usbloadergx/source/libntfs/device.c
giantpune 9e79c9d99b * remove little unused code
* code cleanup
2010-09-18 23:16:05 +00:00

766 lines
23 KiB
C

/**
* device.c - Low level device io functions. Originated from the Linux-NTFS project.
*
* Copyright (c) 2004-2006 Anton Altaparmakov
* Copyright (c) 2004-2006 Szabolcs Szakacsits
*
* 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 (in the main directory of the NTFS-3G
* distribution in the file COPYING); 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_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_MOUNT_H
#include <sys/mount.h>
#endif
#ifdef HAVE_LINUX_FD_H
#include <linux/fd.h>
#endif
#ifdef HAVE_LINUX_HDREG_H
#include <linux/hdreg.h>
#endif
#include "types.h"
#include "mst.h"
#include "debug.h"
#include "device.h"
#include "logging.h"
#include "misc.h"
#if defined(linux) && defined(_IO) && !defined(BLKGETSIZE)
#define BLKGETSIZE _IO(0x12,96) /* Get device size in 512-byte blocks. */
#endif
#if defined(linux) && defined(_IOR) && !defined(BLKGETSIZE64)
#define BLKGETSIZE64 _IOR(0x12,114,size_t) /* Get device size in bytes. */
#endif
#if defined(linux) && !defined(HDIO_GETGEO)
#define HDIO_GETGEO 0x0301 /* Get device geometry. */
#endif
#if defined(linux) && defined(_IO) && !defined(BLKSSZGET)
# define BLKSSZGET _IO(0x12,104) /* Get device sector size in bytes. */
#endif
#if defined(linux) && defined(_IO) && !defined(BLKBSZSET)
# define BLKBSZSET _IOW(0x12,113,size_t) /* Set device block size in bytes. */
#endif
/**
* ntfs_device_alloc - allocate an ntfs device structure and pre-initialize it
* @name: name of the device (must be present)
* @state: initial device state (usually zero)
* @dops: ntfs device operations to use with the device (must be present)
* @priv_data: pointer to private data (optional)
*
* Allocate an ntfs device structure and pre-initialize it with the user-
* specified device operations @dops, device state @state, device name @name,
* and optional private data @priv_data.
*
* Note, @name is copied and can hence be freed after this functions returns.
*
* On success return a pointer to the allocated ntfs device structure and on
* error return NULL with errno set to the error code returned by ntfs_malloc().
*/
struct ntfs_device *ntfs_device_alloc( const char *name, const long state,
struct ntfs_device_operations *dops, void *priv_data )
{
struct ntfs_device *dev;
if ( !name )
{
errno = EINVAL;
return NULL;
}
dev = ntfs_malloc( sizeof( struct ntfs_device ) );
if ( dev )
{
if ( !( dev->d_name = strdup( name ) ) )
{
int eo = errno;
free( dev );
errno = eo;
return NULL;
}
dev->d_ops = dops;
dev->d_state = state;
dev->d_private = priv_data;
}
return dev;
}
/**
* ntfs_device_free - free an ntfs device structure
* @dev: ntfs device structure to free
*
* Free the ntfs device structure @dev.
*
* Return 0 on success or -1 on error with errno set to the error code. The
* following error codes are defined:
* EINVAL Invalid pointer @dev.
* EBUSY Device is still open. Close it before freeing it!
*/
int ntfs_device_free( struct ntfs_device *dev )
{
if ( !dev )
{
errno = EINVAL;
return -1;
}
if ( NDevOpen( dev ) )
{
errno = EBUSY;
return -1;
}
free( dev->d_name );
free( dev );
return 0;
}
/**
* ntfs_pread - positioned read from disk
* @dev: device to read from
* @pos: position in device to read from
* @count: number of bytes to read
* @b: output data buffer
*
* This function will read @count bytes from device @dev at position @pos into
* the data buffer @b.
*
* On success, return the number of successfully read bytes. If this number is
* lower than @count this means that we have either reached end of file or
* encountered an error during the read so that the read is partial. 0 means
* end of file or nothing to read (@count is 0).
*
* On error and nothing has been read, return -1 with errno set appropriately
* to the return code of either seek, read, or set to EINVAL in case of
* invalid arguments.
