Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 | /*
* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 only,
* as published by the Free Software Foundation.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License version 2 for more details. A copy is
* included in the COPYING file that accompanied this code.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* GPL HEADER END
*/
/*
* Copyright (c) 2011 Intel Corporation
*
* Copyright 2012 Xyratex Technology Limited
*/
/*
* lustre/ptlrpc/nrs.c
*
* Network Request Scheduler (NRS)
*
* Allows to reorder the handling of RPCs at servers.
*
* Author: Liang Zhen <liang@whamcloud.com>
* Author: Nikitas Angelinas <nikitas_angelinas@xyratex.com>
*/
/**
* \addtogoup nrs
* @{
*/
#define DEBUG_SUBSYSTEM S_RPC
#include <obd_support.h>
#include <obd_class.h>
#include <lustre_net.h>
#include <lprocfs_status.h>
#include <linux/libcfs/libcfs.h>
#include "ptlrpc_internal.h"
/* XXX: This is just for liblustre. Remove the #if defined directive when the
* "cfs_" prefix is dropped from cfs_list_head. */
extern struct list_head ptlrpc_all_services;
/**
* NRS core object.
*/
struct nrs_core nrs_core;
static int nrs_policy_init(struct ptlrpc_nrs_policy *policy)
{
return policy->pol_desc->pd_ops->op_policy_init != NULL ?
policy->pol_desc->pd_ops->op_policy_init(policy) : 0;
}
static void nrs_policy_fini(struct ptlrpc_nrs_policy *policy)
{
LASSERT(policy->pol_ref == 0);
LASSERT(policy->pol_req_queued == 0);
if (policy->pol_desc->pd_ops->op_policy_fini != NULL)
policy->pol_desc->pd_ops->op_policy_fini(policy);
}
static int nrs_policy_ctl_locked(struct ptlrpc_nrs_policy *policy,
enum ptlrpc_nrs_ctl opc, void *arg)
{
/**
* The policy may be stopped, but the lprocfs files and
* ptlrpc_nrs_policy instances remain present until unregistration time.
* Do not perform the ctl operation if the policy is stopped, as
* policy->pol_private will be NULL in such a case.
*/
if (policy->pol_state == NRS_POL_STATE_STOPPED)
return -ENODEV;
return policy->pol_desc->pd_ops->op_policy_ctl != NULL ?
policy->pol_desc->pd_ops->op_policy_ctl(policy, opc, arg) :
-ENOSYS;
}
static void nrs_policy_stop0(struct ptlrpc_nrs_policy *policy)
{
struct ptlrpc_nrs *nrs = policy->pol_nrs;
if (policy->pol_desc->pd_ops->op_policy_stop != NULL) {
spin_unlock(&nrs->nrs_lock);
policy->pol_desc->pd_ops->op_policy_stop(policy);
spin_lock(&nrs->nrs_lock);
}
LASSERT(list_empty(&policy->pol_list_queued));
LASSERT(policy->pol_req_queued == 0 &&
policy->pol_req_started == 0);
policy->pol_private = NULL;
policy->pol_state = NRS_POL_STATE_STOPPED;
if (atomic_dec_and_test(&policy->pol_desc->pd_refs))
module_put(policy->pol_desc->pd_owner);
}
static int nrs_policy_stop_locked(struct ptlrpc_nrs_policy *policy)
{
struct ptlrpc_nrs *nrs = policy->pol_nrs;
if (nrs->nrs_policy_fallback == policy && !nrs->nrs_stopping)
return -EPERM;
if (policy->pol_state == NRS_POL_STATE_STARTING)
return -EAGAIN;
/* In progress or already stopped */
if (policy->pol_state != NRS_POL_STATE_STARTED)
return 0;
policy->pol_state = NRS_POL_STATE_STOPPING;
/* Immediately make it invisible */
if (nrs->nrs_policy_primary == policy) {
nrs->nrs_policy_primary = NULL;
} else {
LASSERT(nrs->nrs_policy_fallback == policy);
nrs->nrs_policy_fallback = NULL;
}
/* I have the only refcount */
if (policy->pol_ref == 1)
nrs_policy_stop0(policy);
return 0;
}
/**
* Transitions the \a nrs NRS head's primary policy to
* ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPING and if the policy has no
* pending usage references, to ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED.
*
* \param[in] nrs the NRS head to carry out this operation on
*/
static void nrs_policy_stop_primary(struct ptlrpc_nrs *nrs)
{
struct ptlrpc_nrs_policy *tmp = nrs->nrs_policy_primary;
if (tmp == NULL) {
return;
}
nrs->nrs_policy_primary = NULL;
LASSERT(tmp->pol_state == NRS_POL_STATE_STARTED);
tmp->pol_state = NRS_POL_STATE_STOPPING;
if (tmp->pol_ref == 0)
nrs_policy_stop0(tmp);
}
/**
* Transitions a policy across the ptlrpc_nrs_pol_state range of values, in
* response to an lprocfs command to start a policy.
*
* If a primary policy different to the current one is specified, this function
* will transition the new policy to the
* ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTING and then to
* ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTED, and will then transition
* the old primary policy (if there is one) to
* ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPING, and if there are no outstanding
* references on the policy to ptlrpc_nrs_pol_stae::NRS_POL_STATE_STOPPED.
*
* If the fallback policy is specified, this is taken to indicate an instruction
* to stop the current primary policy, without substituting it with another
* primary policy, so the primary policy (if any) is transitioned to
* ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPING, and if there are no outstanding
* references on the policy to ptlrpc_nrs_pol_stae::NRS_POL_STATE_STOPPED. In
* this case, the fallback policy is only left active in the NRS head.
*/
static int nrs_policy_start_locked(struct ptlrpc_nrs_policy *policy)
{
struct ptlrpc_nrs *nrs = policy->pol_nrs;
int rc = 0;
/**
* Don't allow multiple starting which is too complex, and has no real
* benefit.
*/
if (nrs->nrs_policy_starting)
return -EAGAIN;
LASSERT(policy->pol_state != NRS_POL_STATE_STARTING);
if (policy->pol_state == NRS_POL_STATE_STOPPING)
return -EAGAIN;
if (policy->pol_flags & PTLRPC_NRS_FL_FALLBACK) {
/**
* This is for cases in which the user sets the policy to the
* fallback policy (currently fifo for all services); i.e. the
* user is resetting the policy to the default; so we stop the
* primary policy, if any.
*/
if (policy == nrs->nrs_policy_fallback) {
nrs_policy_stop_primary(nrs);
return 0;
}
/**
* If we reach here, we must be setting up the fallback policy
* at service startup time, and only a single policy with the
* nrs_policy_flags::PTLRPC_NRS_FL_FALLBACK flag set can
* register with NRS core.
