[Devel] [PATCH vz9 v1 31/63] dm-ploop: convert high_prio to status

[Alexander Atanasov]

convert bool high prio to status bit - reduce size and gain atomicity

https://virtuozzo.atlassian.net/browse/VSTOR-91817
Signed-off-by: Alexander Atanasov <alexander.atanasov at virtuozzo.com>
---
 drivers/md/dm-ploop-bat.c |  1 -
 drivers/md/dm-ploop-map.c | 10 +++++-----
 drivers/md/dm-ploop.h     |  3 +--
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c
index 33069d580e87..afbd43d74c6a 100644
--- a/drivers/md/dm-ploop-bat.c
+++ b/drivers/md/dm-ploop-bat.c
@@ -88,7 +88,6 @@ static struct md_page *ploop_alloc_md_page(u32 id)
 	md->page = page;
 	md->kmpage = kmap(page);
 	md->id = id;
-	md->high_prio = false;
 	spin_lock_init(&md->md_lock);
 
 	return md;
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index bd80dac34073..55d619cefe50 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -576,10 +576,9 @@ static void ploop_md_up_prio(struct ploop *ploop, struct md_page *md)
 	write_lock_irqsave(&ploop->bat_rwlock, flags);
 	if (test_bit(MD_WRITEBACK, &md->status))
 		goto out;
-	if (md->high_prio)
+	if (test_and_set_bit(MD_HIGHPRIO, &md->status))
 		goto out;
 
-	md->high_prio = true;
 	WARN_ON_ONCE(!test_bit(MD_DIRTY, &md->status));
 out:
 	write_unlock_irqrestore(&ploop->bat_rwlock, flags);
@@ -1859,15 +1858,16 @@ static void ploop_submit_metadata_writeback(struct ploop *ploop)
 	llist_for_each_safe(pos, t, ll_wb_batch) {
 		md = list_entry((struct list_head *)pos, typeof(*md), wb_link);
 		INIT_LIST_HEAD(&md->wb_link);
-		if (!llist_empty(&md->wait_llist) || md->high_prio ||
+		if (!llist_empty(&md->wait_llist) ||
+		    test_bit(MD_HIGHPRIO, &md->status) ||
 		    time_before(md->dirty_timeout, timeout) ||
 		    ploop->force_md_writeback) {
 			/* L1L2 mustn't be redirtyed, when wb in-flight! */
 			WARN_ON_ONCE(!test_bit(MD_DIRTY, &md->status));
 			WARN_ON_ONCE(test_bit(MD_WRITEBACK, &md->status));
-			md->high_prio = false;
 			set_bit(MD_WRITEBACK, &md->status);
 			clear_bit(MD_DIRTY, &md->status);
+			clear_bit(MD_HIGHPRIO, &md->status);
 			ploop_index_wb_submit(ploop, md->piwb);
 		} else {
 			llist_add((struct llist_node *)&md->wb_link, &ploop->wb_batch_llist);
@@ -2025,7 +2025,7 @@ static int ploop_prepare_flush(struct ploop *ploop, struct pio *pio)
 		md = list_entry((struct list_head *)pos, typeof(*md), wb_link);
 		md_inflight++;
 		md->piwb->flush_pio = flush_pio;
-		md->high_prio = true;
+		set_bit(MD_HIGHPRIO, &md->status);
 	}
 
 	atomic_set(&flush_pio->md_inflight, md_inflight);
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index 91176b3d8b35..bf4b15ddd69a 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -117,6 +117,7 @@ struct md_page {
 	u32 id; /* Number of this page starting from hdr */
 #define MD_DIRTY	(1U << 1) /* Page contains changes and wants writeback */
 #define MD_WRITEBACK	(1U << 2) /* Writeback was submitted */
+#define MD_HIGHPRIO	(1U << 3) /* High priority writeback  */
 	unsigned long status;
 	struct page *page;
 	void *kmpage;
@@ -127,8 +128,6 @@ struct md_page {
 	struct ploop_index_wb *piwb;
 
 	spinlock_t md_lock;
-
-	bool high_prio;
 	unsigned long dirty_timeout;
 };
 
-- 
2.43.0