fs/xfs/xfs_log.c

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_types.h"
  21 #include "xfs_log.h"
  22 #include "xfs_trans.h"
  23 #include "xfs_sb.h"
  24 #include "xfs_ag.h"
  25 #include "xfs_mount.h"
  26 #include "xfs_error.h"
  27 #include "xfs_log_priv.h"
  28 #include "xfs_buf_item.h"
  29 #include "xfs_bmap_btree.h"
  30 #include "xfs_alloc_btree.h"
  31 #include "xfs_ialloc_btree.h"
  32 #include "xfs_log_recover.h"
  33 #include "xfs_trans_priv.h"
  34 #include "xfs_dinode.h"
  35 #include "xfs_inode.h"
  36 #include "xfs_trace.h"
  37 #include "xfs_fsops.h"
  38 #include "xfs_cksum.h"
  39
  40 kmem_zone_t     *xfs_log_ticket_zone;
  41
  42 /* Local miscellaneous function prototypes */
  43 STATIC int
  44 xlog_commit_record(
  45         struct xlog             *log,
  46         struct xlog_ticket      *ticket,
  47         struct xlog_in_core     **iclog,
  48         xfs_lsn_t               *commitlsnp);
  49
  50 STATIC struct xlog *
  51 xlog_alloc_log(
  52         struct xfs_mount        *mp,
  53         struct xfs_buftarg      *log_target,
  54         xfs_daddr_t             blk_offset,
  55         int                     num_bblks);
  56 STATIC int
  57 xlog_space_left(
  58         struct xlog             *log,
  59         atomic64_t              *head);
  60 STATIC int
  61 xlog_sync(
  62         struct xlog             *log,
  63         struct xlog_in_core     *iclog);
  64 STATIC void
  65 xlog_dealloc_log(
  66         struct xlog             *log);
  67
  68 /* local state machine functions */
  69 STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
  70 STATIC void
  71 xlog_state_do_callback(
  72         struct xlog             *log,
  73         int                     aborted,
  74         struct xlog_in_core     *iclog);
  75 STATIC int
  76 xlog_state_get_iclog_space(
  77         struct xlog             *log,
  78         int                     len,
  79         struct xlog_in_core     **iclog,
  80         struct xlog_ticket      *ticket,
  81         int                     *continued_write,
  82         int                     *logoffsetp);
  83 STATIC int
  84 xlog_state_release_iclog(
  85         struct xlog             *log,
  86         struct xlog_in_core     *iclog);
  87 STATIC void
  88 xlog_state_switch_iclogs(
  89         struct xlog             *log,
  90         struct xlog_in_core     *iclog,
  91         int                     eventual_size);
  92 STATIC void
  93 xlog_state_want_sync(
  94         struct xlog             *log,
  95         struct xlog_in_core     *iclog);
  96
  97 STATIC void
  98 xlog_grant_push_ail(
  99         struct xlog             *log,
 100         int                     need_bytes);
 101 STATIC void
 102 xlog_regrant_reserve_log_space(
 103         struct xlog             *log,
 104         struct xlog_ticket      *ticket);
 105 STATIC void
 106 xlog_ungrant_log_space(
 107         struct xlog             *log,
 108         struct xlog_ticket      *ticket);
 109
 110 #if defined(DEBUG)
 111 STATIC void
 112 xlog_verify_dest_ptr(
 113         struct xlog             *log,
 114         char                    *ptr);
 115 STATIC void
 116 xlog_verify_grant_tail(
 117         struct xlog *log);
 118 STATIC void
 119 xlog_verify_iclog(
 120         struct xlog             *log,
 121         struct xlog_in_core     *iclog,
 122         int                     count,
 123         bool                    syncing);
 124 STATIC void
 125 xlog_verify_tail_lsn(
 126         struct xlog             *log,
 127         struct xlog_in_core     *iclog,
 128         xfs_lsn_t               tail_lsn);
 129 #else
 130 #define xlog_verify_dest_ptr(a,b)
 131 #define xlog_verify_grant_tail(a)
 132 #define xlog_verify_iclog(a,b,c,d)
 133 #define xlog_verify_tail_lsn(a,b,c)
 134 #endif
 135
 136 STATIC int
 137 xlog_iclogs_empty(
 138         struct xlog             *log);
 139
 140 static void
 141 xlog_grant_sub_space(
 142         struct xlog             *log,
 143         atomic64_t              *head,
 144         int                     bytes)
 145 {
 146         int64_t head_val = atomic64_read(head);
 147         int64_t new, old;
 148
 149         do {
 150                 int     cycle, space;
 151
 152                 xlog_crack_grant_head_val(head_val, &cycle, &space);
 153
 154                 space -= bytes;
 155                 if (space < 0) {
 156                         space += log->l_logsize;
 157                         cycle--;
 158                 }
 159
 160                 old = head_val;
 161                 new = xlog_assign_grant_head_val(cycle, space);
 162                 head_val = atomic64_cmpxchg(head, old, new);
 163         } while (head_val != old);
 164 }
 165
 166 static void
 167 xlog_grant_add_space(
 168         struct xlog             *log,
 169         atomic64_t              *head,
 170         int                     bytes)
 171 {
 172         int64_t head_val = atomic64_read(head);
 173         int64_t new, old;
 174
 175         do {
 176                 int             tmp;
 177                 int             cycle, space;
 178
 179                 xlog_crack_grant_head_val(head_val, &cycle, &space);
 180
 181                 tmp = log->l_logsize - space;
 182                 if (tmp > bytes)
 183                         space += bytes;
 184                 else {
 185                         space = bytes - tmp;
 186                         cycle++;
 187                 }
 188
 189                 old = head_val;
 190                 new = xlog_assign_grant_head_val(cycle, space);
 191                 head_val = atomic64_cmpxchg(head, old, new);
 192         } while (head_val != old);
 193 }
 194
 195 STATIC void
 196 xlog_grant_head_init(
 197         struct xlog_grant_head  *head)
 198 {
 199         xlog_assign_grant_head(&head->grant, 1, 0);
 200         INIT_LIST_HEAD(&head->waiters);
 201         spin_lock_init(&head->lock);
 202 }
 203
 204 STATIC void
 205 xlog_grant_head_wake_all(
 206         struct xlog_grant_head  *head)
 207 {
 208         struct xlog_ticket      *tic;
 209
 210         spin_lock(&head->lock);
 211         list_for_each_entry(tic, &head->waiters, t_queue)
 212                 wake_up_process(tic->t_task);
 213         spin_unlock(&head->lock);
 214 }
 215
 216 static inline int
 217 xlog_ticket_reservation(
 218         struct xlog             *log,
 219         struct xlog_grant_head  *head,
 220         struct xlog_ticket      *tic)
 221 {
 222         if (head == &log->l_write_head) {
 223                 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
 224                 return tic->t_unit_res;
 225         } else {
 226                 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
 227                         return tic->t_unit_res * tic->t_cnt;
 228                 else
 229                         return tic->t_unit_res;
 230         }
 231 }
 232
 233 STATIC bool
 234 xlog_grant_head_wake(
 235         struct xlog             *log,
 236         struct xlog_grant_head  *head,
 237         int                     *free_bytes)
 238 {
 239         struct xlog_ticket      *tic;
 240         int                     need_bytes;
 241
 242         list_for_each_entry(tic, &head->waiters, t_queue) {
 243                 need_bytes = xlog_ticket_reservation(log, head, tic);
 244                 if (*free_bytes < need_bytes)
 245                         return false;
 246
 247                 *free_bytes -= need_bytes;
 248                 trace_xfs_log_grant_wake_up(log, tic);
 249                 wake_up_process(tic->t_task);
 250         }
 251
 252         return true;
 253 }
 254
 255 STATIC int
 256 xlog_grant_head_wait(
 257         struct xlog             *log,
 258         struct xlog_grant_head  *head,
 259         struct xlog_ticket      *tic,
 260         int                     need_bytes)
 261 {
 262         list_add_tail(&tic->t_queue, &head->waiters);
 263
 264         do {
 265                 if (XLOG_FORCED_SHUTDOWN(log))
 266                         goto shutdown;
 267                 xlog_grant_push_ail(log, need_bytes);
 268
 269                 __set_current_state(TASK_UNINTERRUPTIBLE);
 270                 spin_unlock(&head->lock);
 271
 272                 XFS_STATS_INC(xs_sleep_logspace);
 273
 274                 trace_xfs_log_grant_sleep(log, tic);
 275                 schedule();
 276                 trace_xfs_log_grant_wake(log, tic);
 277
 278                 spin_lock(&head->lock);
 279                 if (XLOG_FORCED_SHUTDOWN(log))
 280                         goto shutdown;
 281         } while (xlog_space_left(log, &head->grant) < need_bytes);
 282
 283         list_del_init(&tic->t_queue);
 284         return 0;
 285 shutdown:
 286         list_del_init(&tic->t_queue);
 287         return XFS_ERROR(EIO);
 288 }
 289
 290 /*
 291  * Atomically get the log space required for a log ticket.
 292  *
 293  * Once a ticket gets put onto head->waiters, it will only return after the
 294  * needed reservation is satisfied.
 295  *
 296  * This function is structured so that it has a lock free fast path. This is
 297  * necessary because every new transaction reservation will come through this
 298  * path. Hence any lock will be globally hot if we take it unconditionally on
 299  * every pass.
 300  *
 301  * As tickets are only ever moved on and off head->waiters under head->lock, we
 302  * only need to take that lock if we are going to add the ticket to the queue
 303  * and sleep. We can avoid taking the lock if the ticket was never added to
 304  * head->waiters because the t_queue list head will be empty and we hold the
 305  * only reference to it so it can safely be checked unlocked.
 306  */
 307 STATIC int
 308 xlog_grant_head_check(
 309         struct xlog             *log,
 310         struct xlog_grant_head  *head,
 311         struct xlog_ticket      *tic,
 312         int                     *need_bytes)
 313 {
 314         int                     free_bytes;
 315         int                     error = 0;
 316
 317         ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
 318
 319         /*
 320          * If there are other waiters on the queue then give them a chance at
 321          * logspace before us.  Wake up the first waiters, if we do not wake
 322          * up all the waiters then go to sleep waiting for more free space,
 323          * otherwise try to get some space for this transaction.
 324          */
 325         *need_bytes = xlog_ticket_reservation(log, head, tic);
 326         free_bytes = xlog_space_left(log, &head->grant);
 327         if (!list_empty_careful(&head->waiters)) {
 328                 spin_lock(&head->lock);
 329                 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
 330                     free_bytes < *need_bytes) {
 331                         error = xlog_grant_head_wait(log, head, tic,
 332                                                      *need_bytes);
 333                 }
 334                 spin_unlock(&head->lock);
 335         } else if (free_bytes < *need_bytes) {
 336                 spin_lock(&head->lock);
 337                 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
 338                 spin_unlock(&head->lock);
 339         }
 340
 341         return error;
 342 }
 343
 344 static void
 345 xlog_tic_reset_res(xlog_ticket_t *tic)
 346 {
 347         tic->t_res_num = 0;
 348         tic->t_res_arr_sum = 0;
 349         tic->t_res_num_ophdrs = 0;
 350 }
 351
 352 static void
 353 xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
 354 {
 355         if (tic->t_res_num == XLOG_TIC_LEN_MAX) {
 356                 /* add to overflow and start again */
 357                 tic->t_res_o_flow += tic->t_res_arr_sum;
 358                 tic->t_res_num = 0;
 359                 tic->t_res_arr_sum = 0;
 360         }
 361
 362         tic->t_res_arr[tic->t_res_num].r_len = len;
 363         tic->t_res_arr[tic->t_res_num].r_type = type;
 364         tic->t_res_arr_sum += len;
 365         tic->t_res_num++;
 366 }
 367
 368 /*
 369  * Replenish the byte reservation required by moving the grant write head.
 370  */
 371 int
 372 xfs_log_regrant(
 373         struct xfs_mount        *mp,
 374         struct xlog_ticket      *tic)
 375 {
 376         struct xlog             *log = mp->m_log;
 377         int                     need_bytes;
 378         int                     error = 0;
 379
 380         if (XLOG_FORCED_SHUTDOWN(log))
 381                 return XFS_ERROR(EIO);
 382
 383         XFS_STATS_INC(xs_try_logspace);
 384
 385         /*
 386          * This is a new transaction on the ticket, so we need to change the
 387          * transaction ID so that the next transaction has a different TID in
 388          * the log. Just add one to the existing tid so that we can see chains
 389          * of rolling transactions in the log easily.
 390          */
 391         tic->t_tid++;
 392
 393         xlog_grant_push_ail(log, tic->t_unit_res);
 394
 395         tic->t_curr_res = tic->t_unit_res;
 396         xlog_tic_reset_res(tic);
 397
 398         if (tic->t_cnt > 0)
 399                 return 0;
 400
 401         trace_xfs_log_regrant(log, tic);
 402
 403         error = xlog_grant_head_check(log, &log->l_write_head, tic,
 404                                       &need_bytes);
 405         if (error)
 406                 goto out_error;
 407
 408         xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
 409         trace_xfs_log_regrant_exit(log, tic);
 410         xlog_verify_grant_tail(log);
 411         return 0;
 412
 413 out_error:
 414         /*
 415          * If we are failing, make sure the ticket doesn't have any current
 416          * reservations.  We don't want to add this back when the ticket/
 417          * transaction gets cancelled.
 418          */
 419         tic->t_curr_res = 0;
 420         tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
 421         return error;
 422 }
 423
 424 /*
 425  * Reserve log space and return a ticket corresponding the reservation.
 426  *
 427  * Each reservation is going to reserve extra space for a log record header.
 428  * When writes happen to the on-disk log, we don't subtract the length of the
 429  * log record header from any reservation.  By wasting space in each
 430  * reservation, we prevent over allocation problems.
 431  */
 432 int
 433 xfs_log_reserve(
 434         struct xfs_mount        *mp,
 435         int                     unit_bytes,
 436         int                     cnt,
 437         struct xlog_ticket      **ticp,
 438         __uint8_t               client,
 439         bool                    permanent,
 440         uint                    t_type)
 441 {
 442         struct xlog             *log = mp->m_log;
 443         struct xlog_ticket      *tic;
 444         int                     need_bytes;
 445         int                     error = 0;
 446
 447         ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
 448
 449         if (XLOG_FORCED_SHUTDOWN(log))
 450                 return XFS_ERROR(EIO);
 451
 452         XFS_STATS_INC(xs_try_logspace);
 453
 454         ASSERT(*ticp == NULL);
 455         tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
 456                                 KM_SLEEP | KM_MAYFAIL);
 457         if (!tic)
 458                 return XFS_ERROR(ENOMEM);
 459
 460         tic->t_trans_type = t_type;
 461         *ticp = tic;
 462
 463         xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
 464                                             : tic->t_unit_res);
 465
 466         trace_xfs_log_reserve(log, tic);
 467
 468         error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
 469                                       &need_bytes);
 470         if (error)
 471                 goto out_error;
 472
 473         xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
 474         xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
 475         trace_xfs_log_reserve_exit(log, tic);
 476         xlog_verify_grant_tail(log);
 477         return 0;
 478
 479 out_error:
 480         /*
 481          * If we are failing, make sure the ticket doesn't have any current
 482          * reservations.  We don't want to add this back when the ticket/
 483          * transaction gets cancelled.
 484          */
 485         tic->t_curr_res = 0;
 486         tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
 487         return error;
 488 }
 489
 490
 491 /*
 492  * NOTES:
 493  *
 494  *      1. currblock field gets updated at startup and after in-core logs
 495  *              marked as with WANT_SYNC.
 496  */
 497
 498 /*
 499  * This routine is called when a user of a log manager ticket is done with
 500  * the reservation.  If the ticket was ever used, then a commit record for
 501  * the associated transaction is written out as a log operation header with
 502  * no data.  The flag XLOG_TIC_INITED is set when the first write occurs with
 503  * a given ticket.  If the ticket was one with a permanent reservation, then
 504  * a few operations are done differently.  Permanent reservation tickets by
 505  * default don't release the reservation.  They just commit the current
 506  * transaction with the belief that the reservation is still needed.  A flag
 507  * must be passed in before permanent reservations are actually released.
 508  * When these type of tickets are not released, they need to be set into
 509  * the inited state again.  By doing this, a start record will be written
 510  * out when the next write occurs.
 511  */
 512 xfs_lsn_t
 513 xfs_log_done(
 514         struct xfs_mount        *mp,
 515         struct xlog_ticket      *ticket,
 516         struct xlog_in_core     **iclog,
 517         uint                    flags)
 518 {
 519         struct xlog             *log = mp->m_log;
 520         xfs_lsn_t               lsn = 0;
 521
 522         if (XLOG_FORCED_SHUTDOWN(log) ||
 523             /*
 524              * If nothing was ever written, don't write out commit record.
 525              * If we get an error, just continue and give back the log ticket.
 526              */
 527             (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
 528              (xlog_commit_record(log, ticket, iclog, &lsn)))) {
 529                 lsn = (xfs_lsn_t) -1;
 530                 if (ticket->t_flags & XLOG_TIC_PERM_RESERV) {
 531                         flags |= XFS_LOG_REL_PERM_RESERV;
 532                 }
 533         }
 534
 535
 536         if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0 ||
 537             (flags & XFS_LOG_REL_PERM_RESERV)) {
 538                 trace_xfs_log_done_nonperm(log, ticket);
 539
 540                 /*
 541                  * Release ticket if not permanent reservation or a specific
 542                  * request has been made to release a permanent reservation.
