Commit b177fe85 authored by Vishal Verma's avatar Vishal Verma Committed by Dan Williams
Browse files

libnvdimm, btt: ensure that initializing metadata clears poison 



If we had badblocks/poison in the metadata area of a BTT, recreating the
BTT would not clear the poison in all cases, notably the flog area. This
is because rw_bytes will only clear errors if the request being sent
down is 512B aligned and sized.

Make sure that when writing the map and info blocks, the rw_bytes being
sent are of the correct size/alignment. For the flog, instead of doing
the smaller log_entry writes only, first do a 'wipe' of the entire area
by writing zeroes in large enough chunks so that errors get cleared.

Cc: Andy Rudoff <andy.rudoff@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 3ae3d67b

drivers/nvdimm/btt.c

+47 −7
Original line number Diff line number Diff line
@@ -57,6 +57,14 @@ static int btt_info_write(struct arena_info *arena, struct btt_sb *super) 
{

	int ret;



	/*

	 * infooff and info2off should always be at least 512B aligned.

	 * We rely on that to make sure rw_bytes does error clearing

	 * correctly, so make sure that is the case.

	 */

	WARN_ON_ONCE(!IS_ALIGNED(arena->infooff, 512));

	WARN_ON_ONCE(!IS_ALIGNED(arena->info2off, 512));



	ret = arena_write_bytes(arena, arena->info2off, super,

			sizeof(struct btt_sb), 0);

	if (ret)
@@ -394,9 +402,17 @@ static int btt_map_init(struct arena_info *arena) 
	if (!zerobuf)

		return -ENOMEM;



	/*

	 * mapoff should always be at least 512B  aligned. We rely on that to

	 * make sure rw_bytes does error clearing correctly, so make sure that

	 * is the case.

	 */

	WARN_ON_ONCE(!IS_ALIGNED(arena->mapoff, 512));



	while (mapsize) {

		size_t size = min(mapsize, chunk_size);



		WARN_ON_ONCE(size < 512);

		ret = arena_write_bytes(arena, arena->mapoff + offset, zerobuf,

				size, 0);

		if (ret)
@@ -418,11 +434,36 @@ static int btt_map_init(struct arena_info *arena) 
 */

static int btt_log_init(struct arena_info *arena)

{

	size_t logsize = arena->info2off - arena->logoff;

	size_t chunk_size = SZ_4K, offset = 0;

	struct log_entry log;

	void *zerobuf;

	int ret;

	u32 i;

	struct log_entry log, zerolog;



	memset(&zerolog, 0, sizeof(zerolog));

	zerobuf = kzalloc(chunk_size, GFP_KERNEL);

	if (!zerobuf)

		return -ENOMEM;

	/*

	 * logoff should always be at least 512B  aligned. We rely on that to

	 * make sure rw_bytes does error clearing correctly, so make sure that

	 * is the case.

	 */

	WARN_ON_ONCE(!IS_ALIGNED(arena->logoff, 512));



	while (logsize) {

		size_t size = min(logsize, chunk_size);



		WARN_ON_ONCE(size < 512);

		ret = arena_write_bytes(arena, arena->logoff + offset, zerobuf,

				size, 0);

		if (ret)

			goto free;



		offset += size;

		logsize -= size;

		cond_resched();

	}



	for (i = 0; i < arena->nfree; i++) {

		log.lba = cpu_to_le32(i);
@@ -431,13 +472,12 @@ static int btt_log_init(struct arena_info *arena) 
		log.seq = cpu_to_le32(LOG_SEQ_INIT);

		ret = __btt_log_write(arena, i, 0, &log, 0);

		if (ret)

			return ret;

		ret = __btt_log_write(arena, i, 1, &zerolog, 0);

		if (ret)

			return ret;

			goto free;

	}



	return 0;

 free:

	kfree(zerobuf);

	return ret;

}



static int btt_freelist_init(struct arena_info *arena)

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