From 75e9f2a30211c9969efaa9ce5285962160e8497f Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay@vrfy.org>
Date: Thu, 9 Jan 2014 07:37:22 +0800
Subject: [PATCH] pool: use own lock to protect the slices lists

---
 handle.c |  2 --
 pool.c   | 34 +++++++++++++++++++++++++++-------
 pool.h   |  2 +-
 3 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/handle.c b/handle.c
index 2a7c3f4..3a03a0e 100644
--- a/handle.c
+++ b/handle.c
@@ -559,9 +559,7 @@ static long kdbus_handle_ioctl_ep_connected(struct file *file, unsigned int cmd,
 			break;
 		}
 
-		mutex_lock(&conn->lock);
 		ret = kdbus_pool_free_range(conn->pool, off);
-		mutex_unlock(&conn->lock);
 		break;
 	}
 
diff --git a/pool.c b/pool.c
index 5f7339e..e3e2995 100644
--- a/pool.c
+++ b/pool.c
@@ -33,6 +33,7 @@
  * @f:			The backing shmem file
  * @size:		The size of the file
  * @busy:		The currently used size
+ * @lock		Pool data lock
  * @slices:		All slices sorted by address
  * @slices_busy:	Tree of allocated slices
  * @slices_free:	Tree of free slices
@@ -53,6 +54,7 @@ struct kdbus_pool {
 	struct file *f;
 	size_t size;
 	size_t busy;
+	struct mutex lock;
 
 	struct list_head slices;
 	struct rb_root slices_busy;
@@ -318,6 +320,7 @@ int kdbus_pool_new(struct kdbus_pool **pool, size_t size)
 	p->busy = 0;
 	p->slices_free = RB_ROOT;
 	p->slices_busy = RB_ROOT;
+	mutex_init(&p->lock);
 
 	INIT_LIST_HEAD(&p->slices);
 	list_add(&s->entry, &p->slices);
@@ -359,9 +362,15 @@ void kdbus_pool_free(struct kdbus_pool *pool)
  *
  * Returns: the number of unallocated bytes in the pool
  */
-size_t kdbus_pool_remain(const struct kdbus_pool *pool)
+size_t kdbus_pool_remain(struct kdbus_pool *pool)
 {
-	return pool->size - pool->busy;
+	size_t size;
+
+	mutex_lock(&pool->lock);
+	size =  pool->size - pool->busy;
+	mutex_unlock(&pool->lock);
+
+	return size;
 }
 
 /**
@@ -381,7 +390,9 @@ int kdbus_pool_alloc_range(struct kdbus_pool *pool, size_t size, size_t *off)
 	struct kdbus_slice *s;
 	int ret;
 
+	mutex_lock(&pool->lock);
 	ret = kdbus_pool_alloc_slice(pool, size, &s);
+	mutex_unlock(&pool->lock);
 	if (ret < 0)
 		return ret;
 
@@ -402,19 +413,28 @@ int kdbus_pool_alloc_range(struct kdbus_pool *pool, size_t size, size_t *off)
 int kdbus_pool_free_range(struct kdbus_pool *pool, size_t off)
 {
 	struct kdbus_slice *slice;
+	int ret = 0;
 
 	if (!pool)
 		return 0;
 
-	if (off >= pool->size)
-		return -EINVAL;
+	mutex_lock(&pool->lock);
+	if (off >= pool->size) {
+		ret = -EINVAL;
+		goto exit_unlock;
+	}
 
 	slice = kdbus_pool_find_slice(pool, off);
-	if (!slice)
-		return -ENXIO;
+	if (!slice) {
+		ret = -ENXIO;
+		goto exit_unlock;
+	}
 
 	kdbus_pool_free_slice(pool, slice);
-	return 0;
+
+exit_unlock:
+	mutex_unlock(&pool->lock);
+	return ret;
 }
 
 /* copy data from a file to ia page in the receiver's pool */
diff --git a/pool.h b/pool.h
index a450ff4..b0453b2 100644
--- a/pool.h
+++ b/pool.h
@@ -20,7 +20,7 @@ void kdbus_pool_free(struct kdbus_pool *pool);
 
 int kdbus_pool_alloc_range(struct kdbus_pool *pool, size_t size, size_t *off);
 int kdbus_pool_free_range(struct kdbus_pool *pool, size_t off);
-size_t kdbus_pool_remain(const struct kdbus_pool *pool);
+size_t kdbus_pool_remain(struct kdbus_pool *pool);
 ssize_t kdbus_pool_write(const struct kdbus_pool *pool, size_t off,
 			 void *data, size_t len);
 ssize_t kdbus_pool_write_user(const struct kdbus_pool *pool, size_t off,
-- 
2.34.1