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* [PATCH 1/4] md/r5cache: flush data only stripes in r5l_recovery_log()
@ 2017-01-13  1:22 Song Liu
  2017-01-13  1:22 ` [PATCH 2/4] md/r5cache: read data into orig_page for prexor of cached data Song Liu
                   ` (3 more replies)
  0 siblings, 4 replies; 7+ messages in thread
From: Song Liu @ 2017-01-13  1:22 UTC (permalink / raw)
  To: linux-raid
  Cc: neilb, shli, kernel-team, dan.j.williams, hch, liuzhengyuan,
	liuyun01, Song Liu, Jes.Sorensen

When there is data only stripes in the journal, we flush them out in
r5l_recovery_log(). Ths logic is implemented in a new function:
r5c_recovery_flush_data_only_stripes():

1. enable write back cache
2. set flag R5C_PRE_INIT_FLUSH in conf->cache_state
3. flush all stripes
4. wake up conf->mddev->thread
5. wait for all stripes get flushed (reuse wait_for_quiescent)
6. clear R5C_PRE_INIT_FLUSH
7. disable write back cache

do_release_stripe() will wake up the wait when conf->active_stripe
reduces to 0.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 drivers/md/raid5-cache.c | 58 +++++++++++++++++++++++++++++++++++-------------
 drivers/md/raid5.c       |  4 ++++
 drivers/md/raid5.h       |  3 +++
 3 files changed, 49 insertions(+), 16 deletions(-)

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 0c88648..2bbc38b 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -2102,7 +2102,7 @@ static int
 r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
 				       struct r5l_recovery_ctx *ctx)
 {
-	struct stripe_head *sh, *next;
+	struct stripe_head *sh;
 	struct mddev *mddev = log->rdev->mddev;
 	struct page *page;
 	sector_t next_checkpoint = MaxSector;
@@ -2116,7 +2116,7 @@ r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
 
 	WARN_ON(list_empty(&ctx->cached_list));
 
-	list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
+	list_for_each_entry(sh, &ctx->cached_list, lru) {
 		struct r5l_meta_block *mb;
 		int i;
 		int offset;
@@ -2166,14 +2166,41 @@ r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
 		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;
 }
 
+static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
+						 struct r5l_recovery_ctx *ctx)
+{
+	struct mddev *mddev = log->rdev->mddev;
+	struct r5conf *conf = mddev->private;
+	struct stripe_head *sh, *next;
+
+	if (ctx->data_only_stripes == 0)
+		return;
+
+	log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK;
+	set_bit(R5C_PRE_INIT_FLUSH, &conf->cache_state);
+
+	list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
+		r5c_make_stripe_write_out(sh);
+		set_bit(STRIPE_HANDLE, &sh->state);
+		list_del_init(&sh->lru);
+		raid5_release_stripe(sh);
+	}
+
+	md_wakeup_thread(conf->mddev->thread);
+	/* reuse conf->wait_for_quiescent in recovery */
+	wait_event(conf->wait_for_quiescent,
+		   atomic_read(&conf->active_stripes) == 0);
+
+	clear_bit(R5C_PRE_INIT_FLUSH, &conf->cache_state);
+	log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
+}
+
 static int r5l_recovery_log(struct r5l_log *log)
 {
 	struct mddev *mddev = log->rdev->mddev;
@@ -2200,32 +2227,31 @@ static int r5l_recovery_log(struct r5l_log *log)
 	pos = ctx.pos;
 	ctx.seq += 10000;
 
-	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);
-	}
 
 	if ((ctx.data_only_stripes == 0) && (ctx.data_parity_stripes == 0))
 		pr_debug("md/raid:%s: starting from clean shutdown\n",
 			 mdname(mddev));
-	else {
+	else
 		pr_debug("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
 			 mdname(mddev), ctx.data_only_stripes,
 			 ctx.data_parity_stripes);
 
-		if (ctx.data_only_stripes > 0)
-			if (r5c_recovery_rewrite_data_only_stripes(log, &ctx)) {
-				pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
-				       mdname(mddev));
-				return -EIO;
-			}
+	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 if (r5c_recovery_rewrite_data_only_stripes(log, &ctx)) {
+		pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
+		       mdname(mddev));
+		return -EIO;
 	}
 
 	log->log_start = ctx.pos;
 	log->seq = ctx.seq;
 	log->last_checkpoint = pos;
 	r5l_write_super(log, pos);
+
+	r5c_recovery_flush_data_only_stripes(log, &ctx);
 	return 0;
 }
 
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index b8e45cc..0d2082d 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -266,6 +266,10 @@ static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
 			    < IO_THRESHOLD)
 				md_wakeup_thread(conf->mddev->thread);
 		atomic_dec(&conf->active_stripes);
+		if (test_bit(R5C_PRE_INIT_FLUSH, &conf->cache_state) &&
+		    atomic_read(&conf->active_stripes) == 0)
+			wake_up(&sh->raid_conf->wait_for_quiescent);
+
 		if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
 			if (!r5c_is_writeback(conf->log))
 				list_add_tail(&sh->lru, temp_inactive_list);
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 3bb9ffc..c582086 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -564,6 +564,9 @@ enum r5_cache_state {
 	R5C_EXTRA_PAGE_IN_USE,	/* a stripe is using disk_info.extra_page
 				 * for prexor
 				 */
+	R5C_PRE_INIT_FLUSH,	/* flushing data only stripes recovered from
+				 * the journal
+				 */
 };
 
 struct r5conf {
-- 
2.9.3


^ permalink raw reply related	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2017-01-21 18:06 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-01-13  1:22 [PATCH 1/4] md/r5cache: flush data only stripes in r5l_recovery_log() Song Liu
2017-01-13  1:22 ` [PATCH 2/4] md/r5cache: read data into orig_page for prexor of cached data Song Liu
2017-01-21 18:04   ` Shaohua Li
2017-01-13  1:22 ` [PATCH 3/4] md/raid5: move comment of fetch_block to right location Song Liu
2017-01-13  1:22 ` [PATCH 4/4] md/r5cache: shift complex rmw from read path to write path Song Liu
2017-01-21 18:06   ` Shaohua Li
2017-01-21 18:03 ` [PATCH 1/4] md/r5cache: flush data only stripes in r5l_recovery_log() Shaohua Li

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