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 + root which are stored in the inode. */ 33 34 #define EXT4_SINGLEDATA_TRANS_BLOCKS(sb) \ 35 (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS) \ 36 ? 27U : 8U) 37 38 /* Extended attribute operations touch at most two data buffers, 39 * two bitmap buffers, and two group summaries, in addition to the inode 40 * and the superblock, which are already accounted for. */ 41 42 #define EXT4_XATTR_TRANS_BLOCKS 6U 43 44 /* Define the minimum size for a transaction which modifies data. This 45 * needs to take into account the fact that we may end up modifying two 46 * quota files too (one for the group, one for the user quota). The 47 * superblock only gets updated once, of course, so don't bother 48 * counting that again for the quota updates. */ 49 50 #define EXT4_DATA_TRANS_BLOCKS(sb) (EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \ 51 EXT4_XATTR_TRANS_BLOCKS - 2 + \ 52 EXT4_MAXQUOTAS_TRANS_BLOCKS(sb)) 53 54 /* 55 * Define the number of metadata blocks we need to account to modify data. 56 * 57 * This include super block, inode block, quota blocks and xattr blocks 58 */ 59 #define EXT4_META_TRANS_BLOCKS(sb) (EXT4_XATTR_TRANS_BLOCKS + \ 60 EXT4_MAXQUOTAS_TRANS_BLOCKS(sb)) 61 62 /* Delete operations potentially hit one directory's namespace plus an 63 * entire inode, plus arbitrary amounts of bitmap/indirection data. Be 64 * generous. We can grow the delete transaction later if necessary. */ 65 66 #define EXT4_DELETE_TRANS_BLOCKS(sb) (2 * EXT4_DATA_TRANS_BLOCKS(sb) + 64) 67 68 /* Define an arbitrary limit for the amount of data we will anticipate 69 * writing to any given transaction. For unbounded transactions such as 70 * write(2) and truncate(2) we can write more than this, but we always 71 * start off at the maximum transaction size and grow the transaction 72 * optimistically as we go. */ 73 74 #define EXT4_MAX_TRANS_DATA 64U 75 76 /* We break up a large truncate or write transaction once the handle's 77 * buffer credits gets this low, we need either to extend the 78 * transaction or to start a new one. Reserve enough space here for 79 * inode, bitmap, superblock, group and indirection updates for at least 80 * one block, plus two quota updates. Quota allocations are not 81 * needed. */ 82 83 #define EXT4_RESERVE_TRANS_BLOCKS 12U 84 85 #define EXT4_INDEX_EXTRA_TRANS_BLOCKS 8 86 87 #ifdef CONFIG_QUOTA 88 /* Amount of blocks needed for quota update - we know that the structure was 89 * allocated so we need to update only data block */ 90 #define EXT4_QUOTA_TRANS_BLOCKS(sb) (test_opt(sb, QUOTA) ? 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) ? (DQUOT_INIT_ALLOC*\ 94 (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_INIT_REWRITE) : 0) 95 96 #define EXT4_QUOTA_DEL_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_DEL_ALLOC*\ 97 (EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_DEL_REWRITE) : 0) 98 #else 99 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0 100 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0 101 #define EXT4_QUOTA_DEL_BLOCKS(sb) 0 102 #endif 103 #define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb)) 104 #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb)) 105 #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb)) 106 107 /** 108 * struct ext4_journal_cb_entry - Base structure for callback information. 109 * 110 * This struct is a 'seed' structure for a using with your own callback 111 * structs. If you are using callbacks you must allocate one of these 112 * or another struct of your own definition which has this struct 113 * as it's first element and pass it to ext4_journal_callback_add(). 114 */ 115 struct ext4_journal_cb_entry { 116 /* list information for other callbacks attached to the same handle */ 117 struct list_head jce_list; 118 119 /* Function to call with this callback structure */ 120 void (*jce_func)(struct super_block *sb, 121 struct ext4_journal_cb_entry *jce, int error); 122 123 /* user data goes here */ 124 }; 125 126 /** 127 * ext4_journal_callback_add: add a function to call after transaction commit 128 * @handle: active journal transaction handle to register callback on 129 * @func: callback function to call after the transaction has committed: 130 * @sb: superblock of current filesystem for transaction 131 * @jce: returned journal callback data 132 * @rc: journal state at commit (0 = transaction committed properly) 133 * @jce: journal callback data (internal and function private data struct) 134 * 135 * The registered function will be called in the context of the journal thread 136 * after the transaction for which the handle was created has completed. 