[PATCH v4 14/25] md/md-llbitmap: refuse reshape while llbitmap still needs sync
From: Yu Kuai <yukuai@kernel.org>
Date: 2026-08-01 17:27:02
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Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
From: Yu Kuai <yukuai@fygo.io> Reject reshape when llbitmap still contains NeedSync or Syncing bits. This keeps reshape from starting until the current llbitmap state has been reconciled. Signed-off-by: Yu Kuai <yukuai@fygo.io> --- drivers/md/md-llbitmap.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/drivers/md/md-llbitmap.c b/drivers/md/md-llbitmap.c
index f41f9ba2063b..3b121b372cd8 100644
--- a/drivers/md/md-llbitmap.c
+++ b/drivers/md/md-llbitmap.c@@ -1703,6 +1703,29 @@ static void llbitmap_dirty_bits(struct mddev *mddev, unsigned long s, llbitmap_state_machine(mddev->bitmap, s, e, BitmapActionStartwrite); } +static int llbitmap_reshape_can_start(struct mddev *mddev) +{ + struct llbitmap *llbitmap = mddev->bitmap; + unsigned long chunk; + int ret = 0; + + if (!llbitmap) + return 0; + + mutex_lock(&mddev->bitmap_info.mutex); + for (chunk = 0; chunk < llbitmap->chunks; chunk++) { + enum llbitmap_state state = llbitmap_read(llbitmap, chunk); + + if (state == BitNeedSync || state == BitSyncing) { + ret = -EBUSY; + break; + } + } + mutex_unlock(&mddev->bitmap_info.mutex); + + return ret; +} + static void llbitmap_reshape_finish(struct mddev *mddev) { struct llbitmap *llbitmap = mddev->bitmap;
@@ -2025,6 +2048,7 @@ static struct bitmap_operations llbitmap_ops = { .dirty_bits = llbitmap_dirty_bits, .prepare_range = llbitmap_prepare_range, .reshape_finish = llbitmap_reshape_finish, + .reshape_can_start = llbitmap_reshape_can_start, .write_all = llbitmap_write_all, .groups = md_llbitmap_groups,
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2.51.0