git.oblomov.eu Git - linux-2.6/blob - fs/gfs2/log.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 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 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
  18 #include "gfs2.h"
  19 #include "lm_interface.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)) /
  51                 ssize;
  52
  53         if (nstruct > first) {
  54                 second = (sdp->sd_sb.sb_bsize -
  55                           sizeof(struct gfs2_meta_header)) / ssize;
  56                 blks += DIV_ROUND_UP(nstruct - first, second);
  57         }
  58
  59         return blks;
  60 }
  61
  62 void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
  63 {
  64         struct list_head *head = &sdp->sd_ail1_list;
  65         uint64_t sync_gen;
  66         struct list_head *first, *tmp;
  67         struct gfs2_ail *first_ai, *ai;
  68
  69         gfs2_log_lock(sdp);
  70         if (list_empty(head)) {
  71                 gfs2_log_unlock(sdp);
  72                 return;
  73         }
  74         sync_gen = sdp->sd_ail_sync_gen++;
  75
  76         first = head->prev;
  77         first_ai = list_entry(first, struct gfs2_ail, ai_list);
  78         first_ai->ai_sync_gen = sync_gen;
  79         gfs2_ail1_start_one(sdp, first_ai);
  80
  81         if (flags & DIO_ALL)
  82                 first = NULL;
  83
  84         for (;;) {
  85                 if (first && (head->prev != first ||
  86                               gfs2_ail1_empty_one(sdp, first_ai, 0)))
  87                         break;
  88
  89                 for (tmp = head->prev; tmp != head; tmp = tmp->prev) {
  90                         ai = list_entry(tmp, struct gfs2_ail, ai_list);
  91                         if (ai->ai_sync_gen >= sync_gen)
  92                                 continue;
  93                         ai->ai_sync_gen = sync_gen;
  94                         gfs2_ail1_start_one(sdp, ai);
  95                         break;
  96                 }
  97
  98                 if (tmp == head)
  99                         break;
 100         }
 101
 102         gfs2_log_unlock(sdp);
 103 }
 104
 105 int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
 106 {
 107         struct gfs2_ail *ai, *s;
 108         int ret;
 109
 110         gfs2_log_lock(sdp);
 111
 112         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
 113                 if (gfs2_ail1_empty_one(sdp, ai, flags))
 114                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
 115                 else if (!(flags & DIO_ALL))
 116                         break;
 117         }
 118
 119         ret = list_empty(&sdp->sd_ail1_list);
 120
 121         gfs2_log_unlock(sdp);
 122
 123         return ret;
 124 }
 125
 126 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 127 {
 128         struct gfs2_ail *ai, *safe;
 129         unsigned int old_tail = sdp->sd_log_tail;
 130         int wrap = (new_tail < old_tail);
 131         int a, b, rm;
 132
 133         gfs2_log_lock(sdp);
 134
 135         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
 136                 a = (old_tail <= ai->ai_first);
 137                 b = (ai->ai_first < new_tail);
 138                 rm = (wrap) ? (a || b) : (a && b);
 139                 if (!rm)
 140                         continue;
 141
 142                 gfs2_ail2_empty_one(sdp, ai);
 143                 list_del(&ai->ai_list);
 144                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
 145                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
 146                 kfree(ai);
 147         }
 148
 149         gfs2_log_unlock(sdp);
 150 }
 151
 152 /**
 153  * gfs2_log_reserve - Make a log reservation
 154  * @sdp: The GFS2 superblock
 155  * @blks: The number of blocks to reserve
 156  *
 157  * Returns: errno
 158  */
 159
 160 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 161 {
 162         unsigned int try = 0;
 163
 164         if (gfs2_assert_warn(sdp, blks) ||
 165             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 166                 return -EINVAL;
 167
 168         mutex_lock(&sdp->sd_log_reserve_mutex);
 169         gfs2_log_lock(sdp);
 170         while(sdp->sd_log_blks_free <= blks) {
 171                 gfs2_log_unlock(sdp);
 172                 gfs2_ail1_empty(sdp, 0);
 173                 gfs2_log_flush(sdp, NULL);
 174
 175                 if (try++)
 176                         gfs2_ail1_start(sdp, 0);
 177                 gfs2_log_lock(sdp);
 178         }
 179         sdp->sd_log_blks_free -= blks;
 180         /* printk(KERN_INFO "reserved %u blocks (%u left)\n", blks, sdp->sd_log_blks_free); */
 181         gfs2_log_unlock(sdp);
 182         mutex_unlock(&sdp->sd_log_reserve_mutex);
