fs/xfs/xfs_log.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   4  * All Rights Reserved.
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_log_format.h"
  11 #include "xfs_trans_resv.h"
  12 #include "xfs_mount.h"
  13 #include "xfs_errortag.h"
  14 #include "xfs_error.h"
  15 #include "xfs_trans.h"
  16 #include "xfs_trans_priv.h"
  17 #include "xfs_log.h"
  18 #include "xfs_log_priv.h"
  19 #include "xfs_trace.h"
  20 #include "xfs_sysfs.h"
  21 #include "xfs_sb.h"
  22 #include "xfs_health.h"
  23
  24 kmem_zone_t     *xfs_log_ticket_zone;
  25
  26 /* Local miscellaneous function prototypes */
  27 STATIC int
  28 xlog_commit_record(
  29         struct xlog             *log,
  30         struct xlog_ticket      *ticket,
  31         struct xlog_in_core     **iclog,
  32         xfs_lsn_t               *commitlsnp);
  33
  34 STATIC struct xlog *
  35 xlog_alloc_log(
  36         struct xfs_mount        *mp,
  37         struct xfs_buftarg      *log_target,
  38         xfs_daddr_t             blk_offset,
  39         int                     num_bblks);
  40 STATIC int
  41 xlog_space_left(
  42         struct xlog             *log,
  43         atomic64_t              *head);
  44 STATIC void
  45 xlog_dealloc_log(
  46         struct xlog             *log);
  47
  48 /* local state machine functions */
  49 STATIC void xlog_state_done_syncing(
  50         struct xlog_in_core     *iclog);
  51 STATIC int
  52 xlog_state_get_iclog_space(
  53         struct xlog             *log,
  54         int                     len,
  55         struct xlog_in_core     **iclog,
  56         struct xlog_ticket      *ticket,
  57         int                     *continued_write,
  58         int                     *logoffsetp);
  59 STATIC void
  60 xlog_state_switch_iclogs(
  61         struct xlog             *log,
  62         struct xlog_in_core     *iclog,
  63         int                     eventual_size);
  64 STATIC void
  65 xlog_grant_push_ail(
  66         struct xlog             *log,
  67         int                     need_bytes);
  68 STATIC void
  69 xlog_regrant_reserve_log_space(
  70         struct xlog             *log,
  71         struct xlog_ticket      *ticket);
  72 STATIC void
  73 xlog_ungrant_log_space(
  74         struct xlog             *log,
  75         struct xlog_ticket      *ticket);
  76 STATIC void
  77 xlog_sync(
  78         struct xlog             *log,
  79         struct xlog_in_core     *iclog);
  80 #if defined(DEBUG)
  81 STATIC void
  82 xlog_verify_dest_ptr(
  83         struct xlog             *log,
  84         void                    *ptr);
  85 STATIC void
  86 xlog_verify_grant_tail(
  87         struct xlog *log);
  88 STATIC void
  89 xlog_verify_iclog(
  90         struct xlog             *log,
  91         struct xlog_in_core     *iclog,
  92         int                     count);
  93 STATIC void
  94 xlog_verify_tail_lsn(
  95         struct xlog             *log,
  96         struct xlog_in_core     *iclog,
  97         xfs_lsn_t               tail_lsn);
  98 #else
  99 #define xlog_verify_dest_ptr(a,b)
 100 #define xlog_verify_grant_tail(a)
 101 #define xlog_verify_iclog(a,b,c)
 102 #define xlog_verify_tail_lsn(a,b,c)
 103 #endif
 104
 105 STATIC int
 106 xlog_iclogs_empty(
 107         struct xlog             *log);
 108
 109 static void
 110 xlog_grant_sub_space(
 111         struct xlog             *log,
 112         atomic64_t              *head,
 113         int                     bytes)
 114 {
 115         int64_t head_val = atomic64_read(head);
 116         int64_t new, old;
 117
 118         do {
 119                 int     cycle, space;
 120
 121                 xlog_crack_grant_head_val(head_val, &cycle, &space);
 122
 123                 space -= bytes;
 124                 if (space < 0) {
 125                         space += log->l_logsize;
 126                         cycle--;
 127                 }
 128
 129                 old = head_val;
 130                 new = xlog_assign_grant_head_val(cycle, space);
 131                 head_val = atomic64_cmpxchg(head, old, new);
 132         } while (head_val != old);
 133 }
 134
 135 static void
 136 xlog_grant_add_space(
 137         struct xlog             *log,
 138         atomic64_t              *head,
 139         int                     bytes)
 140 {
 141         int64_t head_val = atomic64_read(head);
 142         int64_t new, old;
 143
 144         do {
 145                 int             tmp;
 146                 int             cycle, space;
 147
 148                 xlog_crack_grant_head_val(head_val, &cycle, &space);
 149
 150                 tmp = log->l_logsize - space;
 151                 if (tmp > bytes)
 152                         space += bytes;
 153                 else {
 154                         space = bytes - tmp;
 155                         cycle++;
 156                 }
 157
 158                 old = head_val;
 159                 new = xlog_assign_grant_head_val(cycle, space);
 160                 head_val = atomic64_cmpxchg(head, old, new);
 161         } while (head_val != old);
 162 }
 163
 164 STATIC void
 165 xlog_grant_head_init(
 166         struct xlog_grant_head  *head)
 167 {
 168         xlog_assign_grant_head(&head->grant, 1, 0);
 169         INIT_LIST_HEAD(&head->waiters);
 170         spin_lock_init(&head->lock);
 171 }
 172
 173 STATIC void
 174 xlog_grant_head_wake_all(
 175         struct xlog_grant_head  *head)
 176 {
 177         struct xlog_ticket      *tic;
 178
 179         spin_lock(&head->lock);
 180         list_for_each_entry(tic, &head->waiters, t_queue)
 181                 wake_up_process(tic->t_task);
 182         spin_unlock(&head->lock);
 183 }
 184
 185 static inline int
 186 xlog_ticket_reservation(
 187         struct xlog             *log,
 188         struct xlog_grant_head  *head,
 189         struct xlog_ticket      *tic)
 190 {
 191         if (head == &log->l_write_head) {
 192                 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
 193                 return tic->t_unit_res;
 194         } else {
 195                 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
 196                         return tic->t_unit_res * tic->t_cnt;
 197                 else
 198                         return tic->t_unit_res;
 199         }
 200 }
 201
 202 STATIC bool
 203 xlog_grant_head_wake(
 204         struct xlog             *log,
 205         struct xlog_grant_head  *head,
 206         int                     *free_bytes)
 207 {
 208         struct xlog_ticket      *tic;
 209         int                     need_bytes;
 210         bool                    woken_task = false;
 211
 212         list_for_each_entry(tic, &head->waiters, t_queue) {
 213
 214                 /*
 215                  * There is a chance that the size of the CIL checkpoints in
 216                  * progress at the last AIL push target calculation resulted in
 217                  * limiting the target to the log head (l_last_sync_lsn) at the
 218                  * time. This may not reflect where the log head is now as the
 219                  * CIL checkpoints may have completed.
 220                  *
 221                  * Hence when we are woken here, it may be that the head of the
 222                  * log that has moved rather than the tail. As the tail didn't
 223                  * move, there still won't be space available for the
 224                  * reservation we require.  However, if the AIL has already
 225                  * pushed to the target defined by the old log head location, we
 226                  * will hang here waiting for something else to update the AIL
 227                  * push target.
 228                  *
 229                  * Therefore, if there isn't space to wake the first waiter on
 230                  * the grant head, we need to push the AIL again to ensure the
 231                  * target reflects both the current log tail and log head
 232                  * position before we wait for the tail to move again.
 233                  */
 234
 235                 need_bytes = xlog_ticket_reservation(log, head, tic);
 236                 if (*free_bytes < need_bytes) {
 237                         if (!woken_task)
 238                                 xlog_grant_push_ail(log, need_bytes);
 239                         return false;
 240                 }
 241
 242                 *free_bytes -= need_bytes;
 243                 trace_xfs_log_grant_wake_up(log, tic);
 244                 wake_up_process(tic->t_task);
 245                 woken_task = true;
 246         }
 247
 248         return true;
 249 }
 250
 251 STATIC int
 252 xlog_grant_head_wait(
 253         struct xlog             *log,
 254         struct xlog_grant_head  *head,
 255         struct xlog_ticket      *tic,
 256         int                     need_bytes) __releases(&head->lock)
 257                                             __acquires(&head->lock)
 258 {
 259         list_add_tail(&tic->t_queue, &head->waiters);
 260
 261         do {
 262                 if (XLOG_FORCED_SHUTDOWN(log))
 263                         goto shutdown;
 264                 xlog_grant_push_ail(log, need_bytes);
 265
 266                 __set_current_state(TASK_UNINTERRUPTIBLE);
 267                 spin_unlock(&head->lock);
 268
 269                 XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
 270
 271                 trace_xfs_log_grant_sleep(log, tic);
 272                 schedule();
 273                 trace_xfs_log_grant_wake(log, tic);
 274
 275                 spin_lock(&head->lock);
 276                 if (XLOG_FORCED_SHUTDOWN(log))
 277                         goto shutdown;
 278         } while (xlog_space_left(log, &head->grant) < need_bytes);
 279
 280         list_del_init(&tic->t_queue);
 281         return 0;
 282 shutdown:
 283         list_del_init(&tic->t_queue);
 284         return -EIO;
 285 }
 286
 287 /*
 288  * Atomically get the log space required for a log ticket.
 289  *
 290  * Once a ticket gets put onto head->waiters, it will only return after the
 291  * needed reservation is satisfied.
 292  *
 293  * This function is structured so that it has a lock free fast path. This is
 294  * necessary because every new transaction reservation will come through this
 295  * path. Hence any lock will be globally hot if we take it unconditionally on
 296  * every pass.
 297  *
 298  * As tickets are only ever moved on and off head->waiters under head->lock, we
 299  * only need to take that lock if we are going to add the ticket to the queue
 300  * and sleep. We can avoid taking the lock if the ticket was never added to
 301  * head->waiters because the t_queue list head will be empty and we hold the
 302  * only reference to it so it can safely be checked unlocked.
 303  */
 304 STATIC int
 305 xlog_grant_head_check(
 306         struct xlog             *log,
 307         struct xlog_grant_head  *head,
 308         struct xlog_ticket      *tic,
 309         int                     *need_bytes)
 310 {
 311         int                     free_bytes;
 312         int                     error = 0;
 313
 314         ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
 315
 316         /*
 317          * If there are other waiters on the queue then give them a chance at
 318          * logspace before us.  Wake up the first waiters, if we do not wake
 319          * up all the waiters then go to sleep waiting for more free space,
 320          * otherwise try to get some space for this transaction.
 321          */
 322         *need_bytes = xlog_ticket_reservation(log, head, tic);
 323         free_bytes = xlog_space_left(log, &head->grant);
 324         if (!list_empty_careful(&head->waiters)) {
 325                 spin_lock(&head->lock);
 326                 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
 327                     free_bytes < *need_bytes) {
 328                         error = xlog_grant_head_wait(log, head, tic,
 329                                                      *need_bytes);
 330                 }
 331                 spin_unlock(&head->lock);
 332         } else if (free_bytes < *need_bytes) {
 333                 spin_lock(&head->lock);
 334                 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
 335                 spin_unlock(&head->lock);
 336         }
 337
 338         return error;
 339 }
 340
 341 static void
 342 xlog_tic_reset_res(xlog_ticket_t *tic)
 343 {
 344         tic->t_res_num = 0;
 345         tic->t_res_arr_sum = 0;
 346         tic->t_res_num_ophdrs = 0;
 347 }
 348
 349 static void
 350 xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
 351 {
 352         if (tic->t_res_num == XLOG_TIC_LEN_MAX) {
 353                 /* add to overflow and start again */
 354                 tic->t_res_o_flow += tic->t_res_arr_sum;
 355                 tic->t_res_num = 0;
 356                 tic->t_res_arr_sum = 0;
 357         }
 358
 359         tic->t_res_arr[tic->t_res_num].r_len = len;
 360         tic->t_res_arr[tic->t_res_num].r_type = type;
 361         tic->t_res_arr_sum += len;
 362         tic->t_res_num++;
 363 }
 364
 365 /*
 366  * Replenish the byte reservation required by moving the grant write head.
 367  */
 368 int
 369 xfs_log_regrant(
 370         struct xfs_mount        *mp,
 371         struct xlog_ticket      *tic)
 372 {
 373         struct xlog             *log = mp->m_log;
 374         int                     need_bytes;
 375         int                     error = 0;
 376
 377         if (XLOG_FORCED_SHUTDOWN(log))
 378                 return -EIO;
 379
 380         XFS_STATS_INC(mp, xs_try_logspace);
 381
 382         /*
 383          * This is a new transaction on the ticket, so we need to change the
 384          * transaction ID so that the next transaction has a different TID in
 385          * the log. Just add one to the existing tid so that we can see chains
 386          * of rolling transactions in the log easily.
 387          */
 388         tic->t_tid++;
 389
 390         xlog_grant_push_ail(log, tic->t_unit_res);
 391
 392         tic->t_curr_res = tic->t_unit_res;
 393         xlog_tic_reset_res(tic);
 394
 395         if (tic->t_cnt > 0)
 396                 return 0;
 397
 398         trace_xfs_log_regrant(log, tic);
 399
 400         error = xlog_grant_head_check(log, &log->l_write_head, tic,
 401                                       &need_bytes);
 402         if (error)
 403                 goto out_error;
 404
 405         xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
 406         trace_xfs_log_regrant_exit(log, tic);
 407         xlog_verify_grant_tail(log);
 408         return 0;
 409
 410 out_error:
 411         /*
 412          * If we are failing, make sure the ticket doesn't have any current
 413          * reservations.  We don't want to add this back when the ticket/
 414          * transaction gets cancelled.
 415          */
 416         tic->t_curr_res = 0;
 417         tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
 418         return error;
 419 }
 420
 421 /*
 422  * Reserve log space and return a ticket corresponding to the reservation.
 423  *
 424  * Each reservation is going to reserve extra space for a log record header.
 425  * When writes happen to the on-disk log, we don't subtract the length of the
 426  * log record header from any reservation.  By wasting space in each
 427  * reservation, we prevent over allocation problems.
 428  */
 429 int
 430 xfs_log_reserve(
 431         struct xfs_mount        *mp,
 432         int                     unit_bytes,
 433         int                     cnt,
 434         struct xlog_ticket      **ticp,
 435         uint8_t                 client,
 436         bool                    permanent)
 437 {
 438         struct xlog             *log = mp->m_log;
 439         struct xlog_ticket      *tic;
 440         int                     need_bytes;
 441         int                     error = 0;
 442
 443         ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
 444
 445         if (XLOG_FORCED_SHUTDOWN(log))
 446                 return -EIO;
 447
 448         XFS_STATS_INC(mp, xs_try_logspace);
 449
 450         ASSERT(*ticp == NULL);
 451         tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent, 0);
 452         *ticp = tic;
 453
 454         xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
 455                                             : tic->t_unit_res);
 456
 457         trace_xfs_log_reserve(log, tic);
 458
 459         error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
 460                                       &need_bytes);
 461         if (error)
 462                 goto out_error;
 463
 464         xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
 465         xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
 466         trace_xfs_log_reserve_exit(log, tic);
 467         xlog_verify_grant_tail(log);
 468         return 0;
 469
 470 out_error:
 471         /*
 472          * If we are failing, make sure the ticket doesn't have any current
 473          * reservations.  We don't want to add this back when the ticket/
 474          * transaction gets cancelled.
 475          */
 476         tic->t_curr_res = 0;
 477         tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
 478         return error;
 479 }
 480
 481
 482 /*
 483  * NOTES:
 484  *
 485  *      1. currblock field gets updated at startup and after in-core logs
 486  *              marked as with WANT_SYNC.
 487  */
 488
 489 /*
 490  * This routine is called when a user of a log manager ticket is done with
 491  * the reservation.  If the ticket was ever used, then a commit record for
 492  * the associated transaction is written out as a log operation header with
 493  * no data.  The flag XLOG_TIC_INITED is set when the first write occurs with
 494  * a given ticket.  If the ticket was one with a permanent reservation, then
 495  * a few operations are done differently.  Permanent reservation tickets by
 496  * default don't release the reservation.  They just commit the current
 497  * transaction with the belief that the reservation is still needed.  A flag
 498  * must be passed in before permanent reservations are actually released.
 499  * When these type of tickets are not released, they need to be set into
 500  * the inited state again.  By doing this, a start record will be written
 501  * out when the next write occurs.
 502  */
 503 xfs_lsn_t
 504 xfs_log_done(
 505         struct xfs_mount        *mp,
 506         struct xlog_ticket      *ticket,
 507         struct xlog_in_core     **iclog,
 508         bool                    regrant)
 509 {
 510         struct xlog             *log = mp->m_log;
 511         xfs_lsn_t               lsn = 0;
 512
 513         if (XLOG_FORCED_SHUTDOWN(log) ||
 514             /*
 515              * If nothing was ever written, don't write out commit record.
 516              * If we get an error, just continue and give back the log ticket.
 517              */
 518             (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
 519              (xlog_commit_record(log, ticket, iclog, &lsn)))) {
 520                 lsn = (xfs_lsn_t) -1;
 521                 regrant = false;
 522         }
 523
 524
 525         if (!regrant) {
 526                 trace_xfs_log_done_nonperm(log, ticket);
 527
 528                 /*
 529                  * Release ticket if not permanent reservation or a specific
 530                  * request has been made to release a permanent reservation.
