lustre/llite/pcc.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2017, DDN Storage Corporation.
  24  */
  25 /*
  26  * Persistent Client Cache
  27  *
  28  * PCC is a new framework which provides a group of local cache on Lustre
  29  * client side. It works in two modes: RW-PCC enables a read-write cache on the
  30  * local SSDs of a single client; RO-PCC provides a read-only cache on the
  31  * local SSDs of multiple clients. Less overhead is visible to the applications
  32  * and network latencies and lock conflicts can be significantly reduced.
  33  *
  34  * For RW-PCC, no global namespace will be provided. Each client uses its own
  35  * local storage as a cache for itself. Local file system is used to manage
  36  * the data on local caches. Cached I/O is directed to local file system while
  37  * normal I/O is directed to OSTs. RW-PCC uses HSM for data synchronization.
  38  * It uses HSM copytool to restore file from local caches to Lustre OSTs. Each
  39  * PCC has a copytool instance running with unique archive number. Any remote
  40  * access from another Lustre client would trigger the data synchronization. If
  41  * a client with RW-PCC goes offline, the cached data becomes inaccessible for
  42  * other client temporarily. And after the RW-PCC client reboots and the
  43  * copytool restarts, the data will be accessible again.
  44  *
  45  * Following is what will happen in different conditions for RW-PCC:
  46  *
  47  * > When file is being created on RW-PCC
  48  *
  49  * A normal HSM released file is created on MDT;
  50  * An empty mirror file is created on local cache;
  51  * The HSM status of the Lustre file will be set to archived and released;
  52  * The archive number will be set to the proper value.
  53  *
  54  * > When file is being prefetched to RW-PCC
  55  *
  56  * An file is copied to the local cache;
  57  * The HSM status of the Lustre file will be set to archived and released;
  58  * The archive number will be set to the proper value.
  59  *
  60  * > When file is being accessed from PCC
  61  *
  62  * Data will be read directly from local cache;
  63  * Metadata will be read from MDT, except file size;
  64  * File size will be got from local cache.
  65  *
  66  * > When PCC cached file is being accessed on another client
  67  *
  68  * RW-PCC cached files are automatically restored when a process on another
  69  * client tries to read or modify them. The corresponding I/O will block
  70  * waiting for the released file to be restored. This is transparent to the
  71  * process.
  72  *
  73  * For RW-PCC, when a file is being created, a rule-based policy is used to
  74  * determine whether it will be cached. Rule-based caching of newly created
  75  * files can determine which file can use a cache on PCC directly without any
  76  * admission control.
  77  *
  78  * RW-PCC design can accelerate I/O intensive applications with one-to-one
  79  * mappings between files and accessing clients. However, in several use cases,
  80  * files will never be updated, but need to be read simultaneously from many
  81  * clients. RO-PCC implements a read-only caching on Lustre clients using
  82  * SSDs. RO-PCC is based on the same framework as RW-PCC, expect
  83  * that no HSM mechanism is used.
  84  *
  85  * The main advantages to use this SSD cache on the Lustre clients via PCC
  86  * is that:
  87  * - The I/O stack becomes much simpler for the cached data, as there is no
  88  *   interference with I/Os from other clients, which enables easier
  89  *   performance optimizations;
  90  * - The requirements on the HW inside the client nodes are small, any kind of
  91  *   SSDs or even HDDs can be used as cache devices;
  92  * - Caching reduces the pressure on the object storage targets (OSTs), as
  93  *   small or random I/Os can be regularized to big sequential I/Os and
  94  *   temporary files do not even need to be flushed to OSTs.
  95  *
  96  * PCC can accelerate applications with certain I/O patterns:
  97  * - small-sized random writes (< 1MB) from a single client
  98  * - repeated read of data that is larger than RAM
  99  * - clients with high network latency
 100  *
 101  * Author: Li Xi <lixi@ddn.com>
 102  * Author: Qian Yingjin <qian@ddn.com>
 103  */
 104
 105 #define DEBUG_SUBSYSTEM S_LLITE
 106
 107 #include "pcc.h"
 108 #include <linux/namei.h>
 109 #include <linux/file.h>
 110 #include <lustre_compat.h>
 111 #include "llite_internal.h"
 112
 113 struct kmem_cache *pcc_inode_slab;
 114
 115 int pcc_super_init(struct pcc_super *super)
 116 {
 117         struct cred *cred;
 118
 119         super->pccs_cred = cred = prepare_creds();
 120         if (!cred)
 121                 return -ENOMEM;
 122
 123         /* Never override disk quota limits or use reserved space */
 124         cap_lower(cred->cap_effective, CAP_SYS_RESOURCE);
 125         init_rwsem(&super->pccs_rw_sem);
 126         INIT_LIST_HEAD(&super->pccs_datasets);
 127
 128         return 0;
 129 }
 130
 131 /* Rule based auto caching */
 132 static void pcc_id_list_free(struct list_head *id_list)
 133 {
 134         struct pcc_match_id *id, *n;
 135
 136         list_for_each_entry_safe(id, n, id_list, pmi_linkage) {
 137                 list_del_init(&id->pmi_linkage);
 138                 OBD_FREE_PTR(id);
 139         }
 140 }
 141
 142 static void pcc_fname_list_free(struct list_head *fname_list)
 143 {
 144         struct pcc_match_fname *fname, *n;
 145
 146         list_for_each_entry_safe(fname, n, fname_list, pmf_linkage) {
 147                 OBD_FREE(fname->pmf_name, strlen(fname->pmf_name) + 1);
 148                 list_del_init(&fname->pmf_linkage);
 149                 OBD_FREE_PTR(fname);
 150         }
 151 }
 152
 153 static void pcc_expression_free(struct pcc_expression *expr)
 154 {
 155         LASSERT(expr->pe_field >= PCC_FIELD_UID &&
 156                 expr->pe_field < PCC_FIELD_MAX);
 157         switch (expr->pe_field) {
 158         case PCC_FIELD_UID:
 159         case PCC_FIELD_GID:
 160         case PCC_FIELD_PROJID:
 161                 pcc_id_list_free(&expr->pe_cond);
 162                 break;
 163         case PCC_FIELD_FNAME:
 164                 pcc_fname_list_free(&expr->pe_cond);
 165                 break;
 166         default:
 167                 LBUG();
 168         }
 169         OBD_FREE_PTR(expr);
 170 }
 171
 172 static void pcc_conjunction_free(struct pcc_conjunction *conjunction)
 173 {
 174         struct pcc_expression *expression, *n;
 175
 176         LASSERT(list_empty(&conjunction->pc_linkage));
 177         list_for_each_entry_safe(expression, n,
 178                                  &conjunction->pc_expressions,
 179                                  pe_linkage) {
 180                 list_del_init(&expression->pe_linkage);
 181                 pcc_expression_free(expression);
 182         }
 183         OBD_FREE_PTR(conjunction);
 184 }
 185
 186 static void pcc_rule_conds_free(struct list_head *cond_list)
 187 {
 188         struct pcc_conjunction *conjunction, *n;
 189
 190         list_for_each_entry_safe(conjunction, n, cond_list, pc_linkage) {
 191                 list_del_init(&conjunction->pc_linkage);
 192                 pcc_conjunction_free(conjunction);
 193         }
 194 }
 195
 196 static void pcc_cmd_fini(struct pcc_cmd *cmd)
 197 {
 198         if (cmd->pccc_cmd == PCC_ADD_DATASET) {
 199                 if (!list_empty(&cmd->u.pccc_add.pccc_conds))
 200                         pcc_rule_conds_free(&cmd->u.pccc_add.pccc_conds);
 201                 if (cmd->u.pccc_add.pccc_conds_str)
 202                         OBD_FREE(cmd->u.pccc_add.pccc_conds_str,
 203                                  strlen(cmd->u.pccc_add.pccc_conds_str) + 1);
 204         }
 205 }
 206
 207 #define PCC_DISJUNCTION_DELIM   (',')
 208 #define PCC_CONJUNCTION_DELIM   ('&')
 209 #define PCC_EXPRESSION_DELIM    ('=')
 210
 211 static int
 212 pcc_fname_list_add(struct cfs_lstr *id, struct list_head *fname_list)
 213 {
 214         struct pcc_match_fname *fname;
 215
 216         OBD_ALLOC(fname, sizeof(struct pcc_match_fname));
 217         if (fname == NULL)
 218                 return -ENOMEM;
 219
 220         OBD_ALLOC(fname->pmf_name, id->ls_len + 1);
 221         if (fname->pmf_name == NULL) {
 222                 OBD_FREE(fname, sizeof(struct pcc_match_fname));
 223                 return -ENOMEM;
 224         }
 225
 226         memcpy(fname->pmf_name, id->ls_str, id->ls_len);
 227         list_add_tail(&fname->pmf_linkage, fname_list);
 228         return 0;
 229 }
 230
 231 static int
 232 pcc_fname_list_parse(char *str, int len, struct list_head *fname_list)
 233 {
 234         struct cfs_lstr src;
 235         struct cfs_lstr res;
 236         int rc = 0;
 237
 238         ENTRY;
 239
 240         src.ls_str = str;
 241         src.ls_len = len;
 242         INIT_LIST_HEAD(fname_list);
 243         while (src.ls_str) {
 244                 rc = cfs_gettok(&src, ' ', &res);
 245                 if (rc == 0) {
 246                         rc = -EINVAL;
 247                         break;
 248                 }
 249                 rc = pcc_fname_list_add(&res, fname_list);
 250                 if (rc)
 251                         break;
 252         }
 253         if (rc)
 254                 pcc_fname_list_free(fname_list);
 255         RETURN(rc);
 256 }
 257
 258 static int
 259 pcc_id_list_parse(char *str, int len, struct list_head *id_list,
 260                   enum pcc_field type)
 261 {
 262         struct cfs_lstr src;
 263         struct cfs_lstr res;
 264         int rc = 0;
 265
 266         ENTRY;
 267
 268         if (type != PCC_FIELD_UID && type != PCC_FIELD_GID &&
 269             type != PCC_FIELD_PROJID)
 270                 RETURN(-EINVAL);
 271
 272         src.ls_str = str;
 273         src.ls_len = len;
 274         INIT_LIST_HEAD(id_list);
 275         while (src.ls_str) {
 276                 struct pcc_match_id *id;
 277                 __u32 id_val;
 278
 279                 if (cfs_gettok(&src, ' ', &res) == 0)
 280                         GOTO(out, rc = -EINVAL);
 281
 282                 if (!cfs_str2num_check(res.ls_str, res.ls_len,
 283                                        &id_val, 0, (u32)~0U))
 284                         GOTO(out, rc = -EINVAL);
 285
 286                 OBD_ALLOC_PTR(id);
 287                 if (id == NULL)
 288                         GOTO(out, rc = -ENOMEM);
 289
 290                 id->pmi_id = id_val;
 291                 list_add_tail(&id->pmi_linkage, id_list);
 292         }
 293 out:
 294         if (rc)
 295                 pcc_id_list_free(id_list);
 296         RETURN(rc);
 297 }
 298
 299 static inline bool
 300 pcc_check_field(struct cfs_lstr *field, char *str)
 301 {
 302         int len = strlen(str);
 303
 304         return (field->ls_len == len &&
 305                 strncmp(field->ls_str, str, len) == 0);
 306 }
 307
 308 static int
 309 pcc_expression_parse(struct cfs_lstr *src, struct list_head *cond_list)
 310 {
 311         struct pcc_expression *expr;
 312         struct cfs_lstr field;
 313         int rc = 0;
 314
 315         OBD_ALLOC(expr, sizeof(struct pcc_expression));
 316         if (expr == NULL)
 317                 return -ENOMEM;
 318
 319         rc = cfs_gettok(src, PCC_EXPRESSION_DELIM, &field);
 320         if (rc == 0 || src->ls_len <= 2 || src->ls_str[0] != '{' ||
 321             src->ls_str[src->ls_len - 1] != '}')
 322                 GOTO(out, rc = -EINVAL);
 323
 324         /* Skip '{' and '}' */
 325         src->ls_str++;
 326         src->ls_len -= 2;
 327
 328         if (pcc_check_field(&field, "uid")) {
 329                 if (pcc_id_list_parse(src->ls_str,
 330                                       src->ls_len,
 331                                       &expr->pe_cond,
 332                                       PCC_FIELD_UID) < 0)
 333                         GOTO(out, rc = -EINVAL);
 334                 expr->pe_field = PCC_FIELD_UID;
 335         } else if (pcc_check_field(&field, "gid")) {
 336                 if (pcc_id_list_parse(src->ls_str,
 337                                       src->ls_len,
 338                                       &expr->pe_cond,
 339                                       PCC_FIELD_GID) < 0)
 340                         GOTO(out, rc = -EINVAL);
 341                 expr->pe_field = PCC_FIELD_GID;
