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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4 * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
   5 */
   6
   7#include <linux/sched.h>
   8#include <linux/slab.h>
   9#include <linux/spinlock.h>
  10#include <linux/completion.h>
  11#include <linux/buffer_head.h>
  12#include <linux/gfs2_ondisk.h>
  13#include <linux/crc32.h>
  14#include <linux/crc32c.h>
  15#include <linux/delay.h>
  16#include <linux/kthread.h>
  17#include <linux/freezer.h>
  18#include <linux/bio.h>
  19#include <linux/blkdev.h>
  20#include <linux/writeback.h>
  21#include <linux/list_sort.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#include "trans.h"
  34
  35static void gfs2_log_shutdown(struct gfs2_sbd *sdp);
  36
  37/**
  38 * gfs2_struct2blk - compute stuff
  39 * @sdp: the filesystem
  40 * @nstruct: the number of 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
  48unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct)
  49{
  50	unsigned int blks;
  51	unsigned int first, second;
  52
  53	blks = 1;
  54	first = sdp->sd_ldptrs;
  55
  56	if (nstruct > first) {
  57		second = sdp->sd_inptrs;
  58		blks += DIV_ROUND_UP(nstruct - first, second);
  59	}
  60
  61	return blks;
  62}
  63
  64/**
  65 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
  66 * @mapping: The associated mapping (maybe NULL)
  67 * @bd: The gfs2_bufdata to remove
  68 *
  69 * The ail lock _must_ be held when calling this function
  70 *
  71 */
  72
  73static void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
  74{
  75	bd->bd_tr = NULL;
  76	list_del_init(&bd->bd_ail_st_list);
  77	list_del_init(&bd->bd_ail_gl_list);
  78	atomic_dec(&bd->bd_gl->gl_ail_count);
  79	brelse(bd->bd_bh);
  80}
  81
  82/**
  83 * gfs2_ail1_start_one - Start I/O on a part of the AIL
  84 * @sdp: the filesystem
  85 * @wbc: The writeback control structure
  86 * @ai: The ail structure
  87 *
  88 */
  89
  90static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
  91			       struct writeback_control *wbc,
  92			       struct gfs2_trans *tr)
  93__releases(&sdp->sd_ail_lock)
  94__acquires(&sdp->sd_ail_lock)
  95{
  96	struct gfs2_glock *gl = NULL;
  97	struct address_space *mapping;
  98	struct gfs2_bufdata *bd, *s;
  99	struct buffer_head *bh;
 100	int ret = 0;
 101
 102	list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) {
 103		bh = bd->bd_bh;
 104
 105		gfs2_assert(sdp, bd->bd_tr == tr);
 106
 107		if (!buffer_busy(bh)) {
 108			if (buffer_uptodate(bh)) {
 109				list_move(&bd->bd_ail_st_list,
 110					  &tr->tr_ail2_list);
 111				continue;
 112			}
 113			if (!cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
 114				gfs2_io_error_bh(sdp, bh);
 115				gfs2_withdraw_delayed(sdp);
 116			}
 117		}
 118
 119		if (gfs2_withdrawn(sdp)) {
 120			gfs2_remove_from_ail(bd);
 121			continue;
 122		}
 123		if (!buffer_dirty(bh))
 124			continue;
 125		if (gl == bd->bd_gl)
 126			continue;
 127		gl = bd->bd_gl;
 128		list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list);
 129		mapping = bh->b_page->mapping;
 130		if (!mapping)
 131			continue;
 132		spin_unlock(&sdp->sd_ail_lock);
 133		ret = generic_writepages(mapping, wbc);
 134		spin_lock(&sdp->sd_ail_lock);
 135		if (ret || wbc->nr_to_write <= 0)
 136			break;
 137		return -EBUSY;
 138	}
 139
 140	return ret;
 141}
 142
 143static void dump_ail_list(struct gfs2_sbd *sdp)
 144{
 145	struct gfs2_trans *tr;
 146	struct gfs2_bufdata *bd;
 147	struct buffer_head *bh;
 148
 149	list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
 150		list_for_each_entry_reverse(bd, &tr->tr_ail1_list,
 151					    bd_ail_st_list) {
 152			bh = bd->bd_bh;
 153			fs_err(sdp, "bd %p: blk:0x%llx bh=%p ", bd,
 154			       (unsigned long long)bd->bd_blkno, bh);
 155			if (!bh) {
 156				fs_err(sdp, "\n");
 157				continue;
 158			}
 159			fs_err(sdp, "0x%llx up2:%d dirt:%d lkd:%d req:%d "
 160			       "map:%d new:%d ar:%d aw:%d delay:%d "
 161			       "io err:%d unwritten:%d dfr:%d pin:%d esc:%d\n",
 162			       (unsigned long long)bh->b_blocknr,
 163			       buffer_uptodate(bh), buffer_dirty(bh),
 164			       buffer_locked(bh), buffer_req(bh),
 165			       buffer_mapped(bh), buffer_new(bh),
 166			       buffer_async_read(bh), buffer_async_write(bh),
 167			       buffer_delay(bh), buffer_write_io_error(bh),
 168			       buffer_unwritten(bh),
 169			       buffer_defer_completion(bh),
 170			       buffer_pinned(bh), buffer_escaped(bh));
 171		}
 172	}
 173}
 174
 175/**
 176 * gfs2_ail1_flush - start writeback of some ail1 entries 
 177 * @sdp: The super block
 178 * @wbc: The writeback control structure
 179 *
 180 * Writes back some ail1 entries, according to the limits in the
 181 * writeback control structure
 182 */
 183
 184void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
 185{
 186	struct list_head *head = &sdp->sd_ail1_list;
 187	struct gfs2_trans *tr;
 188	struct blk_plug plug;
 189	int ret;
 190	unsigned long flush_start = jiffies;
 191
 192	trace_gfs2_ail_flush(sdp, wbc, 1);
 193	blk_start_plug(&plug);
 194	spin_lock(&sdp->sd_ail_lock);
 195restart:
 196	ret = 0;
 197	if (time_after(jiffies, flush_start + (HZ * 600))) {
 198		fs_err(sdp, "Error: In %s for ten minutes! t=%d\n",
 199		       __func__, current->journal_info ? 1 : 0);
 200		dump_ail_list(sdp);
 201		goto out;
 202	}
 203	list_for_each_entry_reverse(tr, head, tr_list) {
 204		if (wbc->nr_to_write <= 0)
 205			break;
 206		ret = gfs2_ail1_start_one(sdp, wbc, tr);
 207		if (ret) {
 208			if (ret == -EBUSY)
 209				goto restart;
 210			break;
 211		}
 212	}
 213out:
 214	spin_unlock(&sdp->sd_ail_lock);
 215	blk_finish_plug(&plug);
 216	if (ret) {
 217		gfs2_lm(sdp, "gfs2_ail1_start_one (generic_writepages) "
 218			"returned: %d\n", ret);
 219		gfs2_withdraw(sdp);
 220	}
 221	trace_gfs2_ail_flush(sdp, wbc, 0);
 222}
 223
 224/**
 225 * gfs2_ail1_start - start writeback of all ail1 entries
 226 * @sdp: The superblock
 227 */
 228
 229static void gfs2_ail1_start(struct gfs2_sbd *sdp)
 230{
 231	struct writeback_control wbc = {
 232		.sync_mode = WB_SYNC_NONE,
 233		.nr_to_write = LONG_MAX,
 234		.range_start = 0,
 235		.range_end = LLONG_MAX,
 236	};
 237
 238	return gfs2_ail1_flush(sdp, &wbc);
 239}
 240
 241/**
 242 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 243 * @sdp: the filesystem
 244 * @tr: the transaction
 245 * @max_revokes: If nonzero, issue revokes for the bd items for written buffers
 246 *
 247 */
 248
 249static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
 250				int *max_revokes)
 251{
 252	struct gfs2_bufdata *bd, *s;
 253	struct buffer_head *bh;
 254
 255	list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list,
 256					 bd_ail_st_list) {
 257		bh = bd->bd_bh;
 258		gfs2_assert(sdp, bd->bd_tr == tr);
 259		/*
 260		 * If another process flagged an io error, e.g. writing to the
 261		 * journal, error all other bhs and move them off the ail1 to
 262		 * prevent a tight loop when unmount tries to flush ail1,
 263		 * regardless of whether they're still busy. If no outside
 264		 * errors were found and the buffer is busy, move to the next.
