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 23 #include "gfs2.h" 24 #include "incore.h" 25 #include "bmap.h" 26 #include "glock.h" 27 #include "log.h" 28 #include "lops.h" 29 #include "meta_io.h" 30 #include "util.h" 31 #include "dir.h" 32 #include "trace_gfs2.h" 33 34 #define PULL 1 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_ail = 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_ail *ai) 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, &ai->ai_ail1_list, bd_ail_st_list) { 104 bh = bd->bd_bh; 105 106 gfs2_assert(sdp, bd->bd_ail == ai); 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, &ai->ai_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, &ai->ai_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_ail *ai; 149 150 trace_gfs2_ail_flush(sdp, wbc, 1); 151 spin_lock(&sdp->sd_ail_lock); 152 restart: 153 list_for_each_entry_reverse(ai, head, ai_list) { 154 if (wbc->nr_to_write <= 0) 155 break; 156 if (gfs2_ail1_start_one(sdp, wbc, ai)) 157 goto restart; 158 } 159 spin_unlock(&sdp->sd_ail_lock); 160 trace_gfs2_ail_flush(sdp, wbc, 0); 161 } 162 163 /** 164 * gfs2_ail1_start - start writeback of all ail1 entries 165 * @sdp: The superblock 166 */ 167 168 static void gfs2_ail1_start(struct gfs2_sbd *sdp) 169 { 170 struct writeback_control wbc = { 171 .sync_mode = WB_SYNC_NONE, 172 .nr_to_write = LONG_MAX, 173 .range_start = 0, 174 .range_end = LLONG_MAX, 175 }; 176 177 return gfs2_ail1_flush(sdp, &wbc); 178 } 179 180 /** 181 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced 182 * @sdp: the filesystem 183 * @ai: the AIL entry 184 * 185 */ 186 187 static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) 188 { 189 struct gfs2_bufdata *bd, *s; 190 struct buffer_head *bh; 191 192 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, 193 bd_ail_st_list) { 194 bh = bd->bd_bh; 195 gfs2_assert(sdp, bd->bd_ail == ai); 196 if (buffer_busy(bh)) 197 continue; 198 if (!buffer_uptodate(bh)) 199 gfs2_io_error_bh(sdp, bh); 200 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); 201 } 202 203 } 204 205 /** 206 * gfs2_ail1_empty - Try to empty the ail1 lists 207 * @sdp: The superblock 208 * 209 * Tries to empty the ail1 lists, starting with the oldest first 210 */ 211 212 static int gfs2_ail1_empty(struct gfs2_sbd *sdp) 213 { 214 struct gfs2_ail *ai, *s; 215 int ret; 216 217 spin_lock(&sdp->sd_ail_lock); 218 list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) { 219 gfs2_ail1_empty_one(sdp, ai); 220 if (list_empty(&ai->ai_ail1_list)) 221 list_move(&ai->ai_list, &sdp->sd_ail2_list); 222 else 223 break; 224 } 225 ret = list_empty(&sdp->sd_ail1_list); 226 spin_unlock(&sdp->sd_ail_lock); 227 228 return ret; 229 } 230 231 static void gfs2_ail1_wait(struct gfs2_sbd *sdp) 232 { 233 struct gfs2_ail *ai; 234 struct gfs2_bufdata *bd; 235 struct buffer_head *bh; 236 237 spin_lock(&sdp->sd_ail_lock); 238 list_for_each_entry_reverse(ai, &sdp->sd_ail1_list, ai_list) { 239 list_for_each_entry(bd, &ai->ai_ail1_list, bd_ail_st_list) { 240 bh = bd->bd_bh; 241 if (!buffer_locked(bh)) 242 continue; 243 get_bh(bh); 244 spin_unlock(&sdp->sd_ail_lock); 245 wait_on_buffer(bh); 246 brelse(bh); 247 return; 248 } 249 } 250 spin_unlock(&sdp->sd_ail_lock); 251 } 252 253 /** 254 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced 255 * @sdp: the filesystem 256 * @ai: the AIL entry 257 * 258 */ 259 260 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) 261 { 262 struct list_head *head = &ai->ai_ail2_list; 263 struct gfs2_bufdata *bd; 264 265 while (!list_empty(head)) { 266 bd = list_entry(head->prev, struct gfs2_bufdata, 267 bd_ail_st_list); 268 gfs2_assert(sdp, bd->bd_ail == ai); 269 gfs2_remove_from_ail(bd); 270 } 271 } 272 273 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail) 274 { 275 struct gfs2_ail *ai, *safe; 276 unsigned int old_tail = sdp->sd_log_tail; 277 int wrap = (new_tail < old_tail); 278 int a, b, rm; 279 280 spin_lock(&sdp->sd_ail_lock); 281 282 list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) { 283 a = (old_tail <= ai->ai_first); 284 b = (ai->ai_first < new_tail); 285 rm = (wrap) ? (a || b) : (a && b); 286 if (!rm) 287 continue; 288 289 gfs2_ail2_empty_one(sdp, ai); 290 list_del(&ai->ai_list); 291 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list)); 292 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list)); 293 kfree(ai); 294 } 295 296 spin_unlock(&sdp->sd_ail_lock); 297 } 298 299 /** 300 * gfs2_log_reserve - Make a log reservation 301 * @sdp: The GFS2 superblock 302 * @blks: The number of blocks to reserve 303 * 304 * Note that we never give out the last few blocks of the journal. Thats 305 * due to the fact that there is a small number of header blocks 306 * associated with each log flush. The exact number can't be known until 307 * flush time, so we ensure that we have just enough free blocks at all 308 * times to avoid running out during a log flush. 309 * 310 * We no longer flush the log here, instead we wake up logd to do that 311 * for us. To avoid the thundering herd and to ensure that we deal fairly 312 * with queued waiters, we use an exclusive wait. This means that when we 313 * get woken with enough journal space to get our reservation, we need to 314 * wake the next waiter on the list. 315 * 316 * Returns: errno 317 */ 318 319 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) 320 { 321 unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize); 322 unsigned wanted = blks + reserved_blks; 323 DEFINE_WAIT(wait); 324 int did_wait = 0; 325 unsigned int free_blocks; 326 327 if (gfs2_assert_warn(sdp, blks) || 328 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) 329 return -EINVAL; 330 retry: 331 free_blocks = atomic_read(&sdp->sd_log_blks_free); 332 if (unlikely(free_blocks <= wanted)) { 333 do { 334 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait, 335 TASK_UNINTERRUPTIBLE); 336 wake_up(&sdp->sd_logd_waitq); 337 did_wait = 1; 338 if (atomic_read(&sdp->sd_log_blks_free) <= wanted) 339 io_schedule(); 340 free_blocks = atomic_read(&sdp->sd_log_blks_free); 341 } while(free_blocks <= wanted); 342 finish_wait(&sdp->sd_log_waitq, &wait); 343 } 344 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks, 345 free_blocks - blks) != free_blocks) 346 goto retry; 347 trace_gfs2_log_blocks(sdp, -blks); 348 349 /* 350 * If we waited, then so might others, wake them up _after_ we get 351 * our share of the log. 352 */ 353 if (unlikely(did_wait)) 354 wake_up(&sdp->sd_log_waitq); 355 356 down_read(&sdp->sd_log_flush_lock); 357 358 return 0; 359 } 360 361 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn) 362 { 363 struct gfs2_journal_extent *je; 364 365 list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) { 366 if (lbn >= je->lblock && lbn < je->lblock + je->blocks) 367 return je->dblock + lbn - je->lblock; 368 } 369 370 return -1; 371 } 372 373 /** 374 * log_distance - Compute distance between two journal blocks 375 * @sdp: The GFS2 superblock 376 * @newer: The most recent journal block of the pair 377 * @older: The older journal block of the pair 378 * 379 * Compute the distance (in the journal direction) between two 380 * blocks in the journal 381 * 382 * Returns: the distance in blocks 383 */ 384 385 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer, 386 unsigned int older) 387 { 388 int dist; 389 390 dist = newer - older; 391 if (dist < 0) 392 dist += sdp->sd_jdesc->jd_blocks; 393 394 return dist; 395 } 396 397 /** 398 * calc_reserved - Calculate the number of blocks to reserve when 399 * refunding a transaction's unused buffers. 400 * @sdp: The GFS2 superblock 401 * 402 * This is complex. We need to reserve room for all our currently used 403 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and 404 * all our journaled data buffers for journaled files (e.g. files in the 405 * meta_fs like rindex, or files for which chattr +j was done.) 406 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush 407 * will count it as free space (sd_log_blks_free) and corruption will follow. 408 * 409 * We can have metadata bufs and jdata bufs in the same journal. So each 410 * type gets its own log header, for which we need to reserve a block. 