
 378         case ZFS_PROP_NAME:
 379                 dsl_dataset_name(ds, strval);
 380                 break;
 381         case ZFS_PROP_MOUNTPOINT:
 382                 error = dsl_get_mountpoint(ds, dsname, strval, setpoint);
 383                 break;
 384         case ZFS_PROP_VERSION:
 385                 /* should be a snapshot or filesystem */
 386                 ASSERT(ds_type != ZFS_TYPE_VOLUME);
 387                 error = dmu_objset_from_ds(ds, &os);
 388                 /* look in the master node for the version */
 389                 if (error == 0) {
 390                         error = zap_lookup(os, MASTER_NODE_OBJ, ZPL_VERSION_STR,
 391                             sizeof (numval), 1, &numval);
 392                 }
 393                 break;
 394         case ZFS_PROP_DEFER_DESTROY:
 395                 numval = dsl_get_defer_destroy(ds);
 396                 break;
 397         case ZFS_PROP_USERREFS:
 398                 numval = dsl_get_userrefs(ds);
 399                 break;
 400         case ZFS_PROP_FILESYSTEM_COUNT:
 401                 error = dsl_dir_get_filesystem_count(ds->ds_dir, &numval);
 402                 (void) strcpy(setpoint, "");
 403                 break;
 404         case ZFS_PROP_SNAPSHOT_COUNT:
 405                 error = dsl_dir_get_snapshot_count(ds->ds_dir, &numval);
 406                 (void) strcpy(setpoint, "");
 407                 break;
 408         case ZFS_PROP_NUMCLONES:
 409                 numval = dsl_get_numclones(ds);
 410                 break;
 411         case ZFS_PROP_INCONSISTENT:
 412                 numval = dsl_get_inconsistent(ds);
 413                 break;
 414         case ZFS_PROP_RECEIVE_RESUME_TOKEN: {
 415                 char *token = get_receive_resume_stats_impl(ds);
 416
 417                 VERIFY3U(strlcpy(strval, token, ZAP_MAXVALUELEN),
 418                     <, ZAP_MAXVALUELEN);
 419                 if (strcmp(strval, "") == 0) {
 420                         char *childval = get_child_receive_stats(ds);
 421
 422                         VERIFY3U(strlcpy(strval, childval, ZAP_MAXVALUELEN),
 423                             <, ZAP_MAXVALUELEN);
 424                         if (strcmp(strval, "") == 0)
 425                                 error = ENOENT;
 426
 427                         strfree(childval);
 428                 }
 429                 strfree(token);
 430                 break;
 431         }
 432         case ZFS_PROP_VOLSIZE:
 433                 ASSERT(ds_type == ZFS_TYPE_VOLUME ||
 434                     ds_type == ZFS_TYPE_SNAPSHOT);
 435                 error = dmu_objset_from_ds(ds, &os);
 436                 if (error == 0) {
 437                         error = zap_lookup(os, ZVOL_ZAP_OBJ, "size",
 438                             sizeof (numval), 1, &numval);
 439                 }
 440                 if (error == 0)
 441                         (void) strcpy(setpoint, dsname);
 442
 443                 break;
 444         case ZFS_PROP_VOLBLOCKSIZE: {
 445                 ASSERT(ds_type == ZFS_TYPE_VOLUME);
 446                 dmu_object_info_t doi;
 447                 error = dmu_objset_from_ds(ds, &os);
 448                 if (error == 0) {
 449                         error = dmu_object_info(os, ZVOL_OBJ, &doi);
 450                         if (error == 0)
 451                                 numval = doi.doi_data_block_size;
 452                 }
 453                 break;
 454         }
 455
 456         case ZFS_PROP_KEYSTATUS:
 457         case ZFS_PROP_KEYFORMAT: {
 458                 /* provide defaults in case no crypto obj exists */
 459                 setpoint[0] = '\0';
 460                 if (zfs_prop == ZFS_PROP_KEYSTATUS)
 461                         numval = ZFS_KEYSTATUS_NONE;
 462                 else
 463                         numval = ZFS_KEYFORMAT_NONE;
 464
 465                 nvlist_t *nvl, *propval;
 466                 nvl = fnvlist_alloc();
 467                 dsl_dataset_crypt_stats(ds, nvl);
 468                 if (nvlist_lookup_nvlist(nvl, zfs_prop_to_name(zfs_prop),
 469                     &propval) == 0) {
 470                         char *source;
 471
 472                         (void) nvlist_lookup_uint64(propval, ZPROP_VALUE,
 473                             &numval);
 474                         if (nvlist_lookup_string(propval, ZPROP_SOURCE,
 475                             &source) == 0)
 476                                 strlcpy(setpoint, source, sizeof (setpoint));