 265		 * If the ail buffer is not busy and caught an error, flag it
 266		 * for others.
 267		 */
 268		if (!sdp->sd_log_error && buffer_busy(bh))
 269			continue;
 270		if (!buffer_uptodate(bh) &&
 271		    !cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
 272			gfs2_io_error_bh(sdp, bh);
 273			gfs2_withdraw_delayed(sdp);
 274		}
 275		/*
 276		 * If we have space for revokes and the bd is no longer on any
 277		 * buf list, we can just add a revoke for it immediately and
 278		 * avoid having to put it on the ail2 list, where it would need
 279		 * to be revoked later.
 280		 */
 281		if (*max_revokes && list_empty(&bd->bd_list)) {
 282			gfs2_add_revoke(sdp, bd);
 283			(*max_revokes)--;
 284			continue;
 285		}
 286		list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
 287	}
 288}
 289
 290/**
 291 * gfs2_ail1_empty - Try to empty the ail1 lists
 292 * @sdp: The superblock
 293 * @max_revokes: If non-zero, add revokes where appropriate
 294 *
 295 * Tries to empty the ail1 lists, starting with the oldest first
 296 */
 297
 298static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int max_revokes)
 299{
 300	struct gfs2_trans *tr, *s;
 301	int oldest_tr = 1;
 302	int ret;
 303
 304	spin_lock(&sdp->sd_ail_lock);
 305	list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {
 306		gfs2_ail1_empty_one(sdp, tr, &max_revokes);
 307		if (list_empty(&tr->tr_ail1_list) && oldest_tr)
 308			list_move(&tr->tr_list, &sdp->sd_ail2_list);
 309		else
 310			oldest_tr = 0;
 311	}
 312	ret = list_empty(&sdp->sd_ail1_list);
 313	spin_unlock(&sdp->sd_ail_lock);
 314
 315	if (test_bit(SDF_WITHDRAWING, &sdp->sd_flags)) {
 316		gfs2_lm(sdp, "fatal: I/O error(s)\n");
 317		gfs2_withdraw(sdp);
 318	}
 319
 320	return ret;
 321}
 322
 323static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
 324{
 325	struct gfs2_trans *tr;
 326	struct gfs2_bufdata *bd;
 327	struct buffer_head *bh;
 328
 329	spin_lock(&sdp->sd_ail_lock);
 330	list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
 331		list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) {
 332			bh = bd->bd_bh;
 333			if (!buffer_locked(bh))
 334				continue;
 335			get_bh(bh);
 336			spin_unlock(&sdp->sd_ail_lock);
 337			wait_on_buffer(bh);
 338			brelse(bh);
 339			return;
 340		}
 341	}
 342	spin_unlock(&sdp->sd_ail_lock);
 343}
 344
 345/**
 346 * gfs2_ail_empty_tr - empty one of the ail lists for a transaction
 347 */
 348
 349static void gfs2_ail_empty_tr(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
 350			      struct list_head *head)
 351{
 352	struct gfs2_bufdata *bd;
 353
 354	while (!list_empty(head)) {
 355		bd = list_first_entry(head, struct gfs2_bufdata,
 356				      bd_ail_st_list);
 357		gfs2_assert(sdp, bd->bd_tr == tr);
 358		gfs2_remove_from_ail(bd);
 359	}
 360}
 361
 362static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 363{
 364	struct gfs2_trans *tr, *safe;
 365	unsigned int old_tail = sdp->sd_log_tail;
 366	int wrap = (new_tail < old_tail);
 367	int a, b, rm;
 368
 369	spin_lock(&sdp->sd_ail_lock);
 370
 371	list_for_each_entry_safe(tr, safe, &sdp->sd_ail2_list, tr_list) {
 372		a = (old_tail <= tr->tr_first);
 373		b = (tr->tr_first < new_tail);
 374		rm = (wrap) ? (a || b) : (a && b);
 375		if (!rm)
 376			continue;
 377
 378		gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 379		list_del(&tr->tr_list);
 380		gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
 381		gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
 382		gfs2_trans_free(sdp, tr);
 383	}
 384
 385	spin_unlock(&sdp->sd_ail_lock);
 386}
 387
 388/**
 389 * gfs2_log_release - Release a given number of log blocks
 390 * @sdp: The GFS2 superblock
 391 * @blks: The number of blocks
 392 *
 393 */
 394
 395void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 396{
 397
 398	atomic_add(blks, &sdp->sd_log_blks_free);
 399	trace_gfs2_log_blocks(sdp, blks);
 400	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
 401				  sdp->sd_jdesc->jd_blocks);
 402	up_read(&sdp->sd_log_flush_lock);
 403}
 404
 405/**
 406 * gfs2_log_reserve - Make a log reservation
 407 * @sdp: The GFS2 superblock
 408 * @blks: The number of blocks to reserve
 409 *
 410 * Note that we never give out the last few blocks of the journal. Thats
 411 * due to the fact that there is a small number of header blocks
 412 * associated with each log flush. The exact number can't be known until
 413 * flush time, so we ensure that we have just enough free blocks at all
 414 * times to avoid running out during a log flush.
 415 *
 416 * We no longer flush the log here, instead we wake up logd to do that
 417 * for us. To avoid the thundering herd and to ensure that we deal fairly
 418 * with queued waiters, we use an exclusive wait. This means that when we
 419 * get woken with enough journal space to get our reservation, we need to
 420 * wake the next waiter on the list.
 421 *
 422 * Returns: errno
 423 */
 424
 425int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 426{
 427	int ret = 0;
 428	unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize);
 429	unsigned wanted = blks + reserved_blks;
 430	DEFINE_WAIT(wait);
 431	int did_wait = 0;
 432	unsigned int free_blocks;
 433
 434	if (gfs2_assert_warn(sdp, blks) ||
 435	    gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 436		return -EINVAL;
 437	atomic_add(blks, &sdp->sd_log_blks_needed);
 438retry:
 439	free_blocks = atomic_read(&sdp->sd_log_blks_free);
 440	if (unlikely(free_blocks <= wanted)) {
 441		do {
 442			prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
 443					TASK_UNINTERRUPTIBLE);
 444			wake_up(&sdp->sd_logd_waitq);
 445			did_wait = 1;
 446			if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
 447				io_schedule();
 448			free_blocks = atomic_read(&sdp->sd_log_blks_free);
 449		} while(free_blocks <= wanted);
 450		finish_wait(&sdp->sd_log_waitq, &wait);
 451	}
 452	atomic_inc(&sdp->sd_reserving_log);
 453	if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
 454				free_blocks - blks) != free_blocks) {
 455		if (atomic_dec_and_test(&sdp->sd_reserving_log))
 456			wake_up(&sdp->sd_reserving_log_wait);
 457		goto retry;
 458	}
 459	atomic_sub(blks, &sdp->sd_log_blks_needed);
 460	trace_gfs2_log_blocks(sdp, -blks);
 461
 462	/*
 463	 * If we waited, then so might others, wake them up _after_ we get
 464	 * our share of the log.
 465	 */
 466	if (unlikely(did_wait))
 467		wake_up(&sdp->sd_log_waitq);
 468
 469	down_read(&sdp->sd_log_flush_lock);
 470	if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) {
 471		gfs2_log_release(sdp, blks);
 472		ret = -EROFS;
 473	}
 474	if (atomic_dec_and_test(&sdp->sd_reserving_log))
 475		wake_up(&sdp->sd_reserving_log_wait);
 476	return ret;
 477}
 478
 479/**
 480 * log_distance - Compute distance between two journal blocks
 481 * @sdp: The GFS2 superblock
 482 * @newer: The most recent journal block of the pair
 483 * @older: The older journal block of the pair
 484 *
 485 *   Compute the distance (in the journal direction) between two
 486 *   blocks in the journal
 487 *
 488 * Returns: the distance in blocks
 489 */
 490
 491static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 492					unsigned int older)
 493{
 494	int dist;
 495
 496	dist = newer - older;
 497	if (dist < 0)
 498		dist += sdp->sd_jdesc->jd_blocks;
 499
 500	return dist;
 501}
 502
 503/**
 504 * calc_reserved - Calculate the number of blocks to reserve when
 505 *                 refunding a transaction's unused buffers.
