From mboxrd@z Thu Jan 1 00:00:00 1970 From: JackieLiu Subject: [PATCH 4/4] md/raid5-cache: adjust the write position of the empty block and mark it as a checkpoint Date: Mon, 28 Nov 2016 16:19:21 +0800 Message-ID: <20161128081921.5641-4-liuyun01@kylinos.cn> References: <20161128081921.5641-1-liuyun01@kylinos.cn> Return-path: In-Reply-To: <20161128081921.5641-1-liuyun01@kylinos.cn> Sender: linux-raid-owner@vger.kernel.org To: songliubraving@fb.com Cc: liuzhengyuan@kylinos.cn, linux-raid@vger.kernel.org, JackieLiu List-Id: linux-raid.ids 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. Reviewed-by: Zhengyuan Liu Signed-off-by: JackieLiu --- drivers/md/raid5-cache.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 9e72180..20594f7 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -2072,7 +2072,6 @@ 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; @@ -2132,6 +2131,7 @@ 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; ctx.pos = log->last_checkpoint; ctx.seq = log->last_cp_seq; @@ -2149,6 +2149,10 @@ static int r5l_recovery_log(struct r5l_log *log) if (ret) return ret; + pos = ctx.pos; + r5l_log_write_empty_meta_block(log, ctx.pos, (ctx.seq += 10)); + ctx.pos = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS); + if ((ctx.data_only_stripes == 0) && (ctx.data_parity_stripes == 0)) pr_debug("md/raid:%s: starting from clean shutdown\n", mdname(mddev)); @@ -2167,9 +2171,9 @@ static int r5l_recovery_log(struct r5l_log *log) log->log_start = ctx.pos; log->next_checkpoint = ctx.pos; + log->last_checkpoint = pos; log->seq = ctx.seq; - r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq); - r5l_write_super(log, ctx.pos); + r5l_write_super(log, pos); return 0; } -- 2.7.4