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   1 /*
   2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
   3  */
   4 /* Reiserfs block (de)allocator, bitmap-based. */
   5
   6 #include <linux/time.h>
   7 #include <linux/reiserfs_fs.h>
   8 #include <linux/errno.h>
   9 #include <linux/buffer_head.h>
  10 #include <linux/kernel.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/reiserfs_fs_sb.h>
  13 #include <linux/reiserfs_fs_i.h>
  14 #include <linux/quotaops.h>
  15
  16 #define PREALLOCATION_SIZE 9
  17
  18 /* different reiserfs block allocator options */
  19
  20 #define SB_ALLOC_OPTS(s) (REISERFS_SB(s)->s_alloc_options.bits)
  21
  22 #define  _ALLOC_concentrating_formatted_nodes 0
  23 #define  _ALLOC_displacing_large_files 1
  24 #define  _ALLOC_displacing_new_packing_localities 2
  25 #define  _ALLOC_old_hashed_relocation 3
  26 #define  _ALLOC_new_hashed_relocation 4
  27 #define  _ALLOC_skip_busy 5
  28 #define  _ALLOC_displace_based_on_dirid 6
  29 #define  _ALLOC_hashed_formatted_nodes 7
  30 #define  _ALLOC_old_way 8
  31 #define  _ALLOC_hundredth_slices 9
  32 #define  _ALLOC_dirid_groups 10
  33 #define  _ALLOC_oid_groups 11
  34 #define  _ALLOC_packing_groups 12
  35
  36 #define  concentrating_formatted_nodes(s)       test_bit(_ALLOC_concentrating_formatted_nodes, &SB_ALLOC_OPTS(s))
  37 #define  displacing_large_files(s)              test_bit(_ALLOC_displacing_large_files, &SB_ALLOC_OPTS(s))
  38 #define  displacing_new_packing_localities(s)   test_bit(_ALLOC_displacing_new_packing_localities, &SB_ALLOC_OPTS(s))
  39
  40 #define SET_OPTION(optname) \
  41    do { \
  42         reiserfs_warning(s, "reiserfs: option \"%s\" is set", #optname); \
  43         set_bit(_ALLOC_ ## optname , &SB_ALLOC_OPTS(s)); \
  44     } while(0)
  45 #define TEST_OPTION(optname, s) \
  46     test_bit(_ALLOC_ ## optname , &SB_ALLOC_OPTS(s))
  47
  48 static inline void get_bit_address(struct super_block *s,
  49                                    b_blocknr_t block, int *bmap_nr, int *offset)
  50 {
  51         /* It is in the bitmap block number equal to the block
  52          * number divided by the number of bits in a block. */
  53         *bmap_nr = block / (s->s_blocksize << 3);
  54         /* Within that bitmap block it is located at bit offset *offset. */
  55         *offset = block & ((s->s_blocksize << 3) - 1);
  56         return;
  57 }
  58
  59 #ifdef CONFIG_REISERFS_CHECK
  60 int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
  61 {
  62         int i, j;
  63
  64         if (block == 0 || block >= SB_BLOCK_COUNT(s)) {
  65                 reiserfs_warning(s,
  66                                  "vs-4010: is_reusable: block number is out of range %lu (%u)",
  67                                  block, SB_BLOCK_COUNT(s));
  68                 return 0;
  69         }
  70
  71         /* it can't be one of the bitmap blocks */
  72         for (i = 0; i < SB_BMAP_NR(s); i++)
  73                 if (block == SB_AP_BITMAP(s)[i].bh->b_blocknr) {
  74                         reiserfs_warning(s, "vs: 4020: is_reusable: "
  75                                          "bitmap block %lu(%u) can't be freed or reused",
  76                                          block, SB_BMAP_NR(s));
  77                         return 0;
  78                 }
  79
  80         get_bit_address(s, block, &i, &j);
  81
  82         if (i >= SB_BMAP_NR(s)) {
  83                 reiserfs_warning(s,
  84                                  "vs-4030: is_reusable: there is no so many bitmap blocks: "
  85                                  "block=%lu, bitmap_nr=%d", block, i);
  86                 return 0;
  87         }
  88
  89         if ((bit_value == 0 &&
  90              reiserfs_test_le_bit(j, SB_AP_BITMAP(s)[i].bh->b_data)) ||
  91             (bit_value == 1 &&
  92              reiserfs_test_le_bit(j, SB_AP_BITMAP(s)[i].bh->b_data) == 0)) {
  93                 reiserfs_warning(s,
  94                                  "vs-4040: is_reusable: corresponding bit of block %lu does not "
  95                                  "match required value (i==%d, j==%d) test_bit==%d",
  96                                  block, i, j, reiserfs_test_le_bit(j,
  97                                                                    SB_AP_BITMAP
  98                                                                    (s)[i].bh->
  99                                                                    b_data));
 100
 101                 return 0;
 102         }
 103
 104         if (bit_value == 0 && block == SB_ROOT_BLOCK(s)) {
 105                 reiserfs_warning(s,
 106                                  "vs-4050: is_reusable: this is root block (%u), "
 107                                  "it must be busy", SB_ROOT_BLOCK(s));
 108                 return 0;
 109         }
 110
 111         return 1;
 112 }
 113 #endif                          /* CONFIG_REISERFS_CHECK */
 114
 115 /* searches in journal structures for a given block number (bmap, off). If block
 116    is found in reiserfs journal it suggests next free block candidate to test. */
 117 static inline int is_block_in_journal(struct super_block *s, int bmap, int
 118                                       off, int *next)
 119 {
 120         b_blocknr_t tmp;
 121
 122         if (reiserfs_in_journal(s, bmap, off, 1, &tmp)) {
 123                 if (tmp) {      /* hint supplied */
 124                         *next = tmp;
 125                         PROC_INFO_INC(s, scan_bitmap.in_journal_hint);
 126                 } else {
 127                         (*next) = off + 1;      /* inc offset to avoid looping. */
 128                         PROC_INFO_INC(s, scan_bitmap.in_journal_nohint);
 129                 }
 130                 PROC_INFO_INC(s, scan_bitmap.retry);
 131                 return 1;
 132         }
 133         return 0;
 134 }
 135
 136 /* it searches for a window of zero bits with given minimum and maximum lengths in one bitmap
 137  * block; */
 138 static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
 139                              int bmap_n, int *beg, int boundary, int min,
 140                              int max, int unfm)
 141 {
 142         struct super_block *s = th->t_super;
 143         struct reiserfs_bitmap_info *bi = &SB_AP_BITMAP(s)[bmap_n];
 144         int end, next;
 145         int org = *beg;
 146
 147         BUG_ON(!th->t_trans_id);
 148
 149         RFALSE(bmap_n >= SB_BMAP_NR(s), "Bitmap %d is out of range (0..%d)",
 150                bmap_n, SB_BMAP_NR(s) - 1);
 151         PROC_INFO_INC(s, scan_bitmap.bmap);
 152 /* this is unclear and lacks comments, explain how journal bitmaps
 153    work here for the reader.  Convey a sense of the design here. What
 154    is a window? */
 155 /* - I mean `a window of zero bits' as in description of this function - Zam. */
 156
 157         if (!bi) {
 158                 reiserfs_warning(s, "NULL bitmap info pointer for bitmap %d",
 159                                  bmap_n);
 160                 return 0;
 161         }
 162         if (buffer_locked(bi->bh)) {
 163                 PROC_INFO_INC(s, scan_bitmap.wait);
 164                 __wait_on_buffer(bi->bh);
 165         }
 166
 167         while (1) {
 168               cont:
 169                 if (bi->free_count < min)
 170                         return 0;       // No free blocks in this bitmap
 171
 172                 /* search for a first zero bit -- beggining of a window */
