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Date:   Tue, 6 Feb 2018 11:22:34 +0100
From:   Jan Kara <jack@suse.cz>
To:     Wang Long <wanglong19@meituan.com>
Cc:     darrick.wong@oracle.com, tytso@mit.edu, jack@suse.com,
        linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] jbd2: remove the conditional test
Message-ID: <20180206102234.s3yjrtjkfaup5vas@quack2.suse.cz>
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On Mon 05-02-18 22:24:39, Wang Long wrote:
> kmem_cache_destroy already handles null pointers, so we can remove the
> conditional test entirely.
> 
> This patch also set NULL after the kmem_cache_destroy in function
> jbd2_journal_destroy_handle_cache.
> 
> Signed-off-by: Wang Long <wanglong19@meituan.com>

Looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/jbd2/journal.c     | 18 +++++++-----------
>  fs/jbd2/revoke.c      | 12 ++++--------
>  fs/jbd2/transaction.c |  6 ++----
>  3 files changed, 13 insertions(+), 23 deletions(-)
> 
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index 93016bb..3c27a61a 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -2286,8 +2286,7 @@ static void jbd2_journal_destroy_slabs(void)
>  	int i;
>  
>  	for (i = 0; i < JBD2_MAX_SLABS; i++) {
> -		if (jbd2_slab[i])
> -			kmem_cache_destroy(jbd2_slab[i]);
> +		kmem_cache_destroy(jbd2_slab[i]);
>  		jbd2_slab[i] = NULL;
>  	}
>  }
> @@ -2388,10 +2387,8 @@ static int jbd2_journal_init_journal_head_cache(void)
>  
>  static void jbd2_journal_destroy_journal_head_cache(void)
>  {
> -	if (jbd2_journal_head_cache) {
> -		kmem_cache_destroy(jbd2_journal_head_cache);
> -		jbd2_journal_head_cache = NULL;
> -	}
> +	kmem_cache_destroy(jbd2_journal_head_cache);
> +	jbd2_journal_head_cache = NULL;
>  }
>  
>  /*
> @@ -2649,11 +2646,10 @@ static int __init jbd2_journal_init_handle_cache(void)
>  
>  static void jbd2_journal_destroy_handle_cache(void)
>  {
> -	if (jbd2_handle_cache)
> -		kmem_cache_destroy(jbd2_handle_cache);
> -	if (jbd2_inode_cache)
> -		kmem_cache_destroy(jbd2_inode_cache);
> -
> +	kmem_cache_destroy(jbd2_handle_cache);
> +	jbd2_handle_cache = NULL;
> +	kmem_cache_destroy(jbd2_inode_cache);
> +	jbd2_inode_cache = NULL;
>  }
>  
>  /*
> diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
> index 696ef15..240779e 100644
> --- a/fs/jbd2/revoke.c
> +++ b/fs/jbd2/revoke.c
> @@ -180,14 +180,10 @@ static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal,
>  
>  void jbd2_journal_destroy_revoke_caches(void)
>  {
> -	if (jbd2_revoke_record_cache) {
> -		kmem_cache_destroy(jbd2_revoke_record_cache);
> -		jbd2_revoke_record_cache = NULL;
> -	}
> -	if (jbd2_revoke_table_cache) {
> -		kmem_cache_destroy(jbd2_revoke_table_cache);
> -		jbd2_revoke_table_cache = NULL;
> -	}
> +	kmem_cache_destroy(jbd2_revoke_record_cache);
> +	jbd2_revoke_record_cache = NULL;
> +	kmem_cache_destroy(jbd2_revoke_table_cache);
> +	jbd2_revoke_table_cache = NULL;
>  }
>  
>  int __init jbd2_journal_init_revoke_caches(void)
> diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
> index ac31103..3b642e0 100644
> --- a/fs/jbd2/transaction.c
> +++ b/fs/jbd2/transaction.c
> @@ -49,10 +49,8 @@ int __init jbd2_journal_init_transaction_cache(void)
>  
>  void jbd2_journal_destroy_transaction_cache(void)
>  {
> -	if (transaction_cache) {
> -		kmem_cache_destroy(transaction_cache);
> -		transaction_cache = NULL;
> -	}
> +	kmem_cache_destroy(transaction_cache);
> +	transaction_cache = NULL;
>  }
>  
>  void jbd2_journal_free_transaction(transaction_t *transaction)
> -- 
> 1.8.3.1
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR