Re: [patch 1/2] mm: dont clear PG_uptodate in invalidate_complete_page2()

[Jamie Lokier <jamie@shareable.org>]

Linus Torvalds wrote:
> I also really don't think this even fixes the problems you have with 
> FUSE/NFSD - because you'll still be reading zeroes for a truncated file. 
> Yes, you get the rigth counts, but you don't get the right data.
...
> That's "correct" from a splice() kind of standpoint (it's essentially a 
> temporary mmap() with MAP_PRIVATE), but the thing is, it just sounds like 
> the whole "page went away" thing is a more fundamental issue. It sounds 
> like nfds should hold a read-lock on the file while it has any IO in 
> flight, or something like that.

I'm thinking any kind of user-space server using splice() will not
want to transmit zeros either, when another process truncates the file.
E.g. Apache, Samba, etc.

Does this problem affect sendfile() users?

-- Jamie