/*
* reads the tree block backref for an extent. tree level and root are returned
* through out_level and out_root. ptr must point to a 0 value for the first
* call and may be modified (see __get_extent_inline_ref comment).
* returns 0 if data was provided, 1 if there was no more data to provide or
* <0 on error.
*/
int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
struct btrfs_extent_item *ei, u32 item_size,
u64 *out_root, u8 *out_level)
{
int ret;
int type;
struct btrfs_tree_block_info *info;
struct btrfs_extent_inline_ref *eiref;
if (*ptr == (unsigned long)-1)
return 1;
while (1) {
ret = __get_extent_inline_ref(ptr, eb, ei, item_size,
&eiref, &type);
if (ret < 0)
return ret;
if (type == BTRFS_TREE_BLOCK_REF_KEY ||
type == BTRFS_SHARED_BLOCK_REF_KEY)
break;
if (ret == 1)
return 1;
}
/* we can treat both ref types equally here */
info = (struct btrfs_tree_block_info *)(ei + 1);
*out_root = btrfs_extent_inline_ref_offset(eb, eiref);
*out_level = btrfs_tree_block_level(eb, info);
if (ret == 1)
*ptr = (unsigned long)-1;
return 0;
}
static void print_extent_item(struct extent_buffer *eb, int slot, int metadata)
{
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
struct btrfs_extent_data_ref *dref;
struct btrfs_shared_data_ref *sref;
struct btrfs_disk_key key;
unsigned long end;
unsigned long ptr;
int type;
u32 item_size = btrfs_item_size_nr(eb, slot);
u64 flags;
u64 offset;
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);
printf("\t\textent refs %u\n",
btrfs_extent_refs_v0(eb, ei0));
return;
#else
BUG();
#endif
}
ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item);
flags = btrfs_extent_flags(eb, ei);
printf("\t\textent refs %llu gen %llu flags %llu\n",
(unsigned long long)btrfs_extent_refs(eb, ei),
(unsigned long long)btrfs_extent_generation(eb, ei),
(unsigned long long)flags);
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !metadata) {
struct btrfs_tree_block_info *info;
info = (struct btrfs_tree_block_info *)(ei + 1);
btrfs_tree_block_key(eb, info, &key);
printf("\t\ttree block ");
btrfs_print_key(&key);
printf(" level %d\n", btrfs_tree_block_level(eb, info));
iref = (struct btrfs_extent_inline_ref *)(info + 1);
} else if (metadata) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(eb, &tmp, slot);
printf("\t\ttree block skinny level %d\n", (int)tmp.offset);
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
} else{
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
}
ptr = (unsigned long)iref;
end = (unsigned long)ei + item_size;
while (ptr < end) {
iref = (struct btrfs_extent_inline_ref *)ptr;
type = btrfs_extent_inline_ref_type(eb, iref);
offset = btrfs_extent_inline_ref_offset(eb, iref);
switch (type) {
case BTRFS_TREE_BLOCK_REF_KEY:
printf("\t\ttree block backref root %llu\n",
(unsigned long long)offset);
break;
case BTRFS_SHARED_BLOCK_REF_KEY:
printf("\t\tshared block backref parent %llu\n",
(unsigned long long)offset);
break;
case BTRFS_EXTENT_DATA_REF_KEY:
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
printf("\t\textent data backref root %llu "
"objectid %llu offset %llu count %u\n",
(unsigned long long)btrfs_extent_data_ref_root(eb, dref),
(unsigned long long)btrfs_extent_data_ref_objectid(eb, dref),
(unsigned long long)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));
break;
default:
return;
}
ptr += btrfs_extent_inline_ref_size(type);
}
WARN_ON(ptr > end);
}
/*
* add all inline backrefs for bytenr to the list
*/
static int __add_inline_refs(struct btrfs_fs_info *fs_info,
struct btrfs_path *path, u64 bytenr,
int *info_level, struct list_head *prefs)
{
int ret = 0;
int slot;
struct extent_buffer *leaf;
struct btrfs_key key;
struct btrfs_key found_key;
unsigned long ptr;
unsigned long end;
struct btrfs_extent_item *ei;
u64 flags;
u64 item_size;
/*
* enumerate all inline refs
*/
leaf = path->nodes[0];
slot = path->slots[0];
item_size = btrfs_item_size_nr(leaf, slot);
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
flags = btrfs_extent_flags(leaf, ei);
btrfs_item_key_to_cpu(leaf, &found_key, slot);