 506 * @sdp: The GFS2 superblock
 507 *
 508 * This is complex.  We need to reserve room for all our currently used
 509 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and 
 510 * all our journaled data buffers for journaled files (e.g. files in the 
 511 * meta_fs like rindex, or files for which chattr +j was done.)
 512 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
 513 * will count it as free space (sd_log_blks_free) and corruption will follow.
 514 *
 515 * We can have metadata bufs and jdata bufs in the same journal.  So each
 516 * type gets its own log header, for which we need to reserve a block.
 517 * In fact, each type has the potential for needing more than one header 
 518 * in cases where we have more buffers than will fit on a journal page.
 519 * Metadata journal entries take up half the space of journaled buffer entries.
 520 * Thus, metadata entries have buf_limit (502) and journaled buffers have
 521 * databuf_limit (251) before they cause a wrap around.
 522 *
 523 * Also, we need to reserve blocks for revoke journal entries and one for an
 524 * overall header for the lot.
 525 *
 526 * Returns: the number of blocks reserved
 527 */
 528static unsigned int calc_reserved(struct gfs2_sbd *sdp)
 529{
 530	unsigned int reserved = 0;
 531	unsigned int mbuf;
 532	unsigned int dbuf;
 533	struct gfs2_trans *tr = sdp->sd_log_tr;
 534
 535	if (tr) {
 536		mbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm;
 537		dbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
 538		reserved = mbuf + dbuf;
 539		/* Account for header blocks */
 540		reserved += DIV_ROUND_UP(mbuf, buf_limit(sdp));
 541		reserved += DIV_ROUND_UP(dbuf, databuf_limit(sdp));
 542	}
 543
 544	if (sdp->sd_log_committed_revoke > 0)
 545		reserved += gfs2_struct2blk(sdp, sdp->sd_log_committed_revoke);
 546	/* One for the overall header */
 547	if (reserved)
 548		reserved++;
 549	return reserved;
 550}
 551
 552static unsigned int current_tail(struct gfs2_sbd *sdp)
 553{
 554	struct gfs2_trans *tr;
 555	unsigned int tail;
 556
 557	spin_lock(&sdp->sd_ail_lock);
 558
 559	if (list_empty(&sdp->sd_ail1_list)) {
 560		tail = sdp->sd_log_head;
 561	} else {
 562		tr = list_last_entry(&sdp->sd_ail1_list, struct gfs2_trans,
 563				tr_list);
 564		tail = tr->tr_first;
 565	}
 566
 567	spin_unlock(&sdp->sd_ail_lock);
 568
 569	return tail;
 570}
 571
 572static 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
 587void log_flush_wait(struct gfs2_sbd *sdp)
 588{
 589	DEFINE_WAIT(wait);
 590
 591	if (atomic_read(&sdp->sd_log_in_flight)) {
 592		do {
 593			prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
 594					TASK_UNINTERRUPTIBLE);
 595			if (atomic_read(&sdp->sd_log_in_flight))
 596				io_schedule();
 597		} while(atomic_read(&sdp->sd_log_in_flight));
 598		finish_wait(&sdp->sd_log_flush_wait, &wait);
 599	}
 600}
 601
 602static int ip_cmp(void *priv, struct list_head *a, struct list_head *b)
 603{
 604	struct gfs2_inode *ipa, *ipb;
 605
 606	ipa = list_entry(a, struct gfs2_inode, i_ordered);
 607	ipb = list_entry(b, struct gfs2_inode, i_ordered);
 608
 609	if (ipa->i_no_addr < ipb->i_no_addr)
 610		return -1;
 611	if (ipa->i_no_addr > ipb->i_no_addr)
 612		return 1;
 613	return 0;
 614}
 615
 616static void __ordered_del_inode(struct gfs2_inode *ip)
 617{
 618	if (!list_empty(&ip->i_ordered))
 619		list_del_init(&ip->i_ordered);
 620}
 621
 622static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 623{
 624	struct gfs2_inode *ip;
 625	LIST_HEAD(written);
 626
 627	spin_lock(&sdp->sd_ordered_lock);
 628	list_sort(NULL, &sdp->sd_log_ordered, &ip_cmp);
 629	while (!list_empty(&sdp->sd_log_ordered)) {
 630		ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
 631		if (ip->i_inode.i_mapping->nrpages == 0) {
 632			__ordered_del_inode(ip);
 633			continue;
 634		}
 635		list_move(&ip->i_ordered, &written);
 636		spin_unlock(&sdp->sd_ordered_lock);
 637		filemap_fdatawrite(ip->i_inode.i_mapping);
 638		spin_lock(&sdp->sd_ordered_lock);
 639	}
 640	list_splice(&written, &sdp->sd_log_ordered);
 641	spin_unlock(&sdp->sd_ordered_lock);
 642}
 643
 644static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
 645{
 646	struct gfs2_inode *ip;
 647
 648	spin_lock(&sdp->sd_ordered_lock);
 649	while (!list_empty(&sdp->sd_log_ordered)) {
 650		ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
 651		__ordered_del_inode(ip);
 652		if (ip->i_inode.i_mapping->nrpages == 0)
 653			continue;
 654		spin_unlock(&sdp->sd_ordered_lock);
 655		filemap_fdatawait(ip->i_inode.i_mapping);
 656		spin_lock(&sdp->sd_ordered_lock);
 657	}
 658	spin_unlock(&sdp->sd_ordered_lock);
 659}
 660
 661void gfs2_ordered_del_inode(struct gfs2_inode *ip)
 662{
 663	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 664
 665	spin_lock(&sdp->sd_ordered_lock);
 666	__ordered_del_inode(ip);
 667	spin_unlock(&sdp->sd_ordered_lock);
 668}
 669
 670void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 671{
 672	struct buffer_head *bh = bd->bd_bh;
 673	struct gfs2_glock *gl = bd->bd_gl;
 674
 675	sdp->sd_log_num_revoke++;
 676	if (atomic_inc_return(&gl->gl_revokes) == 1)
 677		gfs2_glock_hold(gl);
 678	bh->b_private = NULL;
 679	bd->bd_blkno = bh->b_blocknr;
 680	gfs2_remove_from_ail(bd); /* drops ref on bh */
 681	bd->bd_bh = NULL;
 682	set_bit(GLF_LFLUSH, &gl->gl_flags);
 683	list_add(&bd->bd_list, &sdp->sd_log_revokes);
 684}
 685
 686void gfs2_glock_remove_revoke(struct gfs2_glock *gl)
 687{
 688	if (atomic_dec_return(&gl->gl_revokes) == 0) {
 689		clear_bit(GLF_LFLUSH, &gl->gl_flags);
 690		gfs2_glock_queue_put(gl);
 691	}
 692}
 693
 694/**
 695 * gfs2_write_revokes - Add as many revokes to the system transaction as we can
 696 * @sdp: The GFS2 superblock
 697 *
 698 * Our usual strategy is to defer writing revokes as much as we can in the hope
 699 * that we'll eventually overwrite the journal, which will make those revokes
 700 * go away.  This changes when we flush the log: at that point, there will
 701 * likely be some left-over space in the last revoke block of that transaction.
 702 * We can fill that space with additional revokes for blocks that have already
 703 * been written back.  This will basically come at no cost now, and will save
 704 * us from having to keep track of those blocks on the AIL2 list later.