411 * In fact, each type has the potential for needing more than one header 412 * in cases where we have more buffers than will fit on a journal page. 413 * Metadata journal entries take up half the space of journaled buffer entries. 414 * Thus, metadata entries have buf_limit (502) and journaled buffers have 415 * databuf_limit (251) before they cause a wrap around. 416 * 417 * Also, we need to reserve blocks for revoke journal entries and one for an 418 * overall header for the lot. 419 * 420 * Returns: the number of blocks reserved 421 */ 422 static unsigned int calc_reserved(struct gfs2_sbd *sdp) 423 { 424 unsigned int reserved = 0; 425 unsigned int mbuf_limit, metabufhdrs_needed; 426 unsigned int dbuf_limit, databufhdrs_needed; 427 unsigned int revokes = 0; 428 429 mbuf_limit = buf_limit(sdp); 430 metabufhdrs_needed = (sdp->sd_log_commited_buf + 431 (mbuf_limit - 1)) / mbuf_limit; 432 dbuf_limit = databuf_limit(sdp); 433 databufhdrs_needed = (sdp->sd_log_commited_databuf + 434 (dbuf_limit - 1)) / dbuf_limit; 435 436 if (sdp->sd_log_commited_revoke > 0) 437 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, 438 sizeof(u64)); 439 440 reserved = sdp->sd_log_commited_buf + metabufhdrs_needed + 441 sdp->sd_log_commited_databuf + databufhdrs_needed + 442 revokes; 443 /* One for the overall header */ 444 if (reserved) 445 reserved++; 446 return reserved; 447 } 448 449 static unsigned int current_tail(struct gfs2_sbd *sdp) 450 { 451 struct gfs2_ail *ai; 452 unsigned int tail; 453 454 spin_lock(&sdp->sd_ail_lock); 455 456 if (list_empty(&sdp->sd_ail1_list)) { 457 tail = sdp->sd_log_head; 458 } else { 459 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list); 460 tail = ai->ai_first; 461 } 462 463 spin_unlock(&sdp->sd_ail_lock); 464 465 return tail; 466 } 467 468 void gfs2_log_incr_head(struct gfs2_sbd *sdp) 469 { 470 if (sdp->sd_log_flush_head == sdp->sd_log_tail) 471 BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head); 472 473 if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) { 474 sdp->sd_log_flush_head = 0; 475 sdp->sd_log_flush_wrapped = 1; 476 } 477 } 478 479 /** 480 * gfs2_log_write_endio - End of I/O for a log buffer 481 * @bh: The buffer head 482 * @uptodate: I/O Status 483 * 484 */ 485 486 static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate) 487 { 488 struct gfs2_sbd *sdp = bh->b_private; 489 bh->b_private = NULL; 490 491 end_buffer_write_sync(bh, uptodate); 492 if (atomic_dec_and_test(&sdp->sd_log_in_flight)) 493 wake_up(&sdp->sd_log_flush_wait); 494 } 495 496 /** 497 * gfs2_log_get_buf - Get and initialize a buffer to use for log control data 498 * @sdp: The GFS2 superblock 499 * 500 * Returns: the buffer_head 501 */ 502 503 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp) 504 { 505 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 506 struct buffer_head *bh; 507 508 bh = sb_getblk(sdp->sd_vfs, blkno); 509 lock_buffer(bh); 510 memset(bh->b_data, 0, bh->b_size); 511 set_buffer_uptodate(bh); 512 clear_buffer_dirty(bh); 513 gfs2_log_incr_head(sdp); 514 atomic_inc(&sdp->sd_log_in_flight); 515 bh->b_private = sdp; 516 bh->b_end_io = gfs2_log_write_endio; 517 518 return bh; 519 } 520 521 /** 522 * gfs2_fake_write_endio - 523 * @bh: The buffer head 524 * @uptodate: The I/O Status 525 * 526 */ 527 528 static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate) 529 { 530 struct buffer_head *real_bh = bh->b_private; 531 struct gfs2_bufdata *bd = real_bh->b_private; 532 struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd; 533 534 end_buffer_write_sync(bh, uptodate); 535 free_buffer_head(bh); 536 unlock_buffer(real_bh); 537 brelse(real_bh); 538 if (atomic_dec_and_test(&sdp->sd_log_in_flight)) 539 wake_up(&sdp->sd_log_flush_wait); 540 } 541 542 /** 543 * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log 544 * @sdp: the filesystem 545 * @data: the data the buffer_head should point to 546 * 547 * Returns: the log buffer descriptor 548 */ 549 550 