1 /* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2007 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/delay.h> 18 #include <linux/kthread.h> 19 #include <linux/freezer.h> 20 #include <linux/bio.h> 21 22 #include "gfs2.h" 23 #include "incore.h" 24 #include "bmap.h" 25 #include "glock.h" 26 #include "log.h" 27 #include "lops.h" 28 #include "meta_io.h" 29 #include "util.h" 30 #include "dir.h" 31 #include "trace_gfs2.h" 32 33 #define PULL 1 34 35 /** 36 * gfs2_struct2blk - compute stuff 37 * @sdp: the filesystem 38 * @nstruct: the number of structures 39 * @ssize: the size of the structures 40 * 41 * Compute the number of log descriptor blocks needed to hold a certain number 42 * of structures of a certain size. 43 * 44 * Returns: the number of blocks needed (minimum is always 1) 45 */ 46 47 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct, 48 unsigned int ssize) 49 { 50 unsigned int blks; 51 unsigned int first, second; 52 53 blks = 1; 54 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize; 55 56 if (nstruct > first) { 57 second = (sdp->sd_sb.sb_bsize - 58 sizeof(struct gfs2_meta_header)) / ssize; 59 blks += DIV_ROUND_UP(nstruct - first, second); 60 } 61 62 return blks; 63 } 64 65 /** 66 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters 67 * @mapping: The associated mapping (maybe NULL) 68 * @bd: The gfs2_bufdata to remove 69 * 70 * The log lock _must_ be held when calling this function 71 * 72 */ 73 74 void gfs2_remove_from_ail(struct gfs2_bufdata *bd) 75 { 76 bd->bd_ail = NULL; 77 list_del_init(&bd->bd_ail_st_list); 78 list_del_init(&bd->bd_ail_gl_list); 79 atomic_dec(&bd->bd_gl->gl_ail_count); 80 brelse(bd->bd_bh); 81 } 82 83 /** 84 * gfs2_ail1_start_one - Start I/O on a part of the AIL 85 * @sdp: the filesystem 86 * @tr: the part of the AIL 87 * 88 */ 89 90 static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) 91 __releases(&sdp->sd_log_lock) 92 __acquires(&sdp->sd_log_lock) 93 { 94 struct gfs2_bufdata *bd, *s; 95 struct buffer_head *bh; 96 int retry; 97 98 do { 99 retry = 0; 100 101 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, 102 bd_ail_st_list) { 103 bh = bd->bd_bh; 104 105 gfs2_assert(sdp, bd->bd_ail == ai); 106 107 if (!buffer_busy(bh)) { 108 if (!buffer_uptodate(bh)) 109 gfs2_io_error_bh(sdp, bh); 110 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); 111 continue; 112 } 113 114 if (!buffer_dirty(bh)) 115 continue; 116 117 list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list); 118 119 get_bh(bh); 120 gfs2_log_unlock(sdp); 121 lock_buffer(bh); 122 if (test_clear_buffer_dirty(bh)) { 123 bh->b_end_io = end_buffer_write_sync; 124 submit_bh(WRITE_SYNC_PLUG, bh); 125 } else { 126 unlock_buffer(bh); 127 brelse(bh); 128 } 129 gfs2_log_lock(sdp); 130 131 retry = 1; 132 break; 133 } 134 } while (retry); 135 } 136 137 /** 138 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced 139 * @sdp: the filesystem 140 * @ai: the AIL entry 141 * 142 */ 143 144 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags) 145 { 146 struct gfs2_bufdata *bd, *s; 147 struct buffer_head *bh; 148 149 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, 150 bd_ail_st_list) { 151 bh = bd->bd_bh; 152 153 gfs2_assert(sdp, bd->bd_ail == ai); 154 155 if (buffer_busy(bh)) { 156 if (flags & DIO_ALL) 157 continue; 158 else 159 break; 160 } 161 162 if (!buffer_uptodate(bh)) 163 gfs2_io_error_bh(sdp, bh); 164 165 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); 166 } 167 168 return list_empty(&ai->ai_ail1_list); 169 } 170 171 static void gfs2_ail1_start(struct gfs2_sbd *sdp) 172 { 173 struct list_head *head; 174 u64 sync_gen; 175 struct gfs2_ail *ai; 176 int done = 0; 177 178 gfs2_log_lock(sdp); 