diff mbox

[16/18] xfs: refactor the tail of xfs_writepage_map

Message ID 20180530100013.31358-17-hch@lst.de (mailing list archive)
State New, archived
Headers show

Commit Message

Christoph Hellwig May 30, 2018, 10 a.m. UTC
Rejuggle how we deal with the different error vs non-error and have
ioends vs not have ioend cases to keep the fast path streamlined, and
the duplicate code at a minimum.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_aops.c | 65 +++++++++++++++++++++++------------------------
 1 file changed, 32 insertions(+), 33 deletions(-)

Comments

Darrick J. Wong May 30, 2018, 6 p.m. UTC | #1
On Wed, May 30, 2018 at 12:00:11PM +0200, Christoph Hellwig wrote:
> Rejuggle how we deal with the different error vs non-error and have
> ioends vs not have ioend cases to keep the fast path streamlined, and
> the duplicate code at a minimum.
> 
> 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 | 65 +++++++++++++++++++++++------------------------
>  1 file changed, 32 insertions(+), 33 deletions(-)
> 
> diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> index 38021023131e..ac417ef326a9 100644
> --- a/fs/xfs/xfs_aops.c
> +++ b/fs/xfs/xfs_aops.c
> @@ -873,7 +873,14 @@ xfs_writepage_map(
>  	 * submission of outstanding ioends on the writepage context so they are
>  	 * treated correctly on error.
>  	 */
> -	if (count) {
> +	if (unlikely(error)) {
> +		if (!count) {
> +			xfs_aops_discard_page(page);
> +			ClearPageUptodate(page);
> +			unlock_page(page);
> +			goto done;
> +		}
> +
>  		/*
>  		 * If the page was not fully cleaned, we need to ensure that the
>  		 * higher layers come back to it correctly.  That means we need
> @@ -882,43 +889,35 @@ xfs_writepage_map(
>  		 * so another attempt to write this page in this writeback sweep
>  		 * will be made.
>  		 */
> -		if (error) {
> -			set_page_writeback_keepwrite(page);
> -		} else {
> -			clear_page_dirty_for_io(page);
> -			set_page_writeback(page);
> -		}
> -		unlock_page(page);
> -
> -		/*
> -		 * Preserve the original error if there was one, otherwise catch
> -		 * submission errors here and propagate into subsequent ioend
> -		 * submissions.
> -		 */
> -		list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
> -			int error2;
> -
> -			list_del_init(&ioend->io_list);
> -			error2 = xfs_submit_ioend(wbc, ioend, error);
> -			if (error2 && !error)
> -				error = error2;
> -		}
> -	} else if (error) {
> -		xfs_aops_discard_page(page);
> -		ClearPageUptodate(page);
> -		unlock_page(page);
> +		set_page_writeback_keepwrite(page);
>  	} else {
> -		/*
> -		 * We can end up here with no error and nothing to write if we
> -		 * race with a partial page truncate on a sub-page block sized
> -		 * filesystem. In that case we need to mark the page clean.
> -		 */
>  		clear_page_dirty_for_io(page);
>  		set_page_writeback(page);
> -		unlock_page(page);
> -		end_page_writeback(page);
>  	}
>  
> +	unlock_page(page);
> +
> +	/*
> +	 * Preserve the original error if there was one, otherwise catch
> +	 * submission errors here and propagate into subsequent ioend
> +	 * submissions.
> +	 */
> +	list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
> +		int error2;
> +
> +		list_del_init(&ioend->io_list);
> +		error2 = xfs_submit_ioend(wbc, ioend, error);
> +		if (error2 && !error)
> +			error = error2;
> +	}
> +
> +	/*
> +	 * We can end up here with no error and nothing to write if we race with
> +	 * a partial page truncate on a sub-page block sized filesystem.
> +	 */
> +	if (!count)
> +		end_page_writeback(page);
> +done:
>  	mapping_set_error(page->mapping, error);
>  	return error;
>  }
> -- 
> 2.17.0
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
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Brian Foster May 31, 2018, 1:49 p.m. UTC | #2
On Wed, May 30, 2018 at 12:00:11PM +0200, Christoph Hellwig wrote:
> Rejuggle how we deal with the different error vs non-error and have
> ioends vs not have ioend cases to keep the fast path streamlined, and
> the duplicate code at a minimum.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---

