From 3d52f6a327227cfeab5e5f02e55a3593f5601d30 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Mon, 20 Oct 2008 17:05:00 +0200
Subject: [PATCH] --- yaml --- r: 125834 b: refs/heads/master c:
 12c77527e4138bc3b17d17b0e0c909e4fc84924f h: refs/heads/master v: v3

---
 [refs]                         |  2 +-
 trunk/fs/dquot.c               | 36 ++++++++++++++++++++++++++++++++++
 trunk/include/linux/quotaops.h |  3 +++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 6d119e1d480a..bc83ff1e27fc 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3d9ea253a0e73dccaa869888ec2ceb17ea76c810
+refs/heads/master: 12c77527e4138bc3b17d17b0e0c909e4fc84924f
diff --git a/trunk/fs/dquot.c b/trunk/fs/dquot.c
index ae8fd9e645cc..075dc76904e7 100644
--- a/trunk/fs/dquot.c
+++ b/trunk/fs/dquot.c
@@ -476,6 +476,41 @@ static void invalidate_dquots(struct super_block *sb, int type)
 	spin_unlock(&dq_list_lock);
 }
 
+/* Call callback for every active dquot on given filesystem */
+int dquot_scan_active(struct super_block *sb,
+		      int (*fn)(struct dquot *dquot, unsigned long priv),
+		      unsigned long priv)
+{
+	struct dquot *dquot, *old_dquot = NULL;
+	int ret = 0;
+
+	mutex_lock(&sb_dqopt(sb)->dqonoff_mutex);
+	spin_lock(&dq_list_lock);
+	list_for_each_entry(dquot, &inuse_list, dq_inuse) {
+		if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags))
+			continue;
+		if (dquot->dq_sb != sb)
+			continue;
+		/* Now we have active dquot so we can just increase use count */
+		atomic_inc(&dquot->dq_count);
+		dqstats.lookups++;
+		spin_unlock(&dq_list_lock);
+		dqput(old_dquot);
+		old_dquot = dquot;
+		ret = fn(dquot, priv);
+		if (ret < 0)
+			goto out;
+		spin_lock(&dq_list_lock);
+		/* We are safe to continue now because our dquot could not
+		 * be moved out of the inuse list while we hold the reference */
+	}
+	spin_unlock(&dq_list_lock);
+out:
+	dqput(old_dquot);
+	mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex);
+	return ret;
+}
+
 int vfs_quota_sync(struct super_block *sb, int type)
 {
 	struct list_head *dirty;
@@ -2318,6 +2353,7 @@ EXPORT_SYMBOL(vfs_quota_on_path);
 EXPORT_SYMBOL(vfs_quota_on_mount);
 EXPORT_SYMBOL(vfs_quota_disable);
 EXPORT_SYMBOL(vfs_quota_off);
+EXPORT_SYMBOL(dquot_scan_active);
 EXPORT_SYMBOL(vfs_quota_sync);
 EXPORT_SYMBOL(vfs_get_dqinfo);
 EXPORT_SYMBOL(vfs_set_dqinfo);
diff --git a/trunk/include/linux/quotaops.h b/trunk/include/linux/quotaops.h
index e3a10272d471..f4913948c305 100644
--- a/trunk/include/linux/quotaops.h
+++ b/trunk/include/linux/quotaops.h
@@ -28,6 +28,9 @@ int dquot_drop_locked(struct inode *inode);
 struct dquot *dqget(struct super_block *sb, unsigned int id, int type);
 void dqput(struct dquot *dquot);
 int dquot_is_cached(struct super_block *sb, unsigned int id, int type);
+int dquot_scan_active(struct super_block *sb,
+		      int (*fn)(struct dquot *dquot, unsigned long priv),
+		      unsigned long priv);
 
 int dquot_alloc_space(struct inode *inode, qsize_t number, int prealloc);
 int dquot_alloc_inode(const struct inode *inode, qsize_t number);