NVDIMM and DAX for v7.4

DAX fixes:
 dax: fix wrong error code returned from dax_dedupe_file_range_compare()
 dax: fix dax_range_compare_iter() to use correct size and address offset
 dax: Return errors from dax_core_init()
 dax/bus: Return errors for invalid mapping targets
 
 NVDIMM fixes:
 libnvdimm: Handle negative return from nvdimm_clear_poison() in nsio_rw_bytes()
 nvdimm/pmem: Release gendisk on probe failure
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Merge tag 'libnvdimm-for-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull NVDIMM and DAX updates from Alison Schofield:
 "A small set of fixes: error handling corrections in the DAX core
  and bus code, a fix to the DAX file range comparison helpers, and
  two libnvdimm/pmem fixes for error and probe failure paths"

* tag 'libnvdimm-for-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: fix wrong error code returned from dax_dedupe_file_range_compare()
  dax/bus: Return errors for invalid mapping targets
  dax: fix dax_range_compare_iter() to use correct size and address offset
  dax: Return errors from dax_core_init()
  libnvdimm: Handle negative return from nvdimm_clear_poison() in nsio_rw_bytes()
  nvdimm/pmem: Release gendisk on probe failure

drivers/dax/bus.c

@@ -1192,7 +1192,7 @@ static ssize_t mapping_store(struct device *dev, struct device_attribute *attr,
 		return rc;
 	if (!dax_region->dev->driver) {
 		up_write(&dax_region_rwsem);
-		return rc;
+		return -ENXIO;
 	}
 	rc = down_write_killable(&dax_dev_rwsem);
 	if (rc) {
@@ -1201,8 +1201,12 @@ static ssize_t mapping_store(struct device *dev, struct device_attribute *attr,
 	}
 
 	to_alloc = range_len(&r);
-	if (alloc_is_aligned(dev_dax, to_alloc))
+	if (!alloc_is_aligned(dev_dax, to_alloc)) {
+		dev_dbg(dev, "%s: size: %zu misaligned\n", __func__, to_alloc);
+		rc = -EINVAL;
+	} else {
 		rc = alloc_dev_dax_range(dev_dax, r.start, to_alloc);
+	}
 	up_write(&dax_dev_rwsem);
 	up_write(&dax_region_rwsem);
 

drivers/dax/super.c

@@ -738,7 +738,7 @@ static int __init dax_core_init(void)
 	unregister_chrdev_region(dax_devt, MINORMASK+1);
 err_chrdev:
 	dax_fs_exit();
-	return 0;
+	return rc;
 }
 
 static void __exit dax_core_exit(void)

drivers/nvdimm/claim.c

@@ -263,7 +263,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
 			might_sleep();
 			cleared = nvdimm_clear_poison(&ndns->dev,
 					nsio->res.start + offset, size);
-			if (cleared < size)
+			if (cleared < 0 || cleared < size)
 				rc = -EIO;
 			if (cleared > 0 && cleared / 512) {
 				cleared /= 512;

drivers/nvdimm/pmem.c

@@ -563,8 +563,10 @@ static int pmem_attach_disk(struct device *dev,
 	nvdimm_namespace_disk_name(ndns, disk->disk_name);
 	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
 			/ 512);
-	if (devm_init_badblocks(dev, &pmem->bb))
-		return -ENOMEM;
+	if (devm_init_badblocks(dev, &pmem->bb)) {
+		rc = -ENOMEM;
+		goto out;
+	}
 	nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range);
 	disk->bb = &pmem->bb;
 

fs/dax.c

@@ -2190,6 +2190,7 @@ static int dax_range_compare_iter(struct iomap_iter *it_src,
 	const struct iomap *dmap = &it_dest->iomap;
 	loff_t pos1 = it_src->pos, pos2 = it_dest->pos;
 	void *saddr, *daddr;
+	size_t size1, size2;
 	int id, ret;
 
 	len = min(len, min(smap->length, dmap->length));
@@ -2205,17 +2206,18 @@ static int dax_range_compare_iter(struct iomap_iter *it_src,
 	}
 
 	id = dax_read_lock();
-	ret = dax_iomap_direct_access(smap, pos1, ALIGN(pos1 + len, PAGE_SIZE),
-				      &saddr, NULL);
+	size1 = ALIGN(len + offset_in_page(pos1), PAGE_SIZE);
+	ret = dax_iomap_direct_access(smap, pos1, size1, &saddr, NULL);
 	if (ret < 0)
 		goto out_unlock;
 
-	ret = dax_iomap_direct_access(dmap, pos2, ALIGN(pos2 + len, PAGE_SIZE),
-				      &daddr, NULL);
+	size2 = ALIGN(len + offset_in_page(pos2), PAGE_SIZE);
+	ret = dax_iomap_direct_access(dmap, pos2, size2, &daddr, NULL);
 	if (ret < 0)
 		goto out_unlock;
 
-	*same = !memcmp(saddr, daddr, len);
+	*same = !memcmp(saddr + offset_in_page(pos1),
+			daddr + offset_in_page(pos2), len);
 	if (!*same)
 		len = 0;
 	dax_read_unlock(id);
@@ -2254,7 +2256,7 @@ int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
 		status = dax_range_compare_iter(&src_iter, &dst_iter,
 				min(src_iter.len, dst_iter.len), same);
 		if (status < 0)
-			return ret;
+			return status;
 		src_iter.status = dst_iter.status = status;
 	}
 	return ret;