1 /* 2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. 3 * Copyright (c) 2008 Dave Chinner 4 * All Rights Reserved. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it would be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 */ 19 #include "xfs.h" 20 #include "xfs_fs.h" 21 #include "xfs_types.h" 22 #include "xfs_log.h" 23 #include "xfs_inum.h" 24 #include "xfs_trans.h" 25 #include "xfs_sb.h" 26 #include "xfs_ag.h" 27 #include "xfs_mount.h" 28 #include "xfs_trans_priv.h" 29 #include "xfs_error.h" 30 31 STATIC void xfs_ail_insert(struct xfs_ail *, xfs_log_item_t *); 32 STATIC xfs_log_item_t * xfs_ail_delete(struct xfs_ail *, xfs_log_item_t *); 33 STATIC xfs_log_item_t * xfs_ail_min(struct xfs_ail *); 34 STATIC xfs_log_item_t * xfs_ail_next(struct xfs_ail *, xfs_log_item_t *); 35 36 #ifdef DEBUG 37 STATIC void xfs_ail_check(struct xfs_ail *, xfs_log_item_t *); 38 #else 39 #define xfs_ail_check(a,l) 40 #endif /* DEBUG */ 41 42 43 /* 44 * This is called by the log manager code to determine the LSN 45 * of the tail of the log. This is exactly the LSN of the first 46 * item in the AIL. If the AIL is empty, then this function 47 * returns 0. 48 * 49 * We need the AIL lock in order to get a coherent read of the 50 * lsn of the last item in the AIL. 51 */ 52 xfs_lsn_t 53 xfs_trans_ail_tail( 54 struct xfs_ail *ailp) 55 { 56 xfs_lsn_t lsn; 57 xfs_log_item_t *lip; 58 59 spin_lock(&ailp->xa_lock); 60 lip = xfs_ail_min(ailp); 61 if (lip == NULL) { 62 lsn = (xfs_lsn_t)0; 63 } else { 64 lsn = lip->li_lsn; 65 } 66 spin_unlock(&ailp->xa_lock); 67 68 return lsn; 69 } 70 71 /* 72 * xfs_trans_push_ail 73 * 74 * This routine is called to move the tail of the AIL forward. It does this by 75 * trying to flush items in the AIL whose lsns are below the given 76 * threshold_lsn. 77 * 78 * the push is run asynchronously in a separate thread, so we return the tail 79 * of the log right now instead of the tail after the push. This means we will 80 * either continue right away, or we will sleep waiting on the async thread to 81 * do its work. 82 * 83 * We do this unlocked - we only need to know whether there is anything in the 84 * AIL at the time we are called. We don't need to access the contents of 85 * any of the objects, so the lock is not needed. 86 */ 87 void 88 xfs_trans_ail_push( 89 struct xfs_ail *ailp, 90 xfs_lsn_t threshold_lsn) 91 { 92 xfs_log_item_t *lip; 93 94 lip = xfs_ail_min(ailp); 95 if (lip && !XFS_FORCED_SHUTDOWN(ailp->xa_mount)) { 96 if (XFS_LSN_CMP(threshold_lsn, ailp->xa_target) > 0) 97 xfsaild_wakeup(ailp, threshold_lsn); 98 } 99 } 100 101 /* 102 * AIL traversal cursor initialisation. 103 * 104 * The cursor keeps track of where our current traversal is up 105 * to by tracking the next ƣtem in the list for us. However, for 106 * this to be safe, removing an object from the AIL needs to invalidate 107 * any cursor that points to it. hence the traversal cursor needs to 108 * be linked to the struct xfs_ail so that deletion can search all the 109 * active cursors for invalidation. 110 * 111 * We don't link the push cursor because it is embedded in the struct 112 * xfs_ail and hence easily findable. 113 */ 114 STATIC void 115 xfs_trans_ail_cursor_init( 116 struct xfs_ail *ailp, 117 struct xfs_ail_cursor *cur) 118 { 119 cur->item = NULL; 120 if (cur == &ailp->xa_cursors) 121 return; 122 123 cur->next = ailp->xa_cursors.next; 124 ailp->xa_cursors.next = cur; 125 } 126 127 /* 128 * Set the cursor to the next item, because when we look 129 * up the cursor the current item may have been freed. 