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