git.oblomov.eu Git - linux-2.6/blob - fs/btrfs/file-item.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/bio.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/highmem.h>
  22 #include "ctree.h"
  23 #include "disk-io.h"
  24 #include "transaction.h"
  25 #include "print-tree.h"
  26
  27 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
  28                                sizeof(struct btrfs_item) * 2) / \
  29                                BTRFS_CRC32_SIZE) - 1))
  30 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
  31                              struct btrfs_root *root,
  32                              u64 objectid, u64 pos,
  33                              u64 disk_offset, u64 disk_num_bytes,
  34                              u64 num_bytes, u64 offset, u64 ram_bytes,
  35                              u8 compression, u8 encryption, u16 other_encoding)
  36 {
  37         int ret = 0;
  38         struct btrfs_file_extent_item *item;
  39         struct btrfs_key file_key;
  40         struct btrfs_path *path;
  41         struct extent_buffer *leaf;
  42
  43         path = btrfs_alloc_path();
  44         BUG_ON(!path);
  45         file_key.objectid = objectid;
  46         file_key.offset = pos;
  47         btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
  48
  49         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
  50                                       sizeof(*item));
  51         if (ret < 0)
  52                 goto out;
  53         BUG_ON(ret);
  54         leaf = path->nodes[0];
  55         item = btrfs_item_ptr(leaf, path->slots[0],
  56                               struct btrfs_file_extent_item);
  57         btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset);
  58         btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
  59         btrfs_set_file_extent_offset(leaf, item, offset);
  60         btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
  61         btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes);
  62         btrfs_set_file_extent_generation(leaf, item, trans->transid);
  63         btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
  64         btrfs_set_file_extent_compression(leaf, item, compression);
  65         btrfs_set_file_extent_encryption(leaf, item, encryption);
  66         btrfs_set_file_extent_other_encoding(leaf, item, other_encoding);
  67
  68         btrfs_mark_buffer_dirty(leaf);
  69 out:
  70         btrfs_free_path(path);
  71         return ret;
  72 }
  73
  74 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
  75                                           struct btrfs_root *root,
  76                                           struct btrfs_path *path,
  77                                           u64 objectid, u64 offset,
  78                                           int cow)
  79 {
  80         int ret;
  81         struct btrfs_key file_key;
  82         struct btrfs_key found_key;
  83         struct btrfs_csum_item *item;
  84         struct extent_buffer *leaf;
  85         u64 csum_offset = 0;
  86         int csums_in_item;
  87
  88         file_key.objectid = objectid;
  89         file_key.offset = offset;
  90         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
  91         ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
  92         if (ret < 0)
  93                 goto fail;
  94         leaf = path->nodes[0];
  95         if (ret > 0) {
  96                 ret = 1;
  97                 if (path->slots[0] == 0)
  98                         goto fail;
  99                 path->slots[0]--;
 100                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 101                 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
 102                     found_key.objectid != objectid) {
 103                         goto fail;
 104                 }
 105                 csum_offset = (offset - found_key.offset) >>
 106                                 root->fs_info->sb->s_blocksize_bits;
 107                 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
 108                 csums_in_item /= BTRFS_CRC32_SIZE;
 109
 110                 if (csum_offset >= csums_in_item) {
 111                         ret = -EFBIG;
 112                         goto fail;
 113                 }
 114         }
 115         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 116         item = (struct btrfs_csum_item *)((unsigned char *)item +
 117                                           csum_offset * BTRFS_CRC32_SIZE);
 118         return item;
 119 fail:
 120         if (ret > 0)
 121                 ret = -ENOENT;
 122         return ERR_PTR(ret);
 123 }
 124
 125
 126 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 127                              struct btrfs_root *root,
 128                              struct btrfs_path *path, u64 objectid,
