[PATCH v2 01/20] md: add exact bitmap mapping and reshape hooks

From: Yu Kuai <[email protected]>

Add bitmap mapping and reshape hooks needed by llbitmap reshape
support without teaching md core to account a single bio against
multiple bitmap ranges.

This also adds the old/new bitmap geometry helpers used by
personalities to describe reshape mapping to llbitmap.

Signed-off-by: Yu Kuai <[email protected]>
---
 drivers/md/md-bitmap.c   |  8 ++++++++
 drivers/md/md-bitmap.h   |  8 ++++++++
 drivers/md/md-llbitmap.c |  8 ++++++++
 drivers/md/md.c          | 12 ++++++++----
 drivers/md/md.h          |  4 ++++
 5 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 0f02e2956398..4c31807e6bcc 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -1730,6 +1730,13 @@ static void bitmap_start_write(struct mddev *mddev, sector_t offset,
 	}
 }
 
+static void bitmap_prepare_range(struct mddev *mddev, sector_t *offset,
+				 unsigned long *sectors)
+{
+	if (mddev->pers->bitmap_sector)
+		mddev->pers->bitmap_sector(mddev, offset, sectors);
+}
+
 static void bitmap_end_write(struct mddev *mddev, sector_t offset,
 			     unsigned long sectors)
 {
@@ -3083,6 +3090,7 @@ static struct bitmap_operations bitmap_ops = {
 	.flush			= bitmap_flush,
 	.write_all		= bitmap_write_all,
 	.dirty_bits		= bitmap_dirty_bits,
+	.prepare_range		= bitmap_prepare_range,
 	.unplug			= bitmap_unplug,
 	.daemon_work		= bitmap_daemon_work,
 
diff --git a/drivers/md/md-bitmap.h b/drivers/md/md-bitmap.h
index f46674bdfeb9..26cd07737aab 100644
--- a/drivers/md/md-bitmap.h
+++ b/drivers/md/md-bitmap.h
@@ -93,6 +93,14 @@ struct bitmap_operations {
 	void (*write_all)(struct mddev *mddev);
 	void (*dirty_bits)(struct mddev *mddev, unsigned long s,
 			   unsigned long e);
+	/* Prepare a range for this bitmap implementation. */
+	void (*prepare_range)(struct mddev *mddev,
+			      sector_t *offset,
+			      unsigned long *sectors);
+	void (*reshape_finish)(struct mddev *mddev);
+	int (*reshape_can_start)(struct mddev *mddev);
+	void (*reshape_mark)(struct mddev *mddev, sector_t old_pos,
+			     sector_t new_pos);
 	void (*unplug)(struct mddev *mddev, bool sync);
 	void (*daemon_work)(struct mddev *mddev);
 
diff --git a/drivers/md/md-llbitmap.c b/drivers/md/md-llbitmap.c
index 5a4e2abaa757..f0c20afa354e 100644
--- a/drivers/md/md-llbitmap.c
+++ b/drivers/md/md-llbitmap.c
@@ -1188,6 +1188,13 @@ static void llbitmap_destroy(struct mddev *mddev)
 	mutex_unlock(&mddev->bitmap_info.mutex);
 }
 
+static void llbitmap_prepare_range(struct mddev *mddev, sector_t *offset,
+				   unsigned long *sectors)
+{
+	if (mddev->pers->bitmap_sector)
+		mddev->pers->bitmap_sector(mddev, offset, sectors);
+}
+
 static void llbitmap_start_write(struct mddev *mddev, sector_t offset,
 				 unsigned long sectors)
 {
@@ -1780,6 +1787,7 @@ static struct bitmap_operations llbitmap_ops = {
 	.update_sb		= llbitmap_update_sb,
 	.get_stats		= llbitmap_get_stats,
 	.dirty_bits		= llbitmap_dirty_bits,
+	.prepare_range		= llbitmap_prepare_range,
 	.write_all		= llbitmap_write_all,
 
 	.groups			= md_llbitmap_groups,
diff --git a/drivers/md/md.c b/drivers/md/md.c
index d1465bcd86c8..3b20a57b8c7e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9361,6 +9361,12 @@ void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev,
 }
 EXPORT_SYMBOL_GPL(md_submit_discard_bio);
 
+static void md_bitmap_prepare_range(struct mddev *mddev, sector_t *offset,
+				    unsigned long *sectors)
+{
+	mddev->bitmap_ops->prepare_range(mddev, offset, sectors);
+}
+
 static void md_bitmap_start(struct mddev *mddev,
 			    struct md_io_clone *md_io_clone)
 {
@@ -9368,10 +9374,8 @@ static void md_bitmap_start(struct mddev *mddev,
 			   mddev->bitmap_ops->start_discard :
 			   mddev->bitmap_ops->start_write;
 
-	if (mddev->pers->bitmap_sector)
-		mddev->pers->bitmap_sector(mddev, &md_io_clone->offset,
-					   &md_io_clone->sectors);
-
+	md_bitmap_prepare_range(mddev, &md_io_clone->offset,
+				&md_io_clone->sectors);
 	fn(mddev, md_io_clone->offset, md_io_clone->sectors);
 }
 
diff --git a/drivers/md/md.h b/drivers/md/md.h
index d8daf0f75cbb..110cf0f8b107 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -798,6 +798,10 @@ struct md_personality
 	/* convert io ranges from array to bitmap */
 	void (*bitmap_sector)(struct mddev *mddev, sector_t *offset,
 			      unsigned long *sectors);
+	void (*bitmap_sector_map)(struct mddev *mddev, sector_t *offset,
+				  unsigned long *sectors, bool previous);
+	sector_t (*bitmap_sync_size)(struct mddev *mddev, bool previous);
+	sector_t (*bitmap_array_sectors)(struct mddev *mddev, bool previous);
 };
 
 struct md_sysfs_entry {
-- 
2.51.0