[PATCH] invalidate_inode_pages2(): ignore page refcounts (bd4c8ce4) · Commits · 戴 / test

The recent fix to invalidate_inode_pages() (git commit ) managed to unfix invalidate_inode_pages2(). The problem is that various bits of code in the kernel can take transient refs on pages: the page scanner will do this when inspecting a batch of pages, and the lru_cache_add() batching pagevecs also hold a ref. Net result is transient failures in invalidate_inode_pages2(). This affects NFS directory invalidation (observed) and presumably also block-backed direct-io (not yet reported). Fix it by reverting invalidate_inode_pages2() back to the old version which ignores the page refcounts. We may come up with something more clever later, but for now we need a 2.6.18 fix for NFS. Cc: Chuck Lever <cel@citi.umich.edu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Signed-off-by:

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

Linus Torvalds <torvalds@osdl.org>

mm/truncate.c

+32 −2

Original line number	Diff line number	Diff line
		@@ -287,9 +287,39 @@ unsigned long invalidate_inode_pages(struct address_space *mapping)
		{
		return invalidate_mapping_pages(mapping, 0, ~0UL);
		}

		EXPORT_SYMBOL(invalidate_inode_pages);

		/*
		* This is like invalidate_complete_page(), except it ignores the page's
		* refcount. We do this because invalidate_inode_pages2() needs stronger
		* invalidation guarantees, and cannot afford to leave pages behind because
		* shrink_list() has a temp ref on them, or because they're transiently sitting
		* in the lru_cache_add() pagevecs.
		*/
		static int
		invalidate_complete_page2(struct address_space mapping, struct page page)
		{
		if (page->mapping != mapping)
		return 0;

		if (PagePrivate(page) && !try_to_release_page(page, 0))
		return 0;

		write_lock_irq(&mapping->tree_lock);
		if (PageDirty(page))
		goto failed;

		BUG_ON(PagePrivate(page));
		__remove_from_page_cache(page);
		write_unlock_irq(&mapping->tree_lock);
		ClearPageUptodate(page);
		page_cache_release(page); /* pagecache ref */
		return 1;
		failed:
		write_unlock_irq(&mapping->tree_lock);
		return 0;
		}

		/**
		* invalidate_inode_pages2_range - remove range of pages from an address_space
		* @mapping: the address_space
		@@ -356,7 +386,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
		}
		}
		was_dirty = test_clear_page_dirty(page);
		if (!invalidate_complete_page(mapping, page)) {
		if (!invalidate_complete_page2(mapping, page)) {
		if (was_dirty)
		set_page_dirty(page);
		ret = -EIO;

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