Re: CVS commit: src/sys/ufs/lfs

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

On Sat, Dec 18, 2010 at 12:01:46AM +0000, Eduardo Horvath wrote:
 > Modified Files:
 >      src/sys/ufs/lfs: lfs_vnops.c
 > 
 > Log Message:
 > Byebye deadlock.

What lock is supposed to protect ip->i_flags? A quick survey of
related code suggests that it's supposed to be lfs_lock.

...However, it looks as if that and quite a few other uses of
ip->i_flags ought to be ip->i_flag instead. ip->i_flags holds the
chflags() flags; the inode state flags are supposed to be in
ip->i_flag.

It looks as if all uses of IN_PAGING use ip->i_flags, so it's at least
consistent, but it's wrong. There's also one reference to IN_CLEANING
in ip->i_flags, which has no chance of ever working.

Using lfs_lock to protect either of these isn't consistent with the
ufs code though, AFAIK, so I don't think it's really safe
regardless...

(The existence of i_flag and i_flags members in the same structure
seems to date to the ffsv2 import, but it's sort of been this way via
macros since 4.4. Definitely brickworthy.)

-- 
David A. Holland
dholland%netbsd.org@localhost