[PATCH 0/2] xfs: more return cleanups

[PATCH 0/2] xfs: more return cleanups

[Dave Chinner]

Hi folks,

I noticed a bit of inconsistency when reviewing the shift extent
return cleanups that coccinelle flagged. The first was that the
out_error labels were basically meaningless - it jsut returns the
error, and we have much neater ways of doing that. Also, the logic
flow through xfs_bmse_shift_one() jumped around all over the place -
it can be done lots neater without any gotos at all, and is easier
to read as a result.

These patches apply on top of the for-next branch (the
xfs-coccinelle-cleanups branch to be precise).

Cheers,

Dave.

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[PATCH 1/2] xfs: cleanup xfs_bmse_shift_one goto mess

[Dave Chinner]

From: Dave Chinner <dchinner@redhat.com>

xfs_bmse_shift_one() jumps around determining whether to shift or
merge, making the code flow difficult to follow. Clean it up and
use direct error returns (including XFS_WANT_CORRUPTED_RETURN) to
make the code flow better and be easier to read.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 fs/xfs/libxfs/xfs_bmap.c | 43 +++++++++++++++++--------------------------
 1 file changed, 17 insertions(+), 26 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 20d2e96..0628a67 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5544,35 +5544,29 @@ xfs_bmse_shift_one(
 	startoff = got.br_startoff - offset_shift_fsb;
 
 	/* delalloc extents should be prevented by caller */
-	XFS_WANT_CORRUPTED_GOTO(!isnullstartblock(got.br_startblock),
-				out_error);
+	XFS_WANT_CORRUPTED_RETURN(!isnullstartblock(got.br_startblock));
 
 	/*
-	 * If this is the first extent in the file, make sure there's enough
-	 * room at the start of the file and jump right to the shift as there's
-	 * no left extent to merge.
+	 * Check for merge if we've got an extent to the left, otherwise make
+	 * sure there's enough room at the start of the file for the shift.
 	 */
-	if (*current_ext == 0) {
-		if (got.br_startoff < offset_shift_fsb)
-			return -EINVAL;
-		goto shift_extent;
-	}
+	if (*current_ext) {
+		/* grab the left extent and check for a large enough hole */
+		leftp = xfs_iext_get_ext(ifp, *current_ext - 1);
+		xfs_bmbt_get_all(leftp, &left);
 
-	/* grab the left extent and check for a large enough hole */
-	leftp = xfs_iext_get_ext(ifp, *current_ext - 1);
-	xfs_bmbt_get_all(leftp, &left);
+		if (startoff < left.br_startoff + left.br_blockcount)
+			return -EINVAL;
 
-	if (startoff < left.br_startoff + left.br_blockcount)
+		/* check whether to merge the extent or shift it down */
+		if (xfs_bmse_can_merge(&left, &got, offset_shift_fsb)) {
+			return xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
+					      *current_ext, gotp, leftp, cur,
+					      logflags);
+		}
+	} else if (got.br_startoff < offset_shift_fsb)
 		return -EINVAL;
 
-	/* check whether to merge the extent or shift it down */
-	if (!xfs_bmse_can_merge(&left, &got, offset_shift_fsb))
-		goto shift_extent;
-
-	return xfs_bmse_merge(ip, whichfork, offset_shift_fsb, *current_ext,
-			      gotp, leftp, cur, logflags);
-
-shift_extent:
 	/*
 	 * Increment the extent index for the next iteration, update the start
 	 * offset of the in-core extent and update the btree if applicable.
@@ -5589,14 +5583,11 @@ shift_extent:
 				   got.br_blockcount, &i);
 	if (error)
 		return error;
-	XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
+	XFS_WANT_CORRUPTED_RETURN(i == 1);
 
 	got.br_startoff = startoff;
 	return xfs_bmbt_update(cur, got.br_startoff, got.br_startblock,
 				got.br_blockcount, got.br_state);
-
-out_error:
-	return error;
 }
 
 /*
-- 
2.0.0

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[PATCH 2/2] xfs: cleanup xfs_bmse_merge returns

[Dave Chinner]

From: Dave Chinner <dchinner@redhat.com>

Signed-off-by: Dave Chinner <dchinner@redhat.com>

xfs_bmse_merge() has a jump label for return that just returns the
error value. Convert all the code to just return the error directly
and use XFS_WANT_CORRUPTED_RETURN. This also allows the final call
to xfs_bmbt_update() to return directly.

