[linux-block.git] / fs / btrfs / backref.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2011 STRATO.  All rights reserved.
 */

#ifndef BTRFS_BACKREF_H
#define BTRFS_BACKREF_H

#include <linux/btrfs.h>
#include "ulist.h"
#include "disk-io.h"
#include "extent_io.h"

struct inode_fs_paths {
	struct btrfs_path		*btrfs_path;
	struct btrfs_root		*fs_root;
	struct btrfs_data_container	*fspath;
};

struct btrfs_backref_shared_cache_entry {
	u64 bytenr;
	u64 gen;
	bool is_shared;
};

struct btrfs_backref_shared_cache {
	/*
	 * A path from a root to a leaf that has a file extent item pointing to
	 * a given data extent should never exceed the maximum b+tree height.
	 */
	struct btrfs_backref_shared_cache_entry entries[BTRFS_MAX_LEVEL];
};

typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root,
		void *ctx);

int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
			struct btrfs_path *path, struct btrfs_key *found_key,
			u64 *flags);

int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
			    struct btrfs_key *key, struct btrfs_extent_item *ei,
			    u32 item_size, u64 *out_root, u8 *out_level);

int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
				u64 extent_item_objectid,
				u64 extent_offset, int search_commit_root,
				iterate_extent_inodes_t *iterate, void *ctx,
				bool ignore_offset);

int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
				struct btrfs_path *path, void *ctx,
				bool ignore_offset);

int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);

int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
			 struct btrfs_fs_info *fs_info, u64 bytenr,
			 u64 time_seq, struct ulist **leafs,
			 const u64 *extent_item_pos, bool ignore_offset);
int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
			 struct btrfs_fs_info *fs_info, u64 bytenr,
			 u64 time_seq, struct ulist **roots,
			 bool skip_commit_root_sem);
char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
			u32 name_len, unsigned long name_off,
			struct extent_buffer *eb_in, u64 parent,
			char *dest, u32 size);

struct btrfs_data_container *init_data_container(u32 total_bytes);
struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
					struct btrfs_path *path);
void free_ipath(struct inode_fs_paths *ipath);

int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
			  u64 start_off, struct btrfs_path *path,
			  struct btrfs_inode_extref **ret_extref,
			  u64 *found_off);
int btrfs_is_data_extent_shared(struct btrfs_root *root, u64 inum, u64 bytenr,
				u64 extent_gen,
				struct ulist *roots, struct ulist *tmp,
				struct btrfs_backref_shared_cache *cache);

int __init btrfs_prelim_ref_init(void);
void __cold btrfs_prelim_ref_exit(void);

struct prelim_ref {
	struct rb_node rbnode;
	u64 root_id;
	struct btrfs_key key_for_search;
	int level;
	int count;
	struct extent_inode_elem *inode_list;
	u64 parent;
	u64 wanted_disk_byte;
};

/*
 * Iterate backrefs of one extent.
 *
 * Now it only supports iteration of tree block in commit root.
 */
struct btrfs_backref_iter {
	u64 bytenr;
	struct btrfs_path *path;
	struct btrfs_fs_info *fs_info;
	struct btrfs_key cur_key;
	u32 item_ptr;
	u32 cur_ptr;
	u32 end_ptr;
};

struct btrfs_backref_iter *btrfs_backref_iter_alloc(
		struct btrfs_fs_info *fs_info, gfp_t gfp_flag);

static inline void btrfs_backref_iter_free(struct btrfs_backref_iter *iter)
{
	if (!iter)
		return;
	btrfs_free_path(iter->path);
	kfree(iter);
}

static inline struct extent_buffer *btrfs_backref_get_eb(
		struct btrfs_backref_iter *iter)
{
	if (!iter)
		return NULL;
	return iter->path->nodes[0];
}