 129                              u64 offset, int mod)
 130 {
 131         int ret;
 132         struct btrfs_key file_key;
 133         int ins_len = mod < 0 ? -1 : 0;
 134         int cow = mod != 0;
 135
 136         file_key.objectid = objectid;
 137         file_key.offset = offset;
 138         btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
 139         ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
 140         return ret;
 141 }
 142
 143 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
 144                           struct bio *bio)
 145 {
 146         u32 sum;
 147         struct bio_vec *bvec = bio->bi_io_vec;
 148         int bio_index = 0;
 149         u64 offset;
 150         u64 item_start_offset = 0;
 151         u64 item_last_offset = 0;
 152         u32 diff;
 153         int ret;
 154         struct btrfs_path *path;
 155         struct btrfs_csum_item *item = NULL;
 156         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 157
 158         path = btrfs_alloc_path();
 159         if (bio->bi_size > PAGE_CACHE_SIZE * 8)
 160                 path->reada = 2;
 161
 162         WARN_ON(bio->bi_vcnt <= 0);
 163
 164         while(bio_index < bio->bi_vcnt) {
 165                 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 166                 ret = btrfs_find_ordered_sum(inode, offset, &sum);
 167                 if (ret == 0)
 168                         goto found;
 169
 170                 if (!item || offset < item_start_offset ||
 171                     offset >= item_last_offset) {
 172                         struct btrfs_key found_key;
 173                         u32 item_size;
 174
 175                         if (item)
 176                                 btrfs_release_path(root, path);
 177                         item = btrfs_lookup_csum(NULL, root, path,
 178                                                  inode->i_ino, offset, 0);
 179                         if (IS_ERR(item)) {
 180                                 ret = PTR_ERR(item);
 181                                 if (ret == -ENOENT || ret == -EFBIG)
 182                                         ret = 0;
 183                                 sum = 0;
 184                                 printk("no csum found for inode %lu start "
 185                                        "%llu\n", inode->i_ino,
 186                                        (unsigned long long)offset);
 187                                 item = NULL;
 188                                 goto found;
 189                         }
 190                         btrfs_item_key_to_cpu(path->nodes[0], &found_key,
 191                                               path->slots[0]);
 192
 193                         item_start_offset = found_key.offset;
 194                         item_size = btrfs_item_size_nr(path->nodes[0],
 195                                                        path->slots[0]);
 196                         item_last_offset = item_start_offset +
 197                                 (item_size / BTRFS_CRC32_SIZE) *
 198                                 root->sectorsize;
 199                         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 200                                               struct btrfs_csum_item);
 201                 }
 202                 /*
 203                  * this byte range must be able to fit inside
 204                  * a single leaf so it will also fit inside a u32
 205                  */
 206                 diff = offset - item_start_offset;
 207                 diff = diff / root->sectorsize;
 208                 diff = diff * BTRFS_CRC32_SIZE;
 209
 210                 read_extent_buffer(path->nodes[0], &sum,
 211                                    ((unsigned long)item) + diff,
 212                                    BTRFS_CRC32_SIZE);
 213 found:
 214                 set_state_private(io_tree, offset, sum);
 215                 bio_index++;
 216                 bvec++;
 217         }
 218         btrfs_free_path(path);
 219         return 0;
 220 }
 221
 222 int btrfs_csum_file_bytes(struct btrfs_root *root, struct inode *inode,
 223                           u64 start, unsigned long len)
 224 {
 225         struct btrfs_ordered_sum *sums;
 226         struct btrfs_sector_sum *sector_sum;
 227         struct btrfs_ordered_extent *ordered;
 228         char *data;
 229         struct page *page;
 230         unsigned long total_bytes = 0;
 231         unsigned long this_sum_bytes = 0;
 232
 233         sums = kzalloc(btrfs_ordered_sum_size(root, len), GFP_NOFS);
 234         if (!sums)
 235                 return -ENOMEM;
 236
 237         sector_sum = sums->sums;
 238         sums->file_offset = start;
 239         sums->len = len;
 240         INIT_LIST_HEAD(&sums->list);
 241         ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
 242         BUG_ON(!ordered);
