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Commit 1e20932a authored by Chris Mason's avatar Chris Mason
Browse files

Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into for-linus 



Conflicts:
	fs/btrfs/ulist.h

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parents cfc442b6 c3193108

fs/btrfs/backref.c

+350 −145
Original line number Diff line number Diff line
@@ -24,22 +24,135 @@ 
#include "delayed-ref.h"

#include "locking.h"



struct extent_inode_elem {

	u64 inum;

	u64 offset;

	struct extent_inode_elem *next;

};



static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb,

				struct btrfs_file_extent_item *fi,

				u64 extent_item_pos,

				struct extent_inode_elem **eie)

{

	u64 data_offset;

	u64 data_len;

	struct extent_inode_elem *e;



	data_offset = btrfs_file_extent_offset(eb, fi);

	data_len = btrfs_file_extent_num_bytes(eb, fi);



	if (extent_item_pos < data_offset ||

	    extent_item_pos >= data_offset + data_len)

		return 1;



	e = kmalloc(sizeof(*e), GFP_NOFS);

	if (!e)

		return -ENOMEM;



	e->next = *eie;

	e->inum = key->objectid;

	e->offset = key->offset + (extent_item_pos - data_offset);

	*eie = e;



	return 0;

}



static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte,

				u64 extent_item_pos,

				struct extent_inode_elem **eie)

{

	u64 disk_byte;

	struct btrfs_key key;

	struct btrfs_file_extent_item *fi;

	int slot;

	int nritems;

	int extent_type;

	int ret;



	/*

	 * from the shared data ref, we only have the leaf but we need

	 * the key. thus, we must look into all items and see that we

	 * find one (some) with a reference to our extent item.

	 */

	nritems = btrfs_header_nritems(eb);

	for (slot = 0; slot < nritems; ++slot) {

		btrfs_item_key_to_cpu(eb, &key, slot);

		if (key.type != BTRFS_EXTENT_DATA_KEY)

			continue;

		fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);

		extent_type = btrfs_file_extent_type(eb, fi);

		if (extent_type == BTRFS_FILE_EXTENT_INLINE)

			continue;

		/* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */

		disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);

		if (disk_byte != wanted_disk_byte)

			continue;



		ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie);

		if (ret < 0)

			return ret;

	}



	return 0;

}



/*

 * this structure records all encountered refs on the way up to the root

 */

struct __prelim_ref {

	struct list_head list;

	u64 root_id;

	struct btrfs_key key;

	struct btrfs_key key_for_search;

	int level;

	int count;

	struct extent_inode_elem *inode_list;

	u64 parent;

	u64 wanted_disk_byte;

};



/*

 * the rules for all callers of this function are:

 * - obtaining the parent is the goal

 * - if you add a key, you must know that it is a correct key

 * - if you cannot add the parent or a correct key, then we will look into the

 *   block later to set a correct key

 *

 * delayed refs

 * ============

 *        backref type | shared | indirect | shared | indirect

 * information         |   tree |     tree |   data |     data

 * --------------------+--------+----------+--------+----------

 *      parent logical |    y   |     -    |    -   |     -

 *      key to resolve |    -   |     y    |    y   |     y

 *  tree block logical |    -   |     -    |    -   |     -

 *  root for resolving |    y   |     y    |    y   |     y

 *

 * - column 1:       we've the parent -> done

 * - column 2, 3, 4: we use the key to find the parent

 *

 * on disk refs (inline or keyed)

 * ==============================

 *        backref type | shared | indirect | shared | indirect

 * information         |   tree |     tree |   data |     data

 * --------------------+--------+----------+--------+----------

 *      parent logical |    y   |     -    |    y   |     -

 *      key to resolve |    -   |     -    |    -   |     y

 *  tree block logical |    y   |     y    |    y   |     y

 *  root for resolving |    -   |     y    |    y   |     y

 *

 * - column 1, 3: we've the parent -> done

 * - column 2:    we take the first key from the block to find the parent

 *                (see __add_missing_keys)

 * - column 4:    we use the key to find the parent

 *

 * additional information that's available but not required to find the parent

 * block might help in merging entries to gain some speed.