 705 */
 706void gfs2_write_revokes(struct gfs2_sbd *sdp)
 707{
 708	/* number of revokes we still have room for */
 709	int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64);
 710
 711	gfs2_log_lock(sdp);
 712	while (sdp->sd_log_num_revoke > max_revokes)
 713		max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64);
 714	max_revokes -= sdp->sd_log_num_revoke;
 715	if (!sdp->sd_log_num_revoke) {
 716		atomic_dec(&sdp->sd_log_blks_free);
 717		/* If no blocks have been reserved, we need to also
 718		 * reserve a block for the header */
 719		if (!sdp->sd_log_blks_reserved)
 720			atomic_dec(&sdp->sd_log_blks_free);
 721	}
 722	gfs2_ail1_empty(sdp, max_revokes);
 723	gfs2_log_unlock(sdp);
 724
 725	if (!sdp->sd_log_num_revoke) {
 726		atomic_inc(&sdp->sd_log_blks_free);
 727		if (!sdp->sd_log_blks_reserved)
 728			atomic_inc(&sdp->sd_log_blks_free);
 729	}
 730}
 731
 732/**
 733 * gfs2_write_log_header - Write a journal log header buffer at lblock
 734 * @sdp: The GFS2 superblock
 735 * @jd: journal descriptor of the journal to which we are writing
 736 * @seq: sequence number
 737 * @tail: tail of the log
 738 * @lblock: value for lh_blkno (block number relative to start of journal)
 739 * @flags: log header flags GFS2_LOG_HEAD_*
 740 * @op_flags: flags to pass to the bio
 741 *
 742 * Returns: the initialized log buffer descriptor
 743 */
 744
 745void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd,
 746			   u64 seq, u32 tail, u32 lblock, u32 flags,
 747			   int op_flags)
 748{
 749	struct gfs2_log_header *lh;
 750	u32 hash, crc;
 751	struct page *page;
 752	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 753	struct timespec64 tv;
 754	struct super_block *sb = sdp->sd_vfs;
 755	u64 dblock;
 756
 757	if (gfs2_withdrawn(sdp))
 758		goto out;
 759
 760	page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
 761	lh = page_address(page);
 762	clear_page(lh);
 763
 764	lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 765	lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 766	lh->lh_header.__pad0 = cpu_to_be64(0);
 767	lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 768	lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
 769	lh->lh_sequence = cpu_to_be64(seq);
 770	lh->lh_flags = cpu_to_be32(flags);
 771	lh->lh_tail = cpu_to_be32(tail);
 772	lh->lh_blkno = cpu_to_be32(lblock);
 773	hash = ~crc32(~0, lh, LH_V1_SIZE);
 774	lh->lh_hash = cpu_to_be32(hash);
 775
 776	ktime_get_coarse_real_ts64(&tv);
 777	lh->lh_nsec = cpu_to_be32(tv.tv_nsec);
 778	lh->lh_sec = cpu_to_be64(tv.tv_sec);
 779	if (!list_empty(&jd->extent_list))
 780		dblock = gfs2_log_bmap(jd, lblock);
 781	else {
 782		int ret = gfs2_lblk_to_dblk(jd->jd_inode, lblock, &dblock);
 783		if (gfs2_assert_withdraw(sdp, ret == 0))
 784			return;
 785	}
 786	lh->lh_addr = cpu_to_be64(dblock);
 787	lh->lh_jinode = cpu_to_be64(GFS2_I(jd->jd_inode)->i_no_addr);
 788
 789	/* We may only write local statfs, quota, etc., when writing to our
 790	   own journal. The values are left 0 when recovering a journal
 791	   different from our own. */
 792	if (!(flags & GFS2_LOG_HEAD_RECOVERY)) {
 793		lh->lh_statfs_addr =
 794			cpu_to_be64(GFS2_I(sdp->sd_sc_inode)->i_no_addr);
 795		lh->lh_quota_addr =
 796			cpu_to_be64(GFS2_I(sdp->sd_qc_inode)->i_no_addr);
 797
 798		spin_lock(&sdp->sd_statfs_spin);
 799		lh->lh_local_total = cpu_to_be64(l_sc->sc_total);
 800		lh->lh_local_free = cpu_to_be64(l_sc->sc_free);
 801		lh->lh_local_dinodes = cpu_to_be64(l_sc->sc_dinodes);
 802		spin_unlock(&sdp->sd_statfs_spin);
 803	}
 804
 805	BUILD_BUG_ON(offsetof(struct gfs2_log_header, lh_crc) != LH_V1_SIZE);
 806
 807	crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
 808		     sb->s_blocksize - LH_V1_SIZE - 4);
 809	lh->lh_crc = cpu_to_be32(crc);
 810
 811	gfs2_log_write(sdp, page, sb->s_blocksize, 0, dblock);
 812	gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE | op_flags);
 813out:
 814	log_flush_wait(sdp);
 815}
 816
 817/**
 818 * log_write_header - Get and initialize a journal header buffer
 819 * @sdp: The GFS2 superblock
 820 * @flags: The log header flags, including log header origin
 821 *
 822 * Returns: the initialized log buffer descriptor
 823 */
 824
 825static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
 826{
 827	unsigned int tail;
 828	int op_flags = REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC;
 829	enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
 830
 831	gfs2_assert_withdraw(sdp, (state != SFS_FROZEN));
 832	tail = current_tail(sdp);
 833
 834	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
 835		gfs2_ordered_wait(sdp);
 836		log_flush_wait(sdp);
 837		op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
 838	}
 839	sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 840	gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++, tail,
 841			      sdp->sd_log_flush_head, flags, op_flags);
 842	gfs2_log_incr_head(sdp);
 843
 844	if (sdp->sd_log_tail != tail)
 845		log_pull_tail(sdp, tail);
 846}
 847
 848/**
 849 * ail_drain - drain the ail lists after a withdraw
 850 * @sdp: Pointer to GFS2 superblock
 851 */
 852static void ail_drain(struct gfs2_sbd *sdp)
 853{
 854	struct gfs2_trans *tr;
 855
 856	spin_lock(&sdp->sd_ail_lock);
 857	/*
 858	 * For transactions on the sd_ail1_list we need to drain both the
 859	 * ail1 and ail2 lists. That's because function gfs2_ail1_start_one
 860	 * (temporarily) moves items from its tr_ail1 list to tr_ail2 list
 861	 * before revokes are sent for that block. Items on the sd_ail2_list
 862	 * should have already gotten beyond that point, so no need.
 863	 */
 864	while (!list_empty(&sdp->sd_ail1_list)) {
 865		tr = list_first_entry(&sdp->sd_ail1_list, struct gfs2_trans,
 866				      tr_list);
 867		gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail1_list);
 868		gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 869		list_del(&tr->tr_list);
 870		gfs2_trans_free(sdp, tr);
 871	}
 872	while (!list_empty(&sdp->sd_ail2_list)) {
 873		tr = list_first_entry(&sdp->sd_ail2_list, struct gfs2_trans,
 874				      tr_list);
 875		gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 876		list_del(&tr->tr_list);
 877		gfs2_trans_free(sdp, tr);
 878	}
 879	spin_unlock(&sdp->sd_ail_lock);
 880}
 881
 882/**
 883 * empty_ail1_list - try to start IO and empty the ail1 list
 884 * @sdp: Pointer to GFS2 superblock
 885 */
 886static void empty_ail1_list(struct gfs2_sbd *sdp)
 887{
 888	unsigned long start = jiffies;
 889
 890	for (;;) {
 891		if (time_after(jiffies, start + (HZ * 600))) {
 892			fs_err(sdp, "Error: In %s for 10 minutes! t=%d\n",
 893			       __func__, current->journal_info ? 1 : 0);
 894			dump_ail_list(sdp);
 895			return;
 896		}
 897		gfs2_ail1_start(sdp);
 898		gfs2_ail1_wait(sdp);
 899		if (gfs2_ail1_empty(sdp, 0))
 900			return;
 901	}
 902}
 903
 904/**
 905 * drain_bd - drain the buf and databuf queue for a failed transaction
 906 * @tr: the transaction to drain
 907 *
 908 * When this is called, we're taking an error exit for a log write that failed
 909 * but since we bypassed the after_commit functions, we need to remove the
 910 * items from the buf and databuf queue.