137 * 138 * No locks are held when the callback function is called, so it is safe to 139 * call blocking functions from within the callback, but the callback should 140 * not block or run for too long, or the filesystem will be blocked waiting for 141 * the next transaction to commit. No journaling functions can be used, or 142 * there is a risk of deadlock. 143 * 144 * There is no guaranteed calling order of multiple registered callbacks on 145 * the same transaction. 146 */ 147 static inline void ext4_journal_callback_add(handle_t *handle, 148 void (*func)(struct super_block *sb, 149 struct ext4_journal_cb_entry *jce, 150 int rc), 151 struct ext4_journal_cb_entry *jce) 152 { 153 struct ext4_sb_info *sbi = 154 EXT4_SB(handle->h_transaction->t_journal->j_private); 155 156 /* Add the jce to transaction's private list */ 157 jce->jce_func = func; 158 spin_lock(&sbi->s_md_lock); 159 list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list); 160 spin_unlock(&sbi->s_md_lock); 161 } 162 163 /** 164 * ext4_journal_callback_del: delete a registered callback 165 * @handle: active journal transaction handle on which callback was registered 166 * @jce: registered journal callback entry to unregister 167 */ 168 static inline void ext4_journal_callback_del(handle_t *handle, 169 struct ext4_journal_cb_entry *jce) 170 { 171 struct ext4_sb_info *sbi = 172 EXT4_SB(handle->h_transaction->t_journal->j_private); 173 174 spin_lock(&sbi->s_md_lock); 175 list_del_init(&jce->jce_list); 176 spin_unlock(&sbi->s_md_lock); 177 } 178 179 int 180 ext4_mark_iloc_dirty(handle_t *handle, 181 struct inode *inode, 182 struct ext4_iloc *iloc); 183 184 /* 185 * On success, We end up with an outstanding reference count against 186 * iloc->bh. This _must_ be cleaned up later. 187 */ 188 189 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode, 190 struct ext4_iloc *iloc); 191 192 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode); 193 194 /* 195 * Wrapper functions with which ext4 calls into JBD. 196 */ 197 void ext4_journal_abort_handle(const char *caller, unsigned int line, 198 const char *err_fn, 199 struct buffer_head *bh, handle_t *handle, int err); 200 201 int __ext4_journal_get_write_access(const char *where, unsigned int line, 202 handle_t *handle, struct buffer_head *bh); 203 204 int __ext4_forget(const char *where, unsigned int line, handle_t *handle, 205 int is_metadata, struct inode *inode, 206 struct buffer_head *bh, ext4_fsblk_t blocknr); 207 208 int __ext4_journal_get_create_access(const char *where, unsigned int line, 209 handle_t *handle, struct buffer_head *bh); 210 211 int __ext4_handle_dirty_metadata(const char *where, unsigned int line, 212 handle_t *handle, struct inode *inode, 213 struct buffer_head *bh); 214 215 int __ext4_handle_dirty_super(const char *where, unsigned int line, 216 handle_t *handle, struct super_block *sb, 217 int now); 218 219 #define ext4_journal_get_write_access(handle, bh) \ 220 __ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh)) 221 #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \ 222 __ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \ 223 (bh), (block_nr)) 224 #define ext4_journal_get_create_access(handle, bh) \ 225 __ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh)) 226 #define ext4_handle_dirty_metadata(handle, inode, bh) \ 227 __ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \ 228 (bh)) 229 #define ext4_handle_dirty_super_now(handle, sb) \ 230 __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb), 1) 231 #define ext4_handle_dirty_super(handle, sb) \ 232 __ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb), 0) 233 234 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks); 235 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle); 236 237 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096) 238 239 /* Note: Do not use this for NULL handles. This is only to determine if 240 * a properly allocated handle is using a journal or not. */ 241 static inline int ext4_handle_valid(handle_t *handle) 242 { 243 if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT) 244 return 0; 245 return 1; 246 } 247 248 static inline void ext4_handle_sync(handle_t *handle) 249 { 250 if (ext4_handle_valid(handle)) 251 handle->h_sync = 1; 252 } 253 254 static inline void ext4_handle_release_buffer(handle_t *handle, 255 struct