 342         } else if (pcc_check_field(&field, "projid")) {
 343                 if (pcc_id_list_parse(src->ls_str,
 344                                       src->ls_len,
 345                                       &expr->pe_cond,
 346                                       PCC_FIELD_PROJID) < 0)
 347                         GOTO(out, rc = -EINVAL);
 348                 expr->pe_field = PCC_FIELD_PROJID;
 349         } else if (pcc_check_field(&field, "fname")) {
 350                 if (pcc_fname_list_parse(src->ls_str,
 351                                          src->ls_len,
 352                                          &expr->pe_cond) < 0)
 353                         GOTO(out, rc = -EINVAL);
 354                 expr->pe_field = PCC_FIELD_FNAME;
 355         } else {
 356                 GOTO(out, rc = -EINVAL);
 357         }
 358
 359         list_add_tail(&expr->pe_linkage, cond_list);
 360         return 0;
 361 out:
 362         OBD_FREE_PTR(expr);
 363         return rc;
 364 }
 365
 366 static int
 367 pcc_conjunction_parse(struct cfs_lstr *src, struct list_head *cond_list)
 368 {
 369         struct pcc_conjunction *conjunction;
 370         struct cfs_lstr expr;
 371         int rc = 0;
 372
 373         OBD_ALLOC(conjunction, sizeof(struct pcc_conjunction));
 374         if (conjunction == NULL)
 375                 return -ENOMEM;
 376
 377         INIT_LIST_HEAD(&conjunction->pc_expressions);
 378         list_add_tail(&conjunction->pc_linkage, cond_list);
 379
 380         while (src->ls_str) {
 381                 rc = cfs_gettok(src, PCC_CONJUNCTION_DELIM, &expr);
 382                 if (rc == 0) {
 383                         rc = -EINVAL;
 384                         break;
 385                 }
 386                 rc = pcc_expression_parse(&expr,
 387                                           &conjunction->pc_expressions);
 388                 if (rc)
 389                         break;
 390         }
 391         return rc;
 392 }
 393
 394 static int pcc_conds_parse(char *str, int len, struct list_head *cond_list)
 395 {
 396         struct cfs_lstr src;
 397         struct cfs_lstr res;
 398         int rc = 0;
 399
 400         src.ls_str = str;
 401         src.ls_len = len;
 402         INIT_LIST_HEAD(cond_list);
 403         while (src.ls_str) {
 404                 rc = cfs_gettok(&src, PCC_DISJUNCTION_DELIM, &res);
 405                 if (rc == 0) {
 406                         rc = -EINVAL;
 407                         break;
 408                 }
 409                 rc = pcc_conjunction_parse(&res, cond_list);
 410                 if (rc)
 411                         break;
 412         }
 413         return rc;
 414 }
 415
 416 static int pcc_id_parse(struct pcc_cmd *cmd, const char *id)
 417 {
 418         int rc;
 419
 420         OBD_ALLOC(cmd->u.pccc_add.pccc_conds_str, strlen(id) + 1);
 421         if (cmd->u.pccc_add.pccc_conds_str == NULL)
 422                 return -ENOMEM;
 423
 424         memcpy(cmd->u.pccc_add.pccc_conds_str, id, strlen(id));
 425
 426         rc = pcc_conds_parse(cmd->u.pccc_add.pccc_conds_str,
 427                              strlen(cmd->u.pccc_add.pccc_conds_str),
 428                              &cmd->u.pccc_add.pccc_conds);
 429         if (rc)
 430                 pcc_cmd_fini(cmd);
 431
 432         return rc;
 433 }
 434
 435 static int
 436 pcc_parse_value_pair(struct pcc_cmd *cmd, char *buffer)
 437 {
 438         char *key, *val;
 439         unsigned long id;
 440         int rc;
 441
 442         val = buffer;
 443         key = strsep(&val, "=");
 444         if (val == NULL || strlen(val) == 0)
 445                 return -EINVAL;
 446
 447         /* Key of the value pair */
 448         if (strcmp(key, "rwid") == 0) {
 449                 rc = kstrtoul(val, 10, &id);
 450                 if (rc)
 451                         return rc;
 452                 if (id <= 0)
 453                         return -EINVAL;
 454                 cmd->u.pccc_add.pccc_rwid = id;
 455         } else if (strcmp(key, "roid") == 0) {
 456                 rc = kstrtoul(val, 10, &id);
 457                 if (rc)
 458                         return rc;
 459                 if (id <= 0)
 460                         return -EINVAL;
 461                 cmd->u.pccc_add.pccc_roid = id;
 462         } else if (strcmp(key, "open_attach") == 0) {
 463                 rc = kstrtoul(val, 10, &id);
 464                 if (rc)
 465                         return rc;
 466                 if (id > 0)
 467                         cmd->u.pccc_add.pccc_flags |= PCC_DATASET_OPEN_ATTACH;
 468         } else if (strcmp(key, "rwpcc") == 0) {
 469                 rc = kstrtoul(val, 10, &id);
 470                 if (rc)
 471                         return rc;
 472                 if (id > 0)
 473                         cmd->u.pccc_add.pccc_flags |= PCC_DATASET_RWPCC;
 474         } else if (strcmp(key, "ropcc") == 0) {
 475                 rc = kstrtoul(val, 10, &id);
 476                 if (rc)
 477                         return rc;
 478                 if (id > 0)
 479                         cmd->u.pccc_add.pccc_flags |= PCC_DATASET_ROPCC;
 480         } else {
 481                 return -EINVAL;
 482         }
 483
 484         return 0;
 485 }
 486
 487 static int
 488 pcc_parse_value_pairs(struct pcc_cmd *cmd, char *buffer)
 489 {
 490         char *val;
 491         char *token;
 492         int rc;
 493
 494         val = buffer;
 495         while (val != NULL && strlen(val) != 0) {
 496                 token = strsep(&val, " ");
 497                 rc = pcc_parse_value_pair(cmd, token);
 498                 if (rc)
 499                         return rc;
 500         }
 501
 502         switch (cmd->pccc_cmd) {
 503         case PCC_ADD_DATASET:
 504                 if (cmd->u.pccc_add.pccc_flags & PCC_DATASET_RWPCC &&
 505                     cmd->u.pccc_add.pccc_flags & PCC_DATASET_ROPCC)
 506                         return -EINVAL;
 507                 /*
 508                  * By default, a PCC backend can provide caching service for
 509                  * both RW-PCC and RO-PCC.
 510                  */
 511                 if ((cmd->u.pccc_add.pccc_flags & PCC_DATASET_PCC_ALL) == 0)
 512                         cmd->u.pccc_add.pccc_flags |= PCC_DATASET_PCC_ALL;
 513                 break;
 514         case PCC_DEL_DATASET:
 515         case PCC_CLEAR_ALL:
 516                 break;
 517         default:
 518                 return -EINVAL;
 519         }
 520         return 0;
 521 }
 522
 523 static void
 524 pcc_dataset_rule_fini(struct pcc_match_rule *rule)
 525 {
 526         if (!list_empty(&rule->pmr_conds))
 527                 pcc_rule_conds_free(&rule->pmr_conds);
 528         LASSERT(rule->pmr_conds_str != NULL);
 529         OBD_FREE(rule->pmr_conds_str, strlen(rule->pmr_conds_str) + 1);
 530 }
 531
 532 static int
 533 pcc_dataset_rule_init(struct pcc_match_rule *rule, struct pcc_cmd *cmd)
 534 {
 535         int rc = 0;
 536
 537         LASSERT(cmd->u.pccc_add.pccc_conds_str);
 538         OBD_ALLOC(rule->pmr_conds_str,
 539                   strlen(cmd->u.pccc_add.pccc_conds_str) + 1);
 540         if (rule->pmr_conds_str == NULL)
 541                 return -ENOMEM;
 542
 543         memcpy(rule->pmr_conds_str,
 544                cmd->u.pccc_add.pccc_conds_str,
 545                strlen(cmd->u.pccc_add.pccc_conds_str));
 546
 547         INIT_LIST_HEAD(&rule->pmr_conds);
 548         if (!list_empty(&cmd->u.pccc_add.pccc_conds))
 549                 rc = pcc_conds_parse(rule->pmr_conds_str,
 550                                           strlen(rule->pmr_conds_str),
 551                                           &rule->pmr_conds);
 552
 553         if (rc)
 554                 pcc_dataset_rule_fini(rule);
 555
 556         return rc;
 557 }
 558
 559 /* Rule Matching */
 560 static int
 561 pcc_id_list_match(struct list_head *id_list, __u32 id_val)
 562 {
 563         struct pcc_match_id *id;
 564
 565         list_for_each_entry(id, id_list, pmi_linkage) {
 566                 if (id->pmi_id == id_val)
 567                         return 1;
 568         }
 569         return 0;
 570 }
 571
 572 static bool
 573 cfs_match_wildcard(const char *pattern, const char *content)
 574 {
 575         if (*pattern == '\0' && *content == '\0')
 576                 return true;
 577
 578         if (*pattern == '*' && *(pattern + 1) != '\0' && *content == '\0')
 579                 return false;
 580
 581         while (*pattern == *content) {
 582                 pattern++;
 583                 content++;
 584                 if (*pattern == '\0' && *content == '\0')
 585                         return true;
 586
 587                 if (*pattern == '*' && *(pattern + 1) != '\0' &&
 588                     *content == '\0')
 589                         return false;
 590         }
 591
 592         if (*pattern == '*')
 593                 return (cfs_match_wildcard(pattern + 1, content) ||
 594                         cfs_match_wildcard(pattern, content + 1));
 595
 596         return false;
 597 }
 598
 599 static int
 600 pcc_fname_list_match(struct list_head *fname_list, const char *name)
 601 {
 602         struct pcc_match_fname *fname;
 603
 604         list_for_each_entry(fname, fname_list, pmf_linkage) {
 605                 if (cfs_match_wildcard(fname->pmf_name, name))
 606                         return 1;
 607         }
 608         return 0;
 609 }
 610
 611 static int
 612 pcc_expression_match(struct pcc_expression *expr, struct pcc_matcher *matcher)
 613 {
 614         switch (expr->pe_field) {
 615         case PCC_FIELD_UID:
 616                 return pcc_id_list_match(&expr->pe_cond, matcher->pm_uid);
 617         case PCC_FIELD_GID:
 618                 return pcc_id_list_match(&expr->pe_cond, matcher->pm_gid);
 619         case PCC_FIELD_PROJID:
 620                 return pcc_id_list_match(&expr->pe_cond, matcher->pm_projid);
 621         case PCC_FIELD_FNAME:
 622                 return pcc_fname_list_match(&expr->pe_cond,
 623                                             matcher->pm_name->name);
 624         default:
 625                 return 0;
 626         }
 627 }
 628
 629 static int
 630 pcc_conjunction_match(struct pcc_conjunction *conjunction,
 631                       struct pcc_matcher *matcher)
 632 {
 633         struct pcc_expression *expr;
 634         int matched;
 635
 636         list_for_each_entry(expr, &conjunction->pc_expressions, pe_linkage) {
 637                 matched = pcc_expression_match(expr, matcher);
 638                 if (!matched)
 639                         return 0;
 640         }
 641
 642         return 1;
 643 }
 644
 645 static int
 646 pcc_cond_match(struct pcc_match_rule *rule, struct pcc_matcher *matcher)
 647 {
 648         struct pcc_conjunction *conjunction;
 649         int matched;
 650
 651         list_for_each_entry(conjunction, &rule->pmr_conds, pc_linkage) {
 652                 matched = pcc_conjunction_match(conjunction, matcher);
 653                 if (matched)
 654                         return 1;
 655         }
 656
 657         return 0;
 658 }
 659
 660 struct pcc_dataset*
 661 pcc_dataset_match_get(struct pcc_super *super, struct pcc_matcher *matcher)
 662 {
 663         struct pcc_dataset *dataset;
 664         struct pcc_dataset *selected = NULL;
 665
 666         down_read(&super->pccs_rw_sem);
 667         list_for_each_entry(dataset, &super->pccs_datasets, pccd_linkage) {
 668                 if (!(dataset->pccd_flags & PCC_DATASET_RWPCC))
 669                         continue;
 670
 671                 if (pcc_cond_match(&dataset->pccd_rule, matcher)) {
 672                         atomic_inc(&dataset->pccd_refcount);
 673                         selected = dataset;
 674                         break;
 675                 }
 676         }
 677         up_read(&super->pccs_rw_sem);
 678         if (selected)
 679                 CDEBUG(D_CACHE, "PCC create, matched %s - %d:%d:%d:%s\n",
 680                        dataset->pccd_rule.pmr_conds_str,
 681                        matcher->pm_uid, matcher->pm_gid,
 682                        matcher->pm_projid, matcher->pm_name->name);
 683
 684         return selected;
 685 }
 686
 687 /**
 688  * pcc_dataset_add - Add a Cache policy to control which files need be
 689  * cached and where it will be cached.
