Re: bin/45191 (newfs_v7fs(8) doesn't work on a disk partition)

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR bin/45191; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: bin/45191 (newfs_v7fs(8) doesn't work on a disk partition)
Date: Thu, 4 Aug 2011 16:06:56 +0000

 On Wed, Aug 03, 2011 at 06:10:05PM +0000, Matthias Scheler wrote:
  >  tron@lyssa:/usr/src/sbin/newfs_v7fs#newfs_v7fs /dev/rwd1e
  >  newfs_v7fs: mmap failed. use direct I/O.: Invalid argument
  >  tron@lyssa:/usr/src/sbin/newfs_v7fs#
  >  
  >  It would be nice to get rid of the mmap(2) error message.
 
 Indeed. However, it doesn't fully make sense: if the multiplication
 for the length overflows, you should get a small page-aligned number,
 mmap should succeed but give only a small mapping, and you should get
 SIGSEGV afterwards when writing past the end of that mapping.
 
 If the multiplication doesn't overflow but the size is too large to
 map in 4G, I would think you ought to get ENOMEM. However, mmap(2)
 doesn't seem to document an error for this case.
 
 The cases it does document for EINVAL do not apply...
 
 Also, now it's looking to me like the change I made yesterday
 shouldn't have had any effect at all, so I really don't get it.
 
  >  nd a progress report would be nice as "newfs_v7fs" doesn't seem
  > to be particular fast.  But neither of those is strictly related to
  > this PR.
 
 -P?
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost