xref: /linux/fs/btrfs/transaction.h (revision 8ea636848aca35b9f97c5b5dee30225cf2dd0fe6)
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,
16 	TRANS_STATE_COMMIT_START,
17 	TRANS_STATE_COMMIT_DOING,
18 	TRANS_STATE_UNBLOCKED,
19 	TRANS_STATE_COMPLETED,
20 	TRANS_STATE_MAX,
21 };
22 
23 #define BTRFS_TRANS_HAVE_FREE_BGS	0
24 #define BTRFS_TRANS_DIRTY_BG_RUN	1
25 #define BTRFS_TRANS_CACHE_ENOSPC	2
26 
27 struct btrfs_transaction {
28 	u64 transid;
29 	/*
30 	 * total external writers(USERSPACE/START/ATTACH) in this
31 	 * transaction, it must be zero before the transaction is
32 	 * being committed
33 	 */
34 	atomic_t num_extwriters;
35 	/*
36 	 * total writers in this transaction, it must be zero before the
37 	 * transaction can end
38 	 */
39 	atomic_t num_writers;
40 	refcount_t use_count;
41 
42 	unsigned long flags;
43 
44 	/* Be protected by fs_info->trans_lock when we want to change it. */
45 	enum btrfs_trans_state state;
46 	int aborted;
47 	struct list_head list;
48 	struct extent_io_tree dirty_pages;
49 	time64_t start_time;
50 	wait_queue_head_t writer_wait;
51 	wait_queue_head_t commit_wait;
52 	struct list_head pending_snapshots;
53 	struct list_head dev_update_list;
54 	struct list_head switch_commits;
55 	struct list_head dirty_bgs;
56 
57 	/*
58 	 * There is no explicit lock which protects io_bgs, rather its
59 	 * consistency is implied by the fact that all the sites which modify
60 	 * it do so under some form of transaction critical section, namely:
61 	 *
62 	 * - btrfs_start_dirty_block_groups - This function can only ever be
63 	 *   run by one of the transaction committers. Refer to
64 	 *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
65 	 *
66 	 * - btrfs_write_dirty_blockgroups - this is called by
67 	 *   commit_cowonly_roots from transaction critical section
68 	 *   (TRANS_STATE_COMMIT_DOING)
69 	 *
70 	 * - btrfs_cleanup_dirty_bgs - called on transaction abort
71 	 */
72 	struct list_head io_bgs;
73 	struct list_head dropped_roots;
74 	struct extent_io_tree pinned_extents;
75 
76 	/*
77 	 * we need to make sure block group deletion doesn't race with
78 	 * free space cache writeout.  This mutex keeps them from stomping
79 	 * on each other
80 	 */
81 	struct mutex cache_write_mutex;
82 	spinlock_t dirty_bgs_lock;
83 	/* Protected by spin lock fs_info->unused_bgs_lock. */
84 	struct list_head deleted_bgs;
85 	spinlock_t dropped_roots_lock;
86 	struct btrfs_delayed_ref_root delayed_refs;
87 	struct btrfs_fs_info *fs_info;
88 };
89 
90 #define __TRANS_FREEZABLE	(1U << 0)
91 
92 #define __TRANS_START		(1U << 9)
93 #define __TRANS_ATTACH		(1U << 10)
94 #define __TRANS_JOIN		(1U << 11)
95 #define __TRANS_JOIN_NOLOCK	(1U << 12)
96 #define __TRANS_DUMMY		(1U << 13)
97 #define __TRANS_JOIN_NOSTART	(1U << 14)
98 
99 #define TRANS_START		(__TRANS_START | __TRANS_FREEZABLE)
100 #define TRANS_ATTACH		(__TRANS_ATTACH)
101 #define TRANS_JOIN		(__TRANS_JOIN | __TRANS_FREEZABLE)
102 #define TRANS_JOIN_NOLOCK	(__TRANS_JOIN_NOLOCK)
103 #define TRANS_JOIN_NOSTART	(__TRANS_JOIN_NOSTART)
104 
105 #define TRANS_EXTWRITERS	(__TRANS_START | __TRANS_ATTACH)
106 
107 #define BTRFS_SEND_TRANS_STUB	((void *)1)
108 
109 struct btrfs_trans_handle {
110 	u64 transid;
111 	u64 bytes_reserved;
112 	u64 chunk_bytes_reserved;
113 	unsigned long delayed_ref_updates;
114 	struct btrfs_transaction *transaction;
115 	struct btrfs_block_rsv *block_rsv;
116 	struct btrfs_block_rsv *orig_rsv;
117 	refcount_t use_count;
118 	unsigned int type;
119 	/*
120 	 * Error code of transaction abort, set outside of locks and must use
121 	 * the READ_ONCE/WRITE_ONCE access
122 	 */
123 	short aborted;
124 	bool adding_csums;
125 	bool allocating_chunk;
126 	bool can_flush_pending_bgs;
127 	bool reloc_reserved;
128 	bool dirty;
129 	struct btrfs_root *root;
130 	struct btrfs_fs_info *fs_info;
131 	struct list_head new_bgs;
132 };
133 
134 /*
135  * The abort status can be changed between calls and is not protected by locks.
