ntfs-3g-system-compression/src/plugin.c

103 lines
2.7 KiB
C

/*
* plugin.c - NTFS-3G system compression plugin
*
* Copyright (C) 2015 Jean-Pierre Andre
* Copyright (C) 2015-2016 Eric Biggers
*
* 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 the Free Software
* Foundation, either version 2 of the License, or (at your option) any later
* version.
*
* This program 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <fuse.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <ntfs-3g/inode.h>
#include <ntfs-3g/plugin.h>
#include "system_compression.h"
static int compressed_getattr(ntfs_inode *ni, const REPARSE_POINT *reparse,
struct stat *stbuf)
{
s64 compressed_size = ntfs_get_system_compressed_file_size(ni, reparse);
if (compressed_size >= 0) {
/* System-compressed file */
stbuf->st_size = ni->data_size;
stbuf->st_blocks = (compressed_size + 511) >> 9;
stbuf->st_mode = S_IFREG | 0555;
return 0;
}
/* Not a system compressed file, or another error occurred */
return -errno;
}
static int compressed_open(ntfs_inode *ni __attribute__((unused)),
const REPARSE_POINT *reparse __attribute__((unused)),
struct fuse_file_info *fi)
{
if ((fi->flags & O_ACCMODE) != O_RDONLY)
return -EOPNOTSUPP;
return 0;
}
static int compressed_release(ntfs_inode *ni __attribute__((unused)),
const REPARSE_POINT *reparse __attribute__((unused)),
struct fuse_file_info *fi __attribute__((unused)))
{
return 0;
}
static int compressed_read(ntfs_inode *ni, const REPARSE_POINT *reparse,
char *buf, size_t size, off_t offset,
struct fuse_file_info *fi __attribute__((unused)))
{
struct ntfs_system_decompression_ctx *dctx;
ssize_t res;
/* TODO: there needs to be more investigation into reusing decompression
* contexts for multiple reads. */
dctx = ntfs_open_system_decompression_ctx(ni, reparse);
if (!dctx)
return -errno;
res = ntfs_read_system_compressed_data(dctx, offset, size, buf);
ntfs_close_system_decompression_ctx(dctx);
if (res < 0)
return -errno;
return res;
}
static const struct plugin_operations ops = {
.getattr = compressed_getattr,
.open = compressed_open,
.release = compressed_release,
.read = compressed_read,
};
const struct plugin_operations *init(le32 tag)
{
if (tag == IO_REPARSE_TAG_WOF)
return &ops;
errno = EINVAL;
return NULL;
}