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 /**
  40  * nilfs_bmap_lookup_at_level - find a data block or node block
  41  * @bmap: bmap
  42  * @key: key
  43  * @level: level
  44  * @ptrp: place to store the value associated to @key
  45  *
  46  * Description: nilfs_bmap_lookup_at_level() finds a record whose key
  47  * matches @key in the block at @level of the bmap.
  48  *
  49  * Return Value: On success, 0 is returned and the record associated with @key
  50  * is stored in the place pointed by @ptrp. On error, one of the following
  51  * negative error codes is returned.
  52  *
  53  * %-EIO - I/O error.
  54  *
  55  * %-ENOMEM - Insufficient amount of memory available.
  56  *
  57  * %-ENOENT - A record associated with @key does not exist.
  58  */
  59 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
  60                                __u64 *ptrp)
  61 {
  62         sector_t blocknr;
  63         int ret;
  64
  65         down_read(&bmap->b_sem);
  66         ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
  67         if (ret < 0)
  68                 goto out;
  69         if (NILFS_BMAP_USE_VBN(bmap)) {
  70                 ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
  71                                           &blocknr);
  72                 if (!ret)
  73                         *ptrp = blocknr;
  74         }
  75
  76  out:
  77         up_read(&bmap->b_sem);
  78         return ret;
  79 }
  80
  81 int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
  82                              unsigned maxblocks)
  83 {
  84         int ret;
  85
  86         down_read(&bmap->b_sem);
  87         ret = bmap->b_ops->bop_lookup_contig(bmap, key, ptrp, maxblocks);
  88         up_read(&bmap->b_sem);
  89         return ret;
  90 }
  91
  92 static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
  93 {
  94         __u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
  95         __u64 ptrs[NILFS_BMAP_SMALL_HIGH + 1];
  96         int ret, n;
  97
  98         if (bmap->b_ops->bop_check_insert != NULL) {
  99                 ret = bmap->b_ops->bop_check_insert(bmap, key);
 100                 if (ret > 0) {
 101                         n = bmap->b_ops->bop_gather_data(
 102                                 bmap, keys, ptrs, NILFS_BMAP_SMALL_HIGH + 1);
 103                         if (n < 0)
 104                                 return n;
 105                         ret = nilfs_btree_convert_and_insert(
 106                                 bmap, key, ptr, keys, ptrs, n);
 107                         if (ret == 0)
 108                                 bmap->b_u.u_flags |= NILFS_BMAP_LARGE;
 109
 110                         return ret;
 111                 } else if (ret < 0)
 112                         return ret;
 113         }
 114
 115         return bmap->b_ops->bop_insert(bmap, key, ptr);
 116 }
 117
 118 /**
 119  * nilfs_bmap_insert - insert a new key-record pair into a bmap
 120  * @bmap: bmap
 121  * @key: key
 122  * @rec: record
 123  *
 124  * Description: nilfs_bmap_insert() inserts the new key-record pair specified
 125  * by @key and @rec into @bmap.
 126  *
 127  * Return Value: On success, 0 is returned. On error, one of the following
 128  * negative error codes is returned.
 129  *
 130  * %-EIO - I/O error.
 131  *
 132  * %-ENOMEM - Insufficient amount of memory available.
 133  *
 134  * %-EEXIST - A record associated with @key already exist.
