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 #include <linux/writeback.h> 22 #include <linux/list_sort.h> 23 24 #include "gfs2.h" 25 #include "incore.h" 26 #include "bmap.h" 27 #include "glock.h" 28 #include "log.h" 29 #include "lops.h" 30 #include "meta_io.h" 31 #include "util.h" 32 #include "dir.h" 33 #include "trace_gfs2.h" 34 35 #define PULL 1 36 37 /** 38 * gfs2_struct2blk - compute stuff 39 * @sdp: the filesystem 40 * @nstruct: the number of structures 41 * @ssize: the size of the structures 42 * 43 * Compute the number of log descriptor blocks needed to hold a certain number 44 * of structures of a certain size. 45 * 46 * Returns: the number of blocks needed (minimum is always 1) 47 */ 48 49 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct, 50 unsigned int ssize) 51 { 52 unsigned int blks; 53 unsigned int first, second; 54 55 blks = 1; 56 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize; 57 58 if (nstruct > first) { 59 second = (sdp->sd_sb.sb_bsize - 60 sizeof(struct gfs2_meta_header)) / ssize; 61 blks += DIV_ROUND_UP(nstruct - first, second); 62 } 63 64 return blks; 65 } 66 67 /** 68 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters 69 * @mapping: The associated mapping (maybe NULL) 70 * @bd: The gfs2_bufdata to remove 71 * 72 * The ail lock _must_ be held when calling this function 73 * 74 */ 75 76 void gfs2_remove_from_ail(struct gfs2_bufdata *bd) 77 { 78 bd->bd_ail = NULL; 79 list_del_init(&bd->bd_ail_st_list); 80 list_del_init(&bd->bd_ail_gl_list); 81 atomic_dec(&bd->bd_gl->gl_ail_count); 82 brelse(bd->bd_bh); 83 } 84 85 /** 86 * gfs2_ail1_start_one - Start I/O on a part of the AIL 87 * @sdp: the filesystem 88 * @wbc: The writeback control structure 89 * @ai: The ail structure 90 * 91 */ 92 93 static int gfs2_ail1_start_one(struct gfs2_sbd *sdp, 94 struct writeback_control *wbc, 95 struct gfs2_ail *ai) 96 __releases(&sdp->sd_ail_lock) 97 __acquires(&sdp->sd_ail_lock) 98 { 99 struct gfs2_glock *gl = NULL; 100 struct address_space *mapping; 101 struct gfs2_bufdata *bd, *s; 102 struct buffer_head *bh; 103 104 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) { 105 bh = bd->bd_bh; 106 107 gfs2_assert(sdp, bd->bd_ail == ai); 108 109 if (!buffer_busy(bh)) { 110 if (!buffer_uptodate(bh)) 111 gfs2_io_error_bh(sdp, bh); 112 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); 113 continue; 114 } 115 116 if (!buffer_dirty(bh)) 117 continue; 118 if (gl == bd->bd_gl) 119 continue; 120 gl = bd->bd_gl; 121 list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list); 122 mapping = bh->b_page->mapping; 123 if (!mapping) 124 continue; 125 spin_unlock(&sdp->sd_ail_lock); 126 generic_writepages(mapping, wbc); 127 spin_lock(&sdp->sd_ail_lock); 128 if (wbc->nr_to_write <= 0) 129 break; 130 return 1; 131 } 132 133 return 0; 134 } 135 136 137 /** 138 * gfs2_ail1_flush - start writeback of some ail1 entries 139 * @sdp: The super block 140 * @wbc: The writeback control structure 141 * 142 * Writes back some ail1 entries, according to the limits in the 143 * writeback control structure 144 */ 145 146 void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc) 147 { 148 struct list_head *head = &sdp->sd_ail1_list; 149 struct gfs2_ail *ai; 150 151 trace_gfs2_ail_flush(sdp, wbc, 1); 152 spin_lock(&sdp->sd_ail_lock); 153 restart: 154 list_for_each_entry_reverse(ai, head, ai_list) { 155 if (wbc->nr_to_write <= 0) 156 break; 157 if (gfs2_ail1_start_one(sdp, wbc, ai)) 158 goto restart; 159 } 160 spin_unlock(&sdp->sd_ail_lock); 161 trace_gfs2_ail_flush(sdp, wbc, 