mirror of
https://github.com/sheumann/hush.git
synced 2024-08-19 13:28:57 +00:00
704 lines
17 KiB
C
704 lines
17 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* unix_io.c --- This is the Unix (well, really POSIX) implementation
|
|
* of the I/O manager.
|
|
*
|
|
* Implements a one-block write-through cache.
|
|
*
|
|
* Includes support for Windows NT support under Cygwin.
|
|
*
|
|
* Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
|
|
* 2002 by Theodore Ts'o.
|
|
*
|
|
* %Begin-Header%
|
|
* This file may be redistributed under the terms of the GNU Public
|
|
* License.
|
|
* %End-Header%
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#if HAVE_UNISTD_H
|
|
#include <unistd.h>
|
|
#endif
|
|
#if HAVE_ERRNO_H
|
|
#include <errno.h>
|
|
#endif
|
|
#include <fcntl.h>
|
|
#include <time.h>
|
|
#ifdef __linux__
|
|
#include <sys/utsname.h>
|
|
#endif
|
|
#if HAVE_SYS_STAT_H
|
|
#include <sys/stat.h>
|
|
#endif
|
|
#if HAVE_SYS_TYPES_H
|
|
#include <sys/types.h>
|
|
#endif
|
|
#include <sys/resource.h>
|
|
|
|
#include "ext2_fs.h"
|
|
#include "ext2fs.h"
|
|
|
|
/*
|
|
* For checking structure magic numbers...
|
|
*/
|
|
|
|
#define EXT2_CHECK_MAGIC(struct, code) \
|
|
if ((struct)->magic != (code)) return (code)
|
|
|
|
struct unix_cache {
|
|
char *buf;
|
|
unsigned long block;
|
|
int access_time;
|
|
unsigned dirty:1;
|
|
unsigned in_use:1;
|
|
};
|
|
|
|
#define CACHE_SIZE 8
|
|
#define WRITE_DIRECT_SIZE 4 /* Must be smaller than CACHE_SIZE */
|
|
#define READ_DIRECT_SIZE 4 /* Should be smaller than CACHE_SIZE */
|
|
|
|
struct unix_private_data {
|
|
int magic;
|
|
int dev;
|
|
int flags;
|
|
int access_time;
|
|
ext2_loff_t offset;
|
|
struct unix_cache cache[CACHE_SIZE];
|
|
};
|
|
|
|
static errcode_t unix_open(const char *name, int flags, io_channel *channel);
|
|
static errcode_t unix_close(io_channel channel);
|
|
static errcode_t unix_set_blksize(io_channel channel, int blksize);
|
|
static errcode_t unix_read_blk(io_channel channel, unsigned long block,
|
|
int count, void *data);
|
|
static errcode_t unix_write_blk(io_channel channel, unsigned long block,
|
|
int count, const void *data);
|
|
static errcode_t unix_flush(io_channel channel);
|
|
static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
|
|
int size, const void *data);
|
|
static errcode_t unix_set_option(io_channel channel, const char *option,
|
|
const char *arg);
|
|
|
|
static void reuse_cache(io_channel channel, struct unix_private_data *data,
|
|
struct unix_cache *cache, unsigned long block);
|
|
|
|
/* __FreeBSD_kernel__ is defined by GNU/kFreeBSD - the FreeBSD kernel
|
|
* does not know buffered block devices - everything is raw. */
|
|
#if defined(__CYGWIN__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
|
|
#define NEED_BOUNCE_BUFFER
|
|
#else
|
|
#undef NEED_BOUNCE_BUFFER
|
|
#endif
|
|
|
|
static struct struct_io_manager struct_unix_manager = {
|
|