 911 */
 912static void trans_drain(struct gfs2_trans *tr)
 913{
 914	struct gfs2_bufdata *bd;
 915	struct list_head *head;
 916
 917	if (!tr)
 918		return;
 919
 920	head = &tr->tr_buf;
 921	while (!list_empty(head)) {
 922		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
 923		list_del_init(&bd->bd_list);
 924		kmem_cache_free(gfs2_bufdata_cachep, bd);
 925	}
 926	head = &tr->tr_databuf;
 927	while (!list_empty(head)) {
 928		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
 929		list_del_init(&bd->bd_list);
 930		kmem_cache_free(gfs2_bufdata_cachep, bd);
 931	}
 932}
 933
 934/**
 935 * gfs2_log_flush - flush incore transaction(s)
 936 * @sdp: the filesystem
 937 * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 938 * @flags: The log header flags: GFS2_LOG_HEAD_FLUSH_* and debug flags
 939 *
 940 */
 941
 942void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)
 943{
 944	struct gfs2_trans *tr = NULL;
 945	enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
 946
 947	down_write(&sdp->sd_log_flush_lock);
 948
 949	/*
 950	 * Do this check while holding the log_flush_lock to prevent new
 951	 * buffers from being added to the ail via gfs2_pin()
 952	 */
 953	if (gfs2_withdrawn(sdp))
 954		goto out;
 955
 956	/* Log might have been flushed while we waited for the flush lock */
 957	if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
 958		up_write(&sdp->sd_log_flush_lock);
 959		return;
 960	}
 961	trace_gfs2_log_flush(sdp, 1, flags);
 962
 963	if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN)
 964		clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 965
 966	sdp->sd_log_flush_head = sdp->sd_log_head;
 967	tr = sdp->sd_log_tr;
 968	if (tr) {
 969		sdp->sd_log_tr = NULL;
 970		tr->tr_first = sdp->sd_log_flush_head;
 971		if (unlikely (state == SFS_FROZEN))
 972			if (gfs2_assert_withdraw_delayed(sdp,
 973			       !tr->tr_num_buf_new && !tr->tr_num_databuf_new))
 974				goto out;
 975	}
 976
 977	if (unlikely(state == SFS_FROZEN))
 978		if (gfs2_assert_withdraw_delayed(sdp, !sdp->sd_log_num_revoke))
 979			goto out;
 980	if (gfs2_assert_withdraw_delayed(sdp,
 981			sdp->sd_log_num_revoke == sdp->sd_log_committed_revoke))
 982		goto out;
 983
 984	gfs2_ordered_write(sdp);
 985	if (gfs2_withdrawn(sdp))
 986		goto out;
 987	lops_before_commit(sdp, tr);
 988	if (gfs2_withdrawn(sdp))
 989		goto out;
 990	gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE);
 991	if (gfs2_withdrawn(sdp))
 992		goto out;
 993
 994	if (sdp->sd_log_head != sdp->sd_log_flush_head) {
 995		log_flush_wait(sdp);
 996		log_write_header(sdp, flags);
 997	} else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 998		atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
 999		trace_gfs2_log_blocks(sdp, -1);
1000		log_write_header(sdp, flags);
1001	}
1002	if (gfs2_withdrawn(sdp))
1003		goto out;
1004	lops_after_commit(sdp, tr);
1005
1006	gfs2_log_lock(sdp);
1007	sdp->sd_log_head = sdp->sd_log_flush_head;
1008	sdp->sd_log_blks_reserved = 0;
1009	sdp->sd_log_committed_revoke = 0;
1010
1011	spin_lock(&sdp->sd_ail_lock);
1012	if (tr && !list_empty(&tr->tr_ail1_list)) {
1013		list_add(&tr->tr_list, &sdp->sd_ail1_list);
1014		tr = NULL;
1015	}
1016	spin_unlock(&sdp->sd_ail_lock);
1017	gfs2_log_unlock(sdp);
1018
1019	if (!(flags & GFS2_LOG_HEAD_FLUSH_NORMAL)) {
1020		if (!sdp->sd_log_idle) {
1021			empty_ail1_list(sdp);
1022			if (gfs2_withdrawn(sdp))
1023				goto out;
1024			atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
1025			trace_gfs2_log_blocks(sdp, -1);
1026			log_write_header(sdp, flags);
1027			sdp->sd_log_head = sdp->sd_log_flush_head;
1028		}
1029		if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
1030			     GFS2_LOG_HEAD_FLUSH_FREEZE))
1031			gfs2_log_shutdown(sdp);
1032		if (flags & GFS2_LOG_HEAD_FLUSH_FREEZE)
1033			atomic_set(&sdp->sd_freeze_state, SFS_FROZEN);
1034	}
1035
1036out:
1037	if (gfs2_withdrawn(sdp)) {
1038		trans_drain(tr);
1039		/**
1040		 * If the tr_list is empty, we're withdrawing during a log
1041		 * flush that targets a transaction, but the transaction was
1042		 * never queued onto any of the ail lists. Here we add it to
1043		 * ail1 just so that ail_drain() will find and free it.
1044		 */
1045		spin_lock(&sdp->sd_ail_lock);
1046		if (tr && list_empty(&tr->tr_list))
1047			list_add(&tr->tr_list, &sdp->sd_ail1_list);
1048		spin_unlock(&sdp->sd_ail_lock);
1049		ail_drain(sdp); /* frees all transactions */
1050		tr = NULL;
1051	}
1052
1053	trace_gfs2_log_flush(sdp, 0, flags);
1054	up_write(&sdp->sd_log_flush_lock);
1055
1056	gfs2_trans_free(sdp, tr);
1057}
1058
1059/**
1060 * gfs2_merge_trans - Merge a new transaction into a cached transaction
1061 * @old: Original transaction to be expanded
1062 * @new: New transaction to be merged
1063 */
1064
1065static void gfs2_merge_trans(struct gfs2_sbd *sdp, struct gfs2_trans *new)
1066{
1067	struct gfs2_trans *old = sdp->sd_log_tr;
1068
1069	WARN_ON_ONCE(!test_bit(TR_ATTACHED, &old->tr_flags));
1070
1071	old->tr_num_buf_new	+= new->tr_num_buf_new;
1072	old->tr_num_databuf_new	+= new->tr_num_databuf_new;
1073	old->tr_num_buf_rm	+= new->tr_num_buf_rm;
1074	old->tr_num_databuf_rm	+= new->tr_num_databuf_rm;
1075	old->tr_num_revoke	+= new->tr_num_revoke;
1076	old->tr_num_revoke_rm	+= new->tr_num_revoke_rm;
1077
1078	list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
1079	list_splice_tail_init(&new->tr_buf, &old->tr_buf);
1080
1081	spin_lock(&sdp->sd_ail_lock);
1082	list_splice_tail_init(&new->tr_ail1_list, &old->tr_ail1_list);
1083	list_splice_tail_init(&new->tr_ail2_list, &old->tr_ail2_list);
1084	spin_unlock(&sdp->sd_ail_lock);
1085}
1086
1087static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
1088{
1089	unsigned int reserved;
1090	unsigned int unused;
1091	unsigned int maxres;
1092
1093	gfs2_log_lock(sdp);
1094
1095	if (sdp->sd_log_tr) {
1096		gfs2_merge_trans(sdp, tr);
1097	} else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
1098		gfs2_assert_withdraw(sdp, test_bit(TR_ALLOCED, &tr->tr_flags));
1099		sdp->sd_log_tr = tr;
1100		set_bit(TR_ATTACHED, &tr->tr_flags);
1101	}
1102
1103	sdp->sd_log_committed_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
1104	reserved = calc_reserved(sdp);
1105	maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
1106	gfs2_assert_withdraw(sdp, maxres >= reserved);
1107	unused = maxres - reserved;
1108	atomic_add(unused, &sdp->sd_log_blks_free);
1109	trace_gfs2_log_blocks(sdp, unused);
1110	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
1111			     sdp->sd_jdesc->jd_blocks);
1112	sdp->sd_log_blks_reserved = reserved;
1113
1114	gfs2_log_unlock(sdp);
1115}
1116
1117/**
1118 * gfs2_log_commit - Commit a transaction to the log
1119 * @sdp: the filesystem
1120 * @tr: the transaction
1121 *
1122 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
1123 * or the total number of used blocks (pinned blocks plus AIL blocks)
1124 * is greater than thresh2.
1125 *
1126 * At mount time thresh1 is 2/5ths of journal size, thresh2 is 4/5ths of
1127 * journal size.
1128 *
1129 * Returns: errno
1130 */
1131
1132void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
1133{
1134	log_refund(sdp, tr);
1135
1136	if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
1137	    ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
1138	    atomic_read(&sdp->sd_log_thresh2)))
1139		wake_up(&sdp->sd_logd_waitq);
1140}
1141
1142/**
1143 * gfs2_log_shutdown - write a shutdown header into a journal
1144 * @sdp: the filesystem
1145 *
1146 */
1147
1148static void gfs2_log_shutdown(struct gfs2_sbd *sdp)
1149{
1150	gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
1151	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
1152	gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
1153
1154	sdp->sd_log_flush_head = sdp->sd_log_head;
1155
1156	log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT | GFS2_LFC_SHUTDOWN);
1157
1158	gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
1159	gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
1160
1161	sdp->sd_log_head = sdp->sd_log_flush_head;
1162	sdp->sd_log_tail = sdp->sd_log_head;
1163}
1164
1165static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
1166{
1167	return (atomic_read(&sdp->sd_log_pinned) +
1168		atomic_read(&sdp->sd_log_blks_needed) >=
1169		atomic_read(&sdp->sd_log_thresh1));
1170}
1171
1172static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
1173{
1174	unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
1175
1176	if (test_and_clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags))
1177		return 1;
1178
1179	return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
1180		atomic_read(&sdp->sd_log_thresh2);
1181}
1182
1183/**
1184 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
1185 * @sdp: Pointer to GFS2 superblock
1186 *
1187 * Also, periodically check to make sure that we're using the most recent
1188 * journal index.
