1 /* 2 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. 3 * All Rights Reserved. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 #ifndef __XFS_LOG_PRIV_H__ 19 #define __XFS_LOG_PRIV_H__ 20 21 struct xfs_buf; 22 struct xlog; 23 struct xlog_ticket; 24 struct xfs_mount; 25 26 /* 27 * Macros, structures, prototypes for internal log manager use. 28 */ 29 30 #define XLOG_MIN_ICLOGS 2 31 #define XLOG_MAX_ICLOGS 8 32 #define XLOG_HEADER_MAGIC_NUM 0xFEEDbabe /* Invalid cycle number */ 33 #define XLOG_VERSION_1 1 34 #define XLOG_VERSION_2 2 /* Large IClogs, Log sunit */ 35 #define XLOG_VERSION_OKBITS (XLOG_VERSION_1 | XLOG_VERSION_2) 36 #define XLOG_MIN_RECORD_BSIZE (16*1024) /* eventually 32k */ 37 #define XLOG_BIG_RECORD_BSIZE (32*1024) /* 32k buffers */ 38 #define XLOG_MAX_RECORD_BSIZE (256*1024) 39 #define XLOG_HEADER_CYCLE_SIZE (32*1024) /* cycle data in header */ 40 #define XLOG_MIN_RECORD_BSHIFT 14 /* 16384 == 1 << 14 */ 41 #define XLOG_BIG_RECORD_BSHIFT 15 /* 32k == 1 << 15 */ 42 #define XLOG_MAX_RECORD_BSHIFT 18 /* 256k == 1 << 18 */ 43 #define XLOG_BTOLSUNIT(log, b) (((b)+(log)->l_mp->m_sb.sb_logsunit-1) / \ 44 (log)->l_mp->m_sb.sb_logsunit) 45 #define XLOG_LSUNITTOB(log, su) ((su) * (log)->l_mp->m_sb.sb_logsunit) 46 47 #define XLOG_HEADER_SIZE 512 48 49 #define XLOG_REC_SHIFT(log) \ 50 BTOBB(1 << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \ 51 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT)) 52 #define XLOG_TOTAL_REC_SHIFT(log) \ 53 BTOBB(XLOG_MAX_ICLOGS << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \ 54 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT)) 55 56 static inline xfs_lsn_t xlog_assign_lsn(uint cycle, uint block) 57 { 58 return ((xfs_lsn_t)cycle << 32) | block; 59 } 60 61 static inline uint xlog_get_cycle(char *ptr) 62 { 63 if (be32_to_cpu(*(__be32 *)ptr) == XLOG_HEADER_MAGIC_NUM) 64 return be32_to_cpu(*((__be32 *)ptr + 1)); 65 else 66 return be32_to_cpu(*(__be32 *)ptr); 67 } 68 69 #define BLK_AVG(blk1, blk2) ((blk1+blk2) >> 1) 70 71 #ifdef __KERNEL__ 72 73 /* 74 * get client id from packed copy. 75 * 76 * this hack is here because the xlog_pack code copies four bytes 77 * of xlog_op_header containing the fields oh_clientid, oh_flags 78 * and oh_res2 into the packed copy. 79 * 80 * later on this four byte chunk is treated as an int and the 81 * client id is pulled out. 82 * 83 * this has endian issues, of course. 84 */ 85 static inline uint xlog_get_client_id(__be32 i) 86 { 87 return be32_to_cpu(i) >> 24; 88 } 89 90 /* 91 * In core log state 92 */ 93 #define XLOG_STATE_ACTIVE 0x0001 /* Current IC log being written to */ 94 #define XLOG_STATE_WANT_SYNC 0x0002 /* Want to sync this iclog; no more writes */ 95 #define XLOG_STATE_SYNCING 0x0004 /* This IC log is syncing */ 96 #define XLOG_STATE_DONE_SYNC 0x0008 /* Done syncing to disk */ 97 #define XLOG_STATE_DO_CALLBACK \ 98 0x0010 /* Process callback functions */ 99 #define XLOG_STATE_CALLBACK 0x0020 /* Callback functions now */ 100 #define XLOG_STATE_DIRTY 0x0040 /* Dirty IC log, not ready for ACTIVE status*/ 101 #define XLOG_STATE_IOERROR 0x0080 /* IO error happened in sync'ing log */ 102 #define XLOG_STATE_ALL 0x7FFF /* All possible valid flags */ 103 #define XLOG_STATE_NOTUSED 0x8000 /* This IC log not being used */ 104 #endif /* __KERNEL__ */ 105 106 /* 107 * Flags to log operation header 108 * 109 * The first write of a new transaction will be preceded with a start 110 * record, XLOG_START_TRANS. Once a transaction is committed, a commit 111 * record is written, XLOG_COMMIT_TRANS. If a single region can not fit into 112 * the remainder of the current active in-core log, it is split up into 113 * multiple regions. Each partial region will be marked with a 114 * XLOG_CONTINUE_TRANS until the last one, which gets marked with XLOG_END_TRANS. 