/*
 * For metadata with EXTENT_ITEM key (non-skinny) case, the first inline data
 * is btrfs_tree_block_info, without a btrfs_extent_inline_ref header.
 *
 * This helper determines if that's the case.
 */
static inline bool btrfs_backref_has_tree_block_info(
		struct btrfs_backref_iter *iter)
{
	if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY &&
	    iter->cur_ptr - iter->item_ptr == sizeof(struct btrfs_extent_item))
		return true;
	return false;
}

int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr);

int btrfs_backref_iter_next(struct btrfs_backref_iter *iter);

static inline bool btrfs_backref_iter_is_inline_ref(
		struct btrfs_backref_iter *iter)
{
	if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY ||
	    iter->cur_key.type == BTRFS_METADATA_ITEM_KEY)
		return true;
	return false;
}

static inline void btrfs_backref_iter_release(struct btrfs_backref_iter *iter)
{
	iter->bytenr = 0;
	iter->item_ptr = 0;
	iter->cur_ptr = 0;
	iter->end_ptr = 0;
	btrfs_release_path(iter->path);
	memset(&iter->cur_key, 0, sizeof(iter->cur_key));
}

/*
 * Backref cache related structures
 *
 * The whole objective of backref_cache is to build a bi-directional map
 * of tree blocks (represented by backref_node) and all their parents.
 */

/*
 * Represent a tree block in the backref cache
 */
struct btrfs_backref_node {
	struct {
		struct rb_node rb_node;
		u64 bytenr;
	}; /* Use rb_simple_node for search/insert */

	u64 new_bytenr;
	/* Objectid of tree block owner, can be not uptodate */
	u64 owner;
	/* Link to pending, changed or detached list */
	struct list_head list;

	/* List of upper level edges, which link this node to its parents */
	struct list_head upper;
	/* List of lower level edges, which link this node to its children */
	struct list_head lower;

	/* NULL if this node is not tree root */
	struct btrfs_root *root;
	/* Extent buffer got by COWing the block */
	struct extent_buffer *eb;
	/* Level of the tree block */
	unsigned int level:8;
	/* Is the block in a non-shareable tree */
	unsigned int cowonly:1;
	/* 1 if no child node is in the cache */
	unsigned int lowest:1;
	/* Is the extent buffer locked */
	unsigned int locked:1;
	/* Has the block been processed */
	unsigned int processed:1;
	/* Have backrefs of this block been checked */
	unsigned int checked:1;
	/*
	 * 1 if corresponding block has been COWed but some upper level block
	 * pointers may not point to the new location
	 */
	unsigned int pending:1;
	/* 1 if the backref node isn't connected to any other backref node */
	unsigned int detached:1;

	/*
	 * For generic purpose backref cache, where we only care if it's a reloc
	 * root, doesn't care the source subvolid.
	 */
	unsigned int is_reloc_root:1;
};

#define LOWER	0
#define UPPER	1

/*
 * Represent an edge connecting upper and lower backref nodes.
 */
struct btrfs_backref_edge {
	/*
	 * list[LOWER] is linked to btrfs_backref_node::upper of lower level
	 * node, and list[UPPER] is linked to btrfs_backref_node::lower of
	 * upper level node.
	 *
	 * Also, build_backref_tree() uses list[UPPER] for pending edges, before
	 * linking list[UPPER] to its upper level nodes.
	 */
	struct list_head list[2];

	/* Two related nodes */
	struct btrfs_backref_node *node[2];
};

struct btrfs_backref_cache {
	/* Red black tree of all backref nodes in the cache */
	struct rb_root rb_root;
	/* For passing backref nodes to btrfs_reloc_cow_block */
	struct btrfs_backref_node *path[BTRFS_MAX_LEVEL];
	/*
	 * List of blocks that have been COWed but some block pointers in upper
	 * level blocks may not reflect the new location
	 */
	struct list_head pending[BTRFS_MAX_LEVEL];
	/* List of backref nodes with no child node */
	struct list_head leaves;
	/* List of blocks that have been COWed in current transaction */
	struct list_head changed;
	/* List of detached backref node. */
	struct list_head detached;

	u64 last_trans;

	int nr_nodes;
	int nr_edges;