0); 162 } 163 164 /** 165 * gfs2_ail1_start - start writeback of all ail1 entries 166 * @sdp: The superblock 167 */ 168 169 static void gfs2_ail1_start(struct gfs2_sbd *sdp) 170 { 171 struct writeback_control wbc = { 172 .sync_mode = WB_SYNC_NONE, 173 .nr_to_write = LONG_MAX, 174 .range_start = 0, 175 .range_end = LLONG_MAX, 176 }; 177 178 return gfs2_ail1_flush(sdp, &wbc); 179 } 180 181 /** 182 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced 183 * @sdp: the filesystem 184 * @ai: the AIL entry 185 * 186 */ 187 188 static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) 189 { 190 struct gfs2_bufdata *bd, *s; 191 struct buffer_head *bh; 192 193 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, 194 bd_ail_st_list) { 195 bh = bd->bd_bh; 196 gfs2_assert(sdp, bd->bd_ail == ai); 197 if (buffer_busy(bh)) 198 continue; 199 if (!buffer_uptodate(bh)) 200 gfs2_io_error_bh(sdp, bh); 201 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); 202 } 203 204 } 205 206 /** 207 * gfs2_ail1_empty - Try to empty the ail1 lists 208 * @sdp: The superblock 209 * 210 * Tries to empty the ail1 lists, starting with the oldest first 211 */ 212 213 static int gfs2_ail1_empty(struct gfs2_sbd *sdp) 214 { 215 struct gfs2_ail *ai, *s; 216 int ret; 217 218 spin_lock(&sdp->sd_ail_lock); 219 list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) { 220 gfs2_ail1_empty_one(sdp, ai); 221 if (list_empty(&ai->ai_ail1_list)) 222 list_move(&ai->ai_list, &sdp->sd_ail2_list); 223 else 224 break; 225 } 226 ret = list_empty(&sdp->sd_ail1_list); 227 spin_unlock(&sdp->sd_ail_lock); 228 229 return ret; 230 } 231 232 static void gfs2_ail1_wait(struct gfs2_sbd *sdp) 233 { 234 struct gfs2_ail *ai; 235 struct gfs2_bufdata *bd; 236 struct buffer_head *bh; 237 238 spin_lock(&sdp->sd_ail_lock); 239 list_for_each_entry_reverse(ai, &sdp->sd_ail1_list, ai_list) { 240 list_for_each_entry(bd, &ai->ai_ail1_list, bd_ail_st_list) { 241 bh = bd->bd_bh; 242 if (!buffer_locked(bh)) 243 continue; 244 get_bh(bh); 245 spin_unlock(&sdp->sd_ail_lock); 246 wait_on_buffer(bh); 247 brelse(bh); 248 return; 249 } 250 } 251 spin_unlock(&sdp->sd_ail_lock); 252 } 253 254 /** 255 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced 256 * @sdp: the filesystem 257 * @ai: the AIL entry 258 * 259 */ 260 261 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) 262 { 263 struct list_head *head = &ai->ai_ail2_list; 264 struct gfs2_bufdata *bd; 265 266 while (!list_empty(head)) { 267 bd = list_entry(head->prev, struct gfs2_bufdata, 268 bd_ail_st_list); 269 gfs2_assert(sdp, bd->bd_ail == ai); 270 gfs2_remove_from_ail(bd); 271 } 272 } 273 274 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail) 275 { 276 struct gfs2_ail *ai, *safe; 277 unsigned int old_tail = sdp->sd_log_tail; 278 int wrap = (new_tail < old_tail); 279 int a, b, rm; 280 281 spin_lock(&sdp->sd_ail_lock); 282 283 list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) { 284 a = (old_tail <= ai->ai_first); 285 b = (ai->ai_first < new_tail); 286 rm = (wrap) ? (a || b) : (a && b); 287 if (!rm) 288 continue; 289 290 gfs2_ail2_empty_one(sdp, ai); 291 list_del(&ai->ai_list); 292 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list)); 293 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list)); 294 kfree(ai); 295 } 296 297 spin_unlock(&sdp->sd_ail_lock); 298 } 299 300 /** 301 * gfs2_log_reserve - Make a log reservation 302 * @sdp: The GFS2 superblock 303 * @blks: The number of blocks to reserve 304 * 305 * Note that we never give out the last few blocks of the journal. Thats 306 * due to the fact that there is a small number of header blocks 307 * associated with each log flush. The exact number can't be known until 308 * flush time, so we ensure that we have just enough free blocks at all 309 * times to avoid running out during a log flush. 