 243
 244         while(len > 0) {
 245                 if (start >= ordered->file_offset + ordered->len ||
 246                     start < ordered->file_offset) {
 247                         sums->len = this_sum_bytes;
 248                         this_sum_bytes = 0;
 249                         btrfs_add_ordered_sum(inode, ordered, sums);
 250                         btrfs_put_ordered_extent(ordered);
 251
 252                         sums = kzalloc(btrfs_ordered_sum_size(root, len),
 253                                        GFP_NOFS);
 254                         BUG_ON(!sums);
 255                         sector_sum = sums->sums;
 256                         sums->len = len;
 257                         sums->file_offset = start;
 258                         ordered = btrfs_lookup_ordered_extent(inode,
 259                                                       sums->file_offset);
 260                         BUG_ON(!ordered);
 261                 }
 262
 263                 page = find_get_page(inode->i_mapping,
 264                                      start >> PAGE_CACHE_SHIFT);
 265
 266                 data = kmap_atomic(page, KM_USER0);
 267                 sector_sum->sum = ~(u32)0;
 268                 sector_sum->sum = btrfs_csum_data(root, data, sector_sum->sum,
 269                                                   PAGE_CACHE_SIZE);
 270                 kunmap_atomic(data, KM_USER0);
 271                 btrfs_csum_final(sector_sum->sum,
 272                                  (char *)&sector_sum->sum);
 273                 sector_sum->offset = page_offset(page);
 274                 page_cache_release(page);
 275
 276                 sector_sum++;
 277                 total_bytes += PAGE_CACHE_SIZE;
 278                 this_sum_bytes += PAGE_CACHE_SIZE;
 279                 start += PAGE_CACHE_SIZE;
 280
 281                 WARN_ON(len < PAGE_CACHE_SIZE);
 282                 len -= PAGE_CACHE_SIZE;
 283         }
 284         btrfs_add_ordered_sum(inode, ordered, sums);
 285         btrfs_put_ordered_extent(ordered);
 286         return 0;
 287 }
 288
 289 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 290                        struct bio *bio)
 291 {
 292         struct btrfs_ordered_sum *sums;
 293         struct btrfs_sector_sum *sector_sum;
 294         struct btrfs_ordered_extent *ordered;
 295         char *data;
 296         struct bio_vec *bvec = bio->bi_io_vec;
 297         int bio_index = 0;
 298         unsigned long total_bytes = 0;
 299         unsigned long this_sum_bytes = 0;
 300         u64 offset;
 301
 302         WARN_ON(bio->bi_vcnt <= 0);
 303         sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
 304         if (!sums)
 305                 return -ENOMEM;
 306
 307         sector_sum = sums->sums;
 308         sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 309         sums->len = bio->bi_size;
 310         INIT_LIST_HEAD(&sums->list);
 311         ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
 312         BUG_ON(!ordered);
 313
 314         while(bio_index < bio->bi_vcnt) {
 315                 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 316                 if (offset >= ordered->file_offset + ordered->len ||
 317                     offset < ordered->file_offset) {
 318                         unsigned long bytes_left;
 319                         sums->len = this_sum_bytes;
 320                         this_sum_bytes = 0;
 321                         btrfs_add_ordered_sum(inode, ordered, sums);
 322                         btrfs_put_ordered_extent(ordered);
 323
 324                         bytes_left = bio->bi_size - total_bytes;
 325
 326                         sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
 327                                        GFP_NOFS);
 328                         BUG_ON(!sums);
 329                         sector_sum = sums->sums;
 330                         sums->len = bytes_left;
 331                         sums->file_offset = offset;
 332                         ordered = btrfs_lookup_ordered_extent(inode,
 333                                                       sums->file_offset);
 334                         BUG_ON(!ordered);
 335                 }
 336
 337                 data = kmap_atomic(bvec->bv_page, KM_USER0);
 338                 sector_sum->sum = ~(u32)0;
 339                 sector_sum->sum = btrfs_csum_data(root,
 340                                                   data + bvec->bv_offset,
 341                                                   sector_sum->sum,
 342                                                   bvec->bv_len);
 343                 kunmap_atomic(data, KM_USER0);
 344                 btrfs_csum_final(sector_sum->sum,
 345                                  (char *)&sector_sum->sum);
 346                 sector_sum->offset = page_offset(bvec->bv_page) +