 135  */
 136 int nilfs_bmap_insert(struct nilfs_bmap *bmap,
 137                       unsigned long key,
 138                       unsigned long rec)
 139 {
 140         int ret;
 141
 142         down_write(&bmap->b_sem);
 143         ret = nilfs_bmap_do_insert(bmap, key, rec);
 144         up_write(&bmap->b_sem);
 145         return ret;
 146 }
 147
 148 static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
 149 {
 150         __u64 keys[NILFS_BMAP_LARGE_LOW + 1];
 151         __u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
 152         int ret, n;
 153
 154         if (bmap->b_ops->bop_check_delete != NULL) {
 155                 ret = bmap->b_ops->bop_check_delete(bmap, key);
 156                 if (ret > 0) {
 157                         n = bmap->b_ops->bop_gather_data(
 158                                 bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
 159                         if (n < 0)
 160                                 return n;
 161                         ret = nilfs_direct_delete_and_convert(
 162                                 bmap, key, keys, ptrs, n);
 163                         if (ret == 0)
 164                                 bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;
 165
 166                         return ret;
 167                 } else if (ret < 0)
 168                         return ret;
 169         }
 170
 171         return bmap->b_ops->bop_delete(bmap, key);
 172 }
 173
 174 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, unsigned long *key)
 175 {
 176         __u64 lastkey;
 177         int ret;
 178
 179         down_read(&bmap->b_sem);
 180         ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 181         if (!ret)
 182                 *key = lastkey;
 183         up_read(&bmap->b_sem);
 184         return ret;
 185 }
 186
 187 /**
 188  * nilfs_bmap_delete - delete a key-record pair from a bmap
 189  * @bmap: bmap
 190  * @key: key
 191  *
 192  * Description: nilfs_bmap_delete() deletes the key-record pair specified by
 193  * @key from @bmap.
 194  *
 195  * Return Value: On success, 0 is returned. On error, one of the following
 196  * negative error codes is returned.
 197  *
 198  * %-EIO - I/O error.
 199  *
 200  * %-ENOMEM - Insufficient amount of memory available.
 201  *
 202  * %-ENOENT - A record associated with @key does not exist.
 203  */
 204 int nilfs_bmap_delete(struct nilfs_bmap *bmap, unsigned long key)
 205 {
 206         int ret;
 207
 208         down_write(&bmap->b_sem);
 209         ret = nilfs_bmap_do_delete(bmap, key);
 210         up_write(&bmap->b_sem);
 211         return ret;
 212 }
 213
 214 static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, unsigned long key)
 215 {
 216         __u64 lastkey;
 217         int ret;
 218
 219         ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 220         if (ret < 0) {
 221                 if (ret == -ENOENT)
 222                         ret = 0;
 223                 return ret;
 224         }
 225
 226         while (key <= lastkey) {
 227                 ret = nilfs_bmap_do_delete(bmap, lastkey);
 228                 if (ret < 0)
 229                         return ret;
 230                 ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 231                 if (ret < 0) {
 232                         if (ret == -ENOENT)
 233                                 ret = 0;
 234                         return ret;
 235                 }
 236         }
 237         return 0;
 238 }
 239
 240 /**
 241  * nilfs_bmap_truncate - truncate a bmap to a specified key
 242  * @bmap: bmap
 243  * @key: key
 244  *
 245  * Description: nilfs_bmap_truncate() removes key-record pairs whose keys are
 246  * greater than or equal to @key from @bmap.
 247  *
 248  * Return Value: On success, 0 is returned. On error, one of the following
 249  * negative error codes is returned.
 250  *
 251  * %-EIO - I/O error.
 252  *
 253  * %-ENOMEM - Insufficient amount of memory available.
 254  */
 255 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, unsigned long key)
 256 {
 257         int ret;
 258
 259         down_write(&bmap->b_sem);
 260         ret = nilfs_bmap_do_truncate(bmap, key);
 261         up_write(&bmap->b_sem);
 262         return ret;
 263 }
 264
 265 /**
 266  * nilfs_bmap_clear - free resources a bmap holds
 267  * @bmap: bmap
 268  *
 269  * Description: nilfs_bmap_clear() frees resources associated with @bmap.
 270  */
 271 void nilfs_bmap_clear(struct nilfs_bmap *bmap)
 272 {
 273         down_write(&bmap->b_sem);
 274         if (bmap->b_ops->bop_clear != NULL)
 275                 bmap->b_ops->bop_clear(bmap);
 276         up_write(&bmap->b_sem);
 277 }
 278
 279 /**
 280  * nilfs_bmap_propagate - propagate dirty state
 281  * @bmap: bmap
 282  * @bh: buffer head
 283  *
 284  * Description: nilfs_bmap_propagate() marks the buffers that directly or
 285  * indirectly refer to the block specified by @bh dirty.
