pstore/zone,blk: Add support for pmsg frontend (0dc06826) · Commits · 戴 / test

fs/pstore/Kconfig

+12 −0

Original line number	Diff line number	Diff line
		@@ -224,3 +224,15 @@ config PSTORE_BLK_MAX_REASON

		NOTE that, both Kconfig and module parameters can configure
		pstore/blk, but module parameters have priority over Kconfig.

		config PSTORE_BLK_PMSG_SIZE
		int "Size in Kbytes of pmsg to store"
		depends on PSTORE_BLK
		depends on PSTORE_PMSG
		default 64
		help
		This just sets size of pmsg (pmsg_size) for pstore/blk. The size is
		in KB and must be a multiple of 4.

		NOTE that, both Kconfig and module parameters can configure
		pstore/blk, but module parameters have priority over Kconfig.

fs/pstore/blk.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -27,6 +27,14 @@ module_param(max_reason, int, 0400);
		MODULE_PARM_DESC(max_reason,
		"maximum reason for kmsg dump (default 2: Oops and Panic)");

		#if IS_ENABLED(CONFIG_PSTORE_PMSG)
		static long pmsg_size = CONFIG_PSTORE_BLK_PMSG_SIZE;
		#else
		static long pmsg_size = -1;
		#endif
		module_param(pmsg_size, long, 0400);
		MODULE_PARM_DESC(pmsg_size, "pmsg size in kbytes");

		/*
		* blkdev - the block device to use for pstore storage
		*
		@@ -133,6 +141,7 @@ static int psblk_register_do(struct pstore_device_info *dev)
		}

		verify_size(kmsg_size, 4096, dev->flags & PSTORE_FLAGS_DMESG);
		verify_size(pmsg_size, 4096, dev->flags & PSTORE_FLAGS_PMSG);
		#undef verify_size

		pstore_zone_info->total_size = dev->total_size;

fs/pstore/zone.c

+259 −9

Original line number	Diff line number	Diff line
		@@ -27,12 +27,14 @@
		*
		* @sig: signature to indicate header (PSZ_SIG xor PSZONE-type value)
		* @datalen: length of data in @data
		* @start: offset into @data where the beginning of the stored bytes begin
		* @data: zone data.
		*/
		struct psz_buffer {
		#define PSZ_SIG (0x43474244) /* DBGC */
		uint32_t sig;
		atomic_t datalen;
		atomic_t start;
		uint8_t data[];
		};

		@@ -88,9 +90,11 @@ struct pstore_zone {
		* struct psz_context - all about running state of pstore/zone
		*
		* @kpszs: kmsg dump storage zones
		* @ppsz: pmsg storage zone
		* @kmsg_max_cnt: max count of @kpszs
		* @kmsg_read_cnt: counter of total read kmsg dumps
		* @kmsg_write_cnt: counter of total kmsg dump writes
		* @pmsg_read_cnt: counter of total read pmsg zone
		* @oops_counter: counter of oops dumps
		* @panic_counter: counter of panic dumps
		* @recovered: whether finished recovering data from storage
		@@ -101,9 +105,11 @@ struct pstore_zone {
		*/
		struct psz_context {
		struct pstore_zone **kpszs;
		struct pstore_zone *ppsz;
		unsigned int kmsg_max_cnt;
		unsigned int kmsg_read_cnt;
		unsigned int kmsg_write_cnt;
		unsigned int pmsg_read_cnt;
		/*
		* These counters should be calculated during recovery.
		* It records the oops/panic times after crashes rather than boots.
		@@ -143,15 +149,20 @@ static inline int buffer_datalen(struct pstore_zone *zone)
		return atomic_read(&zone->buffer->datalen);
		}

		static inline int buffer_start(struct pstore_zone *zone)
		{
		return atomic_read(&zone->buffer->start);
		}

		static inline bool is_on_panic(void)
		{
		return atomic_read(&pstore_zone_cxt.on_panic);
		}

		static ssize_t psz_zone_read(struct pstore_zone zone, char buf,
		static ssize_t psz_zone_read_buffer(struct pstore_zone zone, char buf,
		size_t len, unsigned long off)
		{
		if (!buf \|\| !zone->buffer)
		if (!buf \|\| !zone \|\| !zone->buffer)
		return -EINVAL;
		if (off > zone->buffer_size)
		return -EINVAL;
		@@ -160,6 +171,18 @@ static ssize_t psz_zone_read(struct pstore_zone zone, char buf,
		return len;
		}

		static int psz_zone_read_oldbuf(struct pstore_zone zone, char buf,
		size_t len, unsigned long off)
		{
		if (!buf \|\| !zone \|\| !zone->oldbuf)
		return -EINVAL;
		if (off > zone->buffer_size)
		return -EINVAL;
		len = min_t(size_t, len, zone->buffer_size - off);
		memcpy(buf, zone->oldbuf->data + off, len);
		return 0;
		}

