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/atomic.h> 10 #include <linux/refcount.h> 11 #include <linux/list.h> 12 #include <linux/time64.h> 13 #include <linux/mutex.h> 14 #include <linux/wait.h> 15 #include "btrfs_inode.h" 16 #include "delayed-ref.h" 17 #include "extent-io-tree.h" 18 #include "block-rsv.h" 19 #include "messages.h" 20 #include "misc.h" 21 22 struct dentry; 23 struct inode; 24 struct btrfs_pending_snapshot; 25 struct btrfs_fs_info; 26 struct btrfs_root_item; 27 struct btrfs_root; 28 struct btrfs_path; 29 30 /* 31 * Signal that a direct IO write is in progress, to avoid deadlock for sync 32 * direct IO writes when fsync is called during the direct IO write path. 33 */ 34 #define BTRFS_TRANS_DIO_WRITE_STUB ((void *) 1) 35 36 /* Radix-tree tag for roots that are part of the trasaction. */ 37 #define BTRFS_ROOT_TRANS_TAG 0 38 39 enum btrfs_trans_state { 40 TRANS_STATE_RUNNING, 41 TRANS_STATE_COMMIT_PREP, 42 TRANS_STATE_COMMIT_START, 43 TRANS_STATE_COMMIT_DOING, 44 TRANS_STATE_UNBLOCKED, 45 TRANS_STATE_SUPER_COMMITTED, 46 TRANS_STATE_COMPLETED, 47 TRANS_STATE_MAX, 48 }; 49 50 #define BTRFS_TRANS_HAVE_FREE_BGS 0 51 #define BTRFS_TRANS_DIRTY_BG_RUN 1 52 #define BTRFS_TRANS_CACHE_ENOSPC 2 53 54 struct btrfs_transaction { 55 u64 transid; 56 /* 57 * total external writers(USERSPACE/START/ATTACH) in this 58 * transaction, it must be zero before the transaction is 59 * being committed 60 */ 61 atomic_t num_extwriters; 62 /* 63 * total writers in this transaction, it must be zero before the 64 * transaction can end 65 */ 66 atomic_t num_writers; 67 refcount_t use_count; 68 69 unsigned long flags; 70 71 /* Be protected by fs_info->trans_lock when we want to change it. */ 72 enum btrfs_trans_state state; 73 int aborted; 74 struct list_head list; 75 struct extent_io_tree dirty_pages; 76 time64_t start_time; 77 wait_queue_head_t writer_wait; 78 wait_queue_head_t commit_wait; 79 struct list_head pending_snapshots; 80 struct list_head dev_update_list; 81 struct list_head switch_commits; 82 struct list_head dirty_bgs; 83 84 /* 85 * There is no explicit lock which protects io_bgs, rather its 86 * consistency is implied by the fact that all the sites which modify 87 * it do so under some form of transaction critical section, namely: 88 * 89 * - btrfs_start_dirty_block_groups - This function can only ever be 90 * run by one of the transaction committers. Refer to 91 * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction 92 * 93 * - btrfs_write_dirty_blockgroups - this is called by 94 * commit_cowonly_roots from transaction critical section 95 * (TRANS_STATE_COMMIT_DOING) 96 * 97 * - btrfs_cleanup_dirty_bgs - called on transaction abort 98 */ 99 struct list_head io_bgs; 100 struct list_head dropped_roots; 101 struct extent_io_tree pinned_extents; 102 103 /* 104 * we need to make sure block group deletion doesn't race with 105 * free space cache writeout. This mutex keeps them from stomping 106 * on each other 107 */ 108 struct mutex cache_write_mutex; 109 spinlock_t dirty_bgs_lock; 110 /* Protected by spin lock fs_info->unused_bgs_lock. */ 111 struct list_head deleted_bgs; 112 spinlock_t dropped_roots_lock; 113 struct btrfs_delayed_ref_root delayed_refs; 114 struct btrfs_fs_info *fs_info; 115 116 /* 117 * Number of ordered extents the transaction must wait for before 118 * committing. These are ordered extents started by a fast fsync. 119 */ 120 atomic_t pending_ordered; 121 wait_queue_head_t pending_wait; 122 }; 123 124 enum { 125 ENUM_BIT(__TRANS_FREEZABLE), 126 ENUM_BIT(__TRANS_START), 127 ENUM_BIT(__TRANS_ATTACH), 128 ENUM_BIT(__TRANS_JOIN), 129 ENUM_BIT(__TRANS_JOIN_NOLOCK), 130 ENUM_BIT(__TRANS_DUMMY), 131 ENUM_BIT(__TRANS_JOIN_NOSTART), 132 }; 133 134 #define TRANS_START (__TRANS_START | __TRANS_FREEZABLE) 135 #define TRANS_ATTACH (__TRANS_ATTACH) 136 #define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE) 137 #define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK) 138 #define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART) 139 140 #define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH) 141 142 struct btrfs_trans_handle { 143 u64 transid; 144 u64 bytes_reserved; 145 u64 delayed_refs_bytes_reserved; 146 u64 chunk_bytes_reserved; 147 unsigned long delayed_ref_updates; 148 unsigned long delayed_ref_csum_deletions; 149 struct btrfs_transaction *transaction; 150 struct btrfs_block_rsv *block_rsv; 151 struct btrfs_block_rsv *orig_rsv; 152 /* Set by a task that wants to create a snapshot. */ 153 struct btrfs_pending_snapshot *pending_snapshot; 154 refcount_t use_count; 155 unsigned int type; 156 /* 157 * Error code of transaction abort, set outside of locks and must use 158 * the READ_ONCE/WRITE_ONCE access 159 */ 160 short aborted; 161 bool adding_csums; 162 bool allocating_chunk; 163 bool removing_chunk; 164 bool reloc_reserved; 165 bool in_fsync; 166 struct btrfs_fs_info *fs_info; 167 struct list_head new_bgs; 168 struct btrfs_block_rsv delayed_rsv; 169 }; 170 171 /* 172 * The abort status can be changed between calls and is not protected by locks. 