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/blkdev.h> 22 #include <linux/writeback.h> 23 #include <linux/list_sort.h> 24 25 #include "gfs2.h" 26 #include "incore.h" 27 #include "bmap.h" 28 #include "glock.h" 29 #include "log.h" 30 #include "lops.h" 31 #include "meta_io.h" 32 #include "util.h" 33 #include "dir.h" 34 #include "trace_gfs2.h" 35 36 /** 37 * gfs2_struct2blk - compute stuff 38 * @sdp: the filesystem 39 * @nstruct: the number of structures 40 * @ssize: the size of the structures 41 * 42 * Compute the number of log descriptor blocks needed to hold a certain number 43 * of structures of a certain size. 44 * 45 * Returns: the number of blocks needed (minimum is always 1) 46 */ 47 48 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct, 49 unsigned int ssize) 50 { 51 unsigned int blks; 52 unsigned int first, second; 53 54 blks = 1; 55 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize; 56 57 if (nstruct > first) { 58 second = (sdp->sd_sb.sb_bsize - 59 sizeof(struct gfs2_meta_header)) / ssize; 60 blks += DIV_ROUND_UP(nstruct - first, second); 61 } 62 63 return blks; 64 } 65 66 /** 67 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters 68 * @mapping: The associated mapping (maybe NULL) 69 * @bd: The gfs2_bufdata to remove 70 * 71 * The ail lock _must_ be held when calling this function 72 * 73 */ 74 75 void gfs2_remove_from_ail(struct gfs2_bufdata *bd) 76 { 77 bd->bd_tr = NULL; 78 list_del_init(&bd->bd_ail_st_list); 79 list_del_init(&bd->bd_ail_gl_list); 80 atomic_dec(&bd->bd_gl->gl_ail_count); 81 brelse(bd->bd_bh); 82 } 83 84 /** 85 * gfs2_ail1_start_one - Start I/O on a part of the AIL 86 * @sdp: the filesystem 87 * @wbc: The writeback control structure 88 * @ai: The ail structure 89 * 90 */ 91 92 static int gfs2_ail1_start_one(struct gfs2_sbd *sdp, 93 struct writeback_control *wbc, 94 struct gfs2_trans *tr) 95 __releases(&sdp->sd_ail_lock) 96 __acquires(&sdp->sd_ail_lock) 97 { 98 struct gfs2_glock *gl = NULL; 99 struct address_space *mapping; 100 struct gfs2_bufdata *bd, *s; 101 struct buffer_head *bh; 102 103 list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) { 104 bh = bd->bd_bh; 105 106 gfs2_assert(sdp, bd->bd_tr == tr); 107 108 if (!buffer_busy(bh)) { 109 if (!buffer_uptodate(bh)) 110 gfs2_io_error_bh(sdp, bh); 111 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list); 112 continue; 113 } 114 115 if (!buffer_dirty(bh)) 116 continue; 117 if (gl == bd->bd_gl) 118 continue; 119 gl = bd->bd_gl; 120 list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list); 121 mapping = bh->b_page->mapping; 122 if (!mapping) 123 continue; 124 spin_unlock(&sdp->sd_ail_lock); 125 generic_writepages(mapping, wbc); 126 spin_lock(&sdp->sd_ail_lock); 127 if (wbc->nr_to_write <= 0) 128 break; 129 return 1; 130 } 131 132 return 0; 133 } 134 135 136 /** 137 * gfs2_ail1_flush - start writeback of some ail1 entries 138 * @sdp: The super block 139 * @wbc: The writeback control structure 140 * 141 * Writes back some ail1 entries, according to the limits in the 142 * writeback control structure 143 */ 144 145 void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc) 146 { 147 struct list_head *head = &sdp->sd_ail1_list; 148 struct gfs2_trans *tr; 149 struct blk_plug plug; 150 151 trace_gfs2_ail_flush(sdp, wbc, 1); 152 blk_start_plug(&plug); 153 spin_lock(&sdp->sd_ail_lock); 154 restart: 155 list_for_each_entry_reverse(tr, head, tr_list) { 156 if (wbc->nr_to_write <= 0) 157 break; 158 if (gfs2_ail1_start_one(sdp, wbc, tr)) 159 goto restart; 160 } 161 spin_unlock(&sdp->sd_ail_lock); 162 blk_finish_plug(&plug); 163 trace_gfs2_ail_flush(sdp, wbc, 0); 164 } 165 