diff mbox series

[13/19] xfs: factor out a helper to calculate the end_fsb

Message ID 20190909182722.16783-14-hch@lst.de (mailing list archive)
State Superseded, archived
Headers show
Series [01/19] iomap: better document the IOMAP_F_* flags | expand

Commit Message

Christoph Hellwig Sept. 9, 2019, 6:27 p.m. UTC
We have lots of places that want to calculate the final fsb for
a offset + count in bytes and check that the result fits into
s_maxbytes.  Factor out a helper for that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_iomap.c | 40 ++++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 20 deletions(-)

Comments

Allison Henderson Sept. 14, 2019, 12:42 a.m. UTC | #1
Looks Ok to me:
Reviewed-by: Allison Collins <allison.henderson@oracle.com>

On 9/9/19 11:27 AM, Christoph Hellwig wrote:
> We have lots of places that want to calculate the final fsb for
> a offset + count in bytes and check that the result fits into
> s_maxbytes.  Factor out a helper for that.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   fs/xfs/xfs_iomap.c | 40 ++++++++++++++++++++--------------------
>   1 file changed, 20 insertions(+), 20 deletions(-)
> 
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index d12eacdc9bba..0ba67a8d8169 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -102,6 +102,17 @@ xfs_hole_to_iomap(
>   	iomap->dax_dev = xfs_find_daxdev_for_inode(VFS_I(ip));
>   }
>   
> +static inline xfs_fileoff_t
> +xfs_iomap_end_fsb(
> +	struct xfs_mount	*mp,
> +	loff_t			offset,
> +	loff_t			count)
> +{
> +	ASSERT(offset <= mp->m_super->s_maxbytes);
> +	return min(XFS_B_TO_FSB(mp, offset + count),
> +		   XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
> +}
> +
>   xfs_extlen_t
>   xfs_eof_alignment(
>   	struct xfs_inode	*ip,
> @@ -172,8 +183,8 @@ xfs_iomap_write_direct(
>   	int		nmaps)
>   {
>   	xfs_mount_t	*mp = ip->i_mount;
> -	xfs_fileoff_t	offset_fsb;
> -	xfs_fileoff_t	last_fsb;
> +	xfs_fileoff_t	offset_fsb = XFS_B_TO_FSBT(mp, offset);
> +	xfs_fileoff_t	last_fsb = xfs_iomap_end_fsb(mp, offset, count);
>   	xfs_filblks_t	count_fsb, resaligned;
>   	xfs_extlen_t	extsz;
>   	int		nimaps;
> @@ -192,8 +203,6 @@ xfs_iomap_write_direct(
>   
>   	ASSERT(xfs_isilocked(ip, lockmode));
>   
> -	offset_fsb = XFS_B_TO_FSBT(mp, offset);
> -	last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
>   	if ((offset + count) > XFS_ISIZE(ip)) {
>   		/*
>   		 * Assert that the in-core extent list is present since this can
> @@ -533,9 +542,7 @@ xfs_file_iomap_begin_delay(
>   	struct xfs_inode	*ip = XFS_I(inode);
>   	struct xfs_mount	*mp = ip->i_mount;
>   	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
> -	xfs_fileoff_t		maxbytes_fsb =
> -		XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
> -	xfs_fileoff_t		end_fsb;
> +	xfs_fileoff_t		end_fsb = xfs_iomap_end_fsb(mp, offset, count);
>   	struct xfs_bmbt_irec	imap, cmap;
