io.c (02.09.09)
exFAT file system implementation library.
- Copyright (C) 2009, 2010 Andrew Nayenko
+ Copyright (C) 2010-2013 Andrew Nayenko
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#define _XOPEN_SOURCE 500 /* for pread() and pwrite() in Linux */
#include "exfat.h"
#include <inttypes.h>
#include <sys/types.h>
-#include <sys/uio.h>
#include <sys/stat.h>
+#include <sys/mount.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
+#ifdef __APPLE__
+#include <sys/disk.h>
+#endif
#ifdef USE_UBLIO
#include <sys/uio.h>
#include <ublio.h>
#endif
-#if _FILE_OFFSET_BITS != 64
- #error You should define _FILE_OFFSET_BITS=64
-#endif
-
struct exfat_dev
{
int fd;
+ enum exfat_mode mode;
+ off_t size; /* in bytes */
#ifdef USE_UBLIO
off_t pos;
ublio_filehandle_t ufh;
#endif
};
-struct exfat_dev* exfat_open(const char* spec, int ro)
+static int open_ro(const char* spec)
+{
+ return open(spec, O_RDONLY);
+}
+
+static int open_rw(const char* spec)
+{
+ int fd = open(spec, O_RDWR);
+#ifdef __linux__
+ int ro = 0;
+
+ /*
+ This ioctl is needed because after "blockdev --setro" kernel still
+ allows to open the device in read-write mode but fails writes.
+ */
+ if (fd != -1 && ioctl(fd, BLKROGET, &ro) == 0 && ro)
+ {
+ close(fd);
+ return -1;
+ }
+#endif
+ return fd;
+}
+
+struct exfat_dev* exfat_open(const char* spec, enum exfat_mode mode)
{
struct exfat_dev* dev;
struct stat stbuf;
return NULL;
}
- dev->fd = open(spec, ro ? O_RDONLY : O_RDWR);
- if (dev->fd < 0)
+ switch (mode)
{
+ case EXFAT_MODE_RO:
+ dev->fd = open_ro(spec);
+ if (dev->fd == -1)
+ {
+ free(dev);
+ exfat_error("failed to open `%s' in read-only mode", spec);
+ return NULL;
+ }
+ dev->mode = EXFAT_MODE_RO;
+ break;
+ case EXFAT_MODE_RW:
+ dev->fd = open_rw(spec);
+ if (dev->fd == -1)
+ {
+ free(dev);
+ exfat_error("failed to open `%s' in read-write mode", spec);
+ return NULL;
+ }
+ dev->mode = EXFAT_MODE_RW;
+ break;
+ case EXFAT_MODE_ANY:
+ dev->fd = open_rw(spec);
+ if (dev->fd != -1)
+ {
+ dev->mode = EXFAT_MODE_RW;
+ break;
+ }
+ dev->fd = open_ro(spec);
+ if (dev->fd != -1)
+ {
+ dev->mode = EXFAT_MODE_RO;
+ exfat_warn("`%s' is write-protected, mounting read-only", spec);
+ break;
+ }
free(dev);
- exfat_error("failed to open `%s' in read-%s mode", spec,
- ro ? "only" : "write");
+ exfat_error("failed to open `%s'", spec);
return NULL;
}
+
if (fstat(dev->fd, &stbuf) != 0)
{
close(dev->fd);
return NULL;
}
+#ifdef __APPLE__
+ if (!S_ISREG(stbuf.st_mode))
+ {
+ uint32_t block_size = 0;
+ uint64_t blocks = 0;
+
+ if (ioctl(dev->fd, DKIOCGETBLOCKSIZE, &block_size) != 0)
+ {
+ close(dev->fd);
+ free(dev);
+ exfat_error("failed to get block size");
+ return NULL;
+ }
+ if (ioctl(dev->fd, DKIOCGETBLOCKCOUNT, &blocks) != 0)
+ {
+ close(dev->fd);
+ free(dev);
+ exfat_error("failed to get blocks count");
+ return NULL;
+ }
+ dev->size = blocks * block_size;
+ }
+ else
+#endif
+ {
+ /* works for Linux, FreeBSD, Solaris */
+ dev->size = exfat_seek(dev, 0, SEEK_END);
+ if (dev->size <= 0)
+ {
+ close(dev->fd);
+ free(dev);
+ exfat_error("failed to get size of `%s'", spec);
+ return NULL;
+ }
+ if (exfat_seek(dev, 0, SEEK_SET) == -1)
+ {
+ close(dev->fd);
+ free(dev);
+ exfat_error("failed to seek to the beginning of `%s'", spec);
+ return NULL;
+ }
+ }
+
#ifdef USE_UBLIO
memset(&up, 0, sizeof(struct ublio_param));
up.up_blocksize = 256 * 1024;
return 0;
}
+enum exfat_mode exfat_get_mode(const struct exfat_dev* dev)
+{
+ return dev->mode;
+}
+
+off_t exfat_get_size(const struct exfat_dev* dev)
+{
+ return dev->size;
+}
+
off_t exfat_seek(struct exfat_dev* dev, off_t offset, int whence)
{
#ifdef USE_UBLIO
cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
if (CLUSTER_INVALID(cluster))
{
- exfat_error("got invalid cluster");
+ exfat_error("invalid cluster 0x%x while reading", cluster);
return -1;
}
{
if (CLUSTER_INVALID(cluster))
{
- exfat_error("got invalid cluster");
+ exfat_error("invalid cluster 0x%x while reading", cluster);
return -1;
}
lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
}
if (!ef->ro && !ef->noatime)
exfat_update_atime(node);
- return size - remainder;
+ return MIN(size, node->size - offset) - remainder;
}
ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
off_t lsize, loffset, remainder;
if (offset + size > node->size)
- {
- int rc = exfat_truncate(ef, node, offset + size);
- if (rc != 0)
- return rc;
- }
+ if (exfat_truncate(ef, node, offset + size) != 0)
+ return -1;
if (size == 0)
return 0;
cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
if (CLUSTER_INVALID(cluster))
{
- exfat_error("got invalid cluster");
+ exfat_error("invalid cluster 0x%x while writing", cluster);
return -1;
}
{
if (CLUSTER_INVALID(cluster))
{
- exfat_error("got invalid cluster");
+ exfat_error("invalid cluster 0x%x while writing", cluster);
return -1;
}
lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);