 183
 184         down_read(&sdp->sd_log_flush_lock);
 185
 186         return 0;
 187 }
 188
 189 /**
 190  * gfs2_log_release - Release a given number of log blocks
 191  * @sdp: The GFS2 superblock
 192  * @blks: The number of blocks
 193  *
 194  */
 195
 196 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 197 {
 198
 199         gfs2_log_lock(sdp);
 200         sdp->sd_log_blks_free += blks;
 201         /* printk(KERN_INFO "released %u blocks (%u left)\n", blks, sdp->sd_log_blks_free); */
 202         gfs2_assert_withdraw(sdp,
 203                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 204         gfs2_log_unlock(sdp);
 205         up_read(&sdp->sd_log_flush_lock);
 206 }
 207
 208 static uint64_t log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
 209 {
 210         int new = 0;
 211         uint64_t dbn;
 212         int error;
 213         int bdy;
 214
 215         error = gfs2_block_map(sdp->sd_jdesc->jd_inode, lbn, &new, &dbn, &bdy);
 216         gfs2_assert_withdraw(sdp, !error && dbn);
 217
 218         return dbn;
 219 }
 220
 221 /**
 222  * log_distance - Compute distance between two journal blocks
 223  * @sdp: The GFS2 superblock
 224  * @newer: The most recent journal block of the pair
 225  * @older: The older journal block of the pair
 226  *
 227  *   Compute the distance (in the journal direction) between two
 228  *   blocks in the journal
 229  *
 230  * Returns: the distance in blocks
 231  */
 232
 233 static inline unsigned int log_distance(struct gfs2_sbd *sdp,
 234                                         unsigned int newer,
 235                                         unsigned int older)
 236 {
 237         int dist;
 238
 239         dist = newer - older;
 240         if (dist < 0)
 241                 dist += sdp->sd_jdesc->jd_blocks;
 242
 243         return dist;
 244 }
 245
 246 static unsigned int current_tail(struct gfs2_sbd *sdp)
 247 {
 248         struct gfs2_ail *ai;
 249         unsigned int tail;
 250
 251         gfs2_log_lock(sdp);
 252
 253         if (list_empty(&sdp->sd_ail1_list))
 254                 tail = sdp->sd_log_head;
 255         else {
 256                 ai = list_entry(sdp->sd_ail1_list.prev,
 257                                 struct gfs2_ail, ai_list);
 258                 tail = ai->ai_first;
 259         }
 260
 261         gfs2_log_unlock(sdp);
 262
 263         return tail;
 264 }
 265
 266 static inline void log_incr_head(struct gfs2_sbd *sdp)
 267 {
 268         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
 269                 gfs2_assert_withdraw(sdp,
 270                                 sdp->sd_log_flush_head == sdp->sd_log_head);
 271
 272         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
 273                 sdp->sd_log_flush_head = 0;
 274                 sdp->sd_log_flush_wrapped = 1;
 275         }
 276 }
 277
 278 /**
 279  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 280  * @sdp: The GFS2 superblock
 281  *
 282  * Returns: the buffer_head
 283  */
 284
 285 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 286 {
 287         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 288         struct gfs2_log_buf *lb;
 289         struct buffer_head *bh;
 290
 291         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 292         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 293
 294         bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
 295         lock_buffer(bh);
 296         memset(bh->b_data, 0, bh->b_size);
 297         set_buffer_uptodate(bh);
 298         clear_buffer_dirty(bh);
 299         unlock_buffer(bh);
 300
 301         log_incr_head(sdp);
 302
 303         return bh;
 304 }
 305
 306 /**
 307  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 308  * @sdp: the filesystem
 309  * @data: the data the buffer_head should point to
 310  *
 311  * Returns: the log buffer descriptor
 312  */
 313
 314 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 315                                       struct buffer_head *real)
 316 {
 317         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 318         struct gfs2_log_buf *lb;
 319         struct buffer_head *bh;
 320
 321         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 322         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 323         lb->lb_real = real;
 324
 325         bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 326         atomic_set(&bh->b_count, 1);
 327         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
 328         set_bh_page(bh, real->b_page, bh_offset(real));
 329         bh->b_blocknr = blkno;
 330         bh->b_size = sdp->sd_sb.sb_bsize;
 331         bh->b_bdev = sdp->sd_vfs->s_bdev;
 332
 333         log_incr_head(sdp);
 334
