3 exFAT file system implementation library.
5 Free exFAT implementation.
6 Copyright (C) 2010-2016 Andrew Nayenko
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
29 void exfat_stat(const struct exfat* ef, const struct exfat_node* node,
32 memset(stbuf, 0, sizeof(struct stat));
33 if (node->flags & EXFAT_ATTRIB_DIR)
34 stbuf->st_mode = S_IFDIR | (0777 & ~ef->dmask);
36 stbuf->st_mode = S_IFREG | (0777 & ~ef->fmask);
38 stbuf->st_uid = ef->uid;
39 stbuf->st_gid = ef->gid;
40 stbuf->st_size = node->size;
41 stbuf->st_blocks = DIV_ROUND_UP(node->size, CLUSTER_SIZE(*ef->sb)) *
42 CLUSTER_SIZE(*ef->sb) / 512;
43 stbuf->st_mtime = node->mtime;
44 stbuf->st_atime = node->atime;
45 /* set ctime to mtime to ensure we don't break programs that rely on ctime
47 stbuf->st_ctime = node->mtime;
50 void exfat_get_name(const struct exfat_node* node, char* buffer, size_t n)
52 if (utf16_to_utf8(buffer, node->name, n, EXFAT_NAME_MAX) != 0)
53 exfat_bug("failed to convert name to UTF-8");
56 uint16_t exfat_start_checksum(const struct exfat_entry_meta1* entry)
61 for (i = 0; i < sizeof(struct exfat_entry); i++)
62 if (i != 2 && i != 3) /* skip checksum field itself */
63 sum = ((sum << 15) | (sum >> 1)) + ((const uint8_t*) entry)[i];
67 uint16_t exfat_add_checksum(const void* entry, uint16_t sum)
71 for (i = 0; i < sizeof(struct exfat_entry); i++)
72 sum = ((sum << 15) | (sum >> 1)) + ((const uint8_t*) entry)[i];
76 le16_t exfat_calc_checksum(const struct exfat_entry_meta1* meta1,
77 const struct exfat_entry_meta2* meta2, const le16_t* name)
80 const int name_entries = DIV_ROUND_UP(utf16_length(name), EXFAT_ENAME_MAX);
83 checksum = exfat_start_checksum(meta1);
84 checksum = exfat_add_checksum(meta2, checksum);
85 for (i = 0; i < name_entries; i++)
87 struct exfat_entry_name name_entry = {EXFAT_ENTRY_FILE_NAME, 0};
88 memcpy(name_entry.name, name + i * EXFAT_ENAME_MAX,
89 MIN(EXFAT_ENAME_MAX, EXFAT_NAME_MAX - i * EXFAT_ENAME_MAX) *
91 checksum = exfat_add_checksum(&name_entry, checksum);
93 return cpu_to_le16(checksum);
96 uint32_t exfat_vbr_start_checksum(const void* sector, size_t size)
101 for (i = 0; i < size; i++)
102 /* skip volume_state and allocated_percent fields */
103 if (i != 0x6a && i != 0x6b && i != 0x70)
104 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
108 uint32_t exfat_vbr_add_checksum(const void* sector, size_t size, uint32_t sum)
112 for (i = 0; i < size; i++)
113 sum = ((sum << 31) | (sum >> 1)) + ((const uint8_t*) sector)[i];
117 le16_t exfat_calc_name_hash(const struct exfat* ef, const le16_t* name)
120 size_t length = utf16_length(name);
123 for (i = 0; i < length; i++)
125 uint16_t c = le16_to_cpu(name[i]);
127 /* convert to upper case */
130 hash = ((hash << 15) | (hash >> 1)) + (c & 0xff);
131 hash = ((hash << 15) | (hash >> 1)) + (c >> 8);
133 return cpu_to_le16(hash);
136 void exfat_humanize_bytes(uint64_t value, struct exfat_human_bytes* hb)
139 /* 16 EB (minus 1 byte) is the largest size that can be represented by
141 const char* units[] = {"bytes", "KB", "MB", "GB", "TB", "PB", "EB"};
142 uint64_t divisor = 1;
145 for (i = 0; ; i++, divisor *= 1024)
147 temp = (value + divisor / 2) / divisor;
151 if (temp / 1024 * 1024 == temp)
160 void exfat_print_info(const struct exfat_super_block* sb,
161 uint32_t free_clusters)
163 struct exfat_human_bytes hb;
164 off_t total_space = le64_to_cpu(sb->sector_count) * SECTOR_SIZE(*sb);
165 off_t avail_space = (off_t) free_clusters * CLUSTER_SIZE(*sb);
167 printf("File system version %hhu.%hhu\n",
168 sb->version.major, sb->version.minor);
169 exfat_humanize_bytes(SECTOR_SIZE(*sb), &hb);
170 printf("Sector size %10"PRIu64" %s\n", hb.value, hb.unit);
171 exfat_humanize_bytes(CLUSTER_SIZE(*sb), &hb);
172 printf("Cluster size %10"PRIu64" %s\n", hb.value, hb.unit);
173 exfat_humanize_bytes(total_space, &hb);
174 printf("Volume size %10"PRIu64" %s\n", hb.value, hb.unit);
175 exfat_humanize_bytes(total_space - avail_space, &hb);
176 printf("Used space %10"PRIu64" %s\n", hb.value, hb.unit);
177 exfat_humanize_bytes(avail_space, &hb);
178 printf("Available space %10"PRIu64" %s\n", hb.value, hb.unit);