 */



static int __add_prelim_ref(struct list_head *head, u64 root_id,

			    struct btrfs_key *key, int level, u64 parent,

			    u64 wanted_disk_byte, int count)

			    struct btrfs_key *key, int level,

			    u64 parent, u64 wanted_disk_byte, int count)

{

	struct __prelim_ref *ref;
@@ -50,10 +163,11 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id, 


	ref->root_id = root_id;

	if (key)

		ref->key = *key;

		ref->key_for_search = *key;

	else

		memset(&ref->key, 0, sizeof(ref->key));

		memset(&ref->key_for_search, 0, sizeof(ref->key_for_search));



	ref->inode_list = NULL;

	ref->level = level;

	ref->count = count;

	ref->parent = parent;
@@ -64,18 +178,26 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id, 
}



static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,

				struct ulist *parents,

				struct extent_buffer *eb, int level,

				u64 wanted_objectid, u64 wanted_disk_byte)

				struct ulist *parents, int level,

				struct btrfs_key *key, u64 wanted_disk_byte,

				const u64 *extent_item_pos)

{

	int ret;

	int slot;

	int slot = path->slots[level];

	struct extent_buffer *eb = path->nodes[level];

	struct btrfs_file_extent_item *fi;

	struct btrfs_key key;

	struct extent_inode_elem *eie = NULL;

	u64 disk_byte;

	u64 wanted_objectid = key->objectid;



add_parent:

	ret = ulist_add(parents, eb->start, 0, GFP_NOFS);

	if (level == 0 && extent_item_pos) {

		fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);

		ret = check_extent_in_eb(key, eb, fi, *extent_item_pos, &eie);

		if (ret < 0)

			return ret;

	}

	ret = ulist_add(parents, eb->start, (unsigned long)eie, GFP_NOFS);

	if (ret < 0)

		return ret;
@@ -89,6 +211,7 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, 
	 * repeat this until we don't find any additional EXTENT_DATA items.

	 */

	while (1) {

		eie = NULL;

		ret = btrfs_next_leaf(root, path);

		if (ret < 0)

			return ret;
@@ -97,9 +220,9 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, 


		eb = path->nodes[0];

		for (slot = 0; slot < btrfs_header_nritems(eb); ++slot) {

			btrfs_item_key_to_cpu(eb, &key, slot);

			if (key.objectid != wanted_objectid ||

			    key.type != BTRFS_EXTENT_DATA_KEY)

			btrfs_item_key_to_cpu(eb, key, slot);

			if (key->objectid != wanted_objectid ||

			    key->type != BTRFS_EXTENT_DATA_KEY)

				return 0;

			fi = btrfs_item_ptr(eb, slot,

						struct btrfs_file_extent_item);
@@ -118,8 +241,10 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, 
 */

static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,

					int search_commit_root,

					u64 time_seq,

					struct __prelim_ref *ref,

					struct ulist *parents)

					struct ulist *parents,

					const u64 *extent_item_pos)

{

	struct btrfs_path *path;

	struct btrfs_root *root;
@@ -152,12 +277,13 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, 
		goto out;



	path->lowest_level = level;

	ret = btrfs_search_slot(NULL, root, &ref->key, path, 0, 0);

	ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq);

	pr_debug("search slot in root %llu (level %d, ref count %d) returned "

		 "%d for key (%llu %u %llu)\n",

		 (unsigned long long)ref->root_id, level, ref->count, ret,

		 (unsigned long long)ref->key.objectid, ref->key.type,

		 (unsigned long long)ref->key.offset);

		 (unsigned long long)ref->key_for_search.objectid,

		 ref->key_for_search.type,

		 (unsigned long long)ref->key_for_search.offset);

	if (ret < 0)

		goto out;
@@ -179,9 +305,8 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, 
		btrfs_item_key_to_cpu(eb, &key, path->slots[0]);

	}



	/* the last two parameters will only be used for level == 0 */

	ret = add_all_parents(root, path, parents, eb, level, key.objectid,

				ref->wanted_disk_byte);

	ret = add_all_parents(root, path, parents, level, &key,

				ref->wanted_disk_byte, extent_item_pos);

out:

	btrfs_free_path(path);

	return ret;
@@ -191,8 +316,9 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, 
 * resolve all indirect backrefs from the list

 */

static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,

				   int search_commit_root,

				   struct list_head *head)

				   int search_commit_root, u64 time_seq,

				   struct list_head *head,

				   const u64 *extent_item_pos)