*/
LASSERT(nrs->nrs_policy_fallback == NULL);
} else {
/**
* Shouldn't start primary policy if w/o fallback policy.
*/
if (nrs->nrs_policy_fallback == NULL)
return -EPERM;
if (policy->pol_state == NRS_POL_STATE_STARTED)
return 0;
}
/**
* Increase the module usage count for policies registering from other
* modules.
*/
if (atomic_inc_return(&policy->pol_desc->pd_refs) == 1 &&
!try_module_get(policy->pol_desc->pd_owner)) {
atomic_dec(&policy->pol_desc->pd_refs);
CERROR("NRS: cannot get module for policy %s; is it alive?\n",
policy->pol_desc->pd_name);
return -ENODEV;
}
/**
* Serialize policy starting across the NRS head
*/
nrs->nrs_policy_starting = 1;
policy->pol_state = NRS_POL_STATE_STARTING;
if (policy->pol_desc->pd_ops->op_policy_start) {
spin_unlock(&nrs->nrs_lock);
rc = policy->pol_desc->pd_ops->op_policy_start(policy);
spin_lock(&nrs->nrs_lock);
if (rc != 0) {
if (atomic_dec_and_test(&policy->pol_desc->pd_refs))
module_put(policy->pol_desc->pd_owner);
policy->pol_state = NRS_POL_STATE_STOPPED;
GOTO(out, rc);
}
}
policy->pol_state = NRS_POL_STATE_STARTED;
if (policy->pol_flags & PTLRPC_NRS_FL_FALLBACK) {
/**
* This path is only used at PTLRPC service setup time.
*/
nrs->nrs_policy_fallback = policy;
} else {
/*
* Try to stop the current primary policy if there is one.
*/
nrs_policy_stop_primary(nrs);
/**
* And set the newly-started policy as the primary one.
*/
nrs->nrs_policy_primary = policy;
}
out:
nrs->nrs_policy_starting = 0;
return rc;
}
/**
* Increases the policy's usage reference count.
*/
static inline void nrs_policy_get_locked(struct ptlrpc_nrs_policy *policy)
{
policy->pol_ref++;
}
/**
* Decreases the policy's usage reference count, and stops the policy in case it
* was already stopping and have no more outstanding usage references (which
* indicates it has no more queued or started requests, and can be safely
* stopped).
*/
static void nrs_policy_put_locked(struct ptlrpc_nrs_policy *policy)
{
LASSERT(policy->pol_ref > 0);
policy->pol_ref--;
if (unlikely(policy->pol_ref == 0 &&
policy->pol_state == NRS_POL_STATE_STOPPING))
nrs_policy_stop0(policy);
}
static void nrs_policy_put(struct ptlrpc_nrs_policy *policy)
{
spin_lock(&policy->pol_nrs->nrs_lock);
nrs_policy_put_locked(policy);
spin_unlock(&policy->pol_nrs->nrs_lock);
}
/**
* Find and return a policy by name.
*/
static struct ptlrpc_nrs_policy * nrs_policy_find_locked(struct ptlrpc_nrs *nrs,
char *name)
{
struct ptlrpc_nrs_policy *tmp;
list_for_each_entry(tmp, &nrs->nrs_policy_list, pol_list) {
if (strncmp(tmp->pol_desc->pd_name, name,
NRS_POL_NAME_MAX) == 0) {
nrs_policy_get_locked(tmp);
return tmp;
}
}
return NULL;
}
/**
* Release references for the resource hierarchy moving upwards towards the
* policy instance resource.
*/
static void nrs_resource_put(struct ptlrpc_nrs_resource *res)
{
struct ptlrpc_nrs_policy *policy = res->res_policy;
if (policy->pol_desc->pd_ops->op_res_put != NULL) {
struct ptlrpc_nrs_resource *parent;
for (; res != NULL; res = parent) {
parent = res->res_parent;
policy->pol_desc->pd_ops->op_res_put(policy, res);
}
}
}
/**
* Obtains references for each resource in the resource hierarchy for request
* \a nrq if it is to be handled by \a policy.
*
* \param[in] policy the policy
* \param[in] nrq the request
* \param[in] moving_req denotes whether this is a call to the function by
* ldlm_lock_reorder_req(), in order to move \a nrq to
* the high-priority NRS head; we should not sleep when
* set.
*
* \retval NULL resource hierarchy references not obtained
* \retval valid-pointer the bottom level of the resource hierarchy
*
* \see ptlrpc_nrs_pol_ops::op_res_get()
*/
static
struct ptlrpc_nrs_resource * nrs_resource_get(struct ptlrpc_nrs_policy *policy,
struct ptlrpc_nrs_request *nrq,
bool moving_req)
{
/**
* Set to NULL to traverse the resource hierarchy from the top.
*/
struct ptlrpc_nrs_resource *res = NULL;
struct ptlrpc_nrs_resource *tmp = NULL;
int rc;
while (1) {
rc = policy->pol_desc->pd_ops->op_res_get(policy, nrq, res,
&tmp, moving_req);
if (rc < 0) {
if (res != NULL)
nrs_resource_put(res);
return NULL;
}
LASSERT(tmp != NULL);
tmp->res_parent = res;
tmp->res_policy = policy;
res = tmp;
tmp = NULL;
/**
* Return once we have obtained a reference to the bottom level
* of the resource hierarchy.
*/
if (rc > 0)
return res;
}
}
/**
* Obtains resources for the resource hierarchies and policy references for
* the fallback and current primary policy (if any), that will later be used
* to handle request \a nrq.
*
* \param[in] nrs the NRS head instance that will be handling request \a nrq.
* \param[in] nrq the request that is being handled.
* \param[out] resp the array where references to the resource hierarchy are
* stored.
* \param[in] moving_req is set when obtaining resources while moving a
* request from a policy on the regular NRS head to a
* policy on the HP NRS head (via
* ldlm_lock_reorder_req()). It signifies that
* allocations to get resources should be atomic; for
* a full explanation, see comment in
* ptlrpc_nrs_pol_ops::op_res_get().
*/
static void nrs_resource_get_safe(struct ptlrpc_nrs *nrs,
struct ptlrpc_nrs_request *nrq,
struct ptlrpc_nrs_resource **resp,
bool moving_req)
{
struct ptlrpc_nrs_policy *primary = NULL;
struct ptlrpc_nrs_policy *fallback = NULL;
memset(resp, 0, sizeof(resp[0]) * NRS_RES_MAX);
/**
* Obtain policy references.
*/
spin_lock(&nrs->nrs_lock);
fallback = nrs->nrs_policy_fallback;
nrs_policy_get_locked(fallback);
primary = nrs->nrs_policy_primary;
if (primary != NULL)
nrs_policy_get_locked(primary);
spin_unlock(&nrs->nrs_lock);
/**
* Obtain resource hierarchy references.
