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                                (unsigned long long)offset,
 140                                (unsigned long long)objectid);
 141                         goto fail;
 142                 }
 143                 found_size = btrfs_file_extent_inline_len(leaf,
 144                                           btrfs_item_nr(leaf, path->slots[0]));
 145                 found_end = key.offset + found_size;
 146
 147                 if (found_end < offset + size) {
 148                         btrfs_release_path(root, path);
 149                         ret = btrfs_search_slot(trans, root, &key, path,
 150                                                 offset + size - found_end, 1);
 151                         BUG_ON(ret != 0);
 152
 153                         ret = btrfs_extend_item(trans, root, path,
 154                                                 offset + size - found_end);
 155                         if (ret) {
 156                                 err = ret;
 157                                 goto fail;
 158                         }
 159                         leaf = path->nodes[0];
 160                         ei = btrfs_item_ptr(leaf, path->slots[0],
 161                                             struct btrfs_file_extent_item);
 162                 }
 163                 if (found_end < offset) {
 164                         ptr = btrfs_file_extent_inline_start(ei) + found_size;
 165                         memset_extent_buffer(leaf, 0, ptr, offset - found_end);
 166                 }
 167         } else {
 168 insert:
 169                 btrfs_release_path(root, path);
 170                 datasize = offset + size - key.offset;
 171                 datasize = btrfs_file_extent_calc_inline_size(datasize);
 172                 ret = btrfs_insert_empty_item(trans, root, path, &key,
 173                                               datasize);
 174                 if (ret) {
 175                         err = ret;
 176                         printk("got bad ret %d\n", ret);
 177                         goto fail;
 178                 }
 179                 leaf = path->nodes[0];
 180                 ei = btrfs_item_ptr(leaf, path->slots[0],
 181                                     struct btrfs_file_extent_item);
 182                 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
 183                 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
 184         }
 185         ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset;
 186         write_extent_buffer(leaf, buffer, ptr, size);
 187         btrfs_mark_buffer_dirty(leaf);
 188 fail:
 189         btrfs_free_path(path);
 190         return err;
 191 }
 192
 193 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
 194                                           struct btrfs_root *root,
 195                                           struct btrfs_path *path,
 196                                           u64 objectid, u64 offset, int cow)
 197 {
 198         int ret;
 199         struct btrfs_key file_key;
 200         struct btrfs_key found_key;
 201         struct btrfs_csum_item *item;
 202         struct extent_buffer *leaf;
 203         u64 csum_offset = 0;
 204         int csums_in_item;
 205
 206         file_key.objectid = objectid;
 207         file_key.offset = offset;
 208         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
 209         ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
 210         if (ret < 0)
 211                 goto fail;
 212         leaf = path->nodes[0];
 213         if (ret > 0) {
 214                 ret = 1;
 215                 if (path->slots[0] == 0)
 216                         goto fail;
 217                 path->slots[0]--;
 218                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 219                 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
 220                     found_key.objectid != objectid) {
 221                         goto fail;
 222                 }
 223                 csum_offset = (offset - found_key.offset) >> root->sectorsize;
 224                 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
 225                 csums_in_item /= BTRFS_CRC32_SIZE;
 226
 227                 if (csum_offset >= csums_in_item) {
 228                         ret = -EFBIG;
 229                         goto fail;
 230                 }
 231         }
 232         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 233         item = (struct btrfs_csum_item *)((unsigned char *)item +
 234                                           csum_offset * BTRFS_CRC32_SIZE);
 235         return item;
 236 fail:
 237         if (ret > 0)
 238                 ret = -ENOENT;
 239         return ERR_PTR(ret);
 240 }
 241
 242
 243 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 244                              struct btrfs_root *root,
 245                              struct btrfs_path *path, u64 objectid,
 246                              u64 offset, int mod)
 247 {
 248         int ret;
 249         struct btrfs_key file_key;
 250         int ins_len = mod < 0 ? -1 : 0;
 251         int cow = mod != 0;
 252
 253         file_key.objectid = objectid;
 254         file_key.offset = offset;
 255         btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
 256         ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
 257         return ret;
 258 }
 259
 260 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
 261                           struct btrfs_root *root,
 262                           struct btrfs_inode_item *inode,
 263                           u64 objectid, u64 offset,
 264                           char *data, size_t len)
 265 {
 266         int ret;
 267         struct btrfs_key file_key;
 268         struct btrfs_key found_key;
 269         u64 next_offset = (u64)-1;
 270         int found_next = 0;
 271         struct btrfs_path *path;
 272         struct btrfs_csum_item *item;
 273         struct extent_buffer *leaf = NULL;
 274         u64 csum_offset;
 275         u32 csum_result = ~(u32)0;
 276         u32 nritems;
 277         u32 ins_size;
 278
 279         path = btrfs_alloc_path();
