afs: Use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding the
size of a structure that has a zero-sized array at the end, along with
memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can now
use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/afs/server_list.c b/fs/afs/server_list.c
index 95d0761cdb34ef3c0a214693651292ba08b2def1..155dc14caef93e515fa8c887895d52f0164ad6a7 100644 (file)
--- a/fs/afs/server_list.c
+++ b/fs/afs/server_list.c
@@ -42,9 +42,7 @@ struct afs_server_list *afs_alloc_server_list(struct afs_cell *cell,
                if (vldb->fs_mask[i] & type_mask)
                        nr_servers++;
 
-       slist = kzalloc(sizeof(struct afs_server_list) +
-                       sizeof(struct afs_server_entry) * nr_servers,
-                       GFP_KERNEL);
+       slist = kzalloc(struct_size(slist, servers, nr_servers), GFP_KERNEL);
        if (!slist)
                goto error;