	/* List of unchecked backref edges during backref cache build */
	struct list_head pending_edge;

	/* List of useless backref nodes during backref cache build */
	struct list_head useless_node;

	struct btrfs_fs_info *fs_info;

	/*
	 * Whether this cache is for relocation
	 *
	 * Reloction backref cache require more info for reloc root compared
	 * to generic backref cache.
	 */
	unsigned int is_reloc;
};

void btrfs_backref_init_cache(struct btrfs_fs_info *fs_info,
			      struct btrfs_backref_cache *cache, int is_reloc);
struct btrfs_backref_node *btrfs_backref_alloc_node(
		struct btrfs_backref_cache *cache, u64 bytenr, int level);
struct btrfs_backref_edge *btrfs_backref_alloc_edge(
		struct btrfs_backref_cache *cache);

#define		LINK_LOWER	(1 << 0)
#define		LINK_UPPER	(1 << 1)
static inline void btrfs_backref_link_edge(struct btrfs_backref_edge *edge,
					   struct btrfs_backref_node *lower,
					   struct btrfs_backref_node *upper,
					   int link_which)
{
	ASSERT(upper && lower && upper->level == lower->level + 1);
	edge->node[LOWER] = lower;
	edge->node[UPPER] = upper;
	if (link_which & LINK_LOWER)
		list_add_tail(&edge->list[LOWER], &lower->upper);
	if (link_which & LINK_UPPER)
		list_add_tail(&edge->list[UPPER], &upper->lower);
}

static inline void btrfs_backref_free_node(struct btrfs_backref_cache *cache,
					   struct btrfs_backref_node *node)
{
	if (node) {
		ASSERT(list_empty(&node->list));
		ASSERT(list_empty(&node->lower));
		ASSERT(node->eb == NULL);
		cache->nr_nodes--;
		btrfs_put_root(node->root);
		kfree(node);
	}
}

static inline void btrfs_backref_free_edge(struct btrfs_backref_cache *cache,
					   struct btrfs_backref_edge *edge)
{
	if (edge) {
		cache->nr_edges--;
		kfree(edge);
	}
}

static inline void btrfs_backref_unlock_node_buffer(
		struct btrfs_backref_node *node)
{
	if (node->locked) {
		btrfs_tree_unlock(node->eb);
		node->locked = 0;
	}
}

static inline void btrfs_backref_drop_node_buffer(
		struct btrfs_backref_node *node)
{
	if (node->eb) {
		btrfs_backref_unlock_node_buffer(node);
		free_extent_buffer(node->eb);
		node->eb = NULL;
	}
}

/*
 * Drop the backref node from cache without cleaning up its children
 * edges.
 *
 * This can only be called on node without parent edges.
 * The children edges are still kept as is.
 */
static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree,
					   struct btrfs_backref_node *node)
{
	ASSERT(list_empty(&node->upper));

	btrfs_backref_drop_node_buffer(node);
	list_del_init(&node->list);
	list_del_init(&node->lower);
	if (!RB_EMPTY_NODE(&node->rb_node))
		rb_erase(&node->rb_node, &tree->rb_root);
	btrfs_backref_free_node(tree, node);
}

void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
				struct btrfs_backref_node *node);

void btrfs_backref_release_cache(struct btrfs_backref_cache *cache);

static inline void btrfs_backref_panic(struct btrfs_fs_info *fs_info,
				       u64 bytenr, int errno)
{
	btrfs_panic(fs_info, errno,
		    "Inconsistency in backref cache found at offset %llu",
		    bytenr);
}

int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache,
				struct btrfs_path *path,
				struct btrfs_backref_iter *iter,
				struct btrfs_key *node_key,
				struct btrfs_backref_node *cur);

int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache,
				     struct btrfs_backref_node *start);

void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache,
				 struct btrfs_backref_node *node);

