The BACKREF_FOUND_SHARED checking will be addressed in an upcoming
patch.
Signed-off-by: Edmund Nadolski <enadol...@suse.com>
Signed-off-by: Jeff Mahoney <je...@suse.com>
---
fs/btrfs/backref.c | 356 ++---------------------------------------------------
1 file changed, 8 insertions(+), 348 deletions(-)
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 35cfa38..0d1e7cb 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -40,265 +40,6 @@ struct extent_inode_elem {
struct extent_inode_elem *next;
};
-/*
- * ref_root is used as the root of the ref tree that hold a collection
- * of unique references.
- */
-struct ref_root {
- struct rb_root rb_root;
-
- /*
- * The unique_refs represents the number of ref_nodes with a positive
- * count stored in the tree. Even if a ref_node (the count is greater
- * than one) is added, the unique_refs will only increase by one.
- */
- unsigned int unique_refs;
-};
-
-/* ref_node is used to store a unique reference to the ref tree. */
-struct ref_node {
- struct rb_node rb_node;
-
- /* For NORMAL_REF, otherwise all these fields should be set to 0 */
- u64 root_id;
- u64 object_id;
- u64 offset;
-
- /* For SHARED_REF, otherwise parent field should be set to 0 */
- u64 parent;
-
- /* Ref to the ref_mod of btrfs_delayed_ref_node */
- int ref_mod;
-};
-
-/* Dynamically allocate and initialize a ref_root */
-static struct ref_root *ref_root_alloc(void)
-{
- struct ref_root *ref_tree;
-
- ref_tree = kmalloc(sizeof(*ref_tree), GFP_NOFS);
- if (!ref_tree)
- return NULL;
-
- ref_tree->rb_root = RB_ROOT;
- ref_tree->unique_refs = 0;
-
- return ref_tree;
-}
-
-/* Free all nodes in the ref tree, and reinit ref_root */
-static void ref_root_fini(struct ref_root *ref_tree)
-{
- struct ref_node *node;
- struct rb_node *next;
-
- while ((next = rb_first(&ref_tree->rb_root)) != NULL) {
- node = rb_entry(next, struct ref_node, rb_node);
- rb_erase(next, &ref_tree->rb_root);
- kfree(node);
- }
-
- ref_tree->rb_root = RB_ROOT;
- ref_tree->unique_refs = 0;
-}
-
-static void ref_root_free(struct ref_root *ref_tree)
-{
- if (!ref_tree)
- return;
-
- ref_root_fini(ref_tree);
- kfree(ref_tree);
-}
-
-/*
- * Compare ref_node with (root_id, object_id, offset, parent)
- *
- * The function compares two ref_node a and b. It returns an integer less
- * than, equal to, or greater than zero , respectively, to be less than, to
- * equal, or be greater than b.
- */
-static int ref_node_cmp(struct ref_node *a, struct ref_node *b)
-{
- if (a->root_id < b->root_id)
- return -1;
- else if (a->root_id > b->root_id)
- return 1;
-
- if (a->object_id < b->object_id)
- return -1;
- else if (a->object_id > b->object_id)
- return 1;
-
- if (a->offset < b->offset)
- return -1;
- else if (a->offset > b->offset)
- return 1;
-
- if (a->parent < b->parent)
- return -1;
- else if (a->parent > b->parent)
- return 1;
-
- return 0;
-}
-
-/*
- * Search ref_node with (root_id, object_id, offset, parent) in the tree
- *
- * if found, the pointer of the ref_node will be returned;
- * if not found, NULL will be returned and pos will point to the rb_node for
- * insert, pos_parent will point to pos'parent for insert;
-*/
-static struct ref_node *__ref_tree_search(struct ref_root *ref_tree,