 531                  */
 532                 xlog_ungrant_log_space(log, ticket);
 533         } else {
 534                 trace_xfs_log_done_perm(log, ticket);
 535
 536                 xlog_regrant_reserve_log_space(log, ticket);
 537                 /* If this ticket was a permanent reservation and we aren't
 538                  * trying to release it, reset the inited flags; so next time
 539                  * we write, a start record will be written out.
 540                  */
 541                 ticket->t_flags |= XLOG_TIC_INITED;
 542         }
 543
 544         xfs_log_ticket_put(ticket);
 545         return lsn;
 546 }
 547
 548 static bool
 549 __xlog_state_release_iclog(
 550         struct xlog             *log,
 551         struct xlog_in_core     *iclog)
 552 {
 553         lockdep_assert_held(&log->l_icloglock);
 554
 555         if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
 556                 /* update tail before writing to iclog */
 557                 xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
 558
 559                 iclog->ic_state = XLOG_STATE_SYNCING;
 560                 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
 561                 xlog_verify_tail_lsn(log, iclog, tail_lsn);
 562                 /* cycle incremented when incrementing curr_block */
 563                 return true;
 564         }
 565
 566         ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
 567         return false;
 568 }
 569
 570 /*
 571  * Flush iclog to disk if this is the last reference to the given iclog and the
 572  * it is in the WANT_SYNC state.
 573  */
 574 static int
 575 xlog_state_release_iclog(
 576         struct xlog             *log,
 577         struct xlog_in_core     *iclog)
 578 {
 579         lockdep_assert_held(&log->l_icloglock);
 580
 581         if (iclog->ic_state == XLOG_STATE_IOERROR)
 582                 return -EIO;
 583
 584         if (atomic_dec_and_test(&iclog->ic_refcnt) &&
 585             __xlog_state_release_iclog(log, iclog)) {
 586                 spin_unlock(&log->l_icloglock);
 587                 xlog_sync(log, iclog);
 588                 spin_lock(&log->l_icloglock);
 589         }
 590
 591         return 0;
 592 }
 593
 594 void
 595 xfs_log_release_iclog(
 596         struct xlog_in_core     *iclog)
 597 {
 598         struct xlog             *log = iclog->ic_log;
 599         bool                    sync = false;
 600
 601         if (atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock)) {
 602                 if (iclog->ic_state != XLOG_STATE_IOERROR)
 603                         sync = __xlog_state_release_iclog(log, iclog);
 604                 spin_unlock(&log->l_icloglock);
 605         }
 606
 607         if (sync)
 608                 xlog_sync(log, iclog);
 609 }
 610
 611 /*
 612  * Mount a log filesystem
 613  *
 614  * mp           - ubiquitous xfs mount point structure
 615  * log_target   - buftarg of on-disk log device
 616  * blk_offset   - Start block # where block size is 512 bytes (BBSIZE)
 617  * num_bblocks  - Number of BBSIZE blocks in on-disk log
 618  *
 619  * Return error or zero.
 620  */
 621 int
 622 xfs_log_mount(
 623         xfs_mount_t     *mp,
 624         xfs_buftarg_t   *log_target,
 625         xfs_daddr_t     blk_offset,
 626         int             num_bblks)
 627 {
 628         bool            fatal = xfs_sb_version_hascrc(&mp->m_sb);
 629         int             error = 0;
 630         int             min_logfsbs;
 631
 632         if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
 633                 xfs_notice(mp, "Mounting V%d Filesystem",
 634                            XFS_SB_VERSION_NUM(&mp->m_sb));
 635         } else {
 636                 xfs_notice(mp,
 637 "Mounting V%d filesystem in no-recovery mode. Filesystem will be inconsistent.",
 638                            XFS_SB_VERSION_NUM(&mp->m_sb));
 639                 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
 640         }
 641
 642         mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
 643         if (IS_ERR(mp->m_log)) {
 644                 error = PTR_ERR(mp->m_log);
 645                 goto out;
 646         }
 647
 648         /*
 649          * Validate the given log space and drop a critical message via syslog
 650          * if the log size is too small that would lead to some unexpected
 651          * situations in transaction log space reservation stage.
 652          *
 653          * Note: we can't just reject the mount if the validation fails.  This
 654          * would mean that people would have to downgrade their kernel just to
 655          * remedy the situation as there is no way to grow the log (short of
 656          * black magic surgery with xfs_db).
 657          *
 658          * We can, however, reject mounts for CRC format filesystems, as the
 659          * mkfs binary being used to make the filesystem should never create a
 660          * filesystem with a log that is too small.
 661          */
 662         min_logfsbs = xfs_log_calc_minimum_size(mp);
 663
 664         if (mp->m_sb.sb_logblocks < min_logfsbs) {
 665                 xfs_warn(mp,
 666                 "Log size %d blocks too small, minimum size is %d blocks",
 667                          mp->m_sb.sb_logblocks, min_logfsbs);
 668                 error = -EINVAL;
 669         } else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) {
 670                 xfs_warn(mp,
 671                 "Log size %d blocks too large, maximum size is %lld blocks",
 672                          mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS);
 673                 error = -EINVAL;
 674         } else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) {
 675                 xfs_warn(mp,
 676                 "log size %lld bytes too large, maximum size is %lld bytes",
 677                          XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
 678                          XFS_MAX_LOG_BYTES);
 679                 error = -EINVAL;
 680         } else if (mp->m_sb.sb_logsunit > 1 &&
 681                    mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) {
 682                 xfs_warn(mp,
 683                 "log stripe unit %u bytes must be a multiple of block size",
 684                          mp->m_sb.sb_logsunit);
 685                 error = -EINVAL;
 686                 fatal = true;
 687         }
 688         if (error) {
 689                 /*
 690                  * Log check errors are always fatal on v5; or whenever bad
 691                  * metadata leads to a crash.
 692                  */
 693                 if (fatal) {
 694                         xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
 695                         ASSERT(0);
 696                         goto out_free_log;
 697                 }
 698                 xfs_crit(mp, "Log size out of supported range.");
 699                 xfs_crit(mp,
 700 "Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
 701         }
 702
 703         /*
 704          * Initialize the AIL now we have a log.
 705          */
 706         error = xfs_trans_ail_init(mp);
 707         if (error) {
 708                 xfs_warn(mp, "AIL initialisation failed: error %d", error);
 709                 goto out_free_log;
 710         }
 711         mp->m_log->l_ailp = mp->m_ail;
 712
 713         /*
 714          * skip log recovery on a norecovery mount.  pretend it all
 715          * just worked.
 716          */
 717         if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
 718                 int     readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
 719
 720                 if (readonly)
 721                         mp->m_flags &= ~XFS_MOUNT_RDONLY;
 722
 723                 error = xlog_recover(mp->m_log);
 724
 725                 if (readonly)
 726                         mp->m_flags |= XFS_MOUNT_RDONLY;
 727                 if (error) {
 728                         xfs_warn(mp, "log mount/recovery failed: error %d",
 729                                 error);
 730                         xlog_recover_cancel(mp->m_log);
 731                         goto out_destroy_ail;
 732                 }
 733         }
 734
 735         error = xfs_sysfs_init(&mp->m_log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
 736                                "log");
 737         if (error)
 738                 goto out_destroy_ail;
 739
 740         /* Normal transactions can now occur */
 741         mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
 742
 743         /*
 744          * Now the log has been fully initialised and we know were our
 745          * space grant counters are, we can initialise the permanent ticket
 746          * needed for delayed logging to work.
 747          */
 748         xlog_cil_init_post_recovery(mp->m_log);
 749
 750         return 0;
 751
 752 out_destroy_ail:
 753         xfs_trans_ail_destroy(mp);
 754 out_free_log:
 755         xlog_dealloc_log(mp->m_log);
 756 out:
 757         return error;
 758 }
 759
 760 /*
 761  * Finish the recovery of the file system.  This is separate from the
 762  * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
 763  * in the root and real-time bitmap inodes between calling xfs_log_mount() and
 764  * here.
 765  *
 766  * If we finish recovery successfully, start the background log work. If we are
 767  * not doing recovery, then we have a RO filesystem and we don't need to start
 768  * it.
 769  */
 770 int
 771 xfs_log_mount_finish(
 772         struct xfs_mount        *mp)
 773 {
 774         int     error = 0;
 775         bool    readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
 776         bool    recovered = mp->m_log->l_flags & XLOG_RECOVERY_NEEDED;
 777
 778         if (mp->m_flags & XFS_MOUNT_NORECOVERY) {
 779                 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
 780                 return 0;
 781         } else if (readonly) {
 782                 /* Allow unlinked processing to proceed */
 783                 mp->m_flags &= ~XFS_MOUNT_RDONLY;
 784         }
 785
 786         /*
 787          * During the second phase of log recovery, we need iget and
 788          * iput to behave like they do for an active filesystem.
 789          * xfs_fs_drop_inode needs to be able to prevent the deletion
 790          * of inodes before we're done replaying log items on those
 791          * inodes.  Turn it off immediately after recovery finishes
 792          * so that we don't leak the quota inodes if subsequent mount
 793          * activities fail.
 794          *
 795          * We let all inodes involved in redo item processing end up on
 796          * the LRU instead of being evicted immediately so that if we do
 797          * something to an unlinked inode, the irele won't cause
 798          * premature truncation and freeing of the inode, which results
 799          * in log recovery failure.  We have to evict the unreferenced
 800          * lru inodes after clearing SB_ACTIVE because we don't
 801          * otherwise clean up the lru if there's a subsequent failure in
 802          * xfs_mountfs, which leads to us leaking the inodes if nothing
 803          * else (e.g. quotacheck) references the inodes before the
 804          * mount failure occurs.
 805          */
 806         mp->m_super->s_flags |= SB_ACTIVE;
 807         error = xlog_recover_finish(mp->m_log);
 808         if (!error)
 809                 xfs_log_work_queue(mp);
 810         mp->m_super->s_flags &= ~SB_ACTIVE;
 811         evict_inodes(mp->m_super);
 812
 813         /*
 814          * Drain the buffer LRU after log recovery. This is required for v4
 815          * filesystems to avoid leaving around buffers with NULL verifier ops,
 816          * but we do it unconditionally to make sure we're always in a clean
 817          * cache state after mount.
 818          *
 819          * Don't push in the error case because the AIL may have pending intents
 820          * that aren't removed until recovery is cancelled.
 821          */
 822         if (!error && recovered) {
 823                 xfs_log_force(mp, XFS_LOG_SYNC);
 824                 xfs_ail_push_all_sync(mp->m_ail);
 825         }
 826         xfs_wait_buftarg(mp->m_ddev_targp);
 827
 828         if (readonly)
 829                 mp->m_flags |= XFS_MOUNT_RDONLY;
 830
 831         return error;
 832 }
 833
 834 /*
 835  * The mount has failed. Cancel the recovery if it hasn't completed and destroy
 836  * the log.
 837  */
 838 void
 839 xfs_log_mount_cancel(
 840         struct xfs_mount        *mp)
 841 {
 842         xlog_recover_cancel(mp->m_log);
 843         xfs_log_unmount(mp);
 844 }
 845
 846 /*
 847  * Wait for the iclog to be written disk, or return an error if the log has been
 848  * shut down.
 849  */
 850 static int
 851 xlog_wait_on_iclog(
 852         struct xlog_in_core     *iclog)
 853                 __releases(iclog->ic_log->l_icloglock)
 854 {
 855         struct xlog             *log = iclog->ic_log;
 856
 857         if (!XLOG_FORCED_SHUTDOWN(log) &&
 858             iclog->ic_state != XLOG_STATE_ACTIVE &&
 859             iclog->ic_state != XLOG_STATE_DIRTY) {
 860                 XFS_STATS_INC(log->l_mp, xs_log_force_sleep);
 861                 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
 862         } else {
 863                 spin_unlock(&log->l_icloglock);
 864         }
 865
 866         if (XLOG_FORCED_SHUTDOWN(log))
 867                 return -EIO;
 868         return 0;
 869 }
 870
 871 /*
 872  * Final log writes as part of unmount.
 873  *
 874  * Mark the filesystem clean as unmount happens.  Note that during relocation
 875  * this routine needs to be executed as part of source-bag while the
 876  * deallocation must not be done until source-end.
 877  */
 878
 879 /* Actually write the unmount record to disk. */
 880 static void
 881 xfs_log_write_unmount_record(
 882         struct xfs_mount        *mp)
 883 {
 884         /* the data section must be 32 bit size aligned */
 885         struct xfs_unmount_log_format magic = {
 886                 .magic = XLOG_UNMOUNT_TYPE,
 887         };
 888         struct xfs_log_iovec reg = {
 889                 .i_addr = &magic,
 890                 .i_len = sizeof(magic),
 891                 .i_type = XLOG_REG_TYPE_UNMOUNT,
 892         };
 893         struct xfs_log_vec vec = {
 894                 .lv_niovecs = 1,
 895                 .lv_iovecp = &reg,
 896         };
 897         struct xlog             *log = mp->m_log;
 898         struct xlog_in_core     *iclog;
 899         struct xlog_ticket      *tic = NULL;
 900         xfs_lsn_t               lsn;
 901         uint                    flags = XLOG_UNMOUNT_TRANS;
 902         int                     error;
 903
 904         error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0);
 905         if (error)
 906                 goto out_err;
 907
 908         /*
 909          * If we think the summary counters are bad, clear the unmount header
 910          * flag in the unmount record so that the summary counters will be
 911          * recalculated during log recovery at next mount.  Refer to
 912          * xlog_check_unmount_rec for more details.
 913          */
 914         if (XFS_TEST_ERROR(xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS), mp,
 915                         XFS_ERRTAG_FORCE_SUMMARY_RECALC)) {
 916                 xfs_alert(mp, "%s: will fix summary counters at next mount",
 917                                 __func__);
 918                 flags &= ~XLOG_UNMOUNT_TRANS;
 919         }
 920
 921         /* remove inited flag, and account for space used */
 922         tic->t_flags = 0;
 923         tic->t_curr_res -= sizeof(magic);
 924         error = xlog_write(log, &vec, tic, &lsn, NULL, flags);
 925         /*
 926          * At this point, we're umounting anyway, so there's no point in
 927          * transitioning log state to IOERROR. Just continue...
 928          */
 929 out_err:
 930         if (error)
 931                 xfs_alert(mp, "%s: unmount record failed", __func__);
 932
 933         spin_lock(&log->l_icloglock);
 934         iclog = log->l_iclog;
 935         atomic_inc(&iclog->ic_refcnt);
 936         if (iclog->ic_state == XLOG_STATE_ACTIVE)
 937                 xlog_state_switch_iclogs(log, iclog, 0);
 938         else
 939                 ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC ||
 940                        iclog->ic_state == XLOG_STATE_IOERROR);
 941         error = xlog_state_release_iclog(log, iclog);
 942         xlog_wait_on_iclog(iclog);
 943
 944         if (tic) {
 945                 trace_xfs_log_umount_write(log, tic);
 946                 xlog_ungrant_log_space(log, tic);
 947                 xfs_log_ticket_put(tic);
 948         }
 949 }
 950
 951 static void
 952 xfs_log_unmount_verify_iclog(
 953         struct xlog             *log)
 954 {
 955         struct xlog_in_core     *iclog = log->l_iclog;
 956
 957         do {
 958                 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
 959                 ASSERT(iclog->ic_offset == 0);
 960         } while ((iclog = iclog->ic_next) != log->l_iclog);
 961 }
 962
 963 /*
 964  * Unmount record used to have a string "Unmount filesystem--" in the
 965  * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
 966  * We just write the magic number now since that particular field isn't
 967  * currently architecture converted and "Unmount" is a bit foo.
 968  * As far as I know, there weren't any dependencies on the old behaviour.
 969  */
 970 static void
 971 xfs_log_unmount_write(
 972         struct xfs_mount        *mp)
 973 {
 974         struct xlog             *log = mp->m_log;
 975
 976         /*
 977          * Don't write out unmount record on norecovery mounts or ro devices.
 978          * Or, if we are doing a forced umount (typically because of IO errors).
 979          */
 980         if (mp->m_flags & XFS_MOUNT_NORECOVERY ||
 981             xfs_readonly_buftarg(log->l_targ)) {
 982                 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
 983                 return;
 984         }
 985
 986         xfs_log_force(mp, XFS_LOG_SYNC);
 987
 988         if (XLOG_FORCED_SHUTDOWN(log))
 989                 return;
 990         xfs_log_unmount_verify_iclog(log);
 991         xfs_log_write_unmount_record(mp);
 992 }
 993
 994 /*
 995  * Empty the log for unmount/freeze.
 996  *
 997  * To do this, we first need to shut down the background log work so it is not
 998  * trying to cover the log as we clean up. We then need to unpin all objects in
 999  * the log so we can then flush them out. Once they have completed their IO and
1000  * run the callbacks removing themselves from the AIL, we can write the unmount
1001  * record.
1002  */
1003 void
1004 xfs_log_quiesce(
1005         struct xfs_mount        *mp)
1006 {
1007         cancel_delayed_work_sync(&mp->m_log->l_work);
1008         xfs_log_force(mp, XFS_LOG_SYNC);
1009
1010         /*
1011          * The superblock buffer is uncached and while xfs_ail_push_all_sync()
1012          * will push it, xfs_wait_buftarg() will not wait for it. Further,
1013          * xfs_buf_iowait() cannot be used because it was pushed with the
1014          * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
1015          * the IO to complete.