>   	struct xfs_iext_cursor	icur, ccur;
>   	xfs_fsblock_t		prealloc_blocks = 0;
> @@ -565,8 +572,6 @@ xfs_file_iomap_begin_delay(
>   			goto out_unlock;
>   	}
>   
> -	end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
> -
>   	/*
>   	 * Search the data fork fork first to look up our source mapping.  We
>   	 * always need the data fork map, as we have to return it to the
> @@ -648,7 +653,7 @@ xfs_file_iomap_begin_delay(
>   		 * the lower level functions are updated.
>   		 */
>   		count = min_t(loff_t, count, 1024 * PAGE_SIZE);
> -		end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
> +		end_fsb = xfs_iomap_end_fsb(mp, offset, count);
>   
>   		if (xfs_is_always_cow_inode(ip))
>   			whichfork = XFS_COW_FORK;
> @@ -674,7 +679,8 @@ xfs_file_iomap_begin_delay(
>   			if (align)
>   				p_end_fsb = roundup_64(p_end_fsb, align);
>   
> -			p_end_fsb = min(p_end_fsb, maxbytes_fsb);
> +			p_end_fsb = min(p_end_fsb,
> +				XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
>   			ASSERT(p_end_fsb > offset_fsb);
>   			prealloc_blocks = p_end_fsb - end_fsb;
>   		}
> @@ -937,7 +943,8 @@ xfs_file_iomap_begin(
>   	struct xfs_inode	*ip = XFS_I(inode);
>   	struct xfs_mount	*mp = ip->i_mount;
>   	struct xfs_bmbt_irec	imap, cmap;
> -	xfs_fileoff_t		offset_fsb, end_fsb;
> +	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;
>   	u16			iomap_flags = 0;
> @@ -963,12 +970,6 @@ xfs_file_iomap_begin(
>   	if (error)
>   		return error;
>   
> -	ASSERT(offset <= mp->m_super->s_maxbytes);
> -	if (offset > mp->m_super->s_maxbytes - length)
> -		length = mp->m_super->s_maxbytes - offset;
> -	offset_fsb = XFS_B_TO_FSBT(mp, offset);
> -	end_fsb = XFS_B_TO_FSB(mp, offset + length);
> -
>   	error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
>   			       &nimaps, 0);
>   	if (error)
> @@ -1189,8 +1190,7 @@ xfs_seek_iomap_begin(
>   		/*
>   		 * Fake a hole until the end of the file.
>   		 */
> -		data_fsb = min(XFS_B_TO_FSB(mp, offset + length),
> -			       XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
> +		data_fsb = xfs_iomap_end_fsb(mp, offset, length);
>   	}
>   
>   	/*
>
Darrick J. Wong Sept. 18, 2019, 5:55 p.m. UTC | #2
On Mon, Sep 09, 2019 at 08:27:16PM +0200, Christoph Hellwig wrote:
> We have lots of places that want to calculate the final fsb for
> a offset + count in bytes and check that the result fits into
> s_maxbytes.  Factor out a helper for that.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_iomap.c | 40 ++++++++++++++++++++--------------------
>  1 file changed, 20 insertions(+), 20 deletions(-)
> 
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index d12eacdc9bba..0ba67a8d8169 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -102,6 +102,17 @@ xfs_hole_to_iomap(
>  	iomap->dax_dev = xfs_find_daxdev_for_inode(VFS_I(ip));
>  }
>  
> +static inline xfs_fileoff_t
> +xfs_iomap_end_fsb(

