[PATCH] [v2] nvdimm-btt: simplify code with the scope based resource management

[Dinghao Liu]

Use the scope based resource management (defined in
linux/cleanup.h) to automate resource lifetime
control on struct btt_sb *super in discover_arenas().

Signed-off-by: Dinghao Liu <dinghao....@zju.edu.cn>
---

Changelog:

v2: Set the __free attribute before kzalloc.
---
 drivers/nvdimm/btt.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index d5593b0dc700..32a9e2f543c5 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -16,6 +16,7 @@
 #include <linux/fs.h>
 #include <linux/nd.h>
 #include <linux/backing-dev.h>
+#include <linux/cleanup.h>
 #include "btt.h"
 #include "nd.h"
 
@@ -847,23 +848,20 @@ static int discover_arenas(struct btt *btt)
 {
        int ret = 0;
        struct arena_info *arena;
-       struct btt_sb *super;
        size_t remaining = btt->rawsize;
        u64 cur_nlba = 0;
        size_t cur_off = 0;
        int num_arenas = 0;
 
-       super = kzalloc(sizeof(*super), GFP_KERNEL);
+       struct btt_sb *super __free(kfree) = kzalloc(sizeof(*super), 
GFP_KERNEL);
        if (!super)
                return -ENOMEM;
 
        while (remaining) {
                /* Alloc memory for arena */
                arena = alloc_arena(btt, 0, 0, 0);
-               if (!arena) {
-                       ret = -ENOMEM;
-                       goto out_super;
-               }
+               if (!arena)
+                       return -ENOMEM;
 
                arena->infooff = cur_off;
                ret = btt_info_read(arena, super);
@@ -919,14 +917,11 @@ static int discover_arenas(struct btt *btt)
        btt->nlba = cur_nlba;
        btt->init_state = INIT_READY;
 
-       kfree(super);
        return ret;
 
  out:
        kfree(arena);
        free_arenas(btt);
- out_super:
-       kfree(super);
        return ret;
 }
 
-- 
2.17.1