fs/nilfs2/bmap.c

   1 /*
   2  * bmap.c - NILFS block mapping.
   3  *
   4  * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * Written by Koji Sato <koji@osrg.net>.
  21  */
  22
  23 #include <linux/fs.h>
  24 #include <linux/string.h>
  25 #include <linux/errno.h>
  26 #include "nilfs.h"
  27 #include "bmap.h"
  28 #include "sb.h"
  29 #include "btnode.h"
  30 #include "mdt.h"
  31 #include "dat.h"
  32 #include "alloc.h"
  33
  34 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
  35 {
  36         return nilfs_dat_inode(NILFS_I_NILFS(bmap->b_inode));
  37 }
  38
  39 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
  40                                __u64 *ptrp)
  41 {
  42         sector_t blocknr;
  43         int ret;
  44
  45         down_read(&bmap->b_sem);
  46         ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
  47         if (ret < 0)
  48                 goto out;
  49         if (NILFS_BMAP_USE_VBN(bmap)) {
  50                 ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
  51                                           &blocknr);
  52                 if (!ret)
  53                         *ptrp = blocknr;
  54         }
  55
  56  out:
  57         up_read(&bmap->b_sem);
  58         return ret;
  59 }
  60
  61 int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
  62                              unsigned maxblocks)
  63 {
  64         int ret;
  65
  66         down_read(&bmap->b_sem);
  67         ret = bmap->b_ops->bop_lookup_contig(bmap, key, ptrp, maxblocks);
  68         up_read(&bmap->b_sem);
  69         return ret;
  70 }
  71
  72 /**
  73  * nilfs_bmap_lookup - find a record
  74  * @bmap: bmap
  75  * @key: key
  76  * @recp: pointer to record
  77  *
  78  * Description: nilfs_bmap_lookup() finds a record whose key matches @key in
  79  * @bmap.
  80  *
  81  * Return Value: On success, 0 is returned and the record associated with @key
  82  * is stored in the place pointed by @recp. On error, one of the following
  83  * negative error codes is returned.
  84  *
  85  * %-EIO - I/O error.
  86  *
  87  * %-ENOMEM - Insufficient amount of memory available.
  88  *
  89  * %-ENOENT - A record associated with @key does not exist.
  90  */
  91 int nilfs_bmap_lookup(struct nilfs_bmap *bmap,
  92                       unsigned long key,
  93                       unsigned long *recp)
  94 {
  95         __u64 ptr;
  96         int ret;
  97
  98         /* XXX: use macro for level 1 */
  99         ret = nilfs_bmap_lookup_at_level(bmap, key, 1, &ptr);
 100         if (recp != NULL)
 101                 *recp = ptr;
 102         return ret;
 103 }
 104
 105 static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 106 {
 107         __u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
 108         __u64 ptrs[NILFS_BMAP_SMALL_HIGH + 1];
 109         int ret, n;
 110
 111         if (bmap->b_ops->bop_check_insert != NULL) {
 112                 ret = bmap->b_ops->bop_check_insert(bmap, key);
 113                 if (ret > 0) {
 114                         n = bmap->b_ops->bop_gather_data(
 115                                 bmap, keys, ptrs, NILFS_BMAP_SMALL_HIGH + 1);
 116                         if (n < 0)
 117                                 return n;
 118                         ret = nilfs_btree_convert_and_insert(
 119                                 bmap, key, ptr, keys, ptrs, n);
 120                         if (ret == 0)
 121                                 bmap->b_u.u_flags |= NILFS_BMAP_LARGE;
 122
 123                         return ret;
 124                 } else if (ret < 0)
 125                         return ret;
 126         }
 127
 128         return bmap->b_ops->bop_insert(bmap, key, ptr);
 129 }
 130
 131 /**
 132  * nilfs_bmap_insert - insert a new key-record pair into a bmap
 133  * @bmap: bmap
 134  * @key: key
 135  * @rec: record
 136  *
 137  * Description: nilfs_bmap_insert() inserts the new key-record pair specified
 138  * by @key and @rec into @bmap.
 139  *
 140  * Return Value: On success, 0 is returned. On error, one of the following
 141  * negative error codes is returned.
 142  *
 143  * %-EIO - I/O error.
 144  *
 145  * %-ENOMEM - Insufficient amount of memory available.
 146  *
 147  * %-EEXIST - A record associated with @key already exist.
