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 <stdio.h>
  20 #include <stdlib.h>
  21 #include "kerncompat.h"
  22 #include "radix-tree.h"
  23 #include "ctree.h"
  24 #include "disk-io.h"
  25 #include "transaction.h"
  26 #include "print-tree.h"
  27 #include "crc32c.h"
  28
  29 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
  30                                sizeof(struct btrfs_item) * 2) / \
  31                                BTRFS_CRC32_SIZE) - 1))
  32 int btrfs_create_file(struct btrfs_trans_handle *trans,
  33                       struct btrfs_root *root, u64 dirid, u64 *objectid)
  34 {
  35         return 0;
  36 }
  37
  38 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
  39                              struct btrfs_root *root,
  40                              u64 objectid, u64 pos, u64 offset,
  41                              u64 disk_num_bytes, u64 num_bytes)
  42 {
  43         int ret = 0;
  44         struct btrfs_file_extent_item *item;
  45         struct btrfs_key file_key;
  46         struct btrfs_path *path;
  47         struct extent_buffer *leaf;
  48
  49         path = btrfs_alloc_path();
  50         BUG_ON(!path);
  51         file_key.objectid = objectid;
  52         file_key.offset = pos;
  53         btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
  54
  55         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
  56                                       sizeof(*item));
  57         if (ret < 0)
  58                 goto out;
  59         BUG_ON(ret);
  60         leaf = path->nodes[0];
  61         item = btrfs_item_ptr(leaf, path->slots[0],
  62                               struct btrfs_file_extent_item);
  63         btrfs_set_file_extent_disk_bytenr(leaf, item, offset);
  64         btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
  65         btrfs_set_file_extent_offset(leaf, item, 0);
  66         btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
  67         btrfs_set_file_extent_generation(leaf, item, trans->transid);
  68         btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
  69         btrfs_mark_buffer_dirty(leaf);
  70 out:
  71         btrfs_free_path(path);
  72         return ret;
  73 }
  74
  75 int btrfs_insert_inline_extent(struct btrfs_trans_handle *trans,
  76                                struct btrfs_root *root, u64 objectid,
  77                                u64 offset, char *buffer, size_t size)
  78 {
  79         struct btrfs_key key;
  80         struct btrfs_path *path;
  81         struct extent_buffer *leaf;
  82         unsigned long ptr;
  83         struct btrfs_file_extent_item *ei;
  84         u32 datasize;
  85         int err = 0;
  86         int ret;
  87
  88         path = btrfs_alloc_path();
  89         if (!path)
  90                 return -ENOMEM;
  91
  92         key.objectid = objectid;
  93         key.offset = offset;
  94         btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
  95
  96         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
  97         if (ret < 0) {
  98                 err = ret;
  99                 goto fail;
 100         }
 101         if (ret == 1) {
 102                 struct btrfs_key found_key;
 103
 104                 if (path->slots[0] == 0)
 105                         goto insert;
 106
 107                 path->slots[0]--;
 108                 leaf = path->nodes[0];
 109                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 110
 111                 if (found_key.objectid != objectid)
 112                         goto insert;
 113
 114                 if (found_key.type != BTRFS_EXTENT_DATA_KEY)
 115                         goto insert;
 116                 ei = btrfs_item_ptr(leaf, path->slots[0],
 117                                     struct btrfs_file_extent_item);
 118
 119                 if (btrfs_file_extent_type(leaf, ei) !=
 120                     BTRFS_FILE_EXTENT_INLINE) {
 121                         goto insert;
 122                 }
 123                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 124                 ret = 0;
 125         }
 126         if (ret == 0) {
 127                 u32 found_size;
 128                 u64 found_end;
 129
 130                 leaf = path->nodes[0];
 131                 ei = btrfs_item_ptr(leaf, path->slots[0],
 132                                     struct btrfs_file_extent_item);
 133
 134                 if (btrfs_file_extent_type(leaf, ei) !=
 135                     BTRFS_FILE_EXTENT_INLINE) {
 136                         err = ret;
 137                         btrfs_print_leaf(root, leaf);
 138                         printk("found wasn't inline offset %llu inode %llu\n",
 139                                offset, objectid);
 140                         goto fail;
 141                 }
 142                 found_size = btrfs_file_extent_inline_len(leaf,
 143                                           btrfs_item_nr(leaf, path->slots[0]));
 144                 found_end = key.offset + found_size;
 145
 146                 if (found_end < offset + size) {
 147                         btrfs_release_path(root, path);
 148                         ret = btrfs_search_slot(trans, root, &key, path,
 149                                                 offset + size - found_end, 1);
 150                         BUG_ON(ret != 0);
 151
 152                         ret = btrfs_extend_item(trans, root, path,
 153                                                 offset + size - found_end);
 154                         if (ret) {
 155                                 err = ret;