*/
resp[NRS_RES_FALLBACK] = nrs_resource_get(fallback, nrq, moving_req);
LASSERT(resp[NRS_RES_FALLBACK] != NULL);
if (primary != NULL) {
resp[NRS_RES_PRIMARY] = nrs_resource_get(primary, nrq,
moving_req);
/**
* A primary policy may exist which may not wish to serve a
* particular request for different reasons; release the
* reference on the policy as it will not be used for this
* request.
*/
if (resp[NRS_RES_PRIMARY] == NULL)
nrs_policy_put(primary);
}
}
/**
* Releases references to resource hierarchies and policies, because they are no
* longer required; used when request handling has been completed, or the
* request is moving to the high priority NRS head.
*
* \param resp the resource hierarchy that is being released
*
* \see ptlrpcnrs_req_hp_move()
* \see ptlrpc_nrs_req_finalize()
*/
static void nrs_resource_put_safe(struct ptlrpc_nrs_resource **resp)
{
struct ptlrpc_nrs_policy *pols[NRS_RES_MAX];
struct ptlrpc_nrs *nrs = NULL;
int i;
for (i = 0; i < NRS_RES_MAX; i++) {
if (resp[i] != NULL) {
pols[i] = resp[i]->res_policy;
nrs_resource_put(resp[i]);
resp[i] = NULL;
} else {
pols[i] = NULL;
}
}
for (i = 0; i < NRS_RES_MAX; i++) {
if (pols[i] == NULL)
continue;
if (nrs == NULL) {
nrs = pols[i]->pol_nrs;
spin_lock(&nrs->nrs_lock);
}
nrs_policy_put_locked(pols[i]);
}
if (nrs != NULL)
spin_unlock(&nrs->nrs_lock);
}
/**
* Obtains an NRS request from \a policy for handling or examination; the
* request should be removed in the 'handling' case.
*
* Calling into this function implies we already know the policy has a request
* waiting to be handled.
*
* \param[in] policy the policy from which a request
* \param[in] peek when set, signifies that we just want to examine the
* request, and not handle it, so the request is not removed
* from the policy.
* \param[in] force when set, it will force a policy to return a request if it
* has one pending
*
* \retval the NRS request to be handled
*/
static inline
struct ptlrpc_nrs_request * nrs_request_get(struct ptlrpc_nrs_policy *policy,
bool peek, bool force)
{
struct ptlrpc_nrs_request *nrq;
LASSERT(policy->pol_req_queued > 0);
nrq = policy->pol_desc->pd_ops->op_req_get(policy, peek, force);
LASSERT(ergo(nrq != NULL, nrs_request_policy(nrq) == policy));
return nrq;
}
/**
* Enqueues request \a nrq for later handling, via one one the policies for
* which resources where earlier obtained via nrs_resource_get_safe(). The
* function attempts to enqueue the request first on the primary policy
* (if any), since this is the preferred choice.
*
* \param nrq the request being enqueued
*
* \see nrs_resource_get_safe()
*/
static inline void nrs_request_enqueue(struct ptlrpc_nrs_request *nrq)
{
struct ptlrpc_nrs_policy *policy;
int rc;
int i;
/**
* Try in descending order, because the primary policy (if any) is
* the preferred choice.
*/
for (i = NRS_RES_MAX - 1; i >= 0; i--) {
if (nrq->nr_res_ptrs[i] == NULL)
continue;
nrq->nr_res_idx = i;
policy = nrq->nr_res_ptrs[i]->res_policy;
rc = policy->pol_desc->pd_ops->op_req_enqueue(policy, nrq);
if (rc == 0) {
policy->pol_nrs->nrs_req_queued++;
policy->pol_req_queued++;
return;
}
}
/**
* Should never get here, as at least the primary policy's
* ptlrpc_nrs_pol_ops::op_req_enqueue() implementation should always
* succeed.
*/
LBUG();
}
/**
* Called when a request has been handled
*
* \param[in] nrs the request that has been handled; can be used for
* job/resource control.
*
* \see ptlrpc_nrs_req_stop_nolock()
*/
static inline void nrs_request_stop(struct ptlrpc_nrs_request *nrq)
{
struct ptlrpc_nrs_policy *policy = nrs_request_policy(nrq);
if (policy->pol_desc->pd_ops->op_req_stop)
policy->pol_desc->pd_ops->op_req_stop(policy, nrq);
LASSERT(policy->pol_nrs->nrs_req_started > 0);
LASSERT(policy->pol_req_started > 0);
policy->pol_nrs->nrs_req_started--;
policy->pol_req_started--;
}
/**
* Handler for operations that can be carried out on policies.
*
* Handles opcodes that are common to all policy types within NRS core, and
* passes any unknown opcodes to the policy-specific control function.
*
* \param[in] nrs the NRS head this policy belongs to.
* \param[in] name the human-readable policy name; should be the same as
* ptlrpc_nrs_pol_desc::pd_name.
* \param[in] opc the opcode of the operation being carried out.
* \param[in,out] arg can be used to pass information in and out between when
* carrying an operation; usually data that is private to
* the policy at some level, or generic policy status
* information.
*
* \retval -ve error condition
* \retval 0 operation was carried out successfully
*/
static int nrs_policy_ctl(struct ptlrpc_nrs *nrs, char *name,
enum ptlrpc_nrs_ctl opc, void *arg)
{
struct ptlrpc_nrs_policy *policy;
int rc = 0;
spin_lock(&nrs->nrs_lock);
policy = nrs_policy_find_locked(nrs, name);
if (policy == NULL)
GOTO(out, rc = -ENOENT);
switch (opc) {
/**
* Unknown opcode, pass it down to the policy-specific control
* function for handling.
*/
default:
rc = nrs_policy_ctl_locked(policy, opc, arg);
break;
/**
* Start \e policy
*/
case PTLRPC_NRS_CTL_START:
rc = nrs_policy_start_locked(policy);
break;
}
out:
if (policy != NULL)
nrs_policy_put_locked(policy);
spin_unlock(&nrs->nrs_lock);
return rc;
}
/**
* Unregisters a policy by name.
*
* \param[in] nrs the NRS head this policy belongs to.
