usbloadergx/source/libntfs/gekko_io.c
2010-02-25 14:55:42 +00:00

648 lines
18 KiB
C

/**
* gekko_io.c - Gekko style disk io functions.
*
* Copyright (c) 2009 Rhys "Shareese" Koedijk
* Copyright (c) 2010 Dimok
*
* This program/include file 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 2 of the License, or
* (at your option) any later version.
*
* This program/include file 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, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif
#ifdef HAVE_MATH_H
#include <math.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#include "ntfs.h"
#include "types.h"
#include "logging.h"
#include "device_io.h"
#include "gekko_io.h"
#include "cache.h"
#include "device.h"
#include "bootsect.h"
#define DEV_FD(dev) ((gekko_fd *)dev->d_private)
/* Prototypes */
static s64 ntfs_device_gekko_io_readbytes(struct ntfs_device *dev, s64 offset, s64 count, void *buf);
static bool ntfs_device_gekko_io_readsectors(struct ntfs_device *dev, sec_t sector, sec_t numSectors, void* buffer);
static s64 ntfs_device_gekko_io_writebytes(struct ntfs_device *dev, s64 offset, s64 count, const void *buf);
static bool ntfs_device_gekko_io_writesectors(struct ntfs_device *dev, sec_t sector, sec_t numSectors, const void* buffer);
/**
*
*/
static int ntfs_device_gekko_io_open(struct ntfs_device *dev, int flags)
{
ntfs_log_trace("dev %p, flags %i\n", dev, flags);
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return -1;
}
// Get the device interface
const DISC_INTERFACE* interface = fd->interface;
if (!interface) {
errno = ENODEV;
return -1;
}
// Start the device interface and ensure that it is inserted
if (!interface->startup()) {
ntfs_log_perror("device failed to start\n");
errno = EIO;
return -1;
}
if (!interface->isInserted()) {
ntfs_log_perror("device media is not inserted\n");
errno = EIO;
return -1;
}
// Check that the device isn't already open (used by another volume?)
if (NDevOpen(dev)) {
ntfs_log_perror("device is busy (already open)\n");
errno = EBUSY;
return -1;
}
// Check that there is a valid NTFS boot sector at the start of the device
NTFS_BOOT_SECTOR boot;
if (interface->readSectors(fd->startSector, 1, &boot)) {
if (!ntfs_boot_sector_is_ntfs(&boot)) {
errno = EINVALPART;
return -1;
}
} else {
ntfs_log_perror("read failure @ sector %d\n", fd->startSector);
errno = EIO;
return -1;
}
// Parse the boot sector
fd->hiddenSectors = le32_to_cpu(boot.bpb.hidden_sectors);
fd->sectorSize = le16_to_cpu(boot.bpb.bytes_per_sector);
fd->sectorCount = sle64_to_cpu(boot.number_of_sectors);
fd->pos = 0;
fd->len = (fd->sectorCount * fd->sectorSize);
fd->ino = le64_to_cpu(boot.volume_serial_number);
// If the device sector size is not 512 bytes then we cannot continue,
// gekko disc I/O works on the assumption that sectors are always 512 bytes long.
// TODO: Implement support for non-512 byte sector sizes through some fancy maths!?
if (fd->sectorSize != BYTES_PER_SECTOR) {
ntfs_log_error("Boot sector claims there is %i bytes per sector; expected %i\n", fd->sectorSize, BYTES_PER_SECTOR);
errno = EIO;
return -1;
}
// Mark the device as read-only (if required)
if (flags & O_RDONLY) {
NDevSetReadOnly(dev);
}
// Create the cache
fd->cache = _NTFS_cache_constructor(fd->cachePageCount, fd->cachePageSize, interface, fd->startSector + fd->sectorCount);
// Mark the device as open
NDevSetBlock(dev);
NDevSetOpen(dev);
return 0;
}
/**
*
*/
static int ntfs_device_gekko_io_close(struct ntfs_device *dev)
{
ntfs_log_trace("dev %p\n", dev);
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return -1;
}
// Check that the device is actually open
if (!NDevOpen(dev)) {
ntfs_log_perror("device is not open\n");
errno = EIO;
return -1;
}
// Mark the device as closed
NDevClearOpen(dev);
NDevClearBlock(dev);
// Flush the device (if dirty and not read-only)
if (NDevDirty(dev) && !NDevReadOnly(dev)) {
ntfs_log_debug("device is dirty, will now sync\n");
// ...?