- struct rb_node ***pos,
- struct rb_node **pos_parent,
- u64 root_id, u64 object_id,
- u64 offset, u64 parent)
-{
- struct ref_node *cur = NULL;
- struct ref_node entry;
- int ret;
-
- entry.root_id = root_id;
- entry.object_id = object_id;
- entry.offset = offset;
- entry.parent = parent;
-
- *pos = &ref_tree->rb_root.rb_node;
-
- while (**pos) {
- *pos_parent = **pos;
- cur = rb_entry(*pos_parent, struct ref_node, rb_node);
-
- ret = ref_node_cmp(cur, &entry);
- if (ret > 0)
- *pos = &(**pos)->rb_left;
- else if (ret < 0)
- *pos = &(**pos)->rb_right;
- else
- return cur;
- }
-
- return NULL;
-}
-
-/*
- * Insert a ref_node to the ref tree
- * @pos used for specifiy the position to insert
- * @pos_parent for specifiy pos's parent
- *
- * success, return 0;
- * ref_node already exists, return -EEXIST;
-*/
-static int ref_tree_insert(struct ref_root *ref_tree, struct rb_node **pos,
- struct rb_node *pos_parent, struct ref_node *ins)
-{
- struct rb_node **p = NULL;
- struct rb_node *parent = NULL;
- struct ref_node *cur = NULL;
-
- if (!pos) {
- cur = __ref_tree_search(ref_tree, &p, &parent, ins->root_id,
- ins->object_id, ins->offset,
- ins->parent);
- if (cur)
- return -EEXIST;
- } else {
- p = pos;
- parent = pos_parent;
- }
-
- rb_link_node(&ins->rb_node, parent, p);
- rb_insert_color(&ins->rb_node, &ref_tree->rb_root);
-
- return 0;
-}
-
-/* Erase and free ref_node, caller should update ref_root->unique_refs */
-static void ref_tree_remove(struct ref_root *ref_tree, struct ref_node *node)
-{
- rb_erase(&node->rb_node, &ref_tree->rb_root);
- kfree(node);
-}
-
-/*
- * Update ref_root->unique_refs
- *
- * Call __ref_tree_search
- * 1. if ref_node doesn't exist, ref_tree_insert this node, and update
- * ref_root->unique_refs:
- * if ref_node->ref_mod > 0, ref_root->unique_refs++;
- * if ref_node->ref_mod < 0, do noting;
- *
- * 2. if ref_node is found, then get origin ref_node->ref_mod, and update
- * ref_node->ref_mod.
- * if ref_node->ref_mod is equal to 0,then call ref_tree_remove
- *
- * according to origin_mod and new_mod, update ref_root->items
- * +----------------+--------------+-------------+
- * | |new_count <= 0|new_count > 0|
- * +----------------+--------------+-------------+
- * |origin_count < 0| 0 | 1 |
- * +----------------+--------------+-------------+
- * |origin_count > 0| -1 | 0 |
- * +----------------+--------------+-------------+
- *
- * In case of allocation failure, -ENOMEM is returned and the ref_tree stays
- * unaltered.
- * Success, return 0
- */
-static int ref_tree_add(struct ref_root *ref_tree, u64 root_id, u64 object_id,
- u64 offset, u64 parent, int count)
-{
- struct ref_node *node = NULL;
- struct rb_node **pos = NULL;
- struct rb_node *pos_parent = NULL;
- int origin_count;
- int ret;
-
- if (!count)
- return 0;
-
- node = __ref_tree_search(ref_tree, &pos, &pos_parent, root_id,
- object_id, offset, parent);
- if (node == NULL) {
- node = kmalloc(sizeof(*node), GFP_NOFS);
- if (!node)
- return -ENOMEM;
-
- node->root_id = root_id;
- node->object_id = object_id;
- node->offset = offset;
- node->parent = parent;
- node->ref_mod = count;
-