 543                  */
 544                 xlog_ungrant_log_space(log, ticket);
 545                 xfs_log_ticket_put(ticket);
 546         } else {
 547                 trace_xfs_log_done_perm(log, ticket);
 548
 549                 xlog_regrant_reserve_log_space(log, ticket);
 550                 /* If this ticket was a permanent reservation and we aren't
 551                  * trying to release it, reset the inited flags; so next time
 552                  * we write, a start record will be written out.
 553                  */
 554                 ticket->t_flags |= XLOG_TIC_INITED;
 555         }
 556
 557         return lsn;
 558 }
 559
 560 /*
 561  * Attaches a new iclog I/O completion callback routine during
 562  * transaction commit.  If the log is in error state, a non-zero
 563  * return code is handed back and the caller is responsible for
 564  * executing the callback at an appropriate time.
 565  */
 566 int
 567 xfs_log_notify(
 568         struct xfs_mount        *mp,
 569         struct xlog_in_core     *iclog,
 570         xfs_log_callback_t      *cb)
 571 {
 572         int     abortflg;
 573
 574         spin_lock(&iclog->ic_callback_lock);
 575         abortflg = (iclog->ic_state & XLOG_STATE_IOERROR);
 576         if (!abortflg) {
 577                 ASSERT_ALWAYS((iclog->ic_state == XLOG_STATE_ACTIVE) ||
 578                               (iclog->ic_state == XLOG_STATE_WANT_SYNC));
 579                 cb->cb_next = NULL;
 580                 *(iclog->ic_callback_tail) = cb;
 581                 iclog->ic_callback_tail = &(cb->cb_next);
 582         }
 583         spin_unlock(&iclog->ic_callback_lock);
 584         return abortflg;
 585 }
 586
 587 int
 588 xfs_log_release_iclog(
 589         struct xfs_mount        *mp,
 590         struct xlog_in_core     *iclog)
 591 {
 592         if (xlog_state_release_iclog(mp->m_log, iclog)) {
 593                 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
 594                 return EIO;
 595         }
 596
 597         return 0;
 598 }
 599
 600 /*
 601  * Mount a log filesystem
 602  *
 603  * mp           - ubiquitous xfs mount point structure
 604  * log_target   - buftarg of on-disk log device
 605  * blk_offset   - Start block # where block size is 512 bytes (BBSIZE)
 606  * num_bblocks  - Number of BBSIZE blocks in on-disk log
 607  *
 608  * Return error or zero.
 609  */
 610 int
 611 xfs_log_mount(
 612         xfs_mount_t     *mp,
 613         xfs_buftarg_t   *log_target,
 614         xfs_daddr_t     blk_offset,
 615         int             num_bblks)
 616 {
 617         int             error = 0;
 618         int             min_logfsbs;
 619
 620         if (!(mp->m_flags & XFS_MOUNT_NORECOVERY))
 621                 xfs_notice(mp, "Mounting Filesystem");
 622         else {
 623                 xfs_notice(mp,
 624 "Mounting filesystem in no-recovery mode.  Filesystem will be inconsistent.");
 625                 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
 626         }
 627
 628         mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
 629         if (IS_ERR(mp->m_log)) {
 630                 error = -PTR_ERR(mp->m_log);
 631                 goto out;
 632         }
 633
 634         /*
 635          * Validate the given log space and drop a critical message via syslog
 636          * if the log size is too small that would lead to some unexpected
 637          * situations in transaction log space reservation stage.
 638          *
 639          * Note: we can't just reject the mount if the validation fails.  This
 640          * would mean that people would have to downgrade their kernel just to
 641          * remedy the situation as there is no way to grow the log (short of
 642          * black magic surgery with xfs_db).
 643          *
 644          * We can, however, reject mounts for CRC format filesystems, as the
 645          * mkfs binary being used to make the filesystem should never create a
 646          * filesystem with a log that is too small.
 647          */
 648         min_logfsbs = xfs_log_calc_minimum_size(mp);
 649
 650         if (mp->m_sb.sb_logblocks < min_logfsbs) {
 651                 xfs_warn(mp,
 652                 "Log size %d blocks too small, minimum size is %d blocks",
 653                          mp->m_sb.sb_logblocks, min_logfsbs);
 654                 error = EINVAL;
 655         } else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) {
 656                 xfs_warn(mp,
 657                 "Log size %d blocks too large, maximum size is %lld blocks",
 658                          mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS);
 659                 error = EINVAL;
 660         } else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) {
 661                 xfs_warn(mp,
 662                 "log size %lld bytes too large, maximum size is %lld bytes",
 663                          XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
 664                          XFS_MAX_LOG_BYTES);
 665                 error = EINVAL;
 666         }
 667         if (error) {
 668                 if (xfs_sb_version_hascrc(&mp->m_sb)) {
 669                         xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
 670                         ASSERT(0);
 671                         goto out_free_log;
 672                 }
 673                 xfs_crit(mp,
 674 "Log size out of supported range. Continuing onwards, but if log hangs are\n"
 675 "experienced then please report this message in the bug report.");
 676         }
 677
 678         /*
 679          * Initialize the AIL now we have a log.
 680          */
 681         error = xfs_trans_ail_init(mp);
 682         if (error) {
 683                 xfs_warn(mp, "AIL initialisation failed: error %d", error);
 684                 goto out_free_log;
 685         }
 686         mp->m_log->l_ailp = mp->m_ail;
 687
 688         /*
 689          * skip log recovery on a norecovery mount.  pretend it all
 690          * just worked.
 691          */
 692         if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
 693                 int     readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
 694
 695                 if (readonly)
 696                         mp->m_flags &= ~XFS_MOUNT_RDONLY;
 697
 698                 error = xlog_recover(mp->m_log);
 699
 700                 if (readonly)
 701                         mp->m_flags |= XFS_MOUNT_RDONLY;
 702                 if (error) {
 703                         xfs_warn(mp, "log mount/recovery failed: error %d",
 704                                 error);
 705                         goto out_destroy_ail;
 706                 }
 707         }
 708
 709         /* Normal transactions can now occur */
 710         mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
 711
 712         /*
 713          * Now the log has been fully initialised and we know were our
 714          * space grant counters are, we can initialise the permanent ticket
 715          * needed for delayed logging to work.
 716          */
 717         xlog_cil_init_post_recovery(mp->m_log);
 718
 719         return 0;
 720
 721 out_destroy_ail:
 722         xfs_trans_ail_destroy(mp);
 723 out_free_log:
 724         xlog_dealloc_log(mp->m_log);
 725 out:
 726         return error;
 727 }
 728
 729 /*
 730  * Finish the recovery of the file system.  This is separate from the
 731  * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
 732  * in the root and real-time bitmap inodes between calling xfs_log_mount() and
 733  * here.
 734  *
 735  * If we finish recovery successfully, start the background log work. If we are
 736  * not doing recovery, then we have a RO filesystem and we don't need to start
 737  * it.
 738  */
 739 int
 740 xfs_log_mount_finish(xfs_mount_t *mp)
 741 {
 742         int     error = 0;
 743
 744         if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
 745                 error = xlog_recover_finish(mp->m_log);
 746                 if (!error)
 747                         xfs_log_work_queue(mp);
 748         } else {
 749                 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
 750         }
 751
 752
 753         return error;
 754 }
 755
 756 /*
 757  * Final log writes as part of unmount.
 758  *
 759  * Mark the filesystem clean as unmount happens.  Note that during relocation
 760  * this routine needs to be executed as part of source-bag while the
 761  * deallocation must not be done until source-end.
 762  */
 763
 764 /*
 765  * Unmount record used to have a string "Unmount filesystem--" in the
 766  * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
 767  * We just write the magic number now since that particular field isn't
 768  * currently architecture converted and "Unmount" is a bit foo.
 769  * As far as I know, there weren't any dependencies on the old behaviour.
 770  */
 771
 772 int
 773 xfs_log_unmount_write(xfs_mount_t *mp)
 774 {
 775         struct xlog      *log = mp->m_log;
 776         xlog_in_core_t   *iclog;
 777 #ifdef DEBUG
 778         xlog_in_core_t   *first_iclog;
 779 #endif
 780         xlog_ticket_t   *tic = NULL;
 781         xfs_lsn_t        lsn;
 782         int              error;
 783
 784         /*
 785          * Don't write out unmount record on read-only mounts.
 786          * Or, if we are doing a forced umount (typically because of IO errors).
 787          */
 788         if (mp->m_flags & XFS_MOUNT_RDONLY)
 789                 return 0;
 790
 791         error = _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
 792         ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log)));
 793
 794 #ifdef DEBUG
 795         first_iclog = iclog = log->l_iclog;
 796         do {
 797                 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
 798                         ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
 799                         ASSERT(iclog->ic_offset == 0);
 800                 }
 801                 iclog = iclog->ic_next;
 802         } while (iclog != first_iclog);
 803 #endif
 804         if (! (XLOG_FORCED_SHUTDOWN(log))) {
 805                 error = xfs_log_reserve(mp, 600, 1, &tic,
 806                                         XFS_LOG, 0, XLOG_UNMOUNT_REC_TYPE);
 807                 if (!error) {
 808                         /* the data section must be 32 bit size aligned */
 809                         struct {
 810                             __uint16_t magic;
 811                             __uint16_t pad1;
 812                             __uint32_t pad2; /* may as well make it 64 bits */
 813                         } magic = {
 814                                 .magic = XLOG_UNMOUNT_TYPE,
 815                         };
 816                         struct xfs_log_iovec reg = {
 817                                 .i_addr = &magic,
 818                                 .i_len = sizeof(magic),
 819                                 .i_type = XLOG_REG_TYPE_UNMOUNT,
 820                         };
 821                         struct xfs_log_vec vec = {
 822                                 .lv_niovecs = 1,
 823                                 .lv_iovecp = &reg,
 824                         };
 825
 826                         /* remove inited flag, and account for space used */
 827                         tic->t_flags = 0;
 828                         tic->t_curr_res -= sizeof(magic);
 829                         error = xlog_write(log, &vec, tic, &lsn,
 830                                            NULL, XLOG_UNMOUNT_TRANS);
 831                         /*
 832                          * At this point, we're umounting anyway,
 833                          * so there's no point in transitioning log state
 834                          * to IOERROR. Just continue...
 835                          */
 836                 }
 837
 838                 if (error)
 839                         xfs_alert(mp, "%s: unmount record failed", __func__);
 840
 841
 842                 spin_lock(&log->l_icloglock);
 843                 iclog = log->l_iclog;
 844                 atomic_inc(&iclog->ic_refcnt);
 845                 xlog_state_want_sync(log, iclog);
 846                 spin_unlock(&log->l_icloglock);
 847                 error = xlog_state_release_iclog(log, iclog);
 848
 849                 spin_lock(&log->l_icloglock);
 850                 if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
 851                       iclog->ic_state == XLOG_STATE_DIRTY)) {
 852                         if (!XLOG_FORCED_SHUTDOWN(log)) {
 853                                 xlog_wait(&iclog->ic_force_wait,
 854                                                         &log->l_icloglock);
 855                         } else {
 856                                 spin_unlock(&log->l_icloglock);
 857                         }
 858                 } else {
 859                         spin_unlock(&log->l_icloglock);
 860                 }
 861                 if (tic) {
 862                         trace_xfs_log_umount_write(log, tic);
 863                         xlog_ungrant_log_space(log, tic);
 864                         xfs_log_ticket_put(tic);
 865                 }
 866         } else {
 867                 /*
 868                  * We're already in forced_shutdown mode, couldn't
 869                  * even attempt to write out the unmount transaction.
 870                  *
 871                  * Go through the motions of sync'ing and releasing
 872                  * the iclog, even though no I/O will actually happen,
 873                  * we need to wait for other log I/Os that may already
 874                  * be in progress.  Do this as a separate section of
 875                  * code so we'll know if we ever get stuck here that
 876                  * we're in this odd situation of trying to unmount
 877                  * a file system that went into forced_shutdown as
 878                  * the result of an unmount..
 879                  */
 880                 spin_lock(&log->l_icloglock);
 881                 iclog = log->l_iclog;
 882                 atomic_inc(&iclog->ic_refcnt);
 883
 884                 xlog_state_want_sync(log, iclog);
 885                 spin_unlock(&log->l_icloglock);
 886                 error =  xlog_state_release_iclog(log, iclog);
 887
 888                 spin_lock(&log->l_icloglock);
 889
 890                 if ( ! (   iclog->ic_state == XLOG_STATE_ACTIVE
 891                         || iclog->ic_state == XLOG_STATE_DIRTY
 892                         || iclog->ic_state == XLOG_STATE_IOERROR) ) {
 893
 894                                 xlog_wait(&iclog->ic_force_wait,
 895                                                         &log->l_icloglock);
 896                 } else {
 897                         spin_unlock(&log->l_icloglock);
 898                 }
 899         }
 900
 901         return error;
 902 }       /* xfs_log_unmount_write */
 903
 904 /*
 905  * Empty the log for unmount/freeze.
 906  *
 907  * To do this, we first need to shut down the background log work so it is not
 908  * trying to cover the log as we clean up. We then need to unpin all objects in
 909  * the log so we can then flush them out. Once they have completed their IO and
 910  * run the callbacks removing themselves from the AIL, we can write the unmount
 911  * record.
 912  */
 913 void
 914 xfs_log_quiesce(
 915         struct xfs_mount        *mp)
 916 {
 917         cancel_delayed_work_sync(&mp->m_log->l_work);
 918         xfs_log_force(mp, XFS_LOG_SYNC);
 919
 920         /*
 921          * The superblock buffer is uncached and while xfs_ail_push_all_sync()
 922          * will push it, xfs_wait_buftarg() will not wait for it. Further,
 923          * xfs_buf_iowait() cannot be used because it was pushed with the
 924          * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
 925          * the IO to complete.
 926          */
 927         xfs_ail_push_all_sync(mp->m_ail);
 928         xfs_wait_buftarg(mp->m_ddev_targp);
 929         xfs_buf_lock(mp->m_sb_bp);
 930         xfs_buf_unlock(mp->m_sb_bp);
 931
 932         xfs_log_unmount_write(mp);
 933 }
 934
 935 /*
 936  * Shut down and release the AIL and Log.
 937  *
 938  * During unmount, we need to ensure we flush all the dirty metadata objects
 939  * from the AIL so that the log is empty before we write the unmount record to
 940  * the log. Once this is done, we can tear down the AIL and the log.
 941  */
 942 void
 943 xfs_log_unmount(
 944         struct xfs_mount        *mp)
 945 {
 946         xfs_log_quiesce(mp);
 947
 948         xfs_trans_ail_destroy(mp);
 949         xlog_dealloc_log(mp->m_log);
 950 }
 951
 952 void
 953 xfs_log_item_init(
 954         struct xfs_mount        *mp,
 955         struct xfs_log_item     *item,
 956         int                     type,
 957         const struct xfs_item_ops *ops)
 958 {
 959         item->li_mountp = mp;
 960         item->li_ailp = mp->m_ail;
 961         item->li_type = type;
 962         item->li_ops = ops;
 963         item->li_lv = NULL;
 964
 965         INIT_LIST_HEAD(&item->li_ail);
 966         INIT_LIST_HEAD(&item->li_cil);
 967 }
 968
 969 /*
 970  * Wake up processes waiting for log space after we have moved the log tail.
 971  */
 972 void
 973 xfs_log_space_wake(
 974         struct xfs_mount        *mp)
 975 {
 976         struct xlog             *log = mp->m_log;
 977         int                     free_bytes;
 978
 979         if (XLOG_FORCED_SHUTDOWN(log))
 980                 return;
 981
 982         if (!list_empty_careful(&log->l_write_head.waiters)) {
 983                 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
 984
 985                 spin_lock(&log->l_write_head.lock);
 986                 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
 987                 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
 988                 spin_unlock(&log->l_write_head.lock);
 989         }
 990
 991         if (!list_empty_careful(&log->l_reserve_head.waiters)) {
 992                 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
 993
 994                 spin_lock(&log->l_reserve_head.lock);
 995                 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
 996                 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
 997                 spin_unlock(&log->l_reserve_head.lock);
 998         }
 999 }
1000
1001 /*
1002  * Determine if we have a transaction that has gone to disk
1003  * that needs to be covered. To begin the transition to the idle state
1004  * firstly the log needs to be idle (no AIL and nothing in the iclogs).
1005  * If we are then in a state where covering is needed, the caller is informed
1006  * that dummy transactions are required to move the log into the idle state.
1007  *
1008  * Because this is called as part of the sync process, we should also indicate
1009  * that dummy transactions should be issued in anything but the covered or
1010  * idle states. This ensures that the log tail is accurately reflected in
1011  * the log at the end of the sync, hence if a crash occurrs avoids replay
1012  * of transactions where the metadata is already on disk.
1013  */
1014 int
1015 xfs_log_need_covered(xfs_mount_t *mp)
1016 {
1017         int             needed = 0;
1018         struct xlog     *log = mp->m_log;
1019
1020         if (!xfs_fs_writable(mp))
1021                 return 0;
1022
1023         spin_lock(&log->l_icloglock);
1024         switch (log->l_covered_state) {
1025         case XLOG_STATE_COVER_DONE:
1026         case XLOG_STATE_COVER_DONE2:
1027         case XLOG_STATE_COVER_IDLE:
1028                 break;
1029         case XLOG_STATE_COVER_NEED:
1030         case XLOG_STATE_COVER_NEED2:
1031                 if (!xfs_ail_min_lsn(log->l_ailp) &&
1032                     xlog_iclogs_empty(log)) {
1033                         if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1034                                 log->l_covered_state = XLOG_STATE_COVER_DONE;
1035                         else
1036                                 log->l_covered_state = XLOG_STATE_COVER_DONE2;
1037                 }
1038                 /* FALLTHRU */
1039         default:
1040                 needed = 1;
1041                 break;
1042         }
1043         spin_unlock(&log->l_icloglock);
1044         return needed;
1045 }
1046
1047 /*
1048  * We may be holding the log iclog lock upon entering this routine.