*/
s64 ntfs_pread( struct ntfs_device *dev, const s64 pos, s64 count, void *b )
{
s64 br, total;
struct ntfs_device_operations *dops;
ntfs_log_trace( "pos %lld, count %lld\n", ( long long )pos, ( long long )count );
if ( !b || count < 0 || pos < 0 )
{
errno = EINVAL;
return -1;
}
if ( !count )
return 0;
dops = dev->d_ops;
for ( total = 0; count; count -= br, total += br )
{
br = dops->pread( dev, ( char* )b + total, count, pos + total );
/* If everything ok, continue. */
if ( br > 0 )
continue;
/* If EOF or error return number of bytes read. */
if ( !br || total )
return total;
/* Nothing read and error, return error status. */
return br;
}
/* Finally, return the number of bytes read. */
return total;
}
/**
* ntfs_pwrite - positioned write to disk
* @dev: device to write to
* @pos: position in file descriptor to write to
* @count: number of bytes to write
* @b: data buffer to write to disk
*
* This function will write @count bytes from data buffer @b to the device @dev
* at position @pos.
*
* On success, return the number of successfully written bytes. If this number
* is lower than @count this means that the write has been interrupted in
* flight or that an error was encountered during the write so that the write
* is partial. 0 means nothing was written (also return 0 when @count is 0).
*
* On error and nothing has been written, return -1 with errno set
* appropriately to the return code of either seek, write, or set
* to EINVAL in case of invalid arguments.
*/
s64 ntfs_pwrite( struct ntfs_device *dev, const s64 pos, s64 count,
const void *b )
{
s64 written, total, ret = -1;
struct ntfs_device_operations *dops;
ntfs_log_trace( "pos %lld, count %lld\n", ( long long )pos, ( long long )count );
if ( !b || count < 0 || pos < 0 )
{
errno = EINVAL;
goto out;
}
if ( !count )
return 0;
if ( NDevReadOnly( dev ) )
{
errno = EROFS;
goto out;
}
dops = dev->d_ops;
NDevSetDirty( dev );
for ( total = 0; count; count -= written, total += written )
{
written = dops->pwrite( dev, ( const char* )b + total, count,
pos + total );
/* If everything ok, continue. */
if ( written > 0 )
continue;
/*
* If nothing written or error return number of bytes written.
*/
if ( !written || total )
break;
/* Nothing written and error, return error status. */
total = written;
break;
}
ret = total;
out:
return ret;
}
/**
* ntfs_mst_pread - multi sector transfer (mst) positioned read
* @dev: device to read from
* @pos: position in file descriptor to read from
* @count: number of blocks to read
* @bksize: size of each block that needs mst deprotecting
* @b: output data buffer
*
* Multi sector transfer (mst) positioned read. This function will read @count
* blocks of size @bksize bytes each from device @dev at position @pos into the
* the data buffer @b.
*
* On success, return the number of successfully read blocks. If this number is
* lower than @count this means that we have reached end of file, that the read
* was interrupted, or that an error was encountered during the read so that
* the read is partial. 0 means end of file or nothing was read (also return 0
* when @count or @bksize are 0).
*
* On error and nothing was read, return -1 with errno set appropriately to the
* return code of either seek, read, or set to EINVAL in case of invalid
* arguments.
*
* NOTE: If an incomplete multi sector transfer has been detected the magic
* will have been changed to magic_BAAD but no error will be returned. Thus it
* is possible that we return count blocks as being read but that any number
* (between zero and count!) of these blocks is actually subject to a multi
* sector transfer error. This should be detected by the caller by checking for
* the magic being "BAAD".
*/
s64 ntfs_mst_pread( struct ntfs_device *dev, const s64 pos, s64 count,
const u32 bksize, void *b )
{
s64 br, i;
if ( bksize & ( bksize - 1 ) || bksize % NTFS_BLOCK_SIZE )
{
errno = EINVAL;
return -1;
}
/* Do the read. */
br = ntfs_pread( dev, pos, count * bksize, b );
if ( br < 0 )
return br;
/*
* Apply fixups to successfully read data, disregarding any errors
* returned from the MST fixup function. This is because we want to
* fixup everything possible and we rely on the fact that the "BAAD"
* magic will be detected later on.
