Re: [patch] rfc: fix splice mapping race?

[Jens Axboe]

On Sun, Jun 18 2006, Nick Piggin wrote:
> Hi, I would be interested in confirmation/comments for this patch.
> 
> I believe splice is unsafe to access the page mapping obtained
> when the page was unlocked: the page could subsequently be truncated
> and the mapping reclaimed (see set_page_dirty_lock comments).
> 
> Modify the remove_mapping precondition to ensure the caller has
> locked the page and obtained the correct mapping. Modify callers to
> ensure the mapping is the correct one.
> 
> In page migration, detect the missing mapping early and bail out if
> that is the case: the page is not going to get un-truncated, so
> retrying is just a waste of time.

splice bit looks good to me!

-- 
Jens Axboe

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