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 "btree.h"
  29 #include "direct.h"
  30 #include "btnode.h"
  31 #include "mdt.h"
  32 #include "dat.h"
  33 #include "alloc.h"
  34
  35 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
  36 {
  37         struct the_nilfs *nilfs = bmap->b_inode->i_sb->s_fs_info;
  38
  39         return nilfs->ns_dat;
  40 }
  41
  42 static int nilfs_bmap_convert_error(struct nilfs_bmap *bmap,
  43                                      const char *fname, int err)
  44 {
  45         struct inode *inode = bmap->b_inode;
  46
  47         if (err == -EINVAL) {
  48                 nilfs_error(inode->i_sb, fname,
  49                             "broken bmap (inode number=%lu)\n", inode->i_ino);
  50                 err = -EIO;
  51         }
  52         return err;
  53 }
  54
  55 /**
  56  * nilfs_bmap_lookup_at_level - find a data block or node block
  57  * @bmap: bmap
  58  * @key: key
  59  * @level: level
  60  * @ptrp: place to store the value associated to @key
  61  *
  62  * Description: nilfs_bmap_lookup_at_level() finds a record whose key
  63  * matches @key in the block at @level of the bmap.
  64  *
  65  * Return Value: On success, 0 is returned and the record associated with @key
  66  * is stored in the place pointed by @ptrp. On error, one of the following
  67  * negative error codes is returned.
  68  *
  69  * %-EIO - I/O error.
  70  *
  71  * %-ENOMEM - Insufficient amount of memory available.
  72  *
  73  * %-ENOENT - A record associated with @key does not exist.
  74  */
  75 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
  76                                __u64 *ptrp)
  77 {
  78         sector_t blocknr;
  79         int ret;
  80
  81         down_read(&bmap->b_sem);
  82         ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
  83         if (ret < 0) {
  84                 ret = nilfs_bmap_convert_error(bmap, __func__, ret);
  85                 goto out;
  86         }
  87         if (NILFS_BMAP_USE_VBN(bmap)) {
  88                 ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
  89                                           &blocknr);
  90                 if (!ret)
  91                         *ptrp = blocknr;
  92         }
  93
  94  out:
  95         up_read(&bmap->b_sem);
  96         return ret;
  97 }
  98
  99 int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
 100                              unsigned maxblocks)
 101 {
 102         int ret;
 103
 104         down_read(&bmap->b_sem);
 105         ret = bmap->b_ops->bop_lookup_contig(bmap, key, ptrp, maxblocks);
 106         up_read(&bmap->b_sem);
 107
 108         return nilfs_bmap_convert_error(bmap, __func__, ret);
 109 }
 110
 111 static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 112 {
 113         __u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
 114         __u64 ptrs[NILFS_BMAP_SMALL_HIGH + 1];
 115         int ret, n;
 116
 117         if (bmap->b_ops->bop_check_insert != NULL) {
 118                 ret = bmap->b_ops->bop_check_insert(bmap, key);
 119                 if (ret > 0) {
 120                         n = bmap->b_ops->bop_gather_data(
 121                                 bmap, keys, ptrs, NILFS_BMAP_SMALL_HIGH + 1);
 122                         if (n < 0)
 123                                 return n;
 124                         ret = nilfs_btree_convert_and_insert(
 125                                 bmap, key, ptr, keys, ptrs, n);
 126                         if (ret == 0)
 127                                 bmap->b_u.u_flags |= NILFS_BMAP_LARGE;
 128
 129                         return ret;
 130                 } else if (ret < 0)
 131                         return ret;
 132         }
 133
 134         return bmap->b_ops->bop_insert(bmap, key, ptr);
 135 }
 136
 137 /**
 138  * nilfs_bmap_insert - insert a new key-record pair into a bmap
 139  * @bmap: bmap
 140  * @key: key
 141  * @rec: record
 142  *
 143  * Description: nilfs_bmap_insert() inserts the new key-record pair specified
 144  * by @key and @rec into @bmap.
 145  *
 146  * Return Value: On success, 0 is returned. On error, one of the following
 147  * negative error codes is returned.
 148  *
 149  * %-EIO - I/O error.
 150  *
 151  * %-ENOMEM - Insufficient amount of memory available.
 152  *
 153  * %-EEXIST - A record associated with @key already exist.