Noticed while reviewing coccinelle return cleanup patches and
wondering why the same return pattern as in xfs_bmse_shift_one()
wasn't picked up by the checker pattern...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 fs/xfs/libxfs/xfs_bmap.c | 23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 0628a67..5a42e2b 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5489,32 +5489,25 @@ xfs_bmse_merge(
 	error = xfs_bmbt_lookup_eq(cur, got.br_startoff, got.br_startblock,
 				   got.br_blockcount, &i);
 	if (error)
-		goto out_error;
-	XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
+		return error;
+	XFS_WANT_CORRUPTED_RETURN(i == 1);
 
 	error = xfs_btree_delete(cur, &i);
 	if (error)
-		goto out_error;
-	XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
+		return error;
+	XFS_WANT_CORRUPTED_RETURN(i == 1);
 
 	/* lookup and update size of the previous extent */
 	error = xfs_bmbt_lookup_eq(cur, left.br_startoff, left.br_startblock,
 				   left.br_blockcount, &i);
 	if (error)
-		goto out_error;
-	XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
+		return error;
+	XFS_WANT_CORRUPTED_RETURN(i == 1);
 
 	left.br_blockcount = blockcount;
 
-	error = xfs_bmbt_update(cur, left.br_startoff, left.br_startblock,
-				left.br_blockcount, left.br_state);
-	if (error)
-		goto out_error;
-
-	return 0;
-
-out_error:
-	return error;
+	return xfs_bmbt_update(cur, left.br_startoff, left.br_startblock,
+			       left.br_blockcount, left.br_state);
 }
 
 /*
-- 
2.0.0

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Re: [PATCH 1/2] xfs: cleanup xfs_bmse_shift_one goto mess

[Brian Foster]

On Mon, Dec 01, 2014 at 03:20:07PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> xfs_bmse_shift_one() jumps around determining whether to shift or
> merge, making the code flow difficult to follow. Clean it up and
> use direct error returns (including XFS_WANT_CORRUPTED_RETURN) to
> make the code flow better and be easier to read.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/libxfs/xfs_bmap.c | 43 +++++++++++++++++--------------------------
>  1 file changed, 17 insertions(+), 26 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> index 20d2e96..0628a67 100644
> --- a/fs/xfs/libxfs/xfs_bmap.c
> +++ b/fs/xfs/libxfs/xfs_bmap.c
> @@ -5544,35 +5544,29 @@ xfs_bmse_shift_one(
>  	startoff = got.br_startoff - offset_shift_fsb;
>  
>  	/* delalloc extents should be prevented by caller */
> -	XFS_WANT_CORRUPTED_GOTO(!isnullstartblock(got.br_startblock),
> -				out_error);
> +	XFS_WANT_CORRUPTED_RETURN(!isnullstartblock(got.br_startblock));
>  
>  	/*
> -	 * If this is the first extent in the file, make sure there's enough
> -	 * room at the start of the file and jump right to the shift as there's
> -	 * no left extent to merge.
> +	 * Check for merge if we've got an extent to the left, otherwise make
> +	 * sure there's enough room at the start of the file for the shift.
>  	 */
> -	if (*current_ext == 0) {
> -		if (got.br_startoff < offset_shift_fsb)
> -			return -EINVAL;
> -		goto shift_extent;
> -	}
> +	if (*current_ext) {
> +		/* grab the left extent and check for a large enough hole */
> +		leftp = xfs_iext_get_ext(ifp, *current_ext - 1);
> +		xfs_bmbt_get_all(leftp, &left);
>  
> -	/* grab the left extent and check for a large enough hole */
> -	leftp = xfs_iext_get_ext(ifp, *current_ext - 1);
> -	xfs_bmbt_get_all(leftp, &left);
> +		if (startoff < left.br_startoff + left.br_blockcount)
> +			return -EINVAL;
>  
> -	if (startoff < left.br_startoff + left.br_blockcount)
> +		/* check whether to merge the extent or shift it down */
> +		if (xfs_bmse_can_merge(&left, &got, offset_shift_fsb)) {
> +			return xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
> +					      *current_ext, gotp, leftp, cur,
> +					      logflags);
> +		}
> +	} else if (got.br_startoff < offset_shift_fsb)
>  		return -EINVAL;
>  
> -	/* check whether to merge the extent or shift it down */
> -	if (!xfs_bmse_can_merge(&left, &got, offset_shift_fsb))
> -		goto shift_extent;
> -
> -	return xfs_bmse_merge(ip, whichfork, offset_shift_fsb, *current_ext,
> -			      gotp, leftp, cur, logflags);
> -
> -shift_extent:
>  	/*
>  	 * Increment the extent index for the next iteration, update the start
>  	 * offset of the in-core extent and update the btree if applicable.
> @@ -5589,14 +5583,11 @@ shift_extent:
>  				   got.br_blockcount, &i);
>  	if (error)
>  		return error;
> -	XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
> +	XFS_WANT_CORRUPTED_RETURN(i == 1);
>  
>  	got.br_startoff = startoff;
>  	return xfs_bmbt_update(cur, got.br_startoff, got.br_startblock,
>  				got.br_blockcount, got.br_state);
> -
> -out_error:
> -	return error;
>  }
>  
>  /*
> -- 
> 2.0.0
> 
> _______________________________________________
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> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs

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Re: [PATCH 2/2] xfs: cleanup xfs_bmse_merge returns

[Brian Foster]

On Mon, Dec 01, 2014 at 03:20:08PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> 
> xfs_bmse_merge() has a jump label for return that just returns the
> error value. Convert all the code to just return the error directly
> and use XFS_WANT_CORRUPTED_RETURN. This also allows the final call
> to xfs_bmbt_update() to return directly.
> 
> Noticed while reviewing coccinelle return cleanup patches and
> wondering why the same return pattern as in xfs_bmse_shift_one()
> wasn't picked up by the checker pattern...
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/libxfs/xfs_bmap.c | 23 ++++++++---------------
>  1 file changed, 8 insertions(+), 15 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> index 0628a67..5a42e2b 100644
> --- a/fs/xfs/libxfs/xfs_bmap.c
> +++ b/fs/xfs/libxfs/xfs_bmap.c
> @@ -5489,32 +5489,25 @@ xfs_bmse_merge(
>  	error = xfs_bmbt_lookup_eq(cur, got.br_startoff, got.br_startblock,
>  				   got.br_blockcount, &i);
>  	if (error)
> -		goto out_error;
> -	XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
> +		return error;
> +	XFS_WANT_CORRUPTED_RETURN(i == 1);
>  
>  	error = xfs_btree_delete(cur, &i);
>  	if (error)
> -		goto out_error;
> -	XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
> +		return error;
> +	XFS_WANT_CORRUPTED_RETURN(i == 1);
>  
>  	/* lookup and update size of the previous extent */
>  	error = xfs_bmbt_lookup_eq(cur, left.br_startoff, left.br_startblock,
>  				   left.br_blockcount, &i);
>  	if (error)
> -		goto out_error;
> -	XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
> +		return error;
> +	XFS_WANT_CORRUPTED_RETURN(i == 1);
>  
>  	left.br_blockcount = blockcount;
>  
> -	error = xfs_bmbt_update(cur, left.br_startoff, left.br_startblock,
> -				left.br_blockcount, left.br_state);
> -	if (error)
> -		goto out_error;
> -
> -	return 0;
> -
> -out_error:
> -	return error;
> +	return xfs_bmbt_update(cur, left.br_startoff, left.br_startblock,
> +			       left.br_blockcount, left.br_state);
>  }
>  
>  /*
> -- 
> 2.0.0
> 
> _______________________________________________
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> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs

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