1 /* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. 4 * 5 * This copyrighted material is made available to anyone wishing to use, 6 * modify, copy, or redistribute it subject to the terms and conditions 7 * of the GNU General Public License version 2. 8 */ 9 10 #include <linux/sched.h> 11 #include <linux/slab.h> 12 #include <linux/spinlock.h> 13 #include <linux/completion.h> 14 #include <linux/buffer_head.h> 15 #include <linux/gfs2_ondisk.h> 16 #include <linux/crc32.h> 17 #include <linux/lm_interface.h> 18 19 #include "gfs2.h" 20 #include "incore.h" 21 #include "bmap.h" 22 #include "glock.h" 23 #include "log.h" 24 #include "lops.h" 25 #include "meta_io.h" 26 #include "util.h" 27 #include "dir.h" 28 29 #define PULL 1 30 31 /** 32 * gfs2_struct2blk - compute stuff 33 * @sdp: the filesystem 34 * @nstruct: the number of structures 35 * @ssize: the size of the structures 36 * 37 * Compute the number of log descriptor blocks needed to hold a certain number 38 * of structures of a certain size. 39 * 40 * Returns: the number of blocks needed (minimum is always 1) 41 */ 42 43 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct, 44 unsigned int ssize) 45 { 46 unsigned int blks; 47 unsigned int first, second; 48 49 blks = 1; 50 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize; 51 52 if (nstruct > first) { 53 second = (sdp->sd_sb.sb_bsize - 54 sizeof(struct gfs2_meta_header)) / ssize; 55 blks += DIV_ROUND_UP(nstruct - first, second); 56 } 57 58 return blks; 59 } 60 61 /** 62 * gfs2_ail1_start_one - Start I/O on a part of the AIL 63 * @sdp: the filesystem 64 * @tr: the part of the AIL 65 * 66 */ 67 68 static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) 69 { 70 struct gfs2_bufdata *bd, *s; 71 struct buffer_head *bh; 72 int retry; 73 74 BUG_ON(!spin_is_locked(&sdp->sd_log_lock)); 75 76 do { 77 retry = 0; 78 79 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, 80 bd_ail_st_list) { 81 bh = bd->bd_bh; 82 83 gfs2_assert(sdp, bd->bd_ail == ai); 84 85 if (!buffer_busy(bh)) { 86 if (!buffer_uptodate(bh)) { 87 gfs2_log_unlock(sdp); 88 gfs2_io_error_bh(sdp, bh); 89 gfs2_log_lock(sdp); 90 } 91 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); 92 continue; 93 } 94 95 if (!buffer_dirty(bh)) 96 continue; 97 98 list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list); 99 100 gfs2_log_unlock(sdp); 101 wait_on_buffer(bh); 102 ll_rw_block(WRITE, 1, &bh); 103 gfs2_log_lock(sdp); 104 105 retry = 1; 106 break; 107 } 108 } while (retry); 109 } 110 111 /** 112 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced 113 * @sdp: the filesystem 114 * @ai: the AIL entry 115 * 116 */ 117 118 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags) 119 { 120 struct gfs2_bufdata *bd, *s; 121 struct buffer_head *bh; 122 123 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, 124 bd_ail_st_list) { 125 bh = bd->bd_bh; 126 127 gfs2_assert(sdp, bd->bd_ail == ai); 128 129 if (buffer_busy(bh)) { 130 if (flags & DIO_ALL) 131 continue; 132 else 133 break; 134 } 135 136 if (!buffer_uptodate(bh)) 137 gfs2_io_error_bh(sdp, bh); 138 139 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); 140 } 141 142 return list_empty(&ai->ai_ail1_list); 143 } 144 145 void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags) 146 { 147 struct list_head *head = &sdp->sd_ail1_list; 148 u64 sync_gen; 149 struct list_head *first; 150 struct gfs2_ail *first_ai, *ai, *tmp; 151 int done = 0; 152 153 gfs2_log_lock(sdp); 154 if (list_empty(head)) { 155 gfs2_log_unlock(sdp); 156 return; 157 } 158 sync_gen = sdp->sd_ail_sync_gen++; 159 160 first = head->prev; 161 first_ai = list_entry(first, struct gfs2_ail, ai_list); 162 first_ai->ai_sync_gen = sync_gen; 163 gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */ 164 165 if (flags & DIO_ALL) 166 first = NULL; 167 168 while(!done) { 169 if (first && (head->prev != first || 170 gfs2_ail1_empty_one(sdp, first_ai, 0))) 171 break; 172 173 done = 1; 174 list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) { 175 if (ai->ai_sync_gen >= sync_gen) 176 continue; 177 ai->ai_sync_gen = sync_gen; 178 gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */ 179 done = 0; 180 break; 181 } 182 } 183 184 gfs2_log_unlock(sdp); 185 } 186 187 int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags) 188 { 189 struct gfs2_ail *ai, *s; 190 int ret; 191 192 gfs2_log_lock(sdp); 193 194 list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) { 195 if (gfs2_ail1_empty_one(sdp, ai, flags)) 196 list_move(&ai->ai_list, &sdp->sd_ail2_list); 197 else if (!(flags & DIO_ALL)) 198 break; 199 } 200 201 ret = list_empty(&sdp->sd_ail1_list); 202 203 gfs2_log_unlock(sdp); 204 205 return ret; 206 } 207 208 209 /** 210 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced 211 * @sdp: the filesystem 212 * @ai: the AIL entry 213 * 214 */ 215 216 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) 217 { 218 struct list_head *head = &ai->ai_ail2_list; 219 struct gfs2_bufdata *bd; 220 221 while (!list_empty(head)) { 222 bd = list_entry(head->prev, struct gfs2_bufdata, 223 bd_ail_st_list); 224 gfs2_assert(sdp, bd->bd_ail == ai); 225 bd->bd_ail = NULL; 226 list_del(&bd->bd_ail_st_list); 227 list_del(&bd->bd_ail_gl_list); 228 atomic_dec(&bd->bd_gl->gl_ail_count); 229 brelse(bd->bd_bh); 230 } 231 } 232 233 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail) 234 { 235 struct gfs2_ail *ai, *safe; 236 unsigned int old_tail = sdp->sd_log_tail; 237 int wrap = (new_tail < old_tail); 238 int a, b, rm; 239 240 gfs2_log_lock(sdp); 241 242 list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) { 243 a = (old_tail <= ai->ai_first); 244 b = (ai->ai_first < new_tail); 245 rm = (wrap) ? (a || b) : (a && b); 246 if (!rm) 247 continue; 248 249 gfs2_ail2_empty_one(sdp, ai); 250 list_del(&ai->ai_list); 251 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list)); 252 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list)); 253 kfree(ai); 254 } 255 256 gfs2_log_unlock(sdp); 257 } 258 259 /** 260 * gfs2_log_reserve - Make a log reservation 261 * @sdp: The GFS2 superblock 262 * @blks: The number of blocks to reserve 263 * 264 * Returns: errno 265 */ 266 267 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) 268 { 269 unsigned int try = 0; 270 271 if (gfs2_assert_warn(sdp, blks) || 272 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) 273 return -EINVAL; 274 275 mutex_lock(&sdp->sd_log_reserve_mutex); 276 gfs2_log_lock(sdp); 277 while(sdp->sd_log_blks_free <= blks) { 278 gfs2_log_unlock(sdp); 279 gfs2_ail1_empty(sdp, 0); 280 gfs2_log_flush(sdp, NULL); 281 282 if (try++) 283 gfs2_ail1_start(sdp, 0); 284 gfs2_log_lock(sdp); 285 } 286 sdp->sd_log_blks_free -= blks; 287 gfs2_log_unlock(sdp); 288 mutex_unlock(&sdp->sd_log_reserve_mutex); 289 290 down_read(&sdp->sd_log_flush_lock); 291 292 return 0; 293 } 294 295 /** 296 * gfs2_log_release - Release a given number of log blocks 297 * @sdp: The GFS2 superblock 298 * @blks: The number of blocks 299 * 300 */ 301 302 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks) 303 { 304 305 gfs2_log_lock(sdp); 306 sdp->sd_log_blks_free += blks; 307 gfs2_assert_withdraw(sdp, 308 sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks); 309 gfs2_log_unlock(sdp); 310 up_read(&sdp->sd_log_flush_lock); 311 } 312 313 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn) 314 { 315 struct inode *inode = sdp->sd_jdesc->jd_inode; 316 int error; 317 struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 }; 318 319 bh_map.b_size = 1 << inode->i_blkbits; 320 error = gfs2_block_map(inode, lbn, 0, &bh_map); 321 if (error || !bh_map.b_blocknr) 322 printk(KERN_INFO "error=%d, dbn=%llu lbn=%u", error, bh_map.b_blocknr, lbn); 323 gfs2_assert_withdraw(sdp, !error && bh_map.b_blocknr); 324 325 return bh_map.b_blocknr; 326 } 327 328 /** 329 * log_distance - Compute distance between two journal blocks 330 * @sdp: The GFS2 superblock 331 * @newer: The most recent journal block of the pair 332 * @older: The older journal block of the pair 333 * 334 * Compute the distance (in the journal direction) between two 335 * blocks in the journal 336 * 337 * Returns: the distance in blocks 338 */ 339 340 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer, 341 unsigned int older) 342 { 343 int dist; 344 345 dist = newer - older; 346 if (dist < 0) 347 dist += sdp->sd_jdesc->jd_blocks; 348 349 return dist; 350 } 351 352 static unsigned int current_tail(struct gfs2_sbd *sdp) 353 { 354 struct gfs2_ail *ai; 355 unsigned int tail; 356 357 gfs2_log_lock(sdp); 358 359 if (list_empty(&sdp->sd_ail1_list)) { 360 tail = sdp->sd_log_head; 361 } else { 362 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list); 363 tail = ai->ai_first; 364 } 365 366 gfs2_log_unlock(sdp); 367 368 return tail; 369 } 370 371 static inline void log_incr_head(struct gfs2_sbd *sdp) 372 { 373 if (sdp->sd_log_flush_head == sdp->sd_log_tail) 374 gfs2_assert_withdraw(sdp, sdp->sd_log_flush_head == sdp->sd_log_head); 375 376 if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) { 377 sdp->sd_log_flush_head = 0; 378 sdp->sd_log_flush_wrapped = 1; 379 } 380 } 381 382 /** 383 * gfs2_log_get_buf - Get and initialize a buffer to use for log control data 384 * @sdp: The GFS2 superblock 385 * 386 * Returns: the buffer_head 387 */ 388 389 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp) 390 { 391 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 392 struct gfs2_log_buf *lb; 393 struct buffer_head *bh; 394 395 lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL); 396 list_add(&lb->lb_list, &sdp->sd_log_flush_list); 397 398 bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno); 399 lock_buffer(bh); 400 memset(bh->b_data, 0, bh->b_size); 401 set_buffer_uptodate(bh); 402 clear_buffer_dirty(bh); 403 unlock_buffer(bh); 404 405 log_incr_head(sdp); 406 407 return bh; 408 } 409 410 /** 411 * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log 412 * @sdp: the filesystem 413 * @data: the data the buffer_head should point to 414 * 415 * Returns: the log buffer descriptor 416 */ 417 418 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp, 419 struct buffer_head *real) 420 { 421 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 422 struct gfs2_log_buf *lb; 423 struct buffer_head *bh; 424 425 lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL); 426 list_add(&lb->lb_list, &sdp->sd_log_flush_list); 427 lb->lb_real = real; 428 429 bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL); 430 atomic_set(&bh->b_count, 1); 431 bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate); 432 set_bh_page(bh, real->b_page, bh_offset(real)); 433 bh->b_blocknr = blkno; 434 bh->b_size = sdp->sd_sb.sb_bsize; 435 bh->b_bdev = sdp->sd_vfs->s_bdev; 436 437 log_incr_head(sdp); 438 439 return bh; 440 } 441 442 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail, int pull) 443 { 444 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail); 445 446 ail2_empty(sdp, new_tail); 447 448 gfs2_log_lock(sdp); 449 sdp->sd_log_blks_free += dist - (pull ? 