libnvdimm: namespace indices: read and validate (4a826c83) · Commits · 戴 / test

drivers/nvdimm/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -10,3 +10,4 @@ libnvdimm-y += dimm.o
		libnvdimm-y += region_devs.o
		libnvdimm-y += region.o
		libnvdimm-y += namespace_devs.o
		libnvdimm-y += label.o

drivers/nvdimm/dimm.c

+23 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		#include <linux/slab.h>
		#include <linux/mm.h>
		#include <linux/nd.h>
		#include "label.h"
		#include "nd.h"

		static void free_data(struct nvdimm_drvdata *ndd)
		@@ -42,6 +43,11 @@ static int nvdimm_probe(struct device *dev)
		return -ENOMEM;

		dev_set_drvdata(dev, ndd);
		ndd->dpa.name = dev_name(dev);
		ndd->ns_current = -1;
		ndd->ns_next = -1;
		ndd->dpa.start = 0;
		ndd->dpa.end = -1;
		ndd->dev = dev;

		rc = nvdimm_init_nsarea(ndd);
		@@ -54,6 +60,17 @@ static int nvdimm_probe(struct device *dev)

		dev_dbg(dev, "config data size: %d\n", ndd->nsarea.config_size);

		nvdimm_bus_lock(dev);
		ndd->ns_current = nd_label_validate(ndd);
		ndd->ns_next = nd_label_next_nsindex(ndd->ns_current);
		nd_label_copy(ndd, to_next_namespace_index(ndd),
		to_current_namespace_index(ndd));
		rc = nd_label_reserve_dpa(ndd);
		nvdimm_bus_unlock(dev);

		if (rc)
		goto err;

		return 0;

		err:
		@@ -64,7 +81,13 @@ static int nvdimm_probe(struct device *dev)
		static int nvdimm_remove(struct device *dev)
		{
		struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
		struct resource res, _r;

		nvdimm_bus_lock(dev);
		dev_set_drvdata(dev, NULL);
		for_each_dpa_resource_safe(ndd, res, _r)
		nvdimm_free_dpa(ndd, res);
		nvdimm_bus_unlock(dev);
		free_data(ndd);

		return 0;

drivers/nvdimm/dimm_devs.c

+29 −1

Original line number	Diff line number	Diff line
		@@ -92,8 +92,12 @@ int nvdimm_init_config_data(struct nvdimm_drvdata *ndd)
		if (ndd->data)
		return 0;

		if (ndd->nsarea.status \|\| ndd->nsarea.max_xfer == 0)
		if (ndd->nsarea.status \|\| ndd->nsarea.max_xfer == 0
		\|\| ndd->nsarea.config_size < ND_LABEL_MIN_SIZE) {
		dev_dbg(ndd->dev, "failed to init config data area: (%d:%d)\n",
		ndd->nsarea.max_xfer, ndd->nsarea.config_size);
		return -ENXIO;
		}

		ndd->data = kmalloc(ndd->nsarea.config_size, GFP_KERNEL);
		if (!ndd->data)
		@@ -243,6 +247,30 @@ struct nvdimm nvdimm_create(struct nvdimm_bus nvdimm_bus, void *provider_data,
		}
		EXPORT_SYMBOL_GPL(nvdimm_create);

		void nvdimm_free_dpa(struct nvdimm_drvdata ndd, struct resource res)
		{
		WARN_ON_ONCE(!is_nvdimm_bus_locked(ndd->dev));
		kfree(res->name);
		__release_region(&ndd->dpa, res->start, resource_size(res));
		}

		struct resource nvdimm_allocate_dpa(struct nvdimm_drvdata ndd,
		struct nd_label_id *label_id, resource_size_t start,
		resource_size_t n)
		{
		char name = kmemdup(label_id, sizeof(label_id), GFP_KERNEL);
		struct resource *res;

		if (!name)
		return NULL;

