2023-12-14 08:40:50

by Dinghao Liu

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

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 <[email protected]>
---

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

2023-12-14 15:43:08

by Dave Jiang

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

On 12/14/23 01:39, Dinghao Liu wrote:
> 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 <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
> ---
>
> 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;
> }
>