[PATCH] mm/cma_debug: Check return value of the debugfs_create_dir()

[PATCH] mm/cma_debug: Check return value of the debugfs_create_dir()

[Alexander Kuleshov]

The debugfs_create_dir() function may fail and return error. If the
root directory not created, we can't create anything inside it. This
patch adds check for this case.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
---
 mm/cma_debug.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/cma_debug.c b/mm/cma_debug.c
index f8e4b60..bfb46e2 100644
--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -171,6 +171,9 @@ static void cma_debugfs_add_one(struct cma *cma, int idx)
 
 	tmp = debugfs_create_dir(name, cma_debugfs_root);
 
+	if (!tmp)
+		return;
+
 	debugfs_create_file("alloc", S_IWUSR, tmp, cma,
 				&cma_alloc_fops);
 
-- 
2.5.0

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Re: [PATCH] mm/cma_debug: Check return value of the debugfs_create_dir()

[Michal Nazarewicz]

On Tue, Aug 25 2015, Alexander Kuleshov wrote:
> The debugfs_create_dir() function may fail and return error. If the
> root directory not created, we can't create anything inside it. This
> patch adds check for this case.
>
> Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>

I’d also add a pr_warn but otherwise:

Acked-by: Michal Nazarewicz <mina86@mina86.com>

> ---
>  mm/cma_debug.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/mm/cma_debug.c b/mm/cma_debug.c
> index f8e4b60..bfb46e2 100644
> --- a/mm/cma_debug.c
> +++ b/mm/cma_debug.c
> @@ -171,6 +171,9 @@ static void cma_debugfs_add_one(struct cma *cma, int idx)
>  
>  	tmp = debugfs_create_dir(name, cma_debugfs_root);
>  
> +	if (!tmp)
> +		return;
> +
>  	debugfs_create_file("alloc", S_IWUSR, tmp, cma,
>  				&cma_alloc_fops);
>  

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