		WARN_ON_ONCE(!is_nvdimm_bus_locked(ndd->dev));
		res = __request_region(&ndd->dpa, start, n, name, 0);
		if (!res)
		kfree(name);
		return res;
		}

		static int count_dimms(struct device dev, void c)
		{
		int *count = c;

drivers/nvdimm/label.c

0 → 100644

+290 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of version 2 of the GNU General Public License as
		* published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful, but
		* WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
		* General Public License for more details.
		*/
		#include <linux/device.h>
		#include <linux/ndctl.h>
		#include <linux/io.h>
		#include <linux/nd.h>
		#include "nd-core.h"
		#include "label.h"
		#include "nd.h"

		static u32 best_seq(u32 a, u32 b)
		{
		a &= NSINDEX_SEQ_MASK;
		b &= NSINDEX_SEQ_MASK;

		if (a == 0 \|\| a == b)
		return b;
		else if (b == 0)
		return a;
		else if (nd_inc_seq(a) == b)
		return b;
		else
		return a;
		}

		size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
		{
		u32 index_span;

		if (ndd->nsindex_size)
		return ndd->nsindex_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.
		*/
		index_span = ndd->nsarea.config_size / 129;
		index_span /= NSINDEX_ALIGN * 2;
		ndd->nsindex_size = index_span * NSINDEX_ALIGN;

		return ndd->nsindex_size;
		}

		int nd_label_validate(struct nvdimm_drvdata *ndd)
		{
		/*
		* On media label format consists of two index blocks followed
		* by an array of labels. None of these structures are ever
		* updated in place. A sequence number tracks the current
		* active index and the next one to write, while labels are
		* written to free slots.
		*
		* +------------+
		* \| \|
		* \| nsindex0 \|
		* \| \|
		* +------------+
		* \| \|
		* \| nsindex1 \|
		* \| \|
		* +------------+
		* \| label0 \|
		* +------------+
		* \| label1 \|
		* +------------+
		* \| \|
		* ....nslot...
		* \| \|
		* +------------+
		* \| labelN \|
		* +------------+
		*/
		struct nd_namespace_index *nsindex[] = {
		to_namespace_index(ndd, 0),
		to_namespace_index(ndd, 1),
		};
		const int num_index = ARRAY_SIZE(nsindex);
		struct device *dev = ndd->dev;
		bool valid[2] = { 0 };
		int i, num_valid = 0;
		u32 seq;

		for (i = 0; i < num_index; i++) {
		u32 nslot;
		u8 sig[NSINDEX_SIG_LEN];
		u64 sum_save, sum, size;

		memcpy(sig, nsindex[i]->sig, NSINDEX_SIG_LEN);
		if (memcmp(sig, NSINDEX_SIGNATURE, NSINDEX_SIG_LEN) != 0) {
		dev_dbg(dev, "%s: nsindex%d signature invalid\n",
		__func__, i);
		continue;
		}
		sum_save = __le64_to_cpu(nsindex[i]->checksum);
		nsindex[i]->checksum = __cpu_to_le64(0);
		sum = nd_fletcher64(nsindex[i], sizeof_namespace_index(ndd), 1);
		nsindex[i]->checksum = __cpu_to_le64(sum_save);
		if (sum != sum_save) {
		dev_dbg(dev, "%s: nsindex%d checksum invalid\n",
		__func__, i);
		continue;
		}

		seq = __le32_to_cpu(nsindex[i]->seq);
		if ((seq & NSINDEX_SEQ_MASK) == 0) {
		dev_dbg(dev, "%s: nsindex%d sequence: %#x invalid\n",
		__func__, i, seq);
		continue;
		}

		/* sanity check the index against expected values */
		if (__le64_to_cpu(nsindex[i]->myoff)
		!= i * sizeof_namespace_index(ndd)) {
		dev_dbg(dev, "%s: nsindex%d myoff: %#llx invalid\n",
		__func__, i, (unsigned long long)
		__le64_to_cpu(nsindex[i]->myoff));
		continue;
		}
		if (__le64_to_cpu(nsindex[i]->otheroff)
		!= (!i) * sizeof_namespace_index(ndd)) {
		dev_dbg(dev, "%s: nsindex%d otheroff: %#llx invalid\n",
		__func__, i, (unsigned long long)
		__le64_to_cpu(nsindex[i]->otheroff));
		continue;
		}

		size = __le64_to_cpu(nsindex[i]->mysize);
		if (size > sizeof_namespace_index(ndd)
		\|\| size < sizeof(struct nd_namespace_index)) {
		dev_dbg(dev, "%s: nsindex%d mysize: %#llx invalid\n",
		__func__, i, size);
		continue;
		}

