diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c
index b22764fe669c..513b20e30afd 100644
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -62,7 +62,7 @@ typedef struct {
 	struct buffer_head *bh;
 } Indirect;
 
-static DEFINE_RWLOCK(pointers_lock);
+static DECLARE_RWSEM(pointers_lock);
 
 static inline void add_chain(Indirect *p, struct buffer_head *bh, sysv_zone_t *v)
 {
@@ -83,7 +83,7 @@ static inline sysv_zone_t *block_end(struct buffer_head *bh)
 }
 
 /*
- * Requires read_lock(&pointers_lock) or write_lock(&pointers_lock)
+ * Requires down_read(&pointers_lock) or down_write(&pointers_lock)
  */
 static Indirect *get_branch(struct inode *inode,
 			    int depth,
@@ -173,11 +173,11 @@ static inline int splice_branch(struct inode *inode,
 	int i;
 
 	/* Verify that place we are splicing to is still there and vacant */
-	write_lock(&pointers_lock);
+	down_write(&pointers_lock);
 	if (!verify_chain(chain, where-1) || *where->p)
 		goto changed;
 	*where->p = where->key;
-	write_unlock(&pointers_lock);
+	up_write(&pointers_lock);
 
 	inode->i_ctime = current_time(inode);
 
@@ -192,7 +192,7 @@ static inline int splice_branch(struct inode *inode,
 	return 0;
 
 changed:
-	write_unlock(&pointers_lock);
+	up_write(&pointers_lock);
 	for (i = 1; i < num; i++)
 		bforget(where[i].bh);
 	for (i = 0; i < num; i++)
@@ -214,9 +214,9 @@ static int get_block(struct inode *inode, sector_t iblock, struct buffer_head *b
 		goto out;
 
 reread:
-	read_lock(&pointers_lock);
+	down_read(&pointers_lock);
 	partial = get_branch(inode, depth, offsets, chain, &err);
-	read_unlock(&pointers_lock);
+	up_read(&pointers_lock);
 
 	/* Simplest case - block found, no allocation needed */
 	if (!partial) {
@@ -287,7 +287,7 @@ static Indirect *find_shared(struct inode *inode,
 	for (k = depth; k > 1 && !offsets[k-1]; k--)
 		;
 
-	write_lock(&pointers_lock);
+	down_write(&pointers_lock);
 	partial = get_branch(inode, k, offsets, chain, &err);
 	if (!partial)
 		partial = chain + k-1;
@@ -296,7 +296,7 @@ static Indirect *find_shared(struct inode *inode,
 	 * fine, it should all survive and (new) top doesn't belong to us.
 	 */
 	if (!partial->key && *partial->p) {
-		write_unlock(&pointers_lock);
+		up_write(&pointers_lock);
 		goto no_top;
 	}
 	for (p=partial; p>chain && all_zeroes((sysv_zone_t*)p->bh->b_data,p->p); p--)
@@ -313,7 +313,7 @@ static Indirect *find_shared(struct inode *inode,
 		*top = *p->p;
 		*p->p = 0;
 	}
-	write_unlock(&pointers_lock);
+	up_write(&pointers_lock);
 
 	while (partial > p) {
 		brelse(partial->bh);