1 /* 2 * Copyright (c) 2010 Red Hat, Inc. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it would be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write the Free Software Foundation, 15 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 16 */ 17 18 #include "xfs.h" 19 #include "xfs_fs.h" 20 #include "xfs_types.h" 21 #include "xfs_bit.h" 22 #include "xfs_log.h" 23 #include "xfs_inum.h" 24 #include "xfs_trans.h" 25 #include "xfs_trans_priv.h" 26 #include "xfs_log_priv.h" 27 #include "xfs_sb.h" 28 #include "xfs_ag.h" 29 #include "xfs_dir2.h" 30 #include "xfs_dmapi.h" 31 #include "xfs_mount.h" 32 #include "xfs_error.h" 33 #include "xfs_alloc.h" 34 35 /* 36 * Perform initial CIL structure initialisation. If the CIL is not 37 * enabled in this filesystem, ensure the log->l_cilp is null so 38 * we can check this conditional to determine if we are doing delayed 39 * logging or not. 40 */ 41 int 42 xlog_cil_init( 43 struct log *log) 44 { 45 struct xfs_cil *cil; 46 struct xfs_cil_ctx *ctx; 47 48 log->l_cilp = NULL; 49 if (!(log->l_mp->m_flags & XFS_MOUNT_DELAYLOG)) 50 return 0; 51 52 cil = kmem_zalloc(sizeof(*cil), KM_SLEEP|KM_MAYFAIL); 53 if (!cil) 54 return ENOMEM; 55 56 ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP|KM_MAYFAIL); 57 if (!ctx) { 58 kmem_free(cil); 59 return ENOMEM; 60 } 61 62 INIT_LIST_HEAD(&cil->xc_cil); 63 INIT_LIST_HEAD(&cil->xc_committing); 64 spin_lock_init(&cil->xc_cil_lock); 65 init_rwsem(&cil->xc_ctx_lock); 66 sv_init(&cil->xc_commit_wait, SV_DEFAULT, "cilwait"); 67 68 INIT_LIST_HEAD(&ctx->committing); 69 INIT_LIST_HEAD(&ctx->busy_extents); 70 ctx->sequence = 1; 71 ctx->cil = cil; 72 cil->xc_ctx = ctx; 73 74 cil->xc_log = log; 75 log->l_cilp = cil; 76 return 0; 77 } 78 79 void 80 xlog_cil_destroy( 81 struct log *log) 82 { 83 if (!log->l_cilp) 84 return; 85 86 if (log->l_cilp->xc_ctx) { 87 if (log->l_cilp->xc_ctx->ticket) 88 xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket); 89 kmem_free(log->l_cilp->xc_ctx); 90 } 91 92 ASSERT(list_empty(&log->l_cilp->xc_cil)); 93 kmem_free(log->l_cilp); 94 } 95 96 /* 97 * Allocate a new ticket. Failing to get a new ticket makes it really hard to 98 * recover, so we don't allow failure here. Also, we allocate in a context that 99 * we don't want to be issuing transactions from, so we need to tell the 100 * allocation code this as well. 101 * 102 * We don't reserve any space for the ticket - we are going to steal whatever 103 * space we require from transactions as they commit. To ensure we reserve all 104 * the space required, we need to set the current reservation of the ticket to 105 * zero so that we know to steal the initial transaction overhead from the 106 * first transaction commit. 107 */ 108 static struct xlog_ticket * 109 xlog_cil_ticket_alloc( 110 struct log *log) 111 { 112 struct xlog_ticket *tic; 113 114 tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, 0, 115 KM_SLEEP|KM_NOFS); 116 tic->t_trans_type = XFS_TRANS_CHECKPOINT; 117 118 /* 119 * set the current reservation to zero so we know to steal the basic 120 * transaction overhead reservation from the first transaction commit. 121 */ 122 tic->t_curr_res = 0; 123 return tic; 124 } 125 126 /* 127 * After the first stage of log recovery is done, we know where the head and 128 * tail of the log are. We need this log initialisation done before we can 129 * initialise the first CIL checkpoint context. 130 * 131 * Here we allocate a log ticket to track space usage during a CIL push. This 132 * ticket is passed to xlog_write() directly so that we don't slowly leak log 133 * space by failing to account for space used by log headers and additional 134 * region headers for split regions. 135 */ 136 void 137 xlog_cil_init_post_recovery( 138 struct log *log) 139 { 140 if (!log->l_cilp) 141 return; 142 143 log->l_cilp->xc_ctx->ticket = xlog_cil_ticket_alloc(log); 144 log->l_cilp->xc_ctx->sequence = 1; 145 log->l_cilp->xc_ctx->commit_lsn = xlog_assign_lsn(log->l_curr_cycle, 146 log->l_curr_block); 147 } 148 149 /* 150 * Insert the log item into the CIL and calculate the difference in space 151 * consumed by the item. Add the space to the checkpoint ticket and calculate 152 * if the change requires additional log metadata. If it does, take that space 153 * as well. Remove the amount of space we addded to the checkpoint ticket from 154 * the current transaction ticket so that the accounting works out correctly. 155 * 156 * If this is the first time the item is being placed into the CIL in this 157 * context, pin it so it can't be written to disk until the CIL is flushed to 158 * the iclog and the iclog written to disk. 159 */ 160 static void 161 xlog_cil_insert( 162 struct log *log, 163 struct xlog_ticket *ticket, 164 struct xfs_log_item *item, 165 struct xfs_log_vec *lv) 166 { 167 struct xfs_cil *cil = log->l_cilp; 168 struct xfs_log_vec *old = lv->lv_item->li_lv; 169 struct xfs_cil_ctx *ctx = cil->xc_ctx; 170 int len; 171 int diff_iovecs; 172 int iclog_space; 173 174 if (old) { 175 /* existing lv on log item, space used is a delta */ 176 ASSERT(!list_empty(&item->li_cil)); 177 ASSERT(old->lv_buf && old->lv_buf_len && old->lv_niovecs); 178 179 len = lv->lv_buf_len - old->lv_buf_len; 180 diff_iovecs = lv->lv_niovecs - old->lv_niovecs; 181 kmem_free(old->lv_buf); 182 kmem_free(old); 183 } else { 184 /* new lv, must pin the log item */ 185 ASSERT(!lv->lv_item->li_lv); 186 ASSERT(list_empty(&item->li_cil)); 187 188 len = lv->lv_buf_len; 189 diff_iovecs = lv->lv_niovecs; 190 IOP_PIN(lv->lv_item); 191 192 } 193 len += diff_iovecs * sizeof(xlog_op_header_t); 194 195 /* attach new log vector to log item */ 196 lv->lv_item->li_lv = lv; 197 198 spin_lock(&cil->xc_cil_lock); 199 list_move_tail(&item->li_cil, &cil->xc_cil); 200 ctx->nvecs += diff_iovecs; 201 202 /* 203 * If this is the first time the item is being committed to the CIL, 204 * store the sequence number on the log item so we can tell 205 * in future commits whether this is the first checkpoint the item is 206 * being committed into. 207 */ 208 if (!item->li_seq) 209 item->li_seq = ctx->sequence; 210 211 /* 212 * Now transfer enough transaction reservation to the context ticket 213 * for the checkpoint. The context ticket is special - the unit 214 * reservation has to grow as well as the current reservation as we 215 * steal from tickets so we can correctly determine the space used 216 * during the transaction commit. 217 */ 218 if (ctx->ticket->t_curr_res == 0) { 219 /* first commit in checkpoint, steal the header reservation */ 220 ASSERT(ticket->t_curr_res >= ctx->ticket->t_unit_res + len); 221 ctx->ticket->t_curr_res = ctx->ticket->t_unit_res; 222 ticket->t_curr_res -= ctx->ticket->t_unit_res; 223 } 224 225 /* do we need space for more log record headers? */ 226 iclog_space = log->l_iclog_size - log->l_iclog_hsize; 227 if (len > 0 && (ctx->space_used / iclog_space != 228 (ctx->space_used + len) / iclog_space)) { 229 int hdrs; 230 231 hdrs = (len + iclog_space - 1) / iclog_space; 232 /* need to take into account split region headers, too */ 233 hdrs *= log->l_iclog_hsize + sizeof(struct xlog_op_header); 234 ctx->ticket->t_unit_res += hdrs; 235 ctx->ticket->t_curr_res += hdrs; 236 ticket->t_curr_res -= hdrs; 237 ASSERT(ticket->t_curr_res >= len); 238 } 239 ticket->t_curr_res -= len; 240 ctx->space_used += len; 241 242 spin_unlock(&cil->xc_cil_lock); 243 } 244 245 /* 246 * Format log item into a flat buffers 247 * 248 * For delayed logging, we need to hold a formatted buffer containing all the 249 * changes on the log item. This enables us to relog the item in memory and 250 * write it out asynchronously without needing to relock the object that was 251 * modified at the time it gets written into the iclog. 