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp, 551 struct buffer_head *real) 552 { 553 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 554 struct buffer_head *bh; 555 556 bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL); 557 atomic_set(&bh->b_count, 1); 558 bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock); 559 set_bh_page(bh, real->b_page, bh_offset(real)); 560 bh->b_blocknr = blkno; 561 bh->b_size = sdp->sd_sb.sb_bsize; 562 bh->b_bdev = sdp->sd_vfs->s_bdev; 563 bh->b_private = real; 564 bh->b_end_io = gfs2_fake_write_endio; 565 566 gfs2_log_incr_head(sdp); 567 atomic_inc(&sdp->sd_log_in_flight); 568 569 return bh; 570 } 571 572 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail) 573 { 574 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail); 575 576 ail2_empty(sdp, new_tail); 577 578 atomic_add(dist, &sdp->sd_log_blks_free); 579 trace_gfs2_log_blocks(sdp, dist); 580 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= 581 sdp->sd_jdesc->jd_blocks); 582 583 sdp->sd_log_tail = new_tail; 584 } 585 586 /** 587 * log_write_header - Get and initialize a journal header buffer 588 * @sdp: The GFS2 superblock 589 * 590 * Returns: the initialized log buffer descriptor 591 */ 592 593 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull) 594 { 595 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); 596 struct buffer_head *bh; 597 struct gfs2_log_header *lh; 598 unsigned int tail; 599 u32 hash; 600 601 bh = sb_getblk(sdp->sd_vfs, blkno); 602 lock_buffer(bh); 603 memset(bh->b_data, 0, bh->b_size); 604 set_buffer_uptodate(bh); 605 clear_buffer_dirty(bh); 606 607 gfs2_ail1_empty(sdp); 608 tail = current_tail(sdp); 609 610 lh = (struct gfs2_log_header *)bh->b_data; 611 memset(lh, 0, sizeof(struct gfs2_log_header)); 612 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC); 613 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH); 614 lh->lh_header.__pad0 = cpu_to_be64(0); 615 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH); 616 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid); 617 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++); 618 lh->lh_flags = cpu_to_be32(flags); 619 lh->lh_tail = cpu_to_be32(tail); 620 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head); 621 hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header)); 622 lh->lh_hash = cpu_to_be32(hash); 623 624 bh->b_end_io = end_buffer_write_sync; 625 get_bh(bh); 626 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) 627 submit_bh(WRITE_SYNC | REQ_META | REQ_PRIO, bh); 628 else 629 submit_bh(WRITE_FLUSH_FUA | REQ_META | REQ_PRIO, bh); 630 wait_on_buffer(bh); 631 632 if (!buffer_uptodate(bh)) 633 gfs2_io_error_bh(sdp, bh); 634 brelse(bh); 635 636 if (sdp->sd_log_tail != tail) 637 log_pull_tail(sdp, tail); 638 else 639 gfs2_assert_withdraw(sdp, !pull); 640 641 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); 642 gfs2_log_incr_head(sdp); 643 } 644 645 static void log_flush_commit(struct gfs2_sbd *sdp) 646 { 647 DEFINE_WAIT(wait); 648 649 if (atomic_read(&sdp->sd_log_in_flight)) { 650 do { 651 prepare_to_wait(&sdp->sd_log_flush_wait, &wait, 652 TASK_UNINTERRUPTIBLE); 653 if (atomic_read(&sdp->sd_log_in_flight)) 654 io_schedule(); 655 } while(atomic_read(&sdp->sd_log_in_flight)); 656 finish_wait(&sdp->sd_log_flush_wait, &wait); 657 } 658 659 log_write_header(sdp, 0, 0); 660 } 661 662 static void gfs2_ordered_write(struct gfs2_sbd *sdp) 663 { 664 struct gfs2_bufdata *bd; 665 struct buffer_head *bh; 666 LIST_HEAD(written); 667 668 gfs2_log_lock(sdp); 669 while (!list_empty(&sdp->sd_log_le_ordered)) { 670 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list); 671 list_move(&bd->bd_le.le_list, &written); 672 bh = bd->bd_bh; 673 if (!buffer_dirty(bh)) 674 continue; 675 get_bh(bh); 676 gfs2_log_unlock(sdp); 677 lock_buffer(bh); 678 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) { 679 bh->b_end_io = end_buffer_write_sync; 680 submit_bh(WRITE_SYNC, bh); 681 } else { 682 unlock_buffer(bh); 683 brelse(bh); 684 } 685 gfs2_log_lock(sdp); 686 } 687 list_splice(&written, &sdp->sd_log_le_ordered); 