[PATCH] invalidate: remove_mapping() fix (a649fd92) · Commits · e / devices / android_kernel_fairphone_FP4

If remove_mapping() failed to remove the page from its mapping, don't go and mark it not uptodate! Makes kernel go dead. (Actually, I don't think the ClearPageUptodate is needed there at all). Says Nick Piggin: "Right, it isn't needed because at this point the page is guaranteed by remove_mapping to have no references (except us) and cannot pick up any new ones because it is removed from pagecache. We can delete it." Signed-off-by:

Andrew Morton <akpm@osdl.org> Acked-by:

Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

mm/truncate.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -96,7 +96,6 @@ invalidate_complete_page(struct address_space mapping, struct page page)
		return 0;

		ret = remove_mapping(mapping, page);
		ClearPageUptodate(page);

		return ret;
		}

mm/vmscan.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -378,6 +378,12 @@ static pageout_t pageout(struct page page, struct address_space mapping)
		return PAGE_CLEAN;
		}

		/*
		* Attempt to detach a locked page from its ->mapping. If it is dirty or if
		* someone else has a ref on the page, abort and return 0. If it was
		* successfully detached, return 1. Assumes the caller has a single ref on
		* this page.
		*/
		int remove_mapping(struct address_space mapping, struct page page)
		{
		BUG_ON(!PageLocked(page));