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