* \param[in] name the human-readable policy name; should be the same as
* ptlrpc_nrs_pol_desc::pd_name
*
* \retval -ve error
* \retval 0 success
*/
static int nrs_policy_unregister(struct ptlrpc_nrs *nrs, char *name)
{
struct ptlrpc_nrs_policy *policy = NULL;
spin_lock(&nrs->nrs_lock);
policy = nrs_policy_find_locked(nrs, name);
if (policy == NULL) {
spin_unlock(&nrs->nrs_lock);
CERROR("Can't find NRS policy %s\n", name);
return -ENOENT;
}
if (policy->pol_ref > 1) {
CERROR("Policy %s is busy with %d references\n", name,
(int)policy->pol_ref);
nrs_policy_put_locked(policy);
spin_unlock(&nrs->nrs_lock);
return -EBUSY;
}
LASSERT(policy->pol_req_queued == 0);
LASSERT(policy->pol_req_started == 0);
if (policy->pol_state != NRS_POL_STATE_STOPPED) {
nrs_policy_stop_locked(policy);
LASSERT(policy->pol_state == NRS_POL_STATE_STOPPED);
}
list_del(&policy->pol_list);
nrs->nrs_num_pols--;
nrs_policy_put_locked(policy);
spin_unlock(&nrs->nrs_lock);
nrs_policy_fini(policy);
LASSERT(policy->pol_private == NULL);
OBD_FREE_PTR(policy);
return 0;
}
/**
* Register a policy from \policy descriptor \a desc with NRS head \a nrs.
*
* \param[in] nrs the NRS head on which the policy will be registered.
* \param[in] desc the policy descriptor from which the information will be
* obtained to register the policy.
*
* \retval -ve error
* \retval 0 success
*/
static int nrs_policy_register(struct ptlrpc_nrs *nrs,
struct ptlrpc_nrs_pol_desc *desc)
{
struct ptlrpc_nrs_policy *policy;
struct ptlrpc_nrs_policy *tmp;
struct ptlrpc_service_part *svcpt = nrs->nrs_svcpt;
int rc;
LASSERT(svcpt != NULL);
LASSERT(desc->pd_ops != NULL);
LASSERT(desc->pd_ops->op_res_get != NULL);
LASSERT(desc->pd_ops->op_req_get != NULL);
LASSERT(desc->pd_ops->op_req_enqueue != NULL);
LASSERT(desc->pd_ops->op_req_dequeue != NULL);
LASSERT(desc->pd_compat != NULL);
OBD_CPT_ALLOC_GFP(policy, svcpt->scp_service->srv_cptable,
svcpt->scp_cpt, sizeof(*policy), GFP_NOFS);
if (policy == NULL)
return -ENOMEM;
policy->pol_nrs = nrs;
policy->pol_desc = desc;
policy->pol_state = NRS_POL_STATE_STOPPED;
policy->pol_flags = desc->pd_flags;
INIT_LIST_HEAD(&policy->pol_list);
INIT_LIST_HEAD(&policy->pol_list_queued);
rc = nrs_policy_init(policy);
if (rc != 0) {
OBD_FREE_PTR(policy);
return rc;
}
spin_lock(&nrs->nrs_lock);
tmp = nrs_policy_find_locked(nrs, policy->pol_desc->pd_name);
if (tmp != NULL) {
CERROR("NRS policy %s has been registered, can't register it "
"for %s\n", policy->pol_desc->pd_name,
svcpt->scp_service->srv_name);
nrs_policy_put_locked(tmp);
spin_unlock(&nrs->nrs_lock);
nrs_policy_fini(policy);
OBD_FREE_PTR(policy);
return -EEXIST;
}
list_add_tail(&policy->pol_list, &nrs->nrs_policy_list);
nrs->nrs_num_pols++;
if (policy->pol_flags & PTLRPC_NRS_FL_REG_START)
rc = nrs_policy_start_locked(policy);
spin_unlock(&nrs->nrs_lock);
if (rc != 0)
(void) nrs_policy_unregister(nrs, policy->pol_desc->pd_name);
return rc;
}
/**
* Enqueue request \a req using one of the policies its resources are referring
* to.
*
* \param[in] req the request to enqueue.
*/
static void ptlrpc_nrs_req_add_nolock(struct ptlrpc_request *req)
{
struct ptlrpc_nrs_policy *policy;
LASSERT(req->rq_nrq.nr_initialized);
LASSERT(!req->rq_nrq.nr_enqueued);
nrs_request_enqueue(&req->rq_nrq);
req->rq_nrq.nr_enqueued = 1;
policy = nrs_request_policy(&req->rq_nrq);
/**
* Add the policy to the NRS head's list of policies with enqueued
* requests, if it has not been added there.
*/
if (unlikely(list_empty(&policy->pol_list_queued)))
list_add_tail(&policy->pol_list_queued,
&policy->pol_nrs->nrs_policy_queued);
}
/**
* Enqueue a request on the high priority NRS head.
*
* \param req the request to enqueue.
*/
static void ptlrpc_nrs_hpreq_add_nolock(struct ptlrpc_request *req)
{
int opc = lustre_msg_get_opc(req->rq_reqmsg);
spin_lock(&req->rq_lock);
req->rq_hp = 1;
ptlrpc_nrs_req_add_nolock(req);
if (opc != OBD_PING)
DEBUG_REQ(D_NET, req, "high priority req");
spin_unlock(&req->rq_lock);
}
/**
* Returns a boolean predicate indicating whether the policy described by
* \a desc is adequate for use with service \a svc.
*
* \param[in] svc the service
* \param[in] desc the policy descriptor
*
* \retval false the policy is not compatible with the service
* \retval true the policy is compatible with the service
*/
static inline bool nrs_policy_compatible(const struct ptlrpc_service *svc,
const struct ptlrpc_nrs_pol_desc *desc)
{
return desc->pd_compat(svc, desc);
}
/**
* Registers all compatible policies in nrs_core.nrs_policies, for NRS head
* \a nrs.
*
* \param[in] nrs the NRS head
*
* \retval -ve error
* \retval 0 success
*
* \pre mutex_is_locked(&nrs_core.nrs_mutex)
*
* \see ptlrpc_service_nrs_setup()
*/
static int nrs_register_policies_locked(struct ptlrpc_nrs *nrs)
{
struct ptlrpc_nrs_pol_desc *desc;
/* for convenience */
struct ptlrpc_service_part *svcpt = nrs->nrs_svcpt;
struct ptlrpc_service *svc = svcpt->scp_service;
int rc = -EINVAL;
LASSERT(mutex_is_locked(&nrs_core.nrs_mutex));
list_for_each_entry(desc, &nrs_core.nrs_policies, pd_list) {
if (nrs_policy_compatible(svc, desc)) {
rc = nrs_policy_register(nrs, desc);
if (rc != 0) {
CERROR("Failed to register NRS policy %s for "
"partition %d of service %s: %d\n",
desc->pd_name, svcpt->scp_cpt,
svc->srv_name, rc);
/**
* Fail registration if any of the policies'
* registration fails.
*/
break;
}
}
}
return rc;
}
/**
* Initializes NRS head \a nrs of service partition \a svcpt, and registers all
* compatible policies in NRS core, with the NRS head.