115 * 116 */ 117 #define XLOG_START_TRANS 0x01 /* Start a new transaction */ 118 #define XLOG_COMMIT_TRANS 0x02 /* Commit this transaction */ 119 #define XLOG_CONTINUE_TRANS 0x04 /* Cont this trans into new region */ 120 #define XLOG_WAS_CONT_TRANS 0x08 /* Cont this trans into new region */ 121 #define XLOG_END_TRANS 0x10 /* End a continued transaction */ 122 #define XLOG_UNMOUNT_TRANS 0x20 /* Unmount a filesystem transaction */ 123 124 #ifdef __KERNEL__ 125 /* 126 * Flags to log ticket 127 */ 128 #define XLOG_TIC_INITED 0x1 /* has been initialized */ 129 #define XLOG_TIC_PERM_RESERV 0x2 /* permanent reservation */ 130 131 #define XLOG_TIC_FLAGS \ 132 { XLOG_TIC_INITED, "XLOG_TIC_INITED" }, \ 133 { XLOG_TIC_PERM_RESERV, "XLOG_TIC_PERM_RESERV" } 134 135 #endif /* __KERNEL__ */ 136 137 #define XLOG_UNMOUNT_TYPE 0x556e /* Un for Unmount */ 138 139 /* 140 * Flags for log structure 141 */ 142 #define XLOG_ACTIVE_RECOVERY 0x2 /* in the middle of recovery */ 143 #define XLOG_RECOVERY_NEEDED 0x4 /* log was recovered */ 144 #define XLOG_IO_ERROR 0x8 /* log hit an I/O error, and being 145 shutdown */ 146 #define XLOG_TAIL_WARN 0x10 /* log tail verify warning issued */ 147 148 typedef __uint32_t xlog_tid_t; 149 150 #ifdef __KERNEL__ 151 /* 152 * Below are states for covering allocation transactions. 153 * By covering, we mean changing the h_tail_lsn in the last on-disk 154 * log write such that no allocation transactions will be re-done during 155 * recovery after a system crash. Recovery starts at the last on-disk 156 * log write. 157 * 158 * These states are used to insert dummy log entries to cover 159 * space allocation transactions which can undo non-transactional changes 160 * after a crash. Writes to a file with space 161 * already allocated do not result in any transactions. Allocations 162 * might include space beyond the EOF. So if we just push the EOF a 163 * little, the last transaction for the file could contain the wrong 164 * size. If there is no file system activity, after an allocation 165 * transaction, and the system crashes, the allocation transaction 166 * will get replayed and the file will be truncated. This could 167 * be hours/days/... after the allocation occurred. 168 * 169 * The fix for this is to do two dummy transactions when the 170 * system is idle. We need two dummy transaction because the h_tail_lsn 171 * in the log record header needs to point beyond the last possible 172 * non-dummy transaction. The first dummy changes the h_tail_lsn to 173 * the first transaction before the dummy. The second dummy causes 174 * h_tail_lsn to point to the first dummy. Recovery starts at h_tail_lsn. 175 * 176 * These dummy transactions get committed when everything 177 * is idle (after there has been some activity). 178 * 179 * There are 5 states used to control this. 180 * 181 * IDLE -- no logging has been done on the file system or 182 * we are done covering previous transactions. 183 * NEED -- logging has occurred and we need a dummy transaction 184 * when the log becomes idle. 185 * DONE -- we were in the NEED state and have committed a dummy 186 * transaction. 187 * NEED2 -- we detected that a dummy transaction has gone to the 188 * on disk log with no other transactions. 189 * DONE2 -- we committed a dummy transaction when in the NEED2 state. 190 * 191 * There are two places where we switch states: 192 * 193 * 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2. 194 * We commit the dummy transaction and switch to DONE or DONE2, 195 * respectively. In all other states, we don't do anything. 196 * 197 * 2.) When we finish writing the on-disk log (xlog_state_clean_log). 