From: Nicolas Pitre <nico@cam.org>
Date: Sat, 5 Sep 2009 04:25:37 +0000 (-0400)
Subject: ext2: fix unbalanced kmap()/kunmap()
X-Git-Tag: v2.6.31-rc9~19
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9de6886ec6e37f45807266a702bb7621498395ad;p=pandora-kernel.git

ext2: fix unbalanced kmap()/kunmap()

In ext2_rename(), dir_page is acquired through ext2_dotdot().  It is
then released through ext2_set_link() but only if old_dir != new_dir.
Failing that, the pkmap reference count is never decremented and the
page remains pinned forever.  Repeat that a couple times with highmem
pages and all pkmap slots get exhausted, and every further kmap() calls
end up stalling on the pkmap_map_wait queue at which point the whole
system comes to a halt.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

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