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