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 static void ext4_bdif_lock(struct ext4_blockdev *bdev)
  46 {
  47         if (!bdev->bdif->lock)
  48                 return;
  49
  50         int r = bdev->bdif->lock(bdev);
  51         ext4_assert(r == EOK);
  52 }
  53
  54 static void ext4_bdif_unlock(struct ext4_blockdev *bdev)
  55 {
  56         if (!bdev->bdif->unlock)
  57                 return;
  58
  59         int r = bdev->bdif->unlock(bdev);
  60         ext4_assert(r == EOK);
  61 }
  62
  63 static int ext4_bdif_bread(struct ext4_blockdev *bdev, void *buf,
  64                            uint64_t blk_id, uint32_t blk_cnt)
  65 {
  66         ext4_bdif_lock(bdev);
  67         int r = bdev->bdif->bread(bdev, buf, blk_id, blk_cnt);
  68         bdev->bdif->bread_ctr++;
  69         ext4_bdif_unlock(bdev);
  70         return r;
  71 }
  72
  73 static int ext4_bdif_bwrite(struct ext4_blockdev *bdev, const void *buf,
  74                             uint64_t blk_id, uint32_t blk_cnt)
  75 {
  76         ext4_bdif_lock(bdev);
  77         int r = bdev->bdif->bwrite(bdev, buf, blk_id, blk_cnt);
  78         bdev->bdif->bwrite_ctr++;
  79         ext4_bdif_unlock(bdev);
  80         return r;
  81 }
  82
  83 int ext4_block_init(struct ext4_blockdev *bdev)
  84 {
  85         int rc;
  86         ext4_assert(bdev);
  87         ext4_assert(bdev->bdif);
  88         ext4_assert(bdev->bdif->open &&
  89                    bdev->bdif->close &&
  90                    bdev->bdif->bread &&
  91                    bdev->bdif->bwrite);
  92
  93         if (bdev->bdif->ph_refctr) {
  94                 bdev->bdif->ph_refctr++;
  95                 return EOK;
  96         }
  97
  98         /*Low level block init*/
  99         rc = bdev->bdif->open(bdev);
 100         if (rc != EOK)
 101                 return rc;
 102
 103         bdev->bdif->ph_refctr = 1;
 104         return EOK;
 105 }
 106
 107 int ext4_block_bind_bcache(struct ext4_blockdev *bdev, struct ext4_bcache *bc)
 108 {
 109         ext4_assert(bdev && bc);
 110         bdev->bc = bc;
 111         bc->bdev = bdev;
 112         return EOK;
 113 }
 114
 115 void ext4_block_set_lb_size(struct ext4_blockdev *bdev, uint64_t lb_bsize)
 116 {
 117         /*Logical block size has to be multiply of physical */
 118         ext4_assert(!(lb_bsize % bdev->bdif->ph_bsize));
 119
 120         bdev->lg_bsize = lb_bsize;
 121         bdev->lg_bcnt = bdev->part_size / lb_bsize;
 122 }
 123
 124 int ext4_block_fini(struct ext4_blockdev *bdev)
 125 {
 126         ext4_assert(bdev);
 127
 128         if (!bdev->bdif->ph_refctr)
 129                 return EOK;
 130
 131         bdev->bdif->ph_refctr--;
 132         if (bdev->bdif->ph_refctr)
 133                 return EOK;
 134
 135         /*Low level block fini*/
 136         return bdev->bdif->close(bdev);
 137 }
 138
 139 int ext4_block_flush_buf(struct ext4_blockdev *bdev, struct ext4_buf *buf)
 140 {
 141         int r;
 142         struct ext4_bcache *bc = bdev->bc;
 143         /*Only flushing unreferenced buffer is allowed.*/
 144         ext4_assert(!buf->refctr);
 145
 146         if (ext4_bcache_test_flag(buf, BC_DIRTY)) {
 147                 r = ext4_blocks_set_direct(bdev, buf->data, buf->lba, 1);
 148
 149                 if (r) {
 150                         if (buf->end_write)
 151                                 buf->end_write(bc, buf, r, buf->end_write_arg);
 152
 153                         return r;
 154                 }
 155
 156                 ext4_bcache_remove_dirty_node(bc, buf);
 157                 ext4_bcache_clear_flag(buf, BC_DIRTY);
 158                 if (buf->end_write)
 159                         buf->end_write(bc, buf, r, buf->end_write_arg);
 160
 161         }
 162         return EOK;
 163 }
 164
 165 int ext4_block_cache_shake(struct ext4_blockdev *bdev)
 166 {
 167         struct ext4_buf *buf;
 168         while (!RB_EMPTY(&bdev->bc->lru_root) &&
 169                 ext4_bcache_is_full(bdev->bc)) {
 170
 171                 buf = ext4_buf_lowest_lru(bdev->bc);
 172                 ext4_assert(buf);
 173                 if (ext4_bcache_test_flag(buf, BC_DIRTY)) {
 174                         int r = ext4_block_flush_buf(bdev, buf);
