3 exFAT file system implementation library.
5 Copyright (C) 2009, 2010 Andrew Nayenko
7 This program is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
27 #include <sys/types.h>
29 #define _XOPEN_SOURCE /* for tzset() in Linux */
32 static uint64_t rootdir_size(const struct exfat* ef)
34 uint64_t clusters = 0;
35 cluster_t rootdir_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
37 while (!CLUSTER_INVALID(rootdir_cluster))
40 /* root directory cannot be contiguous because there is no flag
42 rootdir_cluster = exfat_next_cluster(ef, ef->root, rootdir_cluster);
44 return clusters * CLUSTER_SIZE(*ef->sb);
47 static const char* get_option(const char* options, const char* option_name)
50 size_t length = strlen(option_name);
52 for (p = strstr(options, option_name); p; p = strstr(p + 1, option_name))
53 if ((p == options || p[-1] == ',') && p[length] == '=')
54 return p + length + 1;
58 static int get_int_option(const char* options, const char* option_name,
59 int base, int default_value)
61 const char* p = get_option(options, option_name);
65 return strtol(p, NULL, base);
68 static int match_option(const char* options, const char* option_name)
71 size_t length = strlen(option_name);
73 for (p = strstr(options, option_name); p; p = strstr(p + 1, option_name))
74 if ((p == options || p[-1] == ',') &&
75 (p[length] == ',' || p[length] == '\0'))
80 static void parse_options(struct exfat* ef, const char* options)
82 int sys_umask = umask(0);
85 umask(sys_umask); /* restore umask */
86 opt_umask = get_int_option(options, "umask", 8, sys_umask);
87 ef->dmask = get_int_option(options, "dmask", 8, opt_umask) & 0777;
88 ef->fmask = get_int_option(options, "fmask", 8, opt_umask) & 0777;
90 ef->uid = get_int_option(options, "uid", 10, geteuid());
91 ef->gid = get_int_option(options, "gid", 10, getegid());
93 ef->ro = match_option(options, "ro");
94 ef->noatime = match_option(options, "noatime");
97 static int verify_vbr_checksum(void* block, off_t block_size, int fd)
99 uint32_t vbr_checksum;
102 exfat_read_raw(block, block_size, 0, fd);
103 vbr_checksum = exfat_vbr_start_checksum(block, block_size);
104 for (i = 1; i < 11; i++)
106 exfat_read_raw(block, block_size, i * block_size, fd);
107 vbr_checksum = exfat_vbr_add_checksum(block, block_size, vbr_checksum);
109 exfat_read_raw(block, block_size, i * block_size, fd);
110 for (i = 0; i < block_size / sizeof(vbr_checksum); i++)
111 if (((const uint32_t*) block)[i] != vbr_checksum)
113 exfat_error("invalid VBR checksum 0x%x (expected 0x%x)",
114 ((const uint32_t*) block)[i], vbr_checksum);
120 int exfat_mount(struct exfat* ef, const char* spec, const char* options)
125 memset(ef, 0, sizeof(struct exfat));
127 ef->sb = malloc(sizeof(struct exfat_super_block));
130 exfat_error("memory allocation failed");
133 memset(ef->sb, 0, sizeof(struct exfat_super_block));
135 parse_options(ef, options);
137 ef->fd = open(spec, ef->ro ? O_RDONLY : O_RDWR);
141 exfat_error("failed to open `%s'", spec);
145 exfat_read_raw(ef->sb, sizeof(struct exfat_super_block), 0, ef->fd);
146 if (memcmp(ef->sb->oem_name, "EXFAT ", 8) != 0)
150 exfat_error("exFAT file system is not found");
153 if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
156 exfat_error("unsupported exFAT version: %hhu.%hhu",
157 ef->sb->version.major, ef->sb->version.minor);
161 if (ef->sb->fat_count != 1)
165 exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
168 /* officially exFAT supports cluster size up to 32 MB */
169 if ((int) ef->sb->block_bits + (int) ef->sb->bpc_bits > 25)
173 exfat_error("too big cluster size: 2^%d",
174 (int) ef->sb->block_bits + (int) ef->sb->bpc_bits);
178 ef->zero_block = malloc(BLOCK_SIZE(*ef->sb));
179 if (ef->zero_block == NULL)
183 exfat_error("failed to allocate zero block");
186 /* use zero_block as a temporary buffer for VBR checksum verification */
187 if (verify_vbr_checksum(ef->zero_block, BLOCK_SIZE(*ef->sb), ef->fd) != 0)
189 free(ef->zero_block);
194 memset(ef->zero_block, 0, BLOCK_SIZE(*ef->sb));
196 ef->root = malloc(sizeof(struct exfat_node));
197 if (ef->root == NULL)
199 free(ef->zero_block);
202 exfat_error("failed to allocate root node");
205 memset(ef->root, 0, sizeof(struct exfat_node));
206 ef->root->flags = EXFAT_ATTRIB_DIR;
207 ef->root->start_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
208 ef->root->fptr_cluster = ef->root->start_cluster;
209 ef->root->name[0] = cpu_to_le16('\0');
210 ef->root->size = rootdir_size(ef);
211 /* exFAT does not have time attributes for the root directory */
214 /* always keep at least 1 reference to the root node */
215 exfat_get_node(ef->root);
217 rc = exfat_cache_directory(ef, ef->root);
220 if (ef->upcase == NULL)
222 exfat_error("upcase table is not found");
225 if (ef->cmap.chunk == NULL)
227 exfat_error("clusters bitmap is not found");
234 exfat_put_node(ef, ef->root);
235 exfat_reset_cache(ef);
237 free(ef->zero_block);
243 void exfat_unmount(struct exfat* ef)
245 exfat_put_node(ef, ef->root);
246 exfat_reset_cache(ef);
249 free(ef->zero_block);
250 ef->zero_block = NULL;
251 free(ef->cmap.chunk);
252 ef->cmap.chunk = NULL;
253 if (fsync(ef->fd) < 0)
254 exfat_error("fsync failed");
255 if (close(ef->fd) < 0)
256 exfat_error("close failed");
262 ef->upcase_chars = 0;