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.desnoy...@efficios.com> Cc: Alasdair Kergon <a...@redhat.com> Cc: Mike Snitzer <snit...@kernel.org> Cc: Mikulas Patocka <mpato...@redhat.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Dan Williams <dan.j.willi...@intel.com> Cc: Vishal Verma <vishal.l.ve...@intel.com> Cc: Dave Jiang <dave.ji...@intel.com> Cc: Matthew Wilcox <wi...@infradead.org> Cc: Arnd Bergmann <a...@arndb.de> Cc: Russell King <li...@armlinux.org.uk> Cc: linux-a...@vger.kernel.org Cc: linux-...@vger.kernel.org Cc: linux-fsde...@vger.kernel.org Cc: linux...@kvack.org Cc: linux-...@vger.kernel.org Cc: dm-devel@lists.linux.dev Cc: nvd...@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