		nslot = __le32_to_cpu(nsindex[i]->nslot);
		if (nslot * sizeof(struct nd_namespace_label)
		+ 2 * sizeof_namespace_index(ndd)
		> ndd->nsarea.config_size) {
		dev_dbg(dev, "%s: nsindex%d nslot: %u invalid, config_size: %#x\n",
		__func__, i, nslot,
		ndd->nsarea.config_size);
		continue;
		}
		valid[i] = true;
		num_valid++;
		}

		switch (num_valid) {
		case 0:
		break;
		case 1:
		for (i = 0; i < num_index; i++)
		if (valid[i])
		return i;
		/* can't have num_valid > 0 but valid[] = { false, false } */
		WARN_ON(1);
		break;
		default:
		/* pick the best index... */
		seq = best_seq(__le32_to_cpu(nsindex[0]->seq),
		__le32_to_cpu(nsindex[1]->seq));
		if (seq == (__le32_to_cpu(nsindex[1]->seq) & NSINDEX_SEQ_MASK))
		return 1;
		else
		return 0;
		break;
		}

		return -1;
		}

		void nd_label_copy(struct nvdimm_drvdata ndd, struct nd_namespace_index dst,
		struct nd_namespace_index *src)
		{
		if (dst && src)
		/* pass */;
		else
		return;

		memcpy(dst, src, sizeof_namespace_index(ndd));
		}

		static struct nd_namespace_label nd_label_base(struct nvdimm_drvdata ndd)
		{
		void *base = to_namespace_index(ndd, 0);

		return base + 2 * sizeof_namespace_index(ndd);
		}

		#define for_each_clear_bit_le(bit, addr, size) \
		for ((bit) = find_next_zero_bit_le((addr), (size), 0); \
		(bit) < (size); \
		(bit) = find_next_zero_bit_le((addr), (size), (bit) + 1))

		/**
		* preamble_current - common variable initialization for nd_label_* routines
		* @ndd: dimm container for the relevant label set
		* @nsindex_out: on return set to the currently active namespace index
		* @free: on return set to the free label bitmap in the index
		* @nslot: on return set to the number of slots in the label space
		*/
		static bool preamble_current(struct nvdimm_drvdata *ndd,
		struct nd_namespace_index **nsindex_out,
		unsigned long *free, u32 nslot)
		{
		struct nd_namespace_index *nsindex;

		nsindex = to_current_namespace_index(ndd);
		if (nsindex == NULL)
		return false;

		free = (unsigned long ) nsindex->free;
		*nslot = __le32_to_cpu(nsindex->nslot);
		*nsindex_out = nsindex;

		return true;
		}

		static char nd_label_gen_id(struct nd_label_id label_id, u8 *uuid, u32 flags)
		{
		if (!label_id \|\| !uuid)
		return NULL;
		snprintf(label_id->id, ND_LABEL_ID_SIZE, "%s-%pUb",
		flags & NSLABEL_FLAG_LOCAL ? "blk" : "pmem", uuid);
		return label_id->id;
		}

		static bool slot_valid(struct nd_namespace_label *nd_label, u32 slot)
		{
		/* check that we are written where we expect to be written */
		if (slot != __le32_to_cpu(nd_label->slot))
		return false;

		/* check that DPA allocations are page aligned */
		if ((__le64_to_cpu(nd_label->dpa)
		\| __le64_to_cpu(nd_label->rawsize)) % SZ_4K)
		return false;

		return true;
		}

		int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd)
		{
		struct nd_namespace_index *nsindex;
		unsigned long *free;
		u32 nslot, slot;

		if (!preamble_current(ndd, &nsindex, &free, &nslot))
		return 0; /* no label, nothing to reserve */

		for_each_clear_bit_le(slot, free, nslot) {
		struct nd_namespace_label *nd_label;
		struct nd_region *nd_region = NULL;
		u8 label_uuid[NSLABEL_UUID_LEN];
		struct nd_label_id label_id;
		struct resource *res;
		u32 flags;

		nd_label = nd_label_base(ndd) + slot;

		if (!slot_valid(nd_label, slot))
		continue;

		memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN);
		flags = __le32_to_cpu(nd_label->flags);
		nd_label_gen_id(&label_id, label_uuid, flags);
		res = nvdimm_allocate_dpa(ndd, &label_id,
		__le64_to_cpu(nd_label->dpa),
		__le64_to_cpu(nd_label->rawsize));
		nd_dbg_dpa(nd_region, ndd, res, "reserve\n");
		if (!res)
		return -EBUSY;
		}

		return 0;
		}

drivers/nvdimm/label.h

0 → 100644

+128 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of version 2 of the GNU General Public License as
		* published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful, but
		* WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
		* General Public License for more details.
		*/
		#ifndef __LABEL_H__
		#define __LABEL_H__

