3 exFAT file system implementation library.
5 Free exFAT implementation.
6 Copyright (C) 2010-2017 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.
25 #include <sys/types.h>
31 #if defined(__APPLE__)
33 #elif defined(__OpenBSD__)
34 #include <sys/param.h>
35 #include <sys/disklabel.h>
37 #include <sys/ioctl.h>
39 #include <sys/mount.h>
45 off_t size; /* in bytes */
48 static int open_ro(const char* spec)
50 return open(spec, O_RDONLY);
53 static int open_rw(const char* spec)
55 int fd = open(spec, O_RDWR);
60 This ioctl is needed because after "blockdev --setro" kernel still
61 allows to open the device in read-write mode but fails writes.
63 if (fd != -1 && ioctl(fd, BLKROGET, &ro) == 0 && ro)
73 struct exfat_dev* exfat_open(const char* spec, enum exfat_mode mode)
75 struct exfat_dev* dev;
78 dev = malloc(sizeof(struct exfat_dev));
81 exfat_error("failed to allocate memory for device structure");
88 dev->fd = open_ro(spec);
92 exfat_error("failed to open '%s' in read-only mode: %s", spec,
96 dev->mode = EXFAT_MODE_RO;
99 dev->fd = open_rw(spec);
103 exfat_error("failed to open '%s' in read-write mode: %s", spec,
107 dev->mode = EXFAT_MODE_RW;
110 dev->fd = open_rw(spec);
113 dev->mode = EXFAT_MODE_RW;
116 dev->fd = open_ro(spec);
119 dev->mode = EXFAT_MODE_RO;
120 exfat_warn("'%s' is write-protected, mounting read-only", spec);
124 exfat_error("failed to open '%s': %s", spec, strerror(errno));
128 if (fstat(dev->fd, &stbuf) != 0)
132 exfat_error("failed to fstat '%s'", spec);
135 if (!S_ISBLK(stbuf.st_mode) &&
136 !S_ISCHR(stbuf.st_mode) &&
137 !S_ISREG(stbuf.st_mode))
141 exfat_error("'%s' is neither a device, nor a regular file", spec);
145 #if defined(__APPLE__)
146 if (!S_ISREG(stbuf.st_mode))
148 uint32_t block_size = 0;
151 if (ioctl(dev->fd, DKIOCGETBLOCKSIZE, &block_size) != 0)
155 exfat_error("failed to get block size");
158 if (ioctl(dev->fd, DKIOCGETBLOCKCOUNT, &blocks) != 0)
162 exfat_error("failed to get blocks count");
165 dev->size = blocks * block_size;
168 #elif defined(__OpenBSD__)
169 if (!S_ISREG(stbuf.st_mode))
171 struct disklabel lab;
172 struct partition* pp;
175 if (ioctl(dev->fd, DIOCGDINFO, &lab) == -1)
179 exfat_error("failed to get disklabel");
183 /* Don't need to check that partition letter is valid as we won't get
184 this far otherwise. */
185 partition = strchr(spec, '\0') - 1;
186 pp = &(lab.d_partitions[*partition - 'a']);
187 dev->size = DL_GETPSIZE(pp) * lab.d_secsize;
189 if (pp->p_fstype != FS_NTFS)
190 exfat_warn("partition type is not 0x07 (NTFS/exFAT); "
191 "you can fix this with fdisk(8)");
196 /* works for Linux, FreeBSD, Solaris */
197 dev->size = exfat_seek(dev, 0, SEEK_END);
202 exfat_error("failed to get size of '%s'", spec);
205 if (exfat_seek(dev, 0, SEEK_SET) == -1)
209 exfat_error("failed to seek to the beginning of '%s'", spec);
217 int exfat_close(struct exfat_dev* dev)
221 if (close(dev->fd) != 0)
223 exfat_error("failed to close device: %s", strerror(errno));
230 int exfat_fsync(struct exfat_dev* dev)
234 if (fsync(dev->fd) != 0)
236 exfat_error("fsync failed: %s", strerror(errno));
242 enum exfat_mode exfat_get_mode(const struct exfat_dev* dev)
247 off_t exfat_get_size(const struct exfat_dev* dev)
252 off_t exfat_seek(struct exfat_dev* dev, off_t offset, int whence)
254 #if defined(__ANDROID__)
255 return lseek64(dev->fd, offset, whence);
257 return lseek(dev->fd, offset, whence);
261 ssize_t exfat_read(struct exfat_dev* dev, void* buffer, size_t size)
263 return read(dev->fd, buffer, size);
266 ssize_t exfat_write(struct exfat_dev* dev, const void* buffer, size_t size)
268 return write(dev->fd, buffer, size);
271 ssize_t exfat_pread(struct exfat_dev* dev, void* buffer, size_t size,
274 #if defined(__ANDROID__)
275 return pread64(dev->fd, buffer, size, offset);
277 return pread(dev->fd, buffer, size, offset);
281 ssize_t exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
284 #if defined(__ANDROID__)
285 return pwrite64(dev->fd, buffer, size, offset);
287 return pwrite(dev->fd, buffer, size, offset);
291 ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
292 void* buffer, size_t size, off_t offset)
296 off_t lsize, loffset, remainder;
298 if (offset >= node->size)
303 cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
304 if (CLUSTER_INVALID(cluster))
306 exfat_error("invalid cluster 0x%x while reading", cluster);
310 loffset = offset % CLUSTER_SIZE(*ef->sb);
311 remainder = MIN(size, node->size - offset);
312 while (remainder > 0)
314 if (CLUSTER_INVALID(cluster))
316 exfat_error("invalid cluster 0x%x while reading", cluster);
319 lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
320 if (exfat_pread(ef->dev, bufp, lsize,
321 exfat_c2o(ef, cluster) + loffset) < 0)
323 exfat_error("failed to read cluster %#x", cluster);
329 cluster = exfat_next_cluster(ef, node, cluster);
331 if (!(node->attrib & EXFAT_ATTRIB_DIR) && !ef->ro && !ef->noatime)
332 exfat_update_atime(node);
333 return MIN(size, node->size - offset) - remainder;
336 ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
337 const void* buffer, size_t size, off_t offset)
341 const char* bufp = buffer;
342 off_t lsize, loffset, remainder;
344 if (offset > node->size)
346 rc = exfat_truncate(ef, node, offset, true);
350 if (offset + size > node->size)
352 rc = exfat_truncate(ef, node, offset + size, false);
359 cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
360 if (CLUSTER_INVALID(cluster))
362 exfat_error("invalid cluster 0x%x while writing", cluster);
366 loffset = offset % CLUSTER_SIZE(*ef->sb);
368 while (remainder > 0)
370 if (CLUSTER_INVALID(cluster))
372 exfat_error("invalid cluster 0x%x while writing", cluster);
375 lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
376 if (exfat_pwrite(ef->dev, bufp, lsize,
377 exfat_c2o(ef, cluster) + loffset) < 0)
379 exfat_error("failed to write cluster %#x", cluster);
385 cluster = exfat_next_cluster(ef, node, cluster);
387 if (!(node->attrib & EXFAT_ATTRIB_DIR))
388 /* directory's mtime should be updated by the caller only when it
389 creates or removes something in this directory */
390 exfat_update_mtime(node);
391 return size - remainder;