1 : 0); 450 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks); 451 gfs2_log_unlock(sdp); 452 453 sdp->sd_log_tail = new_tail; 454 } 455 456 /** 457 * log_write_header - Get and initialize a journal header buffer 458 * @sdp: The GFS2 superblock 459 * 460 * Returns: the initialized log buffer descriptor 461 */ 462 463 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull) 464 { 465 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 466 struct buffer_head *bh; 467 struct gfs2_log_header *lh; 468 unsigned int tail; 469 u32 hash; 470 471 bh = sb_getblk(sdp->sd_vfs, blkno); 472 lock_buffer(bh); 473 memset(bh->b_data, 0, bh->b_size); 474 set_buffer_uptodate(bh); 475 clear_buffer_dirty(bh); 476 unlock_buffer(bh); 477 478 gfs2_ail1_empty(sdp, 0); 479 tail = current_tail(sdp); 480 481 lh = (struct gfs2_log_header *)bh->b_data; 482 memset(lh, 0, sizeof(struct gfs2_log_header)); 483 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC); 484 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH); 485 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH); 486 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++); 487 lh->lh_flags = cpu_to_be32(flags); 488 lh->lh_tail = cpu_to_be32(tail); 489 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head); 490 hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header)); 491 lh->lh_hash = cpu_to_be32(hash); 492 493 set_buffer_dirty(bh); 494 if (sync_dirty_buffer(bh)) 495 gfs2_io_error_bh(sdp, bh); 496 brelse(bh); 497 498 if (sdp->sd_log_tail != tail) 499 log_pull_tail(sdp, tail, pull); 500 else 501 gfs2_assert_withdraw(sdp, !pull); 502 503 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); 504 log_incr_head(sdp); 505 } 506 507 static void log_flush_commit(struct gfs2_sbd *sdp) 508 { 509 struct list_head *head = &sdp->sd_log_flush_list; 510 struct gfs2_log_buf *lb; 511 struct buffer_head *bh; 512 513 while (!list_empty(head)) { 514 lb = list_entry(head->next, struct gfs2_log_buf, lb_list); 515 list_del(&lb->lb_list); 516 bh = lb->lb_bh; 517 518 wait_on_buffer(bh); 519 if (!buffer_uptodate(bh)) 520 gfs2_io_error_bh(sdp, bh); 521 if (lb->lb_real) { 522 while (atomic_read(&bh->b_count) != 1) /* Grrrr... */ 523 schedule(); 524 free_buffer_head(bh); 525 } else 526 brelse(bh); 527 kfree(lb); 528 } 529 530 log_write_header(sdp, 0, 0); 531 } 532 533 /** 534 * gfs2_log_flush - flush incore transaction(s) 535 * @sdp: the filesystem 536 * @gl: The glock structure to flush. If NULL, flush the whole incore log 537 * 538 */ 539 540 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl) 541 { 542 struct gfs2_ail *ai; 543 544 down_write(&sdp->sd_log_flush_lock); 545 546 if (gl) { 547 gfs2_log_lock(sdp); 548 if (list_empty(&gl->gl_le.le_list)) { 549 gfs2_log_unlock(sdp); 550 up_write(&sdp->sd_log_flush_lock); 551 return; 552 } 553 gfs2_log_unlock(sdp); 554 } 555 556 ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL); 557 INIT_LIST_HEAD(&ai->ai_ail1_list); 558 INIT_LIST_HEAD(&ai->ai_ail2_list); 559 560 gfs2_assert_withdraw(sdp, sdp->sd_log_num_buf == sdp->sd_log_commited_buf); 561 gfs2_assert_withdraw(sdp, 562 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); 563 564 sdp->sd_log_flush_head = sdp->sd_log_head; 565 sdp->sd_log_flush_wrapped = 0; 566 ai->ai_first = sdp->sd_log_flush_head; 567 568 