[PATCH 23/23] md/md-llbitmap: add Kconfig

[Yu Kuai]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

A new config MD_LLBITMAP is added, user can now using llbitmap to
replace the old bitmap.

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
 drivers/md/Kconfig       | 11 +++++++
 drivers/md/Makefile      |  2 +-
 drivers/md/md-bitmap.h   | 13 ++++++++
 drivers/md/md-llbitmap.c | 66 ++++++++++++++++++++++++++++++++++++++++
 drivers/md/md.c          |  6 ++++
 drivers/md/md.h          |  4 +--
 6 files changed, 99 insertions(+), 3 deletions(-)

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index f913579e731c..07c19b2182ca 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -52,6 +52,17 @@ config MD_BITMAP
 
 	  If unsure, say Y.
 
+config MD_LLBITMAP
+	bool "MD RAID lockless bitmap support"
+	depends on BLK_DEV_MD
+	help
+	  If you say Y here, support for the lockless write intent bitmap will
+	  be enabled.
+
+	  Note, this is an experimental feature.
+
+	  If unsure, say N.
+
 config MD_AUTODETECT
 	bool "Autodetect RAID arrays during kernel boot"
 	depends on BLK_DEV_MD=y
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 87bdfc9fe14c..f1ca25cc1408 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -27,7 +27,7 @@ dm-clone-y	+= dm-clone-target.o dm-clone-metadata.o
 dm-verity-y	+= dm-verity-target.o
 dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
 
-md-mod-y	+= md.o md-bitmap.o
+md-mod-y	+= md.o md-bitmap.o md-llbitmap.o
 raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
 linear-y       += md-linear.o
 
diff --git a/drivers/md/md-bitmap.h b/drivers/md/md-bitmap.h
index a9a0f6a8d96d..8b4f2068931e 100644
--- a/drivers/md/md-bitmap.h
+++ b/drivers/md/md-bitmap.h
@@ -183,4 +183,17 @@ static inline void md_bitmap_exit(void)
 }
 #endif
 
+#ifdef CONFIG_MD_LLBITMAP
+int md_llbitmap_init(void);
+void md_llbitmap_exit(void);
+#else
+static inline int md_llbitmap_init(void)
+{
+	return 0;
+}
+static inline void md_llbitmap_exit(void)
+{
+}
+#endif
+
 #endif
diff --git a/drivers/md/md-llbitmap.c b/drivers/md/md-llbitmap.c
index 38e67d4582ad..8321dcbf1ce2 100644
--- a/drivers/md/md-llbitmap.c
+++ b/drivers/md/md-llbitmap.c
@@ -1487,4 +1487,70 @@ static struct attribute_group md_llbitmap_group = {
 	.attrs = md_llbitmap_attrs,
 };
 
+static struct bitmap_operations llbitmap_ops = {
+	.head = {
+		.type	= MD_BITMAP,
+		.id	= ID_LLBITMAP,
+		.name	= "llbitmap",
+	},
+
+	.enabled		= llbitmap_enabled,
+	.create			= llbitmap_create,
+	.resize			= llbitmap_resize,
+	.load			= llbitmap_load,
+	.destroy		= llbitmap_destroy,
+
+	.start_write		= llbitmap_start_write,
+	.end_write		= llbitmap_end_write,
+	.start_discard		= llbitmap_start_discard,
+	.end_discard		= llbitmap_end_discard,
+	.unplug			= llbitmap_unplug,
+	.flush			= llbitmap_flush,
+
+	.start_behind_write	= llbitmap_start_behind_write,
+	.end_behind_write	= llbitmap_end_behind_write,
+	.wait_behind_writes	= llbitmap_wait_behind_writes,
+
+	.blocks_synced		= llbitmap_blocks_synced,
+	.skip_sync_blocks	= llbitmap_skip_sync_blocks,
+	.start_sync		= llbitmap_start_sync,
+	.end_sync		= llbitmap_end_sync,
+	.close_sync		= llbitmap_close_sync,
+	.cond_end_sync		= llbitmap_cond_end_sync,
+
+	.update_sb		= llbitmap_update_sb,
+	.get_stats		= llbitmap_get_stats,
+	.dirty_bits		= llbitmap_dirty_bits,
+	.write_all		= llbitmap_write_all,
+
+	.group			= &md_llbitmap_group,
+};
+
+int md_llbitmap_init(void)
+{
+	md_llbitmap_io_wq = alloc_workqueue("md_llbitmap_io",
+					 WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
+	if (!md_llbitmap_io_wq)
+		return -ENOMEM;
+
+	md_llbitmap_unplug_wq = alloc_workqueue("md_llbitmap_unplug",
+					 WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
+	if (!md_llbitmap_unplug_wq) {
+		destroy_workqueue(md_llbitmap_io_wq);
+		md_llbitmap_io_wq = NULL;
+		return -ENOMEM;
+	}
+
+	return register_md_submodule(&llbitmap_ops.head);
+}
+
+void md_llbitmap_exit(void)
+{
+	destroy_workqueue(md_llbitmap_io_wq);
+	md_llbitmap_io_wq = NULL;
+	destroy_workqueue(md_llbitmap_unplug_wq);
+	md_llbitmap_unplug_wq = NULL;
+	unregister_md_submodule(&llbitmap_ops.head);
+}
+
 #endif /* CONFIG_MD_LLBITMAP */
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c7f7914b7452..52e19344b73e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -10183,6 +10183,10 @@ static int __init md_init(void)
 	if (ret)
 		return ret;
 
+	ret = md_llbitmap_init();
+	if (ret)
+		goto err_bitmap;
+
 	ret = -ENOMEM;
 	md_wq = alloc_workqueue("md", WQ_MEM_RECLAIM, 0);
 	if (!md_wq)
@@ -10214,6 +10218,8 @@ static int __init md_init(void)
 err_misc_wq:
 	destroy_workqueue(md_wq);
 err_wq:
+	md_llbitmap_exit();
+err_bitmap:
 	md_bitmap_exit();
 	return ret;
 }
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 3adb1660c7ed..aba5f1ffcdfd 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -26,7 +26,7 @@
 enum md_submodule_type {
 	MD_PERSONALITY = 0,
 	MD_CLUSTER,
-	MD_BITMAP, /* TODO */
+	MD_BITMAP,
 };
 
 enum md_submodule_id {
@@ -39,7 +39,7 @@ enum md_submodule_id {
 	ID_RAID10	= 10,
 	ID_CLUSTER,
 	ID_BITMAP,
-	ID_LLBITMAP,	/* TODO */
+	ID_LLBITMAP,
 	ID_BITMAP_NONE,
 };
 
-- 
2.39.2