| From a2948b17f6b936fc52f86c0f92c46d2f91928b79 Mon Sep 17 00:00:00 2001 |
| From: Vaibhav Jain <vaibhav@linux.ibm.com> |
| Date: Fri, 2 Apr 2021 14:55:55 +0530 |
| Subject: libnvdimm/region: Fix nvdimm_has_flush() to handle ND_REGION_ASYNC |
| |
| From: Vaibhav Jain <vaibhav@linux.ibm.com> |
| |
| commit a2948b17f6b936fc52f86c0f92c46d2f91928b79 upstream. |
| |
| In case a platform doesn't provide explicit flush-hints but provides an |
| explicit flush callback via ND_REGION_ASYNC region flag, then |
| nvdimm_has_flush() still returns '0' indicating that writes do not |
| require flushing. This happens on PPC64 with patch at [1] applied, where |
| 'deep_flush' of a region was denied even though an explicit flush |
| function was provided. |
| |
| Fix this by adding a condition to nvdimm_has_flush() to test for the |
| ND_REGION_ASYNC flag on the region and see if a 'region->flush' callback |
| is assigned. |
| |
| Link: http://lore.kernel.org/r/161703936121.36.7260632399582101498.stgit@e1fbed493c87 [1] |
| Fixes: c5d4355d10d4 ("libnvdimm: nd_region flush callback support") |
| Reported-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> |
| Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> |
| Link: https://lore.kernel.org/r/20210402092555.208590-1-vaibhav@linux.ibm.com |
| Signed-off-by: Dan Williams <dan.j.williams@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/nvdimm/region_devs.c | 9 +++++++-- |
| 1 file changed, 7 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/nvdimm/region_devs.c |
| +++ b/drivers/nvdimm/region_devs.c |
| @@ -1239,6 +1239,11 @@ int nvdimm_has_flush(struct nd_region *n |
| || !IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API)) |
| return -ENXIO; |
| |
| + /* Test if an explicit flush function is defined */ |
| + if (test_bit(ND_REGION_ASYNC, &nd_region->flags) && nd_region->flush) |
| + return 1; |
| + |
| + /* Test if any flush hints for the region are available */ |
| for (i = 0; i < nd_region->ndr_mappings; i++) { |
| struct nd_mapping *nd_mapping = &nd_region->mapping[i]; |
| struct nvdimm *nvdimm = nd_mapping->nvdimm; |
| @@ -1249,8 +1254,8 @@ int nvdimm_has_flush(struct nd_region *n |
| } |
| |
| /* |
| - * The platform defines dimm devices without hints, assume |
| - * platform persistence mechanism like ADR |
| + * The platform defines dimm devices without hints nor explicit flush, |
| + * assume platform persistence mechanism like ADR |
| */ |
| return 0; |
| } |