[PATCH 17/38] qrtr: Convert qrtr_ports to XArray

[Matthew Wilcox]

From: "Matthew Wilcox (Oracle)" <wi...@infradead.org>

Replace the qrtr_port_lock mutex with the XArray internal spinlock.

Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
---
 net/qrtr/qrtr.c | 43 +++++++++++++++----------------------------
 1 file changed, 15 insertions(+), 28 deletions(-)

diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index e02fa6be76d2..fdbc20442a93 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -104,8 +104,7 @@ static LIST_HEAD(qrtr_all_nodes);
 static DEFINE_MUTEX(qrtr_node_lock);
 
 /* local port allocation management */
-static DEFINE_IDR(qrtr_ports);
-static DEFINE_MUTEX(qrtr_port_lock);
+static DEFINE_XARRAY_ALLOC(qrtr_ports);
 
 /**
  * struct qrtr_node - endpoint node
@@ -483,11 +482,11 @@ static struct qrtr_sock *qrtr_port_lookup(int port)
        if (port == QRTR_PORT_CTRL)
                port = 0;
 
-       mutex_lock(&qrtr_port_lock);
-       ipc = idr_find(&qrtr_ports, port);
+       xa_lock(&qrtr_ports);
+       ipc = xa_load(&qrtr_ports, port);
        if (ipc)
                sock_hold(&ipc->sk);
-       mutex_unlock(&qrtr_port_lock);
+       xa_unlock(&qrtr_ports);
 
        return ipc;
 }
@@ -526,9 +525,7 @@ static void qrtr_port_remove(struct qrtr_sock *ipc)
 
        __sock_put(&ipc->sk);
 
-       mutex_lock(&qrtr_port_lock);
-       idr_remove(&qrtr_ports, port);
-       mutex_unlock(&qrtr_port_lock);
+       xa_erase(&qrtr_ports, port);
 }
 
 /* Assign port number to socket.
@@ -545,25 +542,19 @@ static int qrtr_port_assign(struct qrtr_sock *ipc, int 
*port)
 {
        int rc;
 
-       mutex_lock(&qrtr_port_lock);
        if (!*port) {
-               rc = idr_alloc(&qrtr_ports, ipc,
-                              QRTR_MIN_EPH_SOCKET, QRTR_MAX_EPH_SOCKET + 1,
-                              GFP_ATOMIC);
-               if (rc >= 0)
-                       *port = rc;
+               rc = xa_alloc(&qrtr_ports, port, ipc,
+                               XA_LIMIT(QRTR_MIN_EPH_SOCKET,
+                                       QRTR_MAX_EPH_SOCKET), GFP_KERNEL);
        } else if (*port < QRTR_MIN_EPH_SOCKET && !capable(CAP_NET_ADMIN)) {
                rc = -EACCES;
        } else if (*port == QRTR_PORT_CTRL) {
-               rc = idr_alloc(&qrtr_ports, ipc, 0, 1, GFP_ATOMIC);
+               rc = xa_insert(&qrtr_ports, 0, ipc, GFP_KERNEL);
        } else {
-               rc = idr_alloc(&qrtr_ports, ipc, *port, *port + 1, GFP_ATOMIC);
-               if (rc >= 0)
-                       *port = rc;
+               rc = xa_insert(&qrtr_ports, *port, ipc, GFP_KERNEL);
        }
-       mutex_unlock(&qrtr_port_lock);
 
-       if (rc == -ENOSPC)
+       if (rc == -EBUSY)
                return -EADDRINUSE;
        else if (rc < 0)
                return rc;
@@ -577,20 +568,16 @@ static int qrtr_port_assign(struct qrtr_sock *ipc, int 
*port)
 static void qrtr_reset_ports(void)
 {
        struct qrtr_sock *ipc;
-       int id;
-
-       mutex_lock(&qrtr_port_lock);
-       idr_for_each_entry(&qrtr_ports, ipc, id) {
-               /* Don't reset control port */
-               if (id == 0)
-                       continue;
+       unsigned long id;
 
+       xa_lock(&qrtr_ports);
+       xa_for_each_start(&qrtr_ports, id, ipc, 1) {
                sock_hold(&ipc->sk);
                ipc->sk.sk_err = ENETRESET;
                ipc->sk.sk_error_report(&ipc->sk);
                sock_put(&ipc->sk);
        }
-       mutex_unlock(&qrtr_port_lock);
+       xa_unlock(&qrtr_ports);
 }
 
 /* Bind socket to address.
-- 
2.23.0.rc1