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 18 struct dentry; 19 struct inode; 20 struct btrfs_pending_snapshot; 21 struct btrfs_fs_info; 22 struct btrfs_root_item; 23 struct btrfs_root; 24 struct btrfs_path; 25 26 /* 27 * Signal that a direct IO write is in progress, to avoid deadlock for sync 28 * direct IO writes when fsync is called during the direct IO write path. 29 */ 30 #define BTRFS_TRANS_DIO_WRITE_STUB ((void *) 1) 31 32 /* Radix-tree tag for roots that are part of the transaction. */ 33 #define BTRFS_ROOT_TRANS_TAG 0 34 35 enum btrfs_trans_state { 36 TRANS_STATE_RUNNING, 37 TRANS_STATE_COMMIT_PREP, 38 TRANS_STATE_COMMIT_START, 39 TRANS_STATE_COMMIT_DOING, 40 TRANS_STATE_UNBLOCKED, 41 TRANS_STATE_SUPER_COMMITTED, 42 TRANS_STATE_COMPLETED, 43 TRANS_STATE_MAX, 44 }; 45 46 #define BTRFS_TRANS_HAVE_FREE_BGS 0 47 #define BTRFS_TRANS_DIRTY_BG_RUN 1 48 #define BTRFS_TRANS_CACHE_ENOSPC 2 49 50 struct btrfs_transaction { 51 u64 transid; 52 /* 53 * total external writers(USERSPACE/START/ATTACH) in this 54 * transaction, it must be zero before the transaction is 55 * being committed 56 */ 57 atomic_t num_extwriters; 58 /* 59 * total writers in this transaction, it must be zero before the 60 * transaction can end 61 */ 62 atomic_t num_writers; 63 refcount_t use_count; 64 65 unsigned long flags; 66 67 /* Be protected by fs_info->trans_lock when we want to change it. */ 68 enum btrfs_trans_state state; 69 int aborted; 70 struct list_head list; 71 struct extent_io_tree dirty_pages; 72 time64_t start_time; 73 wait_queue_head_t writer_wait; 74 wait_queue_head_t commit_wait; 75 struct list_head pending_snapshots; 76 struct list_head dev_update_list; 77 struct list_head switch_commits; 78 struct list_head dirty_bgs; 79 80 /* 81 * There is no explicit lock which protects io_bgs, rather its 82 * consistency is implied by the fact that all the sites which modify 83 * it do so under some form of transaction critical section, namely: 84 * 85 * - btrfs_start_dirty_block_groups - This function can only ever be 86 * run by one of the transaction committers. Refer to 87 * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction 88 * 89 * - btrfs_write_dirty_blockgroups - this is called by 90 * commit_cowonly_roots from transaction critical section 91 * (TRANS_STATE_COMMIT_DOING) 92 * 93 * - btrfs_cleanup_dirty_bgs - called on transaction abort 94 */ 95 struct list_head io_bgs; 96 struct list_head dropped_roots; 97 struct extent_io_tree pinned_extents; 98 99 /* 100 * we need to make sure block group deletion doesn't race with 101 * free space cache writeout. This mutex keeps them from stomping 102 * on each other 103 */ 104 struct mutex cache_write_mutex; 105 spinlock_t dirty_bgs_lock; 106 /* Protected by spin lock fs_info->unused_bgs_lock. */ 107 struct list_head deleted_bgs; 108 spinlock_t dropped_roots_lock; 109 struct btrfs_delayed_ref_root delayed_refs; 110 struct btrfs_fs_info *fs_info; 111 112 /* 113 * Number of ordered extents the transaction must wait for before 114 * committing. These are ordered extents started by a fast fsync. 115 */ 116 atomic_t pending_ordered; 117 wait_queue_head_t pending_wait; 118 }; 119 120 enum { 121 ENUM_BIT(__TRANS_FREEZABLE), 122 ENUM_BIT(__TRANS_START), 123 ENUM_BIT(__TRANS_ATTACH), 124 ENUM_BIT(__TRANS_JOIN), 125 ENUM_BIT(__TRANS_JOIN_NOLOCK), 126 ENUM_BIT(__TRANS_DUMMY), 127 ENUM_BIT(__TRANS_JOIN_NOSTART), 128 }; 129 130 #define TRANS_START (__TRANS_START | __TRANS_FREEZABLE) 131 #define TRANS_ATTACH (__TRANS_ATTACH) 132 #define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE) 133 #define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK) 134 #define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART) 135 136 #define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH) 137 138 struct btrfs_trans_handle { 139 u64 transid; 140 u64 bytes_reserved; 141 u64 delayed_refs_bytes_reserved; 142 u64 chunk_bytes_reserved; 143 unsigned long delayed_ref_updates; 144 unsigned long delayed_ref_csum_deletions; 145 struct btrfs_transaction *transaction; 146 struct btrfs_block_rsv *block_rsv; 147 struct btrfs_block_rsv *orig_rsv; 148 /* Set by a task that wants to create a snapshot. */ 149 struct btrfs_pending_snapshot *pending_snapshot; 150 refcount_t use_count; 151 unsigned int type; 152 /* 153 * Error code of transaction abort, set outside of locks and must use 154 * the READ_ONCE/WRITE_ONCE access 155 */ 156 short aborted; 157 bool adding_csums; 158 bool allocating_chunk; 159 bool removing_chunk; 160 bool reloc_reserved; 161 bool in_fsync; 162 struct btrfs_fs_info *fs_info; 163 struct list_head new_bgs; 164 struct btrfs_block_rsv delayed_rsv; 165 }; 166 167 /* 168 * The abort status can be changed between calls and is not protected by locks. 169 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's 170 * set to a non-zero value it does not change, so the macro should be in checks 171 * but is not necessary for further reads of the value. 