From 1b6cc579ded4f9d7923d9d59147512edd623f4c0 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 25 Sep 2017 09:55:11 -0500 Subject: dirty-bitmap: Avoid size query failure during truncate We've previously fixed several places where we failed to account for possible errors from bdrv_nb_sectors(). Fix another one by making bdrv_dirty_bitmap_truncate() take the new size from the caller instead of querying itself; then adjust the sole caller bdrv_truncate() to pass the size just determined by a successful resize, or to reuse the size given to the original truncate operation when refresh_total_sectors() was not able to confirm the actual size (the two sizes can potentially differ according to rounding constraints), thus avoiding sizing the bitmaps to -1. This also fixes a bug where not all failure paths in bdrv_truncate() would set errp. Note that bdrv_truncate() is still a bit awkward. We may want to revisit it later and clean up things to better guarantee that a resize attempt either fails cleanly up front, or cannot fail after guest-visible changes have been made (if temporary changes are made, then they need to be cleanly rolled back). But that is a task for another day; for now, the goal is the bare minimum fix to ensure that just bdrv_dirty_bitmap_truncate() cannot fail. Signed-off-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: John Snow Reviewed-by: Fam Zheng Signed-off-by: Kevin Wolf --- block/dirty-bitmap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'block') diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index 42a55e4a4b..ee164fb518 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -1,7 +1,7 @@ /* * Block Dirty Bitmap * - * Copyright (c) 2016 Red Hat. Inc + * Copyright (c) 2016-2017 Red Hat. Inc * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal @@ -302,10 +302,10 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs, * Truncates _all_ bitmaps attached to a BDS. * Called with BQL taken. */ -void bdrv_dirty_bitmap_truncate(BlockDriverState *bs) +void bdrv_dirty_bitmap_truncate(BlockDriverState *bs, int64_t bytes) { BdrvDirtyBitmap *bitmap; - uint64_t size = bdrv_nb_sectors(bs); + int64_t size = DIV_ROUND_UP(bytes, BDRV_SECTOR_SIZE); bdrv_dirty_bitmaps_lock(bs); QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { -- cgit v1.2.3