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To: liuye Cc: akpm@linux-foundation.org, david@fromorbit.com, roman.gushchin@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song References: <20250305020123.605496-1-liuye@kylinos.cn> <99A7645C-B8FB-4F28-B4B8-D5372F4C001E@linux.dev> <875d80ee-d99a-4580-8648-36adb1e8591c@kylinos.cn> From: Qi Zheng In-Reply-To: <875d80ee-d99a-4580-8648-36adb1e8591c@kylinos.cn> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 3/5/25 2:10 PM, liuye wrote: > > 在 2025/3/5 11:26, Qi Zheng 写道: >> >> >> On 3/5/25 11:17 AM, Muchun Song wrote: >>> >>> >>>> On Mar 5, 2025, at 10:01, Liu Ye wrote: >>>> >>>> After calling debugfs_change_name function, the return value should be >>>> checked and the old name restored. If debugfs_change_name fails, the >>>> new >>>> name memory should be freed. >>> >>> Seems it is not a big problem, no memory leak at least. The effect is >>> that >>> the shrinker->name is not consistent with the name displayed in debugfs. >>> Right? But the improvement LGTM. So: >> >> Right, so the subject needs to be changed. >> >> Maybe: >> >> mm: shrinker: fix name consistency issue in shrinker_debugfs_rename() >> >> ? > >  I will send a new patch using this subject later. > And add  Reviewed-by：Qi Zheng ？ Sure, with the changes to the subject: Reviewed-by：Qi Zheng Thanks. > > >> >> BTW, it seems that the callers of shrinker_debugfs_rename() did not >> process the return value of the function? > > Yes,  At the same time, I also found that many positions using > debugfs_change_name did not determine the return value. > >> >>> >>> Reviewed-by: Muchun Song >>> >>> Thanks. > Thanks. >>> >>>> >>>> Signed-off-by: Liu Ye >>>> --- >>>> mm/shrinker_debug.c | 8 ++++++-- >>>> 1 file changed, 6 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c >>>> index 794bd433cce0..20eaee3e97f7 100644 >>>> --- a/mm/shrinker_debug.c >>>> +++ b/mm/shrinker_debug.c >>>> @@ -214,10 +214,14 @@ int shrinker_debugfs_rename(struct shrinker >>>> *shrinker, const char *fmt, ...) >>>> ret = debugfs_change_name(shrinker->debugfs_entry, "%s-%d", >>>> shrinker->name, shrinker->debugfs_id); >>>> >>>> +     if (ret) { >>>> +         shrinker->name = old; >>>> +         kfree_const(new); >>>> +     } else { >>>> +         kfree_const(old); >>>> +     } >>>>     mutex_unlock(&shrinker_mutex); >>>> >>>> -     kfree_const(old); >>>> - >>>>     return ret; >>>> } >>>> EXPORT_SYMBOL(shrinker_debugfs_rename); >>>> -- >>>> 2.25.1 >>>> >>> >>