err.no Git - linux-2.6/blob - fs/gfs2/log.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 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 v.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 <asm/semaphore.h>
  18
  19 #include "gfs2.h"
  20 #include "lm_interface.h"
  21 #include "incore.h"
  22 #include "bmap.h"
  23 #include "glock.h"
  24 #include "log.h"
  25 #include "lops.h"
  26 #include "meta_io.h"
  27 #include "util.h"
  28 #include "dir.h"
  29
  30 #define PULL 1
  31
  32 /**
  33  * gfs2_struct2blk - compute stuff
  34  * @sdp: the filesystem
  35  * @nstruct: the number of structures
  36  * @ssize: the size of the structures
  37  *
  38  * Compute the number of log descriptor blocks needed to hold a certain number
  39  * of structures of a certain size.
  40  *
  41  * Returns: the number of blocks needed (minimum is always 1)
  42  */
  43
  44 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
  45                              unsigned int ssize)
  46 {
  47         unsigned int blks;
  48         unsigned int first, second;
  49
  50         blks = 1;
  51         first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) /
  52                 ssize;
  53
  54         if (nstruct > first) {
  55                 second = (sdp->sd_sb.sb_bsize -
  56                           sizeof(struct gfs2_meta_header)) / ssize;
  57                 blks += DIV_ROUND_UP(nstruct - first, second);
  58         }
  59
  60         return blks;
  61 }
  62
  63 void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
  64 {
  65         struct list_head *head = &sdp->sd_ail1_list;
  66         uint64_t sync_gen;
  67         struct list_head *first, *tmp;
  68         struct gfs2_ail *first_ai, *ai;
  69
  70         gfs2_log_lock(sdp);
  71         if (list_empty(head)) {
  72                 gfs2_log_unlock(sdp);
  73                 return;
  74         }
  75         sync_gen = sdp->sd_ail_sync_gen++;
  76
  77         first = head->prev;
  78         first_ai = list_entry(first, struct gfs2_ail, ai_list);
  79         first_ai->ai_sync_gen = sync_gen;
  80         gfs2_ail1_start_one(sdp, first_ai);
  81
  82         if (flags & DIO_ALL)
  83                 first = NULL;
  84
  85         for (;;) {
  86                 if (first && (head->prev != first ||
  87                               gfs2_ail1_empty_one(sdp, first_ai, 0)))
  88                         break;
  89
  90                 for (tmp = head->prev; tmp != head; tmp = tmp->prev) {
  91                         ai = list_entry(tmp, struct gfs2_ail, ai_list);
  92                         if (ai->ai_sync_gen >= sync_gen)
  93                                 continue;
  94                         ai->ai_sync_gen = sync_gen;
  95                         gfs2_ail1_start_one(sdp, ai);
  96                         break;
  97                 }
  98
  99                 if (tmp == head)
 100                         break;
 101         }
 102
 103         gfs2_log_unlock(sdp);
 104 }
 105
 106 int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
 107 {
 108         struct gfs2_ail *ai, *s;
 109         int ret;
 110
 111         gfs2_log_lock(sdp);
 112
 113         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
 114                 if (gfs2_ail1_empty_one(sdp, ai, flags))
 115                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
 116                 else if (!(flags & DIO_ALL))
 117                         break;
 118         }
 119
 120         ret = list_empty(&sdp->sd_ail1_list);
 121
 122         gfs2_log_unlock(sdp);
 123
 124         return ret;
 125 }
 126
 127 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 128 {
 129         struct gfs2_ail *ai, *safe;
 130         unsigned int old_tail = sdp->sd_log_tail;
 131         int wrap = (new_tail < old_tail);
 132         int a, b, rm;
 133
 134         gfs2_log_lock(sdp);
 135
 136         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
 137                 a = (old_tail <= ai->ai_first);
 138                 b = (ai->ai_first < new_tail);
 139                 rm = (wrap) ? (a || b) : (a && b);
 140                 if (!rm)
 141                         continue;
 142
 143                 gfs2_ail2_empty_one(sdp, ai);
 144                 list_del(&ai->ai_list);
 145                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
 146                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
 147                 kfree(ai);
 148         }
 149
 150         gfs2_log_unlock(sdp);
 151 }
 152
 153 /**
 154  * gfs2_log_reserve - Make a log reservation
 155  * @sdp: The GFS2 superblock
 156  * @blks: The number of blocks to reserve
 157  *
 158  * Returns: errno
 159  */
 160
 161 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 162 {
 163         unsigned int try = 0;
 164
 165         if (gfs2_assert_warn(sdp, blks) ||
 166             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 167                 return -EINVAL;
 168
