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                 /* Data in the cache is up-to-date.
 167                  * Reading from physical device is not required */
 168                 return EOK;
 169         }
 170
 171         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 172         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 173
 174         r = bdev->bread(bdev, b->data, pba, pb_cnt);
 175
 176         if (r != EOK) {
 177                 ext4_bcache_free(bdev->bc, b, 0);
 178                 b->lb_id = 0;
 179                 return r;
 180         }
 181
 182         /* Mark buffer up-to-date, since
 183          * fresh data is read from physical device just now. */
 184         ext4_bcache_set_flag(bdev->bc, b->cache_id, BC_UPTODATE);
 185         b->uptodate = true;
 186         bdev->bread_ctr++;
 187         return EOK;
 188 }
 189
 190 int ext4_block_set(struct ext4_blockdev *bdev, struct ext4_block *b)
 191 {
 192         uint64_t pba;
 193         uint32_t pb_cnt;
 194         int r;
 195
 196         ext4_assert(bdev && b);
 197
 198         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 199                 return EIO;
 200
 201         /*Buffer is not marked dirty and is stale*/
 202         if (!b->uptodate && !b->dirty)
 203                 ext4_bcache_clear_flag(bdev->bc, b->cache_id, BC_UPTODATE);
 204
 205         /*No need to write.*/
 206         if (!b->dirty &&
 207             !ext4_bcache_test_flag(bdev->bc, b->cache_id, BC_DIRTY)) {
 208                 ext4_bcache_free(bdev->bc, b, 0);
 209                 return EOK;
 210         }
 211         /* Data is valid, so mark buffer up-to-date. */
 212         ext4_bcache_set_flag(bdev->bc, b->cache_id, BC_UPTODATE);
 213
 214         /*Free cache delay mode*/
 215         if (bdev->cache_write_back) {
 216
 217                 /*Free cache block and mark as free delayed*/
 218                 return ext4_bcache_free(bdev->bc, b, bdev->cache_write_back);
 219         }
 220
 221         if (bdev->bc->refctr[b->cache_id] > 1) {
 222                 ext4_bcache_set_flag(bdev->bc, b->cache_id, BC_DIRTY);
 223                 return ext4_bcache_free(bdev->bc, b, 0);
 224         }
 225
 226         pba = (b->lb_id * bdev->lg_bsize) / bdev->ph_bsize;
 227         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 228
 229         r = bdev->bwrite(bdev, b->data, pba, pb_cnt);
 230         ext4_bcache_clear_flag(bdev->bc, b->cache_id, BC_DIRTY);
 231         if (r != EOK) {
 232                 b->dirty = false;
 233                 ext4_bcache_clear_flag(bdev->bc, b->cache_id, BC_UPTODATE);
 234                 ext4_bcache_free(bdev->bc, b, 0);
 235                 return r;
 236         }
 237
 238         bdev->bwrite_ctr++;
 239         b->dirty = false;
 240         ext4_bcache_free(bdev->bc, b, 0);
 241         return EOK;
 242 }
 243
 244 int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf, uint64_t lba,
 245                            uint32_t cnt)
 246 {
 247         uint64_t pba;
 248         uint32_t pb_cnt;
 249
 250         ext4_assert(bdev && buf);
 251
 252         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 253         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 254
 255         bdev->bread_ctr++;
 256         return bdev->bread(bdev, buf, pba, pb_cnt * cnt);
 257 }
 258
 259 int ext4_blocks_set_direct(struct ext4_blockdev *bdev, const void *buf,
 260                            uint64_t lba, uint32_t cnt)
 261 {
 262         uint64_t pba;
 263         uint32_t pb_cnt;
 264
 265         ext4_assert(bdev && buf);
 266
 267         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 268         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 269
 270         bdev->bwrite_ctr++;
 271
 272         return bdev->bwrite(bdev, buf, pba, pb_cnt * cnt);
 273 }
 274
 275 int ext4_block_writebytes(struct ext4_blockdev *bdev, uint64_t off,
 276                           const void *buf, uint32_t len)
 277 {
 278         uint64_t block_idx;
 279         uint64_t block_end;
 280         uint32_t blen;
 281         uint32_t unalg;
 282         int r = EOK;
 283
 284         const uint8_t *p = (void *)buf;
 285
 286         ext4_assert(bdev && buf);
 287
 288         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 289                 return EIO;
 290
 291         block_idx = off / bdev->ph_bsize;
 292         block_end = block_idx + len / bdev->ph_bsize;
 293
 294         if (!(block_end < bdev->ph_bcnt))
 295                 return EINVAL; /*Ups. Out of range operation*/
 296
 297         /*OK lets deal with the first possible unaligned block*/
 298         unalg = (off & (bdev->ph_bsize - 1));
 299         if (unalg) {
 300
 301                 uint32_t wlen = (bdev->ph_bsize - unalg) > len
 302                                     ? len
 303                                     : (bdev->ph_bsize - unalg);
