| Message ID | 7f9eccd8b1fce1bac45ac9b01a78cf72f54c0a61.1644266862.git.christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] block/rnbd: Remove a useless mutex | expand |
On Mon, Feb 7, 2022 at 9:48 PM Christophe JAILLET <christophe.jaillet@wanadoo.fr> wrote: > > 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> Thanks! > --- > drivers/block/rnbd/rnbd-clt.c | 11 +++-------- > 1 file changed, 3 insertions(+), 8 deletions(-) > > diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c > index 9a880d559ab8..1f63f308eb39 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); > + 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); > -- > 2.32.0 >
On Mon, 7 Feb 2022 21:48:19 +0100, Christophe JAILLET wrote: > 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. > > [...] Applied, thanks! [1/1] block/rnbd: Remove a useless mutex commit: a41cdf83a63122e5c5fb8c8550b812b25a332577 Best regards,
diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c index 9a880d559ab8..1f63f308eb39 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); + 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);
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> --- drivers/block/rnbd/rnbd-clt.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-)