btrfs: Remove V0 extent support

The v0 compat code was introduced in commit 5d4f98a28c
("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 <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Nikolay Borisov 2018-06-21 09:45:00 +03:00 committed by David Sterba
parent 4de426cd39
commit a79865c680
5 changed files with 4 additions and 394 deletions

View File

@ -888,11 +888,7 @@ int btrfs_block_can_be_shared(struct btrfs_root *root,
btrfs_root_last_snapshot(&root->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, &root->state) &&
btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
return 1;
#endif
return 0;
}

View File

@ -55,8 +55,6 @@ struct btrfs_ordered_sum;
#define BTRFS_OLDEST_GENERATION 0ULL
#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.

View File

@ -867,17 +867,7 @@ search_again:
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 {
@ -1036,89 +1026,6 @@ out_free:
* 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, &key, 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, &found_key,
path->slots[0]);
BUG_ON(key.objectid != found_key.objectid);
if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
path->slots[0]++;
continue;
}
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
owner = btrfs_ref_objectid_v0(leaf, ref0);
break;
}
}
btrfs_release_path(path);
if (owner < BTRFS_FIRST_FREE_OBJECTID)
new_size += sizeof(*bi);
new_size -= sizeof(*ei0);
ret = btrfs_search_slot(trans, root, &key, path,
new_size + extra_size, 1);
if (ret < 0)
return ret;
BUG_ON(ret); /* Corruption */
btrfs_extend_item(fs_info, path, new_size);
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, item, refs);
/* FIXME: get real generation */
btrfs_set_extent_generation(leaf, item, 0);
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
btrfs_set_extent_flags(leaf, item,
BTRFS_EXTENT_FLAG_TREE_BLOCK |
BTRFS_BLOCK_FLAG_FULL_BACKREF);
bi = (struct btrfs_tree_block_info *)(item + 1);
/* FIXME: get first key of the block */
memzero_extent_buffer(leaf, (unsigned long)bi, sizeof(*bi));
btrfs_set_tree_block_level(leaf, bi, (int)owner);
} else {
btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
}
btrfs_mark_buffer_dirty(leaf);
return 0;
}
#endif
/*
* is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required,
* is_data == BTRFS_REF_TYPE_DATA, data type is requried,
@ -1247,17 +1154,6 @@ again:
if (parent) {
if (!ret)
return 0;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
key.type = BTRFS_EXTENT_REF_V0_KEY;
btrfs_release_path(path);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (!ret)
return 0;
#endif
goto fail;
}
@ -1400,13 +1296,6 @@ static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
ref2 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
} else {
BUG();
}
@ -1422,14 +1311,6 @@ static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
else {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
btrfs_set_ref_count_v0(leaf, ref0, num_refs);
}
#endif
btrfs_mark_buffer_dirty(leaf);
}
return ret;
@ -1469,13 +1350,6 @@ static noinline u32 extent_data_ref_count(struct btrfs_path *path,
ref2 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
} else {
WARN_ON(1);
}
@ -1503,15 +1377,6 @@ static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (ret == -ENOENT && parent) {
btrfs_release_path(path);
key.type = BTRFS_EXTENT_REF_V0_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
}
#endif
return ret;
}
@ -1676,22 +1541,6 @@ again:
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
if (!insert) {
err = -ENOENT;
goto out;
}
ret = convert_extent_item_v0(trans, fs_info, path, owner,
extra_size);
if (ret < 0) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
@ -2416,17 +2265,6 @@ again:
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
ret = convert_extent_item_v0(trans, fs_info, path, (u64)-1, 0);
if (ret < 0) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
__run_delayed_extent_op(extent_op, leaf, ei);
@ -3238,12 +3076,6 @@ static noinline int check_committed_ref(struct btrfs_root *root,
ret = 1;
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
goto out;
}
#endif
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
if (item_size != sizeof(*ei) +
@ -6888,11 +6720,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
break;
extent_slot--;
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
if (found_extent && item_size < sizeof(*ei))
found_extent = 0;
#endif
if (!found_extent) {
BUG_ON(iref);
ret = remove_extent_backref(trans, path, NULL,
@ -6968,41 +6796,6 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, extent_slot);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
BUG_ON(found_extent || extent_slot != path->slots[0]);
ret = convert_extent_item_v0(trans, info, path, owner_objectid,
0);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_release_path(path);
path->leave_spinning = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
ret = btrfs_search_slot(trans, extent_root, &key, path,
-1, 1);
if (ret) {
btrfs_err(info,
"umm, got %d back from search, was looking for %llu",
ret, bytenr);
btrfs_print_leaf(path->nodes[0]);
}
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
extent_slot = path->slots[0];
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, extent_slot);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, extent_slot,
struct btrfs_extent_item);