{

	int err;

	int ret = 0;
@@ -201,6 +327,7 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, 
	struct __prelim_ref *new_ref;

	struct ulist *parents;

	struct ulist_node *node;

	struct ulist_iterator uiter;



	parents = ulist_alloc(GFP_NOFS);

	if (!parents)
@@ -217,7 +344,8 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, 
		if (ref->count == 0)

			continue;

		err = __resolve_indirect_ref(fs_info, search_commit_root,

					     ref, parents);

					     time_seq, ref, parents,

					     extent_item_pos);

		if (err) {

			if (ret == 0)

				ret = err;
@@ -225,11 +353,14 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, 
		}



		/* we put the first parent into the ref at hand */

		node = ulist_next(parents, NULL);

		ULIST_ITER_INIT(&uiter);

		node = ulist_next(parents, &uiter);

		ref->parent = node ? node->val : 0;

		ref->inode_list =

			node ? (struct extent_inode_elem *)node->aux : 0;



		/* additional parents require new refs being added here */

		while ((node = ulist_next(parents, node))) {

		while ((node = ulist_next(parents, &uiter))) {

			new_ref = kmalloc(sizeof(*new_ref), GFP_NOFS);

			if (!new_ref) {

				ret = -ENOMEM;
@@ -237,6 +368,8 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, 
			}

			memcpy(new_ref, ref, sizeof(*ref));

			new_ref->parent = node->val;

			new_ref->inode_list =

					(struct extent_inode_elem *)node->aux;

			list_add(&new_ref->list, &ref->list);

		}

		ulist_reinit(parents);
@@ -246,10 +379,65 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, 
	return ret;

}



static inline int ref_for_same_block(struct __prelim_ref *ref1,

				     struct __prelim_ref *ref2)

{

	if (ref1->level != ref2->level)

		return 0;

	if (ref1->root_id != ref2->root_id)

		return 0;

	if (ref1->key_for_search.type != ref2->key_for_search.type)

		return 0;

	if (ref1->key_for_search.objectid != ref2->key_for_search.objectid)

		return 0;

	if (ref1->key_for_search.offset != ref2->key_for_search.offset)

		return 0;

	if (ref1->parent != ref2->parent)

		return 0;



	return 1;

}



/*

 * read tree blocks and add keys where required.

 */

static int __add_missing_keys(struct btrfs_fs_info *fs_info,

			      struct list_head *head)

{

	struct list_head *pos;

	struct extent_buffer *eb;



	list_for_each(pos, head) {

		struct __prelim_ref *ref;

		ref = list_entry(pos, struct __prelim_ref, list);



		if (ref->parent)

			continue;

		if (ref->key_for_search.type)

			continue;

		BUG_ON(!ref->wanted_disk_byte);

		eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte,

				     fs_info->tree_root->leafsize, 0);

		BUG_ON(!eb);

		btrfs_tree_read_lock(eb);

		if (btrfs_header_level(eb) == 0)

			btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0);

		else

			btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0);

		btrfs_tree_read_unlock(eb);

		free_extent_buffer(eb);

	}

	return 0;

}



/*

 * merge two lists of backrefs and adjust counts accordingly

 *

 * mode = 1: merge identical keys, if key is set

 *    FIXME: if we add more keys in __add_prelim_ref, we can merge more here.

 *           additionally, we could even add a key range for the blocks we

 *           looked into to merge even more (-> replace unresolved refs by those

 *           having a parent).

 * mode = 2: merge identical parents

 */

static int __merge_refs(struct list_head *head, int mode)
@@ -263,20 +451,21 @@ static int __merge_refs(struct list_head *head, int mode) 


		ref1 = list_entry(pos1, struct __prelim_ref, list);



		if (mode == 1 && ref1->key.type == 0)

			continue;

		for (pos2 = pos1->next, n2 = pos2->next; pos2 != head;

		     pos2 = n2, n2 = pos2->next) {

			struct __prelim_ref *ref2;

			struct __prelim_ref *xchg;



			ref2 = list_entry(pos2, struct __prelim_ref, list);



			if (mode == 1) {

				if (memcmp(&ref1->key, &ref2->key,

					   sizeof(ref1->key)) ||

				    ref1->level != ref2->level ||

				    ref1->root_id != ref2->root_id)

				if (!ref_for_same_block(ref1, ref2))

					continue;

				if (!ref1->parent && ref2->parent) {

					xchg = ref1;

					ref1 = ref2;

					ref2 = xchg;

