fs/reiserfs/dev.c

   1 /*
   2  *  (C) Copyright 2003 - 2004
   3  *  Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20
  21 #include <common.h>
  22 #if (CONFIG_COMMANDS & CFG_CMD_REISER)
  23
  24 #include <config.h>
  25 #include <reiserfs.h>
  26
  27 #include "reiserfs_private.h"
  28
  29 static block_dev_desc_t *reiserfs_block_dev_desc;
  30 static disk_partition_t part_info;
  31
  32
  33 int reiserfs_set_blk_dev(block_dev_desc_t *rbdd, int part)
  34 {
  35         reiserfs_block_dev_desc = rbdd;
  36
  37         if (part == 0) {
  38                 /* disk doesn't use partition table */
  39                 part_info.start = 0;
  40                 part_info.size = rbdd->lba;
  41                 part_info.blksz = rbdd->blksz;
  42         } else {
  43                 if (get_partition_info (reiserfs_block_dev_desc, part, &part_info)) {
  44                         return 0;
  45                 }
  46         }
  47         return (part_info.size);
  48 }
  49
  50
  51 int reiserfs_devread (int sector, int byte_offset, int byte_len, char *buf)
  52 {
  53         char sec_buf[SECTOR_SIZE];
  54         unsigned block_len;
  55 /*
  56         unsigned len = byte_len;
  57         u8 *start = buf;
  58 */
  59         /*
  60         *  Check partition boundaries
  61         */
  62         if (sector < 0
  63             || ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS))
  64             >= part_info.size)) {
  65 /*              errnum = ERR_OUTSIDE_PART; */
  66                 printf (" ** reiserfs_devread() read outside partition\n");
  67                 return 0;
  68         }
  69
  70         /*
  71          *  Get the read to the beginning of a partition.
  72          */
  73         sector += byte_offset >> SECTOR_BITS;
  74         byte_offset &= SECTOR_SIZE - 1;
  75
  76 #if defined(DEBUG)
  77         printf (" <%d, %d, %d> ", sector, byte_offset, byte_len);
  78 #endif
  79
  80
  81         if (reiserfs_block_dev_desc == NULL)
  82                 return 0;
  83
  84
  85         if (byte_offset != 0) {
  86                 /* read first part which isn't aligned with start of sector */
  87                 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev,
  88                     part_info.start+sector, 1, (unsigned long *)sec_buf) != 1) {
  89                         printf (" ** reiserfs_devread() read error\n");
  90                         return 0;
  91                 }
  92                 memcpy(buf, sec_buf+byte_offset, min(SECTOR_SIZE-byte_offset, byte_len));
  93                 buf+=min(SECTOR_SIZE-byte_offset, byte_len);
  94                 byte_len-=min(SECTOR_SIZE-byte_offset, byte_len);
  95                 sector++;
  96         }
  97
  98         /* read sector aligned part */
  99         block_len = byte_len & ~(SECTOR_SIZE-1);
 100         if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev,
 101             part_info.start+sector, block_len/SECTOR_SIZE, (unsigned long *)buf) !=
 102             block_len/SECTOR_SIZE) {
 103                 printf (" ** reiserfs_devread() read error - block\n");
 104                 return 0;
 105         }
 106         buf+=block_len;
 107         byte_len-=block_len;
 108         sector+= block_len/SECTOR_SIZE;
 109
 110         if ( byte_len != 0 ) {
 111                 /* read rest of data which are not in whole sector */
 112                 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev,
 113                     part_info.start+sector, 1, (unsigned long *)sec_buf) != 1) {
 114                         printf (" ** reiserfs_devread() read error - last part\n");
 115                         return 0;
 116                 }
 117                 memcpy(buf, sec_buf, byte_len);
 118         }
 119
 120         return 1;
 121 }
 122
 123 #endif /* CFG_CMD_REISERFS */