1016          */
1017         xfs_ail_push_all_sync(mp->m_ail);
1018         xfs_wait_buftarg(mp->m_ddev_targp);
1019         xfs_buf_lock(mp->m_sb_bp);
1020         xfs_buf_unlock(mp->m_sb_bp);
1021
1022         xfs_log_unmount_write(mp);
1023 }
1024
1025 /*
1026  * Shut down and release the AIL and Log.
1027  *
1028  * During unmount, we need to ensure we flush all the dirty metadata objects
1029  * from the AIL so that the log is empty before we write the unmount record to
1030  * the log. Once this is done, we can tear down the AIL and the log.
1031  */
1032 void
1033 xfs_log_unmount(
1034         struct xfs_mount        *mp)
1035 {
1036         xfs_log_quiesce(mp);
1037
1038         xfs_trans_ail_destroy(mp);
1039
1040         xfs_sysfs_del(&mp->m_log->l_kobj);
1041
1042         xlog_dealloc_log(mp->m_log);
1043 }
1044
1045 void
1046 xfs_log_item_init(
1047         struct xfs_mount        *mp,
1048         struct xfs_log_item     *item,
1049         int                     type,
1050         const struct xfs_item_ops *ops)
1051 {
1052         item->li_mountp = mp;
1053         item->li_ailp = mp->m_ail;
1054         item->li_type = type;
1055         item->li_ops = ops;
1056         item->li_lv = NULL;
1057
1058         INIT_LIST_HEAD(&item->li_ail);
1059         INIT_LIST_HEAD(&item->li_cil);
1060         INIT_LIST_HEAD(&item->li_bio_list);
1061         INIT_LIST_HEAD(&item->li_trans);
1062 }
1063
1064 /*
1065  * Wake up processes waiting for log space after we have moved the log tail.
1066  */
1067 void
1068 xfs_log_space_wake(
1069         struct xfs_mount        *mp)
1070 {
1071         struct xlog             *log = mp->m_log;
1072         int                     free_bytes;
1073
1074         if (XLOG_FORCED_SHUTDOWN(log))
1075                 return;
1076
1077         if (!list_empty_careful(&log->l_write_head.waiters)) {
1078                 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1079
1080                 spin_lock(&log->l_write_head.lock);
1081                 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
1082                 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
1083                 spin_unlock(&log->l_write_head.lock);
1084         }
1085
1086         if (!list_empty_careful(&log->l_reserve_head.waiters)) {
1087                 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1088
1089                 spin_lock(&log->l_reserve_head.lock);
1090                 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1091                 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
1092                 spin_unlock(&log->l_reserve_head.lock);
1093         }
1094 }
1095
1096 /*
1097  * Determine if we have a transaction that has gone to disk that needs to be
1098  * covered. To begin the transition to the idle state firstly the log needs to
1099  * be idle. That means the CIL, the AIL and the iclogs needs to be empty before
1100  * we start attempting to cover the log.
1101  *
1102  * Only if we are then in a state where covering is needed, the caller is
1103  * informed that dummy transactions are required to move the log into the idle
1104  * state.
1105  *
1106  * If there are any items in the AIl or CIL, then we do not want to attempt to
1107  * cover the log as we may be in a situation where there isn't log space
1108  * available to run a dummy transaction and this can lead to deadlocks when the
1109  * tail of the log is pinned by an item that is modified in the CIL.  Hence
1110  * there's no point in running a dummy transaction at this point because we
1111  * can't start trying to idle the log until both the CIL and AIL are empty.
1112  */
1113 static int
1114 xfs_log_need_covered(xfs_mount_t *mp)
1115 {
1116         struct xlog     *log = mp->m_log;
1117         int             needed = 0;
1118
1119         if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
1120                 return 0;
1121
1122         if (!xlog_cil_empty(log))
1123                 return 0;
1124
1125         spin_lock(&log->l_icloglock);
1126         switch (log->l_covered_state) {
1127         case XLOG_STATE_COVER_DONE:
1128         case XLOG_STATE_COVER_DONE2:
1129         case XLOG_STATE_COVER_IDLE:
1130                 break;
1131         case XLOG_STATE_COVER_NEED:
1132         case XLOG_STATE_COVER_NEED2:
1133                 if (xfs_ail_min_lsn(log->l_ailp))
1134                         break;
1135                 if (!xlog_iclogs_empty(log))
1136                         break;
1137
1138                 needed = 1;
1139                 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1140                         log->l_covered_state = XLOG_STATE_COVER_DONE;
1141                 else
1142                         log->l_covered_state = XLOG_STATE_COVER_DONE2;
1143                 break;
1144         default:
1145                 needed = 1;
1146                 break;
1147         }
1148         spin_unlock(&log->l_icloglock);
1149         return needed;
1150 }
1151
1152 /*
1153  * We may be holding the log iclog lock upon entering this routine.
1154  */
1155 xfs_lsn_t
1156 xlog_assign_tail_lsn_locked(
1157         struct xfs_mount        *mp)
1158 {
1159         struct xlog             *log = mp->m_log;
1160         struct xfs_log_item     *lip;
1161         xfs_lsn_t               tail_lsn;
1162
1163         assert_spin_locked(&mp->m_ail->ail_lock);
1164
1165         /*
1166          * To make sure we always have a valid LSN for the log tail we keep
1167          * track of the last LSN which was committed in log->l_last_sync_lsn,
1168          * and use that when the AIL was empty.
1169          */
1170         lip = xfs_ail_min(mp->m_ail);
1171         if (lip)
1172                 tail_lsn = lip->li_lsn;
1173         else
1174                 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1175         trace_xfs_log_assign_tail_lsn(log, tail_lsn);
1176         atomic64_set(&log->l_tail_lsn, tail_lsn);
1177         return tail_lsn;
1178 }
1179
1180 xfs_lsn_t
1181 xlog_assign_tail_lsn(
1182         struct xfs_mount        *mp)
1183 {
1184         xfs_lsn_t               tail_lsn;
1185
1186         spin_lock(&mp->m_ail->ail_lock);
1187         tail_lsn = xlog_assign_tail_lsn_locked(mp);
1188         spin_unlock(&mp->m_ail->ail_lock);
1189
1190         return tail_lsn;
1191 }
1192
1193 /*
1194  * Return the space in the log between the tail and the head.  The head
1195  * is passed in the cycle/bytes formal parms.  In the special case where
1196  * the reserve head has wrapped passed the tail, this calculation is no
1197  * longer valid.  In this case, just return 0 which means there is no space
1198  * in the log.  This works for all places where this function is called
1199  * with the reserve head.  Of course, if the write head were to ever
1200  * wrap the tail, we should blow up.  Rather than catch this case here,
1201  * we depend on other ASSERTions in other parts of the code.   XXXmiken
1202  *
1203  * This code also handles the case where the reservation head is behind
1204  * the tail.  The details of this case are described below, but the end
1205  * result is that we return the size of the log as the amount of space left.
1206  */
1207 STATIC int
1208 xlog_space_left(
1209         struct xlog     *log,
1210         atomic64_t      *head)
1211 {
1212         int             free_bytes;
1213         int             tail_bytes;
1214         int             tail_cycle;
1215         int             head_cycle;
1216         int             head_bytes;
1217
1218         xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1219         xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1220         tail_bytes = BBTOB(tail_bytes);
1221         if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1222                 free_bytes = log->l_logsize - (head_bytes - tail_bytes);
1223         else if (tail_cycle + 1 < head_cycle)
1224                 return 0;
1225         else if (tail_cycle < head_cycle) {
1226                 ASSERT(tail_cycle == (head_cycle - 1));
1227                 free_bytes = tail_bytes - head_bytes;
1228         } else {
1229                 /*
1230                  * The reservation head is behind the tail.
1231                  * In this case we just want to return the size of the
1232                  * log as the amount of space left.
1233                  */
1234                 xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
1235                 xfs_alert(log->l_mp,
1236                           "  tail_cycle = %d, tail_bytes = %d",
1237                           tail_cycle, tail_bytes);
1238                 xfs_alert(log->l_mp,
1239                           "  GH   cycle = %d, GH   bytes = %d",
1240                           head_cycle, head_bytes);
1241                 ASSERT(0);
1242                 free_bytes = log->l_logsize;
1243         }
1244         return free_bytes;
1245 }
1246
1247
1248 static void
1249 xlog_ioend_work(
1250         struct work_struct      *work)
1251 {
1252         struct xlog_in_core     *iclog =
1253                 container_of(work, struct xlog_in_core, ic_end_io_work);
1254         struct xlog             *log = iclog->ic_log;
1255         int                     error;
1256
1257         error = blk_status_to_errno(iclog->ic_bio.bi_status);
1258 #ifdef DEBUG
1259         /* treat writes with injected CRC errors as failed */
1260         if (iclog->ic_fail_crc)
1261                 error = -EIO;
1262 #endif
1263
1264         /*
1265          * Race to shutdown the filesystem if we see an error.
1266          */
1267         if (XFS_TEST_ERROR(error, log->l_mp, XFS_ERRTAG_IODONE_IOERR)) {
1268                 xfs_alert(log->l_mp, "log I/O error %d", error);
1269                 xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
1270         }
1271
1272         xlog_state_done_syncing(iclog);
1273         bio_uninit(&iclog->ic_bio);
1274
1275         /*
1276          * Drop the lock to signal that we are done. Nothing references the
1277          * iclog after this, so an unmount waiting on this lock can now tear it
1278          * down safely. As such, it is unsafe to reference the iclog after the
1279          * unlock as we could race with it being freed.
1280          */
1281         up(&iclog->ic_sema);
1282 }
1283
1284 /*
1285  * Return size of each in-core log record buffer.
1286  *
1287  * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1288  *
1289  * If the filesystem blocksize is too large, we may need to choose a
1290  * larger size since the directory code currently logs entire blocks.
1291  */
1292 STATIC void
1293 xlog_get_iclog_buffer_size(
1294         struct xfs_mount        *mp,
1295         struct xlog             *log)
1296 {
1297         if (mp->m_logbufs <= 0)
1298                 mp->m_logbufs = XLOG_MAX_ICLOGS;
1299         if (mp->m_logbsize <= 0)
1300                 mp->m_logbsize = XLOG_BIG_RECORD_BSIZE;
1301
1302         log->l_iclog_bufs = mp->m_logbufs;
1303         log->l_iclog_size = mp->m_logbsize;
1304
1305         /*
1306          * # headers = size / 32k - one header holds cycles from 32k of data.
1307          */
1308         log->l_iclog_heads =
1309                 DIV_ROUND_UP(mp->m_logbsize, XLOG_HEADER_CYCLE_SIZE);
1310         log->l_iclog_hsize = log->l_iclog_heads << BBSHIFT;
1311 }
1312
1313 void
1314 xfs_log_work_queue(
1315         struct xfs_mount        *mp)
1316 {
1317         queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work,
1318                                 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1319 }
1320
1321 /*
1322  * Every sync period we need to unpin all items in the AIL and push them to
1323  * disk. If there is nothing dirty, then we might need to cover the log to
1324  * indicate that the filesystem is idle.
1325  */
1326 static void
1327 xfs_log_worker(
1328         struct work_struct      *work)
1329 {
1330         struct xlog             *log = container_of(to_delayed_work(work),
1331                                                 struct xlog, l_work);
1332         struct xfs_mount        *mp = log->l_mp;
1333
1334         /* dgc: errors ignored - not fatal and nowhere to report them */
1335         if (xfs_log_need_covered(mp)) {
1336                 /*
1337                  * Dump a transaction into the log that contains no real change.
1338                  * This is needed to stamp the current tail LSN into the log
1339                  * during the covering operation.
1340                  *
1341                  * We cannot use an inode here for this - that will push dirty
1342                  * state back up into the VFS and then periodic inode flushing
1343                  * will prevent log covering from making progress. Hence we
1344                  * synchronously log the superblock instead to ensure the
1345                  * superblock is immediately unpinned and can be written back.
1346                  */
1347                 xfs_sync_sb(mp, true);
1348         } else
1349                 xfs_log_force(mp, 0);
1350
1351         /* start pushing all the metadata that is currently dirty */
1352         xfs_ail_push_all(mp->m_ail);
1353
1354         /* queue us up again */
1355         xfs_log_work_queue(mp);
1356 }
1357
1358 /*
1359  * This routine initializes some of the log structure for a given mount point.
1360  * Its primary purpose is to fill in enough, so recovery can occur.  However,
1361  * some other stuff may be filled in too.
1362  */
1363 STATIC struct xlog *
1364 xlog_alloc_log(
1365         struct xfs_mount        *mp,
1366         struct xfs_buftarg      *log_target,
1367         xfs_daddr_t             blk_offset,
1368         int                     num_bblks)
1369 {
1370         struct xlog             *log;
1371         xlog_rec_header_t       *head;
1372         xlog_in_core_t          **iclogp;
1373         xlog_in_core_t          *iclog, *prev_iclog=NULL;
1374         int                     i;
1375         int                     error = -ENOMEM;
1376         uint                    log2_size = 0;
1377
1378         log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1379         if (!log) {
1380                 xfs_warn(mp, "Log allocation failed: No memory!");
1381                 goto out;
1382         }
1383
1384         log->l_mp          = mp;
1385         log->l_targ        = log_target;
1386         log->l_logsize     = BBTOB(num_bblks);
1387         log->l_logBBstart  = blk_offset;
1388         log->l_logBBsize   = num_bblks;
1389         log->l_covered_state = XLOG_STATE_COVER_IDLE;
1390         log->l_flags       |= XLOG_ACTIVE_RECOVERY;
1391         INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1392
1393         log->l_prev_block  = -1;
1394         /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1395         xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1396         xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1397         log->l_curr_cycle  = 1;     /* 0 is bad since this is initial value */
1398
1399         xlog_grant_head_init(&log->l_reserve_head);
1400         xlog_grant_head_init(&log->l_write_head);
1401
1402         error = -EFSCORRUPTED;
1403         if (xfs_sb_version_hassector(&mp->m_sb)) {
1404                 log2_size = mp->m_sb.sb_logsectlog;
1405                 if (log2_size < BBSHIFT) {
1406                         xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1407                                 log2_size, BBSHIFT);
1408                         goto out_free_log;
1409                 }
1410
1411                 log2_size -= BBSHIFT;
1412                 if (log2_size > mp->m_sectbb_log) {
1413                         xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1414                                 log2_size, mp->m_sectbb_log);
1415                         goto out_free_log;
1416                 }
1417
1418                 /* for larger sector sizes, must have v2 or external log */
1419                 if (log2_size && log->l_logBBstart > 0 &&
1420                             !xfs_sb_version_haslogv2(&mp->m_sb)) {
1421                         xfs_warn(mp,
1422                 "log sector size (0x%x) invalid for configuration.",
1423                                 log2_size);
1424                         goto out_free_log;
1425                 }
1426         }
1427         log->l_sectBBsize = 1 << log2_size;
1428
1429         xlog_get_iclog_buffer_size(mp, log);
1430
1431         spin_lock_init(&log->l_icloglock);
1432         init_waitqueue_head(&log->l_flush_wait);
1433
1434         iclogp = &log->l_iclog;
1435         /*
1436          * The amount of memory to allocate for the iclog structure is
1437          * rather funky due to the way the structure is defined.  It is
1438          * done this way so that we can use different sizes for machines
1439          * with different amounts of memory.  See the definition of
1440          * xlog_in_core_t in xfs_log_priv.h for details.
1441          */
1442         ASSERT(log->l_iclog_size >= 4096);
1443         for (i = 0; i < log->l_iclog_bufs; i++) {
1444                 int align_mask = xfs_buftarg_dma_alignment(mp->m_logdev_targp);
1445                 size_t bvec_size = howmany(log->l_iclog_size, PAGE_SIZE) *
1446                                 sizeof(struct bio_vec);
1447
1448                 iclog = kmem_zalloc(sizeof(*iclog) + bvec_size, KM_MAYFAIL);
1449                 if (!iclog)
1450                         goto out_free_iclog;
1451
1452                 *iclogp = iclog;
1453                 iclog->ic_prev = prev_iclog;
1454                 prev_iclog = iclog;
1455
1456                 iclog->ic_data = kmem_alloc_io(log->l_iclog_size, align_mask,
1457                                                 KM_MAYFAIL | KM_ZERO);
1458                 if (!iclog->ic_data)
1459                         goto out_free_iclog;
1460 #ifdef DEBUG
1461                 log->l_iclog_bak[i] = &iclog->ic_header;
1462 #endif
1463                 head = &iclog->ic_header;
1464                 memset(head, 0, sizeof(xlog_rec_header_t));
1465                 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1466                 head->h_version = cpu_to_be32(
1467                         xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
1468                 head->h_size = cpu_to_be32(log->l_iclog_size);
1469                 /* new fields */
1470                 head->h_fmt = cpu_to_be32(XLOG_FMT);
1471                 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1472
1473                 iclog->ic_size = log->l_iclog_size - log->l_iclog_hsize;
1474                 iclog->ic_state = XLOG_STATE_ACTIVE;
1475                 iclog->ic_log = log;
1476                 atomic_set(&iclog->ic_refcnt, 0);
1477                 spin_lock_init(&iclog->ic_callback_lock);
1478                 INIT_LIST_HEAD(&iclog->ic_callbacks);
1479                 iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
1480
1481                 init_waitqueue_head(&iclog->ic_force_wait);
1482                 init_waitqueue_head(&iclog->ic_write_wait);
1483                 INIT_WORK(&iclog->ic_end_io_work, xlog_ioend_work);
1484                 sema_init(&iclog->ic_sema, 1);
1485
1486                 iclogp = &iclog->ic_next;
1487         }
1488         *iclogp = log->l_iclog;                 /* complete ring */
1489         log->l_iclog->ic_prev = prev_iclog;     /* re-write 1st prev ptr */
1490
1491         log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s",
1492                         WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_HIGHPRI, 0,
1493                         mp->m_super->s_id);
1494         if (!log->l_ioend_workqueue)
1495                 goto out_free_iclog;
1496
1497         error = xlog_cil_init(log);
1498         if (error)
1499                 goto out_destroy_workqueue;
1500         return log;
1501
1502 out_destroy_workqueue:
1503         destroy_workqueue(log->l_ioend_workqueue);
1504 out_free_iclog:
1505         for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1506                 prev_iclog = iclog->ic_next;
1507                 kmem_free(iclog->ic_data);
1508                 kmem_free(iclog);
1509                 if (prev_iclog == log->l_iclog)
1510                         break;
1511         }
1512 out_free_log:
1513         kmem_free(log);
1514 out:
1515         return ERR_PTR(error);
1516 }       /* xlog_alloc_log */
1517
1518
1519 /*
1520  * Write out the commit record of a transaction associated with the given
1521  * ticket.  Return the lsn of the commit record.
