fs/ext4/ext4fs.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2011 - 2012 Samsung Electronics
   4  * EXT4 filesystem implementation in Uboot by
   5  * Uma Shankar <uma.shankar@samsung.com>
   6  * Manjunatha C Achar <a.manjunatha@samsung.com>
   7  *
   8  * ext4ls and ext4load : Based on ext2 ls and load support in Uboot.
   9  *                     Ext4 read optimization taken from Open-Moko
  10  *                     Qi bootloader
  11  *
  12  * (C) Copyright 2004
  13  * esd gmbh <www.esd-electronics.com>
  14  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
  15  *
  16  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
  17  * GRUB  --  GRand Unified Bootloader
  18  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
  19  *
  20  * ext4write : Based on generic ext4 protocol.
  21  */
  22
  23 #include <common.h>
  24 #include <ext_common.h>
  25 #include <ext4fs.h>
  26 #include "ext4_common.h"
  27 #include <div64.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         struct ext_block_cache cache;
  66
  67         ext_cache_init(&cache);
  68
  69         if (blocksize <= 0)
  70                 return -1;
  71
  72         /* Adjust len so it we can't read past the end of the file. */
  73         if (len + pos > filesize)
  74                 len = (filesize - pos);
  75
  76         blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
  77
  78         for (i = lldiv(pos, blocksize); i < blockcnt; i++) {
  79                 long int blknr;
  80                 int blockoff = pos - (blocksize * i);
  81                 int blockend = blocksize;
  82                 int skipfirst = 0;
  83                 blknr = read_allocated_block(&node->inode, i, &cache);
  84                 if (blknr < 0) {
  85                         ext_cache_fini(&cache);
  86                         return -1;
  87                 }
  88
  89                 blknr = blknr << log2_fs_blocksize;
  90
  91                 /* Last block.  */
  92                 if (i == blockcnt - 1) {
  93                         blockend = (len + pos) - (blocksize * i);
  94
  95                         /* The last portion is exactly blocksize. */
  96                         if (!blockend)
  97                                 blockend = blocksize;
  98                 }
  99
 100                 /* First block. */
 101                 if (i == lldiv(pos, blocksize)) {
 102                         skipfirst = blockoff;
 103                         blockend -= skipfirst;
 104                 }
 105                 if (blknr) {
 106                         int status;
 107
 108                         if (previous_block_number != -1) {
 109                                 if (delayed_next == blknr) {
 110                                         delayed_extent += blockend;
 111                                         delayed_next += blockend >> log2blksz;
 112                                 } else {        /* spill */
 113                                         status = ext4fs_devread(delayed_start,
 114                                                         delayed_skipfirst,
 115                                                         delayed_extent,
 116                                                         delayed_buf);
 117                                         if (status == 0) {
 118                                                 ext_cache_fini(&cache);
 119                                                 return -1;
 120                                         }
 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                                 previous_block_number = blknr;
 131                                 delayed_start = blknr;
 132                                 delayed_extent = blockend;
 133                                 delayed_skipfirst = skipfirst;
 134                                 delayed_buf = buf;
 135                                 delayed_next = blknr +
 136                                         (blockend >> log2blksz);
 137                         }
 138                 } else {
 139                         int n;
 140                         if (previous_block_number != -1) {
 141                                 /* spill */
 142                                 status = ext4fs_devread(delayed_start,
 143                                                         delayed_skipfirst,
 144                                                         delayed_extent,
 145                                                         delayed_buf);
 146                                 if (status == 0) {
 147                                         ext_cache_fini(&cache);
