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/*
FUSE: Filesystem in Userspace
Copyright (C) 2016 Nikolaus Rath <Nikolaus@rath.org>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#define FUSE_USE_VERSION 30
#include <config.h>
#include <fuse_lowlevel.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <assert.h>
#include <stddef.h>
#include <unistd.h>
#include <pthread.h>
#ifndef __linux__
#include <limits.h>
#else
#include <linux/limits.h>
#endif
#define FILE_INO 2
#define FILE_NAME "write_me"
/* Command line parsing */
struct options {
int writeback;
int data_size;
} options = {
.writeback = 0,
.data_size = 4096,
};
#define OPTION(t, p) \
{ t, offsetof(struct options, p), 1 }
static const struct fuse_opt option_spec[] = {
OPTION("writeback_cache", writeback),
OPTION("--data-size=%d", data_size),
FUSE_OPT_END
};
static int got_write;
static void tfs_init (void *userdata, struct fuse_conn_info *conn)
{
(void) userdata;
if(options.writeback) {
assert(conn->capable & FUSE_CAP_WRITEBACK_CACHE);
conn->want |= FUSE_CAP_WRITEBACK_CACHE;
}
}
static int tfs_stat(fuse_ino_t ino, struct stat *stbuf) {
stbuf->st_ino = ino;
if (ino == FUSE_ROOT_ID) {
stbuf->st_mode = S_IFDIR | 0755;
stbuf->st_nlink = 1;
}
else if (ino == FILE_INO) {
stbuf->st_mode = S_IFREG | 0222;
stbuf->st_nlink = 1;
stbuf->st_size = 0;
}
else
return -1;
return 0;
}
static void tfs_lookup(fuse_req_t req, fuse_ino_t parent,
const char *name) {
struct fuse_entry_param e;
memset(&e, 0, sizeof(e));
if (parent != FUSE_ROOT_ID)
goto err_out;
else if (strcmp(name, FILE_NAME) == 0)
e.ino = FILE_INO;
else
goto err_out;
if (tfs_stat(e.ino, &e.attr) != 0)
goto err_out;
fuse_reply_entry(req, &e);
return;
err_out:
fuse_reply_err(req, ENOENT);
}
static void tfs_getattr(fuse_req_t req, fuse_ino_t ino,
struct fuse_file_info *fi) {
struct stat stbuf;
(void) fi;
memset(&stbuf, 0, sizeof(stbuf));
if (tfs_stat(ino, &stbuf) != 0)
fuse_reply_err(req, ENOENT);
else
fuse_reply_attr(req, &stbuf, 5);
}
static void tfs_open(fuse_req_t req, fuse_ino_t ino,
struct fuse_file_info *fi) {
if (ino == FUSE_ROOT_ID)
fuse_reply_err(req, EISDIR);
else {
assert(ino == FILE_INO);
fuse_reply_open(req, fi);
}
}
static void tfs_write(fuse_req_t req, fuse_ino_t ino, const char *buf,
size_t size, off_t off, struct fuse_file_info *fi) {
(void) fi; (void) buf; (void) off;
size_t expected;
assert(ino == FILE_INO);
expected = options.data_size;
if(options.writeback)
expected *= 2;
if(size != expected)
fprintf(stderr, "ERROR: Expected %zd bytes, got %zd\n!",
expected, size);
else
got_write = 1;
fuse_reply_write(req, size);
}
static struct fuse_lowlevel_ops tfs_oper = {
.init = tfs_init,
.lookup = tfs_lookup,
.getattr = tfs_getattr,
.open = tfs_open,
.write = tfs_write,
};
static void* run_fs(void *data) {
struct fuse_session *se = (struct fuse_session*) data;
assert(fuse_session_loop(se) == 0);
return NULL;
}
static void test_fs(char *mountpoint) {
char fname[PATH_MAX];
char *buf;
size_t dsize = options.data_size;
int fd;
buf = malloc(dsize);
assert(buf != NULL);
assert((fd = open("/dev/urandom", O_RDONLY)) != -1);
assert(read(fd, buf, dsize) == dsize);
close(fd);
assert(snprintf(fname, PATH_MAX, "%s/" FILE_NAME,
mountpoint) > 0);
fd = open(fname, O_WRONLY);
if (fd == -1) {
perror(fname);
assert(0);
}
assert(write(fd, buf, dsize) == dsize);
assert(write(fd, buf, dsize) == dsize);
free(buf);
close(fd);
}
int main(int argc, char *argv[]) {
struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
struct fuse_session *se;
struct fuse_cmdline_opts fuse_opts;
pthread_t fs_thread;
assert(fuse_opt_parse(&args, &options, option_spec, NULL) == 0);
assert(fuse_parse_cmdline(&args, &fuse_opts) == 0);
#ifndef __FreeBSD__
assert(fuse_opt_add_arg(&args, "-oauto_unmount") == 0);
#endif
se = fuse_session_new(&args, &tfs_oper,
sizeof(tfs_oper), NULL);
fuse_opt_free_args(&args);
assert (se != NULL);
assert(fuse_set_signal_handlers(se) == 0);
assert(fuse_session_mount(se, fuse_opts.mountpoint) == 0);
/* Start file-system thread */
assert(pthread_create(&fs_thread, NULL, run_fs, (void *)se) == 0);
/* Write test data */
test_fs(fuse_opts.mountpoint);
free(fuse_opts.mountpoint);
/* Stop file system */
assert(pthread_cancel(fs_thread) == 0);
fuse_session_unmount(se);
assert(got_write == 1);
fuse_remove_signal_handlers(se);
fuse_session_destroy(se);
printf("Test completed successfully.\n");
return 0;
}
/**
* Local Variables:
* mode: c
* indent-tabs-mode: nil
* c-basic-offset: 4
* End:
*/
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