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Date:   Mon, 7 Jun 2021 17:50:06 +0200
From:   Jan Kara <jack@suse.cz>
To:     Zhang Yi <yi.zhang@huawei.com>
Cc:     linux-ext4@vger.kernel.org, tytso@mit.edu,
        adilger.kernel@dilger.ca, jack@suse.cz, yukuai3@huawei.com
Subject: Re: [RFC PATCH v3 6/8] jbd2: simplify journal_clean_one_cp_list()
Message-ID: <20210607155006.GB29326@quack2.suse.cz>
References: <20210527135641.420514-1-yi.zhang@huawei.com>
 <20210527135641.420514-7-yi.zhang@huawei.com>
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On Thu 27-05-21 21:56:39, Zhang Yi wrote:
> Now that __try_to_free_cp_buf() remove checkpointed buffer or transaction
> when the buffer is not 'busy', which is only called by
> journal_clean_one_cp_list(). This patch simplify this function by remove
> __try_to_free_cp_buf() and invoke __cp_buffer_busy() directly.
> 
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Looks good! Feel free to add:

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

								Honza


> ---
>  fs/jbd2/checkpoint.c | 30 ++++--------------------------
>  1 file changed, 4 insertions(+), 26 deletions(-)
> 
> diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
> index 727389185d24..7dea46cc7099 100644
> --- a/fs/jbd2/checkpoint.c
> +++ b/fs/jbd2/checkpoint.c
> @@ -91,25 +91,6 @@ static inline bool __cp_buffer_busy(struct journal_head *jh)
>  	return (jh->b_transaction || buffer_locked(bh) || buffer_dirty(bh));
>  }
>  
> -/*
> - * Try to release a checkpointed buffer from its transaction.
> - * Returns 1 if we released it and 2 if we also released the
> - * whole transaction.
> - *
> - * Requires j_list_lock
> - */
> -static int __try_to_free_cp_buf(struct journal_head *jh)
> -{
> -	int ret = 0;
> -	struct buffer_head *bh = jh2bh(jh);
> -
> -	if (!jh->b_transaction && !buffer_locked(bh) && !buffer_dirty(bh)) {
> -		JBUFFER_TRACE(jh, "remove from checkpoint list");
> -		ret = __jbd2_journal_remove_checkpoint(jh) + 1;
> -	}
> -	return ret;
> -}
> -
>  /*
>   * __jbd2_log_wait_for_space: wait until there is space in the journal.
>   *
> @@ -444,7 +425,6 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
>  {
>  	struct journal_head *last_jh;
>  	struct journal_head *next_jh = jh;
> -	int ret;
>  
>  	if (!jh)
>  		return 0;
> @@ -453,13 +433,11 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
>  	do {
>  		jh = next_jh;
>  		next_jh = jh->b_cpnext;
> -		if (!destroy)
> -			ret = __try_to_free_cp_buf(jh);
> -		else
> -			ret = __jbd2_journal_remove_checkpoint(jh) + 1;
> -		if (!ret)
> +
> +		if (!destroy && __cp_buffer_busy(jh))
>  			return 0;
> -		if (ret == 2)
> +
> +		if (__jbd2_journal_remove_checkpoint(jh))
>  			return 1;
>  		/*
>  		 * This function only frees up some memory
> -- 
> 2.25.4
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR