fs/gfs2/log.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/gfs2_ondisk.h>
  16 #include <linux/crc32.h>
  17 #include <linux/lm_interface.h>
  18
  19 #include "gfs2.h"
  20 #include "incore.h"
  21 #include "bmap.h"
  22 #include "glock.h"
  23 #include "log.h"
  24 #include "lops.h"
  25 #include "meta_io.h"
  26 #include "util.h"
  27 #include "dir.h"
  28
  29 #define PULL 1
  30
  31 /**
  32  * gfs2_struct2blk - compute stuff
  33  * @sdp: the filesystem
  34  * @nstruct: the number of structures
  35  * @ssize: the size of the structures
  36  *
  37  * Compute the number of log descriptor blocks needed to hold a certain number
  38  * of structures of a certain size.
  39  *
  40  * Returns: the number of blocks needed (minimum is always 1)
  41  */
  42
  43 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
  44                              unsigned int ssize)
  45 {
  46         unsigned int blks;
  47         unsigned int first, second;
  48
  49         blks = 1;
  50         first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
  51
  52         if (nstruct > first) {
  53                 second = (sdp->sd_sb.sb_bsize -
  54                           sizeof(struct gfs2_meta_header)) / ssize;
  55                 blks += DIV_ROUND_UP(nstruct - first, second);
  56         }
  57
  58         return blks;
  59 }
  60
  61 /**
  62  * gfs2_ail1_start_one - Start I/O on a part of the AIL
  63  * @sdp: the filesystem
  64  * @tr: the part of the AIL
  65  *
  66  */
  67
  68 static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
  69 {
  70         struct gfs2_bufdata *bd, *s;
  71         struct buffer_head *bh;
  72         int retry;
  73
  74         BUG_ON(!spin_is_locked(&sdp->sd_log_lock));
  75
  76         do {
  77                 retry = 0;
  78
  79                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
  80                                                  bd_ail_st_list) {
  81                         bh = bd->bd_bh;
  82
  83                         gfs2_assert(sdp, bd->bd_ail == ai);
  84
  85                         if (!buffer_busy(bh)) {
  86                                 if (!buffer_uptodate(bh)) {
  87                                         gfs2_log_unlock(sdp);
  88                                         gfs2_io_error_bh(sdp, bh);
  89                                         gfs2_log_lock(sdp);
  90                                 }
  91                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
  92                                 continue;
  93                         }
  94
  95                         if (!buffer_dirty(bh))
  96                                 continue;
  97
  98                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
  99
 100                         gfs2_log_unlock(sdp);
 101                         wait_on_buffer(bh);
 102                         ll_rw_block(WRITE, 1, &bh);
 103                         gfs2_log_lock(sdp);
 104
 105                         retry = 1;
 106                         break;
 107                 }
 108         } while (retry);
 109 }
 110
 111 /**
 112  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 113  * @sdp: the filesystem
 114  * @ai: the AIL entry
 115  *
 116  */
 117
 118 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 119 {
 120         struct gfs2_bufdata *bd, *s;
 121         struct buffer_head *bh;
 122
 123         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 124                                          bd_ail_st_list) {
 125                 bh = bd->bd_bh;
 126
 127                 gfs2_assert(sdp, bd->bd_ail == ai);
 128
 129                 if (buffer_busy(bh)) {
 130                         if (flags & DIO_ALL)
 131                                 continue;
 132                         else
 133                                 break;
 134                 }
 135
 136                 if (!buffer_uptodate(bh))
 137                         gfs2_io_error_bh(sdp, bh);
 138
 139                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 140         }
 141
 142         return list_empty(&ai->ai_ail1_list);
 143 }
 144
 145 void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
 146 {
 147         struct list_head *head = &sdp->sd_ail1_list;
 148         u64 sync_gen;
 149         struct list_head *first;
 150         struct gfs2_ail *first_ai, *ai, *tmp;
 151         int done = 0;
 152
 153         gfs2_log_lock(sdp);
 154         if (list_empty(head)) {
 155                 gfs2_log_unlock(sdp);
 156                 return;
 157         }
 158         sync_gen = sdp->sd_ail_sync_gen++;
 159
 160         first = head->prev;
 161         first_ai = list_entry(first, struct gfs2_ail, ai_list);
 162         first_ai->ai_sync_gen = sync_gen;
 163         gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */
 164
 165         if (flags & DIO_ALL)
 166                 first = NULL;
 167
 168         while(!done) {
 169                 if (first && (head->prev != first ||
 170                               gfs2_ail1_empty_one(sdp, first_ai, 0)))
 171                         break;
 172
 173                 done = 1;
 174                 list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) {
 175                         if (ai->ai_sync_gen >= sync_gen)
 176                                 continue;
 177                         ai->ai_sync_gen = sync_gen;
 178                         gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
 179                         done = 0;
 180                         break;
 181                 }
 182         }
 183
 184         gfs2_log_unlock(sdp);
 185 }
 186
 187 int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
 188 {
 189         struct gfs2_ail *ai, *s;
 190         int ret;
 191
 192         gfs2_log_lock(sdp);
 193
 194         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
 195                 if (gfs2_ail1_empty_one(sdp, ai, flags))
 196                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
 197                 else if (!(flags & DIO_ALL))
 198                         break;
 199         }
 200
 201         ret = list_empty(&sdp->sd_ail1_list);
 202
 203         gfs2_log_unlock(sdp);
 204
 205         return ret;
 206 }
 207
 208
 209 /**
 210  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 211  * @sdp: the filesystem
 212  * @ai: the AIL entry
 213  *
 214  */
 215
 216 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 217 {
 218         struct list_head *head = &ai->ai_ail2_list;
 219         struct gfs2_bufdata *bd;
 220
 221         while (!list_empty(head)) {
 222                 bd = list_entry(head->prev, struct gfs2_bufdata,
 223                                 bd_ail_st_list);
 224                 gfs2_assert(sdp, bd->bd_ail == ai);
 225                 bd->bd_ail = NULL;
 226                 list_del(&bd->bd_ail_st_list);
 227                 list_del(&bd->bd_ail_gl_list);
 228                 atomic_dec(&bd->bd_gl->gl_ail_count);
 229                 brelse(bd->bd_bh);
 230         }
 231 }
 232
 233 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 234 {
 235         struct gfs2_ail *ai, *safe;
 236         unsigned int old_tail = sdp->sd_log_tail;
 237         int wrap = (new_tail < old_tail);
 238         int a, b, rm;
 239
 240         gfs2_log_lock(sdp);
 241
 242         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
 243                 a = (old_tail <= ai->ai_first);
 244                 b = (ai->ai_first < new_tail);
 245                 rm = (wrap) ? (a || b) : (a && b);
 246                 if (!rm)
 247                         continue;
 248
 249                 gfs2_ail2_empty_one(sdp, ai);
 250                 list_del(&ai->ai_list);
 251                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
 252                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
 253                 kfree(ai);
 254         }
 255
 256         gfs2_log_unlock(sdp);
 257 }
 258
 259 /**
 260  * gfs2_log_reserve - Make a log reservation
 261  * @sdp: The GFS2 superblock
 262  * @blks: The number of blocks to reserve
 263  *
 264  * Returns: errno
 265  */
 266
 267 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 268 {
 269         unsigned int try = 0;
 270
 271         if (gfs2_assert_warn(sdp, blks) ||
 272             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 273                 return -EINVAL;
 274
 275         mutex_lock(&sdp->sd_log_reserve_mutex);
 276         gfs2_log_lock(sdp);
 277         while(sdp->sd_log_blks_free <= blks) {
 278                 gfs2_log_unlock(sdp);
 279                 gfs2_ail1_empty(sdp, 0);
 280                 gfs2_log_flush(sdp, NULL);
 281
 282                 if (try++)
 283                         gfs2_ail1_start(sdp, 0);
 284                 gfs2_log_lock(sdp);
 285         }
 286         sdp->sd_log_blks_free -= blks;
 287         gfs2_log_unlock(sdp);
 288         mutex_unlock(&sdp->sd_log_reserve_mutex);
 289
 290         down_read(&sdp->sd_log_flush_lock);
 291
