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From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>,
	linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 14/19] xfs: split out a new set of read-only iomap ops
Date: Wed, 18 Sep 2019 10:56:28 -0700
Message-ID: <20190918175628.GG2229799@magnolia> (raw)
In-Reply-To: <20190909182722.16783-15-hch@lst.de>

On Mon, Sep 09, 2019 at 08:27:17PM +0200, Christoph Hellwig wrote:
> Start untangling xfs_file_iomap_begin by splitting out the read-only
> case into its own set of iomap_ops with a very simply iomap_begin
> helper.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

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

--D

> ---
>  fs/xfs/xfs_aops.c  |  9 ++++---
>  fs/xfs/xfs_file.c  |  8 +++---
>  fs/xfs/xfs_iomap.c | 61 ++++++++++++++++++++++++++++++++++------------
>  fs/xfs/xfs_iomap.h |  1 +
>  fs/xfs/xfs_iops.c  |  2 +-
>  5 files changed, 58 insertions(+), 23 deletions(-)
> 
> diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> index 4e4a4d7df5ac..fe47a4d52247 100644
> --- a/fs/xfs/xfs_aops.c
> +++ b/fs/xfs/xfs_aops.c
> @@ -1158,7 +1158,7 @@ xfs_vm_bmap(
>  	 */
>  	if (xfs_is_cow_inode(ip) || XFS_IS_REALTIME_INODE(ip))
>  		return 0;
> -	return iomap_bmap(mapping, block, &xfs_iomap_ops);
> +	return iomap_bmap(mapping, block, &xfs_read_iomap_ops);
>  }
>  
>  STATIC int
> @@ -1167,7 +1167,7 @@ xfs_vm_readpage(
>  	struct page		*page)
>  {
>  	trace_xfs_vm_readpage(page->mapping->host, 1);
> -	return iomap_readpage(page, &xfs_iomap_ops);
> +	return iomap_readpage(page, &xfs_read_iomap_ops);
>  }
>  
>  STATIC int
> @@ -1178,7 +1178,7 @@ xfs_vm_readpages(
>  	unsigned		nr_pages)
>  {
>  	trace_xfs_vm_readpages(mapping->host, nr_pages);
> -	return iomap_readpages(mapping, pages, nr_pages, &xfs_iomap_ops);
> +	return iomap_readpages(mapping, pages, nr_pages, &xfs_read_iomap_ops);
>  }
>  
>  static int
> @@ -1188,7 +1188,8 @@ xfs_iomap_swapfile_activate(
>  	sector_t			*span)
>  {
>  	sis->bdev = xfs_find_bdev_for_inode(file_inode(swap_file));
> -	return iomap_swapfile_activate(sis, swap_file, span, &xfs_iomap_ops);
> +	return iomap_swapfile_activate(sis, swap_file, span,
> +			&xfs_read_iomap_ops);
>  }
>  
>  const struct address_space_operations xfs_address_space_operations = {
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 21bd3d575aaa..d8e2e36b84f7 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -187,7 +187,7 @@ xfs_file_dio_aio_read(
>  	file_accessed(iocb->ki_filp);
>  
>  	xfs_ilock(ip, XFS_IOLOCK_SHARED);
> -	ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL);
> +	ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL);
>  	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
>  
>  	return ret;
> @@ -214,7 +214,7 @@ xfs_file_dax_read(
>  		xfs_ilock(ip, XFS_IOLOCK_SHARED);
>  	}
>  
> -	ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
> +	ret = dax_iomap_rw(iocb, to, &xfs_read_iomap_ops);
>  	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
>  
>  	file_accessed(iocb->ki_filp);
> @@ -1131,7 +1131,9 @@ __xfs_filemap_fault(
>  	if (IS_DAX(inode)) {
>  		pfn_t pfn;
>  
> -		ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL, &xfs_iomap_ops);
> +		ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL,
> +				(write_fault && !vmf->cow_page) ?
> +				 &xfs_iomap_ops : &xfs_read_iomap_ops);
>  		if (ret & VM_FAULT_NEEDDSYNC)
>  			ret = dax_finish_sync_fault(vmf, pe_size, pfn);
>  	} else {
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index 0ba67a8d8169..d0ed0cba9041 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -950,11 +950,13 @@ xfs_file_iomap_begin(
