drivers/staging/lustre/lustre/obdclass/llog.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) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2015, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/obdclass/llog.c
  33  *
  34  * OST<->MDS recovery logging infrastructure.
  35  * Invariants in implementation:
  36  * - we do not share logs among different OST<->MDS connections, so that
  37  *   if an OST or MDS fails it need only look at log(s) relevant to itself
  38  *
  39  * Author: Andreas Dilger <adilger@clusterfs.com>
  40  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
  41  * Author: Mikhail Pershin <tappro@whamcloud.com>
  42  */
  43
  44 #define DEBUG_SUBSYSTEM S_LOG
  45
  46 #include "../include/obd_class.h"
  47 #include "../include/lustre_log.h"
  48 #include "llog_internal.h"
  49
  50 /*
  51  * Allocate a new log or catalog handle
  52  * Used inside llog_open().
  53  */
  54 static struct llog_handle *llog_alloc_handle(void)
  55 {
  56         struct llog_handle *loghandle;
  57
  58         loghandle = kzalloc(sizeof(*loghandle), GFP_NOFS);
  59         if (!loghandle)
  60                 return NULL;
  61
  62         init_rwsem(&loghandle->lgh_lock);
  63         spin_lock_init(&loghandle->lgh_hdr_lock);
  64         INIT_LIST_HEAD(&loghandle->u.phd.phd_entry);
  65         atomic_set(&loghandle->lgh_refcount, 1);
  66
  67         return loghandle;
  68 }
  69
  70 /*
  71  * Free llog handle and header data if exists. Used in llog_close() only
  72  */
  73 static void llog_free_handle(struct llog_handle *loghandle)
  74 {
  75         /* failed llog_init_handle */
  76         if (!loghandle->lgh_hdr)
  77                 goto out;
  78
  79         if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_PLAIN)
  80                 LASSERT(list_empty(&loghandle->u.phd.phd_entry));
  81         else if (loghandle->lgh_hdr->llh_flags & LLOG_F_IS_CAT)
  82                 LASSERT(list_empty(&loghandle->u.chd.chd_head));
  83         LASSERT(sizeof(*loghandle->lgh_hdr) == LLOG_CHUNK_SIZE);
  84         kfree(loghandle->lgh_hdr);
  85 out:
  86         kfree(loghandle);
  87 }
  88
  89 void llog_handle_get(struct llog_handle *loghandle)
  90 {
  91         atomic_inc(&loghandle->lgh_refcount);
  92 }
  93
  94 void llog_handle_put(struct llog_handle *loghandle)
  95 {
  96         LASSERT(atomic_read(&loghandle->lgh_refcount) > 0);
  97         if (atomic_dec_and_test(&loghandle->lgh_refcount))
  98                 llog_free_handle(loghandle);
  99 }
 100
 101 static int llog_read_header(const struct lu_env *env,
 102                             struct llog_handle *handle,
 103                             struct obd_uuid *uuid)
 104 {
 105         struct llog_operations *lop;
 106         int rc;
 107
 108         rc = llog_handle2ops(handle, &lop);
 109         if (rc)
 110                 return rc;
 111
 112         if (!lop->lop_read_header)
 113                 return -EOPNOTSUPP;
 114
 115         rc = lop->lop_read_header(env, handle);
 116         if (rc == LLOG_EEMPTY) {
 117                 struct llog_log_hdr *llh = handle->lgh_hdr;
 118
 119                 handle->lgh_last_idx = 0; /* header is record with index 0 */
 120                 llh->llh_count = 1;      /* for the header record */
 121                 llh->llh_hdr.lrh_type = LLOG_HDR_MAGIC;
 122                 llh->llh_hdr.lrh_len = LLOG_CHUNK_SIZE;
 123                 llh->llh_tail.lrt_len = LLOG_CHUNK_SIZE;
 124                 llh->llh_hdr.lrh_index = 0;
 125                 llh->llh_tail.lrt_index = 0;
 126                 llh->llh_timestamp = ktime_get_real_seconds();
 127                 if (uuid)
 128                         memcpy(&llh->llh_tgtuuid, uuid,
 129                                sizeof(llh->llh_tgtuuid));
 130                 llh->llh_bitmap_offset = offsetof(typeof(*llh), llh_bitmap);
 131                 ext2_set_bit(0, llh->llh_bitmap);
 132                 rc = 0;
 133         }
 134         return rc;
 135 }
 136
 137 int llog_init_handle(const struct lu_env *env, struct llog_handle *handle,
 138                      int flags, struct obd_uuid *uuid)
 139 {
 140         enum llog_flag fmt = flags & LLOG_F_EXT_MASK;
 141         struct llog_log_hdr     *llh;
 142         int                      rc;
 143
 144         LASSERT(!handle->lgh_hdr);
 145
 146         llh = kzalloc(sizeof(*llh), GFP_NOFS);
 147         if (!llh)
