xref: /linux/fs/btrfs/transaction.h (revision 791d3ef2e11100449837dc0b6fe884e60ca3a484)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5 
6 #ifndef BTRFS_TRANSACTION_H
7 #define BTRFS_TRANSACTION_H
8 
9 #include <linux/refcount.h>
10 #include "btrfs_inode.h"
11 #include "delayed-ref.h"
12 #include "ctree.h"
13 
14 enum btrfs_trans_state {
15 	TRANS_STATE_RUNNING		= 0,
16 	TRANS_STATE_BLOCKED		= 1,
17 	TRANS_STATE_COMMIT_START	= 2,
18 	TRANS_STATE_COMMIT_DOING	= 3,
19 	TRANS_STATE_UNBLOCKED		= 4,
20 	TRANS_STATE_COMPLETED		= 5,
21 	TRANS_STATE_MAX			= 6,
22 };
23 
24 #define BTRFS_TRANS_HAVE_FREE_BGS	0
25 #define BTRFS_TRANS_DIRTY_BG_RUN	1
26 #define BTRFS_TRANS_CACHE_ENOSPC	2
27 
28 struct btrfs_transaction {
29 	u64 transid;
30 	/*
31 	 * total external writers(USERSPACE/START/ATTACH) in this
32 	 * transaction, it must be zero before the transaction is
33 	 * being committed
34 	 */
35 	atomic_t num_extwriters;
36 	/*
37 	 * total writers in this transaction, it must be zero before the
38 	 * transaction can end
39 	 */
40 	atomic_t num_writers;
41 	refcount_t use_count;
42 	atomic_t pending_ordered;
43 
44 	unsigned long flags;
45 
46 	/* Be protected by fs_info->trans_lock when we want to change it. */
47 	enum btrfs_trans_state state;
48 	int aborted;
49 	struct list_head list;
50 	struct extent_io_tree dirty_pages;
51 	unsigned long start_time;
52 	wait_queue_head_t writer_wait;
53 	wait_queue_head_t commit_wait;
54 	wait_queue_head_t pending_wait;
55 	struct list_head pending_snapshots;
56 	struct list_head pending_chunks;
57 	struct list_head switch_commits;
58 	struct list_head dirty_bgs;
59 
60 	/*
61 	 * There is no explicit lock which protects io_bgs, rather its
62 	 * consistency is implied by the fact that all the sites which modify
63 	 * it do so under some form of transaction critical section, namely:
64 	 *
65 	 * - btrfs_start_dirty_block_groups - This function can only ever be
66 	 *   run by one of the transaction committers. Refer to
67 	 *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
68 	 *
69 	 * - btrfs_write_dirty_blockgroups - this is called by
70 	 *   commit_cowonly_roots from transaction critical section
71 	 *   (TRANS_STATE_COMMIT_DOING)
72 	 *
73 	 * - btrfs_cleanup_dirty_bgs - called on transaction abort
74 	 */
75 	struct list_head io_bgs;
76 	struct list_head dropped_roots;
77 
78 	/*
79 	 * we need to make sure block group deletion doesn't race with
80 	 * free space cache writeout.  This mutex keeps them from stomping
81 	 * on each other
82 	 */
83 	struct mutex cache_write_mutex;
84 	spinlock_t dirty_bgs_lock;
85 	unsigned int num_dirty_bgs;
86 	/* Protected by spin lock fs_info->unused_bgs_lock. */
87 	struct list_head deleted_bgs;
88 	spinlock_t dropped_roots_lock;
89 	struct btrfs_delayed_ref_root delayed_refs;
90 	struct btrfs_fs_info *fs_info;
91 };
92 
93 #define __TRANS_FREEZABLE	(1U << 0)
94 
95 #define __TRANS_START		(1U << 9)
96 #define __TRANS_ATTACH		(1U << 10)
97 #define __TRANS_JOIN		(1U << 11)
98 #define __TRANS_JOIN_NOLOCK	(1U << 12)
99 #define __TRANS_DUMMY		(1U << 13)
100 
101 #define TRANS_START		(__TRANS_START | __TRANS_FREEZABLE)
102 #define TRANS_ATTACH		(__TRANS_ATTACH)
103 #define TRANS_JOIN		(__TRANS_JOIN | __TRANS_FREEZABLE)
104 #define TRANS_JOIN_NOLOCK	(__TRANS_JOIN_NOLOCK)
105 
106 #define TRANS_EXTWRITERS	(__TRANS_START | __TRANS_ATTACH)
107 
108 #define BTRFS_SEND_TRANS_STUB	((void *)1)
109 
110 struct btrfs_trans_handle {
111 	u64 transid;
112 	u64 bytes_reserved;
113 	u64 chunk_bytes_reserved;
114 	unsigned long delayed_ref_updates;
115 	struct btrfs_transaction *transaction;
116 	struct btrfs_block_rsv *block_rsv;
117 	struct btrfs_block_rsv *orig_rsv;
118 	refcount_t use_count;
119 	unsigned int type;
120 	short aborted;
121 	bool adding_csums;
122 	bool allocating_chunk;
123 	bool can_flush_pending_bgs;
124 	bool reloc_reserved;
125 	bool sync;
126 	bool dirty;
127 	struct btrfs_root *root;