 304
 305                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 306
 307                 if (r != EOK)
 308                         return r;
 309
 310                 memcpy(bdev->ph_bbuf + unalg, p, wlen);
 311
 312                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 313                 if (r != EOK)
 314                         return r;
 315
 316                 p += wlen;
 317                 len -= wlen;
 318                 block_idx++;
 319         }
 320
 321         /*Aligned data*/
 322         blen = len / bdev->ph_bsize;
 323         r = bdev->bwrite(bdev, p, block_idx, blen);
 324
 325         if (r != EOK)
 326                 return r;
 327
 328         p += bdev->ph_bsize * blen;
 329         len -= bdev->ph_bsize * blen;
 330
 331         block_idx += blen;
 332
 333         /*Rest of the data*/
 334         if (len) {
 335                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 336                 if (r != EOK)
 337                         return r;
 338
 339                 memcpy(bdev->ph_bbuf, p, len);
 340
 341                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 342
 343                 if (r != EOK)
 344                         return r;
 345         }
 346
 347         return r;
 348 }
 349
 350 int ext4_block_readbytes(struct ext4_blockdev *bdev, uint64_t off, void *buf,
 351                          uint32_t len)
 352 {
 353         uint64_t block_idx;
 354         uint64_t block_end;
 355         uint32_t blen;
 356         uint32_t unalg;
 357         int r = EOK;
 358
 359         uint8_t *p = (void *)buf;
 360
 361         ext4_assert(bdev && buf);
 362
 363         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 364                 return EIO;
 365
 366         block_idx = off / bdev->ph_bsize;
 367         block_end = block_idx + len / bdev->ph_bsize;
 368
 369         if (!(block_end < bdev->ph_bcnt))
 370                 return EINVAL; /*Ups. Out of range operation*/
 371
 372         /*OK lets deal with the first possible unaligned block*/
 373         unalg = (off & (bdev->ph_bsize - 1));
 374         if (unalg) {
 375
 376                 uint32_t rlen = (bdev->ph_bsize - unalg) > len
 377                                     ? len
 378                                     : (bdev->ph_bsize - unalg);
 379
 380                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 381                 if (r != EOK)
 382                         return r;
 383
 384                 memcpy(p, bdev->ph_bbuf + unalg, rlen);
 385
 386                 p += rlen;
 387                 len -= rlen;
 388                 block_idx++;
 389         }
 390
 391         /*Aligned data*/
 392         blen = len / bdev->ph_bsize;
 393
 394         r = bdev->bread(bdev, p, block_idx, blen);
 395
 396         if (r != EOK)
 397                 return r;
 398
 399         p += bdev->ph_bsize * blen;
 400         len -= bdev->ph_bsize * blen;
 401
 402         block_idx += blen;
 403
 404         /*Rest of the data*/
 405         if (len) {
 406                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 407                 if (r != EOK)
 408                         return r;
 409
 410                 memcpy(p, bdev->ph_bbuf, len);
 411         }
 412
 413         return r;
 414 }
 415
 416 int ext4_block_cache_write_back(struct ext4_blockdev *bdev, uint8_t on_off)
 417 {
 418         int r;
 419         uint32_t i;
 420
 421         if (on_off)
 422                 bdev->cache_write_back++;
 423
 424         if (!on_off && bdev->cache_write_back)
 425                 bdev->cache_write_back--;
 426
 427         /*Flush all delayed cache blocks*/
 428         if (!bdev->cache_write_back) {
 429                 for (i = 0; i < bdev->bc->cnt; ++i) {
 430
 431                         /*Check if buffer free was delayed.*/
 432                         if (!bdev->bc->free_delay[i])
 433                                 continue;
 434
 435                         /*Check reference counter.*/
 436                         if (bdev->bc->refctr[i])
 437                                 continue;
 438
 439                         /*Buffer free was delayed and have no reference. Flush
 440                          * it.*/
 441                         r = ext4_blocks_set_direct(
 442                             bdev, bdev->bc->data + bdev->bc->itemsize * i,
 443                             bdev->bc->lba[i], 1);
 444                         if (r != EOK)
 445                                 return r;
 446
 447                         /*No delayed anymore*/
 448                         bdev->bc->free_delay[i] = 0;
 449
 450                         /*Reduce reference counter*/
 451                         bdev->bc->ref_blocks--;
 452                 }
 453         }
 454         return EOK;
 455 }
 456
 457 /**
 458  * @}
 459  */