 173                 *beg = reiserfs_find_next_zero_le_bit
 174                     ((unsigned long *)(bi->bh->b_data), boundary, *beg);
 175
 176                 if (*beg + min > boundary) {    /* search for a zero bit fails or the rest of bitmap block
 177                                                  * cannot contain a zero window of minimum size */
 178                         return 0;
 179                 }
 180
 181                 if (unfm && is_block_in_journal(s, bmap_n, *beg, beg))
 182                         continue;
 183                 /* first zero bit found; we check next bits */
 184                 for (end = *beg + 1;; end++) {
 185                         if (end >= *beg + max || end >= boundary
 186                             || reiserfs_test_le_bit(end, bi->bh->b_data)) {
 187                                 next = end;
 188                                 break;
 189                         }
 190                         /* finding the other end of zero bit window requires looking into journal structures (in
 191                          * case of searching for free blocks for unformatted nodes) */
 192                         if (unfm && is_block_in_journal(s, bmap_n, end, &next))
 193                                 break;
 194                 }
 195
 196                 /* now (*beg) points to beginning of zero bits window,
 197                  * (end) points to one bit after the window end */
 198                 if (end - *beg >= min) {        /* it seems we have found window of proper size */
 199                         int i;
 200                         reiserfs_prepare_for_journal(s, bi->bh, 1);
 201                         /* try to set all blocks used checking are they still free */
 202                         for (i = *beg; i < end; i++) {
 203                                 /* It seems that we should not check in journal again. */
 204                                 if (reiserfs_test_and_set_le_bit
 205                                     (i, bi->bh->b_data)) {
 206                                         /* bit was set by another process
 207                                          * while we slept in prepare_for_journal() */
 208                                         PROC_INFO_INC(s, scan_bitmap.stolen);
 209                                         if (i >= *beg + min) {  /* we can continue with smaller set of allocated blocks,
 210                                                                  * if length of this set is more or equal to `min' */
 211                                                 end = i;
 212                                                 break;
 213                                         }
 214                                         /* otherwise we clear all bit were set ... */
 215                                         while (--i >= *beg)
 216                                                 reiserfs_test_and_clear_le_bit
 217                                                     (i, bi->bh->b_data);
 218                                         reiserfs_restore_prepared_buffer(s,
 219                                                                          bi->
 220                                                                          bh);
 221                                         *beg = org;
 222                                         /* ... and search again in current block from beginning */
 223                                         goto cont;
 224                                 }
 225                         }
 226                         bi->free_count -= (end - *beg);
 227                         journal_mark_dirty(th, s, bi->bh);
 228
 229                         /* free block count calculation */
 230                         reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s),
 231                                                      1);
 232                         PUT_SB_FREE_BLOCKS(s, SB_FREE_BLOCKS(s) - (end - *beg));
 233                         journal_mark_dirty(th, s, SB_BUFFER_WITH_SB(s));
 234
 235                         return end - (*beg);
 236                 } else {
 237                         *beg = next;
 238                 }
 239         }
 240 }
 241
 242 static int bmap_hash_id(struct super_block *s, u32 id)
 243 {
 244         char *hash_in = NULL;
 245         unsigned long hash;
 246         unsigned bm;
 247
 248         if (id <= 2) {
 249                 bm = 1;
 250         } else {
 251                 hash_in = (char *)(&id);
 252                 hash = keyed_hash(hash_in, 4);
 253                 bm = hash % SB_BMAP_NR(s);
 254                 if (!bm)
 255                         bm = 1;
 256         }
 257         /* this can only be true when SB_BMAP_NR = 1 */
 258         if (bm >= SB_BMAP_NR(s))
 259                 bm = 0;
 260         return bm;
 261 }
 262
 263 /*
 264  * hashes the id and then returns > 0 if the block group for the
 265  * corresponding hash is full
 266  */
 267 static inline int block_group_used(struct super_block *s, u32 id)
 268 {
 269         int bm;
 270         bm = bmap_hash_id(s, id);
 271         if (SB_AP_BITMAP(s)[bm].free_count > ((s->s_blocksize << 3) * 60 / 100)) {
 272                 return 0;
 273         }
 274         return 1;
 275 }
 276
 277 /*
 278  * the packing is returned in disk byte order
 279  */
 280 __le32 reiserfs_choose_packing(struct inode * dir)
 281 {
 282         __le32 packing;
 283         if (TEST_OPTION(packing_groups, dir->i_sb)) {
 284                 u32 parent_dir = le32_to_cpu(INODE_PKEY(dir)->k_dir_id);
 285                 /*
 286                  * some versions of reiserfsck expect packing locality 1 to be
 287                  * special
 288                  */
 289                 if (parent_dir == 1 || block_group_used(dir->i_sb, parent_dir))
 290                         packing = INODE_PKEY(dir)->k_objectid;
 291                 else
 292                         packing = INODE_PKEY(dir)->k_dir_id;
 293         } else
 294                 packing = INODE_PKEY(dir)->k_objectid;
 295         return packing;
 296 }
 297
 298 /* Tries to find contiguous zero bit window (given size) in given region of
 299  * bitmap and place new blocks there. Returns number of allocated blocks. */
 300 static int scan_bitmap(struct reiserfs_transaction_handle *th,
 301                        b_blocknr_t * start, b_blocknr_t finish,
 302                        int min, int max, int unfm, unsigned long file_block)
 303 {
 304         int nr_allocated = 0;
 305         struct super_block *s = th->t_super;
 306         /* find every bm and bmap and bmap_nr in this file, and change them all to bitmap_blocknr
 307          * - Hans, it is not a block number - Zam. */
 308
 309         int bm, off;
 310         int end_bm, end_off;
 311         int off_max = s->s_blocksize << 3;
 312
 313         BUG_ON(!th->t_trans_id);
 314
 315         PROC_INFO_INC(s, scan_bitmap.call);
 316         if (SB_FREE_BLOCKS(s) <= 0)
 317                 return 0;       // No point in looking for more free blocks
 318
 319         get_bit_address(s, *start, &bm, &off);
 320         get_bit_address(s, finish, &end_bm, &end_off);
 321         if (bm > SB_BMAP_NR(s))
 322                 return 0;
 323         if (end_bm > SB_BMAP_NR(s))
 324                 end_bm = SB_BMAP_NR(s);
 325
 326         /* When the bitmap is more than 10% free, anyone can allocate.