 292         return 0;
 293 }
 294
 295 /**
 296  * gfs2_log_release - Release a given number of log blocks
 297  * @sdp: The GFS2 superblock
 298  * @blks: The number of blocks
 299  *
 300  */
 301
 302 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 303 {
 304
 305         gfs2_log_lock(sdp);
 306         sdp->sd_log_blks_free += blks;
 307         gfs2_assert_withdraw(sdp,
 308                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 309         gfs2_log_unlock(sdp);
 310         up_read(&sdp->sd_log_flush_lock);
 311 }
 312
 313 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
 314 {
 315         struct inode *inode = sdp->sd_jdesc->jd_inode;
 316         int error;
 317         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 318
 319         bh_map.b_size = 1 << inode->i_blkbits;
 320         error = gfs2_block_map(inode, lbn, 0, &bh_map);
 321         if (error || !bh_map.b_blocknr)
 322                 printk(KERN_INFO "error=%d, dbn=%llu lbn=%u", error, bh_map.b_blocknr, lbn);
 323         gfs2_assert_withdraw(sdp, !error && bh_map.b_blocknr);
 324
 325         return bh_map.b_blocknr;
 326 }
 327
 328 /**
 329  * log_distance - Compute distance between two journal blocks
 330  * @sdp: The GFS2 superblock
 331  * @newer: The most recent journal block of the pair
 332  * @older: The older journal block of the pair
 333  *
 334  *   Compute the distance (in the journal direction) between two
 335  *   blocks in the journal
 336  *
 337  * Returns: the distance in blocks
 338  */
 339
 340 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 341                                         unsigned int older)
 342 {
 343         int dist;
 344
 345         dist = newer - older;
 346         if (dist < 0)
 347                 dist += sdp->sd_jdesc->jd_blocks;
 348
 349         return dist;
 350 }
 351
 352 static unsigned int current_tail(struct gfs2_sbd *sdp)
 353 {
 354         struct gfs2_ail *ai;
 355         unsigned int tail;
 356
 357         gfs2_log_lock(sdp);
 358
 359         if (list_empty(&sdp->sd_ail1_list)) {
 360                 tail = sdp->sd_log_head;
 361         } else {
 362                 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
 363                 tail = ai->ai_first;
 364         }
 365
 366         gfs2_log_unlock(sdp);
 367
 368         return tail;
 369 }
 370
 371 static inline void log_incr_head(struct gfs2_sbd *sdp)
 372 {
 373         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
 374                 gfs2_assert_withdraw(sdp, sdp->sd_log_flush_head == sdp->sd_log_head);
 375
 376         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
 377                 sdp->sd_log_flush_head = 0;
 378                 sdp->sd_log_flush_wrapped = 1;
 379         }
 380 }
 381
 382 /**
 383  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 384  * @sdp: The GFS2 superblock
 385  *
 386  * Returns: the buffer_head
 387  */
 388
 389 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 390 {
 391         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 392         struct gfs2_log_buf *lb;
 393         struct buffer_head *bh;
 394
 395         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 396         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 397
 398         bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
 399         lock_buffer(bh);
 400         memset(bh->b_data, 0, bh->b_size);
 401         set_buffer_uptodate(bh);
 402         clear_buffer_dirty(bh);
 403         unlock_buffer(bh);
 404
 405         log_incr_head(sdp);
 406
 407         return bh;
 408 }
 409
 410 /**
 411  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 412  * @sdp: the filesystem
 413  * @data: the data the buffer_head should point to
 414  *
 415  * Returns: the log buffer descriptor
 416  */
 417
 418 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 419                                       struct buffer_head *real)
 420 {
 421         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 422         struct gfs2_log_buf *lb;
 423         struct buffer_head *bh;
 424
 425         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 426         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 427         lb->lb_real = real;
 428
 429         bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 430         atomic_set(&bh->b_count, 1);
 431         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
 432         set_bh_page(bh, real->b_page, bh_offset(real));
 433         bh->b_blocknr = blkno;
