cregit-Linux how code gets into the kernel

Release 4.11 fs/btrfs/delayed-ref.h

Directory: fs/btrfs
/*
 * Copyright (C) 2008 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */
#ifndef __DELAYED_REF__

#define __DELAYED_REF__

/* these are the possible values of struct btrfs_delayed_ref_node->action */

#define BTRFS_ADD_DELAYED_REF    1 
/* add one backref to the tree */

#define BTRFS_DROP_DELAYED_REF   2 
/* delete one backref from the tree */

#define BTRFS_ADD_DELAYED_EXTENT 3 
/* record a full extent allocation */

#define BTRFS_UPDATE_DELAYED_HEAD 4 
/* not changing ref count on head ref */

/*
 * XXX: Qu: I really hate the design that ref_head and tree/data ref shares the
 * same ref_node structure.
 * Ref_head is in a higher logic level than tree/data ref, and duplicated
 * bytenr/num_bytes in ref_node is really a waste or memory, they should be
 * referred from ref_head.
 * This gets more disgusting after we use list to store tree/data ref in
 * ref_head. Must clean this mess up later.
 */

struct btrfs_delayed_ref_node {
	/*data/tree ref use list, stored in ref_head->ref_list. */
	
struct list_head list;
	/*
         * If action is BTRFS_ADD_DELAYED_REF, also link this node to
         * ref_head->ref_add_list, then we do not need to iterate the
         * whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes.
         */
	
struct list_head add_list;

	/* the starting bytenr of the extent */
	
u64 bytenr;

	/* the size of the extent */
	
u64 num_bytes;

	/* seq number to keep track of insertion order */
	
u64 seq;

	/* ref count on this data structure */
	
atomic_t refs;

	/*
         * how many refs is this entry adding or deleting.  For
         * head refs, this may be a negative number because it is keeping
         * track of the total mods done to the reference count.
         * For individual refs, this will always be a positive number
         *
         * It may be more than one, since it is possible for a single
         * parent to have more than one ref on an extent
         */
	
int ref_mod;

	
unsigned int action:8;
	
unsigned int type:8;
	/* is this node still in the rbtree? */
	
unsigned int is_head:1;
	
unsigned int in_tree:1;
};


struct btrfs_delayed_extent_op {
	
struct btrfs_disk_key key;
	
u8 level;
	
bool update_key;
	
bool update_flags;
	
bool is_data;
	
u64 flags_to_set;
};

/*
 * the head refs are used to hold a lock on a given extent, which allows us
 * to make sure that only one process is running the delayed refs
 * at a time for a single extent.  They also store the sum of all the
 * reference count modifications we've queued up.
 */

struct btrfs_delayed_ref_head {
	
struct btrfs_delayed_ref_node node;

	/*
         * the mutex is held while running the refs, and it is also
         * held when checking the sum of reference modifications.
         */
	
struct mutex mutex;

	
spinlock_t lock;
	
struct list_head ref_list;
	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
	
struct list_head ref_add_list;

	
struct rb_node href_node;

	
struct btrfs_delayed_extent_op *extent_op;

	/*
         * This is used to track the final ref_mod from all the refs associated
         * with this head ref, this is not adjusted as delayed refs are run,
         * this is meant to track if we need to do the csum accounting or not.
         */
	
int total_ref_mod;

	/*
         * For qgroup reserved space freeing.
         *
         * ref_root and reserved will be recorded after
         * BTRFS_ADD_DELAYED_EXTENT is called.
         * And will be used to free reserved qgroup space at
         * run_delayed_refs() time.
         */
	
u64 qgroup_ref_root;
	
u64 qgroup_reserved;

	/*
         * when a new extent is allocated, it is just reserved in memory
         * The actual extent isn't inserted into the extent allocation tree
         * until the delayed ref is processed.  must_insert_reserved is
         * used to flag a delayed ref so the accounting can be updated
         * when a full insert is done.
         *
         * It is possible the extent will be freed before it is ever
         * inserted into the extent allocation tree.  In this case
         * we need to update the in ram accounting to properly reflect
         * the free has happened.
         */
	
unsigned int must_insert_reserved:1;
	
unsigned int is_data:1;
	
unsigned int processing:1;
};


struct btrfs_delayed_tree_ref {
	
struct btrfs_delayed_ref_node node;
	
u64 root;
	
u64 parent;
	
int level;
};


struct btrfs_delayed_data_ref {
	
struct btrfs_delayed_ref_node node;
	
u64 root;
	
u64 parent;
	
u64 objectid;
	
u64 offset;
};


struct btrfs_delayed_ref_root {
	/* head ref rbtree */
	
struct rb_root href_root;