 175                         if (r != EOK)
 176                                 return r;
 177
 178                 }
 179
 180                 ext4_bcache_drop_buf(bdev->bc, buf);
 181         }
 182         return EOK;
 183 }
 184
 185 int ext4_block_get_noread(struct ext4_blockdev *bdev, struct ext4_block *b,
 186                           uint64_t lba)
 187 {
 188         bool is_new;
 189         int r;
 190
 191         ext4_assert(bdev && b);
 192
 193         if (!bdev->bdif->ph_refctr)
 194                 return EIO;
 195
 196         if (!(lba < bdev->lg_bcnt))
 197                 return ERANGE;
 198
 199         b->lb_id = lba;
 200
 201         /*If cache is full we have to (flush and) drop it anyway :(*/
 202         r = ext4_block_cache_shake(bdev);
 203         if (r != EOK)
 204                 return r;
 205
 206         r = ext4_bcache_alloc(bdev->bc, b, &is_new);
 207         if (r != EOK)
 208                 return r;
 209
 210         if (!b->data)
 211                 return ENOMEM;
 212
 213         return EOK;
 214 }
 215
 216 int ext4_block_get(struct ext4_blockdev *bdev, struct ext4_block *b,
 217                    uint64_t lba)
 218 {
 219         int r = ext4_block_get_noread(bdev, b, lba);
 220         if (r != EOK)
 221                 return r;
 222
 223         if (ext4_bcache_test_flag(b->buf, BC_UPTODATE)) {
 224                 /* Data in the cache is up-to-date.
 225                  * Reading from physical device is not required */
 226                 return EOK;
 227         }
 228
 229         r = ext4_blocks_get_direct(bdev, b->data, lba, 1);
 230         if (r != EOK) {
 231                 ext4_bcache_free(bdev->bc, b);
 232                 b->lb_id = 0;
 233                 return r;
 234         }
 235
 236         /* Mark buffer up-to-date, since
 237          * fresh data is read from physical device just now. */
 238         ext4_bcache_set_flag(b->buf, BC_UPTODATE);
 239         return EOK;
 240 }
 241
 242 int ext4_block_set(struct ext4_blockdev *bdev, struct ext4_block *b)
 243 {
 244         ext4_assert(bdev && b);
 245         ext4_assert(b->buf);
 246
 247         if (!bdev->bdif->ph_refctr)
 248                 return EIO;
 249
 250         return ext4_bcache_free(bdev->bc, b);
 251 }
 252
 253 int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf, uint64_t lba,
 254                            uint32_t cnt)
 255 {
 256         uint64_t pba;
 257         uint32_t pb_cnt;
 258
 259         ext4_assert(bdev && buf);
 260
 261         pba = (lba * bdev->lg_bsize + bdev->part_offset) / bdev->bdif->ph_bsize;
 262         pb_cnt = bdev->lg_bsize / bdev->bdif->ph_bsize;
 263
 264         return ext4_bdif_bread(bdev, buf, pba, pb_cnt * cnt);
 265 }
 266
 267 int ext4_blocks_set_direct(struct ext4_blockdev *bdev, const void *buf,
 268                            uint64_t lba, uint32_t cnt)
 269 {
 270         uint64_t pba;
 271         uint32_t pb_cnt;
 272
 273         ext4_assert(bdev && buf);
 274
 275         pba = (lba * bdev->lg_bsize + bdev->part_offset) / bdev->bdif->ph_bsize;
 276         pb_cnt = bdev->lg_bsize / bdev->bdif->ph_bsize;
 277
 278         return ext4_bdif_bwrite(bdev, buf, pba, pb_cnt * cnt);
 279 }
 280
 281 int ext4_block_writebytes(struct ext4_blockdev *bdev, uint64_t off,
 282                           const void *buf, uint32_t len)
 283 {
 284         uint64_t block_idx;
 285         uint32_t blen;
 286         uint32_t unalg;
 287         int r = EOK;
 288
 289         const uint8_t *p = (void *)buf;
 290
 291         ext4_assert(bdev && buf);
 292
 293         if (!bdev->bdif->ph_refctr)
 294                 return EIO;
 295
 296         if (off + len > bdev->part_size)
 297                 return EINVAL; /*Ups. Out of range operation*/
 298
 299         block_idx = ((off + bdev->part_offset) / bdev->bdif->ph_bsize);
 300
 301         /*OK lets deal with the first possible unaligned block*/
 302         unalg = (off & (bdev->bdif->ph_bsize - 1));
 303         if (unalg) {
 304
 305                 uint32_t wlen = (bdev->bdif->ph_bsize - unalg) > len
 306                                     ? len
 307                                     : (bdev->bdif->ph_bsize - unalg);
 308
