94439482a0ec63ad2096df1b7314f4c655503f1a
[sfrench/cifs-2.6.git] / fs / btrfs / transaction.h
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