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