1049  */
1050 xfs_lsn_t
1051 xlog_assign_tail_lsn_locked(
1052         struct xfs_mount        *mp)
1053 {
1054         struct xlog             *log = mp->m_log;
1055         struct xfs_log_item     *lip;
1056         xfs_lsn_t               tail_lsn;
1057
1058         assert_spin_locked(&mp->m_ail->xa_lock);
1059
1060         /*
1061          * To make sure we always have a valid LSN for the log tail we keep
1062          * track of the last LSN which was committed in log->l_last_sync_lsn,
1063          * and use that when the AIL was empty.
1064          */
1065         lip = xfs_ail_min(mp->m_ail);
1066         if (lip)
1067                 tail_lsn = lip->li_lsn;
1068         else
1069                 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1070         atomic64_set(&log->l_tail_lsn, tail_lsn);
1071         return tail_lsn;
1072 }
1073
1074 xfs_lsn_t
1075 xlog_assign_tail_lsn(
1076         struct xfs_mount        *mp)
1077 {
1078         xfs_lsn_t               tail_lsn;
1079
1080         spin_lock(&mp->m_ail->xa_lock);
1081         tail_lsn = xlog_assign_tail_lsn_locked(mp);
1082         spin_unlock(&mp->m_ail->xa_lock);
1083
1084         return tail_lsn;
1085 }
1086
1087 /*
1088  * Return the space in the log between the tail and the head.  The head
1089  * is passed in the cycle/bytes formal parms.  In the special case where
1090  * the reserve head has wrapped passed the tail, this calculation is no
1091  * longer valid.  In this case, just return 0 which means there is no space
1092  * in the log.  This works for all places where this function is called
1093  * with the reserve head.  Of course, if the write head were to ever
1094  * wrap the tail, we should blow up.  Rather than catch this case here,
1095  * we depend on other ASSERTions in other parts of the code.   XXXmiken
1096  *
1097  * This code also handles the case where the reservation head is behind
1098  * the tail.  The details of this case are described below, but the end
1099  * result is that we return the size of the log as the amount of space left.
1100  */
1101 STATIC int
1102 xlog_space_left(
1103         struct xlog     *log,
1104         atomic64_t      *head)
1105 {
1106         int             free_bytes;
1107         int             tail_bytes;
1108         int             tail_cycle;
1109         int             head_cycle;
1110         int             head_bytes;
1111
1112         xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1113         xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1114         tail_bytes = BBTOB(tail_bytes);
1115         if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1116                 free_bytes = log->l_logsize - (head_bytes - tail_bytes);
1117         else if (tail_cycle + 1 < head_cycle)
1118                 return 0;
1119         else if (tail_cycle < head_cycle) {
1120                 ASSERT(tail_cycle == (head_cycle - 1));
1121                 free_bytes = tail_bytes - head_bytes;
1122         } else {
1123                 /*
1124                  * The reservation head is behind the tail.
1125                  * In this case we just want to return the size of the
1126                  * log as the amount of space left.
1127                  */
1128                 xfs_alert(log->l_mp,
1129                         "xlog_space_left: head behind tail\n"
1130                         "  tail_cycle = %d, tail_bytes = %d\n"
1131                         "  GH   cycle = %d, GH   bytes = %d",
1132                         tail_cycle, tail_bytes, head_cycle, head_bytes);
1133                 ASSERT(0);
1134                 free_bytes = log->l_logsize;
1135         }
1136         return free_bytes;
1137 }
1138
1139
1140 /*
1141  * Log function which is called when an io completes.
1142  *
1143  * The log manager needs its own routine, in order to control what
1144  * happens with the buffer after the write completes.
1145  */
1146 void
1147 xlog_iodone(xfs_buf_t *bp)
1148 {
1149         struct xlog_in_core     *iclog = bp->b_fspriv;
1150         struct xlog             *l = iclog->ic_log;
1151         int                     aborted = 0;
1152
1153         /*
1154          * Race to shutdown the filesystem if we see an error.
1155          */
1156         if (XFS_TEST_ERROR((xfs_buf_geterror(bp)), l->l_mp,
1157                         XFS_ERRTAG_IODONE_IOERR, XFS_RANDOM_IODONE_IOERR)) {
1158                 xfs_buf_ioerror_alert(bp, __func__);
1159                 xfs_buf_stale(bp);
1160                 xfs_force_shutdown(l->l_mp, SHUTDOWN_LOG_IO_ERROR);
1161                 /*
1162                  * This flag will be propagated to the trans-committed
1163                  * callback routines to let them know that the log-commit
1164                  * didn't succeed.
1165                  */
1166                 aborted = XFS_LI_ABORTED;
1167         } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
1168                 aborted = XFS_LI_ABORTED;
1169         }
1170
1171         /* log I/O is always issued ASYNC */
1172         ASSERT(XFS_BUF_ISASYNC(bp));
1173         xlog_state_done_syncing(iclog, aborted);
1174         /*
1175          * do not reference the buffer (bp) here as we could race
1176          * with it being freed after writing the unmount record to the
1177          * log.
1178          */
1179 }
1180
1181 /*
1182  * Return size of each in-core log record buffer.
1183  *
1184  * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1185  *
1186  * If the filesystem blocksize is too large, we may need to choose a
1187  * larger size since the directory code currently logs entire blocks.
1188  */
1189
1190 STATIC void
1191 xlog_get_iclog_buffer_size(
1192         struct xfs_mount        *mp,
1193         struct xlog             *log)
1194 {
1195         int size;
1196         int xhdrs;
1197
1198         if (mp->m_logbufs <= 0)
1199                 log->l_iclog_bufs = XLOG_MAX_ICLOGS;
1200         else
1201                 log->l_iclog_bufs = mp->m_logbufs;
1202
1203         /*
1204          * Buffer size passed in from mount system call.
1205          */
1206         if (mp->m_logbsize > 0) {
1207                 size = log->l_iclog_size = mp->m_logbsize;
1208                 log->l_iclog_size_log = 0;
1209                 while (size != 1) {
1210                         log->l_iclog_size_log++;
1211                         size >>= 1;
1212                 }
1213
1214                 if (xfs_sb_version_haslogv2(&mp->m_sb)) {
1215                         /* # headers = size / 32k
1216                          * one header holds cycles from 32k of data
1217                          */
1218
1219                         xhdrs = mp->m_logbsize / XLOG_HEADER_CYCLE_SIZE;
1220                         if (mp->m_logbsize % XLOG_HEADER_CYCLE_SIZE)
1221                                 xhdrs++;
1222                         log->l_iclog_hsize = xhdrs << BBSHIFT;
1223                         log->l_iclog_heads = xhdrs;
1224                 } else {
1225                         ASSERT(mp->m_logbsize <= XLOG_BIG_RECORD_BSIZE);
1226                         log->l_iclog_hsize = BBSIZE;
1227                         log->l_iclog_heads = 1;
1228                 }
1229                 goto done;
1230         }
1231
1232         /* All machines use 32kB buffers by default. */
1233         log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;
1234         log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
1235
1236         /* the default log size is 16k or 32k which is one header sector */
1237         log->l_iclog_hsize = BBSIZE;
1238         log->l_iclog_heads = 1;
1239
1240 done:
1241         /* are we being asked to make the sizes selected above visible? */
1242         if (mp->m_logbufs == 0)
1243                 mp->m_logbufs = log->l_iclog_bufs;
1244         if (mp->m_logbsize == 0)
1245                 mp->m_logbsize = log->l_iclog_size;
1246 }       /* xlog_get_iclog_buffer_size */
1247
1248
1249 void
1250 xfs_log_work_queue(
1251         struct xfs_mount        *mp)
1252 {
1253         queue_delayed_work(mp->m_log_workqueue, &mp->m_log->l_work,
1254                                 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1255 }
1256
1257 /*
1258  * Every sync period we need to unpin all items in the AIL and push them to
1259  * disk. If there is nothing dirty, then we might need to cover the log to
1260  * indicate that the filesystem is idle.
1261  */
1262 void
1263 xfs_log_worker(
1264         struct work_struct      *work)
1265 {
1266         struct xlog             *log = container_of(to_delayed_work(work),
1267                                                 struct xlog, l_work);
1268         struct xfs_mount        *mp = log->l_mp;
1269
1270         /* dgc: errors ignored - not fatal and nowhere to report them */
1271         if (xfs_log_need_covered(mp))
1272                 xfs_fs_log_dummy(mp);
1273         else
1274                 xfs_log_force(mp, 0);
1275
1276         /* start pushing all the metadata that is currently dirty */
1277         xfs_ail_push_all(mp->m_ail);
1278
1279         /* queue us up again */
1280         xfs_log_work_queue(mp);
1281 }
1282
1283 /*
1284  * This routine initializes some of the log structure for a given mount point.
1285  * Its primary purpose is to fill in enough, so recovery can occur.  However,
1286  * some other stuff may be filled in too.
1287  */
1288 STATIC struct xlog *
1289 xlog_alloc_log(
1290         struct xfs_mount        *mp,
1291         struct xfs_buftarg      *log_target,
1292         xfs_daddr_t             blk_offset,
1293         int                     num_bblks)
1294 {
1295         struct xlog             *log;
1296         xlog_rec_header_t       *head;
1297         xlog_in_core_t          **iclogp;
1298         xlog_in_core_t          *iclog, *prev_iclog=NULL;
1299         xfs_buf_t               *bp;
1300         int                     i;
1301         int                     error = ENOMEM;
1302         uint                    log2_size = 0;
1303
1304         log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1305         if (!log) {
1306                 xfs_warn(mp, "Log allocation failed: No memory!");
1307                 goto out;
1308         }
1309
1310         log->l_mp          = mp;
1311         log->l_targ        = log_target;
1312         log->l_logsize     = BBTOB(num_bblks);
1313         log->l_logBBstart  = blk_offset;
1314         log->l_logBBsize   = num_bblks;
1315         log->l_covered_state = XLOG_STATE_COVER_IDLE;
1316         log->l_flags       |= XLOG_ACTIVE_RECOVERY;
1317         INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1318
1319         log->l_prev_block  = -1;
1320         /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1321         xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1322         xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1323         log->l_curr_cycle  = 1;     /* 0 is bad since this is initial value */
1324
1325         xlog_grant_head_init(&log->l_reserve_head);
1326         xlog_grant_head_init(&log->l_write_head);
1327
1328         error = EFSCORRUPTED;
1329         if (xfs_sb_version_hassector(&mp->m_sb)) {
1330                 log2_size = mp->m_sb.sb_logsectlog;
1331                 if (log2_size < BBSHIFT) {
1332                         xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1333                                 log2_size, BBSHIFT);
1334                         goto out_free_log;
1335                 }
1336
1337                 log2_size -= BBSHIFT;
1338                 if (log2_size > mp->m_sectbb_log) {
1339                         xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1340                                 log2_size, mp->m_sectbb_log);
1341                         goto out_free_log;
1342                 }
1343
1344                 /* for larger sector sizes, must have v2 or external log */
1345                 if (log2_size && log->l_logBBstart > 0 &&
1346                             !xfs_sb_version_haslogv2(&mp->m_sb)) {
1347                         xfs_warn(mp,
1348                 "log sector size (0x%x) invalid for configuration.",
1349                                 log2_size);
1350                         goto out_free_log;
1351                 }
1352         }
1353         log->l_sectBBsize = 1 << log2_size;
1354
1355         xlog_get_iclog_buffer_size(mp, log);
1356
1357         error = ENOMEM;
1358         bp = xfs_buf_alloc(mp->m_logdev_targp, 0, BTOBB(log->l_iclog_size), 0);
1359         if (!bp)
1360                 goto out_free_log;
1361         bp->b_iodone = xlog_iodone;
1362         ASSERT(xfs_buf_islocked(bp));
1363         log->l_xbuf = bp;
1364
1365         spin_lock_init(&log->l_icloglock);
1366         init_waitqueue_head(&log->l_flush_wait);
1367
1368         iclogp = &log->l_iclog;
1369         /*
1370          * The amount of memory to allocate for the iclog structure is
1371          * rather funky due to the way the structure is defined.  It is
1372          * done this way so that we can use different sizes for machines
1373          * with different amounts of memory.  See the definition of
1374          * xlog_in_core_t in xfs_log_priv.h for details.
1375          */
1376         ASSERT(log->l_iclog_size >= 4096);
1377         for (i=0; i < log->l_iclog_bufs; i++) {
1378                 *iclogp = kmem_zalloc(sizeof(xlog_in_core_t), KM_MAYFAIL);
1379                 if (!*iclogp)
1380                         goto out_free_iclog;
1381
1382                 iclog = *iclogp;
1383                 iclog->ic_prev = prev_iclog;
1384                 prev_iclog = iclog;
1385
1386                 bp = xfs_buf_get_uncached(mp->m_logdev_targp,
1387                                                 BTOBB(log->l_iclog_size), 0);
1388                 if (!bp)
1389                         goto out_free_iclog;
1390
1391                 bp->b_iodone = xlog_iodone;
1392                 iclog->ic_bp = bp;
1393                 iclog->ic_data = bp->b_addr;
1394 #ifdef DEBUG
1395                 log->l_iclog_bak[i] = (xfs_caddr_t)&(iclog->ic_header);
1396 #endif
1397                 head = &iclog->ic_header;
1398                 memset(head, 0, sizeof(xlog_rec_header_t));
1399                 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1400                 head->h_version = cpu_to_be32(
1401                         xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
1402                 head->h_size = cpu_to_be32(log->l_iclog_size);
1403                 /* new fields */
1404                 head->h_fmt = cpu_to_be32(XLOG_FMT);
1405                 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1406
1407                 iclog->ic_size = BBTOB(bp->b_length) - log->l_iclog_hsize;
1408                 iclog->ic_state = XLOG_STATE_ACTIVE;
1409                 iclog->ic_log = log;
1410                 atomic_set(&iclog->ic_refcnt, 0);
1411                 spin_lock_init(&iclog->ic_callback_lock);
1412                 iclog->ic_callback_tail = &(iclog->ic_callback);
1413                 iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
1414
1415                 ASSERT(xfs_buf_islocked(iclog->ic_bp));
1416                 init_waitqueue_head(&iclog->ic_force_wait);
1417                 init_waitqueue_head(&iclog->ic_write_wait);
1418
1419                 iclogp = &iclog->ic_next;
1420         }
1421         *iclogp = log->l_iclog;                 /* complete ring */
1422         log->l_iclog->ic_prev = prev_iclog;     /* re-write 1st prev ptr */
1423
1424         error = xlog_cil_init(log);
1425         if (error)
1426                 goto out_free_iclog;
1427         return log;
1428
1429 out_free_iclog:
1430         for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1431                 prev_iclog = iclog->ic_next;
1432                 if (iclog->ic_bp)
1433                         xfs_buf_free(iclog->ic_bp);
1434                 kmem_free(iclog);
1435         }
1436         spinlock_destroy(&log->l_icloglock);
1437         xfs_buf_free(log->l_xbuf);
1438 out_free_log:
1439         kmem_free(log);
1440 out:
1441         return ERR_PTR(-error);
1442 }       /* xlog_alloc_log */
1443
1444
1445 /*
1446  * Write out the commit record of a transaction associated with the given
1447  * ticket.  Return the lsn of the commit record.
1448  */
1449 STATIC int
1450 xlog_commit_record(
1451         struct xlog             *log,
1452         struct xlog_ticket      *ticket,
1453         struct xlog_in_core     **iclog,
1454         xfs_lsn_t               *commitlsnp)
1455 {
1456         struct xfs_mount *mp = log->l_mp;
1457         int     error;
1458         struct xfs_log_iovec reg = {
1459                 .i_addr = NULL,
1460                 .i_len = 0,
1461                 .i_type = XLOG_REG_TYPE_COMMIT,
1462         };
1463         struct xfs_log_vec vec = {
1464                 .lv_niovecs = 1,
1465                 .lv_iovecp = &reg,
1466         };
1467
1468         ASSERT_ALWAYS(iclog);
1469         error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
1470                                         XLOG_COMMIT_TRANS);
1471         if (error)
1472                 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1473         return error;
1474 }
1475
1476 /*
1477  * Push on the buffer cache code if we ever use more than 75% of the on-disk
1478  * log space.  This code pushes on the lsn which would supposedly free up
1479  * the 25% which we want to leave free.  We may need to adopt a policy which
1480  * pushes on an lsn which is further along in the log once we reach the high
1481  * water mark.  In this manner, we would be creating a low water mark.
1482  */
1483 STATIC void
1484 xlog_grant_push_ail(
1485         struct xlog     *log,
1486         int             need_bytes)
1487 {
1488         xfs_lsn_t       threshold_lsn = 0;
1489         xfs_lsn_t       last_sync_lsn;
1490         int             free_blocks;
1491         int             free_bytes;
1492         int             threshold_block;
1493         int             threshold_cycle;
1494         int             free_threshold;
1495
1496         ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1497
1498         free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1499         free_blocks = BTOBBT(free_bytes);
1500
1501         /*
1502          * Set the threshold for the minimum number of free blocks in the
1503          * log to the maximum of what the caller needs, one quarter of the
1504          * log, and 256 blocks.