		static int psz_zone_write(struct pstore_zone *zone,
		enum psz_flush_mode flush_mode, const char *buf,
		size_t len, unsigned long off)
		@@ -415,6 +438,93 @@ recover_fail:
		return ret;
		}

		static int psz_recover_zone(struct psz_context cxt, struct pstore_zone zone)
		{
		struct pstore_zone_info *info = cxt->pstore_zone_info;
		struct psz_buffer *oldbuf, tmpbuf;
		int ret = 0;
		char *buf;
		ssize_t rcnt, len, start, off;

		if (!zone \|\| zone->oldbuf)
		return 0;

		if (is_on_panic()) {
		/* save data as much as possible */
		psz_flush_dirty_zone(zone);
		return 0;
		}

		if (unlikely(!info->read))
		return -EINVAL;

		len = sizeof(struct psz_buffer);
		rcnt = info->read((char *)&tmpbuf, len, zone->off);
		if (rcnt != len) {
		pr_debug("read zone %s failed\n", zone->name);
		return (int)rcnt < 0 ? (int)rcnt : -EIO;
		}

		if (tmpbuf.sig != zone->buffer->sig) {
		pr_debug("no valid data in zone %s\n", zone->name);
		return 0;
		}

		if (zone->buffer_size < atomic_read(&tmpbuf.datalen) \|\|
		zone->buffer_size < atomic_read(&tmpbuf.start)) {
		pr_info("found overtop zone: %s: off %lld, size %zu\n",
		zone->name, zone->off, zone->buffer_size);
		/* just keep going */
		return 0;
		}

		if (!atomic_read(&tmpbuf.datalen)) {
		pr_debug("found erased zone: %s: off %lld, size %zu, datalen %d\n",
		zone->name, zone->off, zone->buffer_size,
		atomic_read(&tmpbuf.datalen));
		return 0;
		}

		pr_debug("found nice zone: %s: off %lld, size %zu, datalen %d\n",
		zone->name, zone->off, zone->buffer_size,
		atomic_read(&tmpbuf.datalen));

		len = atomic_read(&tmpbuf.datalen) + sizeof(*oldbuf);
		oldbuf = kzalloc(len, GFP_KERNEL);
		if (!oldbuf)
		return -ENOMEM;

		memcpy(oldbuf, &tmpbuf, sizeof(*oldbuf));
		buf = (char )oldbuf + sizeof(oldbuf);
		len = atomic_read(&oldbuf->datalen);
		start = atomic_read(&oldbuf->start);
		off = zone->off + sizeof(*oldbuf);

		/* get part of data */
		rcnt = info->read(buf, len - start, off + start);
		if (rcnt != len - start) {
		pr_err("read zone %s failed\n", zone->name);
		ret = (int)rcnt < 0 ? (int)rcnt : -EIO;
		goto free_oldbuf;
		}

		/* get the rest of data */
		rcnt = info->read(buf + len - start, start, off);
		if (rcnt != start) {
		pr_err("read zone %s failed\n", zone->name);
		ret = (int)rcnt < 0 ? (int)rcnt : -EIO;
		goto free_oldbuf;
		}

		zone->oldbuf = oldbuf;
		psz_flush_dirty_zone(zone);
		return 0;

		free_oldbuf:
		kfree(oldbuf);
		return ret;
		}

		/**
		* psz_recovery() - recover data from storage
		* @cxt: the context of pstore/zone
		@@ -431,7 +541,12 @@ static inline int psz_recovery(struct psz_context *cxt)
		return 0;

		ret = psz_kmsg_recover(cxt);
		if (ret)
		goto out;

		ret = psz_recover_zone(cxt, cxt->ppsz);

		out:
		if (unlikely(ret))
		pr_err("recover failed\n");
		else {
		@@ -446,9 +561,17 @@ static int psz_pstore_open(struct pstore_info *psi)
		struct psz_context *cxt = psi->data;

		cxt->kmsg_read_cnt = 0;
		cxt->pmsg_read_cnt = 0;
		return 0;
		}

		static inline bool psz_old_ok(struct pstore_zone *zone)
		{
		if (zone && zone->oldbuf && atomic_read(&zone->oldbuf->datalen))
		return true;
		return false;
		}

		static inline bool psz_ok(struct pstore_zone *zone)
		{
		if (zone && zone->buffer && buffer_datalen(zone))
		@@ -473,6 +596,25 @@ static inline int psz_kmsg_erase(struct psz_context *cxt,
		return psz_zone_write(zone, FLUSH_META, NULL, 0, 0);
		}

