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