EXT2_ET_MAGIC_IO_MANAGER,
|
|
"Unix I/O Manager",
|
|
unix_open,
|
|
unix_close,
|
|
unix_set_blksize,
|
|
unix_read_blk,
|
|
unix_write_blk,
|
|
unix_flush,
|
|
#ifdef NEED_BOUNCE_BUFFER
|
|
0,
|
|
#else
|
|
unix_write_byte,
|
|
#endif
|
|
unix_set_option
|
|
};
|
|
|
|
io_manager unix_io_manager = &struct_unix_manager;
|
|
|
|
/*
|
|
* Here are the raw I/O functions
|
|
*/
|
|
#ifndef NEED_BOUNCE_BUFFER
|
|
static errcode_t raw_read_blk(io_channel channel,
|
|
struct unix_private_data *data,
|
|
unsigned long block,
|
|
int count, void *buf)
|
|
{
|
|
errcode_t retval;
|
|
ssize_t size;
|
|
ext2_loff_t location;
|
|
int actual = 0;
|
|
|
|
size = (count < 0) ? -count : count * channel->block_size;
|
|
location = ((ext2_loff_t) block * channel->block_size) + data->offset;
|
|
if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
|
|
retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
|
|
goto error_out;
|
|
}
|
|
actual = read(data->dev, buf, size);
|
|
if (actual != size) {
|
|
if (actual < 0)
|
|
actual = 0;
|
|
retval = EXT2_ET_SHORT_READ;
|
|
goto error_out;
|
|
}
|
|
return 0;
|
|
|
|
error_out:
|
|
memset((char *) buf+actual, 0, size-actual);
|
|
if (channel->read_error)
|
|
retval = (channel->read_error)(channel, block, count, buf,
|
|
size, actual, retval);
|
|
return retval;
|
|
}
|
|
#else /* NEED_BOUNCE_BUFFER */
|
|
/*
|
|
* Windows and FreeBSD block devices only allow sector alignment IO in offset and size
|
|
*/
|
|
static errcode_t raw_read_blk(io_channel channel,
|
|
struct unix_private_data *data,
|
|
unsigned long block,
|
|
int count, void *buf)
|
|
{
|
|
errcode_t retval;
|
|
size_t size, alignsize, fragment;
|
|
ext2_loff_t location;
|
|
int total = 0, actual;
|
|
#define BLOCKALIGN 512
|
|
char sector[BLOCKALIGN];
|
|
|
|
size = (count < 0) ? -count : count * channel->block_size;
|
|
location = ((ext2_loff_t) block * channel->block_size) + data->offset;
|
|
#ifdef DEBUG
|
|
printf("count=%d, size=%d, block=%d, blk_size=%d, location=%lx\n",
|
|
count, size, block, channel->block_size, location);
|
|
#endif
|
|
if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
|
|
retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
|
|
goto error_out;
|
|
}
|
|
fragment = size % BLOCKALIGN;
|
|
alignsize = size - fragment;
|
|
if (alignsize) {
|
|
actual = read(data->dev, buf, alignsize);
|
|
if (actual != alignsize)
|
|
goto short_read;
|
|
}
|
|
if (fragment) {
|
|
actual = read(data->dev, sector, BLOCKALIGN);
|
|
if (actual != BLOCKALIGN)
|
|
goto short_read;
|
|
memcpy(buf+alignsize, sector, fragment);
|
|
}
|
|
return 0;
|
|
|
|
short_read:
|
|
if (actual>0)
|
|
total += actual;
|
|
retval = EXT2_ET_SHORT_READ;
|
|
|
|
error_out:
|
|
memset((char *) buf+total, 0, size-actual);
|
|
if (channel->read_error)
|
|
retval = (channel->read_error)(channel, block, count, buf,
|
|
size, actual, retval);
|
|
return retval;
|
|
}
|
|
#endif
|
|
|
|