I wonder if this function ought to have a comment that it returns the
offset block number of offset + count clamped to the highest offset
supported by the page cache, but ... eh.

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

--D

> +	struct xfs_mount	*mp,
> +	loff_t			offset,
> +	loff_t			count)
> +{
> +	ASSERT(offset <= mp->m_super->s_maxbytes);
> +	return min(XFS_B_TO_FSB(mp, offset + count),
> +		   XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
> +}
> +
>  xfs_extlen_t
>  xfs_eof_alignment(
>  	struct xfs_inode	*ip,
> @@ -172,8 +183,8 @@ xfs_iomap_write_direct(
>  	int		nmaps)
>  {
>  	xfs_mount_t	*mp = ip->i_mount;
> -	xfs_fileoff_t	offset_fsb;
> -	xfs_fileoff_t	last_fsb;
> +	xfs_fileoff_t	offset_fsb = XFS_B_TO_FSBT(mp, offset);
> +	xfs_fileoff_t	last_fsb = xfs_iomap_end_fsb(mp, offset, count);
>  	xfs_filblks_t	count_fsb, resaligned;
>  	xfs_extlen_t	extsz;
>  	int		nimaps;
> @@ -192,8 +203,6 @@ xfs_iomap_write_direct(
>  
>  	ASSERT(xfs_isilocked(ip, lockmode));
>  
> -	offset_fsb = XFS_B_TO_FSBT(mp, offset);
> -	last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
>  	if ((offset + count) > XFS_ISIZE(ip)) {
>  		/*
>  		 * Assert that the in-core extent list is present since this can
> @@ -533,9 +542,7 @@ xfs_file_iomap_begin_delay(
>  	struct xfs_inode	*ip = XFS_I(inode);
>  	struct xfs_mount	*mp = ip->i_mount;
>  	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
> -	xfs_fileoff_t		maxbytes_fsb =
> -		XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
> -	xfs_fileoff_t		end_fsb;
> +	xfs_fileoff_t		end_fsb = xfs_iomap_end_fsb(mp, offset, count);
>  	struct xfs_bmbt_irec	imap, cmap;
>  	struct xfs_iext_cursor	icur, ccur;
>  	xfs_fsblock_t		prealloc_blocks = 0;
> @@ -565,8 +572,6 @@ xfs_file_iomap_begin_delay(
>  			goto out_unlock;
>  	}
>  
> -	end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
> -
>  	/*
>  	 * Search the data fork fork first to look up our source mapping.  We
>  	 * always need the data fork map, as we have to return it to the
> @@ -648,7 +653,7 @@ xfs_file_iomap_begin_delay(
>  		 * the lower level functions are updated.
>  		 */
>  		count = min_t(loff_t, count, 1024 * PAGE_SIZE);
> -		end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
> +		end_fsb = xfs_iomap_end_fsb(mp, offset, count);
>  
>  		if (xfs_is_always_cow_inode(ip))
>  			whichfork = XFS_COW_FORK;
> @@ -674,7 +679,8 @@ xfs_file_iomap_begin_delay(
>  			if (align)
>  				p_end_fsb = roundup_64(p_end_fsb, align);
>  
> -			p_end_fsb = min(p_end_fsb, maxbytes_fsb);
> +			p_end_fsb = min(p_end_fsb,
> +				XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
>  			ASSERT(p_end_fsb > offset_fsb);
>  			prealloc_blocks = p_end_fsb - end_fsb;
>  		}
> @@ -937,7 +943,8 @@ xfs_file_iomap_begin(
>  	struct xfs_inode	*ip = XFS_I(inode);
>  	struct xfs_mount	*mp = ip->i_mount;
>  	struct xfs_bmbt_irec	imap, cmap;
> -	xfs_fileoff_t		offset_fsb, end_fsb;
> +	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;
>  	u16			iomap_flags = 0;
> @@ -963,12 +970,6 @@ xfs_file_iomap_begin(
>  	if (error)
>  		return error;
>  
> -	ASSERT(offset <= mp->m_super->s_maxbytes);
> -	if (offset > mp->m_super->s_maxbytes - length)
> -		length = mp->m_super->s_maxbytes - offset;
> -	offset_fsb = XFS_B_TO_FSBT(mp, offset);
> -	end_fsb = XFS_B_TO_FSB(mp, offset + length);
> -
>  	error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
>  			       &nimaps, 0);
>  	if (error)
> @@ -1189,8 +1190,7 @@ xfs_seek_iomap_begin(
>  		/*
>  		 * Fake a hole until the end of the file.
>  		 */
> -		data_fsb = min(XFS_B_TO_FSB(mp, offset + length),
> -			       XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
> +		data_fsb = xfs_iomap_end_fsb(mp, offset, length);
>  	}
>  
>  	/*
> -- 
> 2.20.1
>
diff mbox series

Patch

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index d12eacdc9bba..0ba67a8d8169 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -102,6 +102,17 @@  xfs_hole_to_iomap(
 	iomap->dax_dev = xfs_find_daxdev_for_inode(VFS_I(ip));
 }
 