 154  */
 155 int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec)
 156 {
 157         int ret;
 158
 159         down_write(&bmap->b_sem);
 160         ret = nilfs_bmap_do_insert(bmap, key, rec);
 161         up_write(&bmap->b_sem);
 162
 163         return nilfs_bmap_convert_error(bmap, __func__, ret);
 164 }
 165
 166 static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
 167 {
 168         __u64 keys[NILFS_BMAP_LARGE_LOW + 1];
 169         __u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
 170         int ret, n;
 171
 172         if (bmap->b_ops->bop_check_delete != NULL) {
 173                 ret = bmap->b_ops->bop_check_delete(bmap, key);
 174                 if (ret > 0) {
 175                         n = bmap->b_ops->bop_gather_data(
 176                                 bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
 177                         if (n < 0)
 178                                 return n;
 179                         ret = nilfs_direct_delete_and_convert(
 180                                 bmap, key, keys, ptrs, n);
 181                         if (ret == 0)
 182                                 bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;
 183
 184                         return ret;
 185                 } else if (ret < 0)
 186                         return ret;
 187         }
 188
 189         return bmap->b_ops->bop_delete(bmap, key);
 190 }
 191
 192 /**
 193  * nilfs_bmap_seek_key - seek a valid entry and return its key
 194  * @bmap: bmap struct
 195  * @start: start key number
 196  * @keyp: place to store valid key
 197  *
 198  * Description: nilfs_bmap_seek_key() seeks a valid key on @bmap
 199  * starting from @start, and stores it to @keyp if found.
 200  *
 201  * Return Value: On success, 0 is returned. On error, one of the following
 202  * negative error codes is returned.
 203  *
 204  * %-EIO - I/O error.
 205  *
 206  * %-ENOMEM - Insufficient amount of memory available.
 207  *
 208  * %-ENOENT - No valid entry was found
 209  */
 210 int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp)
 211 {
 212         int ret;
 213
 214         down_read(&bmap->b_sem);
 215         ret = bmap->b_ops->bop_seek_key(bmap, start, keyp);
 216         up_read(&bmap->b_sem);
 217
 218         if (ret < 0)
 219                 ret = nilfs_bmap_convert_error(bmap, __func__, ret);
 220         return ret;
 221 }
 222
 223 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp)
 224 {
 225         int ret;
 226
 227         down_read(&bmap->b_sem);
 228         ret = bmap->b_ops->bop_last_key(bmap, keyp);
 229         up_read(&bmap->b_sem);
 230
 231         if (ret < 0)
 232                 ret = nilfs_bmap_convert_error(bmap, __func__, ret);
 233         return ret;
 234 }
 235
 236 /**
 237  * nilfs_bmap_delete - delete a key-record pair from a bmap
 238  * @bmap: bmap
 239  * @key: key
 240  *
 241  * Description: nilfs_bmap_delete() deletes the key-record pair specified by
 242  * @key from @bmap.
 243  *
 244  * Return Value: On success, 0 is returned. On error, one of the following
 245  * negative error codes is returned.
 246  *
 247  * %-EIO - I/O error.
 248  *
 249  * %-ENOMEM - Insufficient amount of memory available.
 250  *
 251  * %-ENOENT - A record associated with @key does not exist.
 252  */
 253 int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key)
 254 {
 255         int ret;
 256
 257         down_write(&bmap->b_sem);
 258         ret = nilfs_bmap_do_delete(bmap, key);
 259         up_write(&bmap->b_sem);
 260
 261         return nilfs_bmap_convert_error(bmap, __func__, ret);
 262 }
 263
 264 static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, __u64 key)
 265 {
 266         __u64 lastkey;
 267         int ret;
 268
 269         ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 270         if (ret < 0) {
 271                 if (ret == -ENOENT)
 272                         ret = 0;
 273                 return ret;
 274         }
 275
 276         while (key <= lastkey) {
 277                 ret = nilfs_bmap_do_delete(bmap, lastkey);
 278                 if (ret < 0)
 279                         return ret;
 280                 ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 281                 if (ret < 0) {
 282                         if (ret == -ENOENT)
 283                                 ret = 0;
 284                         return ret;
 285                 }
 286         }
 287         return 0;
 288 }
 289
 290 /**
 291  * nilfs_bmap_truncate - truncate a bmap to a specified key
 292  * @bmap: bmap
 293  * @key: key
 294  *
 295  * Description: nilfs_bmap_truncate() removes key-record pairs whose keys are
 296  * greater than or equal to @key from @bmap.
 297  *
 298  * Return Value: On success, 0 is returned. On error, one of the following
 299  * negative error codes is returned.
 300  *
 301  * %-EIO - I/O error.
 302  *
 303  * %-ENOMEM - Insufficient amount of memory available.