 477                 }
 478                 nvlist_free(nvl);
 479                 break;
 480         }
 481
 482         default:
 483                 /* Did not match these props, check in the dsl_dir */
 484                 error = get_dsl_dir_prop(ds, zfs_prop, &numval);
 485         }
 486         if (error != 0) {
 487                 kmem_free(strval, ZAP_MAXVALUELEN);
 488                 return (error);
 489         }
 490
 491         switch (prop_type) {
 492         case PROP_TYPE_NUMBER: {
 493                 (void) lua_pushnumber(state, numval);
 494                 break;
 495         }
 496         case PROP_TYPE_STRING: {
 497                 (void) lua_pushstring(state, strval);
 498                 break;
 499         }
 500         case PROP_TYPE_INDEX: {
 501                 const char *propval;
 502                 error = zfs_prop_index_to_string(zfs_prop, numval, &propval);
 503                 if (error != 0) {
 504                         kmem_free(strval, ZAP_MAXVALUELEN);
 505                         return (error);
 506                 }
 507                 (void) lua_pushstring(state, propval);
 508                 break;
 509         }
 510         }
 511         kmem_free(strval, ZAP_MAXVALUELEN);
 512
 513         /* Push the source to the stack */
 514         get_prop_src(state, setpoint, zfs_prop);
 515         return (0);
 516 }
 517
 518 /*
 519  * Look up a property and its source in the zap object. If the value is
 520  * present and successfully retrieved, push the value and source on the
 521  * lua stack and return 0. On failure, return a non-zero error value.
 522  */
 523 static int
 524 get_zap_prop(lua_State *state, dsl_dataset_t *ds, zfs_prop_t zfs_prop)
 525 {
 526         int error = 0;
 527         char setpoint[ZFS_MAX_DATASET_NAME_LEN];
 528         char *strval = kmem_alloc(ZAP_MAXVALUELEN, KM_SLEEP);
 529         uint64_t numval;
 530         const char *prop_name = zfs_prop_to_name(zfs_prop);
 531         zprop_type_t prop_type = zfs_prop_get_type(zfs_prop);
 532
 533         if (prop_type == PROP_TYPE_STRING) {
 534                 /* Push value to lua stack */
 535                 error = dsl_prop_get_ds(ds, prop_name, 1,
 536                     ZAP_MAXVALUELEN, strval, setpoint);
 537                 if (error == 0)
 538                         (void) lua_pushstring(state, strval);
 539         } else {
 540                 error = dsl_prop_get_ds(ds, prop_name, sizeof (numval),
 541                     1, &numval, setpoint);
 542
 543                 /* Fill in temorary value for prop, if applicable */
 544                 (void) get_temporary_prop(ds, zfs_prop, &numval, setpoint);
 545
 546                 /* Push value to lua stack */
 547                 if (prop_type == PROP_TYPE_INDEX) {
 548                         const char *propval;
 549                         error = zfs_prop_index_to_string(zfs_prop, numval,
 550                             &propval);
 551                         if (error == 0)
 552                                 (void) lua_pushstring(state, propval);
 553                 } else {
 554                         if (error == 0)
 555                                 (void) lua_pushnumber(state, numval);
 556                 }
 557         }
 558         kmem_free(strval, ZAP_MAXVALUELEN);
 559         if (error == 0)
 560                 get_prop_src(state, setpoint, zfs_prop);
 561         return (error);
 562 }
 563
 564 /*
 565  * Determine whether property is valid for a given dataset
 566  */
 567 boolean_t
 568 prop_valid_for_ds(dsl_dataset_t *ds, zfs_prop_t zfs_prop)
 569 {
 570         int error;
 571         zfs_type_t zfs_type;
 572
 573         /* properties not supported */
 574         if ((zfs_prop == ZFS_PROP_ISCSIOPTIONS) ||
 575             (zfs_prop == ZFS_PROP_MOUNTED))
 576                 return (B_FALSE);
 577
 578         /* if we want the origin prop, ds must be a clone */
 579         if ((zfs_prop == ZFS_PROP_ORIGIN) && (!dsl_dir_is_clone(ds->ds_dir)))
 580                 return (B_FALSE);
 581
 582         error = get_objset_type(ds, &zfs_type);
 583         if (error != 0)
 584                 return (B_FALSE);
 585         return (zfs_prop_valid_for_type(zfs_prop, zfs_type, B_FALSE));
 586 }
 587
 588 /*
 589  * Look up a given dataset property. On success return 2, the number of
 590  * values pushed to the lua stack (property value and source). On a fatal
 591  * error, longjmp. On a non fatal error push nothing.
