From 3c66abbaaf69671dfd3eb9fa7740b5d7ec688231 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Wed, 14 Dec 2016 15:38:01 -0800 Subject: [PATCH] md/r5cache: simplify handling of sh->log_start in recovery We only need to update sh->log_start at the end of recovery, which is r5c_recovery_rewrite_data_only_stripes(), so it is not necessary to set it before that. In this patch, log_start is removed from r5c_recovery_alloc_stripe(). After updating all sh->log_start, rewrite_data_only_stripes() also updates log->next_checkpoints to the last sh->log_start. Signed-off-by: Song Liu Signed-off-by: Shaohua Li --- drivers/md/raid5-cache.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 49aea4231084..b178a8fef266 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1682,8 +1682,7 @@ out: static struct stripe_head * r5c_recovery_alloc_stripe(struct r5conf *conf, - sector_t stripe_sect, - sector_t log_start) + sector_t stripe_sect) { struct stripe_head *sh; @@ -1692,7 +1691,6 @@ r5c_recovery_alloc_stripe(struct r5conf *conf, return NULL; /* no more stripe available */ r5l_recovery_reset_stripe(sh); - sh->log_start = log_start; return sh; } @@ -1862,7 +1860,7 @@ r5c_recovery_analyze_meta_block(struct r5l_log *log, stripe_sect); if (!sh) { - sh = r5c_recovery_alloc_stripe(conf, stripe_sect, ctx->pos); + sh = r5c_recovery_alloc_stripe(conf, stripe_sect); /* * cannot get stripe from raid5_get_active_stripe * try replay some stripes @@ -1871,7 +1869,7 @@ r5c_recovery_analyze_meta_block(struct r5l_log *log, r5c_recovery_replay_stripes( cached_stripe_list, ctx); sh = r5c_recovery_alloc_stripe( - conf, stripe_sect, ctx->pos); + conf, stripe_sect); } if (!sh) { pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n", @@ -1879,8 +1877,8 @@ r5c_recovery_analyze_meta_block(struct r5l_log *log, conf->min_nr_stripes * 2); raid5_set_cache_size(mddev, conf->min_nr_stripes * 2); - sh = r5c_recovery_alloc_stripe( - conf, stripe_sect, ctx->pos); + sh = r5c_recovery_alloc_stripe(conf, + stripe_sect); } if (!sh) { pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n", @@ -1894,7 +1892,6 @@ r5c_recovery_analyze_meta_block(struct r5l_log *log, if (!test_bit(STRIPE_R5C_CACHING, &sh->state) && test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) { r5l_recovery_replay_one_stripe(conf, sh, ctx); - sh->log_start = ctx->pos; list_move_tail(&sh->lru, cached_stripe_list); } r5l_recovery_load_data(log, sh, ctx, payload, @@ -1933,8 +1930,6 @@ static void r5c_recovery_load_one_stripe(struct r5l_log *log, set_bit(R5_UPTODATE, &dev->flags); } } - list_add_tail(&sh->r5c, &log->stripe_in_journal_list); - atomic_inc(&log->stripe_in_journal_count); } /* @@ -2070,6 +2065,7 @@ r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log, struct stripe_head *sh, *next; struct mddev *mddev = log->rdev->mddev; struct page *page; + sector_t next_checkpoint = MaxSector; page = alloc_page(GFP_KERNEL); if (!page) { @@ -2078,6 +2074,8 @@ r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log, return -ENOMEM; } + WARN_ON(list_empty(&ctx->cached_list)); + list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) { struct r5l_meta_block *mb; int i; @@ -2123,12 +2121,15 @@ r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log, sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page, REQ_OP_WRITE, REQ_FUA, false); sh->log_start = ctx->pos; + list_add_tail(&sh->r5c, &log->stripe_in_journal_list); + atomic_inc(&log->stripe_in_journal_count); ctx->pos = write_pos; ctx->seq += 1; - + next_checkpoint = sh->log_start; list_del_init(&sh->lru); raid5_release_stripe(sh); } + log->next_checkpoint = next_checkpoint; __free_page(page); return 0; } @@ -2139,7 +2140,6 @@ static int r5l_recovery_log(struct r5l_log *log) 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; @@ -2164,9 +2164,6 @@ static int r5l_recovery_log(struct r5l_log *log) 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))