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         bc->bdev = bdev;
  67         return EOK;
  68 }
  69
  70 void ext4_block_set_lb_size(struct ext4_blockdev *bdev, uint64_t lb_bsize)
  71 {
  72         /*Logical block size has to be multiply of physical */
  73         ext4_assert(!(lb_bsize % bdev->ph_bsize));
  74
  75         bdev->lg_bsize = lb_bsize;
  76         bdev->lg_bcnt = (bdev->ph_bcnt * bdev->ph_bsize) / lb_bsize;
  77 }
  78
  79 int ext4_block_fini(struct ext4_blockdev *bdev)
  80 {
  81         ext4_assert(bdev);
  82
  83         bdev->flags &= ~(EXT4_BDEV_INITIALIZED);
  84
  85         /*Low level block fini*/
  86         return bdev->close(bdev);
  87 }
  88
  89 int 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
  96         if (ext4_bcache_test_flag(buf, BC_DIRTY)) {
  97                 r = ext4_blocks_set_direct(bdev, buf->data, buf->lba, 1);
  98                 if (r)
  99                         return r;
 100
 101                 ext4_bcache_remove_dirty_node(bc, buf);
 102                 ext4_bcache_clear_flag(buf, BC_DIRTY);
 103         }
 104         return EOK;
 105 }
 106
 107 int ext4_block_cache_shake(struct ext4_blockdev *bdev)
 108 {
 109         struct ext4_buf *buf;
 110         while (!RB_EMPTY(&bdev->bc->lru_root) &&
 111                 ext4_bcache_is_full(bdev->bc)) {
 112
 113                 buf = ext4_buf_lowest_lru(bdev->bc);
 114                 ext4_assert(buf);
 115                 if (ext4_bcache_test_flag(buf, BC_DIRTY)) {
 116                         int r = ext4_block_flush_buf(bdev, buf);
 117                         if (r != EOK)
 118                                 return r;
 119
 120                 }
 121
 122                 ext4_bcache_drop_buf(bdev->bc, buf);
 123         }
 124         return EOK;
 125 }
 126
 127 int ext4_block_get_noread(struct ext4_blockdev *bdev, struct ext4_block *b,
 128                           uint64_t lba)
 129 {
 130         bool is_new;
 131         int r;
 132
 133         ext4_assert(bdev && b);
 134
 135         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 136                 return EIO;
 137
 138         if (!(lba < bdev->lg_bcnt))
 139                 return ERANGE;
 140
 141         b->dirty = 0;
 142         b->lb_id = lba;
 143
 144         /*If cache is full we have to (flush and) drop it anyway :(*/
 145         r = ext4_block_cache_shake(bdev);
 146         if (r != EOK)
 147                 return r;
 148
 149         r = ext4_bcache_alloc(bdev->bc, b, &is_new);
 150         if (r != EOK)
 151                 return r;
 152
 153         if (!b->data)
 154                 return ENOMEM;
 155
 156         return EOK;
 157 }
 158
 159 int ext4_block_get(struct ext4_blockdev *bdev, struct ext4_block *b,
 160                    uint64_t lba)
 161 {
 162         uint64_t pba;
 163         uint32_t pb_cnt;
 164         int r = ext4_block_get_noread(bdev, b, lba);
 165         if (r != EOK)
 166                 return r;
 167
 168         if (b->uptodate) {
 169                 /* Data in the cache is up-to-date.
 170                  * Reading from physical device is not required */
 171                 return EOK;
 172         }
 173
 174         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 175         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 176
 177         r = bdev->bread(bdev, b->data, pba, pb_cnt);
 178
 179         if (r != EOK) {
 180                 ext4_bcache_free(bdev->bc, b);
 181                 b->lb_id = 0;
 182                 return r;
 183         }
 184
 185         /* Mark buffer up-to-date, since
 186          * fresh data is read from physical device just now. */
 187         ext4_bcache_set_flag(b->buf, BC_UPTODATE);
 188         b->uptodate = true;
 189         bdev->bread_ctr++;
 190         return EOK;
 191 }
 192
 193 int ext4_block_set(struct ext4_blockdev *bdev, struct ext4_block *b)
 194 {
 195         ext4_assert(bdev && b);
 196         ext4_assert(b->buf);
 197
 198         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 199                 return EIO;
 200
 201         return ext4_bcache_free(bdev->bc, b);
 202 }
 203
 204 int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf, uint64_t lba,
 205                            uint32_t cnt)
 206 {
 207         uint64_t pba;
 208         uint32_t pb_cnt;
 209
 210         ext4_assert(bdev && buf);
 211
 212         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 213         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 214
 215         bdev->bread_ctr++;
 216         return bdev->bread(bdev, buf, pba, pb_cnt * cnt);
 217 }
 218
 219 int ext4_blocks_set_direct(struct ext4_blockdev *bdev, const void *buf,
 220                            uint64_t lba, uint32_t cnt)
 221 {
 222         uint64_t pba;
 223         uint32_t pb_cnt;
 224
 225         ext4_assert(bdev && buf);
 226
 227         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 228         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 229
 230         bdev->bwrite_ctr++;
 231
 232         return bdev->bwrite(bdev, buf, pba, pb_cnt * cnt);
 233 }
 234
