[Devel] [PATCH rh7] ploop: Fix huge grow of empty image

[Kirill Tkhai]

The following scenario leads to problem:

$ploop init -s 2G root.hds
$ls -h root.hds
-rw------- 1 root root  15M янв 30 13:20 root.hds

Empty image. Grow BAT above current root.hds lenght

$ploop grow -s 3932257M DiskDescriptor.xml

(Requires 16M of BAT)

grow_end is not new actual BAT new size. In case of
image is empty (total size is less then new BAT size)
it points to end of current BAT.

We have to use grow_end + n_alloced, or, the same,
n_needed - 1

https://jira.sw.ru/browse/PSBM-101143

Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 drivers/block/ploop/fmt_ploop1.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/ploop/fmt_ploop1.c b/drivers/block/ploop/fmt_ploop1.c
index 280767f59995..6745d29e5309 100644
--- a/drivers/block/ploop/fmt_ploop1.c
+++ b/drivers/block/ploop/fmt_ploop1.c
@@ -763,7 +763,7 @@ ploop1_prepare_grow(struct ploop_delta * delta, u64 *new_size, int *reloc)
 		/* Does not use rellocated data clusters during grow. */
 		if (delta->holes_bitmap) {
 			i = delta->io.plo->grow_start;
-			while (i <= delta->io.plo->grow_end)
+			while (i <= n_needed - 1)
 				ploop_clear_holes_bitmap_bit(i++, delta);
 		}
 	}