[PATCH v4 02/12] nvdimm/pmem: Treat alloc_dax() -EOPNOTSUPP failure as non-fatal

Mathieu Desnoyers
2024-02-08T18:49:29Z

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

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

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
---
drivers/nvdimm/pmem.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 9fe358090720..f1d9f5c6dbac 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -558,19 +558,21 @@ static int pmem_attach_disk(struct device *dev,
disk->bb = &pmem->bb;

dax_dev = alloc_dax(pmem, &pmem_dax_ops);
- if (IS_ERR(dax_dev)) {
- rc = PTR_ERR(dax_dev);
- goto out;
+ if (IS_ERR_OR_NULL(dax_dev)) {
+ rc = IS_ERR(dax_dev) ? PTR_ERR(dax_dev) : -EOPNOTSUPP;
+ if (rc != -EOPNOTSUPP)
+ goto out;
+ } else {
+ set_dax_nocache(dax_dev);
+ set_dax_nomc(dax_dev);
+ if (is_nvdimm_sync(nd_region))
+ set_dax_synchronous(dax_dev);
+ pmem->dax_dev = dax_dev;
+ rc = dax_add_host(dax_dev, disk);
+ if (rc)
+ goto out_cleanup_dax;
+ dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
}
- set_dax_nocache(dax_dev);
- set_dax_nomc(dax_dev);
- if (is_nvdimm_sync(nd_region))
- set_dax_synchronous(dax_dev);
- pmem->dax_dev = dax_dev;
- rc = dax_add_host(dax_dev, disk);
- if (rc)
- goto out_cleanup_dax;
- dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
rc = device_add_disk(dev, disk, pmem_attribute_groups);
if (rc)
goto out_remove_host;
--
2.39.2