Subject: Re: problem with tmpfs and linux emulation?
To: Christos Zoulas <>
From: Jaromir Dolecek <>
List: current-users
Date: 11/12/2005 21:20:31
On Sat, Nov 12, 2005 at 07:23:40PM +0000, Christos Zoulas wrote:
> >> Presumably, though, the behavior of linux_sys_read would have to depend 
> >> on the underlying file system type -- it does the right thing for, say, 
> >> ffs and ext2fs, but not for tmpfs.
> >
> >But it only work by "accident", not intention.  This method should be used for
> >all filesystems, not just tmpfs.  It's a bit more inefficient, but more correct.
> I don't think that linux uses read to read directories. I think it always
> uses getdents. Something else must be going on. Can someone verify by using
> ktrace?

The most likely suspect is tmpfs_readdir()'s cookie handling.

BTW, is there any reason tmpfs diverges significantly from the
filesystem code style? Like ((struct vop_lookup_args *)v)->a_dvp
assignments and --------------------- separators between functions.
Jaromir Dolecek <>  
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