Quoting r. Andi Kleen <[EMAIL PROTECTED]>:
> Subject: Re: [PATCH] move common compat ioctls to hash
>
> On Mon, Jan 24, 2005 at 10:26:09PM +0200, Michael S. Tsirkin wrote:
> > Hi!
> > The new ioctl code in fs/compat.c can be streamlined a little
> > using the compat hash instead of an explicit switch statement.
> >
> > The attached patch is against 2.6.11-rc2-bk2.
> > Andi, could you please comment? Does this make sence?
>
> Problem is that when a compat_ioctl handler returns -EINVAL
> instead of -ENOIOCTLCMD on unknown ioctl it won't check the common
> ones.
>
> I fear this mistake would be common, that is why I put in the switch.
>
> -Andi
Still, many drivers still need the compat hash lookup to work
properly, and these still require -ENOIOCTLCMD to work properly.
So is it worth it wasting CPU cycles working around only part of the problem?
How about:
1. Adding a comment in fs.h
2. Changing unlocked_ioctl to behave in the same way as compat_ioctl
(this will help since unlocked_ioctl will be well tested),
something along the lines of my old patch below [its against 2.6.11-rc1-bk5].
As a bonus, I expect a small speedup in code using unlocked_ioctl
(as well as compat_ioctl) for datapath things like usb transfers.
Andy, if this sounds convincing, let me know and I'll build a real patch.
MST
diff -rup linux-2.6.10-orig/fs/ioctl.c linux-2.6.10-ioctl-sym/fs/ioctl.c
--- linux-2.6.10-orig/fs/ioctl.c 2005-01-18 10:58:33.609880024 +0200
+++ linux-2.6.10-ioctl-sym/fs/ioctl.c 2005-01-18 10:51:55.690372984 +0200
@@ -24,12 +24,7 @@ static long do_ioctl(struct file *filp,
if (!filp->f_op)
goto out;
- if (filp->f_op->unlocked_ioctl) {
- error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
- if (error == -ENOIOCTLCMD)
- error = -EINVAL;
- goto out;
- } else if (filp->f_op->ioctl) {
+ if (filp->f_op->ioctl) {
lock_kernel();
error = filp->f_op->ioctl(filp->f_dentry->d_inode,
filp, cmd, arg);
@@ -93,6 +91,12 @@ asmlinkage long sys_ioctl(unsigned int f
if (error)
goto out_fput;
+ if (filp->f_op && filp->f_op->unlocked_ioctl) {
+ error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
+ if (error != -ENOIOCTLCMD)
+ goto out_fput;
+ }
+
switch (cmd) {
case FIOCLEX:
set_close_on_exec(fd, 1);
--
I dont speak for Mellanox.
-
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