3 exFAT file system implementation library.
5 Copyright (C) 2010-2013 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/>.
23 #include <sys/types.h>
25 #include <sys/mount.h>
41 off_t size; /* in bytes */
44 ublio_filehandle_t ufh;
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)
72 struct exfat_dev* exfat_open(const char* spec, enum exfat_mode mode)
74 struct exfat_dev* dev;
77 struct ublio_param up;
80 dev = malloc(sizeof(struct exfat_dev));
83 exfat_error("failed to allocate memory for device structure");
90 dev->fd = open_ro(spec);
94 exfat_error("failed to open `%s' in read-only mode", spec);
97 dev->mode = EXFAT_MODE_RO;
100 dev->fd = open_rw(spec);
104 exfat_error("failed to open `%s' in read-write mode", 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'", spec);
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);
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;
170 /* works for Linux, FreeBSD, Solaris */
171 dev->size = exfat_seek(dev, 0, SEEK_END);
176 exfat_error("failed to get size of `%s'", spec);
179 if (exfat_seek(dev, 0, SEEK_SET) == -1)
183 exfat_error("failed to seek to the beginning of `%s'", spec);
189 memset(&up, 0, sizeof(struct ublio_param));
190 up.up_blocksize = 256 * 1024;
193 up.up_priv = &dev->fd;
196 dev->ufh = ublio_open(&up);
197 if (dev->ufh == NULL)
201 exfat_error("failed to initialize ublio");
209 int exfat_close(struct exfat_dev* dev)
212 if (ublio_close(dev->ufh) != 0)
213 exfat_error("failed to close ublio");
215 if (close(dev->fd) != 0)
218 exfat_error("failed to close device");
225 int exfat_fsync(struct exfat_dev* dev)
228 if (ublio_fsync(dev->ufh) != 0)
230 if (fsync(dev->fd) != 0)
233 exfat_error("fsync failed");
239 enum exfat_mode exfat_get_mode(const struct exfat_dev* dev)
244 off_t exfat_get_size(const struct exfat_dev* dev)
249 off_t exfat_seek(struct exfat_dev* dev, off_t offset, int whence)
252 /* XXX SEEK_CUR will be handled incorrectly */
253 return dev->pos = lseek(dev->fd, offset, whence);
255 return lseek(dev->fd, offset, whence);
259 ssize_t exfat_read(struct exfat_dev* dev, void* buffer, size_t size)
262 ssize_t result = ublio_pread(dev->ufh, buffer, size, dev->pos);
267 return read(dev->fd, buffer, size);
271 ssize_t exfat_write(struct exfat_dev* dev, const void* buffer, size_t size)
274 ssize_t result = ublio_pwrite(dev->ufh, buffer, size, dev->pos);
279 return write(dev->fd, buffer, size);
283 void exfat_pread(struct exfat_dev* dev, void* buffer, size_t size,
287 if (ublio_pread(dev->ufh, buffer, size, offset) != size)
289 if (pread(dev->fd, buffer, size, offset) != size)
291 exfat_bug("failed to read %zu bytes from file at %"PRIu64, size,
295 void exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
299 if (ublio_pwrite(dev->ufh, buffer, size, offset) != size)
301 if (pwrite(dev->fd, buffer, size, offset) != size)
303 exfat_bug("failed to write %zu bytes to file at %"PRIu64, size,
307 ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
308 void* buffer, size_t size, off_t offset)
312 off_t lsize, loffset, remainder;
314 if (offset >= node->size)
319 cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
320 if (CLUSTER_INVALID(cluster))
322 exfat_error("invalid cluster 0x%x while reading", cluster);
326 loffset = offset % CLUSTER_SIZE(*ef->sb);
327 remainder = MIN(size, node->size - offset);
328 while (remainder > 0)
330 if (CLUSTER_INVALID(cluster))
332 exfat_error("invalid cluster 0x%x while reading", cluster);
335 lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
336 exfat_pread(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
340 cluster = exfat_next_cluster(ef, node, cluster);
342 if (!ef->ro && !ef->noatime)
343 exfat_update_atime(node);
344 return size - remainder;
347 ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
348 const void* buffer, size_t size, off_t offset)
351 const char* bufp = buffer;
352 off_t lsize, loffset, remainder;
354 if (offset + size > node->size)
355 if (exfat_truncate(ef, node, offset + size) != 0)
360 cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
361 if (CLUSTER_INVALID(cluster))
363 exfat_error("invalid cluster 0x%x while writing", cluster);
367 loffset = offset % CLUSTER_SIZE(*ef->sb);
369 while (remainder > 0)
371 if (CLUSTER_INVALID(cluster))
373 exfat_error("invalid cluster 0x%x while writing", cluster);
376 lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
377 exfat_pwrite(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
381 cluster = exfat_next_cluster(ef, node, cluster);
383 exfat_update_mtime(node);
384 return size - remainder;