 327          * When it's less than 10% free, only files that already use the
 328          * bitmap are allowed. Once we pass 80% full, this restriction
 329          * is lifted.
 330          *
 331          * We do this so that files that grow later still have space close to
 332          * their original allocation. This improves locality, and presumably
 333          * performance as a result.
 334          *
 335          * This is only an allocation policy and does not make up for getting a
 336          * bad hint. Decent hinting must be implemented for this to work well.
 337          */
 338         if (TEST_OPTION(skip_busy, s)
 339             && SB_FREE_BLOCKS(s) > SB_BLOCK_COUNT(s) / 20) {
 340                 for (; bm < end_bm; bm++, off = 0) {
 341                         if ((off && (!unfm || (file_block != 0)))
 342                             || SB_AP_BITMAP(s)[bm].free_count >
 343                             (s->s_blocksize << 3) / 10)
 344                                 nr_allocated =
 345                                     scan_bitmap_block(th, bm, &off, off_max,
 346                                                       min, max, unfm);
 347                         if (nr_allocated)
 348                                 goto ret;
 349                 }
 350                 /* we know from above that start is a reasonable number */
 351                 get_bit_address(s, *start, &bm, &off);
 352         }
 353
 354         for (; bm < end_bm; bm++, off = 0) {
 355                 nr_allocated =
 356                     scan_bitmap_block(th, bm, &off, off_max, min, max, unfm);
 357                 if (nr_allocated)
 358                         goto ret;
 359         }
 360
 361         nr_allocated =
 362             scan_bitmap_block(th, bm, &off, end_off + 1, min, max, unfm);
 363
 364       ret:
 365         *start = bm * off_max + off;
 366         return nr_allocated;
 367
 368 }
 369
 370 static void _reiserfs_free_block(struct reiserfs_transaction_handle *th,
 371                                  struct inode *inode, b_blocknr_t block,
 372                                  int for_unformatted)
 373 {
 374         struct super_block *s = th->t_super;
 375         struct reiserfs_super_block *rs;
 376         struct buffer_head *sbh;
 377         struct reiserfs_bitmap_info *apbi;
 378         int nr, offset;
 379
 380         BUG_ON(!th->t_trans_id);
 381
 382         PROC_INFO_INC(s, free_block);
 383
 384         rs = SB_DISK_SUPER_BLOCK(s);
 385         sbh = SB_BUFFER_WITH_SB(s);
 386         apbi = SB_AP_BITMAP(s);
 387
 388         get_bit_address(s, block, &nr, &offset);
 389
 390         if (nr >= sb_bmap_nr(rs)) {
 391                 reiserfs_warning(s, "vs-4075: reiserfs_free_block: "
 392                                  "block %lu is out of range on %s",
 393                                  block, reiserfs_bdevname(s));
 394                 return;
 395         }
 396
 397         reiserfs_prepare_for_journal(s, apbi[nr].bh, 1);
 398
 399         /* clear bit for the given block in bit map */
 400         if (!reiserfs_test_and_clear_le_bit(offset, apbi[nr].bh->b_data)) {
 401                 reiserfs_warning(s, "vs-4080: reiserfs_free_block: "
 402                                  "free_block (%s:%lu)[dev:blocknr]: bit already cleared",
 403                                  reiserfs_bdevname(s), block);
 404         }
 405         apbi[nr].free_count++;
 406         journal_mark_dirty(th, s, apbi[nr].bh);
 407
 408         reiserfs_prepare_for_journal(s, sbh, 1);
 409         /* update super block */
 410         set_sb_free_blocks(rs, sb_free_blocks(rs) + 1);
 411
 412         journal_mark_dirty(th, s, sbh);
 413         if (for_unformatted)
 414                 DQUOT_FREE_BLOCK_NODIRTY(inode, 1);
 415 }
 416
 417 void reiserfs_free_block(struct reiserfs_transaction_handle *th,
 418                          struct inode *inode, b_blocknr_t block,
 419                          int for_unformatted)
 420 {
 421         struct super_block *s = th->t_super;
 422
 423         BUG_ON(!th->t_trans_id);
 424
 425         RFALSE(!s, "vs-4061: trying to free block on nonexistent device");
 426         RFALSE(is_reusable(s, block, 1) == 0,
 427                "vs-4071: can not free such block");
 428         /* mark it before we clear it, just in case */
 429         journal_mark_freed(th, s, block);
 430         _reiserfs_free_block(th, inode, block, for_unformatted);
 431 }
 432
 433 /* preallocated blocks don't need to be run through journal_mark_freed */
 434 static void reiserfs_free_prealloc_block(struct reiserfs_transaction_handle *th,
 435                                          struct inode *inode, b_blocknr_t block)
 436 {
 437         RFALSE(!th->t_super,
 438                "vs-4060: trying to free block on nonexistent device");
 439         RFALSE(is_reusable(th->t_super, block, 1) == 0,
 440                "vs-4070: can not free such block");
 441         BUG_ON(!th->t_trans_id);
 442         _reiserfs_free_block(th, inode, block, 1);
 443 }
 444
 445 static void __discard_prealloc(struct reiserfs_transaction_handle *th,
 446                                struct reiserfs_inode_info *ei)
 447 {
 448         unsigned long save = ei->i_prealloc_block;
 449         int dirty = 0;
 450         struct inode *inode = &ei->vfs_inode;
 451         BUG_ON(!th->t_trans_id);
 452 #ifdef CONFIG_REISERFS_CHECK
 453         if (ei->i_prealloc_count < 0)
 454                 reiserfs_warning(th->t_super,
 455                                  "zam-4001:%s: inode has negative prealloc blocks count.",
 456                                  __FUNCTION__);
 457 #endif
 458         while (ei->i_prealloc_count > 0) {
 459                 reiserfs_free_prealloc_block(th, inode, ei->i_prealloc_block);
 460                 ei->i_prealloc_block++;
 461                 ei->i_prealloc_count--;
 462                 dirty = 1;
 463         }
 464         if (dirty)
 465                 reiserfs_update_sd(th, inode);
 466         ei->i_prealloc_block = save;
 467         list_del_init(&(ei->i_prealloc_list));
 468 }
 469
 470 /* FIXME: It should be inline function */
 471 void reiserfs_discard_prealloc(struct reiserfs_transaction_handle *th,
 472                                struct inode *inode)
 473 {
 474         struct reiserfs_inode_info *ei = REISERFS_I(inode);
 475         BUG_ON(!th->t_trans_id);
 476         if (ei->i_prealloc_count)
 477                 __discard_prealloc(th, ei);
 478 }
 479
 480 void reiserfs_discard_all_prealloc(struct reiserfs_transaction_handle *th)
 481 {
 482         struct list_head *plist = &SB_JOURNAL(th->t_super)->j_prealloc_list;