 148  */
 149 int nilfs_bmap_insert(struct nilfs_bmap *bmap,
 150                       unsigned long key,
 151                       unsigned long rec)
 152 {
 153         int ret;
 154
 155         down_write(&bmap->b_sem);
 156         ret = nilfs_bmap_do_insert(bmap, key, rec);
 157         up_write(&bmap->b_sem);
 158         return ret;
 159 }
 160
 161 static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
 162 {
 163         __u64 keys[NILFS_BMAP_LARGE_LOW + 1];
 164         __u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
 165         int ret, n;
 166
 167         if (bmap->b_ops->bop_check_delete != NULL) {
 168                 ret = bmap->b_ops->bop_check_delete(bmap, key);
 169                 if (ret > 0) {
 170                         n = bmap->b_ops->bop_gather_data(
 171                                 bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
 172                         if (n < 0)
 173                                 return n;
 174                         ret = nilfs_direct_delete_and_convert(
 175                                 bmap, key, keys, ptrs, n);
 176                         if (ret == 0)
 177                                 bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;
 178
 179                         return ret;
 180                 } else if (ret < 0)
 181                         return ret;
 182         }
 183
 184         return bmap->b_ops->bop_delete(bmap, key);
 185 }
 186
 187 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, unsigned long *key)
 188 {
 189         __u64 lastkey;
 190         int ret;
 191
 192         down_read(&bmap->b_sem);
 193         ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 194         if (!ret)
 195                 *key = lastkey;
 196         up_read(&bmap->b_sem);
 197         return ret;
 198 }
 199
 200 /**
 201  * nilfs_bmap_delete - delete a key-record pair from a bmap
 202  * @bmap: bmap
 203  * @key: key
 204  *
 205  * Description: nilfs_bmap_delete() deletes the key-record pair specified by
 206  * @key from @bmap.
 207  *
 208  * Return Value: On success, 0 is returned. On error, one of the following
 209  * negative error codes is returned.
 210  *
 211  * %-EIO - I/O error.
 212  *
 213  * %-ENOMEM - Insufficient amount of memory available.
 214  *
 215  * %-ENOENT - A record associated with @key does not exist.
 216  */
 217 int nilfs_bmap_delete(struct nilfs_bmap *bmap, unsigned long key)
 218 {
 219         int ret;
 220
 221         down_write(&bmap->b_sem);
 222         ret = nilfs_bmap_do_delete(bmap, key);
 223         up_write(&bmap->b_sem);
 224         return ret;
 225 }
 226
 227 static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, unsigned long key)
 228 {
 229         __u64 lastkey;
 230         int ret;
 231
 232         ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 233         if (ret < 0) {
 234                 if (ret == -ENOENT)
 235                         ret = 0;
 236                 return ret;
 237         }
 238
 239         while (key <= lastkey) {
 240                 ret = nilfs_bmap_do_delete(bmap, lastkey);
 241                 if (ret < 0)
 242                         return ret;
 243                 ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 244                 if (ret < 0) {
 245                         if (ret == -ENOENT)
 246                                 ret = 0;
 247                         return ret;
 248                 }
 249         }
 250         return 0;
 251 }
 252
 253 /**
 254  * nilfs_bmap_truncate - truncate a bmap to a specified key
 255  * @bmap: bmap
 256  * @key: key
 257  *
 258  * Description: nilfs_bmap_truncate() removes key-record pairs whose keys are
 259  * greater than or equal to @key from @bmap.
 260  *
 261  * Return Value: On success, 0 is returned. On error, one of the following
 262  * negative error codes is returned.
 263  *
 264  * %-EIO - I/O error.
 265  *
 266  * %-ENOMEM - Insufficient amount of memory available.
 267  */
 268 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, unsigned long key)
 269 {
 270         int ret;
 271
 272         down_write(&bmap->b_sem);
 273         ret = nilfs_bmap_do_truncate(bmap, key);
 274         up_write(&bmap->b_sem);
 275         return ret;
 276 }
 277
 278 /**
 279  * nilfs_bmap_clear - free resources a bmap holds
 280  * @bmap: bmap
 281  *
 282  * Description: nilfs_bmap_clear() frees resources associated with @bmap.
