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>
34 #if !defined(_FILE_OFFSET_BITS) || (_FILE_OFFSET_BITS != 64)
35 #error You should define _FILE_OFFSET_BITS=64
43 ublio_filehandle_t ufh;
47 struct exfat_dev* exfat_open(const char* spec, int ro)
49 struct exfat_dev* dev;
52 struct ublio_param up;
55 dev = malloc(sizeof(struct exfat_dev));
58 exfat_error("failed to allocate memory for device structure");
62 dev->fd = open(spec, ro ? O_RDONLY : O_RDWR);
66 exfat_error("failed to open `%s' in read-%s mode", spec,
67 ro ? "only" : "write");
70 if (fstat(dev->fd, &stbuf) != 0)
74 exfat_error("failed to fstat `%s'", spec);
77 if (!S_ISBLK(stbuf.st_mode) &&
78 !S_ISCHR(stbuf.st_mode) &&
79 !S_ISREG(stbuf.st_mode))
83 exfat_error("`%s' is neither a device, nor a regular file", spec);
88 memset(&up, 0, sizeof(struct ublio_param));
89 up.up_blocksize = 256 * 1024;
92 up.up_priv = &dev->fd;
95 dev->ufh = ublio_open(&up);
100 exfat_error("failed to initialize ublio");
108 int exfat_close(struct exfat_dev* dev)
111 if (ublio_close(dev->ufh) != 0)
112 exfat_error("failed to close ublio");
114 if (close(dev->fd) != 0)
117 exfat_error("failed to close device");
124 int exfat_fsync(struct exfat_dev* dev)
127 if (ublio_fsync(dev->ufh) != 0)
129 if (fsync(dev->fd) != 0)
132 exfat_error("fsync failed");
138 off_t exfat_seek(struct exfat_dev* dev, off_t offset, int whence)
141 /* XXX SEEK_CUR will be handled incorrectly */
142 return dev->pos = lseek(dev->fd, offset, whence);
144 return lseek(dev->fd, offset, whence);
148 ssize_t exfat_read(struct exfat_dev* dev, void* buffer, size_t size)
151 ssize_t result = ublio_pread(dev->ufh, buffer, size, dev->pos);
156 return read(dev->fd, buffer, size);
160 ssize_t exfat_write(struct exfat_dev* dev, const void* buffer, size_t size)
163 ssize_t result = ublio_pwrite(dev->ufh, buffer, size, dev->pos);
168 return write(dev->fd, buffer, size);
172 void exfat_pread(struct exfat_dev* dev, void* buffer, size_t size,
176 if (ublio_pread(dev->ufh, buffer, size, offset) != size)
178 if (pread(dev->fd, buffer, size, offset) != size)
180 exfat_bug("failed to read %zu bytes from file at %"PRIu64, size,
184 void exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
188 if (ublio_pwrite(dev->ufh, buffer, size, offset) != size)
190 if (pwrite(dev->fd, buffer, size, offset) != size)
192 exfat_bug("failed to write %zu bytes to file at %"PRIu64, size,
196 ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
197 void* buffer, size_t size, off_t offset)
201 off_t lsize, loffset, remainder;
203 if (offset >= node->size)
208 cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
209 if (CLUSTER_INVALID(cluster))
211 exfat_error("got invalid cluster");
215 loffset = offset % CLUSTER_SIZE(*ef->sb);
216 remainder = MIN(size, node->size - offset);
217 while (remainder > 0)
219 if (CLUSTER_INVALID(cluster))
221 exfat_error("got invalid cluster");
224 lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
225 exfat_pread(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
229 cluster = exfat_next_cluster(ef, node, cluster);
231 if (!ef->ro && !ef->noatime)
232 exfat_update_atime(node);
233 return size - remainder;
236 ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
237 const void* buffer, size_t size, off_t offset)
240 const char* bufp = buffer;
241 off_t lsize, loffset, remainder;
243 if (offset + size > node->size)
245 int rc = exfat_truncate(ef, node, offset + size);
252 cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
253 if (CLUSTER_INVALID(cluster))
255 exfat_error("got invalid cluster");
259 loffset = offset % CLUSTER_SIZE(*ef->sb);
261 while (remainder > 0)
263 if (CLUSTER_INVALID(cluster))
265 exfat_error("got invalid cluster");
268 lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
269 exfat_pwrite(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
273 cluster = exfat_next_cluster(ef, node, cluster);
275 exfat_update_mtime(node);
276 return size - remainder;