View File

@ -52,18 +52,8 @@ static void print_extent_item(struct extent_buffer *eb, int slot, int type)
u64 offset;
int ref_index = 0;
if (item_size < sizeof(*ei)) {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
struct btrfs_extent_item_v0 *ei0;
BUG_ON(item_size != sizeof(*ei0));
ei0 = btrfs_item_ptr(eb, slot, struct btrfs_extent_item_v0);
pr_info("\t\textent refs %u\n",
btrfs_extent_refs_v0(eb, ei0));
return;
#else
if (item_size < sizeof(*ei))
BUG();
#endif
}
ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item);
flags = btrfs_extent_flags(eb, ei);
@ -133,20 +123,6 @@ static void print_extent_item(struct extent_buffer *eb, int slot, int type)
WARN_ON(ptr > end);
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static void print_extent_ref_v0(struct extent_buffer *eb, int slot)
{
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(eb, slot, struct btrfs_extent_ref_v0);
printk("\t\textent back ref root %llu gen %llu owner %llu num_refs %lu\n",
btrfs_ref_root_v0(eb, ref0),
btrfs_ref_generation_v0(eb, ref0),
btrfs_ref_objectid_v0(eb, ref0),
(unsigned long)btrfs_ref_count_v0(eb, ref0));
}
#endif
static void print_uuid_item(struct extent_buffer *l, unsigned long offset,
u32 item_size)
{
@ -280,11 +256,7 @@ void btrfs_print_leaf(struct extent_buffer *l)
btrfs_file_extent_ram_bytes(l, fi));
break;
case BTRFS_EXTENT_REF_V0_KEY:
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
print_extent_ref_v0(l, i);
#else
BUG();
#endif
break;
case BTRFS_BLOCK_GROUP_ITEM_KEY:
bi = btrfs_item_ptr(l, i,

View File

@ -586,29 +586,6 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
return btrfs_get_fs_root(fs_info, &key, false);
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static noinline_for_stack
struct btrfs_root *find_tree_root(struct reloc_control *rc,
struct extent_buffer *leaf,
struct btrfs_extent_ref_v0 *ref0)
{
struct btrfs_root *root;
u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
u64 generation = btrfs_ref_generation_v0(leaf, ref0);
BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
root = read_fs_root(rc->extent_root->fs_info, root_objectid);
BUG_ON(IS_ERR(root));
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
generation != btrfs_root_generation(&root->root_item))
return NULL;
return root;
}
#endif
static noinline_for_stack
int find_inline_backref(struct extent_buffer *leaf, int slot,
unsigned long *ptr, unsigned long *end)
@ -621,12 +598,6 @@ int find_inline_backref(struct extent_buffer *leaf, int slot,
btrfs_item_key_to_cpu(leaf, &key, slot);
item_size = btrfs_item_size_nr(leaf, slot);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
return 1;
}
#endif
ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
WARN_ON(!(btrfs_extent_flags(leaf, ei) &
BTRFS_EXTENT_FLAG_TREE_BLOCK));
@ -811,29 +782,8 @@ again:
goto next;
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
key.type == BTRFS_EXTENT_REF_V0_KEY) {
if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(eb, path1->slots[0],
struct btrfs_extent_ref_v0);
if (key.objectid == key.offset) {
root = find_tree_root(rc, eb, ref0);
if (root && !should_ignore_root(root))
cur->root = root;
else
list_add(&cur->list, &useless);
break;
}
if (is_cowonly_root(btrfs_ref_root_v0(eb,
ref0)))
cur->cowonly = 1;
}
#else
ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);
if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
#endif
if (key.objectid == key.offset) {
/*
* only root blocks of reloc trees use
@ -3333,48 +3283,6 @@ int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
return 0;
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static int get_ref_objectid_v0(struct reloc_control *rc,
struct btrfs_path *path,
struct btrfs_key *extent_key,
u64 *ref_objectid, int *path_change)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_ref_v0 *ref0;
int ret;
int slot;
leaf = path->nodes[0];
slot = path->slots[0];
while (1) {
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(rc->extent_root, path);
if (ret < 0)
return ret;
BUG_ON(ret > 0);
leaf = path->nodes[0];
slot = path->slots[0];
if (path_change)
*path_change = 1;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != extent_key->objectid)
return -ENOENT;
if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
slot++;
continue;
}
ref0 = btrfs_item_ptr(leaf, slot,
struct btrfs_extent_ref_v0);
*ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
break;
}
return 0;
}
#endif
/*
* helper to add a tree block to the list.
* the major work is getting the generation and level of the block
@ -3408,22 +3316,7 @@ static int add_tree_block(struct reloc_control *rc,
}
generation = btrfs_extent_generation(eb, ei);
} else {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
u64 ref_owner;
int ret;
BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
ret = get_ref_objectid_v0(rc, path, extent_key,
&ref_owner, NULL);
if (ret < 0)
return ret;
BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
level = (int)ref_owner;
/* FIXME: get real generation */
generation = 0;
#else
BUG();
#endif
}
btrfs_release_path(path);
@ -3781,12 +3674,7 @@ int add_data_references(struct reloc_control *rc,
eb = path->nodes[0];
ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
ptr = end;
else
#endif
ptr += sizeof(struct btrfs_extent_item);
ptr += sizeof(struct btrfs_extent_item);
while (ptr < end) {
iref = (struct btrfs_extent_inline_ref *)ptr;
@ -3832,13 +3720,8 @@ int add_data_references(struct reloc_control *rc,
if (key.objectid != extent_key->objectid)
break;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
key.type == BTRFS_EXTENT_REF_V0_KEY) {
#else
BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
#endif
ret = __add_tree_block(rc, key.offset, blocksize,
blocks);
} else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
@ -4086,39 +3969,7 @@ restart:
BUG_ON(ret);
} else {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
u64 ref_owner;
int path_change = 0;
BUG_ON(item_size !=
sizeof(struct btrfs_extent_item_v0));
ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
&path_change);
if (ret < 0) {
err = ret;
break;
}
if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
else
flags = BTRFS_EXTENT_FLAG_DATA;
if (path_change) {
btrfs_release_path(path);
path->search_commit_root = 1;
path->skip_locking = 1;
ret = btrfs_search_slot(NULL, rc->extent_root,
&key, path, 0, 0);
if (ret < 0) {
err = ret;
break;
}
BUG_ON(ret > 0);
}
#else
BUG();
#endif
}
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {