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 * Number of ordered extents the transaction must wait for before
91 * committing. These are ordered extents started by a fast fsync.
92 */
93 atomic_t pending_ordered;
94 wait_queue_head_t pending_wait;
95 };
96
97 #define __TRANS_FREEZABLE (1U << 0)
98
99 #define __TRANS_START (1U << 9)
100 #define __TRANS_ATTACH (1U << 10)
101 #define __TRANS_JOIN (1U << 11)
102 #define __TRANS_JOIN_NOLOCK (1U << 12)
103 #define __TRANS_DUMMY (1U << 13)
104 #define __TRANS_JOIN_NOSTART (1U << 14)
105
106 #define TRANS_START (__TRANS_START | __TRANS_FREEZABLE)
107 #define TRANS_ATTACH (__TRANS_ATTACH)
108 #define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE)
109 #define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK)
110 #define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART)
111
112 #define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH)
113
114 #define BTRFS_SEND_TRANS_STUB ((void *)1)
115 #define BTRFS_DIO_SYNC_STUB ((void *)2)
116
117 struct btrfs_trans_handle {
118 u64 transid;
119 u64 bytes_reserved;
120 u64 chunk_bytes_reserved;
121 unsigned long delayed_ref_updates;
122 struct btrfs_transaction *transaction;
123 struct btrfs_block_rsv *block_rsv;
124 struct btrfs_block_rsv *orig_rsv;
125 refcount_t use_count;
126 unsigned int type;
127 /*
128 * Error code of transaction abort, set outside of locks and must use
129 * the READ_ONCE/WRITE_ONCE access
130 */
131 short aborted;
132 bool adding_csums;
133 bool allocating_chunk;
134 bool can_flush_pending_bgs;
135 bool reloc_reserved;
136 bool dirty;
137 struct btrfs_root *root;
138 struct btrfs_fs_info *fs_info;
139 struct list_head new_bgs;
140 };
141
142 /*
143 * The abort status can be changed between calls and is not protected by locks.
144 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
145 * set to a non-zero value it does not change, so the macro should be in checks
146 * but is not necessary for further reads of the value.
147 */
148 #define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted)))
149
150 struct btrfs_pending_snapshot {
151 struct dentry *dentry;
152 struct inode *dir;
153 struct btrfs_root *root;
154 struct btrfs_root_item *root_item;
155 struct btrfs_root *snap;
156 struct btrfs_qgroup_inherit *inherit;
157 struct btrfs_path *path;
158 /* block reservation for the operation */
159 struct btrfs_block_rsv block_rsv;
160 /* extra metadata reservation for relocation */
161 int error;
162 /* Preallocated anonymous block device number */
163 dev_t anon_dev;
164 bool readonly;
165 struct list_head list;
166 };
167
btrfs_set_inode_last_trans(struct btrfs_trans_handle * trans,struct btrfs_inode * inode)168 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
169 struct btrfs_inode *inode)
170 {
171 spin_lock(&inode->lock);
172 inode->last_trans = trans->transaction->transid;
173 inode->last_sub_trans = inode->root->log_transid;
174 inode->last_log_commit = inode->root->last_log_commit;
175 spin_unlock(&inode->lock);
176 }
177
178 /*
179 * Make qgroup codes to skip given qgroupid, means the old/new_roots for
180 * qgroup won't contain the qgroupid in it.
181 */
btrfs_set_skip_qgroup(struct btrfs_trans_handle * trans,u64 qgroupid)182 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
183 u64 qgroupid)
184 {
185 struct btrfs_delayed_ref_root *delayed_refs;
186
187 delayed_refs = &trans->transaction->delayed_refs;
188 WARN_ON(delayed_refs->qgroup_to_skip);
189 delayed_refs->qgroup_to_skip = qgroupid;
190 }
191
btrfs_clear_skip_qgroup(struct btrfs_trans_handle * trans)192 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
193 {
194 struct btrfs_delayed_ref_root *delayed_refs;
195
196 delayed_refs = &trans->transaction->delayed_refs;
197 WARN_ON(!delayed_refs->qgroup_to_skip);
198 delayed_refs->qgroup_to_skip = 0;
199 }
200
201 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
202 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
203 unsigned int num_items);
204 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
205 struct btrfs_root *root,
206 unsigned int num_items);
207 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
208 struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root);
209 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root);
210 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
211 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
212 struct btrfs_root *root);
213 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
214
215 void btrfs_add_dead_root(struct btrfs_root *root);
216 int btrfs_defrag_root(struct btrfs_root *root);
217 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
218 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
219 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
220 int wait_for_unblock);
221 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
222 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
223 void btrfs_throttle(struct btrfs_fs_info *fs_info);
224 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
225 struct btrfs_root *root);
226 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
227 struct extent_io_tree *dirty_pages, int mark);
228 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark);
229 int btrfs_transaction_blocked(struct btrfs_fs_info *info);
230 int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
231 void btrfs_put_transaction(struct btrfs_transaction *transaction);
232 void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info);
233 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans,
234 struct btrfs_root *root);
235 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans);
236
237 #endif
238