1505          */
1506         free_threshold = BTOBB(need_bytes);
1507         free_threshold = MAX(free_threshold, (log->l_logBBsize >> 2));
1508         free_threshold = MAX(free_threshold, 256);
1509         if (free_blocks >= free_threshold)
1510                 return;
1511
1512         xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1513                                                 &threshold_block);
1514         threshold_block += free_threshold;
1515         if (threshold_block >= log->l_logBBsize) {
1516                 threshold_block -= log->l_logBBsize;
1517                 threshold_cycle += 1;
1518         }
1519         threshold_lsn = xlog_assign_lsn(threshold_cycle,
1520                                         threshold_block);
1521         /*
1522          * Don't pass in an lsn greater than the lsn of the last
1523          * log record known to be on disk. Use a snapshot of the last sync lsn
1524          * so that it doesn't change between the compare and the set.
1525          */
1526         last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1527         if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1528                 threshold_lsn = last_sync_lsn;
1529
1530         /*
1531          * Get the transaction layer to kick the dirty buffers out to
1532          * disk asynchronously. No point in trying to do this if
1533          * the filesystem is shutting down.
1534          */
1535         if (!XLOG_FORCED_SHUTDOWN(log))
1536                 xfs_ail_push(log->l_ailp, threshold_lsn);
1537 }
1538
1539 /*
1540  * Stamp cycle number in every block
1541  */
1542 STATIC void
1543 xlog_pack_data(
1544         struct xlog             *log,
1545         struct xlog_in_core     *iclog,
1546         int                     roundoff)
1547 {
1548         int                     i, j, k;
1549         int                     size = iclog->ic_offset + roundoff;
1550         __be32                  cycle_lsn;
1551         xfs_caddr_t             dp;
1552
1553         cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1554
1555         dp = iclog->ic_datap;
1556         for (i = 0; i < BTOBB(size); i++) {
1557                 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1558                         break;
1559                 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1560                 *(__be32 *)dp = cycle_lsn;
1561                 dp += BBSIZE;
1562         }
1563
1564         if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1565                 xlog_in_core_2_t *xhdr = iclog->ic_data;
1566
1567                 for ( ; i < BTOBB(size); i++) {
1568                         j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1569                         k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1570                         xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1571                         *(__be32 *)dp = cycle_lsn;
1572                         dp += BBSIZE;
1573                 }
1574
1575                 for (i = 1; i < log->l_iclog_heads; i++)
1576                         xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1577         }
1578 }
1579
1580 /*
1581  * Calculate the checksum for a log buffer.
1582  *
1583  * This is a little more complicated than it should be because the various
1584  * headers and the actual data are non-contiguous.
1585  */
1586 __le32
1587 xlog_cksum(
1588         struct xlog             *log,
1589         struct xlog_rec_header  *rhead,
1590         char                    *dp,
1591         int                     size)
1592 {
1593         __uint32_t              crc;
1594
1595         /* first generate the crc for the record header ... */
1596         crc = xfs_start_cksum((char *)rhead,
1597                               sizeof(struct xlog_rec_header),
1598                               offsetof(struct xlog_rec_header, h_crc));
1599
1600         /* ... then for additional cycle data for v2 logs ... */
1601         if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1602                 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1603                 int             i;
1604
1605                 for (i = 1; i < log->l_iclog_heads; i++) {
1606                         crc = crc32c(crc, &xhdr[i].hic_xheader,
1607                                      sizeof(struct xlog_rec_ext_header));
1608                 }
1609         }
1610
1611         /* ... and finally for the payload */
1612         crc = crc32c(crc, dp, size);
1613
1614         return xfs_end_cksum(crc);
1615 }
1616
1617 /*
1618  * The bdstrat callback function for log bufs. This gives us a central
1619  * place to trap bufs in case we get hit by a log I/O error and need to
1620  * shutdown. Actually, in practice, even when we didn't get a log error,
1621  * we transition the iclogs to IOERROR state *after* flushing all existing
1622  * iclogs to disk. This is because we don't want anymore new transactions to be
1623  * started or completed afterwards.
1624  */
1625 STATIC int
1626 xlog_bdstrat(
1627         struct xfs_buf          *bp)
1628 {
1629         struct xlog_in_core     *iclog = bp->b_fspriv;
1630
1631         if (iclog->ic_state & XLOG_STATE_IOERROR) {
1632                 xfs_buf_ioerror(bp, EIO);
1633                 xfs_buf_stale(bp);
1634                 xfs_buf_ioend(bp, 0);
1635                 /*
1636                  * It would seem logical to return EIO here, but we rely on
1637                  * the log state machine to propagate I/O errors instead of
1638                  * doing it here.
1639                  */
1640                 return 0;
1641         }
1642
1643         xfs_buf_iorequest(bp);
1644         return 0;
1645 }
1646
1647 /*
1648  * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1649  * fashion.  Previously, we should have moved the current iclog
1650  * ptr in the log to point to the next available iclog.  This allows further
1651  * write to continue while this code syncs out an iclog ready to go.
1652  * Before an in-core log can be written out, the data section must be scanned
1653  * to save away the 1st word of each BBSIZE block into the header.  We replace
1654  * it with the current cycle count.  Each BBSIZE block is tagged with the
1655  * cycle count because there in an implicit assumption that drives will
1656  * guarantee that entire 512 byte blocks get written at once.  In other words,
1657  * we can't have part of a 512 byte block written and part not written.  By
1658  * tagging each block, we will know which blocks are valid when recovering
1659  * after an unclean shutdown.
1660  *
1661  * This routine is single threaded on the iclog.  No other thread can be in
1662  * this routine with the same iclog.  Changing contents of iclog can there-
1663  * fore be done without grabbing the state machine lock.  Updating the global
1664  * log will require grabbing the lock though.
1665  *
1666  * The entire log manager uses a logical block numbering scheme.  Only
1667  * log_sync (and then only bwrite()) know about the fact that the log may
1668  * not start with block zero on a given device.  The log block start offset
1669  * is added immediately before calling bwrite().
1670  */
1671
1672 STATIC int
1673 xlog_sync(
1674         struct xlog             *log,
1675         struct xlog_in_core     *iclog)
1676 {
1677         xfs_buf_t       *bp;
1678         int             i;
1679         uint            count;          /* byte count of bwrite */
1680         uint            count_init;     /* initial count before roundup */
1681         int             roundoff;       /* roundoff to BB or stripe */
1682         int             split = 0;      /* split write into two regions */
1683         int             error;
1684         int             v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb);
1685         int             size;
1686
1687         XFS_STATS_INC(xs_log_writes);
1688         ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1689
1690         /* Add for LR header */
1691         count_init = log->l_iclog_hsize + iclog->ic_offset;
1692
1693         /* Round out the log write size */
1694         if (v2 && log->l_mp->m_sb.sb_logsunit > 1) {
1695                 /* we have a v2 stripe unit to use */
1696                 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1697         } else {
1698                 count = BBTOB(BTOBB(count_init));
1699         }
1700         roundoff = count - count_init;
1701         ASSERT(roundoff >= 0);
1702         ASSERT((v2 && log->l_mp->m_sb.sb_logsunit > 1 &&
1703                 roundoff < log->l_mp->m_sb.sb_logsunit)
1704                 ||
1705                 (log->l_mp->m_sb.sb_logsunit <= 1 &&
1706                  roundoff < BBTOB(1)));
1707
1708         /* move grant heads by roundoff in sync */
1709         xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
1710         xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
1711
1712         /* put cycle number in every block */
1713         xlog_pack_data(log, iclog, roundoff);
1714
1715         /* real byte length */
1716         size = iclog->ic_offset;
1717         if (v2)
1718                 size += roundoff;
1719         iclog->ic_header.h_len = cpu_to_be32(size);
1720
1721         bp = iclog->ic_bp;
1722         XFS_BUF_SET_ADDR(bp, BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn)));
1723
1724         XFS_STATS_ADD(xs_log_blocks, BTOBB(count));
1725
1726         /* Do we need to split this write into 2 parts? */
1727         if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) {
1728                 char            *dptr;
1729
1730                 split = count - (BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp)));
1731                 count = BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp));
1732                 iclog->ic_bwritecnt = 2;
1733
1734                 /*
1735                  * Bump the cycle numbers at the start of each block in the
1736                  * part of the iclog that ends up in the buffer that gets
1737                  * written to the start of the log.
1738                  *
1739                  * Watch out for the header magic number case, though.
1740                  */
1741                 dptr = (char *)&iclog->ic_header + count;
1742                 for (i = 0; i < split; i += BBSIZE) {
1743                         __uint32_t cycle = be32_to_cpu(*(__be32 *)dptr);
1744                         if (++cycle == XLOG_HEADER_MAGIC_NUM)
1745                                 cycle++;
1746                         *(__be32 *)dptr = cpu_to_be32(cycle);
1747
1748                         dptr += BBSIZE;
1749                 }
1750         } else {
1751                 iclog->ic_bwritecnt = 1;
1752         }
1753
1754         /* calculcate the checksum */
1755         iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
1756                                             iclog->ic_datap, size);
1757
1758         bp->b_io_length = BTOBB(count);
1759         bp->b_fspriv = iclog;
1760         XFS_BUF_ZEROFLAGS(bp);
1761         XFS_BUF_ASYNC(bp);
1762         bp->b_flags |= XBF_SYNCIO;
1763
1764         if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) {
1765                 bp->b_flags |= XBF_FUA;
1766
1767                 /*
1768                  * Flush the data device before flushing the log to make
1769                  * sure all meta data written back from the AIL actually made
1770                  * it to disk before stamping the new log tail LSN into the
1771                  * log buffer.  For an external log we need to issue the
1772                  * flush explicitly, and unfortunately synchronously here;
1773                  * for an internal log we can simply use the block layer
1774                  * state machine for preflushes.
1775                  */
1776                 if (log->l_mp->m_logdev_targp != log->l_mp->m_ddev_targp)
1777                         xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
1778                 else
1779                         bp->b_flags |= XBF_FLUSH;
1780         }
1781
1782         ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1783         ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1784
1785         xlog_verify_iclog(log, iclog, count, true);
1786
1787         /* account for log which doesn't start at block #0 */
1788         XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1789         /*
1790          * Don't call xfs_bwrite here. We do log-syncs even when the filesystem
1791          * is shutting down.
1792          */
1793         XFS_BUF_WRITE(bp);
1794
1795         error = xlog_bdstrat(bp);
1796         if (error) {
1797                 xfs_buf_ioerror_alert(bp, "xlog_sync");
1798                 return error;
1799         }
1800         if (split) {
1801                 bp = iclog->ic_log->l_xbuf;
1802                 XFS_BUF_SET_ADDR(bp, 0);             /* logical 0 */
1803                 xfs_buf_associate_memory(bp,
1804                                 (char *)&iclog->ic_header + count, split);
1805                 bp->b_fspriv = iclog;
1806                 XFS_BUF_ZEROFLAGS(bp);
1807                 XFS_BUF_ASYNC(bp);
1808                 bp->b_flags |= XBF_SYNCIO;
1809                 if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)
1810                         bp->b_flags |= XBF_FUA;
1811
1812                 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1813                 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1814
1815                 /* account for internal log which doesn't start at block #0 */
1816                 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1817                 XFS_BUF_WRITE(bp);
1818                 error = xlog_bdstrat(bp);
1819                 if (error) {
1820                         xfs_buf_ioerror_alert(bp, "xlog_sync (split)");
1821                         return error;
1822                 }
1823         }
1824         return 0;
1825 }       /* xlog_sync */
1826
1827 /*
1828  * Deallocate a log structure
1829  */
1830 STATIC void
1831 xlog_dealloc_log(
1832         struct xlog     *log)
1833 {
1834         xlog_in_core_t  *iclog, *next_iclog;
1835         int             i;
1836
1837         xlog_cil_destroy(log);
1838
1839         /*
1840          * always need to ensure that the extra buffer does not point to memory
1841          * owned by another log buffer before we free it.
1842          */
1843         xfs_buf_set_empty(log->l_xbuf, BTOBB(log->l_iclog_size));
1844         xfs_buf_free(log->l_xbuf);
1845
1846         iclog = log->l_iclog;
1847         for (i=0; i<log->l_iclog_bufs; i++) {
1848                 xfs_buf_free(iclog->ic_bp);
1849                 next_iclog = iclog->ic_next;
1850                 kmem_free(iclog);
1851                 iclog = next_iclog;
1852         }
1853         spinlock_destroy(&log->l_icloglock);
1854
1855         log->l_mp->m_log = NULL;
1856         kmem_free(log);
1857 }       /* xlog_dealloc_log */
1858
1859 /*
1860  * Update counters atomically now that memcpy is done.
1861  */
1862 /* ARGSUSED */
1863 static inline void
1864 xlog_state_finish_copy(
1865         struct xlog             *log,
1866         struct xlog_in_core     *iclog,
1867         int                     record_cnt,
1868         int                     copy_bytes)
1869 {
1870         spin_lock(&log->l_icloglock);
1871
1872         be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
1873         iclog->ic_offset += copy_bytes;
1874
1875         spin_unlock(&log->l_icloglock);
1876 }       /* xlog_state_finish_copy */
1877
1878
1879
1880
1881 /*
1882  * print out info relating to regions written which consume
1883  * the reservation
1884  */
1885 void
1886 xlog_print_tic_res(
1887         struct xfs_mount        *mp,
1888         struct xlog_ticket      *ticket)
1889 {
1890         uint i;
1891         uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
1892
1893         /* match with XLOG_REG_TYPE_* in xfs_log.h */
1894         static char *res_type_str[XLOG_REG_TYPE_MAX] = {
1895             "bformat",
1896             "bchunk",
1897             "efi_format",
1898             "efd_format",
1899             "iformat",
1900             "icore",
1901             "iext",
1902             "ibroot",
1903             "ilocal",
1904             "iattr_ext",
1905             "iattr_broot",
1906             "iattr_local",
1907             "qformat",
1908             "dquot",
1909             "quotaoff",
1910             "LR header",
1911             "unmount",
1912             "commit",
1913             "trans header"
1914         };
1915         static char *trans_type_str[XFS_TRANS_TYPE_MAX] = {
1916             "SETATTR_NOT_SIZE",
1917             "SETATTR_SIZE",
1918             "INACTIVE",
1919             "CREATE",
1920             "CREATE_TRUNC",
1921             "TRUNCATE_FILE",
1922             "REMOVE",
1923             "LINK",
1924             "RENAME",
1925             "MKDIR",
1926             "RMDIR",
1927             "SYMLINK",
1928             "SET_DMATTRS",
1929             "GROWFS",
1930             "STRAT_WRITE",
1931             "DIOSTRAT",
1932             "WRITE_SYNC",
1933             "WRITEID",
1934             "ADDAFORK",
1935             "ATTRINVAL",
1936             "ATRUNCATE",
1937             "ATTR_SET",
1938             "ATTR_RM",
1939             "ATTR_FLAG",
1940             "CLEAR_AGI_BUCKET",
1941             "QM_SBCHANGE",
1942             "DUMMY1",
1943             "DUMMY2",
1944             "QM_QUOTAOFF",
1945             "QM_DQALLOC",
1946             "QM_SETQLIM",
1947             "QM_DQCLUSTER",
1948             "QM_QINOCREATE",
1949             "QM_QUOTAOFF_END",
1950             "SB_UNIT",
1951             "FSYNC_TS",
1952             "GROWFSRT_ALLOC",
1953             "GROWFSRT_ZERO",
1954             "GROWFSRT_FREE",
1955             "SWAPEXT"
1956         };
1957
1958         xfs_warn(mp,
1959                 "xlog_write: reservation summary:\n"
1960                 "  trans type  = %s (%u)\n"
1961                 "  unit res    = %d bytes\n"
1962                 "  current res = %d bytes\n"
1963                 "  total reg   = %u bytes (o/flow = %u bytes)\n"
1964                 "  ophdrs      = %u (ophdr space = %u bytes)\n"
1965                 "  ophdr + reg = %u bytes\n"
1966                 "  num regions = %u\n",
1967                 ((ticket->t_trans_type <= 0 ||
1968                   ticket->t_trans_type > XFS_TRANS_TYPE_MAX) ?
1969                   "bad-trans-type" : trans_type_str[ticket->t_trans_type-1]),
1970                 ticket->t_trans_type,
1971                 ticket->t_unit_res,
1972                 ticket->t_curr_res,
1973                 ticket->t_res_arr_sum, ticket->t_res_o_flow,
1974                 ticket->t_res_num_ophdrs, ophdr_spc,
1975                 ticket->t_res_arr_sum +
1976                 ticket->t_res_o_flow + ophdr_spc,
1977                 ticket->t_res_num);
1978
1979         for (i = 0; i < ticket->t_res_num; i++) {
1980                 uint r_type = ticket->t_res_arr[i].r_type;
1981                 xfs_warn(mp, "region[%u]: %s - %u bytes\n", i,
1982                             ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
1983                             "bad-rtype" : res_type_str[r_type-1]),
1984                             ticket->t_res_arr[i].r_len);
1985         }
1986
1987         xfs_alert_tag(mp, XFS_PTAG_LOGRES,
1988                 "xlog_write: reservation ran out. Need to up reservation");
1989         xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1990 }
1991
1992 /*
1993  * Calculate the potential space needed by the log vector.  Each region gets
1994  * its own xlog_op_header_t and may need to be double word aligned.