>  	u16			iomap_flags = 0;
>  	unsigned		lockmode;
>  
> +	ASSERT(flags & (IOMAP_WRITE | IOMAP_ZERO));
> +
>  	if (XFS_FORCED_SHUTDOWN(mp))
>  		return -EIO;
>  
> -	if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && !(flags & IOMAP_DIRECT) &&
> -			!IS_DAX(inode) && !xfs_get_extsz_hint(ip)) {
> +	if (!(flags & IOMAP_DIRECT) && !IS_DAX(inode) &&
> +	    !xfs_get_extsz_hint(ip)) {
>  		/* Reserve delalloc blocks for regular writeback. */
>  		return xfs_file_iomap_begin_delay(inode, offset, length, flags,
>  				iomap, srcmap);
> @@ -975,17 +977,6 @@ xfs_file_iomap_begin(
>  	if (error)
>  		goto out_unlock;
>  
> -	if (flags & IOMAP_REPORT) {
> -		/* Trim the mapping to the nearest shared extent boundary. */
> -		error = xfs_reflink_trim_around_shared(ip, &imap, &shared);
> -		if (error)
> -			goto out_unlock;
> -	}
> -
> -	/* Non-modifying mapping requested, so we are done */
> -	if (!(flags & (IOMAP_WRITE | IOMAP_ZERO)))
> -		goto out_found;
> -
>  	/*
>  	 * Break shared extents if necessary. Checks for non-blocking IO have
>  	 * been done up front, so we don't need to do them here.
> @@ -1046,8 +1037,6 @@ xfs_file_iomap_begin(
>  	trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap);
>  
>  out_finish:
> -	if (shared)
> -		iomap_flags |= IOMAP_F_SHARED;
>  	return xfs_bmbt_to_iomap(ip, iomap, &imap, iomap_flags);
>  
>  out_found:
> @@ -1150,6 +1139,48 @@ const struct iomap_ops xfs_iomap_ops = {
>  	.iomap_end		= xfs_file_iomap_end,
>  };
>  
> +static int
> +xfs_read_iomap_begin(
> +	struct inode		*inode,
> +	loff_t			offset,
> +	loff_t			length,
> +	unsigned		flags,
> +	struct iomap		*iomap,
> +	struct iomap		*srcmap)
> +{
> +	struct xfs_inode	*ip = XFS_I(inode);
> +	struct xfs_mount	*mp = ip->i_mount;
> +	struct xfs_bmbt_irec	imap;
> +	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
> +	xfs_fileoff_t		end_fsb = xfs_iomap_end_fsb(mp, offset, length);
> +	int			nimaps = 1, error = 0;
> +	bool			shared = false;
> +	unsigned		lockmode;
> +
> +	ASSERT(!(flags & (IOMAP_WRITE | IOMAP_ZERO)));
> +
> +	if (XFS_FORCED_SHUTDOWN(mp))
> +		return -EIO;
> +
> +	error = xfs_ilock_for_iomap(ip, flags, &lockmode);
> +	if (error)
> +		return error;
> +	error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
> +			       &nimaps, 0);
> +	if (!error && (flags & IOMAP_REPORT))
> +		error = xfs_reflink_trim_around_shared(ip, &imap, &shared);
> +	xfs_iunlock(ip, lockmode);
> +
> +	if (error)
> +		return error;
> +	trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);
> +	return xfs_bmbt_to_iomap(ip, iomap, &imap, shared ? IOMAP_F_SHARED : 0);
> +}
> +
> +const struct iomap_ops xfs_read_iomap_ops = {
> +	.iomap_begin		= xfs_read_iomap_begin,
> +};
> +
>  static int
>  xfs_seek_iomap_begin(
>  	struct inode		*inode,
> diff --git a/fs/xfs/xfs_iomap.h b/fs/xfs/xfs_iomap.h
> index 71d0ae460c44..61b1fc3e5143 100644
> --- a/fs/xfs/xfs_iomap.h
> +++ b/fs/xfs/xfs_iomap.h
> @@ -40,6 +40,7 @@ xfs_aligned_fsb_count(
>  }
>  
>  extern const struct iomap_ops xfs_iomap_ops;
> +extern const struct iomap_ops xfs_read_iomap_ops;
>  extern const struct iomap_ops xfs_seek_iomap_ops;
>  extern const struct iomap_ops xfs_xattr_iomap_ops;
>  
> diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> index ff3c1fae5357..f0c7df82e18b 100644
> --- a/fs/xfs/xfs_iops.c
> +++ b/fs/xfs/xfs_iops.c
> @@ -1113,7 +1113,7 @@ xfs_vn_fiemap(
>  				&xfs_xattr_iomap_ops);
>  	} else {
>  		error = iomap_fiemap(inode, fieinfo, start, length,
> -				&xfs_iomap_ops);
> +				&xfs_read_iomap_ops);
>  	}
>  	xfs_iunlock(XFS_I(inode), XFS_IOLOCK_SHARED);
>  
> -- 
> 2.20.1
> 

