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 #include <config.h> 23 #include <reiserfs.h> 24 25 #include "reiserfs_private.h" 26 27 static block_dev_desc_t *reiserfs_block_dev_desc; 28 static disk_partition_t *part_info; 29 30 31 void reiserfs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info) 32 { 33 reiserfs_block_dev_desc = rbdd; 34 part_info = info; 35 } 36 37 38 int reiserfs_devread (int sector, int byte_offset, int byte_len, char *buf) 39 { 40 char sec_buf[SECTOR_SIZE]; 41 unsigned block_len; 42 /* 43 unsigned len = byte_len; 44 u8 *start = buf; 45 */ 46 /* 47 * Check partition boundaries 48 */ 49 if (sector < 0 50 || ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) 51 >= part_info->size)) { 52 /* errnum = ERR_OUTSIDE_PART; */ 53 printf (" ** reiserfs_devread() read outside partition\n"); 54 return 0; 55 } 56 57 /* 58 * Get the read to the beginning of a partition. 59 */ 60 sector += byte_offset >> SECTOR_BITS; 61 byte_offset &= SECTOR_SIZE - 1; 62 63 #if defined(DEBUG) 64 printf (" <%d, %d, %d> ", sector, byte_offset, byte_len); 65 #endif 66 67 68 if (reiserfs_block_dev_desc == NULL) 69 return 0; 70 71 72 if (byte_offset != 0) { 73 /* read first part which isn't aligned with start of sector */ 74 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev, 75 part_info->start + sector, 1, 76 (unsigned long *)sec_buf) != 1) { 77 printf (" ** reiserfs_devread() read error\n"); 78 return 0; 79 } 80 memcpy(buf, sec_buf+byte_offset, min(SECTOR_SIZE-byte_offset, byte_len)); 81 buf+=min(SECTOR_SIZE-byte_offset, byte_len); 82 byte_len-=min(SECTOR_SIZE-byte_offset, byte_len); 83 sector++; 84 } 85 86 /* read sector aligned part */ 87 block_len = byte_len & ~(SECTOR_SIZE-1); 88 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev, 89 part_info->start + sector, block_len/SECTOR_SIZE, 90 (unsigned long *)buf) != block_len/SECTOR_SIZE) { 91 printf (" ** reiserfs_devread() read error - block\n"); 92 return 0; 93 } 94 buf+=block_len; 95 byte_len-=block_len; 96 sector+= block_len/SECTOR_SIZE; 97 98 if ( byte_len != 0 ) { 99 /* read rest of data which are not in whole sector */ 100 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev, 101 part_info->start + sector, 1, 102 (unsigned long *)sec_buf) != 1) { 103 printf (" ** reiserfs_devread() read error - last part\n"); 104 return 0; 105 } 106 memcpy(buf, sec_buf, byte_len); 107 } 108 109 return 1; 110 } 111