1995  */
1996 static int
1997 xlog_write_calc_vec_length(
1998         struct xlog_ticket      *ticket,
1999         struct xfs_log_vec      *log_vector)
2000 {
2001         struct xfs_log_vec      *lv;
2002         int                     headers = 0;
2003         int                     len = 0;
2004         int                     i;
2005
2006         /* acct for start rec of xact */
2007         if (ticket->t_flags & XLOG_TIC_INITED)
2008                 headers++;
2009
2010         for (lv = log_vector; lv; lv = lv->lv_next) {
2011                 /* we don't write ordered log vectors */
2012                 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
2013                         continue;
2014
2015                 headers += lv->lv_niovecs;
2016
2017                 for (i = 0; i < lv->lv_niovecs; i++) {
2018                         struct xfs_log_iovec    *vecp = &lv->lv_iovecp[i];
2019
2020                         len += vecp->i_len;
2021                         xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
2022                 }
2023         }
2024
2025         ticket->t_res_num_ophdrs += headers;
2026         len += headers * sizeof(struct xlog_op_header);
2027
2028         return len;
2029 }
2030
2031 /*
2032  * If first write for transaction, insert start record  We can't be trying to
2033  * commit if we are inited.  We can't have any "partial_copy" if we are inited.
2034  */
2035 static int
2036 xlog_write_start_rec(
2037         struct xlog_op_header   *ophdr,
2038         struct xlog_ticket      *ticket)
2039 {
2040         if (!(ticket->t_flags & XLOG_TIC_INITED))
2041                 return 0;
2042
2043         ophdr->oh_tid   = cpu_to_be32(ticket->t_tid);
2044         ophdr->oh_clientid = ticket->t_clientid;
2045         ophdr->oh_len = 0;
2046         ophdr->oh_flags = XLOG_START_TRANS;
2047         ophdr->oh_res2 = 0;
2048
2049         ticket->t_flags &= ~XLOG_TIC_INITED;
2050
2051         return sizeof(struct xlog_op_header);
2052 }
2053
2054 static xlog_op_header_t *
2055 xlog_write_setup_ophdr(
2056         struct xlog             *log,
2057         struct xlog_op_header   *ophdr,
2058         struct xlog_ticket      *ticket,
2059         uint                    flags)
2060 {
2061         ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2062         ophdr->oh_clientid = ticket->t_clientid;
2063         ophdr->oh_res2 = 0;
2064
2065         /* are we copying a commit or unmount record? */
2066         ophdr->oh_flags = flags;
2067
2068         /*
2069          * We've seen logs corrupted with bad transaction client ids.  This
2070          * makes sure that XFS doesn't generate them on.  Turn this into an EIO
2071          * and shut down the filesystem.
2072          */
2073         switch (ophdr->oh_clientid)  {
2074         case XFS_TRANSACTION:
2075         case XFS_VOLUME:
2076         case XFS_LOG:
2077                 break;
2078         default:
2079                 xfs_warn(log->l_mp,
2080                         "Bad XFS transaction clientid 0x%x in ticket 0x%p",
2081                         ophdr->oh_clientid, ticket);
2082                 return NULL;
2083         }
2084
2085         return ophdr;
2086 }
2087
2088 /*
2089  * Set up the parameters of the region copy into the log. This has
2090  * to handle region write split across multiple log buffers - this
2091  * state is kept external to this function so that this code can
2092  * be written in an obvious, self documenting manner.
2093  */
2094 static int
2095 xlog_write_setup_copy(
2096         struct xlog_ticket      *ticket,
2097         struct xlog_op_header   *ophdr,
2098         int                     space_available,
2099         int                     space_required,
2100         int                     *copy_off,
2101         int                     *copy_len,
2102         int                     *last_was_partial_copy,
2103         int                     *bytes_consumed)
2104 {
2105         int                     still_to_copy;
2106
2107         still_to_copy = space_required - *bytes_consumed;
2108         *copy_off = *bytes_consumed;
2109
2110         if (still_to_copy <= space_available) {
2111                 /* write of region completes here */
2112                 *copy_len = still_to_copy;
2113                 ophdr->oh_len = cpu_to_be32(*copy_len);
2114                 if (*last_was_partial_copy)
2115                         ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
2116                 *last_was_partial_copy = 0;
2117                 *bytes_consumed = 0;
2118                 return 0;
2119         }
2120
2121         /* partial write of region, needs extra log op header reservation */
2122         *copy_len = space_available;
2123         ophdr->oh_len = cpu_to_be32(*copy_len);
2124         ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2125         if (*last_was_partial_copy)
2126                 ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
2127         *bytes_consumed += *copy_len;
2128         (*last_was_partial_copy)++;
2129
2130         /* account for new log op header */
2131         ticket->t_curr_res -= sizeof(struct xlog_op_header);
2132         ticket->t_res_num_ophdrs++;
2133
2134         return sizeof(struct xlog_op_header);
2135 }
2136
2137 static int
2138 xlog_write_copy_finish(
2139         struct xlog             *log,
2140         struct xlog_in_core     *iclog,
2141         uint                    flags,
2142         int                     *record_cnt,
2143         int                     *data_cnt,
2144         int                     *partial_copy,
2145         int                     *partial_copy_len,
2146         int                     log_offset,
2147         struct xlog_in_core     **commit_iclog)
2148 {
2149         if (*partial_copy) {
2150                 /*
2151                  * This iclog has already been marked WANT_SYNC by
2152                  * xlog_state_get_iclog_space.
2153                  */
2154                 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2155                 *record_cnt = 0;
2156                 *data_cnt = 0;
2157                 return xlog_state_release_iclog(log, iclog);
2158         }
2159
2160         *partial_copy = 0;
2161         *partial_copy_len = 0;
2162
2163         if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
2164                 /* no more space in this iclog - push it. */
2165                 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2166                 *record_cnt = 0;
2167                 *data_cnt = 0;
2168
2169                 spin_lock(&log->l_icloglock);
2170                 xlog_state_want_sync(log, iclog);
2171                 spin_unlock(&log->l_icloglock);
2172
2173                 if (!commit_iclog)
2174                         return xlog_state_release_iclog(log, iclog);
2175                 ASSERT(flags & XLOG_COMMIT_TRANS);
2176                 *commit_iclog = iclog;
2177         }
2178
2179         return 0;
2180 }
2181
2182 /*
2183  * Write some region out to in-core log
2184  *
2185  * This will be called when writing externally provided regions or when
2186  * writing out a commit record for a given transaction.
2187  *
2188  * General algorithm:
2189  *      1. Find total length of this write.  This may include adding to the
2190  *              lengths passed in.
2191  *      2. Check whether we violate the tickets reservation.
2192  *      3. While writing to this iclog
2193  *          A. Reserve as much space in this iclog as can get
2194  *          B. If this is first write, save away start lsn
2195  *          C. While writing this region:
2196  *              1. If first write of transaction, write start record
2197  *              2. Write log operation header (header per region)
2198  *              3. Find out if we can fit entire region into this iclog
2199  *              4. Potentially, verify destination memcpy ptr
2200  *              5. Memcpy (partial) region
2201  *              6. If partial copy, release iclog; otherwise, continue
2202  *                      copying more regions into current iclog
2203  *      4. Mark want sync bit (in simulation mode)
2204  *      5. Release iclog for potential flush to on-disk log.
2205  *
2206  * ERRORS:
2207  * 1.   Panic if reservation is overrun.  This should never happen since
2208  *      reservation amounts are generated internal to the filesystem.
2209  * NOTES:
2210  * 1. Tickets are single threaded data structures.
2211  * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2212  *      syncing routine.  When a single log_write region needs to span
2213  *      multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2214  *      on all log operation writes which don't contain the end of the
2215  *      region.  The XLOG_END_TRANS bit is used for the in-core log
2216  *      operation which contains the end of the continued log_write region.
2217  * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2218  *      we don't really know exactly how much space will be used.  As a result,
2219  *      we don't update ic_offset until the end when we know exactly how many
2220  *      bytes have been written out.
2221  */
2222 int
2223 xlog_write(
2224         struct xlog             *log,
2225         struct xfs_log_vec      *log_vector,
2226         struct xlog_ticket      *ticket,
2227         xfs_lsn_t               *start_lsn,
2228         struct xlog_in_core     **commit_iclog,
2229         uint                    flags)
2230 {
2231         struct xlog_in_core     *iclog = NULL;
2232         struct xfs_log_iovec    *vecp;
2233         struct xfs_log_vec      *lv;
2234         int                     len;
2235         int                     index;
2236         int                     partial_copy = 0;
2237         int                     partial_copy_len = 0;
2238         int                     contwr = 0;
2239         int                     record_cnt = 0;
2240         int                     data_cnt = 0;
2241         int                     error;
2242
2243         *start_lsn = 0;
2244
2245         len = xlog_write_calc_vec_length(ticket, log_vector);
2246
2247         /*
2248          * Region headers and bytes are already accounted for.
2249          * We only need to take into account start records and
2250          * split regions in this function.
2251          */
2252         if (ticket->t_flags & XLOG_TIC_INITED)
2253                 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2254
2255         /*
2256          * Commit record headers need to be accounted for. These
2257          * come in as separate writes so are easy to detect.
2258          */
2259         if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
2260                 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2261
2262         if (ticket->t_curr_res < 0)
2263                 xlog_print_tic_res(log->l_mp, ticket);
2264
2265         index = 0;
2266         lv = log_vector;
2267         vecp = lv->lv_iovecp;
2268         while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2269                 void            *ptr;
2270                 int             log_offset;
2271
2272                 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2273                                                    &contwr, &log_offset);
2274                 if (error)
2275                         return error;
2276
2277                 ASSERT(log_offset <= iclog->ic_size - 1);
2278                 ptr = iclog->ic_datap + log_offset;
2279
2280                 /* start_lsn is the first lsn written to. That's all we need. */
2281                 if (!*start_lsn)
2282                         *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2283
2284                 /*
2285                  * This loop writes out as many regions as can fit in the amount
2286                  * of space which was allocated by xlog_state_get_iclog_space().
2287                  */
2288                 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2289                         struct xfs_log_iovec    *reg;
2290                         struct xlog_op_header   *ophdr;
2291                         int                     start_rec_copy;
2292                         int                     copy_len;
2293                         int                     copy_off;
2294                         bool                    ordered = false;
2295
2296                         /* ordered log vectors have no regions to write */
2297                         if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
2298                                 ASSERT(lv->lv_niovecs == 0);
2299                                 ordered = true;
2300                                 goto next_lv;
2301                         }
2302
2303                         reg = &vecp[index];
2304                         ASSERT(reg->i_len % sizeof(__int32_t) == 0);
2305                         ASSERT((unsigned long)ptr % sizeof(__int32_t) == 0);
2306
2307                         start_rec_copy = xlog_write_start_rec(ptr, ticket);
2308                         if (start_rec_copy) {
2309                                 record_cnt++;
2310                                 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2311                                                    start_rec_copy);
2312                         }
2313
2314                         ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
2315                         if (!ophdr)
2316                                 return XFS_ERROR(EIO);
2317
2318                         xlog_write_adv_cnt(&ptr, &len, &log_offset,
2319                                            sizeof(struct xlog_op_header));
2320
2321                         len += xlog_write_setup_copy(ticket, ophdr,
2322                                                      iclog->ic_size-log_offset,
2323                                                      reg->i_len,
2324                                                      &copy_off, &copy_len,
2325                                                      &partial_copy,
2326                                                      &partial_copy_len);
2327                         xlog_verify_dest_ptr(log, ptr);
2328
2329                         /* copy region */
2330                         ASSERT(copy_len >= 0);
2331                         memcpy(ptr, reg->i_addr + copy_off, copy_len);
2332                         xlog_write_adv_cnt(&ptr, &len, &log_offset, copy_len);
2333
2334                         copy_len += start_rec_copy + sizeof(xlog_op_header_t);
2335                         record_cnt++;
2336                         data_cnt += contwr ? copy_len : 0;
2337
2338                         error = xlog_write_copy_finish(log, iclog, flags,
2339                                                        &record_cnt, &data_cnt,
2340                                                        &partial_copy,
2341                                                        &partial_copy_len,
2342                                                        log_offset,
2343                                                        commit_iclog);
2344                         if (error)
2345                                 return error;
2346
2347                         /*
2348                          * if we had a partial copy, we need to get more iclog
2349                          * space but we don't want to increment the region
2350                          * index because there is still more is this region to
2351                          * write.
2352                          *
2353                          * If we completed writing this region, and we flushed
2354                          * the iclog (indicated by resetting of the record
2355                          * count), then we also need to get more log space. If
2356                          * this was the last record, though, we are done and
2357                          * can just return.
2358                          */
2359                         if (partial_copy)
2360                                 break;
2361
2362                         if (++index == lv->lv_niovecs) {
2363 next_lv:
2364                                 lv = lv->lv_next;
2365                                 index = 0;
2366                                 if (lv)
2367                                         vecp = lv->lv_iovecp;
2368                         }
2369                         if (record_cnt == 0 && ordered == false) {
2370                                 if (!lv)
2371                                         return 0;
2372                                 break;
2373                         }
2374                 }
2375         }
2376
2377         ASSERT(len == 0);
2378
2379         xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
2380         if (!commit_iclog)
2381                 return xlog_state_release_iclog(log, iclog);
2382
2383         ASSERT(flags & XLOG_COMMIT_TRANS);
2384         *commit_iclog = iclog;
2385         return 0;
2386 }
2387
2388
2389 /*****************************************************************************
2390  *
2391  *              State Machine functions
2392  *
2393  *****************************************************************************
2394  */
2395
2396 /* Clean iclogs starting from the head.  This ordering must be
2397  * maintained, so an iclog doesn't become ACTIVE beyond one that
2398  * is SYNCING.  This is also required to maintain the notion that we use
2399  * a ordered wait queue to hold off would be writers to the log when every
2400  * iclog is trying to sync to disk.
2401  *
2402  * State Change: DIRTY -> ACTIVE
2403  */
2404 STATIC void
2405 xlog_state_clean_log(
2406         struct xlog *log)
2407 {
2408         xlog_in_core_t  *iclog;
2409         int changed = 0;
2410
2411         iclog = log->l_iclog;
2412         do {
2413                 if (iclog->ic_state == XLOG_STATE_DIRTY) {
2414                         iclog->ic_state = XLOG_STATE_ACTIVE;
2415                         iclog->ic_offset       = 0;
2416                         ASSERT(iclog->ic_callback == NULL);
2417                         /*
2418                          * If the number of ops in this iclog indicate it just
2419                          * contains the dummy transaction, we can
2420                          * change state into IDLE (the second time around).
2421                          * Otherwise we should change the state into
2422                          * NEED a dummy.
2423                          * We don't need to cover the dummy.
2424                          */
2425                         if (!changed &&
2426                            (be32_to_cpu(iclog->ic_header.h_num_logops) ==
2427                                         XLOG_COVER_OPS)) {
2428                                 changed = 1;
2429                         } else {
2430                                 /*
2431                                  * We have two dirty iclogs so start over
2432                                  * This could also be num of ops indicates
2433                                  * this is not the dummy going out.
2434                                  */
2435                                 changed = 2;
2436                         }
2437                         iclog->ic_header.h_num_logops = 0;
2438                         memset(iclog->ic_header.h_cycle_data, 0,
2439                               sizeof(iclog->ic_header.h_cycle_data));
2440                         iclog->ic_header.h_lsn = 0;
2441                 } else if (iclog->ic_state == XLOG_STATE_ACTIVE)
2442                         /* do nothing */;
2443                 else
2444                         break;  /* stop cleaning */
2445                 iclog = iclog->ic_next;
2446         } while (iclog != log->l_iclog);
2447
2448         /* log is locked when we are called */
2449         /*
2450          * Change state for the dummy log recording.
2451          * We usually go to NEED. But we go to NEED2 if the changed indicates
2452          * we are done writing the dummy record.
2453          * If we are done with the second dummy recored (DONE2), then
2454          * we go to IDLE.