		static inline int psz_record_erase(struct psz_context *cxt,
		struct pstore_zone *zone)
		{
		if (unlikely(!psz_old_ok(zone)))
		return 0;

		kfree(zone->oldbuf);
		zone->oldbuf = NULL;
		/*
		* if there are new data in zone buffer, that means the old data
		* are already invalid. It is no need to flush 0 (erase) to
		* block device.
		*/
		if (!buffer_datalen(zone))
		return psz_zone_write(zone, FLUSH_META, NULL, 0, 0);
		psz_flush_dirty_zone(zone);
		return 0;
		}

		static int psz_pstore_erase(struct pstore_record *record)
		{
		struct psz_context *cxt = record->psi->data;
		@@ -482,6 +624,8 @@ static int psz_pstore_erase(struct pstore_record *record)
		if (record->id >= cxt->kmsg_max_cnt)
		return -EINVAL;
		return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record);
		case PSTORE_TYPE_PMSG:
		return psz_record_erase(cxt, cxt->ppsz);
		default:
		return -EINVAL;
		}
		@@ -555,6 +699,55 @@ static int notrace psz_kmsg_write(struct psz_context *cxt,
		return 0;
		}

		static int notrace psz_record_write(struct pstore_zone *zone,
		struct pstore_record *record)
		{
		size_t start, rem;
		bool is_full_data = false;
		char *buf;
		int cnt;

		if (!zone \|\| !record)
		return -ENOSPC;

		if (atomic_read(&zone->buffer->datalen) >= zone->buffer_size)
		is_full_data = true;

		cnt = record->size;
		buf = record->buf;
		if (unlikely(cnt > zone->buffer_size)) {
		buf += cnt - zone->buffer_size;
		cnt = zone->buffer_size;
		}

		start = buffer_start(zone);
		rem = zone->buffer_size - start;
		if (unlikely(rem < cnt)) {
		psz_zone_write(zone, FLUSH_PART, buf, rem, start);
		buf += rem;
		cnt -= rem;
		start = 0;
		is_full_data = true;
		}

		atomic_set(&zone->buffer->start, cnt + start);
		psz_zone_write(zone, FLUSH_PART, buf, cnt, start);

		/**
		* psz_zone_write will set datalen as start + cnt.
		* It work if actual data length lesser than buffer size.
		* If data length greater than buffer size, pmsg will rewrite to
		* beginning of zone, which make buffer->datalen wrongly.
		* So we should reset datalen as buffer size once actual data length
		* greater than buffer size.
		*/
		if (is_full_data) {
		atomic_set(&zone->buffer->datalen, zone->buffer_size);
		psz_zone_write(zone, FLUSH_META, NULL, 0, 0);
		}
		return 0;
		}

		static int notrace psz_pstore_write(struct pstore_record *record)
		{
		struct psz_context *cxt = record->psi->data;
		@@ -566,6 +759,8 @@ static int notrace psz_pstore_write(struct pstore_record *record)
		switch (record->type) {
		case PSTORE_TYPE_DMESG:
		return psz_kmsg_write(cxt, record);
		case PSTORE_TYPE_PMSG:
		return psz_record_write(cxt->ppsz, record);
		default:
		return -EINVAL;
		}
		@@ -581,6 +776,13 @@ static struct pstore_zone psz_read_next_zone(struct psz_context cxt)
		return zone;
		}

		if (cxt->pmsg_read_cnt == 0) {
		cxt->pmsg_read_cnt++;
		zone = cxt->ppsz;
		if (psz_old_ok(zone))
		return zone;
		}

		return NULL;
		}

		@@ -631,7 +833,7 @@ static ssize_t psz_kmsg_read(struct pstore_zone *zone,
		return -ENOMEM;
		}

		size = psz_zone_read(zone, record->buf + hlen, size,
		size = psz_zone_read_buffer(zone, record->buf + hlen, size,
		sizeof(struct psz_kmsg_header));
		if (unlikely(size < 0)) {
		kfree(record->buf);
		@@ -641,6 +843,32 @@ static ssize_t psz_kmsg_read(struct pstore_zone *zone,
		return size + hlen;
		}

		static ssize_t psz_record_read(struct pstore_zone *zone,
		struct pstore_record *record)
		{
		size_t len;
		struct psz_buffer *buf;

		if (!zone \|\| !record)
		return -ENOSPC;

		buf = (struct psz_buffer *)zone->oldbuf;
		if (!buf)
		return -ENOMSG;

		len = atomic_read(&buf->datalen);
		record->buf = kmalloc(len, GFP_KERNEL);
		if (!record->buf)
		return -ENOMEM;

