SAFE public projects git trees. - safe/jmp/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                                 btrfs_release_path(root, path);
 189                                 goto found;
 190                         }
 191                         btrfs_item_key_to_cpu(path->nodes[0], &found_key,
 192                                               path->slots[0]);
 193
 194                         item_start_offset = found_key.offset;
 195                         item_size = btrfs_item_size_nr(path->nodes[0],
 196                                                        path->slots[0]);
 197                         item_last_offset = item_start_offset +
 198                                 (item_size / BTRFS_CRC32_SIZE) *
 199                                 root->sectorsize;
 200                         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 201                                               struct btrfs_csum_item);
 202                 }
 203                 /*
 204                  * this byte range must be able to fit inside
 205                  * a single leaf so it will also fit inside a u32
 206                  */
 207                 diff = offset - item_start_offset;
 208                 diff = diff / root->sectorsize;
 209                 diff = diff * BTRFS_CRC32_SIZE;
 210
 211                 read_extent_buffer(path->nodes[0], &sum,
 212                                    ((unsigned long)item) + diff,
 213                                    BTRFS_CRC32_SIZE);
 214 found:
 215                 set_state_private(io_tree, offset, sum);
 216                 bio_index++;
 217                 bvec++;
 218         }
 219         btrfs_free_path(path);
 220         return 0;
 221 }
 222
 223 int btrfs_csum_file_bytes(struct btrfs_root *root, struct inode *inode,
 224                           u64 start, unsigned long len)
 225 {
 226         struct btrfs_ordered_sum *sums;
 227         struct btrfs_sector_sum *sector_sum;
 228         struct btrfs_ordered_extent *ordered;
 229         char *data;
 230         struct page *page;
 231         unsigned long total_bytes = 0;
 232         unsigned long this_sum_bytes = 0;
 233
 234         sums = kzalloc(btrfs_ordered_sum_size(root, len), GFP_NOFS);
 235         if (!sums)
 236                 return -ENOMEM;
 237
 238         sector_sum = sums->sums;
 239         sums->file_offset = start;
 240         sums->len = len;
 241         INIT_LIST_HEAD(&sums->list);
 242         ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
 243         BUG_ON(!ordered);
 244
 245         while(len > 0) {
 246                 if (start >= ordered->file_offset + ordered->len ||
 247                     start < ordered->file_offset) {
 248                         sums->len = this_sum_bytes;
 249                         this_sum_bytes = 0;
 250                         btrfs_add_ordered_sum(inode, ordered, sums);
 251                         btrfs_put_ordered_extent(ordered);
 252
 253                         sums = kzalloc(btrfs_ordered_sum_size(root, len),
 254                                        GFP_NOFS);
 255                         BUG_ON(!sums);
 256                         sector_sum = sums->sums;
 257                         sums->len = len;
 258                         sums->file_offset = start;
 259                         ordered = btrfs_lookup_ordered_extent(inode,
 260                                                       sums->file_offset);
 261                         BUG_ON(!ordered);
 262                 }
 263
 264                 page = find_get_page(inode->i_mapping,
 265                                      start >> PAGE_CACHE_SHIFT);
 266
 267                 data = kmap_atomic(page, KM_USER0);
 268                 sector_sum->sum = ~(u32)0;
 269                 sector_sum->sum = btrfs_csum_data(root, data, sector_sum->sum,
 270                                                   PAGE_CACHE_SIZE);
 271                 kunmap_atomic(data, KM_USER0);
 272                 btrfs_csum_final(sector_sum->sum,
 273                                  (char *)&sector_sum->sum);
 274                 sector_sum->offset = page_offset(page);
 275                 page_cache_release(page);
 276
 277                 sector_sum++;
 278                 total_bytes += PAGE_CACHE_SIZE;
 279                 this_sum_bytes += PAGE_CACHE_SIZE;
 280                 start += PAGE_CACHE_SIZE;
 281
 282                 WARN_ON(len < PAGE_CACHE_SIZE);
 283                 len -= PAGE_CACHE_SIZE;
 284         }
 285         btrfs_add_ordered_sum(inode, ordered, sums);
 286         btrfs_put_ordered_extent(ordered);
 287         return 0;
 288 }
 289
 290 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 291                        struct bio *bio)
 292 {
 293         struct btrfs_ordered_sum *sums;
 294         struct btrfs_sector_sum *sector_sum;
 295         struct btrfs_ordered_extent *ordered;
 296         char *data;
 297         struct bio_vec *bvec = bio->bi_io_vec;
 298         int bio_index = 0;
 299         unsigned long total_bytes = 0;
 300         unsigned long this_sum_bytes = 0;
 301         u64 offset;
 302
 303         WARN_ON(bio->bi_vcnt <= 0);
 304         sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
 305         if (!sums)
 306                 return -ENOMEM;
 307
 308         sector_sum = sums->sums;
 309         sums->file_offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 310         sums->len = bio->bi_size;
 311         INIT_LIST_HEAD(&sums->list);
 312         ordered = btrfs_lookup_ordered_extent(inode, sums->file_offset);
 313         BUG_ON(!ordered);
 314
 315         while(bio_index < bio->bi_vcnt) {
