[PATCH] block/rnbd: Remove a useless mutex

From: Christophe JAILLET
Date: Sun Feb 06 2022 - 04:27:20 EST


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.

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
drivers/block/rnbd/rnbd-clt.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
index 9a880d559ab8..eaff369eff36 100644
--- 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);
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);
if (ret < 0) {
pr_err("Failed to initialize device '%s' from session %s, allocating idr failed, err: %d\n",
pathname, sess->sessname, ret);
--
2.32.0