 434         bh->b_size = sdp->sd_sb.sb_bsize;
 435         bh->b_bdev = sdp->sd_vfs->s_bdev;
 436
 437         log_incr_head(sdp);
 438
 439         return bh;
 440 }
 441
 442 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail, int pull)
 443 {
 444         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 445
 446         ail2_empty(sdp, new_tail);
 447
 448         gfs2_log_lock(sdp);
 449         sdp->sd_log_blks_free += dist - (pull ? 1 : 0);
 450         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 451         gfs2_log_unlock(sdp);
 452
 453         sdp->sd_log_tail = new_tail;
 454 }
 455
 456 /**
 457  * log_write_header - Get and initialize a journal header buffer
 458  * @sdp: The GFS2 superblock
 459  *
 460  * Returns: the initialized log buffer descriptor
 461  */
 462
 463 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 464 {
 465         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 466         struct buffer_head *bh;
 467         struct gfs2_log_header *lh;
 468         unsigned int tail;
 469         u32 hash;
 470
 471         bh = sb_getblk(sdp->sd_vfs, blkno);
 472         lock_buffer(bh);
 473         memset(bh->b_data, 0, bh->b_size);
 474         set_buffer_uptodate(bh);
 475         clear_buffer_dirty(bh);
 476         unlock_buffer(bh);
 477
 478         gfs2_ail1_empty(sdp, 0);
 479         tail = current_tail(sdp);
 480
 481         lh = (struct gfs2_log_header *)bh->b_data;
 482         memset(lh, 0, sizeof(struct gfs2_log_header));
 483         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 484         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 485         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 486         lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
 487         lh->lh_flags = cpu_to_be32(flags);
 488         lh->lh_tail = cpu_to_be32(tail);
 489         lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
 490         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 491         lh->lh_hash = cpu_to_be32(hash);
 492
 493         set_buffer_dirty(bh);
 494         if (sync_dirty_buffer(bh))
 495                 gfs2_io_error_bh(sdp, bh);
 496         brelse(bh);
 497
 498         if (sdp->sd_log_tail != tail)
 499                 log_pull_tail(sdp, tail, pull);
 500         else
 501                 gfs2_assert_withdraw(sdp, !pull);
 502
 503         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 504         log_incr_head(sdp);
 505 }
 506
 507 static void log_flush_commit(struct gfs2_sbd *sdp)
 508 {
 509         struct list_head *head = &sdp->sd_log_flush_list;
 510         struct gfs2_log_buf *lb;
 511         struct buffer_head *bh;
 512
 513         while (!list_empty(head)) {
 514                 lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
 515                 list_del(&lb->lb_list);
 516                 bh = lb->lb_bh;
 517
 518                 wait_on_buffer(bh);
 519                 if (!buffer_uptodate(bh))
 520                         gfs2_io_error_bh(sdp, bh);
 521                 if (lb->lb_real) {
 522                         while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
 523                                 schedule();
 524                         free_buffer_head(bh);
 525                 } else
 526                         brelse(bh);
 527                 kfree(lb);
 528         }
 529
 530         log_write_header(sdp, 0, 0);
 531 }
 532
 533 /**
 534  * gfs2_log_flush - flush incore transaction(s)
 535  * @sdp: the filesystem
 536  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 537  *
 538  */
 539
 540 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 541 {
 542         struct gfs2_ail *ai;
 543
 544         down_write(&sdp->sd_log_flush_lock);
 545
 546         if (gl) {
 547                 gfs2_log_lock(sdp);
 548                 if (list_empty(&gl->gl_le.le_list)) {
 549                         gfs2_log_unlock(sdp);
 550                         up_write(&sdp->sd_log_flush_lock);
 551                         return;
 552                 }
 553                 gfs2_log_unlock(sdp);
 554         }
 555
 556         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 557         INIT_LIST_HEAD(&ai->ai_ail1_list);
 558         INIT_LIST_HEAD(&ai->ai_ail2_list);
 559
 560         gfs2_assert_withdraw(sdp, sdp->sd_log_num_buf == sdp->sd_log_commited_buf);
 561         gfs2_assert_withdraw(sdp,
 562                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 563