 316                 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 317                 if (offset >= ordered->file_offset + ordered->len ||
 318                     offset < ordered->file_offset) {
 319                         unsigned long bytes_left;
 320                         sums->len = this_sum_bytes;
 321                         this_sum_bytes = 0;
 322                         btrfs_add_ordered_sum(inode, ordered, sums);
 323                         btrfs_put_ordered_extent(ordered);
 324
 325                         bytes_left = bio->bi_size - total_bytes;
 326
 327                         sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
 328                                        GFP_NOFS);
 329                         BUG_ON(!sums);
 330                         sector_sum = sums->sums;
 331                         sums->len = bytes_left;
 332                         sums->file_offset = offset;
 333                         ordered = btrfs_lookup_ordered_extent(inode,
 334                                                       sums->file_offset);
 335                         BUG_ON(!ordered);
 336                 }
 337
 338                 data = kmap_atomic(bvec->bv_page, KM_USER0);
 339                 sector_sum->sum = ~(u32)0;
 340                 sector_sum->sum = btrfs_csum_data(root,
 341                                                   data + bvec->bv_offset,
 342                                                   sector_sum->sum,
 343                                                   bvec->bv_len);
 344                 kunmap_atomic(data, KM_USER0);
 345                 btrfs_csum_final(sector_sum->sum,
 346                                  (char *)&sector_sum->sum);
 347                 sector_sum->offset = page_offset(bvec->bv_page) +
 348                         bvec->bv_offset;
 349
 350                 sector_sum++;
 351                 bio_index++;
 352                 total_bytes += bvec->bv_len;
 353                 this_sum_bytes += bvec->bv_len;
 354                 bvec++;
 355         }
 356         this_sum_bytes = 0;
 357         btrfs_add_ordered_sum(inode, ordered, sums);
 358         btrfs_put_ordered_extent(ordered);
 359         return 0;
 360 }
 361
 362 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 363                            struct btrfs_root *root, struct inode *inode,
 364                            struct btrfs_ordered_sum *sums)
 365 {
 366         u64 objectid = inode->i_ino;
 367         u64 offset;
 368         int ret;
 369         struct btrfs_key file_key;
 370         struct btrfs_key found_key;
 371         u64 next_offset;
 372         u64 total_bytes = 0;
 373         int found_next;
 374         struct btrfs_path *path;
 375         struct btrfs_csum_item *item;
 376         struct btrfs_csum_item *item_end;
 377         struct extent_buffer *leaf = NULL;
 378         u64 csum_offset;
 379         struct btrfs_sector_sum *sector_sum;
 380         u32 nritems;
 381         u32 ins_size;
 382         char *eb_map;
 383         char *eb_token;
 384         unsigned long map_len;
 385         unsigned long map_start;
 386
 387         path = btrfs_alloc_path();
 388         BUG_ON(!path);
 389         sector_sum = sums->sums;
 390 again:
 391         next_offset = (u64)-1;
 392         found_next = 0;
 393         offset = sector_sum->offset;
 394         file_key.objectid = objectid;
 395         file_key.offset = offset;
 396         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
 397
 398         mutex_lock(&BTRFS_I(inode)->csum_mutex);
 399         item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
 400         if (!IS_ERR(item)) {
 401                 leaf = path->nodes[0];
 402                 ret = 0;
 403                 goto found;
 404         }
 405         ret = PTR_ERR(item);
 406         if (ret == -EFBIG) {
 407                 u32 item_size;
 408                 /* we found one, but it isn't big enough yet */
 409                 leaf = path->nodes[0];
 410                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 411                 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
 412                         /* already at max size, make a new one */
 413                         goto insert;
 414                 }
 415         } else {
 416                 int slot = path->slots[0] + 1;
 417                 /* we didn't find a csum item, insert one */
 418                 nritems = btrfs_header_nritems(path->nodes[0]);
 419                 if (path->slots[0] >= nritems - 1) {
 420                         ret = btrfs_next_leaf(root, path);
 421                         if (ret == 1)
 422                                 found_next = 1;
 423                         if (ret != 0)
 424                                 goto insert;
 425                         slot = 0;
 426                 }
 427                 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
 428                 if (found_key.objectid != objectid ||
 429                     found_key.type != BTRFS_CSUM_ITEM_KEY) {
 430                         found_next = 1;
 431                         goto insert;
 432                 }
 433                 next_offset = found_key.offset;
 434                 found_next = 1;
 435                 goto insert;
 436         }
 437
 438         /*
 439          * at this point, we know the tree has an item, but it isn't big
 440          * enough yet to put our csum in.  Grow it
 441          */
 442         btrfs_release_path(root, path);
 443         ret = btrfs_search_slot(trans, root, &file_key, path,
 444                                 BTRFS_CRC32_SIZE, 1);
 445         if (ret < 0)
 446                 goto fail_unlock;
 447         if (ret == 0) {
 448                 BUG();
 449         }
