Re: Race in buffer code (Was Re: move block #A to block #B on agiven device.)

[Andrea Arcangeli]

On Fri, 5 Nov 1999, Mikulas Patocka wrote:

>What if user does cat /dev/hda1>/dev/null on mounted device while
>filesystem driver does getblk? ... the buffer gets corrupted.

I was considering the case where the buffer returned by getblk is _just_
uptodate. If the block is just uptodate then all potential readers as us
won't even try to start read-io and so the `cp /dev/? /dev/null` won't
trigger any I/O and won't risk to invalidate our memcpy.

Andrea