130 */ 131 STATIC void 132 xfs_trans_ail_cursor_set( 133 struct xfs_ail *ailp, 134 struct xfs_ail_cursor *cur, 135 struct xfs_log_item *lip) 136 { 137 if (lip) 138 cur->item = xfs_ail_next(ailp, lip); 139 } 140 141 /* 142 * Get the next item in the traversal and advance the cursor. 143 * If the cursor was invalidated (inidicated by a lip of 1), 144 * restart the traversal. 145 */ 146 struct xfs_log_item * 147 xfs_trans_ail_cursor_next( 148 struct xfs_ail *ailp, 149 struct xfs_ail_cursor *cur) 150 { 151 struct xfs_log_item *lip = cur->item; 152 153 if ((__psint_t)lip & 1) 154 lip = xfs_ail_min(ailp); 155 xfs_trans_ail_cursor_set(ailp, cur, lip); 156 return lip; 157 } 158 159 /* 160 * Now that the traversal is complete, we need to remove the cursor 161 * from the list of traversing cursors. Avoid removing the embedded 162 * push cursor, but use the fact it is always present to make the 163 * list deletion simple. 164 */ 165 void 166 xfs_trans_ail_cursor_done( 167 struct xfs_ail *ailp, 168 struct xfs_ail_cursor *done) 169 { 170 struct xfs_ail_cursor *prev = NULL; 171 struct xfs_ail_cursor *cur; 172 173 done->item = NULL; 174 if (done == &ailp->xa_cursors) 175 return; 176 prev = &ailp->xa_cursors; 177 for (cur = prev->next; cur; prev = cur, cur = prev->next) { 178 if (cur == done) { 179 prev->next = cur->next; 180 break; 181 } 182 } 183 ASSERT(cur); 184 } 185 186 /* 187 * Invalidate any cursor that is pointing to this item. This is 188 * called when an item is removed from the AIL. Any cursor pointing 189 * to this object is now invalid and the traversal needs to be 190 * terminated so it doesn't reference a freed object. We set the 191 * cursor item to a value of 1 so we can distinguish between an 192 * invalidation and the end of the list when getting the next item 193 * from the cursor. 194 */ 195 STATIC void 196 xfs_trans_ail_cursor_clear( 197 struct xfs_ail *ailp, 198 struct xfs_log_item *lip) 199 { 200 struct xfs_ail_cursor *cur; 201 202 /* need to search all cursors */ 203 for (cur = &ailp->xa_cursors; cur; cur = cur->next) { 204 if (cur->item == lip) 205 cur->item = (struct xfs_log_item *) 206 ((__psint_t)cur->item | 1); 207 } 208 } 209 210 /* 211 * Return the item in the AIL with the current lsn. 212 * Return the current tree generation number for use 213 * in calls to xfs_trans_next_ail(). 214 */ 215 xfs_log_item_t * 216 xfs_trans_ail_cursor_first( 217 struct xfs_ail *ailp, 218 struct xfs_ail_cursor *cur, 219 xfs_lsn_t lsn) 220 { 221 xfs_log_item_t *lip; 222 223 xfs_trans_ail_cursor_init(ailp, cur); 224 lip = xfs_ail_min(ailp); 225 if (lsn == 0) 226 goto out; 227 228 list_for_each_entry(lip, &ailp->xa_ail, li_ail) { 229 if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0) 230 goto out; 231 } 232 lip = NULL; 233 out: 234 xfs_trans_ail_cursor_set(ailp, cur, lip); 235 return lip; 236 } 237 238 /* 239 * xfsaild_push does the work of pushing on the AIL. Returning a timeout of 240 * zero indicates that the caller should sleep until woken. 