[PATCH 1/3] btrfs-progs: dump-tree: output the sequence number for inline references

[Qu Wenruo <wqu@suse.com>]

Commit 6cf11f3e3815 ("btrfs-progs: check: check order of inline extent
refs") fixes a problem that btrfs check never properly verify the
sequence of inline references.

It's not obvious because by default kernel handles EXTENT_DATA_REF_KEY
using its own hash, resulting some seemingly out-of-order result:

	item 0 key (13631488 EXTENT_ITEM 4096) itemoff 16143 itemsize 140
		refs 4 gen 7 flags DATA
		extent data backref root FS_TREE objectid 258 offset 0 count 1
		extent data backref root FS_TREE objectid 257 offset 0 count 1
		extent data backref root FS_TREE objectid 260 offset 0 count 1
		extent data backref root FS_TREE objectid 259 offset 0 count 1

By a quick glance, no one can see the above inline backref items are in
any order.

To make such sequence more obvious, let dump-tree to output a new prefix
to indicate the type and the internal sequence number:

For above case, the new output would look like this:

        item 0 key (13631488 EXTENT_ITEM 4096) itemoff 16143 itemsize 140
                refs 4 gen 7 flags DATA
                (178 0xdfb591fbbf5f519) extent data backref root FS_TREE objectid 258 offset 0 count 1
                (178 0xdfb591fa80d95ea) extent data backref root FS_TREE objectid 257 offset 0 count 1
                (178 0xdfb591f9c0534ff) extent data backref root FS_TREE objectid 260 offset 0 count 1
                (178 0xdfb591f49f9f8e7) extent data backref root FS_TREE objectid 259 offset 0 count 1

Although still not that obvious, it should show the inline data backrefs
has descending sequence number.

For the type part, it's anti-instinctive in ascending order, which is
not that easy to produce.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 kernel-shared/print-tree.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/kernel-shared/print-tree.c b/kernel-shared/print-tree.c
index f6e7539eb191..9e3ebddb97b3 100644
--- a/kernel-shared/print-tree.c
+++ b/kernel-shared/print-tree.c
@@ -487,38 +487,45 @@ void print_extent_item(struct extent_buffer *eb, int slot, int metadata)
 	ptr = (unsigned long)iref;
 	end = (unsigned long)ei + item_size;
 	while (ptr < end) {
+		u64 seq;
+
 		iref = (struct btrfs_extent_inline_ref *)ptr;
 		type = btrfs_extent_inline_ref_type(eb, iref);
 		offset = btrfs_extent_inline_ref_offset(eb, iref);
+		seq = offset;
 		switch (type) {
 		case BTRFS_TREE_BLOCK_REF_KEY:
-			printf("\t\ttree block backref root ");
+			printf("\t\t(%u 0x%llx) tree block backref root ",
+			       type, seq);
 			print_objectid(stdout, offset, 0);
 			printf("\n");
 			break;
 		case BTRFS_SHARED_BLOCK_REF_KEY:
-			printf("\t\tshared block backref parent %llu\n",
-			       (unsigned long long)offset);
+			printf("\t\t(%u 0x%llx) shared block backref parent %llu\n",
+			       type, seq, offset);
 			break;
 		case BTRFS_EXTENT_DATA_REF_KEY:
 			dref = (struct btrfs_extent_data_ref *)(&iref->offset);
-			printf("\t\textent data backref root ");
-			print_objectid(stdout,
-		(unsigned long long)btrfs_extent_data_ref_root(eb, dref), 0);
+			seq = hash_extent_data_ref(
+					btrfs_extent_data_ref_root(eb, dref),
+					btrfs_extent_data_ref_objectid(eb, dref),
+					btrfs_extent_data_ref_offset(eb, dref));
+			printf("\t\t(%u 0x%llx) extent data backref root ",
+			       type, seq);
+			print_objectid(stdout, btrfs_extent_data_ref_root(eb, dref), 0);
 			printf(" objectid %llu offset %llu count %u\n",
-			       (unsigned long long)btrfs_extent_data_ref_objectid(eb, dref),
+			       btrfs_extent_data_ref_objectid(eb, dref),
 			       btrfs_extent_data_ref_offset(eb, dref),
 			       btrfs_extent_data_ref_count(eb, dref));
 			break;
 		case BTRFS_SHARED_DATA_REF_KEY:
 			sref = (struct btrfs_shared_data_ref *)(iref + 1);
-			printf("\t\tshared data backref parent %llu count %u\n",
-			       (unsigned long long)offset,
-			       btrfs_shared_data_ref_count(eb, sref));
+			printf("\t\t(%u 0x%llx) shared data backref parent %llu count %u\n",
+			       type, seq, offset, btrfs_shared_data_ref_count(eb, sref));
 			break;
 		case BTRFS_EXTENT_OWNER_REF_KEY:
-			printf("\t\textent owner root %llu\n",
-			       (unsigned long long)offset);
+			printf("\t\(%u 0x%llx) textent owner root %llu\n",
+			       type, seq, offset);
 			break;
 		default:
 			return;
-- 
2.42.0