*/
count = br / bksize;
for ( i = 0; i < count; ++i )
ntfs_mst_post_read_fixup( ( NTFS_RECORD* )
( ( u8* )b + i * bksize ), bksize );
/* Finally, return the number of complete blocks read. */
return count;
}
/**
* ntfs_mst_pwrite - multi sector transfer (mst) positioned write
* @dev: device to write to
* @pos: position in file descriptor to write to
* @count: number of blocks to write
* @bksize: size of each block that needs mst protecting
* @b: data buffer to write to disk
*
* Multi sector transfer (mst) positioned write. This function will write
* @count blocks of size @bksize bytes each from data buffer @b to the device
* @dev at position @pos.
*
* On success, return the number of successfully written blocks. If this number
* is lower than @count this means that the write has been interrupted or that
* an error was encountered during the write so that the write is partial. 0
* means nothing was written (also return 0 when @count or @bksize are 0).
*
* On error and nothing has been written, return -1 with errno set
* appropriately to the return code of either seek, write, or set
* to EINVAL in case of invalid arguments.
*
* NOTE: We mst protect the data, write it, then mst deprotect it using a quick
* deprotect algorithm (no checking). This saves us from making a copy before
* the write and at the same time causes the usn to be incremented in the
* buffer. This conceptually fits in better with the idea that cached data is
* always deprotected and protection is performed when the data is actually
* going to hit the disk and the cache is immediately deprotected again
* simulating an mst read on the written data. This way cache coherency is
* achieved.
*/
s64 ntfs_mst_pwrite( struct ntfs_device *dev, const s64 pos, s64 count,
const u32 bksize, void *b )
{
s64 written, i;
if ( count < 0 || bksize % NTFS_BLOCK_SIZE )
{
errno = EINVAL;
return -1;
}
if ( !count )
return 0;
/* Prepare data for writing. */
for ( i = 0; i < count; ++i )
{
int err;
err = ntfs_mst_pre_write_fixup( ( NTFS_RECORD* )
( ( u8* )b + i * bksize ), bksize );
if ( err < 0 )
{
/* Abort write at this position. */
if ( !i )
return err;
count = i;
break;
}
}
/* Write the prepared data. */
written = ntfs_pwrite( dev, pos, count * bksize, b );
/* Quickly deprotect the data again. */
for ( i = 0; i < count; ++i )
ntfs_mst_post_write_fixup( ( NTFS_RECORD* )( ( u8* )b + i * bksize ) );
if ( written <= 0 )
return written;
/* Finally, return the number of complete blocks written. */
return written / bksize;
}
/**
* ntfs_cluster_read - read ntfs clusters
* @vol: volume to read from
* @lcn: starting logical cluster number
* @count: number of clusters to read
* @b: output data buffer
*
* Read @count ntfs clusters starting at logical cluster number @lcn from
* volume @vol into buffer @b. Return number of clusters read or -1 on error,
* with errno set to the error code.
*/
s64 ntfs_cluster_read( const ntfs_volume *vol, const s64 lcn, const s64 count,
void *b )
{
s64 br;
if ( !vol || lcn < 0 || count < 0 )
{
errno = EINVAL;
return -1;
}
if ( vol->nr_clusters < lcn + count )
{
errno = ESPIPE;
ntfs_log_perror( "Trying to read outside of volume "
"(%lld < %lld)", ( long long )vol->nr_clusters,
( long long )lcn + count );
return -1;
}
br = ntfs_pread( vol->dev, lcn << vol->cluster_size_bits,
count << vol->cluster_size_bits, b );
if ( br < 0 )
{
ntfs_log_perror( "Error reading cluster(s)" );
return br;
}
return br >> vol->cluster_size_bits;
}
/**
* ntfs_cluster_write - write ntfs clusters
* @vol: volume to write to
* @lcn: starting logical cluster number
* @count: number of clusters to write
* @b: data buffer to write to disk
*
* Write @count ntfs clusters starting at logical cluster number @lcn from
* buffer @b to volume @vol. Return the number of clusters written or -1 on
* error, with errno set to the error code.
