From b177fe85dd27de1ee4c29f59c4e82b3ea3b78784 Mon Sep 17 00:00:00 2001 From: Vishal Verma Date: Wed, 10 May 2017 15:01:31 -0600 Subject: [PATCH] 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 Cc: Dan Williams Signed-off-by: Vishal Verma Signed-off-by: Dan Williams --- drivers/nvdimm/btt.c | 54 +++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 47 insertions(+), 7 deletions(-) diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index aa977cd..983718b 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -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) -- 2.7.4