310 * 311 * We no longer flush the log here, instead we wake up logd to do that 312 * for us. To avoid the thundering herd and to ensure that we deal fairly 313 * with queued waiters, we use an exclusive wait. This means that when we 314 * get woken with enough journal space to get our reservation, we need to 315 * wake the next waiter on the list. 316 * 317 * Returns: errno 318 */ 319 320 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) 321 { 322 unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize); 323 unsigned wanted = blks + reserved_blks; 324 DEFINE_WAIT(wait); 325 int did_wait = 0; 326 unsigned int free_blocks; 327 328 if (gfs2_assert_warn(sdp, blks) || 329 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) 330 return -EINVAL; 331 retry: 332 free_blocks = atomic_read(&sdp->sd_log_blks_free); 333 if (unlikely(free_blocks <= wanted)) { 334 do { 335 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait, 336 TASK_UNINTERRUPTIBLE); 337 wake_up(&sdp->sd_logd_waitq); 338 did_wait = 1; 339 if (atomic_read(&sdp->sd_log_blks_free) <= wanted) 340 io_schedule(); 341 free_blocks = atomic_read(&sdp->sd_log_blks_free); 342 } while(free_blocks <= wanted); 343 finish_wait(&sdp->sd_log_waitq, &wait); 344 } 345 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks, 346 free_blocks - blks) != free_blocks) 347 goto retry; 348 trace_gfs2_log_blocks(sdp, -blks); 349 350 /* 351 * If we waited, then so might others, wake them up _after_ we get 352 * our share of the log. 353 */ 354 if (unlikely(did_wait)) 355 wake_up(&sdp->sd_log_waitq); 356 357 down_read(&sdp->sd_log_flush_lock); 358 359 return 0; 360 } 361 362 u64 gfs2_log_bmap(struct gfs2_sbd *sdp, unsigned int lbn) 363 { 364 struct gfs2_journal_extent *je; 365 366 list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) { 367 if (lbn >= je->lblock && lbn < je->lblock + je->blocks) 368 return je->dblock + lbn - je->lblock; 369 } 370 371 return -1; 372 } 373 374 /** 375 * log_distance - Compute distance between two journal blocks 376 * @sdp: The GFS2 superblock 377 * @newer: The most recent journal block of the pair 378 * @older: The older journal block of the pair 379 * 380 * Compute the distance (in the journal direction) between two 381 * blocks in the journal 382 * 383 * Returns: the distance in blocks 384 */ 385 386 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer, 387 unsigned int older) 388 { 389 int dist; 390 391 dist = newer - older; 392 if (dist < 0) 393 dist += sdp->sd_jdesc->jd_blocks; 394 395 return dist; 396 } 397 398 /** 399 * calc_reserved - Calculate the number of blocks to reserve when 400 * refunding a transaction's unused buffers. 401 * @sdp: The GFS2 superblock 402 * 403 * This is complex. We need to reserve room for all our currently used 404 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and 405 * all our journaled data buffers for journaled files (e.g. files in the 406 * meta_fs like rindex, or files for which chattr +j was done.) 407 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush 408 * will count it as free space (sd_log_blks_free) and corruption will follow. 409 * 410 * We can have metadata bufs and jdata bufs in the same journal. So each 411 * type gets its own log header, for which we need to reserve a block. 