 690  *
 691  * @super:      superblock of pcc
 692  * @cmd:        pcc command
 693  */
 694 static int
 695 pcc_dataset_add(struct pcc_super *super, struct pcc_cmd *cmd)
 696 {
 697         char *pathname = cmd->pccc_pathname;
 698         struct pcc_dataset *dataset;
 699         struct pcc_dataset *tmp;
 700         bool found = false;
 701         int rc;
 702
 703         OBD_ALLOC_PTR(dataset);
 704         if (dataset == NULL)
 705                 return -ENOMEM;
 706
 707         rc = kern_path(pathname, LOOKUP_DIRECTORY, &dataset->pccd_path);
 708         if (unlikely(rc)) {
 709                 OBD_FREE_PTR(dataset);
 710                 return rc;
 711         }
 712         strncpy(dataset->pccd_pathname, pathname, PATH_MAX);
 713         dataset->pccd_rwid = cmd->u.pccc_add.pccc_rwid;
 714         dataset->pccd_roid = cmd->u.pccc_add.pccc_roid;
 715         dataset->pccd_flags = cmd->u.pccc_add.pccc_flags;
 716         atomic_set(&dataset->pccd_refcount, 1);
 717
 718         rc = pcc_dataset_rule_init(&dataset->pccd_rule, cmd);
 719         if (rc) {
 720                 pcc_dataset_put(dataset);
 721                 return rc;
 722         }
 723
 724         down_write(&super->pccs_rw_sem);
 725         list_for_each_entry(tmp, &super->pccs_datasets, pccd_linkage) {
 726                 if (strcmp(tmp->pccd_pathname, pathname) == 0 ||
 727                     (dataset->pccd_rwid != 0 &&
 728                      dataset->pccd_rwid == tmp->pccd_rwid) ||
 729                     (dataset->pccd_roid != 0 &&
 730                      dataset->pccd_roid == tmp->pccd_roid)) {
 731                         found = true;
 732                         break;
 733                 }
 734         }
 735         if (!found)
 736                 list_add(&dataset->pccd_linkage, &super->pccs_datasets);
 737         up_write(&super->pccs_rw_sem);
 738
 739         if (found) {
 740                 pcc_dataset_put(dataset);
 741                 rc = -EEXIST;
 742         }
 743
 744         return rc;
 745 }
 746
 747 struct pcc_dataset *
 748 pcc_dataset_get(struct pcc_super *super, enum lu_pcc_type type, __u32 id)
 749 {
 750         struct pcc_dataset *dataset;
 751         struct pcc_dataset *selected = NULL;
 752
 753         if (id == 0)
 754                 return NULL;
 755
 756         /*
 757          * archive ID (read-write ID) or read-only ID is unique in the list,
 758          * we just return last added one as first priority.
 759          */
 760         down_read(&super->pccs_rw_sem);
 761         list_for_each_entry(dataset, &super->pccs_datasets, pccd_linkage) {
 762                 if (type == LU_PCC_READWRITE && (dataset->pccd_rwid != id ||
 763                     !(dataset->pccd_flags & PCC_DATASET_RWPCC)))
 764                         continue;
 765                 atomic_inc(&dataset->pccd_refcount);
 766                 selected = dataset;
 767                 break;
 768         }
 769         up_read(&super->pccs_rw_sem);
 770         if (selected)
 771                 CDEBUG(D_CACHE, "matched id %u, PCC mode %d\n", id, type);
 772
 773         return selected;
 774 }
 775
 776 void
 777 pcc_dataset_put(struct pcc_dataset *dataset)
 778 {
 779         if (atomic_dec_and_test(&dataset->pccd_refcount)) {
 780                 pcc_dataset_rule_fini(&dataset->pccd_rule);
 781                 path_put(&dataset->pccd_path);
 782                 OBD_FREE_PTR(dataset);
 783         }
 784 }
 785
 786 static int
 787 pcc_dataset_del(struct pcc_super *super, char *pathname)
 788 {
 789         struct list_head *l, *tmp;
 790         struct pcc_dataset *dataset;
 791         int rc = -ENOENT;
 792
 793         down_write(&super->pccs_rw_sem);
 794         list_for_each_safe(l, tmp, &super->pccs_datasets) {
 795                 dataset = list_entry(l, struct pcc_dataset, pccd_linkage);
 796                 if (strcmp(dataset->pccd_pathname, pathname) == 0) {
 797                         list_del_init(&dataset->pccd_linkage);
 798                         pcc_dataset_put(dataset);
 799                         rc = 0;
 800                         break;
 801                 }
 802         }
 803         up_write(&super->pccs_rw_sem);
 804         return rc;
 805 }
 806
 807 static void
 808 pcc_dataset_dump(struct pcc_dataset *dataset, struct seq_file *m)
 809 {
 810         seq_printf(m, "%s:\n", dataset->pccd_pathname);
 811         seq_printf(m, "  rwid: %u\n", dataset->pccd_rwid);
 812         seq_printf(m, "  flags: %x\n", dataset->pccd_flags);
 813         seq_printf(m, "  autocache: %s\n", dataset->pccd_rule.pmr_conds_str);
 814 }
 815
 816 int
 817 pcc_super_dump(struct pcc_super *super, struct seq_file *m)
 818 {
 819         struct pcc_dataset *dataset;
 820
 821         down_read(&super->pccs_rw_sem);
 822         list_for_each_entry(dataset, &super->pccs_datasets, pccd_linkage) {
 823                 pcc_dataset_dump(dataset, m);
 824         }
 825         up_read(&super->pccs_rw_sem);
 826         return 0;
 827 }
 828
 829 static void pcc_remove_datasets(struct pcc_super *super)
 830 {
 831         struct pcc_dataset *dataset, *tmp;
 832
 833         down_write(&super->pccs_rw_sem);
 834         list_for_each_entry_safe(dataset, tmp,
 835                                  &super->pccs_datasets, pccd_linkage) {
 836                 list_del(&dataset->pccd_linkage);
 837                 pcc_dataset_put(dataset);
 838         }
 839         up_write(&super->pccs_rw_sem);
 840 }
 841
 842 void pcc_super_fini(struct pcc_super *super)
 843 {
 844         pcc_remove_datasets(super);
 845         put_cred(super->pccs_cred);
 846 }
 847
 848 static bool pathname_is_valid(const char *pathname)
 849 {
 850         /* Needs to be absolute path */
 851         if (pathname == NULL || strlen(pathname) == 0 ||
 852             strlen(pathname) >= PATH_MAX || pathname[0] != '/')
 853                 return false;
 854         return true;
 855 }
 856
 857 static struct pcc_cmd *
 858 pcc_cmd_parse(char *buffer, unsigned long count)
 859 {
 860         static struct pcc_cmd *cmd;
 861         char *token;
 862         char *val;
 863         int rc = 0;
 864
 865         OBD_ALLOC_PTR(cmd);
 866         if (cmd == NULL)
 867                 GOTO(out, rc = -ENOMEM);
 868
 869         /* clear all setting */
 870         if (strncmp(buffer, "clear", 5) == 0) {
 871                 cmd->pccc_cmd = PCC_CLEAR_ALL;
 872                 GOTO(out, rc = 0);
 873         }
 874
 875         val = buffer;
 876         token = strsep(&val, " ");
 877         if (val == NULL || strlen(val) == 0)
 878                 GOTO(out_free_cmd, rc = -EINVAL);
 879
 880         /* Type of the command */
 881         if (strcmp(token, "add") == 0)
 882                 cmd->pccc_cmd = PCC_ADD_DATASET;
 883         else if (strcmp(token, "del") == 0)
 884                 cmd->pccc_cmd = PCC_DEL_DATASET;
 885         else
 886                 GOTO(out_free_cmd, rc = -EINVAL);
 887
 888         /* Pathname of the dataset */
 889         token = strsep(&val, " ");
 890         if ((val == NULL && cmd->pccc_cmd != PCC_DEL_DATASET) ||
 891             !pathname_is_valid(token))
 892                 GOTO(out_free_cmd, rc = -EINVAL);
 893         cmd->pccc_pathname = token;
 894
 895         if (cmd->pccc_cmd == PCC_ADD_DATASET) {
 896                 /* List of ID */
 897                 LASSERT(val);
 898                 token = val;
 899                 val = strrchr(token, '}');
 900                 if (!val)
 901                         GOTO(out_free_cmd, rc = -EINVAL);
 902
 903                 /* Skip '}' */
 904                 val++;
 905                 if (*val == '\0') {
 906                         val = NULL;
 907                 } else if (*val == ' ') {
 908                         *val = '\0';
 909                         val++;
 910                 } else {
 911                         GOTO(out_free_cmd, rc = -EINVAL);
 912                 }
 913
 914                 rc = pcc_id_parse(cmd, token);
 915                 if (rc)
 916                         GOTO(out_free_cmd, rc);
 917
 918                 rc = pcc_parse_value_pairs(cmd, val);
 919                 if (rc)
 920                         GOTO(out_cmd_fini, rc = -EINVAL);
 921         }
 922         goto out;
 923 out_cmd_fini:
 924         pcc_cmd_fini(cmd);
 925 out_free_cmd:
 926         OBD_FREE_PTR(cmd);
 927 out:
 928         if (rc)
 929                 cmd = ERR_PTR(rc);
 930         return cmd;
 931 }
 932
 933 int pcc_cmd_handle(char *buffer, unsigned long count,
 934                    struct pcc_super *super)
 935 {
 936         int rc = 0;
 937         struct pcc_cmd *cmd;
 938
 939         cmd = pcc_cmd_parse(buffer, count);
 940         if (IS_ERR(cmd))
 941                 return PTR_ERR(cmd);
 942
 943         switch (cmd->pccc_cmd) {
 944         case PCC_ADD_DATASET:
 945                 rc = pcc_dataset_add(super, cmd);
 946                 break;
 947         case PCC_DEL_DATASET:
 948                 rc = pcc_dataset_del(super, cmd->pccc_pathname);
 949                 break;
 950         case PCC_CLEAR_ALL:
 951                 pcc_remove_datasets(super);
 952                 break;
 953         default:
 954                 rc = -EINVAL;
 955                 break;
 956         }
 957
 958         pcc_cmd_fini(cmd);
 959         OBD_FREE_PTR(cmd);
 960         return rc;
 961 }
 962
 963 static inline void pcc_inode_lock(struct inode *inode)
 964 {
 965         mutex_lock(&ll_i2info(inode)->lli_pcc_lock);
 966 }
 967
 968 static inline void pcc_inode_unlock(struct inode *inode)
