156bec294SChris Mason /* 256bec294SChris Mason * Copyright (C) 2008 Oracle. All rights reserved. 356bec294SChris Mason * 456bec294SChris Mason * This program is free software; you can redistribute it and/or 556bec294SChris Mason * modify it under the terms of the GNU General Public 656bec294SChris Mason * License v2 as published by the Free Software Foundation. 756bec294SChris Mason * 856bec294SChris Mason * This program is distributed in the hope that it will be useful, 956bec294SChris Mason * but WITHOUT ANY WARRANTY; without even the implied warranty of 1056bec294SChris Mason * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 1156bec294SChris Mason * General Public License for more details. 1256bec294SChris Mason * 1356bec294SChris Mason * You should have received a copy of the GNU General Public 1456bec294SChris Mason * License along with this program; if not, write to the 1556bec294SChris Mason * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 1656bec294SChris Mason * Boston, MA 021110-1307, USA. 1756bec294SChris Mason */ 1856bec294SChris Mason #ifndef __DELAYED_REF__ 1956bec294SChris Mason #define __DELAYED_REF__ 2056bec294SChris Mason 2144a075bdSWang Sheng-Hui /* these are the possible values of struct btrfs_delayed_ref_node->action */ 2256bec294SChris Mason #define BTRFS_ADD_DELAYED_REF 1 /* add one backref to the tree */ 2356bec294SChris Mason #define BTRFS_DROP_DELAYED_REF 2 /* delete one backref from the tree */ 2456bec294SChris Mason #define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */ 251a81af4dSChris Mason #define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */ 2656bec294SChris Mason 2756bec294SChris Mason struct btrfs_delayed_ref_node { 2856bec294SChris Mason struct rb_node rb_node; 2956bec294SChris Mason 3056bec294SChris Mason /* the starting bytenr of the extent */ 3156bec294SChris Mason u64 bytenr; 3256bec294SChris Mason 3356bec294SChris Mason /* the size of the extent */ 3456bec294SChris Mason u64 num_bytes; 3556bec294SChris Mason 3600f04b88SArne Jansen /* seq number to keep track of insertion order */ 3700f04b88SArne Jansen u64 seq; 3800f04b88SArne Jansen 3956bec294SChris Mason /* ref count on this data structure */ 4056bec294SChris Mason atomic_t refs; 4156bec294SChris Mason 4256bec294SChris Mason /* 4356bec294SChris Mason * how many refs is this entry adding or deleting. For 4456bec294SChris Mason * head refs, this may be a negative number because it is keeping 4556bec294SChris Mason * track of the total mods done to the reference count. 4656bec294SChris Mason * For individual refs, this will always be a positive number 4756bec294SChris Mason * 4856bec294SChris Mason * It may be more than one, since it is possible for a single 4956bec294SChris Mason * parent to have more than one ref on an extent 5056bec294SChris Mason */ 5156bec294SChris Mason int ref_mod; 5256bec294SChris Mason 535d4f98a2SYan Zheng unsigned int action:8; 545d4f98a2SYan Zheng unsigned int type:8; 5556bec294SChris Mason /* is this node still in the rbtree? */ 565d4f98a2SYan Zheng unsigned int is_head:1; 5756bec294SChris Mason unsigned int in_tree:1; 5856bec294SChris Mason }; 5956bec294SChris Mason 605d4f98a2SYan Zheng struct btrfs_delayed_extent_op { 615d4f98a2SYan Zheng struct btrfs_disk_key key; 625d4f98a2SYan Zheng u64 flags_to_set; 635d4f98a2SYan Zheng unsigned int update_key:1; 645d4f98a2SYan Zheng unsigned int update_flags:1; 655d4f98a2SYan Zheng unsigned int is_data:1; 665d4f98a2SYan Zheng }; 675d4f98a2SYan Zheng 6856bec294SChris Mason /* 