179 head = &sdp->sd_ail1_list; 180 if (list_empty(head)) { 181 gfs2_log_unlock(sdp); 182 return; 183 } 184 sync_gen = sdp->sd_ail_sync_gen++; 185 186 while(!done) { 187 done = 1; 188 list_for_each_entry_reverse(ai, head, ai_list) { 189 if (ai->ai_sync_gen >= sync_gen) 190 continue; 191 ai->ai_sync_gen = sync_gen; 192 gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */ 193 done = 0; 194 break; 195 } 196 } 197 198 gfs2_log_unlock(sdp); 199 } 200 201 static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags) 202 { 203 struct gfs2_ail *ai, *s; 204 int ret; 205 206 gfs2_log_lock(sdp); 207 208 list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) { 209 if (gfs2_ail1_empty_one(sdp, ai, flags)) 210 list_move(&ai->ai_list, &sdp->sd_ail2_list); 211 else if (!(flags & DIO_ALL)) 212 break; 213 } 214 215 ret = list_empty(&sdp->sd_ail1_list); 216 217 gfs2_log_unlock(sdp); 218 219 return ret; 220 } 221 222 223 /** 224 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced 225 * @sdp: the filesystem 226 * @ai: the AIL entry 227 * 228 */ 229 230 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) 231 { 232 struct list_head *head = &ai->ai_ail2_list; 233 struct gfs2_bufdata *bd; 234 235 while (!list_empty(head)) { 236 bd = list_entry(head->prev, struct gfs2_bufdata, 237 bd_ail_st_list); 238 gfs2_assert(sdp, bd->bd_ail == ai); 239 gfs2_remove_from_ail(bd); 240 } 241 } 242 243 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail) 244 { 245 struct gfs2_ail *ai, *safe; 246 unsigned int old_tail = sdp->sd_log_tail; 247 int wrap = (new_tail < old_tail); 248 int a, b, rm; 249 250 gfs2_log_lock(sdp); 251 252 list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) { 253 a = (old_tail <= ai->ai_first); 254 b = (ai->ai_first < new_tail); 255 rm = (wrap) ? (a || b) : (a && b); 256 if (!rm) 257 continue; 258 259 gfs2_ail2_empty_one(sdp, ai); 260 list_del(&ai->ai_list); 261 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list)); 262 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list)); 263 kfree(ai); 264 } 265 266 gfs2_log_unlock(sdp); 267 } 268 269 /** 270 * gfs2_log_reserve - Make a log reservation 271 * @sdp: The GFS2 superblock 272 * @blks: The number of blocks to reserve 273 * 274 * Note that we never give out the last few blocks of the journal. Thats 275 * due to the fact that there is a small number of header blocks 276 * associated with each log flush. The exact number can't be known until 277 * flush time, so we ensure that we have just enough free blocks at all 278 * times to avoid running out during a log flush. 279 * 280 * We no longer flush the log here, instead we wake up logd to do that 281 * for us. To avoid the thundering herd and to ensure that we deal fairly 282 * with queued waiters, we use an exclusive wait. This means that when we 283 * get woken with enough journal space to get our reservation, we need to 284 * wake the next waiter on the list. 285 * 286 * Returns: errno 287 */ 288 289 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) 290 { 291 unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize); 292 unsigned wanted = blks + reserved_blks; 293 DEFINE_WAIT(wait); 294 int did_wait = 0; 295 unsigned int free_blocks; 296 297 if (gfs2_assert_warn(sdp, blks) || 298 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) 299 return -EINVAL; 300 retry: 301 free_blocks = atomic_read(&sdp->sd_log_blks_free); 302 if (unlikely(free_blocks <= wanted)) { 303 do { 304 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait, 305 TASK_UNINTERRUPTIBLE); 306 wake_up(&sdp->sd_logd_waitq); 307 did_wait = 1; 308 if (atomic_read(&sdp->sd_log_blks_free) <= wanted) 309 io_schedule(); 310 free_blocks = atomic_read(&sdp->sd_log_blks_free); 