 148                 return -ENOMEM;
 149         handle->lgh_hdr = llh;
 150         /* first assign flags to use llog_client_ops */
 151         llh->llh_flags = flags;
 152         rc = llog_read_header(env, handle, uuid);
 153         if (rc == 0) {
 154                 if (unlikely((llh->llh_flags & LLOG_F_IS_PLAIN &&
 155                               flags & LLOG_F_IS_CAT) ||
 156                              (llh->llh_flags & LLOG_F_IS_CAT &&
 157                               flags & LLOG_F_IS_PLAIN))) {
 158                         CERROR("%s: llog type is %s but initializing %s\n",
 159                                handle->lgh_ctxt->loc_obd->obd_name,
 160                                llh->llh_flags & LLOG_F_IS_CAT ?
 161                                "catalog" : "plain",
 162                                flags & LLOG_F_IS_CAT ? "catalog" : "plain");
 163                         rc = -EINVAL;
 164                         goto out;
 165                 } else if (llh->llh_flags &
 166                            (LLOG_F_IS_PLAIN | LLOG_F_IS_CAT)) {
 167                         /*
 168                          * it is possible to open llog without specifying llog
 169                          * type so it is taken from llh_flags
 170                          */
 171                         flags = llh->llh_flags;
 172                 } else {
 173                         /* for some reason the llh_flags has no type set */
 174                         CERROR("llog type is not specified!\n");
 175                         rc = -EINVAL;
 176                         goto out;
 177                 }
 178                 if (unlikely(uuid &&
 179                              !obd_uuid_equals(uuid, &llh->llh_tgtuuid))) {
 180                         CERROR("%s: llog uuid mismatch: %s/%s\n",
 181                                handle->lgh_ctxt->loc_obd->obd_name,
 182                                (char *)uuid->uuid,
 183                                (char *)llh->llh_tgtuuid.uuid);
 184                         rc = -EEXIST;
 185                         goto out;
 186                 }
 187         }
 188         if (flags & LLOG_F_IS_CAT) {
 189                 LASSERT(list_empty(&handle->u.chd.chd_head));
 190                 INIT_LIST_HEAD(&handle->u.chd.chd_head);
 191                 llh->llh_size = sizeof(struct llog_logid_rec);
 192         } else if (!(flags & LLOG_F_IS_PLAIN)) {
 193                 CERROR("%s: unknown flags: %#x (expected %#x or %#x)\n",
 194                        handle->lgh_ctxt->loc_obd->obd_name,
 195                        flags, LLOG_F_IS_CAT, LLOG_F_IS_PLAIN);
 196                 rc = -EINVAL;
 197         }
 198         llh->llh_flags |= fmt;
 199 out:
 200         if (rc) {
 201                 kfree(llh);
 202                 handle->lgh_hdr = NULL;
 203         }
 204         return rc;
 205 }
 206 EXPORT_SYMBOL(llog_init_handle);
 207
 208 static int llog_process_thread(void *arg)
 209 {
 210         struct llog_process_info        *lpi = arg;
 211         struct llog_handle              *loghandle = lpi->lpi_loghandle;
 212         struct llog_log_hdr             *llh = loghandle->lgh_hdr;
 213         struct llog_process_cat_data    *cd  = lpi->lpi_catdata;
 214         char                            *buf;
 215         __u64                            cur_offset = LLOG_CHUNK_SIZE;
 216         __u64                            last_offset;
 217         int                              rc = 0, index = 1, last_index;
 218         int                              saved_index = 0;
 219         int                              last_called_index = 0;
 220
 221         LASSERT(llh);
 222
 223         buf = kzalloc(LLOG_CHUNK_SIZE, GFP_NOFS);
 224         if (!buf) {
 225                 lpi->lpi_rc = -ENOMEM;
 226                 return 0;
 227         }
 228
 229         if (cd) {
 230                 last_called_index = cd->lpcd_first_idx;
 231                 index = cd->lpcd_first_idx + 1;
 232         }
 233         if (cd && cd->lpcd_last_idx)
 234                 last_index = cd->lpcd_last_idx;
 235         else
 236                 last_index = LLOG_BITMAP_BYTES * 8 - 1;
 237
 238         /* Record is not in this buffer. */
 239         if (index > last_index)
 240                 goto out;
 241
 242         while (rc == 0) {
 243                 struct llog_rec_hdr *rec;
 244
 245                 /* skip records not set in bitmap */