6956bec294SChris Mason * the head refs are used to hold a lock on a given extent, which allows us 7056bec294SChris Mason * to make sure that only one process is running the delayed refs 7156bec294SChris Mason * at a time for a single extent. They also store the sum of all the 7256bec294SChris Mason * reference count modifications we've queued up. 7356bec294SChris Mason */ 7456bec294SChris Mason struct btrfs_delayed_ref_head { 7556bec294SChris Mason struct btrfs_delayed_ref_node node; 7656bec294SChris Mason 7756bec294SChris Mason /* 7856bec294SChris Mason * the mutex is held while running the refs, and it is also 7956bec294SChris Mason * held when checking the sum of reference modifications. 8056bec294SChris Mason */ 8156bec294SChris Mason struct mutex mutex; 8256bec294SChris Mason 83c3e69d58SChris Mason struct list_head cluster; 84c3e69d58SChris Mason 855d4f98a2SYan Zheng struct btrfs_delayed_extent_op *extent_op; 8656bec294SChris Mason /* 8756bec294SChris Mason * when a new extent is allocated, it is just reserved in memory 8856bec294SChris Mason * The actual extent isn't inserted into the extent allocation tree 8956bec294SChris Mason * until the delayed ref is processed. must_insert_reserved is 9056bec294SChris Mason * used to flag a delayed ref so the accounting can be updated 9156bec294SChris Mason * when a full insert is done. 9256bec294SChris Mason * 9356bec294SChris Mason * It is possible the extent will be freed before it is ever 9456bec294SChris Mason * inserted into the extent allocation tree. In this case 9556bec294SChris Mason * we need to update the in ram accounting to properly reflect 9656bec294SChris Mason * the free has happened. 9756bec294SChris Mason */ 9856bec294SChris Mason unsigned int must_insert_reserved:1; 995d4f98a2SYan Zheng unsigned int is_data:1; 10056bec294SChris Mason }; 10156bec294SChris Mason 1025d4f98a2SYan Zheng struct btrfs_delayed_tree_ref { 10356bec294SChris Mason struct btrfs_delayed_ref_node node; 10456bec294SChris Mason u64 root; 1055d4f98a2SYan Zheng u64 parent; 1065d4f98a2SYan Zheng int level; 1075d4f98a2SYan Zheng }; 10856bec294SChris Mason 1095d4f98a2SYan Zheng struct btrfs_delayed_data_ref { 1105d4f98a2SYan Zheng struct btrfs_delayed_ref_node node; 1115d4f98a2SYan Zheng u64 root; 1125d4f98a2SYan Zheng u64 parent; 1135d4f98a2SYan Zheng u64 objectid; 1145d4f98a2SYan Zheng u64 offset; 11556bec294SChris Mason }; 11656bec294SChris Mason 11756bec294SChris Mason struct btrfs_delayed_ref_root { 11856bec294SChris Mason struct rb_root root; 11956bec294SChris Mason 12056bec294SChris Mason /* this spin lock protects the rbtree and the entries inside */ 12156bec294SChris Mason spinlock_t lock; 12256bec294SChris Mason 12356bec294SChris Mason /* how many delayed ref updates we've queued, used by the 12456bec294SChris Mason * throttling code 12556bec294SChris Mason */ 12656bec294SChris Mason unsigned long num_entries; 12756bec294SChris Mason 128c3e69d58SChris Mason /* total number of head nodes in tree */ 129c3e69d58SChris Mason unsigned long num_heads; 130c3e69d58SChris Mason 131c3e69d58SChris Mason /* total number of head nodes ready for processing */ 132c3e69d58SChris Mason unsigned long num_heads_ready; 133c3e69d58SChris Mason 13456bec294SChris Mason /* 13556bec294SChris Mason * set when the tree is flushing before a transaction commit, 13656bec294SChris Mason * used by the throttling code to decide if new updates need 13756bec294SChris Mason * to be run right away 13856bec294SChris Mason */ 13956bec294SChris Mason int flushing; 