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(struct ext4_blockdev *bdev, struct ext4_block *b,
  89                    uint64_t lba)
  90 {
  91         uint64_t pba;
  92         uint32_t pb_cnt;
  93         uint32_t i;
  94         bool is_new;
  95         int r;
  96
  97         ext4_assert(bdev && b);
  98
  99         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 100                 return EIO;
 101
 102         if (!(lba < bdev->lg_bcnt))
 103                 return ERANGE;
 104
 105         b->dirty = 0;
 106         b->lb_id = lba;
 107
 108         /*If cache is full we have to flush it anyway :(*/
 109         if (ext4_bcache_is_full(bdev->bc) && bdev->cache_write_back) {
 110
 111                 uint32_t free_candidate = bdev->bc->cnt;
 112                 uint32_t min_lru = 0xFFFFFFFF;
 113
 114                 for (i = 0; i < bdev->bc->cnt; ++i) {
 115                         /*Check if buffer free was delayed.*/
 116                         if (!bdev->bc->free_delay[i])
 117                                 continue;
 118
 119                         /*Check reference counter.*/
 120                         if (bdev->bc->refctr[i])
 121                                 continue;
 122
 123                         if (bdev->bc->lru_id[i] < min_lru) {
 124                                 min_lru = bdev->bc->lru_id[i];
 125                                 free_candidate = i;
 126                                 continue;
 127                         }
 128                 }
 129
 130                 if (free_candidate < bdev->bc->cnt) {
 131                         /*Buffer free was delayed and have no reference. Flush
 132                          * it.*/
 133                         r = ext4_blocks_set_direct(
 134                             bdev, bdev->bc->data +
 135                                       bdev->bc->itemsize * free_candidate,
 136                             bdev->bc->lba[free_candidate], 1);
 137                         if (r != EOK)
 138                                 return r;
 139
 140                         /*No delayed anymore*/
 141                         bdev->bc->free_delay[free_candidate] = 0;
 142
 143                         /*Reduce reference counter*/
 144                         bdev->bc->ref_blocks--;
 145                 }
 146         }
 147
 148         r = ext4_bcache_alloc(bdev->bc, b, &is_new);
 149         if (r != EOK)
 150                 return r;
 151
 152         if (!is_new) {
 153                 /*Block is in cache. Read from physical device is not required*/
 154                 return EOK;
 155         }
 156
 157         if (!b->data)
 158                 return ENOMEM;
 159
 160         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 161         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 162
 163         r = bdev->bread(bdev, b->data, pba, pb_cnt);
 164
 165         if (r != EOK) {
 166                 ext4_bcache_free(bdev->bc, b, 0);
 167                 b->lb_id = 0;
 168                 return r;
 169         }
 170
 171         bdev->bread_ctr++;
 172         return EOK;
 173 }
 174
 175 int ext4_block_set(struct ext4_blockdev *bdev, struct ext4_block *b)
 176 {
 177         uint64_t pba;
 178         uint32_t pb_cnt;
 179         int r;
 180
 181         ext4_assert(bdev && b);
 182
 183         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 184                 return EIO;
 185
 186         /*No need to write.*/
 187         if (!b->dirty && !bdev->bc->dirty[b->cache_id]) {
 188                 ext4_bcache_free(bdev->bc, b, 0);
 189                 return EOK;
 190         }
 191
 192         /*Free cache delay mode*/
 193         if (bdev->cache_write_back) {
 194
 195                 /*Free cache block and mark as free delayed*/
 196                 return ext4_bcache_free(bdev->bc, b, bdev->cache_write_back);
 197         }
 198
 199         if (bdev->bc->refctr[b->cache_id] > 1) {
 200                 bdev->bc->dirty[b->cache_id] = true;
 201                 return ext4_bcache_free(bdev->bc, b, 0);
 202         }
 203
 204         pba = (b->lb_id * bdev->lg_bsize) / bdev->ph_bsize;
 205         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 206
 207         r = bdev->bwrite(bdev, b->data, pba, pb_cnt);
 208         bdev->bc->dirty[b->cache_id] = false;
 209         if (r != EOK) {
 210                 b->dirty = false;
 211                 ext4_bcache_free(bdev->bc, b, 0);
 212                 return r;
 213         }
 214
 215         bdev->bwrite_ctr++;
 216         b->dirty = false;
 217         ext4_bcache_free(bdev->bc, b, 0);
 218         return EOK;
 219 }
 220
 221 int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf, uint64_t lba,
 222                            uint32_t cnt)
 223 {
 224         uint64_t pba;
 225         uint32_t pb_cnt;
 226
 227         ext4_assert(bdev && buf);
 228
 229         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 230         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 231
 232         bdev->bread_ctr++;
 233         return bdev->bread(bdev, buf, pba, pb_cnt * cnt);
 234 }
 235
 236 int ext4_blocks_set_direct(struct ext4_blockdev *bdev, const void *buf,
 237                            uint64_t lba, uint32_t cnt)
 238 {
 239         uint64_t pba;
 240         uint32_t pb_cnt;
 241
 242         ext4_assert(bdev && buf);
 243
 244         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 245         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 246
 247         bdev->bwrite_ctr++;
 248
 249         return bdev->bwrite(bdev, buf, pba, pb_cnt * cnt);
 250 }
 251
 252 int ext4_block_writebytes(struct ext4_blockdev *bdev, uint64_t off,
 253                           const void *buf, uint32_t len)
 254 {
