[PATCH] fs/resctrl: using guard to simplify lock/unlock code

[Su Hui <suhui@nfschina.com>]

Using guard() to replace *unlock* label. guard() is better than goto
unlock patterns and is more concise. No functional changes.

Signed-off-by: Su Hui <suhui@nfschina.com>
---
 fs/resctrl/monitor.c  | 25 ++++++++-----------------
 fs/resctrl/rdtgroup.c | 29 +++++++++--------------------
 2 files changed, 17 insertions(+), 37 deletions(-)

diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index f5637855c3ac..12e999eb7ed8 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -769,10 +769,10 @@ static int dom_data_init(struct rdt_resource *r)
 	u32 idx_limit = resctrl_arch_system_num_rmid_idx();
 	u32 num_closid = resctrl_arch_get_num_closid(r);
 	struct rmid_entry *entry = NULL;
-	int err = 0, i;
+	int i;
 	u32 idx;
 
-	mutex_lock(&rdtgroup_mutex);
+	guard(mutex)(&rdtgroup_mutex);
 	if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
 		u32 *tmp;
 
@@ -783,10 +783,8 @@ static int dom_data_init(struct rdt_resource *r)
 		 * use.
 		 */
 		tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL);
-		if (!tmp) {
-			err = -ENOMEM;
-			goto out_unlock;
-		}
+		if (!tmp)
+			return -ENOMEM;
 
 		closid_num_dirty_rmid = tmp;
 	}
@@ -797,8 +795,7 @@ static int dom_data_init(struct rdt_resource *r)
 			kfree(closid_num_dirty_rmid);
 			closid_num_dirty_rmid = NULL;
 		}
-		err = -ENOMEM;
-		goto out_unlock;
+		return -ENOMEM;
 	}
 
 	for (i = 0; i < idx_limit; i++) {
@@ -819,18 +816,15 @@ static int dom_data_init(struct rdt_resource *r)
 	entry = __rmid_entry(idx);
 	list_del(&entry->list);
 
-out_unlock:
-	mutex_unlock(&rdtgroup_mutex);
-
-	return err;
+	return 0;
 }
 
 static void dom_data_exit(struct rdt_resource *r)
 {
-	mutex_lock(&rdtgroup_mutex);
+	guard(mutex)(&rdtgroup_mutex);
 
 	if (!r->mon_capable)
-		goto out_unlock;
+		return;
 
 	if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
 		kfree(closid_num_dirty_rmid);
@@ -839,9 +833,6 @@ static void dom_data_exit(struct rdt_resource *r)
 
 	kfree(rmid_ptrs);
 	rmid_ptrs = NULL;
-
-out_unlock:
-	mutex_unlock(&rdtgroup_mutex);
 }
 
 static struct mon_evt llc_occupancy_event = {
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 77d08229d855..73bc1ab05b5e 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -916,14 +916,13 @@ int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns,
 		      struct pid *pid, struct task_struct *tsk)
 {
 	struct rdtgroup *rdtg;
-	int ret = 0;
 
-	mutex_lock(&rdtgroup_mutex);
+	guard(mutex)(&rdtgroup_mutex);
 
 	/* Return empty if resctrl has not been mounted. */
 	if (!resctrl_mounted) {
 		seq_puts(s, "res:\nmon:\n");
-		goto unlock;
+		return 0;
 	}
 
 	list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
@@ -952,17 +951,13 @@ int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns,
 			break;
 		}
 		seq_putc(s, '\n');
-		goto unlock;
+		return 0;
 	}
 	/*
 	 * The above search should succeed. Otherwise return
 	 * with an error.
 	 */
-	ret = -ENOENT;
-unlock:
-	mutex_unlock(&rdtgroup_mutex);
-
-	return ret;
+	return -ENOENT;
 }
 #endif
 
@@ -4132,11 +4127,11 @@ int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
 {
 	int err;
 
-	mutex_lock(&rdtgroup_mutex);
+	guard(mutex)(&rdtgroup_mutex);
 
 	err = domain_setup_mon_state(r, d);
 	if (err)
-		goto out_unlock;
+		return err;
 
 	if (resctrl_is_mbm_enabled()) {
 		INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow);
@@ -4156,10 +4151,7 @@ int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
 	if (resctrl_mounted && resctrl_arch_mon_capable())
 		mkdir_mondata_subdir_allrdtgrp(r, d);
 
-out_unlock:
-	mutex_unlock(&rdtgroup_mutex);
-
-	return err;
+	return 0;
 }
 
 void resctrl_online_cpu(unsigned int cpu)
@@ -4202,7 +4194,7 @@ void resctrl_offline_cpu(unsigned int cpu)
 	struct rdt_mon_domain *d;
 	struct rdtgroup *rdtgrp;
 
-	mutex_lock(&rdtgroup_mutex);
+	guard(mutex)(&rdtgroup_mutex);
 	list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
 		if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) {
 			clear_childcpus(rdtgrp, cpu);
@@ -4211,7 +4203,7 @@ void resctrl_offline_cpu(unsigned int cpu)
 	}
 
 	if (!l3->mon_capable)
-		goto out_unlock;
+		return;
 
 	d = get_mon_domain_from_cpu(cpu, l3);
 	if (d) {
@@ -4225,9 +4217,6 @@ void resctrl_offline_cpu(unsigned int cpu)
 			cqm_setup_limbo_handler(d, 0, cpu);
 		}
 	}
-
-out_unlock:
-	mutex_unlock(&rdtgroup_mutex);
 }
 
 /*
-- 
2.30.2