]> err.no Git - linux-2.6/commit
[PATCH] invalidate_complete_page() race fix
authorAndrew Morton <akpm@osdl.org>
Fri, 8 Sep 2006 16:48:38 +0000 (09:48 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Fri, 8 Sep 2006 17:22:50 +0000 (10:22 -0700)
commit016eb4a0ed06a3677d67a584da901f0e9a63c666
tree574ead6bd03d31ca7036ff2389cb0400f3fd63fc
parent3665d0e58fa44f50c744f85c7e8ad21d5b10e206
[PATCH] invalidate_complete_page() race fix

If a CPU faults this page into pagetables after invalidate_mapping_pages()
checked page_mapped(), invalidate_complete_page() will still proceed to remove
the page from pagecache.  This leaves the page-faulting process with a
detached page.  If it was MAP_SHARED then file data loss will ensue.

Fix that up by checking the page's refcount after taking tree_lock.

Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
mm/truncate.c