 286  *
 287  * Return Value: On success, 0 is returned. On error, one of the following
 288  * negative error codes is returned.
 289  *
 290  * %-EIO - I/O error.
 291  *
 292  * %-ENOMEM - Insufficient amount of memory available.
 293  */
 294 int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
 295 {
 296         int ret;
 297
 298         down_write(&bmap->b_sem);
 299         ret = bmap->b_ops->bop_propagate(bmap, bh);
 300         up_write(&bmap->b_sem);
 301         return ret;
 302 }
 303
 304 /**
 305  * nilfs_bmap_lookup_dirty_buffers -
 306  * @bmap: bmap
 307  * @listp: pointer to buffer head list
 308  */
 309 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
 310                                      struct list_head *listp)
 311 {
 312         if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
 313                 bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
 314 }
 315
 316 /**
 317  * nilfs_bmap_assign - assign a new block number to a block
 318  * @bmap: bmap
 319  * @bhp: pointer to buffer head
 320  * @blocknr: block number
 321  * @binfo: block information
 322  *
 323  * Description: nilfs_bmap_assign() assigns the block number @blocknr to the
 324  * buffer specified by @bh.
 325  *
 326  * Return Value: On success, 0 is returned and the buffer head of a newly
 327  * create buffer and the block information associated with the buffer are
 328  * stored in the place pointed by @bh and @binfo, respectively. On error, one
 329  * of the following negative error codes is returned.
 330  *
 331  * %-EIO - I/O error.
 332  *
 333  * %-ENOMEM - Insufficient amount of memory available.
 334  */
 335 int nilfs_bmap_assign(struct nilfs_bmap *bmap,
 336                       struct buffer_head **bh,
 337                       unsigned long blocknr,
 338                       union nilfs_binfo *binfo)
 339 {
 340         int ret;
 341
 342         down_write(&bmap->b_sem);
 343         ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
 344         up_write(&bmap->b_sem);
 345         return ret;
 346 }
 347
 348 /**
 349  * nilfs_bmap_mark - mark block dirty
 350  * @bmap: bmap
 351  * @key: key
 352  * @level: level
 353  *
 354  * Description: nilfs_bmap_mark() marks the block specified by @key and @level
 355  * as dirty.
 356  *
 357  * Return Value: On success, 0 is returned. On error, one of the following
 358  * negative error codes is returned.
 359  *
 360  * %-EIO - I/O error.
 361  *
 362  * %-ENOMEM - Insufficient amount of memory available.
 363  */
 364 int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
 365 {
 366         int ret;
 367
 368         if (bmap->b_ops->bop_mark == NULL)
 369                 return 0;
 370
 371         down_write(&bmap->b_sem);
 372         ret = bmap->b_ops->bop_mark(bmap, key, level);
 373         up_write(&bmap->b_sem);
 374         return ret;
 375 }
 376
 377 /**
 378  * nilfs_bmap_test_and_clear_dirty - test and clear a bmap dirty state
 379  * @bmap: bmap
 380  *
 381  * Description: nilfs_test_and_clear() is the atomic operation to test and
 382  * clear the dirty state of @bmap.
 383  *
 384  * Return Value: 1 is returned if @bmap is dirty, or 0 if clear.