252 * 253 * This function builds a vector for the changes in each log item in the 254 * transaction. It then works out the length of the buffer needed for each log 255 * item, allocates them and formats the vector for the item into the buffer. 256 * The buffer is then attached to the log item are then inserted into the 257 * Committed Item List for tracking until the next checkpoint is written out. 258 * 259 * We don't set up region headers during this process; we simply copy the 260 * regions into the flat buffer. We can do this because we still have to do a 261 * formatting step to write the regions into the iclog buffer. Writing the 262 * ophdrs during the iclog write means that we can support splitting large 263 * regions across iclog boundares without needing a change in the format of the 264 * item/region encapsulation. 265 * 266 * Hence what we need to do now is change the rewrite the vector array to point 267 * to the copied region inside the buffer we just allocated. This allows us to 268 * format the regions into the iclog as though they are being formatted 269 * directly out of the objects themselves. 270 */ 271 static void 272 xlog_cil_format_items( 273 struct log *log, 274 struct xfs_log_vec *log_vector, 275 struct xlog_ticket *ticket, 276 xfs_lsn_t *start_lsn) 277 { 278 struct xfs_log_vec *lv; 279 280 if (start_lsn) 281 *start_lsn = log->l_cilp->xc_ctx->sequence; 282 283 ASSERT(log_vector); 284 for (lv = log_vector; lv; lv = lv->lv_next) { 285 void *ptr; 286 int index; 287 int len = 0; 288 289 /* build the vector array and calculate it's length */ 290 IOP_FORMAT(lv->lv_item, lv->lv_iovecp); 291 for (index = 0; index < lv->lv_niovecs; index++) 292 len += lv->lv_iovecp[index].i_len; 293 294 lv->lv_buf_len = len; 295 lv->lv_buf = kmem_zalloc(lv->lv_buf_len, KM_SLEEP|KM_NOFS); 296 ptr = lv->lv_buf; 297 298 for (index = 0; index < lv->lv_niovecs; index++) { 299 struct xfs_log_iovec *vec = &lv->lv_iovecp[index]; 300 301 memcpy(ptr, vec->i_addr, vec->i_len); 302 vec->i_addr = ptr; 303 ptr += vec->i_len; 304 } 305 ASSERT(ptr == lv->lv_buf + lv->lv_buf_len); 306 307 xlog_cil_insert(log, ticket, lv->lv_item, lv); 308 } 309 } 310 311 static void 312 xlog_cil_free_logvec( 313 struct xfs_log_vec *log_vector) 314 { 315 struct xfs_log_vec *lv; 316 317 for (lv = log_vector; lv; ) { 318 struct xfs_log_vec *next = lv->lv_next; 319 kmem_free(lv->lv_buf); 320 kmem_free(lv); 321 lv = next; 322 } 323 } 324 325 /* 326 * Commit a transaction with the given vector to the Committed Item List. 327 * 328 * To do this, we need to format the item, pin it in memory if required and 329 * account for the space used by the transaction. Once we have done that we 330 * need to release the unused reservation for the transaction, attach the 331 * transaction to the checkpoint context so we carry the busy extents through 332 * to checkpoint completion, and then unlock all the items in the transaction. 333 * 334 * For more specific information about the order of operations in 335 * xfs_log_commit_cil() please refer to the comments in 336 * xfs_trans_commit_iclog(). 337 * 338 * Called with the context lock already held in read mode to lock out 339 * background commit, returns without it held once background commits are 340 * allowed again. 341 */ 342 int 343 xfs_log_commit_cil( 344 struct xfs_mount *mp, 345 struct xfs_trans *tp, 346 struct xfs_log_vec *log_vector, 347 xfs_lsn_t *commit_lsn, 348 int flags) 349 { 350 struct log *log = mp->m_log; 351 int log_flags = 0; 352 int push = 0; 353 354 if (flags & XFS_TRANS_RELEASE_LOG_RES) 355 log_flags = XFS_LOG_REL_PERM_RESERV; 356 357 if (XLOG_FORCED_SHUTDOWN(log)) { 358 xlog_cil_free_logvec(log_vector); 359 return XFS_ERROR(EIO); 360 } 361 362 /* lock out background commit */ 363 down_read(&log->l_cilp->xc_ctx_lock); 364 xlog_cil_format_items(log, log_vector, tp->t_ticket, commit_lsn); 365 366 /* check we didn't blow the reservation */ 367 if (tp->t_ticket->t_curr_res < 0) 368 xlog_print_tic_res(log->l_mp, tp->t_ticket); 369 370 /* attach the transaction to the CIL if it has any busy extents */ 371 if (!list_empty(&tp->t_busy)) { 372 spin_lock(&log->l_cilp->xc_cil_lock); 373 list_splice_init(&tp->t_busy, 374 &log->l_cilp->xc_ctx->busy_extents); 375 spin_unlock(&log->l_cilp->xc_cil_lock); 376 } 377 378 tp->t_commit_lsn = *commit_lsn; 379 xfs_log_done(mp, tp->t_ticket, NULL, log_flags); 380 xfs_trans_unreserve_and_mod_sb(tp); 381 382 /* check for background commit before unlock */ 383 if (log->l_cilp->xc_ctx->space_used > XLOG_CIL_SPACE_LIMIT(log)) 384 push = 1; 385 up_read(&log->l_cilp->xc_ctx_lock); 386 387 /* 388 * We need to push CIL every so often so we don't cache more than we 389 * can fit in the log. The limit really is that a checkpoint can't be 390 * more than half the log (the current checkpoint is not allowed to 391 * overwrite the previous checkpoint), but commit latency and memory 392 * usage limit this to a smaller size in most cases. 393 */ 394 if (push) 395 xlog_cil_push(log, 0); 396 return 0; 397 } 398 399 /* 400 * Mark all items committed and clear busy extents. We free the log vector 401 * chains in a separate pass so that we unpin the log items as quickly as 402 * possible. 403 */ 404 static void 405 xlog_cil_committed( 406 void *args, 407 int abort) 408 { 409 struct xfs_cil_ctx *ctx = args; 410 struct xfs_log_vec *lv; 411 int abortflag = abort ? XFS_LI_ABORTED : 0; 412 struct xfs_busy_extent *busyp, *n; 413 414 /* unpin all the log items */ 415 for (lv = ctx->lv_chain; lv; lv = lv->lv_next ) { 416 xfs_trans_item_committed(lv->lv_item, ctx->start_lsn, 417 abortflag); 418 } 419 420 list_for_each_entry_safe(busyp, n, &ctx->busy_extents, list) 421 xfs_alloc_busy_clear(ctx->cil->xc_log->l_mp, busyp); 422 423 spin_lock(&ctx->cil->xc_cil_lock); 424 list_del(&ctx->committing); 425 spin_unlock(&ctx->cil->xc_cil_lock); 426 427 xlog_cil_free_logvec(ctx->lv_chain); 428 kmem_free(ctx); 429 } 430 431 /* 432 * Push the Committed Item List to the log. If the push_now flag is not set, 433 * then it is a background flush and so we can chose to ignore it. 434 */ 435 int 436 xlog_cil_push( 437 struct log *log, 438 int push_now) 439 { 440 struct xfs_cil *cil = log->l_cilp; 441 struct xfs_log_vec *lv; 442 struct xfs_cil_ctx *ctx; 443 struct xfs_cil_ctx *new_ctx; 444 struct xlog_in_core *commit_iclog; 445 struct xlog_ticket *tic; 446 int num_lv; 447 int num_iovecs; 448 int len; 449 int error = 0; 450 struct xfs_trans_header thdr; 451 struct xfs_log_iovec lhdr; 452 struct xfs_log_vec lvhdr = { NULL }; 453 xfs_lsn_t commit_lsn; 454 455 if (!cil) 456 return 0; 457 458 new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_SLEEP|KM_NOFS); 459 new_ctx->ticket = xlog_cil_ticket_alloc(log); 460 461 /* lock out transaction commit, but don't block on background push */ 462 if (!down_write_trylock(&cil->xc_ctx_lock)) { 463 if (!push_now) 464 goto out_free_ticket; 465 down_write(&cil->xc_ctx_lock); 466 } 467 ctx = cil->xc_ctx; 468 469 /* check if we've anything to push */ 470 if (list_empty(&cil->xc_cil)) 471 goto out_skip; 472 473 /* check for spurious background flush */ 474 if (!push_now && cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) 475 goto out_skip; 476 477 /* 478 * pull all the log vectors off the items in the CIL, and 479 * remove the items from the CIL. We don't need the CIL lock 480 * here because it's only needed on the transaction commit 481 * side which is currently locked out by the flush lock. 482 */ 483 lv = NULL; 484 num_lv = 0; 485 num_iovecs = 0; 486 len = 0; 487 while (!list_empty(&cil->xc_cil)) { 488 struct xfs_log_item *item; 489 int i; 490 491 item = list_first_entry(&cil->xc_cil, 492 struct xfs_log_item, li_cil); 493 list_del_init(&item->li_cil); 494 if (!ctx->lv_chain) 495 ctx->lv_chain = item->li_lv; 496 else 497 lv->lv_next = item->li_lv; 498 lv = item->li_lv; 499 item->li_lv = NULL; 500 501 num_lv++; 502 num_iovecs += lv->lv_niovecs; 503 for (i = 0; i < lv->lv_niovecs; i++) 504 len += lv->lv_iovecp[i].i_len; 505 } 506 507 /* 508 * initialise the new context and attach it to the CIL. Then attach 509 * the current context to the CIL committing lsit so it can be found 510 * during log forces to extract the commit lsn of the sequence that 511 * needs to be forced. 