140c3e69d58SChris Mason 141c3e69d58SChris Mason u64 run_delayed_start; 14256bec294SChris Mason }; 14356bec294SChris Mason 14478a6184aSMiao Xie extern struct kmem_cache *btrfs_delayed_ref_head_cachep; 14578a6184aSMiao Xie extern struct kmem_cache *btrfs_delayed_tree_ref_cachep; 14678a6184aSMiao Xie extern struct kmem_cache *btrfs_delayed_data_ref_cachep; 14778a6184aSMiao Xie extern struct kmem_cache *btrfs_delayed_extent_op_cachep; 14878a6184aSMiao Xie 14978a6184aSMiao Xie int btrfs_delayed_ref_init(void); 15078a6184aSMiao Xie void btrfs_delayed_ref_exit(void); 15178a6184aSMiao Xie 15278a6184aSMiao Xie static inline struct btrfs_delayed_extent_op * 15378a6184aSMiao Xie btrfs_alloc_delayed_extent_op(void) 15478a6184aSMiao Xie { 15578a6184aSMiao Xie return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS); 15678a6184aSMiao Xie } 15778a6184aSMiao Xie 15878a6184aSMiao Xie static inline void 15978a6184aSMiao Xie btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op) 16078a6184aSMiao Xie { 16178a6184aSMiao Xie if (op) 16278a6184aSMiao Xie kmem_cache_free(btrfs_delayed_extent_op_cachep, op); 16378a6184aSMiao Xie } 16478a6184aSMiao Xie 16556bec294SChris Mason static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref) 16656bec294SChris Mason { 16756bec294SChris Mason WARN_ON(atomic_read(&ref->refs) == 0); 16856bec294SChris Mason if (atomic_dec_and_test(&ref->refs)) { 16956bec294SChris Mason WARN_ON(ref->in_tree); 17078a6184aSMiao Xie switch (ref->type) { 17178a6184aSMiao Xie case BTRFS_TREE_BLOCK_REF_KEY: 17278a6184aSMiao Xie case BTRFS_SHARED_BLOCK_REF_KEY: 17378a6184aSMiao Xie kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref); 17478a6184aSMiao Xie break; 17578a6184aSMiao Xie case BTRFS_EXTENT_DATA_REF_KEY: 17678a6184aSMiao Xie case BTRFS_SHARED_DATA_REF_KEY: 17778a6184aSMiao Xie kmem_cache_free(btrfs_delayed_data_ref_cachep, ref); 17878a6184aSMiao Xie break; 17978a6184aSMiao Xie case 0: 18078a6184aSMiao Xie kmem_cache_free(btrfs_delayed_ref_head_cachep, ref); 18178a6184aSMiao Xie break; 18278a6184aSMiao Xie default: 18378a6184aSMiao Xie BUG(); 18478a6184aSMiao Xie } 18556bec294SChris Mason } 18656bec294SChris Mason } 18756bec294SChris Mason 18866d7e7f0SArne Jansen int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info, 18966d7e7f0SArne Jansen struct btrfs_trans_handle *trans, 1905d4f98a2SYan Zheng u64 bytenr, u64 num_bytes, u64 parent, 1915d4f98a2SYan Zheng u64 ref_root, int level, int action, 19266d7e7f0SArne Jansen struct btrfs_delayed_extent_op *extent_op, 19366d7e7f0SArne Jansen int for_cow); 19466d7e7f0SArne Jansen int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, 19566d7e7f0SArne Jansen struct btrfs_trans_handle *trans, 1965d4f98a2SYan Zheng u64 bytenr, u64 num_bytes, 1975d4f98a2SYan Zheng u64 parent, u64 ref_root, 1985d4f98a2SYan Zheng u64 owner, u64 offset, int action, 19966d7e7f0SArne Jansen struct btrfs_delayed_extent_op *extent_op, 20066d7e7f0SArne Jansen int for_cow); 20166d7e7f0SArne Jansen int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info, 20266d7e7f0SArne Jansen struct btrfs_trans_handle *trans, 2035d4f98a2SYan Zheng u64 bytenr, u64 num_bytes, 2045d4f98a2SYan Zheng struct btrfs_delayed_extent_op *extent_op); 205ae1e206bSJosef Bacik void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans, 206ae1e206bSJosef Bacik struct btrfs_fs_info *fs_info, 207ae1e206bSJosef Bacik struct btrfs_delayed_ref_root *delayed_refs, 208ae1e206bSJosef Bacik struct btrfs_delayed_ref_head *head); 20956bec294SChris Mason 