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);
if (channel->name)
ext2fs_free_mem(&channel->name);
ext2fs_free_mem(&channel);
return retval;
}
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;
}
static errcode_t unix_write_blk64(io_channel channel, unsigned long 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 */
}
/*
* 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_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_blk64(io_channel channel, unsigned long 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 %lu\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 %lu\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 */
}