 592  */
 593 static int
 594 zcp_get_system_prop(lua_State *state, dsl_pool_t *dp, const char *dataset_name,
 595     zfs_prop_t zfs_prop)
 596 {
 597         int error;
 598         /*
 599          * zcp_dataset_hold will either successfully return the requested
 600          * dataset or throw a lua error and longjmp out of the zfs.get_prop call
 601          * without returning.
 602          */
 603         dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
 604         if (ds == NULL)
 605                 return (1); /* not reached; zcp_dataset_hold() longjmp'd */
 606
 607         /* Check that the property is valid for the given dataset */
 608         const char *prop_name = zfs_prop_to_name(zfs_prop);
 609         if (!prop_valid_for_ds(ds, zfs_prop)) {
 610                 dsl_dataset_rele(ds, FTAG);
 611                 return (0);
 612         }
 613
 614         /* Check if the property can be accessed directly */
 615         error = get_special_prop(state, ds, dataset_name, zfs_prop);
 616         if (error == 0) {
 617                 dsl_dataset_rele(ds, FTAG);
 618                 /* The value and source have been pushed by get_special_prop */
 619                 return (2);
 620         }
 621         if (error != ENOENT) {
 622                 dsl_dataset_rele(ds, FTAG);
 623                 return (zcp_handle_error(state, dataset_name,
 624                     prop_name, error));
 625         }
 626
 627         /* If we were unable to find it, look in the zap object */
 628         error = get_zap_prop(state, ds, zfs_prop);
 629         dsl_dataset_rele(ds, FTAG);
 630         if (error != 0) {
 631                 return (zcp_handle_error(state, dataset_name,
 632                     prop_name, error));
 633         }
 634         /* The value and source have been pushed by get_zap_prop */
 635         return (2);
 636 }
 637
 638 #ifdef _KERNEL
 639 static zfs_userquota_prop_t
 640 get_userquota_prop(const char *prop_name)
 641 {
 642         zfs_userquota_prop_t type;
 643         /* Figure out the property type ({user|group}{quota|used}) */
 644         for (type = 0; type < ZFS_NUM_USERQUOTA_PROPS; type++) {
 645                 if (strncmp(prop_name, zfs_userquota_prop_prefixes[type],
 646                     strlen(zfs_userquota_prop_prefixes[type])) == 0)
 647                         break;
 648         }
 649         return (type);
 650 }
 651
 652 /*
 653  * Given the name of a zfs_userquota_prop, this function determines the
 654  * prop type as well as the numeric group/user ids based on the string
 655  * following the '@' in the property name. On success, returns 0. On failure,
 656  * returns a non-zero error.
