fs/ext4/ext4fs.c

   1 /*
   2  * (C) Copyright 2011 - 2012 Samsung Electronics
   3  * EXT4 filesystem implementation in Uboot by
   4  * Uma Shankar <uma.shankar@samsung.com>
   5  * Manjunatha C Achar <a.manjunatha@samsung.com>
   6  *
   7  * ext4ls and ext4load : Based on ext2 ls and load support in Uboot.
   8  *                     Ext4 read optimization taken from Open-Moko
   9  *                     Qi bootloader
  10  *
  11  * (C) Copyright 2004
  12  * esd gmbh <www.esd-electronics.com>
  13  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
  14  *
  15  * based on code from grub2 fs/ext2.c and fs/fshelp.c by
  16  * GRUB  --  GRand Unified Bootloader
  17  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
  18  *
  19  * ext4write : Based on generic ext4 protocol.
  20  *
  21  * SPDX-License-Identifier:     GPL-2.0+
  22  */
  23
  24 #include <common.h>
  25 #include <ext_common.h>
  26 #include <ext4fs.h>
  27 #include "ext4_common.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, int pos,
  49                 unsigned int len, char *buf)
  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 (le32_to_cpu(node->inode.flags) & EXT4_EXTENTS_FL) {
  67                 if (ext4fs_build_extent_cache(&node->inode)) {
  68                         printf("Error building extent cache!\n");
  69                         len = -1;
  70                         goto out_exit;
  71                 }
  72         }
  73
  74         /* Adjust len so it we can't read past the end of the file. */
  75         if (len > filesize)
  76                 len = filesize;
  77
  78         blockcnt = ((len + pos) + blocksize - 1) / blocksize;
  79
  80         for (i = pos / blocksize; i < blockcnt; i++) {
  81                 lbaint_t blknr;
  82                 int blockoff = pos % blocksize;
  83                 int blockend = blocksize;
  84                 int skipfirst = 0;
  85                 blknr = read_allocated_block(&(node->inode), i);
  86                 if (blknr < 0) {
  87                         len = -1;
  88                         goto out_exit;
  89                 }
  90
  91                 blknr = blknr << log2_fs_blocksize;
  92
  93                 /* Last block.  */
  94                 if (i == blockcnt - 1) {
  95                         blockend = (len + pos) % blocksize;
  96
  97                         /* The last portion is exactly blocksize. */
  98                         if (!blockend)
  99                                 blockend = blocksize;
 100                 }
 101
 102                 /* First block. */
 103                 if (i == 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                                                 len = -1;
 121                                                 goto out_exit;
 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                         if (previous_block_number != -1) {
 142                                 /* spill */
 143                                 status = ext4fs_devread(delayed_start,
 144                                                         delayed_skipfirst,
 145                                                         delayed_extent,
 146                                                         delayed_buf);
 147                                 if (status == 0) {
 148                                         len = -1;
 149                                         goto out_exit;
 150                                 }
 151                                 previous_block_number = -1;
 152                         }
 153                         memset(buf, 0, blocksize - skipfirst);
 154                 }
 155                 buf += blocksize - skipfirst;
 156         }
 157         if (previous_block_number != -1) {
 158                 /* spill */
 159                 status = ext4fs_devread(delayed_start,
 160                                         delayed_skipfirst, delayed_extent,
 161                                         delayed_buf);
 162                 if (status == 0) {
 163                         len = -1;
 164                         goto out_exit;
 165                 }
 166                 previous_block_number = -1;
 167         }
 168
 169
 170 out_exit:
 171         ext4fs_free_extent_cache();
 172
 173         return len;
 174 }
 175
 176 int ext4fs_ls(const char *dirname)
 177 {
 178         struct ext2fs_node *dirnode;
 179         int status;
 180
 181         if (dirname == NULL)
 182                 return 0;
 183
 184         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 185                                   FILETYPE_DIRECTORY);
 186         if (status != 1) {
 187                 printf("** Can not find directory. **\n");
 188                 return 1;
 189         }
 190
 191         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 192         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 193
 194         return 0;
 195 }
 196
 197 int ext4fs_exists(const char *filename)
 198 {
 199         int file_len;
 200
 201         file_len = ext4fs_open(filename);
 202         return file_len >= 0;
 203 }
 204
 205 int ext4fs_read(char *buf, unsigned len)
 206 {
 207         if (ext4fs_root == NULL || ext4fs_file == NULL)
 208                 return 0;
 209
 210         return ext4fs_read_file(ext4fs_file, 0, len, buf);
 211 }
 212
 213 int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
 214                  disk_partition_t *fs_partition)
 215 {
 216         ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
 217
 218         if (!ext4fs_mount(fs_partition->size)) {
 219                 ext4fs_close();
 220                 return -1;
 221         }
 222
 223         return 0;
 224 }
 225
 226 int ext4_read_file(const char *filename, void *buf, int offset, int len)
 227 {
 228         int file_len;
 229         int len_read;
 230
 231         if (offset != 0) {
 232                 printf("** Cannot support non-zero offset **\n");
 233                 return -1;
 234         }
 235
 236         file_len = ext4fs_open(filename);
 237         if (file_len < 0) {
 238                 printf("** File not found %s **\n", filename);
 239                 return -1;
 240         }
 241
 242         if (len == 0)
 243                 len = file_len;
 244
 245         len_read = ext4fs_read(buf, len);
 246
 247         return len_read;
 248 }