 335         return bh;
 336 }
 337
 338 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail, int pull)
 339 {
 340         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 341
 342         ail2_empty(sdp, new_tail);
 343
 344         gfs2_log_lock(sdp);
 345         sdp->sd_log_blks_free += dist - ((pull) ? 1 : 0);
 346         /* printk(KERN_INFO "pull tail refunding %u blocks (%u left) pull=%d\n", dist - ((pull) ? 1 : 0), sdp->sd_log_blks_free, pull); */
 347         gfs2_assert_withdraw(sdp,
 348                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 349         gfs2_log_unlock(sdp);
 350
 351         sdp->sd_log_tail = new_tail;
 352 }
 353
 354 /**
 355  * log_write_header - Get and initialize a journal header buffer
 356  * @sdp: The GFS2 superblock
 357  *
 358  * Returns: the initialized log buffer descriptor
 359  */
 360
 361 static void log_write_header(struct gfs2_sbd *sdp, uint32_t flags, int pull)
 362 {
 363         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 364         struct buffer_head *bh;
 365         struct gfs2_log_header *lh;
 366         unsigned int tail;
 367         uint32_t hash;
 368
 369         /* printk(KERN_INFO "log write header start (flags=%08x, pull=%d)\n", flags, pull); */
 370
 371         bh = sb_getblk(sdp->sd_vfs, blkno);
 372         lock_buffer(bh);
 373         memset(bh->b_data, 0, bh->b_size);
 374         set_buffer_uptodate(bh);
 375         clear_buffer_dirty(bh);
 376         unlock_buffer(bh);
 377
 378         gfs2_ail1_empty(sdp, 0);
 379         tail = current_tail(sdp);
 380
 381         lh = (struct gfs2_log_header *)bh->b_data;
 382         memset(lh, 0, sizeof(struct gfs2_log_header));
 383         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 384         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 385         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 386         lh->lh_sequence = be64_to_cpu(sdp->sd_log_sequence++);
 387         lh->lh_flags = be32_to_cpu(flags);
 388         lh->lh_tail = be32_to_cpu(tail);
 389         lh->lh_blkno = be32_to_cpu(sdp->sd_log_flush_head);
 390         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 391         lh->lh_hash = cpu_to_be32(hash);
 392
 393         set_buffer_dirty(bh);
 394         if (sync_dirty_buffer(bh))
 395                 gfs2_io_error_bh(sdp, bh);
 396         brelse(bh);
 397
 398         if (sdp->sd_log_tail != tail)
 399                 log_pull_tail(sdp, tail, pull);
 400         else
 401                 gfs2_assert_withdraw(sdp, !pull);
 402
 403         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 404         log_incr_head(sdp);
 405
 406         /* printk(KERN_INFO "log write header out\n"); */
 407 }
 408
 409 static void log_flush_commit(struct gfs2_sbd *sdp)
 410 {
 411         struct list_head *head = &sdp->sd_log_flush_list;
 412         struct gfs2_log_buf *lb;
 413         struct buffer_head *bh;
 414 #if 0
 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 #endif
 421
 422         while (!list_empty(head)) {
 423                 lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
 424                 list_del(&lb->lb_list);
 425                 bh = lb->lb_bh;
 426
 427                 wait_on_buffer(bh);
 428                 if (!buffer_uptodate(bh))
 429                         gfs2_io_error_bh(sdp, bh);
 430                 if (lb->lb_real) {
 431                         while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
 432                                 schedule();
 433                         free_buffer_head(bh);
 434                 } else
 435                         brelse(bh);
 436                 kfree(lb);
 437         }
 438
 439         log_write_header(sdp, 0, 0);
 440 }
 441
 442 /**
 443  * gfs2_log_flush - flush incore transaction(s)
 444  * @sdp: the filesystem
 445  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 446  *
 447  */
 448
 449 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 450 {
 451         struct gfs2_ail *ai;
 452
 453         down_write(&sdp->sd_log_flush_lock);
 454
 455         if (gl) {
 456                 gfs2_log_lock(sdp);
 457                 if (list_empty(&gl->gl_le.le_list)) {
 458                         gfs2_log_unlock(sdp);
 459                         up_write(&sdp->sd_log_flush_lock);
 460                         return;
 461                 }
 462                 gfs2_log_unlock(sdp);
 463         }
 464
 465         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 466         INIT_LIST_HEAD(&ai->ai_ail1_list);
 467         INIT_LIST_HEAD(&ai->ai_ail2_list);
 468
 469         gfs2_assert_withdraw(sdp,
 470                         sdp->sd_log_num_buf == sdp->sd_log_commited_buf);
 471         gfs2_assert_withdraw(sdp,