166 /** 167 * gfs2_ail1_start - start writeback of all ail1 entries 168 * @sdp: The superblock 169 */ 170 171 static void gfs2_ail1_start(struct gfs2_sbd *sdp) 172 { 173 struct writeback_control wbc = { 174 .sync_mode = WB_SYNC_NONE, 175 .nr_to_write = LONG_MAX, 176 .range_start = 0, 177 .range_end = LLONG_MAX, 178 }; 179 180 return gfs2_ail1_flush(sdp, &wbc); 181 } 182 183 /** 184 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced 185 * @sdp: the filesystem 186 * @ai: the AIL entry 187 * 188 */ 189 190 static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 191 { 192 struct gfs2_bufdata *bd, *s; 193 struct buffer_head *bh; 194 195 list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, 196 bd_ail_st_list) { 197 bh = bd->bd_bh; 198 gfs2_assert(sdp, bd->bd_tr == tr); 199 if (buffer_busy(bh)) 200 continue; 201 if (!buffer_uptodate(bh)) 202 gfs2_io_error_bh(sdp, bh); 203 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list); 204 } 205 206 } 207 208 /** 209 * gfs2_ail1_empty - Try to empty the ail1 lists 210 * @sdp: The superblock 211 * 212 * Tries to empty the ail1 lists, starting with the oldest first 213 */ 214 215 static int gfs2_ail1_empty(struct gfs2_sbd *sdp) 216 { 217 struct gfs2_trans *tr, *s; 218 int oldest_tr = 1; 219 int ret; 220 221 spin_lock(&sdp->sd_ail_lock); 222 list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) { 223 gfs2_ail1_empty_one(sdp, tr); 224 if (list_empty(&tr->tr_ail1_list) && oldest_tr) 225 list_move(&tr->tr_list, &sdp->sd_ail2_list); 226 else 227 oldest_tr = 0; 228 } 229 ret = list_empty(&sdp->sd_ail1_list); 230 spin_unlock(&sdp->sd_ail_lock); 231 232 return ret; 233 } 234 235 static void gfs2_ail1_wait(struct gfs2_sbd *sdp) 236 { 237 struct gfs2_trans *tr; 238 struct gfs2_bufdata *bd; 239 struct buffer_head *bh; 240 241 spin_lock(&sdp->sd_ail_lock); 242 list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) { 243 list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) { 244 bh = bd->bd_bh; 245 if (!buffer_locked(bh)) 246 continue; 247 get_bh(bh); 248 spin_unlock(&sdp->sd_ail_lock); 249 wait_on_buffer(bh); 250 brelse(bh); 251 return; 252 } 253 } 254 spin_unlock(&sdp->sd_ail_lock); 255 } 256 257 /** 258 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced 259 * @sdp: the filesystem 260 * @ai: the AIL entry 261 * 262 */ 263 264 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 265 { 266 struct list_head *head = &tr->tr_ail2_list; 267 struct gfs2_bufdata *bd; 268 269 while (!list_empty(head)) { 270 bd = list_entry(head->prev, struct gfs2_bufdata, 271 bd_ail_st_list); 272 gfs2_assert(sdp, bd->bd_tr == tr); 273 gfs2_remove_from_ail(bd); 274 } 275 } 276 277 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail) 278 { 279 struct gfs2_trans *tr, *safe; 280 unsigned int old_tail = sdp->sd_log_tail; 281 int wrap = (new_tail < old_tail); 282 int a, b, rm; 283 284 spin_lock(&sdp->sd_ail_lock); 285 286 list_for_each_entry_safe(tr, safe, &sdp->sd_ail2_list, tr_list) { 287 a = (old_tail <= tr->tr_first); 288 b = (tr->tr_first < new_tail); 289 rm = (wrap) ? (a || b) : (a && b); 290 if (!rm) 291 continue; 292 293 gfs2_ail2_empty_one(sdp, tr); 294 list_del(&tr->tr_list); 295 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list)); 296 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list)); 297 kfree(tr); 298 } 299 300 spin_unlock(&sdp->sd_ail_lock); 301 } 302 303 /** 304 * gfs2_log_reserve - Make a log reservation 305 * @sdp: The GFS2 superblock 306 * @blks: The number of blocks to reserve 307 * 308 * Note that we never give out the last few blocks of the journal. Thats 309 * due to the fact that there is a small number of header blocks 310 * associated with each log flush. The exact number can't be known until 311 * flush time, so we ensure that we have just enough free blocks at all 312 * times to avoid running out during a log flush. 