fs/ext4/ext4_jbd2.h

   1 /*
   2  * ext4_jbd2.h
   3  *
   4  * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
   5  *
   6  * Copyright 1998--1999 Red Hat corp --- All Rights Reserved
   7  *
   8  * This file is part of the Linux kernel and is made available under
   9  * the terms of the GNU General Public License, version 2, or at your
  10  * option, any later version, incorporated herein by reference.
  11  *
  12  * Ext4-specific journaling extensions.
  13  */
  14
  15 #ifndef _EXT4_JBD2_H
  16 #define _EXT4_JBD2_H
  17
  18 #include <linux/fs.h>
  19 #include <linux/jbd2.h>
  20 #include "ext4.h"
  21
  22 #define EXT4_JOURNAL(inode)     (EXT4_SB((inode)->i_sb)->s_journal)
  23
  24 /* Define the number of blocks we need to account to a transaction to
  25  * modify one block of data.
  26  *
  27  * We may have to touch one inode, one bitmap buffer, up to three
  28  * indirection blocks, the group and superblock summaries, and the data
  29  * block to complete the transaction.
  30  *
  31  * For extents-enabled fs we may have to allocate and modify up to
  32  * 5 levels of tree, data block (for each of these we need bitmap + group
  33  * summaries), root which is stored in the inode, sb
  34  */
  35
  36 #define EXT4_SINGLEDATA_TRANS_BLOCKS(sb)                                \
  37         (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)   \
  38          ? 20U : 8U)
  39
  40 /* Extended attribute operations touch at most two data buffers,
  41  * two bitmap buffers, and two group summaries, in addition to the inode
  42  * and the superblock, which are already accounted for. */
  43
  44 #define EXT4_XATTR_TRANS_BLOCKS         6U
  45
  46 /* Define the minimum size for a transaction which modifies data.  This
  47  * needs to take into account the fact that we may end up modifying two
  48  * quota files too (one for the group, one for the user quota).  The
  49  * superblock only gets updated once, of course, so don't bother
  50  * counting that again for the quota updates. */
  51
  52 #define EXT4_DATA_TRANS_BLOCKS(sb)      (EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \
  53                                          EXT4_XATTR_TRANS_BLOCKS - 2 + \
  54                                          EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
  55
  56 /*
  57  * Define the number of metadata blocks we need to account to modify data.
  58  *
  59  * This include super block, inode block, quota blocks and xattr blocks
  60  */
  61 #define EXT4_META_TRANS_BLOCKS(sb)      (EXT4_XATTR_TRANS_BLOCKS + \
  62                                         EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
  63
  64 /* Define an arbitrary limit for the amount of data we will anticipate
  65  * writing to any given transaction.  For unbounded transactions such as
  66  * write(2) and truncate(2) we can write more than this, but we always
  67  * start off at the maximum transaction size and grow the transaction
  68  * optimistically as we go. */
  69
  70 #define EXT4_MAX_TRANS_DATA             64U
  71
  72 /* We break up a large truncate or write transaction once the handle's
  73  * buffer credits gets this low, we need either to extend the
  74  * transaction or to start a new one.  Reserve enough space here for
  75  * inode, bitmap, superblock, group and indirection updates for at least
  76  * one block, plus two quota updates.  Quota allocations are not
  77  * needed. */
  78
  79 #define EXT4_RESERVE_TRANS_BLOCKS       12U
  80
  81 #define EXT4_INDEX_EXTRA_TRANS_BLOCKS   8
  82
  83 #ifdef CONFIG_QUOTA
  84 /* Amount of blocks needed for quota update - we know that the structure was
  85  * allocated so we need to update only data block */
  86 #define EXT4_QUOTA_TRANS_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
  87                 EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
  88                 1 : 0)
  89 /* Amount of blocks needed for quota insert/delete - we do some block writes
  90  * but inode, sb and group updates are done only once */
  91 #define EXT4_QUOTA_INIT_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
  92                 EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
  93                 (DQUOT_INIT_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
  94                  +3+DQUOT_INIT_REWRITE) : 0)
  95
  96 #define EXT4_QUOTA_DEL_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
  97                 EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) ?\
  98                 (DQUOT_DEL_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
  99                  +3+DQUOT_DEL_REWRITE) : 0)
 100 #else
 101 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
 102 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0
 103 #define EXT4_QUOTA_DEL_BLOCKS(sb) 0
 104 #endif
 105 #define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb))
 106 #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
