diff mbox series

[13/13] writeback: Remove a use of write_cache_pages() from do_writepages()

Message ID 20240203071147.862076-14-hch@lst.de
State New
Headers
Series None |

Commit Message

Christoph Hellwig Feb. 3, 2024, 7:11 a.m. UTC 
  From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Use the new writeback_iter() directly instead of indirecting
through a callback.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
[hch: ported to the while based iter style]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/page-writeback.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

Comments

Jan Kara Feb. 5, 2024, 11:43 a.m. UTC | #1 
On Sat 03-02-24 08:11:47, Christoph Hellwig wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> Use the new writeback_iter() directly instead of indirecting
> through a callback.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> [hch: ported to the while based iter style]
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

I've just noticed one preexisting problem which was made more visible by
your reshuffling:

> +static int writeback_use_writepage(struct address_space *mapping,
> +		struct writeback_control *wbc)
>  {
> -	struct address_space *mapping = data;
> -	int ret = mapping->a_ops->writepage(&folio->page, wbc);
> -	mapping_set_error(mapping, ret);
> -	return ret;
> +	struct folio *folio = NULL;
> +	struct blk_plug plug;
> +	int err;
> +
> +	blk_start_plug(&plug);
> +	while ((folio = writeback_iter(mapping, wbc, folio, &err))) {
> +		err = mapping->a_ops->writepage(&folio->page, wbc);
> +		mapping_set_error(mapping, err);

So if ->writepage() returns AOP_WRITEPAGE_ACTIVATE, we shouldn't call
mapping_set_error() because that's just going to confuse the error
tracking.

> +		if (err == AOP_WRITEPAGE_ACTIVATE) {
> +			folio_unlock(folio);
> +			err = 0;
> +		}
> +	}
> +	blk_finish_plug(&plug);
> +
> +	return err;
>  }

								Honza
Brian Foster Feb. 5, 2024, 3:34 p.m. UTC | #2 
On Sat, Feb 03, 2024 at 08:11:47AM +0100, Christoph Hellwig wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> Use the new writeback_iter() directly instead of indirecting
> through a callback.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> [hch: ported to the while based iter style]
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---

LGTM, modulo Jan's comments:

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

>  mm/page-writeback.c | 31 +++++++++++++++++++------------
>  1 file changed, 19 insertions(+), 12 deletions(-)
> 
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 5fe4cdb7dbd61a..53ff2d8219ddb6 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -2577,13 +2577,25 @@ int write_cache_pages(struct address_space *mapping,
>  }
>  EXPORT_SYMBOL(write_cache_pages);
>  
> -static int writepage_cb(struct folio *folio, struct writeback_control *wbc,
> -		void *data)
> +static int writeback_use_writepage(struct address_space *mapping,
> +		struct writeback_control *wbc)
>  {
> -	struct address_space *mapping = data;
> -	int ret = mapping->a_ops->writepage(&folio->page, wbc);
> -	mapping_set_error(mapping, ret);
> -	return ret;
> +	struct folio *folio = NULL;
> +	struct blk_plug plug;
> +	int err;
> +
> +	blk_start_plug(&plug);
> +	while ((folio = writeback_iter(mapping, wbc, folio, &err))) {
> +		err = mapping->a_ops->writepage(&folio->page, wbc);
> +		mapping_set_error(mapping, err);
> +		if (err == AOP_WRITEPAGE_ACTIVATE) {
> +			folio_unlock(folio);
> +			err = 0;
> +		}
> +	}
> +	blk_finish_plug(&plug);
> +
> +	return err;
>  }
>  
>  int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
> @@ -2599,12 +2611,7 @@ int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
>  		if (mapping->a_ops->writepages) {
>  			ret = mapping->a_ops->writepages(mapping, wbc);
>  		} else if (mapping->a_ops->writepage) {
> -			struct blk_plug plug;
> -
> -			blk_start_plug(&plug);
> -			ret = write_cache_pages(mapping, wbc, writepage_cb,
> -						mapping);
> -			blk_finish_plug(&plug);
> +			ret = writeback_use_writepage(mapping, wbc);
>  		} else {
>  			/* deal with chardevs and other special files */
>  			ret = 0;
> -- 
> 2.39.2
>
diff mbox series

Patch

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 5fe4cdb7dbd61a..53ff2d8219ddb6 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2577,13 +2577,25 @@  int write_cache_pages(struct address_space *mapping,
 }
 EXPORT_SYMBOL(write_cache_pages);
 
-static int writepage_cb(struct folio *folio, struct writeback_control *wbc,
-		void *data)
+static int writeback_use_writepage(struct address_space *mapping,
+		struct writeback_control *wbc)
 {
-	struct address_space *mapping = data;
-	int ret = mapping->a_ops->writepage(&folio->page, wbc);
-	mapping_set_error(mapping, ret);
-	return ret;
+	struct folio *folio = NULL;
+	struct blk_plug plug;
+	int err;
+
+	blk_start_plug(&plug);
+	while ((folio = writeback_iter(mapping, wbc, folio, &err))) {
+		err = mapping->a_ops->writepage(&folio->page, wbc);
+		mapping_set_error(mapping, err);
+		if (err == AOP_WRITEPAGE_ACTIVATE) {
+			folio_unlock(folio);
+			err = 0;
+		}
+	}
+	blk_finish_plug(&plug);
+
+	return err;
 }
 
 int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
@@ -2599,12 +2611,7 @@  int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
 		if (mapping->a_ops->writepages) {
 			ret = mapping->a_ops->writepages(mapping, wbc);
 		} else if (mapping->a_ops->writepage) {
-			struct blk_plug plug;
-
-			blk_start_plug(&plug);
-			ret = write_cache_pages(mapping, wbc, writepage_cb,
-						mapping);
-			blk_finish_plug(&plug);
+			ret = writeback_use_writepage(mapping, wbc);
 		} else {
 			/* deal with chardevs and other special files */
 			ret = 0;