1189 */
1190
1191int gfs2_logd(void *data)
1192{
1193	struct gfs2_sbd *sdp = data;
1194	unsigned long t = 1;
1195	DEFINE_WAIT(wait);
1196	bool did_flush;
1197
1198	while (!kthread_should_stop()) {
1199
1200		if (gfs2_withdrawn(sdp)) {
1201			msleep_interruptible(HZ);
1202			continue;
1203		}
1204		/* Check for errors writing to the journal */
1205		if (sdp->sd_log_error) {
1206			gfs2_lm(sdp,
1207				"GFS2: fsid=%s: error %d: "
1208				"withdrawing the file system to "
1209				"prevent further damage.\n",
1210				sdp->sd_fsname, sdp->sd_log_error);
1211			gfs2_withdraw(sdp);
1212			continue;
1213		}
1214
1215		did_flush = false;
1216		if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
1217			gfs2_ail1_empty(sdp, 0);
1218			gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1219				       GFS2_LFC_LOGD_JFLUSH_REQD);
1220			did_flush = true;
1221		}
1222
1223		if (gfs2_ail_flush_reqd(sdp)) {
1224			gfs2_ail1_start(sdp);
1225			gfs2_ail1_wait(sdp);
1226			gfs2_ail1_empty(sdp, 0);
1227			gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1228				       GFS2_LFC_LOGD_AIL_FLUSH_REQD);
1229			did_flush = true;
1230		}
1231
1232		if (!gfs2_ail_flush_reqd(sdp) || did_flush)
1233			wake_up(&sdp->sd_log_waitq);
1234
1235		t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
1236
1237		try_to_freeze();
1238
1239		do {
1240			prepare_to_wait(&sdp->sd_logd_waitq, &wait,
1241					TASK_INTERRUPTIBLE);
1242			if (!gfs2_ail_flush_reqd(sdp) &&
1243			    !gfs2_jrnl_flush_reqd(sdp) &&
1244			    !kthread_should_stop())
1245				t = schedule_timeout(t);
1246		} while(t && !gfs2_ail_flush_reqd(sdp) &&
1247			!gfs2_jrnl_flush_reqd(sdp) &&
1248			!kthread_should_stop());
1249		finish_wait(&sdp->sd_logd_waitq, &wait);
1250	}
1251
1252	return 0;
1253}
1254
  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/**
 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
 47unsigned 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 ail lock _must_ be held when calling this function
 71 *
 72 */
 73
 74void 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 * @wbc: The writeback control structure
 87 * @ai: The ail structure
 88 *
 89 */
 90
 91static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
 92			       struct writeback_control *wbc,
 93			       struct gfs2_ail *ai)
 94__releases(&sdp->sd_ail_lock)
 95__acquires(&sdp->sd_ail_lock)
 96{
 97	struct gfs2_glock *gl = NULL;
 98	struct address_space *mapping;
 99	struct gfs2_bufdata *bd, *s;
100	struct buffer_head *bh;
101
102	list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, 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		if (gl == bd->bd_gl)
117			continue;
118		gl = bd->bd_gl;
119		list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
120		mapping = bh->b_page->mapping;
121		if (!mapping)
122			continue;
123		spin_unlock(&sdp->sd_ail_lock);
124		generic_writepages(mapping, wbc);
125		spin_lock(&sdp->sd_ail_lock);
126		if (wbc->nr_to_write <= 0)
127			break;
128		return 1;
129	}
130
131	return 0;
132}
133
134
135/**
136 * gfs2_ail1_flush - start writeback of some ail1 entries 
137 * @sdp: The super block
138 * @wbc: The writeback control structure
139 *
140 * Writes back some ail1 entries, according to the limits in the
141 * writeback control structure
142 */
143
144void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
145{
146	struct list_head *head = &sdp->sd_ail1_list;
147	struct gfs2_ail *ai;
148
149	trace_gfs2_ail_flush(sdp, wbc, 1);
150	spin_lock(&sdp->sd_ail_lock);
151restart:
152	list_for_each_entry_reverse(ai, head, ai_list) {
153		if (wbc->nr_to_write <= 0)
154			break;
155		if (gfs2_ail1_start_one(sdp, wbc, ai))
156			goto restart;
157	}
158	spin_unlock(&sdp->sd_ail_lock);
159	trace_gfs2_ail_flush(sdp, wbc, 0);
160}
161
162/**
163 * gfs2_ail1_start - start writeback of all ail1 entries
164 * @sdp: The superblock
165 */
166
167static void gfs2_ail1_start(struct gfs2_sbd *sdp)
168{
169	struct writeback_control wbc = {
170		.sync_mode = WB_SYNC_NONE,
171		.nr_to_write = LONG_MAX,
172		.range_start = 0,
173		.range_end = LLONG_MAX,
174	};
175
176	return gfs2_ail1_flush(sdp, &wbc);
177}
178
179/**
180 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
181 * @sdp: the filesystem
182 * @ai: the AIL entry
183 *
184 */
185
186static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
187{
188	struct gfs2_bufdata *bd, *s;
189	struct buffer_head *bh;
190
191	list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
192					 bd_ail_st_list) {
193		bh = bd->bd_bh;
194		gfs2_assert(sdp, bd->bd_ail == ai);
195		if (buffer_busy(bh))
196			continue;
197		if (!buffer_uptodate(bh))
198			gfs2_io_error_bh(sdp, bh);
199		list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
200	}
201
202}
203
204/**
205 * gfs2_ail1_empty - Try to empty the ail1 lists
206 * @sdp: The superblock
207 *
208 * Tries to empty the ail1 lists, starting with the oldest first
209 */
210
211static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
212{
213	struct gfs2_ail *ai, *s;
214	int ret;
215
216	spin_lock(&sdp->sd_ail_lock);
217	list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
218		gfs2_ail1_empty_one(sdp, ai);
219		if (list_empty(&ai->ai_ail1_list))
220			list_move(&ai->ai_list, &sdp->sd_ail2_list);
221		else
222			break;
223	}
224	ret = list_empty(&sdp->sd_ail1_list);
225	spin_unlock(&sdp->sd_ail_lock);
226
227	return ret;
228}
229
230static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
231{
232	struct gfs2_ail *ai;
233	struct gfs2_bufdata *bd;
234	struct buffer_head *bh;
235
236	spin_lock(&sdp->sd_ail_lock);
237	list_for_each_entry_reverse(ai, &sdp->sd_ail1_list, ai_list) {
238		list_for_each_entry(bd, &ai->ai_ail1_list, bd_ail_st_list) {
239			bh = bd->bd_bh;
240			if (!buffer_locked(bh))
241				continue;
242			get_bh(bh);
243			spin_unlock(&sdp->sd_ail_lock);
244			wait_on_buffer(bh);
245			brelse(bh);
246			return;
247		}
248	}
249	spin_unlock(&sdp->sd_ail_lock);
250}
251
252/**
253 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
254 * @sdp: the filesystem
255 * @ai: the AIL entry
256 *
257 */
258
259static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
260{
261	struct list_head *head = &ai->ai_ail2_list;
262	struct gfs2_bufdata *bd;
263
264	while (!list_empty(head)) {
265		bd = list_entry(head->prev, struct gfs2_bufdata,
266				bd_ail_st_list);
267		gfs2_assert(sdp, bd->bd_ail == ai);
268		gfs2_remove_from_ail(bd);
269	}
270}
271
272static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
273{
274	struct gfs2_ail *ai, *safe;
275	unsigned int old_tail = sdp->sd_log_tail;
276	int wrap = (new_tail < old_tail);
277	int a, b, rm;
278
279	spin_lock(&sdp->sd_ail_lock);
280
281	list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
282		a = (old_tail <= ai->ai_first);
283		b = (ai->ai_first < new_tail);
284		rm = (wrap) ? (a || b) : (a && b);
285		if (!rm)
286			continue;
287
288		gfs2_ail2_empty_one(sdp, ai);
289		list_del(&ai->ai_list);
290		gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
291		gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
292		kfree(ai);
293	}
294
295	spin_unlock(&sdp->sd_ail_lock);
296}
297
298/**
299 * gfs2_log_reserve - Make a log reservation
300 * @sdp: The GFS2 superblock
301 * @blks: The number of blocks to reserve
302 *
303 * Note that we never give out the last few blocks of the journal. Thats
304 * due to the fact that there is a small number of header blocks
305 * associated with each log flush. The exact number can't be known until
306 * flush time, so we ensure that we have just enough free blocks at all
307 * times to avoid running out during a log flush.
