Read from file fails

[Libor Vanek <libor@conet.cz>]

Hi,
can anybody help me with reading from file? I've got this code in my module for 2.6.5-mm6:

char buffer[4096];
ssize_t read;
file *f;
f = filp_open("/some/file",O_RDONLY | O_LARGEFILE,0);
f->f_pos = 0;
read = vfs_read(f,(char __user *) buffer,4096,&f->f_pos);


but here read value is "-14" :-((( any hints?

It seems that file is opened OK (I've tested: 
if (f->f_op->read) {
	read = f->f_op->read(file, buf, count, pos);
}
and result was the same - so I assume that file is opened OK and structure "file f" is filled correctly.

I need to copy files (yes - I know that kernel shouldn't do this but I REALLY need) and  there is nothing like "sys_copy" and "sys_sendfile" is not exported (which seems strange to me but there is nothing like EXPORT_SYMBOL(sys_sendfile) in fs/read_write.c


Thanks,
Libor Vanek