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

>  fs/xfs/xfs_aops.c | 65 +++++++++++++++++++++++------------------------
>  1 file changed, 32 insertions(+), 33 deletions(-)
> 
> diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> index 38021023131e..ac417ef326a9 100644
> --- a/fs/xfs/xfs_aops.c
> +++ b/fs/xfs/xfs_aops.c
> @@ -873,7 +873,14 @@ xfs_writepage_map(
>  	 * submission of outstanding ioends on the writepage context so they are
>  	 * treated correctly on error.
>  	 */
> -	if (count) {
> +	if (unlikely(error)) {
> +		if (!count) {
> +			xfs_aops_discard_page(page);
> +			ClearPageUptodate(page);
> +			unlock_page(page);
> +			goto done;
> +		}
> +
>  		/*
>  		 * If the page was not fully cleaned, we need to ensure that the
>  		 * higher layers come back to it correctly.  That means we need
> @@ -882,43 +889,35 @@ xfs_writepage_map(
>  		 * so another attempt to write this page in this writeback sweep
>  		 * will be made.
>  		 */
> -		if (error) {
> -			set_page_writeback_keepwrite(page);
> -		} else {
> -			clear_page_dirty_for_io(page);
> -			set_page_writeback(page);
> -		}
> -		unlock_page(page);
> -
> -		/*
> -		 * Preserve the original error if there was one, otherwise catch
> -		 * submission errors here and propagate into subsequent ioend
> -		 * submissions.
> -		 */
> -		list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
> -			int error2;
> -
> -			list_del_init(&ioend->io_list);
> -			error2 = xfs_submit_ioend(wbc, ioend, error);
> -			if (error2 && !error)
> -				error = error2;
> -		}
> -	} else if (error) {
> -		xfs_aops_discard_page(page);
> -		ClearPageUptodate(page);
> -		unlock_page(page);
> +		set_page_writeback_keepwrite(page);
>  	} else {
> -		/*
> -		 * We can end up here with no error and nothing to write if we
> -		 * race with a partial page truncate on a sub-page block sized
> -		 * filesystem. In that case we need to mark the page clean.
> -		 */
>  		clear_page_dirty_for_io(page);
>  		set_page_writeback(page);
> -		unlock_page(page);
> -		end_page_writeback(page);
>  	}
>  
> +	unlock_page(page);
> +
> +	/*
> +	 * Preserve the original error if there was one, otherwise catch
> +	 * submission errors here and propagate into subsequent ioend
> +	 * submissions.
> +	 */
> +	list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
> +		int error2;
> +
> +		list_del_init(&ioend->io_list);
> +		error2 = xfs_submit_ioend(wbc, ioend, error);
> +		if (error2 && !error)
> +			error = error2;
> +	}
> +
> +	/*
> +	 * We can end up here with no error and nothing to write if we race with
> +	 * a partial page truncate on a sub-page block sized filesystem.
> +	 */
> +	if (!count)
> +		end_page_writeback(page);
> +done:
>  	mapping_set_error(page->mapping, error);
>  	return error;
>  }
> -- 
> 2.17.0
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 38021023131e..ac417ef326a9 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -873,7 +873,14 @@  xfs_writepage_map(
 	 * submission of outstanding ioends on the writepage context so they are
 	 * treated correctly on error.
 	 */
-	if (count) {
+	if (unlikely(error)) {
+		if (!count) {
+			xfs_aops_discard_page(page);
+			ClearPageUptodate(page);
+			unlock_page(page);
+			goto done;
+		}
+
 		/*
 		 * If the page was not fully cleaned, we need to ensure that the
 		 * higher layers come back to it correctly.  That means we need
@@ -882,43 +889,35 @@  xfs_writepage_map(
 		 * so another attempt to write this page in this writeback sweep
 		 * will be made.
 		 */
-		if (error) {
-			set_page_writeback_keepwrite(page);
-		} else {
-			clear_page_dirty_for_io(page);
-			set_page_writeback(page);
-		}
-		unlock_page(page);
-
-		/*
-		 * Preserve the original error if there was one, otherwise catch
-		 * submission errors here and propagate into subsequent ioend
-		 * submissions.
-		 */
-		list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
-			int error2;
-
-			list_del_init(&ioend->io_list);
-			error2 = xfs_submit_ioend(wbc, ioend, error);
-			if (error2 && !error)
-				error = error2;
-		}
-	} else if (error) {
-		xfs_aops_discard_page(page);
-		ClearPageUptodate(page);
-		unlock_page(page);
+		set_page_writeback_keepwrite(page);
 	} else {
-		/*
-		 * We can end up here with no error and nothing to write if we
-		 * race with a partial page truncate on a sub-page block sized
-		 * filesystem. In that case we need to mark the page clean.
-		 */
 		clear_page_dirty_for_io(page);
 		set_page_writeback(page);
-		unlock_page(page);
-		end_page_writeback(page);
 	}
 
+	unlock_page(page);
+
+	/*
+	 * Preserve the original error if there was one, otherwise catch
+	 * submission errors here and propagate into subsequent ioend
+	 * submissions.
+	 */
+	list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
+		int error2;
+
+		list_del_init(&ioend->io_list);
+		error2 = xfs_submit_ioend(wbc, ioend, error);
+		if (error2 && !error)
+			error = error2;
+	}
+
+	/*
+	 * We can end up here with no error and nothing to write if we race with
+	 * a partial page truncate on a sub-page block sized filesystem.
+	 */
+	if (!count)
+		end_page_writeback(page);
+done:
 	mapping_set_error(page->mapping, error);
 	return error;
 }