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 <blk.h>
  25 #include <ext_common.h>
  26 #include <ext4fs.h>
  27 #include "ext4_common.h"
  28 #include <div64.h>
  29 #include <malloc.h>
  30 #include <part.h>
  31 #include <uuid.h>
  32
  33 int ext4fs_symlinknest;
  34 struct ext_filesystem ext_fs;
  35
  36 struct ext_filesystem *get_fs(void)
  37 {
  38         return &ext_fs;
  39 }
  40
  41 void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
  42 {
  43         if ((node != &ext4fs_root->diropen) && (node != currroot))
  44                 free(node);
  45 }
  46
  47 /*
  48  * Taken from openmoko-kernel mailing list: By Andy green
  49  * Optimized read file API : collects and defers contiguous sector
  50  * reads into one potentially more efficient larger sequential read action
  51  */
  52 int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
  53                 loff_t len, char *buf, loff_t *actread)
  54 {
  55         struct ext_filesystem *fs = get_fs();
  56         int i;
  57         lbaint_t blockcnt;
  58         int log2blksz = fs->dev_desc->log2blksz;
  59         int log2_fs_blocksize = LOG2_BLOCK_SIZE(node->data) - log2blksz;
  60         int blocksize = (1 << (log2_fs_blocksize + log2blksz));
  61         unsigned int filesize = le32_to_cpu(node->inode.size);
  62         lbaint_t previous_block_number = -1;
  63         lbaint_t delayed_start = 0;
  64         lbaint_t delayed_extent = 0;
  65         lbaint_t delayed_skipfirst = 0;
  66         lbaint_t delayed_next = 0;
  67         char *delayed_buf = NULL;
  68         char *start_buf = buf;
  69         short status;
  70         struct ext_block_cache cache;
  71
  72         ext_cache_init(&cache);
  73
  74         /* Adjust len so it we can't read past the end of the file. */
  75         if (len + pos > filesize)
  76                 len = (filesize - pos);
  77
  78         if (blocksize <= 0 || len <= 0) {
  79                 ext_cache_fini(&cache);
  80                 return -1;
  81         }
  82
  83         blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
  84
  85         for (i = lldiv(pos, blocksize); i < blockcnt; i++) {
  86                 long int blknr;
  87                 int blockoff = pos - (blocksize * i);
  88                 int blockend = blocksize;
  89                 int skipfirst = 0;
  90                 blknr = read_allocated_block(&node->inode, i, &cache);
  91                 if (blknr < 0) {
  92                         ext_cache_fini(&cache);
  93                         return -1;
  94                 }
  95
  96                 blknr = blknr << log2_fs_blocksize;
  97
  98                 /* Last block.  */
  99                 if (i == blockcnt - 1) {
 100                         blockend = (len + pos) - (blocksize * i);
 101
 102                         /* The last portion is exactly blocksize. */
 103                         if (!blockend)
 104                                 blockend = blocksize;
 105                 }
 106
 107                 /* First block. */
 108                 if (i == lldiv(pos, blocksize)) {
 109                         skipfirst = blockoff;
 110                         blockend -= skipfirst;
 111                 }
 112                 if (blknr) {
 113                         int status;
 114
 115                         if (previous_block_number != -1) {
 116                                 if (delayed_next == blknr) {
 117                                         delayed_extent += blockend;
 118                                         delayed_next += blockend >> log2blksz;
 119                                 } else {        /* spill */
 120                                         status = ext4fs_devread(delayed_start,
 121                                                         delayed_skipfirst,
 122                                                         delayed_extent,
 123                                                         delayed_buf);
 124                                         if (status == 0) {
 125                                                 ext_cache_fini(&cache);
 126                                                 return -1;
 127                                         }
 128                                         previous_block_number = blknr;
 129                                         delayed_start = blknr;
 130                                         delayed_extent = blockend;
 131                                         delayed_skipfirst = skipfirst;
 132                                         delayed_buf = buf;
 133                                         delayed_next = blknr +
 134                                                 (blockend >> log2blksz);
 135                                 }
 136                         } else {
 137                                 previous_block_number = blknr;
 138                                 delayed_start = blknr;
 139                                 delayed_extent = blockend;
 140                                 delayed_skipfirst = skipfirst;
 141                                 delayed_buf = buf;
 142                                 delayed_next = blknr +
 143                                         (blockend >> log2blksz);
 144                         }
 145                 } else {
 146                         int n;