313 * 314 * We no longer flush the log here, instead we wake up logd to do that 315 * for us. To avoid the thundering herd and to ensure that we deal fairly 316 * with queued waiters, we use an exclusive wait. This means that when we 317 * get woken with enough journal space to get our reservation, we need to 318 * wake the next waiter on the list. 319 * 320 * Returns: errno 321 */ 322 323 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) 324 { 325 unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize); 326 unsigned wanted = blks + reserved_blks; 327 DEFINE_WAIT(wait); 328 int did_wait = 0; 329 unsigned int free_blocks; 330 331 if (gfs2_assert_warn(sdp, blks) || 332 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) 333 return -EINVAL; 334 retry: 335 free_blocks = atomic_read(&sdp->sd_log_blks_free); 336 if (unlikely(free_blocks <= wanted)) { 337 do { 338 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait, 339 TASK_UNINTERRUPTIBLE); 340 wake_up(&sdp->sd_logd_waitq); 341 did_wait = 1; 342 if (atomic_read(&sdp->sd_log_blks_free) <= wanted) 343 io_schedule(); 344 free_blocks = atomic_read(&sdp->sd_log_blks_free); 345 } while(free_blocks <= wanted); 346 finish_wait(&sdp->sd_log_waitq, &wait); 347 } 348 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks, 349 free_blocks - blks) != free_blocks) 350 goto retry; 351 trace_gfs2_log_blocks(sdp, -blks); 352 353 /* 354 * If we waited, then so might others, wake them up _after_ we get 355 * our share of the log. 356 */ 357 if (unlikely(did_wait)) 358 wake_up(&sdp->sd_log_waitq); 359 360 down_read(&sdp->sd_log_flush_lock); 361 362 return 0; 363 } 364 365 /** 366 * log_distance - Compute distance between two journal blocks 367 * @sdp: The GFS2 superblock 368 * @newer: The most recent journal block of the pair 369 * @older: The older journal block of the pair 370 * 371 * Compute the distance (in the journal direction) between two 372 * blocks in the journal 373 * 374 * Returns: the distance in blocks 375 */ 376 377 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer, 378 unsigned int older) 379 { 380 int dist; 381 382 dist = newer - older; 383 if (dist < 0) 384 dist += sdp->sd_jdesc->jd_blocks; 385 386 return dist; 387 } 388 389 /** 390 * calc_reserved - Calculate the number of blocks to reserve when 391 * refunding a transaction's unused buffers. 392 * @sdp: The GFS2 superblock 393 * 394 * This is complex. We need to reserve room for all our currently used 395 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and 396 * all our journaled data buffers for journaled files (e.g. files in the 397 * meta_fs like rindex, or files for which chattr +j was done.) 398 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush 399 * will count it as free space (sd_log_blks_free) and corruption will follow. 400 * 401 * We can have metadata bufs and jdata bufs in the same journal. So each 402 * type gets its own log header, for which we need to reserve a block. 403 * In fact, each type has the potential for needing more than one header 404 * in cases where we have more buffers than will fit on a journal page. 405 * Metadata journal entries take up half the space of journaled buffer entries. 406 * Thus, metadata entries have buf_limit (502) and journaled buffers have 407 * databuf_limit (251) before they cause a wrap around. 