lops_before_commit(sdp); 569 if (!list_empty(&sdp->sd_log_flush_list)) 570 log_flush_commit(sdp); 571 else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle) 572 log_write_header(sdp, 0, PULL); 573 lops_after_commit(sdp, ai); 574 575 gfs2_log_lock(sdp); 576 sdp->sd_log_head = sdp->sd_log_flush_head; 577 sdp->sd_log_blks_free -= sdp->sd_log_num_hdrs; 578 sdp->sd_log_blks_reserved = 0; 579 sdp->sd_log_commited_buf = 0; 580 sdp->sd_log_num_hdrs = 0; 581 sdp->sd_log_commited_revoke = 0; 582 583 if (!list_empty(&ai->ai_ail1_list)) { 584 list_add(&ai->ai_list, &sdp->sd_ail1_list); 585 ai = NULL; 586 } 587 gfs2_log_unlock(sdp); 588 589 sdp->sd_vfs->s_dirt = 0; 590 up_write(&sdp->sd_log_flush_lock); 591 592 kfree(ai); 593 } 594 595 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 596 { 597 unsigned int reserved = 0; 598 unsigned int old; 599 600 gfs2_log_lock(sdp); 601 602 sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm; 603 gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_buf) >= 0); 604 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; 605 gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0); 606 607 if (sdp->sd_log_commited_buf) 608 reserved += sdp->sd_log_commited_buf; 609 if (sdp->sd_log_commited_revoke) 610 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, 611 sizeof(u64)); 612 if (reserved) 613 reserved++; 614 615 old = sdp->sd_log_blks_free; 616 sdp->sd_log_blks_free += tr->tr_reserved - 617 (reserved - sdp->sd_log_blks_reserved); 618 619 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old); 620 gfs2_assert_withdraw(sdp, 621 sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks + 622 sdp->sd_log_num_hdrs); 623 624 sdp->sd_log_blks_reserved = reserved; 625 626 gfs2_log_unlock(sdp); 627 } 628 629 /** 630 * gfs2_log_commit - Commit a transaction to the log 631 * @sdp: the filesystem 632 * @tr: the transaction 633 * 634 * Returns: errno 635 */ 636 637 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 638 { 639 log_refund(sdp, tr); 640 lops_incore_commit(sdp, tr); 641 642 sdp->sd_vfs->s_dirt = 1; 643 up_read(&sdp->sd_log_flush_lock); 644 645 gfs2_log_lock(sdp); 646 if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) { 647 gfs2_log_unlock(sdp); 648 gfs2_log_flush(sdp, NULL); 649 } else { 650 gfs2_log_unlock(sdp); 651 } 652 } 653 654 /** 655 * gfs2_log_shutdown - write a shutdown header into a journal 656 * @sdp: the filesystem 657 * 658 */ 659 660 void gfs2_log_shutdown(struct gfs2_sbd *sdp) 661 { 662 down_write(&sdp->sd_log_flush_lock); 663 664 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); 665 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl); 666 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf); 667 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata); 668 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); 669 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg); 670 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf); 671 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_hdrs); 672 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list)); 673 674 sdp->sd_log_flush_head = sdp->sd_log_head; 675 sdp->sd_log_flush_wrapped = 0; 676 677 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 0); 678 679 gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks); 680 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail); 681 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list)); 682 683 sdp->sd_log_head = sdp->sd_log_flush_head; 684 sdp->sd_log_tail = sdp->sd_log_head; 685 686 up_write(&sdp->sd_log_flush_lock); 687 } 688 689