 483
 484         BUG_ON(!th->t_trans_id);
 485
 486         while (!list_empty(plist)) {
 487                 struct reiserfs_inode_info *ei;
 488                 ei = list_entry(plist->next, struct reiserfs_inode_info,
 489                                 i_prealloc_list);
 490 #ifdef CONFIG_REISERFS_CHECK
 491                 if (!ei->i_prealloc_count) {
 492                         reiserfs_warning(th->t_super,
 493                                          "zam-4001:%s: inode is in prealloc list but has no preallocated blocks.",
 494                                          __FUNCTION__);
 495                 }
 496 #endif
 497                 __discard_prealloc(th, ei);
 498         }
 499 }
 500
 501 void reiserfs_init_alloc_options(struct super_block *s)
 502 {
 503         set_bit(_ALLOC_skip_busy, &SB_ALLOC_OPTS(s));
 504         set_bit(_ALLOC_dirid_groups, &SB_ALLOC_OPTS(s));
 505         set_bit(_ALLOC_packing_groups, &SB_ALLOC_OPTS(s));
 506 }
 507
 508 /* block allocator related options are parsed here */
 509 int reiserfs_parse_alloc_options(struct super_block *s, char *options)
 510 {
 511         char *this_char, *value;
 512
 513         REISERFS_SB(s)->s_alloc_options.bits = 0;       /* clear default settings */
 514
 515         while ((this_char = strsep(&options, ":")) != NULL) {
 516                 if ((value = strchr(this_char, '=')) != NULL)
 517                         *value++ = 0;
 518
 519                 if (!strcmp(this_char, "concentrating_formatted_nodes")) {
 520                         int temp;
 521                         SET_OPTION(concentrating_formatted_nodes);
 522                         temp = (value
 523                                 && *value) ? simple_strtoul(value, &value,
 524                                                             0) : 10;
 525                         if (temp <= 0 || temp > 100) {
 526                                 REISERFS_SB(s)->s_alloc_options.border = 10;
 527                         } else {
 528                                 REISERFS_SB(s)->s_alloc_options.border =
 529                                     100 / temp;
 530                         }
 531                         continue;
 532                 }
 533                 if (!strcmp(this_char, "displacing_large_files")) {
 534                         SET_OPTION(displacing_large_files);
 535                         REISERFS_SB(s)->s_alloc_options.large_file_size =
 536                             (value
 537                              && *value) ? simple_strtoul(value, &value, 0) : 16;
 538                         continue;
 539                 }
 540                 if (!strcmp(this_char, "displacing_new_packing_localities")) {
 541                         SET_OPTION(displacing_new_packing_localities);
 542                         continue;
 543                 };
 544
 545                 if (!strcmp(this_char, "old_hashed_relocation")) {
 546                         SET_OPTION(old_hashed_relocation);
 547                         continue;
 548                 }
 549
 550                 if (!strcmp(this_char, "new_hashed_relocation")) {
 551                         SET_OPTION(new_hashed_relocation);
 552                         continue;
 553                 }
 554
 555                 if (!strcmp(this_char, "dirid_groups")) {
 556                         SET_OPTION(dirid_groups);
 557                         continue;
 558                 }
 559                 if (!strcmp(this_char, "oid_groups")) {
 560                         SET_OPTION(oid_groups);
 561                         continue;
 562                 }
 563                 if (!strcmp(this_char, "packing_groups")) {
 564                         SET_OPTION(packing_groups);
 565                         continue;
 566                 }
 567                 if (!strcmp(this_char, "hashed_formatted_nodes")) {
 568                         SET_OPTION(hashed_formatted_nodes);
 569                         continue;
 570                 }
 571
 572                 if (!strcmp(this_char, "skip_busy")) {
 573                         SET_OPTION(skip_busy);
 574                         continue;
 575                 }
 576
 577                 if (!strcmp(this_char, "hundredth_slices")) {
 578                         SET_OPTION(hundredth_slices);
 579                         continue;
 580                 }
 581
 582                 if (!strcmp(this_char, "old_way")) {
 583                         SET_OPTION(old_way);
 584                         continue;
 585                 }
 586
 587                 if (!strcmp(this_char, "displace_based_on_dirid")) {
 588                         SET_OPTION(displace_based_on_dirid);
 589                         continue;
 590                 }
 591
 592                 if (!strcmp(this_char, "preallocmin")) {
 593                         REISERFS_SB(s)->s_alloc_options.preallocmin =
 594                             (value
 595                              && *value) ? simple_strtoul(value, &value, 0) : 4;
 596                         continue;
 597                 }
 598
 599                 if (!strcmp(this_char, "preallocsize")) {
 600                         REISERFS_SB(s)->s_alloc_options.preallocsize =
 601                             (value
 602                              && *value) ? simple_strtoul(value, &value,
 603                                                          0) :
 604                             PREALLOCATION_SIZE;
 605                         continue;
 606                 }
 607
 608                 reiserfs_warning(s, "zam-4001: %s : unknown option - %s",
 609                                  __FUNCTION__, this_char);
 610                 return 1;
 611         }
 612
 613         reiserfs_warning(s, "allocator options = [%08x]\n", SB_ALLOC_OPTS(s));
 614         return 0;
 615 }
 616
 617 static inline void new_hashed_relocation(reiserfs_blocknr_hint_t * hint)
 618 {
 619         char *hash_in;
 620         if (hint->formatted_node) {
 621                 hash_in = (char *)&hint->key.k_dir_id;
 622         } else {
 623                 if (!hint->inode) {
 624                         //hint->search_start = hint->beg;
 625                         hash_in = (char *)&hint->key.k_dir_id;
 626                 } else
 627                     if (TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
 628                         hash_in = (char *)(&INODE_PKEY(hint->inode)->k_dir_id);
 629                 else
 630                         hash_in =
 631                             (char *)(&INODE_PKEY(hint->inode)->k_objectid);
 632         }
 633
 634         hint->search_start =