+static inline xfs_fileoff_t
+xfs_iomap_end_fsb(
+	struct xfs_mount	*mp,
+	loff_t			offset,
+	loff_t			count)
+{
+	ASSERT(offset <= mp->m_super->s_maxbytes);
+	return min(XFS_B_TO_FSB(mp, offset + count),
+		   XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
+}
+
 xfs_extlen_t
 xfs_eof_alignment(
 	struct xfs_inode	*ip,
@@ -172,8 +183,8 @@  xfs_iomap_write_direct(
 	int		nmaps)
 {
 	xfs_mount_t	*mp = ip->i_mount;
-	xfs_fileoff_t	offset_fsb;
-	xfs_fileoff_t	last_fsb;
+	xfs_fileoff_t	offset_fsb = XFS_B_TO_FSBT(mp, offset);
+	xfs_fileoff_t	last_fsb = xfs_iomap_end_fsb(mp, offset, count);
 	xfs_filblks_t	count_fsb, resaligned;
 	xfs_extlen_t	extsz;
 	int		nimaps;
@@ -192,8 +203,6 @@  xfs_iomap_write_direct(
 
 	ASSERT(xfs_isilocked(ip, lockmode));
 
-	offset_fsb = XFS_B_TO_FSBT(mp, offset);
-	last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
 	if ((offset + count) > XFS_ISIZE(ip)) {
 		/*
 		 * Assert that the in-core extent list is present since this can
@@ -533,9 +542,7 @@  xfs_file_iomap_begin_delay(
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
 	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
-	xfs_fileoff_t		maxbytes_fsb =
-		XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
-	xfs_fileoff_t		end_fsb;
+	xfs_fileoff_t		end_fsb = xfs_iomap_end_fsb(mp, offset, count);
 	struct xfs_bmbt_irec	imap, cmap;
 	struct xfs_iext_cursor	icur, ccur;
 	xfs_fsblock_t		prealloc_blocks = 0;
@@ -565,8 +572,6 @@  xfs_file_iomap_begin_delay(
 			goto out_unlock;
 	}
 
-	end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
-
 	/*
 	 * Search the data fork fork first to look up our source mapping.  We
 	 * always need the data fork map, as we have to return it to the
@@ -648,7 +653,7 @@  xfs_file_iomap_begin_delay(
 		 * the lower level functions are updated.
 		 */
 		count = min_t(loff_t, count, 1024 * PAGE_SIZE);
-		end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
+		end_fsb = xfs_iomap_end_fsb(mp, offset, count);
 
 		if (xfs_is_always_cow_inode(ip))
 			whichfork = XFS_COW_FORK;
@@ -674,7 +679,8 @@  xfs_file_iomap_begin_delay(
 			if (align)
 				p_end_fsb = roundup_64(p_end_fsb, align);
 
-			p_end_fsb = min(p_end_fsb, maxbytes_fsb);
+			p_end_fsb = min(p_end_fsb,
+				XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
 			ASSERT(p_end_fsb > offset_fsb);
 			prealloc_blocks = p_end_fsb - end_fsb;
 		}
@@ -937,7 +943,8 @@  xfs_file_iomap_begin(
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_bmbt_irec	imap, cmap;
-	xfs_fileoff_t		offset_fsb, end_fsb;
+	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;
 	u16			iomap_flags = 0;
@@ -963,12 +970,6 @@  xfs_file_iomap_begin(
 	if (error)
 		return error;
 
-	ASSERT(offset <= mp->m_super->s_maxbytes);
-	if (offset > mp->m_super->s_maxbytes - length)
-		length = mp->m_super->s_maxbytes - offset;
-	offset_fsb = XFS_B_TO_FSBT(mp, offset);
-	end_fsb = XFS_B_TO_FSB(mp, offset + length);
-
 	error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
 			       &nimaps, 0);
 	if (error)
@@ -1189,8 +1190,7 @@  xfs_seek_iomap_begin(
 		/*
 		 * Fake a hole until the end of the file.
 		 */
-		data_fsb = min(XFS_B_TO_FSB(mp, offset + length),
-			       XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
+		data_fsb = xfs_iomap_end_fsb(mp, offset, length);
 	}
 
 	/*