				}

				ref1->count += ref2->count;

			} else {

				if (ref1->parent != ref2->parent)
@@ -296,16 +485,17 @@ static int __merge_refs(struct list_head *head, int mode) 
 * smaller or equal that seq to the list

 */

static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,

			      struct btrfs_key *info_key,

			      struct list_head *prefs)

{

	struct btrfs_delayed_extent_op *extent_op = head->extent_op;

	struct rb_node *n = &head->node.rb_node;

	struct btrfs_key key;

	struct btrfs_key op_key = {0};

	int sgn;

	int ret = 0;



	if (extent_op && extent_op->update_key)

		btrfs_disk_key_to_cpu(info_key, &extent_op->key);

		btrfs_disk_key_to_cpu(&op_key, &extent_op->key);



	while ((n = rb_prev(n))) {

		struct btrfs_delayed_ref_node *node;
@@ -337,7 +527,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
			struct btrfs_delayed_tree_ref *ref;



			ref = btrfs_delayed_node_to_tree_ref(node);

			ret = __add_prelim_ref(prefs, ref->root, info_key,

			ret = __add_prelim_ref(prefs, ref->root, &op_key,

					       ref->level + 1, 0, node->bytenr,

					       node->ref_mod * sgn);

			break;
@@ -346,7 +536,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
			struct btrfs_delayed_tree_ref *ref;



			ref = btrfs_delayed_node_to_tree_ref(node);

			ret = __add_prelim_ref(prefs, ref->root, info_key,

			ret = __add_prelim_ref(prefs, ref->root, NULL,

					       ref->level + 1, ref->parent,

					       node->bytenr,

					       node->ref_mod * sgn);
@@ -354,8 +544,6 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
		}

		case BTRFS_EXTENT_DATA_REF_KEY: {

			struct btrfs_delayed_data_ref *ref;

			struct btrfs_key key;



			ref = btrfs_delayed_node_to_data_ref(node);



			key.objectid = ref->objectid;
@@ -368,7 +556,6 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
		}

		case BTRFS_SHARED_DATA_REF_KEY: {

			struct btrfs_delayed_data_ref *ref;

			struct btrfs_key key;



			ref = btrfs_delayed_node_to_data_ref(node);
@@ -394,8 +581,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, 
 */

static int __add_inline_refs(struct btrfs_fs_info *fs_info,

			     struct btrfs_path *path, u64 bytenr,

			     struct btrfs_key *info_key, int *info_level,

			     struct list_head *prefs)

			     int *info_level, struct list_head *prefs)

{

	int ret = 0;

	int slot;
@@ -411,7 +597,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 
	 * enumerate all inline refs

	 */

	leaf = path->nodes[0];

	slot = path->slots[0] - 1;

	slot = path->slots[0];



	item_size = btrfs_item_size_nr(leaf, slot);

	BUG_ON(item_size < sizeof(*ei));
@@ -424,12 +610,9 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 


	if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {

		struct btrfs_tree_block_info *info;

		struct btrfs_disk_key disk_key;



		info = (struct btrfs_tree_block_info *)ptr;

		*info_level = btrfs_tree_block_level(leaf, info);

		btrfs_tree_block_key(leaf, info, &disk_key);

		btrfs_disk_key_to_cpu(info_key, &disk_key);

		ptr += sizeof(struct btrfs_tree_block_info);

		BUG_ON(ptr > end);

	} else {
@@ -447,7 +630,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 


		switch (type) {

		case BTRFS_SHARED_BLOCK_REF_KEY:

			ret = __add_prelim_ref(prefs, 0, info_key,

			ret = __add_prelim_ref(prefs, 0, NULL,

						*info_level + 1, offset,

						bytenr, 1);

			break;
@@ -462,8 +645,9 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 
			break;

		}

		case BTRFS_TREE_BLOCK_REF_KEY:

			ret = __add_prelim_ref(prefs, offset, info_key,

					       *info_level + 1, 0, bytenr, 1);

			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;
@@ -477,8 +661,8 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 
			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);

			ret = __add_prelim_ref(prefs, root, &key, 0, 0,

					       bytenr, count);

			break;

