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 * SPDX-License-Identifier: GPL-2.0+ 9 */ 10 11 12 #include <common.h> 13 #include <config.h> 14 #include <zfs_common.h> 15 16 static struct blk_desc *zfs_blk_desc; 17 static disk_partition_t *part_info; 18 19 void zfs_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info) 20 { 21 zfs_blk_desc = rbdd; 22 part_info = info; 23 } 24 25 /* err */ 26 int zfs_devread(int sector, int byte_offset, int byte_len, char *buf) 27 { 28 short sec_buffer[SECTOR_SIZE/sizeof(short)]; 29 char *sec_buf = (char *)sec_buffer; 30 unsigned block_len; 31 32 /* 33 * Check partition boundaries 34 */ 35 if ((sector < 0) || 36 ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >= 37 part_info->size)) { 38 /* errnum = ERR_OUTSIDE_PART; */ 39 printf(" ** zfs_devread() read outside partition sector %d\n", sector); 40 return 1; 41 } 42 43 /* 44 * Get the read to the beginning of a partition. 45 */ 46 sector += byte_offset >> SECTOR_BITS; 47 byte_offset &= SECTOR_SIZE - 1; 48 49 debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len); 50 51 if (zfs_blk_desc == NULL) { 52 printf("** Invalid Block Device Descriptor (NULL)\n"); 53 return 1; 54 } 55 56 if (byte_offset != 0) { 57 /* read first part which isn't aligned with start of sector */ 58 if (zfs_blk_desc->block_read(zfs_blk_desc, 59 part_info->start + sector, 1, 60 (void *)sec_buf) != 1) { 61 printf(" ** zfs_devread() read error **\n"); 62 return 1; 63 } 64 memcpy(buf, sec_buf + byte_offset, 65 min(SECTOR_SIZE - byte_offset, byte_len)); 66 buf += min(SECTOR_SIZE - byte_offset, byte_len); 67 byte_len -= min(SECTOR_SIZE - byte_offset, byte_len); 68 sector++; 69 } 70 71 if (byte_len == 0) 72 return 0; 73 74 /* read sector aligned part */ 75 block_len = byte_len & ~(SECTOR_SIZE - 1); 76 77 if (block_len == 0) { 78 u8 p[SECTOR_SIZE]; 79 80 block_len = SECTOR_SIZE; 81 zfs_blk_desc->block_read(zfs_blk_desc, 82 part_info->start + sector, 83 1, (void *)p); 84 memcpy(buf, p, byte_len); 85 return 0; 86 } 87 88 if (zfs_blk_desc->block_read(zfs_blk_desc, part_info->start + sector, 89 block_len / SECTOR_SIZE, 90 (void *)buf) != block_len / SECTOR_SIZE) { 91 printf(" ** zfs_devread() read error - block\n"); 92 return 1; 93 } 94 95 block_len = byte_len & ~(SECTOR_SIZE - 1); 96 buf += block_len; 97 byte_len -= block_len; 98 sector += block_len / SECTOR_SIZE; 99 100 if (byte_len != 0) { 101 /* read rest of data which are not in whole sector */ 102 if (zfs_blk_desc->block_read(zfs_blk_desc, 103 part_info->start + sector, 104 1, (void *)sec_buf) != 1) { 105 printf(" ** zfs_devread() read error - last part\n"); 106 return 1; 107 } 108 memcpy(buf, sec_buf, byte_len); 109 } 110 return 0; 111 } 112