	/* dirty extent records */
	
struct rb_root dirty_extent_root;

	/* this spin lock protects the rbtree and the entries inside */
	
spinlock_t lock;

	/* how many delayed ref updates we've queued, used by the
         * throttling code
         */
	
atomic_t num_entries;

	/* total number of head nodes in tree */
	
unsigned long num_heads;

	/* total number of head nodes ready for processing */
	
unsigned long num_heads_ready;

	
u64 pending_csums;

	/*
         * set when the tree is flushing before a transaction commit,
         * used by the throttling code to decide if new updates need
         * to be run right away
         */
	
int flushing;

	
u64 run_delayed_start;

	/*
         * To make qgroup to skip given root.
         * This is for snapshot, as btrfs_qgroup_inherit() will manually
         * modify counters for snapshot and its source, so we should skip
         * the snapshot in new_root/old_roots or it will get calculated twice
         */
	
u64 qgroup_to_skip;
};

extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
extern struct kmem_cache *btrfs_delayed_extent_op_cachep;

int btrfs_delayed_ref_init(void);
void btrfs_delayed_ref_exit(void);


static inline struct btrfs_delayed_extent_op * btrfs_alloc_delayed_extent_op(void) { return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS); }

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static inline void btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op) { if (op) kmem_cache_free(btrfs_delayed_extent_op_cachep, op); }

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static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref) { WARN_ON(atomic_read(&ref->refs) == 0); if (atomic_dec_and_test(&ref->refs)) { WARN_ON(ref->in_tree); switch (ref->type) { case BTRFS_TREE_BLOCK_REF_KEY: case BTRFS_SHARED_BLOCK_REF_KEY: kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref); break; case BTRFS_EXTENT_DATA_REF_KEY: case BTRFS_SHARED_DATA_REF_KEY: kmem_cache_free(btrfs_delayed_data_ref_cachep, ref); break; case 0: kmem_cache_free(btrfs_delayed_ref_head_cachep, ref); break; default: BUG(); } } }

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Chris Mason4850.53%150.00%
Miao Xie4749.47%150.00%
Total95100.00%2100.00%

int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info, struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, u64 parent, u64 ref_root, int level, int action, struct btrfs_delayed_extent_op *extent_op); int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, u64 parent, u64 ref_root, u64 owner, u64 offset, u64 reserved, int action); int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info, struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, struct btrfs_delayed_extent_op *extent_op); void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_root *delayed_refs, struct btrfs_delayed_ref_head *head); struct btrfs_delayed_ref_head * btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr); int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *head);
static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head) { mutex_unlock(&head->mutex); }

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struct btrfs_delayed_ref_head * btrfs_select_ref_head(struct btrfs_trans_handle *trans); int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_root *delayed_refs, u64 seq); /* * a node might live in a head or a regular ref, this lets you * test for the proper type to use. */
static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node) { return node->is_head; }

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Chris Mason1593.75%150.00%
Zheng Yan16.25%150.00%
Total16100.00%2100.00%

/* * helper functions to cast a node into its container */
static inline struct btrfs_delayed_tree_ref * btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node) { WARN_ON(btrfs_delayed_ref_is_head(node)); return container_of(node, struct btrfs_delayed_tree_ref, node); }

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Zheng Yan3090.91%150.00%
Chris Mason39.09%150.00%
Total33100.00%2100.00%


static inline struct btrfs_delayed_data_ref * btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node) { WARN_ON(btrfs_delayed_ref_is_head(node)); return container_of(node, struct btrfs_delayed_data_ref, node); }

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Chris Mason2781.82%150.00%
Zheng Yan618.18%150.00%
Total33100.00%2100.00%


static inline struct btrfs_delayed_ref_head * btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node) { WARN_ON(!btrfs_delayed_ref_is_head(node)); return container_of(node, struct btrfs_delayed_ref_head, node); }

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Chris Mason34100.00%1100.00%
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#endif

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Chris Mason31241.16%416.00%
Zheng Yan15720.71%14.00%
Miao Xie15019.79%28.00%
Josef Bacik476.20%416.00%
Arne Jansen314.09%28.00%
Qu Wenruo263.43%520.00%
Liu Bo111.45%28.00%
Xiaoguang Wang101.32%14.00%
David Sterba70.92%14.00%
Jan Schmidt50.66%14.00%
Wang Sheng-Hui10.13%14.00%
Nicholas D Steeves10.13%14.00%
Total758100.00%25100.00%
Directory: fs/btrfs
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