412 * In fact, each type has the potential for needing more than one header 413 * in cases where we have more buffers than will fit on a journal page. 414 * Metadata journal entries take up half the space of journaled buffer entries. 415 * Thus, metadata entries have buf_limit (502) and journaled buffers have 416 * databuf_limit (251) before they cause a wrap around. 417 * 418 * Also, we need to reserve blocks for revoke journal entries and one for an 419 * overall header for the lot. 420 * 421 * Returns: the number of blocks reserved 422 */ 423 static unsigned int calc_reserved(struct gfs2_sbd *sdp) 424 { 425 unsigned int reserved = 0; 426 unsigned int mbuf_limit, metabufhdrs_needed; 427 unsigned int dbuf_limit, databufhdrs_needed; 428 unsigned int revokes = 0; 429 430 mbuf_limit = buf_limit(sdp); 431 metabufhdrs_needed = (sdp->sd_log_commited_buf + 432 (mbuf_limit - 1)) / mbuf_limit; 433 dbuf_limit = databuf_limit(sdp); 434 databufhdrs_needed = (sdp->sd_log_commited_databuf + 435 (dbuf_limit - 1)) / dbuf_limit; 436 437 if (sdp->sd_log_commited_revoke > 0) 438 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, 439 sizeof(u64)); 440 441 reserved = sdp->sd_log_commited_buf + metabufhdrs_needed + 442 sdp->sd_log_commited_databuf + databufhdrs_needed + 443 revokes; 444 /* One for the overall header */ 445 if (reserved) 446 reserved++; 447 return reserved; 448 } 449 450 static unsigned int current_tail(struct gfs2_sbd *sdp) 451 { 452 struct gfs2_ail *ai; 453 unsigned int tail; 454 455 spin_lock(&sdp->sd_ail_lock); 456 457 if (list_empty(&sdp->sd_ail1_list)) { 458 tail = sdp->sd_log_head; 459 } else { 460 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list); 461 tail = ai->ai_first; 462 } 463 464 spin_unlock(&sdp->sd_ail_lock); 465 466 return tail; 467 } 468 469 void gfs2_log_incr_head(struct gfs2_sbd *sdp) 470 { 471 BUG_ON((sdp->sd_log_flush_head == sdp->sd_log_tail) && 472 (sdp->sd_log_flush_head != sdp->sd_log_head)); 473 474 if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) { 475 sdp->sd_log_flush_head = 0; 476 sdp->sd_log_flush_wrapped = 1; 477 } 478 } 479 480 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail) 481 { 482 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail); 483 484 ail2_empty(sdp, new_tail); 485 486 atomic_add(dist, &sdp->sd_log_blks_free); 487 trace_gfs2_log_blocks(sdp, dist); 488 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= 489 sdp->sd_jdesc->jd_blocks); 490 491 sdp->sd_log_tail = new_tail; 492 } 493 494 /** 495 * log_write_header - Get and initialize a journal header buffer 496 * @sdp: The GFS2 superblock 497 * 498 * Returns: the initialized log buffer descriptor 499 */ 500 501 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull) 502 { 503 u64 blkno = gfs2_log_bmap(sdp, sdp->sd_log_flush_head); 504 struct buffer_head *bh; 505 struct gfs2_log_header *lh; 506 unsigned int tail; 507 u32 hash; 508 509 bh = sb_getblk(sdp->sd_vfs, blkno); 510 lock_buffer(bh); 511 memset(bh->b_data, 0, bh->b_size); 512 set_buffer_uptodate(bh); 513 clear_buffer_dirty(bh); 514 515 gfs2_ail1_empty(sdp); 516 tail = current_tail(sdp); 517 518 lh = (struct gfs2_log_header *)bh->b_data; 519 memset(lh, 0, sizeof(struct gfs2_log_header)); 520 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC); 521 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH); 522 lh->lh_header.