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 int reiserfs_set_blk_dev(block_dev_desc_t *rbdd, int part) 32 { 33 reiserfs_block_dev_desc = rbdd; 34 35 if (part == 0) { 36 /* disk doesn't use partition table */ 37 part_info.start = 0; 38 part_info.size = rbdd->lba; 39 part_info.blksz = rbdd->blksz; 40 } else { 41 if (get_partition_info (reiserfs_block_dev_desc, part, &part_info)) { 42 return 0; 43 } 44 } 45 return (part_info.size); 46 } 47 48 49 int reiserfs_devread (int sector, int byte_offset, int byte_len, char *buf) 50 { 51 char sec_buf[SECTOR_SIZE]; 52 unsigned block_len; 53 /* 54 unsigned len = byte_len; 55 u8 *start = buf; 56 */ 57 /* 58 * Check partition boundaries 59 */ 60 if (sector < 0 61 || ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) 62 >= part_info.size)) { 63 /* errnum = ERR_OUTSIDE_PART; */ 64 printf (" ** reiserfs_devread() read outside partition\n"); 65 return 0; 66 } 67 68 /* 69 * Get the read to the beginning of a partition. 70 */ 71 sector += byte_offset >> SECTOR_BITS; 72 byte_offset &= SECTOR_SIZE - 1; 73 74 #if defined(DEBUG) 75 printf (" <%d, %d, %d> ", sector, byte_offset, byte_len); 76 #endif 77 78 79 if (reiserfs_block_dev_desc == NULL) 80 return 0; 81 82 83 if (byte_offset != 0) { 84 /* read first part which isn't aligned with start of sector */ 85 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev, 86 part_info.start+sector, 1, (unsigned long *)sec_buf) != 1) { 87 printf (" ** reiserfs_devread() read error\n"); 88 return 0; 89 } 90 memcpy(buf, sec_buf+byte_offset, min(SECTOR_SIZE-byte_offset, byte_len)); 91 buf+=min(SECTOR_SIZE-byte_offset, byte_len); 92 byte_len-=min(SECTOR_SIZE-byte_offset, byte_len); 93 sector++; 94 } 95 96 /* read sector aligned part */ 97 block_len = byte_len & ~(SECTOR_SIZE-1); 98 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev, 99 part_info.start+sector, block_len/SECTOR_SIZE, (unsigned long *)buf) != 100 block_len/SECTOR_SIZE) { 101 printf (" ** reiserfs_devread() read error - block\n"); 102 return 0; 103 } 104 buf+=block_len; 105 byte_len-=block_len; 106 sector+= block_len/SECTOR_SIZE; 107 108 if ( byte_len != 0 ) { 109 /* read rest of data which are not in whole sector */ 110 if (reiserfs_block_dev_desc->block_read(reiserfs_block_dev_desc->dev, 111 part_info.start+sector, 1, (unsigned long *)sec_buf) != 1) { 112 printf (" ** reiserfs_devread() read error - last part\n"); 113 return 0; 114 } 115 memcpy(buf, sec_buf, byte_len); 116 } 117 118 return 1; 119 } 120