198 * 199 * No matter what state we are in, if this isn't the dummy 200 * transaction going out, the next state is NEED. 201 * So, if we aren't in the DONE or DONE2 states, the next state 202 * is NEED. We can't be finishing a write of the dummy record 203 * unless it was committed and the state switched to DONE or DONE2. 204 * 205 * If we are in the DONE state and this was a write of the 206 * dummy transaction, we move to NEED2. 207 * 208 * If we are in the DONE2 state and this was a write of the 209 * dummy transaction, we move to IDLE. 210 * 211 * 212 * Writing only one dummy transaction can get appended to 213 * one file space allocation. When this happens, the log recovery 214 * code replays the space allocation and a file could be truncated. 215 * This is why we have the NEED2 and DONE2 states before going idle. 216 */ 217 218 #define XLOG_STATE_COVER_IDLE 0 219 #define XLOG_STATE_COVER_NEED 1 220 #define XLOG_STATE_COVER_DONE 2 221 #define XLOG_STATE_COVER_NEED2 3 222 #define XLOG_STATE_COVER_DONE2 4 223 224 #define XLOG_COVER_OPS 5 225 226 227 /* Ticket reservation region accounting */ 228 #define XLOG_TIC_LEN_MAX 15 229 230 /* 231 * Reservation region 232 * As would be stored in xfs_log_iovec but without the i_addr which 233 * we don't care about. 234 */ 235 typedef struct xlog_res { 236 uint r_len; /* region length :4 */ 237 uint r_type; /* region's transaction type :4 */ 238 } xlog_res_t; 239 240 typedef struct xlog_ticket { 241 struct list_head t_queue; /* reserve/write queue */ 242 struct task_struct *t_task; /* task that owns this ticket */ 243 xlog_tid_t t_tid; /* transaction identifier : 4 */ 244 atomic_t t_ref; /* ticket reference count : 4 */ 245 int t_curr_res; /* current reservation in bytes : 4 */ 246 int t_unit_res; /* unit reservation in bytes : 4 */ 247 char t_ocnt; /* original count : 1 */ 248 char t_cnt; /* current count : 1 */ 249 char t_clientid; /* who does this belong to; : 1 */ 250 char t_flags; /* properties of reservation : 1 */ 251 uint t_trans_type; /* transaction type : 4 */ 252 253 /* reservation array fields */ 254 uint t_res_num; /* num in array : 4 */ 255 uint t_res_num_ophdrs; /* num op hdrs : 4 */ 256 uint t_res_arr_sum; /* array sum : 4 */ 257 uint t_res_o_flow; /* sum overflow : 4 */ 258 xlog_res_t t_res_arr[XLOG_TIC_LEN_MAX]; /* array of res : 8 * 15 */ 259 } xlog_ticket_t; 260 261 #endif 262 263 264 typedef struct xlog_op_header { 265 __be32 oh_tid; /* transaction id of operation : 4 b */ 266 __be32 oh_len; /* bytes in data region : 4 b */ 267 __u8 oh_clientid; /* who sent me this : 1 b */ 268 __u8 oh_flags; /* : 1 b */ 269 __u16 oh_res2; /* 32 bit align : 2 b */ 270 } xlog_op_header_t; 271 272 273 /* valid values for h_fmt */ 274 #define XLOG_FMT_UNKNOWN 0 275 #define XLOG_FMT_LINUX_LE 1 276 #define XLOG_FMT_LINUX_BE 2 277 #define XLOG_FMT_IRIX_BE 3 278 279 /* our fmt */ 280 #ifdef XFS_NATIVE_HOST 281 #define XLOG_FMT XLOG_FMT_LINUX_BE 282 #else 283 #define XLOG_FMT XLOG_FMT_LINUX_LE 284 #endif 285 286 typedef struct xlog_rec_header { 287 __be32 h_magicno; /* log record (LR) identifier : 4 */ 288 __be32 h_cycle; /* write cycle of log : 4 */ 289 __be32 h_version; /* LR version : 4 */ 290 __be32 h_len; /* len in bytes; should be 64-bit aligned: 4 */ 291 __be64 h_lsn; /* lsn of this LR : 8 */ 292 __be64 h_tail_lsn; /* lsn of 1st LR w/ buffers not committed: 8 */ 293 __le32 h_crc; /* crc of log record : 4 */ 294 __be32 h_prev_block; /* block number to previous LR : 4 */ 295 __be32 h_num_logops; /* number of log operations in this LR : 4 */ 296 __be32 h_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE]; 297 /* new fields */ 298 __be32 h_fmt; /* format of log record : 4 */ 299 uuid_t h_fs_uuid; /* uuid of FS : 16 */ 300 __be32 h_size; /* iclog size : 4 */ 301 } xlog_rec_header_t; 302 303 typedef struct xlog_rec_ext_header { 304 __be32 xh_cycle; /* write cycle of log : 4 */ 305 __be32 xh_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE]; /* : 256 */ 306 } xlog_rec_ext_header_t; 307 308 #ifdef __KERNEL__ 309 310 /* 311 * Quite misnamed, because this union lays out the actual on-disk log buffer. 