1522  */
1523 STATIC int
1524 xlog_commit_record(
1525         struct xlog             *log,
1526         struct xlog_ticket      *ticket,
1527         struct xlog_in_core     **iclog,
1528         xfs_lsn_t               *commitlsnp)
1529 {
1530         struct xfs_mount *mp = log->l_mp;
1531         int     error;
1532         struct xfs_log_iovec reg = {
1533                 .i_addr = NULL,
1534                 .i_len = 0,
1535                 .i_type = XLOG_REG_TYPE_COMMIT,
1536         };
1537         struct xfs_log_vec vec = {
1538                 .lv_niovecs = 1,
1539                 .lv_iovecp = &reg,
1540         };
1541
1542         ASSERT_ALWAYS(iclog);
1543         error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
1544                                         XLOG_COMMIT_TRANS);
1545         if (error)
1546                 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1547         return error;
1548 }
1549
1550 /*
1551  * Push on the buffer cache code if we ever use more than 75% of the on-disk
1552  * log space.  This code pushes on the lsn which would supposedly free up
1553  * the 25% which we want to leave free.  We may need to adopt a policy which
1554  * pushes on an lsn which is further along in the log once we reach the high
1555  * water mark.  In this manner, we would be creating a low water mark.
1556  */
1557 STATIC void
1558 xlog_grant_push_ail(
1559         struct xlog     *log,
1560         int             need_bytes)
1561 {
1562         xfs_lsn_t       threshold_lsn = 0;
1563         xfs_lsn_t       last_sync_lsn;
1564         int             free_blocks;
1565         int             free_bytes;
1566         int             threshold_block;
1567         int             threshold_cycle;
1568         int             free_threshold;
1569
1570         ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1571
1572         free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1573         free_blocks = BTOBBT(free_bytes);
1574
1575         /*
1576          * Set the threshold for the minimum number of free blocks in the
1577          * log to the maximum of what the caller needs, one quarter of the
1578          * log, and 256 blocks.
1579          */
1580         free_threshold = BTOBB(need_bytes);
1581         free_threshold = max(free_threshold, (log->l_logBBsize >> 2));
1582         free_threshold = max(free_threshold, 256);
1583         if (free_blocks >= free_threshold)
1584                 return;
1585
1586         xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1587                                                 &threshold_block);
1588         threshold_block += free_threshold;
1589         if (threshold_block >= log->l_logBBsize) {
1590                 threshold_block -= log->l_logBBsize;
1591                 threshold_cycle += 1;
1592         }
1593         threshold_lsn = xlog_assign_lsn(threshold_cycle,
1594                                         threshold_block);
1595         /*
1596          * Don't pass in an lsn greater than the lsn of the last
1597          * log record known to be on disk. Use a snapshot of the last sync lsn
1598          * so that it doesn't change between the compare and the set.
1599          */
1600         last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1601         if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1602                 threshold_lsn = last_sync_lsn;
1603
1604         /*
1605          * Get the transaction layer to kick the dirty buffers out to
1606          * disk asynchronously. No point in trying to do this if
1607          * the filesystem is shutting down.
1608          */
1609         if (!XLOG_FORCED_SHUTDOWN(log))
1610                 xfs_ail_push(log->l_ailp, threshold_lsn);
1611 }
1612
1613 /*
1614  * Stamp cycle number in every block
1615  */
1616 STATIC void
1617 xlog_pack_data(
1618         struct xlog             *log,
1619         struct xlog_in_core     *iclog,
1620         int                     roundoff)
1621 {
1622         int                     i, j, k;
1623         int                     size = iclog->ic_offset + roundoff;
1624         __be32                  cycle_lsn;
1625         char                    *dp;
1626
1627         cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1628
1629         dp = iclog->ic_datap;
1630         for (i = 0; i < BTOBB(size); i++) {
1631                 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1632                         break;
1633                 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1634                 *(__be32 *)dp = cycle_lsn;
1635                 dp += BBSIZE;
1636         }
1637
1638         if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1639                 xlog_in_core_2_t *xhdr = iclog->ic_data;
1640
1641                 for ( ; i < BTOBB(size); i++) {
1642                         j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1643                         k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1644                         xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1645                         *(__be32 *)dp = cycle_lsn;
1646                         dp += BBSIZE;
1647                 }
1648
1649                 for (i = 1; i < log->l_iclog_heads; i++)
1650                         xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1651         }
1652 }
1653
1654 /*
1655  * Calculate the checksum for a log buffer.
1656  *
1657  * This is a little more complicated than it should be because the various
1658  * headers and the actual data are non-contiguous.
1659  */
1660 __le32
1661 xlog_cksum(
1662         struct xlog             *log,
1663         struct xlog_rec_header  *rhead,
1664         char                    *dp,
1665         int                     size)
1666 {
1667         uint32_t                crc;
1668
1669         /* first generate the crc for the record header ... */
1670         crc = xfs_start_cksum_update((char *)rhead,
1671                               sizeof(struct xlog_rec_header),
1672                               offsetof(struct xlog_rec_header, h_crc));
1673
1674         /* ... then for additional cycle data for v2 logs ... */
1675         if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1676                 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1677                 int             i;
1678                 int             xheads;
1679
1680                 xheads = size / XLOG_HEADER_CYCLE_SIZE;
1681                 if (size % XLOG_HEADER_CYCLE_SIZE)
1682                         xheads++;
1683
1684                 for (i = 1; i < xheads; i++) {
1685                         crc = crc32c(crc, &xhdr[i].hic_xheader,
1686                                      sizeof(struct xlog_rec_ext_header));
1687                 }
1688         }
1689
1690         /* ... and finally for the payload */
1691         crc = crc32c(crc, dp, size);
1692
1693         return xfs_end_cksum(crc);
1694 }
1695
1696 static void
1697 xlog_bio_end_io(
1698         struct bio              *bio)
1699 {
1700         struct xlog_in_core     *iclog = bio->bi_private;
1701
1702         queue_work(iclog->ic_log->l_ioend_workqueue,
1703                    &iclog->ic_end_io_work);
1704 }
1705
1706 static int
1707 xlog_map_iclog_data(
1708         struct bio              *bio,
1709         void                    *data,
1710         size_t                  count)
1711 {
1712         do {
1713                 struct page     *page = kmem_to_page(data);
1714                 unsigned int    off = offset_in_page(data);
1715                 size_t          len = min_t(size_t, count, PAGE_SIZE - off);
1716
1717                 if (bio_add_page(bio, page, len, off) != len)
1718                         return -EIO;
1719
1720                 data += len;
1721                 count -= len;
1722         } while (count);
1723
1724         return 0;
1725 }
1726
1727 STATIC void
1728 xlog_write_iclog(
1729         struct xlog             *log,
1730         struct xlog_in_core     *iclog,
1731         uint64_t                bno,
1732         unsigned int            count,
1733         bool                    need_flush)
1734 {
1735         ASSERT(bno < log->l_logBBsize);
1736
1737         /*
1738          * We lock the iclogbufs here so that we can serialise against I/O
1739          * completion during unmount.  We might be processing a shutdown
1740          * triggered during unmount, and that can occur asynchronously to the
1741          * unmount thread, and hence we need to ensure that completes before
1742          * tearing down the iclogbufs.  Hence we need to hold the buffer lock
1743          * across the log IO to archieve that.
1744          */
1745         down(&iclog->ic_sema);
1746         if (unlikely(iclog->ic_state == XLOG_STATE_IOERROR)) {
1747                 /*
1748                  * It would seem logical to return EIO here, but we rely on
1749                  * the log state machine to propagate I/O errors instead of
1750                  * doing it here.  We kick of the state machine and unlock
1751                  * the buffer manually, the code needs to be kept in sync
1752                  * with the I/O completion path.
1753                  */
1754                 xlog_state_done_syncing(iclog);
1755                 up(&iclog->ic_sema);
1756                 return;
1757         }
1758
1759         bio_init(&iclog->ic_bio, iclog->ic_bvec, howmany(count, PAGE_SIZE));
1760         bio_set_dev(&iclog->ic_bio, log->l_targ->bt_bdev);
1761         iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart + bno;
1762         iclog->ic_bio.bi_end_io = xlog_bio_end_io;
1763         iclog->ic_bio.bi_private = iclog;
1764         iclog->ic_bio.bi_opf = REQ_OP_WRITE | REQ_META | REQ_SYNC | REQ_FUA;
1765         if (need_flush)
1766                 iclog->ic_bio.bi_opf |= REQ_PREFLUSH;
1767
1768         if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) {
1769                 xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
1770                 return;
1771         }
1772         if (is_vmalloc_addr(iclog->ic_data))
1773                 flush_kernel_vmap_range(iclog->ic_data, count);
1774
1775         /*
1776          * If this log buffer would straddle the end of the log we will have
1777          * to split it up into two bios, so that we can continue at the start.
1778          */
1779         if (bno + BTOBB(count) > log->l_logBBsize) {
1780                 struct bio *split;
1781
1782                 split = bio_split(&iclog->ic_bio, log->l_logBBsize - bno,
1783                                   GFP_NOIO, &fs_bio_set);
1784                 bio_chain(split, &iclog->ic_bio);
1785                 submit_bio(split);
1786
1787                 /* restart at logical offset zero for the remainder */
1788                 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart;
1789         }
1790
1791         submit_bio(&iclog->ic_bio);
1792 }
1793
1794 /*
1795  * We need to bump cycle number for the part of the iclog that is
1796  * written to the start of the log. Watch out for the header magic
1797  * number case, though.
1798  */
1799 static void
1800 xlog_split_iclog(
1801         struct xlog             *log,
1802         void                    *data,
1803         uint64_t                bno,
1804         unsigned int            count)
1805 {
1806         unsigned int            split_offset = BBTOB(log->l_logBBsize - bno);
1807         unsigned int            i;
1808
1809         for (i = split_offset; i < count; i += BBSIZE) {
1810                 uint32_t cycle = get_unaligned_be32(data + i);
1811
1812                 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1813                         cycle++;
1814                 put_unaligned_be32(cycle, data + i);
1815         }
1816 }
1817
1818 static int
1819 xlog_calc_iclog_size(
1820         struct xlog             *log,
1821         struct xlog_in_core     *iclog,
1822         uint32_t                *roundoff)
1823 {
1824         uint32_t                count_init, count;
1825         bool                    use_lsunit;
1826
1827         use_lsunit = xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
1828                         log->l_mp->m_sb.sb_logsunit > 1;
1829
1830         /* Add for LR header */
1831         count_init = log->l_iclog_hsize + iclog->ic_offset;
1832
1833         /* Round out the log write size */
1834         if (use_lsunit) {
1835                 /* we have a v2 stripe unit to use */
1836                 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1837         } else {
1838                 count = BBTOB(BTOBB(count_init));
1839         }
1840
1841         ASSERT(count >= count_init);
1842         *roundoff = count - count_init;
1843
1844         if (use_lsunit)
1845                 ASSERT(*roundoff < log->l_mp->m_sb.sb_logsunit);
1846         else
1847                 ASSERT(*roundoff < BBTOB(1));
1848         return count;
1849 }
1850
1851 /*
1852  * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1853  * fashion.  Previously, we should have moved the current iclog
1854  * ptr in the log to point to the next available iclog.  This allows further
1855  * write to continue while this code syncs out an iclog ready to go.
1856  * Before an in-core log can be written out, the data section must be scanned
1857  * to save away the 1st word of each BBSIZE block into the header.  We replace
1858  * it with the current cycle count.  Each BBSIZE block is tagged with the
1859  * cycle count because there in an implicit assumption that drives will
1860  * guarantee that entire 512 byte blocks get written at once.  In other words,
1861  * we can't have part of a 512 byte block written and part not written.  By
1862  * tagging each block, we will know which blocks are valid when recovering
1863  * after an unclean shutdown.
1864  *
1865  * This routine is single threaded on the iclog.  No other thread can be in
1866  * this routine with the same iclog.  Changing contents of iclog can there-
1867  * fore be done without grabbing the state machine lock.  Updating the global
1868  * log will require grabbing the lock though.
1869  *
1870  * The entire log manager uses a logical block numbering scheme.  Only
1871  * xlog_write_iclog knows about the fact that the log may not start with
1872  * block zero on a given device.
1873  */
1874 STATIC void
1875 xlog_sync(
1876         struct xlog             *log,
1877         struct xlog_in_core     *iclog)
1878 {
1879         unsigned int            count;          /* byte count of bwrite */
1880         unsigned int            roundoff;       /* roundoff to BB or stripe */
1881         uint64_t                bno;
1882         unsigned int            size;
1883         bool                    need_flush = true, split = false;
1884
1885         ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1886
1887         count = xlog_calc_iclog_size(log, iclog, &roundoff);
1888
1889         /* move grant heads by roundoff in sync */
1890         xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
1891         xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
1892
1893         /* put cycle number in every block */
1894         xlog_pack_data(log, iclog, roundoff);
1895
1896         /* real byte length */
1897         size = iclog->ic_offset;
1898         if (xfs_sb_version_haslogv2(&log->l_mp->m_sb))
1899                 size += roundoff;
1900         iclog->ic_header.h_len = cpu_to_be32(size);
1901
1902         XFS_STATS_INC(log->l_mp, xs_log_writes);
1903         XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
1904
1905         bno = BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn));
1906
1907         /* Do we need to split this write into 2 parts? */
1908         if (bno + BTOBB(count) > log->l_logBBsize) {
1909                 xlog_split_iclog(log, &iclog->ic_header, bno, count);
1910                 split = true;
1911         }
1912
1913         /* calculcate the checksum */
1914         iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
1915                                             iclog->ic_datap, size);
1916         /*
1917          * Intentionally corrupt the log record CRC based on the error injection
1918          * frequency, if defined. This facilitates testing log recovery in the
1919          * event of torn writes. Hence, set the IOABORT state to abort the log
1920          * write on I/O completion and shutdown the fs. The subsequent mount
1921          * detects the bad CRC and attempts to recover.
1922          */
1923 #ifdef DEBUG
1924         if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) {
1925                 iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA);
1926                 iclog->ic_fail_crc = true;
1927                 xfs_warn(log->l_mp,
1928         "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
1929                          be64_to_cpu(iclog->ic_header.h_lsn));
1930         }
1931 #endif
1932
1933         /*
1934          * Flush the data device before flushing the log to make sure all meta
1935          * data written back from the AIL actually made it to disk before
1936          * stamping the new log tail LSN into the log buffer.  For an external
1937          * log we need to issue the flush explicitly, and unfortunately
1938          * synchronously here; for an internal log we can simply use the block
1939          * layer state machine for preflushes.
1940          */
1941         if (log->l_targ != log->l_mp->m_ddev_targp || split) {
1942                 xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
1943                 need_flush = false;
1944         }
1945
1946         xlog_verify_iclog(log, iclog, count);
1947         xlog_write_iclog(log, iclog, bno, count, need_flush);
1948 }
1949
1950 /*
1951  * Deallocate a log structure
1952  */
1953 STATIC void
1954 xlog_dealloc_log(
1955         struct xlog     *log)
1956 {
1957         xlog_in_core_t  *iclog, *next_iclog;
1958         int             i;
1959
1960         xlog_cil_destroy(log);
1961
1962         /*
1963          * Cycle all the iclogbuf locks to make sure all log IO completion
1964          * is done before we tear down these buffers.
1965          */
1966         iclog = log->l_iclog;
1967         for (i = 0; i < log->l_iclog_bufs; i++) {
1968                 down(&iclog->ic_sema);
1969                 up(&iclog->ic_sema);
1970                 iclog = iclog->ic_next;
1971         }
1972
1973         iclog = log->l_iclog;
1974         for (i = 0; i < log->l_iclog_bufs; i++) {
1975                 next_iclog = iclog->ic_next;
1976                 kmem_free(iclog->ic_data);
1977                 kmem_free(iclog);
1978                 iclog = next_iclog;
1979         }
1980
1981         log->l_mp->m_log = NULL;
1982         destroy_workqueue(log->l_ioend_workqueue);
1983         kmem_free(log);
1984 }       /* xlog_dealloc_log */
1985
1986 /*
1987  * Update counters atomically now that memcpy is done.