512 */ 513 INIT_LIST_HEAD(&new_ctx->committing); 514 INIT_LIST_HEAD(&new_ctx->busy_extents); 515 new_ctx->sequence = ctx->sequence + 1; 516 new_ctx->cil = cil; 517 cil->xc_ctx = new_ctx; 518 519 /* 520 * The switch is now done, so we can drop the context lock and move out 521 * of a shared context. We can't just go straight to the commit record, 522 * though - we need to synchronise with previous and future commits so 523 * that the commit records are correctly ordered in the log to ensure 524 * that we process items during log IO completion in the correct order. 525 * 526 * For example, if we get an EFI in one checkpoint and the EFD in the 527 * next (e.g. due to log forces), we do not want the checkpoint with 528 * the EFD to be committed before the checkpoint with the EFI. Hence 529 * we must strictly order the commit records of the checkpoints so 530 * that: a) the checkpoint callbacks are attached to the iclogs in the 531 * correct order; and b) the checkpoints are replayed in correct order 532 * in log recovery. 533 * 534 * Hence we need to add this context to the committing context list so 535 * that higher sequences will wait for us to write out a commit record 536 * before they do. 537 */ 538 spin_lock(&cil->xc_cil_lock); 539 list_add(&ctx->committing, &cil->xc_committing); 540 spin_unlock(&cil->xc_cil_lock); 541 up_write(&cil->xc_ctx_lock); 542 543 /* 544 * Build a checkpoint transaction header and write it to the log to 545 * begin the transaction. We need to account for the space used by the 546 * transaction header here as it is not accounted for in xlog_write(). 547 * 548 * The LSN we need to pass to the log items on transaction commit is 549 * the LSN reported by the first log vector write. If we use the commit 550 * record lsn then we can move the tail beyond the grant write head. 551 */ 552 tic = ctx->ticket; 553 thdr.th_magic = XFS_TRANS_HEADER_MAGIC; 554 thdr.th_type = XFS_TRANS_CHECKPOINT; 555 thdr.th_tid = tic->t_tid; 556 thdr.th_num_items = num_iovecs; 557 lhdr.i_addr = (xfs_caddr_t)&thdr; 558 lhdr.i_len = sizeof(xfs_trans_header_t); 559 lhdr.i_type = XLOG_REG_TYPE_TRANSHDR; 560 tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t); 561 562 lvhdr.lv_niovecs = 1; 563 lvhdr.lv_iovecp = &lhdr; 564 lvhdr.lv_next = ctx->lv_chain; 565 566 error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0); 567 if (error) 568 goto out_abort; 569 570 /* 571 * now that we've written the checkpoint into the log, strictly 572 * order the commit records so replay will get them in the right order. 573 */ 574 restart: 575 spin_lock(&cil->xc_cil_lock); 576 list_for_each_entry(new_ctx, &cil->xc_committing, committing) { 577 /* 578 * Higher sequences will wait for this one so skip them. 579 * Don't wait for own own sequence, either. 580 */ 581 if (new_ctx->sequence >= ctx->sequence) 582 continue; 583 if (!new_ctx->commit_lsn) { 584 /* 585 * It is still being pushed! Wait for the push to 586 * complete, then start again from the beginning. 587 */ 588 sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0); 589 goto restart; 590 } 591 } 592 spin_unlock(&cil->xc_cil_lock); 593 594 commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, 0); 595 if (error || commit_lsn == -1) 596 goto out_abort; 597 598 /* attach all the transactions w/ busy extents to iclog */ 599 ctx->log_cb.cb_func = xlog_cil_committed; 600 ctx->log_cb.cb_arg = ctx; 601 error = xfs_log_notify(log->l_mp, commit_iclog, &ctx->log_cb); 602 if (error) 603 goto out_abort; 604 605 /* 606 * now the checkpoint commit is complete and we've attached the 607 * callbacks to the iclog we can assign the commit LSN to the context 608 * and wake up anyone who is waiting for the commit to complete. 