*
* \param[in] nrs the NRS head
* \param[in] svcpt the PTLRPC service partition to setup
*
* \retval -ve error
* \retval 0 success
*
* \pre mutex_is_locked(&nrs_core.nrs_mutex)
*/
static int nrs_svcpt_setup_locked0(struct ptlrpc_nrs *nrs,
struct ptlrpc_service_part *svcpt)
{
int rc;
enum ptlrpc_nrs_queue_type queue;
LASSERT(mutex_is_locked(&nrs_core.nrs_mutex));
if (nrs == &svcpt->scp_nrs_reg)
queue = PTLRPC_NRS_QUEUE_REG;
else if (nrs == svcpt->scp_nrs_hp)
queue = PTLRPC_NRS_QUEUE_HP;
else
LBUG();
nrs->nrs_svcpt = svcpt;
nrs->nrs_queue_type = queue;
spin_lock_init(&nrs->nrs_lock);
INIT_LIST_HEAD(&nrs->nrs_policy_list);
INIT_LIST_HEAD(&nrs->nrs_policy_queued);
rc = nrs_register_policies_locked(nrs);
return rc;
}
/**
* Allocates a regular and optionally a high-priority NRS head (if the service
* handles high-priority RPCs), and then registers all available compatible
* policies on those NRS heads.
*
* \param[in,out] svcpt the PTLRPC service partition to setup
*
* \pre mutex_is_locked(&nrs_core.nrs_mutex)
*/
static int nrs_svcpt_setup_locked(struct ptlrpc_service_part *svcpt)
{
struct ptlrpc_nrs *nrs;
int rc;
LASSERT(mutex_is_locked(&nrs_core.nrs_mutex));
/**
* Initialize the regular NRS head.
*/
nrs = nrs_svcpt2nrs(svcpt, false);
rc = nrs_svcpt_setup_locked0(nrs, svcpt);
if (rc < 0)
GOTO(out, rc);
/**
* Optionally allocate a high-priority NRS head.
*/
if (svcpt->scp_service->srv_ops.so_hpreq_handler == NULL)
GOTO(out, rc);
OBD_CPT_ALLOC_PTR(svcpt->scp_nrs_hp,
svcpt->scp_service->srv_cptable,
svcpt->scp_cpt);
if (svcpt->scp_nrs_hp == NULL)
GOTO(out, rc = -ENOMEM);
nrs = nrs_svcpt2nrs(svcpt, true);
rc = nrs_svcpt_setup_locked0(nrs, svcpt);
out:
return rc;
}
/**
* Unregisters all policies on all available NRS heads in a service partition;
* called at PTLRPC service unregistration time.
*
* \param[in] svcpt the PTLRPC service partition
*
* \pre mutex_is_locked(&nrs_core.nrs_mutex)
*/
static void nrs_svcpt_cleanup_locked(struct ptlrpc_service_part *svcpt)
{
struct ptlrpc_nrs *nrs;
struct ptlrpc_nrs_policy *policy;
struct ptlrpc_nrs_policy *tmp;
int rc;
bool hp = false;
LASSERT(mutex_is_locked(&nrs_core.nrs_mutex));
again:
nrs = nrs_svcpt2nrs(svcpt, hp);
nrs->nrs_stopping = 1;
list_for_each_entry_safe(policy, tmp, &nrs->nrs_policy_list,
pol_list) {
rc = nrs_policy_unregister(nrs, policy->pol_desc->pd_name);
LASSERT(rc == 0);
}
/**
* If the service partition has an HP NRS head, clean that up as well.
*/
if (!hp && nrs_svcpt_has_hp(svcpt)) {
hp = true;
goto again;
}
if (hp)
OBD_FREE_PTR(nrs);
}
/**
* Returns the descriptor for a policy as identified by by \a name.
*
* \param[in] name the policy name
*
* \retval the policy descriptor
* \retval NULL
*/
static struct ptlrpc_nrs_pol_desc *nrs_policy_find_desc_locked(const char *name)
{
struct ptlrpc_nrs_pol_desc *tmp;
list_for_each_entry(tmp, &nrs_core.nrs_policies, pd_list) {
if (strncmp(tmp->pd_name, name, NRS_POL_NAME_MAX) == 0)
return tmp;
}
return NULL;
}
/**
* Removes the policy from all supported NRS heads of all partitions of all
* PTLRPC services.
*
* \param[in] desc the policy descriptor to unregister
*
* \retval -ve error
* \retval 0 successfully unregistered policy on all supported NRS heads
*
* \pre mutex_is_locked(&nrs_core.nrs_mutex)
* \pre mutex_is_locked(&ptlrpc_all_services_mutex)
*/
static int nrs_policy_unregister_locked(struct ptlrpc_nrs_pol_desc *desc)
{
struct ptlrpc_nrs *nrs;
struct ptlrpc_service *svc;
struct ptlrpc_service_part *svcpt;
int i;
int rc = 0;
LASSERT(mutex_is_locked(&nrs_core.nrs_mutex));
LASSERT(mutex_is_locked(&ptlrpc_all_services_mutex));
list_for_each_entry(svc, &ptlrpc_all_services, srv_list) {
if (!nrs_policy_compatible(svc, desc) ||
unlikely(svc->srv_is_stopping))
continue;
ptlrpc_service_for_each_part(svcpt, i, svc) {
bool hp = false;
again:
nrs = nrs_svcpt2nrs(svcpt, hp);
rc = nrs_policy_unregister(nrs, desc->pd_name);
/**
* Ignore -ENOENT as the policy may not have registered
* successfully on all service partitions.
*/
if (rc == -ENOENT) {
rc = 0;
} else if (rc != 0) {
CERROR("Failed to unregister NRS policy %s for "
"partition %d of service %s: %d\n",
desc->pd_name, svcpt->scp_cpt,
svcpt->scp_service->srv_name, rc);
return rc;
}
if (!hp && nrs_svc_has_hp(svc)) {
hp = true;
goto again;
}
}
if (desc->pd_ops->op_lprocfs_fini != NULL)
desc->pd_ops->op_lprocfs_fini(svc);
}
return rc;
}
/**
* Registers a new policy with NRS core.
*
* The function will only succeed if policy registration with all compatible
* service partitions (if any) is successful.
*
* N.B. This function should be called either at ptlrpc module initialization
* time when registering a policy that ships with NRS core, or in a
* module's init() function for policies registering from other modules.