241 */ 242 long 243 xfsaild_push( 244 struct xfs_ail *ailp, 245 xfs_lsn_t *last_lsn) 246 { 247 long tout = 0; 248 xfs_lsn_t last_pushed_lsn = *last_lsn; 249 xfs_lsn_t target = ailp->xa_target; 250 xfs_lsn_t lsn; 251 xfs_log_item_t *lip; 252 int flush_log, count, stuck; 253 xfs_mount_t *mp = ailp->xa_mount; 254 struct xfs_ail_cursor *cur = &ailp->xa_cursors; 255 int push_xfsbufd = 0; 256 257 spin_lock(&ailp->xa_lock); 258 xfs_trans_ail_cursor_init(ailp, cur); 259 lip = xfs_trans_ail_cursor_first(ailp, cur, *last_lsn); 260 if (!lip || XFS_FORCED_SHUTDOWN(mp)) { 261 /* 262 * AIL is empty or our push has reached the end. 263 */ 264 xfs_trans_ail_cursor_done(ailp, cur); 265 spin_unlock(&ailp->xa_lock); 266 *last_lsn = 0; 267 return tout; 268 } 269 270 XFS_STATS_INC(xs_push_ail); 271 272 /* 273 * While the item we are looking at is below the given threshold 274 * try to flush it out. We'd like not to stop until we've at least 275 * tried to push on everything in the AIL with an LSN less than 276 * the given threshold. 277 * 278 * However, we will stop after a certain number of pushes and wait 279 * for a reduced timeout to fire before pushing further. This 280 * prevents use from spinning when we can't do anything or there is 281 * lots of contention on the AIL lists. 282 */ 283 lsn = lip->li_lsn; 284 flush_log = stuck = count = 0; 285 while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) { 286 int lock_result; 287 /* 288 * If we can lock the item without sleeping, unlock the AIL 289 * lock and flush the item. Then re-grab the AIL lock so we 290 * can look for the next item on the AIL. List changes are 291 * handled by the AIL lookup functions internally 292 * 293 * If we can't lock the item, either its holder will flush it 294 * or it is already being flushed or it is being relogged. In 295 * any of these case it is being taken care of and we can just 296 * skip to the next item in the list. 297 */ 298 lock_result = IOP_TRYLOCK(lip); 299 spin_unlock(&ailp->xa_lock); 300 switch (lock_result) { 301 case XFS_ITEM_SUCCESS: 302 XFS_STATS_INC(xs_push_ail_success); 303 IOP_PUSH(lip); 304 last_pushed_lsn = lsn; 305 break; 306 307 case XFS_ITEM_PUSHBUF: 308 XFS_STATS_INC(xs_push_ail_pushbuf); 309 IOP_PUSHBUF(lip); 310 last_pushed_lsn = lsn; 311 push_xfsbufd = 1; 312 break; 313 314 case XFS_ITEM_PINNED: 315 XFS_STATS_INC(xs_push_ail_pinned); 316 stuck++; 317 flush_log = 1; 318 break; 319 320 case XFS_ITEM_LOCKED: 321 XFS_STATS_INC(xs_push_ail_locked); 322 last_pushed_lsn = lsn; 323 stuck++; 324 break; 325 326 default: 327 ASSERT(0); 328 break; 329 } 330 331 spin_lock(&ailp->xa_lock); 332 /* should we bother continuing? */ 333 if (XFS_FORCED_SHUTDOWN(mp)) 334 break; 335 ASSERT(mp->m_log); 336 337 count++; 338 339 /* 340 * Are there too many items we can't do anything with? 341 * If we we are skipping too many items because we can't flush 342 * them or they are already being flushed, we back off and 343 * given them time to complete whatever operation is being 344 * done. i.e. remove pressure from the AIL while we can't make 345 * progress so traversals don't slow down further inserts and 346 * removals to/from the AIL. 347 * 348 * The value of 100 is an arbitrary magic number based on 349 * observation. 350 */ 351 if (stuck > 100) 352 break; 353 354 lip = xfs_trans_ail_cursor_next(ailp, cur); 355 if (lip == NULL) 356 break; 357 lsn = lip->li_lsn; 358 } 359 xfs_trans_ail_cursor_done(ailp, cur); 360 spin_unlock(&ailp->xa_lock); 361 362 if (flush_log) { 363 /* 364 * If something we need to push out was pinned, then 365 * push out the log so it will become unpinned and 366 * move forward in the AIL. 367 */ 368 XFS_STATS_INC(xs_push_ail_flush); 369 xfs_log_force(mp, 0); 370 } 371 372 if (push_xfsbufd) { 373 /* we've got delayed write buffers to flush */ 374 wake_up_process(mp->m_ddev_targp->bt_task); 375 } 376 377 if (!count) { 378 /* We're past our target or empty, so idle */ 379 last_pushed_lsn = 0; 380 } else if (XFS_LSN_CMP(lsn, target) >= 0) { 381 /* 382 * We reached the target so wait a bit longer for I/O to 383 * complete and remove pushed items from the AIL before we 384 * start the next scan from the start of the AIL. 385 */ 386 tout = 50; 387 last_pushed_lsn = 0; 388 } else if ((stuck * 100) / count > 90) { 389 /* 390 * Either there is a lot of contention on the AIL or we 391 * are stuck due to operations in progress. "Stuck" in this 392 * case is defined as >90% of the items we tried to push 393 * were stuck. 