		}

		default:
@@ -496,8 +680,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 
 */

static int __add_keyed_refs(struct btrfs_fs_info *fs_info,

			    struct btrfs_path *path, u64 bytenr,

			    struct btrfs_key *info_key, int info_level,

			    struct list_head *prefs)

			    int info_level, struct list_head *prefs)

{

	struct btrfs_root *extent_root = fs_info->extent_root;

	int ret;
@@ -527,7 +710,7 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, 


		switch (key.type) {

		case BTRFS_SHARED_BLOCK_REF_KEY:

			ret = __add_prelim_ref(prefs, 0, info_key,

			ret = __add_prelim_ref(prefs, 0, NULL,

						info_level + 1, key.offset,

						bytenr, 1);

			break;
@@ -543,8 +726,9 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, 
			break;

		}

		case BTRFS_TREE_BLOCK_REF_KEY:

			ret = __add_prelim_ref(prefs, key.offset, info_key,

						info_level + 1, 0, bytenr, 1);

			ret = __add_prelim_ref(prefs, key.offset, NULL,

					       info_level + 1, 0,

					       bytenr, 1);

			break;

		case BTRFS_EXTENT_DATA_REF_KEY: {

			struct btrfs_extent_data_ref *dref;
@@ -582,11 +766,12 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, 
 */

static int find_parent_nodes(struct btrfs_trans_handle *trans,

			     struct btrfs_fs_info *fs_info, u64 bytenr,

			     u64 seq, struct ulist *refs, struct ulist *roots)

			     u64 delayed_ref_seq, u64 time_seq,

			     struct ulist *refs, struct ulist *roots,

			     const u64 *extent_item_pos)

{

	struct btrfs_key key;

	struct btrfs_path *path;

	struct btrfs_key info_key = { 0 };

	struct btrfs_delayed_ref_root *delayed_refs = NULL;

	struct btrfs_delayed_ref_head *head;

	int info_level = 0;
@@ -645,7 +830,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
				btrfs_put_delayed_ref(&head->node);

				goto again;

			}

			ret = __add_delayed_refs(head, seq, &info_key,

			ret = __add_delayed_refs(head, delayed_ref_seq,

						 &prefs_delayed);

			if (ret) {

				spin_unlock(&delayed_refs->lock);
@@ -659,16 +844,17 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
		struct extent_buffer *leaf;

		int slot;



		path->slots[0]--;

		leaf = path->nodes[0];

		slot = path->slots[0] - 1;

		slot = path->slots[0];

		btrfs_item_key_to_cpu(leaf, &key, slot);

		if (key.objectid == bytenr &&

		    key.type == BTRFS_EXTENT_ITEM_KEY) {

			ret = __add_inline_refs(fs_info, path, bytenr,

						&info_key, &info_level, &prefs);

						&info_level, &prefs);

			if (ret)

				goto out;

			ret = __add_keyed_refs(fs_info, path, bytenr, &info_key,

			ret = __add_keyed_refs(fs_info, path, bytenr,

					       info_level, &prefs);

			if (ret)

				goto out;
@@ -676,21 +862,18 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
	}

	btrfs_release_path(path);



	/*

	 * when adding the delayed refs above, the info_key might not have

	 * been known yet. Go over the list and replace the missing keys

	 */

	list_for_each_entry(ref, &prefs_delayed, list) {

		if ((ref->key.offset | ref->key.type | ref->key.objectid) == 0)

			memcpy(&ref->key, &info_key, sizeof(ref->key));

	}

	list_splice_init(&prefs_delayed, &prefs);



	ret = __add_missing_keys(fs_info, &prefs);

	if (ret)

		goto out;



	ret = __merge_refs(&prefs, 1);

	if (ret)

		goto out;



	ret = __resolve_indirect_refs(fs_info, search_commit_root, &prefs);

	ret = __resolve_indirect_refs(fs_info, search_commit_root, time_seq,

				      &prefs, extent_item_pos);

	if (ret)

		goto out;
@@ -709,7 +892,33 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
			BUG_ON(ret < 0);

		}

		if (ref->count && ref->parent) {

			ret = ulist_add(refs, ref->parent, 0, GFP_NOFS);

			struct extent_inode_elem *eie = NULL;

			if (extent_item_pos && !ref->inode_list) {

				u32 bsz;

				struct extent_buffer *eb;

				bsz = btrfs_level_size(fs_info->extent_root,

							info_level);

				eb = read_tree_block(fs_info->extent_root,

							   ref->parent, bsz, 0);

