md-cluster/bitmap: unplug bitmap to sync dirty pages to disk
This patch is doing two distinct but related things.
1. It adds bitmap_unplug() for the main bitmap (mddev->bitmap). As bit
have been set, BITMAP_PAGE_DIRTY is set so bitmap_deamon_work() will
not write those pages out in its regular scans, only bitmap_unplug()
will. If there are no writes to the array, bitmap_unplug() won't be
called, so we need to call it explicitly here.
2. bitmap_write_all() is a bit of a confusing interface as it doesn't
actually write anything. The current code for writing "bitmap" works
but this change makes it a bit clearer.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index de28c80..4a05bac 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1924,14 +1924,14 @@
if (clear_bits) {
bitmap_update_sb(bitmap);
- /* Setting this for the ev_page should be enough.
- * And we do not require both write_all and PAGE_DIRT either
- */
+ /* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
+ * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
for (i = 0; i < bitmap->storage.file_pages; i++)
- set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
- bitmap_write_all(bitmap);
+ if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
+ set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
bitmap_unplug(bitmap);
}
+ bitmap_unplug(mddev->bitmap);
*low = lo;
*high = hi;
err: