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 <blk.h>
  28 #include <config.h>
  29 #include <memalign.h>
  30 #include <ext4fs.h>
  31 #include <ext_common.h>
  32 #include "ext4_common.h"
  33
  34 lbaint_t part_offset;
  35
  36 static struct blk_desc *ext4fs_blk_desc;
  37 static disk_partition_t *part_info;
  38
  39 void ext4fs_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info)
  40 {
  41         assert(rbdd->blksz == (1 << rbdd->log2blksz));
  42         ext4fs_blk_desc = rbdd;
  43         get_fs()->dev_desc = rbdd;
  44         part_info = info;
  45         part_offset = info->start;
  46         get_fs()->total_sect = ((uint64_t)info->size * info->blksz) >>
  47                 get_fs()->dev_desc->log2blksz;
  48 }
  49
  50 int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
  51 {
  52         unsigned block_len;
  53         int log2blksz = ext4fs_blk_desc->log2blksz;
  54         ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (ext4fs_blk_desc ?
  55                                                  ext4fs_blk_desc->blksz :
  56                                                  0));
  57         if (ext4fs_blk_desc == NULL) {
  58                 printf("** Invalid Block Device Descriptor (NULL)\n");
  59                 return 0;
  60         }
  61
  62         /* Check partition boundaries */
  63         if ((sector < 0) ||
  64             ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
  65              >= part_info->size)) {
  66                 printf("%s read outside partition " LBAFU "\n", __func__,
  67                        sector);
  68                 return 0;
  69         }
  70
  71         /* Get the read to the beginning of a partition */
  72         sector += byte_offset >> log2blksz;
  73         byte_offset &= ext4fs_blk_desc->blksz - 1;
  74
  75         debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len);
  76
  77         if (byte_offset != 0) {
  78                 int readlen;
  79                 /* read first part which isn't aligned with start of sector */
  80                 if (blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
  81                               (void *)sec_buf) != 1) {
  82                         printf(" ** ext2fs_devread() read error **\n");
  83                         return 0;
  84                 }
  85                 readlen = min((int)ext4fs_blk_desc->blksz - byte_offset,
  86                               byte_len);
  87                 memcpy(buf, sec_buf + byte_offset, readlen);
  88                 buf += readlen;
  89                 byte_len -= readlen;
  90                 sector++;
  91         }
  92
  93         if (byte_len == 0)
  94                 return 1;
  95
  96         /* read sector aligned part */
  97         block_len = byte_len & ~(ext4fs_blk_desc->blksz - 1);
  98
  99         if (block_len == 0) {
 100                 ALLOC_CACHE_ALIGN_BUFFER(u8, p, ext4fs_blk_desc->blksz);
 101
 102                 block_len = ext4fs_blk_desc->blksz;
 103                 blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
 104                           (void *)p);
 105                 memcpy(buf, p, byte_len);
 106                 return 1;
 107         }
 108
 109         if (blk_dread(ext4fs_blk_desc, part_info->start + sector,
 110                       block_len >> log2blksz, (void *)buf) !=
 111                         block_len >> log2blksz) {
 112                 printf(" ** %s read error - block\n", __func__);
 113                 return 0;
 114         }
 115         block_len = byte_len & ~(ext4fs_blk_desc->blksz - 1);
 116         buf += block_len;
 117         byte_len -= block_len;
 118         sector += block_len / ext4fs_blk_desc->blksz;
 119
 120         if (byte_len != 0) {
 121                 /* read rest of data which are not in whole sector */
 122                 if (blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
 123                               (void *)sec_buf) != 1) {
 124                         printf("* %s read error - last part\n", __func__);
 125                         return 0;
 126                 }
 127                 memcpy(buf, sec_buf, byte_len);
 128         }
 129         return 1;
 130 }
 131
 132 int ext4_read_superblock(char *buffer)
 133 {
 134         struct ext_filesystem *fs = get_fs();
 135         int sect = SUPERBLOCK_START >> fs->dev_desc->log2blksz;
 136         int off = SUPERBLOCK_START % fs->dev_desc->blksz;
 137
 138         return ext4fs_devread(sect, off, SUPERBLOCK_SIZE,
 139                                 buffer);
 140 }