  reply index

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-09 18:27 iomap and xfs COW cleanups Christoph Hellwig
2019-09-09 18:27 ` [PATCH 01/19] iomap: better document the IOMAP_F_* flags Christoph Hellwig
2019-09-14  0:42   ` Allison Collins
2019-09-16 18:08   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 02/19] iomap: remove the unused iomap argument to __iomap_write_end Christoph Hellwig
2019-09-14  0:42   ` Allison Collins
2019-09-16 18:10   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 03/19] iomap: always use AOP_FLAG_NOFS in iomap_write_begin Christoph Hellwig
2019-09-16 18:11   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 04/19] iomap: ignore non-shared or non-data blocks in xfs_file_dirty Christoph Hellwig
2019-09-16 18:12   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 05/19] iomap: move the zeroing case out of iomap_read_page_sync Christoph Hellwig
2019-09-16 18:17   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 06/19] iomap: use write_begin to read pages to unshare Christoph Hellwig
2019-09-16 18:34   ` Darrick J. Wong
2019-09-30 11:07     ` Christoph Hellwig
2019-10-08 15:12       ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 07/19] iomap: use a srcmap for a read-modify-write I/O Christoph Hellwig
2019-09-10 12:48   ` Goldwyn Rodrigues
2019-09-10 14:39     ` hch
2019-09-16 17:57       ` Darrick J. Wong
2019-09-16 18:42   ` Darrick J. Wong
2019-09-18 18:15     ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 08/19] xfs: also call xfs_file_iomap_end_delalloc for zeroing operations Christoph Hellwig
2019-09-18 17:09   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 09/19] xfs: remove xfs_reflink_dirty_extents Christoph Hellwig
2019-09-18 17:17   ` Darrick J. Wong
2019-09-18 17:25     ` Christoph Hellwig
2019-09-18 17:31       ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 10/19] xfs: pass two imaps to xfs_reflink_allocate_cow Christoph Hellwig
2019-09-18 17:26   ` Darrick J. Wong
2019-09-30 11:10     ` Christoph Hellwig
2019-09-09 18:27 ` [PATCH 11/19] xfs: refactor xfs_file_iomap_begin_delay Christoph Hellwig
2019-09-18 17:30   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 12/19] xfs: fill out the srcmap in iomap_begin Christoph Hellwig
2019-09-18 17:52   ` Darrick J. Wong
2019-10-01  6:26     ` Christoph Hellwig
2019-09-09 18:27 ` [PATCH 13/19] xfs: factor out a helper to calculate the end_fsb Christoph Hellwig
2019-09-14  0:42   ` Allison Collins
2019-09-18 17:55   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 14/19] xfs: split out a new set of read-only iomap ops Christoph Hellwig
2019-09-18 17:56   ` Darrick J. Wong [this message]
2019-09-09 18:27 ` [PATCH 15/19] xfs: move xfs_file_iomap_begin_delay around Christoph Hellwig
2019-09-18 17:59   ` Darrick J. Wong
2019-09-30 11:14     ` Christoph Hellwig
2019-09-09 18:27 ` [PATCH 16/19] xfs: split the iomap ops for buffered vs direct writes Christoph Hellwig
2019-09-18 18:00   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 17/19] xfs: rename the whichfork variable in xfs_buffered_write_iomap_begin Christoph Hellwig
2019-09-14  0:42   ` Allison Collins
2019-09-18 18:00   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 18/19] xfs: cleanup xfs_iomap_write_unwritten Christoph Hellwig
2019-09-18 18:06   ` Darrick J. Wong
2019-09-09 18:27 ` [PATCH 19/19] xfs: improve the IOMAP_NOWAIT check for COW inodes Christoph Hellwig
2019-09-18 18:09   ` Darrick J. Wong

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