 969 {
 970         mutex_unlock(&ll_i2info(inode)->lli_pcc_lock);
 971 }
 972
 973 static void pcc_inode_init(struct pcc_inode *pcci, struct ll_inode_info *lli)
 974 {
 975         pcci->pcci_lli = lli;
 976         lli->lli_pcc_inode = pcci;
 977         lli->lli_pcc_state = PCC_STATE_FL_NONE;
 978         atomic_set(&pcci->pcci_refcount, 0);
 979         pcci->pcci_type = LU_PCC_NONE;
 980         pcci->pcci_layout_gen = CL_LAYOUT_GEN_NONE;
 981         atomic_set(&pcci->pcci_active_ios, 0);
 982         init_waitqueue_head(&pcci->pcci_waitq);
 983 }
 984
 985 static void pcc_inode_fini(struct pcc_inode *pcci)
 986 {
 987         struct ll_inode_info *lli = pcci->pcci_lli;
 988
 989         path_put(&pcci->pcci_path);
 990         pcci->pcci_type = LU_PCC_NONE;
 991         OBD_SLAB_FREE_PTR(pcci, pcc_inode_slab);
 992         lli->lli_pcc_inode = NULL;
 993 }
 994
 995 static void pcc_inode_get(struct pcc_inode *pcci)
 996 {
 997         atomic_inc(&pcci->pcci_refcount);
 998 }
 999
1000 static void pcc_inode_put(struct pcc_inode *pcci)
1001 {
1002         if (atomic_dec_and_test(&pcci->pcci_refcount))
1003                 pcc_inode_fini(pcci);
1004 }
1005
1006 void pcc_inode_free(struct inode *inode)
1007 {
1008         struct pcc_inode *pcci = ll_i2pcci(inode);
1009
1010         if (pcci) {
1011                 WARN_ON(atomic_read(&pcci->pcci_refcount) > 1);
1012                 pcc_inode_put(pcci);
1013         }
1014 }
1015
1016 /*
1017  * TODO:
1018  * As Andreas suggested, we'd better use new layout to
1019  * reduce overhead:
1020  * (fid->f_oid >> 16 & oxFFFF)/FID
1021  */
1022 #define MAX_PCC_DATABASE_PATH (6 * 5 + FID_NOBRACE_LEN + 1)
1023 static int pcc_fid2dataset_path(char *buf, int sz, struct lu_fid *fid)
1024 {
1025         return snprintf(buf, sz, "%04x/%04x/%04x/%04x/%04x/%04x/"
1026                         DFID_NOBRACE,
1027                         (fid)->f_oid       & 0xFFFF,
1028                         (fid)->f_oid >> 16 & 0xFFFF,
1029                         (unsigned int)((fid)->f_seq       & 0xFFFF),
1030                         (unsigned int)((fid)->f_seq >> 16 & 0xFFFF),
1031                         (unsigned int)((fid)->f_seq >> 32 & 0xFFFF),
1032                         (unsigned int)((fid)->f_seq >> 48 & 0xFFFF),
1033                         PFID(fid));
1034 }
1035
1036 static inline const struct cred *pcc_super_cred(struct super_block *sb)
1037 {
1038         return ll_s2sbi(sb)->ll_pcc_super.pccs_cred;
1039 }
1040
1041 void pcc_file_init(struct pcc_file *pccf)
1042 {
1043         pccf->pccf_file = NULL;
1044         pccf->pccf_type = LU_PCC_NONE;
1045 }
1046
1047 static inline bool pcc_open_attach_enabled(struct pcc_dataset *dataset)
1048 {
1049         return dataset->pccd_flags & PCC_DATASET_OPEN_ATTACH;
1050 }
1051
1052 static const char pcc_xattr_layout[] = XATTR_USER_PREFIX "PCC.layout";
1053
1054 static int pcc_layout_xattr_set(struct pcc_inode *pcci, __u32 gen)
1055 {
1056         struct dentry *pcc_dentry = pcci->pcci_path.dentry;
1057         struct ll_inode_info *lli = pcci->pcci_lli;
1058         int rc;
1059
1060         ENTRY;
1061
1062         if (!(lli->lli_pcc_state & PCC_STATE_FL_OPEN_ATTACH))
1063                 RETURN(0);
1064
1065 #ifndef HAVE_VFS_SETXATTR
1066         if (!pcc_dentry->d_inode->i_op->setxattr)
1067                 RETURN(-ENOTSUPP);
1068
1069         rc = pcc_dentry->d_inode->i_op->setxattr(pcc_dentry, pcc_xattr_layout,
1070                                                  &gen, sizeof(gen), 0);
1071 #else
1072         rc = __vfs_setxattr(pcc_dentry, pcc_dentry->d_inode, pcc_xattr_layout,
1073                             &gen, sizeof(gen), 0);
1074 #endif
1075         RETURN(rc);
1076 }
1077
1078 static int pcc_get_layout_info(struct inode *inode, struct cl_layout *clt)
1079 {
1080         struct lu_env *env;
1081         struct ll_inode_info *lli = ll_i2info(inode);
1082         __u16 refcheck;
1083         int rc;
1084
1085         ENTRY;
1086
1087         if (!lli->lli_clob)
1088                 RETURN(-EINVAL);
1089
1090         env = cl_env_get(&refcheck);
1091         if (IS_ERR(env))
1092                 RETURN(PTR_ERR(env));
1093
1094         rc = cl_object_layout_get(env, lli->lli_clob, clt);
1095         if (rc)
1096                 CDEBUG(D_INODE, "Cannot get layout for "DFID"\n",
1097                        PFID(ll_inode2fid(inode)));
1098
1099         cl_env_put(env, &refcheck);
1100         RETURN(rc);
1101 }
1102
1103 static int pcc_fid2dataset_fullpath(char *buf, int sz, struct lu_fid *fid,
1104                                     struct pcc_dataset *dataset)
1105 {
1106         return snprintf(buf, sz, "%s/%04x/%04x/%04x/%04x/%04x/%04x/"
1107                         DFID_NOBRACE,
1108                         dataset->pccd_pathname,
1109                         (fid)->f_oid       & 0xFFFF,
1110                         (fid)->f_oid >> 16 & 0xFFFF,
1111                         (unsigned int)((fid)->f_seq       & 0xFFFF),
1112                         (unsigned int)((fid)->f_seq >> 16 & 0xFFFF),
1113                         (unsigned int)((fid)->f_seq >> 32 & 0xFFFF),
1114                         (unsigned int)((fid)->f_seq >> 48 & 0xFFFF),
1115                         PFID(fid));
1116 }
1117
1118 /* Must be called with pcci->pcci_lock held */
1119 static void pcc_inode_attach_init(struct pcc_dataset *dataset,
1120                                   struct pcc_inode *pcci,
1121                                   struct dentry *dentry,
1122                                   enum lu_pcc_type type)
1123 {
1124         pcci->pcci_path.mnt = mntget(dataset->pccd_path.mnt);
1125         pcci->pcci_path.dentry = dentry;
1126         LASSERT(atomic_read(&pcci->pcci_refcount) == 0);
1127         atomic_set(&pcci->pcci_refcount, 1);
1128         pcci->pcci_type = type;
1129         pcci->pcci_attr_valid = false;
1130
1131         if (pcc_open_attach_enabled(dataset)) {
1132                 struct ll_inode_info *lli = pcci->pcci_lli;
1133
1134                 lli->lli_pcc_state |= PCC_STATE_FL_OPEN_ATTACH;
1135         }
1136 }
1137
1138 static inline void pcc_layout_gen_set(struct pcc_inode *pcci,
1139                                       __u32 gen)
1140 {
1141         pcci->pcci_layout_gen = gen;
1142 }
1143
1144 static inline bool pcc_inode_has_layout(struct pcc_inode *pcci)
1145 {
1146         return pcci->pcci_layout_gen != CL_LAYOUT_GEN_NONE;
1147 }
1148
1149 static int pcc_try_dataset_attach(struct inode *inode, __u32 gen,
1150                                   enum lu_pcc_type type,
1151                                   struct pcc_dataset *dataset,
1152                                   bool *cached)
1153 {
1154         struct ll_inode_info *lli = ll_i2info(inode);
1155         struct pcc_inode *pcci = lli->lli_pcc_inode;
1156         const struct cred *old_cred;
1157         struct dentry *pcc_dentry;
1158         struct path path;
1159         char *pathname;
1160         __u32 pcc_gen;
1161         int rc;
1162
1163         ENTRY;
1164
1165         if (type == LU_PCC_READWRITE &&
1166             !(dataset->pccd_flags & PCC_DATASET_RWPCC))
1167                 RETURN(0);
1168
1169         OBD_ALLOC(pathname, PATH_MAX);
1170         if (pathname == NULL)
1171                 RETURN(-ENOMEM);
1172
1173         pcc_fid2dataset_fullpath(pathname, PATH_MAX, &lli->lli_fid, dataset);
1174
1175         old_cred = override_creds(pcc_super_cred(inode->i_sb));
1176         rc = kern_path(pathname, LOOKUP_FOLLOW, &path);
1177         if (rc)
1178                 /* ignore this error */
1179                 GOTO(out, rc = 0);
1180
1181         pcc_dentry = path.dentry;
1182 #ifndef HAVE_VFS_SETXATTR
1183         if (!pcc_dentry->d_inode->i_op->getxattr)
1184                 /* ignore this error */
1185                 GOTO(out_put_path, rc = 0);
1186
1187         rc = pcc_dentry->d_inode->i_op->getxattr(pcc_dentry, pcc_xattr_layout,
1188                                                  &pcc_gen, sizeof(pcc_gen));
1189 #else
1190         rc = __vfs_getxattr(pcc_dentry, pcc_dentry->d_inode, pcc_xattr_layout,
1191                             &pcc_gen, sizeof(pcc_gen));
1192 #endif
1193
1194         if (rc < 0)
1195                 /* ignore this error */
1196                 GOTO(out_put_path, rc = 0);
1197
1198         rc = 0;
1199         /* The file is still valid cached in PCC, attach it immediately. */
1200         if (pcc_gen == gen) {
1201                 CDEBUG(D_CACHE, DFID" L.Gen (%d) consistent, auto attached.\n",
1202                        PFID(&lli->lli_fid), gen);
1203                 if (!pcci) {
1204                         OBD_SLAB_ALLOC_PTR_GFP(pcci, pcc_inode_slab, GFP_NOFS);
1205                         if (pcci == NULL)
1206                                 GOTO(out_put_path, rc = -ENOMEM);
1207
1208                         pcc_inode_init(pcci, lli);
1209                         dget(pcc_dentry);
1210                         pcc_inode_attach_init(dataset, pcci, pcc_dentry, type);
1211                 } else {
1212                         /*
1213                          * This happened when a file was once attached into
1214                          * PCC, and some processes keep this file opened
1215                          * (pcci->refcount > 1) and corresponding PCC file
1216                          * without any I/O activity, and then this file was
1217                          * detached by the manual detach command or the
1218                          * revocation of the layout lock (i.e. cached LRU lock
1219                          * shrinking).
