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,
 156                       unsigned long key,
 157                       unsigned long rec)
 158 {
 159         int ret;
 160
 161         down_write(&bmap->b_sem);
 162         ret = nilfs_bmap_do_insert(bmap, key, rec);
 163         up_write(&bmap->b_sem);
 164
 165         return nilfs_bmap_convert_error(bmap, __func__, ret);
 166 }
 167
 168 static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
 169 {
 170         __u64 keys[NILFS_BMAP_LARGE_LOW + 1];
 171         __u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
 172         int ret, n;
 173
 174         if (bmap->b_ops->bop_check_delete != NULL) {
 175                 ret = bmap->b_ops->bop_check_delete(bmap, key);
 176                 if (ret > 0) {
 177                         n = bmap->b_ops->bop_gather_data(
 178                                 bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
 179                         if (n < 0)
 180                                 return n;
 181                         ret = nilfs_direct_delete_and_convert(
 182                                 bmap, key, keys, ptrs, n);
 183                         if (ret == 0)
 184                                 bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;
 185
 186                         return ret;
 187                 } else if (ret < 0)
 188                         return ret;
 189         }
 190
 191         return bmap->b_ops->bop_delete(bmap, key);
 192 }
 193
 194 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, unsigned long *key)
 195 {
 196         __u64 lastkey;
 197         int ret;
 198
 199         down_read(&bmap->b_sem);
 200         ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 201         up_read(&bmap->b_sem);
 202
 203         if (ret < 0)
 204                 ret = nilfs_bmap_convert_error(bmap, __func__, ret);
 205         else
 206                 *key = lastkey;
 207         return ret;
 208 }
 209
 210 /**
 211  * nilfs_bmap_delete - delete a key-record pair from a bmap
 212  * @bmap: bmap
 213  * @key: key
 214  *
 215  * Description: nilfs_bmap_delete() deletes the key-record pair specified by
 216  * @key from @bmap.
 217  *
 218  * Return Value: On success, 0 is returned. On error, one of the following
 219  * negative error codes is returned.
 220  *
 221  * %-EIO - I/O error.
 222  *
 223  * %-ENOMEM - Insufficient amount of memory available.
 224  *
 225  * %-ENOENT - A record associated with @key does not exist.
 226  */
 227 int nilfs_bmap_delete(struct nilfs_bmap *bmap, unsigned long key)
 228 {
 229         int ret;
 230
 231         down_write(&bmap->b_sem);
 232         ret = nilfs_bmap_do_delete(bmap, key);
 233         up_write(&bmap->b_sem);
 234
 235         return nilfs_bmap_convert_error(bmap, __func__, ret);
 236 }
 237
 238 static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, unsigned long key)
 239 {
 240         __u64 lastkey;
 241         int ret;
 242
 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         while (key <= lastkey) {
 251                 ret = nilfs_bmap_do_delete(bmap, lastkey);
 252                 if (ret < 0)
 253                         return ret;
 254                 ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
 255                 if (ret < 0) {
 256                         if (ret == -ENOENT)
 257                                 ret = 0;
 258                         return ret;
 259                 }
 260         }
 261         return 0;
 262 }
 263
 264 /**
 265  * nilfs_bmap_truncate - truncate a bmap to a specified key
 266  * @bmap: bmap
 267  * @key: key
 268  *
 269  * Description: nilfs_bmap_truncate() removes key-record pairs whose keys are
 270  * greater than or equal to @key from @bmap.
 271  *
 272  * Return Value: On success, 0 is returned. On error, one of the following
 273  * negative error codes is returned.
 274  *
 275  * %-EIO - I/O error.
 276  *
 277  * %-ENOMEM - Insufficient amount of memory available.
 278  */
 279 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, unsigned long key)
 280 {
 281         int ret;
 282
 283         down_write(&bmap->b_sem);
 284         ret = nilfs_bmap_do_truncate(bmap, key);
 285         up_write(&bmap->b_sem);
 286
 287         return nilfs_bmap_convert_error(bmap, __func__, ret);
 288 }
 289
 290 /**
 291  * nilfs_bmap_clear - free resources a bmap holds
 292  * @bmap: bmap
 293  *
 294  * Description: nilfs_bmap_clear() frees resources associated with @bmap.
