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 <linux/xarray.h> 16 #include "btrfs_inode.h" 17 #include "delayed-ref.h" 18 19 struct dentry; 20 struct inode; 21 struct btrfs_pending_snapshot; 22 struct btrfs_fs_info; 23 struct btrfs_root_item; 24 struct btrfs_root; 25 struct btrfs_path; 26 27 /* 28 * Signal that a direct IO write is in progress, to avoid deadlock for sync 29 * direct IO writes when fsync is called during the direct IO write path. 30 */ 31 #define BTRFS_TRANS_DIO_WRITE_STUB ((void *) 1) 32 33 /* Radix-tree tag for roots that are part of the transaction. */ 34 #define BTRFS_ROOT_TRANS_TAG 0 35 36 enum btrfs_trans_state { 37 TRANS_STATE_RUNNING, 38 TRANS_STATE_COMMIT_PREP, 39 TRANS_STATE_COMMIT_START, 40 TRANS_STATE_COMMIT_DOING, 41 TRANS_STATE_UNBLOCKED, 42 TRANS_STATE_SUPER_COMMITTED, 43 TRANS_STATE_COMPLETED, 44 TRANS_STATE_MAX, 45 }; 46 47 #define BTRFS_TRANS_HAVE_FREE_BGS 0 48 #define BTRFS_TRANS_DIRTY_BG_RUN 1 49 #define BTRFS_TRANS_CACHE_ENOSPC 2 50 51 struct btrfs_transaction { 52 u64 transid; 53 /* 54 * total external writers(USERSPACE/START/ATTACH) in this 55 * transaction, it must be zero before the transaction is 56 * being committed 57 */ 58 atomic_t num_extwriters; 59 /* 60 * total writers in this transaction, it must be zero before the 61 * transaction can end 62 */ 63 atomic_t num_writers; 64 refcount_t use_count; 65 66 unsigned long flags; 67 68 /* Be protected by fs_info->trans_lock when we want to change it. */ 69 enum btrfs_trans_state state; 70 int aborted; 71 struct list_head list; 72 struct extent_io_tree dirty_pages; 73 time64_t start_time; 74 wait_queue_head_t writer_wait; 75 wait_queue_head_t commit_wait; 76 struct list_head pending_snapshots; 77 struct list_head dev_update_list; 78 struct list_head switch_commits; 79 struct list_head dirty_bgs; 80 81 /* 82 * There is no explicit lock which protects io_bgs, rather its 83 * consistency is implied by the fact that all the sites which modify 84 * it do so under some form of transaction critical section, namely: 85 * 86 * - btrfs_start_dirty_block_groups - This function can only ever be 87 * run by one of the transaction committers. Refer to 88 * BTRFS_TRANS_DIRTY_BG_RUN usage in btrfs_commit_transaction 89 * 90 * - btrfs_write_dirty_blockgroups - this is called by 91 * commit_cowonly_roots from transaction critical section 92 * (TRANS_STATE_COMMIT_DOING) 93 * 94 * - btrfs_cleanup_dirty_bgs - called on transaction abort 95 */ 96 struct list_head io_bgs; 97 struct list_head dropped_roots; 98 struct extent_io_tree pinned_extents; 99 100 /* 101 * we need to make sure block group deletion doesn't race with 102 * free space cache writeout. This mutex keeps them from stomping 103 * on each other 104 */ 105 struct mutex cache_write_mutex; 106 spinlock_t dirty_bgs_lock; 107 /* Protected by spin lock fs_info->unused_bgs_lock. */ 108 struct list_head deleted_bgs; 109 spinlock_t dropped_roots_lock; 110 struct btrfs_delayed_ref_root delayed_refs; 111 struct btrfs_fs_info *fs_info; 112 113 /* 114 * Number of ordered extents the transaction must wait for before 115 * committing. These are ordered extents started by a fast fsync. 116 */ 117 atomic_t pending_ordered; 118 wait_queue_head_t pending_wait; 119 }; 120 121 enum { 122 ENUM_BIT(__TRANS_FREEZABLE), 123 ENUM_BIT(__TRANS_START), 124 ENUM_BIT(__TRANS_ATTACH), 125 ENUM_BIT(__TRANS_JOIN), 126 ENUM_BIT(__TRANS_JOIN_NOLOCK), 127 ENUM_BIT(__TRANS_DUMMY), 128 ENUM_BIT(__TRANS_JOIN_NOSTART), 129 }; 130 131 #define TRANS_START (__TRANS_START | __TRANS_FREEZABLE) 132 #define TRANS_ATTACH (__TRANS_ATTACH) 133 #define TRANS_JOIN (__TRANS_JOIN | __TRANS_FREEZABLE) 134 #define TRANS_JOIN_NOLOCK (__TRANS_JOIN_NOLOCK) 135 #define TRANS_JOIN_NOSTART (__TRANS_JOIN_NOSTART) 136 137 #define TRANS_EXTWRITERS (__TRANS_START | __TRANS_ATTACH) 138 139 struct btrfs_trans_handle { 140 u64 transid; 141 u64 bytes_reserved; 142 u64 delayed_refs_bytes_reserved; 143 u64 chunk_bytes_reserved; 144 unsigned long delayed_ref_updates; 145 unsigned long delayed_ref_csum_deletions; 146 struct btrfs_transaction *transaction; 147 struct btrfs_block_rsv *block_rsv; 148 struct btrfs_block_rsv *orig_rsv; 149 /* Set by a task that wants to create a snapshot. */ 150 struct btrfs_pending_snapshot *pending_snapshot; 151 refcount_t use_count; 152 unsigned int type; 153 /* 154 * Error code of transaction abort, set outside of locks and must use 155 * the READ_ONCE/WRITE_ONCE access 156 */ 157 short aborted; 158 bool adding_csums; 159 bool allocating_chunk; 160 bool removing_chunk; 161 bool reloc_reserved; 162 bool in_fsync; 163 struct btrfs_fs_info *fs_info; 164 struct list_head new_bgs; 165 struct btrfs_block_rsv delayed_rsv; 166 /* Extent buffers with writeback inhibited by this handle. */ 167 struct xarray writeback_inhibited_ebs; 168 }; 169 170 /* 171 * The abort status can be changed between calls and is not protected by locks. 172 * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's 173 * set to a non-zero value it does not change, so the macro should be in checks 174 * but is not necessary for further reads of the value. 