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 #include <malloc.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         char *start_buf = buf;
  66         short status;
  67         struct ext_block_cache cache;
  68
  69         ext_cache_init(&cache);
  70
  71         /* Adjust len so it we can't read past the end of the file. */
  72         if (len + pos > filesize)
  73                 len = (filesize - pos);
  74
  75         if (blocksize <= 0 || len <= 0) {
  76                 ext_cache_fini(&cache);
  77                 return -1;
  78         }
  79
  80         blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
  81
  82         for (i = lldiv(pos, blocksize); i < blockcnt; i++) {
  83                 long int blknr;
  84                 int blockoff = pos - (blocksize * i);
  85                 int blockend = blocksize;
  86                 int skipfirst = 0;
  87                 blknr = read_allocated_block(&node->inode, i, &cache);
  88                 if (blknr < 0) {
  89                         ext_cache_fini(&cache);
  90                         return -1;
  91                 }
  92
  93                 blknr = blknr << log2_fs_blocksize;
  94
  95                 /* Last block.  */
  96                 if (i == blockcnt - 1) {
  97                         blockend = (len + pos) - (blocksize * i);
  98
  99                         /* The last portion is exactly blocksize. */
 100                         if (!blockend)
 101                                 blockend = blocksize;
 102                 }
 103
 104                 /* First block. */
 105                 if (i == lldiv(pos, blocksize)) {
 106                         skipfirst = blockoff;
 107                         blockend -= skipfirst;
 108                 }
 109                 if (blknr) {
 110                         int status;
 111
 112                         if (previous_block_number != -1) {
 113                                 if (delayed_next == blknr) {
 114                                         delayed_extent += blockend;
 115                                         delayed_next += blockend >> log2blksz;
 116                                 } else {        /* spill */
 117                                         status = ext4fs_devread(delayed_start,
 118                                                         delayed_skipfirst,
 119                                                         delayed_extent,
 120                                                         delayed_buf);
 121                                         if (status == 0) {
 122                                                 ext_cache_fini(&cache);
 123                                                 return -1;
 124                                         }
 125                                         previous_block_number = blknr;
 126                                         delayed_start = blknr;
 127                                         delayed_extent = blockend;
 128                                         delayed_skipfirst = skipfirst;
 129                                         delayed_buf = buf;
 130                                         delayed_next = blknr +
 131                                                 (blockend >> log2blksz);
 132                                 }
 133                         } else {
 134                                 previous_block_number = blknr;
 135                                 delayed_start = blknr;
 136                                 delayed_extent = blockend;
 137                                 delayed_skipfirst = skipfirst;
 138                                 delayed_buf = buf;
 139                                 delayed_next = blknr +
 140                                         (blockend >> log2blksz);
 141                         }
 142                 } else {
 143                         int n;
 144                         int n_left;
 145                         if (previous_block_number != -1) {
 146                                 /* spill */
 147                                 status = ext4fs_devread(delayed_start,
 148                                                         delayed_skipfirst,
 149                                                         delayed_extent,
 150                                                         delayed_buf);
 151                                 if (status == 0) {
 152                                         ext_cache_fini(&cache);
 153                                         return -1;
 154                                 }
 155                                 previous_block_number = -1;
 156                         }
 157                         /* Zero no more than `len' bytes. */
 158                         n = blocksize - skipfirst;
 159                         n_left = len - ( buf - start_buf );
 160                         if (n > n_left)
 161                                 n = n_left;
 162                         memset(buf, 0, n);
 163                 }
 164                 buf += blocksize - skipfirst;
 165         }
 166         if (previous_block_number != -1) {
 167                 /* spill */
 168                 status = ext4fs_devread(delayed_start,
 169                                         delayed_skipfirst, delayed_extent,
 170                                         delayed_buf);
 171                 if (status == 0) {
 172                         ext_cache_fini(&cache);
 173                         return -1;
 174                 }
 175                 previous_block_number = -1;
 176         }
 177
 178         *actread  = len;
 179         ext_cache_fini(&cache);
 180         return 0;
 181 }
 182
 183 int ext4fs_ls(const char *dirname)
 184 {
 185         struct ext2fs_node *dirnode = NULL;
 186         int status;
 187
 188         if (dirname == NULL)
 189                 return 0;
 190
 191         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 192                                   FILETYPE_DIRECTORY);
 193         if (status != 1) {
 194                 printf("** Can not find directory. **\n");
 195                 if (dirnode)
 196                         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 197                 return 1;
 198         }
 199
 200         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 201         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 202
 203         return 0;
 204 }
 205
 206 int ext4fs_exists(const char *filename)
 207 {
 208         loff_t file_len;
 209         int ret;
 210
 211         ret = ext4fs_open(filename, &file_len);
 212         return ret == 0;
 213 }
 214
 215 int ext4fs_size(const char *filename, loff_t *size)
 216 {
 217         return ext4fs_open(filename, size);
 218 }
 219
 220 int ext4fs_read(char *buf, loff_t offset, loff_t len, loff_t *actread)
 221 {
 222         if (ext4fs_root == NULL || ext4fs_file == NULL)
 223                 return -1;
 224
 225         return ext4fs_read_file(ext4fs_file, offset, len, buf, actread);
 226 }
 227
 228 int ext4fs_probe(struct blk_desc *fs_dev_desc,
 229                  disk_partition_t *fs_partition)
 230 {
 231         ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
 232
 233         if (!ext4fs_mount(fs_partition->size)) {
 234                 ext4fs_close();
 235                 return -1;
 236         }
 237
 238         return 0;
 239 }
 240
 241 int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
 242                    loff_t *len_read)
 243 {
 244         loff_t file_len;
 245         int ret;
 246
 247         ret = ext4fs_open(filename, &file_len);
 248         if (ret < 0) {
 249                 printf("** File not found %s **\n", filename);
 250                 return -1;
 251         }
 252
 253         if (len == 0)
 254                 len = file_len;
 255
 256         return ext4fs_read(buf, offset, len, len_read);
 257 }
 258
 259 int ext4fs_uuid(char *uuid_str)
 260 {
 261         if (ext4fs_root == NULL)
 262                 return -1;
 263
 264 #ifdef CONFIG_LIB_UUID
 265         uuid_bin_to_str((unsigned char *)ext4fs_root->sblock.unique_id,
 266                         uuid_str, UUID_STR_FORMAT_STD);
 267
 268         return 0;
 269 #else
 270         return -ENOSYS;
 271 #endif
 272 }
 273
 274 void ext_cache_init(struct ext_block_cache *cache)
 275 {
 276         memset(cache, 0, sizeof(*cache));
 277 }
 278
 279 void ext_cache_fini(struct ext_block_cache *cache)
 280 {
 281         free(cache->buf);
 282         ext_cache_init(cache);
 283 }
 284
 285 int ext_cache_read(struct ext_block_cache *cache, lbaint_t block, int size)
 286 {
 287         /* This could be more lenient, but this is simple and enough for now */
 288         if (cache->buf && cache->block == block && cache->size == size)
 289                 return 1;
 290         ext_cache_fini(cache);
 291         cache->buf = malloc(size);
 292         if (!cache->buf)
 293                 return 0;
 294         if (!ext4fs_devread(block, 0, size, cache->buf)) {
 295                 ext_cache_fini(cache);
 296                 return 0;
 297         }
 298         cache->block = block;
 299         cache->size = size;
 300         return 1;
 301 }