 304  */
 305 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key)
 306 {
 307         int ret;
 308
 309         down_write(&bmap->b_sem);
 310         ret = nilfs_bmap_do_truncate(bmap, key);
 311         up_write(&bmap->b_sem);
 312
 313         return nilfs_bmap_convert_error(bmap, __func__, ret);
 314 }
 315
 316 /**
 317  * nilfs_bmap_clear - free resources a bmap holds
 318  * @bmap: bmap
 319  *
 320  * Description: nilfs_bmap_clear() frees resources associated with @bmap.
 321  */
 322 void nilfs_bmap_clear(struct nilfs_bmap *bmap)
 323 {
 324         down_write(&bmap->b_sem);
 325         if (bmap->b_ops->bop_clear != NULL)
 326                 bmap->b_ops->bop_clear(bmap);
 327         up_write(&bmap->b_sem);
 328 }
 329
 330 /**
 331  * nilfs_bmap_propagate - propagate dirty state
 332  * @bmap: bmap
 333  * @bh: buffer head
 334  *
 335  * Description: nilfs_bmap_propagate() marks the buffers that directly or
 336  * indirectly refer to the block specified by @bh dirty.
 337  *
 338  * Return Value: On success, 0 is returned. On error, one of the following
 339  * negative error codes is returned.
 340  *
 341  * %-EIO - I/O error.
 342  *
 343  * %-ENOMEM - Insufficient amount of memory available.
 344  */
 345 int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
 346 {
 347         int ret;
 348
 349         down_write(&bmap->b_sem);
 350         ret = bmap->b_ops->bop_propagate(bmap, bh);
 351         up_write(&bmap->b_sem);
 352
 353         return nilfs_bmap_convert_error(bmap, __func__, ret);
 354 }
 355
 356 /**
 357  * nilfs_bmap_lookup_dirty_buffers -
 358  * @bmap: bmap
 359  * @listp: pointer to buffer head list
 360  */
 361 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
 362                                      struct list_head *listp)
 363 {
 364         if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
 365                 bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
 366 }
 367
 368 /**
 369  * nilfs_bmap_assign - assign a new block number to a block
 370  * @bmap: bmap
 371  * @bhp: pointer to buffer head
 372  * @blocknr: block number
 373  * @binfo: block information
 374  *
 375  * Description: nilfs_bmap_assign() assigns the block number @blocknr to the
 376  * buffer specified by @bh.
 377  *
 378  * Return Value: On success, 0 is returned and the buffer head of a newly
 379  * create buffer and the block information associated with the buffer are
 380  * stored in the place pointed by @bh and @binfo, respectively. On error, one
 381  * of the following negative error codes is returned.
 382  *
 383  * %-EIO - I/O error.
 384  *
 385  * %-ENOMEM - Insufficient amount of memory available.
 386  */
 387 int nilfs_bmap_assign(struct nilfs_bmap *bmap,
 388                       struct buffer_head **bh,
 389                       unsigned long blocknr,
 390                       union nilfs_binfo *binfo)
 391 {
 392         int ret;
 393
 394         down_write(&bmap->b_sem);
 395         ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
 396         up_write(&bmap->b_sem);
 397
 398         return nilfs_bmap_convert_error(bmap, __func__, ret);
 399 }
 400
 401 /**
 402  * nilfs_bmap_mark - mark block dirty
 403  * @bmap: bmap
 404  * @key: key
 405  * @level: level
 406  *
 407  * Description: nilfs_bmap_mark() marks the block specified by @key and @level
 408  * as dirty.
 409  *
 410  * Return Value: On success, 0 is returned. On error, one of the following
 411  * negative error codes is returned.
 412  *
 413  * %-EIO - I/O error.
 414  *
 415  * %-ENOMEM - Insufficient amount of memory available.
 416  */
 417 int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
 418 {
 419         int ret;
 420
 421         if (bmap->b_ops->bop_mark == NULL)
 422                 return 0;
 423
 424         down_write(&bmap->b_sem);
 425         ret = bmap->b_ops->bop_mark(bmap, key, level);
 426         up_write(&bmap->b_sem);
 427
 428         return nilfs_bmap_convert_error(bmap, __func__, ret);
 429 }
 430
 431 /**
 432  * nilfs_bmap_test_and_clear_dirty - test and clear a bmap dirty state
 433  * @bmap: bmap
 434  *
 435  * Description: nilfs_test_and_clear() is the atomic operation to test and
 436  * clear the dirty state of @bmap.
 437  *
 438  * Return Value: 1 is returned if @bmap is dirty, or 0 if clear.
 439  */
 440 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
 441 {
 442         int ret;
 443
 444         down_write(&bmap->b_sem);
 445         ret = nilfs_bmap_dirty(bmap);
 446         nilfs_bmap_clear_dirty(bmap);
 447         up_write(&bmap->b_sem);
 448         return ret;
 449 }
 450
 451
 452 /*
 453  * Internal use only
 454  */
 455 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
 456                               const struct buffer_head *bh)
 457 {
 458         struct buffer_head *pbh;
 459         __u64 key;
 460
 461         key = page_index(bh->b_page) << (PAGE_SHIFT -
 462                                          bmap->b_inode->i_blkbits);
 463         for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
 464                 key++;
 465
 466         return key;
 467 }
 468
 469 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
 470 {
 471         __s64 diff;
 472
 473         diff = key - bmap->b_last_allocated_key;
 474         if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
 475             (bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
 476             (bmap->b_last_allocated_ptr + diff > 0))
 477                 return bmap->b_last_allocated_ptr + diff;
 478         else
 479                 return NILFS_BMAP_INVALID_PTR;
 480 }
 481
 482 #define NILFS_BMAP_GROUP_DIV    8
 483 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 484 {
 485         struct inode *dat = nilfs_bmap_get_dat(bmap);
 486         unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
 487         unsigned long group = bmap->b_inode->i_ino / entries_per_group;
 488
 489         return group * entries_per_group +
 490                 (bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
 491                 (entries_per_group / NILFS_BMAP_GROUP_DIV);
 492 }
 493
 494 static struct lock_class_key nilfs_bmap_dat_lock_key;
 495 static struct lock_class_key nilfs_bmap_mdt_lock_key;
 496
 497 /**
 498  * nilfs_bmap_read - read a bmap from an inode
 499  * @bmap: bmap
 500  * @raw_inode: on-disk inode
 501  *
 502  * Description: nilfs_bmap_read() initializes the bmap @bmap.
 503  *
 504  * Return Value: On success, 0 is returned. On error, the following negative
 505  * error code is returned.
 506  *
 507  * %-ENOMEM - Insufficient amount of memory available.
 508  */
 509 int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 510 {
 511         if (raw_inode == NULL)
 512                 memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
 513         else
 514                 memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);
 515
 516         init_rwsem(&bmap->b_sem);
 517         bmap->b_state = 0;
 518         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 519         switch (bmap->b_inode->i_ino) {
 520         case NILFS_DAT_INO:
 521                 bmap->b_ptr_type = NILFS_BMAP_PTR_P;
 522                 bmap->b_last_allocated_key = 0;
 523                 bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 524                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 525                 break;
 526         case NILFS_CPFILE_INO:
 527         case NILFS_SUFILE_INO:
 528                 bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
 529                 bmap->b_last_allocated_key = 0;
 530                 bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 531                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 532                 break;
 533         case NILFS_IFILE_INO:
 534                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 535                 /* Fall through */
 536         default:
 537                 bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
 538                 bmap->b_last_allocated_key = 0;
 539                 bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 540                 break;
 541         }
 542
 543         return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
 544                 nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
 545 }
 546
 547 /**
 548  * nilfs_bmap_write - write back a bmap to an inode
 549  * @bmap: bmap
 550  * @raw_inode: on-disk inode
 551  *
 552  * Description: nilfs_bmap_write() stores @bmap in @raw_inode.
 553  */
 554 void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 555 {
 556         down_write(&bmap->b_sem);
 557         memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
 558                NILFS_INODE_BMAP_SIZE * sizeof(__le64));
 559         if (bmap->b_inode->i_ino == NILFS_DAT_INO)
 560                 bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 561
 562         up_write(&bmap->b_sem);
 563 }
 564
 565 void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
 566 {
 567         memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
 568         init_rwsem(&bmap->b_sem);
 569         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 570         bmap->b_ptr_type = NILFS_BMAP_PTR_U;
 571         bmap->b_last_allocated_key = 0;
 572         bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 573         bmap->b_state = 0;
 574         nilfs_btree_init_gc(bmap);
 575 }
 576
 577 void nilfs_bmap_save(const struct nilfs_bmap *bmap,
 578                      struct nilfs_bmap_store *store)
 579 {
 580         memcpy(store->data, bmap->b_u.u_data, sizeof(store->data));
 581         store->last_allocated_key = bmap->b_last_allocated_key;
 582         store->last_allocated_ptr = bmap->b_last_allocated_ptr;
 583         store->state = bmap->b_state;
 584 }
 585
 586 void nilfs_bmap_restore(struct nilfs_bmap *bmap,
 587                         const struct nilfs_bmap_store *store)
 588 {
 589         memcpy(bmap->b_u.u_data, store->data, sizeof(store->data));
 590         bmap->b_last_allocated_key = store->last_allocated_key;
 591         bmap->b_last_allocated_ptr = store->last_allocated_ptr;
 592         bmap->b_state = store->state;
 593 }