				BUG_ON(!eb);

				ret = find_extent_in_eb(eb, bytenr,

							*extent_item_pos, &eie);

				ref->inode_list = eie;

				free_extent_buffer(eb);

			}

			ret = ulist_add_merge(refs, ref->parent,

					      (unsigned long)ref->inode_list,

					      (unsigned long *)&eie, GFP_NOFS);

			if (!ret && extent_item_pos) {

				/*

				 * we've recorded that parent, so we must extend

				 * its inode list here

				 */

				BUG_ON(!eie);

				while (eie->next)

					eie = eie->next;

				eie->next = ref->inode_list;

			}

			BUG_ON(ret < 0);

		}

		kfree(ref);
@@ -734,6 +943,28 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
	return ret;

}



static void free_leaf_list(struct ulist *blocks)

{

	struct ulist_node *node = NULL;

	struct extent_inode_elem *eie;

	struct extent_inode_elem *eie_next;

	struct ulist_iterator uiter;



	ULIST_ITER_INIT(&uiter);

	while ((node = ulist_next(blocks, &uiter))) {

		if (!node->aux)

			continue;

		eie = (struct extent_inode_elem *)node->aux;

		for (; eie; eie = eie_next) {

			eie_next = eie->next;

			kfree(eie);

		}

		node->aux = 0;

	}



	ulist_free(blocks);

}



/*

 * Finds all leafs with a reference to the specified combination of bytenr and

 * offset. key_list_head will point to a list of corresponding keys (caller must
@@ -744,7 +975,9 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, 
 */

static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,

				struct btrfs_fs_info *fs_info, u64 bytenr,

				u64 num_bytes, u64 seq, struct ulist **leafs)

				u64 delayed_ref_seq, u64 time_seq,

				struct ulist **leafs,

				const u64 *extent_item_pos)

{

	struct ulist *tmp;

	int ret;
@@ -758,11 +991,12 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, 
		return -ENOMEM;

	}



	ret = find_parent_nodes(trans, fs_info, bytenr, seq, *leafs, tmp);

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

				time_seq, *leafs, tmp, extent_item_pos);

	ulist_free(tmp);



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

		ulist_free(*leafs);

		free_leaf_list(*leafs);

		return ret;

	}
@@ -784,10 +1018,12 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, 
 */

int btrfs_find_all_roots(struct btrfs_trans_handle *trans,

				struct btrfs_fs_info *fs_info, u64 bytenr,

				u64 num_bytes, u64 seq, struct ulist **roots)

				u64 delayed_ref_seq, u64 time_seq,

				struct ulist **roots)

{

	struct ulist *tmp;

	struct ulist_node *node = NULL;

	struct ulist_iterator uiter;

	int ret;



	tmp = ulist_alloc(GFP_NOFS);
@@ -799,15 +1035,16 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans, 
		return -ENOMEM;

	}



	ULIST_ITER_INIT(&uiter);

	while (1) {

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

					tmp, *roots);

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

					time_seq, tmp, *roots, NULL);

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

			ulist_free(tmp);

			ulist_free(*roots);

			return ret;

		}

		node = ulist_next(tmp, node);

		node = ulist_next(tmp, &uiter);

		if (!node)

			break;

		bytenr = node->val;
@@ -1093,67 +1330,25 @@ int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, 
	return 0;

}



static int iterate_leaf_refs(struct btrfs_fs_info *fs_info, u64 logical,

				u64 orig_extent_item_objectid,

				u64 extent_item_pos, u64 root,

static int iterate_leaf_refs(struct extent_inode_elem *inode_list,

				u64 root, u64 extent_item_objectid,

				iterate_extent_inodes_t *iterate, void *ctx)

{

	u64 disk_byte;

	struct btrfs_key key;

	struct btrfs_file_extent_item *fi;

	struct extent_buffer *eb;

	int slot;

	int nritems;

	struct extent_inode_elem *eie;

	int ret = 0;

	int extent_type;

	u64 data_offset;

	u64 data_len;



	eb = read_tree_block(fs_info->tree_root, logical,

				fs_info->tree_root->leafsize, 0);

	if (!eb)

		return -EIO;



	/*

	 * from the shared data ref, we only have the leaf but we need

	 * the key. thus, we must look into all items and see that we

	 * find one (some) with a reference to our extent item.