 450         if (path->slots[0] == 0) {
 451                 goto insert;
 452         }
 453         path->slots[0]--;
 454         leaf = path->nodes[0];
 455         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 456         csum_offset = (offset - found_key.offset) >>
 457                         root->fs_info->sb->s_blocksize_bits;
 458         if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
 459             found_key.objectid != objectid ||
 460             csum_offset >= MAX_CSUM_ITEMS(root)) {
 461                 goto insert;
 462         }
 463         if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
 464             BTRFS_CRC32_SIZE) {
 465                 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
 466                 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
 467                 if (diff != BTRFS_CRC32_SIZE)
 468                         goto insert;
 469                 ret = btrfs_extend_item(trans, root, path, diff);
 470                 BUG_ON(ret);
 471                 goto csum;
 472         }
 473
 474 insert:
 475         btrfs_release_path(root, path);
 476         csum_offset = 0;
 477         if (found_next) {
 478                 u64 tmp = min((u64)i_size_read(inode), next_offset);
 479                 tmp -= offset & ~((u64)root->sectorsize -1);
 480                 tmp >>= root->fs_info->sb->s_blocksize_bits;
 481                 tmp = max((u64)1, tmp);
 482                 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
 483                 ins_size = BTRFS_CRC32_SIZE * tmp;
 484         } else {
 485                 ins_size = BTRFS_CRC32_SIZE;
 486         }
 487         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
 488                                       ins_size);
 489         if (ret < 0)
 490                 goto fail_unlock;
 491         if (ret != 0) {
 492                 WARN_ON(1);
 493                 goto fail_unlock;
 494         }
 495 csum:
 496         leaf = path->nodes[0];
 497         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 498         ret = 0;
 499         item = (struct btrfs_csum_item *)((unsigned char *)item +
 500                                           csum_offset * BTRFS_CRC32_SIZE);
 501 found:
 502         item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 503         item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
 504                                       btrfs_item_size_nr(leaf, path->slots[0]));
 505         eb_token = NULL;
 506         mutex_unlock(&BTRFS_I(inode)->csum_mutex);
 507         cond_resched();
 508 next_sector:
 509
 510         if (!eb_token ||
 511            (unsigned long)item  + BTRFS_CRC32_SIZE >= map_start + map_len) {
 512                 int err;
 513
 514                 if (eb_token)
 515                         unmap_extent_buffer(leaf, eb_token, KM_USER1);
 516                 eb_token = NULL;
 517                 err = map_private_extent_buffer(leaf, (unsigned long)item,
 518                                                 BTRFS_CRC32_SIZE,
 519                                                 &eb_token, &eb_map,
 520                                                 &map_start, &map_len, KM_USER1);
 521                 if (err)
 522                         eb_token = NULL;
 523         }
 524         if (eb_token) {
 525                 memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
 526                        &sector_sum->sum, BTRFS_CRC32_SIZE);
 527         } else {
 528                 write_extent_buffer(leaf, &sector_sum->sum,
 529                                     (unsigned long)item, BTRFS_CRC32_SIZE);
 530         }
 531
 532         total_bytes += root->sectorsize;
 533         sector_sum++;
 534         if (total_bytes < sums->len) {
 535                 item = (struct btrfs_csum_item *)((char *)item +
 536                                                   BTRFS_CRC32_SIZE);
 537                 if (item < item_end && offset + PAGE_CACHE_SIZE ==
 538                     sector_sum->offset) {
 539                             offset = sector_sum->offset;
 540                         goto next_sector;
 541                 }
 542         }
 543         if (eb_token) {
 544                 unmap_extent_buffer(leaf, eb_token, KM_USER1);
 545                 eb_token = NULL;
 546         }
 547         btrfs_mark_buffer_dirty(path->nodes[0]);
 548         cond_resched();
 549         if (total_bytes < sums->len) {
 550                 btrfs_release_path(root, path);
 551                 goto again;
 552         }
 553 out:
 554         btrfs_free_path(path);
 555         return ret;
 556
 557 fail_unlock:
 558         mutex_unlock(&BTRFS_I(inode)->csum_mutex);
 559         goto out;
 560 }
 561
 562 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
 563                         struct btrfs_root *root, struct btrfs_path *path,
 564                         u64 isize)
 565 {
 566         struct btrfs_key key;
 567         struct extent_buffer *leaf = path->nodes[0];
 568         int slot = path->slots[0];
 569         int ret;
 570         u32 new_item_size;
 571         u64 new_item_span;
 572         u64 blocks;
 573
 574         btrfs_item_key_to_cpu(leaf, &key, slot);
 575         if (isize <= key.offset)
 576                 return 0;
 577         new_item_span = isize - key.offset;
 578         blocks = (new_item_span + root->sectorsize - 1) >>
 579                 root->fs_info->sb->s_blocksize_bits;
 580         new_item_size = blocks * BTRFS_CRC32_SIZE;
 581         if (new_item_size >= btrfs_item_size_nr(leaf, slot))
 582                 return 0;
 583         ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
 584         BUG_ON(ret);
 585         return ret;
 586 }