[Devel] [RFC PATCH vz9 v6 34/62] 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 | 9 ++++-----
 drivers/md/dm-ploop.h     | 2 +-
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c
index 1171294841a7..a6202720927f 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;
 	rwlock_init(&md->lock);
 	return md;
 err_page:
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index 722a1fbf499e..ad500df411c7 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -573,10 +573,9 @@ 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);
@@ -1846,14 +1845,14 @@ 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 (md->high_prio || ktime_after(md->dirty_time, ktimeout)
+		if (test_bit(MD_HIGHPRIO, &md->status) || ktime_after(md->dirty_time, ktimeout)
 		    || 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);
@@ -2018,7 +2017,7 @@ 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 1ecd51f2ac3a..8dfd75e97845 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -118,6 +118,7 @@ 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;
@@ -129,7 +130,6 @@ struct md_page {
 
 	rwlock_t lock;
 
-	bool high_prio;
 	ktime_t dirty_time;
 };
 
-- 
2.43.0