 635             hint->beg + keyed_hash(hash_in, 4) % (hint->end - hint->beg);
 636 }
 637
 638 /*
 639  * Relocation based on dirid, hashing them into a given bitmap block
 640  * files. Formatted nodes are unaffected, a seperate policy covers them
 641  */
 642 static void dirid_groups(reiserfs_blocknr_hint_t * hint)
 643 {
 644         unsigned long hash;
 645         __u32 dirid = 0;
 646         int bm = 0;
 647         struct super_block *sb = hint->th->t_super;
 648         if (hint->inode)
 649                 dirid = le32_to_cpu(INODE_PKEY(hint->inode)->k_dir_id);
 650         else if (hint->formatted_node)
 651                 dirid = hint->key.k_dir_id;
 652
 653         if (dirid) {
 654                 bm = bmap_hash_id(sb, dirid);
 655                 hash = bm * (sb->s_blocksize << 3);
 656                 /* give a portion of the block group to metadata */
 657                 if (hint->inode)
 658                         hash += sb->s_blocksize / 2;
 659                 hint->search_start = hash;
 660         }
 661 }
 662
 663 /*
 664  * Relocation based on oid, hashing them into a given bitmap block
 665  * files. Formatted nodes are unaffected, a seperate policy covers them
 666  */
 667 static void oid_groups(reiserfs_blocknr_hint_t * hint)
 668 {
 669         if (hint->inode) {
 670                 unsigned long hash;
 671                 __u32 oid;
 672                 __u32 dirid;
 673                 int bm;
 674
 675                 dirid = le32_to_cpu(INODE_PKEY(hint->inode)->k_dir_id);
 676
 677                 /* keep the root dir and it's first set of subdirs close to
 678                  * the start of the disk
 679                  */
 680                 if (dirid <= 2)
 681                         hash = (hint->inode->i_sb->s_blocksize << 3);
 682                 else {
 683                         oid = le32_to_cpu(INODE_PKEY(hint->inode)->k_objectid);
 684                         bm = bmap_hash_id(hint->inode->i_sb, oid);
 685                         hash = bm * (hint->inode->i_sb->s_blocksize << 3);
 686                 }
 687                 hint->search_start = hash;
 688         }
 689 }
 690
 691 /* returns 1 if it finds an indirect item and gets valid hint info
 692  * from it, otherwise 0
 693  */
 694 static int get_left_neighbor(reiserfs_blocknr_hint_t * hint)
 695 {
 696         struct path *path;
 697         struct buffer_head *bh;
 698         struct item_head *ih;
 699         int pos_in_item;
 700         __le32 *item;
 701         int ret = 0;
 702
 703         if (!hint->path)        /* reiserfs code can call this function w/o pointer to path
 704                                  * structure supplied; then we rely on supplied search_start */
 705                 return 0;
 706
 707         path = hint->path;
 708         bh = get_last_bh(path);
 709         RFALSE(!bh, "green-4002: Illegal path specified to get_left_neighbor");
 710         ih = get_ih(path);
 711         pos_in_item = path->pos_in_item;
 712         item = get_item(path);
 713
 714         hint->search_start = bh->b_blocknr;
 715
 716         if (!hint->formatted_node && is_indirect_le_ih(ih)) {
 717                 /* for indirect item: go to left and look for the first non-hole entry
 718                    in the indirect item */
 719                 if (pos_in_item == I_UNFM_NUM(ih))
 720                         pos_in_item--;
 721 //          pos_in_item = I_UNFM_NUM (ih) - 1;
 722                 while (pos_in_item >= 0) {
 723                         int t = get_block_num(item, pos_in_item);
 724                         if (t) {
 725                                 hint->search_start = t;
 726                                 ret = 1;
 727                                 break;
 728                         }
 729                         pos_in_item--;
 730                 }
 731         }
 732
 733         /* does result value fit into specified region? */
 734         return ret;
 735 }
 736
 737 /* should be, if formatted node, then try to put on first part of the device
 738    specified as number of percent with mount option device, else try to put
 739    on last of device.  This is not to say it is good code to do so,
 740    but the effect should be measured.  */
 741 static inline void set_border_in_hint(struct super_block *s,
 742                                       reiserfs_blocknr_hint_t * hint)
 743 {
 744         b_blocknr_t border =
 745             SB_BLOCK_COUNT(s) / REISERFS_SB(s)->s_alloc_options.border;
 746
 747         if (hint->formatted_node)
 748                 hint->end = border - 1;
 749         else
 750                 hint->beg = border;
 751 }
 752
 753 static inline void displace_large_file(reiserfs_blocknr_hint_t * hint)
 754 {
 755         if (TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
 756                 hint->search_start =
 757                     hint->beg +
 758                     keyed_hash((char *)(&INODE_PKEY(hint->inode)->k_dir_id),
 759                                4) % (hint->end - hint->beg);
 760         else
 761                 hint->search_start =
 762                     hint->beg +
 763                     keyed_hash((char *)(&INODE_PKEY(hint->inode)->k_objectid),
 764                                4) % (hint->end - hint->beg);
 765 }
 766
 767 static inline void hash_formatted_node(reiserfs_blocknr_hint_t * hint)
 768 {
 769         char *hash_in;
 770
 771         if (!hint->inode)
 772                 hash_in = (char *)&hint->key.k_dir_id;
 773         else if (TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
 774                 hash_in = (char *)(&INODE_PKEY(hint->inode)->k_dir_id);
 775         else
 776                 hash_in = (char *)(&INODE_PKEY(hint->inode)->k_objectid);
 777
 778         hint->search_start =
 779             hint->beg + keyed_hash(hash_in, 4) % (hint->end - hint->beg);
 780 }
 781
 782 static inline int
 783 this_blocknr_allocation_would_make_it_a_large_file(reiserfs_blocknr_hint_t *
 784                                                    hint)
 785 {
 786         return hint->block ==
 787             REISERFS_SB(hint->th->t_super)->s_alloc_options.large_file_size;
 788 }
 789
 790 #ifdef DISPLACE_NEW_PACKING_LOCALITIES
 791 static inline void displace_new_packing_locality(reiserfs_blocknr_hint_t * hint)
 792 {
 793         struct in_core_key *key = &hint->key;
 794
 795         hint->th->displace_new_blocks = 0;
 796         hint->search_start =
 797             hint->beg + keyed_hash((char *)(&key->k_objectid),
 798                                    4) % (hint->end - hint->beg);
 799 }
 800 #endif
 801
 802 static inline int old_hashed_relocation(reiserfs_blocknr_hint_t * hint)