394 * 395 * Backoff a bit more to allow some I/O to complete before 396 * continuing from where we were. 397 */ 398 tout = 20; 399 } else { 400 /* more to do, but wait a short while before continuing */ 401 tout = 10; 402 } 403 *last_lsn = last_pushed_lsn; 404 return tout; 405 } 406 407 408 /* 409 * This is to be called when an item is unlocked that may have 410 * been in the AIL. It will wake up the first member of the AIL 411 * wait list if this item's unlocking might allow it to progress. 412 * If the item is in the AIL, then we need to get the AIL lock 413 * while doing our checking so we don't race with someone going 414 * to sleep waiting for this event in xfs_trans_push_ail(). 415 */ 416 void 417 xfs_trans_unlocked_item( 418 struct xfs_ail *ailp, 419 xfs_log_item_t *lip) 420 { 421 xfs_log_item_t *min_lip; 422 423 /* 424 * If we're forcibly shutting down, we may have 425 * unlocked log items arbitrarily. The last thing 426 * we want to do is to move the tail of the log 427 * over some potentially valid data. 428 */ 429 if (!(lip->li_flags & XFS_LI_IN_AIL) || 430 XFS_FORCED_SHUTDOWN(ailp->xa_mount)) { 431 return; 432 } 433 434 /* 435 * This is the one case where we can call into xfs_ail_min() 436 * without holding the AIL lock because we only care about the 437 * case where we are at the tail of the AIL. If the object isn't 438 * at the tail, it doesn't matter what result we get back. This 439 * is slightly racy because since we were just unlocked, we could 440 * go to sleep between the call to xfs_ail_min and the call to 441 * xfs_log_move_tail, have someone else lock us, commit to us disk, 442 * move us out of the tail of the AIL, and then we wake up. However, 443 * the call to xfs_log_move_tail() doesn't do anything if there's 444 * not enough free space to wake people up so we're safe calling it. 445 */ 446 min_lip = xfs_ail_min(ailp); 447 448 if (min_lip == lip) 449 xfs_log_move_tail(ailp->xa_mount, 1); 450 } /* xfs_trans_unlocked_item */ 451 452 453 /* 454 * Update the position of the item in the AIL with the new 455 * lsn. If it is not yet in the AIL, add it. Otherwise, move 456 * it to its new position by removing it and re-adding it. 457 * 458 * Wakeup anyone with an lsn less than the item's lsn. If the item 459 * we move in the AIL is the minimum one, update the tail lsn in the 460 * log manager. 461 * 462 * This function must be called with the AIL lock held. The lock 463 * is dropped before returning. 464 */ 465 void 466 xfs_trans_ail_update( 467 struct xfs_ail *ailp, 468 xfs_log_item_t *lip, 469 xfs_lsn_t lsn) __releases(ailp->xa_lock) 470 { 471 xfs_log_item_t *dlip = NULL; 472 xfs_log_item_t *mlip; /* ptr to minimum lip */ 473 xfs_lsn_t tail_lsn; 474 475 mlip = xfs_ail_min(ailp); 476 477 if (lip->li_flags & XFS_LI_IN_AIL) { 478 dlip = xfs_ail_delete(ailp, lip); 479 ASSERT(dlip == lip); 480 xfs_trans_ail_cursor_clear(ailp, dlip); 481 } else { 482 lip->li_flags |= XFS_LI_IN_AIL; 483 } 484 485 lip->li_lsn = lsn; 486 xfs_ail_insert(ailp, lip); 487 488 if (mlip == dlip) { 489 mlip = xfs_ail_min(ailp); 490 /* 491 * It is not safe to access mlip after the AIL lock is 492 * dropped, so we must get a copy of li_lsn before we do 493 * so. This is especially important on 32-bit platforms 494 * where accessing and updating 64-bit values like li_lsn 495 * is not atomic. 