175 */ 176 #define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted))) 177 178 struct btrfs_pending_snapshot { 179 struct dentry *dentry; 180 struct btrfs_inode *dir; 181 struct btrfs_root *root; 182 struct btrfs_root_item *root_item; 183 struct btrfs_root *snap; 184 struct btrfs_qgroup_inherit *inherit; 185 struct btrfs_path *path; 186 /* block reservation for the operation */ 187 struct btrfs_block_rsv block_rsv; 188 /* extra metadata reservation for relocation */ 189 int error; 190 /* Preallocated anonymous block device number */ 191 dev_t anon_dev; 192 bool readonly; 193 struct list_head list; 194 }; 195 196 static inline void btrfs_set_inode_last_trans(struct btrfs_trans_handle *trans, 197 struct btrfs_inode *inode) 198 { 199 spin_lock(&inode->lock); 200 inode->last_trans = trans->transaction->transid; 201 inode->last_sub_trans = btrfs_get_root_log_transid(inode->root); 202 inode->last_log_commit = inode->last_sub_trans - 1; 203 spin_unlock(&inode->lock); 204 } 205 206 /* 207 * Make qgroup codes to skip given qgroupid, means the old/new_roots for 208 * qgroup won't contain the qgroupid in it. 209 */ 210 static inline void btrfs_set_skip_qgroup(struct btrfs_trans_handle *trans, 211 u64 qgroupid) 212 { 213 struct btrfs_delayed_ref_root *delayed_refs; 214 215 delayed_refs = &trans->transaction->delayed_refs; 216 WARN_ON(delayed_refs->qgroup_to_skip); 217 delayed_refs->qgroup_to_skip = qgroupid; 218 } 219 220 static inline void btrfs_clear_skip_qgroup(struct btrfs_trans_handle *trans) 221 { 222 struct btrfs_delayed_ref_root *delayed_refs; 223 224 delayed_refs = &trans->transaction->delayed_refs; 225 WARN_ON(!delayed_refs->qgroup_to_skip); 226 delayed_refs->qgroup_to_skip = 0; 227 } 228 229 /* 230 * We want the transaction abort to print stack trace only for errors where the 231 * cause could be a bug, eg. due to ENOSPC, and not for common errors that are 232 * caused by external factors. 233 */ 234 static inline bool btrfs_abort_should_print_stack(int error) 235 { 236 switch (error) { 237 case -EIO: 238 case -EROFS: 239 case -ENOMEM: 240 return false; 241 } 242 return true; 243 } 244 245 /* 246 * Call btrfs_abort_transaction as early as possible when an error condition is 247 * detected, that way the exact stack trace is reported for some errors. 248 */ 249 #define btrfs_abort_transaction(trans, error) \ 250 do { \ 251 bool __first = false; \ 252 /* Report first abort since mount */ \ 253 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \ 254 &((trans)->fs_info->fs_state))) { \ 255 __first = true; \ 256 if (WARN(btrfs_abort_should_print_stack(error), \ 257 KERN_ERR \ 258 "BTRFS: Transaction aborted (error %d)\n", \ 259 (error))) { \ 260 /* Stack trace printed. */ \ 261 } else { \ 262 btrfs_err((trans)->fs_info, \ 263 "Transaction aborted (error %d)", \ 264 (error)); \ 265 } \ 266 } \ 267 __btrfs_abort_transaction((trans), __func__, \ 268 __LINE__, (error), __first); \ 269 } while (0) 270 271 int btrfs_end_transaction(struct btrfs_trans_handle *trans); 272 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, 273 unsigned int num_items); 274 struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv( 275 struct btrfs_root *root, 276 unsigned int num_items); 277 struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root); 278 struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root); 279 struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root); 280 struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root); 281 struct btrfs_trans_handle *btrfs_attach_transaction_barrier( 282 struct btrfs_root *root); 283 int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid); 284 285 void btrfs_add_dead_root(struct btrfs_root *root); 286 void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info); 287 int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info); 288 int btrfs_commit_transaction(struct btrfs_trans_handle *trans); 289 void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans); 290 int btrfs_commit_current_transaction(struct btrfs_root *root); 291 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans); 292 bool btrfs_should_end_transaction(struct btrfs_trans_handle *trans); 293 void btrfs_throttle(struct btrfs_fs_info *fs_info); 294 int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, 295 struct btrfs_root *root); 296 int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info, 297 struct extent_io_tree *dirty_pages, int mark); 298 int btrfs_wait_tree_log_extents(struct btrfs_root *root, int mark); 299 int btrfs_transaction_blocked(struct btrfs_fs_info *info); 300 void btrfs_put_transaction(struct btrfs_transaction *transaction); 301 void btrfs_add_dropped_root(struct btrfs_trans_handle *trans, 302 struct btrfs_root *root); 303 void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans); 304 void __cold __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 305 const char *function, 306 unsigned int line, int error, bool first_hit); 307 308 int __init btrfs_transaction_init(void); 309 void __cold btrfs_transaction_exit(void); 310 311 #endif 312