 803 {
 804         b_blocknr_t border;
 805         u32 hash_in;
 806
 807         if (hint->formatted_node || hint->inode == NULL) {
 808                 return 0;
 809         }
 810
 811         hash_in = le32_to_cpu((INODE_PKEY(hint->inode))->k_dir_id);
 812         border =
 813             hint->beg + (u32) keyed_hash(((char *)(&hash_in)),
 814                                          4) % (hint->end - hint->beg - 1);
 815         if (border > hint->search_start)
 816                 hint->search_start = border;
 817
 818         return 1;
 819 }
 820
 821 static inline int old_way(reiserfs_blocknr_hint_t * hint)
 822 {
 823         b_blocknr_t border;
 824
 825         if (hint->formatted_node || hint->inode == NULL) {
 826                 return 0;
 827         }
 828
 829         border =
 830             hint->beg +
 831             le32_to_cpu(INODE_PKEY(hint->inode)->k_dir_id) % (hint->end -
 832                                                               hint->beg);
 833         if (border > hint->search_start)
 834                 hint->search_start = border;
 835
 836         return 1;
 837 }
 838
 839 static inline void hundredth_slices(reiserfs_blocknr_hint_t * hint)
 840 {
 841         struct in_core_key *key = &hint->key;
 842         b_blocknr_t slice_start;
 843
 844         slice_start =
 845             (keyed_hash((char *)(&key->k_dir_id), 4) % 100) * (hint->end / 100);
 846         if (slice_start > hint->search_start
 847             || slice_start + (hint->end / 100) <= hint->search_start) {
 848                 hint->search_start = slice_start;
 849         }
 850 }
 851
 852 static void determine_search_start(reiserfs_blocknr_hint_t * hint,
 853                                    int amount_needed)
 854 {
 855         struct super_block *s = hint->th->t_super;
 856         int unfm_hint;
 857
 858         hint->beg = 0;
 859         hint->end = SB_BLOCK_COUNT(s) - 1;
 860
 861         /* This is former border algorithm. Now with tunable border offset */
 862         if (concentrating_formatted_nodes(s))
 863                 set_border_in_hint(s, hint);
 864
 865 #ifdef DISPLACE_NEW_PACKING_LOCALITIES
 866         /* whenever we create a new directory, we displace it.  At first we will
 867            hash for location, later we might look for a moderately empty place for
 868            it */
 869         if (displacing_new_packing_localities(s)
 870             && hint->th->displace_new_blocks) {
 871                 displace_new_packing_locality(hint);
 872
 873                 /* we do not continue determine_search_start,
 874                  * if new packing locality is being displaced */
 875                 return;
 876         }
 877 #endif
 878
 879         /* all persons should feel encouraged to add more special cases here and
 880          * test them */
 881
 882         if (displacing_large_files(s) && !hint->formatted_node
 883             && this_blocknr_allocation_would_make_it_a_large_file(hint)) {
 884                 displace_large_file(hint);
 885                 return;
 886         }
 887
 888         /* if none of our special cases is relevant, use the left neighbor in the
 889            tree order of the new node we are allocating for */
 890         if (hint->formatted_node && TEST_OPTION(hashed_formatted_nodes, s)) {
 891                 hash_formatted_node(hint);
 892                 return;
 893         }
 894
 895         unfm_hint = get_left_neighbor(hint);
 896
 897         /* Mimic old block allocator behaviour, that is if VFS allowed for preallocation,
 898            new blocks are displaced based on directory ID. Also, if suggested search_start
 899            is less than last preallocated block, we start searching from it, assuming that
 900            HDD dataflow is faster in forward direction */
 901         if (TEST_OPTION(old_way, s)) {
 902                 if (!hint->formatted_node) {
 903                         if (!reiserfs_hashed_relocation(s))
 904                                 old_way(hint);
 905                         else if (!reiserfs_no_unhashed_relocation(s))
 906                                 old_hashed_relocation(hint);
 907
 908                         if (hint->inode
 909                             && hint->search_start <
 910                             REISERFS_I(hint->inode)->i_prealloc_block)
 911                                 hint->search_start =
 912                                     REISERFS_I(hint->inode)->i_prealloc_block;
 913                 }
 914                 return;
 915         }
 916
 917         /* This is an approach proposed by Hans */
 918         if (TEST_OPTION(hundredth_slices, s)
 919             && !(displacing_large_files(s) && !hint->formatted_node)) {
 920                 hundredth_slices(hint);
 921                 return;
 922         }
 923
 924         /* old_hashed_relocation only works on unformatted */
 925         if (!unfm_hint && !hint->formatted_node &&
 926             TEST_OPTION(old_hashed_relocation, s)) {
 927                 old_hashed_relocation(hint);
 928         }
 929         /* new_hashed_relocation works with both formatted/unformatted nodes */
 930         if ((!unfm_hint || hint->formatted_node) &&
 931             TEST_OPTION(new_hashed_relocation, s)) {
 932                 new_hashed_relocation(hint);
 933         }
 934         /* dirid grouping works only on unformatted nodes */
 935         if (!unfm_hint && !hint->formatted_node && TEST_OPTION(dirid_groups, s)) {
 936                 dirid_groups(hint);
 937         }
 938 #ifdef DISPLACE_NEW_PACKING_LOCALITIES
 939         if (hint->formatted_node && TEST_OPTION(dirid_groups, s)) {
 940                 dirid_groups(hint);
 941         }
 942 #endif
 943
 944         /* oid grouping works only on unformatted nodes */
 945         if (!unfm_hint && !hint->formatted_node && TEST_OPTION(oid_groups, s)) {
 946                 oid_groups(hint);
 947         }
 948         return;
 949 }
 950
 951 static int determine_prealloc_size(reiserfs_blocknr_hint_t * hint)
 952 {
 953         /* make minimum size a mount option and benchmark both ways */
 954         /* we preallocate blocks only for regular files, specific size */
 955         /* benchmark preallocating always and see what happens */
 956
 957         hint->prealloc_size = 0;
 958
 959         if (!hint->formatted_node && hint->preallocate) {
 960                 if (S_ISREG(hint->inode->i_mode)
 961                     && hint->inode->i_size >=
 962                     REISERFS_SB(hint->th->t_super)->s_alloc_options.
 963                     preallocmin * hint->inode->i_sb->s_blocksize)