 283  */
 284 void nilfs_bmap_clear(struct nilfs_bmap *bmap)
 285 {
 286         down_write(&bmap->b_sem);
 287         if (bmap->b_ops->bop_clear != NULL)
 288                 bmap->b_ops->bop_clear(bmap);
 289         up_write(&bmap->b_sem);
 290 }
 291
 292 /**
 293  * nilfs_bmap_propagate - propagate dirty state
 294  * @bmap: bmap
 295  * @bh: buffer head
 296  *
 297  * Description: nilfs_bmap_propagate() marks the buffers that directly or
 298  * indirectly refer to the block specified by @bh dirty.
 299  *
 300  * Return Value: On success, 0 is returned. On error, one of the following
 301  * negative error codes is returned.
 302  *
 303  * %-EIO - I/O error.
 304  *
 305  * %-ENOMEM - Insufficient amount of memory available.
 306  */
 307 int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
 308 {
 309         int ret;
 310
 311         down_write(&bmap->b_sem);
 312         ret = bmap->b_ops->bop_propagate(bmap, bh);
 313         up_write(&bmap->b_sem);
 314         return ret;
 315 }
 316
 317 /**
 318  * nilfs_bmap_lookup_dirty_buffers -
 319  * @bmap: bmap
 320  * @listp: pointer to buffer head list
 321  */
 322 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
 323                                      struct list_head *listp)
 324 {
 325         if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
 326                 bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
 327 }
 328
 329 /**
 330  * nilfs_bmap_assign - assign a new block number to a block
 331  * @bmap: bmap
 332  * @bhp: pointer to buffer head
 333  * @blocknr: block number
 334  * @binfo: block information
 335  *
 336  * Description: nilfs_bmap_assign() assigns the block number @blocknr to the
 337  * buffer specified by @bh.
 338  *
 339  * Return Value: On success, 0 is returned and the buffer head of a newly
 340  * create buffer and the block information associated with the buffer are
 341  * stored in the place pointed by @bh and @binfo, respectively. On error, one
 342  * of the following negative error codes is returned.
 343  *
 344  * %-EIO - I/O error.
 345  *
 346  * %-ENOMEM - Insufficient amount of memory available.
 347  */
 348 int nilfs_bmap_assign(struct nilfs_bmap *bmap,
 349                       struct buffer_head **bh,
 350                       unsigned long blocknr,
 351                       union nilfs_binfo *binfo)
 352 {
 353         int ret;
 354
 355         down_write(&bmap->b_sem);
 356         ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
 357         up_write(&bmap->b_sem);
 358         return ret;
 359 }
 360
 361 /**
 362  * nilfs_bmap_mark - mark block dirty
 363  * @bmap: bmap
 364  * @key: key
 365  * @level: level
 366  *
 367  * Description: nilfs_bmap_mark() marks the block specified by @key and @level
 368  * as dirty.
 369  *
 370  * Return Value: On success, 0 is returned. On error, one of the following
 371  * negative error codes is returned.
 372  *
 373  * %-EIO - I/O error.
 374  *
 375  * %-ENOMEM - Insufficient amount of memory available.
 376  */
 377 int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
 378 {
 379         int ret;
 380
 381         if (bmap->b_ops->bop_mark == NULL)
 382                 return 0;
 383
 384         down_write(&bmap->b_sem);
 385         ret = bmap->b_ops->bop_mark(bmap, key, level);
 386         up_write(&bmap->b_sem);
 387         return ret;
 388 }
 389
 390 /**
 391  * nilfs_bmap_test_and_clear_dirty - test and clear a bmap dirty state
 392  * @bmap: bmap
 393  *
 394  * Description: nilfs_test_and_clear() is the atomic operation to test and
 395  * clear the dirty state of @bmap.
 396  *
 397  * Return Value: 1 is returned if @bmap is dirty, or 0 if clear.