static errcode_t raw_write_blk(io_channel channel,
|
|
struct unix_private_data *data,
|
|
unsigned long block,
|
|
int count, const void *buf)
|
|
{
|
|
ssize_t size;
|
|
ext2_loff_t location;
|
|
int actual = 0;
|
|
errcode_t retval;
|
|
|
|
if (count == 1)
|
|
size = channel->block_size;
|
|
else {
|
|
if (count < 0)
|
|
size = -count;
|
|
else
|
|
size = count * channel->block_size;
|
|
}
|
|
|
|
location = ((ext2_loff_t) block * channel->block_size) + data->offset;
|
|
if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
|
|
retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
|
|
goto error_out;
|
|
}
|
|
|
|
actual = write(data->dev, buf, size);
|
|
if (actual != size) {
|
|
retval = EXT2_ET_SHORT_WRITE;
|
|
goto error_out;
|
|
}
|
|
return 0;
|
|
|
|
error_out:
|
|
if (channel->write_error)
|
|
retval = (channel->write_error)(channel, block, count, buf,
|
|
size, actual, retval);
|
|
return retval;
|
|
}
|
|
|
|
|
|
/*
|
|
* Here we implement the cache functions
|
|
*/
|
|
|
|
/* Allocate the cache buffers */
|
|
static errcode_t alloc_cache(io_channel channel,
|
|
struct unix_private_data *data)
|
|
{
|
|
errcode_t retval;
|
|
struct unix_cache *cache;
|
|
int i;
|
|
|
|
data->access_time = 0;
|
|
for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
|
|
cache->block = 0;
|
|
cache->access_time = 0;
|
|
cache->dirty = 0;
|
|
cache->in_use = 0;
|
|
if ((retval = ext2fs_get_mem(channel->block_size,
|
|
&cache->buf)))
|
|
return retval;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Free the cache buffers */
|
|
static void free_cache(struct unix_private_data *data)
|
|
{
|
|
struct unix_cache *cache;
|
|
int i;
|
|
|
|
data->access_time = 0;
|
|
for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
|
|
cache->block = 0;
|
|
cache->access_time = 0;
|
|
cache->dirty = 0;
|
|
cache->in_use = 0;
|
|
ext2fs_free_mem(&cache->buf);
|
|
cache->buf = 0;
|
|
}
|
|
}
|
|
|
|
#ifndef NO_IO_CACHE
|
|
/*
|
|
* Try to find a block in the cache. If the block is not found, and
|
|
* eldest is a non-zero pointer, then fill in eldest with the cache
|
|
* entry to that should be reused.
|
|
*/
|
|
static struct unix_cache *find_cached_block(struct unix_private_data *data,
|
|
unsigned long block,
|
|
struct unix_cache **eldest)
|
|
{
|
|
struct unix_cache *cache, *unused_cache, *oldest_cache;
|
|
int i;
|
|
|
|
unused_cache = oldest_cache = 0;
|
|
for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
|
|
if (!cache->in_use) {
|
|
if (!unused_cache)
|
|
unused_cache = cache;
|
|
continue;
|
|
}
|
|
if (cache->block == block) {
|
|
cache->access_time = ++data->access_time;
|
|
return cache;
|
|
}
|
|
if (!oldest_cache ||
|
|
(cache->access_time < oldest_cache->access_time))
|
|
oldest_cache = cache;
|
|
}
|
|
if (eldest)
|
|
*eldest = (unused_cache) ? unused_cache : oldest_cache;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Reuse a particular cache entry for another block.