312 */ 313 typedef union xlog_in_core2 { 314 xlog_rec_header_t hic_header; 315 xlog_rec_ext_header_t hic_xheader; 316 char hic_sector[XLOG_HEADER_SIZE]; 317 } xlog_in_core_2_t; 318 319 /* 320 * - A log record header is 512 bytes. There is plenty of room to grow the 321 * xlog_rec_header_t into the reserved space. 322 * - ic_data follows, so a write to disk can start at the beginning of 323 * the iclog. 324 * - ic_forcewait is used to implement synchronous forcing of the iclog to disk. 325 * - ic_next is the pointer to the next iclog in the ring. 326 * - ic_bp is a pointer to the buffer used to write this incore log to disk. 327 * - ic_log is a pointer back to the global log structure. 328 * - ic_callback is a linked list of callback function/argument pairs to be 329 * called after an iclog finishes writing. 330 * - ic_size is the full size of the header plus data. 331 * - ic_offset is the current number of bytes written to in this iclog. 332 * - ic_refcnt is bumped when someone is writing to the log. 333 * - ic_state is the state of the iclog. 334 * 335 * Because of cacheline contention on large machines, we need to separate 336 * various resources onto different cachelines. To start with, make the 337 * structure cacheline aligned. The following fields can be contended on 338 * by independent processes: 339 * 340 * - ic_callback_* 341 * - ic_refcnt 342 * - fields protected by the global l_icloglock 343 * 344 * so we need to ensure that these fields are located in separate cachelines. 345 * We'll put all the read-only and l_icloglock fields in the first cacheline, 346 * and move everything else out to subsequent cachelines. 347 */ 348 typedef struct xlog_in_core { 349 wait_queue_head_t ic_force_wait; 350 wait_queue_head_t ic_write_wait; 351 struct xlog_in_core *ic_next; 352 struct xlog_in_core *ic_prev; 353 struct xfs_buf *ic_bp; 354 struct xlog *ic_log; 355 int ic_size; 356 int ic_offset; 357 int ic_bwritecnt; 358 unsigned short ic_state; 359 char *ic_datap; /* pointer to iclog data */ 360 361 /* Callback structures need their own cacheline */ 362 spinlock_t ic_callback_lock ____cacheline_aligned_in_smp; 363 xfs_log_callback_t *ic_callback; 364 xfs_log_callback_t **ic_callback_tail; 365 366 /* reference counts need their own cacheline */ 367 atomic_t ic_refcnt ____cacheline_aligned_in_smp; 368 xlog_in_core_2_t *ic_data; 369 #define ic_header ic_data->hic_header 370 } xlog_in_core_t; 371 372 /* 373 * The CIL context is used to aggregate per-transaction details as well be 374 * passed to the iclog for checkpoint post-commit processing. After being 375 * passed to the iclog, another context needs to be allocated for tracking the 376 * next set of transactions to be aggregated into a checkpoint. 377 */ 378 struct xfs_cil; 379 380 struct xfs_cil_ctx { 381 struct xfs_cil *cil; 382 xfs_lsn_t sequence; /* chkpt sequence # */ 383 xfs_lsn_t start_lsn; /* first LSN of chkpt commit */ 384 xfs_lsn_t commit_lsn; /* chkpt commit record lsn */ 385 struct xlog_ticket *ticket; /* chkpt ticket */ 386 int nvecs; /* number of regions */ 387 int space_used; /* aggregate size of regions */ 388 struct list_head busy_extents; /* busy extents in chkpt */ 389 struct xfs_log_vec *lv_chain; /* logvecs being pushed */ 390 xfs_log_callback_t log_cb; /* completion callback hook. */ 391 struct list_head committing; /* ctx committing list */ 392 }; 393 394 /* 395 * Committed Item List structure 396 * 397 * This structure is used to track log items that have been committed but not 398 * yet written into the log. It is used only when the delayed logging mount 399 * option is enabled. 