1988  */
1989 static inline void
1990 xlog_state_finish_copy(
1991         struct xlog             *log,
1992         struct xlog_in_core     *iclog,
1993         int                     record_cnt,
1994         int                     copy_bytes)
1995 {
1996         lockdep_assert_held(&log->l_icloglock);
1997
1998         be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
1999         iclog->ic_offset += copy_bytes;
2000 }
2001
2002 /*
2003  * print out info relating to regions written which consume
2004  * the reservation
2005  */
2006 void
2007 xlog_print_tic_res(
2008         struct xfs_mount        *mp,
2009         struct xlog_ticket      *ticket)
2010 {
2011         uint i;
2012         uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
2013
2014         /* match with XLOG_REG_TYPE_* in xfs_log.h */
2015 #define REG_TYPE_STR(type, str) [XLOG_REG_TYPE_##type] = str
2016         static char *res_type_str[] = {
2017             REG_TYPE_STR(BFORMAT, "bformat"),
2018             REG_TYPE_STR(BCHUNK, "bchunk"),
2019             REG_TYPE_STR(EFI_FORMAT, "efi_format"),
2020             REG_TYPE_STR(EFD_FORMAT, "efd_format"),
2021             REG_TYPE_STR(IFORMAT, "iformat"),
2022             REG_TYPE_STR(ICORE, "icore"),
2023             REG_TYPE_STR(IEXT, "iext"),
2024             REG_TYPE_STR(IBROOT, "ibroot"),
2025             REG_TYPE_STR(ILOCAL, "ilocal"),
2026             REG_TYPE_STR(IATTR_EXT, "iattr_ext"),
2027             REG_TYPE_STR(IATTR_BROOT, "iattr_broot"),
2028             REG_TYPE_STR(IATTR_LOCAL, "iattr_local"),
2029             REG_TYPE_STR(QFORMAT, "qformat"),
2030             REG_TYPE_STR(DQUOT, "dquot"),
2031             REG_TYPE_STR(QUOTAOFF, "quotaoff"),
2032             REG_TYPE_STR(LRHEADER, "LR header"),
2033             REG_TYPE_STR(UNMOUNT, "unmount"),
2034             REG_TYPE_STR(COMMIT, "commit"),
2035             REG_TYPE_STR(TRANSHDR, "trans header"),
2036             REG_TYPE_STR(ICREATE, "inode create"),
2037             REG_TYPE_STR(RUI_FORMAT, "rui_format"),
2038             REG_TYPE_STR(RUD_FORMAT, "rud_format"),
2039             REG_TYPE_STR(CUI_FORMAT, "cui_format"),
2040             REG_TYPE_STR(CUD_FORMAT, "cud_format"),
2041             REG_TYPE_STR(BUI_FORMAT, "bui_format"),
2042             REG_TYPE_STR(BUD_FORMAT, "bud_format"),
2043         };
2044         BUILD_BUG_ON(ARRAY_SIZE(res_type_str) != XLOG_REG_TYPE_MAX + 1);
2045 #undef REG_TYPE_STR
2046
2047         xfs_warn(mp, "ticket reservation summary:");
2048         xfs_warn(mp, "  unit res    = %d bytes",
2049                  ticket->t_unit_res);
2050         xfs_warn(mp, "  current res = %d bytes",
2051                  ticket->t_curr_res);
2052         xfs_warn(mp, "  total reg   = %u bytes (o/flow = %u bytes)",
2053                  ticket->t_res_arr_sum, ticket->t_res_o_flow);
2054         xfs_warn(mp, "  ophdrs      = %u (ophdr space = %u bytes)",
2055                  ticket->t_res_num_ophdrs, ophdr_spc);
2056         xfs_warn(mp, "  ophdr + reg = %u bytes",
2057                  ticket->t_res_arr_sum + ticket->t_res_o_flow + ophdr_spc);
2058         xfs_warn(mp, "  num regions = %u",
2059                  ticket->t_res_num);
2060
2061         for (i = 0; i < ticket->t_res_num; i++) {
2062                 uint r_type = ticket->t_res_arr[i].r_type;
2063                 xfs_warn(mp, "region[%u]: %s - %u bytes", i,
2064                             ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
2065                             "bad-rtype" : res_type_str[r_type]),
2066                             ticket->t_res_arr[i].r_len);
2067         }
2068 }
2069
2070 /*
2071  * Print a summary of the transaction.
2072  */
2073 void
2074 xlog_print_trans(
2075         struct xfs_trans        *tp)
2076 {
2077         struct xfs_mount        *mp = tp->t_mountp;
2078         struct xfs_log_item     *lip;
2079
2080         /* dump core transaction and ticket info */
2081         xfs_warn(mp, "transaction summary:");
2082         xfs_warn(mp, "  log res   = %d", tp->t_log_res);
2083         xfs_warn(mp, "  log count = %d", tp->t_log_count);
2084         xfs_warn(mp, "  flags     = 0x%x", tp->t_flags);
2085
2086         xlog_print_tic_res(mp, tp->t_ticket);
2087
2088         /* dump each log item */
2089         list_for_each_entry(lip, &tp->t_items, li_trans) {
2090                 struct xfs_log_vec      *lv = lip->li_lv;
2091                 struct xfs_log_iovec    *vec;
2092                 int                     i;
2093
2094                 xfs_warn(mp, "log item: ");
2095                 xfs_warn(mp, "  type    = 0x%x", lip->li_type);
2096                 xfs_warn(mp, "  flags   = 0x%lx", lip->li_flags);
2097                 if (!lv)
2098                         continue;
2099                 xfs_warn(mp, "  niovecs = %d", lv->lv_niovecs);
2100                 xfs_warn(mp, "  size    = %d", lv->lv_size);
2101                 xfs_warn(mp, "  bytes   = %d", lv->lv_bytes);
2102                 xfs_warn(mp, "  buf len = %d", lv->lv_buf_len);
2103
2104                 /* dump each iovec for the log item */
2105                 vec = lv->lv_iovecp;
2106                 for (i = 0; i < lv->lv_niovecs; i++) {
2107                         int dumplen = min(vec->i_len, 32);
2108
2109                         xfs_warn(mp, "  iovec[%d]", i);
2110                         xfs_warn(mp, "    type  = 0x%x", vec->i_type);
2111                         xfs_warn(mp, "    len   = %d", vec->i_len);
2112                         xfs_warn(mp, "    first %d bytes of iovec[%d]:", dumplen, i);
2113                         xfs_hex_dump(vec->i_addr, dumplen);
2114
2115                         vec++;
2116                 }
2117         }
2118 }
2119
2120 /*
2121  * Calculate the potential space needed by the log vector.  Each region gets
2122  * its own xlog_op_header_t and may need to be double word aligned.
2123  */
2124 static int
2125 xlog_write_calc_vec_length(
2126         struct xlog_ticket      *ticket,
2127         struct xfs_log_vec      *log_vector)
2128 {
2129         struct xfs_log_vec      *lv;
2130         int                     headers = 0;
2131         int                     len = 0;
2132         int                     i;
2133
2134         /* acct for start rec of xact */
2135         if (ticket->t_flags & XLOG_TIC_INITED)
2136                 headers++;
2137
2138         for (lv = log_vector; lv; lv = lv->lv_next) {
2139                 /* we don't write ordered log vectors */
2140                 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
2141                         continue;
2142
2143                 headers += lv->lv_niovecs;
2144
2145                 for (i = 0; i < lv->lv_niovecs; i++) {
2146                         struct xfs_log_iovec    *vecp = &lv->lv_iovecp[i];
2147
2148                         len += vecp->i_len;
2149                         xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
2150                 }
2151         }
2152
2153         ticket->t_res_num_ophdrs += headers;
2154         len += headers * sizeof(struct xlog_op_header);
2155
2156         return len;
2157 }
2158
2159 /*
2160  * If first write for transaction, insert start record  We can't be trying to
2161  * commit if we are inited.  We can't have any "partial_copy" if we are inited.
2162  */
2163 static int
2164 xlog_write_start_rec(
2165         struct xlog_op_header   *ophdr,
2166         struct xlog_ticket      *ticket)
2167 {
2168         if (!(ticket->t_flags & XLOG_TIC_INITED))
2169                 return 0;
2170
2171         ophdr->oh_tid   = cpu_to_be32(ticket->t_tid);
2172         ophdr->oh_clientid = ticket->t_clientid;
2173         ophdr->oh_len = 0;
2174         ophdr->oh_flags = XLOG_START_TRANS;
2175         ophdr->oh_res2 = 0;
2176
2177         ticket->t_flags &= ~XLOG_TIC_INITED;
2178
2179         return sizeof(struct xlog_op_header);
2180 }
2181
2182 static xlog_op_header_t *
2183 xlog_write_setup_ophdr(
2184         struct xlog             *log,
2185         struct xlog_op_header   *ophdr,
2186         struct xlog_ticket      *ticket,
2187         uint                    flags)
2188 {
2189         ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2190         ophdr->oh_clientid = ticket->t_clientid;
2191         ophdr->oh_res2 = 0;
2192
2193         /* are we copying a commit or unmount record? */
2194         ophdr->oh_flags = flags;
2195
2196         /*
2197          * We've seen logs corrupted with bad transaction client ids.  This
2198          * makes sure that XFS doesn't generate them on.  Turn this into an EIO
2199          * and shut down the filesystem.
2200          */
2201         switch (ophdr->oh_clientid)  {
2202         case XFS_TRANSACTION:
2203         case XFS_VOLUME:
2204         case XFS_LOG:
2205                 break;
2206         default:
2207                 xfs_warn(log->l_mp,
2208                         "Bad XFS transaction clientid 0x%x in ticket "PTR_FMT,
2209                         ophdr->oh_clientid, ticket);
2210                 return NULL;
2211         }
2212
2213         return ophdr;
2214 }
2215
2216 /*
2217  * Set up the parameters of the region copy into the log. This has
2218  * to handle region write split across multiple log buffers - this
2219  * state is kept external to this function so that this code can
2220  * be written in an obvious, self documenting manner.
2221  */
2222 static int
2223 xlog_write_setup_copy(
2224         struct xlog_ticket      *ticket,
2225         struct xlog_op_header   *ophdr,
2226         int                     space_available,
2227         int                     space_required,
2228         int                     *copy_off,
2229         int                     *copy_len,
2230         int                     *last_was_partial_copy,
2231         int                     *bytes_consumed)
2232 {
2233         int                     still_to_copy;
2234
2235         still_to_copy = space_required - *bytes_consumed;
2236         *copy_off = *bytes_consumed;
2237
2238         if (still_to_copy <= space_available) {
2239                 /* write of region completes here */
2240                 *copy_len = still_to_copy;
2241                 ophdr->oh_len = cpu_to_be32(*copy_len);
2242                 if (*last_was_partial_copy)
2243                         ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
2244                 *last_was_partial_copy = 0;
2245                 *bytes_consumed = 0;
2246                 return 0;
2247         }
2248
2249         /* partial write of region, needs extra log op header reservation */
2250         *copy_len = space_available;
2251         ophdr->oh_len = cpu_to_be32(*copy_len);
2252         ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2253         if (*last_was_partial_copy)
2254                 ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
2255         *bytes_consumed += *copy_len;
2256         (*last_was_partial_copy)++;
2257
2258         /* account for new log op header */
2259         ticket->t_curr_res -= sizeof(struct xlog_op_header);
2260         ticket->t_res_num_ophdrs++;
2261
2262         return sizeof(struct xlog_op_header);
2263 }
2264
2265 static int
2266 xlog_write_copy_finish(
2267         struct xlog             *log,
2268         struct xlog_in_core     *iclog,
2269         uint                    flags,
2270         int                     *record_cnt,
2271         int                     *data_cnt,
2272         int                     *partial_copy,
2273         int                     *partial_copy_len,
2274         int                     log_offset,
2275         struct xlog_in_core     **commit_iclog)
2276 {
2277         int                     error;
2278
2279         if (*partial_copy) {
2280                 /*
2281                  * This iclog has already been marked WANT_SYNC by
2282                  * xlog_state_get_iclog_space.
2283                  */
2284                 spin_lock(&log->l_icloglock);
2285                 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2286                 *record_cnt = 0;
2287                 *data_cnt = 0;
2288                 goto release_iclog;
2289         }
2290
2291         *partial_copy = 0;
2292         *partial_copy_len = 0;
2293
2294         if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
2295                 /* no more space in this iclog - push it. */
2296                 spin_lock(&log->l_icloglock);
2297                 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2298                 *record_cnt = 0;
2299                 *data_cnt = 0;
2300
2301                 if (iclog->ic_state == XLOG_STATE_ACTIVE)
2302                         xlog_state_switch_iclogs(log, iclog, 0);
2303                 else
2304                         ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2305                                iclog->ic_state == XLOG_STATE_IOERROR);
2306                 if (!commit_iclog)
2307                         goto release_iclog;
2308                 spin_unlock(&log->l_icloglock);
2309                 ASSERT(flags & XLOG_COMMIT_TRANS);
2310                 *commit_iclog = iclog;
2311         }
2312
2313         return 0;
2314
2315 release_iclog:
2316         error = xlog_state_release_iclog(log, iclog);
2317         spin_unlock(&log->l_icloglock);
2318         return error;
2319 }
2320
2321 /*
2322  * Write some region out to in-core log
2323  *
2324  * This will be called when writing externally provided regions or when
2325  * writing out a commit record for a given transaction.
2326  *
2327  * General algorithm:
2328  *      1. Find total length of this write.  This may include adding to the
2329  *              lengths passed in.
2330  *      2. Check whether we violate the tickets reservation.
2331  *      3. While writing to this iclog
2332  *          A. Reserve as much space in this iclog as can get
2333  *          B. If this is first write, save away start lsn
2334  *          C. While writing this region:
2335  *              1. If first write of transaction, write start record
2336  *              2. Write log operation header (header per region)
2337  *              3. Find out if we can fit entire region into this iclog
2338  *              4. Potentially, verify destination memcpy ptr
2339  *              5. Memcpy (partial) region
2340  *              6. If partial copy, release iclog; otherwise, continue
2341  *                      copying more regions into current iclog
2342  *      4. Mark want sync bit (in simulation mode)
2343  *      5. Release iclog for potential flush to on-disk log.
2344  *
2345  * ERRORS:
2346  * 1.   Panic if reservation is overrun.  This should never happen since
2347  *      reservation amounts are generated internal to the filesystem.
2348  * NOTES:
2349  * 1. Tickets are single threaded data structures.
2350  * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2351  *      syncing routine.  When a single log_write region needs to span
2352  *      multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2353  *      on all log operation writes which don't contain the end of the
2354  *      region.  The XLOG_END_TRANS bit is used for the in-core log
2355  *      operation which contains the end of the continued log_write region.
2356  * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2357  *      we don't really know exactly how much space will be used.  As a result,
2358  *      we don't update ic_offset until the end when we know exactly how many
2359  *      bytes have been written out.
2360  */
2361 int
2362 xlog_write(
2363         struct xlog             *log,
2364         struct xfs_log_vec      *log_vector,
2365         struct xlog_ticket      *ticket,
2366         xfs_lsn_t               *start_lsn,
2367         struct xlog_in_core     **commit_iclog,
2368         uint                    flags)
2369 {
2370         struct xlog_in_core     *iclog = NULL;
2371         struct xfs_log_iovec    *vecp;
2372         struct xfs_log_vec      *lv;
2373         int                     len;
2374         int                     index;
2375         int                     partial_copy = 0;
2376         int                     partial_copy_len = 0;
2377         int                     contwr = 0;
2378         int                     record_cnt = 0;
2379         int                     data_cnt = 0;
2380         int                     error = 0;
2381
2382         *start_lsn = 0;
2383
2384         len = xlog_write_calc_vec_length(ticket, log_vector);
2385
2386         /*
2387          * Region headers and bytes are already accounted for.
2388          * We only need to take into account start records and
2389          * split regions in this function.
2390          */
2391         if (ticket->t_flags & XLOG_TIC_INITED)
2392                 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2393
2394         /*
2395          * Commit record headers need to be accounted for. These
2396          * come in as separate writes so are easy to detect.
2397          */
2398         if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
2399                 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2400
2401         if (ticket->t_curr_res < 0) {
2402                 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
2403                      "ctx ticket reservation ran out. Need to up reservation");
2404                 xlog_print_tic_res(log->l_mp, ticket);
2405                 xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
2406         }
2407
2408         index = 0;
2409         lv = log_vector;
2410         vecp = lv->lv_iovecp;
2411         while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2412                 void            *ptr;
2413                 int             log_offset;
2414
2415                 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2416                                                    &contwr, &log_offset);
2417                 if (error)
2418                         return error;
2419
2420                 ASSERT(log_offset <= iclog->ic_size - 1);
2421                 ptr = iclog->ic_datap + log_offset;
2422
2423                 /* start_lsn is the first lsn written to. That's all we need. */
2424                 if (!*start_lsn)
2425                         *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2426
2427                 /*
2428                  * This loop writes out as many regions as can fit in the amount
2429                  * of space which was allocated by xlog_state_get_iclog_space().