136  * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
137  * set to a non-zero value it does not change, so the macro should be in checks
138  * but is not necessary for further reads of the value.
139  */
140 #define TRANS_ABORTED(trans)		(unlikely(READ_ONCE((trans)->aborted)))
141 
142 struct btrfs_pending_snapshot {
143 	struct dentry *dentry;
144 	struct inode *dir;
145 	struct btrfs_root *root;
146 	struct btrfs_root_item *root_item;
147 	struct btrfs_root *snap;
148 	struct btrfs_qgroup_inherit *inherit;
149 	struct btrfs_path *path;
150 	/* block reservation for the operation */
151 	struct btrfs_block_rsv block_rsv;
152 	/* extra metadata reservation for relocation */
153 	int error;
154 	/* Preallocated anonymous block device number */
155 	dev_t anon_dev;
156 	bool readonly;
157 	struct list_head list;
158 };
159 
160 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
161 					      struct btrfs_inode *inode)
162 {
163 	spin_lock(&inode->lock);
164 	inode->last_trans = trans->transaction->transid;
165 	inode->last_sub_trans = inode->root->log_transid;
166 	inode->last_log_commit = inode->root->last_log_commit;
167 	spin_unlock(&inode->lock);
168 }
169 
170 /*
171  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
172  * qgroup won't contain the qgroupid in it.
173  */
174 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
175 					 u64 qgroupid)
176 {
177 	struct btrfs_delayed_ref_root *delayed_refs;
178 
179 	delayed_refs = &trans->transaction->delayed_refs;
180 	WARN_ON(delayed_refs->qgroup_to_skip);
181 	delayed_refs->qgroup_to_skip = qgroupid;
182 }
183 
184 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
185 {
186 	struct btrfs_delayed_ref_root *delayed_refs;
187 
188 	delayed_refs = &trans->transaction->delayed_refs;
189 	WARN_ON(!delayed_refs->qgroup_to_skip);
190 	delayed_refs->qgroup_to_skip = 0;
191 }
192 
193 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
194 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
195 						   unsigned int num_items);
196 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
197 					struct btrfs_root *root,
198 					unsigned int num_items);
199 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
200 struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
201 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
202 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
203 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
204 					struct btrfs_root *root);
205 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
206 
207 void btrfs_add_dead_root(struct btrfs_root *root);
208 int btrfs_defrag_root(struct btrfs_root *root);
209 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
210 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
211 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
212 				   int wait_for_unblock);
213 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
214 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
215 void btrfs_throttle(struct btrfs_fs_info *fs_info);
216 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
217 				struct btrfs_root *root);
218 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
219 				struct extent_io_tree *dirty_pages, int mark);
220 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
221 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
222 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
223 void btrfs_put_transaction(struct btrfs_transaction *transaction);
224 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
225 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
226 			    struct btrfs_root *root);
227 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
228 
229 #endif
230