400 * 401 * This structure tracks the list of committing checkpoint contexts so 402 * we can avoid the problem of having to hold out new transactions during a 403 * flush until we have a the commit record LSN of the checkpoint. We can 404 * traverse the list of committing contexts in xlog_cil_push_lsn() to find a 405 * sequence match and extract the commit LSN directly from there. If the 406 * checkpoint is still in the process of committing, we can block waiting for 407 * the commit LSN to be determined as well. This should make synchronous 408 * operations almost as efficient as the old logging methods. 409 */ 410 struct xfs_cil { 411 struct xlog *xc_log; 412 struct list_head xc_cil; 413 spinlock_t xc_cil_lock; 414 struct xfs_cil_ctx *xc_ctx; 415 struct rw_semaphore xc_ctx_lock; 416 struct list_head xc_committing; 417 wait_queue_head_t xc_commit_wait; 418 xfs_lsn_t xc_current_sequence; 419 struct work_struct xc_push_work; 420 xfs_lsn_t xc_push_seq; 421 }; 422 423 /* 424 * The amount of log space we allow the CIL to aggregate is difficult to size. 425 * Whatever we choose, we have to make sure we can get a reservation for the 426 * log space effectively, that it is large enough to capture sufficient 427 * relogging to reduce log buffer IO significantly, but it is not too large for 428 * the log or induces too much latency when writing out through the iclogs. We 429 * track both space consumed and the number of vectors in the checkpoint 430 * context, so we need to decide which to use for limiting. 431 * 432 * Every log buffer we write out during a push needs a header reserved, which 433 * is at least one sector and more for v2 logs. Hence we need a reservation of 434 * at least 512 bytes per 32k of log space just for the LR headers. That means 435 * 16KB of reservation per megabyte of delayed logging space we will consume, 436 * plus various headers. The number of headers will vary based on the num of 437 * io vectors, so limiting on a specific number of vectors is going to result 438 * in transactions of varying size. IOWs, it is more consistent to track and 439 * limit space consumed in the log rather than by the number of objects being 440 * logged in order to prevent checkpoint ticket overruns. 441 * 442 * Further, use of static reservations through the log grant mechanism is 443 * problematic. It introduces a lot of complexity (e.g. reserve grant vs write 444 * grant) and a significant deadlock potential because regranting write space 445 * can block on log pushes. Hence if we have to regrant log space during a log 446 * push, we can deadlock. 447 * 448 * However, we can avoid this by use of a dynamic "reservation stealing" 449 * technique during transaction commit whereby unused reservation space in the 450 * transaction ticket is transferred to the CIL ctx commit ticket to cover the 451 * space needed by the checkpoint transaction. This means that we never need to 452 * specifically reserve space for the CIL checkpoint transaction, nor do we 453 * need to regrant space once the checkpoint completes. This also means the 454 * checkpoint transaction ticket is specific to the checkpoint context, rather 455 * than the CIL itself. 456 * 457 * With dynamic reservations, we can effectively make up arbitrary limits for 458 * the checkpoint size so long as they don't violate any other size rules. 459 * Recovery imposes a rule that no transaction exceed half the log, so we are 460 * limited by that. Furthermore, the log transaction reservation subsystem 461 * tries to keep 25% of the log free, so we need to keep below that limit or we 462 * risk running out of free log space to start any new transactions. 