btrfs: fix check_shared for fiemap ioctl

 */

#include <linux/vmalloc.h>

#include <linux/rbtree.h>

#include "ctree.h"

#include "disk-io.h"

#include "backref.h"

	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(struct btrfs_key *key, struct extent_buffer *eb,

				struct btrfs_file_extent_item *fi,

				u64 extent_item_pos,

static int __add_inline_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 *total_refs, u64 inum)

{

	int ret = 0;

			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:

			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:

 */

static int __add_keyed_refs(struct btrfs_fs_info *fs_info,

			    struct btrfs_path *path, u64 bytenr,

			    int info_level, struct list_head *prefs, u64 inum)

			    int info_level, struct list_head *prefs,

			    struct ref_root *ref_tree, u64 inum)

{

	struct btrfs_root *extent_root = fs_info->extent_root;

	int ret;

			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:

			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:

 * 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)

			     u64 root_objectid, u64 inum, int check_shared)

{

	struct btrfs_key key;

	struct btrfs_path *path;

	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);

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;

		} 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]) {

		     key.type == BTRFS_METADATA_ITEM_KEY)) {

			ret = __add_inline_refs(fs_info, path, bytenr,

						&info_level, &prefs,

						&total_refs, inum);

						ref_tree, &total_refs,

						inum);

			if (ret)

				goto out;

			ret = __add_keyed_refs(fs_info, path, bytenr,

					       info_level, &prefs, inum);

					       info_level, &prefs,

					       ref_tree, inum);

			if (ret)

				goto out;

		}

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);

	if (!*leafs)

		return -ENOMEM;

	ret = find_parent_nodes(trans, fs_info, bytenr,

				time_seq, *leafs, NULL, extent_item_pos, 0, 0);

	ret = find_parent_nodes(trans, fs_info, bytenr, time_seq,

				*leafs, NULL, extent_item_pos, 0, 0, 0);

	if (ret < 0 && ret != -ENOENT) {

		free_leaf_list(*leafs);

		return ret;

	ULIST_ITER_INIT(&uiter);

	while (1) {

		ret = find_parent_nodes(trans, fs_info, bytenr,

					time_seq, tmp, *roots, NULL, 0, 0);

		ret = find_parent_nodes(trans, fs_info, bytenr, time_seq,

					tmp, *roots, NULL, 0, 0, 0);

		if (ret < 0 && ret != -ENOENT) {

			ulist_free(tmp);

			ulist_free(*roots);

	ULIST_ITER_INIT(&uiter);

	while (1) {

		ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp,

					roots, NULL, root_objectid, inum);

					roots, NULL, root_objectid, inum, 1);

		if (ret == BACKREF_FOUND_SHARED) {

			/* this is the only condition under which we return 1 */

			ret = 1;

#include "locking.h"

#include "rcu-string.h"

#include "backref.h"

#include "transaction.h"

static struct kmem_cache *extent_state_cache;

static struct kmem_cache *extent_buffer_cache;

			flags |= (FIEMAP_EXTENT_DELALLOC |

				  FIEMAP_EXTENT_UNKNOWN);

		} else if (fieinfo->fi_extents_max) {

			struct btrfs_trans_handle *trans;

			u64 bytenr = em->block_start -

				(em->start - em->orig_start);

			disko = em->block_start + offset_in_extent;

			/*

			 * We need a trans handle to get delayed refs

			 */

			trans = btrfs_join_transaction(root);

			/*

			 * It's OK if we can't start a trans we can still check

			 * from commit_root

			 */

			if (IS_ERR(trans))

				trans = NULL;

			/*

			 * As btrfs supports shared space, this information

			 * can be exported to userspace tools via

			 * then we're just getting a count and we can skip the

			 * lookup stuff.

			 */

			ret = btrfs_check_shared(NULL, root->fs_info,

			ret = btrfs_check_shared(trans, root->fs_info,

						 root->objectid,

						 btrfs_ino(inode), bytenr);

			if (trans)

				btrfs_end_transaction(trans, root);

			if (ret < 0)

				goto out_free;

			if (ret)