- ret = ref_tree_insert(ref_tree, pos, pos_parent, node);
- ASSERT(!ret);
- if (ret) {
- kfree(node);
- return ret;
- }
-
- ref_tree->unique_refs += node->ref_mod > 0 ? 1 : 0;
-
- return 0;
- }
-
- origin_count = node->ref_mod;
- node->ref_mod += count;
-
- if (node->ref_mod > 0)
- ref_tree->unique_refs += origin_count > 0 ? 0 : 1;
- else if (node->ref_mod <= 0)
- ref_tree->unique_refs += origin_count > 0 ? -1 : 0;
-
- if (!node->ref_mod)
- ref_tree_remove(ref_tree, node);
-
- return 0;
-}
-
static int check_extent_in_eb(const struct btrfs_key *key,
const struct extent_buffer *eb,
const struct btrfs_file_extent_item *fi,
@@ -964,7 +705,6 @@ static int add_delayed_refs(struct btrfs_delayed_ref_head
*head, u64 seq,
*/
static int add_inline_refs(struct btrfs_path *path, u64 bytenr,
int *info_level, struct list_head *prefs,
- struct ref_root *ref_tree,
u64 *total_refs, u64 inum)
{
int ret = 0;
@@ -1031,13 +771,6 @@ static int add_inline_refs(struct btrfs_path *path, u64
bytenr,
count = btrfs_shared_data_ref_count(leaf, sdref);
ret = add_prelim_ref(prefs, 0, NULL, 0, offset,
bytenr, count, GFP_NOFS);
- if (ref_tree) {
- if (!ret)
- ret = ref_tree_add(ref_tree, 0, 0, 0,
- bytenr, count);
- if (!ret && ref_tree->unique_refs > 1)
- ret = BACKREF_FOUND_SHARED;
- }
break;
}
case BTRFS_TREE_BLOCK_REF_KEY:
@@ -1065,15 +798,6 @@ static int add_inline_refs(struct btrfs_path *path, u64
bytenr,
root = btrfs_extent_data_ref_root(leaf, dref);
ret = add_prelim_ref(prefs, root, &key, 0, 0,
bytenr, count, GFP_NOFS);
- if (ref_tree) {
- if (!ret)
- ret = ref_tree_add(ref_tree, root,
- key.objectid,
- key.offset, 0,
- count);
- if (!ret && ref_tree->unique_refs > 1)
- ret = BACKREF_FOUND_SHARED;
- }
break;
}
default:
@@ -1092,8 +816,7 @@ static int add_inline_refs(struct btrfs_path *path, u64
bytenr,
*/
static int add_keyed_refs(struct btrfs_fs_info *fs_info,
struct btrfs_path *path, u64 bytenr,
- int info_level, struct list_head *prefs,
- struct ref_root *ref_tree, u64 inum)
+ int info_level, struct list_head *prefs, u64 inum)
{
struct btrfs_root *extent_root = fs_info->extent_root;
int ret;
@@ -1135,13 +858,6 @@ static int add_keyed_refs(struct btrfs_fs_info *fs_info,
count = btrfs_shared_data_ref_count(leaf, sdref);
ret = add_prelim_ref(prefs, 0, NULL, 0, key.offset,
bytenr, count, GFP_NOFS);
- if (ref_tree) {
- if (!ret)
- ret = ref_tree_add(ref_tree, 0, 0, 0,
- bytenr, count);
- if (!ret && ref_tree->unique_refs > 1)
- ret = BACKREF_FOUND_SHARED;
- }
break;
}
case BTRFS_TREE_BLOCK_REF_KEY:
@@ -1170,15 +886,6 @@ static int add_keyed_refs(struct btrfs_fs_info *fs_info,
root = btrfs_extent_data_ref_root(leaf, dref);
ret = add_prelim_ref(prefs, root, &key, 0, 0,
bytenr, count, GFP_NOFS);
- if (ref_tree) {
- if (!ret)
- ret = ref_tree_add(ref_tree, root,
- key.objectid,
- key.offset, 0,
- count);
- if (!ret && ref_tree->unique_refs > 1)
- ret = BACKREF_FOUND_SHARED;
- }
break;
}
default:
@@ -1205,16 +912,13 @@ static int add_keyed_refs(struct btrfs_fs_info *fs_info,
* commit root.
* The special case is for qgroup to search roots in commit_transaction().
*
- * If check_shared is set to 1, any extent has more than one ref item, will
- * be returned BACKREF_FOUND_SHARED immediately.