2430                  */
2431                 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2432                         struct xfs_log_iovec    *reg;
2433                         struct xlog_op_header   *ophdr;
2434                         int                     start_rec_copy;
2435                         int                     copy_len;
2436                         int                     copy_off;
2437                         bool                    ordered = false;
2438
2439                         /* ordered log vectors have no regions to write */
2440                         if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
2441                                 ASSERT(lv->lv_niovecs == 0);
2442                                 ordered = true;
2443                                 goto next_lv;
2444                         }
2445
2446                         reg = &vecp[index];
2447                         ASSERT(reg->i_len % sizeof(int32_t) == 0);
2448                         ASSERT((unsigned long)ptr % sizeof(int32_t) == 0);
2449
2450                         start_rec_copy = xlog_write_start_rec(ptr, ticket);
2451                         if (start_rec_copy) {
2452                                 record_cnt++;
2453                                 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2454                                                    start_rec_copy);
2455                         }
2456
2457                         ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
2458                         if (!ophdr)
2459                                 return -EIO;
2460
2461                         xlog_write_adv_cnt(&ptr, &len, &log_offset,
2462                                            sizeof(struct xlog_op_header));
2463
2464                         len += xlog_write_setup_copy(ticket, ophdr,
2465                                                      iclog->ic_size-log_offset,
2466                                                      reg->i_len,
2467                                                      &copy_off, &copy_len,
2468                                                      &partial_copy,
2469                                                      &partial_copy_len);
2470                         xlog_verify_dest_ptr(log, ptr);
2471
2472                         /*
2473                          * Copy region.
2474                          *
2475                          * Unmount records just log an opheader, so can have
2476                          * empty payloads with no data region to copy. Hence we
2477                          * only copy the payload if the vector says it has data
2478                          * to copy.
2479                          */
2480                         ASSERT(copy_len >= 0);
2481                         if (copy_len > 0) {
2482                                 memcpy(ptr, reg->i_addr + copy_off, copy_len);
2483                                 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2484                                                    copy_len);
2485                         }
2486                         copy_len += start_rec_copy + sizeof(xlog_op_header_t);
2487                         record_cnt++;
2488                         data_cnt += contwr ? copy_len : 0;
2489
2490                         error = xlog_write_copy_finish(log, iclog, flags,
2491                                                        &record_cnt, &data_cnt,
2492                                                        &partial_copy,
2493                                                        &partial_copy_len,
2494                                                        log_offset,
2495                                                        commit_iclog);
2496                         if (error)
2497                                 return error;
2498
2499                         /*
2500                          * if we had a partial copy, we need to get more iclog
2501                          * space but we don't want to increment the region
2502                          * index because there is still more is this region to
2503                          * write.
2504                          *
2505                          * If we completed writing this region, and we flushed
2506                          * the iclog (indicated by resetting of the record
2507                          * count), then we also need to get more log space. If
2508                          * this was the last record, though, we are done and
2509                          * can just return.
2510                          */
2511                         if (partial_copy)
2512                                 break;
2513
2514                         if (++index == lv->lv_niovecs) {
2515 next_lv:
2516                                 lv = lv->lv_next;
2517                                 index = 0;
2518                                 if (lv)
2519                                         vecp = lv->lv_iovecp;
2520                         }
2521                         if (record_cnt == 0 && !ordered) {
2522                                 if (!lv)
2523                                         return 0;
2524                                 break;
2525                         }
2526                 }
2527         }
2528
2529         ASSERT(len == 0);
2530
2531         spin_lock(&log->l_icloglock);
2532         xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
2533         if (commit_iclog) {
2534                 ASSERT(flags & XLOG_COMMIT_TRANS);
2535                 *commit_iclog = iclog;
2536         } else {
2537                 error = xlog_state_release_iclog(log, iclog);
2538         }
2539         spin_unlock(&log->l_icloglock);
2540
2541         return error;
2542 }
2543
2544
2545 /*****************************************************************************
2546  *
2547  *              State Machine functions
2548  *
2549  *****************************************************************************
2550  */
2551
2552 static void
2553 xlog_state_activate_iclog(
2554         struct xlog_in_core     *iclog,
2555         int                     *iclogs_changed)
2556 {
2557         ASSERT(list_empty_careful(&iclog->ic_callbacks));
2558
2559         /*
2560          * If the number of ops in this iclog indicate it just contains the
2561          * dummy transaction, we can change state into IDLE (the second time
2562          * around). Otherwise we should change the state into NEED a dummy.
2563          * We don't need to cover the dummy.
2564          */
2565         if (*iclogs_changed == 0 &&
2566             iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) {
2567                 *iclogs_changed = 1;
2568         } else {
2569                 /*
2570                  * We have two dirty iclogs so start over.  This could also be
2571                  * num of ops indicating this is not the dummy going out.
2572                  */
2573                 *iclogs_changed = 2;
2574         }
2575
2576         iclog->ic_state = XLOG_STATE_ACTIVE;
2577         iclog->ic_offset = 0;
2578         iclog->ic_header.h_num_logops = 0;
2579         memset(iclog->ic_header.h_cycle_data, 0,
2580                 sizeof(iclog->ic_header.h_cycle_data));
2581         iclog->ic_header.h_lsn = 0;
2582 }
2583
2584 /*
2585  * Loop through all iclogs and mark all iclogs currently marked DIRTY as
2586  * ACTIVE after iclog I/O has completed.
2587  */
2588 static void
2589 xlog_state_activate_iclogs(
2590         struct xlog             *log,
2591         int                     *iclogs_changed)
2592 {
2593         struct xlog_in_core     *iclog = log->l_iclog;
2594
2595         do {
2596                 if (iclog->ic_state == XLOG_STATE_DIRTY)
2597                         xlog_state_activate_iclog(iclog, iclogs_changed);
2598                 /*
2599                  * The ordering of marking iclogs ACTIVE must be maintained, so
2600                  * an iclog doesn't become ACTIVE beyond one that is SYNCING.
2601                  */
2602                 else if (iclog->ic_state != XLOG_STATE_ACTIVE)
2603                         break;
2604         } while ((iclog = iclog->ic_next) != log->l_iclog);
2605 }
2606
2607 static int
2608 xlog_covered_state(
2609         int                     prev_state,
2610         int                     iclogs_changed)
2611 {
2612         /*
2613          * We usually go to NEED. But we go to NEED2 if the changed indicates we
2614          * are done writing the dummy record.  If we are done with the second
2615          * dummy recored (DONE2), then we go to IDLE.
2616          */
2617         switch (prev_state) {
2618         case XLOG_STATE_COVER_IDLE:
2619         case XLOG_STATE_COVER_NEED:
2620         case XLOG_STATE_COVER_NEED2:
2621                 break;
2622         case XLOG_STATE_COVER_DONE:
2623                 if (iclogs_changed == 1)
2624                         return XLOG_STATE_COVER_NEED2;
2625                 break;
2626         case XLOG_STATE_COVER_DONE2:
2627                 if (iclogs_changed == 1)
2628                         return XLOG_STATE_COVER_IDLE;
2629                 break;
2630         default:
2631                 ASSERT(0);
2632         }
2633
2634         return XLOG_STATE_COVER_NEED;
2635 }
2636
2637 STATIC void
2638 xlog_state_clean_iclog(
2639         struct xlog             *log,
2640         struct xlog_in_core     *dirty_iclog)
2641 {
2642         int                     iclogs_changed = 0;
2643
2644         dirty_iclog->ic_state = XLOG_STATE_DIRTY;
2645
2646         xlog_state_activate_iclogs(log, &iclogs_changed);
2647         wake_up_all(&dirty_iclog->ic_force_wait);
2648
2649         if (iclogs_changed) {
2650                 log->l_covered_state = xlog_covered_state(log->l_covered_state,
2651                                 iclogs_changed);
2652         }
2653 }
2654
2655 STATIC xfs_lsn_t
2656 xlog_get_lowest_lsn(
2657         struct xlog             *log)
2658 {
2659         struct xlog_in_core     *iclog = log->l_iclog;
2660         xfs_lsn_t               lowest_lsn = 0, lsn;
2661
2662         do {
2663                 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
2664                     iclog->ic_state == XLOG_STATE_DIRTY)
2665                         continue;
2666
2667                 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2668                 if ((lsn && !lowest_lsn) || XFS_LSN_CMP(lsn, lowest_lsn) < 0)
2669                         lowest_lsn = lsn;
2670         } while ((iclog = iclog->ic_next) != log->l_iclog);
2671
2672         return lowest_lsn;
2673 }
2674
2675 /*
2676  * Completion of a iclog IO does not imply that a transaction has completed, as
2677  * transactions can be large enough to span many iclogs. We cannot change the
2678  * tail of the log half way through a transaction as this may be the only
2679  * transaction in the log and moving the tail to point to the middle of it
2680  * will prevent recovery from finding the start of the transaction. Hence we
2681  * should only update the last_sync_lsn if this iclog contains transaction
2682  * completion callbacks on it.
2683  *
2684  * We have to do this before we drop the icloglock to ensure we are the only one
2685  * that can update it.
2686  *
2687  * If we are moving the last_sync_lsn forwards, we also need to ensure we kick
2688  * the reservation grant head pushing. This is due to the fact that the push
2689  * target is bound by the current last_sync_lsn value. Hence if we have a large
2690  * amount of log space bound up in this committing transaction then the
2691  * last_sync_lsn value may be the limiting factor preventing tail pushing from
2692  * freeing space in the log. Hence once we've updated the last_sync_lsn we
2693  * should push the AIL to ensure the push target (and hence the grant head) is
2694  * no longer bound by the old log head location and can move forwards and make
2695  * progress again.
2696  */
2697 static void
2698 xlog_state_set_callback(
2699         struct xlog             *log,
2700         struct xlog_in_core     *iclog,
2701         xfs_lsn_t               header_lsn)
2702 {
2703         iclog->ic_state = XLOG_STATE_CALLBACK;
2704
2705         ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2706                            header_lsn) <= 0);
2707
2708         if (list_empty_careful(&iclog->ic_callbacks))
2709                 return;
2710
2711         atomic64_set(&log->l_last_sync_lsn, header_lsn);
2712         xlog_grant_push_ail(log, 0);
2713 }
2714
2715 /*
2716  * Return true if we need to stop processing, false to continue to the next
2717  * iclog. The caller will need to run callbacks if the iclog is returned in the
2718  * XLOG_STATE_CALLBACK state.
2719  */
2720 static bool
2721 xlog_state_iodone_process_iclog(
2722         struct xlog             *log,
2723         struct xlog_in_core     *iclog,
2724         bool                    *ioerror)
2725 {
2726         xfs_lsn_t               lowest_lsn;
2727         xfs_lsn_t               header_lsn;
2728
2729         switch (iclog->ic_state) {
2730         case XLOG_STATE_ACTIVE:
2731         case XLOG_STATE_DIRTY:
2732                 /*
2733                  * Skip all iclogs in the ACTIVE & DIRTY states:
2734                  */
2735                 return false;
2736         case XLOG_STATE_IOERROR:
2737                 /*
2738                  * Between marking a filesystem SHUTDOWN and stopping the log,
2739                  * we do flush all iclogs to disk (if there wasn't a log I/O
2740                  * error). So, we do want things to go smoothly in case of just
2741                  * a SHUTDOWN w/o a LOG_IO_ERROR.
2742                  */
2743                 *ioerror = true;
2744                 return false;
2745         case XLOG_STATE_DONE_SYNC:
2746                 /*
2747                  * Now that we have an iclog that is in the DONE_SYNC state, do
2748                  * one more check here to see if we have chased our tail around.
2749                  * If this is not the lowest lsn iclog, then we will leave it
2750                  * for another completion to process.
2751                  */
2752                 header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2753                 lowest_lsn = xlog_get_lowest_lsn(log);
2754                 if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
2755                         return false;
2756                 xlog_state_set_callback(log, iclog, header_lsn);
2757                 return false;
2758         default:
2759                 /*
2760                  * Can only perform callbacks in order.  Since this iclog is not
2761                  * in the DONE_SYNC state, we skip the rest and just try to
2762                  * clean up.
2763                  */
2764                 return true;
2765         }
2766 }
2767
2768 /*
2769  * Keep processing entries in the iclog callback list until we come around and
2770  * it is empty.  We need to atomically see that the list is empty and change the
2771  * state to DIRTY so that we don't miss any more callbacks being added.
2772  *
2773  * This function is called with the icloglock held and returns with it held. We
2774  * drop it while running callbacks, however, as holding it over thousands of
2775  * callbacks is unnecessary and causes excessive contention if we do.
2776  */
2777 static void
2778 xlog_state_do_iclog_callbacks(
2779         struct xlog             *log,
2780         struct xlog_in_core     *iclog)
2781                 __releases(&log->l_icloglock)
2782                 __acquires(&log->l_icloglock)
2783 {
2784         spin_unlock(&log->l_icloglock);
2785         spin_lock(&iclog->ic_callback_lock);
2786         while (!list_empty(&iclog->ic_callbacks)) {
2787                 LIST_HEAD(tmp);
2788
2789                 list_splice_init(&iclog->ic_callbacks, &tmp);
2790
2791                 spin_unlock(&iclog->ic_callback_lock);
2792                 xlog_cil_process_committed(&tmp);
2793                 spin_lock(&iclog->ic_callback_lock);
2794         }
2795
2796         /*
2797          * Pick up the icloglock while still holding the callback lock so we
2798          * serialise against anyone trying to add more callbacks to this iclog
2799          * now we've finished processing.
2800          */
2801         spin_lock(&log->l_icloglock);
2802         spin_unlock(&iclog->ic_callback_lock);
2803 }
2804
2805 STATIC void
2806 xlog_state_do_callback(
2807         struct xlog             *log)
2808 {
2809         struct xlog_in_core     *iclog;
2810         struct xlog_in_core     *first_iclog;
2811         bool                    cycled_icloglock;
2812         bool                    ioerror;
2813         int                     flushcnt = 0;
2814         int                     repeats = 0;
2815
2816         spin_lock(&log->l_icloglock);
2817         do {
2818                 /*
2819                  * Scan all iclogs starting with the one pointed to by the
2820                  * log.  Reset this starting point each time the log is
2821                  * unlocked (during callbacks).
2822                  *
2823                  * Keep looping through iclogs until one full pass is made
2824                  * without running any callbacks.
2825                  */
2826                 first_iclog = log->l_iclog;
2827                 iclog = log->l_iclog;
2828                 cycled_icloglock = false;
2829                 ioerror = false;
2830                 repeats++;
2831
2832                 do {
2833                         if (xlog_state_iodone_process_iclog(log, iclog,
2834                                                         &ioerror))
2835                                 break;
2836
2837                         if (iclog->ic_state != XLOG_STATE_CALLBACK &&
2838                             iclog->ic_state != XLOG_STATE_IOERROR) {
2839                                 iclog = iclog->ic_next;
2840                                 continue;
2841                         }
2842
2843                         /*
2844                          * Running callbacks will drop the icloglock which means
2845                          * we'll have to run at least one more complete loop.
2846                          */
2847                         cycled_icloglock = true;
2848                         xlog_state_do_iclog_callbacks(log, iclog);
2849                         if (XLOG_FORCED_SHUTDOWN(log))
2850                                 wake_up_all(&iclog->ic_force_wait);
2851                         else
2852                                 xlog_state_clean_iclog(log, iclog);
2853                         iclog = iclog->ic_next;
2854                 } while (first_iclog != iclog);
2855
2856                 if (repeats > 5000) {
2857                         flushcnt += repeats;
2858                         repeats = 0;
2859                         xfs_warn(log->l_mp,
2860                                 "%s: possible infinite loop (%d iterations)",
2861                                 __func__, flushcnt);
2862                 }
2863         } while (!ioerror && cycled_icloglock);
2864
2865         if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE ||
2866             log->l_iclog->ic_state == XLOG_STATE_IOERROR)
2867                 wake_up_all(&log->l_flush_wait);
2868
2869         spin_unlock(&log->l_icloglock);
2870 }
2871
2872
2873 /*
2874  * Finish transitioning this iclog to the dirty state.
2875  *
2876  * Make sure that we completely execute this routine only when this is
2877  * the last call to the iclog.  There is a good chance that iclog flushes,
2878  * when we reach the end of the physical log, get turned into 2 separate
2879  * calls to bwrite.  Hence, one iclog flush could generate two calls to this
2880  * routine.  By using the reference count bwritecnt, we guarantee that only
2881  * the second completion goes through.
2882  *
2883  * Callbacks could take time, so they are done outside the scope of the
2884  * global state machine log lock.
2885  */
2886 STATIC void
2887 xlog_state_done_syncing(
2888         struct xlog_in_core     *iclog)
2889 {
2890         struct xlog             *log = iclog->ic_log;
2891
2892         spin_lock(&log->l_icloglock);
2893         ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2894
2895         /*
2896          * If we got an error, either on the first buffer, or in the case of
2897          * split log writes, on the second, we shut down the file system and
2898          * no iclogs should ever be attempted to be written to disk again.
2899          */
2900         if (!XLOG_FORCED_SHUTDOWN(log)) {
2901                 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING);
2902                 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2903         }
2904
2905         /*
2906          * Someone could be sleeping prior to writing out the next
2907          * iclog buffer, we wake them all, one will get to do the
2908          * I/O, the others get to wait for the result.
2909          */
2910         wake_up_all(&iclog->ic_write_wait);
2911         spin_unlock(&log->l_icloglock);
2912         xlog_state_do_callback(log);    /* also cleans log */
2913 }
2914
2915 /*
2916  * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2917  * sleep.  We wait on the flush queue on the head iclog as that should be
2918  * the first iclog to complete flushing. Hence if all iclogs are syncing,
2919  * we will wait here and all new writes will sleep until a sync completes.
2920  *
2921  * The in-core logs are used in a circular fashion. They are not used
2922  * out-of-order even when an iclog past the head is free.
2923  *
2924  * return:
2925  *      * log_offset where xlog_write() can start writing into the in-core
2926  *              log's data space.
2927  *      * in-core log pointer to which xlog_write() should write.
2928  *      * boolean indicating this is a continued write to an in-core log.
2929  *              If this is the last write, then the in-core log's offset field
2930  *              needs to be incremented, depending on the amount of data which
2931  *              is copied.