408 * 409 * Also, we need to reserve blocks for revoke journal entries and one for an 410 * overall header for the lot. 411 * 412 * Returns: the number of blocks reserved 413 */ 414 static unsigned int calc_reserved(struct gfs2_sbd *sdp) 415 { 416 unsigned int reserved = 0; 417 unsigned int mbuf; 418 unsigned int dbuf; 419 struct gfs2_trans *tr = sdp->sd_log_tr; 420 421 if (tr) { 422 mbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm; 423 dbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm; 424 reserved = mbuf + dbuf; 425 /* Account for header blocks */ 426 reserved += DIV_ROUND_UP(mbuf, buf_limit(sdp)); 427 reserved += DIV_ROUND_UP(dbuf, databuf_limit(sdp)); 428 } 429 430 if (sdp->sd_log_commited_revoke > 0) 431 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, 432 sizeof(u64)); 433 /* One for the overall header */ 434 if (reserved) 435 reserved++; 436 return reserved; 437 } 438 439 static unsigned int current_tail(struct gfs2_sbd *sdp) 440 { 441 struct gfs2_trans *tr; 442 unsigned int tail; 443 444 spin_lock(&sdp->sd_ail_lock); 445 446 if (list_empty(&sdp->sd_ail1_list)) { 447 tail = sdp->sd_log_head; 448 } else { 449 tr = list_entry(sdp->sd_ail1_list.prev, struct gfs2_trans, 450 tr_list); 451 tail = tr->tr_first; 452 } 453 454 spin_unlock(&sdp->sd_ail_lock); 455 456 return tail; 457 } 458 459 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail) 460 { 461 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail); 462 463 ail2_empty(sdp, new_tail); 464 465 atomic_add(dist, &sdp->sd_log_blks_free); 466 trace_gfs2_log_blocks(sdp, dist); 467 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= 468 sdp->sd_jdesc->jd_blocks); 469 470 sdp->sd_log_tail = new_tail; 471 } 472 473 474 static void log_flush_wait(struct gfs2_sbd *sdp) 475 { 476 DEFINE_WAIT(wait); 477 478 if (atomic_read(&sdp->sd_log_in_flight)) { 479 do { 480 prepare_to_wait(&sdp->sd_log_flush_wait, &wait, 481 TASK_UNINTERRUPTIBLE); 482 if (atomic_read(&sdp->sd_log_in_flight)) 483 io_schedule(); 484 } while(atomic_read(&sdp->sd_log_in_flight)); 485 finish_wait(&sdp->sd_log_flush_wait, &wait); 486 } 487 } 488 489 static int ip_cmp(void *priv, struct list_head *a, struct list_head *b) 490 { 491 struct gfs2_inode *ipa, *ipb; 492 493 ipa = list_entry(a, struct gfs2_inode, i_ordered); 494 ipb = list_entry(b, struct gfs2_inode, i_ordered); 495 496 if (ipa->i_no_addr < ipb->i_no_addr) 497 return -1; 498 if (ipa->i_no_addr > ipb->i_no_addr) 499 return 1; 500 return 0; 501 } 502 503 static void gfs2_ordered_write(struct gfs2_sbd *sdp) 504 { 505 struct gfs2_inode *ip; 506 LIST_HEAD(written); 507 508 spin_lock(&sdp->sd_ordered_lock); 509 list_sort(NULL, &sdp->sd_log_le_ordered, &ip_cmp); 510 while (!list_empty(&sdp->sd_log_le_ordered)) { 511 ip = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_inode, i_ordered); 512 list_move(&ip->i_ordered, &written); 513 if (ip->i_inode.i_mapping->nrpages == 0) 514 continue; 515 spin_unlock(&sdp->sd_ordered_lock); 516 filemap_fdatawrite(ip->i_inode.i_mapping); 517 spin_lock(&sdp->sd_ordered_lock); 518 } 519 list_splice(&written, &sdp->sd_log_le_ordered); 520 spin_unlock(&sdp->sd_ordered_lock); 521 } 522 523 static void gfs2_ordered_wait(struct gfs2_sbd *sdp) 524 { 525 struct gfs2_inode *ip; 526 527 spin_lock(&sdp->sd_ordered_lock); 528 while (!list_empty(&sdp->sd_log_le_ordered)) { 529 ip = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_inode, i_ordered); 530 list_del(&ip->i_ordered); 531 WARN_ON(!test_and_clear_bit(GIF_ORDERED, &ip->i_flags)); 532 if (ip->i_inode.i_mapping->nrpages == 0) 533 continue; 534 spin_unlock(&sdp->sd_ordered_lock); 535 filemap_fdatawait(ip->i_inode.i_mapping); 536 spin_lock(&sdp->sd_ordered_lock); 537 } 538 