[PATCH v3] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Denis Efremov <efremov@linux.com>]

Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.
Size computation wrapped in struct_size() macro to prevent potential
integer overflows.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
Changes in v2:
 - size computation wrapped in struct_size()
Changes in v3:
 - int size dropped

 fs/udf/super.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 1c42f544096d..d9eabbe368ff 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1006,18 +1006,10 @@ int udf_compute_nr_groups(struct super_block *sb, u32 partition)
 static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
 {
 	struct udf_bitmap *bitmap;
-	int nr_groups;
-	int size;
-
-	nr_groups = udf_compute_nr_groups(sb, index);
-	size = sizeof(struct udf_bitmap) +
-		(sizeof(struct buffer_head *) * nr_groups);
-
-	if (size <= PAGE_SIZE)
-		bitmap = kzalloc(size, GFP_KERNEL);
-	else
-		bitmap = vzalloc(size); /* TODO: get rid of vzalloc */
+	int nr_groups = udf_compute_nr_groups(sb, index);
 
+	bitmap = kvzalloc(struct_size(bitmap, s_block_bitmap, nr_groups),
+			  GFP_KERNEL);
 	if (!bitmap)
 		return NULL;
 
-- 
2.26.2