 246                 while (index <= last_index &&
 247                        !ext2_test_bit(index, llh->llh_bitmap))
 248                         ++index;
 249
 250                 LASSERT(index <= last_index + 1);
 251                 if (index == last_index + 1)
 252                         break;
 253 repeat:
 254                 CDEBUG(D_OTHER, "index: %d last_index %d\n",
 255                        index, last_index);
 256
 257                 /* get the buf with our target record; avoid old garbage */
 258                 memset(buf, 0, LLOG_CHUNK_SIZE);
 259                 last_offset = cur_offset;
 260                 rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
 261                                      index, &cur_offset, buf, LLOG_CHUNK_SIZE);
 262                 if (rc)
 263                         goto out;
 264
 265                 /* NB: when rec->lrh_len is accessed it is already swabbed
 266                  * since it is used at the "end" of the loop and the rec
 267                  * swabbing is done at the beginning of the loop.
 268                  */
 269                 for (rec = (struct llog_rec_hdr *)buf;
 270                      (char *)rec < buf + LLOG_CHUNK_SIZE;
 271                      rec = llog_rec_hdr_next(rec)) {
 272                         CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
 273                                rec, rec->lrh_type);
 274
 275                         if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
 276                                 lustre_swab_llog_rec(rec);
 277
 278                         CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
 279                                rec->lrh_type, rec->lrh_index);
 280
 281                         if (rec->lrh_index == 0) {
 282                                 /* probably another rec just got added? */
 283                                 rc = 0;
 284                                 if (index <= loghandle->lgh_last_idx)
 285                                         goto repeat;
 286                                 goto out; /* no more records */
 287                         }
 288                         if (rec->lrh_len == 0 ||
 289                             rec->lrh_len > LLOG_CHUNK_SIZE) {
 290                                 CWARN("invalid length %d in llog record for index %d/%d\n",
 291                                       rec->lrh_len,
 292                                       rec->lrh_index, index);
 293                                 rc = -EINVAL;
 294                                 goto out;
 295                         }
 296
 297                         if (rec->lrh_index < index) {
 298                                 CDEBUG(D_OTHER, "skipping lrh_index %d\n",
 299                                        rec->lrh_index);
 300                                 continue;
 301                         }
 302
 303                         CDEBUG(D_OTHER,
 304                                "lrh_index: %d lrh_len: %d (%d remains)\n",
 305                                rec->lrh_index, rec->lrh_len,
 306                                (int)(buf + LLOG_CHUNK_SIZE - (char *)rec));
 307
 308                         loghandle->lgh_cur_idx = rec->lrh_index;
 309                         loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
 310                                                     last_offset;
 311
 312                         /* if set, process the callback on this record */
 313                         if (ext2_test_bit(index, llh->llh_bitmap)) {
 314                                 rc = lpi->lpi_cb(lpi->lpi_env, loghandle, rec,
 315                                                  lpi->lpi_cbdata);
 316                                 last_called_index = index;
 317                                 if (rc)
 318                                         goto out;
 319                         } else {
 320                                 CDEBUG(D_OTHER, "Skipped index %d\n", index);
 321                         }
 322
 323                         /* next record, still in buffer? */
 324                         ++index;
 325                         if (index > last_index) {
 326                                 rc = 0;
 327                                 goto out;
 328                         }
 329                 }
 330         }
 331
 332 out:
 333         if (cd)
 334                 cd->lpcd_last_idx = last_called_index;
 335