 169         mutex_lock(&sdp->sd_log_reserve_mutex);
 170         gfs2_log_lock(sdp);
 171         while(sdp->sd_log_blks_free <= blks) {
 172                 gfs2_log_unlock(sdp);
 173                 gfs2_ail1_empty(sdp, 0);
 174                 gfs2_log_flush(sdp, NULL);
 175
 176                 if (try++)
 177                         gfs2_ail1_start(sdp, 0);
 178                 gfs2_log_lock(sdp);
 179         }
 180         sdp->sd_log_blks_free -= blks;
 181         /* printk(KERN_INFO "reserved %u blocks (%u left)\n", blks, sdp->sd_log_blks_free); */
 182         gfs2_log_unlock(sdp);
 183         mutex_unlock(&sdp->sd_log_reserve_mutex);
 184
 185         down_read(&sdp->sd_log_flush_lock);
 186
 187         return 0;
 188 }
 189
 190 /**
 191  * gfs2_log_release - Release a given number of log blocks
 192  * @sdp: The GFS2 superblock
 193  * @blks: The number of blocks
 194  *
 195  */
 196
 197 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 198 {
 199
 200         gfs2_log_lock(sdp);
 201         sdp->sd_log_blks_free += blks;
 202         /* printk(KERN_INFO "released %u blocks (%u left)\n", blks, sdp->sd_log_blks_free); */
 203         gfs2_assert_withdraw(sdp,
 204                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 205         gfs2_log_unlock(sdp);
 206         up_read(&sdp->sd_log_flush_lock);
 207 }
 208
 209 static uint64_t log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
 210 {
 211         int new = 0;
 212         uint64_t dbn;
 213         int error;
 214
 215         error = gfs2_block_map(sdp->sd_jdesc->jd_inode->u.generic_ip,
 216                                lbn, &new, &dbn, NULL);
 217         gfs2_assert_withdraw(sdp, !error && dbn);
 218
 219         return dbn;
 220 }
 221
 222 /**
 223  * log_distance - Compute distance between two journal blocks
 224  * @sdp: The GFS2 superblock
 225  * @newer: The most recent journal block of the pair
 226  * @older: The older journal block of the pair
 227  *
 228  *   Compute the distance (in the journal direction) between two
 229  *   blocks in the journal
 230  *
 231  * Returns: the distance in blocks
 232  */
 233
 234 static inline unsigned int log_distance(struct gfs2_sbd *sdp,
 235                                         unsigned int newer,
 236                                         unsigned int older)
 237 {
 238         int dist;
 239
 240         dist = newer - older;
 241         if (dist < 0)
 242                 dist += sdp->sd_jdesc->jd_blocks;
 243
 244         return dist;
 245 }
 246
 247 static unsigned int current_tail(struct gfs2_sbd *sdp)
 248 {
 249         struct gfs2_ail *ai;
 250         unsigned int tail;
 251
 252         gfs2_log_lock(sdp);
 253
 254         if (list_empty(&sdp->sd_ail1_list))
 255                 tail = sdp->sd_log_head;
 256         else {
 257                 ai = list_entry(sdp->sd_ail1_list.prev,
 258                                 struct gfs2_ail, ai_list);
 259                 tail = ai->ai_first;
 260         }
 261
 262         gfs2_log_unlock(sdp);
 263
 264         return tail;
 265 }
 266
 267 static inline void log_incr_head(struct gfs2_sbd *sdp)
 268 {
 269         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
 270                 gfs2_assert_withdraw(sdp,
 271                                 sdp->sd_log_flush_head == sdp->sd_log_head);
 272
 273         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
 274                 sdp->sd_log_flush_head = 0;
 275                 sdp->sd_log_flush_wrapped = 1;
 276         }
 277 }
 278
 279 /**
 280  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 281  * @sdp: The GFS2 superblock
 282  *
 283  * Returns: the buffer_head
 284  */
 285
 286 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 287 {
 288         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 289         struct gfs2_log_buf *lb;
 290         struct buffer_head *bh;
 291
 292         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 293         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 294
 295         bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
 296         lock_buffer(bh);
 297         memset(bh->b_data, 0, bh->b_size);
 298         set_buffer_uptodate(bh);
 299         clear_buffer_dirty(bh);
 300         unlock_buffer(bh);
 301
 302         log_incr_head(sdp);
 303
 304         return bh;
 305 }
 306
 307 /**
 308  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 309  * @sdp: the filesystem
 310  * @data: the data the buffer_head should point to
 311  *
 312  * Returns: the log buffer descriptor
 313  */
 314
 315 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 316                                       struct buffer_head *real)
 317 {
 318         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 319         struct gfs2_log_buf *lb;
 320         struct buffer_head *bh;
 321
 322         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 323         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 324         lb->lb_real = real;