172 */ 173 #define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted))) 174 175 struct btrfs_pending_snapshot { 176 struct dentry *dentry; 177 struct btrfs_inode *dir; 178 struct btrfs_root *root; 179 struct btrfs_root_item *root_item; 180 struct btrfs_root *snap; 181 struct btrfs_qgroup_inherit *inherit; 182 struct btrfs_path *path; 183 /* block reservation for the operation */ 184 struct btrfs_block_rsv block_rsv; 185 /* extra metadata reservation for relocation */ 186 int error; 187 /* Preallocated anonymous block device number */ 188 dev_t anon_dev; 189 bool readonly; 190 struct list_head list; 191 }; 192 193 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans, 194 struct btrfs_inode *inode) 195 { 196 spin_lock(&inode->lock); 197 inode->last_trans = trans->transaction->transid; 198 inode->last_sub_trans = btrfs_get_root_log_transid(inode->root); 199 inode->last_log_commit = inode->last_sub_trans - 1; 200 spin_unlock(&inode->lock); 201 } 202 203 /* 204 * Make qgroup codes to skip given qgroupid, means the old/new_roots for 205 * qgroup won't contain the qgroupid in it. 206 */ 207 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans, 208 u64 qgroupid) 209 { 210 struct btrfs_delayed_ref_root *delayed_refs; 211 212 delayed_refs = &trans->transaction->delayed_refs; 213 WARN_ON(delayed_refs->qgroup_to_skip); 214 delayed_refs->qgroup_to_skip = qgroupid; 215 } 216 217 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans) 218 { 219 struct btrfs_delayed_ref_root *delayed_refs; 220 221 delayed_refs = &trans->transaction->delayed_refs; 222 WARN_ON(!delayed_refs->qgroup_to_skip); 223 delayed_refs->qgroup_to_skip = 0; 224 } 225 226 /* 227 * We want the transaction abort to print stack trace only for errors where the 228 * cause could be a bug, eg. due to ENOSPC, and not for common errors that are 229 * caused by external factors. 230 */ 231 static inline bool btrfs_abort_should_print_stack(int error) 232 { 233 switch (error) { 234 case -EIO: 235 case -EROFS: 236 case -ENOMEM: 237 return false; 238 } 239 return true; 240 } 241 242 /* 243 * Call btrfs_abort_transaction as early as possible when an error condition is 244 * detected, that way the exact stack trace is reported for some errors. 245 */ 246 #define btrfs_abort_transaction(trans, error) \ 247 do { \ 248 bool __first = false; \ 249 /* Report first abort since mount */ \ 250 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \ 251 &((trans)->fs_info->fs_state))) { \ 252 __first = true; \ 253 if (WARN(btrfs_abort_should_print_stack(error), \ 254 KERN_ERR \ 255 "BTRFS: Transaction aborted (error %d)\n", \ 256 (error))) { \ 257 /* Stack trace printed. */ \ 258 } else { \ 259 btrfs_err((trans)->fs_info, \ 260 "Transaction aborted (error %d)", \ 261 (error)); \ 262 } \ 263 } \ 264 __btrfs_abort_transaction((trans), __func__, \ 265 __LINE__, (error), __first); \ 266 } while (0) 267 268 int btrfs_end_transaction(struct btrfs_trans_handle *trans); 269 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 270 unsigned int num_items); 271 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv( 272 struct btrfs_root *root, 273 unsigned int num_items); 274 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root); 275 struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root); 276 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root); 277 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root); 278 struct btrfs_trans_handle *btrfs_attach_transaction_barrier( 279 struct btrfs_root *root); 280 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid); 281 282 void btrfs_add_dead_root(struct btrfs_root *root); 283 void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info); 284 int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info); 285 int btrfs_commit_transaction(struct btrfs_trans_handle *trans); 286 void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans); 287 int btrfs_commit_current_transaction(struct btrfs_root *root); 288 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans); 289 bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans); 290 void btrfs_throttle(struct btrfs_fs_info *fs_info); 291 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, 292 struct btrfs_root *root); 293 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info, 294 struct extent_io_tree *dirty_pages, int mark); 295 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark); 296 int btrfs_transaction_blocked(struct btrfs_fs_info *info); 297 void btrfs_put_transaction(struct btrfs_transaction *transaction); 298 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans, 299 struct btrfs_root *root); 300 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans); 301 void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 302 const char *function, 303 unsigned int line, int error, bool first_hit); 304 305 int __init btrfs_transaction_init(void); 306 void __cold btrfs_transaction_exit(void); 307 308 #endif 309