[lustre-devel] [PATCH 09/28] lustre: ldlm: discard varname in ldlm_pool.

From: NeilBrown <neilb@suse.com>
To: lustre-devel@lists.lustre.org
Subject: [lustre-devel] [PATCH 09/28] lustre: ldlm: discard varname in ldlm_pool.
Date: Mon, 04 Mar 2019 17:31:38 +1100	[thread overview]
Message-ID: <155168109840.31333.11593261178506545741.stgit@noble.brown> (raw)
In-Reply-To: <155168107971.31333.14345309795939467246.stgit@noble.brown>

This allocated buffer serves no purpose.
A constant string is copied into it, it is passed to some
function which copies it out again, then the buffer is freed.
Instead, we can pass the constant string to that function.

Signed-off-by: NeilBrown <neilb@suse.com>
---
 drivers/staging/lustre/lustre/ldlm/ldlm_internal.h |    2 --
 drivers/staging/lustre/lustre/ldlm/ldlm_pool.c     |   18 +++++-------------
 2 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h b/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
index d8dcf8a73e4b..c907d880274d 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
@@ -31,8 +31,6 @@
  * Lustre is a trademark of Sun Microsystems, Inc.
  */
 
-#define MAX_STRING_SIZE 128
-
 extern int ldlm_srv_namespace_nr;
 extern int ldlm_cli_namespace_nr;
 extern struct mutex ldlm_srv_namespace_lock;
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c b/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
index 1f81795cc6f6..a984b5df7bc1 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_pool.c
@@ -503,9 +503,9 @@ LDLM_POOL_SYSFS_READER_NOLOCK_SHOW(lock_volume_factor, atomic);
 LDLM_POOL_SYSFS_WRITER_NOLOCK_STORE(lock_volume_factor, atomic);
 LUSTRE_RW_ATTR(lock_volume_factor);
 
-#define LDLM_POOL_ADD_VAR(name, var, ops)			\
+#define LDLM_POOL_ADD_VAR(_name, var, ops)			\
 	do {							\
-		snprintf(var_name, MAX_STRING_SIZE, #name);	\
+		pool_vars[0].name = #_name;			\
 		pool_vars[0].data = var;			\
 		pool_vars[0].fops = ops;			\
 		ldebugfs_add_vars(pl->pl_debugfs_entry, pool_vars, NULL);\
@@ -557,25 +557,18 @@ static int ldlm_pool_debugfs_init(struct ldlm_pool *pl)
 						 ns_pool);
 	struct dentry *debugfs_ns_parent;
 	struct lprocfs_vars pool_vars[2];
-	char *var_name = NULL;
 	int rc = 0;
 
-	var_name = kzalloc(MAX_STRING_SIZE + 1, GFP_NOFS);
-	if (!var_name)
-		return -ENOMEM;
-
 	debugfs_ns_parent = ns->ns_debugfs_entry;
 	if (IS_ERR_OR_NULL(debugfs_ns_parent)) {
 		CERROR("%s: debugfs entry is not initialized\n",
 		       ldlm_ns_name(ns));
 		rc = -EINVAL;
-		goto out_free_name;
+		goto out;
 	}
 	pl->pl_debugfs_entry = debugfs_create_dir("pool", debugfs_ns_parent);
 
-	var_name[MAX_STRING_SIZE] = '\0';
 	memset(pool_vars, 0, sizeof(pool_vars));
-	pool_vars[0].name = var_name;
 
 	LDLM_POOL_ADD_VAR(state, pl, &lprocfs_pool_state_fops);
 
@@ -583,7 +576,7 @@ static int ldlm_pool_debugfs_init(struct ldlm_pool *pl)
 					   LDLM_POOL_FIRST_STAT, 0);
 	if (!pl->pl_stats) {
 		rc = -ENOMEM;
-		goto out_free_name;
+		goto out;
 	}
 
 	lprocfs_counter_init(pl->pl_stats, LDLM_POOL_GRANTED_STAT,
@@ -622,8 +615,7 @@ static int ldlm_pool_debugfs_init(struct ldlm_pool *pl)
 	debugfs_create_file("stats", 0644, pl->pl_debugfs_entry, pl->pl_stats,
 			    &lprocfs_stats_seq_fops);
 
-out_free_name:
-	kfree(var_name);
+out:
 	return rc;
 }
 
