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,size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
  28                                    sizeof(struct btrfs_item) * 2) / \
  29                                   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 bytenr, int cow)
  78 {
  79         int ret;
  80         struct btrfs_key file_key;
  81         struct btrfs_key found_key;
  82         struct btrfs_csum_item *item;
  83         struct extent_buffer *leaf;
  84         u64 csum_offset = 0;
  85         u16 csum_size =
  86                 btrfs_super_csum_size(&root->fs_info->super_copy);
  87         int csums_in_item;
  88
  89         file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
  90         file_key.offset = bytenr;
  91         btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
  92         ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
  93         if (ret < 0)
  94                 goto fail;
  95         leaf = path->nodes[0];
  96         if (ret > 0) {
  97                 ret = 1;
  98                 if (path->slots[0] == 0)
  99                         goto fail;
 100                 path->slots[0]--;
 101                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 102                 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
 103                         goto fail;
 104
 105                 csum_offset = (bytenr - 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 /= csum_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 * csum_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, u32 *dst)
 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         u64 disk_bytenr;
 153         u32 diff;
 154         u16 csum_size =
 155                 btrfs_super_csum_size(&root->fs_info->super_copy);
 156         int ret;
 157         struct btrfs_path *path;
 158         struct btrfs_csum_item *item = NULL;
 159         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 160
 161         path = btrfs_alloc_path();
 162         if (bio->bi_size > PAGE_CACHE_SIZE * 8)
 163                 path->reada = 2;
 164
 165         WARN_ON(bio->bi_vcnt <= 0);
 166
 167         disk_bytenr = (u64)bio->bi_sector << 9;
 168         while(bio_index < bio->bi_vcnt) {
 169                 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 170                 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
 171                 if (ret == 0)
 172                         goto found;
 173
 174                 if (!item || disk_bytenr < item_start_offset ||
 175                     disk_bytenr >= item_last_offset) {
 176                         struct btrfs_key found_key;
 177                         u32 item_size;
 178
 179                         if (item)
 180                                 btrfs_release_path(root, path);
 181                         item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
 182                                                  path, disk_bytenr, 0);
 183                         if (IS_ERR(item)) {
 184                                 ret = PTR_ERR(item);
 185                                 if (ret == -ENOENT || ret == -EFBIG)
 186                                         ret = 0;
 187                                 sum = 0;
 188                                 printk("no csum found for inode %lu start "
 189                                        "%llu\n", inode->i_ino,
 190                                        (unsigned long long)offset);
 191                                 item = NULL;
 192                                 btrfs_release_path(root, path);
 193                                 goto found;
 194                         }
 195                         btrfs_item_key_to_cpu(path->nodes[0], &found_key,
 196                                               path->slots[0]);
 197
 198                         item_start_offset = found_key.offset;
 199                         item_size = btrfs_item_size_nr(path->nodes[0],
 200                                                        path->slots[0]);
 201                         item_last_offset = item_start_offset +
 202                                 (item_size / csum_size) *
 203                                 root->sectorsize;
 204                         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 205                                               struct btrfs_csum_item);
 206                 }
 207                 /*
 208                  * this byte range must be able to fit inside
 209                  * a single leaf so it will also fit inside a u32
 210                  */
 211                 diff = disk_bytenr - item_start_offset;
 212                 diff = diff / root->sectorsize;
 213                 diff = diff * csum_size;
 214
 215                 read_extent_buffer(path->nodes[0], &sum,
 216                                    ((unsigned long)item) + diff,
 217                                    csum_size);
 218 found:
 219                 if (dst)
 220                         *dst++ = sum;
 221                 else
 222                         set_state_private(io_tree, offset, sum);
 223                 disk_bytenr += bvec->bv_len;
 224                 bio_index++;
 225                 bvec++;
 226         }
 227         btrfs_free_path(path);
 228         return 0;
 229 }
 230
 231 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 232                        struct bio *bio, u64 file_start, int contig)
 233 {
 234         struct btrfs_ordered_sum *sums;
 235         struct btrfs_sector_sum *sector_sum;
 236         struct btrfs_ordered_extent *ordered;
 237         char *data;
 238         struct bio_vec *bvec = bio->bi_io_vec;
 239         int bio_index = 0;
 240         unsigned long total_bytes = 0;
 241         unsigned long this_sum_bytes = 0;
 242         u64 offset;
 243         u64 disk_bytenr;
 244
 245         WARN_ON(bio->bi_vcnt <= 0);
 246         sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
 247         if (!sums)
 248                 return -ENOMEM;
 249
 250         sector_sum = sums->sums;
 251         disk_bytenr = (u64)bio->bi_sector << 9;
 252         sums->len = bio->bi_size;
