[PATCH 2/2] xfs: disable large folio support in xfile_create

From: Christoph Hellwig <hch@lst.de>
To: Matthew Wilcox <willy@infradead.org>,
	Hugh Dickins <hughd@google.com>,
	Chandan Babu R <chandan.babu@oracle.com>
Cc: "Darrick J . Wong" <djwong@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	David Howells <dhowells@redhat.com>,
	Jarkko Sakkinen <jarkko@kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	Christian Koenig <christian.koenig@amd.com>,
	Huang Rui <ray.huang@amd.com>,
	Jani Nikula <jani.nikula@linux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>,
	Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
	intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	x86@kernel.org, linux-sgx@vger.kernel.org, linux-mm@kvack.org,
	linux-fsdevel@vger.kernel.org, keyrings@vger.kernel.org
Subject: [PATCH 2/2] xfs: disable large folio support in xfile_create
Date: Wed, 10 Jan 2024 10:21:09 +0100	[thread overview]
Message-ID: <20240110092109.1950011-3-hch@lst.de> (raw)
In-Reply-To: <20240110092109.1950011-1-hch@lst.de>

The xfarray code will crash if large folios are force enabled using:

   echo force > /sys/kernel/mm/transparent_hugepage/shmem_enabled

Fixing this will require a bit of an API change, and prefeably sorting out
the hwpoison story for pages vs folio and where it is placed in the shmem
API.  For now use this one liner to disable large folios.

Reported-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/scrub/xfile.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
index 090c3ead43fdf1..1a8d1bedd0b0dc 100644
--- a/fs/xfs/scrub/xfile.c
+++ b/fs/xfs/scrub/xfile.c
@@ -94,6 +94,11 @@ xfile_create(
 
 	lockdep_set_class(&inode->i_rwsem, &xfile_i_mutex_key);
 
+	/*
+	 * We're not quite ready for large folios yet.
+	 */
+	mapping_clear_large_folios(inode->i_mapping);
+
 	trace_xfile_create(xf);
 
 	*xfilep = xf;
-- 
2.39.2