 657  * 'domain' must be free'd by caller using strfree()
 658  */
 659 static int
 660 parse_userquota_prop(const char *prop_name, zfs_userquota_prop_t *type,
 661     char **domain, uint64_t *rid)
 662 {
 663         char *cp, *end, *domain_val;
 664
 665         *type = get_userquota_prop(prop_name);
 666         if (*type >= ZFS_NUM_USERQUOTA_PROPS)
 667                 return (EINVAL);
 668
 669         *rid = 0;
 670         cp = strchr(prop_name, '@') + 1;
 671         if (strncmp(cp, "S-1-", 4) == 0) {
 672                 /*
 673                  * It's a numeric SID (eg "S-1-234-567-89") and we want to
 674                  * seperate the domain id and the rid
 675                  */
 676                 int domain_len = strrchr(cp, '-') - cp;
 677                 domain_val = kmem_alloc(domain_len + 1, KM_SLEEP);
 678                 (void) strncpy(domain_val, cp, domain_len);
 679                 domain_val[domain_len] = '\0';
 680                 cp += domain_len + 1;
 681
 682                 (void) ddi_strtoll(cp, &end, 10, (longlong_t *)rid);
 683                 if (*end != '\0') {
 684                         strfree(domain_val);
 685                         return (EINVAL);
 686                 }
 687         } else {
 688                 /* It's only a user/group ID (eg "12345"), just get the rid */
 689                 domain_val = NULL;
 690                 (void) ddi_strtoll(cp, &end, 10, (longlong_t *)rid);
 691                 if (*end != '\0')
 692                         return (EINVAL);
 693         }
 694         *domain = domain_val;
 695         return (0);
 696 }
 697
 698 /*
 699  * Look up {user|group}{quota|used} property for given dataset. On success
 700  * push the value (quota or used amount) and the setpoint. On failure, push
 701  * a lua error.
 702  */
 703 static int
 704 zcp_get_userquota_prop(lua_State *state, dsl_pool_t *dp,
 705     const char *dataset_name, const char *prop_name)
 706 {
 707         zfsvfs_t *zfvp;
 708         zfsvfs_t *zfsvfs;
 709         int error;
 710         zfs_userquota_prop_t type;
 711         char *domain;
 712         uint64_t rid, value = 0;
 713         objset_t *os;
 714
 715         dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
 716         if (ds == NULL)
 717                 return (1); /* not reached; zcp_dataset_hold() longjmp'd */
 718
 719         error = parse_userquota_prop(prop_name, &type, &domain, &rid);
 720         if (error == 0) {
 721                 error = dmu_objset_from_ds(ds, &os);
 722                 if (error == 0) {
 723                         zfsvfs = kmem_zalloc(sizeof (zfsvfs_t), KM_SLEEP);
 724                         error = zfsvfs_create_impl(&zfvp, zfsvfs, os);
 725                         if (error == 0) {
 726                                 error = zfs_userspace_one(zfvp, type, domain,
 727                                     rid, &value);
 728                                 zfsvfs_free(zfvp);
 729                         }
 730                 }
 731                 if (domain != NULL)
 732                         strfree(domain);
 733         }
 734         dsl_dataset_rele(ds, FTAG);
 735
 736         if ((value == 0) && ((type == ZFS_PROP_USERQUOTA) ||
 737             (type == ZFS_PROP_GROUPQUOTA)))
 738                 error = ENOENT;
 739         if (error != 0) {
 740                 return (zcp_handle_error(state, dataset_name,
 741                     prop_name, error));
 742         }
 743
 744         (void) lua_pushnumber(state, value);
 745         (void) lua_pushstring(state, dataset_name);
 746         return (2);
 747 }
 748 #endif
 749
 750 /*
 751  * Determines the name of the snapshot referenced in the written property
 752  * name. Returns snapshot name in snap_name, a buffer that must be at least
 753  * as large as ZFS_MAX_DATASET_NAME_LEN
 754  */
 755 static void
 756 parse_written_prop(const char *dataset_name, const char *prop_name,
 757     char *snap_name)
 758 {
 759         ASSERT(zfs_prop_written(prop_name));
 760         const char *name = prop_name + ZFS_WRITTEN_PROP_PREFIX_LEN;
 761         if (strchr(name, '@') == NULL) {
 762                 (void) sprintf(snap_name, "%s@%s", dataset_name, name);
 763         } else {
 764                 (void) strcpy(snap_name, name);
 765         }
 766 }
 767
 768 /*
 769  * Look up written@ property for given dataset. On success
 770  * push the value and the setpoint. If error is fatal, we will
 771  * longjmp, otherwise push nothing.