// Mark the device as clean
NDevClearDirty(dev);
}
// Flush and destroy the cache (if required)
if (fd->cache) {
_NTFS_cache_flush(fd->cache);
_NTFS_cache_destructor(fd->cache);
}
// Shutdown the device interface
/*const DISC_INTERFACE* interface = fd->interface;
if (interface) {
interface->shutdown();
}*/
// Free the device driver private data
ntfs_free(dev->d_private);
dev->d_private = NULL;
return 0;
}
/**
*
*/
static s64 ntfs_device_gekko_io_seek(struct ntfs_device *dev, s64 offset, int whence)
{
ntfs_log_trace("dev %p, offset %Li, whence %i\n", dev, offset, whence);
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return -1;
}
// Set the current position on the device (in bytes)
switch(whence) {
case SEEK_SET: fd->pos = MIN(MAX(offset, 0), fd->len); break;
case SEEK_CUR: fd->pos = MIN(MAX(fd->pos + offset, 0), fd->len); break;
case SEEK_END: fd->pos = MIN(MAX(fd->len + offset, 0), fd->len); break;
}
return 0;
}
/**
*
*/
static s64 ntfs_device_gekko_io_read(struct ntfs_device *dev, void *buf, s64 count)
{
return ntfs_device_gekko_io_readbytes(dev, DEV_FD(dev)->pos, count, buf);
}
/**
*
*/
static s64 ntfs_device_gekko_io_write(struct ntfs_device *dev, const void *buf, s64 count)
{
return ntfs_device_gekko_io_writebytes(dev, DEV_FD(dev)->pos, count, buf);
}
/**
*
*/
static s64 ntfs_device_gekko_io_pread(struct ntfs_device *dev, void *buf, s64 count, s64 offset)
{
return ntfs_device_gekko_io_readbytes(dev, offset, count, buf);
}
/**
*
*/
static s64 ntfs_device_gekko_io_pwrite(struct ntfs_device *dev, const void *buf, s64 count, s64 offset)
{
return ntfs_device_gekko_io_writebytes(dev, offset, count, buf);
}
/**
*
*/
static s64 ntfs_device_gekko_io_readbytes(struct ntfs_device *dev, s64 offset, s64 count, void *buf)
{
ntfs_log_trace("dev %p, offset %Li, count %Li\n", dev, offset, count);
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return -1;
}
// Get the device interface
const DISC_INTERFACE* interface = fd->interface;
if (!interface) {
errno = ENODEV;
return -1;
}
if(!count)
return 0;
sec_t sec_start = (sec_t) fd->startSector;
sec_t sec_count = 1;
u32 buffer_offset = 0;
u8 *buffer = NULL;
// Determine the range of sectors required for this read
if (offset > 0) {
sec_start += (sec_t) floor((f64) offset/fd->sectorSize);
buffer_offset = (u32) (offset % fd->sectorSize);
}
if (count > fd->sectorSize) {
sec_count = (sec_t) ceil((f64) count/fd->sectorSize);
if(buffer_offset > 0)
sec_count += 1;
}
// If this read happens to be on the sector boundaries then do the read straight into the destination buffer
if((offset % fd->sectorSize == 0) && (count % fd->sectorSize == 0)) {
// Read from the device
ntfs_log_trace("direct read from sector %d (%d sector(s) long)\n", sec_start, sec_count);
if (!ntfs_device_gekko_io_readsectors(dev, sec_start, sec_count, buf)) {
ntfs_log_perror("direct read failure @ sector %d (%d sector(s) long)\n", sec_start, sec_count);
errno = EIO;
return -1;
}
// Else read into a buffer and copy over only what was requested
}
else
{
// Allocate a buffer to hold the read data
buffer = (u8*)ntfs_alloc(sec_count * fd->sectorSize);
if (!buffer) {
errno = ENOMEM;
return -1;
}
// Read from the device
ntfs_log_trace("buffered read from sector %d (%d sector(s) long)\n", sec_start, sec_count);
ntfs_log_trace("count: %d sec_count:%d fd->sectorSize: %d )\n", (u32)count, (u32)sec_count,(u32)fd->sectorSize);
