[PATCH] igrab() should check for I_CLEAR

When igrab() is calling __iget() on an inode it should check if
clear_inode() has been called on the inode already.  Otherwise there is a
race window between clear_inode() and destroy_inode() where igrab() calls
__iget() which leads to already free inodes on the inode lists.

Signed-off-by: Vandana Rungta <vandana@novell.com>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>