libnvdimm, pmem: clarify the write+clear_poison+write flow

[cascardo/linux.git] / drivers / nvdimm / pmem.c

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 12c86fa..f798899 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -103,6 +103,20 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
                        flush_dcache_page(page);
                }
        } else {
+               /*
+                * Note that we write the data both before and after
+                * clearing poison.  The write before clear poison
+                * handles situations where the latest written data is
+                * preserved and the clear poison operation simply marks
+                * the address range as valid without changing the data.
+                * In this case application software can assume that an
+                * interrupted write will either return the new good
+                * data or an error.
+                *
+                * However, if pmem_clear_poison() leaves the data in an
+                * indeterminate state we need to perform the write
+                * after clear poison.
+                */
                flush_dcache_page(page);
                memcpy_to_pmem(pmem_addr, mem + off, len);
                if (unlikely(bad_pmem)) {
@@ -244,7 +258,9 @@ static void pmem_detach_disk(struct pmem_device *pmem)
 static int pmem_attach_disk(struct device *dev,
                struct nd_namespace_common *ndns, struct pmem_device *pmem)
 {
+       struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
        int nid = dev_to_node(dev);
+       struct resource bb_res;
        struct gendisk *disk;
 
        blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
@@ -271,8 +287,17 @@ static int pmem_attach_disk(struct device *dev,
        devm_exit_badblocks(dev, &pmem->bb);
        if (devm_init_badblocks(dev, &pmem->bb))
                return -ENOMEM;
-       nvdimm_namespace_add_poison(ndns, &pmem->bb, pmem->data_offset);
-
+       bb_res.start = nsio->res.start + pmem->data_offset;
+       bb_res.end = nsio->res.end;
+       if (is_nd_pfn(dev)) {
+               struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+               struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+
+               bb_res.start += __le32_to_cpu(pfn_sb->start_pad);
+               bb_res.end -= __le32_to_cpu(pfn_sb->end_trunc);
+       }
+       nvdimm_badblocks_populate(to_nd_region(dev->parent), &pmem->bb,
+                       &bb_res);
        disk->bb = &pmem->bb;
        add_disk(disk);
        revalidate_disk(disk);
@@ -553,7 +578,7 @@ static int nd_pmem_probe(struct device *dev)
        ndns->rw_bytes = pmem_rw_bytes;
        if (devm_init_badblocks(dev, &pmem->bb))
                return -ENOMEM;
-       nvdimm_namespace_add_poison(ndns, &pmem->bb, 0);
+       nvdimm_badblocks_populate(nd_region, &pmem->bb, &nsio->res);
 
        if (is_nd_btt(dev)) {
                /* btt allocates its own request_queue */
@@ -595,14 +620,25 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
 {
        struct pmem_device *pmem = dev_get_drvdata(dev);
        struct nd_namespace_common *ndns = pmem->ndns;
+       struct nd_region *nd_region = to_nd_region(dev->parent);
+       struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+       struct resource res = {
+               .start = nsio->res.start + pmem->data_offset,
+               .end = nsio->res.end,
+       };
 
        if (event != NVDIMM_REVALIDATE_POISON)
                return;
 
-       if (is_nd_btt(dev))
-               nvdimm_namespace_add_poison(ndns, &pmem->bb, 0);
-       else
-               nvdimm_namespace_add_poison(ndns, &pmem->bb, pmem->data_offset);
+       if (is_nd_pfn(dev)) {
+               struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+               struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+
+               res.start += __le32_to_cpu(pfn_sb->start_pad);
+               res.end -= __le32_to_cpu(pfn_sb->end_trunc);
+       }
+
+       nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);
 }
 
 MODULE_ALIAS("pmem");