128 	struct btrfs_fs_info *fs_info;
129 	struct list_head new_bgs;
130 };
131 
132 struct btrfs_pending_snapshot {
133 	struct dentry *dentry;
134 	struct inode *dir;
135 	struct btrfs_root *root;
136 	struct btrfs_root_item *root_item;
137 	struct btrfs_root *snap;
138 	struct btrfs_qgroup_inherit *inherit;
139 	struct btrfs_path *path;
140 	/* block reservation for the operation */
141 	struct btrfs_block_rsv block_rsv;
142 	/* extra metadata reservation for relocation */
143 	int error;
144 	bool readonly;
145 	struct list_head list;
146 };
147 
148 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
149 					      struct inode *inode)
150 {
151 	spin_lock(&BTRFS_I(inode)->lock);
152 	BTRFS_I(inode)->last_trans = trans->transaction->transid;
153 	BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
154 	BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
155 	spin_unlock(&BTRFS_I(inode)->lock);
156 }
157 
158 /*
159  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
160  * qgroup won't contain the qgroupid in it.
161  */
162 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
163 					 u64 qgroupid)
164 {
165 	struct btrfs_delayed_ref_root *delayed_refs;
166 
167 	delayed_refs = &trans->transaction->delayed_refs;
168 	WARN_ON(delayed_refs->qgroup_to_skip);
169 	delayed_refs->qgroup_to_skip = qgroupid;
170 }
171 
172 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
173 {
174 	struct btrfs_delayed_ref_root *delayed_refs;
175 
176 	delayed_refs = &trans->transaction->delayed_refs;
177 	WARN_ON(!delayed_refs->qgroup_to_skip);
178 	delayed_refs->qgroup_to_skip = 0;
179 }
180 
181 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
182 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
183 						   unsigned int num_items);
184 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
185 					struct btrfs_root *root,
186 					unsigned int num_items,
187 					int min_factor);
188 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
189 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
190 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
191 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
192 					struct btrfs_root *root);
193 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
194 
195 void btrfs_add_dead_root(struct btrfs_root *root);
196 int btrfs_defrag_root(struct btrfs_root *root);
197 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
198 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
199 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
200 				   int wait_for_unblock);
201 
202 /*
203  * Try to commit transaction asynchronously, so this is safe to call
204  * even holding a spinlock.
205  *
206  * It's done by informing transaction_kthread to commit transaction without
207  * waiting for commit interval.
208  */
209 static inline void btrfs_commit_transaction_locksafe(
210 		struct btrfs_fs_info *fs_info)
211 {
212 	set_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags);
213 	wake_up_process(fs_info->transaction_kthread);
214 }
215 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
216 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
217 void btrfs_throttle(struct btrfs_fs_info *fs_info);
218 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
219 				struct btrfs_root *root);
220 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
221 				struct extent_io_tree *dirty_pages, int mark);
222 int btrfs_wait_extents(struct btrfs_fs_info *fs_info,
223 		       struct extent_io_tree *dirty_pages);
224 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
225 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
226 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
227 void btrfs_put_transaction(struct btrfs_transaction *transaction);
228 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
229 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
230 			    struct btrfs_root *root);
231 
232 #endif
233