 156                                 goto fail;
 157                         }
 158                         leaf = path->nodes[0];
 159                         ei = btrfs_item_ptr(leaf, path->slots[0],
 160                                             struct btrfs_file_extent_item);
 161                 }
 162                 if (found_end < offset) {
 163                         ptr = btrfs_file_extent_inline_start(ei) + found_size;
 164                         memset_extent_buffer(leaf, 0, ptr, offset - found_end);
 165                 }
 166         } else {
 167 insert:
 168                 btrfs_release_path(root, path);
 169                 datasize = offset + size - key.offset;
 170                 datasize = btrfs_file_extent_calc_inline_size(datasize);
 171                 ret = btrfs_insert_empty_item(trans, root, path, &key,
 172                                               datasize);
 173                 if (ret) {
 174                         err = ret;
 175                         printk("got bad ret %d\n", ret);
 176                         goto fail;
 177                 }
 178                 leaf = path->nodes[0];
 179                 ei = btrfs_item_ptr(leaf, path->slots[0],
 180                                     struct btrfs_file_extent_item);
 181                 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
 182                 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
 183         }
 184         ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset;
 185         write_extent_buffer(leaf, buffer, ptr, size);
 186         btrfs_mark_buffer_dirty(leaf);
 187 fail:
 188         btrfs_free_path(path);
 189         return err;
 190 }
 191
 192 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
 193                                           struct btrfs_root *root,
 194                                           struct btrfs_path *path,
 195                                           u64 objectid, u64 offset, int cow)
 196 {
 197         int ret;
 198         struct btrfs_key file_key;
 199         struct btrfs_key found_key;
 200         struct btrfs_csum_item *item;
 201         struct extent_buffer *leaf;
 202         u64 csum_offset = 0;
 203         int csums_in_item;
 204
 205         file_key.objectid = objectid;
 206         file_key.offset = offset;
 207         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
 208         ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
 209         if (ret < 0)
 210                 goto fail;
 211         leaf = path->nodes[0];
 212         if (ret > 0) {
 213                 ret = 1;
 214                 if (path->slots[0] == 0)
 215                         goto fail;
 216                 path->slots[0]--;
 217                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 218                 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
 219                     found_key.objectid != objectid) {
 220                         goto fail;
 221                 }
 222                 csum_offset = (offset - found_key.offset) >> root->sectorsize;
 223                 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
 224                 csums_in_item /= BTRFS_CRC32_SIZE;
 225
 226                 if (csum_offset >= csums_in_item) {
 227                         ret = -EFBIG;
 228                         goto fail;
 229                 }
 230         }
 231         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 232         item = (struct btrfs_csum_item *)((unsigned char *)item +
 233                                           csum_offset * BTRFS_CRC32_SIZE);
 234         return item;
 235 fail:
 236         if (ret > 0)
 237                 ret = -ENOENT;
 238         return ERR_PTR(ret);
 239 }
 240
 241
 242 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 243                              struct btrfs_root *root,
 244                              struct btrfs_path *path, u64 objectid,
 245                              u64 offset, int mod)
 246 {
 247         int ret;
 248         struct btrfs_key file_key;
 249         int ins_len = mod < 0 ? -1 : 0;
 250         int cow = mod != 0;
 251
 252         file_key.objectid = objectid;
 253         file_key.offset = offset;
 254         btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
 255         ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
 256         return ret;
 257 }
 258
 259 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
 260                           struct btrfs_root *root,
 261                           struct btrfs_inode_item *inode,
 262                           u64 objectid, u64 offset,
 263                           char *data, size_t len)
 264 {
 265         int ret;
 266         struct btrfs_key file_key;
 267         struct btrfs_key found_key;
 268         u64 next_offset = (u64)-1;
 269         int found_next = 0;
 270         struct btrfs_path *path;
 271         struct btrfs_csum_item *item;
 272         struct extent_buffer *leaf = NULL;
 273         u64 csum_offset;
 274         u32 csum_result = ~(u32)0;
 275         u32 nritems;
 276         u32 ins_size;
 277
 278         path = btrfs_alloc_path();
 279         BUG_ON(!path);
 280
 281         file_key.objectid = objectid;
 282         file_key.offset = offset;
 283         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
 284
 285         item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
 286         if (!IS_ERR(item)) {
 287                 leaf = path->nodes[0];
 288                 goto found;
 289         }
 290         ret = PTR_ERR(item);
 291         if (ret == -EFBIG) {
 292                 u32 item_size;
