root/fs/ext4/ext4_jbd2.h

INCLUDED FROM

DEFINITIONS

1. _ext4_journal_callback_add
2. ext4_journal_callback_add
3. ext4_journal_callback_try_del
4. ext4_handle_valid
5. ext4_handle_sync
6. ext4_handle_is_aborted
7. ext4_handle_has_enough_credits
8. __ext4_journal_start
9. ext4_journal_free_reserved
10. ext4_journal_current_handle
11. ext4_journal_extend
12. ext4_journal_restart
13. ext4_journal_blocks_per_page
14. ext4_journal_force_commit
15. ext4_jbd2_inode_add_write
16. ext4_jbd2_inode_add_wait
17. ext4_update_inode_fsync_trans
18. ext4_inode_journal_mode
19. ext4_should_journal_data
20. ext4_should_order_data
21. ext4_should_writeback_data
22. ext4_should_dioread_nolock

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * ext4_jbd2.h
   4  *
   5  * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
   6  *
   7  * Copyright 1998--1999 Red Hat corp --- All Rights Reserved
   8  *
   9  * Ext4-specific journaling extensions.
  10  */
  11 
  12 #ifndef _EXT4_JBD2_H
  13 #define _EXT4_JBD2_H
  14 
  15 #include <linux/fs.h>
  16 #include <linux/jbd2.h>
  17 #include "ext4.h"
  18 
  19 #define EXT4_JOURNAL(inode)     (EXT4_SB((inode)->i_sb)->s_journal)
  20 
  21 /* Define the number of blocks we need to account to a transaction to
  22  * modify one block of data.
  23  *
  24  * We may have to touch one inode, one bitmap buffer, up to three
  25  * indirection blocks, the group and superblock summaries, and the data
  26  * block to complete the transaction.
  27  *
  28  * For extents-enabled fs we may have to allocate and modify up to
  29  * 5 levels of tree, data block (for each of these we need bitmap + group
  30  * summaries), root which is stored in the inode, sb
  31  */
  32 
  33 #define EXT4_SINGLEDATA_TRANS_BLOCKS(sb)                                \
  34         (ext4_has_feature_extents(sb) ? 20U : 8U)
  35 
  36 /* Extended attribute operations touch at most two data buffers,
  37  * two bitmap buffers, and two group summaries, in addition to the inode
  38  * and the superblock, which are already accounted for. */
  39 
  40 #define EXT4_XATTR_TRANS_BLOCKS         6U
  41 
  42 /* Define the minimum size for a transaction which modifies data.  This
  43  * needs to take into account the fact that we may end up modifying two
  44  * quota files too (one for the group, one for the user quota).  The
  45  * superblock only gets updated once, of course, so don't bother
  46  * counting that again for the quota updates. */
  47 
  48 #define EXT4_DATA_TRANS_BLOCKS(sb)      (EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \
  49                                          EXT4_XATTR_TRANS_BLOCKS - 2 + \
  50                                          EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
  51 
  52 /*
  53  * Define the number of metadata blocks we need to account to modify data.
  54  *
  55  * This include super block, inode block, quota blocks and xattr blocks
  56  */
  57 #define EXT4_META_TRANS_BLOCKS(sb)      (EXT4_XATTR_TRANS_BLOCKS + \
  58                                         EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
  59 
  60 /* Define an arbitrary limit for the amount of data we will anticipate
  61  * writing to any given transaction.  For unbounded transactions such as
  62  * write(2) and truncate(2) we can write more than this, but we always
  63  * start off at the maximum transaction size and grow the transaction
  64  * optimistically as we go. */
  65 
  66 #define EXT4_MAX_TRANS_DATA             64U
  67 
  68 /* We break up a large truncate or write transaction once the handle's
  69  * buffer credits gets this low, we need either to extend the
  70  * transaction or to start a new one.  Reserve enough space here for
  71  * inode, bitmap, superblock, group and indirection updates for at least
  72  * one block, plus two quota updates.  Quota allocations are not
  73  * needed. */
  74 
  75 #define EXT4_RESERVE_TRANS_BLOCKS       12U
  76 
  77 /*
  78  * Number of credits needed if we need to insert an entry into a
  79  * directory.  For each new index block, we need 4 blocks (old index
  80  * block, new index block, bitmap block, bg summary).  For normal
  81  * htree directories there are 2 levels; if the largedir feature
  82  * enabled it's 3 levels.