 564         sdp->sd_log_flush_head = sdp->sd_log_head;
 565         sdp->sd_log_flush_wrapped = 0;
 566         ai->ai_first = sdp->sd_log_flush_head;
 567
 568         lops_before_commit(sdp);
 569         if (!list_empty(&sdp->sd_log_flush_list))
 570                 log_flush_commit(sdp);
 571         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle)
 572                 log_write_header(sdp, 0, PULL);
 573         lops_after_commit(sdp, ai);
 574
 575         gfs2_log_lock(sdp);
 576         sdp->sd_log_head = sdp->sd_log_flush_head;
 577         sdp->sd_log_blks_free -= sdp->sd_log_num_hdrs;
 578         sdp->sd_log_blks_reserved = 0;
 579         sdp->sd_log_commited_buf = 0;
 580         sdp->sd_log_num_hdrs = 0;
 581         sdp->sd_log_commited_revoke = 0;
 582
 583         if (!list_empty(&ai->ai_ail1_list)) {
 584                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 585                 ai = NULL;
 586         }
 587         gfs2_log_unlock(sdp);
 588
 589         sdp->sd_vfs->s_dirt = 0;
 590         up_write(&sdp->sd_log_flush_lock);
 591
 592         kfree(ai);
 593 }
 594
 595 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 596 {
 597         unsigned int reserved = 0;
 598         unsigned int old;
 599
 600         gfs2_log_lock(sdp);
 601
 602         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 603         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_buf) >= 0);
 604         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 605         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 606
 607         if (sdp->sd_log_commited_buf)
 608                 reserved += sdp->sd_log_commited_buf;
 609         if (sdp->sd_log_commited_revoke)
 610                 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
 611                                             sizeof(u64));
 612         if (reserved)
 613                 reserved++;
 614
 615         old = sdp->sd_log_blks_free;
 616         sdp->sd_log_blks_free += tr->tr_reserved -
 617                                  (reserved - sdp->sd_log_blks_reserved);
 618
 619         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
 620         gfs2_assert_withdraw(sdp,
 621                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks +
 622                              sdp->sd_log_num_hdrs);
 623
 624         sdp->sd_log_blks_reserved = reserved;
 625
 626         gfs2_log_unlock(sdp);
 627 }
 628
 629 /**
 630  * gfs2_log_commit - Commit a transaction to the log
 631  * @sdp: the filesystem
 632  * @tr: the transaction
 633  *
 634  * Returns: errno
 635  */
 636
 637 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 638 {
 639         log_refund(sdp, tr);
 640         lops_incore_commit(sdp, tr);
 641
 642         sdp->sd_vfs->s_dirt = 1;
 643         up_read(&sdp->sd_log_flush_lock);
 644
 645         gfs2_log_lock(sdp);
 646         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) {
 647                 gfs2_log_unlock(sdp);
 648                 gfs2_log_flush(sdp, NULL);
 649         } else {
 650                 gfs2_log_unlock(sdp);
 651         }
 652 }
 653
 654 /**
 655  * gfs2_log_shutdown - write a shutdown header into a journal
 656  * @sdp: the filesystem
 657  *
 658  */
 659
 660 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 661 {
 662         down_write(&sdp->sd_log_flush_lock);
 663
 664         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 665         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
 666         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 667         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
 668         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 669         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 670         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 671         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_hdrs);
 672         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 673
 674         sdp->sd_log_flush_head = sdp->sd_log_head;
 675         sdp->sd_log_flush_wrapped = 0;
 676
 677         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 0);
 678
 679         gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
 680         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 681         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 682
 683         sdp->sd_log_head = sdp->sd_log_flush_head;
 684         sdp->sd_log_tail = sdp->sd_log_head;
 685
 686         up_write(&sdp->sd_log_flush_lock);
 687 }
 688