[PATCH] nvme: target: use struct_size() in kmalloc()

[xiaolinkui]

Use struct_size() to keep code sample.
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;
    struct boo entry[];
};

instance = kmalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);

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

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

Signed-off-by: xiaolinkui <xiaolin...@kylinos.cn>
---
 drivers/nvme/target/admin-cmd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 9f72d51..6f9f830 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -248,8 +248,8 @@ static void nvmet_execute_get_log_page_ana(struct nvmet_req 
*req)
        u16 status;
 
        status = NVME_SC_INTERNAL;
-       desc = kmalloc(sizeof(struct nvme_ana_group_desc) +
-                       NVMET_MAX_NAMESPACES * sizeof(__le32), GFP_KERNEL);
+       desc = kmalloc(struct_size(desc, nsids, NVMET_MAX_NAMESPACES),
+                       GFP_KERNEL);
        if (!desc)
                goto out;
 
-- 
2.7.4