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         /* Adjust len so it we can't read past the end of the file. */
  67         if (len > filesize)
  68                 len = filesize;
  69
  70         blockcnt = ((len + pos) + blocksize - 1) / blocksize;
  71
  72         for (i = pos / blocksize; i < blockcnt; i++) {
  73                 lbaint_t blknr;
  74                 int blockoff = pos % blocksize;
  75                 int blockend = blocksize;
  76                 int skipfirst = 0;
  77                 blknr = read_allocated_block(&(node->inode), i);
  78                 if (blknr < 0)
  79                         return -1;
  80
  81                 blknr = blknr << log2_fs_blocksize;
  82
  83                 /* Last block.  */
  84                 if (i == blockcnt - 1) {
  85                         blockend = (len + pos) % blocksize;
  86
  87                         /* The last portion is exactly blocksize. */
  88                         if (!blockend)
  89                                 blockend = blocksize;
  90                 }
  91
  92                 /* First block. */
  93                 if (i == pos / blocksize) {
  94                         skipfirst = blockoff;
  95                         blockend -= skipfirst;
  96                 }
  97                 if (blknr) {
  98                         int status;
  99
 100                         if (previous_block_number != -1) {
 101                                 if (delayed_next == blknr) {
 102                                         delayed_extent += blockend;
 103                                         delayed_next += blockend >> log2blksz;
 104                                 } else {        /* spill */
 105                                         status = ext4fs_devread(delayed_start,
 106                                                         delayed_skipfirst,
 107                                                         delayed_extent,
 108                                                         delayed_buf);
 109                                         if (status == 0)
 110                                                 return -1;
 111                                         previous_block_number = blknr;
 112                                         delayed_start = blknr;
 113                                         delayed_extent = blockend;
 114                                         delayed_skipfirst = skipfirst;
 115                                         delayed_buf = buf;
 116                                         delayed_next = blknr +
 117                                                 (blockend >> log2blksz);
 118                                 }
 119                         } else {
 120                                 previous_block_number = blknr;
 121                                 delayed_start = blknr;
 122                                 delayed_extent = blockend;
 123                                 delayed_skipfirst = skipfirst;
 124                                 delayed_buf = buf;
 125                                 delayed_next = blknr +
 126                                         (blockend >> log2blksz);
 127                         }
 128                 } else {
 129                         if (previous_block_number != -1) {
 130                                 /* spill */
 131                                 status = ext4fs_devread(delayed_start,
 132                                                         delayed_skipfirst,
 133                                                         delayed_extent,
 134                                                         delayed_buf);
 135                                 if (status == 0)
 136                                         return -1;
 137                                 previous_block_number = -1;
 138                         }
 139                         memset(buf, 0, blocksize - skipfirst);
 140                 }
 141                 buf += blocksize - skipfirst;
 142         }
 143         if (previous_block_number != -1) {
 144                 /* spill */
 145                 status = ext4fs_devread(delayed_start,
 146                                         delayed_skipfirst, delayed_extent,
 147                                         delayed_buf);
 148                 if (status == 0)
 149                         return -1;
 150                 previous_block_number = -1;
 151         }
 152
 153         return len;
 154 }
 155
 156 int ext4fs_ls(const char *dirname)
 157 {
 158         struct ext2fs_node *dirnode;
 159         int status;
 160
 161         if (dirname == NULL)
 162                 return 0;
 163
 164         status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
 165                                   FILETYPE_DIRECTORY);
 166         if (status != 1) {
 167                 printf("** Can not find directory. **\n");
 168                 return 1;
 169         }
 170
 171         ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
 172         ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 173
 174         return 0;
 175 }
 176
 177 int ext4fs_exists(const char *filename)
 178 {
 179         int file_len;
 180
 181         file_len = ext4fs_open(filename);
 182         return file_len >= 0;
 183 }
 184
 185 int ext4fs_read(char *buf, unsigned len)
 186 {
 187         if (ext4fs_root == NULL || ext4fs_file == NULL)
 188                 return 0;
 189
 190         return ext4fs_read_file(ext4fs_file, 0, len, buf);
 191 }
 192
 193 int ext4fs_probe(block_dev_desc_t *fs_dev_desc,
 194                  disk_partition_t *fs_partition)
 195 {
 196         ext4fs_set_blk_dev(fs_dev_desc, fs_partition);
 197
 198         if (!ext4fs_mount(fs_partition->size)) {
 199                 ext4fs_close();
 200                 return -1;
 201         }
 202
 203         return 0;
 204 }
 205
 206 int ext4_read_file(const char *filename, void *buf, int offset, int len)
 207 {
 208         int file_len;
 209         int len_read;
 210
 211         if (offset != 0) {
 212                 printf("** Cannot support non-zero offset **\n");
 213                 return -1;
 214         }
 215
 216         file_len = ext4fs_open(filename);
 217         if (file_len < 0) {
 218                 printf("** File not found %s **\n", filename);
 219                 return -1;
 220         }
 221
 222         if (len == 0)
 223                 len = file_len;
 224
 225         len_read = ext4fs_read(buf, len);
 226
 227         return len_read;
 228 }