 148                                         return -1;
 149                                 }
 150                                 previous_block_number = -1;
 151                         }
 152                         /* Zero no more than `len' bytes. */
 153                         n = blocksize - skipfirst;
 154                         if (n > len)
 155                                 n = len;
 156                         memset(buf, 0, n);
 157                 }
 158                 buf += blocksize - skipfirst;
 159         }
 160         if (previous_block_number != -1) {
 161                 /* spill */
 162                 status = ext4fs_devread(delayed_start,
 163                                         delayed_skipfirst, delayed_extent,
 164                                         delayed_buf);
 165                 if (status == 0) {
 166                         ext_cache_fini(&cache);
 167                         return -1;
 168                 }
 169                 previous_block_number = -1;
 170         }
 171
 172         *actread  = len;
 173         ext_cache_fini(&cache);
 174         return 0;
 175 }
 176
 177 int ext4fs_ls(const char *dirname)
 178 {
 179         struct ext2fs_node *dirnode = NULL;
 180         int status;
 181
 182         if (dirname == NULL)
 183                 return 0;
 184
 185         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 186                                   FILETYPE_DIRECTORY);
 187         if (status != 1) {
 188                 printf("** Can not find directory. **\n");
 189                 if (dirnode)
 190                         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 191                 return 1;
 192         }
 193
 194         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 195         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 196
 197         return 0;
 198 }
 199
 200 int ext4fs_exists(const char *filename)
 201 {
 202         loff_t file_len;
 203         int ret;
 204
 205         ret = ext4fs_open(filename, &file_len);
 206         return ret == 0;
 207 }
 208
 209 int ext4fs_size(const char *filename, loff_t *size)
 210 {
 211         return ext4fs_open(filename, size);
 212 }
 213
 214 int ext4fs_read(char *buf, loff_t offset, loff_t len, loff_t *actread)
 215 {
 216         if (ext4fs_root == NULL || ext4fs_file == NULL)
 217                 return -1;
 218
 219         return ext4fs_read_file(ext4fs_file, offset, len, buf, actread);
 220 }
 221
 222 int ext4fs_probe(struct blk_desc *fs_dev_desc,
 223                  disk_partition_t *fs_partition)
 224 {
 225         ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
 226
 227         if (!ext4fs_mount(fs_partition->size)) {
 228                 ext4fs_close();
 229                 return -1;
 230         }
 231
 232         return 0;
 233 }
 234
 235 int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
 236                    loff_t *len_read)
 237 {
 238         loff_t file_len;
 239         int ret;
 240
 241         ret = ext4fs_open(filename, &file_len);
 242         if (ret < 0) {
 243                 printf("** File not found %s **\n", filename);
 244                 return -1;
 245         }
 246
 247         if (len == 0)
 248                 len = file_len;
 249
 250         return ext4fs_read(buf, offset, len, len_read);
 251 }
 252
 253 int ext4fs_uuid(char *uuid_str)
 254 {
 255         if (ext4fs_root == NULL)
 256                 return -1;
 257
 258 #ifdef CONFIG_LIB_UUID
 259         uuid_bin_to_str((unsigned char *)ext4fs_root->sblock.unique_id,
 260                         uuid_str, UUID_STR_FORMAT_STD);
 261
 262         return 0;
 263 #else
 264         return -ENOSYS;
 265 #endif
 266 }
 267
 268 void ext_cache_init(struct ext_block_cache *cache)
 269 {
 270         memset(cache, 0, sizeof(*cache));
 271 }
 272
 273 void ext_cache_fini(struct ext_block_cache *cache)
 274 {
 275         free(cache->buf);
 276         ext_cache_init(cache);
 277 }
 278
 279 int ext_cache_read(struct ext_block_cache *cache, lbaint_t block, int size)
 280 {
 281         /* This could be more lenient, but this is simple and enough for now */
 282         if (cache->buf && cache->block == block && cache->size == size)
 283                 return 1;
 284         ext_cache_fini(cache);
 285         cache->buf = malloc(size);
 286         if (!cache->buf)
 287                 return 0;
 288         if (!ext4fs_devread(block, 0, size, cache->buf)) {
 289                 free(cache->buf);
 290                 return 0;
 291         }
 292         cache->block = block;
 293         cache->size = size;
 294         return 1;
 295 }