[Devel] [PATCH hci-8.1 v4 05/11] dm-ploop: set delta is_raw before applying its mappings

[Alexander Ivanov]

ploop_apply_delta_mappings() takes is_raw from deltas[level], but
ploop_add_delta() sets deltas[level].is_raw only after the mappings
are applied. So a raw delta is handled as a non-raw one: its md_root
is empty, ploop_md_first_entry() returns NULL and d_md->kmpage
dereferences it.

This has been the case since the driver was added in commit
6ddad5a4d226 ("dm-ploop: Add ploop target driver"), i.e. raw deltas
have never worked here; this is not a regression.

Set is_raw before applying the mappings.

https://virtuozzo.atlassian.net/browse/VSTOR-148171
Feature: dm-ploop: ploop target driver

Signed-off-by: Alexander Ivanov <alexander.ivanov at virtuozzo.com>
Reviewed-by: Denis V. Lunev <den at openvz.org>
---
 drivers/md/dm-ploop-bat.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c
index 4fc99400a0a4..3427d1a90d81 100644
--- a/drivers/md/dm-ploop-bat.c
+++ b/drivers/md/dm-ploop-bat.c
@@ -512,6 +512,7 @@ int ploop_add_delta(struct ploop *ploop, u32 level, struct file *file, bool is_r
 	if (level != ploop_top_level(ploop) && nr_be > deltas[level + 1].nr_be)
 		goto out;
 
+	deltas[level].is_raw = is_raw;
 	ploop_apply_delta_mappings(ploop, deltas, level, &md_root, nr_be);
 
 	deltas[level].file = file;
@@ -532,7 +533,6 @@ int ploop_add_delta(struct ploop *ploop, u32 level, struct file *file, bool is_r
 	deltas[level].file_size = file_size;
 	deltas[level].file_preallocated_area_start = file_size;
 	deltas[level].nr_be = nr_be;
-	deltas[level].is_raw = is_raw;
 	ret = 0;
 out:
 	ploop_free_md_pages_tree(&md_root);
-- 
2.53.0