/*
io.c (02.09.09)
exFAT file system implementation library.
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
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "exfat.h"
#include <inttypes.h>
#include <sys/types.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
struct exfat_dev
{
int fd;
enum exfat_mode mode;
off64_t size; /* in bytes */
#ifdef USE_UBLIO
off64_t pos;
ublio_filehandle_t ufh;
#endif
};
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;
#ifdef USE_UBLIO
struct ublio_param up;
#endif
dev = malloc(sizeof(struct exfat_dev));
if (dev == NULL)
{
exfat_error("failed to allocate memory for device structure");
return NULL;
}
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'", spec);
return NULL;
}
if (fstat(dev->fd, &stbuf) != 0)
{
close(dev->fd);
free(dev);
exfat_error("failed to fstat `%s'", spec);
return NULL;
}
if (!S_ISBLK(stbuf.st_mode) &&
!S_ISCHR(stbuf.st_mode) &&
!S_ISREG(stbuf.st_mode))
{
close(dev->fd);
free(dev);
exfat_error("`%s' is neither a device, nor a regular file", spec);
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;
up.up_items = 64;
up.up_grace = 32;
up.up_priv = &dev->fd;
dev->pos = 0;
dev->ufh = ublio_open(&up);
if (dev->ufh == NULL)
{
close(dev->fd);
free(dev);
exfat_error("failed to initialize ublio");
return NULL;
}
#endif
return dev;
}
int exfat_close(struct exfat_dev* dev)
{
#ifdef USE_UBLIO
if (ublio_close(dev->ufh) != 0)
exfat_error("failed to close ublio");
#endif
if (close(dev->fd) != 0)
{
free(dev);
exfat_error("failed to close device");
return 1;
}
free(dev);
return 0;
}
int exfat_fsync(struct exfat_dev* dev)
{
#ifdef USE_UBLIO
if (ublio_fsync(dev->ufh) != 0)
#else
if (fsync(dev->fd) != 0)
#endif
{
exfat_error("fsync failed");
return 1;
}
return 0;
}
enum exfat_mode exfat_get_mode(const struct exfat_dev* dev)
{
return dev->mode;
}
off64_t exfat_get_size(const struct exfat_dev* dev)
{
return dev->size;
}
off64_t exfat_seek(struct exfat_dev* dev, off64_t offset, int whence)
{
#ifdef USE_UBLIO
/* XXX SEEK_CUR will be handled incorrectly */
return dev->pos = lseek64(dev->fd, offset, whence);
#else
return lseek64(dev->fd, offset, whence);
#endif
}
ssize_t exfat_read(struct exfat_dev* dev, void* buffer, size_t size)
{
#ifdef USE_UBLIO
ssize_t result = ublio_pread(dev->ufh, buffer, size, dev->pos);
if (result >= 0)
dev->pos += size;
return result;
#else
return read(dev->fd, buffer, size);
#endif
}
ssize_t exfat_write(struct exfat_dev* dev, const void* buffer, size_t size)
{
#ifdef USE_UBLIO
ssize_t result = ublio_pwrite(dev->ufh, buffer, size, dev->pos);
if (result >= 0)
dev->pos += size;
return result;
#else
return write(dev->fd, buffer, size);
#endif
}
void exfat_pread(struct exfat_dev* dev, void* buffer, size_t size,
off64_t offset)
{
#ifdef USE_UBLIO
if (ublio_pread(dev->ufh, buffer, size, offset) != size)
#else
if (pread64(dev->fd, buffer, size, offset) != size)
#endif
exfat_bug("failed to read %zu bytes from file at %"PRIu64, size,
(uint64_t) offset);
}
void exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
off64_t offset)
{
#ifdef USE_UBLIO
if (ublio_pwrite(dev->ufh, buffer, size, offset) != size)
#else
if (pwrite64(dev->fd, buffer, size, offset) != size)
#endif
exfat_bug("failed to write %zu bytes to file at %"PRIu64, size,
(uint64_t) offset);
}
ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
void* buffer, size_t size, off64_t offset)
{
cluster_t cluster;
char* bufp = buffer;
off64_t lsize, loffset, remainder;
if (offset >= node->size)
return 0;
if (size == 0)
return 0;
cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
if (CLUSTER_INVALID(cluster))
{
exfat_error("invalid cluster 0x%x while reading", cluster);
return -1;
}
loffset = offset % CLUSTER_SIZE(*ef->sb);
remainder = MIN(size, node->size - offset);
while (remainder > 0)
{
if (CLUSTER_INVALID(cluster))
{
exfat_error("invalid cluster 0x%x while reading", cluster);
return -1;
}
lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
exfat_pread(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
bufp += lsize;
loffset = 0;
remainder -= lsize;
cluster = exfat_next_cluster(ef, node, cluster);
}
if (!ef->ro && !ef->noatime)
exfat_update_atime(node);
return MIN(size, node->size - offset) - remainder;
}
ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
const void* buffer, size_t size, off64_t offset)
{
cluster_t cluster;
const char* bufp = buffer;
off64_t lsize, loffset, remainder;
if (offset > node->size)
if (exfat_truncate(ef, node, offset, true) != 0)
return -1;
if (offset + size > node->size)
if (exfat_truncate(ef, node, offset + size, false) != 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("invalid cluster 0x%x while writing", cluster);
return -1;
}
loffset = offset % CLUSTER_SIZE(*ef->sb);
remainder = size;
while (remainder > 0)
{
if (CLUSTER_INVALID(cluster))
{
exfat_error("invalid cluster 0x%x while writing", cluster);
return -1;
}
lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
exfat_pwrite(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
bufp += lsize;
loffset = 0;
remainder -= lsize;
cluster = exfat_next_cluster(ef, node, cluster);
}
exfat_update_mtime(node);
return size - remainder;
}