  83  */
  84 #define EXT4_INDEX_EXTRA_TRANS_BLOCKS   12U
  85 
  86 #ifdef CONFIG_QUOTA
  87 /* Amount of blocks needed for quota update - we know that the structure was
  88  * allocated so we need to update only data block */
  89 #define EXT4_QUOTA_TRANS_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
  90                 ext4_has_feature_quota(sb)) ? 1 : 0)
  91 /* Amount of blocks needed for quota insert/delete - we do some block writes
  92  * but inode, sb and group updates are done only once */
  93 #define EXT4_QUOTA_INIT_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
  94                 ext4_has_feature_quota(sb)) ?\
  95                 (DQUOT_INIT_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
  96                  +3+DQUOT_INIT_REWRITE) : 0)
  97 
  98 #define EXT4_QUOTA_DEL_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
  99                 ext4_has_feature_quota(sb)) ?\
 100                 (DQUOT_DEL_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
 101                  +3+DQUOT_DEL_REWRITE) : 0)
 102 #else
 103 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
 104 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0
 105 #define EXT4_QUOTA_DEL_BLOCKS(sb) 0
 106 #endif
 107 #define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb))
 108 #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
 109 #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
 110 
 111 /*
 112  * Ext4 handle operation types -- for logging purposes
 113  */
 114 #define EXT4_HT_MISC             0
 115 #define EXT4_HT_INODE            1
 116 #define EXT4_HT_WRITE_PAGE       2
 117 #define EXT4_HT_MAP_BLOCKS       3
 118 #define EXT4_HT_DIR              4
 119 #define EXT4_HT_TRUNCATE         5
 120 #define EXT4_HT_QUOTA            6
 121 #define EXT4_HT_RESIZE           7
 122 #define EXT4_HT_MIGRATE          8
 123 #define EXT4_HT_MOVE_EXTENTS     9
 124 #define EXT4_HT_XATTR           10
 125 #define EXT4_HT_EXT_CONVERT     11
 126 #define EXT4_HT_MAX             12
 127 
 128 /**
 129  *   struct ext4_journal_cb_entry - Base structure for callback information.
 130  *
 131  *   This struct is a 'seed' structure for a using with your own callback
 132  *   structs. If you are using callbacks you must allocate one of these
 133  *   or another struct of your own definition which has this struct
 134  *   as it's first element and pass it to ext4_journal_callback_add().
 135  */
 136 struct ext4_journal_cb_entry {
 137         /* list information for other callbacks attached to the same handle */
 138         struct list_head jce_list;
 139 
 140         /*  Function to call with this callback structure */
 141         void (*jce_func)(struct super_block *sb,
 142                          struct ext4_journal_cb_entry *jce, int error);
 143 
 144         /* user data goes here */
 145 };
 146 
 147 /**
 148  * ext4_journal_callback_add: add a function to call after transaction commit
 149  * @handle: active journal transaction handle to register callback on
 150  * @func: callback function to call after the transaction has committed:
 151  *        @sb: superblock of current filesystem for transaction
 152  *        @jce: returned journal callback data
 153  *        @rc: journal state at commit (0 = transaction committed properly)
 154  * @jce: journal callback data (internal and function private data struct)
 155  *
 156  * The registered function will be called in the context of the journal thread
 157  * after the transaction for which the handle was created has completed.
 158  *
 159  * No locks are held when the callback function is called, so it is safe to
 160  * call blocking functions from within the callback, but the callback should
 161  * not block or run for too long, or the filesystem will be blocked waiting for
 162  * the next transaction to commit. No journaling functions can be used, or
 163  * there is a risk of deadlock.
 164  *
 165  * There is no guaranteed calling order of multiple registered callbacks on
 166  * the same transaction.
 167  */
 168 static inline void _ext4_journal_callback_add(handle_t *handle,
 169                         struct ext4_journal_cb_entry *jce)
 170 {
 171         /* Add the jce to transaction's private list */
 172         list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list);
 173 }
 174 
 175 static inline void ext4_journal_callback_add(handle_t *handle,
 176                         void (*func)(struct super_block *sb,
 177                                      struct ext4_journal_cb_entry *jce,
 178                                      int rc),
 179                         struct ext4_journal_cb_entry *jce)
 180 {
 181         struct ext4_sb_info *sbi =
 182                         EXT4_SB(handle->h_transaction->t_journal->j_private);
 183 
 184         /* Add the jce to transaction's private list */
 185         jce->jce_func = func;
 186         spin_lock(&sbi->s_md_lock);
 187         _ext4_journal_callback_add(handle, jce);
 188         spin_unlock(&sbi->s_md_lock);
 189 }
 190 
 191 
 192 /**
 193  * ext4_journal_callback_del: delete a registered callback
 194  * @handle: active journal transaction handle on which callback was registered
 195  * @jce: registered journal callback entry to unregister
 196  * Return true if object was successfully removed
 197  */
 198 static inline bool ext4_journal_callback_try_del(handle_t *handle,
 199                                              struct ext4_journal_cb_entry *jce)
 200 {
 201         bool deleted;
 202         struct ext4_sb_info *sbi =
 203                         EXT4_SB(handle->h_transaction->t_journal->j_private);
 204 
 205         spin_lock(&sbi->s_md_lock);
 206         deleted = !list_empty(&jce->jce_list);
 207         list_del_init(&jce->jce_list);
 208         spin_unlock(&sbi->s_md_lock);
 209         return deleted;
 210 }
 211 
 212 int
 213 ext4_mark_iloc_dirty(handle_t *handle,
 214                      struct inode *inode,
 215                      struct ext4_iloc *iloc);
 216 
 217 /*
 218  * On success, We end up with an outstanding reference count against
 219  * iloc->bh.  This _must_ be cleaned up later.