spin_unlock(&sdp->sd_ordered_lock); 539 } 540 541 void gfs2_ordered_del_inode(struct gfs2_inode *ip) 542 { 543 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 544 545 spin_lock(&sdp->sd_ordered_lock); 546 if (test_and_clear_bit(GIF_ORDERED, &ip->i_flags)) 547 list_del(&ip->i_ordered); 548 spin_unlock(&sdp->sd_ordered_lock); 549 } 550 551 void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd) 552 { 553 struct buffer_head *bh = bd->bd_bh; 554 struct gfs2_glock *gl = bd->bd_gl; 555 556 bh->b_private = NULL; 557 bd->bd_blkno = bh->b_blocknr; 558 gfs2_remove_from_ail(bd); /* drops ref on bh */ 559 bd->bd_bh = NULL; 560 bd->bd_ops = &gfs2_revoke_lops; 561 sdp->sd_log_num_revoke++; 562 atomic_inc(&gl->gl_revokes); 563 set_bit(GLF_LFLUSH, &gl->gl_flags); 564 list_add(&bd->bd_list, &sdp->sd_log_le_revoke); 565 } 566 567 void gfs2_write_revokes(struct gfs2_sbd *sdp) 568 { 569 struct gfs2_trans *tr; 570 struct gfs2_bufdata *bd, *tmp; 571 int have_revokes = 0; 572 int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64); 573 574 gfs2_ail1_empty(sdp); 575 spin_lock(&sdp->sd_ail_lock); 576 list_for_each_entry(tr, &sdp->sd_ail1_list, tr_list) { 577 list_for_each_entry(bd, &tr->tr_ail2_list, bd_ail_st_list) { 578 if (list_empty(&bd->bd_list)) { 579 have_revokes = 1; 580 goto done; 581 } 582 } 583 } 584 done: 585 spin_unlock(&sdp->sd_ail_lock); 586 if (have_revokes == 0) 587 return; 588 while (sdp->sd_log_num_revoke > max_revokes) 589 max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64); 590 max_revokes -= sdp->sd_log_num_revoke; 591 if (!sdp->sd_log_num_revoke) { 592 atomic_dec(&sdp->sd_log_blks_free); 593 /* If no blocks have been reserved, we need to also 594 * reserve a block for the header */ 595 if (!sdp->sd_log_blks_reserved) 596 atomic_dec(&sdp->sd_log_blks_free); 597 } 598 gfs2_log_lock(sdp); 599 spin_lock(&sdp->sd_ail_lock); 600 list_for_each_entry(tr, &sdp->sd_ail1_list, tr_list) { 601 list_for_each_entry_safe(bd, tmp, &tr->tr_ail2_list, bd_ail_st_list) { 602 if (max_revokes == 0) 603 goto out_of_blocks; 604 if (!list_empty(&bd->bd_list)) 605 continue; 606 gfs2_add_revoke(sdp, bd); 607 max_revokes--; 608 } 609 } 610 out_of_blocks: 611 spin_unlock(&sdp->sd_ail_lock); 612 gfs2_log_unlock(sdp); 613 614 if (!sdp->sd_log_num_revoke) { 615 atomic_inc(&sdp->sd_log_blks_free); 616 if (!sdp->sd_log_blks_reserved) 617 atomic_inc(&sdp->sd_log_blks_free); 618 } 619 } 620 621 /** 622 * log_write_header - Get and initialize a journal header buffer 623 * @sdp: The GFS2 superblock 624 * 625 * Returns: the initialized log buffer descriptor 626 */ 627 628 static void log_write_header(struct gfs2_sbd *sdp, u32 flags) 629 { 630 struct gfs2_log_header *lh; 631 unsigned int tail; 632 u32 hash; 633 int rw = WRITE_FLUSH_FUA | REQ_META; 634 struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO); 635 lh = page_address(page); 636 clear_page(lh); 637 638 tail = current_tail(sdp); 639 640 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC); 641 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH); 642 lh->lh_header.__pad0 = cpu_to_be64(0); 643 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH); 644 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid); 645 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++); 646 lh->lh_flags = cpu_to_be32(flags); 647 lh->lh_tail = cpu_to_be32(tail); 648 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head); 649 hash = gfs2_disk_hash(page_address(page), sizeof(struct gfs2_log_header)); 650 lh->lh_hash = cpu_to_be32(hash); 651 652 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) { 653 gfs2_ordered_wait(sdp); 654 log_flush_wait(sdp); 655 rw = WRITE_SYNC | REQ_META | REQ_PRIO; 656 } 657 658 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); 659 gfs2_log_write_page(sdp, page); 660 gfs2_log_flush_bio(sdp, rw); 661 log_flush_wait(sdp); 662 663 if (sdp->sd_log_tail != tail) 664 log_pull_tail(sdp, tail); 665 } 666 667 /** 668 * gfs2_log_flush - flush incore transaction(s) 669 * @sdp: the filesystem 670 * @gl: The glock structure to flush. If NULL, flush the whole incore log 671 * 672 */ 673 674 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl) 675 { 676 struct gfs2_trans *tr; 677 678 down_write(&sdp->sd_log_flush_lock); 679 680 /* Log might have been flushed while we waited for the flush lock */ 681 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) { 682 up_write(&sdp->sd_log_flush_lock); 683 return; 684 } 685 trace_gfs2_log_flush(sdp, 1); 686 687 sdp->sd_log_flush_head = sdp->sd_log_head; 688 sdp->sd_log_flush_wrapped = 0; 689 tr = sdp->sd_log_tr; 690 if (tr) { 691 sdp->sd_log_tr = NULL; 692 INIT_LIST_HEAD(&tr->tr_ail1_list); 693 INIT_LIST_HEAD(&tr->tr_ail2_list); 694 tr->tr_first = sdp->sd_log_flush_head; 695 } 696 697 gfs2_assert_withdraw(sdp, 698 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); 699 700 gfs2_ordered_write(sdp); 701 lops_before_commit(sdp, tr); 702 gfs2_log_flush_bio(sdp, WRITE); 703 704 if (sdp->sd_log_head != sdp->sd_log_flush_head) { 705 log_flush_wait(sdp); 706 log_write_header(sdp, 0); 707 } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){ 708 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ 709 trace_gfs2_log_blocks(sdp, -1); 710 log_write_header(sdp, 0); 711 } 712 lops_after_commit(sdp, tr); 713 714 gfs2_log_lock(sdp); 715 sdp->sd_log_head = sdp->sd_log_flush_head; 716 sdp->sd_log_blks_reserved = 0; 717 sdp->sd_log_commited_revoke = 0; 718 719 spin_lock(&sdp->sd_ail_lock); 720 if (tr && !list_empty(&tr->tr_ail1_list)) { 721 list_add(&tr->tr_list, &sdp->sd_ail1_list); 722 tr = NULL; 723 } 724 spin_unlock(&sdp->sd_ail_lock); 725 gfs2_log_unlock(sdp); 726 trace_gfs2_log_flush(sdp, 0); 727 up_write(&sdp->sd_log_flush_lock); 728 729 kfree(tr); 730 } 731 732 /** 733 * gfs2_merge_trans - Merge a new transaction into a cached transaction 734 * @old: Original transaction to be expanded 735 * @new: New transaction to be merged 736 */ 737 738 static void gfs2_merge_trans(struct gfs2_trans *old, struct gfs2_trans *new) 739 { 740 WARN_ON_ONCE(old->tr_attached != 1); 741 742 old->tr_num_buf_new += new->tr_num_buf_new; 743 old->tr_num_databuf_new += new->tr_num_databuf_new; 744 old->tr_num_buf_rm += new->tr_num_buf_rm; 745 old->tr_num_databuf_rm += new->tr_num_databuf_rm; 746 old->tr_num_revoke += new->tr_num_revoke; 747 old->tr_num_revoke_rm += new->tr_num_revoke_rm; 748 749 list_splice_tail_init(&new->tr_databuf, &old->tr_databuf); 750 list_splice_tail_init(&new->tr_buf, &old->tr_buf); 751 } 752 753 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 754 { 755 unsigned int reserved; 756 unsigned int unused; 757 unsigned int maxres; 758 759 gfs2_log_lock(sdp); 760 761 if (sdp->sd_log_tr) { 762 gfs2_merge_trans(sdp->sd_log_tr, tr); 763 } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) { 764 gfs2_assert_withdraw(sdp, tr->tr_t_gh.gh_gl); 765 sdp->sd_log_tr = tr; 766 tr->tr_attached = 1; 767 } 768 769 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; 770 reserved = calc_reserved(sdp); 771 maxres = sdp->sd_log_blks_reserved + tr->tr_reserved; 772 gfs2_assert_withdraw(sdp, maxres >= reserved); 773 unused = maxres - reserved; 774 atomic_add(unused, &sdp->sd_log_blks_free); 775 trace_gfs2_log_blocks(sdp, unused); 776 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= 777 sdp->sd_jdesc->jd_blocks); 778 sdp->sd_log_blks_reserved = reserved; 779 780 gfs2_log_unlock(sdp); 781 } 782 783 /** 784 * gfs2_log_commit - Commit a transaction to the log 785 * @sdp: the filesystem 786 * @tr: the transaction 787 * 788 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1 789 * or the total number of used blocks (pinned blocks plus AIL blocks) 790 * is greater than thresh2. 