diff mbox series

[v2,md-6.14,4/5] md/raid5: implement pers->bitmap_sector()

Message ID 20250109015145.158868-5-yukuai1@huaweicloud.com (mailing list archive)
State Accepted
Headers show
Series md/md-bitmap: move bitmap_{start, end}write to md upper layer | expand

Commit Message

Yu Kuai Jan. 9, 2025, 1:51 a.m. UTC 
From: Yu Kuai <yukuai3@huawei.com>

Bitmap is used for the whole array for raid1/raid10, hence IO for the
array can be used directly for bitmap. However, bitmap is used for
underlying disks for raid5, hence IO for the array can't be used
directly for bitmap.

Implement pers->bitmap_sector() for raid5 to convert IO ranges from the
array to the underlying disks.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 drivers/md/raid5.c | 145 ++++++++++++++++++++++++++++++---------------
 1 file changed, 98 insertions(+), 47 deletions(-)

Comments

Song Liu Jan. 9, 2025, 6:36 p.m. UTC | #1 
On Wed, Jan 8, 2025 at 5:56 PM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>
> From: Yu Kuai <yukuai3@huawei.com>
>
> Bitmap is used for the whole array for raid1/raid10, hence IO for the
> array can be used directly for bitmap. However, bitmap is used for
> underlying disks for raid5, hence IO for the array can't be used
> directly for bitmap.
>
> Implement pers->bitmap_sector() for raid5 to convert IO ranges from the
> array to the underlying disks.
>
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
>  drivers/md/raid5.c | 145 ++++++++++++++++++++++++++++++---------------
>  1 file changed, 98 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index a5a619400d8f..5377f4c3fffc 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -63,6 +63,13 @@
>
>  #define RAID5_MAX_REQ_STRIPES 256
>
> +enum reshape_loc {
> +       LOC_NO_RESHAPE,
> +       LOC_AHEAD_OF_RESHAPE,
> +       LOC_INSIDE_RESHAPE,
> +       LOC_BEHIND_RESHAPE,
> +};
> +

It is unnecessary to move this enum definition and some functions.
I moved them back.

Thanks,
Song


>  static bool devices_handle_discard_safely = false;
>  module_param(devices_handle_discard_safely, bool, 0644);
>  MODULE_PARM_DESC(devices_handle_discard_safely,
> @@ -2947,6 +2954,94 @@ static void raid5_error(struct mddev *mddev, struct md_rdev *rdev)
>         r5c_update_on_rdev_error(mddev, rdev);
>  }
>
> +static bool ahead_of_reshape(struct mddev *mddev, sector_t sector,
> +                            sector_t reshape_sector)
> +{
> +       return mddev->reshape_backwards ? sector < reshape_sector :
> +                                         sector >= reshape_sector;
> +}
> +
> +static bool range_ahead_of_reshape(struct mddev *mddev, sector_t min,
> +                                  sector_t max, sector_t reshape_sector)
> +{
> +       return mddev->reshape_backwards ? max < reshape_sector :
> +                                         min >= reshape_sector;
> +}
> +

[...]

> +static enum reshape_loc get_reshape_loc(struct mddev *mddev,
> +               struct r5conf *conf, sector_t logical_sector)
> +{
> +       sector_t reshape_progress, reshape_safe;
> +       /*
diff mbox series

Patch

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index a5a619400d8f..5377f4c3fffc 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -63,6 +63,13 @@ 
 
 #define RAID5_MAX_REQ_STRIPES 256
 
+enum reshape_loc {
+	LOC_NO_RESHAPE,
+	LOC_AHEAD_OF_RESHAPE,
+	LOC_INSIDE_RESHAPE,
+	LOC_BEHIND_RESHAPE,
+};
+
 static bool devices_handle_discard_safely = false;
 module_param(devices_handle_discard_safely, bool, 0644);
 MODULE_PARM_DESC(devices_handle_discard_safely,
@@ -2947,6 +2954,94 @@  static void raid5_error(struct mddev *mddev, struct md_rdev *rdev)
 	r5c_update_on_rdev_error(mddev, rdev);
 }
 