 347                         bvec->bv_offset;
 348
 349                 sector_sum++;
 350                 bio_index++;
 351                 total_bytes += bvec->bv_len;
 352                 this_sum_bytes += bvec->bv_len;
 353                 bvec++;
 354         }
 355         this_sum_bytes = 0;
 356         btrfs_add_ordered_sum(inode, ordered, sums);
 357         btrfs_put_ordered_extent(ordered);
 358         return 0;
 359 }
 360
 361 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 362                            struct btrfs_root *root, struct inode *inode,
 363                            struct btrfs_ordered_sum *sums)
 364 {
 365         u64 objectid = inode->i_ino;
 366         u64 offset;
 367         int ret;
 368         struct btrfs_key file_key;
 369         struct btrfs_key found_key;
 370         u64 next_offset;
 371         u64 total_bytes = 0;
 372         int found_next;
 373         struct btrfs_path *path;
 374         struct btrfs_csum_item *item;
 375         struct btrfs_csum_item *item_end;
 376         struct extent_buffer *leaf = NULL;
 377         u64 csum_offset;
 378         struct btrfs_sector_sum *sector_sum;
 379         u32 nritems;
 380         u32 ins_size;
 381         char *eb_map;
 382         char *eb_token;
 383         unsigned long map_len;
 384         unsigned long map_start;
 385
 386         path = btrfs_alloc_path();
 387         BUG_ON(!path);
 388         sector_sum = sums->sums;
 389 again:
 390         next_offset = (u64)-1;
 391         found_next = 0;
 392         offset = sector_sum->offset;
 393         file_key.objectid = objectid;
 394         file_key.offset = offset;
 395         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
 396
 397         mutex_lock(&BTRFS_I(inode)->csum_mutex);
 398         item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
 399         if (!IS_ERR(item)) {
 400                 leaf = path->nodes[0];
 401                 ret = 0;
 402                 goto found;
 403         }
 404         ret = PTR_ERR(item);
 405         if (ret == -EFBIG) {
 406                 u32 item_size;
 407                 /* we found one, but it isn't big enough yet */
 408                 leaf = path->nodes[0];
 409                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 410                 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
 411                         /* already at max size, make a new one */
 412                         goto insert;
 413                 }
 414         } else {
 415                 int slot = path->slots[0] + 1;
 416                 /* we didn't find a csum item, insert one */
 417                 nritems = btrfs_header_nritems(path->nodes[0]);
 418                 if (path->slots[0] >= nritems - 1) {
 419                         ret = btrfs_next_leaf(root, path);
 420                         if (ret == 1)
 421                                 found_next = 1;
 422                         if (ret != 0)
 423                                 goto insert;
 424                         slot = 0;
 425                 }
 426                 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
 427                 if (found_key.objectid != objectid ||
 428                     found_key.type != BTRFS_CSUM_ITEM_KEY) {
 429                         found_next = 1;
 430                         goto insert;
 431                 }
 432                 next_offset = found_key.offset;
 433                 found_next = 1;
 434                 goto insert;
 435         }
 436
 437         /*
 438          * at this point, we know the tree has an item, but it isn't big
 439          * enough yet to put our csum in.  Grow it
 440          */
 441         btrfs_release_path(root, path);
 442         ret = btrfs_search_slot(trans, root, &file_key, path,
 443                                 BTRFS_CRC32_SIZE, 1);
 444         if (ret < 0)
 445                 goto fail_unlock;
 446         if (ret == 0) {
 447                 BUG();
 448         }
 449         if (path->slots[0] == 0) {
 450                 goto insert;
 451         }
 452         path->slots[0]--;
 453         leaf = path->nodes[0];
 454         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 455         csum_offset = (offset - found_key.offset) >>
 456                         root->fs_info->sb->s_blocksize_bits;
 457         if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
 458             found_key.objectid != objectid ||
 459             csum_offset >= MAX_CSUM_ITEMS(root)) {
 460                 goto insert;
 461         }
 462         if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
 463             BTRFS_CRC32_SIZE) {
 464                 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
 465                 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
 466                 if (diff != BTRFS_CRC32_SIZE)