 325
 326         bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 327         atomic_set(&bh->b_count, 1);
 328         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
 329         set_bh_page(bh, real->b_page, bh_offset(real));
 330         bh->b_blocknr = blkno;
 331         bh->b_size = sdp->sd_sb.sb_bsize;
 332         bh->b_bdev = sdp->sd_vfs->s_bdev;
 333
 334         log_incr_head(sdp);
 335
 336         return bh;
 337 }
 338
 339 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail, int pull)
 340 {
 341         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 342
 343         ail2_empty(sdp, new_tail);
 344
 345         gfs2_log_lock(sdp);
 346         sdp->sd_log_blks_free += dist - ((pull) ? 1 : 0);
 347         /* printk(KERN_INFO "pull tail refunding %u blocks (%u left) pull=%d\n", dist - ((pull) ? 1 : 0), sdp->sd_log_blks_free, pull); */
 348         gfs2_assert_withdraw(sdp,
 349                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 350         gfs2_log_unlock(sdp);
 351
 352         sdp->sd_log_tail = new_tail;
 353 }
 354
 355 /**
 356  * log_write_header - Get and initialize a journal header buffer
 357  * @sdp: The GFS2 superblock
 358  *
 359  * Returns: the initialized log buffer descriptor
 360  */
 361
 362 static void log_write_header(struct gfs2_sbd *sdp, uint32_t flags, int pull)
 363 {
 364         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 365         struct buffer_head *bh;
 366         struct gfs2_log_header *lh;
 367         unsigned int tail;
 368         uint32_t hash;
 369
 370         /* printk(KERN_INFO "log write header start (flags=%08x, pull=%d)\n", flags, pull); */
 371
 372         bh = sb_getblk(sdp->sd_vfs, blkno);
 373         lock_buffer(bh);
 374         memset(bh->b_data, 0, bh->b_size);
 375         set_buffer_uptodate(bh);
 376         clear_buffer_dirty(bh);
 377         unlock_buffer(bh);
 378
 379         gfs2_ail1_empty(sdp, 0);
 380         tail = current_tail(sdp);
 381
 382         lh = (struct gfs2_log_header *)bh->b_data;
 383         memset(lh, 0, sizeof(struct gfs2_log_header));
 384         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 385         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 386         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 387         lh->lh_sequence = be64_to_cpu(sdp->sd_log_sequence++);
 388         lh->lh_flags = be32_to_cpu(flags);
 389         lh->lh_tail = be32_to_cpu(tail);
 390         lh->lh_blkno = be32_to_cpu(sdp->sd_log_flush_head);
 391         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 392         lh->lh_hash = cpu_to_be32(hash);
 393
 394         set_buffer_dirty(bh);
 395         if (sync_dirty_buffer(bh))
 396                 gfs2_io_error_bh(sdp, bh);
 397         brelse(bh);
 398
 399         if (sdp->sd_log_tail != tail)
 400                 log_pull_tail(sdp, tail, pull);
 401         else
 402                 gfs2_assert_withdraw(sdp, !pull);
 403
 404         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 405         log_incr_head(sdp);
 406
 407         /* printk(KERN_INFO "log write header out\n"); */
 408 }
 409
 410 static void log_flush_commit(struct gfs2_sbd *sdp)
 411 {
 412         struct list_head *head = &sdp->sd_log_flush_list;
 413         struct gfs2_log_buf *lb;
 414         struct buffer_head *bh;
 415         unsigned int d;
 416
 417         d = log_distance(sdp, sdp->sd_log_flush_head, sdp->sd_log_head);
 418
 419         gfs2_assert_withdraw(sdp, d + 1 == sdp->sd_log_blks_reserved);
 420
 421         while (!list_empty(head)) {
 422                 lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
 423                 list_del(&lb->lb_list);
 424                 bh = lb->lb_bh;
 425
 426                 wait_on_buffer(bh);
 427                 if (!buffer_uptodate(bh))
 428                         gfs2_io_error_bh(sdp, bh);
 429                 if (lb->lb_real) {
 430                         while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
 431                                 schedule();
 432                         free_buffer_head(bh);
 433                 } else
 434                         brelse(bh);
 435                 kfree(lb);
 436         }
 437
 438         log_write_header(sdp, 0, 0);
 439 }
 440
 441 /**
 442  * gfs2_log_flush - flush incore transaction(s)
 443  * @sdp: the filesystem
 444  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 445  *
 446  */
 447
 448 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 449 {
 450         struct gfs2_ail *ai;
 451
 452         down_write(&sdp->sd_log_flush_lock);
 453
 454         if (gl) {
 455                 gfs2_log_lock(sdp);
 456                 if (list_empty(&gl->gl_le.le_list)) {
 457                         gfs2_log_unlock(sdp);
 458                         up_write(&sdp->sd_log_flush_lock);
 459                         return;
 460                 }
 461                 gfs2_log_unlock(sdp);