1220                          */
1221                         pcc_inode_get(pcci);
1222                         pcci->pcci_type = type;
1223                 }
1224                 pcc_layout_gen_set(pcci, gen);
1225                 *cached = true;
1226         }
1227 out_put_path:
1228         path_put(&path);
1229 out:
1230         revert_creds(old_cred);
1231         OBD_FREE(pathname, PATH_MAX);
1232         RETURN(rc);
1233 }
1234
1235 static int pcc_try_datasets_attach(struct inode *inode, __u32 gen,
1236                                    enum lu_pcc_type type, bool *cached)
1237 {
1238         struct pcc_dataset *dataset, *tmp;
1239         struct pcc_super *super = &ll_i2sbi(inode)->ll_pcc_super;
1240         int rc = 0;
1241
1242         ENTRY;
1243
1244         down_read(&super->pccs_rw_sem);
1245         list_for_each_entry_safe(dataset, tmp,
1246                                  &super->pccs_datasets, pccd_linkage) {
1247                 if (!pcc_open_attach_enabled(dataset))
1248                         continue;
1249                 rc = pcc_try_dataset_attach(inode, gen, type, dataset, cached);
1250                 if (rc < 0 || (!rc && *cached))
1251                         break;
1252         }
1253         up_read(&super->pccs_rw_sem);
1254
1255         RETURN(rc);
1256 }
1257
1258 static int pcc_try_open_attach(struct inode *inode, bool *cached)
1259 {
1260         struct pcc_super *super = &ll_i2sbi(inode)->ll_pcc_super;
1261         struct cl_layout clt = {
1262                 .cl_layout_gen = 0,
1263                 .cl_is_released = false,
1264         };
1265         int rc;
1266
1267         ENTRY;
1268
1269         /*
1270          * Quick check whether there is PCC device.
1271          */
1272         if (list_empty(&super->pccs_datasets))
1273                 RETURN(0);
1274
1275         /*
1276          * The file layout lock was cancelled. And this open does not
1277          * obtain valid layout lock from MDT (i.e. the file is being
1278          * HSM restoring).
1279          */
1280         if (ll_layout_version_get(ll_i2info(inode)) == CL_LAYOUT_GEN_NONE)
1281                 RETURN(0);
1282
1283         rc = pcc_get_layout_info(inode, &clt);
1284         if (rc)
1285                 RETURN(rc);
1286
1287         if (clt.cl_is_released)
1288                 rc = pcc_try_datasets_attach(inode, clt.cl_layout_gen,
1289                                              LU_PCC_READWRITE, cached);
1290
1291         RETURN(rc);
1292 }
1293
1294 int pcc_file_open(struct inode *inode, struct file *file)
1295 {
1296         struct pcc_inode *pcci;
1297         struct ll_inode_info *lli = ll_i2info(inode);
1298         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1299         struct pcc_file *pccf = &fd->fd_pcc_file;
1300         struct file *pcc_file;
1301         struct path *path;
1302         struct qstr *dname;
1303         bool cached = false;
1304         int rc = 0;
1305
1306         ENTRY;
1307
1308         if (!S_ISREG(inode->i_mode))
1309                 RETURN(0);
1310
1311         pcc_inode_lock(inode);
1312         pcci = ll_i2pcci(inode);
1313
1314         if (lli->lli_pcc_state & PCC_STATE_FL_ATTACHING)
1315                 GOTO(out_unlock, rc = 0);
1316
1317         if (!pcci || !pcc_inode_has_layout(pcci)) {
1318                 rc = pcc_try_open_attach(inode, &cached);
1319                 if (rc < 0 || !cached)
1320                         GOTO(out_unlock, rc);
1321
1322                 if (!pcci)
1323                         pcci = ll_i2pcci(inode);
1324         }
1325
1326         pcc_inode_get(pcci);
1327         WARN_ON(pccf->pccf_file);
1328
1329         path = &pcci->pcci_path;
1330         dname = &path->dentry->d_name;
1331         CDEBUG(D_CACHE, "opening pcc file '%.*s'\n", dname->len,
1332                dname->name);
1333
1334 #ifdef HAVE_DENTRY_OPEN_USE_PATH
1335         pcc_file = dentry_open(path, file->f_flags,
1336                                pcc_super_cred(inode->i_sb));
1337 #else
1338         pcc_file = dentry_open(path->dentry, path->mnt, file->f_flags,
1339                                pcc_super_cred(inode->i_sb));
1340 #endif
1341         if (IS_ERR_OR_NULL(pcc_file)) {
1342                 rc = pcc_file == NULL ? -EINVAL : PTR_ERR(pcc_file);
1343                 pcc_inode_put(pcci);
1344         } else {
1345                 pccf->pccf_file = pcc_file;
1346                 pccf->pccf_type = pcci->pcci_type;
1347         }
1348
1349 out_unlock:
1350         pcc_inode_unlock(inode);
1351         RETURN(rc);
1352 }
1353
1354 void pcc_file_release(struct inode *inode, struct file *file)
1355 {
1356         struct pcc_inode *pcci;
1357         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1358         struct pcc_file *pccf;
1359         struct path *path;
1360         struct qstr *dname;
1361
1362         ENTRY;
1363
1364         if (!S_ISREG(inode->i_mode) || fd == NULL)
1365                 RETURN_EXIT;
1366
1367         pccf = &fd->fd_pcc_file;
1368         pcc_inode_lock(inode);
1369         if (pccf->pccf_file == NULL)
1370                 goto out;
1371
1372         pcci = ll_i2pcci(inode);
1373         LASSERT(pcci);
1374         path = &pcci->pcci_path;
1375         dname = &path->dentry->d_name;
1376         CDEBUG(D_CACHE, "releasing pcc file \"%.*s\"\n", dname->len,
1377                dname->name);
1378         pcc_inode_put(pcci);
1379         fput(pccf->pccf_file);
1380         pccf->pccf_file = NULL;
1381 out:
1382         pcc_inode_unlock(inode);
1383         RETURN_EXIT;
1384 }
1385
1386 static void pcc_io_init(struct inode *inode, bool *cached)
1387 {
1388         struct pcc_inode *pcci;
1389
1390         pcc_inode_lock(inode);
1391         pcci = ll_i2pcci(inode);
1392         if (pcci && pcc_inode_has_layout(pcci)) {
1393                 LASSERT(atomic_read(&pcci->pcci_refcount) > 0);
1394                 atomic_inc(&pcci->pcci_active_ios);
1395                 *cached = true;
1396         } else {
1397                 *cached = false;
1398         }
1399         pcc_inode_unlock(inode);
1400 }
1401
1402 static void pcc_io_fini(struct inode *inode)
1403 {
1404         struct pcc_inode *pcci = ll_i2pcci(inode);
1405
1406         LASSERT(pcci && atomic_read(&pcci->pcci_active_ios) > 0);
1407         if (atomic_dec_and_test(&pcci->pcci_active_ios))
1408                 wake_up_all(&pcci->pcci_waitq);
1409 }
1410
1411
1412 static ssize_t
1413 __pcc_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
1414 {
1415         struct file *file = iocb->ki_filp;
1416
1417 #ifdef HAVE_FILE_OPERATIONS_READ_WRITE_ITER
1418         return file->f_op->read_iter(iocb, iter);
1419 #else
1420         struct iovec iov;
1421         struct iov_iter i;
1422         ssize_t bytes = 0;
1423
1424         iov_for_each(iov, i, *iter) {
1425                 ssize_t res;
1426
1427                 res = file->f_op->aio_read(iocb, &iov, 1, iocb->ki_pos);
1428                 if (-EIOCBQUEUED == res)
1429                         res = wait_on_sync_kiocb(iocb);
1430                 if (res <= 0) {
1431                         if (bytes == 0)
1432                                 bytes = res;
1433                         break;
1434                 }
1435
1436                 bytes += res;
1437                 if (res < iov.iov_len)
1438                         break;
1439         }
1440
1441         if (bytes > 0)
1442                 iov_iter_advance(iter, bytes);
1443         return bytes;
1444 #endif
1445 }
1446
1447 ssize_t pcc_file_read_iter(struct kiocb *iocb,
1448                            struct iov_iter *iter, bool *cached)
1449 {
1450         struct file *file = iocb->ki_filp;
1451         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1452         struct pcc_file *pccf = &fd->fd_pcc_file;
1453         struct inode *inode = file_inode(file);
1454         ssize_t result;
1455
1456         ENTRY;
1457
1458         if (pccf->pccf_file == NULL) {
1459                 *cached = false;
1460                 RETURN(0);
1461         }
1462
1463         pcc_io_init(inode, cached);
1464         if (!*cached)
1465                 RETURN(0);
1466
1467         iocb->ki_filp = pccf->pccf_file;
1468         /* generic_file_aio_read does not support ext4-dax,
1469          * __pcc_file_read_iter uses ->aio_read hook directly
1470          * to add support for ext4-dax.
1471          */
1472         result = __pcc_file_read_iter(iocb, iter);
1473         iocb->ki_filp = file;
1474
1475         pcc_io_fini(inode);
1476         RETURN(result);
1477 }
1478
1479 static ssize_t
1480 __pcc_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
1481 {
1482         struct file *file = iocb->ki_filp;
1483
1484 #ifdef HAVE_FILE_OPERATIONS_READ_WRITE_ITER
1485         return file->f_op->write_iter(iocb, iter);
1486 #else
1487         struct iovec iov;
1488         struct iov_iter i;
1489         ssize_t bytes = 0;
1490
1491         iov_for_each(iov, i, *iter) {
1492                 ssize_t res;
1493
1494                 res = file->f_op->aio_write(iocb, &iov, 1, iocb->ki_pos);
1495                 if (-EIOCBQUEUED == res)
1496                         res = wait_on_sync_kiocb(iocb);
1497                 if (res <= 0) {
1498                         if (bytes == 0)
1499                                 bytes = res;
1500                         break;
1501                 }
1502
1503                 bytes += res;
1504                 if (res < iov.iov_len)
1505                         break;
1506         }
1507
1508         if (bytes > 0)
1509                 iov_iter_advance(iter, bytes);
1510         return bytes;
1511 #endif
1512 }
1513
1514 ssize_t pcc_file_write_iter(struct kiocb *iocb,
1515                             struct iov_iter *iter, bool *cached)
1516 {
1517         struct file *file = iocb->ki_filp;
1518         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1519         struct pcc_file *pccf = &fd->fd_pcc_file;
1520         struct inode *inode = file_inode(file);
1521         ssize_t result;
1522
1523         ENTRY;
1524
1525         if (pccf->pccf_file == NULL) {
1526                 *cached = false;
1527                 RETURN(0);
1528         }
1529
1530         if (pccf->pccf_type != LU_PCC_READWRITE) {
1531                 *cached = false;
1532                 RETURN(-EAGAIN);
1533         }
1534
1535         pcc_io_init(inode, cached);
1536         if (!*cached)
1537                 RETURN(0);
1538
1539         if (OBD_FAIL_CHECK(OBD_FAIL_LLITE_PCC_FAKE_ERROR))
1540                 GOTO(out, result = -ENOSPC);
1541
1542         iocb->ki_filp = pccf->pccf_file;
1543
1544         /* Since __pcc_file_write_iter makes write calls via
1545          * the normal vfs interface to the local PCC file system,
1546          * the inode lock is not needed.