 964                         hint->prealloc_size =
 965                             REISERFS_SB(hint->th->t_super)->s_alloc_options.
 966                             preallocsize - 1;
 967         }
 968         return CARRY_ON;
 969 }
 970
 971 /* XXX I know it could be merged with upper-level function;
 972    but may be result function would be too complex. */
 973 static inline int allocate_without_wrapping_disk(reiserfs_blocknr_hint_t * hint,
 974                                                  b_blocknr_t * new_blocknrs,
 975                                                  b_blocknr_t start,
 976                                                  b_blocknr_t finish, int min,
 977                                                  int amount_needed,
 978                                                  int prealloc_size)
 979 {
 980         int rest = amount_needed;
 981         int nr_allocated;
 982
 983         while (rest > 0 && start <= finish) {
 984                 nr_allocated = scan_bitmap(hint->th, &start, finish, min,
 985                                            rest + prealloc_size,
 986                                            !hint->formatted_node, hint->block);
 987
 988                 if (nr_allocated == 0)  /* no new blocks allocated, return */
 989                         break;
 990
 991                 /* fill free_blocknrs array first */
 992                 while (rest > 0 && nr_allocated > 0) {
 993                         *new_blocknrs++ = start++;
 994                         rest--;
 995                         nr_allocated--;
 996                 }
 997
 998                 /* do we have something to fill prealloc. array also ? */
 999                 if (nr_allocated > 0) {
1000                         /* it means prealloc_size was greater that 0 and we do preallocation */
1001                         list_add(&REISERFS_I(hint->inode)->i_prealloc_list,
1002                                  &SB_JOURNAL(hint->th->t_super)->
1003                                  j_prealloc_list);
1004                         REISERFS_I(hint->inode)->i_prealloc_block = start;
1005                         REISERFS_I(hint->inode)->i_prealloc_count =
1006                             nr_allocated;
1007                         break;
1008                 }
1009         }
1010
1011         return (amount_needed - rest);
1012 }
1013
1014 static inline int blocknrs_and_prealloc_arrays_from_search_start
1015     (reiserfs_blocknr_hint_t * hint, b_blocknr_t * new_blocknrs,
1016      int amount_needed) {
1017         struct super_block *s = hint->th->t_super;
1018         b_blocknr_t start = hint->search_start;
1019         b_blocknr_t finish = SB_BLOCK_COUNT(s) - 1;
1020         int passno = 0;
1021         int nr_allocated = 0;
1022         int bigalloc = 0;
1023
1024         determine_prealloc_size(hint);
1025         if (!hint->formatted_node) {
1026                 int quota_ret;
1027 #ifdef REISERQUOTA_DEBUG
1028                 reiserfs_debug(s, REISERFS_DEBUG_CODE,
1029                                "reiserquota: allocating %d blocks id=%u",
1030                                amount_needed, hint->inode->i_uid);
1031 #endif
1032                 quota_ret =
1033                     DQUOT_ALLOC_BLOCK_NODIRTY(hint->inode, amount_needed);
1034                 if (quota_ret)  /* Quota exceeded? */
1035                         return QUOTA_EXCEEDED;
1036                 if (hint->preallocate && hint->prealloc_size) {
1037 #ifdef REISERQUOTA_DEBUG
1038                         reiserfs_debug(s, REISERFS_DEBUG_CODE,
1039                                        "reiserquota: allocating (prealloc) %d blocks id=%u",
1040                                        hint->prealloc_size, hint->inode->i_uid);
1041 #endif
1042                         quota_ret =
1043                             DQUOT_PREALLOC_BLOCK_NODIRTY(hint->inode,
1044                                                          hint->prealloc_size);
1045                         if (quota_ret)
1046                                 hint->preallocate = hint->prealloc_size = 0;
1047                 }
1048                 /* for unformatted nodes, force large allocations */
1049                 bigalloc = amount_needed;
1050         }
1051
1052         do {
1053                 /* in bigalloc mode, nr_allocated should stay zero until
1054                  * the entire allocation is filled
1055                  */
1056                 if (unlikely(bigalloc && nr_allocated)) {
1057                         reiserfs_warning(s, "bigalloc is %d, nr_allocated %d\n",
1058                                          bigalloc, nr_allocated);
1059                         /* reset things to a sane value */
1060                         bigalloc = amount_needed - nr_allocated;
1061                 }
1062                 /*
1063                  * try pass 0 and pass 1 looking for a nice big
1064                  * contiguous allocation.  Then reset and look
1065                  * for anything you can find.
1066                  */
1067                 if (passno == 2 && bigalloc) {
1068                         passno = 0;
1069                         bigalloc = 0;
1070                 }
1071                 switch (passno++) {
1072                 case 0: /* Search from hint->search_start to end of disk */
1073                         start = hint->search_start;
1074                         finish = SB_BLOCK_COUNT(s) - 1;
1075                         break;
1076                 case 1: /* Search from hint->beg to hint->search_start */
1077                         start = hint->beg;
1078                         finish = hint->search_start;
1079                         break;
1080                 case 2: /* Last chance: Search from 0 to hint->beg */
1081                         start = 0;
1082                         finish = hint->beg;
1083                         break;
1084                 default:        /* We've tried searching everywhere, not enough space */
1085                         /* Free the blocks */
1086                         if (!hint->formatted_node) {
1087 #ifdef REISERQUOTA_DEBUG
1088                                 reiserfs_debug(s, REISERFS_DEBUG_CODE,
1089                                                "reiserquota: freeing (nospace) %d blocks id=%u",
1090                                                amount_needed +
1091                                                hint->prealloc_size -
1092                                                nr_allocated,
1093                                                hint->inode->i_uid);
1094 #endif
1095                                 DQUOT_FREE_BLOCK_NODIRTY(hint->inode, amount_needed + hint->prealloc_size - nr_allocated);      /* Free not allocated blocks */
1096                         }
1097                         while (nr_allocated--)
1098                                 reiserfs_free_block(hint->th, hint->inode,
1099                                                     new_blocknrs[nr_allocated],
1100                                                     !hint->formatted_node);
1101
1102                         return NO_DISK_SPACE;
1103                 }
1104         } while ((nr_allocated += allocate_without_wrapping_disk(hint,
1105                                                                  new_blocknrs +
1106                                                                  nr_allocated,
1107                                                                  start, finish,
1108                                                                  bigalloc ?
