fs/ext4/ext4fs.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  * ext4ls and ext4load : Based on ext2 ls and load support in Uboot.
   8  *                     Ext4 read optimization taken from Open-Moko
   9  *                     Qi bootloader
  10  *
  11  * (C) Copyright 2004
  12  * esd gmbh <www.esd-electronics.com>
  13  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
  14  *
  15  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
  16  * GRUB  --  GRand Unified Bootloader
  17  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
  18  *
  19  * ext4write : Based on generic ext4 protocol.
  20  *
  21  * SPDX-License-Identifier:     GPL-2.0+
  22  */
  23
  24 #include <common.h>
  25 #include <ext_common.h>
  26 #include <ext4fs.h>
  27 #include "ext4_common.h"
  28
  29 int ext4fs_symlinknest;
  30 struct ext_filesystem ext_fs;
  31
  32 struct ext_filesystem *get_fs(void)
  33 {
  34         return &ext_fs;
  35 }
  36
  37 void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
  38 {
  39         if ((node != &ext4fs_root->diropen) && (node != currroot))
  40                 free(node);
  41 }
  42
  43 /*
  44  * Taken from openmoko-kernel mailing list: By Andy green
  45  * Optimized read file API : collects and defers contiguous sector
  46  * reads into one potentially more efficient larger sequential read action
  47  */
  48 int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
  49                 loff_t len, char *buf, loff_t *actread)
  50 {
  51         struct ext_filesystem *fs = get_fs();
  52         int i;
  53         lbaint_t blockcnt;
  54         int log2blksz = fs->dev_desc->log2blksz;
  55         int log2_fs_blocksize = LOG2_BLOCK_SIZE(node->data) - log2blksz;
  56         int blocksize = (1 << (log2_fs_blocksize + log2blksz));
  57         unsigned int filesize = __le32_to_cpu(node->inode.size);
  58         lbaint_t previous_block_number = -1;
  59         lbaint_t delayed_start = 0;
  60         lbaint_t delayed_extent = 0;
  61         lbaint_t delayed_skipfirst = 0;
  62         lbaint_t delayed_next = 0;
  63         char *delayed_buf = NULL;
  64         short status;
  65
  66         /* Adjust len so it we can't read past the end of the file. */
  67         if (len > filesize)
  68                 len = filesize;
  69
  70         blockcnt = ((len + pos) + blocksize - 1) / blocksize;
  71
  72         for (i = pos / blocksize; i < blockcnt; i++) {
  73                 lbaint_t blknr;
  74                 int blockoff = pos % blocksize;
  75                 int blockend = blocksize;
  76                 int skipfirst = 0;
  77                 blknr = read_allocated_block(&(node->inode), i);
  78                 if (blknr < 0)
  79                         return -1;
  80
  81                 blknr = blknr << log2_fs_blocksize;
  82
  83                 /* Last block.  */
  84                 if (i == blockcnt - 1) {
  85                         blockend = (len + pos) % blocksize;
  86
  87                         /* The last portion is exactly blocksize. */
  88                         if (!blockend)
  89                                 blockend = blocksize;
  90                 }
  91
  92                 /* First block. */
  93                 if (i == pos / blocksize) {
  94                         skipfirst = blockoff;
  95                         blockend -= skipfirst;
  96                 }
  97                 if (blknr) {
  98                         int status;
  99
 100                         if (previous_block_number != -1) {
 101                                 if (delayed_next == blknr) {
 102                                         delayed_extent += blockend;
 103                                         delayed_next += blockend >> log2blksz;
 104                                 } else {        /* spill */
 105                                         status = ext4fs_devread(delayed_start,
 106                                                         delayed_skipfirst,
 107                                                         delayed_extent,
 108                                                         delayed_buf);
 109                                         if (status == 0)
 110                                                 return -1;
 111                                         previous_block_number = blknr;
 112                                         delayed_start = blknr;
 113                                         delayed_extent = blockend;
 114                                         delayed_skipfirst = skipfirst;
 115                                         delayed_buf = buf;
 116                                         delayed_next = blknr +
 117                                                 (blockend >> log2blksz);
