Messages in this thread |  | | Date | Mon, 23 Oct 2000 16:13:08 -0400 (EDT) | From | Alexander Viro <> | Subject | Re: 2.4.0-test10-pre3:Oops in mm/filemap.c:filemap_write_pa |
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On Mon, 23 Oct 2000, Linus Torvalds wrote:
> Al, any ideas? I have this feeling that the simplest fix is just to leave > the race open, and make truncate_complete_page() just leave such a "racy" > page in the page cache. It will still race, and the invalid page will > still exist, but the end result should be harmless.
Provided that we clean it - why the hell do we want to take it out of the pagecache? I don't see any fundamental reasons to prohibit pages past the ->i_size being hashed. Methods _must_ check for ->i_size, but they do it anyway. All race-prevention is based on page locks and ->i_sem.
Yes, filemap_nopage() should check for i_size at the very end and fail if the page became off-limits. But that's completely unrelated issue - it's mmap semantics, not pagecache one.
The point being: we should _never_ drop ->mapping unless the page is irrevocably going away. We can (and probably should) drop the off-limits page as soon as ->count hits zero, but we should not do it before that.
Comments?
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