 462         }
 463
 464         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 465         INIT_LIST_HEAD(&ai->ai_ail1_list);
 466         INIT_LIST_HEAD(&ai->ai_ail2_list);
 467
 468         gfs2_assert_withdraw(sdp,
 469                         sdp->sd_log_num_buf == sdp->sd_log_commited_buf);
 470         gfs2_assert_withdraw(sdp,
 471                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 472
 473         sdp->sd_log_flush_head = sdp->sd_log_head;
 474         sdp->sd_log_flush_wrapped = 0;
 475         ai->ai_first = sdp->sd_log_flush_head;
 476
 477         lops_before_commit(sdp);
 478         if (!list_empty(&sdp->sd_log_flush_list))
 479                 log_flush_commit(sdp);
 480         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle)
 481                 log_write_header(sdp, 0, PULL);
 482         lops_after_commit(sdp, ai);
 483         sdp->sd_log_head = sdp->sd_log_flush_head;
 484
 485         /* printk(KERN_INFO "sd_log_num_hdrs %u\n", sdp->sd_log_num_hdrs); */
 486
 487         sdp->sd_log_blks_reserved =
 488                 sdp->sd_log_commited_buf =
 489                 sdp->sd_log_num_hdrs =
 490                 sdp->sd_log_commited_revoke = 0;
 491
 492         gfs2_log_lock(sdp);
 493         if (!list_empty(&ai->ai_ail1_list)) {
 494                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 495                 ai = NULL;
 496         }
 497         gfs2_log_unlock(sdp);
 498
 499         sdp->sd_vfs->s_dirt = 0;
 500         up_write(&sdp->sd_log_flush_lock);
 501
 502         kfree(ai);
 503 }
 504
 505 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 506 {
 507         unsigned int reserved = 1;
 508         unsigned int old;
 509
 510         gfs2_log_lock(sdp);
 511
 512         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 513         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_buf) >= 0);
 514         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 515         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 516
 517         if (sdp->sd_log_commited_buf)
 518                 reserved += 1 + sdp->sd_log_commited_buf +
 519                             sdp->sd_log_commited_buf/503;
 520         if (sdp->sd_log_commited_revoke)
 521                 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
 522                                             sizeof(uint64_t));
 523
 524         old = sdp->sd_log_blks_free;
 525         sdp->sd_log_blks_free += tr->tr_reserved -
 526                                  (reserved - sdp->sd_log_blks_reserved);
 527
 528         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
 529         gfs2_assert_withdraw(sdp,
 530                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 531
 532         sdp->sd_log_blks_reserved = reserved;
 533
 534         gfs2_log_unlock(sdp);
 535 }
 536
 537 /**
 538  * gfs2_log_commit - Commit a transaction to the log
 539  * @sdp: the filesystem
 540  * @tr: the transaction
 541  *
 542  * Returns: errno
 543  */
 544
 545 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 546 {
 547         log_refund(sdp, tr);
 548         lops_incore_commit(sdp, tr);
 549
 550         sdp->sd_vfs->s_dirt = 1;
 551         up_read(&sdp->sd_log_flush_lock);
 552
 553         gfs2_log_lock(sdp);
 554         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) {
 555                 gfs2_log_unlock(sdp);
 556                 gfs2_log_flush(sdp, NULL);
 557         } else
 558                 gfs2_log_unlock(sdp);
 559 }
 560
 561 /**
 562  * gfs2_log_shutdown - write a shutdown header into a journal
 563  * @sdp: the filesystem
 564  *
 565  */
 566
 567 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 568 {
 569         down_write(&sdp->sd_log_flush_lock);
 570
 571         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 572         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
 573         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 574         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
 575         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 576         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 577         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 578         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 579
 580         sdp->sd_log_flush_head = sdp->sd_log_head;
 581         sdp->sd_log_flush_wrapped = 0;
 582
 583         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 0);
 584
 585         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free ==
 586                              sdp->sd_jdesc->jd_blocks);
 587         gfs2_assert_withdraw(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 588         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail2_list));
 589
 590         sdp->sd_log_head = sdp->sd_log_flush_head;
 591         sdp->sd_log_tail = sdp->sd_log_head;
 592
 593         up_write(&sdp->sd_log_flush_lock);
 594 }
 595