 472                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 473
 474         sdp->sd_log_flush_head = sdp->sd_log_head;
 475         sdp->sd_log_flush_wrapped = 0;
 476         ai->ai_first = sdp->sd_log_flush_head;
 477
 478         lops_before_commit(sdp);
 479         if (!list_empty(&sdp->sd_log_flush_list))
 480                 log_flush_commit(sdp);
 481         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle)
 482                 log_write_header(sdp, 0, PULL);
 483         lops_after_commit(sdp, ai);
 484         sdp->sd_log_head = sdp->sd_log_flush_head;
 485
 486         /* printk(KERN_INFO "sd_log_num_hdrs %u\n", sdp->sd_log_num_hdrs); */
 487         sdp->sd_log_blks_free -= sdp->sd_log_num_hdrs;
 488
 489         sdp->sd_log_blks_reserved =
 490                 sdp->sd_log_commited_buf =
 491                 sdp->sd_log_num_hdrs =
 492                 sdp->sd_log_commited_revoke = 0;
 493
 494         gfs2_log_lock(sdp);
 495         if (!list_empty(&ai->ai_ail1_list)) {
 496                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 497                 ai = NULL;
 498         }
 499         gfs2_log_unlock(sdp);
 500
 501         sdp->sd_vfs->s_dirt = 0;
 502         up_write(&sdp->sd_log_flush_lock);
 503
 504         kfree(ai);
 505 }
 506
 507 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 508 {
 509         unsigned int reserved = 1;
 510         unsigned int old;
 511
 512         gfs2_log_lock(sdp);
 513
 514         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 515         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_buf) >= 0);
 516         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 517         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 518
 519         if (sdp->sd_log_commited_buf)
 520                 reserved += sdp->sd_log_commited_buf;
 521         if (sdp->sd_log_commited_revoke)
 522                 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
 523                                             sizeof(uint64_t));
 524
 525         old = sdp->sd_log_blks_free;
 526         sdp->sd_log_blks_free += tr->tr_reserved -
 527                                  (reserved - sdp->sd_log_blks_reserved);
 528
 529         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
 530         gfs2_assert_withdraw(sdp,
 531                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks +
 532                              sdp->sd_log_num_hdrs);
 533
 534         sdp->sd_log_blks_reserved = reserved;
 535
 536         gfs2_log_unlock(sdp);
 537 }
 538
 539 /**
 540  * gfs2_log_commit - Commit a transaction to the log
 541  * @sdp: the filesystem
 542  * @tr: the transaction
 543  *
 544  * Returns: errno
 545  */
 546
 547 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 548 {
 549         log_refund(sdp, tr);
 550         lops_incore_commit(sdp, tr);
 551
 552         sdp->sd_vfs->s_dirt = 1;
 553         up_read(&sdp->sd_log_flush_lock);
 554
 555         gfs2_log_lock(sdp);
 556         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) {
 557                 gfs2_log_unlock(sdp);
 558                 gfs2_log_flush(sdp, NULL);
 559         } else
 560                 gfs2_log_unlock(sdp);
 561 }
 562
 563 /**
 564  * gfs2_log_shutdown - write a shutdown header into a journal
 565  * @sdp: the filesystem
 566  *
 567  */
 568
 569 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 570 {
 571         down_write(&sdp->sd_log_flush_lock);
 572
 573         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 574         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
 575         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 576         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
 577         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 578         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 579         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 580         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_hdrs);
 581         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 582
 583         sdp->sd_log_flush_head = sdp->sd_log_head;
 584         sdp->sd_log_flush_wrapped = 0;
 585
 586         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 0);
 587
 588         /* printk(KERN_INFO "sd_log_blks_free %u, sd_jdesc->jd_blocks %u\n", sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks); */
 589         gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
 590         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 591         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 592
 593         sdp->sd_log_head = sdp->sd_log_flush_head;
 594         sdp->sd_log_tail = sdp->sd_log_head;
 595
 596         up_write(&sdp->sd_log_flush_lock);
 597 }
 598