__pad0 = cpu_to_be64(0); 523 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH); 524 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid); 525 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++); 526 lh->lh_flags = cpu_to_be32(flags); 527 lh->lh_tail = cpu_to_be32(tail); 528 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head); 529 hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header)); 530 lh->lh_hash = cpu_to_be32(hash); 531 532 bh->b_end_io = end_buffer_write_sync; 533 get_bh(bh); 534 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) 535 submit_bh(WRITE_SYNC | REQ_META | REQ_PRIO, bh); 536 else 537 submit_bh(WRITE_FLUSH_FUA | REQ_META, bh); 538 wait_on_buffer(bh); 539 540 if (!buffer_uptodate(bh)) 541 gfs2_io_error_bh(sdp, bh); 542 brelse(bh); 543 544 if (sdp->sd_log_tail != tail) 545 log_pull_tail(sdp, tail); 546 else 547 gfs2_assert_withdraw(sdp, !pull); 548 549 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); 550 gfs2_log_incr_head(sdp); 551 } 552 553 static void log_flush_commit(struct gfs2_sbd *sdp) 554 { 555 DEFINE_WAIT(wait); 556 557 if (atomic_read(&sdp->sd_log_in_flight)) { 558 do { 559 prepare_to_wait(&sdp->sd_log_flush_wait, &wait, 560 TASK_UNINTERRUPTIBLE); 561 if (atomic_read(&sdp->sd_log_in_flight)) 562 io_schedule(); 563 } while(atomic_read(&sdp->sd_log_in_flight)); 564 finish_wait(&sdp->sd_log_flush_wait, &wait); 565 } 566 567 log_write_header(sdp, 0, 0); 568 } 569 570 int bd_cmp(void *priv, struct list_head *a, struct list_head *b) 571 { 572 struct gfs2_bufdata *bda, *bdb; 573 574 bda = list_entry(a, struct gfs2_bufdata, bd_le.le_list); 575 bdb = list_entry(b, struct gfs2_bufdata, bd_le.le_list); 576 577 if (bda->bd_bh->b_blocknr < bdb->bd_bh->b_blocknr) 578 return -1; 579 if (bda->bd_bh->b_blocknr > bdb->bd_bh->b_blocknr) 580 return 1; 581 return 0; 582 } 583 584 static void gfs2_ordered_write(struct gfs2_sbd *sdp) 585 { 586 struct gfs2_bufdata *bd; 587 struct buffer_head *bh; 588 LIST_HEAD(written); 589 590 gfs2_log_lock(sdp); 591 list_sort(NULL, &sdp->sd_log_le_ordered, &bd_cmp); 592 while (!list_empty(&sdp->sd_log_le_ordered)) { 593 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list); 594 list_move(&bd->bd_le.le_list, &written); 595 bh = bd->bd_bh; 596 if (!buffer_dirty(bh)) 597 continue; 598 get_bh(bh); 599 gfs2_log_unlock(sdp); 600 lock_buffer(bh); 601 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) { 602 bh->b_end_io = end_buffer_write_sync; 603 submit_bh(WRITE_SYNC, bh); 604 } else { 605 unlock_buffer(bh); 606 brelse(bh); 607 } 608 gfs2_log_lock(sdp); 609 } 610 list_splice(&written, &sdp->sd_log_le_ordered); 611 gfs2_log_unlock(sdp); 612 } 613 614 static void gfs2_ordered_wait(struct gfs2_sbd *sdp) 615 { 616 struct gfs2_bufdata *bd; 617 struct buffer_head *bh; 618 619 gfs2_log_lock(sdp); 620 while (!list_empty(&sdp->sd_log_le_ordered)) { 621 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list); 622 bh = bd->bd_bh; 623 if (buffer_locked(bh)) { 624 get_bh(bh); 625 gfs2_log_unlock(sdp); 626 wait_on_buffer(bh); 627 brelse(bh); 628 gfs2_log_lock(sdp); 629 continue; 630 } 631 list_del_init(&bd->bd_le.le_list); 632 } 633 gfs2_log_unlock(sdp); 634 } 635 636 /** 637 * gfs2_log_flush - flush incore transaction(s) 638 * @sdp: the filesystem 639 * @gl: The glock structure to flush. If NULL, flush the whole incore log 640 * 641 */ 642 643 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl) 644 { 645 struct gfs2_ail *ai; 646 647 down_write(&sdp->sd_log_flush_lock); 648 649 /* Log might have been flushed while we waited for the flush lock */ 650 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) { 651 