lwext4/ext4_blockdev.c

   1 /*
   2  * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup lwext4
  30  * @{
  31  */
  32 /**
  33  * @file  ext4_blockdev.c
  34  * @brief Block device module.
  35  */
  36
  37 #include "ext4_config.h"
  38 #include "ext4_blockdev.h"
  39 #include "ext4_errno.h"
  40 #include "ext4_debug.h"
  41
  42 #include <string.h>
  43 #include <stdlib.h>
  44
  45 int ext4_block_init(struct ext4_blockdev *bdev)
  46 {
  47         int rc;
  48         ext4_assert(bdev);
  49
  50         ext4_assert(bdev->open && bdev->close && bdev->bread && bdev->bwrite);
  51
  52         /*Low level block init*/
  53         rc = bdev->open(bdev);
  54         if (rc != EOK)
  55                 return rc;
  56
  57         bdev->flags |= EXT4_BDEV_INITIALIZED;
  58
  59         return EOK;
  60 }
  61
  62 int ext4_block_bind_bcache(struct ext4_blockdev *bdev, struct ext4_bcache *bc)
  63 {
  64         ext4_assert(bdev && bc);
  65         bdev->bc = bc;
  66         return EOK;
  67 }
  68
  69 void ext4_block_set_lb_size(struct ext4_blockdev *bdev, uint64_t lb_bsize)
  70 {
  71         /*Logical block size has to be multiply of physical */
  72         ext4_assert(!(lb_bsize % bdev->ph_bsize));
  73
  74         bdev->lg_bsize = lb_bsize;
  75         bdev->lg_bcnt = (bdev->ph_bcnt * bdev->ph_bsize) / lb_bsize;
  76 }
  77
  78 int ext4_block_fini(struct ext4_blockdev *bdev)
  79 {
  80         ext4_assert(bdev);
  81
  82         bdev->flags &= ~(EXT4_BDEV_INITIALIZED);
  83
  84         /*Low level block fini*/
  85         return bdev->close(bdev);
  86 }
  87
  88 int ext4_block_get_noread(struct ext4_blockdev *bdev, struct ext4_block *b,
  89                           uint64_t lba)
  90 {
  91         uint32_t i;
  92         bool is_new;
  93         int r;
  94
  95         ext4_assert(bdev && b);
  96
  97         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
  98                 return EIO;
  99
 100         if (!(lba < bdev->lg_bcnt))
 101                 return ERANGE;
 102
 103         b->dirty = 0;
 104         b->lb_id = lba;
 105
 106         /*If cache is full we have to flush it anyway :(*/
 107         if (ext4_bcache_is_full(bdev->bc) && bdev->cache_write_back) {
 108
 109                 uint32_t free_candidate = bdev->bc->cnt;
 110                 uint32_t min_lru = 0xFFFFFFFF;
 111
 112                 for (i = 0; i < bdev->bc->cnt; ++i) {
 113                         /*Check if buffer free was delayed.*/
 114                         if (!bdev->bc->free_delay[i])
 115                                 continue;
 116
 117                         /*Check reference counter.*/
 118                         if (bdev->bc->refctr[i])
 119                                 continue;
 120
 121                         if (bdev->bc->lru_id[i] < min_lru) {
 122                                 min_lru = bdev->bc->lru_id[i];
 123                                 free_candidate = i;
 124                                 continue;
 125                         }
 126                 }
 127
 128                 if (free_candidate < bdev->bc->cnt) {
 129                         /*Buffer free was delayed and have no reference. Flush
 130                          * it.*/
 131                         r = ext4_blocks_set_direct(
 132                             bdev, bdev->bc->data +
 133                                       bdev->bc->itemsize * free_candidate,
 134                             bdev->bc->lba[free_candidate], 1);
 135                         if (r != EOK)
 136                                 return r;
 137
 138                         /*No delayed anymore*/
 139                         bdev->bc->free_delay[free_candidate] = 0;
 140
 141                         /*Reduce reference counter*/
 142                         bdev->bc->ref_blocks--;
 143                 }
 144         }
 145
 146         r = ext4_bcache_alloc(bdev->bc, b, &is_new);
 147         if (r != EOK)
 148                 return r;
 149
 150         if (!b->data)
 151                 return ENOMEM;
 152
 153         return EOK;
 154 }
 155
 156 int ext4_block_get(struct ext4_blockdev *bdev, struct ext4_block *b,
 157                    uint64_t lba)
 158 {
 159         uint64_t pba;
 160         uint32_t pb_cnt;
 161         int r = ext4_block_get_noread(bdev, b, lba);
 162         if (r != EOK)
 163                 return r;
 164
 165         if (b->uptodate) {
 166                 /*Block is in cache. Read from physical device is not required*/
 167                 return EOK;
 168         }
 169
 170         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 171         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 172
