linux-kernel - Re: [PATCH 2/3] iomap: Use bitmap ops to set uptodate bits

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 22 Aug 2020 06:59:47 +0100
From:   Christoph Hellwig <hch@...radead.org>
To:     "Matthew Wilcox (Oracle)" <willy@...radead.org>
Cc:     Yu Kuai <yukuai3@...wei.com>, hch@...radead.org,
        darrick.wong@...cle.com, david@...morbit.com,
        linux-xfs@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org, yi.zhang@...wei.com
Subject: Re: [PATCH 2/3] iomap: Use bitmap ops to set uptodate bits

On Fri, Aug 21, 2020 at 01:46:05PM +0100, Matthew Wilcox (Oracle) wrote:
> Now that the bitmap is protected by a spinlock, we can use the
> more efficient bitmap ops instead of individual test/set bit ops.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
> ---
>  fs/iomap/buffered-io.c | 12 ++----------
>  1 file changed, 2 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 639d54a4177e..dbf9572dabe9 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -134,19 +134,11 @@ iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len)
>  	struct inode *inode = page->mapping->host;
>  	unsigned first = off >> inode->i_blkbits;
>  	unsigned last = (off + len - 1) >> inode->i_blkbits;
> -	bool uptodate = true;
>  	unsigned long flags;
> -	unsigned int i;
>  
>  	spin_lock_irqsave(&iop->uptodate_lock, flags);
> -	for (i = 0; i < i_blocks_per_page(inode, page); i++) {
> -		if (i >= first && i <= last)
> -			set_bit(i, iop->uptodate);
> -		else if (!test_bit(i, iop->uptodate))
> -			uptodate = false;
> -	}
> -
> -	if (uptodate)
> +	bitmap_set(iop->uptodate, first, last - first + 1);
> +	if (bitmap_full(iop->uptodate, i_blocks_per_page(inode, page)))
>  		SetPageUptodate(page);
>  	spin_unlock_irqrestore(&iop->uptodate_lock, flags);

Can you respin this to be based on current Linus' tree without
i_blocks_per_page?  With that it looks good:

Reviewed-by: Christoph Hellwig <hch@....de>