496 */ 497 tail_lsn = mlip->li_lsn; 498 spin_unlock(&ailp->xa_lock); 499 xfs_log_move_tail(ailp->xa_mount, tail_lsn); 500 } else { 501 spin_unlock(&ailp->xa_lock); 502 } 503 504 505 } /* xfs_trans_update_ail */ 506 507 /* 508 * Delete the given item from the AIL. It must already be in 509 * the AIL. 510 * 511 * Wakeup anyone with an lsn less than item's lsn. If the item 512 * we delete in the AIL is the minimum one, update the tail lsn in the 513 * log manager. 514 * 515 * Clear the IN_AIL flag from the item, reset its lsn to 0, and 516 * bump the AIL's generation count to indicate that the tree 517 * has changed. 518 * 519 * This function must be called with the AIL lock held. The lock 520 * is dropped before returning. 521 */ 522 void 523 xfs_trans_ail_delete( 524 struct xfs_ail *ailp, 525 xfs_log_item_t *lip) __releases(ailp->xa_lock) 526 { 527 xfs_log_item_t *dlip; 528 xfs_log_item_t *mlip; 529 xfs_lsn_t tail_lsn; 530 531 if (lip->li_flags & XFS_LI_IN_AIL) { 532 mlip = xfs_ail_min(ailp); 533 dlip = xfs_ail_delete(ailp, lip); 534 ASSERT(dlip == lip); 535 xfs_trans_ail_cursor_clear(ailp, dlip); 536 537 538 lip->li_flags &= ~XFS_LI_IN_AIL; 539 lip->li_lsn = 0; 540 541 if (mlip == dlip) { 542 mlip = xfs_ail_min(ailp); 543 /* 544 * It is not safe to access mlip after the AIL lock 545 * is dropped, so we must get a copy of li_lsn 546 * before we do so. This is especially important 547 * on 32-bit platforms where accessing and updating 548 * 64-bit values like li_lsn is not atomic. 549 */ 550 tail_lsn = mlip ? mlip->li_lsn : 0; 551 spin_unlock(&ailp->xa_lock); 552 xfs_log_move_tail(ailp->xa_mount, tail_lsn); 553 } else { 554 spin_unlock(&ailp->xa_lock); 555 } 556 } 557 else { 558 /* 559 * If the file system is not being shutdown, we are in 560 * serious trouble if we get to this stage. 561 */ 562 struct xfs_mount *mp = ailp->xa_mount; 563 564 spin_unlock(&ailp->xa_lock); 565 if (!XFS_FORCED_SHUTDOWN(mp)) { 566 xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp, 567 "%s: attempting to delete a log item that is not in the AIL", 568 __func__); 569 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); 570 } 571 } 572 } 573 574 575 576 /* 577 * The active item list (AIL) is a doubly linked list of log 578 * items sorted by ascending lsn. The base of the list is 579 * a forw/back pointer pair embedded in the xfs mount structure. 580 * The base is initialized with both pointers pointing to the 581 * base. This case always needs to be distinguished, because 582 * the base has no lsn to look at. We almost always insert 583 * at the end of the list, so on inserts we search from the 584 * end of the list to find where the new item belongs. 585 */ 586 587 /* 588 * Initialize the doubly linked list to point only to itself. 589 */ 590 int 591 xfs_trans_ail_init( 592 xfs_mount_t *mp) 593 { 594 struct xfs_ail *ailp; 595 int error; 596 597 ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL); 598 if (!ailp) 599 return ENOMEM; 600 601 ailp->xa_mount = mp; 602 INIT_LIST_HEAD(&ailp->xa_ail); 603 spin_lock_init(&ailp->xa_lock); 604 error = xfsaild_start(ailp); 605 if (error) 606 goto out_free_ailp; 607 mp->m_ail = ailp; 608 return 0; 609 610 out_free_ailp: 611 kmem_free(ailp); 612 return error; 613 } 614 615 void 616 xfs_trans_ail_destroy( 617 xfs_mount_t *mp) 618 { 619 struct xfs_ail *ailp = mp->m_ail; 620 621 xfsaild_stop(ailp); 622 kmem_free(ailp); 623 } 624 625 /* 626 * Insert the given log item into the AIL. 627 * We almost always insert at the end of the list, so on inserts 628 * we search from the end of the list to find where the 629 * new item belongs. 