Re: kern/41189: kernel panic xen dom0 using mke2fs & WAPBL

[yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)]

The following reply was made to PR kern/41189; it has been noted by GNATS.

From: yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)
To: ad%netbsd.org@localhost
Cc: dholland-bugs%netbsd.org@localhost, tech-kern%netbsd.org@localhost, 
gnats-bugs%NetBSD.org@localhost
Subject: Re: kern/41189: kernel panic xen dom0 using mke2fs & WAPBL
Date: Sun, 10 May 2009 05:41:55 +0000 (UTC)

 hi,
 
 > I should have been clearer. Have a look at the bigger picture.
 > 
 > - We have longstanding problems with device nodes showing up in multiple
 >   file systems. For 6.0 we have devfs coming along, which will at some point
 >   in its development likely eliminate the need to support device nodes on
 >   other file systems. So devfs will give us a 1:1 mapping between device
 >   instances and vnodes (or maybe devfs inodes).
 
 i don't think devfs is necessary here.
 just giving up updating timestamps of mounted VBLK special files is enough.
 
 > - We have longstanding problems providing block device semantics. Block
 >   devices are an interesting toy but they have no real application. Disk
 >   character devices suffice with one exception: on NetBSD, transfers on
 >   these devices must be aligned. So there is no need for physio to cache,
 >   it could simply buffer to allow misaligned transfers.
 
 are there applications of the misaligned transfers?
 
 YAMAMOTO Takashi