#endif
Commit	Line	Data
9888c340	1	/* SPDX-License-Identifier: GPL-2.0 */
a542ad1b JS	2	/*
a542ad1b JS	3	* Copyright (C) 2011 STRATO. All rights reserved.
a542ad1b JS	4	*/
a542ad1b JS	5
9888c340 DS	6	#ifndef BTRFS_BACKREF_H
9888c340 DS	7	#define BTRFS_BACKREF_H
a542ad1b	8
55e301fd	9	#include <linux/btrfs.h>
8da6d581	10	#include "ulist.h"
741188d3	11	#include "disk-io.h"
91cb916c	12	#include "extent_io.h"
a542ad1b JS	13
	14	struct inode_fs_paths {
	15	struct btrfs_path *btrfs_path;
	16	struct btrfs_root *fs_root;
	17	struct btrfs_data_container *fspath;
	18	};
	19
12a824dc FM	20	struct btrfs_backref_shared_cache_entry {
	21	u64 bytenr;
	22	u64 gen;
	23	bool is_shared;
	24	};
	25
	26	struct btrfs_backref_shared_cache {
	27	/*
	28	* A path from a root to a leaf that has a file extent item pointing to
	29	* a given data extent should never exceed the maximum b+tree height.
	30	*/
	31	struct btrfs_backref_shared_cache_entry entries[BTRFS_MAX_LEVEL];
	32	};
	33
a542ad1b JS	34	typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root,
a542ad1b JS	35	void *ctx);
a542ad1b	36
a542ad1b	37	int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
69917e43 LB	38	struct btrfs_path path, struct btrfs_key found_key,
69917e43 LB	39	u64 *flags);
a542ad1b JS	40
a542ad1b JS	41	int tree_backref_for_extent(unsigned long ptr, struct extent_buffer eb,
6eda71d0 LB	42	struct btrfs_key key, struct btrfs_extent_item ei,
6eda71d0 LB	43	u32 item_size, u64 out_root, u8 out_level);
a542ad1b JS	44
a542ad1b JS	45	int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
a542ad1b	46	u64 extent_item_objectid,
7a3ae2f8	47	u64 extent_offset, int search_commit_root,
c995ab3c ZB	48	iterate_extent_inodes_t iterate, void ctx,
c995ab3c ZB	49	bool ignore_offset);
a542ad1b JS	50
a542ad1b JS	51	int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
e3059ec0	52	struct btrfs_path path, void ctx,
c995ab3c	53	bool ignore_offset);
a542ad1b JS	54
	55	int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
	56
19b546d7 QW	57	int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
	58	struct btrfs_fs_info *fs_info, u64 bytenr,
	59	u64 time_seq, struct ulist **leafs,
	60	const u64 *extent_item_pos, bool ignore_offset);
8da6d581	61	int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
fcebe456	62	struct btrfs_fs_info *fs_info, u64 bytenr,
c7bcbb21	63	u64 time_seq, struct ulist **roots,
8949b9a1	64	bool skip_commit_root_sem);
96b5bd77 JS	65	char btrfs_ref_to_path(struct btrfs_root fs_root, struct btrfs_path *path,
	66	u32 name_len, unsigned long name_off,
	67	struct extent_buffer *eb_in, u64 parent,
	68	char *dest, u32 size);
8da6d581	69
a542ad1b JS	70	struct btrfs_data_container *init_data_container(u32 total_bytes);
	71	struct inode_fs_paths init_ipath(s32 total_bytes, struct btrfs_root fs_root,
	72	struct btrfs_path *path);
	73	void free_ipath(struct inode_fs_paths *ipath);
	74
f186373f MF	75	int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
	76	u64 start_off, struct btrfs_path *path,
	77	struct btrfs_inode_extref **ret_extref,
	78	u64 *found_off);
8eedadda	79	int btrfs_is_data_extent_shared(struct btrfs_root *root, u64 inum, u64 bytenr,
b8f164e3	80	u64 extent_gen,
12a824dc FM	81	struct ulist roots, struct ulist tmp,
12a824dc FM	82	struct btrfs_backref_shared_cache *cache);
f186373f	83