688 gfs2_log_unlock(sdp); 689 } 690 691 static void gfs2_ordered_wait(struct gfs2_sbd *sdp) 692 { 693 struct gfs2_bufdata *bd; 694 struct buffer_head *bh; 695 696 gfs2_log_lock(sdp); 697 while (!list_empty(&sdp->sd_log_le_ordered)) { 698 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list); 699 bh = bd->bd_bh; 700 if (buffer_locked(bh)) { 701 get_bh(bh); 702 gfs2_log_unlock(sdp); 703 wait_on_buffer(bh); 704 brelse(bh); 705 gfs2_log_lock(sdp); 706 continue; 707 } 708 list_del_init(&bd->bd_le.le_list); 709 } 710 gfs2_log_unlock(sdp); 711 } 712 713 /** 714 * gfs2_log_flush - flush incore transaction(s) 715 * @sdp: the filesystem 716 * @gl: The glock structure to flush. If NULL, flush the whole incore log 717 * 718 */ 719 720 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl) 721 { 722 struct gfs2_ail *ai; 723 724 down_write(&sdp->sd_log_flush_lock); 725 726 /* Log might have been flushed while we waited for the flush lock */ 727 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) { 728 up_write(&sdp->sd_log_flush_lock); 729 return; 730 } 731 trace_gfs2_log_flush(sdp, 1); 732 733 ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL); 734 INIT_LIST_HEAD(&ai->ai_ail1_list); 735 INIT_LIST_HEAD(&ai->ai_ail2_list); 736 737 if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) { 738 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf, 739 sdp->sd_log_commited_buf); 740 gfs2_assert_withdraw(sdp, 0); 741 } 742 if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) { 743 printk(KERN_INFO "GFS2: log databuf %u %u\n", 744 sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf); 745 gfs2_assert_withdraw(sdp, 0); 746 } 747 gfs2_assert_withdraw(sdp, 748 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); 749 750 sdp->sd_log_flush_head = sdp->sd_log_head; 751 sdp->sd_log_flush_wrapped = 0; 752 ai->ai_first = sdp->sd_log_flush_head; 753 754 gfs2_ordered_write(sdp); 755 lops_before_commit(sdp); 756 gfs2_ordered_wait(sdp); 757 758 if (sdp->sd_log_head != sdp->sd_log_flush_head) 759 log_flush_commit(sdp); 760 else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){ 761 gfs2_log_lock(sdp); 762 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ 763 trace_gfs2_log_blocks(sdp, -1); 764 gfs2_log_unlock(sdp); 765 log_write_header(sdp, 0, PULL); 766 } 767 lops_after_commit(sdp, ai); 768 769 gfs2_log_lock(sdp); 770 sdp->sd_log_head = sdp->sd_log_flush_head; 771 sdp->sd_log_blks_reserved = 0; 772 sdp->sd_log_commited_buf = 0; 773 sdp->sd_log_commited_databuf = 0; 774 sdp->sd_log_commited_revoke = 0; 775 776 spin_lock(&sdp->sd_ail_lock); 777 if (!list_empty(&ai->ai_ail1_list)) { 778 list_add(&ai->ai_list, &sdp->sd_ail1_list); 779 ai = NULL; 780 } 781 spin_unlock(&sdp->sd_ail_lock); 782 gfs2_log_unlock(sdp); 783 trace_gfs2_log_flush(sdp, 0); 784 up_write(&sdp->sd_log_flush_lock); 785 786 kfree(ai); 787 } 788 789 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 790 { 791 unsigned int reserved; 792 unsigned int unused; 793 794 gfs2_log_lock(sdp); 795 796 sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm; 797 sdp->sd_log_commited_databuf += tr->tr_num_databuf_new - 798 tr->tr_num_databuf_rm; 799 gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) || 800 (((int)sdp->sd_log_commited_databuf) >= 0)); 801 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; 802 reserved = calc_reserved(sdp); 803 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved); 804 unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved; 805 atomic_add(unused, &sdp->sd_log_blks_free); 806 trace_gfs2_log_blocks(sdp, unused); 807 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= 808 sdp->sd_jdesc->jd_blocks); 809 sdp->sd_log_blks_reserved = reserved; 810 811 gfs2_log_unlock(sdp); 812 } 813 814 static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 815 { 816 struct list_head *head = &tr->tr_list_buf; 817 struct gfs2_bufdata *bd; 818 819 gfs2_log_lock(sdp); 820 while (!list_empty(head)) { 821 bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr); 822 list_del_init(&bd->bd_list_tr); 823 tr->tr_num_buf--; 824 } 825 gfs2_log_unlock(sdp); 826 gfs2_assert_warn(sdp, !tr->tr_num_buf); 827 } 828 829 /** 830 * gfs2_log_commit - Commit a transaction to the log 831 * @sdp: the filesystem 832 * @tr: the transaction 833 * 834 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1 835 * or the total number of used blocks (pinned blocks plus AIL blocks) 836 * is greater than thresh2. 