173 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's 174 * set to a non-zero value it does not change, so the macro should be in checks 175 * but is not necessary for further reads of the value. 176 */ 177 #define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted))) 178 179 struct btrfs_pending_snapshot { 180 struct dentry *dentry; 181 struct btrfs_inode *dir; 182 struct btrfs_root *root; 183 struct btrfs_root_item *root_item; 184 struct btrfs_root *snap; 185 struct btrfs_qgroup_inherit *inherit; 186 struct btrfs_path *path; 187 /* block reservation for the operation */ 188 struct btrfs_block_rsv block_rsv; 189 /* extra metadata reservation for relocation */ 190 int error; 191 /* Preallocated anonymous block device number */ 192 dev_t anon_dev; 193 bool readonly; 194 struct list_head list; 195 }; 196 197 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans, 198 struct btrfs_inode *inode) 199 { 200 spin_lock(&inode->lock); 201 inode->last_trans = trans->transaction->transid; 202 inode->last_sub_trans = btrfs_get_root_log_transid(inode->root); 203 inode->last_log_commit = inode->last_sub_trans - 1; 204 spin_unlock(&inode->lock); 205 } 206 207 /* 208 * Make qgroup codes to skip given qgroupid, means the old/new_roots for 209 * qgroup won't contain the qgroupid in it. 210 */ 211 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans, 212 u64 qgroupid) 213 { 214 struct btrfs_delayed_ref_root *delayed_refs; 215 216 delayed_refs = &trans->transaction->delayed_refs; 217 WARN_ON(delayed_refs->qgroup_to_skip); 218 delayed_refs->qgroup_to_skip = qgroupid; 219 } 220 221 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans) 222 { 223 struct btrfs_delayed_ref_root *delayed_refs; 224 225 delayed_refs = &trans->transaction->delayed_refs; 226 WARN_ON(!delayed_refs->qgroup_to_skip); 227 delayed_refs->qgroup_to_skip = 0; 228 } 229 230 bool __cold abort_should_print_stack(int error); 231 232 /* 233 * Call btrfs_abort_transaction as early as possible when an error condition is 234 * detected, that way the exact stack trace is reported for some errors. 235 */ 236 #define btrfs_abort_transaction(trans, error) \ 237 do { \ 238 bool __first = false; \ 239 /* Report first abort since mount */ \ 240 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \ 241 &((trans)->fs_info->fs_state))) { \ 242 __first = true; \ 243 if (WARN(abort_should_print_stack(error), \ 244 KERN_ERR \ 245 "BTRFS: Transaction aborted (error %d)\n", \ 246 (error))) { \ 247 /* Stack trace printed. */ \ 248 } else { \ 249 btrfs_err((trans)->fs_info, \ 250 "Transaction aborted (error %d)", \ 251 (error)); \ 252 } \ 253 } \ 254 __btrfs_abort_transaction((trans), __func__, \ 255 __LINE__, (error), __first); \ 256 } while (0) 257 258 int btrfs_end_transaction(struct btrfs_trans_handle *trans); 259 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 260 unsigned int num_items); 261 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv( 262 struct btrfs_root *root, 263 unsigned int num_items); 264 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root); 265 struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root); 266 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root); 267 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root); 268 struct btrfs_trans_handle *btrfs_attach_transaction_barrier( 269 struct btrfs_root *root); 270 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid); 271 272 void btrfs_add_dead_root(struct btrfs_root *root); 273 void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info); 274 int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info); 275 int btrfs_commit_transaction(struct btrfs_trans_handle *trans); 276 void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans); 277 int btrfs_commit_current_transaction(struct btrfs_root *root); 278 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans); 279 bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans); 280 void btrfs_throttle(struct btrfs_fs_info *fs_info); 281 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, 282 struct btrfs_root *root); 283 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info, 284 struct extent_io_tree *dirty_pages, int mark); 285 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark); 286 int btrfs_transaction_blocked(struct btrfs_fs_info *info); 287 void btrfs_put_transaction(struct btrfs_transaction *transaction); 288 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans, 289 struct btrfs_root *root); 290 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans); 291 void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 292 const char *function, 293 unsigned int line, int error, bool first_hit); 294 295 int __init btrfs_transaction_init(void); 296 void __cold btrfs_transaction_exit(void); 297 298 #endif 299