609 */ 610 spin_lock(&cil->xc_cil_lock); 611 ctx->commit_lsn = commit_lsn; 612 sv_broadcast(&cil->xc_commit_wait); 613 spin_unlock(&cil->xc_cil_lock); 614 615 /* release the hounds! */ 616 return xfs_log_release_iclog(log->l_mp, commit_iclog); 617 618 out_skip: 619 up_write(&cil->xc_ctx_lock); 620 out_free_ticket: 621 xfs_log_ticket_put(new_ctx->ticket); 622 kmem_free(new_ctx); 623 return 0; 624 625 out_abort: 626 xlog_cil_committed(ctx, XFS_LI_ABORTED); 627 return XFS_ERROR(EIO); 628 } 629 630 /* 631 * Conditionally push the CIL based on the sequence passed in. 632 * 633 * We only need to push if we haven't already pushed the sequence 634 * number given. Hence the only time we will trigger a push here is 635 * if the push sequence is the same as the current context. 636 * 637 * We return the current commit lsn to allow the callers to determine if a 638 * iclog flush is necessary following this call. 639 * 640 * XXX: Initially, just push the CIL unconditionally and return whatever 641 * commit lsn is there. It'll be empty, so this is broken for now. 642 */ 643 xfs_lsn_t 644 xlog_cil_push_lsn( 645 struct log *log, 646 xfs_lsn_t push_seq) 647 { 648 struct xfs_cil *cil = log->l_cilp; 649 struct xfs_cil_ctx *ctx; 650 xfs_lsn_t commit_lsn = NULLCOMMITLSN; 651 652 restart: 653 down_write(&cil->xc_ctx_lock); 654 ASSERT(push_seq <= cil->xc_ctx->sequence); 655 656 /* check to see if we need to force out the current context */ 657 if (push_seq == cil->xc_ctx->sequence) { 658 up_write(&cil->xc_ctx_lock); 659 xlog_cil_push(log, 1); 660 goto restart; 661 } 662 663 /* 664 * See if we can find a previous sequence still committing. 665 * We can drop the flush lock as soon as we have the cil lock 666 * because we are now only comparing contexts protected by 667 * the cil lock. 668 * 669 * We need to wait for all previous sequence commits to complete 670 * before allowing the force of push_seq to go ahead. Hence block 671 * on commits for those as well. 672 */ 673 spin_lock(&cil->xc_cil_lock); 674 up_write(&cil->xc_ctx_lock); 675 list_for_each_entry(ctx, &cil->xc_committing, committing) { 676 if (ctx->sequence > push_seq) 677 continue; 678 if (!ctx->commit_lsn) { 679 /* 680 * It is still being pushed! Wait for the push to 681 * complete, then start again from the beginning. 682 */ 683 sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0); 684 goto restart; 685 } 686 if (ctx->sequence != push_seq) 687 continue; 688 /* found it! */ 689 commit_lsn = ctx->commit_lsn; 690 } 691 spin_unlock(&cil->xc_cil_lock); 692 return commit_lsn; 693 } 694 695 /* 696 * Check if the current log item was first committed in this sequence. 697 * We can't rely on just the log item being in the CIL, we have to check 698 * the recorded commit sequence number. 699 * 700 * Note: for this to be used in a non-racy manner, it has to be called with 701 * CIL flushing locked out. As a result, it should only be used during the 702 * transaction commit process when deciding what to format into the item. 703 */ 704 bool 705 xfs_log_item_in_current_chkpt( 706 struct xfs_log_item *lip) 707 { 708 struct xfs_cil_ctx *ctx; 709 710 if (!(lip->li_mountp->m_flags & XFS_MOUNT_DELAYLOG)) 711 return false; 712 if (list_empty(&lip->li_cil)) 713 return false; 714 715 ctx = lip->li_mountp->m_log->l_cilp->xc_ctx; 716 717 /* 718 * li_seq is written on the first commit of a log item to record the 719 * first checkpoint it is written to. Hence if it is different to the 720 * current sequence, we're in a new checkpoint. 721 */ 722 if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0) 723 return false; 724 return true; 725 } 726