791 * 792 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of 793 * journal size. 794 * 795 * Returns: errno 796 */ 797 798 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 799 { 800 log_refund(sdp, tr); 801 802 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) || 803 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) > 804 atomic_read(&sdp->sd_log_thresh2))) 805 wake_up(&sdp->sd_logd_waitq); 806 } 807 808 /** 809 * gfs2_log_shutdown - write a shutdown header into a journal 810 * @sdp: the filesystem 811 * 812 */ 813 814 void gfs2_log_shutdown(struct gfs2_sbd *sdp) 815 { 816 down_write(&sdp->sd_log_flush_lock); 817 818 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); 819 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); 820 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list)); 821 822 sdp->sd_log_flush_head = sdp->sd_log_head; 823 sdp->sd_log_flush_wrapped = 0; 824 825 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT); 826 827 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks); 828 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail); 829 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list)); 830 831 sdp->sd_log_head = sdp->sd_log_flush_head; 832 sdp->sd_log_tail = sdp->sd_log_head; 833 834 up_write(&sdp->sd_log_flush_lock); 835 } 836 837 838 /** 839 * gfs2_meta_syncfs - sync all the buffers in a filesystem 840 * @sdp: the filesystem 841 * 842 */ 843 844 void gfs2_meta_syncfs(struct gfs2_sbd *sdp) 845 { 846 gfs2_log_flush(sdp, NULL); 847 for (;;) { 848 gfs2_ail1_start(sdp); 849 gfs2_ail1_wait(sdp); 850 if (gfs2_ail1_empty(sdp)) 851 break; 852 } 853 gfs2_log_flush(sdp, NULL); 854 } 855 856 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp) 857 { 858 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1)); 859 } 860 861 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp) 862 { 863 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free); 864 return used_blocks >= atomic_read(&sdp->sd_log_thresh2); 865 } 866 867 /** 868 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks 869 * @sdp: Pointer to GFS2 superblock 870 * 871 * Also, periodically check to make sure that we're using the most recent 872 * journal index. 873 */ 874 875 int gfs2_logd(void *data) 876 { 877 struct gfs2_sbd *sdp = data; 878 unsigned long t = 1; 879 DEFINE_WAIT(wait); 880 881 while (!kthread_should_stop()) { 882 883 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { 884 gfs2_ail1_empty(sdp); 885 gfs2_log_flush(sdp, NULL); 886 } 887 888 if (gfs2_ail_flush_reqd(sdp)) { 889 gfs2_ail1_start(sdp); 890 gfs2_ail1_wait(sdp); 891 gfs2_ail1_empty(sdp); 892 gfs2_log_flush(sdp, NULL); 893 } 894 895 if (!gfs2_ail_flush_reqd(sdp)) 896 wake_up(&sdp->sd_log_waitq); 897 898 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ; 899 900 try_to_freeze(); 901 902 do { 903 prepare_to_wait(&sdp->sd_logd_waitq, &wait, 904 TASK_INTERRUPTIBLE); 905 if (!gfs2_ail_flush_reqd(sdp) && 906 !gfs2_jrnl_flush_reqd(sdp) && 907 !kthread_should_stop()) 908 t = schedule_timeout(t); 909 } while(t && !gfs2_ail_flush_reqd(sdp) && 910 !gfs2_jrnl_flush_reqd(sdp) && 911 !kthread_should_stop()); 912 finish_wait(&sdp->sd_logd_waitq, &wait); 913 } 914 915 return 0; 916 } 917 918