[PATCH] move remove_dquot_ref to dqout.c

Remove_dquot_ref can move to dqout.c instead of beeing in inode.c under
#ifdef CONFIG_QUOTA.  Also clean the resulting code up a tiny little bit by
testing sb->dq_op earlier - it's constant over a filesystems lifetime.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/dquot.c b/fs/dquot.c
index a561fb2..5bdc4b2 100644
--- a/fs/dquot.c
+++ b/fs/dquot.c
@@ -79,6 +79,7 @@
 #include <linux/buffer_head.h>
 #include <linux/capability.h>
 #include <linux/quotaops.h>
+#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
 
 #include <asm/uaccess.h>
 
@@ -755,15 +756,30 @@
 	}
 }
 
+static void remove_dquot_ref(struct super_block *sb, int type,
+		struct list_head *tofree_head)
+{
+	struct inode *inode;
+
+	spin_lock(&inode_lock);
+	list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+		if (!IS_NOQUOTA(inode))
+			remove_inode_dquot_ref(inode, type, tofree_head);
+	}
+	spin_unlock(&inode_lock);
+}
+
 /* Gather all references from inodes and drop them */
 static void drop_dquot_ref(struct super_block *sb, int type)
 {
 	LIST_HEAD(tofree_head);
 
-	down_write(&sb_dqopt(sb)->dqptr_sem);
-	remove_dquot_ref(sb, type, &tofree_head);
-	up_write(&sb_dqopt(sb)->dqptr_sem);
-	put_dquot_list(&tofree_head);
+	if (sb->dq_op) {
+		down_write(&sb_dqopt(sb)->dqptr_sem);
+		remove_dquot_ref(sb, type, &tofree_head);
+		up_write(&sb_dqopt(sb)->dqptr_sem);
+		put_dquot_list(&tofree_head);
+	}
 }
 
 static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number)