	 */

	nritems = btrfs_header_nritems(eb);

	for (slot = 0; slot < nritems; ++slot) {

		btrfs_item_key_to_cpu(eb, &key, slot);

		if (key.type != BTRFS_EXTENT_DATA_KEY)

			continue;

		fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);

		extent_type = btrfs_file_extent_type(eb, fi);

		if (extent_type == BTRFS_FILE_EXTENT_INLINE)

			continue;

		/* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */

		disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);

		if (disk_byte != orig_extent_item_objectid)

			continue;



		data_offset = btrfs_file_extent_offset(eb, fi);

		data_len = btrfs_file_extent_num_bytes(eb, fi);



		if (extent_item_pos < data_offset ||

		    extent_item_pos >= data_offset + data_len)

			continue;



	for (eie = inode_list; eie; eie = eie->next) {

		pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), "

				"root %llu\n", orig_extent_item_objectid,

				key.objectid, key.offset, root);

		ret = iterate(key.objectid,

				key.offset + (extent_item_pos - data_offset),

				root, ctx);

			 "root %llu\n", extent_item_objectid,

			 eie->inum, eie->offset, root);

		ret = iterate(eie->inum, eie->offset, root, ctx);

		if (ret) {

			pr_debug("stopping iteration because ret=%d\n", ret);

			pr_debug("stopping iteration for %llu due to ret=%d\n",

				 extent_item_objectid, ret);

			break;

		}

	}



	free_extent_buffer(eb);



	return ret;

}
@@ -1175,7 +1370,10 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info, 
	struct ulist *roots = NULL;

	struct ulist_node *ref_node = NULL;

	struct ulist_node *root_node = NULL;

	struct seq_list seq_elem;

	struct seq_list seq_elem = {};

	struct seq_list tree_mod_seq_elem = {};

	struct ulist_iterator ref_uiter;

	struct ulist_iterator root_uiter;

	struct btrfs_delayed_ref_root *delayed_refs = NULL;



	pr_debug("resolving all inodes for extent %llu\n",
@@ -1192,34 +1390,41 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info, 
		spin_lock(&delayed_refs->lock);

		btrfs_get_delayed_seq(delayed_refs, &seq_elem);

		spin_unlock(&delayed_refs->lock);

		btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);

	}



	ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid,

				   extent_item_pos, seq_elem.seq,

				   &refs);



				   seq_elem.seq, tree_mod_seq_elem.seq, &refs,

				   &extent_item_pos);

	if (ret)

		goto out;



	while (!ret && (ref_node = ulist_next(refs, ref_node))) {

		ret = btrfs_find_all_roots(trans, fs_info, ref_node->val, -1,

						seq_elem.seq, &roots);

	ULIST_ITER_INIT(&ref_uiter);

	while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {

		ret = btrfs_find_all_roots(trans, fs_info, ref_node->val,

						seq_elem.seq,

						tree_mod_seq_elem.seq, &roots);

		if (ret)

			break;

		while (!ret && (root_node = ulist_next(roots, root_node))) {

			pr_debug("root %llu references leaf %llu\n",

					root_node->val, ref_node->val);

			ret = iterate_leaf_refs(fs_info, ref_node->val,

						extent_item_objectid,

						extent_item_pos, root_node->val,

		ULIST_ITER_INIT(&root_uiter);

		while (!ret && (root_node = ulist_next(roots, &root_uiter))) {

			pr_debug("root %llu references leaf %llu, data list "

				 "%#lx\n", root_node->val, ref_node->val,

				 ref_node->aux);

			ret = iterate_leaf_refs(

				(struct extent_inode_elem *)ref_node->aux,

				root_node->val, extent_item_objectid,

				iterate, ctx);

		}

		ulist_free(roots);

		roots = NULL;

	}



	ulist_free(refs);

	free_leaf_list(refs);

	ulist_free(roots);

out:

	if (!search_commit_root) {

		btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);

		btrfs_put_delayed_seq(delayed_refs, &seq_elem);

		btrfs_end_transaction(trans, fs_info->extent_root);

	}