 309                 r = ext4_bdif_bread(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
 310                 if (r != EOK)
 311                         return r;
 312
 313                 memcpy(bdev->bdif->ph_bbuf + unalg, p, wlen);
 314                 r = ext4_bdif_bwrite(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
 315                 if (r != EOK)
 316                         return r;
 317
 318                 p += wlen;
 319                 len -= wlen;
 320                 block_idx++;
 321         }
 322
 323         /*Aligned data*/
 324         blen = len / bdev->bdif->ph_bsize;
 325         r = ext4_bdif_bwrite(bdev, p, block_idx, blen);
 326         if (r != EOK)
 327                 return r;
 328
 329         p += bdev->bdif->ph_bsize * blen;
 330         len -= bdev->bdif->ph_bsize * blen;
 331
 332         block_idx += blen;
 333
 334         /*Rest of the data*/
 335         if (len) {
 336                 r = ext4_bdif_bread(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
 337                 if (r != EOK)
 338                         return r;
 339
 340                 memcpy(bdev->bdif->ph_bbuf, p, len);
 341                 r = ext4_bdif_bwrite(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
 342                 if (r != EOK)
 343                         return r;
 344         }
 345
 346         return r;
 347 }
 348
 349 int ext4_block_readbytes(struct ext4_blockdev *bdev, uint64_t off, void *buf,
 350                          uint32_t len)
 351 {
 352         uint64_t block_idx;
 353         uint32_t blen;
 354         uint32_t unalg;
 355         int r = EOK;
 356
 357         uint8_t *p = (void *)buf;
 358
 359         ext4_assert(bdev && buf);
 360
 361         if (!bdev->bdif->ph_refctr)
 362                 return EIO;
 363
 364         if (off + len > bdev->part_size)
 365                 return EINVAL; /*Ups. Out of range operation*/
 366
 367         block_idx = ((off + bdev->part_offset) / bdev->bdif->ph_bsize);
 368
 369         /*OK lets deal with the first possible unaligned block*/
 370         unalg = (off & (bdev->bdif->ph_bsize - 1));
 371         if (unalg) {
 372
 373                 uint32_t rlen = (bdev->bdif->ph_bsize - unalg) > len
 374                                     ? len
 375                                     : (bdev->bdif->ph_bsize - unalg);
 376
 377                 r = ext4_bdif_bread(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
 378                 if (r != EOK)
 379                         return r;
 380
 381                 memcpy(p, bdev->bdif->ph_bbuf + unalg, rlen);
 382
 383                 p += rlen;
 384                 len -= rlen;
 385                 block_idx++;
 386         }
 387
 388         /*Aligned data*/
 389         blen = len / bdev->bdif->ph_bsize;
 390
 391         r = ext4_bdif_bread(bdev, p, block_idx, blen);
 392         if (r != EOK)
 393                 return r;
 394
 395         p += bdev->bdif->ph_bsize * blen;
 396         len -= bdev->bdif->ph_bsize * blen;
 397
 398         block_idx += blen;
 399
 400         /*Rest of the data*/
 401         if (len) {
 402                 r = ext4_bdif_bread(bdev, bdev->bdif->ph_bbuf, block_idx, 1);
 403                 if (r != EOK)
 404                         return r;
 405
 406                 memcpy(p, bdev->bdif->ph_bbuf, len);
 407         }
 408
 409         return r;
 410 }
 411
 412 int ext4_block_cache_write_back(struct ext4_blockdev *bdev, uint8_t on_off)
 413 {
 414         int r;
 415         struct ext4_buf *buf;
 416
 417         if (on_off)
 418                 bdev->cache_write_back++;
 419
 420         if (!on_off && bdev->cache_write_back)
 421                 bdev->cache_write_back--;
 422
 423         if (bdev->cache_write_back)
 424                 return EOK;
 425
 426         /*Flush all delayed cache blocks*/
 427         while (!SLIST_EMPTY(&bdev->bc->dirty_list)) {
 428
 429                 buf = SLIST_FIRST(&bdev->bc->dirty_list);
 430                 ext4_assert(buf);
 431                 r = ext4_block_flush_buf(bdev, buf);
 432                 if (r != EOK)
 433                         return r;
 434
 435         }
 436         return EOK;
 437 }
 438
 439 /**
 440  * @}
 441  */