Commit 70535441 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: backref: move btrfs_backref_(node|edge|cache) structures to backref.h 



These 3 structures are the main part of btrfs backref cache, move them
to backref.h to build the basis for later reuse.

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent a26195a5

fs/btrfs/backref.h

+116 −0
Original line number Diff line number Diff line
@@ -150,4 +150,120 @@ static inline void btrfs_backref_iter_release(struct btrfs_backref_iter *iter) 
	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 rb_node rb_node;

	u64 bytenr;



	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 non-reference counted 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;

};



#endif

fs/btrfs/relocation.c

+0 −113
Original line number Diff line number Diff line
@@ -80,120 +80,7 @@ struct tree_entry { 
	u64 bytenr;

};



/*

 * present a tree block in the backref cache

 */

struct btrfs_backref_node {

	struct rb_node rb_node;

	u64 bytenr;



	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 COW the block */

	struct extent_buffer *eb;

	/* level of tree block */

	unsigned int level:8;

	/* is the block in non-reference counted tree */

	unsigned int cowonly:1;

	/* 1 if no child node 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

#define RELOCATION_RESERVED_NODES	256

/*

 * present 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;



	/* The list of unchecked backref edges during backref cache build */

	struct list_head pending_edge;



	/* The 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;

};



/*

 * map address of tree root to tree

 */

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