2455          */
2456         if (changed) {
2457                 switch (log->l_covered_state) {
2458                 case XLOG_STATE_COVER_IDLE:
2459                 case XLOG_STATE_COVER_NEED:
2460                 case XLOG_STATE_COVER_NEED2:
2461                         log->l_covered_state = XLOG_STATE_COVER_NEED;
2462                         break;
2463
2464                 case XLOG_STATE_COVER_DONE:
2465                         if (changed == 1)
2466                                 log->l_covered_state = XLOG_STATE_COVER_NEED2;
2467                         else
2468                                 log->l_covered_state = XLOG_STATE_COVER_NEED;
2469                         break;
2470
2471                 case XLOG_STATE_COVER_DONE2:
2472                         if (changed == 1)
2473                                 log->l_covered_state = XLOG_STATE_COVER_IDLE;
2474                         else
2475                                 log->l_covered_state = XLOG_STATE_COVER_NEED;
2476                         break;
2477
2478                 default:
2479                         ASSERT(0);
2480                 }
2481         }
2482 }       /* xlog_state_clean_log */
2483
2484 STATIC xfs_lsn_t
2485 xlog_get_lowest_lsn(
2486         struct xlog     *log)
2487 {
2488         xlog_in_core_t  *lsn_log;
2489         xfs_lsn_t       lowest_lsn, lsn;
2490
2491         lsn_log = log->l_iclog;
2492         lowest_lsn = 0;
2493         do {
2494             if (!(lsn_log->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY))) {
2495                 lsn = be64_to_cpu(lsn_log->ic_header.h_lsn);
2496                 if ((lsn && !lowest_lsn) ||
2497                     (XFS_LSN_CMP(lsn, lowest_lsn) < 0)) {
2498                         lowest_lsn = lsn;
2499                 }
2500             }
2501             lsn_log = lsn_log->ic_next;
2502         } while (lsn_log != log->l_iclog);
2503         return lowest_lsn;
2504 }
2505
2506
2507 STATIC void
2508 xlog_state_do_callback(
2509         struct xlog             *log,
2510         int                     aborted,
2511         struct xlog_in_core     *ciclog)
2512 {
2513         xlog_in_core_t     *iclog;
2514         xlog_in_core_t     *first_iclog;        /* used to know when we've
2515                                                  * processed all iclogs once */
2516         xfs_log_callback_t *cb, *cb_next;
2517         int                flushcnt = 0;
2518         xfs_lsn_t          lowest_lsn;
2519         int                ioerrors;    /* counter: iclogs with errors */
2520         int                loopdidcallbacks; /* flag: inner loop did callbacks*/
2521         int                funcdidcallbacks; /* flag: function did callbacks */
2522         int                repeats;     /* for issuing console warnings if
2523                                          * looping too many times */
2524         int                wake = 0;
2525
2526         spin_lock(&log->l_icloglock);
2527         first_iclog = iclog = log->l_iclog;
2528         ioerrors = 0;
2529         funcdidcallbacks = 0;
2530         repeats = 0;
2531
2532         do {
2533                 /*
2534                  * Scan all iclogs starting with the one pointed to by the
2535                  * log.  Reset this starting point each time the log is
2536                  * unlocked (during callbacks).
2537                  *
2538                  * Keep looping through iclogs until one full pass is made
2539                  * without running any callbacks.
2540                  */
2541                 first_iclog = log->l_iclog;
2542                 iclog = log->l_iclog;
2543                 loopdidcallbacks = 0;
2544                 repeats++;
2545
2546                 do {
2547
2548                         /* skip all iclogs in the ACTIVE & DIRTY states */
2549                         if (iclog->ic_state &
2550                             (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY)) {
2551                                 iclog = iclog->ic_next;
2552                                 continue;
2553                         }
2554
2555                         /*
2556                          * Between marking a filesystem SHUTDOWN and stopping
2557                          * the log, we do flush all iclogs to disk (if there
2558                          * wasn't a log I/O error). So, we do want things to
2559                          * go smoothly in case of just a SHUTDOWN  w/o a
2560                          * LOG_IO_ERROR.
2561                          */
2562                         if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
2563                                 /*
2564                                  * Can only perform callbacks in order.  Since
2565                                  * this iclog is not in the DONE_SYNC/
2566                                  * DO_CALLBACK state, we skip the rest and
2567                                  * just try to clean up.  If we set our iclog
2568                                  * to DO_CALLBACK, we will not process it when
2569                                  * we retry since a previous iclog is in the
2570                                  * CALLBACK and the state cannot change since
2571                                  * we are holding the l_icloglock.
2572                                  */
2573                                 if (!(iclog->ic_state &
2574                                         (XLOG_STATE_DONE_SYNC |
2575                                                  XLOG_STATE_DO_CALLBACK))) {
2576                                         if (ciclog && (ciclog->ic_state ==
2577                                                         XLOG_STATE_DONE_SYNC)) {
2578                                                 ciclog->ic_state = XLOG_STATE_DO_CALLBACK;
2579                                         }
2580                                         break;
2581                                 }
2582                                 /*
2583                                  * We now have an iclog that is in either the
2584                                  * DO_CALLBACK or DONE_SYNC states. The other
2585                                  * states (WANT_SYNC, SYNCING, or CALLBACK were
2586                                  * caught by the above if and are going to
2587                                  * clean (i.e. we aren't doing their callbacks)
2588                                  * see the above if.
2589                                  */
2590
2591                                 /*
2592                                  * We will do one more check here to see if we
2593                                  * have chased our tail around.
2594                                  */
2595
2596                                 lowest_lsn = xlog_get_lowest_lsn(log);
2597                                 if (lowest_lsn &&
2598                                     XFS_LSN_CMP(lowest_lsn,
2599                                                 be64_to_cpu(iclog->ic_header.h_lsn)) < 0) {
2600                                         iclog = iclog->ic_next;
2601                                         continue; /* Leave this iclog for
2602                                                    * another thread */
2603                                 }
2604
2605                                 iclog->ic_state = XLOG_STATE_CALLBACK;
2606
2607
2608                                 /*
2609                                  * Completion of a iclog IO does not imply that
2610                                  * a transaction has completed, as transactions
2611                                  * can be large enough to span many iclogs. We
2612                                  * cannot change the tail of the log half way
2613                                  * through a transaction as this may be the only
2614                                  * transaction in the log and moving th etail to
2615                                  * point to the middle of it will prevent
2616                                  * recovery from finding the start of the
2617                                  * transaction. Hence we should only update the
2618                                  * last_sync_lsn if this iclog contains
2619                                  * transaction completion callbacks on it.
2620                                  *
2621                                  * We have to do this before we drop the
2622                                  * icloglock to ensure we are the only one that
2623                                  * can update it.
2624                                  */
2625                                 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2626                                         be64_to_cpu(iclog->ic_header.h_lsn)) <= 0);
2627                                 if (iclog->ic_callback)
2628                                         atomic64_set(&log->l_last_sync_lsn,
2629                                                 be64_to_cpu(iclog->ic_header.h_lsn));
2630
2631                         } else
2632                                 ioerrors++;
2633
2634                         spin_unlock(&log->l_icloglock);
2635
2636                         /*
2637                          * Keep processing entries in the callback list until
2638                          * we come around and it is empty.  We need to
2639                          * atomically see that the list is empty and change the
2640                          * state to DIRTY so that we don't miss any more
2641                          * callbacks being added.
2642                          */
2643                         spin_lock(&iclog->ic_callback_lock);
2644                         cb = iclog->ic_callback;
2645                         while (cb) {
2646                                 iclog->ic_callback_tail = &(iclog->ic_callback);
2647                                 iclog->ic_callback = NULL;
2648                                 spin_unlock(&iclog->ic_callback_lock);
2649
2650                                 /* perform callbacks in the order given */
2651                                 for (; cb; cb = cb_next) {
2652                                         cb_next = cb->cb_next;
2653                                         cb->cb_func(cb->cb_arg, aborted);
2654                                 }
2655                                 spin_lock(&iclog->ic_callback_lock);
2656                                 cb = iclog->ic_callback;
2657                         }
2658
2659                         loopdidcallbacks++;
2660                         funcdidcallbacks++;
2661
2662                         spin_lock(&log->l_icloglock);
2663                         ASSERT(iclog->ic_callback == NULL);
2664                         spin_unlock(&iclog->ic_callback_lock);
2665                         if (!(iclog->ic_state & XLOG_STATE_IOERROR))
2666                                 iclog->ic_state = XLOG_STATE_DIRTY;
2667
2668                         /*
2669                          * Transition from DIRTY to ACTIVE if applicable.
2670                          * NOP if STATE_IOERROR.
2671                          */
2672                         xlog_state_clean_log(log);
2673
2674                         /* wake up threads waiting in xfs_log_force() */
2675                         wake_up_all(&iclog->ic_force_wait);
2676
2677                         iclog = iclog->ic_next;
2678                 } while (first_iclog != iclog);
2679
2680                 if (repeats > 5000) {
2681                         flushcnt += repeats;
2682                         repeats = 0;
2683                         xfs_warn(log->l_mp,
2684                                 "%s: possible infinite loop (%d iterations)",
2685                                 __func__, flushcnt);
2686                 }
2687         } while (!ioerrors && loopdidcallbacks);
2688
2689         /*
2690          * make one last gasp attempt to see if iclogs are being left in
2691          * limbo..
2692          */
2693 #ifdef DEBUG
2694         if (funcdidcallbacks) {
2695                 first_iclog = iclog = log->l_iclog;
2696                 do {
2697                         ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK);
2698                         /*
2699                          * Terminate the loop if iclogs are found in states
2700                          * which will cause other threads to clean up iclogs.
2701                          *
2702                          * SYNCING - i/o completion will go through logs
2703                          * DONE_SYNC - interrupt thread should be waiting for
2704                          *              l_icloglock
2705                          * IOERROR - give up hope all ye who enter here
2706                          */
2707                         if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2708                             iclog->ic_state == XLOG_STATE_SYNCING ||
2709                             iclog->ic_state == XLOG_STATE_DONE_SYNC ||
2710                             iclog->ic_state == XLOG_STATE_IOERROR )
2711                                 break;
2712                         iclog = iclog->ic_next;
2713                 } while (first_iclog != iclog);
2714         }
2715 #endif
2716
2717         if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR))
2718                 wake = 1;
2719         spin_unlock(&log->l_icloglock);
2720
2721         if (wake)
2722                 wake_up_all(&log->l_flush_wait);
2723 }
2724
2725
2726 /*
2727  * Finish transitioning this iclog to the dirty state.
2728  *
2729  * Make sure that we completely execute this routine only when this is
2730  * the last call to the iclog.  There is a good chance that iclog flushes,
2731  * when we reach the end of the physical log, get turned into 2 separate
2732  * calls to bwrite.  Hence, one iclog flush could generate two calls to this
2733  * routine.  By using the reference count bwritecnt, we guarantee that only
2734  * the second completion goes through.
2735  *
2736  * Callbacks could take time, so they are done outside the scope of the
2737  * global state machine log lock.
2738  */
2739 STATIC void
2740 xlog_state_done_syncing(
2741         xlog_in_core_t  *iclog,
2742         int             aborted)
2743 {
2744         struct xlog        *log = iclog->ic_log;
2745
2746         spin_lock(&log->l_icloglock);
2747
2748         ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
2749                iclog->ic_state == XLOG_STATE_IOERROR);
2750         ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2751         ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2);
2752
2753
2754         /*
2755          * If we got an error, either on the first buffer, or in the case of
2756          * split log writes, on the second, we mark ALL iclogs STATE_IOERROR,
2757          * and none should ever be attempted to be written to disk
2758          * again.
2759          */
2760         if (iclog->ic_state != XLOG_STATE_IOERROR) {
2761                 if (--iclog->ic_bwritecnt == 1) {
2762                         spin_unlock(&log->l_icloglock);
2763                         return;
2764                 }
2765                 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2766         }
2767
2768         /*
2769          * Someone could be sleeping prior to writing out the next
2770          * iclog buffer, we wake them all, one will get to do the
2771          * I/O, the others get to wait for the result.
2772          */
2773         wake_up_all(&iclog->ic_write_wait);
2774         spin_unlock(&log->l_icloglock);
2775         xlog_state_do_callback(log, aborted, iclog);    /* also cleans log */
2776 }       /* xlog_state_done_syncing */
2777
2778
2779 /*
2780  * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2781  * sleep.  We wait on the flush queue on the head iclog as that should be
2782  * the first iclog to complete flushing. Hence if all iclogs are syncing,
2783  * we will wait here and all new writes will sleep until a sync completes.
2784  *
2785  * The in-core logs are used in a circular fashion. They are not used
2786  * out-of-order even when an iclog past the head is free.
2787  *
2788  * return:
2789  *      * log_offset where xlog_write() can start writing into the in-core
2790  *              log's data space.
2791  *      * in-core log pointer to which xlog_write() should write.
2792  *      * boolean indicating this is a continued write to an in-core log.
2793  *              If this is the last write, then the in-core log's offset field
2794  *              needs to be incremented, depending on the amount of data which
2795  *              is copied.
2796  */
2797 STATIC int
2798 xlog_state_get_iclog_space(
2799         struct xlog             *log,
2800         int                     len,
2801         struct xlog_in_core     **iclogp,
2802         struct xlog_ticket      *ticket,
2803         int                     *continued_write,
2804         int                     *logoffsetp)
2805 {
2806         int               log_offset;
2807         xlog_rec_header_t *head;
2808         xlog_in_core_t    *iclog;
2809         int               error;
2810
2811 restart:
2812         spin_lock(&log->l_icloglock);
2813         if (XLOG_FORCED_SHUTDOWN(log)) {
2814                 spin_unlock(&log->l_icloglock);
2815                 return XFS_ERROR(EIO);
2816         }
2817
2818         iclog = log->l_iclog;
2819         if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2820                 XFS_STATS_INC(xs_log_noiclogs);
2821
2822                 /* Wait for log writes to have flushed */
2823                 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
2824                 goto restart;
2825         }
2826
2827         head = &iclog->ic_header;
2828
2829         atomic_inc(&iclog->ic_refcnt);  /* prevents sync */
2830         log_offset = iclog->ic_offset;
2831
2832         /* On the 1st write to an iclog, figure out lsn.  This works
2833          * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2834          * committing to.  If the offset is set, that's how many blocks
2835          * must be written.
2836          */
2837         if (log_offset == 0) {
2838                 ticket->t_curr_res -= log->l_iclog_hsize;
2839                 xlog_tic_add_region(ticket,
2840                                     log->l_iclog_hsize,
2841                                     XLOG_REG_TYPE_LRHEADER);
2842                 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
2843                 head->h_lsn = cpu_to_be64(
2844                         xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
2845                 ASSERT(log->l_curr_block >= 0);
2846         }
2847
2848         /* If there is enough room to write everything, then do it.  Otherwise,
2849          * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2850          * bit is on, so this will get flushed out.  Don't update ic_offset
2851          * until you know exactly how many bytes get copied.  Therefore, wait
2852          * until later to update ic_offset.
2853          *
2854          * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2855          * can fit into remaining data section.
2856          */
2857         if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2858                 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2859
2860                 /*
2861                  * If I'm the only one writing to this iclog, sync it to disk.
2862                  * We need to do an atomic compare and decrement here to avoid
2863                  * racing with concurrent atomic_dec_and_lock() calls in
2864                  * xlog_state_release_iclog() when there is more than one
2865                  * reference to the iclog.
2866                  */
2867                 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) {
2868                         /* we are the only one */
2869                         spin_unlock(&log->l_icloglock);
2870                         error = xlog_state_release_iclog(log, iclog);
2871                         if (error)
2872                                 return error;
2873                 } else {
2874                         spin_unlock(&log->l_icloglock);
2875                 }
2876                 goto restart;
2877         }
2878
2879         /* Do we have enough room to write the full amount in the remainder
2880          * of this iclog?  Or must we continue a write on the next iclog and
2881          * mark this iclog as completely taken?  In the case where we switch
2882          * iclogs (to mark it taken), this particular iclog will release/sync
2883          * to disk in xlog_write().
2884          */
2885         if (len <= iclog->ic_size - iclog->ic_offset) {
2886                 *continued_write = 0;
2887                 iclog->ic_offset += len;
2888         } else {
2889                 *continued_write = 1;
2890                 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2891         }
2892         *iclogp = iclog;
2893
2894         ASSERT(iclog->ic_offset <= iclog->ic_size);
2895         spin_unlock(&log->l_icloglock);
2896
2897         *logoffsetp = log_offset;
2898         return 0;
2899 }       /* xlog_state_get_iclog_space */
2900
2901 /* The first cnt-1 times through here we don't need to
2902  * move the grant write head because the permanent
2903  * reservation has reserved cnt times the unit amount.
2904  * Release part of current permanent unit reservation and
2905  * reset current reservation to be one units worth.  Also
2906  * move grant reservation head forward.
2907  */
2908 STATIC void
2909 xlog_regrant_reserve_log_space(
2910         struct xlog             *log,
2911         struct xlog_ticket      *ticket)
2912 {
2913         trace_xfs_log_regrant_reserve_enter(log, ticket);
2914
2915         if (ticket->t_cnt > 0)
2916                 ticket->t_cnt--;
2917
2918         xlog_grant_sub_space(log, &log->l_reserve_head.grant,
2919                                         ticket->t_curr_res);
2920         xlog_grant_sub_space(log, &log->l_write_head.grant,
2921                                         ticket->t_curr_res);
2922         ticket->t_curr_res = ticket->t_unit_res;
2923         xlog_tic_reset_res(ticket);
2924
2925         trace_xfs_log_regrant_reserve_sub(log, ticket);
2926
2927         /* just return if we still have some of the pre-reserved space */
2928         if (ticket->t_cnt > 0)
2929                 return;
2930
2931         xlog_grant_add_space(log, &log->l_reserve_head.grant,
2932                                         ticket->t_unit_res);
2933
2934         trace_xfs_log_regrant_reserve_exit(log, ticket);
2935
2936         ticket->t_curr_res = ticket->t_unit_res;
2937         xlog_tic_reset_res(ticket);
2938 }       /* xlog_regrant_reserve_log_space */
2939
2940
2941 /*
2942  * Give back the space left from a reservation.
2943  *
2944  * All the information we need to make a correct determination of space left
2945  * is present.  For non-permanent reservations, things are quite easy.  The
2946  * count should have been decremented to zero.  We only need to deal with the
2947  * space remaining in the current reservation part of the ticket.  If the
2948  * ticket contains a permanent reservation, there may be left over space which
2949  * needs to be released.  A count of N means that N-1 refills of the current
2950  * reservation can be done before we need to ask for more space.  The first
2951  * one goes to fill up the first current reservation.  Once we run out of
2952  * space, the count will stay at zero and the only space remaining will be
2953  * in the current reservation field.
