The v0 compat code was introduced in commit 5d4f98a28c7d
("Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)") 9
years ago, which was merged in 2.6.31. This means that the code is
there to support filesystems which are _VERY_ old and if you are using
btrfs on such an old kernel, you have much bigger problems. This coupled
with the fact that no one is likely testing/maintining this code likely
means it has bugs lurking. All things considered I think 43 kernel
releases later it's high time this remnant of the past got removed.
This patch removes all code wrapped in #ifdefs but leaves the BUG_ONs in case
we have a v0 with no support intact as a sort of safety-net.
Signed-off-by: Nikolay Borisov
---
fs/btrfs/ctree.c | 6 +-
fs/btrfs/ctree.h | 2 -
fs/btrfs/extent-tree.c | 209 +
fs/btrfs/print-tree.c | 30 +--
fs/btrfs/relocation.c | 151 +--
5 files changed, 4 insertions(+), 394 deletions(-)
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 6879697520d5..d1273ec2e0d5 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -888,11 +888,7 @@ int btrfs_block_can_be_shared(struct btrfs_root *root,
btrfs_root_last_snapshot(>root_item) ||
btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
return 1;
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
- if (test_bit(BTRFS_ROOT_REF_COWS, >state) &&
- btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
- return 1;
-#endif
+
return 0;
}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e671a1fcbbec..bc52bf7ac572 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -55,8 +55,6 @@ struct btrfs_ordered_sum;
#define BTRFS_OLDEST_GENERATION0ULL
-#define BTRFS_COMPAT_EXTENT_TREE_V0
-
/*
* the max metadata block size. This limit is somewhat artificial,
* but the memmove costs go through the roof for larger blocks.
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0f7e797236dc..4129831523a2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -870,17 +870,7 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle
*trans,
num_refs = btrfs_extent_refs(leaf, ei);
extent_flags = btrfs_extent_flags(leaf, ei);
} else {
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
- struct btrfs_extent_item_v0 *ei0;
- BUG_ON(item_size != sizeof(*ei0));
- ei0 = btrfs_item_ptr(leaf, path->slots[0],
-struct btrfs_extent_item_v0);
- num_refs = btrfs_extent_refs_v0(leaf, ei0);
- /* FIXME: this isn't correct for data */
- extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
-#else
BUG();
-#endif
}
BUG_ON(num_refs == 0);
} else {
@@ -1039,89 +1029,6 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle
*trans,
* tree block info structure.
*/
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
- struct btrfs_fs_info *fs_info,
- struct btrfs_path *path,
- u64 owner, u32 extra_size)
-{
- struct btrfs_root *root = fs_info->extent_root;
- struct btrfs_extent_item *item;
- struct btrfs_extent_item_v0 *ei0;
- struct btrfs_extent_ref_v0 *ref0;
- struct btrfs_tree_block_info *bi;
- struct extent_buffer *leaf;
- struct btrfs_key key;
- struct btrfs_key found_key;
- u32 new_size = sizeof(*item);
- u64 refs;
- int ret;
-
- leaf = path->nodes[0];
- BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
-
- btrfs_item_key_to_cpu(leaf, , path->slots[0]);
- ei0 = btrfs_item_ptr(leaf, path->slots[0],
-struct btrfs_extent_item_v0);
- refs = btrfs_extent_refs_v0(leaf, ei0);
-
- if (owner == (u64)-1) {
- while (1) {
- if (path->slots[0] >= btrfs_header_nritems(leaf)) {
- ret = btrfs_next_leaf(root, path);
- if (ret < 0)
- return ret;
- BUG_ON(ret > 0); /* Corruption */
- leaf = path->nodes[0];
- }
- btrfs_item_key_to_cpu(leaf, _key,
- path->slots[0]);
- BUG_ON(key.objectid != found_key.objectid);
- if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
- path->slots[0]++;
- continue;
- }
-