b9e9a6cb	84	int __init btrfs_prelim_ref_init(void);
e67c718b	85	void __cold btrfs_prelim_ref_exit(void);
00142756 JM	86
	87	struct prelim_ref {
	88	struct rb_node rbnode;
	89	u64 root_id;
	90	struct btrfs_key key_for_search;
	91	int level;
	92	int count;
	93	struct extent_inode_elem *inode_list;
	94	u64 parent;
	95	u64 wanted_disk_byte;
	96	};
	97
a37f232b QW	98	/*
	99	* Iterate backrefs of one extent.
	100	*
	101	* Now it only supports iteration of tree block in commit root.
	102	*/
	103	struct btrfs_backref_iter {
	104	u64 bytenr;
	105	struct btrfs_path *path;
	106	struct btrfs_fs_info *fs_info;
	107	struct btrfs_key cur_key;
	108	u32 item_ptr;
	109	u32 cur_ptr;
	110	u32 end_ptr;
	111	};
	112
	113	struct btrfs_backref_iter *btrfs_backref_iter_alloc(
	114	struct btrfs_fs_info *fs_info, gfp_t gfp_flag);
	115
	116	static inline void btrfs_backref_iter_free(struct btrfs_backref_iter *iter)
	117	{
	118	if (!iter)
	119	return;
	120	btrfs_free_path(iter->path);
	121	kfree(iter);
	122	}
	123
c39c2ddc QW	124	static inline struct extent_buffer *btrfs_backref_get_eb(
	125	struct btrfs_backref_iter *iter)
	126	{
	127	if (!iter)
	128	return NULL;
	129	return iter->path->nodes[0];
	130	}
	131
	132	/*
	133	* For metadata with EXTENT_ITEM key (non-skinny) case, the first inline data
	134	* is btrfs_tree_block_info, without a btrfs_extent_inline_ref header.
	135	*
	136	* This helper determines if that's the case.
	137	*/
	138	static inline bool btrfs_backref_has_tree_block_info(
	139	struct btrfs_backref_iter *iter)
	140	{
	141	if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY &&
	142	iter->cur_ptr - iter->item_ptr == sizeof(struct btrfs_extent_item))
	143	return true;
	144	return false;
	145	}
	146
a37f232b QW	147	int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr);
a37f232b QW	148
c39c2ddc QW	149	int btrfs_backref_iter_next(struct btrfs_backref_iter *iter);
	150
	151	static inline bool btrfs_backref_iter_is_inline_ref(
	152	struct btrfs_backref_iter *iter)
	153	{
	154	if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY \|\|
	155	iter->cur_key.type == BTRFS_METADATA_ITEM_KEY)
	156	return true;
	157	return false;
	158	}
	159
a37f232b QW	160	static inline void btrfs_backref_iter_release(struct btrfs_backref_iter *iter)
	161	{
	162	iter->bytenr = 0;
	163	iter->item_ptr = 0;
	164	iter->cur_ptr = 0;
	165	iter->end_ptr = 0;
	166	btrfs_release_path(iter->path);
	167	memset(&iter->cur_key, 0, sizeof(iter->cur_key));
	168	}
	169
70535441 QW	170	/*
	171	* Backref cache related structures
	172	*
	173	* The whole objective of backref_cache is to build a bi-directional map
	174	* of tree blocks (represented by backref_node) and all their parents.
	175	*/
	176
	177	/*
	178	* Represent a tree block in the backref cache
	179	*/
	180	struct btrfs_backref_node {
e9a28dc5 QW	181	struct {
	182	struct rb_node rb_node;
	183	u64 bytenr;
	184	}; /* Use rb_simple_node for search/insert */
70535441 QW	185
	186	u64 new_bytenr;
	187	/* Objectid of tree block owner, can be not uptodate */
	188	u64 owner;
	189	/* Link to pending, changed or detached list */
	190	struct list_head list;
	191
	192	/* List of upper level edges, which link this node to its parents */
	193	struct list_head upper;
	194	/* List of lower level edges, which link this node to its children */
