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->dirty = 0;
 150         b->lb_id = lba;
 151
 152         /*If cache is full we have to (flush and) drop it anyway :(*/
 153         r = ext4_block_cache_shake(bdev);
 154         if (r != EOK)
 155                 return r;
 156
 157         r = ext4_bcache_alloc(bdev->bc, b, &is_new);
 158         if (r != EOK)
 159                 return r;
 160
 161         if (!b->data)
 162                 return ENOMEM;
 163
 164         return EOK;
 165 }
 166
 167 int ext4_block_get(struct ext4_blockdev *bdev, struct ext4_block *b,
 168                    uint64_t lba)
 169 {
 170         int r = ext4_block_get_noread(bdev, b, lba);
 171         if (r != EOK)
 172                 return r;
 173
 174         if (b->uptodate) {
 175                 /* Data in the cache is up-to-date.
 176                  * Reading from physical device is not required */
 177                 return EOK;
 178         }
 179
 180         r = ext4_blocks_get_direct(bdev, b->data, lba, 1);
 181         if (r != EOK) {
 182                 ext4_bcache_free(bdev->bc, b);
 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         return EOK;
 192 }
 193
 194 int ext4_block_set(struct ext4_blockdev *bdev, struct ext4_block *b)
 195 {
 196         ext4_assert(bdev && b);
 197         ext4_assert(b->buf);
 198
 199         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 200                 return EIO;
 201
 202         return ext4_bcache_free(bdev->bc, b);
 203 }
 204
 205 int ext4_blocks_get_direct(struct ext4_blockdev *bdev, void *buf, uint64_t lba,
 206                            uint32_t cnt)
 207 {
 208         uint64_t pba;
 209         uint32_t pb_cnt;
 210
 211         ext4_assert(bdev && buf);
 212
 213         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 214         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 215
 216         bdev->bread_ctr++;
 217         return bdev->bread(bdev, buf, pba, pb_cnt * cnt);
 218 }
 219
 220 int ext4_blocks_set_direct(struct ext4_blockdev *bdev, const void *buf,
 221                            uint64_t lba, uint32_t cnt)
 222 {
 223         uint64_t pba;
 224         uint32_t pb_cnt;
 225
 226         ext4_assert(bdev && buf);
 227
 228         pba = (lba * bdev->lg_bsize) / bdev->ph_bsize;
 229         pb_cnt = bdev->lg_bsize / bdev->ph_bsize;
 230
 231         bdev->bwrite_ctr++;
 232
 233         return bdev->bwrite(bdev, buf, pba, pb_cnt * cnt);
 234 }
 235
 236 int ext4_block_writebytes(struct ext4_blockdev *bdev, uint64_t off,
 237                           const void *buf, uint32_t len)
 238 {
 239         uint64_t block_idx;
 240         uint64_t block_end;
 241         uint32_t blen;
 242         uint32_t unalg;
 243         int r = EOK;
 244
 245         const uint8_t *p = (void *)buf;
 246
 247         ext4_assert(bdev && buf);
 248
 249         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 250                 return EIO;
 251
 252         block_idx = off / bdev->ph_bsize;
 253         block_end = block_idx + len / bdev->ph_bsize;
 254
 255         if (!(block_end < bdev->ph_bcnt))
 256                 return EINVAL; /*Ups. Out of range operation*/
 257
 258         /*OK lets deal with the first possible unaligned block*/
 259         unalg = (off & (bdev->ph_bsize - 1));
 260         if (unalg) {
 261
 262                 uint32_t wlen = (bdev->ph_bsize - unalg) > len
 263                                     ? len
 264                                     : (bdev->ph_bsize - unalg);
 265
 266                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 267                 if (r != EOK)
 268                         return r;
 269
 270                 memcpy(bdev->ph_bbuf + unalg, p, wlen);
 271
 272                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 273                 if (r != EOK)
