Subject: Re: problem with tmpfs and linux emulation?
To: Steven M. Bellovin <smb@cs.columbia.edu>
From: Matt Thomas <matt@3am-software.com>
List: current-users
Date: 11/12/2005 10:57:11
Steven M. Bellovin wrote:
> In message <437637E2.6010101@3am-software.com>, Matt Thomas writes:
>
>>Bill Studenmund wrote:
>>
>>I don't see the problem. Instead of using sys_read, linux would have its
>>linux_sys_read. It would look up the fd, see if it's a DTYPE_VNODE, and if so
>>check to see if it's a directory. It's only a problem is you are relying on t
>>he standard sys_read routine.
>
>
> 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.
--
Matt Thomas email: matt@3am-software.com
3am Software Foundry www: http://3am-software.com/bio/matt/
Cupertino, CA disclaimer: I avow all knowledge of this message.