ext4: use kmem_cache_zalloc instead of kmem_cache_alloc/memset

Using kmem_cache_zalloc() instead of kmem_cache_alloc() and memset().

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index bb821a9..8ec6f88 100644 (file)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2232,12 +2232,11 @@ int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
                sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
        i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
 
-       meta_group_info[i] = kmem_cache_alloc(cachep, GFP_KERNEL);
+       meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_KERNEL);
        if (meta_group_info[i] == NULL) {
                ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
                goto exit_group_info;
        }
-       memset(meta_group_info[i], 0, kmem_cache_size(cachep));
        set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
                &(meta_group_info[i]->bb_state));
 
@@ -4010,7 +4009,6 @@ ext4_mb_initialize_context(struct ext4_allocation_context *ac,
        ext4_get_group_no_and_offset(sb, goal, &group, &block);
 
        /* set up allocation goals */
-       memset(ac, 0, sizeof(struct ext4_allocation_context));
        ac->ac_b_ex.fe_logical = ar->logical & ~(sbi->s_cluster_ratio - 1);
        ac->ac_status = AC_STATUS_CONTINUE;
        ac->ac_sb = sb;
@@ -4293,7 +4291,7 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
                }
        }
 
-       ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
+       ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
        if (!ac) {
                ar->len = 0;
                *errp = -ENOMEM;