Commit bd4c8ce4 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
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[PATCH] invalidate_inode_pages2(): ignore page refcounts

The recent fix to invalidate_inode_pages() (git commit 016eb4a0

) 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: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d025c9db
......@@ -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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