|
|
*/
|
|
static void reuse_cache(io_channel channel, struct unix_private_data *data,
|
|
struct unix_cache *cache, unsigned long block)
|
|
{
|
|
if (cache->dirty && cache->in_use)
|
|
raw_write_blk(channel, data, cache->block, 1, cache->buf);
|
|
|
|
cache->in_use = 1;
|
|
cache->dirty = 0;
|
|
cache->block = block;
|
|
cache->access_time = ++data->access_time;
|
|
}
|
|
|
|
/*
|
|
* Flush all of the blocks in the cache
|
|
*/
|
|
static errcode_t flush_cached_blocks(io_channel channel,
|
|
struct unix_private_data *data,
|
|
int invalidate)
|
|
|
|
{
|
|
struct unix_cache *cache;
|
|
errcode_t retval, retval2;
|
|
int i;
|
|
|
|
retval2 = 0;
|
|
for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
|
|
if (!cache->in_use)
|
|
continue;
|
|
|
|
if (invalidate)
|
|
cache->in_use = 0;
|
|
|
|
if (!cache->dirty)
|
|
continue;
|
|
|
|
retval = raw_write_blk(channel, data,
|
|
cache->block, 1, cache->buf);
|
|
if (retval)
|
|
retval2 = retval;
|
|
else
|
|
cache->dirty = 0;
|
|
}
|
|
return retval2;
|
|
}
|
|
#endif /* NO_IO_CACHE */
|
|
|
|
static errcode_t unix_open(const char *name, int flags, io_channel *channel)
|
|
{
|
|
io_channel io = NULL;
|
|
struct unix_private_data *data = NULL;
|
|
errcode_t retval;
|
|
int open_flags;
|
|
struct stat st;
|
|
#ifdef __linux__
|
|
struct utsname ut;
|
|
#endif
|
|
|
|
if (name == 0)
|
|
return EXT2_ET_BAD_DEVICE_NAME;
|
|
retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
|
|
if (retval)
|
|
return retval;
|
|
memset(io, 0, sizeof(struct struct_io_channel));
|
|
io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
|
|
retval = ext2fs_get_mem(sizeof(struct unix_private_data), &data);
|
|
if (retval)
|
|
goto cleanup;
|
|
|
|
io->manager = unix_io_manager;
|
|
retval = ext2fs_get_mem(strlen(name)+1, &io->name);
|
|
if (retval)
|
|
goto cleanup;
|
|
|
|
strcpy(io->name, name);
|
|
io->private_data = data;
|
|
io->block_size = 1024;
|
|
io->read_error = 0;
|
|
io->write_error = 0;
|
|
io->refcount = 1;
|
|
|
|
memset(data, 0, sizeof(struct unix_private_data));
|
|
data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL;
|
|
|
|
if ((retval = alloc_cache(io, data)))
|
|
goto cleanup;
|
|
|
|
open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY;
|
|
#ifdef CONFIG_LFS
|
|
data->dev = open64(io->name, open_flags);
|
|
#else
|
|
data->dev = open(io->name, open_flags);
|
|
#endif
|
|
if (data->dev < 0) {
|
|
retval = errno;
|
|
goto cleanup;
|
|
}
|
|
|
|
#ifdef __linux__
|
|
#undef RLIM_INFINITY
|
|
#if (defined(__alpha__) || ((defined(__sparc__) || defined(__mips__)) && (SIZEOF_LONG == 4)))
|
|
#define RLIM_INFINITY ((unsigned long)(~0UL>>1))
|
|
#else
|
|
#define RLIM_INFINITY (~0UL)
|
|
#endif
|
|
/*
|
|
* Work around a bug in 2.4.10-2.4.18 kernels where writes to
|
|
* block devices are wrongly getting hit by the filesize
|
|
* limit. This workaround isn't perfect, since it won't work
|
|
* if glibc wasn't built against 2.2 header files. (Sigh.)
|
|
*
|
|
*/
|
|
if ((flags & IO_FLAG_RW) &&
|
|
(uname(&ut) == 0) &&
|
|
((ut.release[0] == '2') && (ut.release[1] == '.') &&
|
|
(ut.release[2] == '4') && (ut.release[3] == '.') &&
|
|
(ut.release[4] == '1') && (ut.release[5] >= '0') &&
|
|
(ut.release[5] < '8')) &&
|
|
(fstat(data->dev, &st) == 0) &&
|
|
(S_ISBLK(st.st_mode))) {
|
|
struct rlimit rlim;
|
|
|
|
rlim.rlim_cur = rlim.rlim_max = (unsigned long) RLIM_INFINITY;
|
|
setrlimit(RLIMIT_FSIZE, &rlim);
|
|
getrlimit(RLIMIT_FSIZE, &rlim);
|
|
if (((unsigned long) rlim.rlim_cur) <
|
|
((unsigned long) rlim.rlim_max)) {
|
|
rlim.rlim_cur = rlim.rlim_max;
|
|
setrlimit(RLIMIT_FSIZE, &rlim);
|
|
}
|
|
}
|
|
#endif
|
|
*channel = io;
|
|
return 0;
|
|
|
|
cleanup:
|
|
if (data) {
|
|
free_cache(data);
|
|
ext2fs_free_mem(&data);
|
|
}
|
|
ext2fs_free_mem(&io);
|
|
return retval;
|
|
}
|
|
|
|
