io.c (02.09.09)
exFAT file system implementation library.
- Copyright (C) 2009, 2010 Andrew Nayenko
+ Copyright (C) 2010-2012 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
#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>
-#define __USE_UNIX98 /* for pread() in Linux */
#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
+#if !defined(_FILE_OFFSET_BITS) || (_FILE_OFFSET_BITS != 64)
#error You should define _FILE_OFFSET_BITS=64
#endif
-int exfat_open(const char* spec, int ro)
+struct exfat_dev
{
int fd;
- struct stat stbuf;
+ enum exfat_mode mode;
+ off_t size; /* in bytes */
+#ifdef USE_UBLIO
+ off_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;
- fd = open(spec, ro ? O_RDONLY : O_RDWR);
- if (fd < 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)
{
- exfat_error("failed to open `%s' in read-%s mode", spec,
- ro ? "only" : "write");
+ close(fd);
return -1;
}
- if (fstat(fd, &stbuf) != 0)
+#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_close(fd);
+ 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 -1;
+ return NULL;
}
- if (!S_ISBLK(stbuf.st_mode) && !S_ISREG(stbuf.st_mode))
+ if (!S_ISBLK(stbuf.st_mode) &&
+ !S_ISCHR(stbuf.st_mode) &&
+ !S_ISREG(stbuf.st_mode))
{
- exfat_close(fd);
- exfat_error("`%s' is neither a block device, nor a regular file",
- spec);
- return -1;
+ close(dev->fd);
+ free(dev);
+ exfat_error("`%s' is neither a device, nor a regular file", spec);
+ return NULL;
}
- return fd;
+
+#ifdef __APPLE__
+ if (S_ISBLK(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 device size");
+ 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(int fd)
+int exfat_close(struct exfat_dev* dev)
{
- if (close(fd) != 0)
+#ifdef USE_UBLIO
+ if (ublio_close(dev->ufh) != 0)
+ exfat_error("failed to close ublio");
+#endif
+ if (close(dev->fd) != 0)
{
- exfat_error("close failed");
+ free(dev);
+ exfat_error("failed to close device");
return 1;
}
+ free(dev);
return 0;
}
-int exfat_fsync(int fd)
+int exfat_fsync(struct exfat_dev* dev)
{
- if (fsync(fd) != 0)
+#ifdef USE_UBLIO
+ if (ublio_fsync(dev->ufh) != 0)
+#else
+ if (fsync(dev->fd) != 0)
+#endif
{
exfat_error("fsync failed");
return 1;
return 0;
}
-void exfat_pread(int fd, void* buffer, size_t size, off_t offset)
+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)
{
- if (pread(fd, buffer, size, offset) != size)
+#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(int fd, const void* buffer, size_t size, off_t offset)
+void exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
+ off_t offset)
{
- if (pwrite(fd, buffer, size, offset) != size)
+#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);
}
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);
- exfat_pread(ef->fd, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
+ exfat_pread(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
bufp += lsize;
loffset = 0;
remainder -= lsize;
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);
- exfat_pwrite(ef->fd, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
+ exfat_pwrite(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
bufp += lsize;
loffset = 0;
remainder -= lsize;
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