md: be more careful setting MD_CHANGE_CLEAN (676e42d8) · Commits · 戴 / test

When MD_CHANGE_CLEAN is set we might block in md_write_start. So we should only set it when fairly sure that something will clear it. There are two places where it is set so as to encourage a metadata update to record the progress of resync/recovery. This should only be done if the internal metadata update mechanisms are in use, which can be tested by by inspecting '->persistent'. Signed-off-by:

NeilBrown <neilb@suse.de>

drivers/md/bitmap.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1526,6 +1526,7 @@ void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
		atomic_read(&bitmap->mddev->recovery_active) == 0);

		bitmap->mddev->curr_resync_completed = bitmap->mddev->curr_resync;
		if (bitmap->mddev->persistent)
		set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
		sector &= ~((1ULL << CHUNK_BLOCK_SHIFT(bitmap)) - 1);
		s = 0;

drivers/md/md.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -6753,6 +6753,7 @@ void md_do_sync(mddev_t *mddev)
		atomic_read(&mddev->recovery_active) == 0);
		mddev->curr_resync_completed =
		mddev->curr_resync;
		if (mddev->persistent)
		set_bit(MD_CHANGE_CLEAN, &mddev->flags);
		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
		}

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