 220  */
 221 
 222 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 223                         struct ext4_iloc *iloc);
 224 
 225 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
 226 
 227 int ext4_expand_extra_isize(struct inode *inode,
 228                             unsigned int new_extra_isize,
 229                             struct ext4_iloc *iloc);
 230 /*
 231  * Wrapper functions with which ext4 calls into JBD.
 232  */
 233 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 234                                     handle_t *handle, struct buffer_head *bh);
 235 
 236 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 237                   int is_metadata, struct inode *inode,
 238                   struct buffer_head *bh, ext4_fsblk_t blocknr);
 239 
 240 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 241                                 handle_t *handle, struct buffer_head *bh);
 242 
 243 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 244                                  handle_t *handle, struct inode *inode,
 245                                  struct buffer_head *bh);
 246 
 247 int __ext4_handle_dirty_super(const char *where, unsigned int line,
 248                               handle_t *handle, struct super_block *sb);
 249 
 250 #define ext4_journal_get_write_access(handle, bh) \
 251         __ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
 252 #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
 253         __ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \
 254                       (bh), (block_nr))
 255 #define ext4_journal_get_create_access(handle, bh) \
 256         __ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh))
 257 #define ext4_handle_dirty_metadata(handle, inode, bh) \
 258         __ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
 259                                      (bh))
 260 #define ext4_handle_dirty_super(handle, sb) \
 261         __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb))
 262 
 263 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
 264                                   int type, int blocks, int rsv_blocks);
 265 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
 266 
 267 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
 268 
 269 /* Note:  Do not use this for NULL handles.  This is only to determine if
 270  * a properly allocated handle is using a journal or not. */
 271 static inline int ext4_handle_valid(handle_t *handle)
 272 {
 273         if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
 274                 return 0;
 275         return 1;
 276 }
 277 
 278 static inline void ext4_handle_sync(handle_t *handle)
 279 {
 280         if (ext4_handle_valid(handle))
 281                 handle->h_sync = 1;
 282 }
 283 
 284 static inline int ext4_handle_is_aborted(handle_t *handle)
 285 {
 286         if (ext4_handle_valid(handle))
 287                 return is_handle_aborted(handle);
 288         return 0;
 289 }
 290 
 291 static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
 292 {
 293         if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
 294                 return 0;
 295         return 1;
 296 }
 297 
 298 #define ext4_journal_start_sb(sb, type, nblocks)                        \
 299         __ext4_journal_start_sb((sb), __LINE__, (type), (nblocks), 0)
 300 
 301 #define ext4_journal_start(inode, type, nblocks)                        \
 302         __ext4_journal_start((inode), __LINE__, (type), (nblocks), 0)
 303 
 304 #define ext4_journal_start_with_reserve(inode, type, blocks, rsv_blocks) \
 305         __ext4_journal_start((inode), __LINE__, (type), (blocks), (rsv_blocks))
 306 
 307 static inline handle_t *__ext4_journal_start(struct inode *inode,
 308                                              unsigned int line, int type,
 309                                              int blocks, int rsv_blocks)
 310 {
 311         return __ext4_journal_start_sb(inode->i_sb, line, type, blocks,
 312                                        rsv_blocks);
 313 }
 314 
 315 #define ext4_journal_stop(handle) \
 316         __ext4_journal_stop(__func__, __LINE__, (handle))
 317 
 318 #define ext4_journal_start_reserved(handle, type) \
 319         __ext4_journal_start_reserved((handle), __LINE__, (type))
 320 
 321 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 322                                         int type);
 323 
 324 static inline void ext4_journal_free_reserved(handle_t *handle)
 325 {
 326         if (ext4_handle_valid(handle))
 327                 jbd2_journal_free_reserved(handle);
 328 }
 329 
 330 static inline handle_t *ext4_journal_current_handle(void)
 331 {
 332         return journal_current_handle();
 333 }
 334 
 335 static inline int ext4_journal_extend(handle_t *handle, int nblocks)
 336 {
 337         if (ext4_handle_valid(handle))
 338                 return jbd2_journal_extend(handle, nblocks);
 339         return 0;