308 *
309 * We no longer flush the log here, instead we wake up logd to do that
310 * for us. To avoid the thundering herd and to ensure that we deal fairly
311 * with queued waiters, we use an exclusive wait. This means that when we
312 * get woken with enough journal space to get our reservation, we need to
313 * wake the next waiter on the list.
314 *
315 * Returns: errno
316 */
317
318int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
319{
320	unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
321	unsigned wanted = blks + reserved_blks;
322	DEFINE_WAIT(wait);
323	int did_wait = 0;
324	unsigned int free_blocks;
325
326	if (gfs2_assert_warn(sdp, blks) ||
327	    gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
328		return -EINVAL;
329retry:
330	free_blocks = atomic_read(&sdp->sd_log_blks_free);
331	if (unlikely(free_blocks <= wanted)) {
332		do {
333			prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
334					TASK_UNINTERRUPTIBLE);
335			wake_up(&sdp->sd_logd_waitq);
336			did_wait = 1;
337			if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
338				io_schedule();
339			free_blocks = atomic_read(&sdp->sd_log_blks_free);
340		} while(free_blocks <= wanted);
341		finish_wait(&sdp->sd_log_waitq, &wait);
342	}
343	if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
344				free_blocks - blks) != free_blocks)
345		goto retry;
346	trace_gfs2_log_blocks(sdp, -blks);
347
348	/*
349	 * If we waited, then so might others, wake them up _after_ we get
350	 * our share of the log.
351	 */
352	if (unlikely(did_wait))
353		wake_up(&sdp->sd_log_waitq);
354
355	down_read(&sdp->sd_log_flush_lock);
356
357	return 0;
358}
359
360/**
361 * log_distance - Compute distance between two journal blocks
362 * @sdp: The GFS2 superblock
363 * @newer: The most recent journal block of the pair
364 * @older: The older journal block of the pair
365 *
366 *   Compute the distance (in the journal direction) between two
367 *   blocks in the journal
368 *
369 * Returns: the distance in blocks
370 */
371
372static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
373					unsigned int older)
374{
375	int dist;
376
377	dist = newer - older;
378	if (dist < 0)
379		dist += sdp->sd_jdesc->jd_blocks;
380
381	return dist;
382}
383
384/**
385 * calc_reserved - Calculate the number of blocks to reserve when
386 *                 refunding a transaction's unused buffers.
387 * @sdp: The GFS2 superblock
388 *
389 * This is complex.  We need to reserve room for all our currently used
390 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and 
391 * all our journaled data buffers for journaled files (e.g. files in the 
392 * meta_fs like rindex, or files for which chattr +j was done.)
393 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
394 * will count it as free space (sd_log_blks_free) and corruption will follow.
395 *
396 * We can have metadata bufs and jdata bufs in the same journal.  So each
397 * type gets its own log header, for which we need to reserve a block.
398 * In fact, each type has the potential for needing more than one header 
399 * in cases where we have more buffers than will fit on a journal page.
400 * Metadata journal entries take up half the space of journaled buffer entries.
401 * Thus, metadata entries have buf_limit (502) and journaled buffers have
402 * databuf_limit (251) before they cause a wrap around.
403 *
404 * Also, we need to reserve blocks for revoke journal entries and one for an
405 * overall header for the lot.
406 *
407 * Returns: the number of blocks reserved
408 */
409static unsigned int calc_reserved(struct gfs2_sbd *sdp)
410{
411	unsigned int reserved = 0;
412	unsigned int mbuf_limit, metabufhdrs_needed;
413	unsigned int dbuf_limit, databufhdrs_needed;
414	unsigned int revokes = 0;
415
416	mbuf_limit = buf_limit(sdp);
417	metabufhdrs_needed = (sdp->sd_log_commited_buf +
418			      (mbuf_limit - 1)) / mbuf_limit;
419	dbuf_limit = databuf_limit(sdp);
420	databufhdrs_needed = (sdp->sd_log_commited_databuf +
421			      (dbuf_limit - 1)) / dbuf_limit;
422
423	if (sdp->sd_log_commited_revoke > 0)
424		revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
425					  sizeof(u64));
426
427	reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
428		sdp->sd_log_commited_databuf + databufhdrs_needed +
429		revokes;
430	/* One for the overall header */
431	if (reserved)
432		reserved++;
433	return reserved;
434}
435
436static unsigned int current_tail(struct gfs2_sbd *sdp)
437{
438	struct gfs2_ail *ai;
439	unsigned int tail;
440
441	spin_lock(&sdp->sd_ail_lock);
442
443	if (list_empty(&sdp->sd_ail1_list)) {
444		tail = sdp->sd_log_head;
445	} else {
446		ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
447		tail = ai->ai_first;
448	}
449
450	spin_unlock(&sdp->sd_ail_lock);
451
452	return tail;
453}
454
455static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
456{
457	unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
458
459	ail2_empty(sdp, new_tail);
460
461	atomic_add(dist, &sdp->sd_log_blks_free);
462	trace_gfs2_log_blocks(sdp, dist);
463	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
464			     sdp->sd_jdesc->jd_blocks);
465
466	sdp->sd_log_tail = new_tail;
467}
468
469
470static void log_flush_wait(struct gfs2_sbd *sdp)
471{
472	DEFINE_WAIT(wait);
473
474	if (atomic_read(&sdp->sd_log_in_flight)) {
475		do {
476			prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
477					TASK_UNINTERRUPTIBLE);
478			if (atomic_read(&sdp->sd_log_in_flight))
479				io_schedule();
480		} while(atomic_read(&sdp->sd_log_in_flight));
481		finish_wait(&sdp->sd_log_flush_wait, &wait);
482	}
483}
484
485static int bd_cmp(void *priv, struct list_head *a, struct list_head *b)
486{
487	struct gfs2_bufdata *bda, *bdb;
488
489	bda = list_entry(a, struct gfs2_bufdata, bd_list);
490	bdb = list_entry(b, struct gfs2_bufdata, bd_list);
491
492	if (bda->bd_bh->b_blocknr < bdb->bd_bh->b_blocknr)
493		return -1;
494	if (bda->bd_bh->b_blocknr > bdb->bd_bh->b_blocknr)
495		return 1;
496	return 0;
497}
498
499static void gfs2_ordered_write(struct gfs2_sbd *sdp)
500{
501	struct gfs2_bufdata *bd;
502	struct buffer_head *bh;
503	LIST_HEAD(written);
504
505	gfs2_log_lock(sdp);
506	list_sort(NULL, &sdp->sd_log_le_ordered, &bd_cmp);
507	while (!list_empty(&sdp->sd_log_le_ordered)) {
508		bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_list);
509		list_move(&bd->bd_list, &written);
510		bh = bd->bd_bh;
511		if (!buffer_dirty(bh))
512			continue;
513		get_bh(bh);
514		gfs2_log_unlock(sdp);
515		lock_buffer(bh);
516		if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
517			bh->b_end_io = end_buffer_write_sync;
518			submit_bh(WRITE_SYNC, bh);
519		} else {
520			unlock_buffer(bh);
521			brelse(bh);
522		}
523		gfs2_log_lock(sdp);
524	}
525	list_splice(&written, &sdp->sd_log_le_ordered);
526	gfs2_log_unlock(sdp);
527}
528
529static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
530{
531	struct gfs2_bufdata *bd;
532	struct buffer_head *bh;
533
534	gfs2_log_lock(sdp);
535	while (!list_empty(&sdp->sd_log_le_ordered)) {
536		bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_list);
537		bh = bd->bd_bh;
538		if (buffer_locked(bh)) {
539			get_bh(bh);
540			gfs2_log_unlock(sdp);
541			wait_on_buffer(bh);
542			brelse(bh);
543			gfs2_log_lock(sdp);
544			continue;
545		}
546		list_del_init(&bd->bd_list);
547	}
548	gfs2_log_unlock(sdp);
549}
550
551/**
552 * log_write_header - Get and initialize a journal header buffer
553 * @sdp: The GFS2 superblock
554 *
555 * Returns: the initialized log buffer descriptor
556 */
557
558static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
559{
560	struct gfs2_log_header *lh;
561	unsigned int tail;
562	u32 hash;
563	int rw = WRITE_FLUSH_FUA | REQ_META;
564	struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
565	lh = page_address(page);
566	clear_page(lh);
567
568	gfs2_ail1_empty(sdp);
569	tail = current_tail(sdp);
570