 467                         goto insert;
 468                 ret = btrfs_extend_item(trans, root, path, diff);
 469                 BUG_ON(ret);
 470                 goto csum;
 471         }
 472
 473 insert:
 474         btrfs_release_path(root, path);
 475         csum_offset = 0;
 476         if (found_next) {
 477                 u64 tmp = min((u64)i_size_read(inode), next_offset);
 478                 tmp -= offset & ~((u64)root->sectorsize -1);
 479                 tmp >>= root->fs_info->sb->s_blocksize_bits;
 480                 tmp = max((u64)1, tmp);
 481                 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
 482                 ins_size = BTRFS_CRC32_SIZE * tmp;
 483         } else {
 484                 ins_size = BTRFS_CRC32_SIZE;
 485         }
 486         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
 487                                       ins_size);
 488         if (ret < 0)
 489                 goto fail_unlock;
 490         if (ret != 0) {
 491                 WARN_ON(1);
 492                 goto fail_unlock;
 493         }
 494 csum:
 495         leaf = path->nodes[0];
 496         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 497         ret = 0;
 498         item = (struct btrfs_csum_item *)((unsigned char *)item +
 499                                           csum_offset * BTRFS_CRC32_SIZE);
 500 found:
 501         item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 502         item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
 503                                       btrfs_item_size_nr(leaf, path->slots[0]));
 504         eb_token = NULL;
 505         mutex_unlock(&BTRFS_I(inode)->csum_mutex);
 506         cond_resched();
 507 next_sector:
 508
 509         if (!eb_token ||
 510            (unsigned long)item  + BTRFS_CRC32_SIZE >= map_start + map_len) {
 511                 int err;
 512
 513                 if (eb_token)
 514                         unmap_extent_buffer(leaf, eb_token, KM_USER1);
 515                 eb_token = NULL;
 516                 err = map_private_extent_buffer(leaf, (unsigned long)item,
 517                                                 BTRFS_CRC32_SIZE,
 518                                                 &eb_token, &eb_map,
 519                                                 &map_start, &map_len, KM_USER1);
 520                 if (err)
 521                         eb_token = NULL;
 522         }
 523         if (eb_token) {
 524                 memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
 525                        &sector_sum->sum, BTRFS_CRC32_SIZE);
 526         } else {
 527                 write_extent_buffer(leaf, &sector_sum->sum,
 528                                     (unsigned long)item, BTRFS_CRC32_SIZE);
 529         }
 530
 531         total_bytes += root->sectorsize;
 532         sector_sum++;
 533         if (total_bytes < sums->len) {
 534                 item = (struct btrfs_csum_item *)((char *)item +
 535                                                   BTRFS_CRC32_SIZE);
 536                 if (item < item_end && offset + PAGE_CACHE_SIZE ==
 537                     sector_sum->offset) {
 538                             offset = sector_sum->offset;
 539                         goto next_sector;
 540                 }
 541         }
 542         if (eb_token) {
 543                 unmap_extent_buffer(leaf, eb_token, KM_USER1);
 544                 eb_token = NULL;
 545         }
 546         btrfs_mark_buffer_dirty(path->nodes[0]);
 547         cond_resched();
 548         if (total_bytes < sums->len) {
 549                 btrfs_release_path(root, path);
 550                 goto again;
 551         }
 552 out:
 553         btrfs_free_path(path);
 554         return ret;
 555
 556 fail_unlock:
 557         mutex_unlock(&BTRFS_I(inode)->csum_mutex);
 558         goto out;
 559 }
 560
 561 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
 562                         struct btrfs_root *root, struct btrfs_path *path,
 563                         u64 isize)
 564 {
 565         struct btrfs_key key;
 566         struct extent_buffer *leaf = path->nodes[0];
 567         int slot = path->slots[0];
 568         int ret;
 569         u32 new_item_size;
 570         u64 new_item_span;
 571         u64 blocks;
 572
 573         btrfs_item_key_to_cpu(leaf, &key, slot);
 574         if (isize <= key.offset)
 575                 return 0;
 576         new_item_span = isize - key.offset;
 577         blocks = (new_item_span + root->sectorsize - 1) >>
 578                 root->fs_info->sb->s_blocksize_bits;
 579         new_item_size = blocks * BTRFS_CRC32_SIZE;
 580         if (new_item_size >= btrfs_item_size_nr(leaf, slot))
 581                 return 0;
 582         ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
 583         BUG_ON(ret);
 584         return ret;
 585 }