*
* \param[in] conf configuration information for the new policy to register
*
* \retval -ve error
* \retval 0 success
*/
int ptlrpc_nrs_policy_register(struct ptlrpc_nrs_pol_conf *conf)
{
struct ptlrpc_service *svc;
struct ptlrpc_nrs_pol_desc *desc;
int rc = 0;
LASSERT(conf != NULL);
LASSERT(conf->nc_ops != NULL);
LASSERT(conf->nc_compat != NULL);
LASSERT(ergo(conf->nc_compat == nrs_policy_compat_one,
conf->nc_compat_svc_name != NULL));
LASSERT(ergo((conf->nc_flags & PTLRPC_NRS_FL_REG_EXTERN) != 0,
conf->nc_owner != NULL));
conf->nc_name[NRS_POL_NAME_MAX - 1] = '\0';
/**
* External policies are not allowed to start immediately upon
* registration, as there is a relatively higher chance that their
* registration might fail. In such a case, some policy instances may
* already have requests queued wen unregistration needs to happen as
* part o cleanup; since there is currently no way to drain requests
* from a policy unless the service is unregistering, we just disallow
* this.
*/
if ((conf->nc_flags & PTLRPC_NRS_FL_REG_EXTERN) &&
(conf->nc_flags & (PTLRPC_NRS_FL_FALLBACK |
PTLRPC_NRS_FL_REG_START))) {
CERROR("NRS: failing to register policy %s. Please check "
"policy flags; external policies cannot act as fallback "
"policies, or be started immediately upon registration "
"without interaction with lprocfs\n", conf->nc_name);
return -EINVAL;
}
mutex_lock(&nrs_core.nrs_mutex);
if (nrs_policy_find_desc_locked(conf->nc_name) != NULL) {
CERROR("NRS: failing to register policy %s which has already "
"been registered with NRS core!\n",
conf->nc_name);
GOTO(fail, rc = -EEXIST);
}
OBD_ALLOC_PTR(desc);
if (desc == NULL)
GOTO(fail, rc = -ENOMEM);
strncpy(desc->pd_name, conf->nc_name, NRS_POL_NAME_MAX);
desc->pd_ops = conf->nc_ops;
desc->pd_compat = conf->nc_compat;
desc->pd_compat_svc_name = conf->nc_compat_svc_name;
if ((conf->nc_flags & PTLRPC_NRS_FL_REG_EXTERN) != 0)
desc->pd_owner = conf->nc_owner;
desc->pd_flags = conf->nc_flags;
atomic_set(&desc->pd_refs, 0);
/**
* For policies that are held in the same module as NRS (currently
* ptlrpc), do not register the policy with all compatible services,
* as the services will not have started at this point, since we are
* calling from ptlrpc module initialization code. In such cases each
* service will register all compatible policies later, via
* ptlrpc_service_nrs_setup().
*/
if ((conf->nc_flags & PTLRPC_NRS_FL_REG_EXTERN) == 0)
goto internal;
/**
* Register the new policy on all compatible services
*/
mutex_lock(&ptlrpc_all_services_mutex);
list_for_each_entry(svc, &ptlrpc_all_services, srv_list) {
struct ptlrpc_service_part *svcpt;
int i;
int rc2;
if (!nrs_policy_compatible(svc, desc) ||
unlikely(svc->srv_is_stopping))
continue;
ptlrpc_service_for_each_part(svcpt, i, svc) {
struct ptlrpc_nrs *nrs;
bool hp = false;
again:
nrs = nrs_svcpt2nrs(svcpt, hp);
rc = nrs_policy_register(nrs, desc);
if (rc != 0) {
CERROR("Failed to register NRS policy %s for "
"partition %d of service %s: %d\n",
desc->pd_name, svcpt->scp_cpt,
svcpt->scp_service->srv_name, rc);
rc2 = nrs_policy_unregister_locked(desc);
/**
* Should not fail at this point
*/
LASSERT(rc2 == 0);
mutex_unlock(&ptlrpc_all_services_mutex);
OBD_FREE_PTR(desc);
GOTO(fail, rc);
}
if (!hp && nrs_svc_has_hp(svc)) {
hp = true;
goto again;
}
}
/**
* No need to take a reference to other modules here, as we
* will be calling from the module's init() function.
*/
if (desc->pd_ops->op_lprocfs_init != NULL) {
rc = desc->pd_ops->op_lprocfs_init(svc);
if (rc != 0) {
rc2 = nrs_policy_unregister_locked(desc);
/**
* Should not fail at this point
*/
LASSERT(rc2 == 0);
mutex_unlock(&ptlrpc_all_services_mutex);
OBD_FREE_PTR(desc);
GOTO(fail, rc);
}
}
}
mutex_unlock(&ptlrpc_all_services_mutex);
internal:
list_add_tail(&desc->pd_list, &nrs_core.nrs_policies);
fail:
mutex_unlock(&nrs_core.nrs_mutex);
return rc;
}
EXPORT_SYMBOL(ptlrpc_nrs_policy_register);
/**
* Unregisters a previously registered policy with NRS core. All instances of
* the policy on all NRS heads of all supported services are removed.
*
* N.B. This function should only be called from a module's exit() function.
* Although it can be used for policies that ship alongside NRS core, the
* function is primarily intended for policies that register externally,
* from other modules.
*
* \param[in] conf configuration information for the policy to unregister
*
* \retval -ve error
* \retval 0 success
*/
int ptlrpc_nrs_policy_unregister(struct ptlrpc_nrs_pol_conf *conf)
{
struct ptlrpc_nrs_pol_desc *desc;
int rc;
LASSERT(conf != NULL);
if (conf->nc_flags & PTLRPC_NRS_FL_FALLBACK) {
CERROR("Unable to unregister a fallback policy, unless the "
"PTLRPC service is stopping.\n");
return -EPERM;
}
conf->nc_name[NRS_POL_NAME_MAX - 1] = '\0';
mutex_lock(&nrs_core.nrs_mutex);
desc = nrs_policy_find_desc_locked(conf->nc_name);
if (desc == NULL) {
CERROR("Failing to unregister NRS policy %s which has "
"not been registered with NRS core!\n",
conf->nc_name);
GOTO(not_exist, rc = -ENOENT);
}
mutex_lock(&ptlrpc_all_services_mutex);
rc = nrs_policy_unregister_locked(desc);
if (rc < 0) {
if (rc == -EBUSY)
CERROR("Please first stop policy %s on all service "
"partitions and then retry to unregister the "
"policy.\n", conf->nc_name);
GOTO(fail, rc);
}
CDEBUG(D_INFO, "Unregistering policy %s from NRS core.\n",
conf->nc_name);
list_del(&desc->pd_list);
OBD_FREE_PTR(desc);
fail:
mutex_unlock(&ptlrpc_all_services_mutex);
not_exist:
mutex_unlock(&nrs_core.nrs_mutex);
return rc;
}
EXPORT_SYMBOL(ptlrpc_nrs_policy_unregister);
/**
* Setup NRS heads on all service partitions of service \a svc, and register
* all compatible policies on those NRS heads.
*
* To be called from within ptl
* \param[in] svc the service to setup
*
* \retval -ve error, the calling logic should eventually call
* ptlrpc_service_nrs_cleanup() to undo any work performed
* by this function.
