1 /* 2 * 3 * based on code of fs/reiserfs/dev.c by 4 * 5 * (C) Copyright 2003 - 2004 6 * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 21 */ 22 23 24 #include <common.h> 25 #include <config.h> 26 #include <zfs_common.h> 27 28 static block_dev_desc_t *zfs_block_dev_desc; 29 static disk_partition_t *part_info; 30 31 void zfs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info) 32 { 33 zfs_block_dev_desc = rbdd; 34 part_info = info; 35 } 36 37 /* err */ 38 int zfs_devread(int sector, int byte_offset, int byte_len, char *buf) 39 { 40 short sec_buffer[SECTOR_SIZE/sizeof(short)]; 41 char *sec_buf = (char *)sec_buffer; 42 unsigned block_len; 43 44 /* 45 * Check partition boundaries 46 */ 47 if ((sector < 0) || 48 ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >= 49 part_info->size)) { 50 /* errnum = ERR_OUTSIDE_PART; */ 51 printf(" ** zfs_devread() read outside partition sector %d\n", sector); 52 return 1; 53 } 54 55 /* 56 * Get the read to the beginning of a partition. 57 */ 58 sector += byte_offset >> SECTOR_BITS; 59 byte_offset &= SECTOR_SIZE - 1; 60 61 debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len); 62 63 if (zfs_block_dev_desc == NULL) { 64 printf("** Invalid Block Device Descriptor (NULL)\n"); 65 return 1; 66 } 67 68 if (byte_offset != 0) { 69 /* read first part which isn't aligned with start of sector */ 70 if (zfs_block_dev_desc->block_read(zfs_block_dev_desc->dev, 71 part_info->start + sector, 1, 72 (unsigned long *)sec_buf) != 1) { 73 printf(" ** zfs_devread() read error **\n"); 74 return 1; 75 } 76 memcpy(buf, sec_buf + byte_offset, 77 min(SECTOR_SIZE - byte_offset, byte_len)); 78 buf += min(SECTOR_SIZE - byte_offset, byte_len); 79 byte_len -= min(SECTOR_SIZE - byte_offset, byte_len); 80 sector++; 81 } 82 83 if (byte_len == 0) 84 return 0; 85 86 /* read sector aligned part */ 87 block_len = byte_len & ~(SECTOR_SIZE - 1); 88 89 if (block_len == 0) { 90 u8 p[SECTOR_SIZE]; 91 92 block_len = SECTOR_SIZE; 93 zfs_block_dev_desc->block_read(zfs_block_dev_desc->dev, 94 part_info->start + sector, 95 1, (unsigned long *)p); 96 memcpy(buf, p, byte_len); 97 return 0; 98 } 99 100 if (zfs_block_dev_desc->block_read(zfs_block_dev_desc->dev, 101 part_info->start + sector, block_len / SECTOR_SIZE, 102 (unsigned long *) buf) != block_len / SECTOR_SIZE) { 103 printf(" ** zfs_devread() read error - block\n"); 104 return 1; 105 } 106 107 block_len = byte_len & ~(SECTOR_SIZE - 1); 108 buf += block_len; 109 byte_len -= block_len; 110 sector += block_len / SECTOR_SIZE; 111 112 if (byte_len != 0) { 113 /* read rest of data which are not in whole sector */ 114 if (zfs_block_dev_desc-> 115 block_read(zfs_block_dev_desc->dev, 116 part_info->start + sector, 1, 117 (unsigned long *) sec_buf) != 1) { 118 printf(" ** zfs_devread() read error - last part\n"); 119 return 1; 120 } 121 memcpy(buf, sec_buf, byte_len); 122 } 123 return 0; 124 } 125