+static bool ahead_of_reshape(struct mddev *mddev, sector_t sector,
+			     sector_t reshape_sector)
+{
+	return mddev->reshape_backwards ? sector < reshape_sector :
+					  sector >= reshape_sector;
+}
+
+static bool range_ahead_of_reshape(struct mddev *mddev, sector_t min,
+				   sector_t max, sector_t reshape_sector)
+{
+	return mddev->reshape_backwards ? max < reshape_sector :
+					  min >= reshape_sector;
+}
+
+static enum reshape_loc get_reshape_loc(struct mddev *mddev,
+		struct r5conf *conf, sector_t logical_sector)
+{
+	sector_t reshape_progress, reshape_safe;
+	/*
+	 * Spinlock is needed as reshape_progress may be
+	 * 64bit on a 32bit platform, and so it might be
+	 * possible to see a half-updated value
+	 * Of course reshape_progress could change after
+	 * the lock is dropped, so once we get a reference
+	 * to the stripe that we think it is, we will have
+	 * to check again.
+	 */
+	spin_lock_irq(&conf->device_lock);
+	reshape_progress = conf->reshape_progress;
+	reshape_safe = conf->reshape_safe;
+	spin_unlock_irq(&conf->device_lock);
+	if (reshape_progress == MaxSector)
+		return LOC_NO_RESHAPE;
+	if (ahead_of_reshape(mddev, logical_sector, reshape_progress))
+		return LOC_AHEAD_OF_RESHAPE;
+	if (ahead_of_reshape(mddev, logical_sector, reshape_safe))
+		return LOC_INSIDE_RESHAPE;
+	return LOC_BEHIND_RESHAPE;
+}
+
+static void raid5_bitmap_sector(struct mddev *mddev, sector_t *offset,
+				unsigned long *sectors)
+{
+	struct r5conf *conf = mddev->private;
+	sector_t start = *offset;
+	sector_t end = start + *sectors;
+	sector_t prev_start = start;
+	sector_t prev_end = end;
+	int sectors_per_chunk;
+	enum reshape_loc loc;
+	int dd_idx;
+
+	sectors_per_chunk = conf->chunk_sectors *
+		(conf->raid_disks - conf->max_degraded);
+	start = round_down(start, sectors_per_chunk);
+	end = round_up(end, sectors_per_chunk);
+
+	start = raid5_compute_sector(conf, start, 0, &dd_idx, NULL);
+	end = raid5_compute_sector(conf, end, 0, &dd_idx, NULL);
+
+	/*
+	 * For LOC_INSIDE_RESHAPE, this IO will wait for reshape to make
+	 * progress, hence it's the same as LOC_BEHIND_RESHAPE.
+	 */
+	loc = get_reshape_loc(mddev, conf, prev_start);
+	if (likely(loc != LOC_AHEAD_OF_RESHAPE)) {
+		*offset = start;
+		*sectors = end - start;
+		return;
+	}
+
+	sectors_per_chunk = conf->prev_chunk_sectors *
+		(conf->previous_raid_disks - conf->max_degraded);
+	prev_start = round_down(prev_start, sectors_per_chunk);
+	prev_end = round_down(prev_end, sectors_per_chunk);
+
+	prev_start = raid5_compute_sector(conf, prev_start, 1, &dd_idx, NULL);
+	prev_end = raid5_compute_sector(conf, prev_end, 1, &dd_idx, NULL);
+
+	/*
+	 * for LOC_AHEAD_OF_RESHAPE, reshape can make progress before this IO
+	 * is handled in make_stripe_request(), we can't know this here hence
+	 * we set bits for both.
+	 */
+	*offset = min(start, prev_start);
+	*sectors = max(end, prev_end) - *offset;
+}
+
 /*
  * Input: a 'big' sector number,
  * Output: index of the data and parity disk, and the sector # in them.
@@ -5792,20 +5887,6 @@  static void make_discard_request(struct mddev *mddev, struct bio *bi)
 	bio_endio(bi);
 }
 
-static bool ahead_of_reshape(struct mddev *mddev, sector_t sector,
-			     sector_t reshape_sector)
-{
-	return mddev->reshape_backwards ? sector < reshape_sector :
-					  sector >= reshape_sector;
-}
-
-static bool range_ahead_of_reshape(struct mddev *mddev, sector_t min,
-				   sector_t max, sector_t reshape_sector)
-{
-	return mddev->reshape_backwards ? max < reshape_sector :
-					  min >= reshape_sector;
-}
-
 static bool stripe_ahead_of_reshape(struct mddev *mddev, struct r5conf *conf,
 				    struct stripe_head *sh)
 {
@@ -5885,39 +5966,6 @@  static int add_all_stripe_bios(struct r5conf *conf,
 	return 1;
 }
 
-enum reshape_loc {
-	LOC_NO_RESHAPE,
-	LOC_AHEAD_OF_RESHAPE,
-	LOC_INSIDE_RESHAPE,
-	LOC_BEHIND_RESHAPE,
-};
-
-static enum reshape_loc get_reshape_loc(struct mddev *mddev,
-		struct r5conf *conf, sector_t logical_sector)
-{
-	sector_t reshape_progress, reshape_safe;
-	/*
-	 * Spinlock is needed as reshape_progress may be
-	 * 64bit on a 32bit platform, and so it might be
-	 * possible to see a half-updated value
-	 * Of course reshape_progress could change after
-	 * the lock is dropped, so once we get a reference
-	 * to the stripe that we think it is, we will have
-	 * to check again.
-	 */
-	spin_lock_irq(&conf->device_lock);
-	reshape_progress = conf->reshape_progress;
-	reshape_safe = conf->reshape_safe;
-	spin_unlock_irq(&conf->device_lock);
-	if (reshape_progress == MaxSector)
-		return LOC_NO_RESHAPE;
-	if (ahead_of_reshape(mddev, logical_sector, reshape_progress))
-		return LOC_AHEAD_OF_RESHAPE;
-	if (ahead_of_reshape(mddev, logical_sector, reshape_safe))
-		return LOC_INSIDE_RESHAPE;
-	return LOC_BEHIND_RESHAPE;
-}
-
 static enum stripe_result make_stripe_request(struct mddev *mddev,
 		struct r5conf *conf, struct stripe_request_ctx *ctx,
 		sector_t logical_sector, struct bio *bi)
@@ -8966,6 +9014,7 @@  static struct md_personality raid6_personality =
 	.takeover	= raid6_takeover,
 	.change_consistency_policy = raid5_change_consistency_policy,
 	.prepare_suspend = raid5_prepare_suspend,
+	.bitmap_sector	= raid5_bitmap_sector,
 };
 static struct md_personality raid5_personality =
 {
@@ -8991,6 +9040,7 @@  static struct md_personality raid5_personality =
 	.takeover	= raid5_takeover,
 	.change_consistency_policy = raid5_change_consistency_policy,
 	.prepare_suspend = raid5_prepare_suspend,
+	.bitmap_sector	= raid5_bitmap_sector,
 };
 
 static struct md_personality raid4_personality =
@@ -9017,6 +9067,7 @@  static struct md_personality raid4_personality =
 	.takeover	= raid4_takeover,
 	.change_consistency_policy = raid5_change_consistency_policy,
 	.prepare_suspend = raid5_prepare_suspend,
+	.bitmap_sector	= raid5_bitmap_sector,
 };
 
 static int __init raid5_init(void)