static void cusexmp_ioctl(fuse_req_t req, int cmd, void *arg,
struct fuse_file_info *fi, unsigned flags,
const void *in_buf, size_t in_bufsz, size_t out_bufsz)
{
int is_read = 0;
(void)fi;
if (flags & FUSE_IOCTL_COMPAT) {
fuse_reply_err(req, ENOSYS);
return;
}
switch (cmd) {
case FIOC_GET_SIZE:
if (!out_bufsz) {
struct iovec iov = { arg, sizeof(size_t) };
fuse_reply_ioctl_retry(req, NULL, 0, &iov, 1);
} else
fuse_reply_ioctl(req, 0, &cusexmp_size,
sizeof(cusexmp_size));
break;
case FIOC_SET_SIZE:
if (!in_bufsz) {
struct iovec iov = { arg, sizeof(size_t) };
fuse_reply_ioctl_retry(req, &iov, 1, NULL, 0);
} else {
cusexmp_resize(*(size_t *)in_buf);
fuse_reply_ioctl(req, 0, NULL, 0);
}
break;
case FIOC_READ:
is_read = 1;
/* no break */
case FIOC_WRITE:
fioc_do_rw(req, arg, in_buf, in_bufsz, out_bufsz, is_read);
break;
default:
fuse_reply_err(req, EINVAL);
}
}
static void fioc_do_rw(fuse_req_t req, void *addr, const void *in_buf,
size_t in_bufsz, size_t out_bufsz, int is_read)
{
const struct fioc_rw_arg *arg;
struct iovec in_iov[2], out_iov[3], iov[3];
size_t cur_size;
/* read in arg */
in_iov[0].iov_base = addr;
in_iov[0].iov_len = sizeof(*arg);
if (!in_bufsz) {
fuse_reply_ioctl_retry(req, in_iov, 1, NULL, 0);
return;
}
arg = in_buf;
in_buf += sizeof(*arg);
in_bufsz -= sizeof(*arg);
/* prepare size outputs */
out_iov[0].iov_base =
addr + (unsigned long)&(((struct fioc_rw_arg *)0)->prev_size);
out_iov[0].iov_len = sizeof(arg->prev_size);
out_iov[1].iov_base =
addr + (unsigned long)&(((struct fioc_rw_arg *)0)->new_size);
out_iov[1].iov_len = sizeof(arg->new_size);
/* prepare client buf */
if (is_read) {
out_iov[2].iov_base = arg->buf;
out_iov[2].iov_len = arg->size;
if (!out_bufsz) {
fuse_reply_ioctl_retry(req, in_iov, 1, out_iov, 3);
return;
}
} else {
in_iov[1].iov_base = arg->buf;
in_iov[1].iov_len = arg->size;
if (arg->size && !in_bufsz) {
fuse_reply_ioctl_retry(req, in_iov, 2, out_iov, 2);
return;
}
}
/* we're all set */
cur_size = cusexmp_size;
iov[0].iov_base = &cur_size;
iov[0].iov_len = sizeof(cur_size);
iov[1].iov_base = &cusexmp_size;
iov[1].iov_len = sizeof(cusexmp_size);
if (is_read) {
size_t off = arg->offset;
size_t size = arg->size;
if (off >= cusexmp_size)
off = cusexmp_size;
if (size > cusexmp_size - off)
size = cusexmp_size - off;
iov[2].iov_base = cusexmp_buf + off;
iov[2].iov_len = size;
fuse_reply_ioctl_iov(req, size, iov, 3);
} else {
if (cusexmp_expand(arg->offset + in_bufsz)) {
fuse_reply_err(req, ENOMEM);
return;
}
memcpy(cusexmp_buf + arg->offset, in_buf, in_bufsz);
fuse_reply_ioctl_iov(req, in_bufsz, iov, 2);
}
}