1109                                                                  bigalloc : 1,
1110                                                                  amount_needed -
1111                                                                  nr_allocated,
1112                                                                  hint->
1113                                                                  prealloc_size))
1114                  < amount_needed);
1115         if (!hint->formatted_node &&
1116             amount_needed + hint->prealloc_size >
1117             nr_allocated + REISERFS_I(hint->inode)->i_prealloc_count) {
1118                 /* Some of preallocation blocks were not allocated */
1119 #ifdef REISERQUOTA_DEBUG
1120                 reiserfs_debug(s, REISERFS_DEBUG_CODE,
1121                                "reiserquota: freeing (failed prealloc) %d blocks id=%u",
1122                                amount_needed + hint->prealloc_size -
1123                                nr_allocated -
1124                                REISERFS_I(hint->inode)->i_prealloc_count,
1125                                hint->inode->i_uid);
1126 #endif
1127                 DQUOT_FREE_BLOCK_NODIRTY(hint->inode, amount_needed +
1128                                          hint->prealloc_size - nr_allocated -
1129                                          REISERFS_I(hint->inode)->
1130                                          i_prealloc_count);
1131         }
1132
1133         return CARRY_ON;
1134 }
1135
1136 /* grab new blocknrs from preallocated list */
1137 /* return amount still needed after using them */
1138 static int use_preallocated_list_if_available(reiserfs_blocknr_hint_t * hint,
1139                                               b_blocknr_t * new_blocknrs,
1140                                               int amount_needed)
1141 {
1142         struct inode *inode = hint->inode;
1143
1144         if (REISERFS_I(inode)->i_prealloc_count > 0) {
1145                 while (amount_needed) {
1146
1147                         *new_blocknrs++ = REISERFS_I(inode)->i_prealloc_block++;
1148                         REISERFS_I(inode)->i_prealloc_count--;
1149
1150                         amount_needed--;
1151
1152                         if (REISERFS_I(inode)->i_prealloc_count <= 0) {
1153                                 list_del(&REISERFS_I(inode)->i_prealloc_list);
1154                                 break;
1155                         }
1156                 }
1157         }
1158         /* return amount still needed after using preallocated blocks */
1159         return amount_needed;
1160 }
1161
1162 int reiserfs_allocate_blocknrs(reiserfs_blocknr_hint_t * hint, b_blocknr_t * new_blocknrs, int amount_needed, int reserved_by_us        /* Amount of blocks we have
1163                                                                                                                                            already reserved */ )
1164 {
1165         int initial_amount_needed = amount_needed;
1166         int ret;
1167         struct super_block *s = hint->th->t_super;
1168
1169         /* Check if there is enough space, taking into account reserved space */
1170         if (SB_FREE_BLOCKS(s) - REISERFS_SB(s)->reserved_blocks <
1171             amount_needed - reserved_by_us)
1172                 return NO_DISK_SPACE;
1173         /* should this be if !hint->inode &&  hint->preallocate? */
1174         /* do you mean hint->formatted_node can be removed ? - Zam */
1175         /* hint->formatted_node cannot be removed because we try to access
1176            inode information here, and there is often no inode assotiated with
1177            metadata allocations - green */
1178
1179         if (!hint->formatted_node && hint->preallocate) {
1180                 amount_needed = use_preallocated_list_if_available
1181                     (hint, new_blocknrs, amount_needed);
1182                 if (amount_needed == 0) /* all blocknrs we need we got from
1183                                            prealloc. list */
1184                         return CARRY_ON;
1185                 new_blocknrs += (initial_amount_needed - amount_needed);
1186         }
1187
1188         /* find search start and save it in hint structure */
1189         determine_search_start(hint, amount_needed);
1190         if (hint->search_start >= SB_BLOCK_COUNT(s))
1191                 hint->search_start = SB_BLOCK_COUNT(s) - 1;
1192
1193         /* allocation itself; fill new_blocknrs and preallocation arrays */
1194         ret = blocknrs_and_prealloc_arrays_from_search_start
1195             (hint, new_blocknrs, amount_needed);
1196
1197         /* we used prealloc. list to fill (partially) new_blocknrs array. If final allocation fails we
1198          * need to return blocks back to prealloc. list or just free them. -- Zam (I chose second
1199          * variant) */
1200
1201         if (ret != CARRY_ON) {
1202                 while (amount_needed++ < initial_amount_needed) {
1203                         reiserfs_free_block(hint->th, hint->inode,
1204                                             *(--new_blocknrs), 1);
1205                 }
1206         }
1207         return ret;
1208 }
1209
1210 /* These 2 functions are here to provide blocks reservation to the rest of kernel */
1211 /* Reserve @blocks amount of blocks in fs pointed by @sb. Caller must make sure
1212    there are actually this much blocks on the FS available */
1213 void reiserfs_claim_blocks_to_be_allocated(struct super_block *sb,      /* super block of
1214                                                                            filesystem where
1215                                                                            blocks should be
1216                                                                            reserved */
1217                                            int blocks   /* How much to reserve */
1218     )
1219 {
1220
1221         /* Fast case, if reservation is zero - exit immediately. */
1222         if (!blocks)
1223                 return;
1224
1225         spin_lock(&REISERFS_SB(sb)->bitmap_lock);
1226         REISERFS_SB(sb)->reserved_blocks += blocks;
1227         spin_unlock(&REISERFS_SB(sb)->bitmap_lock);
1228 }
1229
1230 /* Unreserve @blocks amount of blocks in fs pointed by @sb */
1231 void reiserfs_release_claimed_blocks(struct super_block *sb,    /* super block of
1232                                                                    filesystem where
1233                                                                    blocks should be
1234                                                                    reserved */
1235                                      int blocks /* How much to unreserve */
1236     )
1237 {
1238
1239         /* Fast case, if unreservation is zero - exit immediately. */
1240         if (!blocks)
1241                 return;
1242
1243         spin_lock(&REISERFS_SB(sb)->bitmap_lock);
1244         REISERFS_SB(sb)->reserved_blocks -= blocks;
1245         spin_unlock(&REISERFS_SB(sb)->bitmap_lock);
1246         RFALSE(REISERFS_SB(sb)->reserved_blocks < 0,
1247                "amount of blocks reserved became zero?");
1248 }
1249
1250 /* This function estimates how much pages we will be able to write to FS
1251    used for reiserfs_file_write() purposes for now. */
1252 int reiserfs_can_fit_pages(struct super_block *sb       /* superblock of filesystem
1253                                                            to estimate space */ )
1254 {
1255         int space;
1256
1257         spin_lock(&REISERFS_SB(sb)->bitmap_lock);
1258         space =
1259             (SB_FREE_BLOCKS(sb) -
1260              REISERFS_SB(sb)->reserved_blocks) >> (PAGE_CACHE_SHIFT -
1261                                                    sb->s_blocksize_bits);
1262         spin_unlock(&REISERFS_SB(sb)->bitmap_lock);
1263
1264         return space > 0 ? space : 0;
1265 }