Re: udev breakages - was: Re: Need of an ".async_probe()" type of callback at driver's core - Was: Re: [PATCH] [media] drxk: change it to use request_firmware_nowait()

[Al Viro <viro@ZenIV.linux.org.uk>]

On Wed, Oct 03, 2012 at 09:38:52AM -0700, Linus Torvalds wrote:
> Yeah, that bugzilla shows the problem with Kay as a maintainer too,
> not willing to own up to problems he caused.
> 
> Can you actually see the problem? I did add the attached patch as an
> attachment to the bugzilla, so the reporter there may be able to test
> it, but it's been open for a long while..
> 
> Anyway. Attached is a really stupid patch that tries to do the "direct
> firmware load" as suggested by Ivan. It has not been tested very
> extensively at all (but I did test that it loaded the brcmsmac
> firmware images on my laptop so it has the *potential* to work).

+	if (!S_ISREG(inode->i_mode))
+		return false;
+	size = i_size_read(inode);

Probably better to do vfs_getattr() and check mode and size in kstat; if
it's sufficiently hot for that to hurt, we are fucked anyway.

+		file = filp_open(path, O_RDONLY, 0);
+		if (IS_ERR(file))
+			continue;
+printk("from file '%s' ", path);
+		success = fw_read_file_contents(file, fw);
+		filp_close(file, NULL);

fput(file), please.  We have enough misuses of filp_close() as it is...

> We are apparently better off trying to avoid udev like the plague.
> Doing something very similar to this for module loading is probably a
> good idea too.

That, or just adding usr/udev in the kernel git tree and telling the
vertical integrators to go kiss a lamprey...