*/
s64 ntfs_cluster_write( const ntfs_volume *vol, const s64 lcn,
const s64 count, const void *b )
{
s64 bw;
if ( !vol || lcn < 0 || count < 0 )
{
errno = EINVAL;
return -1;
}
if ( vol->nr_clusters < lcn + count )
{
errno = ESPIPE;
ntfs_log_perror( "Trying to write outside of volume "
"(%lld < %lld)", ( long long )vol->nr_clusters,
( long long )lcn + count );
return -1;
}
if ( !NVolReadOnly( vol ) )
bw = ntfs_pwrite( vol->dev, lcn << vol->cluster_size_bits,
count << vol->cluster_size_bits, b );
else
bw = count << vol->cluster_size_bits;
if ( bw < 0 )
{
ntfs_log_perror( "Error writing cluster(s)" );
return bw;
}
return bw >> vol->cluster_size_bits;
}
/**
* ntfs_device_offset_valid - test if a device offset is valid
* @dev: open device
* @ofs: offset to test for validity
*
* Test if the offset @ofs is an existing location on the device described
* by the open device structure @dev.
*
* Return 0 if it is valid and -1 if it is not valid.
*/
static int ntfs_device_offset_valid( struct ntfs_device *dev, s64 ofs )
{
char ch;
if ( dev->d_ops->seek( dev, ofs, SEEK_SET ) >= 0 &&
dev->d_ops->read( dev, &ch, 1 ) == 1 )
return 0;
return -1;
}
/**
* ntfs_device_size_get - return the size of a device in blocks
* @dev: open device
* @block_size: block size in bytes in which to return the result
*
* Return the number of @block_size sized blocks in the device described by the
* open device @dev.
*
* Adapted from e2fsutils-1.19, Copyright (C) 1995 Theodore Ts'o.
*
* On error return -1 with errno set to the error code.
*/
s64 ntfs_device_size_get( struct ntfs_device *dev, int block_size )
{
s64 high, low;
if ( !dev || block_size <= 0 || ( block_size - 1 ) & block_size )
{
errno = EINVAL;
return -1;
}
#ifdef BLKGETSIZE64
{ u64 size;
if ( dev->d_ops->ioctl( dev, BLKGETSIZE64, &size ) >= 0 )
{
ntfs_log_debug( "BLKGETSIZE64 nr bytes = %llu (0x%llx)\n",
( unsigned long long )size,
( unsigned long long )size );
return ( s64 )size / block_size;
}
}
#endif
#ifdef BLKGETSIZE
{ unsigned long size;
if ( dev->d_ops->ioctl( dev, BLKGETSIZE, &size ) >= 0 )
{
ntfs_log_debug( "BLKGETSIZE nr 512 byte blocks = %lu (0x%lx)\n",
size, size );
return ( s64 )size * 512 / block_size;
}
}
#endif
#ifdef FDGETPRM
{ struct floppy_struct this_floppy;
if ( dev->d_ops->ioctl( dev, FDGETPRM, &this_floppy ) >= 0 )
{
ntfs_log_debug( "FDGETPRM nr 512 byte blocks = %lu (0x%lx)\n",
( unsigned long )this_floppy.size,
( unsigned long )this_floppy.size );
return ( s64 )this_floppy.size * 512 / block_size;
}
}
#endif
/*
* We couldn't figure it out by using a specialized ioctl,
* so do binary search to find the size of the device.
*/
low = 0LL;
for ( high = 1024LL; !ntfs_device_offset_valid( dev, high ); high <<= 1 )
low = high;
while ( low < high - 1LL )
{
const s64 mid = ( low + high ) / 2;
if ( !ntfs_device_offset_valid( dev, mid ) )
low = mid;
else
high = mid;
}
dev->d_ops->seek( dev, 0LL, SEEK_SET );
return ( low + 1LL ) / block_size;
}
/**
* ntfs_device_partition_start_sector_get - get starting sector of a partition
* @dev: open device
*
* On success, return the starting sector of the partition @dev in the parent
* block device of @dev. On error return -1 with errno set to the error code.
*
* The following error codes are defined:
* EINVAL Input parameter error
* EOPNOTSUPP System does not support HDIO_GETGEO ioctl
* ENOTTY @dev is a file or a device not supporting HDIO_GETGEO
*/
s64 ntfs_device_partition_start_sector_get( struct ntfs_device *dev )
{
if ( !dev )
{
errno = EINVAL;
return -1;
}
#ifdef HDIO_GETGEO
{ struct hd_geometry geo;
if ( !dev->d_ops->ioctl( dev, HDIO_GETGEO, &geo ) )
{
ntfs_log_debug( "HDIO_GETGEO start_sect = %lu (0x%lx)\n",
geo.start, geo.start );
return geo.start;
}
}
#else
errno = EOPNOTSUPP;
#endif
return -1;
}
/**
* ntfs_device_heads_get - get number of heads of device
* @dev: open device
*
* On success, return the number of heads on the device @dev. On error return
* -1 with errno set to the error code.