311 } while(free_blocks <= wanted); 312 finish_wait(&sdp->sd_log_waitq, &wait); 313 } 314 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks, 315 free_blocks - blks) != free_blocks) 316 goto retry; 317 trace_gfs2_log_blocks(sdp, -blks); 318 319 /* 320 * If we waited, then so might others, wake them up _after_ we get 321 * our share of the log. 322 */ 323 if (unlikely(did_wait)) 324 wake_up(&sdp->sd_log_waitq); 325 326 down_read(&sdp->sd_log_flush_lock); 327 328 return 0; 329 } 330 331 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn) 332 { 333 struct gfs2_journal_extent *je; 334 335 list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) { 336 if (lbn >= je->lblock && lbn < je->lblock + je->blocks) 337 return je->dblock + lbn - je->lblock; 338 } 339 340 return -1; 341 } 342 343 /** 344 * log_distance - Compute distance between two journal blocks 345 * @sdp: The GFS2 superblock 346 * @newer: The most recent journal block of the pair 347 * @older: The older journal block of the pair 348 * 349 * Compute the distance (in the journal direction) between two 350 * blocks in the journal 351 * 352 * Returns: the distance in blocks 353 */ 354 355 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer, 356 unsigned int older) 357 { 358 int dist; 359 360 dist = newer - older; 361 if (dist < 0) 362 dist += sdp->sd_jdesc->jd_blocks; 363 364 return dist; 365 } 366 367 /** 368 * calc_reserved - Calculate the number of blocks to reserve when 369 * refunding a transaction's unused buffers. 370 * @sdp: The GFS2 superblock 371 * 372 * This is complex. We need to reserve room for all our currently used 373 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and 374 * all our journaled data buffers for journaled files (e.g. files in the 375 * meta_fs like rindex, or files for which chattr +j was done.) 376 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush 377 * will count it as free space (sd_log_blks_free) and corruption will follow. 378 * 379 * We can have metadata bufs and jdata bufs in the same journal. So each 380 * type gets its own log header, for which we need to reserve a block. 381 * In fact, each type has the potential for needing more than one header 382 * in cases where we have more buffers than will fit on a journal page. 383 * Metadata journal entries take up half the space of journaled buffer entries. 384 * Thus, metadata entries have buf_limit (502) and journaled buffers have 385 * databuf_limit (251) before they cause a wrap around. 386 * 387 * Also, we need to reserve blocks for revoke journal entries and one for an 388 * overall header for the lot. 389 * 390 * Returns: the number of blocks reserved 391 */ 392 static unsigned int calc_reserved(struct gfs2_sbd *sdp) 393 { 394 unsigned int reserved = 0; 395 unsigned int mbuf_limit, metabufhdrs_needed; 396 unsigned int dbuf_limit, databufhdrs_needed; 397 unsigned int revokes = 0; 398 399 mbuf_limit = buf_limit(sdp); 400 metabufhdrs_needed = (sdp->sd_log_commited_buf + 401 (mbuf_limit - 1)) / mbuf_limit; 402 dbuf_limit = databuf_limit(sdp); 403 databufhdrs_needed = (sdp->sd_log_commited_databuf + 404 (dbuf_limit - 1)) / dbuf_limit; 405 406 if (sdp->sd_log_commited_revoke > 0) 407 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, 408 sizeof(u64)); 409 410 reserved = sdp->sd_log_commited_buf + metabufhdrs_needed + 411 sdp->sd_log_commited_databuf + databufhdrs_needed + 412 revokes; 413 /* One for the overall header */ 414 if (reserved) 415 reserved++; 416 return reserved; 417 } 418 419 static unsigned int current_tail(struct gfs2_sbd *sdp) 420 { 421 struct gfs2_ail *ai; 422 unsigned int tail; 423 424 gfs2_log_lock(sdp); 425 426 if (list_empty(&sdp->sd_ail1_list)) { 