1547          */
1548         result = __pcc_file_write_iter(iocb, iter);
1549         iocb->ki_filp = file;
1550 out:
1551         pcc_io_fini(inode);
1552         RETURN(result);
1553 }
1554
1555 int pcc_inode_setattr(struct inode *inode, struct iattr *attr,
1556                       bool *cached)
1557 {
1558         int rc;
1559         const struct cred *old_cred;
1560         struct iattr attr2 = *attr;
1561         struct dentry *pcc_dentry;
1562         struct pcc_inode *pcci;
1563
1564         ENTRY;
1565
1566         if (!S_ISREG(inode->i_mode)) {
1567                 *cached = false;
1568                 RETURN(0);
1569         }
1570
1571         pcc_io_init(inode, cached);
1572         if (!*cached)
1573                 RETURN(0);
1574
1575         attr2.ia_valid = attr->ia_valid & (ATTR_SIZE | ATTR_ATIME |
1576                          ATTR_ATIME_SET | ATTR_MTIME | ATTR_MTIME_SET |
1577                          ATTR_CTIME | ATTR_UID | ATTR_GID);
1578         pcci = ll_i2pcci(inode);
1579         pcc_dentry = pcci->pcci_path.dentry;
1580         inode_lock(pcc_dentry->d_inode);
1581         old_cred = override_creds(pcc_super_cred(inode->i_sb));
1582         rc = pcc_dentry->d_inode->i_op->setattr(pcc_dentry, &attr2);
1583         revert_creds(old_cred);
1584         inode_unlock(pcc_dentry->d_inode);
1585
1586         pcc_io_fini(inode);
1587         RETURN(rc);
1588 }
1589
1590 int pcc_inode_getattr(struct inode *inode, bool *cached)
1591 {
1592         struct ll_inode_info *lli = ll_i2info(inode);
1593         const struct cred *old_cred;
1594         struct kstat stat;
1595         s64 atime;
1596         s64 mtime;
1597         s64 ctime;
1598         int rc;
1599
1600         ENTRY;
1601
1602         if (!S_ISREG(inode->i_mode)) {
1603                 *cached = false;
1604                 RETURN(0);
1605         }
1606
1607         pcc_io_init(inode, cached);
1608         if (!*cached)
1609                 RETURN(0);
1610
1611         old_cred = override_creds(pcc_super_cred(inode->i_sb));
1612         rc = ll_vfs_getattr(&ll_i2pcci(inode)->pcci_path, &stat);
1613         revert_creds(old_cred);
1614         if (rc)
1615                 GOTO(out, rc);
1616
1617         ll_inode_size_lock(inode);
1618         if (inode->i_atime.tv_sec < lli->lli_atime ||
1619             lli->lli_update_atime) {
1620                 inode->i_atime.tv_sec = lli->lli_atime;
1621                 lli->lli_update_atime = 0;
1622         }
1623         inode->i_mtime.tv_sec = lli->lli_mtime;
1624         inode->i_ctime.tv_sec = lli->lli_ctime;
1625
1626         atime = inode->i_atime.tv_sec;
1627         mtime = inode->i_mtime.tv_sec;
1628         ctime = inode->i_ctime.tv_sec;
1629
1630         if (atime < stat.atime.tv_sec)
1631                 atime = stat.atime.tv_sec;
1632
1633         if (ctime < stat.ctime.tv_sec)
1634                 ctime = stat.ctime.tv_sec;
1635
1636         if (mtime < stat.mtime.tv_sec)
1637                 mtime = stat.mtime.tv_sec;
1638
1639         i_size_write(inode, stat.size);
1640         inode->i_blocks = stat.blocks;
1641
1642         inode->i_atime.tv_sec = atime;
1643         inode->i_mtime.tv_sec = mtime;
1644         inode->i_ctime.tv_sec = ctime;
1645
1646         ll_inode_size_unlock(inode);
1647 out:
1648         pcc_io_fini(inode);
1649         RETURN(rc);
1650 }
1651
1652 ssize_t pcc_file_splice_read(struct file *in_file, loff_t *ppos,
1653                              struct pipe_inode_info *pipe,
1654                              size_t count, unsigned int flags,
1655                              bool *cached)
1656 {
1657         struct inode *inode = file_inode(in_file);
1658         struct ll_file_data *fd = LUSTRE_FPRIVATE(in_file);
1659         struct file *pcc_file = fd->fd_pcc_file.pccf_file;
1660         ssize_t result;
1661
1662         ENTRY;
1663
1664         *cached = false;
1665         if (!pcc_file)
1666                 RETURN(0);
1667
1668         if (!file_inode(pcc_file)->i_fop->splice_read)
1669                 RETURN(-ENOTSUPP);
1670
1671         pcc_io_init(inode, cached);
1672         if (!*cached)
1673                 RETURN(0);
1674
1675         result = file_inode(pcc_file)->i_fop->splice_read(pcc_file,
1676                                                           ppos, pipe, count,
1677                                                           flags);
1678
1679         pcc_io_fini(inode);
1680         RETURN(result);
1681 }
1682
1683 int pcc_fsync(struct file *file, loff_t start, loff_t end,
1684               int datasync, bool *cached)
1685 {
1686         struct inode *inode = file_inode(file);
1687         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1688         struct file *pcc_file = fd->fd_pcc_file.pccf_file;
1689         int rc;
1690
1691         ENTRY;
1692
1693         if (!pcc_file) {
1694                 *cached = false;
1695                 RETURN(0);
1696         }
1697
1698         pcc_io_init(inode, cached);
1699         if (!*cached)
1700                 RETURN(0);
1701
1702         rc = file_inode(pcc_file)->i_fop->fsync(pcc_file,
1703                                                 start, end, datasync);
1704
1705         pcc_io_fini(inode);
1706         RETURN(rc);
1707 }
1708
1709 int pcc_file_mmap(struct file *file, struct vm_area_struct *vma,
1710                   bool *cached)
1711 {
1712         struct inode *inode = file_inode(file);
1713         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1714         struct file *pcc_file = fd->fd_pcc_file.pccf_file;
1715         struct pcc_inode *pcci;
1716         int rc = 0;
1717
1718         ENTRY;
1719
1720         if (!pcc_file || !file_inode(pcc_file)->i_fop->mmap) {
1721                 *cached = false;
1722                 RETURN(0);
1723         }
1724
1725         pcc_inode_lock(inode);
1726         pcci = ll_i2pcci(inode);
1727         if (pcci && pcc_inode_has_layout(pcci)) {
1728                 LASSERT(atomic_read(&pcci->pcci_refcount) > 1);
1729                 *cached = true;
1730                 vma->vm_file = pcc_file;
1731                 rc = file_inode(pcc_file)->i_fop->mmap(pcc_file, vma);
1732                 vma->vm_file = file;
1733                 /* Save the vm ops of backend PCC */
1734                 vma->vm_private_data = (void *)vma->vm_ops;
1735         } else {
1736                 *cached = false;
1737         }
1738         pcc_inode_unlock(inode);
1739
1740         RETURN(rc);
1741 }
1742
1743 void pcc_vm_open(struct vm_area_struct *vma)
1744 {
1745         struct pcc_inode *pcci;
1746         struct file *file = vma->vm_file;
1747         struct inode *inode = file_inode(file);
1748         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1749         struct file *pcc_file = fd->fd_pcc_file.pccf_file;
1750         struct vm_operations_struct *pcc_vm_ops = vma->vm_private_data;
1751
1752         ENTRY;
1753
1754         if (!pcc_file || !pcc_vm_ops || !pcc_vm_ops->open)
1755                 RETURN_EXIT;
1756
1757         pcc_inode_lock(inode);
1758         pcci = ll_i2pcci(inode);
1759         if (pcci && pcc_inode_has_layout(pcci)) {
1760                 vma->vm_file = pcc_file;
1761                 pcc_vm_ops->open(vma);
1762                 vma->vm_file = file;
1763         }
1764         pcc_inode_unlock(inode);
1765         EXIT;
1766 }
1767
1768 void pcc_vm_close(struct vm_area_struct *vma)
1769 {
1770         struct file *file = vma->vm_file;
1771         struct inode *inode = file_inode(file);
1772         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1773         struct file *pcc_file = fd->fd_pcc_file.pccf_file;
1774         struct vm_operations_struct *pcc_vm_ops = vma->vm_private_data;
1775
1776         ENTRY;
1777
1778         if (!pcc_file || !pcc_vm_ops || !pcc_vm_ops->close)
1779                 RETURN_EXIT;
1780
1781         pcc_inode_lock(inode);
1782         /* Layout lock maybe revoked here */
1783         vma->vm_file = pcc_file;
1784         pcc_vm_ops->close(vma);
1785         vma->vm_file = file;
1786         pcc_inode_unlock(inode);
1787         EXIT;
1788 }
1789
1790 int pcc_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
1791                      bool *cached)
1792 {
1793         struct page *page = vmf->page;
1794         struct mm_struct *mm = vma->vm_mm;
1795         struct file *file = vma->vm_file;
1796         struct inode *inode = file_inode(file);
1797         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1798         struct file *pcc_file = fd->fd_pcc_file.pccf_file;
1799         struct vm_operations_struct *pcc_vm_ops = vma->vm_private_data;
1800         int rc;
1801
1802         ENTRY;
1803
1804         if (!pcc_file || !pcc_vm_ops) {
1805                 *cached = false;
1806                 RETURN(0);
1807         }
1808
1809         if (!pcc_vm_ops->page_mkwrite &&
1810             page->mapping == pcc_file->f_mapping) {
1811                 CDEBUG(D_MMAP,
1812                        "%s: PCC backend fs not support ->page_mkwrite()\n",
1813                        ll_i2sbi(inode)->ll_fsname);
1814                 pcc_ioctl_detach(inode, PCC_DETACH_OPT_NONE);
1815                 up_read(&mm->mmap_sem);
1816                 *cached = true;
1817                 RETURN(VM_FAULT_RETRY | VM_FAULT_NOPAGE);
1818         }
1819         /* Pause to allow for a race with concurrent detach */
1820         OBD_FAIL_TIMEOUT(OBD_FAIL_LLITE_PCC_MKWRITE_PAUSE, cfs_fail_val);
1821
1822         pcc_io_init(inode, cached);
1823         if (!*cached) {
1824                 /* This happens when the file is detached from PCC after got
1825                  * the fault page via ->fault() on the inode of the PCC copy.
1826                  * Here it can not simply fall back to normal Lustre I/O path.
1827                  * The reason is that the address space of fault page used by
1828                  * ->page_mkwrite() is still the one of PCC inode. In the
1829                  * normal Lustre ->page_mkwrite() I/O path, it will be wrongly
1830                  * handled as the address space of the fault page is not
1831                  * consistent with the one of the Lustre inode (though the
1832                  * fault page was truncated).
1833                  * As the file is detached from PCC, the fault page must
1834                  * be released frist, and retry the mmap write (->fault() and
1835                  * ->page_mkwrite).
1836                  * We use an ugly and tricky method by returning
1837                  * VM_FAULT_NOPAGE | VM_FAULT_RETRY to the caller
1838                  * __do_page_fault and retry the memory fault handling.
1839                  */
1840                 if (page->mapping == pcc_file->f_mapping) {
1841                         *cached = true;
1842                         up_read(&mm->mmap_sem);
1843                         RETURN(VM_FAULT_RETRY | VM_FAULT_NOPAGE);
1844                 }
1845
1846                 RETURN(0);
1847         }
1848
1849         /*
1850          * This fault injection can also be used to simulate -ENOSPC and
1851          * -EDQUOT failure of underlying PCC backend fs.