- *
* FIXME some caching might speed things up
*/
static int find_parent_nodes(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
u64 time_seq, struct ulist *refs,
struct ulist *roots, const u64 *extent_item_pos,
- u64 root_objectid, u64 inum, int check_shared)
+ u64 root_objectid, u64 inum)
{
struct btrfs_key key;
struct btrfs_path *path;
@@ -1226,7 +930,6 @@ static int find_parent_nodes(struct btrfs_trans_handle
*trans,
struct list_head prefs;
struct prelim_ref *ref;
struct extent_inode_elem *eie = NULL;
- struct ref_root *ref_tree = NULL;
u64 total_refs = 0;
INIT_LIST_HEAD(&prefs);
@@ -1258,18 +961,6 @@ static int find_parent_nodes(struct btrfs_trans_handle
*trans,
again:
head = NULL;
- if (check_shared) {
- if (!ref_tree) {
- ref_tree = ref_root_alloc();
- if (!ref_tree) {
- ret = -ENOMEM;
- goto out;
- }
- } else {
- ref_root_fini(ref_tree);
- }
- }
-
ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
@@ -1314,36 +1005,6 @@ static int find_parent_nodes(struct btrfs_trans_handle
*trans,
} else {
spin_unlock(&delayed_refs->lock);
}
-
- if (check_shared && !list_empty(&prefs_delayed)) {
- /*
- * Add all delay_ref to the ref_tree and check if there
- * are multiple ref items added.
- */
- list_for_each_entry(ref, &prefs_delayed, list) {
- if (ref->key_for_search.type) {
- ret = ref_tree_add(ref_tree,
- ref->root_id,
- ref->key_for_search.objectid,
- ref->key_for_search.offset,
- 0, ref->count);
- if (ret)
- goto out;
- } else {
- ret = ref_tree_add(ref_tree, 0, 0, 0,
- ref->parent, ref->count);
- if (ret)
- goto out;
- }
-
- }
-
- if (ref_tree->unique_refs > 1) {
- ret = BACKREF_FOUND_SHARED;
- goto out;
- }
-
- }
}
if (path->slots[0]) {
@@ -1358,12 +1019,11 @@ static int find_parent_nodes(struct btrfs_trans_handle
*trans,
(key.type == BTRFS_EXTENT_ITEM_KEY ||
key.type == BTRFS_METADATA_ITEM_KEY)) {
ret = add_inline_refs(path, bytenr, &info_level,
- &prefs, ref_tree, &total_refs,
- inum);
+ &prefs, &total_refs, inum);
if (ret)
goto out;
ret = add_keyed_refs(fs_info, path, bytenr, info_level,
- &prefs, ref_tree, inum);
+ &prefs, inum);
if (ret)
goto out;
}
@@ -1447,7 +1107,6 @@ static int find_parent_nodes(struct btrfs_trans_handle
*trans,
out:
btrfs_free_path(path);
- ref_root_free(ref_tree);
while (!list_empty(&prefs)) {
ref = list_first_entry(&prefs, struct prelim_ref, list);
list_del(&ref->list);
@@ -1502,7 +1161,7 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle
*trans,
return -ENOMEM;
ret = find_parent_nodes(trans, fs_info, bytenr, time_seq,
- *leafs, NULL, extent_item_pos, 0, 0, 0);
+ *leafs, NULL, extent_item_pos, 0, 0);
if (ret < 0 && ret != -ENOENT) {
free_leaf_list(*leafs);
return ret;
@@ -1545,7 +1204,7 @@ static int btrfs_find_all_roots_safe(struct
btrfs_trans_handle *trans,
ULIST_ITER_INIT(&uiter);
while (1) {
ret = find_parent_nodes(trans, fs_info, bytenr, time_seq,
- tmp, *roots, NULL, 0, 0, 0);
+ tmp, *roots, NULL, 0, 0);
if (ret < 0 && ret != -ENOENT) {
ulist_free(tmp);
ulist_free(*roots);
@@ -1620,8 +1279,9 @@ int btrfs_check_shared(struct btrfs_root *root, u64 inum,
u64 bytenr)
ULIST_ITER_INIT(&uiter);
while (1) {
+ /* TODO - short-circuit when only checking for shared... */
ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp,
- roots, NULL, root->objectid, inum, 1);
+ roots, NULL, root->objectid, inum);
if (ret == BACKREF_FOUND_SHARED) {
/* this is the only condition under which we return 1 */
ret = 1;
--
2.10.2
--
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