ptr = (unsigned long)(ei + 1);
end = (unsigned long)ei + item_size;
if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
struct btrfs_tree_block_info *info;
info = (struct btrfs_tree_block_info *)ptr;
*info_level = btrfs_tree_block_level(leaf, info);
ptr += sizeof(struct btrfs_tree_block_info);
BUG_ON(ptr > end);
} else if (found_key.type == BTRFS_METADATA_ITEM_KEY) {
*info_level = found_key.offset;
} else {
BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
}
while (ptr < end) {
struct btrfs_extent_inline_ref *iref;
u64 offset;
int type;
iref = (struct btrfs_extent_inline_ref *)ptr;
type = btrfs_extent_inline_ref_type(leaf, iref);
offset = btrfs_extent_inline_ref_offset(leaf, iref);
switch (type) {
case BTRFS_SHARED_BLOCK_REF_KEY:
ret = __add_prelim_ref(prefs, 0, NULL,
*info_level + 1, offset,
bytenr, 1);
break;
case BTRFS_SHARED_DATA_REF_KEY: {
struct btrfs_shared_data_ref *sdref;
int count;
sdref = (struct btrfs_shared_data_ref *)(iref + 1);
count = btrfs_shared_data_ref_count(leaf, sdref);
ret = __add_prelim_ref(prefs, 0, NULL, 0, offset,
bytenr, count);
break;
}
case BTRFS_TREE_BLOCK_REF_KEY:
ret = __add_prelim_ref(prefs, offset, NULL,
*info_level + 1, 0,
bytenr, 1);
break;
case BTRFS_EXTENT_DATA_REF_KEY: {
struct btrfs_extent_data_ref *dref;
int count;
u64 root;
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
count = btrfs_extent_data_ref_count(leaf, dref);
key.objectid = btrfs_extent_data_ref_objectid(leaf,
dref);
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = btrfs_extent_data_ref_offset(leaf, dref);
root = btrfs_extent_data_ref_root(leaf, dref);
ret = __add_prelim_ref(prefs, root, &key, 0, 0,
bytenr, count);
break;
}
default:
WARN_ON(1);
}
if (ret)
return ret;
ptr += btrfs_extent_inline_ref_size(type);
}
return 0;
}
static void print_extent_item(struct extent_buffer *eb, int slot, int type)
{
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
struct btrfs_extent_data_ref *dref;
struct btrfs_shared_data_ref *sref;
struct btrfs_disk_key key;
unsigned long end;
unsigned long ptr;
u32 item_size = btrfs_item_size_nr(eb, slot);
u64 flags;
u64 offset;
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);
printk(KERN_INFO "\t\textent refs %u\n",
btrfs_extent_refs_v0(eb, ei0));
return;
#else
BUG();
#endif
}
ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item);
flags = btrfs_extent_flags(eb, ei);
printk(KERN_INFO "\t\textent refs %llu gen %llu flags %llu\n",
btrfs_extent_refs(eb, ei), btrfs_extent_generation(eb, ei),
flags);
if ((type == BTRFS_EXTENT_ITEM_KEY) &&
flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
struct btrfs_tree_block_info *info;
info = (struct btrfs_tree_block_info *)(ei + 1);
btrfs_tree_block_key(eb, info, &key);
printk(KERN_INFO "\t\ttree block key (%llu %u %llu) "
"level %d\n",
btrfs_disk_key_objectid(&key), key.type,
btrfs_disk_key_offset(&key),
btrfs_tree_block_level(eb, info));
iref = (struct btrfs_extent_inline_ref *)(info + 1);
} else {
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
}
ptr = (unsigned long)iref;
end = (unsigned long)ei + item_size;
while (ptr < end) {
iref = (struct btrfs_extent_inline_ref *)ptr;
type = btrfs_extent_inline_ref_type(eb, iref);
offset = btrfs_extent_inline_ref_offset(eb, iref);
switch (type) {
case BTRFS_TREE_BLOCK_REF_KEY:
printk(KERN_INFO "\t\ttree block backref "
"root %llu\n", offset);
break;
case BTRFS_SHARED_BLOCK_REF_KEY:
printk(KERN_INFO "\t\tshared block backref "
"parent %llu\n", offset);
break;
case BTRFS_EXTENT_DATA_REF_KEY:
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
print_extent_data_ref(eb, dref);
break;
case BTRFS_SHARED_DATA_REF_KEY:
sref = (struct btrfs_shared_data_ref *)(iref + 1);
printk(KERN_INFO "\t\tshared data backref "
"parent %llu count %u\n",
offset, btrfs_shared_data_ref_count(eb, sref));
break;
default:
BUG();
}
ptr += btrfs_extent_inline_ref_size(type);
}
WARN_ON(ptr > end);
}
/*
* calls iterate() for every inode that references the extent identified by
* the given parameters. will use the path given as a parameter and return it
* released.
