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