837 * 838 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of 839 * journal size. 840 * 841 * Returns: errno 842 */ 843 844 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 845 { 846 log_refund(sdp, tr); 847 buf_lo_incore_commit(sdp, tr); 848 849 up_read(&sdp->sd_log_flush_lock); 850 851 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) || 852 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) > 853 atomic_read(&sdp->sd_log_thresh2))) 854 wake_up(&sdp->sd_logd_waitq); 855 } 856 857 /** 858 * gfs2_log_shutdown - write a shutdown header into a journal 859 * @sdp: the filesystem 860 * 861 */ 862 863 void gfs2_log_shutdown(struct gfs2_sbd *sdp) 864 { 865 down_write(&sdp->sd_log_flush_lock); 866 867 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); 868 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf); 869 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); 870 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg); 871 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf); 872 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list)); 873 874 sdp->sd_log_flush_head = sdp->sd_log_head; 875 sdp->sd_log_flush_wrapped = 0; 876 877 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 878 (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL); 879 880 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks); 881 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail); 882 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list)); 883 884 sdp->sd_log_head = sdp->sd_log_flush_head; 885 sdp->sd_log_tail = sdp->sd_log_head; 886 887 up_write(&sdp->sd_log_flush_lock); 888 } 889 890 891 /** 892 * gfs2_meta_syncfs - sync all the buffers in a filesystem 893 * @sdp: the filesystem 894 * 895 */ 896 897 void gfs2_meta_syncfs(struct gfs2_sbd *sdp) 898 { 899 gfs2_log_flush(sdp, NULL); 900 for (;;) { 901 gfs2_ail1_start(sdp); 902 gfs2_ail1_wait(sdp); 903 if (gfs2_ail1_empty(sdp)) 904 break; 905 } 906 gfs2_log_flush(sdp, NULL); 907 } 908 909 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp) 910 { 911 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1)); 912 } 913 914 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp) 915 { 916 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free); 917 return used_blocks >= atomic_read(&sdp->sd_log_thresh2); 918 } 919 920 /** 921 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks 922 * @sdp: Pointer to GFS2 superblock 923 * 924 * Also, periodically check to make sure that we're using the most recent 925 * journal index. 926 */ 927 928 int gfs2_logd(void *data) 929 { 930 struct gfs2_sbd *sdp = data; 931 unsigned long t = 1; 932 DEFINE_WAIT(wait); 933 unsigned preflush; 934 935 while (!kthread_should_stop()) { 936 937 preflush = atomic_read(&sdp->sd_log_pinned); 938 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { 939 gfs2_ail1_empty(sdp); 940 gfs2_log_flush(sdp, NULL); 941 } 942 943 if (gfs2_ail_flush_reqd(sdp)) { 944 gfs2_ail1_start(sdp); 945 gfs2_ail1_wait(sdp); 946 gfs2_ail1_empty(sdp); 947 gfs2_log_flush(sdp, NULL); 948 } 949 950 if (!gfs2_ail_flush_reqd(sdp)) 951 wake_up(&sdp->sd_log_waitq); 952 953 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ; 954 if (freezing(current)) 955 refrigerator(); 956 957 do { 958 prepare_to_wait(&sdp->sd_logd_waitq, &wait, 959 TASK_INTERRUPTIBLE); 960 if (!gfs2_ail_flush_reqd(sdp) && 961 !gfs2_jrnl_flush_reqd(sdp) && 962 !kthread_should_stop()) 963 t = schedule_timeout(t); 964 } while(t && !gfs2_ail_flush_reqd(sdp) && 965 !gfs2_jrnl_flush_reqd(sdp) && 966 !kthread_should_stop()); 967 finish_wait(&sdp->sd_logd_waitq, &wait); 968 } 969 970 return 0; 971 } 972 973