 107 #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
 108
 109 static inline int ext4_jbd2_credits_xattr(struct inode *inode)
 110 {
 111         int credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb);
 112
 113         /*
 114          * In case of inline data, we may push out the data to a block,
 115          * so we need to reserve credits for this eventuality
 116          */
 117         if (ext4_has_inline_data(inode))
 118                 credits += ext4_writepage_trans_blocks(inode) + 1;
 119         return credits;
 120 }
 121
 122
 123 /*
 124  * Ext4 handle operation types -- for logging purposes
 125  */
 126 #define EXT4_HT_MISC             0
 127 #define EXT4_HT_INODE            1
 128 #define EXT4_HT_WRITE_PAGE       2
 129 #define EXT4_HT_MAP_BLOCKS       3
 130 #define EXT4_HT_DIR              4
 131 #define EXT4_HT_TRUNCATE         5
 132 #define EXT4_HT_QUOTA            6
 133 #define EXT4_HT_RESIZE           7
 134 #define EXT4_HT_MIGRATE          8
 135 #define EXT4_HT_MOVE_EXTENTS     9
 136 #define EXT4_HT_XATTR           10
 137 #define EXT4_HT_EXT_CONVERT     11
 138 #define EXT4_HT_MAX             12
 139
 140 /**
 141  *   struct ext4_journal_cb_entry - Base structure for callback information.
 142  *
 143  *   This struct is a 'seed' structure for a using with your own callback
 144  *   structs. If you are using callbacks you must allocate one of these
 145  *   or another struct of your own definition which has this struct
 146  *   as it's first element and pass it to ext4_journal_callback_add().
 147  */
 148 struct ext4_journal_cb_entry {
 149         /* list information for other callbacks attached to the same handle */
 150         struct list_head jce_list;
 151
 152         /*  Function to call with this callback structure */
 153         void (*jce_func)(struct super_block *sb,
 154                          struct ext4_journal_cb_entry *jce, int error);
 155
 156         /* user data goes here */
 157 };
 158
 159 /**
 160  * ext4_journal_callback_add: add a function to call after transaction commit
 161  * @handle: active journal transaction handle to register callback on
 162  * @func: callback function to call after the transaction has committed:
 163  *        @sb: superblock of current filesystem for transaction
 164  *        @jce: returned journal callback data
 165  *        @rc: journal state at commit (0 = transaction committed properly)
 166  * @jce: journal callback data (internal and function private data struct)
 167  *
 168  * The registered function will be called in the context of the journal thread
 169  * after the transaction for which the handle was created has completed.
 170  *
 171  * No locks are held when the callback function is called, so it is safe to
 172  * call blocking functions from within the callback, but the callback should
 173  * not block or run for too long, or the filesystem will be blocked waiting for
 174  * the next transaction to commit. No journaling functions can be used, or
 175  * there is a risk of deadlock.
 176  *
 177  * There is no guaranteed calling order of multiple registered callbacks on
 178  * the same transaction.
 179  */
 180 static inline void ext4_journal_callback_add(handle_t *handle,
 181                         void (*func)(struct super_block *sb,
 182                                      struct ext4_journal_cb_entry *jce,
 183                                      int rc),
 184                         struct ext4_journal_cb_entry *jce)
 185 {
 186         struct ext4_sb_info *sbi =
 187                         EXT4_SB(handle->h_transaction->t_journal->j_private);
 188
 189         /* Add the jce to transaction's private list */
 190         jce->jce_func = func;
 191         spin_lock(&sbi->s_md_lock);
 192         list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list);
 193         spin_unlock(&sbi->s_md_lock);
 194 }
 195
 196 /**
 197  * ext4_journal_callback_del: delete a registered callback
 198  * @handle: active journal transaction handle on which callback was registered
 199  * @jce: registered journal callback entry to unregister
 200  * Return true if object was successfully removed
 201  */
 202 static inline bool ext4_journal_callback_try_del(handle_t *handle,
 203                                              struct ext4_journal_cb_entry *jce)
 204 {
 205         bool deleted;
 206         struct ext4_sb_info *sbi =
 207                         EXT4_SB(handle->h_transaction->t_journal->j_private);
 208
 209         spin_lock(&sbi->s_md_lock);
 210         deleted = !list_empty(&jce->jce_list);
 211         list_del_init(&jce->jce_list);
 212         spin_unlock(&sbi->s_md_lock);
 213         return deleted;
 214 }
 215
 216 int
 217 ext4_mark_iloc_dirty(handle_t *handle,
 218                      struct inode *inode,
 219                      struct ext4_iloc *iloc);
 220
 221 /*
 222  * On success, We end up with an outstanding reference count against
 223  * iloc->bh.  This _must_ be cleaned up later.