 295  */
 296 void nilfs_bmap_clear(struct nilfs_bmap *bmap)
 297 {
 298         down_write(&bmap->b_sem);
 299         if (bmap->b_ops->bop_clear != NULL)
 300                 bmap->b_ops->bop_clear(bmap);
 301         up_write(&bmap->b_sem);
 302 }
 303
 304 /**
 305  * nilfs_bmap_propagate - propagate dirty state
 306  * @bmap: bmap
 307  * @bh: buffer head
 308  *
 309  * Description: nilfs_bmap_propagate() marks the buffers that directly or
 310  * indirectly refer to the block specified by @bh dirty.
 311  *
 312  * Return Value: On success, 0 is returned. On error, one of the following
 313  * negative error codes is returned.
 314  *
 315  * %-EIO - I/O error.
 316  *
 317  * %-ENOMEM - Insufficient amount of memory available.
 318  */
 319 int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
 320 {
 321         int ret;
 322
 323         down_write(&bmap->b_sem);
 324         ret = bmap->b_ops->bop_propagate(bmap, bh);
 325         up_write(&bmap->b_sem);
 326
 327         return nilfs_bmap_convert_error(bmap, __func__, ret);
 328 }
 329
 330 /**
 331  * nilfs_bmap_lookup_dirty_buffers -
 332  * @bmap: bmap
 333  * @listp: pointer to buffer head list
 334  */
 335 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
 336                                      struct list_head *listp)
 337 {
 338         if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
 339                 bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
 340 }
 341
 342 /**
 343  * nilfs_bmap_assign - assign a new block number to a block
 344  * @bmap: bmap
 345  * @bhp: pointer to buffer head
 346  * @blocknr: block number
 347  * @binfo: block information
 348  *
 349  * Description: nilfs_bmap_assign() assigns the block number @blocknr to the
 350  * buffer specified by @bh.
 351  *
 352  * Return Value: On success, 0 is returned and the buffer head of a newly
 353  * create buffer and the block information associated with the buffer are
 354  * stored in the place pointed by @bh and @binfo, respectively. On error, one
 355  * of the following negative error codes is returned.
 356  *
 357  * %-EIO - I/O error.
 358  *
 359  * %-ENOMEM - Insufficient amount of memory available.
 360  */
 361 int nilfs_bmap_assign(struct nilfs_bmap *bmap,
 362                       struct buffer_head **bh,
 363                       unsigned long blocknr,
 364                       union nilfs_binfo *binfo)
 365 {
 366         int ret;
 367
 368         down_write(&bmap->b_sem);
 369         ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
 370         up_write(&bmap->b_sem);
 371
 372         return nilfs_bmap_convert_error(bmap, __func__, ret);
 373 }
 374
 375 /**
 376  * nilfs_bmap_mark - mark block dirty
 377  * @bmap: bmap
 378  * @key: key
 379  * @level: level
 380  *
 381  * Description: nilfs_bmap_mark() marks the block specified by @key and @level
 382  * as dirty.
 383  *
 384  * Return Value: On success, 0 is returned. On error, one of the following
 385  * negative error codes is returned.
 386  *
 387  * %-EIO - I/O error.
 388  *
 389  * %-ENOMEM - Insufficient amount of memory available.
 390  */
 391 int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
 392 {
 393         int ret;
 394
 395         if (bmap->b_ops->bop_mark == NULL)
 396                 return 0;
 397
 398         down_write(&bmap->b_sem);
 399         ret = bmap->b_ops->bop_mark(bmap, key, level);
 400         up_write(&bmap->b_sem);
 401
 402         return nilfs_bmap_convert_error(bmap, __func__, ret);
 403 }
 404
 405 /**
 406  * nilfs_bmap_test_and_clear_dirty - test and clear a bmap dirty state
 407  * @bmap: bmap
 408  *
 409  * Description: nilfs_test_and_clear() is the atomic operation to test and
 410  * clear the dirty state of @bmap.
 411  *
 412  * Return Value: 1 is returned if @bmap is dirty, or 0 if clear.
