block/rnbd: Remove a useless mutex

According to lib/idr.c,
   The IDA handles its own locking.  It is safe to call any of the IDA
   functions without synchronisation in your code.

so the 'ida_lock' mutex can just be removed.
It is here only to protect some ida_simple_get()/ida_simple_remove() calls.

While at it, switch to ida_alloc_XXX()/ida_free() instead to
ida_simple_get()/ida_simple_remove().
The latter is deprecated and more verbose.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/7f9eccd8b1fce1bac45ac9b01a78cf72f54c0a61.1644266862.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
index 9a880d559ab86669a5a49ac8ad194bec666e01e9..1f63f308eb3942532bfd6283776aff72d771ddce 100644 (file)
--- a/drivers/block/rnbd/rnbd-clt.c
+++ b/drivers/block/rnbd/rnbd-clt.c
@@ -23,7 +23,6 @@ MODULE_LICENSE("GPL");
 
 static int rnbd_client_major;
 static DEFINE_IDA(index_ida);
-static DEFINE_MUTEX(ida_lock);
 static DEFINE_MUTEX(sess_lock);
 static LIST_HEAD(sess_list);
 
@@ -55,9 +54,7 @@ static void rnbd_clt_put_dev(struct rnbd_clt_dev *dev)
        if (!refcount_dec_and_test(&dev->refcount))
                return;
 
-       mutex_lock(&ida_lock);
-       ida_simple_remove(&index_ida, dev->clt_device_id);
-       mutex_unlock(&ida_lock);
+       ida_free(&index_ida, dev->clt_device_id);
        kfree(dev->hw_queues);
        kfree(dev->pathname);
        rnbd_clt_put_sess(dev->sess);
@@ -1460,10 +1457,8 @@ static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess,
                goto out_alloc;
        }
 
-       mutex_lock(&ida_lock);
-       ret = ida_simple_get(&index_ida, 0, 1 << (MINORBITS - RNBD_PART_BITS),
-                            GFP_KERNEL);
-       mutex_unlock(&ida_lock);
+       ret = ida_alloc_max(&index_ida, 1 << (MINORBITS - RNBD_PART_BITS),
+                           GFP_KERNEL);
        if (ret < 0) {
                pr_err("Failed to initialize device '%s' from session %s, allocating idr failed, err: %d\n",
                       pathname, sess->sessname, ret);