static errcode_t unix_close(io_channel channel)
|
|
{
|
|
struct unix_private_data *data;
|
|
errcode_t retval = 0;
|
|
|
|
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
|
|
data = (struct unix_private_data *) channel->private_data;
|
|
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
|
|
|
|
if (--channel->refcount > 0)
|
|
return 0;
|
|
|
|
#ifndef NO_IO_CACHE
|
|
retval = flush_cached_blocks(channel, data, 0);
|
|
#endif
|
|
|
|
if (close(data->dev) < 0)
|
|
retval = errno;
|
|
free_cache(data);
|
|
|
|
ext2fs_free_mem(&channel->private_data);
|
|
ext2fs_free_mem(&channel->name);
|
|
ext2fs_free_mem(&channel);
|
|
return retval;
|
|
}
|
|
|
|
static errcode_t unix_set_blksize(io_channel channel, int blksize)
|
|
{
|
|
struct unix_private_data *data;
|
|
errcode_t retval;
|
|
|
|
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
|
|
data = (struct unix_private_data *) channel->private_data;
|
|
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
|
|
|
|
if (channel->block_size != blksize) {
|
|
#ifndef NO_IO_CACHE
|
|
if ((retval = flush_cached_blocks(channel, data, 0)))
|
|
return retval;
|
|
#endif
|
|
|
|
channel->block_size = blksize;
|
|
free_cache(data);
|
|
if ((retval = alloc_cache(channel, data)))
|
|
return retval;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
static errcode_t unix_read_blk(io_channel channel, unsigned long block,
|
|
int count, void *buf)
|
|
{
|
|
struct unix_private_data *data;
|
|
struct unix_cache *cache, *reuse[READ_DIRECT_SIZE];
|
|
errcode_t retval;
|
|
char *cp;
|
|
int i, j;
|
|
|
|
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
|
|
data = (struct unix_private_data *) channel->private_data;
|
|
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
|
|
|
|
#ifdef NO_IO_CACHE
|
|
return raw_read_blk(channel, data, block, count, buf);
|
|
#else
|
|
/*
|
|
* If we're doing an odd-sized read or a very large read,
|
|
* flush out the cache and then do a direct read.
|
|
*/
|
|
if (count < 0 || count > WRITE_DIRECT_SIZE) {
|
|
if ((retval = flush_cached_blocks(channel, data, 0)))
|
|
return retval;
|
|
return raw_read_blk(channel, data, block, count, buf);
|
|
}
|
|
|
|
cp = buf;
|
|
while (count > 0) {
|
|
/* If it's in the cache, use it! */
|
|
if ((cache = find_cached_block(data, block, &reuse[0]))) {
|
|
#ifdef DEBUG
|
|
printf("Using cached block %d\n", block);
|
|
#endif
|
|
memcpy(cp, cache->buf, channel->block_size);
|
|
count--;
|
|
block++;
|
|
cp += channel->block_size;
|
|
continue;
|
|
}
|
|
/*
|
|
* Find the number of uncached blocks so we can do a
|
|
* single read request
|
|
*/
|
|
for (i=1; i < count; i++)
|
|
if (find_cached_block(data, block+i, &reuse[i]))
|
|
break;
|
|
#ifdef DEBUG
|
|
printf("Reading %d blocks starting at %d\n", i, block);
|
|
#endif
|
|
if ((retval = raw_read_blk(channel, data, block, i, cp)))
|
|
return retval;
|
|
|
|
/* Save the results in the cache */
|
|
for (j=0; j < i; j++) {
|
|
count--;
|
|
cache = reuse[j];
|
|
reuse_cache(channel, data, cache, block++);
|
|
memcpy(cache->buf, cp, channel->block_size);
|
|
cp += channel->block_size;
|
|
}
|
|
}
|
|
return 0;
|
|
#endif /* NO_IO_CACHE */
|
|
}
|
|
|
|
static errcode_t unix_write_blk(io_channel channel, unsigned long block,
|
|
int count, const void *buf)
|
|
{
|
|
struct unix_private_data *data;
|
|
struct unix_cache *cache, *reuse;
|
|
errcode_t retval = 0;
|
|
const char *cp;
|
|
int writethrough;
|
|
|
|
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
|
|
data = (struct unix_private_data *) channel->private_data;
|
|
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
|
|
|
|
#ifdef NO_IO_CACHE
|
|
return raw_write_blk(channel, data, block, count, buf);
|
|
#else
|
|
/*
|
|
* If we're doing an odd-sized write or a very large write,
|
|
* flush out the cache completely and then do a direct write.