up_write(&sdp->sd_log_flush_lock); 652 return; 653 } 654 trace_gfs2_log_flush(sdp, 1); 655 656 ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL); 657 INIT_LIST_HEAD(&ai->ai_ail1_list); 658 INIT_LIST_HEAD(&ai->ai_ail2_list); 659 660 if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) { 661 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf, 662 sdp->sd_log_commited_buf); 663 gfs2_assert_withdraw(sdp, 0); 664 } 665 if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) { 666 printk(KERN_INFO "GFS2: log databuf %u %u\n", 667 sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf); 668 gfs2_assert_withdraw(sdp, 0); 669 } 670 gfs2_assert_withdraw(sdp, 671 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); 672 673 sdp->sd_log_flush_head = sdp->sd_log_head; 674 sdp->sd_log_flush_wrapped = 0; 675 ai->ai_first = sdp->sd_log_flush_head; 676 677 gfs2_ordered_write(sdp); 678 lops_before_commit(sdp); 679 gfs2_ordered_wait(sdp); 680 681 if (sdp->sd_log_head != sdp->sd_log_flush_head) 682 log_flush_commit(sdp); 683 else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){ 684 gfs2_log_lock(sdp); 685 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ 686 trace_gfs2_log_blocks(sdp, -1); 687 gfs2_log_unlock(sdp); 688 log_write_header(sdp, 0, PULL); 689 } 690 lops_after_commit(sdp, ai); 691 692 gfs2_log_lock(sdp); 693 sdp->sd_log_head = sdp->sd_log_flush_head; 694 sdp->sd_log_blks_reserved = 0; 695 sdp->sd_log_commited_buf = 0; 696 sdp->sd_log_commited_databuf = 0; 697 sdp->sd_log_commited_revoke = 0; 698 699 spin_lock(&sdp->sd_ail_lock); 700 if (!list_empty(&ai->ai_ail1_list)) { 701 list_add(&ai->ai_list, &sdp->sd_ail1_list); 702 ai = NULL; 703 } 704 spin_unlock(&sdp->sd_ail_lock); 705 gfs2_log_unlock(sdp); 706 trace_gfs2_log_flush(sdp, 0); 707 up_write(&sdp->sd_log_flush_lock); 708 709 kfree(ai); 710 } 711 712 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 713 { 714 unsigned int reserved; 715 unsigned int unused; 716 717 gfs2_log_lock(sdp); 718 719 sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm; 720 sdp->sd_log_commited_databuf += tr->tr_num_databuf_new - 721 tr->tr_num_databuf_rm; 722 gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) || 723 (((int)sdp->sd_log_commited_databuf) >= 0)); 724 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; 725 reserved = calc_reserved(sdp); 726 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved); 727 unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved; 728 atomic_add(unused, &sdp->sd_log_blks_free); 729 trace_gfs2_log_blocks(sdp, unused); 730 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= 731 sdp->sd_jdesc->jd_blocks); 732 sdp->sd_log_blks_reserved = reserved; 733 734 gfs2_log_unlock(sdp); 735 } 736 737 static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 738 { 739 struct list_head *head = &tr->tr_list_buf; 740 struct gfs2_bufdata *bd; 741 742 gfs2_log_lock(sdp); 743 while (!list_empty(head)) { 744 bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr); 745 list_del_init(&bd->bd_list_tr); 746 tr->tr_num_buf--; 747 } 748 gfs2_log_unlock(sdp); 749 gfs2_assert_warn(sdp, !tr->tr_num_buf); 750 } 751 752 /** 753 * gfs2_log_commit - Commit a transaction to the log 754 * @sdp: the filesystem 755 * @tr: the transaction 756 * 757 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1 758 * or the total number of used blocks (pinned blocks plus AIL blocks) 759 * is greater than thresh2. 