static void __process_write_request(struct stream *s)
{
int np = 0;
struct stream_request *req;
while (!event_list_empty(&s->write_queue[IO_WAIT])) {
int ret;
req = event_list_first_entry(&s->write_queue[IO_WAIT], struct stream_request, node);
ret = __do_write(s, req);
if (ret && ret != -EAGAIN && ret != -EINTR)
goto out;
if (!ret)
__move_to_queue(req, &s->write_queue[IO_FIN]);
else
break;
np++;
}
return;
out:
__move_to_queue(req, &s->write_queue[IO_FIN]);
}
ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
{
struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
struct kiocb kiocb;
ssize_t ret;
init_sync_kiocb(&kiocb, filp);
kiocb.ki_pos = *ppos;
kiocb.ki_left = len;
kiocb.ki_nbytes = len;
for (;;) {
ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
if (ret != -EIOCBRETRY)
break;
wait_on_retry_sync_kiocb(&kiocb);
}
if (-EIOCBQUEUED == ret)
ret = wait_on_sync_kiocb(&kiocb);
*ppos = kiocb.ki_pos;
return ret;
}
EXPORT_SYMBOL(do_sync_write);
static ssize_t __do_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
if (file->f_op->write)
return file->f_op->write(file, buf, len, ppos);
else
return do_sync_write(file, buf, len, ppos);
}
static ssize_t do_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos, int force_block)
{
unsigned int saved_flags;
ssize_t ret, count;
if (!force_block)
return __do_write(file, buf, len, ppos);
/* Pretty much a copy of do_read() */
saved_flags = file->f_flags;
file->f_flags &= ~O_NONBLOCK;
ret = 0;
while (len > 0) {
count = __do_write(file, buf, len, ppos);
if (count == 0)
break;
if (count < 0) {
ret = count;
break;
}
len -= count;
buf += count;
ret += count;
}
file->f_flags = saved_flags;
return ret;
}