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 static int
  89 ext4_block_flush_buf(struct ext4_blockdev *bdev, struct ext4_buf *buf)
  90 {
  91         int r;
  92         struct ext4_bcache *bc = bdev->bc;
  93         /*Only flushing unreferenced buffer is allowed.*/
  94         ext4_assert(!buf->refctr);
  95         if (ext4_bcache_test_flag(buf, BC_DIRTY)) {
  96                 r = ext4_blocks_set_direct(bdev, buf->data, buf->lba, 1);
  97                 if (r)
  98                         return r;
  99
 100                 SLIST_REMOVE(&bc->dirty_list,
 101                                 buf,
 102                                 ext4_buf,
 103                                 dirty_node);
 104                 ext4_bcache_clear_flag(buf, BC_DIRTY);
 105         }
 106         return EOK;
 107 }
 108
 109 int ext4_block_cache_shake(struct ext4_blockdev *bdev)
 110 {
 111         struct ext4_buf *buf;
 112         while (!RB_EMPTY(&bdev->bc->lru_root) &&
 113                 ext4_bcache_is_full(bdev->bc)) {
 114
 115                 buf = ext4_buf_lowest_lru(bdev->bc);
 116                 ext4_assert(buf);
 117                 if (ext4_bcache_test_flag(buf, BC_DIRTY)) {
 118                         int r = ext4_block_flush_buf(bdev, buf);
 119                         if (r != EOK)
 120                                 return r;
 121
 122                 }
 123
 124                 ext4_bcache_drop_buf(bdev->bc, buf);
 125         }
 126         return EOK;
 127 }
 128
 129 int ext4_block_get_noread(struct ext4_blockdev *bdev, struct ext4_block *b,
 130                           uint64_t lba)
 131 {
 132         bool is_new;
 133         int r;
 134
 135         ext4_assert(bdev && b);
 136
 137         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 138                 return EIO;
 139
 140         if (!(lba < bdev->lg_bcnt))
 141                 return ERANGE;
 142
 143         b->dirty = 0;
 144         b->lb_id = lba;
 145
 146         /*If cache is full we have to (flush and) drop it anyway :(*/
 147         r = ext4_block_cache_shake(bdev);
 148         if (r != EOK)
 149                 return r;
 150
 151         r = ext4_bcache_alloc(bdev->bc, b, &is_new);
 152         if (r != EOK)
 153                 return r;
 154
 155         if (!b->data)
 156                 return ENOMEM;
 157
 158         return EOK;
 159 }
 160
 161 int ext4_block_get(struct ext4_blockdev *bdev, struct ext4_block *b,
 162                    uint64_t lba)
 163 {
 164         uint64_t pba;
 165         uint32_t pb_cnt;
 166         int r = ext4_block_get_noread(bdev, b, lba);
 167         if (r != EOK)
 168                 return r;
 169
 170         if (b->uptodate) {
 171                 /* Data in the cache is up-to-date.
 172                  * Reading from physical device is not required */
 173                 return EOK;
 174         }
 175
 176         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 177         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 178
 179         r = bdev->bread(bdev, b->data, pba, pb_cnt);
 180
 181         if (r != EOK) {
 182                 ext4_bcache_free(bdev->bc, b, 0);
 183                 b->lb_id = 0;
 184                 return r;
 185         }
 186
 187         /* Mark buffer up-to-date, since
 188          * fresh data is read from physical device just now. */
 189         ext4_bcache_set_flag(b->buf, BC_UPTODATE);
 190         b->uptodate = true;
 191         bdev->bread_ctr++;
 192         return EOK;
 193 }
 194
 195 int ext4_block_set(struct ext4_blockdev *bdev, struct ext4_block *b)
 196 {
 197         uint64_t pba;
 198         uint32_t pb_cnt;
 199         int r;
 200
 201         ext4_assert(bdev && b);
 202         ext4_assert(b->buf);
 203
 204         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 205                 return EIO;
 206
 207         /*Free cache delay mode*/
 208         if (bdev->cache_write_back) {
 209
 210                 /*Free cache block and mark as free delayed*/
 211                 return ext4_bcache_free(bdev->bc, b, bdev->cache_write_back);
 212         }
 213
 214         if (b->buf->refctr > 1)
 215                 return ext4_bcache_free(bdev->bc, b, 0);
 216
 217         /*We handle the dirty flag ourselves.*/
 218         if (ext4_bcache_test_flag(b->buf, BC_DIRTY) || b->dirty) {
 219                 b->uptodate = true;
 220                 ext4_bcache_set_flag(b->buf, BC_UPTODATE);
