[PATCH v2 03/18] fsdax: Include unmapped inodes for page-idle detection

From: Dan Williams <dan.j.williams@intel.com>
To: akpm@linux-foundation.org
Cc: Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
	"Darrick J. Wong" <djwong@kernel.org>,
	Jason Gunthorpe <jgg@nvidia.com>, Christoph Hellwig <hch@lst.de>,
	John Hubbard <jhubbard@nvidia.com>,
	linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev,
	linux-xfs@vger.kernel.org, linux-mm@kvack.org,
	linux-ext4@vger.kernel.org
Subject: [PATCH v2 03/18] fsdax: Include unmapped inodes for page-idle detection
Date: Thu, 15 Sep 2022 20:35:27 -0700	[thread overview]
Message-ID: <166329932730.2786261.8645669907699123863.stgit@dwillia2-xfh.jf.intel.com> (raw)
In-Reply-To: <166329930818.2786261.6086109734008025807.stgit@dwillia2-xfh.jf.intel.com>

A page can remain pinned even after it has been unmapped from userspace
/ removed from the rmap. In advance of requiring that all
dax_insert_entry() events are followed up 'break layouts' before a
truncate event, make sure that 'break layouts' can find unmapped
entries.

Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 fs/dax.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/dax.c b/fs/dax.c
index e762b9c04fb4..76bad1c095c0 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -698,7 +698,7 @@ struct page *dax_layout_busy_page_range(struct address_space *mapping,
 	if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
 		return NULL;
 
-	if (!dax_mapping(mapping) || !mapping_mapped(mapping))
+	if (!dax_mapping(mapping))
 		return NULL;
 
 	/* If end == LLONG_MAX, all pages from start to till end of file */