 385  */
 386 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
 387 {
 388         int ret;
 389
 390         down_write(&bmap->b_sem);
 391         ret = nilfs_bmap_dirty(bmap);
 392         nilfs_bmap_clear_dirty(bmap);
 393         up_write(&bmap->b_sem);
 394         return ret;
 395 }
 396
 397
 398 /*
 399  * Internal use only
 400  */
 401
 402 void nilfs_bmap_add_blocks(const struct nilfs_bmap *bmap, int n)
 403 {
 404         inode_add_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
 405 }
 406
 407 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *bmap, int n)
 408 {
 409         inode_sub_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
 410 }
 411
 412 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
 413                               const struct buffer_head *bh)
 414 {
 415         struct buffer_head *pbh;
 416         __u64 key;
 417
 418         key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
 419                                          bmap->b_inode->i_blkbits);
 420         for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
 421                 key++;
 422
 423         return key;
 424 }
 425
 426 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
 427 {
 428         __s64 diff;
 429
 430         diff = key - bmap->b_last_allocated_key;
 431         if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
 432             (bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
 433             (bmap->b_last_allocated_ptr + diff > 0))
 434                 return bmap->b_last_allocated_ptr + diff;
 435         else
 436                 return NILFS_BMAP_INVALID_PTR;
 437 }
 438
 439 #define NILFS_BMAP_GROUP_DIV    8
 440 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 441 {
 442         struct inode *dat = nilfs_bmap_get_dat(bmap);
 443         unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
 444         unsigned long group = bmap->b_inode->i_ino / entries_per_group;
 445
 446         return group * entries_per_group +
 447                 (bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
 448                 (entries_per_group / NILFS_BMAP_GROUP_DIV);
 449 }
 450
 451 static struct lock_class_key nilfs_bmap_dat_lock_key;
 452 static struct lock_class_key nilfs_bmap_mdt_lock_key;
 453
 454 /**
 455  * nilfs_bmap_read - read a bmap from an inode
 456  * @bmap: bmap
 457  * @raw_inode: on-disk inode
 458  *
 459  * Description: nilfs_bmap_read() initializes the bmap @bmap.
 460  *
 461  * Return Value: On success, 0 is returned. On error, the following negative
 462  * error code is returned.
 463  *
 464  * %-ENOMEM - Insufficient amount of memory available.
 465  */
 466 int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 467 {
 468         if (raw_inode == NULL)
 469                 memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
 470         else
 471                 memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);
 472
 473         init_rwsem(&bmap->b_sem);
 474         bmap->b_state = 0;
 475         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 476         switch (bmap->b_inode->i_ino) {
 477         case NILFS_DAT_INO:
 478                 bmap->b_ptr_type = NILFS_BMAP_PTR_P;
 479                 bmap->b_last_allocated_key = 0;
 480                 bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 481                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 482                 break;
 483         case NILFS_CPFILE_INO:
 484         case NILFS_SUFILE_INO:
 485                 bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
 486                 bmap->b_last_allocated_key = 0;
 487                 bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 488                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 489                 break;
 490         case NILFS_IFILE_INO:
 491                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 492                 /* Fall through */
 493         default:
 494                 bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
 495                 bmap->b_last_allocated_key = 0;
 496                 bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 497                 break;
 498         }
 499
 500         return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
 501                 nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
 502 }
 503
 504 /**
 505  * nilfs_bmap_write - write back a bmap to an inode
 506  * @bmap: bmap
 507  * @raw_inode: on-disk inode
 508  *
 509  * Description: nilfs_bmap_write() stores @bmap in @raw_inode.
 510  */
 511 void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 512 {
 513         down_write(&bmap->b_sem);
 514         memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
 515                NILFS_INODE_BMAP_SIZE * sizeof(__le64));
 516         if (bmap->b_inode->i_ino == NILFS_DAT_INO)
 517                 bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 518
 519         up_write(&bmap->b_sem);
 520 }
 521
 522 void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
 523 {
 524         memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
 525         init_rwsem(&bmap->b_sem);
 526         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 527         bmap->b_ptr_type = NILFS_BMAP_PTR_U;
 528         bmap->b_last_allocated_key = 0;
 529         bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 530         bmap->b_state = 0;
 531         nilfs_btree_init_gc(bmap);
 532 }
 533
 534 void nilfs_bmap_init_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
 535 {
 536         memcpy(gcbmap, bmap, sizeof(union nilfs_bmap_union));
 537         init_rwsem(&gcbmap->b_sem);
 538         lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 539         gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;
 540 }
 541
 542 void nilfs_bmap_commit_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
 543 {
 544         memcpy(bmap, gcbmap, sizeof(union nilfs_bmap_union));
 545         init_rwsem(&bmap->b_sem);
 546         lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 547         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 548 }