libnvdimm: nd_region flush callback support

This patch adds functionality to perform flush from guest
to host over VIRTIO. We are registering a callback based
on 'nd_region' type. virtio_pmem driver requires this special
flush function. For rest of the region types we are registering
existing flush function. Report error returned by host fsync
failure to userspace.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Pankaj Gupta
2019-07-05 19:33:22 +05:30
committed by Dan Williams
parent db5d00c93e
commit c5d4355d10
6 changed files with 47 additions and 12 deletions
+24 -2
View File
@@ -287,7 +287,9 @@ static ssize_t deep_flush_store(struct device *dev, struct device_attribute *att
return rc;
if (!flush)
return -EINVAL;
nvdimm_flush(nd_region);
rc = nvdimm_flush(nd_region, NULL);
if (rc)
return rc;
return len;
}
@@ -1077,6 +1079,11 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
dev->of_node = ndr_desc->of_node;
nd_region->ndr_size = resource_size(ndr_desc->res);
nd_region->ndr_start = ndr_desc->res->start;
if (ndr_desc->flush)
nd_region->flush = ndr_desc->flush;
else
nd_region->flush = NULL;
nd_device_register(dev);
return nd_region;
@@ -1117,11 +1124,24 @@ struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
}
EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
{
int rc = 0;
if (!nd_region->flush)
rc = generic_nvdimm_flush(nd_region);
else {
if (nd_region->flush(nd_region, bio))
rc = -EIO;
}
return rc;
}
/**
* nvdimm_flush - flush any posted write queues between the cpu and pmem media
* @nd_region: blk or interleaved pmem region
*/
void nvdimm_flush(struct nd_region *nd_region)
int generic_nvdimm_flush(struct nd_region *nd_region)
{
struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
int i, idx;
@@ -1145,6 +1165,8 @@ void nvdimm_flush(struct nd_region *nd_region)
if (ndrd_get_flush_wpq(ndrd, i, 0))
writeq(1, ndrd_get_flush_wpq(ndrd, i, idx));
wmb();
return 0;
}
EXPORT_SYMBOL_GPL(nvdimm_flush);