 772  */
 773 static int
 774 zcp_get_written_prop(lua_State *state, dsl_pool_t *dp,
 775     const char *dataset_name, const char *prop_name)
 776 {
 777         char snap_name[ZFS_MAX_DATASET_NAME_LEN];
 778         uint64_t used, comp, uncomp;
 779         dsl_dataset_t *old;
 780         int error = 0;
 781
 782         parse_written_prop(dataset_name, prop_name, snap_name);
 783         dsl_dataset_t *new = zcp_dataset_hold(state, dp, dataset_name, FTAG);
 784         if (new == NULL)
 785                 return (1); /* not reached; zcp_dataset_hold() longjmp'd */
 786
 787         error = dsl_dataset_hold(dp, snap_name, FTAG, &old);
 788         if (error != 0) {
 789                 dsl_dataset_rele(new, FTAG);
 790                 return (zcp_dataset_hold_error(state, dp, snap_name,
 791                     error));
 792         }
 793         error = dsl_dataset_space_written(old, new,
 794             &used, &comp, &uncomp);
 795
 796         dsl_dataset_rele(old, FTAG);
 797         dsl_dataset_rele(new, FTAG);
 798
 799         if (error != 0) {
 800                 return (zcp_handle_error(state, dataset_name,
 801                     snap_name, error));
 802         }
 803         (void) lua_pushnumber(state, used);
 804         (void) lua_pushstring(state, dataset_name);
 805         return (2);
 806 }
 807
 808 static int zcp_get_prop(lua_State *state);
 809 static zcp_lib_info_t zcp_get_prop_info = {
 810         .name = "get_prop",
 811         .func = zcp_get_prop,
 812         .pargs = {
 813             { .za_name = "dataset", .za_lua_type = LUA_TSTRING},
 814             { .za_name = "property", .za_lua_type =  LUA_TSTRING},
 815             {NULL, 0}
 816         },
 817         .kwargs = {
 818             {NULL, 0}
 819         }
 820 };
 821
 822 static int
 823 zcp_get_prop(lua_State *state)
 824 {
 825         const char *dataset_name;
 826         const char *property_name;
 827         dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
 828         zcp_lib_info_t *libinfo = &zcp_get_prop_info;
 829
 830         zcp_parse_args(state, libinfo->name, libinfo->pargs, libinfo->kwargs);
 831
 832         dataset_name = lua_tostring(state, 1);
 833         property_name = lua_tostring(state, 2);
 834
 835         /* User defined property */
 836         if (zfs_prop_user(property_name)) {
 837                 return (zcp_get_user_prop(state, dp,
 838                     dataset_name, property_name));
 839         }
 840         /* userspace property */
 841         if (zfs_prop_userquota(property_name)) {
 842 #ifdef _KERNEL
 843                 return (zcp_get_userquota_prop(state, dp,
 844                     dataset_name, property_name));
 845 #else
 846                 return (luaL_error(state,
 847                     "user quota properties only supported in kernel mode",
 848                     property_name));
 849 #endif
 850         }
 851         /* written@ property */
 852         if (zfs_prop_written(property_name)) {
 853                 return (zcp_get_written_prop(state, dp,
 854                     dataset_name, property_name));
 855         }
 856
 857         zfs_prop_t zfs_prop = zfs_name_to_prop(property_name);
 858         /* Valid system property */
 859         if (zfs_prop != ZPROP_INVAL) {
 860                 return (zcp_get_system_prop(state, dp, dataset_name,
 861                     zfs_prop));
 862         }
 863
 864         /* Invalid property name */
 865         return (luaL_error(state,
 866             "'%s' is not a valid property", property_name));
 867 }
 868
 869 int
 870 zcp_load_get_lib(lua_State *state)
 871 {
 872         lua_pushcclosure(state, zcp_get_prop_info.func, 0);
 873         lua_setfield(state, -2, zcp_get_prop_info.name);
 874
 875         return (1);
 876 }