 293                 /* we found one, but it isn't big enough yet */
 294                 leaf = path->nodes[0];
 295                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 296                 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
 297                         /* already at max size, make a new one */
 298                         goto insert;
 299                 }
 300         } else {
 301                 int slot = path->slots[0] + 1;
 302                 /* we didn't find a csum item, insert one */
 303                 nritems = btrfs_header_nritems(path->nodes[0]);
 304                 if (path->slots[0] >= nritems - 1) {
 305                         ret = btrfs_next_leaf(root, path);
 306                         if (ret == 1)
 307                                 found_next = 1;
 308                         if (ret != 0)
 309                                 goto insert;
 310                         slot = 0;
 311                 }
 312                 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
 313                 if (found_key.objectid != objectid ||
 314                     found_key.type != BTRFS_CSUM_ITEM_KEY) {
 315                         found_next = 1;
 316                         goto insert;
 317                 }
 318                 next_offset = found_key.offset;
 319                 found_next = 1;
 320                 goto insert;
 321         }
 322
 323         /*
 324          * at this point, we know the tree has an item, but it isn't big
 325          * enough yet to put our csum in.  Grow it
 326          */
 327         btrfs_release_path(root, path);
 328         ret = btrfs_search_slot(trans, root, &file_key, path,
 329                                 BTRFS_CRC32_SIZE, 1);
 330         if (ret < 0)
 331                 goto fail;
 332         if (ret == 0) {
 333                 BUG();
 334         }
 335         if (path->slots[0] == 0) {
 336                 goto insert;
 337         }
 338         path->slots[0]--;
 339         leaf = path->nodes[0];
 340         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 341         csum_offset = (offset - found_key.offset) / root->sectorsize;
 342         if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
 343             found_key.objectid != objectid ||
 344             csum_offset >= MAX_CSUM_ITEMS(root)) {
 345                 goto insert;
 346         }
 347         if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
 348             BTRFS_CRC32_SIZE) {
 349                 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
 350                 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
 351                 if (diff != BTRFS_CRC32_SIZE)
 352                         goto insert;
 353                 ret = btrfs_extend_item(trans, root, path, diff);
 354                 BUG_ON(ret);
 355                 goto csum;
 356         }
 357
 358 insert:
 359         btrfs_release_path(root, path);
 360         csum_offset = 0;
 361         if (found_next) {
 362                 u64 tmp = min(btrfs_stack_inode_size(inode), next_offset);
 363                 tmp -= offset & ~((u64)root->sectorsize -1);
 364                 tmp /= root->sectorsize;
 365                 tmp = max((u64)1, tmp);
 366                 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
 367                 ins_size = BTRFS_CRC32_SIZE * tmp;
 368         } else {
 369                 ins_size = BTRFS_CRC32_SIZE;
 370         }
 371         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
 372                                       ins_size);
 373         if (ret < 0)
 374                 goto fail;
 375         if (ret != 0) {
 376                 WARN_ON(1);
 377                 goto fail;
 378         }
 379 csum:
 380         leaf = path->nodes[0];
 381         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 382         ret = 0;
 383         item = (struct btrfs_csum_item *)((unsigned char *)item +
 384                                           csum_offset * BTRFS_CRC32_SIZE);
 385 found:
 386         csum_result = btrfs_csum_data(root, data, csum_result, len);
 387         btrfs_csum_final(csum_result, (char *)&csum_result);
 388         if (csum_result == 0) {
 389                 printk("csum result is 0 for inode %Lu offset %Lu\n",
 390                        objectid, offset);
 391         }
 392
 393         write_extent_buffer(leaf, &csum_result, (unsigned long)item,
 394                             BTRFS_CRC32_SIZE);
 395         btrfs_mark_buffer_dirty(path->nodes[0]);
 396 fail:
 397         btrfs_release_path(root, path);
 398         btrfs_free_path(path);
 399         return ret;
 400 }
 401
 402 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
 403                         struct btrfs_root *root, struct btrfs_path *path,
 404                         u64 isize)
 405 {
 406         struct btrfs_key key;
 407         struct extent_buffer *leaf = path->nodes[0];
 408         int slot = path->slots[0];
 409         int ret;
 410         u32 new_item_size;
 411         u64 new_item_span;
 412         u64 blocks;
 413
 414         btrfs_item_key_to_cpu(leaf, &key, slot);
 415         if (isize <= key.offset)
 416                 return 0;
 417         new_item_span = isize - key.offset;
 418         blocks = (new_item_span + root->sectorsize - 1) / root->sectorsize;
 419         new_item_size = blocks * BTRFS_CRC32_SIZE;
 420         if (new_item_size >= btrfs_item_size_nr(leaf, slot))
 421                 return 0;
 422         ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
 423         BUG_ON(ret);
 424         return ret;
 425 }