From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 7 Nov 2024 19:11:53 +0000 (-0700)
Subject: mm/readahead: add readahead_control->dropbehind member
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=baa3c3d56ad5ee210fdf84efbece8cc3aa9b9e46;p=linux-block.git

mm/readahead: add readahead_control->dropbehind member

If ractl->dropbehind is set to true, then folios created are marked as
dropbehind as well.

Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index bcf0865a38ae..5da4b6d42fae 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -1353,6 +1353,7 @@ struct readahead_control {
 	pgoff_t _index;
 	unsigned int _nr_pages;
 	unsigned int _batch_count;
+	bool dropbehind;
 	bool _workingset;
 	unsigned long _pflags;
 };
diff --git a/mm/readahead.c b/mm/readahead.c
index 8a62ad4106ff..c0a6dc5d5686 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -191,7 +191,13 @@ static void read_pages(struct readahead_control *rac)
 static struct folio *ractl_alloc_folio(struct readahead_control *ractl,
 				       gfp_t gfp_mask, unsigned int order)
 {
-	return filemap_alloc_folio(gfp_mask, order);
+	struct folio *folio;
+
+	folio = filemap_alloc_folio(gfp_mask, order);
+	if (folio && ractl->dropbehind)
+		__folio_set_dropbehind(folio);
+
+	return folio;
 }
 
 /**