 224  */
 225
 226 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 227                         struct ext4_iloc *iloc);
 228
 229 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
 230
 231 /*
 232  * Wrapper functions with which ext4 calls into JBD.
 233  */
 234 int __ext4_journal_get_write_access(const char *where, unsigned int line,
 235                                     handle_t *handle, struct buffer_head *bh);
 236
 237 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 238                   int is_metadata, struct inode *inode,
 239                   struct buffer_head *bh, ext4_fsblk_t blocknr);
 240
 241 int __ext4_journal_get_create_access(const char *where, unsigned int line,
 242                                 handle_t *handle, struct buffer_head *bh);
 243
 244 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 245                                  handle_t *handle, struct inode *inode,
 246                                  struct buffer_head *bh);
 247
 248 int __ext4_handle_dirty_super(const char *where, unsigned int line,
 249                               handle_t *handle, struct super_block *sb);
 250
 251 #define ext4_journal_get_write_access(handle, bh) \
 252         __ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
 253 #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
 254         __ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \
 255                       (bh), (block_nr))
 256 #define ext4_journal_get_create_access(handle, bh) \
 257         __ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh))
 258 #define ext4_handle_dirty_metadata(handle, inode, bh) \
 259         __ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
 260                                      (bh))
 261 #define ext4_handle_dirty_super(handle, sb) \
 262         __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb))
 263
 264 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
 265                                   int type, int blocks, int rsv_blocks);
 266 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
 267
 268 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
 269
 270 /* Note:  Do not use this for NULL handles.  This is only to determine if
 271  * a properly allocated handle is using a journal or not. */
 272 static inline int ext4_handle_valid(handle_t *handle)
 273 {
 274         if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
 275                 return 0;
 276         return 1;
 277 }
 278
 279 static inline void ext4_handle_sync(handle_t *handle)
 280 {
 281         if (ext4_handle_valid(handle))
 282                 handle->h_sync = 1;
 283 }
 284
 285 static inline int ext4_handle_is_aborted(handle_t *handle)
 286 {
 287         if (ext4_handle_valid(handle))
 288                 return is_handle_aborted(handle);
 289         return 0;
 290 }
 291
 292 static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
 293 {
 294         if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
 295                 return 0;
 296         return 1;
 297 }
 298
 299 #define ext4_journal_start_sb(sb, type, nblocks)                        \
 300         __ext4_journal_start_sb((sb), __LINE__, (type), (nblocks), 0)
 301
 302 #define ext4_journal_start(inode, type, nblocks)                        \
 303         __ext4_journal_start((inode), __LINE__, (type), (nblocks), 0)
 304
 305 #define ext4_journal_start_with_reserve(inode, type, blocks, rsv_blocks) \
 306         __ext4_journal_start((inode), __LINE__, (type), (blocks), (rsv_blocks))
 307
 308 static inline handle_t *__ext4_journal_start(struct inode *inode,
 309                                              unsigned int line, int type,
 310                                              int blocks, int rsv_blocks)
 311 {
 312         return __ext4_journal_start_sb(inode->i_sb, line, type, blocks,
 313                                        rsv_blocks);
 314 }
 315
 316 #define ext4_journal_stop(handle) \
 317         __ext4_journal_stop(__func__, __LINE__, (handle))
 318
 319 #define ext4_journal_start_reserved(handle, type) \
 320         __ext4_journal_start_reserved((handle), __LINE__, (type))
 321
 322 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 323                                         int type);
 324
 325 static inline void ext4_journal_free_reserved(handle_t *handle)
 326 {
 327         if (ext4_handle_valid(handle))
 328                 jbd2_journal_free_reserved(handle);
 329 }
 330
 331 static inline handle_t *ext4_journal_current_handle(void)