buffer_head *bh) 256 { 257 if (ext4_handle_valid(handle)) 258 jbd2_journal_release_buffer(handle, bh); 259 } 260 261 static inline int ext4_handle_is_aborted(handle_t *handle) 262 { 263 if (ext4_handle_valid(handle)) 264 return is_handle_aborted(handle); 265 return 0; 266 } 267 268 static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed) 269 { 270 if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed) 271 return 0; 272 return 1; 273 } 274 275 static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks) 276 { 277 return ext4_journal_start_sb(inode->i_sb, nblocks); 278 } 279 280 #define ext4_journal_stop(handle) \ 281 __ext4_journal_stop(__func__, __LINE__, (handle)) 282 283 static inline handle_t *ext4_journal_current_handle(void) 284 { 285 return journal_current_handle(); 286 } 287 288 static inline int ext4_journal_extend(handle_t *handle, int nblocks) 289 { 290 if (ext4_handle_valid(handle)) 291 return jbd2_journal_extend(handle, nblocks); 292 return 0; 293 } 294 295 static inline int ext4_journal_restart(handle_t *handle, int nblocks) 296 { 297 if (ext4_handle_valid(handle)) 298 return jbd2_journal_restart(handle, nblocks); 299 return 0; 300 } 301 302 static inline int ext4_journal_blocks_per_page(struct inode *inode) 303 { 304 if (EXT4_JOURNAL(inode) != NULL) 305 return jbd2_journal_blocks_per_page(inode); 306 return 0; 307 } 308 309 static inline int ext4_journal_force_commit(journal_t *journal) 310 { 311 if (journal) 312 return jbd2_journal_force_commit(journal); 313 return 0; 314 } 315 316 static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode) 317 { 318 if (ext4_handle_valid(handle)) 319 return jbd2_journal_file_inode(handle, EXT4_I(inode)->jinode); 320 return 0; 321 } 322 323 static inline void ext4_update_inode_fsync_trans(handle_t *handle, 324 struct inode *inode, 325 int datasync) 326 { 327 struct ext4_inode_info *ei = EXT4_I(inode); 328 329 if (ext4_handle_valid(handle)) { 330 ei->i_sync_tid = handle->h_transaction->t_tid; 331 if (datasync) 332 ei->i_datasync_tid = handle->h_transaction->t_tid; 333 } 334 } 335 336 /* super.c */ 337 int ext4_force_commit(struct super_block *sb); 338 339 /* 340 * Ext4 inode journal modes 341 */ 342 #define EXT4_INODE_JOURNAL_DATA_MODE 0x01 /* journal data mode */ 343 #define EXT4_INODE_ORDERED_DATA_MODE 0x02 /* ordered data mode */ 344 #define EXT4_INODE_WRITEBACK_DATA_MODE 0x04 /* writeback data mode */ 345 346 static inline int ext4_inode_journal_mode(struct inode *inode) 347 { 348 if (EXT4_JOURNAL(inode) == NULL) 349 return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */ 350 /* We do not support data journalling with delayed allocation */ 351 if (!S_ISREG(inode->i_mode) || 352 test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) 353 return EXT4_INODE_JOURNAL_DATA_MODE; /* journal data */ 354 if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) && 355 !test_opt(inode->i_sb, DELALLOC)) 356 return EXT4_INODE_JOURNAL_DATA_MODE; /* journal data */ 357 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) 358 return EXT4_INODE_ORDERED_DATA_MODE; /* ordered */ 359 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA) 360 return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */ 361 else 362 BUG(); 363 } 364 365 static inline int ext4_should_journal_data(struct inode *inode) 366 { 367 return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE; 368 } 369 370 static inline int ext4_should_order_data(struct inode *inode) 371 { 372 return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE; 373 } 374 375 static inline int ext4_should_writeback_data(struct inode *inode) 376 { 377 return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE; 378 } 379 380 /* 381 * This function controls whether or not we should try to go down the 382 * dioread_nolock code paths, which makes it safe to avoid taking 383 * i_mutex for direct I/O reads. This only works for extent-based 384 * files, and it doesn't work if data journaling is enabled, since the 385 * dioread_nolock code uses b_private to pass information back to the 386 * I/O completion handler, and this conflicts with the jbd's use of 387 * b_private. 388 */ 389 static inline int ext4_should_dioread_nolock(struct inode *inode) 390 { 391 if (!test_opt(inode->i_sb, DIOREAD_NOLOCK)) 392 return 0; 393 if (!S_ISREG(inode->i_mode)) 394 return 0; 395 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) 396 return 0; 397 if (ext4_should_journal_data(inode)) 398 return 0; 399 return 1; 400 } 401 402 #endif /* _EXT4_JBD2_H */ 403