[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 <[e-mail]>
Signed-off-by: Jan Blunck <[e-mail]>
Cc: Al Viro <[e-mail]>
Cc: Neil Brown <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/inode.c

···
 struct inode *igrab(struct inode *inode)
 {
 	spin_lock(&inode_lock);
-	if (!(inode->i_state & (I_FREEING|I_WILL_FREE)))
+	if (!(inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)))
 		__iget(inode);
 	else
 		/*