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ALSA: seq: ports: Use guard() for locking 

We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.

Only the code refactoring, and no functional changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-15-tiwai@suse.de
This commit is contained in:
Takashi Iwai 2024-02-27 09:52:56 +01:00
parent 6768bd1000
commit a02f7a170f
1 changed files with 49 additions and 65 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

114
sound/core/seq/seq_ports.c
View File

@ -48,17 +48,15 @@ struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client,
if (client == NULL)
return NULL;
read_lock(&client->ports_lock);
guard(read_lock)(&client->ports_lock);
list_for_each_entry(port, &client->ports_list_head, list) {
if (port->addr.port == num) {
if (port->closing)
break; /* deleting now */
snd_use_lock_use(&port->use_lock);
read_unlock(&client->ports_lock);
return port;
}
}
read_unlock(&client->ports_lock);
return NULL; /* not found */
}
@ -73,7 +71,7 @@ struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *cl
num = pinfo->addr.port;
found = NULL;
read_lock(&client->ports_lock);
guard(read_lock)(&client->ports_lock);
list_for_each_entry(port, &client->ports_list_head, list) {
if ((port->capability & SNDRV_SEQ_PORT_CAP_INACTIVE) &&
!check_inactive)
@ -93,7 +91,6 @@ struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *cl
else
snd_use_lock_use(&found->use_lock);
}
read_unlock(&client->ports_lock);
return found;
}
@ -145,13 +142,12 @@ int snd_seq_create_port(struct snd_seq_client *client, int port,
snd_use_lock_use(&new_port->use_lock);
num = max(port, 0);
mutex_lock(&client->ports_mutex);
write_lock_irq(&client->ports_lock);
guard(mutex)(&client->ports_mutex);
guard(write_lock_irq)(&client->ports_lock);
list_for_each_entry(p, &client->ports_list_head, list) {
if (p->addr.port == port) {
kfree(new_port);
num = -EBUSY;
goto unlock;
return -EBUSY;
}
if (p->addr.port > num)
break;
@ -164,9 +160,6 @@ int snd_seq_create_port(struct snd_seq_client *client, int port,
new_port->addr.port = num; /* store the port number in the port */
sprintf(new_port->name, "port-%d", num);
*port_ret = new_port;
unlock:
write_unlock_irq(&client->ports_lock);
mutex_unlock(&client->ports_mutex);
return num;
}
@ -281,19 +274,18 @@ int snd_seq_delete_port(struct snd_seq_client *client, int port)
{
struct snd_seq_client_port *found = NULL, *p;
mutex_lock(&client->ports_mutex);
write_lock_irq(&client->ports_lock);
list_for_each_entry(p, &client->ports_list_head, list) {
if (p->addr.port == port) {
/* ok found. delete from the list at first */
list_del(&p->list);
client->num_ports--;
found = p;
break;
scoped_guard(mutex, &client->ports_mutex) {
guard(write_lock_irq)(&client->ports_lock);
list_for_each_entry(p, &client->ports_list_head, list) {
if (p->addr.port == port) {
/* ok found. delete from the list at first */
list_del(&p->list);
client->num_ports--;
found = p;
break;
}
}
}
write_unlock_irq(&client->ports_lock);
mutex_unlock(&client->ports_mutex);
if (found)
return port_delete(client, found);
else
@ -309,16 +301,16 @@ int snd_seq_delete_all_ports(struct snd_seq_client *client)
/* move the port list to deleted_list, and
* clear the port list in the client data.
*/
mutex_lock(&client->ports_mutex);
write_lock_irq(&client->ports_lock);
if (! list_empty(&client->ports_list_head)) {
list_add(&deleted_list, &client->ports_list_head);
list_del_init(&client->ports_list_head);
} else {
INIT_LIST_HEAD(&deleted_list);
guard(mutex)(&client->ports_mutex);
scoped_guard(write_lock_irq, &client->ports_lock) {
if (!list_empty(&client->ports_list_head)) {
list_add(&deleted_list, &client->ports_list_head);
list_del_init(&client->ports_list_head);