 398  */
 399 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
 400 {
 401         int ret;
 402
 403         down_write(&bmap->b_sem);
 404         ret = nilfs_bmap_dirty(bmap);
 405         nilfs_bmap_clear_dirty(bmap);
 406         up_write(&bmap->b_sem);
 407         return ret;
 408 }
 409
 410
 411 /*
 412  * Internal use only
 413  */
 414
 415 void nilfs_bmap_add_blocks(const struct nilfs_bmap *bmap, int n)
 416 {
 417         inode_add_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
 418         if (NILFS_MDT(bmap->b_inode))
 419                 nilfs_mdt_mark_dirty(bmap->b_inode);
 420         else
 421                 mark_inode_dirty(bmap->b_inode);
 422 }
 423
 424 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *bmap, int n)
 425 {
 426         inode_sub_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
 427         if (NILFS_MDT(bmap->b_inode))
 428                 nilfs_mdt_mark_dirty(bmap->b_inode);
 429         else
 430                 mark_inode_dirty(bmap->b_inode);
 431 }
 432
 433 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
 434                               const struct buffer_head *bh)
 435 {
 436         struct buffer_head *pbh;
 437         __u64 key;
 438
 439         key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
 440                                          bmap->b_inode->i_blkbits);
 441         for (pbh = page_buffers(bh->b_page); pbh != bh;
 442              pbh = pbh->b_this_page, key++);
 443
 444         return key;
 445 }
 446
 447 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
 448 {
 449         __s64 diff;
 450
 451         diff = key - bmap->b_last_allocated_key;
 452         if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
 453             (bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
 454             (bmap->b_last_allocated_ptr + diff > 0))
 455                 return bmap->b_last_allocated_ptr + diff;
 456         else
 457                 return NILFS_BMAP_INVALID_PTR;
 458 }
 459
 460 #define NILFS_BMAP_GROUP_DIV    8
 461 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 462 {
 463         struct inode *dat = nilfs_bmap_get_dat(bmap);
 464         unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
 465         unsigned long group = bmap->b_inode->i_ino / entries_per_group;
 466
 467         return group * entries_per_group +
 468                 (bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
 469                 (entries_per_group / NILFS_BMAP_GROUP_DIV);
 470 }
 471
 472 int nilfs_bmap_prepare_alloc_v(struct nilfs_bmap *bmap,
 473                                  union nilfs_bmap_ptr_req *req)
 474 {
 475         return nilfs_dat_prepare_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 476 }
 477
 478 void nilfs_bmap_commit_alloc_v(struct nilfs_bmap *bmap,
 479                                  union nilfs_bmap_ptr_req *req)
 480 {
 481         nilfs_dat_commit_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 482 }
 483
 484 void nilfs_bmap_abort_alloc_v(struct nilfs_bmap *bmap,
 485                               union nilfs_bmap_ptr_req *req)
 486 {
 487         nilfs_dat_abort_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 488 }
 489
 490 int nilfs_bmap_start_v(struct nilfs_bmap *bmap, union nilfs_bmap_ptr_req *req,
 491                        sector_t blocknr)
 492 {
 493         struct inode *dat = nilfs_bmap_get_dat(bmap);
 494         int ret;
 495
 496         ret = nilfs_dat_prepare_start(dat, &req->bpr_req);
 497         if (likely(!ret))
 498                 nilfs_dat_commit_start(dat, &req->bpr_req, blocknr);
 499         return ret;
 500 }
 501
 502 int nilfs_bmap_prepare_end_v(struct nilfs_bmap *bmap,
 503                              union nilfs_bmap_ptr_req *req)
 504 {
 505         return nilfs_dat_prepare_end(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 506 }
 507
 508 void nilfs_bmap_commit_end_v(struct nilfs_bmap *bmap,
 509                              union nilfs_bmap_ptr_req *req)
 510 {
 511         nilfs_dat_commit_end(nilfs_bmap_get_dat(bmap), &req->bpr_req,
 512                              bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 513 }
 514
 515 void nilfs_bmap_abort_end_v(struct nilfs_bmap *bmap,
 516                             union nilfs_bmap_ptr_req *req)
 517 {
 518         nilfs_dat_abort_end(nilfs_bmap_get_dat(bmap), &req->bpr_req);
 519 }
 520
 521 int nilfs_bmap_move_v(const struct nilfs_bmap *bmap, __u64 vblocknr,
 522                       sector_t blocknr)
 523 {
 524         return nilfs_dat_move(nilfs_bmap_get_dat(bmap), vblocknr, blocknr);
 525 }
 526
 527 int nilfs_bmap_mark_dirty(const struct nilfs_bmap *bmap, __u64 vblocknr)
 528 {
 529         return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(bmap), vblocknr);
 530 }
 531
 532 int nilfs_bmap_prepare_update_v(struct nilfs_bmap *bmap,
 533                                 union nilfs_bmap_ptr_req *oldreq,
 534                                 union nilfs_bmap_ptr_req *newreq)
 535 {
 536         struct inode *dat = nilfs_bmap_get_dat(bmap);
 537         int ret;
 538
 539         ret = nilfs_dat_prepare_end(dat, &oldreq->bpr_req);