 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(b->buf, BC_DIRTY);
 227                 if (r != EOK) {
 228                         b->dirty = true;
 229                         ext4_bcache_free(bdev->bc, b, 0);
 230                         return r;
 231                 }
 232
 233                 b->dirty = false;
 234                 bdev->bwrite_ctr++;
 235         }
 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                 if (r != EOK)
 303                         return r;
 304
 305                 memcpy(bdev->ph_bbuf + unalg, p, wlen);
 306
 307                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 308                 if (r != EOK)
 309                         return r;
 310
 311                 p += wlen;
 312                 len -= wlen;
 313                 block_idx++;
 314         }
 315
 316         /*Aligned data*/
 317         blen = len / bdev->ph_bsize;
 318         r = bdev->bwrite(bdev, p, block_idx, blen);
 319         if (r != EOK)
 320                 return r;
 321
 322         p += bdev->ph_bsize * blen;
 323         len -= bdev->ph_bsize * blen;
 324
 325         block_idx += blen;
 326
 327         /*Rest of the data*/
 328         if (len) {
 329                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 330                 if (r != EOK)
 331                         return r;
 332
 333                 memcpy(bdev->ph_bbuf, p, len);
 334
 335                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 336                 if (r != EOK)
 337                         return r;
 338         }
 339
 340         return r;
 341 }
 342
 343 int ext4_block_readbytes(struct ext4_blockdev *bdev, uint64_t off, void *buf,
 344                          uint32_t len)
 345 {
 346         uint64_t block_idx;
 347         uint64_t block_end;
 348         uint32_t blen;
 349         uint32_t unalg;
 350         int r = EOK;
 351
 352         uint8_t *p = (void *)buf;
 353
 354         ext4_assert(bdev && buf);
 355
 356         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 357                 return EIO;
 358
 359         block_idx = off / bdev->ph_bsize;
 360         block_end = block_idx + len / bdev->ph_bsize;
 361
 362         if (!(block_end < bdev->ph_bcnt))
 363                 return EINVAL; /*Ups. Out of range operation*/
 364
 365         /*OK lets deal with the first possible unaligned block*/
 366         unalg = (off & (bdev->ph_bsize - 1));
 367         if (unalg) {
 368
 369                 uint32_t rlen = (bdev->ph_bsize - unalg) > len
 370                                     ? len
 371                                     : (bdev->ph_bsize - unalg);
 372
 373                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 374                 if (r != EOK)
 375                         return r;
 376
 377                 memcpy(p, bdev->ph_bbuf + unalg, rlen);
 378
 379                 p += rlen;
 380                 len -= rlen;
 381                 block_idx++;
 382         }
 383
 384         /*Aligned data*/
 385         blen = len / bdev->ph_bsize;
 386
 387         r = bdev->bread(bdev, p, block_idx, blen);
 388         if (r != EOK)
 389                 return r;
 390
 391         p += bdev->ph_bsize * blen;
 392         len -= bdev->ph_bsize * blen;
 393
 394         block_idx += blen;
 395
 396         /*Rest of the data*/
 397         if (len) {
 398                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 399                 if (r != EOK)
 400                         return r;
 401
 402                 memcpy(p, bdev->ph_bbuf, len);
 403         }
 404
 405         return r;
 406 }
 407
 408 int ext4_block_cache_write_back(struct ext4_blockdev *bdev, uint8_t on_off)
 409 {
 410         int r;
 411         struct ext4_buf *buf;
 412
 413         if (on_off)
 414                 bdev->cache_write_back++;
 415
 416         if (!on_off && bdev->cache_write_back)
 417                 bdev->cache_write_back--;
 418
 419         if (bdev->cache_write_back)
 420                 return EOK;
 421
 422         /*Flush all delayed cache blocks*/
 423         while (!SLIST_EMPTY(&bdev->bc->dirty_list)) {
 424
 425                 buf = SLIST_FIRST(&bdev->bc->dirty_list);
 426                 ext4_assert(buf);
 427                 r = ext4_block_flush_buf(bdev, buf);
 428                 if (r != EOK)
 429                         return r;
 430
 431         }
 432         return EOK;
 433 }
 434
 435 /**
 436  * @}
 437  */