		#include <linux/ndctl.h>
		#include <linux/sizes.h>
		#include <linux/io.h>

		enum {
		NSINDEX_SIG_LEN = 16,
		NSINDEX_ALIGN = 256,
		NSINDEX_SEQ_MASK = 0x3,
		NSLABEL_UUID_LEN = 16,
		NSLABEL_NAME_LEN = 64,
		NSLABEL_FLAG_ROLABEL = 0x1, /* read-only label */
		NSLABEL_FLAG_LOCAL = 0x2, /* DIMM-local namespace */
		NSLABEL_FLAG_BTT = 0x4, /* namespace contains a BTT */
		NSLABEL_FLAG_UPDATING = 0x8, /* label being updated */
		BTT_ALIGN = 4096, /* all btt structures */
		BTTINFO_SIG_LEN = 16,
		BTTINFO_UUID_LEN = 16,
		BTTINFO_FLAG_ERROR = 0x1, /* error state (read-only) */
		BTTINFO_MAJOR_VERSION = 1,
		ND_LABEL_MIN_SIZE = 512 * 129, /* see sizeof_namespace_index() */
		ND_LABEL_ID_SIZE = 50,
		};

		static const char NSINDEX_SIGNATURE[] = "NAMESPACE_INDEX\0";

		/**
		* struct nd_namespace_index - label set superblock
		* @sig: NAMESPACE_INDEX\0
		* @flags: placeholder
		* @seq: sequence number for this index
		* @myoff: offset of this index in label area
		* @mysize: size of this index struct
		* @otheroff: offset of other index
		* @labeloff: offset of first label slot
		* @nslot: total number of label slots
		* @major: label area major version
		* @minor: label area minor version
		* @checksum: fletcher64 of all fields
		* @free[0]: bitmap, nlabel bits
		*
		* The size of free[] is rounded up so the total struct size is a
		* multiple of NSINDEX_ALIGN bytes. Any bits this allocates beyond
		* nlabel bits must be zero.
		*/
		struct nd_namespace_index {
		u8 sig[NSINDEX_SIG_LEN];
		__le32 flags;
		__le32 seq;
		__le64 myoff;
		__le64 mysize;
		__le64 otheroff;
		__le64 labeloff;
		__le32 nslot;
		__le16 major;
		__le16 minor;
		__le64 checksum;
		u8 free[0];
		};

		/**
		* struct nd_namespace_label - namespace superblock
		* @uuid: UUID per RFC 4122
		* @name: optional name (NULL-terminated)
		* @flags: see NSLABEL_FLAG_*
		* @nlabel: num labels to describe this ns
		* @position: labels position in set
		* @isetcookie: interleave set cookie
		* @lbasize: LBA size in bytes or 0 for pmem
		* @dpa: DPA of NVM range on this DIMM
		* @rawsize: size of namespace
		* @slot: slot of this label in label area
		* @unused: must be zero
		*/
		struct nd_namespace_label {
		u8 uuid[NSLABEL_UUID_LEN];
		u8 name[NSLABEL_NAME_LEN];
		__le32 flags;
		__le16 nlabel;
		__le16 position;
		__le64 isetcookie;
		__le64 lbasize;
		__le64 dpa;
		__le64 rawsize;
		__le32 slot;
		__le32 unused;
		};

		/**
		* struct nd_label_id - identifier string for dpa allocation
		* @id: "{blk\|pmem}-<namespace uuid>"
		*/
		struct nd_label_id {
		char id[ND_LABEL_ID_SIZE];
		};

		/*
		* If the 'best' index is invalid, so is the 'next' index. Otherwise,
		* the next index is MOD(index+1, 2)
		*/
		static inline int nd_label_next_nsindex(int index)
		{
		if (index < 0)
		return -1;

		return (index + 1) % 2;
		}

		struct nvdimm_drvdata;
		int nd_label_validate(struct nvdimm_drvdata *ndd);
		void nd_label_copy(struct nvdimm_drvdata ndd, struct nd_namespace_index dst,
		struct nd_namespace_index *src);
		size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd);
		#endif /* __LABEL_H__ */

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