463 * 464 * In order to keep background CIL push efficient, we will set a lower 465 * threshold at which background pushing is attempted without blocking current 466 * transaction commits. A separate, higher bound defines when CIL pushes are 467 * enforced to ensure we stay within our maximum checkpoint size bounds. 468 * threshold, yet give us plenty of space for aggregation on large logs. 469 */ 470 #define XLOG_CIL_SPACE_LIMIT(log) (log->l_logsize >> 3) 471 #define XLOG_CIL_HARD_SPACE_LIMIT(log) (3 * (log->l_logsize >> 4)) 472 473 /* 474 * ticket grant locks, queues and accounting have their own cachlines 475 * as these are quite hot and can be operated on concurrently. 476 */ 477 struct xlog_grant_head { 478 spinlock_t lock ____cacheline_aligned_in_smp; 479 struct list_head waiters; 480 atomic64_t grant; 481 }; 482 483 /* 484 * The reservation head lsn is not made up of a cycle number and block number. 485 * Instead, it uses a cycle number and byte number. Logs don't expect to 486 * overflow 31 bits worth of byte offset, so using a byte number will mean 487 * that round off problems won't occur when releasing partial reservations. 488 */ 489 struct xlog { 490 /* The following fields don't need locking */ 491 struct xfs_mount *l_mp; /* mount point */ 492 struct xfs_ail *l_ailp; /* AIL log is working with */ 493 struct xfs_cil *l_cilp; /* CIL log is working with */ 494 struct xfs_buf *l_xbuf; /* extra buffer for log 495 * wrapping */ 496 struct xfs_buftarg *l_targ; /* buftarg of log */ 497 struct delayed_work l_work; /* background flush work */ 498 uint l_flags; 499 uint l_quotaoffs_flag; /* XFS_DQ_*, for QUOTAOFFs */ 500 struct list_head *l_buf_cancel_table; 501 int l_iclog_hsize; /* size of iclog header */ 502 int l_iclog_heads; /* # of iclog header sectors */ 503 uint l_sectBBsize; /* sector size in BBs (2^n) */ 504 int l_iclog_size; /* size of log in bytes */ 505 int l_iclog_size_log; /* log power size of log */ 506 int l_iclog_bufs; /* number of iclog buffers */ 507 xfs_daddr_t l_logBBstart; /* start block of log */ 508 int l_logsize; /* size of log in bytes */ 509 int l_logBBsize; /* size of log in BB chunks */ 510 511 /* The following block of fields are changed while holding icloglock */ 512 wait_queue_head_t l_flush_wait ____cacheline_aligned_in_smp; 513 /* waiting for iclog flush */ 514 int l_covered_state;/* state of "covering disk 515 * log entries" */ 516 xlog_in_core_t *l_iclog; /* head log queue */ 517 spinlock_t l_icloglock; /* grab to change iclog state */ 518 int l_curr_cycle; /* Cycle number of log writes */ 519 int l_prev_cycle; /* Cycle number before last 520 * block increment */ 521 int l_curr_block; /* current logical log block */ 522 int l_prev_block; /* previous logical log block */ 523 524 /* 525 * l_last_sync_lsn and l_tail_lsn are atomics so they can be set and 526 * read without needing to hold specific locks. To avoid operations 527 * contending with other hot objects, place each of them on a separate 528 * cacheline. 529 */ 530 /* lsn of last LR on disk */ 531 atomic64_t l_last_sync_lsn ____cacheline_aligned_in_smp; 532 /* lsn of 1st LR with unflushed * buffers */ 533 atomic64_t l_tail_lsn ____cacheline_aligned_in_smp; 534 535 struct xlog_grant_head l_reserve_head; 536 struct xlog_grant_head l_write_head; 537 538 /* The following field are used for debugging; need to hold icloglock */ 539 #ifdef DEBUG 540 char *l_iclog_bak[XLOG_MAX_ICLOGS]; 541 #endif 542 543 }; 544 545 #define XLOG_BUF_CANCEL_BUCKET(log, blkno) \ 546 ((log)->l_buf_cancel_table + ((__uint64_t)blkno % XLOG_BC_TABLE_SIZE)) 547 548 #define XLOG_FORCED_SHUTDOWN(log) ((log)->l_flags & XLOG_IO_ERROR) 549 550 /* common routines */ 551 extern int 552 xlog_recover( 553 struct xlog *log); 554 