On 2018/5/20 5:53 PM, Kai Krakow wrote:
> From: Coly Li <colyli@xxxxxxx>
>
> 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@xxxxxxxxxxxxxxx
> Signed-off-by: Coly Li <colyli@xxxxxxx>
> Reported-by: Massimo B. <massimo.b@xxxxxxx>
> Reported-by: Kai Krakow <kai@xxxxxxxxxxx>
> Tested-by: Kai Krakow <kai@xxxxxxxxxxx>
> Acked-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> (cherry picked from commit 1c1a2ee1b53b006754073eefc65d2b2cedb5264b)
> Signed-off-by: Kai Krakow <kai@xxxxxxxxxxx>
Reviewed-by: Coly Li <colyli@xxxxxxx>
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);
>
