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  * SPDX-License-Identifier:     GPL-2.0+
  18  */
  19
  20 /*
  21  * Changelog:
  22  *      0.1 - Newly created file for ext4fs support. Taken from
  23  *              fs/ext2/dev.c file in uboot.
  24  */
  25
  26 #include <common.h>
  27 #include <config.h>
  28 #include <ext4fs.h>
  29 #include <ext_common.h>
  30 #include "ext4_common.h"
  31
  32 lbaint_t part_offset;
  33
  34 static block_dev_desc_t *ext4fs_block_dev_desc;
  35 static disk_partition_t *part_info;
  36
  37 void ext4fs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
  38 {
  39         assert(rbdd->blksz == (1 << rbdd->log2blksz));
  40         ext4fs_block_dev_desc = rbdd;
  41         get_fs()->dev_desc = rbdd;
  42         part_info = info;
  43         part_offset = info->start;
  44         get_fs()->total_sect = (info->size * info->blksz) >>
  45                 get_fs()->dev_desc->log2blksz;
  46 }
  47
  48 int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
  49 {
  50         unsigned block_len;
  51         int log2blksz = ext4fs_block_dev_desc->log2blksz;
  52         ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (ext4fs_block_dev_desc ?
  53                                                  ext4fs_block_dev_desc->blksz :
  54                                                  0));
  55         if (ext4fs_block_dev_desc == NULL) {
  56                 printf("** Invalid Block Device Descriptor (NULL)\n");
  57                 return 0;
  58         }
  59
  60         /* Check partition boundaries */
  61         if ((sector < 0) ||
  62             ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
  63              >= part_info->size)) {
  64                 printf("%s read outside partition " LBAFU "\n", __func__,
  65                        sector);
  66                 return 0;
  67         }
  68
  69         /* Get the read to the beginning of a partition */
  70         sector += byte_offset >> log2blksz;
  71         byte_offset &= ext4fs_block_dev_desc->blksz - 1;
  72
  73         debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len);
  74
  75         if (byte_offset != 0) {
  76                 /* read first part which isn't aligned with start of sector */
  77                 if (ext4fs_block_dev_desc->
  78                     block_read(ext4fs_block_dev_desc->dev,
  79                                 part_info->start + sector, 1,
  80                                 (unsigned long *) sec_buf) != 1) {
  81                         printf(" ** ext2fs_devread() read error **\n");
  82                         return 0;
  83                 }
  84                 memcpy(buf, sec_buf + byte_offset,
  85                         min(ext4fs_block_dev_desc->blksz
  86                             - byte_offset, byte_len));
  87                 buf += min(ext4fs_block_dev_desc->blksz
  88                            - byte_offset, byte_len);
  89                 byte_len -= min(ext4fs_block_dev_desc->blksz
  90                                 - byte_offset, byte_len);
  91                 sector++;
  92         }
  93
  94         if (byte_len == 0)
  95                 return 1;
  96
  97         /* read sector aligned part */
  98         block_len = byte_len & ~(ext4fs_block_dev_desc->blksz - 1);
  99
 100         if (block_len == 0) {
 101                 ALLOC_CACHE_ALIGN_BUFFER(u8, p, ext4fs_block_dev_desc->blksz);
 102
 103                 block_len = ext4fs_block_dev_desc->blksz;
 104                 ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
 105                                                   part_info->start + sector,
 106                                                   1, (unsigned long *)p);
 107                 memcpy(buf, p, byte_len);
 108                 return 1;
 109         }
 110
 111         if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
 112                                                part_info->start + sector,
 113                                                block_len >> log2blksz,
 114                                                (unsigned long *) buf) !=
 115                                                block_len >> log2blksz) {
 116                 printf(" ** %s read error - block\n", __func__);
 117                 return 0;
 118         }
 119         block_len = byte_len & ~(ext4fs_block_dev_desc->blksz - 1);
 120         buf += block_len;
 121         byte_len -= block_len;
 122         sector += block_len / ext4fs_block_dev_desc->blksz;
 123
 124         if (byte_len != 0) {
 125                 /* read rest of data which are not in whole sector */
 126                 if (ext4fs_block_dev_desc->
 127                     block_read(ext4fs_block_dev_desc->dev,
 128                                 part_info->start + sector, 1,
 129                                 (unsigned long *) sec_buf) != 1) {
 130                         printf("* %s read error - last part\n", __func__);
 131                         return 0;
 132                 }
 133                 memcpy(buf, sec_buf, byte_len);
 134         }
 135         return 1;
 136 }
 137
 138 int ext4_read_superblock(char *buffer)
 139 {
 140         struct ext_filesystem *fs = get_fs();
 141         int sect = SUPERBLOCK_START >> fs->dev_desc->log2blksz;
 142         int off = SUPERBLOCK_START % fs->dev_desc->blksz;
 143
 144         return ext4fs_devread(sect, off, SUPERBLOCK_SIZE,
 145                                 buffer);
 146 }