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 #include <div64.h>
  29
  30 int ext4fs_symlinknest;
  31 struct ext_filesystem ext_fs;
  32
  33 struct ext_filesystem *get_fs(void)
  34 {
  35         return &ext_fs;
  36 }
  37
  38 void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
  39 {
  40         if ((node != &ext4fs_root->diropen) && (node != currroot))
  41                 free(node);
  42 }
  43
  44 /*
  45  * Taken from openmoko-kernel mailing list: By Andy green
  46  * Optimized read file API : collects and defers contiguous sector
  47  * reads into one potentially more efficient larger sequential read action
  48  */
  49 int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
  50                 loff_t len, char *buf, loff_t *actread)
  51 {
  52         struct ext_filesystem *fs = get_fs();
  53         int i;
  54         lbaint_t blockcnt;
  55         int log2blksz = fs->dev_desc->log2blksz;
  56         int log2_fs_blocksize = LOG2_BLOCK_SIZE(node->data) - log2blksz;
  57         int blocksize = (1 << (log2_fs_blocksize + log2blksz));
  58         unsigned int filesize = __le32_to_cpu(node->inode.size);
  59         lbaint_t previous_block_number = -1;
  60         lbaint_t delayed_start = 0;
  61         lbaint_t delayed_extent = 0;
  62         lbaint_t delayed_skipfirst = 0;
  63         lbaint_t delayed_next = 0;
  64         char *delayed_buf = NULL;
  65         short status;
  66
  67         /* Adjust len so it we can't read past the end of the file. */
  68         if (len > filesize)
  69                 len = filesize;
  70
  71         blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
  72
  73         for (i = lldiv(pos, blocksize); i < blockcnt; i++) {
  74                 lbaint_t blknr;
  75                 int blockoff = pos - (blocksize * i);
  76                 int blockend = blocksize;
  77                 int skipfirst = 0;
  78                 blknr = read_allocated_block(&(node->inode), i);
  79                 if (blknr < 0)
  80                         return -1;
  81
  82                 blknr = blknr << log2_fs_blocksize;
  83
  84                 /* Last block.  */
  85                 if (i == blockcnt - 1) {
  86                         blockend = (len + pos) - (blocksize * i);
  87
  88                         /* The last portion is exactly blocksize. */
  89                         if (!blockend)
  90                                 blockend = blocksize;
  91                 }
  92
  93                 /* First block. */
  94                 if (i == lldiv(pos, blocksize)) {
  95                         skipfirst = blockoff;
  96                         blockend -= skipfirst;
  97                 }
  98                 if (blknr) {
  99                         int status;
 100
 101                         if (previous_block_number != -1) {
 102                                 if (delayed_next == blknr) {
 103                                         delayed_extent += blockend;
 104                                         delayed_next += blockend >> log2blksz;
 105                                 } else {        /* spill */
 106                                         status = ext4fs_devread(delayed_start,
 107                                                         delayed_skipfirst,
 108                                                         delayed_extent,
 109                                                         delayed_buf);
 110                                         if (status == 0)
 111                                                 return -1;
 112                                         previous_block_number = blknr;
 113                                         delayed_start = blknr;
 114                                         delayed_extent = blockend;
 115                                         delayed_skipfirst = skipfirst;
 116                                         delayed_buf = buf;
 117                                         delayed_next = blknr +
 118                                                 (blockend >> log2blksz);
 119                                 }
 120                         } else {
 121                                 previous_block_number = blknr;
 122                                 delayed_start = blknr;
 123                                 delayed_extent = blockend;
 124                                 delayed_skipfirst = skipfirst;
 125                                 delayed_buf = buf;
 126                                 delayed_next = blknr +
 127                                         (blockend >> log2blksz);
 128                         }
 129                 } else {
 130                         if (previous_block_number != -1) {
 131                                 /* spill */
 132                                 status = ext4fs_devread(delayed_start,
 133                                                         delayed_skipfirst,
 134                                                         delayed_extent,
 135                                                         delayed_buf);
 136                                 if (status == 0)
 137                                         return -1;
 138                                 previous_block_number = -1;
 139                         }
 140                         memset(buf, 0, blocksize - skipfirst);
 141                 }
 142                 buf += blocksize - skipfirst;
 143         }
 144         if (previous_block_number != -1) {
 145                 /* spill */
 146                 status = ext4fs_devread(delayed_start,
 147                                         delayed_skipfirst, delayed_extent,
 148                                         delayed_buf);
 149                 if (status == 0)
 150                         return -1;
 151                 previous_block_number = -1;
 152         }
 153
 154         *actread  = len;
 155         return 0;
 156 }
 157
 158 int ext4fs_ls(const char *dirname)
 159 {
 160         struct ext2fs_node *dirnode;
 161         int status;
 162
 163         if (dirname == NULL)
 164                 return 0;
 165
 166         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 167                                   FILETYPE_DIRECTORY);
 168         if (status != 1) {
 169                 printf("** Can not find directory. **\n");
 170                 return 1;
 171         }
 172
 173         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 174         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 175
 176         return 0;
 177 }
 178
 179 int ext4fs_exists(const char *filename)
 180 {
 181         loff_t file_len;
 182         int ret;
 183
 184         ret = ext4fs_open(filename, &file_len);
 185         return ret == 0;
 186 }
 187
 188 int ext4fs_size(const char *filename, loff_t *size)
 189 {
 190         return ext4fs_open(filename, size);
 191 }
 192
 193 int ext4fs_read(char *buf, loff_t len, loff_t *actread)
 194 {
 195         if (ext4fs_root == NULL || ext4fs_file == NULL)
 196                 return 0;
 197
 198         return ext4fs_read_file(ext4fs_file, 0, len, buf, actread);
 199 }
 200
 201 int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
 202                  disk_partition_t *fs_partition)
 203 {
 204         ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
 205
 206         if (!ext4fs_mount(fs_partition->size)) {
 207                 ext4fs_close();
 208                 return -1;
 209         }
 210
 211         return 0;
 212 }
 213
 214 int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
 215                    loff_t *len_read)
 216 {
 217         loff_t file_len;
 218         int ret;
 219
 220         if (offset != 0) {
 221                 printf("** Cannot support non-zero offset **\n");
 222                 return -1;
 223         }
 224
 225         ret = ext4fs_open(filename, &file_len);
 226         if (ret < 0) {
 227                 printf("** File not found %s **\n", filename);
 228                 return -1;
 229         }
 230
 231         if (len == 0)
 232                 len = file_len;
 233
 234         return ext4fs_read(buf, len, len_read);
 235 }
 236
 237 int ext4fs_uuid(char *uuid_str)
 238 {
 239         if (ext4fs_root == NULL)
 240                 return -1;
 241
 242 #ifdef CONFIG_LIB_UUID
 243         uuid_bin_to_str((unsigned char *)ext4fs_root->sblock.unique_id,
 244                         uuid_str, UUID_STR_FORMAT_STD);
 245
 246         return 0;
 247 #else
 248         return -ENOSYS;
 249 #endif
 250 }