ioctl

[Erik Cederstrand]

> Den 15. sep. 2016 kl. 10.40 skrev Erik Cederstrand <erik at cederstrand.dk>:
> 
> Hi folks,
> 
> I managed to get a 64-bit Oracle instantclient running under 64-bit Linux so I can connect to an Oracle database using the Oracle client "sqlplus".
> 
> Now, whenever I run sqlplus, I get this message in /var/log/messages:
> 
>   kernel: linux: pid 92000 (sqlplus): ioctl fd=3, cmd=0x1268 ('',104) is not implemented
> 
> 0x1268 is BLKSSZGET according to linux_ioctl.h.
> 
> The message is harmless as sqlplus seems to be working correctly, but I would like to get rid of it and learn new things along the way.
> 
> I think the message comes from this code: https://github.com/freebsd/freebsd/blob/master/sys/compat/linux/linux_ioctl.c#L3606
> 
> Apparently, the Linux compat code does not implement the ioctl() system call at all. Is this a deliberate choice?

Well, that was a pretty bad analysis. I found that the linux_ioctl_disk() method handles disk ioctl's, but not BLKSSZGET, so here's a patch (I still barely know what I'm doing):

--- sys/compat/linux/linux_ioctl.c.orig	2016-09-15 13:09:59.747254000 +0200
+++ sys/compat/linux/linux_ioctl.c	2016-09-15 13:15:59.382396000 +0200
@@ -296,6 +296,15 @@
 		return (copyout(&sectorsize, (void *)args->arg,
 		    sizeof(sectorsize)));
 		break;
+	case LINUX_BLKSSZGET:
+		error = fo_ioctl(fp, DIOCGSECTORSIZE,
+		    (caddr_t)&sectorsize, td->td_ucred, td);
+		fdrop(fp, td);
+		if (error)
+			return (error);
+		return (copyout(&sectorsize, (void *)args->arg,
+		    sizeof(sectorsize)));
+		break;
 	}
 	fdrop(fp, td);
 	return (ENOIOCTL);

... and the messages are gone. Is this an acceptable approach?

Erik