*
* \see ptlrpc_register_service()
* \see ptlrpc_service_nrs_cleanup()
*/
int ptlrpc_service_nrs_setup(struct ptlrpc_service *svc)
{
struct ptlrpc_service_part *svcpt;
const struct ptlrpc_nrs_pol_desc *desc;
int i;
int rc = 0;
mutex_lock(&nrs_core.nrs_mutex);
/**
* Initialize NRS heads on all service CPTs.
*/
ptlrpc_service_for_each_part(svcpt, i, svc) {
rc = nrs_svcpt_setup_locked(svcpt);
if (rc != 0)
GOTO(failed, rc);
}
/**
* Set up lprocfs interfaces for all supported policies for the
* service.
*/
list_for_each_entry(desc, &nrs_core.nrs_policies, pd_list) {
if (!nrs_policy_compatible(svc, desc))
continue;
if (desc->pd_ops->op_lprocfs_init != NULL) {
rc = desc->pd_ops->op_lprocfs_init(svc);
if (rc != 0)
GOTO(failed, rc);
}
}
failed:
mutex_unlock(&nrs_core.nrs_mutex);
return rc;
}
/**
* Unregisters all policies on all service partitions of service \a svc.
*
* \param[in] svc the PTLRPC service to unregister
*/
void ptlrpc_service_nrs_cleanup(struct ptlrpc_service *svc)
{
struct ptlrpc_service_part *svcpt;
const struct ptlrpc_nrs_pol_desc *desc;
int i;
mutex_lock(&nrs_core.nrs_mutex);
/**
* Clean up NRS heads on all service partitions
*/
ptlrpc_service_for_each_part(svcpt, i, svc)
nrs_svcpt_cleanup_locked(svcpt);
/**
* Clean up lprocfs interfaces for all supported policies for the
* service.
*/
list_for_each_entry(desc, &nrs_core.nrs_policies, pd_list) {
if (!nrs_policy_compatible(svc, desc))
continue;
if (desc->pd_ops->op_lprocfs_fini != NULL)
desc->pd_ops->op_lprocfs_fini(svc);
}
mutex_unlock(&nrs_core.nrs_mutex);
}
/**
* Obtains NRS head resources for request \a req.
*
* These could be either on the regular or HP NRS head of \a svcpt; resources
* taken on the regular head can later be swapped for HP head resources by
* ldlm_lock_reorder_req().
*
* \param[in] svcpt the service partition
* \param[in] req the request
* \param[in] hp which NRS head of \a svcpt to use
*/
void ptlrpc_nrs_req_initialize(struct ptlrpc_service_part *svcpt,
struct ptlrpc_request *req, bool hp)
{
struct ptlrpc_nrs *nrs = nrs_svcpt2nrs(svcpt, hp);
memset(&req->rq_nrq, 0, sizeof(req->rq_nrq));
nrs_resource_get_safe(nrs, &req->rq_nrq, req->rq_nrq.nr_res_ptrs,
false);
/**
* It is fine to access \e nr_initialized without locking as there is
* no contention at this early stage.
*/
req->rq_nrq.nr_initialized = 1;
}
/**
* Releases resources for a request; is called after the request has been
* handled.
*
* \param[in] req the request
*
* \see ptlrpc_server_finish_request()
*/
void ptlrpc_nrs_req_finalize(struct ptlrpc_request *req)
{
if (req->rq_nrq.nr_initialized) {
nrs_resource_put_safe(req->rq_nrq.nr_res_ptrs);
/* no protection on bit nr_initialized because no
* contention at this late stage */
req->rq_nrq.nr_finalized = 1;
}
}
void ptlrpc_nrs_req_stop_nolock(struct ptlrpc_request *req)
{
if (req->rq_nrq.nr_started)
nrs_request_stop(&req->rq_nrq);
}
/**
* Enqueues request \a req on either the regular or high-priority NRS head
* of service partition \a svcpt.
*
* \param[in] svcpt the service partition
* \param[in] req the request to be enqueued
* \param[in] hp whether to enqueue the request on the regular or
* high-priority NRS head.
*/
void ptlrpc_nrs_req_add(struct ptlrpc_service_part *svcpt,
struct ptlrpc_request *req, bool hp)
{
spin_lock(&svcpt->scp_req_lock);
if (hp)
ptlrpc_nrs_hpreq_add_nolock(req);
else
ptlrpc_nrs_req_add_nolock(req);
spin_unlock(&svcpt->scp_req_lock);
}
static void nrs_request_removed(struct ptlrpc_nrs_policy *policy)
{
LASSERT(policy->pol_nrs->nrs_req_queued > 0);
LASSERT(policy->pol_req_queued > 0);
policy->pol_nrs->nrs_req_queued--;
policy->pol_req_queued--;
/**
* If the policy has no more requests queued, remove it from
* ptlrpc_nrs::nrs_policy_queued.
*/
if (unlikely(policy->pol_req_queued == 0)) {
list_del_init(&policy->pol_list_queued);
/**
* If there are other policies with queued requests, move the
* current policy to the end so that we can round robin over
* all policies and drain the requests.
*/
} else if (policy->pol_req_queued != policy->pol_nrs->nrs_req_queued) {
LASSERT(policy->pol_req_queued <
policy->pol_nrs->nrs_req_queued);
list_move_tail(&policy->pol_list_queued,
&policy->pol_nrs->nrs_policy_queued);
}
}
/**
* Obtains a request for handling from an NRS head of service partition
* \a svcpt.
*
* \param[in] svcpt the service partition
* \param[in] hp whether to obtain a request from the regular or
* high-priority NRS head.
* \param[in] peek when set, signifies that we just want to examine the
* request, and not handle it, so the request is not removed
* from the policy.
* \param[in] force when set, it will force a policy to return a request if it
* has one pending
*
* \retval the request to be handled
* \retval NULL the head has no requests to serve
*/
struct ptlrpc_request *
ptlrpc_nrs_req_get_nolock0(struct ptlrpc_service_part *svcpt, bool hp,
bool peek, bool force)
{
struct ptlrpc_nrs *nrs = nrs_svcpt2nrs(svcpt, hp);
struct ptlrpc_nrs_policy *policy;
struct ptlrpc_nrs_request *nrq;
/**
* Always try to drain requests from all NRS polices even if they are
* inactive, because the user can change policy status at runtime.
*/
list_for_each_entry(policy, &nrs->nrs_policy_queued,
pol_list_queued) {
nrq = nrs_request_get(policy, peek, force);
if (nrq != NULL) {
if (likely(!peek)) {
nrq->nr_started = 1;
policy->pol_req_started++;
policy->pol_nrs->nrs_req_started++;
nrs_request_removed(policy);
}
return container_of(nrq, struct ptlrpc_request, rq_nrq);
}
}
return NULL;
}
/**
* Dequeues request \a req from the policy it has been enqueued on.
