Messages in this thread | | | Date | Sun, 17 Dec 2006 17:22:57 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: 2.6.19 file content corruption on ext3 |
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On Sun, 17 Dec 2006, Andrew Morton wrote: > > From my quick reading, all callers of try_to_free_buffers() have already > unmapped the page from pagetables, and given that the reported ext3 corruption > happens on uniprocessor, non-preempt kernels, I doubt if this patch will fix > things.
Hmm. One possible explanation: maybe the page actually _did_ get unmapped from the page tables, but got added back?
I don't think we lock the page when faulting it in (we want it to be uptodate, but not necessarily locked). So assuming the pageout sequence always _does_ follow the rule that it only does try_to_free_buffers() on pages that aren't mapped, what actually protects them from not becoming mapped (and dirtied) during that sequence?
So we should probably do a "wait_for_page()" in do_no_page()?
Or maybe only do it for write accesses (since we don't really care about getting mapped readably)? If so, we need to do it in the write case of do_no_page() _and_ in the do_wp_page() case. Hmm?
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