	195	struct list_head lower;
	196
	197	/* NULL if this node is not tree root */
	198	struct btrfs_root *root;
	199	/* Extent buffer got by COWing the block */
	200	struct extent_buffer *eb;
	201	/* Level of the tree block */
	202	unsigned int level:8;
92a7cc42	203	/* Is the block in a non-shareable tree */
70535441 QW	204	unsigned int cowonly:1;
	205	/* 1 if no child node is in the cache */
	206	unsigned int lowest:1;
	207	/* Is the extent buffer locked */
	208	unsigned int locked:1;
	209	/* Has the block been processed */
	210	unsigned int processed:1;
	211	/* Have backrefs of this block been checked */
	212	unsigned int checked:1;
	213	/*
	214	* 1 if corresponding block has been COWed but some upper level block
	215	* pointers may not point to the new location
	216	*/
	217	unsigned int pending:1;
	218	/* 1 if the backref node isn't connected to any other backref node */
	219	unsigned int detached:1;
	220
	221	/*
	222	* For generic purpose backref cache, where we only care if it's a reloc
	223	* root, doesn't care the source subvolid.
	224	*/
	225	unsigned int is_reloc_root:1;
	226	};
	227
	228	#define LOWER 0
	229	#define UPPER 1
	230
	231	/*
	232	* Represent an edge connecting upper and lower backref nodes.
	233	*/
	234	struct btrfs_backref_edge {
	235	/*
	236	* list[LOWER] is linked to btrfs_backref_node::upper of lower level
	237	* node, and list[UPPER] is linked to btrfs_backref_node::lower of
	238	* upper level node.
	239	*
	240	* Also, build_backref_tree() uses list[UPPER] for pending edges, before
	241	* linking list[UPPER] to its upper level nodes.
	242	*/
	243	struct list_head list[2];
	244
	245	/* Two related nodes */
	246	struct btrfs_backref_node *node[2];
	247	};
	248
	249	struct btrfs_backref_cache {
	250	/* Red black tree of all backref nodes in the cache */
	251	struct rb_root rb_root;
	252	/* For passing backref nodes to btrfs_reloc_cow_block */
	253	struct btrfs_backref_node *path[BTRFS_MAX_LEVEL];
	254	/*
	255	* List of blocks that have been COWed but some block pointers in upper
	256	* level blocks may not reflect the new location
	257	*/
	258	struct list_head pending[BTRFS_MAX_LEVEL];
	259	/* List of backref nodes with no child node */
	260	struct list_head leaves;
	261	/* List of blocks that have been COWed in current transaction */
	262	struct list_head changed;
	263	/* List of detached backref node. */
	264	struct list_head detached;
	265
	266	u64 last_trans;
	267
268	int nr_nodes;
269	int nr_edges;
270
271	/* List of unchecked backref edges during backref cache build */
272	struct list_head pending_edge;
273
274	/* List of useless backref nodes during backref cache build */
275	struct list_head useless_node;
276
277	struct btrfs_fs_info *fs_info;
278
279	/*
280	* Whether this cache is for relocation
281	*
282	* Reloction backref cache require more info for reloc root compared
283	* to generic backref cache.
284	*/
285	unsigned int is_reloc;
286	};
287
584fb121 QW	288	void btrfs_backref_init_cache(struct btrfs_fs_info *fs_info,
584fb121 QW	289	struct btrfs_backref_cache *cache, int is_reloc);
b1818dab QW	290	struct btrfs_backref_node *btrfs_backref_alloc_node(
b1818dab QW	291	struct btrfs_backref_cache *cache, u64 bytenr, int level);
47254d07 QW	292	struct btrfs_backref_edge *btrfs_backref_alloc_edge(