571	lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
572	lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
573	lh->lh_header.__pad0 = cpu_to_be64(0);
574	lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
575	lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
576	lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
577	lh->lh_flags = cpu_to_be32(flags);
578	lh->lh_tail = cpu_to_be32(tail);
579	lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
580	hash = gfs2_disk_hash(page_address(page), sizeof(struct gfs2_log_header));
581	lh->lh_hash = cpu_to_be32(hash);
582
583	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
584		gfs2_ordered_wait(sdp);
585		log_flush_wait(sdp);
586		rw = WRITE_SYNC | REQ_META | REQ_PRIO;
587	}
588
589	sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
590	gfs2_log_write_page(sdp, page);
591	gfs2_log_flush_bio(sdp, rw);
592	log_flush_wait(sdp);
593
594	if (sdp->sd_log_tail != tail)
595		log_pull_tail(sdp, tail);
596}
597
598/**
599 * gfs2_log_flush - flush incore transaction(s)
600 * @sdp: the filesystem
601 * @gl: The glock structure to flush.  If NULL, flush the whole incore log
602 *
603 */
604
605void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
606{
607	struct gfs2_ail *ai;
608
609	down_write(&sdp->sd_log_flush_lock);
610
611	/* Log might have been flushed while we waited for the flush lock */
612	if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
613		up_write(&sdp->sd_log_flush_lock);
614		return;
615	}
616	trace_gfs2_log_flush(sdp, 1);
617
618	ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
619	INIT_LIST_HEAD(&ai->ai_ail1_list);
620	INIT_LIST_HEAD(&ai->ai_ail2_list);
621
622	if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
623		printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
624		       sdp->sd_log_commited_buf);
625		gfs2_assert_withdraw(sdp, 0);
626	}
627	if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
628		printk(KERN_INFO "GFS2: log databuf %u %u\n",
629		       sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
630		gfs2_assert_withdraw(sdp, 0);
631	}
632	gfs2_assert_withdraw(sdp,
633			sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
634
635	sdp->sd_log_flush_head = sdp->sd_log_head;
636	sdp->sd_log_flush_wrapped = 0;
637	ai->ai_first = sdp->sd_log_flush_head;
638
639	gfs2_ordered_write(sdp);
640	lops_before_commit(sdp);
641	gfs2_log_flush_bio(sdp, WRITE);
642
643	if (sdp->sd_log_head != sdp->sd_log_flush_head) {
644		log_write_header(sdp, 0);
645	} else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
646		atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
647		trace_gfs2_log_blocks(sdp, -1);
648		log_write_header(sdp, 0);
649	}
650	lops_after_commit(sdp, ai);
651
652	gfs2_log_lock(sdp);
653	sdp->sd_log_head = sdp->sd_log_flush_head;
654	sdp->sd_log_blks_reserved = 0;
655	sdp->sd_log_commited_buf = 0;
656	sdp->sd_log_commited_databuf = 0;
657	sdp->sd_log_commited_revoke = 0;
658
659	spin_lock(&sdp->sd_ail_lock);
660	if (!list_empty(&ai->ai_ail1_list)) {
661		list_add(&ai->ai_list, &sdp->sd_ail1_list);
662		ai = NULL;
663	}
664	spin_unlock(&sdp->sd_ail_lock);
665	gfs2_log_unlock(sdp);
666	trace_gfs2_log_flush(sdp, 0);
667	up_write(&sdp->sd_log_flush_lock);
668
669	kfree(ai);
670}
671
672static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
673{
674	unsigned int reserved;
675	unsigned int unused;
676
677	gfs2_log_lock(sdp);
678
679	sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
680	sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
681		tr->tr_num_databuf_rm;
682	gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
683			     (((int)sdp->sd_log_commited_databuf) >= 0));
684	sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
685	reserved = calc_reserved(sdp);
686	gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
687	unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
688	atomic_add(unused, &sdp->sd_log_blks_free);
689	trace_gfs2_log_blocks(sdp, unused);
690	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
691			     sdp->sd_jdesc->jd_blocks);
692	sdp->sd_log_blks_reserved = reserved;
693
694	gfs2_log_unlock(sdp);
695}
696
697/**
698 * gfs2_log_commit - Commit a transaction to the log
699 * @sdp: the filesystem
700 * @tr: the transaction
701 *
702 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
703 * or the total number of used blocks (pinned blocks plus AIL blocks)
704 * is greater than thresh2.
705 *
706 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
707 * journal size.
708 *
709 * Returns: errno
710 */
711
712void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
713{
714	log_refund(sdp, tr);
715	up_read(&sdp->sd_log_flush_lock);
716
717	if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
718	    ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
719	    atomic_read(&sdp->sd_log_thresh2)))
720		wake_up(&sdp->sd_logd_waitq);
721}
722
723/**
724 * gfs2_log_shutdown - write a shutdown header into a journal
725 * @sdp: the filesystem
726 *
727 */
728
729void gfs2_log_shutdown(struct gfs2_sbd *sdp)
730{
731	down_write(&sdp->sd_log_flush_lock);
732
733	gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
734	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
735	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
736	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
737	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
738	gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
739
740	sdp->sd_log_flush_head = sdp->sd_log_head;
741	sdp->sd_log_flush_wrapped = 0;
742
743	log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT);
744
745	gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
746	gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
747	gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
748
749	sdp->sd_log_head = sdp->sd_log_flush_head;
750	sdp->sd_log_tail = sdp->sd_log_head;
751
752	up_write(&sdp->sd_log_flush_lock);
753}
754
755
756/**
757 * gfs2_meta_syncfs - sync all the buffers in a filesystem
758 * @sdp: the filesystem
759 *
760 */
761
762void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
763{
764	gfs2_log_flush(sdp, NULL);
765	for (;;) {
766		gfs2_ail1_start(sdp);
767		gfs2_ail1_wait(sdp);
768		if (gfs2_ail1_empty(sdp))
769			break;
770	}
771	gfs2_log_flush(sdp, NULL);
772}
773
774static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
775{
776	return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1));
777}
778
779static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
780{
781	unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
782	return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
783}
784
785/**
786 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
787 * @sdp: Pointer to GFS2 superblock
788 *
789 * Also, periodically check to make sure that we're using the most recent
790 * journal index.
791 */
792
793int gfs2_logd(void *data)
794{
795	struct gfs2_sbd *sdp = data;
796	unsigned long t = 1;
797	DEFINE_WAIT(wait);
798
799	while (!kthread_should_stop()) {
800
801		if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
802			gfs2_ail1_empty(sdp);
803			gfs2_log_flush(sdp, NULL);
804		}
805
806		if (gfs2_ail_flush_reqd(sdp)) {
807			gfs2_ail1_start(sdp);
808			gfs2_ail1_wait(sdp);
809			gfs2_ail1_empty(sdp);
810			gfs2_log_flush(sdp, NULL);
811		}
812
813		if (!gfs2_ail_flush_reqd(sdp))
814			wake_up(&sdp->sd_log_waitq);
815
816		t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
817
818		try_to_freeze();
819
820		do {
821			prepare_to_wait(&sdp->sd_logd_waitq, &wait,
822					TASK_INTERRUPTIBLE);
823			if (!gfs2_ail_flush_reqd(sdp) &&
824			    !gfs2_jrnl_flush_reqd(sdp) &&
825			    !kthread_should_stop())
826				t = schedule_timeout(t);
827		} while(t && !gfs2_ail_flush_reqd(sdp) &&
828			!gfs2_jrnl_flush_reqd(sdp) &&
829			!kthread_should_stop());
830		finish_wait(&sdp->sd_logd_waitq, &wait);
831	}
832
833	return 0;
834}
835