2932  */
2933 STATIC int
2934 xlog_state_get_iclog_space(
2935         struct xlog             *log,
2936         int                     len,
2937         struct xlog_in_core     **iclogp,
2938         struct xlog_ticket      *ticket,
2939         int                     *continued_write,
2940         int                     *logoffsetp)
2941 {
2942         int               log_offset;
2943         xlog_rec_header_t *head;
2944         xlog_in_core_t    *iclog;
2945
2946 restart:
2947         spin_lock(&log->l_icloglock);
2948         if (XLOG_FORCED_SHUTDOWN(log)) {
2949                 spin_unlock(&log->l_icloglock);
2950                 return -EIO;
2951         }
2952
2953         iclog = log->l_iclog;
2954         if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2955                 XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
2956
2957                 /* Wait for log writes to have flushed */
2958                 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
2959                 goto restart;
2960         }
2961
2962         head = &iclog->ic_header;
2963
2964         atomic_inc(&iclog->ic_refcnt);  /* prevents sync */
2965         log_offset = iclog->ic_offset;
2966
2967         /* On the 1st write to an iclog, figure out lsn.  This works
2968          * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2969          * committing to.  If the offset is set, that's how many blocks
2970          * must be written.
2971          */
2972         if (log_offset == 0) {
2973                 ticket->t_curr_res -= log->l_iclog_hsize;
2974                 xlog_tic_add_region(ticket,
2975                                     log->l_iclog_hsize,
2976                                     XLOG_REG_TYPE_LRHEADER);
2977                 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
2978                 head->h_lsn = cpu_to_be64(
2979                         xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
2980                 ASSERT(log->l_curr_block >= 0);
2981         }
2982
2983         /* If there is enough room to write everything, then do it.  Otherwise,
2984          * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2985          * bit is on, so this will get flushed out.  Don't update ic_offset
2986          * until you know exactly how many bytes get copied.  Therefore, wait
2987          * until later to update ic_offset.
2988          *
2989          * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2990          * can fit into remaining data section.
2991          */
2992         if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2993                 int             error = 0;
2994
2995                 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2996
2997                 /*
2998                  * If we are the only one writing to this iclog, sync it to
2999                  * disk.  We need to do an atomic compare and decrement here to
3000                  * avoid racing with concurrent atomic_dec_and_lock() calls in
3001                  * xlog_state_release_iclog() when there is more than one
3002                  * reference to the iclog.
3003                  */
3004                 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1))
3005                         error = xlog_state_release_iclog(log, iclog);
3006                 spin_unlock(&log->l_icloglock);
3007                 if (error)
3008                         return error;
3009                 goto restart;
3010         }
3011
3012         /* Do we have enough room to write the full amount in the remainder
3013          * of this iclog?  Or must we continue a write on the next iclog and
3014          * mark this iclog as completely taken?  In the case where we switch
3015          * iclogs (to mark it taken), this particular iclog will release/sync
3016          * to disk in xlog_write().
3017          */
3018         if (len <= iclog->ic_size - iclog->ic_offset) {
3019                 *continued_write = 0;
3020                 iclog->ic_offset += len;
3021         } else {
3022                 *continued_write = 1;
3023                 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
3024         }
3025         *iclogp = iclog;
3026
3027         ASSERT(iclog->ic_offset <= iclog->ic_size);
3028         spin_unlock(&log->l_icloglock);
3029
3030         *logoffsetp = log_offset;
3031         return 0;
3032 }       /* xlog_state_get_iclog_space */
3033
3034 /* The first cnt-1 times through here we don't need to
3035  * move the grant write head because the permanent
3036  * reservation has reserved cnt times the unit amount.
3037  * Release part of current permanent unit reservation and
3038  * reset current reservation to be one units worth.  Also
3039  * move grant reservation head forward.
3040  */
3041 STATIC void
3042 xlog_regrant_reserve_log_space(
3043         struct xlog             *log,
3044         struct xlog_ticket      *ticket)
3045 {
3046         trace_xfs_log_regrant_reserve_enter(log, ticket);
3047
3048         if (ticket->t_cnt > 0)
3049                 ticket->t_cnt--;
3050
3051         xlog_grant_sub_space(log, &log->l_reserve_head.grant,
3052                                         ticket->t_curr_res);
3053         xlog_grant_sub_space(log, &log->l_write_head.grant,
3054                                         ticket->t_curr_res);
3055         ticket->t_curr_res = ticket->t_unit_res;
3056         xlog_tic_reset_res(ticket);
3057
3058         trace_xfs_log_regrant_reserve_sub(log, ticket);
3059
3060         /* just return if we still have some of the pre-reserved space */
3061         if (ticket->t_cnt > 0)
3062                 return;
3063
3064         xlog_grant_add_space(log, &log->l_reserve_head.grant,
3065                                         ticket->t_unit_res);
3066
3067         trace_xfs_log_regrant_reserve_exit(log, ticket);
3068
3069         ticket->t_curr_res = ticket->t_unit_res;
3070         xlog_tic_reset_res(ticket);
3071 }       /* xlog_regrant_reserve_log_space */
3072
3073
3074 /*
3075  * Give back the space left from a reservation.
3076  *
3077  * All the information we need to make a correct determination of space left
3078  * is present.  For non-permanent reservations, things are quite easy.  The
3079  * count should have been decremented to zero.  We only need to deal with the
3080  * space remaining in the current reservation part of the ticket.  If the
3081  * ticket contains a permanent reservation, there may be left over space which
3082  * needs to be released.  A count of N means that N-1 refills of the current
3083  * reservation can be done before we need to ask for more space.  The first
3084  * one goes to fill up the first current reservation.  Once we run out of
3085  * space, the count will stay at zero and the only space remaining will be
3086  * in the current reservation field.
3087  */
3088 STATIC void
3089 xlog_ungrant_log_space(
3090         struct xlog             *log,
3091         struct xlog_ticket      *ticket)
3092 {
3093         int     bytes;
3094
3095         if (ticket->t_cnt > 0)
3096                 ticket->t_cnt--;
3097
3098         trace_xfs_log_ungrant_enter(log, ticket);
3099         trace_xfs_log_ungrant_sub(log, ticket);
3100
3101         /*
3102          * If this is a permanent reservation ticket, we may be able to free
3103          * up more space based on the remaining count.
3104          */
3105         bytes = ticket->t_curr_res;
3106         if (ticket->t_cnt > 0) {
3107                 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
3108                 bytes += ticket->t_unit_res*ticket->t_cnt;
3109         }
3110
3111         xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
3112         xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
3113
3114         trace_xfs_log_ungrant_exit(log, ticket);
3115
3116         xfs_log_space_wake(log->l_mp);
3117 }
3118
3119 /*
3120  * Mark the current iclog in the ring as WANT_SYNC and move the current iclog
3121  * pointer to the next iclog in the ring.
3122  *
3123  * When called from xlog_state_get_iclog_space(), the exact size of the iclog
3124  * has not yet been determined, all we know is that we have run out of space in
3125  * the current iclog.
3126  */
3127 STATIC void
3128 xlog_state_switch_iclogs(
3129         struct xlog             *log,
3130         struct xlog_in_core     *iclog,
3131         int                     eventual_size)
3132 {
3133         ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3134         assert_spin_locked(&log->l_icloglock);
3135
3136         if (!eventual_size)
3137                 eventual_size = iclog->ic_offset;
3138         iclog->ic_state = XLOG_STATE_WANT_SYNC;
3139         iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3140         log->l_prev_block = log->l_curr_block;
3141         log->l_prev_cycle = log->l_curr_cycle;
3142
3143         /* roll log?: ic_offset changed later */
3144         log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3145
3146         /* Round up to next log-sunit */
3147         if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3148             log->l_mp->m_sb.sb_logsunit > 1) {
3149                 uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
3150                 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3151         }
3152
3153         if (log->l_curr_block >= log->l_logBBsize) {
3154                 /*
3155                  * Rewind the current block before the cycle is bumped to make
3156                  * sure that the combined LSN never transiently moves forward
3157                  * when the log wraps to the next cycle. This is to support the
3158                  * unlocked sample of these fields from xlog_valid_lsn(). Most
3159                  * other cases should acquire l_icloglock.
3160                  */
3161                 log->l_curr_block -= log->l_logBBsize;
3162                 ASSERT(log->l_curr_block >= 0);
3163                 smp_wmb();
3164                 log->l_curr_cycle++;
3165                 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3166                         log->l_curr_cycle++;
3167         }
3168         ASSERT(iclog == log->l_iclog);
3169         log->l_iclog = iclog->ic_next;
3170 }       /* xlog_state_switch_iclogs */
3171
3172 /*
3173  * Write out all data in the in-core log as of this exact moment in time.
3174  *
3175  * Data may be written to the in-core log during this call.  However,
3176  * we don't guarantee this data will be written out.  A change from past
3177  * implementation means this routine will *not* write out zero length LRs.
3178  *
3179  * Basically, we try and perform an intelligent scan of the in-core logs.
3180  * If we determine there is no flushable data, we just return.  There is no
3181  * flushable data if:
3182  *
3183  *      1. the current iclog is active and has no data; the previous iclog
3184  *              is in the active or dirty state.
3185  *      2. the current iclog is drity, and the previous iclog is in the
3186  *              active or dirty state.
3187  *
3188  * We may sleep if:
3189  *
3190  *      1. the current iclog is not in the active nor dirty state.
3191  *      2. the current iclog dirty, and the previous iclog is not in the
3192  *              active nor dirty state.
3193  *      3. the current iclog is active, and there is another thread writing
3194  *              to this particular iclog.
3195  *      4. a) the current iclog is active and has no other writers
3196  *         b) when we return from flushing out this iclog, it is still
3197  *              not in the active nor dirty state.
3198  */
3199 int
3200 xfs_log_force(
3201         struct xfs_mount        *mp,
3202         uint                    flags)
3203 {
3204         struct xlog             *log = mp->m_log;
3205         struct xlog_in_core     *iclog;
3206         xfs_lsn_t               lsn;
3207
3208         XFS_STATS_INC(mp, xs_log_force);
3209         trace_xfs_log_force(mp, 0, _RET_IP_);
3210
3211         xlog_cil_force(log);
3212
3213         spin_lock(&log->l_icloglock);
3214         iclog = log->l_iclog;
3215         if (iclog->ic_state == XLOG_STATE_IOERROR)
3216                 goto out_error;
3217
3218         if (iclog->ic_state == XLOG_STATE_DIRTY ||
3219             (iclog->ic_state == XLOG_STATE_ACTIVE &&
3220              atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) {
3221                 /*
3222                  * If the head is dirty or (active and empty), then we need to
3223                  * look at the previous iclog.
3224                  *
3225                  * If the previous iclog is active or dirty we are done.  There
3226                  * is nothing to sync out. Otherwise, we attach ourselves to the
3227                  * previous iclog and go to sleep.
3228                  */
3229                 iclog = iclog->ic_prev;
3230         } else if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3231                 if (atomic_read(&iclog->ic_refcnt) == 0) {
3232                         /*
3233                          * We are the only one with access to this iclog.
3234                          *
3235                          * Flush it out now.  There should be a roundoff of zero
3236                          * to show that someone has already taken care of the
3237                          * roundoff from the previous sync.
3238                          */
3239                         atomic_inc(&iclog->ic_refcnt);
3240                         lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3241                         xlog_state_switch_iclogs(log, iclog, 0);
3242                         if (xlog_state_release_iclog(log, iclog))
3243                                 goto out_error;
3244
3245                         if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn)
3246                                 goto out_unlock;
3247                 } else {
3248                         /*
3249                          * Someone else is writing to this iclog.
3250                          *
3251                          * Use its call to flush out the data.  However, the
3252                          * other thread may not force out this LR, so we mark
3253                          * it WANT_SYNC.
3254                          */
3255                         xlog_state_switch_iclogs(log, iclog, 0);
3256                 }
3257         } else {
3258                 /*
3259                  * If the head iclog is not active nor dirty, we just attach
3260                  * ourselves to the head and go to sleep if necessary.
3261                  */
3262                 ;
3263         }
3264
3265         if (flags & XFS_LOG_SYNC)
3266                 return xlog_wait_on_iclog(iclog);
3267 out_unlock:
3268         spin_unlock(&log->l_icloglock);
3269         return 0;
3270 out_error:
3271         spin_unlock(&log->l_icloglock);
3272         return -EIO;
3273 }
3274
3275 static int
3276 __xfs_log_force_lsn(
3277         struct xfs_mount        *mp,
3278         xfs_lsn_t               lsn,
3279         uint                    flags,
3280         int                     *log_flushed,
3281         bool                    already_slept)
3282 {
3283         struct xlog             *log = mp->m_log;
3284         struct xlog_in_core     *iclog;
3285
3286         spin_lock(&log->l_icloglock);
3287         iclog = log->l_iclog;
3288         if (iclog->ic_state == XLOG_STATE_IOERROR)
3289                 goto out_error;
3290
3291         while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3292                 iclog = iclog->ic_next;
3293                 if (iclog == log->l_iclog)
3294                         goto out_unlock;
3295         }
3296
3297         if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3298                 /*
3299                  * We sleep here if we haven't already slept (e.g. this is the
3300                  * first time we've looked at the correct iclog buf) and the
3301                  * buffer before us is going to be sync'ed.  The reason for this
3302                  * is that if we are doing sync transactions here, by waiting
3303                  * for the previous I/O to complete, we can allow a few more
3304                  * transactions into this iclog before we close it down.
3305                  *
3306                  * Otherwise, we mark the buffer WANT_SYNC, and bump up the
3307                  * refcnt so we can release the log (which drops the ref count).
3308                  * The state switch keeps new transaction commits from using
3309                  * this buffer.  When the current commits finish writing into
3310                  * the buffer, the refcount will drop to zero and the buffer
3311                  * will go out then.
3312                  */
3313                 if (!already_slept &&
3314                     (iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC ||
3315                      iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) {
3316                         XFS_STATS_INC(mp, xs_log_force_sleep);
3317
3318                         xlog_wait(&iclog->ic_prev->ic_write_wait,
3319                                         &log->l_icloglock);
3320                         return -EAGAIN;
3321                 }
3322                 atomic_inc(&iclog->ic_refcnt);
3323                 xlog_state_switch_iclogs(log, iclog, 0);
3324                 if (xlog_state_release_iclog(log, iclog))
3325                         goto out_error;
3326                 if (log_flushed)
3327                         *log_flushed = 1;
3328         }
3329
3330         if (flags & XFS_LOG_SYNC)
3331                 return xlog_wait_on_iclog(iclog);
3332 out_unlock:
3333         spin_unlock(&log->l_icloglock);
3334         return 0;
3335 out_error:
3336         spin_unlock(&log->l_icloglock);
3337         return -EIO;
3338 }
3339
3340 /*
3341  * Force the in-core log to disk for a specific LSN.
3342  *
3343  * Find in-core log with lsn.
3344  *      If it is in the DIRTY state, just return.
3345  *      If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3346  *              state and go to sleep or return.
3347  *      If it is in any other state, go to sleep or return.
3348  *
3349  * Synchronous forces are implemented with a wait queue.  All callers trying
3350  * to force a given lsn to disk must wait on the queue attached to the
3351  * specific in-core log.  When given in-core log finally completes its write
3352  * to disk, that thread will wake up all threads waiting on the queue.
3353  */
3354 int
3355 xfs_log_force_lsn(
3356         struct xfs_mount        *mp,
3357         xfs_lsn_t               lsn,
3358         uint                    flags,
3359         int                     *log_flushed)
3360 {
3361         int                     ret;
3362         ASSERT(lsn != 0);
3363
3364         XFS_STATS_INC(mp, xs_log_force);
3365         trace_xfs_log_force(mp, lsn, _RET_IP_);
3366
3367         lsn = xlog_cil_force_lsn(mp->m_log, lsn);
3368         if (lsn == NULLCOMMITLSN)
3369                 return 0;
3370
3371         ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, false);
3372         if (ret == -EAGAIN)
3373                 ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, true);
3374         return ret;
3375 }
3376
3377 /*****************************************************************************
3378  *
3379  *              TICKET functions
3380  *
3381  *****************************************************************************
3382  */
3383
3384 /*
3385  * Free a used ticket when its refcount falls to zero.
3386  */
3387 void
3388 xfs_log_ticket_put(
3389         xlog_ticket_t   *ticket)
3390 {
3391         ASSERT(atomic_read(&ticket->t_ref) > 0);
3392         if (atomic_dec_and_test(&ticket->t_ref))
3393                 kmem_cache_free(xfs_log_ticket_zone, ticket);
3394 }
3395
3396 xlog_ticket_t *
3397 xfs_log_ticket_get(
3398         xlog_ticket_t   *ticket)
3399 {
3400         ASSERT(atomic_read(&ticket->t_ref) > 0);
3401         atomic_inc(&ticket->t_ref);
3402         return ticket;
3403 }
3404
3405 /*
3406  * Figure out the total log space unit (in bytes) that would be
3407  * required for a log ticket.
3408  */
3409 int
3410 xfs_log_calc_unit_res(
3411         struct xfs_mount        *mp,
3412         int                     unit_bytes)
3413 {
3414         struct xlog             *log = mp->m_log;
3415         int                     iclog_space;
3416         uint                    num_headers;
3417
3418         /*
3419          * Permanent reservations have up to 'cnt'-1 active log operations
3420          * in the log.  A unit in this case is the amount of space for one
3421          * of these log operations.  Normal reservations have a cnt of 1
3422          * and their unit amount is the total amount of space required.
