From 9f59258d300494be3055f2e47f26b21f5c8ad710 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Mon, 3 Aug 2026 03:50:35 +0800 Subject: [PATCH] md/raid5: add exact old and new llbitmap mapping helpers Teach RAID5 to export exact old and new llbitmap mappings and the corresponding sync and array sizes for reshape-aware bitmap users. Tested-by: Mykola Marzhan Link: https://patch.msgid.link/20260802195038.164272-27-yukuai@kernel.org Signed-off-by: Yu Kuai --- drivers/md/raid5.c | 81 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 57 insertions(+), 24 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 2cc2546a29ae..88bf5a9ce573 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6015,6 +6015,34 @@ static enum reshape_loc get_reshape_loc(struct mddev *mddev, return LOC_BEHIND_RESHAPE; } +static void raid5_bitmap_sector_map(struct mddev *mddev, sector_t *offset, + unsigned long *sectors, + bool previous) +{ + struct r5conf *conf = mddev->private; + sector_t start = *offset; + sector_t end = start + *sectors; + int sectors_per_chunk; + int dd_idx; + + if (previous) + sectors_per_chunk = conf->prev_chunk_sectors * + (conf->previous_raid_disks - conf->max_degraded); + else + sectors_per_chunk = conf->chunk_sectors * + (conf->raid_disks - conf->max_degraded); + sector_div(start, sectors_per_chunk); + start *= sectors_per_chunk; + if (sector_div(end, sectors_per_chunk)) + end++; + end *= sectors_per_chunk; + + start = raid5_compute_sector(conf, start, previous, &dd_idx, NULL); + end = raid5_compute_sector(conf, end, previous, &dd_idx, NULL); + *offset = start; + *sectors = end - start; +} + static void raid5_bitmap_sector(struct mddev *mddev, sector_t *offset, unsigned long *sectors) { @@ -6022,21 +6050,11 @@ static void raid5_bitmap_sector(struct mddev *mddev, sector_t *offset, sector_t start = *offset; sector_t end = start + *sectors; sector_t prev_start = start; - sector_t prev_end = end; - int sectors_per_chunk; + unsigned long prev_sectors = end - start; enum reshape_loc loc; - int dd_idx; - sectors_per_chunk = conf->chunk_sectors * - (conf->raid_disks - conf->max_degraded); - sector_div(start, sectors_per_chunk); - start *= sectors_per_chunk; - if (sector_div(end, sectors_per_chunk)) - end++; - end *= sectors_per_chunk; - - start = raid5_compute_sector(conf, start, 0, &dd_idx, NULL); - end = raid5_compute_sector(conf, end, 0, &dd_idx, NULL); + raid5_bitmap_sector_map(mddev, &start, sectors, false); + end = start + *sectors; /* * For LOC_INSIDE_RESHAPE, this IO will wait for reshape to make @@ -6045,19 +6063,10 @@ static void raid5_bitmap_sector(struct mddev *mddev, sector_t *offset, 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); - sector_div(prev_start, sectors_per_chunk); - prev_start *= sectors_per_chunk; - sector_div(prev_end, sectors_per_chunk); - 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); + raid5_bitmap_sector_map(mddev, &prev_start, &prev_sectors, true); /* * for LOC_AHEAD_OF_RESHAPE, reshape can make progress before this IO @@ -6065,7 +6074,7 @@ static void raid5_bitmap_sector(struct mddev *mddev, sector_t *offset, * we set bits for both. */ *offset = min(start, prev_start); - *sectors = max(end, prev_end) - *offset; + *sectors = max(end, prev_start + prev_sectors) - *offset; } static enum stripe_result make_stripe_request(struct mddev *mddev, @@ -9131,6 +9140,21 @@ static void raid5_prepare_suspend(struct mddev *mddev) wake_up(&conf->wait_for_reshape); } +static sector_t raid5_bitmap_sync_size(struct mddev *mddev, bool previous) +{ + return mddev->dev_sectors; +} + +static sector_t raid5_bitmap_array_sectors(struct mddev *mddev, bool previous) +{ + struct r5conf *conf = mddev->private; + + if (previous) + return raid5_size(mddev, mddev->dev_sectors, + conf->previous_raid_disks); + return raid5_size(mddev, mddev->dev_sectors, conf->raid_disks); +} + static struct md_personality raid6_personality = { .head = { @@ -9160,6 +9184,9 @@ static struct md_personality raid6_personality = .change_consistency_policy = raid5_change_consistency_policy, .prepare_suspend = raid5_prepare_suspend, .bitmap_sector = raid5_bitmap_sector, + .bitmap_sector_map = raid5_bitmap_sector_map, + .bitmap_sync_size = raid5_bitmap_sync_size, + .bitmap_array_sectors = raid5_bitmap_array_sectors, }; static struct md_personality raid5_personality = { @@ -9190,6 +9217,9 @@ static struct md_personality raid5_personality = .change_consistency_policy = raid5_change_consistency_policy, .prepare_suspend = raid5_prepare_suspend, .bitmap_sector = raid5_bitmap_sector, + .bitmap_sector_map = raid5_bitmap_sector_map, + .bitmap_sync_size = raid5_bitmap_sync_size, + .bitmap_array_sectors = raid5_bitmap_array_sectors, }; static struct md_personality raid4_personality = @@ -9221,6 +9251,9 @@ static struct md_personality raid4_personality = .change_consistency_policy = raid5_change_consistency_policy, .prepare_suspend = raid5_prepare_suspend, .bitmap_sector = raid5_bitmap_sector, + .bitmap_sector_map = raid5_bitmap_sector_map, + .bitmap_sync_size = raid5_bitmap_sync_size, + .bitmap_array_sectors = raid5_bitmap_array_sectors, }; static int __init raid5_init(void)