 173         r = bdev->bread(bdev, b->data, pba, pb_cnt);
 174
 175         if (r != EOK) {
 176                 ext4_bcache_free(bdev->bc, b, 0);
 177                 b->lb_id = 0;
 178                 return r;
 179         }
 180
 181         ext4_bcache_set_flag(bdev->bc, b->cache_id, BC_UPTODATE);
 182         b->uptodate = true;
 183         bdev->bread_ctr++;
 184         return EOK;
 185 }
 186
 187 int ext4_block_set(struct ext4_blockdev *bdev, struct ext4_block *b)
 188 {
 189         uint64_t pba;
 190         uint32_t pb_cnt;
 191         int r;
 192
 193         ext4_assert(bdev && b);
 194
 195         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 196                 return EIO;
 197
 198         /*Buffer is not marked dirty and is stale*/
 199         if (!b->uptodate && !b->dirty)
 200                 ext4_bcache_clear_flag(bdev->bc, b->cache_id, BC_UPTODATE);
 201
 202         /*No need to write.*/
 203         if (!b->dirty &&
 204             !ext4_bcache_test_flag(bdev->bc, b->cache_id, BC_DIRTY)) {
 205                 ext4_bcache_free(bdev->bc, b, 0);
 206                 return EOK;
 207         }
 208         ext4_bcache_set_flag(bdev->bc, b->cache_id, BC_UPTODATE);
 209
 210         /*Free cache delay mode*/
 211         if (bdev->cache_write_back) {
 212
 213                 /*Free cache block and mark as free delayed*/
 214                 return ext4_bcache_free(bdev->bc, b, bdev->cache_write_back);
 215         }
 216
 217         if (bdev->bc->refctr[b->cache_id] > 1) {
 218                 ext4_bcache_set_flag(bdev->bc, b->cache_id, BC_DIRTY);
 219                 return ext4_bcache_free(bdev->bc, b, 0);
 220         }
 221
 222         pba = (b->lb_id * bdev->lg_bsize) / bdev->ph_bsize;
 223         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 224
 225         r = bdev->bwrite(bdev, b->data, pba, pb_cnt);
 226         ext4_bcache_clear_flag(bdev->bc, b->cache_id, BC_DIRTY);
 227         if (r != EOK) {
 228                 b->dirty = false;
 229                 ext4_bcache_clear_flag(bdev->bc, b->cache_id, BC_UPTODATE);
 230                 ext4_bcache_free(bdev->bc, b, 0);
 231                 return r;
 232         }
 233
 234         bdev->bwrite_ctr++;
 235         b->dirty = false;
 236         ext4_bcache_free(bdev->bc, b, 0);
 237         return EOK;
 238 }
 239
 240 int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf, uint64_t lba,
 241                            uint32_t cnt)
 242 {
 243         uint64_t pba;
 244         uint32_t pb_cnt;
 245
 246         ext4_assert(bdev && buf);
 247
 248         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 249         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 250
 251         bdev->bread_ctr++;
 252         return bdev->bread(bdev, buf, pba, pb_cnt * cnt);
 253 }
 254
 255 int ext4_blocks_set_direct(struct ext4_blockdev *bdev, const void *buf,
 256                            uint64_t lba, uint32_t cnt)
 257 {
 258         uint64_t pba;
 259         uint32_t pb_cnt;
 260
 261         ext4_assert(bdev && buf);
 262
 263         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 264         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 265
 266         bdev->bwrite_ctr++;
 267
 268         return bdev->bwrite(bdev, buf, pba, pb_cnt * cnt);
 269 }
 270
 271 int ext4_block_writebytes(struct ext4_blockdev *bdev, uint64_t off,
 272                           const void *buf, uint32_t len)
 273 {
 274         uint64_t block_idx;
 275         uint64_t block_end;
 276         uint32_t blen;
 277         uint32_t unalg;
 278         int r = EOK;
 279
 280         const uint8_t *p = (void *)buf;
 281
 282         ext4_assert(bdev && buf);
 283
 284         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 285                 return EIO;
 286
 287         block_idx = off / bdev->ph_bsize;
 288         block_end = block_idx + len / bdev->ph_bsize;
 289
 290         if (!(block_end < bdev->ph_bcnt))
 291                 return EINVAL; /*Ups. Out of range operation*/
 292
 293         /*OK lets deal with the first possible unaligned block*/
 294         unalg = (off & (bdev->ph_bsize - 1));
 295         if (unalg) {
 296
 297                 uint32_t wlen = (bdev->ph_bsize - unalg) > len
 298                                     ? len
 299                                     : (bdev->ph_bsize - unalg);
 300
 301                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 302
 303                 if (r != EOK)
 304                         return r;
 305
 306                 memcpy(bdev->ph_bbuf + unalg, p, wlen);
