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
  66         if (blocksize <= 0)
  67                 return -1;
  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         blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
  74
  75         for (i = lldiv(pos, blocksize); i < blockcnt; i++) {
  76                 long int blknr;
  77                 int blockoff = pos - (blocksize * i);
  78                 int blockend = blocksize;
  79                 int skipfirst = 0;
  80                 blknr = read_allocated_block(&(node->inode), i);
  81                 if (blknr < 0)
  82                         return -1;
  83
  84                 blknr = blknr << log2_fs_blocksize;
  85
  86                 /* Last block.  */
  87                 if (i == blockcnt - 1) {
  88                         blockend = (len + pos) - (blocksize * i);
  89
  90                         /* The last portion is exactly blocksize. */
  91                         if (!blockend)
  92                                 blockend = blocksize;
  93                 }
  94
  95                 /* First block. */
  96                 if (i == lldiv(pos, blocksize)) {
  97                         skipfirst = blockoff;
  98                         blockend -= skipfirst;
  99                 }
 100                 if (blknr) {
 101                         int status;
 102
 103                         if (previous_block_number != -1) {
 104                                 if (delayed_next == blknr) {
 105                                         delayed_extent += blockend;
 106                                         delayed_next += blockend >> log2blksz;
 107                                 } else {        /* spill */
 108                                         status = ext4fs_devread(delayed_start,
 109                                                         delayed_skipfirst,
 110                                                         delayed_extent,
 111                                                         delayed_buf);
 112                                         if (status == 0)
 113                                                 return -1;
 114                                         previous_block_number = blknr;
 115                                         delayed_start = blknr;
 116                                         delayed_extent = blockend;
 117                                         delayed_skipfirst = skipfirst;
 118                                         delayed_buf = buf;
 119                                         delayed_next = blknr +
 120                                                 (blockend >> log2blksz);
 121                                 }
 122                         } else {
 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                         int n;
 133                         if (previous_block_number != -1) {
 134                                 /* spill */
 135                                 status = ext4fs_devread(delayed_start,
 136                                                         delayed_skipfirst,
 137                                                         delayed_extent,
 138                                                         delayed_buf);
 139                                 if (status == 0)
 140                                         return -1;
 141                                 previous_block_number = -1;
 142                         }
 143                         /* Zero no more than `len' bytes. */
 144                         n = blocksize - skipfirst;
 145                         if (n > len)
 146                                 n = len;
 147                         memset(buf, 0, n);
 148                 }
 149                 buf += blocksize - skipfirst;
 150         }
 151         if (previous_block_number != -1) {
 152                 /* spill */
 153                 status = ext4fs_devread(delayed_start,
 154                                         delayed_skipfirst, delayed_extent,
 155                                         delayed_buf);
 156                 if (status == 0)
 157                         return -1;
 158                 previous_block_number = -1;
 159         }
 160
 161         *actread  = len;
 162         return 0;
 163 }
 164
 165 int ext4fs_ls(const char *dirname)
 166 {
 167         struct ext2fs_node *dirnode = NULL;
 168         int status;
 169
 170         if (dirname == NULL)
 171                 return 0;
 172
 173         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 174                                   FILETYPE_DIRECTORY);
 175         if (status != 1) {
 176                 printf("** Can not find directory. **\n");
 177                 if (dirnode)
 178                         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 179                 return 1;
 180         }
 181
 182         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 183         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 184
 185         return 0;
 186 }
 187
 188 int ext4fs_exists(const char *filename)
 189 {
 190         loff_t file_len;
 191         int ret;
 192
 193         ret = ext4fs_open(filename, &file_len);
 194         return ret == 0;
 195 }
 196
 197 int ext4fs_size(const char *filename, loff_t *size)
 198 {
 199         return ext4fs_open(filename, size);
 200 }
 201
 202 int ext4fs_read(char *buf, loff_t offset, loff_t len, loff_t *actread)
 203 {
 204         if (ext4fs_root == NULL || ext4fs_file == NULL)
 205                 return -1;
 206
 207         return ext4fs_read_file(ext4fs_file, offset, len, buf, actread);
 208 }
 209
 210 int ext4fs_probe(struct blk_desc *fs_dev_desc,
 211                  disk_partition_t *fs_partition)
 212 {
 213         ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
 214
 215         if (!ext4fs_mount(fs_partition->size)) {
 216                 ext4fs_close();
 217                 return -1;
 218         }
 219
 220         return 0;
 221 }
 222
 223 int ext4_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
 224                    loff_t *len_read)
 225 {
 226         loff_t file_len;
 227         int ret;
 228
 229         ret = ext4fs_open(filename, &file_len);
 230         if (ret < 0) {
 231                 printf("** File not found %s **\n", filename);
 232                 return -1;
 233         }
 234
 235         if (len == 0)
 236                 len = file_len;
 237
 238         return ext4fs_read(buf, offset, len, len_read);
 239 }
 240
 241 int ext4fs_uuid(char *uuid_str)
 242 {
 243         if (ext4fs_root == NULL)
 244                 return -1;
 245
 246 #ifdef CONFIG_LIB_UUID
 247         uuid_bin_to_str((unsigned char *)ext4fs_root->sblock.unique_id,
 248                         uuid_str, UUID_STR_FORMAT_STD);
 249
 250         return 0;
 251 #else
 252         return -ENOSYS;
 253 #endif
 254 }