		if (unlikely(psz_zone_read_oldbuf(zone, record->buf, len, 0))) {
		kfree(record->buf);
		return -ENOMSG;
		}

		return len;
		}

		static ssize_t psz_pstore_read(struct pstore_record *record)
		{
		struct psz_context *cxt = record->psi->data;
		@@ -665,6 +893,9 @@ next_zone:
		readop = psz_kmsg_read;
		record->id = cxt->kmsg_read_cnt - 1;
		break;
		case PSTORE_TYPE_PMSG:
		readop = psz_record_read;
		break;
		default:
		goto next_zone;
		}
		@@ -720,6 +951,8 @@ static void psz_free_all_zones(struct psz_context *cxt)
		{
		if (cxt->kpszs)
		psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt);
		if (cxt->ppsz)
		psz_free_zone(&cxt->ppsz);
		}

		static struct pstore_zone *psz_init_zone(enum pstore_type_id type,
		@@ -753,8 +986,10 @@ static struct pstore_zone *psz_init_zone(enum pstore_type_id type,
		zone->type = type;
		zone->buffer_size = size - sizeof(struct psz_buffer);
		zone->buffer->sig = type ^ PSZ_SIG;
		zone->oldbuf = NULL;
		atomic_set(&zone->dirty, 0);
		atomic_set(&zone->buffer->datalen, 0);
		atomic_set(&zone->buffer->start, 0);

		*off += size;

		@@ -809,19 +1044,28 @@ static int psz_alloc_zones(struct psz_context *cxt)
		struct pstore_zone_info *info = cxt->pstore_zone_info;
		loff_t off = 0;
		int err;
		size_t size;
		size_t off_size = 0;

		size = info->total_size;
		cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off, size,
		off_size += info->pmsg_size;
		cxt->ppsz = psz_init_zone(PSTORE_TYPE_PMSG, &off, info->pmsg_size);
		if (IS_ERR(cxt->ppsz)) {
		err = PTR_ERR(cxt->ppsz);
		cxt->ppsz = NULL;
		goto free_out;
		}

		cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off,
		info->total_size - off_size,
		info->kmsg_size, &cxt->kmsg_max_cnt);
		if (IS_ERR(cxt->kpszs)) {
		err = PTR_ERR(cxt->kpszs);
		cxt->kpszs = NULL;
		goto fail_out;
		goto free_out;
		}

		return 0;
		fail_out:
		free_out:
		psz_free_all_zones(cxt);
		return err;
		}

		@@ -844,7 +1088,7 @@ int register_pstore_zone(struct pstore_zone_info *info)
		return -EINVAL;
		}

		if (!info->kmsg_size) {
		if (!info->kmsg_size && !info->pmsg_size) {
		pr_warn("at least one record size must be non-zero\n");
		return -EINVAL;
		}
		@@ -866,6 +1110,7 @@ int register_pstore_zone(struct pstore_zone_info *info)

		check_size(total_size, 4096);
		check_size(kmsg_size, SECTOR_SIZE);
		check_size(pmsg_size, SECTOR_SIZE);

		#undef check_size

		@@ -891,6 +1136,7 @@ int register_pstore_zone(struct pstore_zone_info *info)
		pr_debug("register %s with properties:\n", info->name);
		pr_debug("\ttotal size : %ld Bytes\n", info->total_size);
		pr_debug("\tkmsg size : %ld Bytes\n", info->kmsg_size);
		pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size);

		err = psz_alloc_zones(cxt);
		if (err) {
		@@ -920,6 +1166,10 @@ int register_pstore_zone(struct pstore_zone_info *info)
		pr_cont(",panic_write");
		pr_cont(")");
		}
		if (info->pmsg_size) {
		cxt->pstore.flags \|= PSTORE_FLAGS_PMSG;
		pr_cont(" pmsg");
		}
		pr_cont("\n");

		err = pstore_register(&cxt->pstore);

include/linux/pstore_zone.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@ typedef ssize_t (pstore_zone_write_op)(const char , size_t, loff_t);
		* @kmsg_size: The size of oops/panic zone. Zero means disabled, otherwise,
		* it must be multiple of SECTOR_SIZE(512 Bytes).
		* @max_reason: Maximum kmsg dump reason to store.
		* @pmsg_size: The size of pmsg zone which is the same as @kmsg_size.
		* @read: The general read operation. Both of the function parameters
		* @size and @offset are relative value to storage.
		* On success, the number of bytes should be returned, others
		@@ -33,6 +34,7 @@ struct pstore_zone_info {
		unsigned long total_size;
		unsigned long kmsg_size;
		int max_reason;
		unsigned long pmsg_size;
		pstore_zone_read_op read;
		pstore_zone_write_op write;
		pstore_zone_write_op panic_write;

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