nilfs2: fix dirty page accounting leak causing hang at write

commit b1e19e5601277845b4f17ecd7c9ba04f73ee11aa upstream.

Bruno Prémont and Dunphy, Bill noticed me that NILFS will certainly
hang on ARM-based targets.

I found this was caused by an underflow of dirty pages counter.  A
b-tree cache routine was marking page dirty without adjusting page
account information.

This fixes the dirty page accounting leak and resolves the hang on
arm-based targets.

Reported-by: Bruno Prémont <bonbons@linux-vserver.org>
Reported-by: Dunphy, Bill <WDunphy@tandbergdata.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c
index 5be2c8b6549a9e5552d45a0aa7228c12e8ecbd90..862ad299aad0bd6517c1a8c07d319bf17845e465 100644 (file)
--- a/fs/nilfs2/btnode.c
+++ b/fs/nilfs2/btnode.c
@@ -276,8 +276,7 @@ void nilfs_btnode_commit_change_key(struct address_space *btnc,
                                       "invalid oldkey %lld (newkey=%lld)",
                                       (unsigned long long)oldkey,
                                       (unsigned long long)newkey);
-               if (!test_set_buffer_dirty(obh) && TestSetPageDirty(opage))
-                       BUG();
+               nilfs_btnode_mark_dirty(obh);
 
                spin_lock_irq(&btnc->tree_lock);
                radix_tree_delete(&btnc->page_tree, oldkey);