1852          */
1853         if (OBD_FAIL_CHECK(OBD_FAIL_LLITE_PCC_DETACH_MKWRITE)) {
1854                 pcc_io_fini(inode);
1855                 pcc_ioctl_detach(inode, PCC_DETACH_OPT_NONE);
1856                 up_read(&mm->mmap_sem);
1857                 RETURN(VM_FAULT_RETRY | VM_FAULT_NOPAGE);
1858         }
1859
1860         vma->vm_file = pcc_file;
1861 #ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
1862         rc = pcc_vm_ops->page_mkwrite(vmf);
1863 #else
1864         rc = pcc_vm_ops->page_mkwrite(vma, vmf);
1865 #endif
1866         vma->vm_file = file;
1867
1868         pcc_io_fini(inode);
1869         RETURN(rc);
1870 }
1871
1872 int pcc_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
1873               bool *cached)
1874 {
1875         struct file *file = vma->vm_file;
1876         struct inode *inode = file_inode(file);
1877         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
1878         struct file *pcc_file = fd->fd_pcc_file.pccf_file;
1879         struct vm_operations_struct *pcc_vm_ops = vma->vm_private_data;
1880         int rc;
1881
1882         ENTRY;
1883
1884         if (!pcc_file || !pcc_vm_ops || !pcc_vm_ops->fault) {
1885                 *cached = false;
1886                 RETURN(0);
1887         }
1888
1889         pcc_io_init(inode, cached);
1890         if (!*cached)
1891                 RETURN(0);
1892
1893         vma->vm_file = pcc_file;
1894 #ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
1895         rc = pcc_vm_ops->fault(vmf);
1896 #else
1897         rc = pcc_vm_ops->fault(vma, vmf);
1898 #endif
1899         vma->vm_file = file;
1900
1901         pcc_io_fini(inode);
1902         RETURN(rc);
1903 }
1904
1905 static void pcc_layout_wait(struct pcc_inode *pcci)
1906 {
1907         struct l_wait_info lwi = { 0 };
1908
1909         while (atomic_read(&pcci->pcci_active_ios) > 0) {
1910                 CDEBUG(D_CACHE, "Waiting for IO completion: %d\n",
1911                        atomic_read(&pcci->pcci_active_ios));
1912                 l_wait_event(pcci->pcci_waitq,
1913                              atomic_read(&pcci->pcci_active_ios) == 0, &lwi);
1914         }
1915 }
1916
1917 static void __pcc_layout_invalidate(struct pcc_inode *pcci)
1918 {
1919         pcci->pcci_type = LU_PCC_NONE;
1920         pcc_layout_gen_set(pcci, CL_LAYOUT_GEN_NONE);
1921         pcc_layout_wait(pcci);
1922 }
1923
1924 void pcc_layout_invalidate(struct inode *inode)
1925 {
1926         struct pcc_inode *pcci;
1927
1928         ENTRY;
1929
1930         pcc_inode_lock(inode);
1931         pcci = ll_i2pcci(inode);
1932         if (pcci && pcc_inode_has_layout(pcci)) {
1933                 LASSERT(atomic_read(&pcci->pcci_refcount) > 0);
1934                 __pcc_layout_invalidate(pcci);
1935
1936                 CDEBUG(D_CACHE, "Invalidate "DFID" layout gen %d\n",
1937                        PFID(&ll_i2info(inode)->lli_fid), pcci->pcci_layout_gen);
1938
1939                 pcc_inode_put(pcci);
1940         }
1941         pcc_inode_unlock(inode);
1942
1943         EXIT;
1944 }
1945
1946 static int pcc_inode_remove(struct inode *inode, struct dentry *pcc_dentry)
1947 {
1948         int rc;
1949
1950         rc = ll_vfs_unlink(pcc_dentry->d_parent->d_inode, pcc_dentry);
1951         if (rc)
1952                 CWARN("%s: failed to unlink PCC file %.*s, rc = %d\n",
1953                       ll_i2sbi(inode)->ll_fsname, pcc_dentry->d_name.len,
1954                       pcc_dentry->d_name.name, rc);
1955
1956         return rc;
1957 }
1958
1959 /* Create directory under base if directory does not exist */
1960 static struct dentry *
1961 pcc_mkdir(struct dentry *base, const char *name, umode_t mode)
1962 {
1963         int rc;
1964         struct dentry *dentry;
1965         struct inode *dir = base->d_inode;
1966
1967         inode_lock(dir);
1968         dentry = lookup_one_len(name, base, strlen(name));
1969         if (IS_ERR(dentry))
1970                 goto out;
1971
1972         if (d_is_positive(dentry))
1973                 goto out;
1974
1975         rc = vfs_mkdir(dir, dentry, mode);
1976         if (rc) {
1977                 dput(dentry);
1978                 dentry = ERR_PTR(rc);
1979                 goto out;
1980         }
1981 out:
1982         inode_unlock(dir);
1983         return dentry;
1984 }
1985
1986 static struct dentry *
1987 pcc_mkdir_p(struct dentry *root, char *path, umode_t mode)
1988 {
1989         char *ptr, *entry_name;
1990         struct dentry *parent;
1991         struct dentry *child = ERR_PTR(-EINVAL);
1992
1993         ptr = path;
1994         while (*ptr == '/')
1995                 ptr++;
1996
1997         entry_name = ptr;
1998         parent = dget(root);
1999         while ((ptr = strchr(ptr, '/')) != NULL) {
2000                 *ptr = '\0';
2001                 child = pcc_mkdir(parent, entry_name, mode);
2002                 *ptr = '/';
2003                 dput(parent);
2004                 if (IS_ERR(child))
2005                         break;
2006
2007                 parent = child;
2008                 ptr++;
2009                 entry_name = ptr;
2010         }
2011
2012         return child;
2013 }
2014
2015 /* Create file under base. If file already exist, return failure */
2016 static struct dentry *
2017 pcc_create(struct dentry *base, const char *name, umode_t mode)
2018 {
2019         int rc;
2020         struct dentry *dentry;
2021         struct inode *dir = base->d_inode;
2022
2023         inode_lock(dir);
2024         dentry = lookup_one_len(name, base, strlen(name));
2025         if (IS_ERR(dentry))
2026                 goto out;
2027
2028         if (d_is_positive(dentry))
2029                 goto out;
2030
2031         rc = vfs_create(dir, dentry, mode, LL_VFS_CREATE_FALSE);
2032         if (rc) {
2033                 dput(dentry);
2034                 dentry = ERR_PTR(rc);
2035                 goto out;
2036         }
2037 out:
2038         inode_unlock(dir);
2039         return dentry;
2040 }
2041
2042 static int __pcc_inode_create(struct pcc_dataset *dataset,
2043                               struct lu_fid *fid,
2044                               struct dentry **dentry)
2045 {
2046         char *path;
2047         struct dentry *base;
2048         struct dentry *child;
2049         int rc = 0;
2050
2051         OBD_ALLOC(path, MAX_PCC_DATABASE_PATH);
2052         if (path == NULL)
2053                 return -ENOMEM;
2054
2055         pcc_fid2dataset_path(path, MAX_PCC_DATABASE_PATH, fid);
2056
2057         base = pcc_mkdir_p(dataset->pccd_path.dentry, path, 0);
2058         if (IS_ERR(base)) {
2059                 rc = PTR_ERR(base);
2060                 GOTO(out, rc);
2061         }
2062
2063         snprintf(path, MAX_PCC_DATABASE_PATH, DFID_NOBRACE, PFID(fid));
2064         child = pcc_create(base, path, 0);
2065         if (IS_ERR(child)) {
2066                 rc = PTR_ERR(child);
2067                 GOTO(out_base, rc);
2068         }
2069         *dentry = child;
2070
2071 out_base:
2072         dput(base);
2073 out:
2074         OBD_FREE(path, MAX_PCC_DATABASE_PATH);
2075         return rc;
2076 }
2077
2078 /* TODO: Set the project ID for PCC copy */
2079 int pcc_inode_store_ugpid(struct dentry *dentry, kuid_t uid, kgid_t gid)
2080 {
2081         struct inode *inode = dentry->d_inode;
2082         struct iattr attr;
2083         int rc;
2084
2085         ENTRY;
2086
2087         attr.ia_valid = ATTR_UID | ATTR_GID;
2088         attr.ia_uid = uid;
2089         attr.ia_gid = gid;
2090
2091         inode_lock(inode);
2092         rc = notify_change(dentry, &attr, NULL);
2093         inode_unlock(inode);
2094
2095         RETURN(rc);
2096 }
2097
2098 int pcc_inode_create(struct super_block *sb, struct pcc_dataset *dataset,
2099                      struct lu_fid *fid, struct dentry **pcc_dentry)
2100 {
2101         const struct cred *old_cred;
2102         int rc;
2103
2104         old_cred = override_creds(pcc_super_cred(sb));
2105         rc = __pcc_inode_create(dataset, fid, pcc_dentry);
2106         revert_creds(old_cred);
2107         return rc;
2108 }
2109
2110 int pcc_inode_create_fini(struct pcc_dataset *dataset, struct inode *inode,
2111                           struct dentry *pcc_dentry)
2112 {
2113         const struct cred *old_cred;
2114         struct pcc_inode *pcci;
2115         int rc = 0;
2116
2117         ENTRY;
2118
2119         old_cred = override_creds(pcc_super_cred(inode->i_sb));
2120         pcc_inode_lock(inode);
2121         LASSERT(ll_i2pcci(inode) == NULL);
2122         OBD_SLAB_ALLOC_PTR_GFP(pcci, pcc_inode_slab, GFP_NOFS);
2123         if (pcci == NULL)
2124                 GOTO(out_put, rc = -ENOMEM);
2125
2126         rc = pcc_inode_store_ugpid(pcc_dentry, old_cred->suid,
2127                                    old_cred->sgid);
2128         if (rc)
2129                 GOTO(out_put, rc);
2130
2131         pcc_inode_init(pcci, ll_i2info(inode));
2132         pcc_inode_attach_init(dataset, pcci, pcc_dentry, LU_PCC_READWRITE);
2133
2134         rc = pcc_layout_xattr_set(pcci, 0);
2135         if (rc) {
2136                 (void) pcc_inode_remove(inode, pcci->pcci_path.dentry);
2137                 pcc_inode_put(pcci);
2138                 GOTO(out_unlock, rc);
2139         }
2140
2141         /* Set the layout generation of newly created file with 0 */
2142         pcc_layout_gen_set(pcci, 0);
2143
2144 out_put:
2145         if (rc) {
2146                 (void) pcc_inode_remove(inode, pcc_dentry);
2147                 dput(pcc_dentry);
2148
2149                 if (pcci)
2150                         OBD_SLAB_FREE_PTR(pcci, pcc_inode_slab);
2151         }
2152 out_unlock:
2153         pcc_inode_unlock(inode);
2154         revert_creds(old_cred);
2155         RETURN(rc);
2156 }
2157
2158 static int pcc_filp_write(struct file *filp, const void *buf, ssize_t count,
2159                           loff_t *offset)
2160 {
2161         while (count > 0) {
2162                 ssize_t size;
2163
2164                 size = cfs_kernel_write(filp, buf, count, offset);
2165                 if (size < 0)
2166                         return size;
2167                 count -= size;
2168                 buf += size;
2169         }
2170         return 0;
2171 }
2172
2173 static int pcc_copy_data(struct file *src, struct file *dst)
2174 {
2175         int rc = 0;
2176         ssize_t rc2;
2177         loff_t pos, offset = 0;
2178         size_t buf_len = 1048576;
2179         void *buf;
2180
2181         ENTRY;
2182
2183         OBD_ALLOC_LARGE(buf, buf_len);
2184         if (buf == NULL)
2185                 RETURN(-ENOMEM);
2186
2187         while (1) {
2188                 pos = offset;
2189                 rc2 = cfs_kernel_read(src, buf, buf_len, &pos);