*
* The following error codes are defined:
* EINVAL Input parameter error
* EOPNOTSUPP System does not support HDIO_GETGEO ioctl
* ENOTTY @dev is a file or a device not supporting HDIO_GETGEO
*/
int ntfs_device_heads_get( struct ntfs_device *dev )
{
if ( !dev )
{
errno = EINVAL;
return -1;
}
#ifdef HDIO_GETGEO
{ struct hd_geometry geo;
if ( !dev->d_ops->ioctl( dev, HDIO_GETGEO, &geo ) )
{
ntfs_log_debug( "HDIO_GETGEO heads = %u (0x%x)\n",
( unsigned )geo.heads,
( unsigned )geo.heads );
return geo.heads;
}
}
#else
errno = EOPNOTSUPP;
#endif
return -1;
}
/**
* ntfs_device_sectors_per_track_get - get number of sectors per track of device
* @dev: open device
*
* On success, return the number of sectors per track on the device @dev. On
* error return -1 with errno set to the error code.
*
* The following error codes are defined:
* EINVAL Input parameter error
* EOPNOTSUPP System does not support HDIO_GETGEO ioctl
* ENOTTY @dev is a file or a device not supporting HDIO_GETGEO
*/
int ntfs_device_sectors_per_track_get( struct ntfs_device *dev )
{
if ( !dev )
{
errno = EINVAL;
return -1;
}
#ifdef HDIO_GETGEO
{ struct hd_geometry geo;
if ( !dev->d_ops->ioctl( dev, HDIO_GETGEO, &geo ) )
{
ntfs_log_debug( "HDIO_GETGEO sectors_per_track = %u (0x%x)\n",
( unsigned )geo.sectors,
( unsigned )geo.sectors );
return geo.sectors;
}
}
#else
errno = EOPNOTSUPP;
#endif
return -1;
}
/**
* ntfs_device_sector_size_get - get sector size of a device
* @dev: open device
*
* On success, return the sector size in bytes of the device @dev.
* On error return -1 with errno set to the error code.
*
* The following error codes are defined:
* EINVAL Input parameter error
* EOPNOTSUPP System does not support BLKSSZGET ioctl
* ENOTTY @dev is a file or a device not supporting BLKSSZGET
*/
int ntfs_device_sector_size_get( struct ntfs_device *dev )
{
if ( !dev )
{
errno = EINVAL;
return -1;
}
#ifdef BLKSSZGET
{
int sect_size = 0;
if ( !dev->d_ops->ioctl( dev, BLKSSZGET, &sect_size ) )
{
ntfs_log_debug( "BLKSSZGET sector size = %d bytes\n",
sect_size );
return sect_size;
}
}
#else
errno = EOPNOTSUPP;
#endif
return -1;
}
/**
* ntfs_device_block_size_set - set block size of a device
* @dev: open device
* @block_size: block size to set @dev to
*
* On success, return 0.
* On error return -1 with errno set to the error code.
*
* The following error codes are defined:
* EINVAL Input parameter error
* EOPNOTSUPP System does not support BLKBSZSET ioctl
* ENOTTY @dev is a file or a device not supporting BLKBSZSET
*/
int ntfs_device_block_size_set( struct ntfs_device *dev,
int block_size __attribute__( ( unused ) ) )
{
if ( !dev )
{
errno = EINVAL;
return -1;
}
#ifdef BLKBSZSET
{
size_t s_block_size = block_size;
if ( !dev->d_ops->ioctl( dev, BLKBSZSET, &s_block_size ) )
{
ntfs_log_debug( "Used BLKBSZSET to set block size to "
"%d bytes.\n", block_size );
return 0;
}
/* If not a block device, pretend it was successful. */
if ( !NDevBlock( dev ) )
return 0;
}
#else
/* If not a block device, pretend it was successful. */
if ( !NDevBlock( dev ) )
return 0;
errno = EOPNOTSUPP;
#endif
return -1;
}