630 */ 631 STATIC void 632 xfs_ail_insert( 633 struct xfs_ail *ailp, 634 xfs_log_item_t *lip) 635 /* ARGSUSED */ 636 { 637 xfs_log_item_t *next_lip; 638 639 /* 640 * If the list is empty, just insert the item. 641 */ 642 if (list_empty(&ailp->xa_ail)) { 643 list_add(&lip->li_ail, &ailp->xa_ail); 644 return; 645 } 646 647 list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) { 648 if (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0) 649 break; 650 } 651 652 ASSERT((&next_lip->li_ail == &ailp->xa_ail) || 653 (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0)); 654 655 list_add(&lip->li_ail, &next_lip->li_ail); 656 657 xfs_ail_check(ailp, lip); 658 return; 659 } 660 661 /* 662 * Delete the given item from the AIL. Return a pointer to the item. 663 */ 664 /*ARGSUSED*/ 665 STATIC xfs_log_item_t * 666 xfs_ail_delete( 667 struct xfs_ail *ailp, 668 xfs_log_item_t *lip) 669 /* ARGSUSED */ 670 { 671 xfs_ail_check(ailp, lip); 672 673 list_del(&lip->li_ail); 674 675 return lip; 676 } 677 678 /* 679 * Return a pointer to the first item in the AIL. 680 * If the AIL is empty, then return NULL. 681 */ 682 STATIC xfs_log_item_t * 683 xfs_ail_min( 684 struct xfs_ail *ailp) 685 /* ARGSUSED */ 686 { 687 if (list_empty(&ailp->xa_ail)) 688 return NULL; 689 690 return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); 691 } 692 693 /* 694 * Return a pointer to the item which follows 695 * the given item in the AIL. If the given item 696 * is the last item in the list, then return NULL. 697 */ 698 STATIC xfs_log_item_t * 699 xfs_ail_next( 700 struct xfs_ail *ailp, 701 xfs_log_item_t *lip) 702 /* ARGSUSED */ 703 { 704 if (lip->li_ail.next == &ailp->xa_ail) 705 return NULL; 706 707 return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail); 708 } 709 710 #ifdef DEBUG 711 /* 712 * Check that the list is sorted as it should be. 713 */ 714 STATIC void 715 xfs_ail_check( 716 struct xfs_ail *ailp, 717 xfs_log_item_t *lip) 718 { 719 xfs_log_item_t *prev_lip; 720 721 if (list_empty(&ailp->xa_ail)) 722 return; 723 724 /* 725 * Check the next and previous entries are valid. 726 */ 727 ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); 728 prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail); 729 if (&prev_lip->li_ail != &ailp->xa_ail) 730 ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); 731 732 prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail); 733 if (&prev_lip->li_ail != &ailp->xa_ail) 734 ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0); 735 736 737 #ifdef XFS_TRANS_DEBUG 738 /* 739 * Walk the list checking lsn ordering, and that every entry has the 740 * XFS_LI_IN_AIL flag set. This is really expensive, so only do it 741 * when specifically debugging the transaction subsystem. 742 */ 743 prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); 744 list_for_each_entry(lip, &ailp->xa_ail, li_ail) { 745 if (&prev_lip->li_ail != &ailp->xa_ail) 746 ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); 747 ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); 748 prev_lip = lip; 749 } 750 #endif /* XFS_TRANS_DEBUG */ 751 } 752 #endif /* DEBUG */ 753