2101887be66SChris Mason struct btrfs_delayed_ref_head * 2111887be66SChris Mason btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr); 212c3e69d58SChris Mason int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans, 213c3e69d58SChris Mason struct btrfs_delayed_ref_head *head); 214093486c4SMiao Xie static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head) 215093486c4SMiao Xie { 216093486c4SMiao Xie mutex_unlock(&head->mutex); 217093486c4SMiao Xie } 218093486c4SMiao Xie 219c3e69d58SChris Mason int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans, 220c3e69d58SChris Mason struct list_head *cluster, u64 search_start); 221093486c4SMiao Xie void btrfs_release_ref_cluster(struct list_head *cluster); 22200f04b88SArne Jansen 223097b8a7cSJan Schmidt int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, 224097b8a7cSJan Schmidt struct btrfs_delayed_ref_root *delayed_refs, 22500f04b88SArne Jansen u64 seq); 22600f04b88SArne Jansen 22700f04b88SArne Jansen /* 228546adb0dSJan Schmidt * delayed refs with a ref_seq > 0 must be held back during backref walking. 229546adb0dSJan Schmidt * this only applies to items in one of the fs-trees. for_cow items never need 230546adb0dSJan Schmidt * to be held back, so they won't get a ref_seq number. 231546adb0dSJan Schmidt */ 232546adb0dSJan Schmidt static inline int need_ref_seq(int for_cow, u64 rootid) 233546adb0dSJan Schmidt { 234546adb0dSJan Schmidt if (for_cow) 235546adb0dSJan Schmidt return 0; 236546adb0dSJan Schmidt 237546adb0dSJan Schmidt if (rootid == BTRFS_FS_TREE_OBJECTID) 238546adb0dSJan Schmidt return 1; 239546adb0dSJan Schmidt 240546adb0dSJan Schmidt if ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID) 241546adb0dSJan Schmidt return 1; 242546adb0dSJan Schmidt 243546adb0dSJan Schmidt return 0; 244546adb0dSJan Schmidt } 245546adb0dSJan Schmidt 246546adb0dSJan Schmidt /* 24756bec294SChris Mason * a node might live in a head or a regular ref, this lets you 24856bec294SChris Mason * test for the proper type to use. 24956bec294SChris Mason */ 25056bec294SChris Mason static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node) 25156bec294SChris Mason { 2525d4f98a2SYan Zheng return node->is_head; 25356bec294SChris Mason } 25456bec294SChris Mason 25556bec294SChris Mason /* 25656bec294SChris Mason * helper functions to cast a node into its container 25756bec294SChris Mason */ 2585d4f98a2SYan Zheng static inline struct btrfs_delayed_tree_ref * 2595d4f98a2SYan Zheng btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node) 26056bec294SChris Mason { 26156bec294SChris Mason WARN_ON(btrfs_delayed_ref_is_head(node)); 2625d4f98a2SYan Zheng return container_of(node, struct btrfs_delayed_tree_ref, node); 2635d4f98a2SYan Zheng } 26456bec294SChris Mason 2655d4f98a2SYan Zheng static inline struct btrfs_delayed_data_ref * 2665d4f98a2SYan Zheng btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node) 2675d4f98a2SYan Zheng { 2685d4f98a2SYan Zheng WARN_ON(btrfs_delayed_ref_is_head(node)); 2695d4f98a2SYan Zheng return container_of(node, struct btrfs_delayed_data_ref, node); 27056bec294SChris Mason } 27156bec294SChris Mason 27256bec294SChris Mason static inline struct btrfs_delayed_ref_head * 27356bec294SChris Mason btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node) 27456bec294SChris Mason { 27556bec294SChris Mason WARN_ON(!btrfs_delayed_ref_is_head(node)); 27656bec294SChris Mason return container_of(node, struct btrfs_delayed_ref_head, node); 27756bec294SChris Mason } 27856bec294SChris Mason #endif 279