/*
io.c (02.09.09)
exFAT file system implementation library.
Copyright (C) 2009, 2010 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 .
*/
#define _XOPEN_SOURCE 500 /* for pread() and pwrite() in Linux */
#include "exfat.h"
#include
#include
#include
#include
#include
#include
#include
#ifdef USE_UBLIO
#include
#include
#endif
#if _FILE_OFFSET_BITS != 64
#error You should define _FILE_OFFSET_BITS=64
#endif
struct exfat_dev
{
int fd;
#ifdef USE_UBLIO
off_t pos;
ublio_filehandle_t ufh;
#endif
};
struct exfat_dev* exfat_open(const char* spec, int ro)
{
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;
}
dev->fd = open(spec, ro ? O_RDONLY : O_RDWR);
if (dev->fd < 0)
{
free(dev);
exfat_error("failed to open `%s' in read-%s mode", spec,
ro ? "only" : "write");
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 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;
}
off_t exfat_seek(struct exfat_dev* dev, off_t offset, int whence)
{
#ifdef USE_UBLIO
/* XXX SEEK_CUR will be handled incorrectly */
return dev->pos = lseek(dev->fd, offset, whence);
#else
return lseek(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,
off_t offset)
{
#ifdef USE_UBLIO
if (ublio_pread(dev->ufh, buffer, size, offset) != size)
#else
if (pread(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,
off_t offset)
{
#ifdef USE_UBLIO
if (ublio_pwrite(dev->ufh, buffer, size, offset) != size)
#else
if (pwrite(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, off_t offset)
{
cluster_t cluster;
char* bufp = buffer;
off_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("got invalid cluster");
return -1;
}
loffset = offset % CLUSTER_SIZE(*ef->sb);
remainder = MIN(size, node->size - offset);
while (remainder > 0)
{
if (CLUSTER_INVALID(cluster))
{
exfat_error("got invalid 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 size - remainder;
}
ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
const void* buffer, size_t size, off_t offset)
{
cluster_t cluster;
const char* bufp = buffer;
off_t lsize, loffset, remainder;
if (offset + size > node->size)
{
int rc = exfat_truncate(ef, node, offset + size);
if (rc != 0)
return rc;
}
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");
return -1;
}
loffset = offset % CLUSTER_SIZE(*ef->sb);
remainder = size;
while (remainder > 0)
{
if (CLUSTER_INVALID(cluster))
{
exfat_error("got invalid 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;
}