 332 {
 333         return journal_current_handle();
 334 }
 335
 336 static inline int ext4_journal_extend(handle_t *handle, int nblocks)
 337 {
 338         if (ext4_handle_valid(handle))
 339                 return jbd2_journal_extend(handle, nblocks);
 340         return 0;
 341 }
 342
 343 static inline int ext4_journal_restart(handle_t *handle, int nblocks)
 344 {
 345         if (ext4_handle_valid(handle))
 346                 return jbd2_journal_restart(handle, nblocks);
 347         return 0;
 348 }
 349
 350 static inline int ext4_journal_blocks_per_page(struct inode *inode)
 351 {
 352         if (EXT4_JOURNAL(inode) != NULL)
 353                 return jbd2_journal_blocks_per_page(inode);
 354         return 0;
 355 }
 356
 357 static inline int ext4_journal_force_commit(journal_t *journal)
 358 {
 359         if (journal)
 360                 return jbd2_journal_force_commit(journal);
 361         return 0;
 362 }
 363
 364 static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
 365 {
 366         if (ext4_handle_valid(handle))
 367                 return jbd2_journal_file_inode(handle, EXT4_I(inode)->jinode);
 368         return 0;
 369 }
 370
 371 static inline void ext4_update_inode_fsync_trans(handle_t *handle,
 372                                                  struct inode *inode,
 373                                                  int datasync)
 374 {
 375         struct ext4_inode_info *ei = EXT4_I(inode);
 376
 377         if (ext4_handle_valid(handle)) {
 378                 ei->i_sync_tid = handle->h_transaction->t_tid;
 379                 if (datasync)
 380                         ei->i_datasync_tid = handle->h_transaction->t_tid;
 381         }
 382 }
 383
 384 /* super.c */
 385 int ext4_force_commit(struct super_block *sb);
 386
 387 /*
 388  * Ext4 inode journal modes
 389  */
 390 #define EXT4_INODE_JOURNAL_DATA_MODE    0x01 /* journal data mode */
 391 #define EXT4_INODE_ORDERED_DATA_MODE    0x02 /* ordered data mode */
 392 #define EXT4_INODE_WRITEBACK_DATA_MODE  0x04 /* writeback data mode */
 393
 394 static inline int ext4_inode_journal_mode(struct inode *inode)
 395 {
 396         if (EXT4_JOURNAL(inode) == NULL)
 397                 return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
 398         /* We do not support data journalling with delayed allocation */
 399         if (!S_ISREG(inode->i_mode) ||
 400             test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 401                 return EXT4_INODE_JOURNAL_DATA_MODE;    /* journal data */
 402         if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
 403             !test_opt(inode->i_sb, DELALLOC))
 404                 return EXT4_INODE_JOURNAL_DATA_MODE;    /* journal data */
 405         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
 406                 return EXT4_INODE_ORDERED_DATA_MODE;    /* ordered */
 407         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
 408                 return EXT4_INODE_WRITEBACK_DATA_MODE;  /* writeback */
 409         else
 410                 BUG();
 411 }
 412
 413 static inline int ext4_should_journal_data(struct inode *inode)
 414 {
 415         return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
 416 }
 417
 418 static inline int ext4_should_order_data(struct inode *inode)
 419 {
 420         return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
 421 }
 422
 423 static inline int ext4_should_writeback_data(struct inode *inode)
 424 {
 425         return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE;
 426 }
 427
 428 /*
 429  * This function controls whether or not we should try to go down the
 430  * dioread_nolock code paths, which makes it safe to avoid taking
 431  * i_mutex for direct I/O reads.  This only works for extent-based
 432  * files, and it doesn't work if data journaling is enabled, since the
 433  * dioread_nolock code uses b_private to pass information back to the
 434  * I/O completion handler, and this conflicts with the jbd's use of
 435  * b_private.
 436  */
 437 static inline int ext4_should_dioread_nolock(struct inode *inode)
 438 {
 439         if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
 440                 return 0;
 441         if (!S_ISREG(inode->i_mode))
 442                 return 0;
 443         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
 444                 return 0;
 445         if (ext4_should_journal_data(inode))
 446                 return 0;
 447         return 1;
 448 }
 449
 450 #endif  /* _EXT4_JBD2_H */