fs/reiserfs/dev.c

   1 /*
   2  *  (C) Copyright 2003 - 2004
   3  *  Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8
   9 #include <common.h>
  10 #include <config.h>
  11 #include <reiserfs.h>
  12
  13 #include "reiserfs_private.h"
  14
  15 static block_dev_desc_t *reiserfs_block_dev_desc;
  16 static disk_partition_t *part_info;
  17
  18
  19 void reiserfs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
  20 {
  21         reiserfs_block_dev_desc = rbdd;
  22         part_info = info;
  23 }
  24
  25
  26 int reiserfs_devread (int sector, int byte_offset, int byte_len, char *buf)
  27 {
  28         char sec_buf[SECTOR_SIZE];
  29         unsigned block_len;
  30 /*
  31         unsigned len = byte_len;
  32         u8 *start = buf;
  33 */
  34         /*
  35         *  Check partition boundaries
  36         */
  37         if (sector < 0
  38             || ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS))
  39             >= part_info->size)) {
  40 /*              errnum = ERR_OUTSIDE_PART; */
  41                 printf (" ** reiserfs_devread() read outside partition\n");
  42                 return 0;
  43         }
  44
  45         /*
  46          *  Get the read to the beginning of a partition.
  47          */
  48         sector += byte_offset >> SECTOR_BITS;
  49         byte_offset &= SECTOR_SIZE - 1;
  50
  51 #if defined(DEBUG)
  52         printf (" <%d, %d, %d> ", sector, byte_offset, byte_len);
  53 #endif
  54
  55
  56         if (reiserfs_block_dev_desc == NULL)
  57                 return 0;
  58
  59
  60         if (byte_offset != 0) {
  61                 /* read first part which isn't aligned with start of sector */
  62                 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev,
  63                     part_info->start + sector, 1,
  64                     (unsigned long *)sec_buf) != 1) {
  65                         printf (" ** reiserfs_devread() read error\n");
  66                         return 0;
  67                 }
  68                 memcpy(buf, sec_buf+byte_offset, min(SECTOR_SIZE-byte_offset, byte_len));
  69                 buf+=min(SECTOR_SIZE-byte_offset, byte_len);
  70                 byte_len-=min(SECTOR_SIZE-byte_offset, byte_len);
  71                 sector++;
  72         }
  73
  74         /* read sector aligned part */
  75         block_len = byte_len & ~(SECTOR_SIZE-1);
  76         if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev,
  77             part_info->start + sector, block_len/SECTOR_SIZE,
  78             (unsigned long *)buf) != block_len/SECTOR_SIZE) {
  79                 printf (" ** reiserfs_devread() read error - block\n");
  80                 return 0;
  81         }
  82         buf+=block_len;
  83         byte_len-=block_len;
  84         sector+= block_len/SECTOR_SIZE;
  85
  86         if ( byte_len != 0 ) {
  87                 /* read rest of data which are not in whole sector */
  88                 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev,
  89                     part_info->start + sector, 1,
  90                     (unsigned long *)sec_buf) != 1) {
  91                         printf (" ** reiserfs_devread() read error - last part\n");
  92                         return 0;
  93                 }
  94                 memcpy(buf, sec_buf, byte_len);
  95         }
  96
  97         return 1;
  98 }