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