[PATCH] bcache: return 0 from bch_debug_init() if CONFIG_DEBUG_FS=n

[PATCH] bcache: return 0 from bch_debug_init() if CONFIG_DEBUG_FS=n

[Coly Li]

Commit 539d39eb2708 ("bcache: fix wrong return value in bch_debug_init()")
returns the return value of debugfs_create_dir() to bcache_init(). When
CONFIG_DEBUG_FS=n, bch_debug_init() always returns 1 and makes
bcache_init() failedi.

This patch makes bch_debug_init() always returns 0 if CONFIG_DEBUG_FS=n,
so bcache can continue to work for the kernels which don't have debugfs
enanbled.

Fixes: Commit 539d39eb2708 ("bcache: fix wrong return value in bch_debug_init()")
Cc: stable@vger.kernel.org
Signed-off-by: Coly Li <colyli@suse.de>
Reported-by: Massimo B. <massimo.b@gmx.net>
Reported-by: Kai Krakow <kai@kaishome.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
---
 drivers/md/bcache/bcache.h | 5 +++++
 drivers/md/bcache/debug.c  | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 3a0cfb237af9..5b3fe87f32ee 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -994,8 +994,13 @@ void bch_open_buckets_free(struct cache_set *);
 
 int bch_cache_allocator_start(struct cache *ca);
 
+#ifdef CONFIG_DEBUG_FS
 void bch_debug_exit(void);
 int bch_debug_init(struct kobject *);
+#else
+static inline void bch_debug_exit(void) {};
+static inline int bch_debug_init(struct kobject *kobj) { return 0; };
+#endif
 void bch_request_exit(void);
 int bch_request_init(void);
 
diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index 4e63c6f6c04d..34a0ed4ed70c 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -240,8 +240,6 @@ void bch_debug_init_cache_set(struct cache_set *c)
 	}
 }
 
-#endif
-
 void bch_debug_exit(void)
 {
 	if (!IS_ERR_OR_NULL(bcache_debug))
@@ -254,3 +252,5 @@ int __init bch_debug_init(struct kobject *kobj)
 
 	return IS_ERR_OR_NULL(bcache_debug);
 }
+
+#endif
-- 
2.16.3

Re: [PATCH] bcache: return 0 from bch_debug_init() if CONFIG_DEBUG_FS=n

[Coly Li]

On 2018/5/20 5:53 PM, Kai Krakow wrote:
> From: Coly Li <colyli@suse.de>
> 
> Commit 539d39eb2708 ("bcache: fix wrong return value in bch_debug_init()")
> returns the return value of debugfs_create_dir() to bcache_init(). When
> CONFIG_DEBUG_FS=n, bch_debug_init() always returns 1 and makes
> bcache_init() failedi.
> 
> This patch makes bch_debug_init() always returns 0 if CONFIG_DEBUG_FS=n,
> so bcache can continue to work for the kernels which don't have debugfs
> enanbled.
> 
> Changelog:
> v4: Add Acked-by from Kent Overstreet.
> v3: Use IS_ENABLED(CONFIG_DEBUG_FS) to replace #ifdef DEBUG_FS.
> v2: Remove a warning information
> v1: Initial version.
> 
> Fixes: Commit 539d39eb2708 ("bcache: fix wrong return value in bch_debug_init()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Coly Li <colyli@suse.de>
> Reported-by: Massimo B. <massimo.b@gmx.net>
> Reported-by: Kai Krakow <kai@kaishome.de>
> Tested-by: Kai Krakow <kai@kaishome.de>
> Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> (cherry picked from commit 1c1a2ee1b53b006754073eefc65d2b2cedb5264b)
> Signed-off-by: Kai Krakow <kai@kaishome.de>

Reviewed-by: Coly Li <colyli@suse.de>

Thanks for the back port.

Coly Li

> ---
>  drivers/md/bcache/debug.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
> index af89408befe8..b218426a6493 100644
> --- a/drivers/md/bcache/debug.c
> +++ b/drivers/md/bcache/debug.c
> @@ -251,6 +251,9 @@ void bch_debug_exit(void)
>  
>  int __init bch_debug_init(struct kobject *kobj)
>  {
> +	if (!IS_ENABLED(CONFIG_DEBUG_FS))
> +		return 0;
> +
>  	debug = debugfs_create_dir("bcache", NULL);
>  
>  	return IS_ERR_OR_NULL(debug);
> 

[PATCH] bcache: return 0 from bch_debug_init() if CONFIG_DEBUG_FS=n

[Kai Krakow]

From: Coly Li <colyli@suse.de>

Commit 539d39eb2708 ("bcache: fix wrong return value in bch_debug_init()")
returns the return value of debugfs_create_dir() to bcache_init(). When
CONFIG_DEBUG_FS=n, bch_debug_init() always returns 1 and makes
bcache_init() failedi.

This patch makes bch_debug_init() always returns 0 if CONFIG_DEBUG_FS=n,
so bcache can continue to work for the kernels which don't have debugfs
enanbled.

Changelog:
v4: Add Acked-by from Kent Overstreet.
v3: Use IS_ENABLED(CONFIG_DEBUG_FS) to replace #ifdef DEBUG_FS.
v2: Remove a warning information
v1: Initial version.

Fixes: Commit 539d39eb2708 ("bcache: fix wrong return value in bch_debug_init()")
Cc: stable@vger.kernel.org
Signed-off-by: Coly Li <colyli@suse.de>
Reported-by: Massimo B. <massimo.b@gmx.net>
Reported-by: Kai Krakow <kai@kaishome.de>
Tested-by: Kai Krakow <kai@kaishome.de>
Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 1c1a2ee1b53b006754073eefc65d2b2cedb5264b)
Signed-off-by: Kai Krakow <kai@kaishome.de>
---
 drivers/md/bcache/debug.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index af89408befe8..b218426a6493 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -251,6 +251,9 @@ void bch_debug_exit(void)
 
 int __init bch_debug_init(struct kobject *kobj)
 {
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return 0;
+
 	debug = debugfs_create_dir("bcache", NULL);
 
 	return IS_ERR_OR_NULL(debug);
-- 
2.16.1