760 * 761 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of 762 * journal size. 763 * 764 * Returns: errno 765 */ 766 767 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 768 { 769 log_refund(sdp, tr); 770 buf_lo_incore_commit(sdp, tr); 771 772 up_read(&sdp->sd_log_flush_lock); 773 774 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) || 775 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) > 776 atomic_read(&sdp->sd_log_thresh2))) 777 wake_up(&sdp->sd_logd_waitq); 778 } 779 780 /** 781 * gfs2_log_shutdown - write a shutdown header into a journal 782 * @sdp: the filesystem 783 * 784 */ 785 786 void gfs2_log_shutdown(struct gfs2_sbd *sdp) 787 { 788 down_write(&sdp->sd_log_flush_lock); 789 790 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); 791 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf); 792 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); 793 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg); 794 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf); 795 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list)); 796 797 sdp->sd_log_flush_head = sdp->sd_log_head; 798 sdp->sd_log_flush_wrapped = 0; 799 800 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 801 (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL); 802 803 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks); 804 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail); 805 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list)); 806 807 sdp->sd_log_head = sdp->sd_log_flush_head; 808 sdp->sd_log_tail = sdp->sd_log_head; 809 810 up_write(&sdp->sd_log_flush_lock); 811 } 812 813 814 /** 815 * gfs2_meta_syncfs - sync all the buffers in a filesystem 816 * @sdp: the filesystem 817 * 818 */ 819 820 void gfs2_meta_syncfs(struct gfs2_sbd *sdp) 821 { 822 gfs2_log_flush(sdp, NULL); 823 for (;;) { 824 gfs2_ail1_start(sdp); 825 gfs2_ail1_wait(sdp); 826 if (gfs2_ail1_empty(sdp)) 827 break; 828 } 829 gfs2_log_flush(sdp, NULL); 830 } 831 832 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp) 833 { 834 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1)); 835 } 836 837 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp) 838 { 839 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free); 840 return used_blocks >= atomic_read(&sdp->sd_log_thresh2); 841 } 842 843 /** 844 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks 845 * @sdp: Pointer to GFS2 superblock 846 * 847 * Also, periodically check to make sure that we're using the most recent 848 * journal index. 849 */ 850 851 int gfs2_logd(void *data) 852 { 853 struct gfs2_sbd *sdp = data; 854 unsigned long t = 1; 855 DEFINE_WAIT(wait); 856 unsigned preflush; 857 858 while (!kthread_should_stop()) { 859 860 preflush = atomic_read(&sdp->sd_log_pinned); 861 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { 862 gfs2_ail1_empty(sdp); 863 gfs2_log_flush(sdp, NULL); 864 } 865 866 if (gfs2_ail_flush_reqd(sdp)) { 867 gfs2_ail1_start(sdp); 868 gfs2_ail1_wait(sdp); 869 gfs2_ail1_empty(sdp); 870 gfs2_log_flush(sdp, NULL); 871 } 872 873 if (!gfs2_ail_flush_reqd(sdp)) 874 wake_up(&sdp->sd_log_waitq); 875 876 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ; 877 878 try_to_freeze(); 879 880 do { 881 prepare_to_wait(&sdp->sd_logd_waitq, &wait, 882 TASK_INTERRUPTIBLE); 883 if (!gfs2_ail_flush_reqd(sdp) && 884 !gfs2_jrnl_flush_reqd(sdp) && 885 !kthread_should_stop()) 886 t = schedule_timeout(t); 887 } while(t && !gfs2_ail_flush_reqd(sdp) && 888 !gfs2_jrnl_flush_reqd(sdp) && 889 !kthread_should_stop()); 890 finish_wait(&sdp->sd_logd_waitq, &wait); 891 } 892 893 return 0; 894 } 895 896