[Devel] [PATCH RHEL7 COMMIT] ploop: Fix huge grow of empty image

[Kirill Tkhai]

The commit is pushed to "branch-rh7-3.10.0-957.27.2.vz7.107.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-957.27.2.vz7.107.14
------>
commit 0ca1fee2c217c96aebaef2eafcc827e549ee4d60
Author: Kirill Tkhai <ktkhai at virtuozzo.com>
Date:   Thu Jan 30 10:51:48 2020 +0000

    ploop: Fix huge grow of empty image
    
    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 981978c..68955af 100644
--- a/drivers/block/ploop/fmt_ploop1.c
+++ b/drivers/block/ploop/fmt_ploop1.c
@@ -761,7 +761,7 @@ 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);
 		}
 	}