427 tail = sdp->sd_log_head; 428 } else { 429 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list); 430 tail = ai->ai_first; 431 } 432 433 gfs2_log_unlock(sdp); 434 435 return tail; 436 } 437 438 void gfs2_log_incr_head(struct gfs2_sbd *sdp) 439 { 440 if (sdp->sd_log_flush_head == sdp->sd_log_tail) 441 BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head); 442 443 if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) { 444 sdp->sd_log_flush_head = 0; 445 sdp->sd_log_flush_wrapped = 1; 446 } 447 } 448 449 /** 450 * gfs2_log_write_endio - End of I/O for a log buffer 451 * @bh: The buffer head 452 * @uptodate: I/O Status 453 * 454 */ 455 456 static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate) 457 { 458 struct gfs2_sbd *sdp = bh->b_private; 459 bh->b_private = NULL; 460 461 end_buffer_write_sync(bh, uptodate); 462 if (atomic_dec_and_test(&sdp->sd_log_in_flight)) 463 wake_up(&sdp->sd_log_flush_wait); 464 } 465 466 /** 467 * gfs2_log_get_buf - Get and initialize a buffer to use for log control data 468 * @sdp: The GFS2 superblock 469 * 470 * Returns: the buffer_head 471 */ 472 473 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp) 474 { 475 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 476 struct buffer_head *bh; 477 478 bh = sb_getblk(sdp->sd_vfs, blkno); 479 lock_buffer(bh); 480 memset(bh->b_data, 0, bh->b_size); 481 set_buffer_uptodate(bh); 482 clear_buffer_dirty(bh); 483 gfs2_log_incr_head(sdp); 484 atomic_inc(&sdp->sd_log_in_flight); 485 bh->b_private = sdp; 486 bh->b_end_io = gfs2_log_write_endio; 487 488 return bh; 489 } 490 491 /** 492 * gfs2_fake_write_endio - 493 * @bh: The buffer head 494 * @uptodate: The I/O Status 495 * 496 */ 497 498 static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate) 499 { 500 struct buffer_head *real_bh = bh->b_private; 501 struct gfs2_bufdata *bd = real_bh->b_private; 502 struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd; 503 504 end_buffer_write_sync(bh, uptodate); 505 free_buffer_head(bh); 506 unlock_buffer(real_bh); 507 brelse(real_bh); 508 if (atomic_dec_and_test(&sdp->sd_log_in_flight)) 509 wake_up(&sdp->sd_log_flush_wait); 510 } 511 512 /** 513 * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log 514 * @sdp: the filesystem 515 * @data: the data the buffer_head should point to 516 * 517 * Returns: the log buffer descriptor 518 */ 519 520 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp, 521 struct buffer_head *real) 522 { 523 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 524 struct buffer_head *bh; 525 526 bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL); 527 atomic_set(&bh->b_count, 1); 528 bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock); 529 set_bh_page(bh, real->b_page, bh_offset(real)); 530 bh->b_blocknr = blkno; 531 bh->b_size = sdp->sd_sb.sb_bsize; 532 bh->b_bdev = sdp->sd_vfs->s_bdev; 533 bh->b_private = real; 534 bh->b_end_io = gfs2_fake_write_endio; 535 536 gfs2_log_incr_head(sdp); 537 atomic_inc(&sdp->sd_log_in_flight); 538 539 return bh; 540 } 541 542 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail) 543 { 544 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail); 545 546 ail2_empty(sdp, new_tail); 547 548 atomic_add(dist, &sdp->sd_log_blks_free); 549 trace_gfs2_log_blocks(sdp, dist); 550 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= 551 sdp->sd_jdesc->jd_blocks); 552 553 sdp->sd_log_tail = new_tail; 554 } 555 556 /** 557 * log_write_header - Get and initialize a journal header buffer 558 * @sdp: The GFS2 superblock 559 * 560 * Returns: the initialized log buffer descriptor 561 */ 562 563 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull) 564 { 565 