[PATCH v4 05/12] virtio: Treat alloc_dax() -EOPNOTSUPP failure as non-fatal

Mathieu Desnoyers
2024-02-08T18:49:32Z

In preparation for checking whether the architecture has data cache
aliasing within alloc_dax(), modify the error handling of virtio
virtio_fs_setup_dax() to treat alloc_dax() -EOPNOTSUPP failure as
non-fatal.

For the transition, consider that alloc_dax() returning NULL is the
same as returning -EOPNOTSUPP.

Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arch@vger.kernel.org
Cc: linux-cxl@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Cc: dm-devel@lists.linux.dev
Cc: nvdimm@lists.linux.dev
---
fs/fuse/virtio_fs.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 5f1be1da92ce..621b1bca2d55 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -16,6 +16,7 @@
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/highmem.h>
+#include <linux/cleanup.h>
#include <linux/uio.h>
#include "fuse_i.h"

@@ -795,8 +796,11 @@ static void virtio_fs_cleanup_dax(void *data)
put_dax(dax_dev);
}

+DEFINE_FREE(cleanup_dax, struct dax_dev *, if (!IS_ERR_OR_NULL(_T)) virtio_fs_cleanup_dax(_T))
+
static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
{
+ struct dax_device *dax_dev __free(cleanup_dax) = NULL;
struct virtio_shm_region cache_reg;
struct dev_pagemap *pgmap;
bool have_cache;
@@ -804,6 +808,12 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
if (!IS_ENABLED(CONFIG_FUSE_DAX))
return 0;

+ dax_dev = alloc_dax(fs, &virtio_fs_dax_ops);
+ if (IS_ERR_OR_NULL(dax_dev)) {
+ int rc = IS_ERR(dax_dev) ? PTR_ERR(dax_dev) : -EOPNOTSUPP;
+ return rc == -EOPNOTSUPP ? 0 : rc;
+ }
+
/* Get cache region */
have_cache = virtio_get_shm_region(vdev, &cache_reg,
(u8)VIRTIO_FS_SHMCAP_ID_CACHE);
@@ -849,10 +859,7 @@ static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
dev_dbg(&vdev->dev, "%s: window kaddr 0x%px phys_addr 0x%llx len 0x%llx\n",
__func__, fs->window_kaddr, cache_reg.addr, cache_reg.len);

- fs->dax_dev = alloc_dax(fs, &virtio_fs_dax_ops);
- if (IS_ERR(fs->dax_dev))
- return PTR_ERR(fs->dax_dev);
-
+ fs->dax_dev = no_free_ptr(dax_dev);
return devm_add_action_or_reset(&vdev->dev, virtio_fs_cleanup_dax,
fs->dax_dev);
}
--
2.39.2