patman: Minor help message/README fixes
[oweals/u-boot.git] / 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 #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 }