Commit 010228e4 authored Jul 02, 2018 by Guoqing Jiang Committed by Shaohua Li Jul 05, 2018

md-cluster: clear another node's suspend_area after the copy is finished



When one node leaves cluster or stops the resyncing
(resync or recovery) array, then other nodes need to
call recover_bitmaps to continue the unfinished task.

But we need to clear suspend_area later after other
nodes copy the resync information to their bitmap
(by call bitmap_copy_from_slot). Otherwise, all nodes
could write to the suspend_area even the suspend_area
is not handled by any node, because area_resyncing
returns 0 at the beginning of raid1_write_request.
Which means one node could write suspend_area while
another node is resyncing the same area, then data
could be inconsistent.

So let's clear suspend_area later to avoid above issue
with the protection of bm lock. Also it is straightforward
to clear suspend_area after nodes have copied the resync
info to bitmap.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

parent 06c85639

drivers/md/md-cluster.c

+10 −9

Original line number	Diff line number	Diff line
		@@ -304,15 +304,6 @@ static void recover_bitmaps(struct md_thread *thread)
		while (cinfo->recovery_map) {
		slot = fls64((u64)cinfo->recovery_map) - 1;

		/* Clear suspend_area associated with the bitmap */
		spin_lock_irq(&cinfo->suspend_lock);
		list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
		if (slot == s->slot) {
		list_del(&s->list);
		kfree(s);
		}
		spin_unlock_irq(&cinfo->suspend_lock);

		snprintf(str, 64, "bitmap%04d", slot);
		bm_lockres = lockres_init(mddev, str, NULL, 1);
		if (!bm_lockres) {
		@@ -331,6 +322,16 @@ static void recover_bitmaps(struct md_thread *thread)
		pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
		goto clear_bit;
		}

		/* Clear suspend_area associated with the bitmap */
		spin_lock_irq(&cinfo->suspend_lock);
		list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
		if (slot == s->slot) {
		list_del(&s->list);
		kfree(s);
		}
		spin_unlock_irq(&cinfo->suspend_lock);

		if (hi > 0) {
		if (lo < mddev->recovery_cp)
		mddev->recovery_cp = lo;