2954  */
2955 STATIC void
2956 xlog_ungrant_log_space(
2957         struct xlog             *log,
2958         struct xlog_ticket      *ticket)
2959 {
2960         int     bytes;
2961
2962         if (ticket->t_cnt > 0)
2963                 ticket->t_cnt--;
2964
2965         trace_xfs_log_ungrant_enter(log, ticket);
2966         trace_xfs_log_ungrant_sub(log, ticket);
2967
2968         /*
2969          * If this is a permanent reservation ticket, we may be able to free
2970          * up more space based on the remaining count.
2971          */
2972         bytes = ticket->t_curr_res;
2973         if (ticket->t_cnt > 0) {
2974                 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
2975                 bytes += ticket->t_unit_res*ticket->t_cnt;
2976         }
2977
2978         xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
2979         xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
2980
2981         trace_xfs_log_ungrant_exit(log, ticket);
2982
2983         xfs_log_space_wake(log->l_mp);
2984 }
2985
2986 /*
2987  * Flush iclog to disk if this is the last reference to the given iclog and
2988  * the WANT_SYNC bit is set.
2989  *
2990  * When this function is entered, the iclog is not necessarily in the
2991  * WANT_SYNC state.  It may be sitting around waiting to get filled.
2992  *
2993  *
2994  */
2995 STATIC int
2996 xlog_state_release_iclog(
2997         struct xlog             *log,
2998         struct xlog_in_core     *iclog)
2999 {
3000         int             sync = 0;       /* do we sync? */
3001
3002         if (iclog->ic_state & XLOG_STATE_IOERROR)
3003                 return XFS_ERROR(EIO);
3004
3005         ASSERT(atomic_read(&iclog->ic_refcnt) > 0);
3006         if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock))
3007                 return 0;
3008
3009         if (iclog->ic_state & XLOG_STATE_IOERROR) {
3010                 spin_unlock(&log->l_icloglock);
3011                 return XFS_ERROR(EIO);
3012         }
3013         ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
3014                iclog->ic_state == XLOG_STATE_WANT_SYNC);
3015
3016         if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
3017                 /* update tail before writing to iclog */
3018                 xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
3019                 sync++;
3020                 iclog->ic_state = XLOG_STATE_SYNCING;
3021                 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
3022                 xlog_verify_tail_lsn(log, iclog, tail_lsn);
3023                 /* cycle incremented when incrementing curr_block */
3024         }
3025         spin_unlock(&log->l_icloglock);
3026
3027         /*
3028          * We let the log lock go, so it's possible that we hit a log I/O
3029          * error or some other SHUTDOWN condition that marks the iclog
3030          * as XLOG_STATE_IOERROR before the bwrite. However, we know that
3031          * this iclog has consistent data, so we ignore IOERROR
3032          * flags after this point.
3033          */
3034         if (sync)
3035                 return xlog_sync(log, iclog);
3036         return 0;
3037 }       /* xlog_state_release_iclog */
3038
3039
3040 /*
3041  * This routine will mark the current iclog in the ring as WANT_SYNC
3042  * and move the current iclog pointer to the next iclog in the ring.
3043  * When this routine is called from xlog_state_get_iclog_space(), the
3044  * exact size of the iclog has not yet been determined.  All we know is
3045  * that every data block.  We have run out of space in this log record.
3046  */
3047 STATIC void
3048 xlog_state_switch_iclogs(
3049         struct xlog             *log,
3050         struct xlog_in_core     *iclog,
3051         int                     eventual_size)
3052 {
3053         ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3054         if (!eventual_size)
3055                 eventual_size = iclog->ic_offset;
3056         iclog->ic_state = XLOG_STATE_WANT_SYNC;
3057         iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3058         log->l_prev_block = log->l_curr_block;
3059         log->l_prev_cycle = log->l_curr_cycle;
3060
3061         /* roll log?: ic_offset changed later */
3062         log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3063
3064         /* Round up to next log-sunit */
3065         if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3066             log->l_mp->m_sb.sb_logsunit > 1) {
3067                 __uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
3068                 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3069         }
3070
3071         if (log->l_curr_block >= log->l_logBBsize) {
3072                 log->l_curr_cycle++;
3073                 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3074                         log->l_curr_cycle++;
3075                 log->l_curr_block -= log->l_logBBsize;
3076                 ASSERT(log->l_curr_block >= 0);
3077         }
3078         ASSERT(iclog == log->l_iclog);
3079         log->l_iclog = iclog->ic_next;
3080 }       /* xlog_state_switch_iclogs */
3081
3082 /*
3083  * Write out all data in the in-core log as of this exact moment in time.
3084  *
3085  * Data may be written to the in-core log during this call.  However,
3086  * we don't guarantee this data will be written out.  A change from past
3087  * implementation means this routine will *not* write out zero length LRs.
3088  *
3089  * Basically, we try and perform an intelligent scan of the in-core logs.
3090  * If we determine there is no flushable data, we just return.  There is no
3091  * flushable data if:
3092  *
3093  *      1. the current iclog is active and has no data; the previous iclog
3094  *              is in the active or dirty state.
3095  *      2. the current iclog is drity, and the previous iclog is in the
3096  *              active or dirty state.
3097  *
3098  * We may sleep if:
3099  *
3100  *      1. the current iclog is not in the active nor dirty state.
3101  *      2. the current iclog dirty, and the previous iclog is not in the
3102  *              active nor dirty state.
3103  *      3. the current iclog is active, and there is another thread writing
3104  *              to this particular iclog.
3105  *      4. a) the current iclog is active and has no other writers
3106  *         b) when we return from flushing out this iclog, it is still
3107  *              not in the active nor dirty state.
3108  */
3109 int
3110 _xfs_log_force(
3111         struct xfs_mount        *mp,
3112         uint                    flags,
3113         int                     *log_flushed)
3114 {
3115         struct xlog             *log = mp->m_log;
3116         struct xlog_in_core     *iclog;
3117         xfs_lsn_t               lsn;
3118
3119         XFS_STATS_INC(xs_log_force);
3120
3121         xlog_cil_force(log);
3122
3123         spin_lock(&log->l_icloglock);
3124
3125         iclog = log->l_iclog;
3126         if (iclog->ic_state & XLOG_STATE_IOERROR) {
3127                 spin_unlock(&log->l_icloglock);
3128                 return XFS_ERROR(EIO);
3129         }
3130
3131         /* If the head iclog is not active nor dirty, we just attach
3132          * ourselves to the head and go to sleep.
3133          */
3134         if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3135             iclog->ic_state == XLOG_STATE_DIRTY) {
3136                 /*
3137                  * If the head is dirty or (active and empty), then
3138                  * we need to look at the previous iclog.  If the previous
3139                  * iclog is active or dirty we are done.  There is nothing
3140                  * to sync out.  Otherwise, we attach ourselves to the
3141                  * previous iclog and go to sleep.
3142                  */
3143                 if (iclog->ic_state == XLOG_STATE_DIRTY ||
3144                     (atomic_read(&iclog->ic_refcnt) == 0
3145                      && iclog->ic_offset == 0)) {
3146                         iclog = iclog->ic_prev;
3147                         if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3148                             iclog->ic_state == XLOG_STATE_DIRTY)
3149                                 goto no_sleep;
3150                         else
3151                                 goto maybe_sleep;
3152                 } else {
3153                         if (atomic_read(&iclog->ic_refcnt) == 0) {
3154                                 /* We are the only one with access to this
3155                                  * iclog.  Flush it out now.  There should
3156                                  * be a roundoff of zero to show that someone
3157                                  * has already taken care of the roundoff from
3158                                  * the previous sync.
3159                                  */
3160                                 atomic_inc(&iclog->ic_refcnt);
3161                                 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3162                                 xlog_state_switch_iclogs(log, iclog, 0);
3163                                 spin_unlock(&log->l_icloglock);
3164
3165                                 if (xlog_state_release_iclog(log, iclog))
3166                                         return XFS_ERROR(EIO);
3167
3168                                 if (log_flushed)
3169                                         *log_flushed = 1;
3170                                 spin_lock(&log->l_icloglock);
3171                                 if (be64_to_cpu(iclog->ic_header.h_lsn) == lsn &&
3172                                     iclog->ic_state != XLOG_STATE_DIRTY)
3173                                         goto maybe_sleep;
3174                                 else
3175                                         goto no_sleep;
3176                         } else {
3177                                 /* Someone else is writing to this iclog.
3178                                  * Use its call to flush out the data.  However,
3179                                  * the other thread may not force out this LR,
3180                                  * so we mark it WANT_SYNC.
3181                                  */
3182                                 xlog_state_switch_iclogs(log, iclog, 0);
3183                                 goto maybe_sleep;
3184                         }
3185                 }
3186         }
3187
3188         /* By the time we come around again, the iclog could've been filled
3189          * which would give it another lsn.  If we have a new lsn, just
3190          * return because the relevant data has been flushed.
3191          */
3192 maybe_sleep:
3193         if (flags & XFS_LOG_SYNC) {
3194                 /*
3195                  * We must check if we're shutting down here, before
3196                  * we wait, while we're holding the l_icloglock.
3197                  * Then we check again after waking up, in case our
3198                  * sleep was disturbed by a bad news.
3199                  */
3200                 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3201                         spin_unlock(&log->l_icloglock);
3202                         return XFS_ERROR(EIO);
3203                 }
3204                 XFS_STATS_INC(xs_log_force_sleep);
3205                 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3206                 /*
3207                  * No need to grab the log lock here since we're
3208                  * only deciding whether or not to return EIO
3209                  * and the memory read should be atomic.
3210                  */
3211                 if (iclog->ic_state & XLOG_STATE_IOERROR)
3212                         return XFS_ERROR(EIO);
3213                 if (log_flushed)
3214                         *log_flushed = 1;
3215         } else {
3216
3217 no_sleep:
3218                 spin_unlock(&log->l_icloglock);
3219         }
3220         return 0;
3221 }
3222
3223 /*
3224  * Wrapper for _xfs_log_force(), to be used when caller doesn't care
3225  * about errors or whether the log was flushed or not. This is the normal
3226  * interface to use when trying to unpin items or move the log forward.
3227  */
3228 void
3229 xfs_log_force(
3230         xfs_mount_t     *mp,
3231         uint            flags)
3232 {
3233         int     error;
3234
3235         trace_xfs_log_force(mp, 0);
3236         error = _xfs_log_force(mp, flags, NULL);
3237         if (error)
3238                 xfs_warn(mp, "%s: error %d returned.", __func__, error);
3239 }
3240
3241 /*
3242  * Force the in-core log to disk for a specific LSN.
3243  *
3244  * Find in-core log with lsn.
3245  *      If it is in the DIRTY state, just return.
3246  *      If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3247  *              state and go to sleep or return.
3248  *      If it is in any other state, go to sleep or return.
3249  *
3250  * Synchronous forces are implemented with a signal variable. All callers
3251  * to force a given lsn to disk will wait on a the sv attached to the
3252  * specific in-core log.  When given in-core log finally completes its
3253  * write to disk, that thread will wake up all threads waiting on the
3254  * sv.
3255  */
3256 int
3257 _xfs_log_force_lsn(
3258         struct xfs_mount        *mp,
3259         xfs_lsn_t               lsn,
3260         uint                    flags,
3261         int                     *log_flushed)
3262 {
3263         struct xlog             *log = mp->m_log;
3264         struct xlog_in_core     *iclog;
3265         int                     already_slept = 0;
3266
3267         ASSERT(lsn != 0);
3268
3269         XFS_STATS_INC(xs_log_force);
3270
3271         lsn = xlog_cil_force_lsn(log, lsn);
3272         if (lsn == NULLCOMMITLSN)
3273                 return 0;
3274
3275 try_again:
3276         spin_lock(&log->l_icloglock);
3277         iclog = log->l_iclog;
3278         if (iclog->ic_state & XLOG_STATE_IOERROR) {
3279                 spin_unlock(&log->l_icloglock);
3280                 return XFS_ERROR(EIO);
3281         }
3282
3283         do {
3284                 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3285                         iclog = iclog->ic_next;
3286                         continue;
3287                 }
3288
3289                 if (iclog->ic_state == XLOG_STATE_DIRTY) {
3290                         spin_unlock(&log->l_icloglock);
3291                         return 0;
3292                 }
3293
3294                 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3295                         /*
3296                          * We sleep here if we haven't already slept (e.g.
3297                          * this is the first time we've looked at the correct
3298                          * iclog buf) and the buffer before us is going to
3299                          * be sync'ed. The reason for this is that if we
3300                          * are doing sync transactions here, by waiting for
3301                          * the previous I/O to complete, we can allow a few
3302                          * more transactions into this iclog before we close
3303                          * it down.
3304                          *
3305                          * Otherwise, we mark the buffer WANT_SYNC, and bump
3306                          * up the refcnt so we can release the log (which
3307                          * drops the ref count).  The state switch keeps new
3308                          * transaction commits from using this buffer.  When
3309                          * the current commits finish writing into the buffer,
3310                          * the refcount will drop to zero and the buffer will
3311                          * go out then.
3312                          */
3313                         if (!already_slept &&
3314                             (iclog->ic_prev->ic_state &
3315                              (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
3316                                 ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
3317
3318                                 XFS_STATS_INC(xs_log_force_sleep);
3319
3320                                 xlog_wait(&iclog->ic_prev->ic_write_wait,
3321                                                         &log->l_icloglock);
3322                                 if (log_flushed)
3323                                         *log_flushed = 1;
3324                                 already_slept = 1;
3325                                 goto try_again;
3326                         }
3327                         atomic_inc(&iclog->ic_refcnt);
3328                         xlog_state_switch_iclogs(log, iclog, 0);
3329                         spin_unlock(&log->l_icloglock);
3330                         if (xlog_state_release_iclog(log, iclog))
3331                                 return XFS_ERROR(EIO);
3332                         if (log_flushed)
3333                                 *log_flushed = 1;
3334                         spin_lock(&log->l_icloglock);
3335                 }
3336
3337                 if ((flags & XFS_LOG_SYNC) && /* sleep */
3338                     !(iclog->ic_state &
3339                       (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))) {
3340                         /*
3341                          * Don't wait on completion if we know that we've
3342                          * gotten a log write error.
3343                          */
3344                         if (iclog->ic_state & XLOG_STATE_IOERROR) {
3345                                 spin_unlock(&log->l_icloglock);
3346                                 return XFS_ERROR(EIO);
3347                         }
3348                         XFS_STATS_INC(xs_log_force_sleep);
3349                         xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3350                         /*
3351                          * No need to grab the log lock here since we're
3352                          * only deciding whether or not to return EIO
3353                          * and the memory read should be atomic.
3354                          */
3355                         if (iclog->ic_state & XLOG_STATE_IOERROR)
3356                                 return XFS_ERROR(EIO);
3357
3358                         if (log_flushed)
3359                                 *log_flushed = 1;
3360                 } else {                /* just return */
3361                         spin_unlock(&log->l_icloglock);
3362                 }
3363
3364                 return 0;
3365         } while (iclog != log->l_iclog);
3366
3367         spin_unlock(&log->l_icloglock);
3368         return 0;
3369 }
3370
3371 /*
3372  * Wrapper for _xfs_log_force_lsn(), to be used when caller doesn't care
3373  * about errors or whether the log was flushed or not. This is the normal
3374  * interface to use when trying to unpin items or move the log forward.
3375  */
3376 void
3377 xfs_log_force_lsn(
3378         xfs_mount_t     *mp,
3379         xfs_lsn_t       lsn,
3380         uint            flags)
3381 {
3382         int     error;
3383
3384         trace_xfs_log_force(mp, lsn);
3385         error = _xfs_log_force_lsn(mp, lsn, flags, NULL);
3386         if (error)
3387                 xfs_warn(mp, "%s: error %d returned.", __func__, error);
3388 }
3389
3390 /*
3391  * Called when we want to mark the current iclog as being ready to sync to
3392  * disk.
3393  */
3394 STATIC void
3395 xlog_state_want_sync(
3396         struct xlog             *log,
3397         struct xlog_in_core     *iclog)
3398 {
3399         assert_spin_locked(&log->l_icloglock);
3400
3401         if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3402                 xlog_state_switch_iclogs(log, iclog, 0);
3403         } else {
3404                 ASSERT(iclog->ic_state &
3405                         (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3406         }
3407 }
3408
3409
3410 /*****************************************************************************
3411  *
3412  *              TICKET functions
3413  *
3414  *****************************************************************************
3415  */
3416
3417 /*
3418  * Free a used ticket when its refcount falls to zero.
3419  */
3420 void
3421 xfs_log_ticket_put(
3422         xlog_ticket_t   *ticket)
3423 {
3424         ASSERT(atomic_read(&ticket->t_ref) > 0);
3425         if (atomic_dec_and_test(&ticket->t_ref))
3426                 kmem_zone_free(xfs_log_ticket_zone, ticket);
3427 }
3428
3429 xlog_ticket_t *
3430 xfs_log_ticket_get(
3431         xlog_ticket_t   *ticket)
3432 {
3433         ASSERT(atomic_read(&ticket->t_ref) > 0);
3434         atomic_inc(&ticket->t_ref);
3435         return ticket;
3436 }
3437
3438 /*
3439  * Figure out the total log space unit (in bytes) that would be
3440  * required for a log ticket.
