xref: /openbmc/linux/fs/btrfs/transaction.h (revision bcf3a3e7)
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #ifndef __BTRFS_TRANSACTION__
20 #define __BTRFS_TRANSACTION__
21 
22 #include <linux/refcount.h>
23 #include "btrfs_inode.h"
24 #include "delayed-ref.h"
25 #include "ctree.h"
26 
27 enum btrfs_trans_state {
28 	TRANS_STATE_RUNNING		= 0,
29 	TRANS_STATE_BLOCKED		= 1,
30 	TRANS_STATE_COMMIT_START	= 2,
31 	TRANS_STATE_COMMIT_DOING	= 3,
32 	TRANS_STATE_UNBLOCKED		= 4,
33 	TRANS_STATE_COMPLETED		= 5,
34 	TRANS_STATE_MAX			= 6,
35 };
36 
37 #define BTRFS_TRANS_HAVE_FREE_BGS	0
38 #define BTRFS_TRANS_DIRTY_BG_RUN	1
39 #define BTRFS_TRANS_CACHE_ENOSPC	2
40 
41 struct btrfs_transaction {
42 	u64 transid;
43 	/*
44 	 * total external writers(USERSPACE/START/ATTACH) in this
45 	 * transaction, it must be zero before the transaction is
46 	 * being committed
47 	 */
48 	atomic_t num_extwriters;
49 	/*
50 	 * total writers in this transaction, it must be zero before the
51 	 * transaction can end
52 	 */
53 	atomic_t num_writers;
54 	refcount_t use_count;
55 	atomic_t pending_ordered;
56 
57 	unsigned long flags;
58 
59 	/* Be protected by fs_info->trans_lock when we want to change it. */
60 	enum btrfs_trans_state state;
61 	int aborted;
62 	struct list_head list;
63 	struct extent_io_tree dirty_pages;
64 	unsigned long start_time;
65 	wait_queue_head_t writer_wait;
66 	wait_queue_head_t commit_wait;
67 	wait_queue_head_t pending_wait;
68 	struct list_head pending_snapshots;
69 	struct list_head pending_chunks;
70 	struct list_head switch_commits;
71 	struct list_head dirty_bgs;
72 
73 	/*
74 	 * There is no explicit lock which protects io_bgs, rather its
75 	 * consistency is implied by the fact that all the sites which modify
76 	 * it do so under some form of transaction critical section, namely:
77 	 *
78 	 * - btrfs_start_dirty_block_groups - This function can only ever be
79 	 *   run by one of the transaction committers. Refer to
80 	 *   BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction
81 	 *
82 	 * - btrfs_write_dirty_blockgroups - this is called by
83 	 *   commit_cowonly_roots from transaction critical section
84 	 *   (TRANS_STATE_COMMIT_DOING)
85 	 *
86 	 * - btrfs_cleanup_dirty_bgs - called on transaction abort
87 	 */
88 	struct list_head io_bgs;
89 	struct list_head dropped_roots;
90 
91 	/*
92 	 * we need to make sure block group deletion doesn't race with
93 	 * free space cache writeout.  This mutex keeps them from stomping
94 	 * on each other
95 	 */
96 	struct mutex cache_write_mutex;
97 	spinlock_t dirty_bgs_lock;
98 	unsigned int num_dirty_bgs;
99 	/* Protected by spin lock fs_info->unused_bgs_lock. */
100 	struct list_head deleted_bgs;
101 	spinlock_t dropped_roots_lock;
102 	struct btrfs_delayed_ref_root delayed_refs;
103 	struct btrfs_fs_info *fs_info;
104 };
105 
106 #define __TRANS_FREEZABLE	(1U << 0)
107 
108 #define __TRANS_START		(1U << 9)
109 #define __TRANS_ATTACH		(1U << 10)
110 #define __TRANS_JOIN		(1U << 11)
111 #define __TRANS_JOIN_NOLOCK	(1U << 12)
112 #define __TRANS_DUMMY		(1U << 13)
113 
114 #define TRANS_START		(__TRANS_START | __TRANS_FREEZABLE)
115 #define TRANS_ATTACH		(__TRANS_ATTACH)
116 #define TRANS_JOIN		(__TRANS_JOIN | __TRANS_FREEZABLE)
117 #define TRANS_JOIN_NOLOCK	(__TRANS_JOIN_NOLOCK)
118 
119 #define TRANS_EXTWRITERS	(__TRANS_START | __TRANS_ATTACH)
120 
121 #define BTRFS_SEND_TRANS_STUB	((void *)1)
122 
123 struct btrfs_trans_handle {
124 	u64 transid;
125 	u64 bytes_reserved;
126 	u64 chunk_bytes_reserved;
127 	unsigned long delayed_ref_updates;
128 	struct btrfs_transaction *transaction;
129 	struct btrfs_block_rsv *block_rsv;
130 	struct btrfs_block_rsv *orig_rsv;
131 	refcount_t use_count;
132 	unsigned int type;
133 	short aborted;
134 	bool adding_csums;
135 	bool allocating_chunk;
136 	bool can_flush_pending_bgs;
137 	bool reloc_reserved;
138 	bool sync;
139 	bool dirty;
140 	struct btrfs_root *root;
141 	struct btrfs_fs_info *fs_info;
142 	struct list_head new_bgs;
143 };
144 
145 struct btrfs_pending_snapshot {
146 	struct dentry *dentry;
147 	struct inode *dir;
148 	struct btrfs_root *root;
149 	struct btrfs_root_item *root_item;
150 	struct btrfs_root *snap;
151 	struct btrfs_qgroup_inherit *inherit;
152 	struct btrfs_path *path;
153 	/* block reservation for the operation */
154 	struct btrfs_block_rsv block_rsv;
155 	u64 qgroup_reserved;
156 	/* extra metadata reservation for relocation */
157 	int error;
158 	bool readonly;
159 	struct list_head list;
160 };
161 
162 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans,
163 					      struct inode *inode)
164 {
165 	spin_lock(&BTRFS_I(inode)->lock);
166 	BTRFS_I(inode)->last_trans = trans->transaction->transid;
167 	BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
168 	BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
169 	spin_unlock(&BTRFS_I(inode)->lock);
170 }
171 
172 /*
173  * Make qgroup codes to skip given qgroupid, means the old/new_roots for
174  * qgroup won't contain the qgroupid in it.
175  */
176 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans,
177 					 u64 qgroupid)
178 {
179 	struct btrfs_delayed_ref_root *delayed_refs;
180 
181 	delayed_refs = &trans->transaction->delayed_refs;
182 	WARN_ON(delayed_refs->qgroup_to_skip);
183 	delayed_refs->qgroup_to_skip = qgroupid;
184 }
185 
186 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans)
187 {
188 	struct btrfs_delayed_ref_root *delayed_refs;
189 
190 	delayed_refs = &trans->transaction->delayed_refs;
191 	WARN_ON(!delayed_refs->qgroup_to_skip);
192 	delayed_refs->qgroup_to_skip = 0;
193 }
194 
195 int btrfs_end_transaction(struct btrfs_trans_handle *trans);
196 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
197 						   unsigned int num_items);
198 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
199 					struct btrfs_root *root,
200 					unsigned int num_items,
201 					int min_factor);
202 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root);
203 struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root);
204 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root);
205 struct btrfs_trans_handle *btrfs_attach_transaction_barrier(
206 					struct btrfs_root *root);
207 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
208 
209 void btrfs_add_dead_root(struct btrfs_root *root);
210 int btrfs_defrag_root(struct btrfs_root *root);
211 int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
212 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
213 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
214 				   int wait_for_unblock);
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 #endif
232