 336         kfree(buf);
 337         lpi->lpi_rc = rc;
 338         return 0;
 339 }
 340
 341 static int llog_process_thread_daemonize(void *arg)
 342 {
 343         struct llog_process_info        *lpi = arg;
 344         struct lu_env                    env;
 345         int                              rc;
 346
 347         unshare_fs_struct();
 348
 349         /* client env has no keys, tags is just 0 */
 350         rc = lu_env_init(&env, LCT_LOCAL | LCT_MG_THREAD);
 351         if (rc)
 352                 goto out;
 353         lpi->lpi_env = &env;
 354
 355         rc = llog_process_thread(arg);
 356
 357         lu_env_fini(&env);
 358 out:
 359         complete(&lpi->lpi_completion);
 360         return rc;
 361 }
 362
 363 int llog_process_or_fork(const struct lu_env *env,
 364                          struct llog_handle *loghandle,
 365                          llog_cb_t cb, void *data, void *catdata, bool fork)
 366 {
 367         struct llog_process_info *lpi;
 368         int                   rc;
 369
 370         lpi = kzalloc(sizeof(*lpi), GFP_NOFS);
 371         if (!lpi)
 372                 return -ENOMEM;
 373         lpi->lpi_loghandle = loghandle;
 374         lpi->lpi_cb     = cb;
 375         lpi->lpi_cbdata    = data;
 376         lpi->lpi_catdata   = catdata;
 377
 378         if (fork) {
 379                 struct task_struct *task;
 380
 381                 /* The new thread can't use parent env,
 382                  * init the new one in llog_process_thread_daemonize.
 383                  */
 384                 lpi->lpi_env = NULL;
 385                 init_completion(&lpi->lpi_completion);
 386                 task = kthread_run(llog_process_thread_daemonize, lpi,
 387                                    "llog_process_thread");
 388                 if (IS_ERR(task)) {
 389                         rc = PTR_ERR(task);
 390                         CERROR("%s: cannot start thread: rc = %d\n",
 391                                loghandle->lgh_ctxt->loc_obd->obd_name, rc);
 392                         goto out_lpi;
 393                 }
 394                 wait_for_completion(&lpi->lpi_completion);
 395         } else {
 396                 lpi->lpi_env = env;
 397                 llog_process_thread(lpi);
 398         }
 399         rc = lpi->lpi_rc;
 400 out_lpi:
 401         kfree(lpi);
 402         return rc;
 403 }
 404 EXPORT_SYMBOL(llog_process_or_fork);
 405
 406 int llog_process(const struct lu_env *env, struct llog_handle *loghandle,
 407                  llog_cb_t cb, void *data, void *catdata)
 408 {
 409         return llog_process_or_fork(env, loghandle, cb, data, catdata, true);
 410 }
 411 EXPORT_SYMBOL(llog_process);
 412
 413 int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
 414               struct llog_handle **lgh, struct llog_logid *logid,
 415               char *name, enum llog_open_param open_param)
 416 {
 417         int      raised;
 418         int      rc;
 419
 420         LASSERT(ctxt);
 421         LASSERT(ctxt->loc_logops);
 422
 423         if (!ctxt->loc_logops->lop_open) {
 424                 *lgh = NULL;
 425                 return -EOPNOTSUPP;
 426         }
 427
 428         *lgh = llog_alloc_handle();
 429         if (!*lgh)
 430                 return -ENOMEM;
 431         (*lgh)->lgh_ctxt = ctxt;
 432         (*lgh)->lgh_logops = ctxt->loc_logops;
 433
 434         raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
 435         if (!raised)
 436                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
 437         rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
 438         if (!raised)
 439                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
 440         if (rc) {
 441                 llog_free_handle(*lgh);
 442                 *lgh = NULL;
 443         }
 444         return rc;
 445 }
 446 EXPORT_SYMBOL(llog_open);
 447
 448 int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
 449 {
 450         struct llog_operations  *lop;
 451         int                      rc;
 452
 453         rc = llog_handle2ops(loghandle, &lop);
 454         if (rc)
 455                 goto out;
 456         if (!lop->lop_close) {
 457                 rc = -EOPNOTSUPP;
 458                 goto out;
 459         }
 460         rc = lop->lop_close(env, loghandle);
 461 out:
 462         llog_handle_put(loghandle);
 463         return rc;
 464 }
 465 EXPORT_SYMBOL(llog_close);