 253         INIT_LIST_HEAD(&sums->list);
 254
 255         if (contig)
 256                 offset = file_start;
 257         else
 258                 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 259
 260         ordered = btrfs_lookup_ordered_extent(inode, offset);
 261         BUG_ON(!ordered);
 262         sums->bytenr = ordered->start;
 263
 264         while(bio_index < bio->bi_vcnt) {
 265                 if (!contig)
 266                         offset = page_offset(bvec->bv_page) + bvec->bv_offset;
 267
 268                 if (!contig && (offset >= ordered->file_offset + ordered->len ||
 269                     offset < ordered->file_offset)) {
 270                         unsigned long bytes_left;
 271                         sums->len = this_sum_bytes;
 272                         this_sum_bytes = 0;
 273                         btrfs_add_ordered_sum(inode, ordered, sums);
 274                         btrfs_put_ordered_extent(ordered);
 275
 276                         bytes_left = bio->bi_size - total_bytes;
 277
 278                         sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
 279                                        GFP_NOFS);
 280                         BUG_ON(!sums);
 281                         sector_sum = sums->sums;
 282                         sums->len = bytes_left;
 283                         ordered = btrfs_lookup_ordered_extent(inode, offset);
 284                         BUG_ON(!ordered);
 285                         sums->bytenr = ordered->start;
 286                 }
 287
 288                 data = kmap_atomic(bvec->bv_page, KM_USER0);
 289                 sector_sum->sum = ~(u32)0;
 290                 sector_sum->sum = btrfs_csum_data(root,
 291                                                   data + bvec->bv_offset,
 292                                                   sector_sum->sum,
 293                                                   bvec->bv_len);
 294                 kunmap_atomic(data, KM_USER0);
 295                 btrfs_csum_final(sector_sum->sum,
 296                                  (char *)&sector_sum->sum);
 297                 sector_sum->bytenr = disk_bytenr;
 298
 299                 sector_sum++;
 300                 bio_index++;
 301                 total_bytes += bvec->bv_len;
 302                 this_sum_bytes += bvec->bv_len;
 303                 disk_bytenr += bvec->bv_len;
 304                 offset += bvec->bv_len;
 305                 bvec++;
 306         }
 307         this_sum_bytes = 0;
 308         btrfs_add_ordered_sum(inode, ordered, sums);
 309         btrfs_put_ordered_extent(ordered);
 310         return 0;
 311 }
 312
 313 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 314                            struct btrfs_root *root,
 315                            struct btrfs_ordered_sum *sums)
 316 {
 317         u64 bytenr;
 318         int ret;
 319         struct btrfs_key file_key;
 320         struct btrfs_key found_key;
 321         u64 next_offset;
 322         u64 total_bytes = 0;
 323         int found_next;
 324         struct btrfs_path *path;
 325         struct btrfs_csum_item *item;
 326         struct btrfs_csum_item *item_end;
 327         struct extent_buffer *leaf = NULL;
 328         u64 csum_offset;
 329         struct btrfs_sector_sum *sector_sum;
 330         u32 nritems;
 331         u32 ins_size;
 332         char *eb_map;
 333         char *eb_token;
 334         unsigned long map_len;
 335         unsigned long map_start;
 336         u16 csum_size =
 337                 btrfs_super_csum_size(&root->fs_info->super_copy);
 338
 339         path = btrfs_alloc_path();
 340         BUG_ON(!path);
 341         sector_sum = sums->sums;
 342 again:
 343         next_offset = (u64)-1;
 344         found_next = 0;
 345         file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
 346         file_key.offset = sector_sum->bytenr;
 347         bytenr = sector_sum->bytenr;
 348         btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
 349
 350         item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
 351         if (!IS_ERR(item)) {
 352                 leaf = path->nodes[0];
 353                 ret = 0;
 354                 goto found;
 355         }
 356         ret = PTR_ERR(item);
 357         if (ret == -EFBIG) {
 358                 u32 item_size;
 359                 /* we found one, but it isn't big enough yet */
 360                 leaf = path->nodes[0];
 361                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 362                 if ((item_size / csum_size) >=
 363                     MAX_CSUM_ITEMS(root, csum_size)) {
 364                         /* already at max size, make a new one */
 365                         goto insert;
 366                 }
 367         } else {
 368                 int slot = path->slots[0] + 1;
 369                 /* we didn't find a csum item, insert one */
 370                 nritems = btrfs_header_nritems(path->nodes[0]);
 371                 if (path->slots[0] >= nritems - 1) {
 372                         ret = btrfs_next_leaf(root, path);
 373                         if (ret == 1)
 374                                 found_next = 1;
 375                         if (ret != 0)
 376                                 goto insert;
 377                         slot = 0;
 378                 }
 379                 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
 380                 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
 381                     found_key.type != BTRFS_EXTENT_CSUM_KEY) {
 382                         found_next = 1;
 383                         goto insert;
 384                 }
 385                 next_offset = found_key.offset;
 386                 found_next = 1;
 387                 goto insert;
 388         }
 389
 390         /*
 391          * at this point, we know the tree has an item, but it isn't big
 392          * enough yet to put our csum in.  Grow it
 393          */
 394         btrfs_release_path(root, path);
 395         ret = btrfs_search_slot(trans, root, &file_key, path,
 396                                 csum_size, 1);
 397         if (ret < 0)
 398                 goto fail_unlock;