if (!ntfs_device_gekko_io_readsectors(dev, sec_start, sec_count, buffer)) {
ntfs_log_perror("buffered read failure @ sector %d (%d sector(s) long)\n", sec_start, sec_count);
ntfs_free(buffer);
errno = EIO;
return -1;
}
// Copy what was requested to the destination buffer
memcpy(buf, buffer + buffer_offset, count);
ntfs_free(buffer);
}
return count;
}
/**
*
*/
static s64 ntfs_device_gekko_io_writebytes(struct ntfs_device *dev, s64 offset, s64 count, const void *buf)
{
ntfs_log_trace("dev %p, offset %lli, count %lli\n", dev, offset, count);
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return -1;
}
// Get the device interface
const DISC_INTERFACE* interface = fd->interface;
if (!interface) {
errno = ENODEV;
return -1;
}
// Check that the device can be written to
if (NDevReadOnly(dev)) {
errno = EROFS;
return -1;
}
if(!count)
return 0;
sec_t sec_start = (sec_t) fd->startSector;
sec_t sec_count = 1;
u32 buffer_offset = 0;
u8 *buffer = NULL;
// Determine the range of sectors required for this write
if (offset > 0) {
sec_start += (sec_t) floor((f64) offset/fd->sectorSize);
buffer_offset = (u32) (offset % fd->sectorSize);
}
if (count > fd->sectorSize) {
sec_count = (sec_t) ceil((f64) count/fd->sectorSize);
if(buffer_offset > 0)
sec_count += 1;
}
// If this write happens to be on the sector boundaries then do the write straight to disc
if((offset % fd->sectorSize == 0) && (count % fd->sectorSize == 0)) {
// Write to the device
ntfs_log_trace("direct write to sector %d (%d sector(s) long)\n", sec_start, sec_count);
if (!ntfs_device_gekko_io_writesectors(dev, sec_start, sec_count, buf)) {
ntfs_log_perror("direct write failure @ sector %d (%d sector(s) long)\n", sec_start, sec_count);
errno = EIO;
return -1;
}
// Else write from a buffer aligned to the sector boundaries
} else {
// Allocate a buffer to hold the write data
buffer = (u8 *) ntfs_alloc(sec_count * fd->sectorSize);
if (!buffer) {
errno = ENOMEM;
return -1;
}
// Read the first and last sectors of the buffer from disc (if required)
// NOTE: This is done because the data does not line up with the sector boundaries,
// we just read in the buffer edges where the data overlaps with the rest of the disc
if (!ntfs_device_gekko_io_readsectors(dev, sec_start, sec_count, buffer)) {
ntfs_log_perror("read failure @ sector %d\n", sec_start);
ntfs_free(buffer);
errno = EIO;
return -1;
}
// Copy the data into the write buffer
memcpy(buffer + buffer_offset, buf, count);
// Write to the device
ntfs_log_trace("buffered write to sector %d (%d sector(s) long)\n", sec_start, sec_count);
if (!ntfs_device_gekko_io_writesectors(dev, sec_start, sec_count, buffer)) {
ntfs_log_perror("buffered write failure @ sector %d\n", sec_start);
ntfs_free(buffer);
errno = EIO;
return -1;
}
// Free the buffer
ntfs_free(buffer);
}
// Mark the device as dirty (if we actually wrote anything)
if (count > 0)
NDevSetDirty(dev);
return count;
}
static bool ntfs_device_gekko_io_readsectors(struct ntfs_device *dev, sec_t sector, sec_t numSectors, void* buffer)
{
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return false;
}
// Read the sectors from disc (or cache, if enabled)
if (fd->cache)
return _NTFS_cache_readSectors(fd->cache, sector, numSectors, buffer);
else
return fd->interface->readSectors(sector, numSectors, buffer);
return false;
}
static bool ntfs_device_gekko_io_writesectors(struct ntfs_device *dev, sec_t sector, sec_t numSectors, const void* buffer)