3423          *
3424          * The following lines of code account for non-transaction data
3425          * which occupy space in the on-disk log.
3426          *
3427          * Normal form of a transaction is:
3428          * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3429          * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3430          *
3431          * We need to account for all the leadup data and trailer data
3432          * around the transaction data.
3433          * And then we need to account for the worst case in terms of using
3434          * more space.
3435          * The worst case will happen if:
3436          * - the placement of the transaction happens to be such that the
3437          *   roundoff is at its maximum
3438          * - the transaction data is synced before the commit record is synced
3439          *   i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3440          *   Therefore the commit record is in its own Log Record.
3441          *   This can happen as the commit record is called with its
3442          *   own region to xlog_write().
3443          *   This then means that in the worst case, roundoff can happen for
3444          *   the commit-rec as well.
3445          *   The commit-rec is smaller than padding in this scenario and so it is
3446          *   not added separately.
3447          */
3448
3449         /* for trans header */
3450         unit_bytes += sizeof(xlog_op_header_t);
3451         unit_bytes += sizeof(xfs_trans_header_t);
3452
3453         /* for start-rec */
3454         unit_bytes += sizeof(xlog_op_header_t);
3455
3456         /*
3457          * for LR headers - the space for data in an iclog is the size minus
3458          * the space used for the headers. If we use the iclog size, then we
3459          * undercalculate the number of headers required.
3460          *
3461          * Furthermore - the addition of op headers for split-recs might
3462          * increase the space required enough to require more log and op
3463          * headers, so take that into account too.
3464          *
3465          * IMPORTANT: This reservation makes the assumption that if this
3466          * transaction is the first in an iclog and hence has the LR headers
3467          * accounted to it, then the remaining space in the iclog is
3468          * exclusively for this transaction.  i.e. if the transaction is larger
3469          * than the iclog, it will be the only thing in that iclog.
3470          * Fundamentally, this means we must pass the entire log vector to
3471          * xlog_write to guarantee this.
3472          */
3473         iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3474         num_headers = howmany(unit_bytes, iclog_space);
3475
3476         /* for split-recs - ophdrs added when data split over LRs */
3477         unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3478
3479         /* add extra header reservations if we overrun */
3480         while (!num_headers ||
3481                howmany(unit_bytes, iclog_space) > num_headers) {
3482                 unit_bytes += sizeof(xlog_op_header_t);
3483                 num_headers++;
3484         }
3485         unit_bytes += log->l_iclog_hsize * num_headers;
3486
3487         /* for commit-rec LR header - note: padding will subsume the ophdr */
3488         unit_bytes += log->l_iclog_hsize;
3489
3490         /* for roundoff padding for transaction data and one for commit record */
3491         if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) {
3492                 /* log su roundoff */
3493                 unit_bytes += 2 * mp->m_sb.sb_logsunit;
3494         } else {
3495                 /* BB roundoff */
3496                 unit_bytes += 2 * BBSIZE;
3497         }
3498
3499         return unit_bytes;
3500 }
3501
3502 /*
3503  * Allocate and initialise a new log ticket.
3504  */
3505 struct xlog_ticket *
3506 xlog_ticket_alloc(
3507         struct xlog             *log,
3508         int                     unit_bytes,
3509         int                     cnt,
3510         char                    client,
3511         bool                    permanent,
3512         xfs_km_flags_t          alloc_flags)
3513 {
3514         struct xlog_ticket      *tic;
3515         int                     unit_res;
3516
3517         tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
3518         if (!tic)
3519                 return NULL;
3520
3521         unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes);
3522
3523         atomic_set(&tic->t_ref, 1);
3524         tic->t_task             = current;
3525         INIT_LIST_HEAD(&tic->t_queue);
3526         tic->t_unit_res         = unit_res;
3527         tic->t_curr_res         = unit_res;
3528         tic->t_cnt              = cnt;
3529         tic->t_ocnt             = cnt;
3530         tic->t_tid              = prandom_u32();
3531         tic->t_clientid         = client;
3532         tic->t_flags            = XLOG_TIC_INITED;
3533         if (permanent)
3534                 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3535
3536         xlog_tic_reset_res(tic);
3537
3538         return tic;
3539 }
3540
3541
3542 /******************************************************************************
3543  *
3544  *              Log debug routines
3545  *
3546  ******************************************************************************
3547  */
3548 #if defined(DEBUG)
3549 /*
3550  * Make sure that the destination ptr is within the valid data region of
3551  * one of the iclogs.  This uses backup pointers stored in a different
3552  * part of the log in case we trash the log structure.
3553  */
3554 STATIC void
3555 xlog_verify_dest_ptr(
3556         struct xlog     *log,
3557         void            *ptr)
3558 {
3559         int i;
3560         int good_ptr = 0;
3561
3562         for (i = 0; i < log->l_iclog_bufs; i++) {
3563                 if (ptr >= log->l_iclog_bak[i] &&
3564                     ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
3565                         good_ptr++;
3566         }
3567
3568         if (!good_ptr)
3569                 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3570 }
3571
3572 /*
3573  * Check to make sure the grant write head didn't just over lap the tail.  If
3574  * the cycles are the same, we can't be overlapping.  Otherwise, make sure that
3575  * the cycles differ by exactly one and check the byte count.
3576  *
3577  * This check is run unlocked, so can give false positives. Rather than assert
3578  * on failures, use a warn-once flag and a panic tag to allow the admin to
3579  * determine if they want to panic the machine when such an error occurs. For
3580  * debug kernels this will have the same effect as using an assert but, unlinke
3581  * an assert, it can be turned off at runtime.
3582  */
3583 STATIC void
3584 xlog_verify_grant_tail(
3585         struct xlog     *log)
3586 {
3587         int             tail_cycle, tail_blocks;
3588         int             cycle, space;
3589
3590         xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3591         xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3592         if (tail_cycle != cycle) {
3593                 if (cycle - 1 != tail_cycle &&
3594                     !(log->l_flags & XLOG_TAIL_WARN)) {
3595                         xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3596                                 "%s: cycle - 1 != tail_cycle", __func__);
3597                         log->l_flags |= XLOG_TAIL_WARN;
3598                 }
3599
3600                 if (space > BBTOB(tail_blocks) &&
3601                     !(log->l_flags & XLOG_TAIL_WARN)) {
3602                         xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3603                                 "%s: space > BBTOB(tail_blocks)", __func__);
3604                         log->l_flags |= XLOG_TAIL_WARN;
3605                 }
3606         }
3607 }
3608
3609 /* check if it will fit */
3610 STATIC void
3611 xlog_verify_tail_lsn(
3612         struct xlog             *log,
3613         struct xlog_in_core     *iclog,
3614         xfs_lsn_t               tail_lsn)
3615 {
3616     int blocks;
3617
3618     if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3619         blocks =
3620             log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3621         if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3622                 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3623     } else {
3624         ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3625
3626         if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3627                 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3628
3629         blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3630         if (blocks < BTOBB(iclog->ic_offset) + 1)
3631                 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3632     }
3633 }       /* xlog_verify_tail_lsn */
3634
3635 /*
3636  * Perform a number of checks on the iclog before writing to disk.
3637  *
3638  * 1. Make sure the iclogs are still circular
3639  * 2. Make sure we have a good magic number
3640  * 3. Make sure we don't have magic numbers in the data
3641  * 4. Check fields of each log operation header for:
3642  *      A. Valid client identifier
3643  *      B. tid ptr value falls in valid ptr space (user space code)
3644  *      C. Length in log record header is correct according to the
3645  *              individual operation headers within record.
3646  * 5. When a bwrite will occur within 5 blocks of the front of the physical
3647  *      log, check the preceding blocks of the physical log to make sure all
3648  *      the cycle numbers agree with the current cycle number.
3649  */
3650 STATIC void
3651 xlog_verify_iclog(
3652         struct xlog             *log,
3653         struct xlog_in_core     *iclog,
3654         int                     count)
3655 {
3656         xlog_op_header_t        *ophead;
3657         xlog_in_core_t          *icptr;
3658         xlog_in_core_2_t        *xhdr;
3659         void                    *base_ptr, *ptr, *p;
3660         ptrdiff_t               field_offset;
3661         uint8_t                 clientid;
3662         int                     len, i, j, k, op_len;
3663         int                     idx;
3664
3665         /* check validity of iclog pointers */
3666         spin_lock(&log->l_icloglock);
3667         icptr = log->l_iclog;
3668         for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
3669                 ASSERT(icptr);
3670
3671         if (icptr != log->l_iclog)
3672                 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3673         spin_unlock(&log->l_icloglock);
3674
3675         /* check log magic numbers */
3676         if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3677                 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3678
3679         base_ptr = ptr = &iclog->ic_header;
3680         p = &iclog->ic_header;
3681         for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
3682                 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3683                         xfs_emerg(log->l_mp, "%s: unexpected magic num",
3684                                 __func__);
3685         }
3686
3687         /* check fields */
3688         len = be32_to_cpu(iclog->ic_header.h_num_logops);
3689         base_ptr = ptr = iclog->ic_datap;
3690         ophead = ptr;
3691         xhdr = iclog->ic_data;
3692         for (i = 0; i < len; i++) {
3693                 ophead = ptr;
3694
3695                 /* clientid is only 1 byte */
3696                 p = &ophead->oh_clientid;
3697                 field_offset = p - base_ptr;
3698                 if (field_offset & 0x1ff) {
3699                         clientid = ophead->oh_clientid;
3700                 } else {
3701                         idx = BTOBBT((char *)&ophead->oh_clientid - iclog->ic_datap);
3702                         if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3703                                 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3704                                 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3705                                 clientid = xlog_get_client_id(
3706                                         xhdr[j].hic_xheader.xh_cycle_data[k]);
3707                         } else {
3708                                 clientid = xlog_get_client_id(
3709                                         iclog->ic_header.h_cycle_data[idx]);
3710                         }
3711                 }
3712                 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3713                         xfs_warn(log->l_mp,
3714                                 "%s: invalid clientid %d op "PTR_FMT" offset 0x%lx",
3715                                 __func__, clientid, ophead,
3716                                 (unsigned long)field_offset);
3717
3718                 /* check length */
3719                 p = &ophead->oh_len;
3720                 field_offset = p - base_ptr;
3721                 if (field_offset & 0x1ff) {
3722                         op_len = be32_to_cpu(ophead->oh_len);
3723                 } else {
3724                         idx = BTOBBT((uintptr_t)&ophead->oh_len -
3725                                     (uintptr_t)iclog->ic_datap);
3726                         if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3727                                 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3728                                 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3729                                 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3730                         } else {
3731                                 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3732                         }
3733                 }
3734                 ptr += sizeof(xlog_op_header_t) + op_len;
3735         }
3736 }       /* xlog_verify_iclog */
3737 #endif
3738
3739 /*
3740  * Mark all iclogs IOERROR. l_icloglock is held by the caller.
3741  */
3742 STATIC int
3743 xlog_state_ioerror(
3744         struct xlog     *log)
3745 {
3746         xlog_in_core_t  *iclog, *ic;
3747
3748         iclog = log->l_iclog;
3749         if (iclog->ic_state != XLOG_STATE_IOERROR) {
3750                 /*
3751                  * Mark all the incore logs IOERROR.
3752                  * From now on, no log flushes will result.
3753                  */
3754                 ic = iclog;
3755                 do {
3756                         ic->ic_state = XLOG_STATE_IOERROR;
3757                         ic = ic->ic_next;
3758                 } while (ic != iclog);
3759                 return 0;
3760         }
3761         /*
3762          * Return non-zero, if state transition has already happened.
3763          */
3764         return 1;
3765 }
3766
3767 /*
3768  * This is called from xfs_force_shutdown, when we're forcibly
3769  * shutting down the filesystem, typically because of an IO error.
3770  * Our main objectives here are to make sure that:
3771  *      a. if !logerror, flush the logs to disk. Anything modified
3772  *         after this is ignored.
3773  *      b. the filesystem gets marked 'SHUTDOWN' for all interested
3774  *         parties to find out, 'atomically'.
3775  *      c. those who're sleeping on log reservations, pinned objects and
3776  *          other resources get woken up, and be told the bad news.
3777  *      d. nothing new gets queued up after (b) and (c) are done.
3778  *
3779  * Note: for the !logerror case we need to flush the regions held in memory out
3780  * to disk first. This needs to be done before the log is marked as shutdown,
3781  * otherwise the iclog writes will fail.
3782  */
3783 int
3784 xfs_log_force_umount(
3785         struct xfs_mount        *mp,
3786         int                     logerror)
3787 {
3788         struct xlog     *log;
3789         int             retval;
3790
3791         log = mp->m_log;
3792
3793         /*
3794          * If this happens during log recovery, don't worry about
3795          * locking; the log isn't open for business yet.
3796          */
3797         if (!log ||
3798             log->l_flags & XLOG_ACTIVE_RECOVERY) {
3799                 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3800                 if (mp->m_sb_bp)
3801                         mp->m_sb_bp->b_flags |= XBF_DONE;
3802                 return 0;
3803         }
3804
3805         /*
3806          * Somebody could've already done the hard work for us.
3807          * No need to get locks for this.
3808          */
3809         if (logerror && log->l_iclog->ic_state == XLOG_STATE_IOERROR) {
3810                 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3811                 return 1;
3812         }
3813
3814         /*
3815          * Flush all the completed transactions to disk before marking the log
3816          * being shut down. We need to do it in this order to ensure that
3817          * completed operations are safely on disk before we shut down, and that
3818          * we don't have to issue any buffer IO after the shutdown flags are set
3819          * to guarantee this.
3820          */
3821         if (!logerror)
3822                 xfs_log_force(mp, XFS_LOG_SYNC);
3823
3824         /*
3825          * mark the filesystem and the as in a shutdown state and wake
3826          * everybody up to tell them the bad news.
3827          */
3828         spin_lock(&log->l_icloglock);
3829         mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3830         if (mp->m_sb_bp)
3831                 mp->m_sb_bp->b_flags |= XBF_DONE;
3832
3833         /*
3834          * Mark the log and the iclogs with IO error flags to prevent any
3835          * further log IO from being issued or completed.
3836          */
3837         log->l_flags |= XLOG_IO_ERROR;
3838         retval = xlog_state_ioerror(log);
3839         spin_unlock(&log->l_icloglock);
3840
3841         /*
3842          * We don't want anybody waiting for log reservations after this. That
3843          * means we have to wake up everybody queued up on reserveq as well as
3844          * writeq.  In addition, we make sure in xlog_{re}grant_log_space that
3845          * we don't enqueue anything once the SHUTDOWN flag is set, and this
3846          * action is protected by the grant locks.
3847          */
3848         xlog_grant_head_wake_all(&log->l_reserve_head);
3849         xlog_grant_head_wake_all(&log->l_write_head);
3850
3851         /*
3852          * Wake up everybody waiting on xfs_log_force. Wake the CIL push first
3853          * as if the log writes were completed. The abort handling in the log
3854          * item committed callback functions will do this again under lock to
3855          * avoid races.
3856          */
3857         spin_lock(&log->l_cilp->xc_push_lock);
3858         wake_up_all(&log->l_cilp->xc_commit_wait);
3859         spin_unlock(&log->l_cilp->xc_push_lock);
3860         xlog_state_do_callback(log);
3861
3862         /* return non-zero if log IOERROR transition had already happened */
3863         return retval;
3864 }
3865
3866 STATIC int
3867 xlog_iclogs_empty(
3868         struct xlog     *log)
3869 {
3870         xlog_in_core_t  *iclog;
3871
3872         iclog = log->l_iclog;
3873         do {
3874                 /* endianness does not matter here, zero is zero in
3875                  * any language.
3876                  */
3877                 if (iclog->ic_header.h_num_logops)
3878                         return 0;
3879                 iclog = iclog->ic_next;
3880         } while (iclog != log->l_iclog);
3881         return 1;
3882 }
3883
3884 /*
3885  * Verify that an LSN stamped into a piece of metadata is valid. This is
3886  * intended for use in read verifiers on v5 superblocks.
3887  */
3888 bool
3889 xfs_log_check_lsn(
3890         struct xfs_mount        *mp,
3891         xfs_lsn_t               lsn)
3892 {
3893         struct xlog             *log = mp->m_log;
3894         bool                    valid;
3895
3896         /*
3897          * norecovery mode skips mount-time log processing and unconditionally
3898          * resets the in-core LSN. We can't validate in this mode, but
3899          * modifications are not allowed anyways so just return true.
3900          */
3901         if (mp->m_flags & XFS_MOUNT_NORECOVERY)
3902                 return true;
3903
3904         /*
3905          * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
3906          * handled by recovery and thus safe to ignore here.
3907          */
3908         if (lsn == NULLCOMMITLSN)
3909                 return true;
3910
3911         valid = xlog_valid_lsn(mp->m_log, lsn);
3912
3913         /* warn the user about what's gone wrong before verifier failure */
3914         if (!valid) {
3915                 spin_lock(&log->l_icloglock);
3916                 xfs_warn(mp,
3917 "Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
3918 "Please unmount and run xfs_repair (>= v4.3) to resolve.",
3919                          CYCLE_LSN(lsn), BLOCK_LSN(lsn),
3920                          log->l_curr_cycle, log->l_curr_block);
3921                 spin_unlock(&log->l_icloglock);
3922         }
3923
3924         return valid;
3925 }
3926
3927 bool
3928 xfs_log_in_recovery(
3929         struct xfs_mount        *mp)
3930 {
3931         struct xlog             *log = mp->m_log;
3932
3933         return log->l_flags & XLOG_ACTIVE_RECOVERY;
3934 }