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