 274                         return r;
 275
 276                 p += wlen;
 277                 len -= wlen;
 278                 block_idx++;
 279         }
 280
 281         /*Aligned data*/
 282         blen = len / bdev->ph_bsize;
 283         r = bdev->bwrite(bdev, p, block_idx, blen);
 284         if (r != EOK)
 285                 return r;
 286
 287         p += bdev->ph_bsize * blen;
 288         len -= bdev->ph_bsize * blen;
 289
 290         block_idx += blen;
 291
 292         /*Rest of the data*/
 293         if (len) {
 294                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 295                 if (r != EOK)
 296                         return r;
 297
 298                 memcpy(bdev->ph_bbuf, p, len);
 299
 300                 r = bdev->bwrite(bdev, bdev->ph_bbuf, block_idx, 1);
 301                 if (r != EOK)
 302                         return r;
 303         }
 304
 305         return r;
 306 }
 307
 308 int ext4_block_readbytes(struct ext4_blockdev *bdev, uint64_t off, void *buf,
 309                          uint32_t len)
 310 {
 311         uint64_t block_idx;
 312         uint64_t block_end;
 313         uint32_t blen;
 314         uint32_t unalg;
 315         int r = EOK;
 316
 317         uint8_t *p = (void *)buf;
 318
 319         ext4_assert(bdev && buf);
 320
 321         if (!(bdev->flags & EXT4_BDEV_INITIALIZED))
 322                 return EIO;
 323
 324         block_idx = off / bdev->ph_bsize;
 325         block_end = block_idx + len / bdev->ph_bsize;
 326
 327         if (!(block_end < bdev->ph_bcnt))
 328                 return EINVAL; /*Ups. Out of range operation*/
 329
 330         /*OK lets deal with the first possible unaligned block*/
 331         unalg = (off & (bdev->ph_bsize - 1));
 332         if (unalg) {
 333
 334                 uint32_t rlen = (bdev->ph_bsize - unalg) > len
 335                                     ? len
 336                                     : (bdev->ph_bsize - unalg);
 337
 338                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 339                 if (r != EOK)
 340                         return r;
 341
 342                 memcpy(p, bdev->ph_bbuf + unalg, rlen);
 343
 344                 p += rlen;
 345                 len -= rlen;
 346                 block_idx++;
 347         }
 348
 349         /*Aligned data*/
 350         blen = len / bdev->ph_bsize;
 351
 352         r = bdev->bread(bdev, p, block_idx, blen);
 353         if (r != EOK)
 354                 return r;
 355
 356         p += bdev->ph_bsize * blen;
 357         len -= bdev->ph_bsize * blen;
 358
 359         block_idx += blen;
 360
 361         /*Rest of the data*/
 362         if (len) {
 363                 r = bdev->bread(bdev, bdev->ph_bbuf, block_idx, 1);
 364                 if (r != EOK)
 365                         return r;
 366
 367                 memcpy(p, bdev->ph_bbuf, len);
 368         }
 369
 370         return r;
 371 }
 372
 373 int ext4_block_cache_write_back(struct ext4_blockdev *bdev, uint8_t on_off)
 374 {
 375         int r;
 376         struct ext4_buf *buf;
 377
 378         if (on_off)
 379                 bdev->cache_write_back++;
 380
 381         if (!on_off && bdev->cache_write_back)
 382                 bdev->cache_write_back--;
 383
 384         if (bdev->cache_write_back)
 385                 return EOK;
 386
 387         /*Flush all delayed cache blocks*/
 388         while (!SLIST_EMPTY(&bdev->bc->dirty_list)) {
 389
 390                 buf = SLIST_FIRST(&bdev->bc->dirty_list);
 391                 ext4_assert(buf);
 392                 r = ext4_block_flush_buf(bdev, buf);
 393                 if (r != EOK)
 394                         return r;
 395
 396         }
 397         return EOK;
 398 }
 399
 400 /**
 401  * @}
 402  */