extern int 555 xlog_recover_finish( 556 struct xlog *log); 557 558 extern __le32 xlog_cksum(struct xlog *log, struct xlog_rec_header *rhead, 559 char *dp, int size); 560 561 extern kmem_zone_t *xfs_log_ticket_zone; 562 struct xlog_ticket * 563 xlog_ticket_alloc( 564 struct xlog *log, 565 int unit_bytes, 566 int count, 567 char client, 568 bool permanent, 569 xfs_km_flags_t alloc_flags); 570 571 572 static inline void 573 xlog_write_adv_cnt(void **ptr, int *len, int *off, size_t bytes) 574 { 575 *ptr += bytes; 576 *len -= bytes; 577 *off += bytes; 578 } 579 580 void xlog_print_tic_res(struct xfs_mount *mp, struct xlog_ticket *ticket); 581 int 582 xlog_write( 583 struct xlog *log, 584 struct xfs_log_vec *log_vector, 585 struct xlog_ticket *tic, 586 xfs_lsn_t *start_lsn, 587 struct xlog_in_core **commit_iclog, 588 uint flags); 589 590 /* 591 * When we crack an atomic LSN, we sample it first so that the value will not 592 * change while we are cracking it into the component values. This means we 593 * will always get consistent component values to work from. This should always 594 * be used to sample and crack LSNs that are stored and updated in atomic 595 * variables. 596 */ 597 static inline void 598 xlog_crack_atomic_lsn(atomic64_t *lsn, uint *cycle, uint *block) 599 { 600 xfs_lsn_t val = atomic64_read(lsn); 601 602 *cycle = CYCLE_LSN(val); 603 *block = BLOCK_LSN(val); 604 } 605 606 /* 607 * Calculate and assign a value to an atomic LSN variable from component pieces. 608 */ 609 static inline void 610 xlog_assign_atomic_lsn(atomic64_t *lsn, uint cycle, uint block) 611 { 612 atomic64_set(lsn, xlog_assign_lsn(cycle, block)); 613 } 614 615 /* 616 * When we crack the grant head, we sample it first so that the value will not 617 * change while we are cracking it into the component values. This means we 618 * will always get consistent component values to work from. 619 */ 620 static inline void 621 xlog_crack_grant_head_val(int64_t val, int *cycle, int *space) 622 { 623 *cycle = val >> 32; 624 *space = val & 0xffffffff; 625 } 626 627 static inline void 628 xlog_crack_grant_head(atomic64_t *head, int *cycle, int *space) 629 { 630 xlog_crack_grant_head_val(atomic64_read(head), cycle, space); 631 } 632 633 static inline int64_t 634 xlog_assign_grant_head_val(int cycle, int space) 635 { 636 return ((int64_t)cycle << 32) | space; 637 } 638 639 static inline void 640 xlog_assign_grant_head(atomic64_t *head, int cycle, int space) 641 { 642 atomic64_set(head, xlog_assign_grant_head_val(cycle, space)); 643 } 644 645 /* 646 * Committed Item List interfaces 647 */ 648 int 649 xlog_cil_init(struct xlog *log); 650 void 651 xlog_cil_init_post_recovery(struct xlog *log); 652 void 653 xlog_cil_destroy(struct xlog *log); 654 655 /* 656 * CIL force routines 657 */ 658 xfs_lsn_t 659 xlog_cil_force_lsn( 660 struct xlog *log, 661 xfs_lsn_t sequence); 662 663 static inline void 664 xlog_cil_force(struct xlog *log) 665 { 666 xlog_cil_force_lsn(log, log->l_cilp->xc_current_sequence); 667 } 668 669 /* 670 * Unmount record type is used as a pseudo transaction type for the ticket. 671 * It's value must be outside the range of XFS_TRANS_* values. 672 */ 673 #define XLOG_UNMOUNT_REC_TYPE (-1U) 674 675 /* 676 * Wrapper function for waiting on a wait queue serialised against wakeups 677 * by a spinlock. This matches the semantics of all the wait queues used in the 678 * log code. 679 */ 680 static inline void xlog_wait(wait_queue_head_t *wq, spinlock_t *lock) 681 { 682 DECLARE_WAITQUEUE(wait, current); 683 684 add_wait_queue_exclusive(wq, &wait); 685 __set_current_state(TASK_UNINTERRUPTIBLE); 686 spin_unlock(lock); 687 schedule(); 688 remove_wait_queue(wq, &wait); 689 } 690 #endif /* __KERNEL__ */ 691 692 #endif /* __XFS_LOG_PRIV_H__ */ 693