*
* \param[in] req the request
*/
void ptlrpc_nrs_req_del_nolock(struct ptlrpc_request *req)
{
struct ptlrpc_nrs_policy *policy = nrs_request_policy(&req->rq_nrq);
policy->pol_desc->pd_ops->op_req_dequeue(policy, &req->rq_nrq);
req->rq_nrq.nr_enqueued = 0;
nrs_request_removed(policy);
}
/**
* Returns whether there are any requests currently enqueued on any of the
* policies of service partition's \a svcpt NRS head specified by \a hp. Should
* be called while holding ptlrpc_service_part::scp_req_lock to get a reliable
* result.
*
* \param[in] svcpt the service partition to enquire.
* \param[in] hp whether the regular or high-priority NRS head is to be
* enquired.
*
* \retval false the indicated NRS head has no enqueued requests.
* \retval true the indicated NRS head has some enqueued requests.
*/
bool ptlrpc_nrs_req_pending_nolock(struct ptlrpc_service_part *svcpt, bool hp)
{
struct ptlrpc_nrs *nrs = nrs_svcpt2nrs(svcpt, hp);
return nrs->nrs_req_queued > 0;
};
/**
* Moves request \a req from the regular to the high-priority NRS head.
*
* \param[in] req the request to move
*/
void ptlrpc_nrs_req_hp_move(struct ptlrpc_request *req)
{
struct ptlrpc_service_part *svcpt = req->rq_rqbd->rqbd_svcpt;
struct ptlrpc_nrs_request *nrq = &req->rq_nrq;
struct ptlrpc_nrs_resource *res1[NRS_RES_MAX];
struct ptlrpc_nrs_resource *res2[NRS_RES_MAX];
/**
* Obtain the high-priority NRS head resources.
*/
nrs_resource_get_safe(nrs_svcpt2nrs(svcpt, true), nrq, res1, true);
spin_lock(&svcpt->scp_req_lock);
if (!ptlrpc_nrs_req_can_move(req))
goto out;
ptlrpc_nrs_req_del_nolock(req);
memcpy(res2, nrq->nr_res_ptrs, NRS_RES_MAX * sizeof(res2[0]));
memcpy(nrq->nr_res_ptrs, res1, NRS_RES_MAX * sizeof(res1[0]));
ptlrpc_nrs_hpreq_add_nolock(req);
memcpy(res1, res2, NRS_RES_MAX * sizeof(res1[0]));
out:
spin_unlock(&svcpt->scp_req_lock);
/**
* Release either the regular NRS head resources if we moved the
* request, or the high-priority NRS head resources if we took a
* reference earlier in this function and ptlrpc_nrs_req_can_move()
* returned false.
*/
nrs_resource_put_safe(res1);
}
/**
* Carries out a control operation \a opc on the policy identified by the
* human-readable \a name, on either all partitions, or only on the first
* partition of service \a svc.
*
* \param[in] svc the service the policy belongs to.
* \param[in] queue whether to carry out the command on the policy which
* belongs to the regular, high-priority, or both NRS
* heads of service partitions of \a svc.
* \param[in] name the policy to act upon, by human-readable name
* \param[in] opc the opcode of the operation to carry out
* \param[in] single when set, the operation will only be carried out on the
* NRS heads of the first service partition of \a svc.
* This is useful for some policies which e.g. share
* identical values on the same parameters of different
* service partitions; when reading these parameters via
* lprocfs, these policies may just want to obtain and
* print out the values from the first service partition.
* Storing these values centrally elsewhere then could be
* another solution for this.
* \param[in,out] arg can be used as a generic in/out buffer between control
* operations and the user environment.
*
*\retval -ve error condition
*\retval 0 operation was carried out successfully
*/
int ptlrpc_nrs_policy_control(const struct ptlrpc_service *svc,
enum ptlrpc_nrs_queue_type queue, char *name,
enum ptlrpc_nrs_ctl opc, bool single, void *arg)
{
struct ptlrpc_service_part *svcpt;
int i;
int rc = 0;
LASSERT(opc != PTLRPC_NRS_CTL_INVALID);
if ((queue & PTLRPC_NRS_QUEUE_BOTH) == 0)
return -EINVAL;
ptlrpc_service_for_each_part(svcpt, i, svc) {
if ((queue & PTLRPC_NRS_QUEUE_REG) != 0) {
rc = nrs_policy_ctl(nrs_svcpt2nrs(svcpt, false), name,
opc, arg);
if (rc != 0 || (queue == PTLRPC_NRS_QUEUE_REG &&
single))
GOTO(out, rc);
}
if ((queue & PTLRPC_NRS_QUEUE_HP) != 0) {
/**
* XXX: We could optionally check for
* nrs_svc_has_hp(svc) here, and return an error if it
* is false. Right now we rely on the policies' lprocfs
* handlers that call the present function to make this
* check; if they fail to do so, they might hit the
* assertion inside nrs_svcpt2nrs() below.
*/
rc = nrs_policy_ctl(nrs_svcpt2nrs(svcpt, true), name,
opc, arg);
if (rc != 0 || single)
GOTO(out, rc);
}
}
out:
return rc;
}
/* ptlrpc/nrs_fifo.c */
extern struct ptlrpc_nrs_pol_conf nrs_conf_fifo;
/**
* Adds all policies that ship with the ptlrpc module, to NRS core's list of
* policies \e nrs_core.nrs_policies.
*
* \retval 0 all policies have been registered successfully
* \retval -ve error
*/
int ptlrpc_nrs_init(void)
{
int rc;
mutex_init(&nrs_core.nrs_mutex);
INIT_LIST_HEAD(&nrs_core.nrs_policies);
rc = ptlrpc_nrs_policy_register(&nrs_conf_fifo);
if (rc != 0)
GOTO(fail, rc);
return rc;
fail:
/**
* Since no PTLRPC services have been started at this point, all we need
* to do for cleanup is to free the descriptors.
*/
ptlrpc_nrs_fini();
return rc;
}
/**
* Removes all policy descriptors from nrs_core::nrs_policies, and frees the
* policy descriptors.
*
* Since all PTLRPC services are stopped at this point, there are no more
* instances of any policies, because each service will have stopped its policy
* instances in ptlrpc_service_nrs_cleanup(), so we just need to free the
* descriptors here.
*/
void ptlrpc_nrs_fini(void)
{
struct ptlrpc_nrs_pol_desc *desc;
struct ptlrpc_nrs_pol_desc *tmp;
list_for_each_entry_safe(desc, tmp, &nrs_core.nrs_policies,
pd_list) {
list_del_init(&desc->pd_list);
OBD_FREE_PTR(desc);
}
}
/** @} nrs */
|