* when the iterator function returns a non-zero value, iteration stops.
*/
int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
struct btrfs_path *path,
u64 extent_item_objectid,
u64 extent_offset,
iterate_extent_inodes_t *iterate, void *ctx)
{
unsigned long ptr = 0;
int last;
int ret;
int type;
u64 logical;
u32 item_size;
struct btrfs_extent_inline_ref *eiref;
struct btrfs_extent_data_ref *dref;
struct extent_buffer *eb;
struct btrfs_extent_item *ei;
struct btrfs_key key;
struct list_head data_refs = LIST_HEAD_INIT(data_refs);
struct list_head shared_refs = LIST_HEAD_INIT(shared_refs);
struct __data_ref *ref_d;
struct __shared_ref *ref_s;
eb = path->nodes[0];
ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
item_size = btrfs_item_size_nr(eb, path->slots[0]);
/* first we iterate the inline refs, ... */
do {
last = __get_extent_inline_ref(&ptr, eb, ei, item_size,
&eiref, &type);
if (last == -ENOENT) {
ret = 0;
break;
}
if (last < 0) {
ret = last;
break;
}
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
dref = (struct btrfs_extent_data_ref *)(&eiref->offset);
ret = __data_list_add_eb(&data_refs, eb, dref);
} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
logical = btrfs_extent_inline_ref_offset(eb, eiref);
ret = __shared_list_add(&shared_refs, logical);
}
} while (!ret && !last);
/* ... then we proceed to in-tree references and ... */
while (!ret) {
++path->slots[0];
if (path->slots[0] > btrfs_header_nritems(eb)) {
ret = btrfs_next_leaf(fs_info->extent_root, path);
if (ret) {
if (ret == 1)
ret = 0; /* we're done */
break;
}
eb = path->nodes[0];
}
btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
if (key.objectid != extent_item_objectid)
break;
if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
dref = btrfs_item_ptr(eb, path->slots[0],
struct btrfs_extent_data_ref);
ret = __data_list_add_eb(&data_refs, eb, dref);
} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
static int __iter_shared_inline_ref_inodes(struct btrfs_fs_info *fs_info,
u64 logical, u64 inum,
u64 extent_data_item_offset,
u64 extent_offset,
struct btrfs_path *path,
struct list_head *data_refs,
iterate_extent_inodes_t *iterate,
void *ctx)
{
u64 ref_root;
u32 item_size;
struct btrfs_key key;
struct extent_buffer *eb;
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *eiref;
struct __data_ref *ref;
int ret;
int type;
int last;
unsigned long ptr = 0;
WARN_ON(!list_empty(data_refs));
ret = extent_from_logical(fs_info, logical, path, &key);
if (ret & BTRFS_EXTENT_FLAG_DATA)
ret = -EIO;
if (ret < 0)
goto out;
eb = path->nodes[0];
ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
item_size = btrfs_item_size_nr(eb, path->slots[0]);
ret = 0;
ref_root = 0;
/*
* as done in iterate_extent_inodes, we first build a list of refs to
* iterate, then free the path and then iterate them to avoid deadlocks.
*/
do {
last = __get_extent_inline_ref(&ptr, eb, ei, item_size,
&eiref, &type);
if (last < 0) {
ret = last;
goto out;
}
if (type == BTRFS_TREE_BLOCK_REF_KEY ||
type == BTRFS_SHARED_BLOCK_REF_KEY) {
ref_root = btrfs_extent_inline_ref_offset(eb, eiref);
ret = __data_list_add(data_refs, inum,
extent_data_item_offset,
ref_root);
}
} while (!ret && !last);
btrfs_release_path(path);
if (ref_root == 0) {
printk(KERN_ERR "btrfs: failed to find tree block ref "
"for shared data backref %llu\n", logical);
WARN_ON(1);
ret = -EIO;
}
out:
while (!list_empty(data_refs)) {
ref = list_first_entry(data_refs, struct __data_ref, list);
list_del(&ref->list);
if (!ret)
ret = iterate(ref->inum, extent_offset +
ref->extent_data_item_offset,
ref->root, ctx);
kfree(ref);
}
return ret;
}