 413  */
 414 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
 415 {
 416         int ret;
 417
 418         down_write(&bmap->b_sem);
 419         ret = nilfs_bmap_dirty(bmap);
 420         nilfs_bmap_clear_dirty(bmap);
 421         up_write(&bmap->b_sem);
 422         return ret;
 423 }
 424
 425
 426 /*
 427  * Internal use only
 428  */
 429 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
 430                               const struct buffer_head *bh)
 431 {
 432         struct buffer_head *pbh;
 433         __u64 key;
 434
 435         key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
 436                                          bmap->b_inode->i_blkbits);
 437         for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
 438                 key++;
 439
 440         return key;
 441 }
 442
 443 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
 444 {
 445         __s64 diff;
 446
 447         diff = key - bmap->b_last_allocated_key;
 448         if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
 449             (bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
 450             (bmap->b_last_allocated_ptr + diff > 0))
 451                 return bmap->b_last_allocated_ptr + diff;
 452         else
 453                 return NILFS_BMAP_INVALID_PTR;
 454 }
 455
 456 #define NILFS_BMAP_GROUP_DIV    8
 457 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 458 {
 459         struct inode *dat = nilfs_bmap_get_dat(bmap);
 460         unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
 461         unsigned long group = bmap->b_inode->i_ino / entries_per_group;
 462
 463         return group * entries_per_group +
 464                 (bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
 465                 (entries_per_group / NILFS_BMAP_GROUP_DIV);
 466 }
 467
 468 static struct lock_class_key nilfs_bmap_dat_lock_key;
 469 static struct lock_class_key nilfs_bmap_mdt_lock_key;
 470
 471 /**
 472  * nilfs_bmap_read - read a bmap from an inode
 473  * @bmap: bmap
 474  * @raw_inode: on-disk inode
 475  *
 476  * Description: nilfs_bmap_read() initializes the bmap @bmap.
 477  *
 478  * Return Value: On success, 0 is returned. On error, the following negative
 479  * error code is returned.
 480  *
 481  * %-ENOMEM - Insufficient amount of memory available.
 482  */
 483 int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 484 {
 485         if (raw_inode == NULL)
 486                 memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
 487         else
 488                 memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);
 489
 490         init_rwsem(&bmap->b_sem);
 491         bmap->b_state = 0;
 492         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 493         switch (bmap->b_inode->i_ino) {
 494         case NILFS_DAT_INO:
 495                 bmap->b_ptr_type = NILFS_BMAP_PTR_P;
 496                 bmap->b_last_allocated_key = 0;
 497                 bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 498                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 499                 break;
 500         case NILFS_CPFILE_INO:
 501         case NILFS_SUFILE_INO:
 502                 bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
 503                 bmap->b_last_allocated_key = 0;
 504                 bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 505                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 506                 break;
 507         case NILFS_IFILE_INO:
 508                 lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 509                 /* Fall through */
 510         default:
 511                 bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
 512                 bmap->b_last_allocated_key = 0;
 513                 bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 514                 break;
 515         }
 516
 517         return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
 518                 nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
 519 }
 520
 521 /**
 522  * nilfs_bmap_write - write back a bmap to an inode
 523  * @bmap: bmap
 524  * @raw_inode: on-disk inode
 525  *
 526  * Description: nilfs_bmap_write() stores @bmap in @raw_inode.
 527  */
 528 void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 529 {
 530         down_write(&bmap->b_sem);
 531         memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
 532                NILFS_INODE_BMAP_SIZE * sizeof(__le64));
 533         if (bmap->b_inode->i_ino == NILFS_DAT_INO)
 534                 bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
 535
 536         up_write(&bmap->b_sem);
 537 }
 538
 539 void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
 540 {
 541         memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
 542         init_rwsem(&bmap->b_sem);
 543         bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 544         bmap->b_ptr_type = NILFS_BMAP_PTR_U;
 545         bmap->b_last_allocated_key = 0;
 546         bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 547         bmap->b_state = 0;
 548         nilfs_btree_init_gc(bmap);
 549 }
 550
 551 void nilfs_bmap_save(const struct nilfs_bmap *bmap,
 552                      struct nilfs_bmap_store *store)
 553 {
 554         memcpy(store->data, bmap->b_u.u_data, sizeof(store->data));
 555         store->last_allocated_key = bmap->b_last_allocated_key;
 556         store->last_allocated_ptr = bmap->b_last_allocated_ptr;
 557         store->state = bmap->b_state;
 558 }
 559
 560 void nilfs_bmap_restore(struct nilfs_bmap *bmap,
 561                         const struct nilfs_bmap_store *store)
 562 {
 563         memcpy(bmap->b_u.u_data, store->data, sizeof(store->data));
 564         bmap->b_last_allocated_key = store->last_allocated_key;
 565         bmap->b_last_allocated_ptr = store->last_allocated_ptr;
 566         bmap->b_state = store->state;
 567 }