 540         if (ret < 0)
 541                 return ret;
 542         ret = nilfs_dat_prepare_alloc(dat, &newreq->bpr_req);
 543         if (ret < 0)
 544                 nilfs_dat_abort_end(dat, &oldreq->bpr_req);
 545
 546         return ret;
 547 }
 548
 549 void nilfs_bmap_commit_update_v(struct nilfs_bmap *bmap,
 550                                 union nilfs_bmap_ptr_req *oldreq,
 551                                 union nilfs_bmap_ptr_req *newreq)
 552 {
 553         struct inode *dat = nilfs_bmap_get_dat(bmap);
 554
 555         nilfs_dat_commit_end(dat, &oldreq->bpr_req,
 556                              bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
 557         nilfs_dat_commit_alloc(dat, &newreq->bpr_req);
 558 }
 559
 560 void nilfs_bmap_abort_update_v(struct nilfs_bmap *bmap,
 561                                union nilfs_bmap_ptr_req *oldreq,
 562                                union nilfs_bmap_ptr_req *newreq)
 563 {
 564         struct inode *dat = nilfs_bmap_get_dat(bmap);
 565
 566         nilfs_dat_abort_end(dat, &oldreq->bpr_req);
 567         nilfs_dat_abort_alloc(dat, &newreq->bpr_req);
 568 }
 569
 570 static struct lock_class_key nilfs_bmap_dat_lock_key;
 571 static struct lock_class_key nilfs_bmap_mdt_lock_key;
 572
 573 /**
 574  * nilfs_bmap_read - read a bmap from an inode
 575  * @bmap: bmap
 576  * @raw_inode: on-disk inode
 577  *
 578  * Description: nilfs_bmap_read() initializes the bmap @bmap.
 579  *
 580  * Return Value: On success, 0 is returned. On error, the following negative
 581  * error code is returned.
 582  *
 583  * %-ENOMEM - Insufficient amount of memory available.
 584  */
 585 int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 586 {
 587         if (raw_inode == NULL)
 588                 memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
 589         else
 590                 memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);
 591
 592         init_rwsem(&bmap->b_sem);
 593         bmap->b_state = 0;
 594         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 595         switch (bmap->b_inode->i_ino) {
 596         case NILFS_DAT_INO:
 597                 bmap->b_ptr_type = NILFS_BMAP_PTR_P;
 598                 bmap->b_last_allocated_key = 0;
 599                 bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 600                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 601                 break;
 602         case NILFS_CPFILE_INO:
 603         case NILFS_SUFILE_INO:
 604                 bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
 605                 bmap->b_last_allocated_key = 0;
 606                 bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 607                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 608                 break;
 609         case NILFS_IFILE_INO:
 610                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 611                 /* Fall through */
 612         default:
 613                 bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
 614                 bmap->b_last_allocated_key = 0;
 615                 bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 616                 break;
 617         }
 618
 619         return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
 620                 nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
 621 }
 622
 623 /**
 624  * nilfs_bmap_write - write back a bmap to an inode
 625  * @bmap: bmap
 626  * @raw_inode: on-disk inode
 627  *
 628  * Description: nilfs_bmap_write() stores @bmap in @raw_inode.
 629  */
 630 void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 631 {
 632         down_write(&bmap->b_sem);
 633         memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
 634                NILFS_INODE_BMAP_SIZE * sizeof(__le64));
 635         if (bmap->b_inode->i_ino == NILFS_DAT_INO)
 636                 bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 637
 638         up_write(&bmap->b_sem);
 639 }
 640
 641 void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
 642 {
 643         memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
 644         init_rwsem(&bmap->b_sem);
 645         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 646         bmap->b_ptr_type = NILFS_BMAP_PTR_U;
 647         bmap->b_last_allocated_key = 0;
 648         bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 649         bmap->b_state = 0;
 650         nilfs_btree_init_gc(bmap);
 651 }
 652
 653 void nilfs_bmap_init_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
 654 {
 655         memcpy(gcbmap, bmap, sizeof(union nilfs_bmap_union));
 656         init_rwsem(&gcbmap->b_sem);
 657         lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 658         gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;
 659 }
 660
 661 void nilfs_bmap_commit_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
 662 {
 663         memcpy(bmap, gcbmap, sizeof(union nilfs_bmap_union));
 664         init_rwsem(&bmap->b_sem);
 665         lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 666         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 667 }