 255         uint64_t block_idx;
 256         uint64_t block_end;
 257         uint32_t blen;
 258         uint32_t unalg;
 259         int r = EOK;
 260
 261         const uint8_t *p = (void *)buf;
 262
 263         ext4_assert(bdev && buf);
 264
 265         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 266                 return EIO;
 267
 268         block_idx = off / bdev->ph_bsize;
 269         block_end = block_idx + len / bdev->ph_bsize;
 270
 271         if (!(block_end < bdev->ph_bcnt))
 272                 return EINVAL; /*Ups. Out of range operation*/
 273
 274         /*OK lets deal with the first possible unaligned block*/
 275         unalg = (off & (bdev->ph_bsize - 1));
 276         if (unalg) {
 277
 278                 uint32_t wlen = (bdev->ph_bsize - unalg) > len
 279                                     ? len
 280                                     : (bdev->ph_bsize - unalg);
 281
 282                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 283
 284                 if (r != EOK)
 285                         return r;
 286
 287                 memcpy(bdev->ph_bbuf + unalg, p, wlen);
 288
 289                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 290                 if (r != EOK)
 291                         return r;
 292
 293                 p += wlen;
 294                 len -= wlen;
 295                 block_idx++;
 296         }
 297
 298         /*Aligned data*/
 299         blen = len / bdev->ph_bsize;
 300         r = bdev->bwrite(bdev, p, block_idx, blen);
 301
 302         if (r != EOK)
 303                 return r;
 304
 305         p += bdev->ph_bsize * blen;
 306         len -= bdev->ph_bsize * blen;
 307
 308         block_idx += blen;
 309
 310         /*Rest of the data*/
 311         if (len) {
 312                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 313                 if (r != EOK)
 314                         return r;
 315
 316                 memcpy(bdev->ph_bbuf, p, len);
 317
 318                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 319
 320                 if (r != EOK)
 321                         return r;
 322         }
 323
 324         return r;
 325 }
 326
 327 int ext4_block_readbytes(struct ext4_blockdev *bdev, uint64_t off, void *buf,
 328                          uint32_t len)
 329 {
 330         uint64_t block_idx;
 331         uint64_t block_end;
 332         uint32_t blen;
 333         uint32_t unalg;
 334         int r = EOK;
 335
 336         uint8_t *p = (void *)buf;
 337
 338         ext4_assert(bdev && buf);
 339
 340         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 341                 return EIO;
 342
 343         block_idx = off / bdev->ph_bsize;
 344         block_end = block_idx + len / bdev->ph_bsize;
 345
 346         if (!(block_end < bdev->ph_bcnt))
 347                 return EINVAL; /*Ups. Out of range operation*/
 348
 349         /*OK lets deal with the first possible unaligned block*/
 350         unalg = (off & (bdev->ph_bsize - 1));
 351         if (unalg) {
 352
 353                 uint32_t rlen = (bdev->ph_bsize - unalg) > len
 354                                     ? len
 355                                     : (bdev->ph_bsize - unalg);
 356
 357                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 358                 if (r != EOK)
 359                         return r;
 360
 361                 memcpy(p, bdev->ph_bbuf + unalg, rlen);
 362
 363                 p += rlen;
 364                 len -= rlen;
 365                 block_idx++;
 366         }
 367
 368         /*Aligned data*/
 369         blen = len / bdev->ph_bsize;
 370
 371         r = bdev->bread(bdev, p, block_idx, blen);
 372
 373         if (r != EOK)
 374                 return r;
 375
 376         p += bdev->ph_bsize * blen;
 377         len -= bdev->ph_bsize * blen;
 378
 379         block_idx += blen;
 380
 381         /*Rest of the data*/
 382         if (len) {
 383                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 384                 if (r != EOK)
 385                         return r;
 386
 387                 memcpy(p, bdev->ph_bbuf, len);
 388         }
 389
 390         return r;
 391 }
 392
 393 int ext4_block_cache_write_back(struct ext4_blockdev *bdev, uint8_t on_off)
 394 {
 395         int r;
 396         uint32_t i;
 397
 398         if (on_off)
 399                 bdev->cache_write_back++;
 400
 401         if (!on_off && bdev->cache_write_back)
 402                 bdev->cache_write_back--;
 403
 404         /*Flush all delayed cache blocks*/
 405         if (!bdev->cache_write_back) {
 406                 for (i = 0; i < bdev->bc->cnt; ++i) {
 407
 408                         /*Check if buffer free was delayed.*/
 409                         if (!bdev->bc->free_delay[i])
 410                                 continue;
 411
 412                         /*Check reference counter.*/
 413                         if (bdev->bc->refctr[i])
 414                                 continue;
 415
 416                         /*Buffer free was delayed and have no reference. Flush
 417                          * it.*/
 418                         r = ext4_blocks_set_direct(
 419                             bdev, bdev->bc->data + bdev->bc->itemsize * i,
 420                             bdev->bc->lba[i], 1);
 421                         if (r != EOK)
 422                                 return r;
 423
 424                         /*No delayed anymore*/
 425                         bdev->bc->free_delay[i] = 0;
 426
 427                         /*Reduce reference counter*/
 428                         bdev->bc->ref_blocks--;
 429                 }
 430         }
 431         return EOK;
 432 }
 433
 434 /**
 435  * @}
 436  */