Re: [PATCH v2 4/5] xfs: Support large pages

From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: linux-fsdevel@vger.kernel.org, hch@lst.de,
	linux-xfs@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v2 4/5] xfs: Support large pages
Date: Wed, 18 Sep 2019 14:31:08 -0700	[thread overview]
Message-ID: <20190918213108.GE2229799@magnolia> (raw)
In-Reply-To: <20190821003039.12555-5-willy@infradead.org>

On Tue, Aug 20, 2019 at 05:30:38PM -0700, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> Mostly this is just checking the page size of each page instead of
> assuming PAGE_SIZE.  Clean up the logic in writepage a little.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Looks ok, let's see what happens when I get back to the "make xfs use
iomap writeback" series...

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  fs/xfs/xfs_aops.c | 19 +++++++++----------
>  1 file changed, 9 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> index 102cfd8a97d6..1a26e9ca626b 100644
> --- a/fs/xfs/xfs_aops.c
> +++ b/fs/xfs/xfs_aops.c
> @@ -765,7 +765,7 @@ xfs_add_to_ioend(
>  	struct xfs_mount	*mp = ip->i_mount;
>  	struct block_device	*bdev = xfs_find_bdev_for_inode(inode);
>  	unsigned		len = i_blocksize(inode);
> -	unsigned		poff = offset & (PAGE_SIZE - 1);
> +	unsigned		poff = offset & (page_size(page) - 1);
>  	bool			merged, same_page = false;
>  	sector_t		sector;
>  
> @@ -843,7 +843,7 @@ xfs_aops_discard_page(
>  	if (error && !XFS_FORCED_SHUTDOWN(mp))
>  		xfs_alert(mp, "page discard unable to remove delalloc mapping.");
>  out_invalidate:
> -	xfs_vm_invalidatepage(page, 0, PAGE_SIZE);
> +	xfs_vm_invalidatepage(page, 0, page_size(page));
>  }
>  
>  /*
> @@ -984,8 +984,7 @@ xfs_do_writepage(
>  	struct xfs_writepage_ctx *wpc = data;
>  	struct inode		*inode = page->mapping->host;
>  	loff_t			offset;
> -	uint64_t              end_offset;
> -	pgoff_t                 end_index;
> +	uint64_t		end_offset;
>  
>  	trace_xfs_writepage(inode, page, 0, 0);
>  
> @@ -1024,10 +1023,9 @@ xfs_do_writepage(
>  	 * ---------------------------------^------------------|
>  	 */
>  	offset = i_size_read(inode);
> -	end_index = offset >> PAGE_SHIFT;
> -	if (page->index < end_index)
> -		end_offset = (xfs_off_t)(page->index + 1) << PAGE_SHIFT;
> -	else {
> +	end_offset = file_offset_of_next_page(page);
> +
> +	if (end_offset > offset) {
>  		/*
>  		 * Check whether the page to write out is beyond or straddles
>  		 * i_size or not.
> @@ -1039,7 +1037,8 @@ xfs_do_writepage(
>  		 * |				    |      Straddles     |
>  		 * ---------------------------------^-----------|--------|
>  		 */
> -		unsigned offset_into_page = offset & (PAGE_SIZE - 1);
> +		unsigned offset_into_page = offset_in_this_page(page, offset);
> +		pgoff_t end_index = offset >> PAGE_SHIFT;
>  
>  		/*
>  		 * Skip the page if it is fully outside i_size, e.g. due to a
> @@ -1070,7 +1069,7 @@ xfs_do_writepage(
>  		 * memory is zeroed when mapped, and writes to that region are
>  		 * not written out to the file."
>  		 */
> -		zero_user_segment(page, offset_into_page, PAGE_SIZE);
> +		zero_user_segment(page, offset_into_page, page_size(page));
>  
>  		/* Adjust the end_offset to the end of file */
>  		end_offset = offset;
> -- 
> 2.23.0.rc1
> 