 399         if (ret == 0) {
 400                 BUG();
 401         }
 402         if (path->slots[0] == 0) {
 403                 goto insert;
 404         }
 405         path->slots[0]--;
 406         leaf = path->nodes[0];
 407         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 408         csum_offset = (bytenr - found_key.offset) >>
 409                         root->fs_info->sb->s_blocksize_bits;
 410         if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
 411             found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
 412             csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
 413                 goto insert;
 414         }
 415         if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
 416             csum_size) {
 417                 u32 diff = (csum_offset + 1) * csum_size;
 418                 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
 419                 if (diff != csum_size)
 420                         goto insert;
 421                 ret = btrfs_extend_item(trans, root, path, diff);
 422                 BUG_ON(ret);
 423                 goto csum;
 424         }
 425
 426 insert:
 427         btrfs_release_path(root, path);
 428         csum_offset = 0;
 429         if (found_next) {
 430                 u64 tmp = total_bytes + root->sectorsize;
 431                 u64 next_sector = sector_sum->bytenr;
 432                 struct btrfs_sector_sum *next = sector_sum + 1;
 433
 434                 while(tmp < sums->len) {
 435                         if (next_sector + root->sectorsize != next->bytenr)
 436                                 break;
 437                         tmp += root->sectorsize;
 438                         next_sector = next->bytenr;
 439                         next++;
 440                 }
 441                 tmp = min(tmp, next_offset - file_key.offset);
 442                 tmp >>= root->fs_info->sb->s_blocksize_bits;
 443                 tmp = max((u64)1, tmp);
 444                 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
 445                 ins_size = csum_size * tmp;
 446         } else {
 447                 ins_size = csum_size;
 448         }
 449         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
 450                                       ins_size);
 451         if (ret < 0)
 452                 goto fail_unlock;
 453         if (ret != 0) {
 454                 WARN_ON(1);
 455                 goto fail_unlock;
 456         }
 457 csum:
 458         leaf = path->nodes[0];
 459         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 460         ret = 0;
 461         item = (struct btrfs_csum_item *)((unsigned char *)item +
 462                                           csum_offset * csum_size);
 463 found:
 464         item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 465         item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
 466                                       btrfs_item_size_nr(leaf, path->slots[0]));
 467         eb_token = NULL;
 468         cond_resched();
 469 next_sector:
 470
 471         if (!eb_token ||
 472            (unsigned long)item + csum_size >= map_start + map_len) {
 473                 int err;
 474
 475                 if (eb_token)
 476                         unmap_extent_buffer(leaf, eb_token, KM_USER1);
 477                 eb_token = NULL;
 478                 err = map_private_extent_buffer(leaf, (unsigned long)item,
 479                                                 csum_size,
 480                                                 &eb_token, &eb_map,
 481                                                 &map_start, &map_len, KM_USER1);
 482                 if (err)
 483                         eb_token = NULL;
 484         }
 485         if (eb_token) {
 486                 memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
 487                        &sector_sum->sum, csum_size);
 488         } else {
 489                 write_extent_buffer(leaf, &sector_sum->sum,
 490                                     (unsigned long)item, csum_size);
 491         }
 492
 493         total_bytes += root->sectorsize;
 494         sector_sum++;
 495         if (total_bytes < sums->len) {
 496                 item = (struct btrfs_csum_item *)((char *)item +
 497                                                   csum_size);
 498                 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
 499                     sector_sum->bytenr) {
 500                         bytenr = sector_sum->bytenr;
 501                         goto next_sector;
 502                 }
 503         }
 504         if (eb_token) {
 505                 unmap_extent_buffer(leaf, eb_token, KM_USER1);
 506                 eb_token = NULL;
 507         }
 508         btrfs_mark_buffer_dirty(path->nodes[0]);
 509         cond_resched();
 510         if (total_bytes < sums->len) {
 511                 btrfs_release_path(root, path);
 512                 goto again;
 513         }
 514 out:
 515         btrfs_free_path(path);
 516         return ret;
 517
 518 fail_unlock:
 519         goto out;
 520 }
 521
 522 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
 523                         struct btrfs_root *root, struct btrfs_path *path,
 524                         u64 isize)
 525 {
 526         struct btrfs_key key;
 527         struct extent_buffer *leaf = path->nodes[0];
 528         int slot = path->slots[0];
 529         int ret;
 530         u32 new_item_size;
 531         u64 new_item_span;
 532         u64 blocks;
 533
 534         btrfs_item_key_to_cpu(leaf, &key, slot);
 535         if (isize <= key.offset)
 536                 return 0;
 537         new_item_span = isize - key.offset;
 538         blocks = (new_item_span + root->sectorsize - 1) >>
 539                 root->fs_info->sb->s_blocksize_bits;
 540         new_item_size = blocks *
 541                 btrfs_super_csum_size(&root->fs_info->super_copy);
 542         if (new_item_size >= btrfs_item_size_nr(leaf, slot))
 543                 return 0;
 544         ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
 545         BUG_ON(ret);
 546         return ret;
 547 }