idr_get_new_exact ?

Commit Message

Ohad Ben Cohen Sept. 20, 2010, 2:11 p.m. UTC

None

Patch

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 6649176..6220900 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -964,14 +964,7 @@  retry:
 		return -ENOMEM;

 	mutex_lock(&core_lock);
-	/* "above" here means "above or equal to", sigh;
-	 * we need the "equal to" result to force the result
-	 */
-	status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
-	if (status == 0 && id != adap->nr) {
-		status = -EBUSY;
-		idr_remove(&i2c_adapter_idr, id);
-	}
+	status = idr_get_new_exact(&i2c_adapter_idr, adap, adap->nr, &id);
 	mutex_unlock(&core_lock);
 	if (status == -EAGAIN)
 		goto retry;
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index b930b81..1756c99 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -1945,23 +1945,16 @@  static int cma_alloc_port(struct idr *ps,
struct rdma_id_private *id_priv,
 		return -ENOMEM;

 	do {
-		ret = idr_get_new_above(ps, bind_list, snum, &port);
+		ret = idr_get_new_exact(ps, bind_list, snum, &port);
 	} while ((ret == -EAGAIN) && idr_pre_get(ps, GFP_KERNEL));

 	if (ret)
 		goto err1;

-	if (port != snum) {
-		ret = -EADDRNOTAVAIL;
-		goto err2;
-	}
-
 	bind_list->ps = ps;
 	bind_list->port = (unsigned short) port;
 	cma_bind_port(bind_list, id_priv);
 	return 0;
-err2:
-	idr_remove(ps, port);
 err1:
 	kfree(bind_list);
 	return ret;
diff --git a/drivers/infiniband/hw/cxgb3/iwch.h
b/drivers/infiniband/hw/cxgb3/iwch.h
index a1c4457..71d9cae 100644
--- a/drivers/infiniband/hw/cxgb3/iwch.h
+++ b/drivers/infiniband/hw/cxgb3/iwch.h
@@ -160,8 +160,7 @@  static inline int insert_handle(struct iwch_dev
*rhp, struct idr *idr,
 			return -ENOMEM;
 		}
 		spin_lock_irq(&rhp->lock);
-		ret = idr_get_new_above(idr, handle, id, &newid);
-		BUG_ON(newid != id);
+		ret = idr_get_new_exact(idr, handle, id, &newid);
 		spin_unlock_irq(&rhp->lock);
 	} while (ret == -EAGAIN);

diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index ed459b8..45567b1 100644
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -190,8 +190,7 @@  static inline int insert_handle(struct c4iw_dev
*rhp, struct idr *idr,
 		if (!idr_pre_get(idr, GFP_KERNEL))
 			return -ENOMEM;
 		spin_lock_irq(&rhp->lock);
-		ret = idr_get_new_above(idr, handle, id, &newid);
-		BUG_ON(newid != id);
+		ret = idr_get_new_exact(idr, handle, id, &newid);
 		spin_unlock_irq(&rhp->lock);
 	} while (ret == -EAGAIN);

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ac384b2..dee497c 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1873,16 +1873,10 @@  static int specific_minor(int minor)
 		goto out;
 	}

-	r = idr_get_new_above(&_minor_idr, MINOR_ALLOCED, minor, &m);
+	r = idr_get_new_exact(&_minor_idr, MINOR_ALLOCED, minor, &m);
 	if (r)
 		goto out;

-	if (m != minor) {
-		idr_remove(&_minor_idr, m);
-		r = -EBUSY;
-		goto out;
-	}
-
 out:
 	spin_unlock(&_minor_lock);
 	return r;
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index 736b917..3bb63e5 100644
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -2865,15 +2865,10 @@  again:
 		return -ENOMEM;
 	}

-	err = idr_get_new_above(p, ptr, n, &unit);
+	err = idr_get_new_exact(p, ptr, n, &unit);
 	if (err == -EAGAIN)
 		goto again;

-	if (unit != n) {
-		idr_remove(p, unit);
-		return -EINVAL;
-	}
-
 	return unit;
 }

diff --git a/include/linux/idr.h b/include/linux/idr.h
index e968db7..748b67e 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -104,6 +104,7 @@  void *idr_find(struct idr *idp, int id);
 int idr_pre_get(struct idr *idp, gfp_t gfp_mask);
 int idr_get_new(struct idr *idp, void *ptr, int *id);
 int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id);
+int idr_get_new_exact(struct idr *idp, void *ptr, int requested_id, int *id);
 int idr_for_each(struct idr *idp,
 		 int (*fn)(int id, void *p, void *data), void *data);
 void *idr_get_next(struct idr *idp, int *nextid);
diff --git a/lib/idr.c b/lib/idr.c
index 7f1a4f0..53cc161 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -430,6 +430,45 @@  void idr_remove(struct idr *idp, int id)
 EXPORT_SYMBOL(idr_remove);

 /**
+ * idr_get_new_exact - allocate new idr entry equal to a requested id
+ * @idp: idr handle
+ * @ptr: pointer you want associated with the id
+ * @requested_id: id to search for
+ * @id: pointer to the allocated handle
+ *
+ * This is the allocate id function.  It should be called with any
+ * required locks.
+ *
+ * If memory is required, it will return -EAGAIN, you should unlock
+ * and go back to the idr_pre_get() call.  If the idr is full, it will
+ * return -ENOSPC. If the requested id is already taken, it will return
+ * -EBUSY.
+ *
+ * @id returns @requested_id on success
+ */
+int idr_get_new_exact(struct idr *idp, void *ptr, int requested_id, int *id)
+{
+	int rv;
+
+	rv = idr_get_new_above_int(idp, ptr, requested_id);
+	/*
+	 * This is a cheap hack until the IDR code can be fixed to
+	 * return proper error values.
+	 */
+	if (rv < 0)
+		return _idr_rc_to_errno(rv);
+
+	if (requested_id != rv) {
+		idr_remove(idp, rv);
+		return -EBUSY;
+	}
+
+	*id = rv;
+	return 0;
+}
+EXPORT_SYMBOL(idr_get_new_exact);
+
+/**
  * idr_remove_all - remove all ids from the given idr tree
  * @idp: idr handle
  *