Btrfs: add one more sanity check for shared ref type

Every shared ref has a parent tree block, which can be get from
btrfs_extent_inline_ref_offset().  And the tree block must be aligned
to the nodesize, so we'd know this inline ref is not valid if this
block's bytenr is not aligned to the nodesize, in which case, most
likely the ref type has been misused.

This adds the above mentioned check and also updates
print_extent_item() called by btrfs_print_leaf() to point out the
invalid ref while printing the tree structure.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 25 insertions, 4 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 51a691532fd8..96e49fd5b888 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1158,19 +1158,40 @@ int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb,
 				     enum btrfs_inline_ref_type is_data)
 {
 	int type = btrfs_extent_inline_ref_type(eb, iref);
+	u64 offset = btrfs_extent_inline_ref_offset(eb, iref);
 
 	if (type == BTRFS_TREE_BLOCK_REF_KEY ||
 	    type == BTRFS_SHARED_BLOCK_REF_KEY ||
 	    type == BTRFS_SHARED_DATA_REF_KEY ||
 	    type == BTRFS_EXTENT_DATA_REF_KEY) {
 		if (is_data == BTRFS_REF_TYPE_BLOCK) {
-			if (type == BTRFS_TREE_BLOCK_REF_KEY ||
-			    type == BTRFS_SHARED_BLOCK_REF_KEY)
+			if (type == BTRFS_TREE_BLOCK_REF_KEY)
 				return type;
+			if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
+				ASSERT(eb->fs_info);
+				/*
+				 * Every shared one has parent tree
+				 * block, which must be aligned to
+				 * nodesize.
+				 */
+				if (offset &&
+				    IS_ALIGNED(offset, eb->fs_info->nodesize))
+					return type;
+			}
 		} else if (is_data == BTRFS_REF_TYPE_DATA) {
-			if (type == BTRFS_EXTENT_DATA_REF_KEY ||
-			    type == BTRFS_SHARED_DATA_REF_KEY)
+			if (type == BTRFS_EXTENT_DATA_REF_KEY)
 				return type;
+			if (type == BTRFS_SHARED_DATA_REF_KEY) {
+				ASSERT(eb->fs_info);
+				/*
+				 * Every shared one has parent tree
+				 * block, which must be aligned to
+				 * nodesize.
+				 */
+				if (offset &&
+				    IS_ALIGNED(offset, eb->fs_info->nodesize))
+					return type;
+			}
 		} else {
 			ASSERT(is_data == BTRFS_REF_TYPE_ANY);
 			return type;