 307
 308                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 309                 if (r != EOK)
 310                         return r;
 311
 312                 p += wlen;
 313                 len -= wlen;
 314                 block_idx++;
 315         }
 316
 317         /*Aligned data*/
 318         blen = len / bdev->ph_bsize;
 319         r = bdev->bwrite(bdev, p, block_idx, blen);
 320
 321         if (r != EOK)
 322                 return r;
 323
 324         p += bdev->ph_bsize * blen;
 325         len -= bdev->ph_bsize * blen;
 326
 327         block_idx += blen;
 328
 329         /*Rest of the data*/
 330         if (len) {
 331                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 332                 if (r != EOK)
 333                         return r;
 334
 335                 memcpy(bdev->ph_bbuf, p, len);
 336
 337                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 338
 339                 if (r != EOK)
 340                         return r;
 341         }
 342
 343         return r;
 344 }
 345
 346 int ext4_block_readbytes(struct ext4_blockdev *bdev, uint64_t off, void *buf,
 347                          uint32_t len)
 348 {
 349         uint64_t block_idx;
 350         uint64_t block_end;
 351         uint32_t blen;
 352         uint32_t unalg;
 353         int r = EOK;
 354
 355         uint8_t *p = (void *)buf;
 356
 357         ext4_assert(bdev && buf);
 358
 359         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 360                 return EIO;
 361
 362         block_idx = off / bdev->ph_bsize;
 363         block_end = block_idx + len / bdev->ph_bsize;
 364
 365         if (!(block_end < bdev->ph_bcnt))
 366                 return EINVAL; /*Ups. Out of range operation*/
 367
 368         /*OK lets deal with the first possible unaligned block*/
 369         unalg = (off & (bdev->ph_bsize - 1));
 370         if (unalg) {
 371
 372                 uint32_t rlen = (bdev->ph_bsize - unalg) > len
 373                                     ? len
 374                                     : (bdev->ph_bsize - unalg);
 375
 376                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 377                 if (r != EOK)
 378                         return r;
 379
 380                 memcpy(p, bdev->ph_bbuf + unalg, rlen);
 381
 382                 p += rlen;
 383                 len -= rlen;
 384                 block_idx++;
 385         }
 386
 387         /*Aligned data*/
 388         blen = len / bdev->ph_bsize;
 389
 390         r = bdev->bread(bdev, p, block_idx, blen);
 391
 392         if (r != EOK)
 393                 return r;
 394
 395         p += bdev->ph_bsize * blen;
 396         len -= bdev->ph_bsize * blen;
 397
 398         block_idx += blen;
 399
 400         /*Rest of the data*/
 401         if (len) {
 402                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 403                 if (r != EOK)
 404                         return r;
 405
 406                 memcpy(p, bdev->ph_bbuf, len);
 407         }
 408
 409         return r;
 410 }
 411
 412 int ext4_block_cache_write_back(struct ext4_blockdev *bdev, uint8_t on_off)
 413 {
 414         int r;
 415         uint32_t i;
 416
 417         if (on_off)
 418                 bdev->cache_write_back++;
 419
 420         if (!on_off && bdev->cache_write_back)
 421                 bdev->cache_write_back--;
 422
 423         /*Flush all delayed cache blocks*/
 424         if (!bdev->cache_write_back) {
 425                 for (i = 0; i < bdev->bc->cnt; ++i) {
 426
 427                         /*Check if buffer free was delayed.*/
 428                         if (!bdev->bc->free_delay[i])
 429                                 continue;
 430
 431                         /*Check reference counter.*/
 432                         if (bdev->bc->refctr[i])
 433                                 continue;
 434
 435                         /*Buffer free was delayed and have no reference. Flush
 436                          * it.*/
 437                         r = ext4_blocks_set_direct(
 438                             bdev, bdev->bc->data + bdev->bc->itemsize * i,
 439                             bdev->bc->lba[i], 1);
 440                         if (r != EOK)
 441                                 return r;
 442
 443                         /*No delayed anymore*/
 444                         bdev->bc->free_delay[i] = 0;
 445
 446                         /*Reduce reference counter*/
 447                         bdev->bc->ref_blocks--;
 448                 }
 449         }
 450         return EOK;
 451 }
 452
 453 /**
 454  * @}
 455  */