From b094fa9d322302afe65ef67cdd89fada6578320b Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Mon, 3 Aug 2026 03:50:26 +0800 Subject: [PATCH] md/md-llbitmap: finish reshape geometry Commit the staged llbitmap geometry when reshape finishes. When assembling a stopped reshape, md_run() creates the bitmap before publishing mddev->pers. llbitmap_read_sb() can therefore only initialize the reshape fields from the old on-disk sync size. Refresh the staged reshape geometry again from llbitmap_load(), after mddev->pers is available, and expand the in-memory page controls before replaying bitmap state. Reproduce on the old kernel by creating a RAID10 llbitmap with four active disks and two spares, growing it to six disks, then stopping and assembling while reshape is still running. The llbitmap chunk count was 32704 before grow, 49056 during reshape, then rolled back to 32704 after reassemble. The fixed kernel kept the target geometry across the same stop/reassemble flow: 65440 chunks before grow, 98160 during reshape, and 98160 after reassemble. Link: https://lore.kernel.org/all/20260726185916.2223460-1-mykola@meshstor.io/ Tested-by: Mykola Marzhan Link: https://patch.msgid.link/20260802195038.164272-18-yukuai@kernel.org Signed-off-by: Yu Kuai --- drivers/md/md-llbitmap.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/md/md-llbitmap.c b/drivers/md/md-llbitmap.c index 421a9a4ebbae..4e7070c14840 100644 --- a/drivers/md/md-llbitmap.c +++ b/drivers/md/md-llbitmap.c @@ -1371,11 +1371,20 @@ static int llbitmap_load(struct mddev *mddev) { enum llbitmap_action action = BitmapActionReload; struct llbitmap *llbitmap = mddev->bitmap; + int ret; if (test_and_clear_bit(BITMAP_STALE, &llbitmap->flags)) action = BitmapActionStale; + mutex_lock(&mddev->bitmap_info.mutex); + llbitmap_refresh_reshape(llbitmap); + ret = llbitmap_expand_pages(llbitmap, llbitmap->chunks); + if (ret) { + mutex_unlock(&mddev->bitmap_info.mutex); + return ret; + } llbitmap_state_machine(llbitmap, 0, llbitmap->chunks - 1, action); + mutex_unlock(&mddev->bitmap_info.mutex); return 0; } @@ -1709,6 +1718,30 @@ static void llbitmap_dirty_bits(struct mddev *mddev, unsigned long s, llbitmap_state_machine(mddev->bitmap, s, e, BitmapActionStartwrite); } +static void llbitmap_reshape_finish(struct mddev *mddev) +{ + struct llbitmap *llbitmap = mddev->bitmap; + + if (mddev->pers->quiesce) + mddev->pers->quiesce(mddev, 1); + + mutex_lock(&mddev->bitmap_info.mutex); + llbitmap_flush(mddev); + + llbitmap->chunksize = llbitmap->reshape_chunksize; + llbitmap->chunkshift = ffz(~llbitmap->chunksize); + llbitmap->chunks = llbitmap->reshape_chunks; + llbitmap->sync_size = llbitmap->reshape_sync_size; + llbitmap_refresh_reshape(llbitmap); + mddev->bitmap_info.chunksize = llbitmap->chunksize; + llbitmap_update_sb(llbitmap); + __llbitmap_flush(mddev); + mutex_unlock(&mddev->bitmap_info.mutex); + + if (mddev->pers->quiesce) + mddev->pers->quiesce(mddev, 0); +} + static void llbitmap_write_sb(struct llbitmap *llbitmap) { int nr_blocks = DIV_ROUND_UP(BITMAP_DATA_OFFSET, llbitmap->io_size); @@ -2000,6 +2033,7 @@ static struct bitmap_operations llbitmap_ops = { .get_stats = llbitmap_get_stats, .dirty_bits = llbitmap_dirty_bits, .prepare_range = llbitmap_prepare_range, + .reshape_finish = llbitmap_reshape_finish, .write_all = llbitmap_write_all, .groups = md_llbitmap_groups,