 147                         int n_left;
 148                         if (previous_block_number != -1) {
 149                                 /* spill */
 150                                 status = ext4fs_devread(delayed_start,
 151                                                         delayed_skipfirst,
 152                                                         delayed_extent,
 153                                                         delayed_buf);
 154                                 if (status == 0) {
 155                                         ext_cache_fini(&cache);
 156                                         return -1;
 157                                 }
 158                                 previous_block_number = -1;
 159                         }
 160                         /* Zero no more than `len' bytes. */
 161                         n = blocksize - skipfirst;
 162                         n_left = len - ( buf - start_buf );
 163                         if (n > n_left)
 164                                 n = n_left;
 165                         memset(buf, 0, n);
 166                 }
 167                 buf += blocksize - skipfirst;
 168         }
 169         if (previous_block_number != -1) {
 170                 /* spill */
 171                 status = ext4fs_devread(delayed_start,
 172                                         delayed_skipfirst, delayed_extent,
 173                                         delayed_buf);
 174                 if (status == 0) {
 175                         ext_cache_fini(&cache);
 176                         return -1;
 177                 }
 178                 previous_block_number = -1;
 179         }
 180
 181         *actread  = len;
 182         ext_cache_fini(&cache);
 183         return 0;
 184 }
 185
 186 int ext4fs_ls(const char *dirname)
 187 {
 188         struct ext2fs_node *dirnode = NULL;
 189         int status;
 190
 191         if (dirname == NULL)
 192                 return 0;
 193
 194         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 195                                   FILETYPE_DIRECTORY);
 196         if (status != 1) {
 197                 printf("** Can not find directory. **\n");
 198                 if (dirnode)
 199                         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 200                 return 1;
 201         }
 202
 203         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 204         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 205
 206         return 0;
 207 }
 208
 209 int ext4fs_exists(const char *filename)
 210 {
 211         loff_t file_len;
 212         int ret;
 213
 214         ret = ext4fs_open(filename, &file_len);
 215         return ret == 0;
 216 }
 217
 218 int ext4fs_size(const char *filename, loff_t *size)
 219 {
 220         return ext4fs_open(filename, size);
 221 }
 222
 223 int ext4fs_read(char *buf, loff_t offset, loff_t len, loff_t *actread)
 224 {
 225         if (ext4fs_root == NULL || ext4fs_file == NULL)
 226                 return -1;
 227
 228         return ext4fs_read_file(ext4fs_file, offset, len, buf, actread);
 229 }
 230
 231 int ext4fs_probe(struct blk_desc *fs_dev_desc,
 232                  struct disk_partition *fs_partition)
 233 {
 234         ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
 235
 236         if (!ext4fs_mount(fs_partition->size)) {
 237                 ext4fs_close();
 238                 return -1;
 239         }
 240
 241         return 0;
 242 }
 243
 244 int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
 245                    loff_t *len_read)
 246 {
 247         loff_t file_len;
 248         int ret;
 249
 250         ret = ext4fs_open(filename, &file_len);
 251         if (ret < 0) {
 252                 printf("** File not found %s **\n", filename);
 253                 return -1;
 254         }
 255
 256         if (len == 0)
 257                 len = file_len;
 258
 259         return ext4fs_read(buf, offset, len, len_read);
 260 }
 261
 262 int ext4fs_uuid(char *uuid_str)
 263 {
 264         if (ext4fs_root == NULL)
 265                 return -1;
 266
 267 #ifdef CONFIG_LIB_UUID
 268         uuid_bin_to_str((unsigned char *)ext4fs_root->sblock.unique_id,
 269                         uuid_str, UUID_STR_FORMAT_STD);
 270
 271         return 0;
 272 #else
 273         return -ENOSYS;
 274 #endif
 275 }
 276
 277 void ext_cache_init(struct ext_block_cache *cache)
 278 {
 279         memset(cache, 0, sizeof(*cache));
 280 }
 281
 282 void ext_cache_fini(struct ext_block_cache *cache)
 283 {
 284         free(cache->buf);
 285         ext_cache_init(cache);
 286 }
 287
 288 int ext_cache_read(struct ext_block_cache *cache, lbaint_t block, int size)
 289 {
 290         /* This could be more lenient, but this is simple and enough for now */
 291         if (cache->buf && cache->block == block && cache->size == size)
 292                 return 1;
 293         ext_cache_fini(cache);
 294         cache->buf = memalign(ARCH_DMA_MINALIGN, size);
 295         if (!cache->buf)
 296                 return 0;
 297         if (!ext4fs_devread(block, 0, size, cache->buf)) {
 298                 ext_cache_fini(cache);
 299                 return 0;
 300         }
 301         cache->block = block;
 302         cache->size = size;
 303         return 1;
 304 }