btrfs-progs: chunk-recovery: Fix a float point error

Fix a zero division causing chunk-recovery fail.

Also fix a typo "strpie_length" -> "stripe_length".

Reported-by: Scotty Edmonds <scotty@scottyedmonds.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/btrfsck.h b/btrfsck.h
index 0882a383..e16f52f5 100644
--- a/btrfsck.h
+++ b/btrfsck.h
@@ -142,6 +142,23 @@ static inline unsigned long btrfs_chunk_record_size(int num_stripes)
 }
 void free_chunk_cache_tree(struct cache_tree *chunk_cache);
 
+/*
+ * Function to check validation for num_stripes, or it can call
+ * float point error for 0 division
+ * return < 0 for invalid combination
+ * return 0 for valid combination
+ */
+static inline int check_num_stripes(u64 type, int num_stripes)
+{
+	if (num_stripes == 0)
+		return -1;
+	if (type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes <= 1)
+		return -1;
+	if (type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes <= 2)
+		return -1;
+	return 0;
+}
+
 u64 calc_stripe_length(u64 type, u64 length, int num_stripes);
 /* For block group tree */
 static inline void block_group_tree_init(struct block_group_tree *tree)