 118                                 }
 119                         } else {
 120                                 previous_block_number = blknr;
 121                                 delayed_start = blknr;
 122                                 delayed_extent = blockend;
 123                                 delayed_skipfirst = skipfirst;
 124                                 delayed_buf = buf;
 125                                 delayed_next = blknr +
 126                                         (blockend >> log2blksz);
 127                         }
 128                 } else {
 129                         if (previous_block_number != -1) {
 130                                 /* spill */
 131                                 status = ext4fs_devread(delayed_start,
 132                                                         delayed_skipfirst,
 133                                                         delayed_extent,
 134                                                         delayed_buf);
 135                                 if (status == 0)
 136                                         return -1;
 137                                 previous_block_number = -1;
 138                         }
 139                         memset(buf, 0, blocksize - skipfirst);
 140                 }
 141                 buf += blocksize - skipfirst;
 142         }
 143         if (previous_block_number != -1) {
 144                 /* spill */
 145                 status = ext4fs_devread(delayed_start,
 146                                         delayed_skipfirst, delayed_extent,
 147                                         delayed_buf);
 148                 if (status == 0)
 149                         return -1;
 150                 previous_block_number = -1;
 151         }
 152
 153         *actread  = len;
 154         return 0;
 155 }
 156
 157 int ext4fs_ls(const char *dirname)
 158 {
 159         struct ext2fs_node *dirnode;
 160         int status;
 161
 162         if (dirname == NULL)
 163                 return 0;
 164
 165         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 166                                   FILETYPE_DIRECTORY);
 167         if (status != 1) {
 168                 printf("** Can not find directory. **\n");
 169                 return 1;
 170         }
 171
 172         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 173         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 174
 175         return 0;
 176 }
 177
 178 int ext4fs_exists(const char *filename)
 179 {
 180         loff_t file_len;
 181         int ret;
 182
 183         ret = ext4fs_open(filename, &file_len);
 184         return ret == 0;
 185 }
 186
 187 int ext4fs_size(const char *filename)
 188 {
 189         loff_t  size;
 190         int ret;
 191
 192         ret = ext4fs_open(filename, &size);
 193         if (ret)
 194                 return ret;
 195         else
 196                 return size;
 197 }
 198
 199 int ext4fs_read(char *buf, loff_t len, loff_t *actread)
 200 {
 201         if (ext4fs_root == NULL || ext4fs_file == NULL)
 202                 return 0;
 203
 204         return ext4fs_read_file(ext4fs_file, 0, len, buf, actread);
 205 }
 206
 207 int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
 208                  disk_partition_t *fs_partition)
 209 {
 210         ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
 211
 212         if (!ext4fs_mount(fs_partition->size)) {
 213                 ext4fs_close();
 214                 return -1;
 215         }
 216
 217         return 0;
 218 }
 219
 220 int ext4_read_file(const char *filename, void *buf, int offset, int len)
 221 {
 222         loff_t file_len;
 223         loff_t len_read;
 224         int ret;
 225
 226         if (offset != 0) {
 227                 printf("** Cannot support non-zero offset **\n");
 228                 return -1;
 229         }
 230
 231         ret = ext4fs_open(filename, &file_len);
 232         if (ret < 0) {
 233                 printf("** File not found %s **\n", filename);
 234                 return -1;
 235         }
 236
 237         if (len == 0)
 238                 len = file_len;
 239
 240         ret = ext4fs_read(buf, len, &len_read);
 241
 242         if (ret)
 243                 return ret;
 244         else
 245                 return len_read;
 246 }
 247
 248 int ext4fs_uuid(char *uuid_str)
 249 {
 250         if (ext4fs_root == NULL)
 251                 return -1;
 252
 253 #ifdef CONFIG_LIB_UUID
 254         uuid_bin_to_str((unsigned char *)ext4fs_root->sblock.unique_id,
 255                         uuid_str, UUID_STR_FORMAT_STD);
 256
 257         return 0;
 258 #else
 259         return -ENOSYS;
 260 #endif
 261 }