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Commit 9e694d9c authored by Toshi Kani's avatar Toshi Kani Committed by Dan Williams
Browse files

libnvdimm, label: change nvdimm_num_label_slots per UEFI 2.7 



sizeof_namespace_index() fails when NVDIMM devices have the minimum
1024 bytes label storage area.  nvdimm_num_label_slots() returns 3
slots while the area is only big enough for 2 slots.

Change nvdimm_num_label_slots() to calculate a number of label slots
according to UEFI 2.7 spec.

Signed-off-by: default avatarToshi Kani <toshi.kani@hpe.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 36de6f51

drivers/nvdimm/label.c

+24 −10
Original line number Diff line number Diff line
@@ -45,9 +45,27 @@ unsigned sizeof_namespace_label(struct nvdimm_drvdata *ndd) 
	return ndd->nslabel_size;

}



static size_t __sizeof_namespace_index(u32 nslot)

{

	return ALIGN(sizeof(struct nd_namespace_index) + DIV_ROUND_UP(nslot, 8),

			NSINDEX_ALIGN);

}



static int __nvdimm_num_label_slots(struct nvdimm_drvdata *ndd,

		size_t index_size)

{

	return (ndd->nsarea.config_size - index_size * 2) /

			sizeof_namespace_label(ndd);

}



int nvdimm_num_label_slots(struct nvdimm_drvdata *ndd)

{

	return ndd->nsarea.config_size / (sizeof_namespace_label(ndd) + 1);

	u32 tmp_nslot, n;



	tmp_nslot = ndd->nsarea.config_size / sizeof_namespace_label(ndd);

	n = __sizeof_namespace_index(tmp_nslot) / NSINDEX_ALIGN;



	return __nvdimm_num_label_slots(ndd, NSINDEX_ALIGN * n);

}



size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
@@ -55,18 +73,14 @@ size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd) 
	u32 nslot, space, size;



	/*

	 * The minimum index space is 512 bytes, with that amount of

	 * index we can describe ~1400 labels which is less than a byte

	 * of overhead per label.  Round up to a byte of overhead per

	 * label and determine the size of the index region.  Yes, this

	 * starts to waste space at larger config_sizes, but it's

	 * unlikely we'll ever see anything but 128K.

	 * Per UEFI 2.7, the minimum size of the Label Storage Area is large

	 * enough to hold 2 index blocks and 2 labels.  The minimum index

	 * block size is 256 bytes, and the minimum label size is 256 bytes.

	 */

	nslot = nvdimm_num_label_slots(ndd);

	space = ndd->nsarea.config_size - nslot * sizeof_namespace_label(ndd);

	size = ALIGN(sizeof(struct nd_namespace_index) + DIV_ROUND_UP(nslot, 8),

			NSINDEX_ALIGN) * 2;

	if (size <= space)

	size = __sizeof_namespace_index(nslot) * 2;

	if (size <= space && nslot >= 2)

		return size / 2;



	dev_err(ndd->dev, "label area (%d) too small to host (%d byte) labels\n",