3 exFAT file system implementation library.
5 Copyright (C) 2010-2012 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>
37 #if !defined(_FILE_OFFSET_BITS) || (_FILE_OFFSET_BITS != 64)
38 #error You should define _FILE_OFFSET_BITS=64
45 off_t size; /* in bytes */
48 ublio_filehandle_t ufh;
52 static int open_ro(const char* spec)
54 return open(spec, O_RDONLY);
57 static int open_rw(const char* spec)
59 int fd = open(spec, O_RDWR);
64 This ioctl is needed because after "blockdev --setro" kernel still
65 allows to open the device in read-write mode but fails writes.
67 if (fd != -1 && ioctl(fd, BLKROGET, &ro) == 0 && ro)
76 struct exfat_dev* exfat_open(const char* spec, enum exfat_mode mode)
78 struct exfat_dev* dev;
81 struct ublio_param up;
84 dev = malloc(sizeof(struct exfat_dev));
87 exfat_error("failed to allocate memory for device structure");
94 dev->fd = open_ro(spec);
98 exfat_error("failed to open `%s' in read-only mode", spec);
101 dev->mode = EXFAT_MODE_RO;
104 dev->fd = open_rw(spec);
108 exfat_error("failed to open `%s' in read-write mode", spec);
111 dev->mode = EXFAT_MODE_RW;
114 dev->fd = open_rw(spec);
117 dev->mode = EXFAT_MODE_RW;
120 dev->fd = open_ro(spec);
123 dev->mode = EXFAT_MODE_RO;
124 exfat_warn("`%s' is write-protected, mounting read-only", spec);
128 exfat_error("failed to open `%s'", spec);
132 if (fstat(dev->fd, &stbuf) != 0)
136 exfat_error("failed to fstat `%s'", spec);
139 if (!S_ISBLK(stbuf.st_mode) &&
140 !S_ISCHR(stbuf.st_mode) &&
141 !S_ISREG(stbuf.st_mode))
145 exfat_error("`%s' is neither a device, nor a regular file", spec);
150 if (S_ISBLK(stbuf.st_mode))
152 uint32_t block_size = 0;
155 if (ioctl(dev->fd, DKIOCGETBLOCKSIZE, &block_size) != 0)
159 exfat_error("failed to get block size");
162 if (ioctl(dev->fd, DKIOCGETBLOCKCOUNT, &blocks) != 0)
166 exfat_error("failed to get blocks count");
169 dev->size = blocks * block_size;
174 /* works for Linux, FreeBSD, Solaris */
175 dev->size = exfat_seek(dev, 0, SEEK_END);
180 exfat_error("failed to get device size");
186 memset(&up, 0, sizeof(struct ublio_param));
187 up.up_blocksize = 256 * 1024;
190 up.up_priv = &dev->fd;
193 dev->ufh = ublio_open(&up);
194 if (dev->ufh == NULL)
198 exfat_error("failed to initialize ublio");
206 int exfat_close(struct exfat_dev* dev)
209 if (ublio_close(dev->ufh) != 0)
210 exfat_error("failed to close ublio");
212 if (close(dev->fd) != 0)
215 exfat_error("failed to close device");
222 int exfat_fsync(struct exfat_dev* dev)
225 if (ublio_fsync(dev->ufh) != 0)
227 if (fsync(dev->fd) != 0)
230 exfat_error("fsync failed");
236 enum exfat_mode exfat_get_mode(const struct exfat_dev* dev)
241 off_t exfat_get_size(const struct exfat_dev* dev)
246 off_t exfat_seek(struct exfat_dev* dev, off_t offset, int whence)
249 /* XXX SEEK_CUR will be handled incorrectly */
250 return dev->pos = lseek(dev->fd, offset, whence);
252 return lseek(dev->fd, offset, whence);
256 ssize_t exfat_read(struct exfat_dev* dev, void* buffer, size_t size)
259 ssize_t result = ublio_pread(dev->ufh, buffer, size, dev->pos);
264 return read(dev->fd, buffer, size);
268 ssize_t exfat_write(struct exfat_dev* dev, const void* buffer, size_t size)
271 ssize_t result = ublio_pwrite(dev->ufh, buffer, size, dev->pos);
276 return write(dev->fd, buffer, size);
280 void exfat_pread(struct exfat_dev* dev, void* buffer, size_t size,
284 if (ublio_pread(dev->ufh, buffer, size, offset) != size)
286 if (pread(dev->fd, buffer, size, offset) != size)
288 exfat_bug("failed to read %zu bytes from file at %"PRIu64, size,
292 void exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
296 if (ublio_pwrite(dev->ufh, buffer, size, offset) != size)
298 if (pwrite(dev->fd, buffer, size, offset) != size)
300 exfat_bug("failed to write %zu bytes to file at %"PRIu64, size,
304 ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
305 void* buffer, size_t size, off_t offset)
309 off_t lsize, loffset, remainder;
311 if (offset >= node->size)
316 cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
317 if (CLUSTER_INVALID(cluster))
319 exfat_error("invalid cluster 0x%x while reading", cluster);
323 loffset = offset % CLUSTER_SIZE(*ef->sb);
324 remainder = MIN(size, node->size - offset);
325 while (remainder > 0)
327 if (CLUSTER_INVALID(cluster))
329 exfat_error("invalid cluster 0x%x while reading", cluster);
332 lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
333 exfat_pread(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
337 cluster = exfat_next_cluster(ef, node, cluster);
339 if (!ef->ro && !ef->noatime)
340 exfat_update_atime(node);
341 return size - remainder;
344 ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
345 const void* buffer, size_t size, off_t offset)
348 const char* bufp = buffer;
349 off_t lsize, loffset, remainder;
351 if (offset + size > node->size)
353 int rc = exfat_truncate(ef, node, offset + size);
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;