From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 24 Apr 2012 16:09:02 +0000 (-0700)
Subject: 3.0-stable patches
X-Git-Tag: v3.0.30~16
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=975e45cca990903b04fcc675b7ebc68b091f31c4;p=thirdparty%2Fkernel%2Fstable-queue.git

3.0-stable patches

added patches:
	mm-fix-s390-bug-by-__set_page_dirty_no_writeback-on-swap.patch
---

diff --git a/queue-3.0/mm-fix-s390-bug-by-__set_page_dirty_no_writeback-on-swap.patch b/queue-3.0/mm-fix-s390-bug-by-__set_page_dirty_no_writeback-on-swap.patch
new file mode 100644
index 00000000000..c00f11974fc
--- /dev/null
+++ b/queue-3.0/mm-fix-s390-bug-by-__set_page_dirty_no_writeback-on-swap.patch
@@ -0,0 +1,57 @@
+From aca50bd3b4c4bb5528a1878158ba7abce41de534 Mon Sep 17 00:00:00 2001
+From: Hugh Dickins <hughd@google.com>
+Date: Mon, 23 Apr 2012 11:14:50 -0700
+Subject: mm: fix s390 BUG by __set_page_dirty_no_writeback on swap
+
+From: Hugh Dickins <hughd@google.com>
+
+commit aca50bd3b4c4bb5528a1878158ba7abce41de534 upstream.
+
+Mel reports a BUG_ON(slot == NULL) in radix_tree_tag_set() on s390
+3.0.13: called from __set_page_dirty_nobuffers() when page_remove_rmap()
+tries to transfer dirty flag from s390 storage key to struct page and
+radix_tree.
+
+That would be because of reclaim's shrink_page_list() calling
+add_to_swap() on this page at the same time: first PageSwapCache is set
+(causing page_mapping(page) to appear as &swapper_space), then
+page->private set, then tree_lock taken, then page inserted into
+radix_tree - so there's an interval before taking the lock when the
+radix_tree slot is empty.
+
+We could fix this by moving __add_to_swap_cache()'s spin_lock_irq up
+before the SetPageSwapCache.  But a better fix is simply to do what's
+five years overdue: Ken Chen introduced __set_page_dirty_no_writeback()
+(if !PageDirty TestSetPageDirty) for tmpfs to skip all the radix_tree
+overhead, and swap is just the same - it ignores the radix_tree tag, and
+does not participate in dirty page accounting, so should be using
+__set_page_dirty_no_writeback() too.
+
+s390 testing now confirms that this does indeed fix the problem.
+
+Reported-by: Mel Gorman <mgorman@suse.de>
+Signed-off-by: Hugh Dickins <hughd@google.com>
+Acked-by: Mel Gorman <mgorman@suse.de>
+Cc: Andrew Morton <akpm@linux-foundation.org>
+Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
+Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
+Cc: Rik van Riel <riel@redhat.com>
+Cc: Ken Chen <kenchen@google.com>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ mm/swap_state.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/mm/swap_state.c
++++ b/mm/swap_state.c
+@@ -28,7 +28,7 @@
+  */
+ static const struct address_space_operations swap_aops = {
+ 	.writepage	= swap_writepage,
+-	.set_page_dirty	= __set_page_dirty_nobuffers,
++	.set_page_dirty	= __set_page_dirty_no_writeback,
+ 	.migratepage	= migrate_page,
+ };
+ 
diff --git a/queue-3.0/series b/queue-3.0/series
index df27703e0b2..be71ba31ddf 100644
--- a/queue-3.0/series
+++ b/queue-3.0/series
@@ -12,3 +12,4 @@ uwb-fix-error-handling.patch
 davinci_mdio-fix-mdio-timeout-check.patch
 media-rc-core-set-mode-for-winbond-cir.patch
 cfg80211-fix-interface-combinations-check.patch
+mm-fix-s390-bug-by-__set_page_dirty_no_writeback-on-swap.patch