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 566 struct buffer_head *bh; 567 struct gfs2_log_header *lh; 568 unsigned int tail; 569 u32 hash; 570 571 bh = sb_getblk(sdp->sd_vfs, blkno); 572 lock_buffer(bh); 573 memset(bh->b_data, 0, bh->b_size); 574 set_buffer_uptodate(bh); 575 clear_buffer_dirty(bh); 576 577 gfs2_ail1_empty(sdp, 0); 578 tail = current_tail(sdp); 579 580 lh = (struct gfs2_log_header *)bh->b_data; 581 memset(lh, 0, sizeof(struct gfs2_log_header)); 582 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC); 583 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH); 584 lh->lh_header.__pad0 = cpu_to_be64(0); 585 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH); 586 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid); 587 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++); 588 lh->lh_flags = cpu_to_be32(flags); 589 lh->lh_tail = cpu_to_be32(tail); 590 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head); 591 hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header)); 592 lh->lh_hash = cpu_to_be32(hash); 593 594 bh->b_end_io = end_buffer_write_sync; 595 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) 596 goto skip_barrier; 597 get_bh(bh); 598 submit_bh(WRITE_BARRIER | REQ_META, bh); 599 wait_on_buffer(bh); 600 if (buffer_eopnotsupp(bh)) { 601 clear_buffer_eopnotsupp(bh); 602 set_buffer_uptodate(bh); 603 fs_info(sdp, "barrier sync failed - disabling barriers\n"); 604 set_bit(SDF_NOBARRIERS, &sdp->sd_flags); 605 lock_buffer(bh); 606 skip_barrier: 607 get_bh(bh); 608 submit_bh(WRITE_SYNC | REQ_META, bh); 609 wait_on_buffer(bh); 610 } 611 if (!buffer_uptodate(bh)) 612 gfs2_io_error_bh(sdp, bh); 613 brelse(bh); 614 615 if (sdp->sd_log_tail != tail) 616 log_pull_tail(sdp, tail); 617 else 618 gfs2_assert_withdraw(sdp, !pull); 619 620 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); 621 gfs2_log_incr_head(sdp); 622 } 623 624 static void log_flush_commit(struct gfs2_sbd *sdp) 625 { 626 DEFINE_WAIT(wait); 627 628 if (atomic_read(&sdp->sd_log_in_flight)) { 629 do { 630 prepare_to_wait(&sdp->sd_log_flush_wait, &wait, 631 TASK_UNINTERRUPTIBLE); 632 if (atomic_read(&sdp->sd_log_in_flight)) 633 io_schedule(); 634 } while(atomic_read(&sdp->sd_log_in_flight)); 635 finish_wait(&sdp->sd_log_flush_wait, &wait); 636 } 637 638 log_write_header(sdp, 0, 0); 639 } 640 641 static void gfs2_ordered_write(struct gfs2_sbd *sdp) 642 { 643 struct gfs2_bufdata *bd; 644 struct buffer_head *bh; 645 LIST_HEAD(written); 646 647 gfs2_log_lock(sdp); 648 while (!list_empty(&sdp->sd_log_le_ordered)) { 649 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list); 650 list_move(&bd->bd_le.le_list, &written); 651 bh = bd->bd_bh; 652 if (!buffer_dirty(bh)) 653 continue; 654 get_bh(bh); 655 gfs2_log_unlock(sdp); 656 lock_buffer(bh); 657 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) { 658 bh->b_end_io = end_buffer_write_sync; 659 submit_bh(WRITE_SYNC_PLUG, bh); 660 } else { 661 unlock_buffer(bh); 662 brelse(bh); 663 } 664 gfs2_log_lock(sdp); 665 } 666 list_splice(&written, &sdp->sd_log_le_ordered); 667 gfs2_log_unlock(sdp); 668 } 669 670 static void gfs2_ordered_wait(struct gfs2_sbd *sdp) 671 { 672 struct gfs2_bufdata *bd; 673 struct buffer_head *bh; 674 675 gfs2_log_lock(sdp); 676 while (!list_empty(&sdp->sd_log_le_ordered)) { 677 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list); 678 bh = bd->bd_bh; 679 if (buffer_locked(bh)) { 680 get_bh(bh); 681 gfs2_log_unlock(sdp); 682 wait_on_buffer(bh); 683 brelse(bh); 684 gfs2_log_lock(sdp); 685 continue; 686 } 687 list_del_init(&bd->bd_le.le_list); 688 } 689 gfs2_log_unlock(sdp); 690 } 691 692 /** 693 * gfs2_log_flush - flush incore transaction(s) 694 * @sdp: the