{
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return false;
}
// Write the sectors to disc (or cache, if enabled)
if (fd->cache)
return _NTFS_cache_writeSectors(fd->cache, sector, numSectors, buffer);
else
return fd->interface->writeSectors(sector, numSectors, buffer);
return false;
}
/**
*
*/
static int ntfs_device_gekko_io_sync(struct ntfs_device *dev)
{
gekko_fd *fd = DEV_FD(dev);
ntfs_log_trace("dev %p\n", dev);
// Check that the device can be written to
if (NDevReadOnly(dev)) {
errno = EROFS;
return -1;
}
// Mark the device as clean
NDevClearDirty(dev);
// Flush any sectors in the disc cache (if required)
if (fd->cache) {
if (!_NTFS_cache_flush(fd->cache)) {
errno = EIO;
return -1;
}
}
return 0;
}
/**
*
*/
static int ntfs_device_gekko_io_stat(struct ntfs_device *dev, struct stat *buf)
{
ntfs_log_trace("dev %p, buf %p\n", dev, buf);
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return -1;
}
// Short circuit cases were we don't actually have to do anything
if (!buf)
return 0;
// Build the device mode
mode_t mode = (S_IFBLK) |
(S_IRUSR | S_IRGRP | S_IROTH) |
((!NDevReadOnly(dev)) ? (S_IWUSR | S_IWGRP | S_IWOTH) : 0);
// Zero out the stat buffer
memset(buf, 0, sizeof(struct stat));
// Build the device stats
buf->st_dev = fd->interface->ioType;
buf->st_ino = fd->ino;
buf->st_mode = mode;
buf->st_rdev = fd->interface->ioType;
buf->st_blksize = fd->sectorSize;
buf->st_blocks = fd->sectorCount;
return 0;
}
/**
*
*/
static int ntfs_device_gekko_io_ioctl(struct ntfs_device *dev, int request, void *argp)
{
ntfs_log_trace("dev %p, request %i, argp %p\n", dev, request, argp);
// Get the device driver descriptor
gekko_fd *fd = DEV_FD(dev);
if (!fd) {
errno = EBADF;
return -1;
}
// Figure out which i/o control was requested
switch (request) {
// Get block device size (sectors)
#if defined(BLKGETSIZE)
case BLKGETSIZE: {
*(u32*)argp = fd->sectorCount;
return 0;
}
#endif
// Get block device size (bytes)
#if defined(BLKGETSIZE64)
case BLKGETSIZE64: {
*(u64*)argp = (fd->sectorCount * fd->sectorSize);
return 0;
}
#endif
// Get hard drive geometry
#if defined(HDIO_GETGEO)
case HDIO_GETGEO: {
struct hd_geometry *geo = (struct hd_geometry*)argp;
geo->sectors = 0;
geo->heads = 0;
geo->cylinders = 0;
geo->start = fd->hiddenSectors;
return -1;
}
#endif
// Get block device sector size (bytes)
#if defined(BLKSSZGET)
case BLKSSZGET: {
*(int*)argp = fd->sectorSize;
return 0;
}
#endif
// Set block device block size (bytes)
#if defined(BLKBSZSET)
case BLKBSZSET: {
int sectorSize = *(int*)argp;
if (sectorSize != BYTES_PER_SECTOR) {
ntfs_log_perror("Attempt to set sector size to an unsupported value (%i), ignored\n", sectorSize);
errno = EOPNOTSUPP;
return -1;
}
fd->sectorSize = sectorSize;
return 0;
}
#endif
// Unimplemented ioctrl
default: {
ntfs_log_perror("Unimplemented ioctrl %i\n", request);
errno = EOPNOTSUPP;
return -1;
}
}
return 0;
}
/**
* Device operations for working with gekko style devices and files.
*/
struct ntfs_device_operations ntfs_device_gekko_io_ops = {
.open = ntfs_device_gekko_io_open,
.close = ntfs_device_gekko_io_close,
.seek = ntfs_device_gekko_io_seek,
.read = ntfs_device_gekko_io_read,
.write = ntfs_device_gekko_io_write,
.pread = ntfs_device_gekko_io_pread,
.pwrite = ntfs_device_gekko_io_pwrite,
.sync = ntfs_device_gekko_io_sync,
.stat = ntfs_device_gekko_io_stat,
.ioctl = ntfs_device_gekko_io_ioctl,
};