47254d07 QW	293	struct btrfs_backref_cache *cache);
584fb121	294
f39911e5 QW	295	#define LINK_LOWER (1 << 0)
	296	#define LINK_UPPER (1 << 1)
	297	static inline void btrfs_backref_link_edge(struct btrfs_backref_edge *edge,
	298	struct btrfs_backref_node *lower,
	299	struct btrfs_backref_node *upper,
	300	int link_which)
	301	{
	302	ASSERT(upper && lower && upper->level == lower->level + 1);
	303	edge->node[LOWER] = lower;
	304	edge->node[UPPER] = upper;
	305	if (link_which & LINK_LOWER)
	306	list_add_tail(&edge->list[LOWER], &lower->upper);
	307	if (link_which & LINK_UPPER)
	308	list_add_tail(&edge->list[UPPER], &upper->lower);
	309	}
	310
741188d3 QW	311	static inline void btrfs_backref_free_node(struct btrfs_backref_cache *cache,
	312	struct btrfs_backref_node *node)
	313	{
	314	if (node) {
eddda68d JB	315	ASSERT(list_empty(&node->list));
	316	ASSERT(list_empty(&node->lower));
	317	ASSERT(node->eb == NULL);
741188d3 QW	318	cache->nr_nodes--;
	319	btrfs_put_root(node->root);
	320	kfree(node);
	321	}
	322	}
	323
	324	static inline void btrfs_backref_free_edge(struct btrfs_backref_cache *cache,
	325	struct btrfs_backref_edge *edge)
	326	{
	327	if (edge) {
	328	cache->nr_edges--;
	329	kfree(edge);
	330	}
	331	}
	332
b0fe7078 QW	333	static inline void btrfs_backref_unlock_node_buffer(
	334	struct btrfs_backref_node *node)
	335	{
	336	if (node->locked) {
	337	btrfs_tree_unlock(node->eb);
	338	node->locked = 0;
	339	}
	340	}
	341
	342	static inline void btrfs_backref_drop_node_buffer(
	343	struct btrfs_backref_node *node)
	344	{
	345	if (node->eb) {
	346	btrfs_backref_unlock_node_buffer(node);
	347	free_extent_buffer(node->eb);
	348	node->eb = NULL;
	349	}
	350	}
	351
	352	/*
	353	* Drop the backref node from cache without cleaning up its children
	354	* edges.
	355	*
	356	* This can only be called on node without parent edges.
	357	* The children edges are still kept as is.
	358	*/
	359	static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree,
	360	struct btrfs_backref_node *node)
	361	{
eddda68d	362	ASSERT(list_empty(&node->upper));
b0fe7078 QW	363
b0fe7078 QW	364	btrfs_backref_drop_node_buffer(node);
eddda68d JB	365	list_del_init(&node->list);
eddda68d JB	366	list_del_init(&node->lower);
b0fe7078 QW	367	if (!RB_EMPTY_NODE(&node->rb_node))
	368	rb_erase(&node->rb_node, &tree->rb_root);
	369	btrfs_backref_free_node(tree, node);
	370	}
	371
023acb07 QW	372	void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
	373	struct btrfs_backref_node *node);
	374
13fe1bdb QW	375	void btrfs_backref_release_cache(struct btrfs_backref_cache *cache);
13fe1bdb QW	376
982c92cb QW	377	static inline void btrfs_backref_panic(struct btrfs_fs_info *fs_info,
	378	u64 bytenr, int errno)
	379	{
	380	btrfs_panic(fs_info, errno,
	381	"Inconsistency in backref cache found at offset %llu",
	382	bytenr);
	383	}
	384
1b60d2ec QW	385	int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache,
	386	struct btrfs_path *path,
	387	struct btrfs_backref_iter *iter,
	388	struct btrfs_key *node_key,
	389	struct btrfs_backref_node *cur);
	390
fc997ed0 QW	391	int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache,
	392	struct btrfs_backref_node *start);
	393
1b23ea18 QW	394	void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache,
	395	struct btrfs_backref_node *node);
	396
a542ad1b	397	#endif