|
|
*/
|
|
if (count < 0 || count > WRITE_DIRECT_SIZE) {
|
|
if ((retval = flush_cached_blocks(channel, data, 1)))
|
|
return retval;
|
|
return raw_write_blk(channel, data, block, count, buf);
|
|
}
|
|
|
|
/*
|
|
* For a moderate-sized multi-block write, first force a write
|
|
* if we're in write-through cache mode, and then fill the
|
|
* cache with the blocks.
|
|
*/
|
|
writethrough = channel->flags & CHANNEL_FLAGS_WRITETHROUGH;
|
|
if (writethrough)
|
|
retval = raw_write_blk(channel, data, block, count, buf);
|
|
|
|
cp = buf;
|
|
while (count > 0) {
|
|
cache = find_cached_block(data, block, &reuse);
|
|
if (!cache) {
|
|
cache = reuse;
|
|
reuse_cache(channel, data, cache, block);
|
|
}
|
|
memcpy(cache->buf, cp, channel->block_size);
|
|
cache->dirty = !writethrough;
|
|
count--;
|
|
block++;
|
|
cp += channel->block_size;
|
|
}
|
|
return retval;
|
|
#endif /* NO_IO_CACHE */
|
|
}
|
|
|
|
static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
|
|
int size, const void *buf)
|
|
{
|
|
struct unix_private_data *data;
|
|
errcode_t retval = 0;
|
|
ssize_t actual;
|
|
|
|
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
|
|
data = (struct unix_private_data *) channel->private_data;
|
|
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
|
|
|
|
#ifndef NO_IO_CACHE
|
|
/*
|
|
* Flush out the cache completely
|
|
*/
|
|
if ((retval = flush_cached_blocks(channel, data, 1)))
|
|
return retval;
|
|
#endif
|
|
|
|
if (lseek(data->dev, offset + data->offset, SEEK_SET) < 0)
|
|
return errno;
|
|
|
|
actual = write(data->dev, buf, size);
|
|
if (actual != size)
|
|
return EXT2_ET_SHORT_WRITE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Flush data buffers to disk.
|
|
*/
|
|
static errcode_t unix_flush(io_channel channel)
|
|
{
|
|
struct unix_private_data *data;
|
|
errcode_t retval = 0;
|
|
|
|
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
|
|
data = (struct unix_private_data *) channel->private_data;
|
|
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
|
|
|
|
#ifndef NO_IO_CACHE
|
|
retval = flush_cached_blocks(channel, data, 0);
|
|
#endif
|
|
fsync(data->dev);
|
|
return retval;
|
|
}
|
|
|
|
static errcode_t unix_set_option(io_channel channel, const char *option,
|
|
const char *arg)
|
|
{
|
|
struct unix_private_data *data;
|
|
unsigned long tmp;
|
|
char *end;
|
|
|
|
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
|
|
data = (struct unix_private_data *) channel->private_data;
|
|
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
|
|
|
|
if (!strcmp(option, "offset")) {
|
|
if (!arg)
|
|
return EXT2_ET_INVALID_ARGUMENT;
|
|
|
|
tmp = strtoul(arg, &end, 0);
|
|
if (*end)
|
|
return EXT2_ET_INVALID_ARGUMENT;
|
|
data->offset = tmp;
|
|
return 0;
|
|
}
|
|
return EXT2_ET_INVALID_ARGUMENT;
|
|
}
|