linux-ext4 - Re: [PATCH] ext4: remove redundant check buffer

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Message-ID: <20210426050545.m3fbtlwdf32lgqvu@riteshh-domain>
Date:   Mon, 26 Apr 2021 10:35:45 +0530
From:   riteshh <riteshh@...ux.ibm.com>
To:     Joseph Qi <joseph.qi@...ux.alibaba.com>
Cc:     tytso@....edu, adilger.kernel@...ger.ca, linux-ext4@...r.kernel.org
Subject: Re: [PATCH] ext4: remove redundant check buffer_uptodate()

On 21/04/26 11:23AM, Joseph Qi wrote:
> Now set_buffer_uptodate() will test first and then set, so we don't have
> to check buffer_uptodate() first, remove it to simplify code.

Maybe we can change below function as well then.
No need to check same thing twice since set_buffer_uptodate() is already doing
the check.
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index b258e8279266..856bd9981409 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3749,7 +3749,7 @@ static inline int ext4_buffer_uptodate(struct buffer_head *bh)
         * have to read the block because we may read the old data
         * successfully.
         */
-       if (!buffer_uptodate(bh) && buffer_write_io_error(bh))
+       if (buffer_write_io_error(bh))
                set_buffer_uptodate(bh);
        return buffer_uptodate(bh);
 }

With that pls feel free to add:
Reviewed-by: Ritesh Harjani <riteshh@...ux.ibm.com>

>
> Signed-off-by: Joseph Qi <joseph.qi@...ux.alibaba.com>
> ---
>  fs/ext4/inode.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 0948a43..9e02538 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -1065,10 +1065,8 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
>  	    block++, block_start = block_end, bh = bh->b_this_page) {
>  		block_end = block_start + blocksize;
>  		if (block_end <= from || block_start >= to) {
> -			if (PageUptodate(page)) {
> -				if (!buffer_uptodate(bh))
> -					set_buffer_uptodate(bh);
> -			}
> +			if (PageUptodate(page))
> +				set_buffer_uptodate(bh);
>  			continue;
>  		}
>  		if (buffer_new(bh))
> @@ -1092,8 +1090,7 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
>  			}
>  		}
>  		if (PageUptodate(page)) {
> -			if (!buffer_uptodate(bh))
> -				set_buffer_uptodate(bh);
> +			set_buffer_uptodate(bh);
>  			continue;
>  		}
>  		if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
> --
> 1.8.3.1
>