fs/ext4/dev.c

   1 /*
   2  * (C) Copyright 2011 - 2012 Samsung Electronics
   3  * EXT4 filesystem implementation in Uboot by
   4  * Uma Shankar <uma.shankar@samsung.com>
   5  * Manjunatha C Achar <a.manjunatha@samsung.com>
   6  *
   7  * made from existing ext2/dev.c file of Uboot
   8  * (C) Copyright 2004
   9  * esd gmbh <www.esd-electronics.com>
  10  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
  11  *
  12  * based on code of fs/reiserfs/dev.c by
  13  *
  14  * (C) Copyright 2003 - 2004
  15  * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 2 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  30  *
  31  */
  32
  33 /*
  34  * Changelog:
  35  *      0.1 - Newly created file for ext4fs support. Taken from
  36  *              fs/ext2/dev.c file in uboot.
  37  */
  38
  39 #include <common.h>
  40 #include <config.h>
  41 #include <ext4fs.h>
  42 #include <ext_common.h>
  43 #include "ext4_common.h"
  44
  45 unsigned long part_offset;
  46
  47 static block_dev_desc_t *ext4fs_block_dev_desc;
  48 static disk_partition_t *part_info;
  49
  50 void ext4fs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
  51 {
  52         assert(rbdd->blksz == (1 << rbdd->log2blksz));
  53         ext4fs_block_dev_desc = rbdd;
  54         get_fs()->dev_desc = rbdd;
  55         part_info = info;
  56         part_offset = info->start;
  57         get_fs()->total_sect = (info->size * info->blksz) >>
  58                 get_fs()->dev_desc->log2blksz;
  59 }
  60
  61 int ext4fs_devread(int sector, int byte_offset, int byte_len, char *buf)
  62 {
  63         unsigned block_len;
  64         int log2blksz = ext4fs_block_dev_desc->log2blksz;
  65         ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (ext4fs_block_dev_desc ?
  66                                                  ext4fs_block_dev_desc->blksz :
  67                                                  0));
  68         if (ext4fs_block_dev_desc == NULL) {
  69                 printf("** Invalid Block Device Descriptor (NULL)\n");
  70                 return 0;
  71         }
  72
  73         /* Check partition boundaries */
  74         if ((sector < 0) ||
  75             ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
  76              >= part_info->size)) {
  77                 printf("%s read outside partition %d\n", __func__, sector);
  78                 return 0;
  79         }
  80
  81         /* Get the read to the beginning of a partition */
  82         sector += byte_offset >> log2blksz;
  83         byte_offset &= ext4fs_block_dev_desc->blksz - 1;
  84
  85         debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len);
  86
  87         if (byte_offset != 0) {
  88                 /* read first part which isn't aligned with start of sector */
  89                 if (ext4fs_block_dev_desc->
  90                     block_read(ext4fs_block_dev_desc->dev,
  91                                 part_info->start + sector, 1,
  92                                 (unsigned long *) sec_buf) != 1) {
  93                         printf(" ** ext2fs_devread() read error **\n");
  94                         return 0;
  95                 }
  96                 memcpy(buf, sec_buf + byte_offset,
  97                         min(ext4fs_block_dev_desc->blksz
  98                             - byte_offset, byte_len));
  99                 buf += min(ext4fs_block_dev_desc->blksz
 100                            - byte_offset, byte_len);
 101                 byte_len -= min(ext4fs_block_dev_desc->blksz
 102                                 - byte_offset, byte_len);
 103                 sector++;
 104         }
 105
 106         if (byte_len == 0)
 107                 return 1;
 108
 109         /* read sector aligned part */
 110         block_len = byte_len & ~(ext4fs_block_dev_desc->blksz - 1);
 111
 112         if (block_len == 0) {
 113                 ALLOC_CACHE_ALIGN_BUFFER(u8, p, ext4fs_block_dev_desc->blksz);
 114
 115                 block_len = ext4fs_block_dev_desc->blksz;
 116                 ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
 117                                                   part_info->start + sector,
 118                                                   1, (unsigned long *)p);
 119                 memcpy(buf, p, byte_len);
 120                 return 1;
 121         }
 122
 123         if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
 124                                                part_info->start + sector,
 125                                                block_len >> log2blksz,
 126                                                (unsigned long *) buf) !=
 127                                                block_len >> log2blksz) {
 128                 printf(" ** %s read error - block\n", __func__);
 129                 return 0;
 130         }
 131         block_len = byte_len & ~(ext4fs_block_dev_desc->blksz - 1);
 132         buf += block_len;
 133         byte_len -= block_len;
 134         sector += block_len / ext4fs_block_dev_desc->blksz;
 135
 136         if (byte_len != 0) {
 137                 /* read rest of data which are not in whole sector */
 138                 if (ext4fs_block_dev_desc->
 139                     block_read(ext4fs_block_dev_desc->dev,
 140                                 part_info->start + sector, 1,
 141                                 (unsigned long *) sec_buf) != 1) {
 142                         printf("* %s read error - last part\n", __func__);
 143                         return 0;
 144                 }
 145                 memcpy(buf, sec_buf, byte_len);
 146         }
 147         return 1;
 148 }
 149
 150 int ext4_read_superblock(char *buffer)
 151 {
 152         struct ext_filesystem *fs = get_fs();
 153         int sect = SUPERBLOCK_START >> fs->dev_desc->log2blksz;
 154         int off = SUPERBLOCK_START % fs->dev_desc->blksz;
 155
 156         return ext4fs_devread(sect, off, SUPERBLOCK_SIZE,
 157                                 buffer);
 158 }