 280         BUG_ON(!path);
 281
 282         file_key.objectid = objectid;
 283         file_key.offset = offset;
 284         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
 285
 286         item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
 287         if (!IS_ERR(item)) {
 288                 leaf = path->nodes[0];
 289                 goto found;
 290         }
 291         ret = PTR_ERR(item);
 292         if (ret == -EFBIG) {
 293                 u32 item_size;
 294                 /* we found one, but it isn't big enough yet */
 295                 leaf = path->nodes[0];
 296                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 297                 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
 298                         /* already at max size, make a new one */
 299                         goto insert;
 300                 }
 301         } else {
 302                 int slot = path->slots[0] + 1;
 303                 /* we didn't find a csum item, insert one */
 304                 nritems = btrfs_header_nritems(path->nodes[0]);
 305                 if (path->slots[0] >= nritems - 1) {
 306                         ret = btrfs_next_leaf(root, path);
 307                         if (ret == 1)
 308                                 found_next = 1;
 309                         if (ret != 0)
 310                                 goto insert;
 311                         slot = 0;
 312                 }
 313                 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
 314                 if (found_key.objectid != objectid ||
 315                     found_key.type != BTRFS_CSUM_ITEM_KEY) {
 316                         found_next = 1;
 317                         goto insert;
 318                 }
 319                 next_offset = found_key.offset;
 320                 found_next = 1;
 321                 goto insert;
 322         }
 323
 324         /*
 325          * at this point, we know the tree has an item, but it isn't big
 326          * enough yet to put our csum in.  Grow it
 327          */
 328         btrfs_release_path(root, path);
 329         ret = btrfs_search_slot(trans, root, &file_key, path,
 330                                 BTRFS_CRC32_SIZE, 1);
 331         if (ret < 0)
 332                 goto fail;
 333         if (ret == 0) {
 334                 BUG();
 335         }
 336         if (path->slots[0] == 0) {
 337                 goto insert;
 338         }
 339         path->slots[0]--;
 340         leaf = path->nodes[0];
 341         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 342         csum_offset = (offset - found_key.offset) / root->sectorsize;
 343         if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
 344             found_key.objectid != objectid ||
 345             csum_offset >= MAX_CSUM_ITEMS(root)) {
 346                 goto insert;
 347         }
 348         if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
 349             BTRFS_CRC32_SIZE) {
 350                 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
 351                 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
 352                 if (diff != BTRFS_CRC32_SIZE)
 353                         goto insert;
 354                 ret = btrfs_extend_item(trans, root, path, diff);
 355                 BUG_ON(ret);
 356                 goto csum;
 357         }
 358
 359 insert:
 360         btrfs_release_path(root, path);
 361         csum_offset = 0;
 362         if (found_next) {
 363                 u64 tmp = min(btrfs_stack_inode_size(inode), next_offset);
 364                 tmp -= offset & ~((u64)root->sectorsize -1);
 365                 tmp /= root->sectorsize;
 366                 tmp = max((u64)1, tmp);
 367                 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
 368                 ins_size = BTRFS_CRC32_SIZE * tmp;
 369         } else {
 370                 ins_size = BTRFS_CRC32_SIZE;
 371         }
 372         ret = btrfs_insert_empty_item(trans, root, path, &file_key,
 373                                       ins_size);
 374         if (ret < 0)
 375                 goto fail;
 376         if (ret != 0) {
 377                 WARN_ON(1);
 378                 goto fail;
 379         }
 380 csum:
 381         leaf = path->nodes[0];
 382         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
 383         ret = 0;
 384         item = (struct btrfs_csum_item *)((unsigned char *)item +
 385                                           csum_offset * BTRFS_CRC32_SIZE);
 386 found:
 387         csum_result = btrfs_csum_data(root, data, csum_result, len);
 388         btrfs_csum_final(csum_result, (char *)&csum_result);
 389         if (csum_result == 0) {
 390                 printk("csum result is 0 for inode %llu offset %llu\n",
 391                        (unsigned long long)objectid,
 392                        (unsigned long long)offset);
 393         }
 394
 395         write_extent_buffer(leaf, &csum_result, (unsigned long)item,
 396                             BTRFS_CRC32_SIZE);
 397         btrfs_mark_buffer_dirty(path->nodes[0]);
 398 fail:
 399         btrfs_release_path(root, path);
 400         btrfs_free_path(path);
 401         return ret;
 402 }
 403
 404 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
 405                         struct btrfs_root *root, struct btrfs_path *path,
 406                         u64 isize)
 407 {
 408         struct btrfs_key key;
 409         struct extent_buffer *leaf = path->nodes[0];
 410         int slot = path->slots[0];
 411         int ret;
 412         u32 new_item_size;
 413         u64 new_item_span;
 414         u64 blocks;
 415
 416         btrfs_item_key_to_cpu(leaf, &key, slot);
 417         if (isize <= key.offset)
 418                 return 0;
 419         new_item_span = isize - key.offset;
 420         blocks = (new_item_span + root->sectorsize - 1) / root->sectorsize;
 421         new_item_size = blocks * BTRFS_CRC32_SIZE;
 422         if (new_item_size >= btrfs_item_size_nr(leaf, slot))
 423                 return 0;
 424         ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);
 425         BUG_ON(ret);
 426         return ret;
 427 }