2190                 if (rc2 < 0)
2191                         GOTO(out_free, rc = rc2);
2192                 else if (rc2 == 0)
2193                         break;
2194
2195                 pos = offset;
2196                 rc = pcc_filp_write(dst, buf, rc2, &pos);
2197                 if (rc < 0)
2198                         GOTO(out_free, rc);
2199                 offset += rc2;
2200         }
2201
2202 out_free:
2203         OBD_FREE_LARGE(buf, buf_len);
2204         RETURN(rc);
2205 }
2206
2207 static int pcc_attach_allowed_check(struct inode *inode)
2208 {
2209         struct ll_inode_info *lli = ll_i2info(inode);
2210         struct pcc_inode *pcci;
2211         int rc = 0;
2212
2213         ENTRY;
2214
2215         pcc_inode_lock(inode);
2216         if (lli->lli_pcc_state & PCC_STATE_FL_ATTACHING)
2217                 GOTO(out_unlock, rc = -EBUSY);
2218
2219         pcci = ll_i2pcci(inode);
2220         if (pcci && pcc_inode_has_layout(pcci))
2221                 GOTO(out_unlock, rc = -EEXIST);
2222
2223         lli->lli_pcc_state |= PCC_STATE_FL_ATTACHING;
2224 out_unlock:
2225         pcc_inode_unlock(inode);
2226         RETURN(rc);
2227 }
2228
2229 int pcc_readwrite_attach(struct file *file, struct inode *inode,
2230                          __u32 archive_id)
2231 {
2232         struct pcc_dataset *dataset;
2233         struct ll_inode_info *lli = ll_i2info(inode);
2234         struct pcc_inode *pcci;
2235         const struct cred *old_cred;
2236         struct dentry *dentry;
2237         struct file *pcc_filp;
2238         struct path path;
2239         int rc;
2240
2241         ENTRY;
2242
2243         rc = pcc_attach_allowed_check(inode);
2244         if (rc)
2245                 RETURN(rc);
2246
2247         dataset = pcc_dataset_get(&ll_i2sbi(inode)->ll_pcc_super,
2248                                   LU_PCC_READWRITE, archive_id);
2249         if (dataset == NULL)
2250                 RETURN(-ENOENT);
2251
2252         old_cred = override_creds(pcc_super_cred(inode->i_sb));
2253         rc = __pcc_inode_create(dataset, &lli->lli_fid, &dentry);
2254         if (rc) {
2255                 revert_creds(old_cred);
2256                 GOTO(out_dataset_put, rc);
2257         }
2258
2259         path.mnt = dataset->pccd_path.mnt;
2260         path.dentry = dentry;
2261 #ifdef HAVE_DENTRY_OPEN_USE_PATH
2262         pcc_filp = dentry_open(&path, O_TRUNC | O_WRONLY | O_LARGEFILE,
2263                                current_cred());
2264 #else
2265         pcc_filp = dentry_open(path.dentry, path.mnt,
2266                                O_TRUNC | O_WRONLY | O_LARGEFILE,
2267                                current_cred());
2268 #endif
2269         if (IS_ERR_OR_NULL(pcc_filp)) {
2270                 rc = pcc_filp == NULL ? -EINVAL : PTR_ERR(pcc_filp);
2271                 revert_creds(old_cred);
2272                 GOTO(out_dentry, rc);
2273         }
2274
2275         rc = pcc_inode_store_ugpid(dentry, old_cred->uid, old_cred->gid);
2276         revert_creds(old_cred);
2277         if (rc)
2278                 GOTO(out_fput, rc);
2279
2280         rc = pcc_copy_data(file, pcc_filp);
2281         if (rc)
2282                 GOTO(out_fput, rc);
2283
2284         /* Pause to allow for a race with concurrent HSM remove */
2285         OBD_FAIL_TIMEOUT(OBD_FAIL_LLITE_PCC_ATTACH_PAUSE, cfs_fail_val);
2286
2287         pcc_inode_lock(inode);
2288         pcci = ll_i2pcci(inode);
2289         LASSERT(!pcci);
2290         OBD_SLAB_ALLOC_PTR_GFP(pcci, pcc_inode_slab, GFP_NOFS);
2291         if (pcci == NULL)
2292                 GOTO(out_unlock, rc = -ENOMEM);
2293
2294         pcc_inode_init(pcci, lli);
2295         pcc_inode_attach_init(dataset, pcci, dentry, LU_PCC_READWRITE);
2296 out_unlock:
2297         pcc_inode_unlock(inode);
2298 out_fput:
2299         fput(pcc_filp);
2300 out_dentry:
2301         if (rc) {
2302                 old_cred = override_creds(pcc_super_cred(inode->i_sb));
2303                 (void) pcc_inode_remove(inode, dentry);
2304                 revert_creds(old_cred);
2305                 dput(dentry);
2306         }
2307 out_dataset_put:
2308         pcc_dataset_put(dataset);
2309         RETURN(rc);
2310 }
2311
2312 int pcc_readwrite_attach_fini(struct file *file, struct inode *inode,
2313                               __u32 gen, bool lease_broken, int rc,
2314                               bool attached)
2315 {
2316         struct ll_inode_info *lli = ll_i2info(inode);
2317         const struct cred *old_cred;
2318         struct pcc_inode *pcci;
2319         __u32 gen2;
2320
2321         ENTRY;
2322
2323         old_cred = override_creds(pcc_super_cred(inode->i_sb));
2324         pcc_inode_lock(inode);
2325         pcci = ll_i2pcci(inode);
2326         lli->lli_pcc_state &= ~PCC_STATE_FL_ATTACHING;
2327         if (rc || lease_broken) {
2328                 if (attached && pcci)
2329                         pcc_inode_put(pcci);
2330
2331                 GOTO(out_unlock, rc);
2332         }
2333
2334         /* PCC inode may be released due to layout lock revocatioin */
2335         if (!pcci)
2336                 GOTO(out_unlock, rc = -ESTALE);
2337
2338         LASSERT(attached);
2339         rc = pcc_layout_xattr_set(pcci, gen);
2340         if (rc)
2341                 GOTO(out_put, rc);
2342
2343         rc = ll_layout_refresh(inode, &gen2);
2344         if (!rc) {
2345                 if (gen2 == gen) {
2346                         pcc_layout_gen_set(pcci, gen);
2347                 } else {
2348                         CDEBUG(D_CACHE,
2349                                DFID" layout changed from %d to %d.\n",
2350                                PFID(ll_inode2fid(inode)), gen, gen2);
2351                         GOTO(out_put, rc = -ESTALE);
2352                 }
2353         }
2354
2355 out_put:
2356         if (rc) {
2357                 (void) pcc_inode_remove(inode, pcci->pcci_path.dentry);
2358                 pcc_inode_put(pcci);
2359         }
2360 out_unlock:
2361         pcc_inode_unlock(inode);
2362         revert_creds(old_cred);
2363         RETURN(rc);
2364 }
2365
2366 static int pcc_hsm_remove(struct inode *inode)
2367 {
2368         struct hsm_user_request *hur;
2369         __u32 gen;
2370         int len;
2371         int rc;
2372
2373         ENTRY;
2374
2375         rc = ll_layout_restore(inode, 0, OBD_OBJECT_EOF);
2376         if (rc) {
2377                 CDEBUG(D_CACHE, DFID" RESTORE failure: %d\n",
2378                        PFID(&ll_i2info(inode)->lli_fid), rc);
2379                 RETURN(rc);
2380         }
2381
2382         ll_layout_refresh(inode, &gen);
2383
2384         len = sizeof(struct hsm_user_request) +
2385               sizeof(struct hsm_user_item);
2386         OBD_ALLOC(hur, len);
2387         if (hur == NULL)
2388                 RETURN(-ENOMEM);
2389
2390         hur->hur_request.hr_action = HUA_REMOVE;
2391         hur->hur_request.hr_archive_id = 0;
2392         hur->hur_request.hr_flags = 0;
2393         memcpy(&hur->hur_user_item[0].hui_fid, &ll_i2info(inode)->lli_fid,
2394                sizeof(hur->hur_user_item[0].hui_fid));
2395         hur->hur_user_item[0].hui_extent.offset = 0;
2396         hur->hur_user_item[0].hui_extent.length = OBD_OBJECT_EOF;
2397         hur->hur_request.hr_itemcount = 1;
2398         rc = obd_iocontrol(LL_IOC_HSM_REQUEST, ll_i2sbi(inode)->ll_md_exp,
2399                            len, hur, NULL);
2400         if (rc)
2401                 CDEBUG(D_CACHE, DFID" HSM REMOVE failure: %d\n",
2402                        PFID(&ll_i2info(inode)->lli_fid), rc);
2403
2404         OBD_FREE(hur, len);
2405         RETURN(rc);
2406 }
2407
2408 int pcc_ioctl_detach(struct inode *inode, __u32 opt)
2409 {
2410         struct ll_inode_info *lli = ll_i2info(inode);
2411         struct pcc_inode *pcci;
2412         bool hsm_remove = false;
2413         int rc = 0;
2414
2415         ENTRY;
2416
2417         pcc_inode_lock(inode);
2418         pcci = lli->lli_pcc_inode;
2419         if (!pcci || lli->lli_pcc_state & PCC_STATE_FL_ATTACHING ||
2420             !pcc_inode_has_layout(pcci))
2421                 GOTO(out_unlock, rc = 0);
2422
2423         LASSERT(atomic_read(&pcci->pcci_refcount) > 0);
2424
2425         if (pcci->pcci_type == LU_PCC_READWRITE) {
2426                 if (opt == PCC_DETACH_OPT_UNCACHE)
2427                         hsm_remove = true;
2428
2429                 __pcc_layout_invalidate(pcci);
2430                 pcc_inode_put(pcci);
2431         }
2432
2433 out_unlock:
2434         pcc_inode_unlock(inode);
2435         if (hsm_remove) {
2436                 const struct cred *old_cred;
2437
2438                 old_cred = override_creds(pcc_super_cred(inode->i_sb));
2439                 rc = pcc_hsm_remove(inode);
2440                 revert_creds(old_cred);
2441         }
2442
2443         RETURN(rc);
2444 }
2445
2446 int pcc_ioctl_state(struct file *file, struct inode *inode,
2447                     struct lu_pcc_state *state)
2448 {
2449         int rc = 0;
2450         int count;
2451         char *buf;
2452         char *path;
2453         int buf_len = sizeof(state->pccs_path);
2454         struct ll_file_data *fd = LUSTRE_FPRIVATE(file);
2455         struct pcc_file *pccf = &fd->fd_pcc_file;
2456         struct pcc_inode *pcci;
2457
2458         ENTRY;
2459
2460         if (buf_len <= 0)
2461                 RETURN(-EINVAL);
2462
2463         OBD_ALLOC(buf, buf_len);
2464         if (buf == NULL)
2465                 RETURN(-ENOMEM);
2466
2467         pcc_inode_lock(inode);
2468         pcci = ll_i2pcci(inode);
2469         if (pcci == NULL) {
2470                 state->pccs_type = LU_PCC_NONE;
2471                 GOTO(out_unlock, rc = 0);
2472         }
2473
2474         count = atomic_read(&pcci->pcci_refcount);
2475         if (count == 0) {
2476                 state->pccs_type = LU_PCC_NONE;
2477                 state->pccs_open_count = 0;
2478                 GOTO(out_unlock, rc = 0);
2479         }
2480
2481         if (pcc_inode_has_layout(pcci))
2482                 count--;
2483         if (pccf->pccf_file != NULL)
2484                 count--;
2485         state->pccs_type = pcci->pcci_type;
2486         state->pccs_open_count = count;
2487         state->pccs_flags = ll_i2info(inode)->lli_pcc_state;
2488         path = dentry_path_raw(pcci->pcci_path.dentry, buf, buf_len);
2489         if (IS_ERR(path))
2490                 GOTO(out_unlock, rc = PTR_ERR(path));
2491
2492         if (strlcpy(state->pccs_path, path, buf_len) >= buf_len)
2493                 GOTO(out_unlock, rc = -ENAMETOOLONG);
2494
2495 out_unlock:
2496         pcc_inode_unlock(inode);
2497         OBD_FREE(buf, buf_len);
2498         RETURN(rc);
2499 }