[2/3] Prevent attempt to insert extent record with max_size==0

Commit Message

Christophe de Dinechin April 28, 2017, 9:13 a.m. UTC

When this happens, we will trip a BUG_ON(end < start) in insert_state
because in check_extent_refs, we use this max_size expecting it's not zero:

  set_extent_dirty(root->fs_info->excluded_extents,
                   rec->start,
                   rec->start + rec->max_size - 1);

See https://bugzilla.redhat.com/show_bug.cgi?id=1435567
for an example where this scenario occurs.

Signed-off-by: Christophe de Dinechin <[e-mail]>
---
 cmds-check.c | 1 +
 1 file changed, 1 insertion(+)

Patch

diff --git a/cmds-check.c b/cmds-check.c
index 2d3ebc1..58e65d6 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -6029,6 +6029,7 @@  static int add_extent_rec_nolookup(struct cache_tree *extent_cache,
 	struct extent_record *rec;
 	int ret = 0;
 
+        BUG_ON(tmpl->max_size == 0);
 	rec = malloc(sizeof(*rec));
 	if (!rec)
 		return -ENOMEM;