 235 int ext4_block_writebytes(struct ext4_blockdev *bdev, uint64_t off,
 236                           const void *buf, uint32_t len)
 237 {
 238         uint64_t block_idx;
 239         uint64_t block_end;
 240         uint32_t blen;
 241         uint32_t unalg;
 242         int r = EOK;
 243
 244         const uint8_t *p = (void *)buf;
 245
 246         ext4_assert(bdev && buf);
 247
 248         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 249                 return EIO;
 250
 251         block_idx = off / bdev->ph_bsize;
 252         block_end = block_idx + len / bdev->ph_bsize;
 253
 254         if (!(block_end < bdev->ph_bcnt))
 255                 return EINVAL; /*Ups. Out of range operation*/
 256
 257         /*OK lets deal with the first possible unaligned block*/
 258         unalg = (off & (bdev->ph_bsize - 1));
 259         if (unalg) {
 260
 261                 uint32_t wlen = (bdev->ph_bsize - unalg) > len
 262                                     ? len
 263                                     : (bdev->ph_bsize - unalg);
 264
 265                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 266                 if (r != EOK)
 267                         return r;
 268
 269                 memcpy(bdev->ph_bbuf + unalg, p, wlen);
 270
 271                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 272                 if (r != EOK)
 273                         return r;
 274
 275                 p += wlen;
 276                 len -= wlen;
 277                 block_idx++;
 278         }
 279
 280         /*Aligned data*/
 281         blen = len / bdev->ph_bsize;
 282         r = bdev->bwrite(bdev, p, block_idx, blen);
 283         if (r != EOK)
 284                 return r;
 285
 286         p += bdev->ph_bsize * blen;
 287         len -= bdev->ph_bsize * blen;
 288
 289         block_idx += blen;
 290
 291         /*Rest of the data*/
 292         if (len) {
 293                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 294                 if (r != EOK)
 295                         return r;
 296
 297                 memcpy(bdev->ph_bbuf, p, len);
 298
 299                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 300                 if (r != EOK)
 301                         return r;
 302         }
 303
 304         return r;
 305 }
 306
 307 int ext4_block_readbytes(struct ext4_blockdev *bdev, uint64_t off, void *buf,
 308                          uint32_t len)
 309 {
 310         uint64_t block_idx;
 311         uint64_t block_end;
 312         uint32_t blen;
 313         uint32_t unalg;
 314         int r = EOK;
 315
 316         uint8_t *p = (void *)buf;
 317
 318         ext4_assert(bdev && buf);
 319
 320         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 321                 return EIO;
 322
 323         block_idx = off / bdev->ph_bsize;
 324         block_end = block_idx + len / bdev->ph_bsize;
 325
 326         if (!(block_end < bdev->ph_bcnt))
 327                 return EINVAL; /*Ups. Out of range operation*/
 328
 329         /*OK lets deal with the first possible unaligned block*/
 330         unalg = (off & (bdev->ph_bsize - 1));
 331         if (unalg) {
 332
 333                 uint32_t rlen = (bdev->ph_bsize - unalg) > len
 334                                     ? len
 335                                     : (bdev->ph_bsize - unalg);
 336
 337                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 338                 if (r != EOK)
 339                         return r;
 340
 341                 memcpy(p, bdev->ph_bbuf + unalg, rlen);
 342
 343                 p += rlen;
 344                 len -= rlen;
 345                 block_idx++;
 346         }
 347
 348         /*Aligned data*/
 349         blen = len / bdev->ph_bsize;
 350
 351         r = bdev->bread(bdev, p, block_idx, blen);
 352         if (r != EOK)
 353                 return r;
 354
 355         p += bdev->ph_bsize * blen;
 356         len -= bdev->ph_bsize * blen;
 357
 358         block_idx += blen;
 359
 360         /*Rest of the data*/
 361         if (len) {
 362                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 363                 if (r != EOK)
 364                         return r;
 365
 366                 memcpy(p, bdev->ph_bbuf, len);
 367         }
 368
 369         return r;
 370 }
 371
 372 int ext4_block_cache_write_back(struct ext4_blockdev *bdev, uint8_t on_off)
 373 {
 374         int r;
 375         struct ext4_buf *buf;
 376
 377         if (on_off)
 378                 bdev->cache_write_back++;
 379
 380         if (!on_off && bdev->cache_write_back)
 381                 bdev->cache_write_back--;
 382
 383         if (bdev->cache_write_back)
 384                 return EOK;
 385
 386         /*Flush all delayed cache blocks*/
 387         while (!SLIST_EMPTY(&bdev->bc->dirty_list)) {
 388
 389                 buf = SLIST_FIRST(&bdev->bc->dirty_list);
 390                 ext4_assert(buf);
 391                 r = ext4_block_flush_buf(bdev, buf);
 392                 if (r != EOK)
 393                         return r;
 394
 395         }
 396         return EOK;
 397 }
 398
 399 /**
 400  * @}
 401  */