filesystem 695 * @gl: The glock structure to flush. If NULL, flush the whole incore log 696 * 697 */ 698 699 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl) 700 { 701 struct gfs2_ail *ai; 702 703 down_write(&sdp->sd_log_flush_lock); 704 705 /* Log might have been flushed while we waited for the flush lock */ 706 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) { 707 up_write(&sdp->sd_log_flush_lock); 708 return; 709 } 710 trace_gfs2_log_flush(sdp, 1); 711 712 ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL); 713 INIT_LIST_HEAD(&ai->ai_ail1_list); 714 INIT_LIST_HEAD(&ai->ai_ail2_list); 715 716 if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) { 717 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf, 718 sdp->sd_log_commited_buf); 719 gfs2_assert_withdraw(sdp, 0); 720 } 721 if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) { 722 printk(KERN_INFO "GFS2: log databuf %u %u\n", 723 sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf); 724 gfs2_assert_withdraw(sdp, 0); 725 } 726 gfs2_assert_withdraw(sdp, 727 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); 728 729 sdp->sd_log_flush_head = sdp->sd_log_head; 730 sdp->sd_log_flush_wrapped = 0; 731 ai->ai_first = sdp->sd_log_flush_head; 732 733 gfs2_ordered_write(sdp); 734 lops_before_commit(sdp); 735 gfs2_ordered_wait(sdp); 736 737 if (sdp->sd_log_head != sdp->sd_log_flush_head) 738 log_flush_commit(sdp); 739 else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){ 740 gfs2_log_lock(sdp); 741 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ 742 trace_gfs2_log_blocks(sdp, -1); 743 gfs2_log_unlock(sdp); 744 log_write_header(sdp, 0, PULL); 745 } 746 lops_after_commit(sdp, ai); 747 748 gfs2_log_lock(sdp); 749 sdp->sd_log_head = sdp->sd_log_flush_head; 750 sdp->sd_log_blks_reserved = 0; 751 sdp->sd_log_commited_buf = 0; 752 sdp->sd_log_commited_databuf = 0; 753 sdp->sd_log_commited_revoke = 0; 754 755 if (!list_empty(&ai->ai_ail1_list)) { 756 list_add(&ai->ai_list, &sdp->sd_ail1_list); 757 ai = NULL; 758 } 759 gfs2_log_unlock(sdp); 760 trace_gfs2_log_flush(sdp, 0); 761 up_write(&sdp->sd_log_flush_lock); 762 763 kfree(ai); 764 } 765 766 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 767 { 768 unsigned int reserved; 769 unsigned int unused; 770 771 gfs2_log_lock(sdp); 772 773 sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm; 774 sdp->sd_log_commited_databuf += tr->tr_num_databuf_new - 775 tr->tr_num_databuf_rm; 776 gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) || 777 (((int)sdp->sd_log_commited_databuf) >= 0)); 778 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; 779 reserved = calc_reserved(sdp); 780 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved); 781 unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved; 782 atomic_add(unused, &sdp->sd_log_blks_free); 783 trace_gfs2_log_blocks(sdp, unused); 784 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= 785 sdp->sd_jdesc->jd_blocks); 786 sdp->sd_log_blks_reserved = reserved; 787 788 gfs2_log_unlock(sdp); 789 } 790 791 static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 792 { 793 struct list_head *head = &tr->tr_list_buf; 794 struct gfs2_bufdata *bd; 795 796 gfs2_log_lock(sdp); 797 while (!list_empty(head)) { 798 bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr); 799 list_del_init(&bd->bd_list_tr); 800 tr->tr_num_buf--; 801 } 802 gfs2_log_unlock(sdp); 803 gfs2_assert_warn(sdp, !tr->tr_num_buf); 804 } 805 806 /** 807 * gfs2_log_commit - Commit a transaction to the log 808 * @sdp: the filesystem 809 * @tr: the transaction 810 * 811 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1 812 * or the total number of used blocks (pinned blocks plus AIL blocks) 813 * is greater than thresh2. 814 * 815 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of 816 * journal size. 817 * 818 * Returns: errno 819 */ 820 821 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 822 { 823 log_refund(sdp, tr); 824 buf_lo_incore_commit(sdp, tr); 825 826 up_read(&sdp->sd_log_flush_lock); 827 828 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) || 829 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) > 830 atomic_read(&sdp->sd_log_thresh2))) 831 wake_up(&sdp->sd_logd_waitq); 832 } 833 834 /** 835 * gfs2_log_shutdown - write a shutdown header into a journal 836 * @sdp: the filesystem 837 * 838 */ 839 840 void gfs2_log_shutdown(struct gfs2_sbd *sdp) 841 { 842 down_write(&sdp->sd_log_flush_lock); 843 844 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); 845 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf); 846 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); 847 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg); 848 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf); 849 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list)); 850 851 sdp->sd_log_flush_head = sdp->sd_log_head; 852 sdp->sd_log_flush_wrapped = 0; 853 854 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 855 (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL); 856 857 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks); 858 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail); 859 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list)); 860 861 sdp->sd_log_head = sdp->sd_log_flush_head; 862 sdp->sd_log_tail = sdp->sd_log_head; 863 864 up_write(&sdp->sd_log_flush_lock); 865 } 866 867 868 /** 869 * gfs2_meta_syncfs - sync all the buffers in a filesystem 870 * @sdp: the filesystem 871 * 872 */ 873 874 void gfs2_meta_syncfs(struct gfs2_sbd *sdp) 875 { 876 gfs2_log_flush(sdp, NULL); 877 for (;;) { 878 gfs2_ail1_start(sdp); 879 if (gfs2_ail1_empty(sdp, DIO_ALL)) 880 break; 881 msleep(10); 882 } 883 } 884 885 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp) 886 { 887 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1)); 888 } 889 890 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp) 891 { 892 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free); 893 return used_blocks >= atomic_read(&sdp->sd_log_thresh2); 894 } 895 896 /** 897 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks 898 * @sdp: Pointer to GFS2 superblock 899 * 900 * Also, periodically check to make sure that we're using the most recent 901 * journal index. 902 */ 903 904 int gfs2_logd(void *data) 905 { 906 struct gfs2_sbd *sdp = data; 907 unsigned long t = 1; 908 DEFINE_WAIT(wait); 909 unsigned preflush; 910 911 while (!kthread_should_stop()) { 912 913 preflush = atomic_read(&sdp->sd_log_pinned); 914 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { 915 gfs2_ail1_empty(sdp, DIO_ALL); 916 gfs2_log_flush(sdp, NULL); 917 gfs2_ail1_empty(sdp, DIO_ALL); 918 } 919 920 if (gfs2_ail_flush_reqd(sdp)) { 921 gfs2_ail1_start(sdp); 922 io_schedule(); 923 gfs2_ail1_empty(sdp, 0); 924 gfs2_log_flush(sdp, NULL); 925 gfs2_ail1_empty(sdp, DIO_ALL); 926 } 927 928 wake_up(&sdp->sd_log_waitq); 929 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ; 930 if (freezing(current)) 931 refrigerator(); 932 933 do { 934 prepare_to_wait(&sdp->sd_logd_waitq, &wait, 935 TASK_UNINTERRUPTIBLE); 936 if (!gfs2_ail_flush_reqd(sdp) && 937 !gfs2_jrnl_flush_reqd(sdp) && 938 !kthread_should_stop()) 939 t = schedule_timeout(t); 940 } while(t && !gfs2_ail_flush_reqd(sdp) && 941 !gfs2_jrnl_flush_reqd(sdp) && 942 !kthread_should_stop()); 943 finish_wait(&sdp->sd_logd_waitq, &wait); 944 } 945 946 return 0; 947 } 948 949