3441  */
3442 int
3443 xfs_log_calc_unit_res(
3444         struct xfs_mount        *mp,
3445         int                     unit_bytes)
3446 {
3447         struct xlog             *log = mp->m_log;
3448         int                     iclog_space;
3449         uint                    num_headers;
3450
3451         /*
3452          * Permanent reservations have up to 'cnt'-1 active log operations
3453          * in the log.  A unit in this case is the amount of space for one
3454          * of these log operations.  Normal reservations have a cnt of 1
3455          * and their unit amount is the total amount of space required.
3456          *
3457          * The following lines of code account for non-transaction data
3458          * which occupy space in the on-disk log.
3459          *
3460          * Normal form of a transaction is:
3461          * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3462          * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3463          *
3464          * We need to account for all the leadup data and trailer data
3465          * around the transaction data.
3466          * And then we need to account for the worst case in terms of using
3467          * more space.
3468          * The worst case will happen if:
3469          * - the placement of the transaction happens to be such that the
3470          *   roundoff is at its maximum
3471          * - the transaction data is synced before the commit record is synced
3472          *   i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3473          *   Therefore the commit record is in its own Log Record.
3474          *   This can happen as the commit record is called with its
3475          *   own region to xlog_write().
3476          *   This then means that in the worst case, roundoff can happen for
3477          *   the commit-rec as well.
3478          *   The commit-rec is smaller than padding in this scenario and so it is
3479          *   not added separately.
3480          */
3481
3482         /* for trans header */
3483         unit_bytes += sizeof(xlog_op_header_t);
3484         unit_bytes += sizeof(xfs_trans_header_t);
3485
3486         /* for start-rec */
3487         unit_bytes += sizeof(xlog_op_header_t);
3488
3489         /*
3490          * for LR headers - the space for data in an iclog is the size minus
3491          * the space used for the headers. If we use the iclog size, then we
3492          * undercalculate the number of headers required.
3493          *
3494          * Furthermore - the addition of op headers for split-recs might
3495          * increase the space required enough to require more log and op
3496          * headers, so take that into account too.
3497          *
3498          * IMPORTANT: This reservation makes the assumption that if this
3499          * transaction is the first in an iclog and hence has the LR headers
3500          * accounted to it, then the remaining space in the iclog is
3501          * exclusively for this transaction.  i.e. if the transaction is larger
3502          * than the iclog, it will be the only thing in that iclog.
3503          * Fundamentally, this means we must pass the entire log vector to
3504          * xlog_write to guarantee this.
3505          */
3506         iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3507         num_headers = howmany(unit_bytes, iclog_space);
3508
3509         /* for split-recs - ophdrs added when data split over LRs */
3510         unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3511
3512         /* add extra header reservations if we overrun */
3513         while (!num_headers ||
3514                howmany(unit_bytes, iclog_space) > num_headers) {
3515                 unit_bytes += sizeof(xlog_op_header_t);
3516                 num_headers++;
3517         }
3518         unit_bytes += log->l_iclog_hsize * num_headers;
3519
3520         /* for commit-rec LR header - note: padding will subsume the ophdr */
3521         unit_bytes += log->l_iclog_hsize;
3522
3523         /* for roundoff padding for transaction data and one for commit record */
3524         if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) {
3525                 /* log su roundoff */
3526                 unit_bytes += 2 * mp->m_sb.sb_logsunit;
3527         } else {
3528                 /* BB roundoff */
3529                 unit_bytes += 2 * BBSIZE;
3530         }
3531
3532         return unit_bytes;
3533 }
3534
3535 /*
3536  * Allocate and initialise a new log ticket.
3537  */
3538 struct xlog_ticket *
3539 xlog_ticket_alloc(
3540         struct xlog             *log,
3541         int                     unit_bytes,
3542         int                     cnt,
3543         char                    client,
3544         bool                    permanent,
3545         xfs_km_flags_t          alloc_flags)
3546 {
3547         struct xlog_ticket      *tic;
3548         int                     unit_res;
3549
3550         tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
3551         if (!tic)
3552                 return NULL;
3553
3554         unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes);
3555
3556         atomic_set(&tic->t_ref, 1);
3557         tic->t_task             = current;
3558         INIT_LIST_HEAD(&tic->t_queue);
3559         tic->t_unit_res         = unit_res;
3560         tic->t_curr_res         = unit_res;
3561         tic->t_cnt              = cnt;
3562         tic->t_ocnt             = cnt;
3563         tic->t_tid              = prandom_u32();
3564         tic->t_clientid         = client;
3565         tic->t_flags            = XLOG_TIC_INITED;
3566         tic->t_trans_type       = 0;
3567         if (permanent)
3568                 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3569
3570         xlog_tic_reset_res(tic);
3571
3572         return tic;
3573 }
3574
3575
3576 /******************************************************************************
3577  *
3578  *              Log debug routines
3579  *
3580  ******************************************************************************
3581  */
3582 #if defined(DEBUG)
3583 /*
3584  * Make sure that the destination ptr is within the valid data region of
3585  * one of the iclogs.  This uses backup pointers stored in a different
3586  * part of the log in case we trash the log structure.
3587  */
3588 void
3589 xlog_verify_dest_ptr(
3590         struct xlog     *log,
3591         char            *ptr)
3592 {
3593         int i;
3594         int good_ptr = 0;
3595
3596         for (i = 0; i < log->l_iclog_bufs; i++) {
3597                 if (ptr >= log->l_iclog_bak[i] &&
3598                     ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
3599                         good_ptr++;
3600         }
3601
3602         if (!good_ptr)
3603                 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3604 }
3605
3606 /*
3607  * Check to make sure the grant write head didn't just over lap the tail.  If
3608  * the cycles are the same, we can't be overlapping.  Otherwise, make sure that
3609  * the cycles differ by exactly one and check the byte count.
3610  *
3611  * This check is run unlocked, so can give false positives. Rather than assert
3612  * on failures, use a warn-once flag and a panic tag to allow the admin to
3613  * determine if they want to panic the machine when such an error occurs. For
3614  * debug kernels this will have the same effect as using an assert but, unlinke
3615  * an assert, it can be turned off at runtime.
3616  */
3617 STATIC void
3618 xlog_verify_grant_tail(
3619         struct xlog     *log)
3620 {
3621         int             tail_cycle, tail_blocks;
3622         int             cycle, space;
3623
3624         xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3625         xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3626         if (tail_cycle != cycle) {
3627                 if (cycle - 1 != tail_cycle &&
3628                     !(log->l_flags & XLOG_TAIL_WARN)) {
3629                         xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3630                                 "%s: cycle - 1 != tail_cycle", __func__);
3631                         log->l_flags |= XLOG_TAIL_WARN;
3632                 }
3633
3634                 if (space > BBTOB(tail_blocks) &&
3635                     !(log->l_flags & XLOG_TAIL_WARN)) {
3636                         xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3637                                 "%s: space > BBTOB(tail_blocks)", __func__);
3638                         log->l_flags |= XLOG_TAIL_WARN;
3639                 }
3640         }
3641 }
3642
3643 /* check if it will fit */
3644 STATIC void
3645 xlog_verify_tail_lsn(
3646         struct xlog             *log,
3647         struct xlog_in_core     *iclog,
3648         xfs_lsn_t               tail_lsn)
3649 {
3650     int blocks;
3651
3652     if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3653         blocks =
3654             log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3655         if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3656                 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3657     } else {
3658         ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3659
3660         if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3661                 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3662
3663         blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3664         if (blocks < BTOBB(iclog->ic_offset) + 1)
3665                 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3666     }
3667 }       /* xlog_verify_tail_lsn */
3668
3669 /*
3670  * Perform a number of checks on the iclog before writing to disk.
3671  *
3672  * 1. Make sure the iclogs are still circular
3673  * 2. Make sure we have a good magic number
3674  * 3. Make sure we don't have magic numbers in the data
3675  * 4. Check fields of each log operation header for:
3676  *      A. Valid client identifier
3677  *      B. tid ptr value falls in valid ptr space (user space code)
3678  *      C. Length in log record header is correct according to the
3679  *              individual operation headers within record.
3680  * 5. When a bwrite will occur within 5 blocks of the front of the physical
3681  *      log, check the preceding blocks of the physical log to make sure all
3682  *      the cycle numbers agree with the current cycle number.
3683  */
3684 STATIC void
3685 xlog_verify_iclog(
3686         struct xlog             *log,
3687         struct xlog_in_core     *iclog,
3688         int                     count,
3689         bool                    syncing)
3690 {
3691         xlog_op_header_t        *ophead;
3692         xlog_in_core_t          *icptr;
3693         xlog_in_core_2_t        *xhdr;
3694         xfs_caddr_t             ptr;
3695         xfs_caddr_t             base_ptr;
3696         __psint_t               field_offset;
3697         __uint8_t               clientid;
3698         int                     len, i, j, k, op_len;
3699         int                     idx;
3700
3701         /* check validity of iclog pointers */
3702         spin_lock(&log->l_icloglock);
3703         icptr = log->l_iclog;
3704         for (i=0; i < log->l_iclog_bufs; i++) {
3705                 if (icptr == NULL)
3706                         xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3707                 icptr = icptr->ic_next;
3708         }
3709         if (icptr != log->l_iclog)
3710                 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3711         spin_unlock(&log->l_icloglock);
3712
3713         /* check log magic numbers */
3714         if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3715                 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3716
3717         ptr = (xfs_caddr_t) &iclog->ic_header;
3718         for (ptr += BBSIZE; ptr < ((xfs_caddr_t)&iclog->ic_header) + count;
3719              ptr += BBSIZE) {
3720                 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3721                         xfs_emerg(log->l_mp, "%s: unexpected magic num",
3722                                 __func__);
3723         }
3724
3725         /* check fields */
3726         len = be32_to_cpu(iclog->ic_header.h_num_logops);
3727         ptr = iclog->ic_datap;
3728         base_ptr = ptr;
3729         ophead = (xlog_op_header_t *)ptr;
3730         xhdr = iclog->ic_data;
3731         for (i = 0; i < len; i++) {
3732                 ophead = (xlog_op_header_t *)ptr;
3733
3734                 /* clientid is only 1 byte */
3735                 field_offset = (__psint_t)
3736                                ((xfs_caddr_t)&(ophead->oh_clientid) - base_ptr);
3737                 if (!syncing || (field_offset & 0x1ff)) {
3738                         clientid = ophead->oh_clientid;
3739                 } else {
3740                         idx = BTOBBT((xfs_caddr_t)&(ophead->oh_clientid) - iclog->ic_datap);
3741                         if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3742                                 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3743                                 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3744                                 clientid = xlog_get_client_id(
3745                                         xhdr[j].hic_xheader.xh_cycle_data[k]);
3746                         } else {
3747                                 clientid = xlog_get_client_id(
3748                                         iclog->ic_header.h_cycle_data[idx]);
3749                         }
3750                 }
3751                 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3752                         xfs_warn(log->l_mp,
3753                                 "%s: invalid clientid %d op 0x%p offset 0x%lx",
3754                                 __func__, clientid, ophead,
3755                                 (unsigned long)field_offset);
3756
3757                 /* check length */
3758                 field_offset = (__psint_t)
3759                                ((xfs_caddr_t)&(ophead->oh_len) - base_ptr);
3760                 if (!syncing || (field_offset & 0x1ff)) {
3761                         op_len = be32_to_cpu(ophead->oh_len);
3762                 } else {
3763                         idx = BTOBBT((__psint_t)&ophead->oh_len -
3764                                     (__psint_t)iclog->ic_datap);
3765                         if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3766                                 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3767                                 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3768                                 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3769                         } else {
3770                                 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3771                         }
3772                 }
3773                 ptr += sizeof(xlog_op_header_t) + op_len;
3774         }
3775 }       /* xlog_verify_iclog */
3776 #endif
3777
3778 /*
3779  * Mark all iclogs IOERROR. l_icloglock is held by the caller.
3780  */
3781 STATIC int
3782 xlog_state_ioerror(
3783         struct xlog     *log)
3784 {
3785         xlog_in_core_t  *iclog, *ic;
3786
3787         iclog = log->l_iclog;
3788         if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
3789                 /*
3790                  * Mark all the incore logs IOERROR.
3791                  * From now on, no log flushes will result.
3792                  */
3793                 ic = iclog;
3794                 do {
3795                         ic->ic_state = XLOG_STATE_IOERROR;
3796                         ic = ic->ic_next;
3797                 } while (ic != iclog);
3798                 return 0;
3799         }
3800         /*
3801          * Return non-zero, if state transition has already happened.
3802          */
3803         return 1;
3804 }
3805
3806 /*
3807  * This is called from xfs_force_shutdown, when we're forcibly
3808  * shutting down the filesystem, typically because of an IO error.
3809  * Our main objectives here are to make sure that:
3810  *      a. the filesystem gets marked 'SHUTDOWN' for all interested
3811  *         parties to find out, 'atomically'.
3812  *      b. those who're sleeping on log reservations, pinned objects and
3813  *          other resources get woken up, and be told the bad news.
3814  *      c. nothing new gets queued up after (a) and (b) are done.
3815  *      d. if !logerror, flush the iclogs to disk, then seal them off
3816  *         for business.
3817  *
3818  * Note: for delayed logging the !logerror case needs to flush the regions
3819  * held in memory out to the iclogs before flushing them to disk. This needs
3820  * to be done before the log is marked as shutdown, otherwise the flush to the
3821  * iclogs will fail.
3822  */
3823 int
3824 xfs_log_force_umount(
3825         struct xfs_mount        *mp,
3826         int                     logerror)
3827 {
3828         struct xlog     *log;
3829         int             retval;
3830
3831         log = mp->m_log;
3832
3833         /*
3834          * If this happens during log recovery, don't worry about
3835          * locking; the log isn't open for business yet.
3836          */
3837         if (!log ||
3838             log->l_flags & XLOG_ACTIVE_RECOVERY) {
3839                 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3840                 if (mp->m_sb_bp)
3841                         XFS_BUF_DONE(mp->m_sb_bp);
3842                 return 0;
3843         }
3844
3845         /*
3846          * Somebody could've already done the hard work for us.
3847          * No need to get locks for this.
3848          */
3849         if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
3850                 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3851                 return 1;
3852         }
3853         retval = 0;
3854
3855         /*
3856          * Flush the in memory commit item list before marking the log as
3857          * being shut down. We need to do it in this order to ensure all the
3858          * completed transactions are flushed to disk with the xfs_log_force()
3859          * call below.
3860          */
3861         if (!logerror)
3862                 xlog_cil_force(log);
3863
3864         /*
3865          * mark the filesystem and the as in a shutdown state and wake
3866          * everybody up to tell them the bad news.
3867          */
3868         spin_lock(&log->l_icloglock);
3869         mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3870         if (mp->m_sb_bp)
3871                 XFS_BUF_DONE(mp->m_sb_bp);
3872
3873         /*
3874          * This flag is sort of redundant because of the mount flag, but
3875          * it's good to maintain the separation between the log and the rest
3876          * of XFS.
3877          */
3878         log->l_flags |= XLOG_IO_ERROR;
3879
3880         /*
3881          * If we hit a log error, we want to mark all the iclogs IOERROR
3882          * while we're still holding the loglock.
3883          */
3884         if (logerror)
3885                 retval = xlog_state_ioerror(log);
3886         spin_unlock(&log->l_icloglock);
3887
3888         /*
3889          * We don't want anybody waiting for log reservations after this. That
3890          * means we have to wake up everybody queued up on reserveq as well as
3891          * writeq.  In addition, we make sure in xlog_{re}grant_log_space that
3892          * we don't enqueue anything once the SHUTDOWN flag is set, and this
3893          * action is protected by the grant locks.
3894          */
3895         xlog_grant_head_wake_all(&log->l_reserve_head);
3896         xlog_grant_head_wake_all(&log->l_write_head);
3897
3898         if (!(log->l_iclog->ic_state & XLOG_STATE_IOERROR)) {
3899                 ASSERT(!logerror);
3900                 /*
3901                  * Force the incore logs to disk before shutting the
3902                  * log down completely.
3903                  */
3904                 _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
3905
3906                 spin_lock(&log->l_icloglock);
3907                 retval = xlog_state_ioerror(log);
3908                 spin_unlock(&log->l_icloglock);
3909         }
3910         /*
3911          * Wake up everybody waiting on xfs_log_force.
3912          * Callback all log item committed functions as if the
3913          * log writes were completed.
3914          */
3915         xlog_state_do_callback(log, XFS_LI_ABORTED, NULL);
3916
3917 #ifdef XFSERRORDEBUG
3918         {
3919                 xlog_in_core_t  *iclog;
3920
3921                 spin_lock(&log->l_icloglock);
3922                 iclog = log->l_iclog;
3923                 do {
3924                         ASSERT(iclog->ic_callback == 0);
3925                         iclog = iclog->ic_next;
3926                 } while (iclog != log->l_iclog);
3927                 spin_unlock(&log->l_icloglock);
3928         }
3929 #endif
3930         /* return non-zero if log IOERROR transition had already happened */
3931         return retval;
3932 }
3933
3934 STATIC int
3935 xlog_iclogs_empty(
3936         struct xlog     *log)
3937 {
3938         xlog_in_core_t  *iclog;
3939
3940         iclog = log->l_iclog;
3941         do {
3942                 /* endianness does not matter here, zero is zero in
3943                  * any language.
3944                  */
3945                 if (iclog->ic_header.h_num_logops)
3946                         return 0;
3947                 iclog = iclog->ic_next;
3948         } while (iclog != log->l_iclog);
3949         return 1;
3950 }
3951