From 43b9674832cc41ad0ad7b7e2ec397e47dcd5f6c3 Mon Sep 17 00:00:00 2001 From: JackieLiu Date: Mon, 5 Dec 2016 11:58:53 +0800 Subject: [PATCH] md/raid5-cache: adjust the write position of the empty block if no data blocks When recovery is complete, we write an empty block and record his position first, then make the data-only stripes rewritten done, the location of the empty block as the last checkpoint position to write into the super block. And we should update last_checkpoint to this empty block position. ------------------------------------------------------------------ | old log | empty block | data only stripes | invalid log | ------------------------------------------------------------------ ^ ^ ^ | |- log->last_checkpoint |- log->log_start | |- log->last_cp_seq |- log->next_checkpoint |- log->seq=n |- log->seq=10+n At the same time, if there is no data-only stripes, this scene may appear, | meta1 | meta2 | meta3 | meta 1 is valid, meta 2 is invalid. meta 3 could be valid. so we should The solution is we create a new meta in meta2 with its seq == meta1's seq + 10 and let superblock points to meta2. Signed-off-by: JackieLiu Reviewed-by: Zhengyuan Liu Reviewed-by: Song Liu Signed-off-by: Shaohua Li --- drivers/md/raid5-cache.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index c36f86b47252..5efb876a588d 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -2077,7 +2077,6 @@ r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log, return -ENOMEM; } - ctx->seq += 10; list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) { struct r5l_meta_block *mb; int i; @@ -2137,6 +2136,8 @@ static int r5l_recovery_log(struct r5l_log *log) struct mddev *mddev = log->rdev->mddev; struct r5l_recovery_ctx ctx; int ret; + sector_t pos; + struct stripe_head *sh; ctx.pos = log->last_checkpoint; ctx.seq = log->last_cp_seq; @@ -2154,6 +2155,18 @@ static int r5l_recovery_log(struct r5l_log *log) if (ret) return ret; + pos = ctx.pos; + ctx.seq += 10; + + if (ctx.data_only_stripes == 0) { + log->next_checkpoint = ctx.pos; + r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq++); + ctx.pos = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS); + } else { + sh = list_last_entry(&ctx.cached_list, struct stripe_head, lru); + log->next_checkpoint = sh->log_start; + } + if ((ctx.data_only_stripes == 0) && (ctx.data_parity_stripes == 0)) pr_debug("md/raid:%s: starting from clean shutdown\n", mdname(mddev)); @@ -2171,10 +2184,9 @@ static int r5l_recovery_log(struct r5l_log *log) } log->log_start = ctx.pos; - log->next_checkpoint = ctx.pos; log->seq = ctx.seq; - r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq); - r5l_write_super(log, ctx.pos); + log->last_checkpoint = pos; + r5l_write_super(log, pos); return 0; }