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/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU LGPLv2.
See the file COPYING.LIB
*/
#include "fuse_lowlevel.h"
#include "fuse_kernel.h"
#include "fuse_i.h"
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <assert.h>
static int fuse_kern_chan_receive(struct fuse_chan **chp, char *buf,
size_t size)
{
struct fuse_chan *ch = *chp;
int err;
ssize_t res;
struct fuse_session *se = fuse_chan_session(ch);
assert(se != NULL);
restart:
res = read(fuse_chan_fd(ch), buf, size);
err = errno;
if (fuse_session_exited(se))
return 0;
if (res == -1) {
/* ENOENT means the operation was interrupted, it's safe
to restart */
if (err == ENOENT)
goto restart;
if (err == ENODEV) {
fuse_session_exit(se);
return 0;
}
/* Errors occuring during normal operation: EINTR (read
interrupted), EAGAIN (nonblocking I/O), ENODEV (filesystem
umounted) */
if (err != EINTR && err != EAGAIN)
perror("fuse: reading device");
return -err;
}
if ((size_t) res < sizeof(struct fuse_in_header)) {
fprintf(stderr, "short read on fuse device\n");
return -EIO;
}
return res;
}
static int fuse_kern_chan_send(struct fuse_chan *ch, const struct iovec iov[],
size_t count)
{
if (iov) {
ssize_t res = writev(fuse_chan_fd(ch), iov, count);
int err = errno;
if (res == -1) {
struct fuse_session *se = fuse_chan_session(ch);
assert(se != NULL);
/* ENOENT means the operation was interrupted */
if (!fuse_session_exited(se) && err != ENOENT)
perror("fuse: writing device");
return -err;
}
}
return 0;
}
static void fuse_kern_chan_destroy(struct fuse_chan *ch)
{
close(fuse_chan_fd(ch));
}
#define MIN_BUFSIZE 0x21000
struct fuse_chan *fuse_kern_chan_new(int fd)
{
struct fuse_chan_ops op = {
.receive = fuse_kern_chan_receive,
.send = fuse_kern_chan_send,
.destroy = fuse_kern_chan_destroy,
};
size_t bufsize = getpagesize() + 0x1000;
bufsize = bufsize < MIN_BUFSIZE ? MIN_BUFSIZE : bufsize;
return fuse_chan_new(&op, fd, bufsize, NULL);
}
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