Messages in this thread |  | | Subject | Re: [PATCH] zerocopy NFS updated | From | (Eric W. Biederman) | Date | 13 Apr 2002 13:19:46 -0600 |
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Andi Kleen <ak@suse.de> writes:
> > I wonder if it is reasonable to depend on that: -- i.e. I'll only ever > > see zeros, not say random bytes, or ones or something. I'm sure that's > > so with the current kernel, and probably all of them ever (except for > > bugs) but I wonder whether it's ok to rely on that. > > With truncates you should only ever see zeros. If you want this guarantee > over system crashes you need to make sure to use the right file system > though (e.g. ext2 or reiserfs without the ordered data mode patches or > ext3 in writeback mode could give you junk if the system crashes at the > wrong time). Still depending on only seeing zeroes would > seem to be a bit fragile on me (what happens when the disk dies for > example?), using some other locking protocol is probably more safe.
Could the garbage from ext3 in writeback mode be considered an information leak? I know that is why most places in the kernel initialize pages to 0. So you don't accidentally see what another user put there.
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