} else {
INIT_LIST_HEAD(&deleted_list);
}
client->num_ports = 0;
}
client->num_ports = 0;
write_unlock_irq(&client->ports_lock);
/* remove each port in deleted_list */
list_for_each_entry_safe(port, tmp, &deleted_list, list) {
@ -326,7 +318,6 @@ int snd_seq_delete_all_ports(struct snd_seq_client *client)
snd_seq_system_client_ev_port_exit(port->addr.client, port->addr.port);
port_delete(client, port);
}
mutex_unlock(&client->ports_mutex);
return 0;
}
@ -506,42 +497,37 @@ static int check_and_subscribe_port(struct snd_seq_client *client,
int err;
grp = is_src ? &port->c_src : &port->c_dest;
err = -EBUSY;
down_write(&grp->list_mutex);
guard(rwsem_write)(&grp->list_mutex);
if (exclusive) {
if (!list_empty(&grp->list_head))
goto __error;
return -EBUSY;
} else {
if (grp->exclusive)
goto __error;
return -EBUSY;
/* check whether already exists */
list_for_each(p, &grp->list_head) {
s = get_subscriber(p, is_src);
if (match_subs_info(&subs->info, &s->info))
goto __error;
return -EBUSY;
}
}
err = subscribe_port(client, port, grp, &subs->info, ack);
if (err < 0) {
grp->exclusive = 0;
goto __error;
return err;
}
/* add to list */
write_lock_irq(&grp->list_lock);
guard(write_lock_irq)(&grp->list_lock);
if (is_src)
list_add_tail(&subs->src_list, &grp->list_head);
else
list_add_tail(&subs->dest_list, &grp->list_head);
grp->exclusive = exclusive;
atomic_inc(&subs->ref_count);
write_unlock_irq(&grp->list_lock);
err = 0;
__error:
up_write(&grp->list_mutex);
return err;
return 0;
}
/* called with grp->list_mutex held */
@ -556,12 +542,12 @@ static void __delete_and_unsubscribe_port(struct snd_seq_client *client,
grp = is_src ? &port->c_src : &port->c_dest;
list = is_src ? &subs->src_list : &subs->dest_list;
write_lock_irq(&grp->list_lock);
empty = list_empty(list);
if (!empty)
list_del_init(list);
grp->exclusive = 0;
write_unlock_irq(&grp->list_lock);
scoped_guard(write_lock_irq, &grp->list_lock) {
empty = list_empty(list);
if (!empty)
list_del_init(list);
grp->exclusive = 0;
}
if (!empty)
unsubscribe_port(client, port, grp, &subs->info, ack);
@ -575,9 +561,8 @@ static void delete_and_unsubscribe_port(struct snd_seq_client *client,
struct snd_seq_port_subs_info *grp;
grp = is_src ? &port->c_src : &port->c_dest;
down_write(&grp->list_mutex);
guard(rwsem_write)(&grp->list_mutex);
__delete_and_unsubscribe_port(client, port, subs, is_src, ack);
up_write(&grp->list_mutex);
}
/* connect two ports */
@ -639,18 +624,18 @@ int snd_seq_port_disconnect(struct snd_seq_client *connector,
/* always start from deleting the dest port for avoiding concurrent
* deletions
*/
down_write(&dest->list_mutex);
/* look for the connection */
list_for_each_entry(subs, &dest->list_head, dest_list) {
if (match_subs_info(info, &subs->info)) {
__delete_and_unsubscribe_port(dest_client, dest_port,
subs, false,
connector->number != dest_client->number);
err = 0;
break;
scoped_guard(rwsem_write, &dest->list_mutex) {
/* look for the connection */
list_for_each_entry(subs, &dest->list_head, dest_list) {
if (match_subs_info(info, &subs->info)) {
__delete_and_unsubscribe_port(dest_client, dest_port,
subs, false,
connector->number != dest_client->number);
err = 0;
break;
}
}
}
up_write(&dest->list_mutex);
if (err < 0)
return err;
@ -669,7 +654,7 @@ int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
struct snd_seq_subscribers *s;
int err = -ENOENT;
down_read(&src_grp->list_mutex);
guard(rwsem_read)(&src_grp->list_mutex);
list_for_each_entry(s, &src_grp->list_head, src_list) {
if (addr_match(dest_addr, &s->info.dest)) {
*subs = s->info;
@ -677,7 +662,6 @@ int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
break;
}
}
up_read(&src_grp->list_mutex);
return err;
}