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