 340 }
 341 
 342 static inline int ext4_journal_restart(handle_t *handle, int nblocks)
 343 {
 344         if (ext4_handle_valid(handle))
 345                 return jbd2_journal_restart(handle, nblocks);
 346         return 0;
 347 }
 348 
 349 static inline int ext4_journal_blocks_per_page(struct inode *inode)
 350 {
 351         if (EXT4_JOURNAL(inode) != NULL)
 352                 return jbd2_journal_blocks_per_page(inode);
 353         return 0;
 354 }
 355 
 356 static inline int ext4_journal_force_commit(journal_t *journal)
 357 {
 358         if (journal)
 359                 return jbd2_journal_force_commit(journal);
 360         return 0;
 361 }
 362 
 363 static inline int ext4_jbd2_inode_add_write(handle_t *handle,
 364                 struct inode *inode, loff_t start_byte, loff_t length)
 365 {
 366         if (ext4_handle_valid(handle))
 367                 return jbd2_journal_inode_ranged_write(handle,
 368                                 EXT4_I(inode)->jinode, start_byte, length);
 369         return 0;
 370 }
 371 
 372 static inline int ext4_jbd2_inode_add_wait(handle_t *handle,
 373                 struct inode *inode, loff_t start_byte, loff_t length)
 374 {
 375         if (ext4_handle_valid(handle))
 376                 return jbd2_journal_inode_ranged_wait(handle,
 377                                 EXT4_I(inode)->jinode, start_byte, length);
 378         return 0;
 379 }
 380 
 381 static inline void ext4_update_inode_fsync_trans(handle_t *handle,
 382                                                  struct inode *inode,
 383                                                  int datasync)
 384 {
 385         struct ext4_inode_info *ei = EXT4_I(inode);
 386 
 387         if (ext4_handle_valid(handle) && !is_handle_aborted(handle)) {
 388                 ei->i_sync_tid = handle->h_transaction->t_tid;
 389                 if (datasync)
 390                         ei->i_datasync_tid = handle->h_transaction->t_tid;
 391         }
 392 }
 393 
 394 /* super.c */
 395 int ext4_force_commit(struct super_block *sb);
 396 
 397 /*
 398  * Ext4 inode journal modes
 399  */
 400 #define EXT4_INODE_JOURNAL_DATA_MODE    0x01 /* journal data mode */
 401 #define EXT4_INODE_ORDERED_DATA_MODE    0x02 /* ordered data mode */
 402 #define EXT4_INODE_WRITEBACK_DATA_MODE  0x04 /* writeback data mode */
 403 
 404 static inline int ext4_inode_journal_mode(struct inode *inode)
 405 {
 406         if (EXT4_JOURNAL(inode) == NULL)
 407                 return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
 408         /* We do not support data journalling with delayed allocation */
 409         if (!S_ISREG(inode->i_mode) ||
 410             test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
 411             (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
 412             !test_opt(inode->i_sb, DELALLOC))) {
 413                 /* We do not support data journalling for encrypted data */
 414                 if (S_ISREG(inode->i_mode) && IS_ENCRYPTED(inode))
 415                         return EXT4_INODE_ORDERED_DATA_MODE;  /* ordered */
 416                 return EXT4_INODE_JOURNAL_DATA_MODE;    /* journal data */
 417         }
 418         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 419                 return EXT4_INODE_ORDERED_DATA_MODE;    /* ordered */
 420         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 421                 return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
 422         BUG();
 423 }
 424 
 425 static inline int ext4_should_journal_data(struct inode *inode)
 426 {
 427         return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
 428 }
 429 
 430 static inline int ext4_should_order_data(struct inode *inode)
 431 {
 432         return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
 433 }
 434 
 435 static inline int ext4_should_writeback_data(struct inode *inode)
 436 {
 437         return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE;
 438 }
 439 
 440 /*
 441  * This function controls whether or not we should try to go down the
 442  * dioread_nolock code paths, which makes it safe to avoid taking
 443  * i_mutex for direct I/O reads.  This only works for extent-based
 444  * files, and it doesn't work if data journaling is enabled, since the
 445  * dioread_nolock code uses b_private to pass information back to the
 446  * I/O completion handler, and this conflicts with the jbd's use of
 447  * b_private.
 448  */
 449 static inline int ext4_should_dioread_nolock(struct inode *inode)
 450 {
 451         if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
 452                 return 0;
 453         if (!S_ISREG(inode->i_mode))
 454                 return 0;
 455         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
 456                 return 0;
 457         if (ext4_should_journal_data(inode))
 458                 return 0;
 459         return 1;
 460 }
 461 
 462 #endif  /* _EXT4_JBD2_H */