1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
   4 * Copyright (C) 2010 Red Hat, Inc.
   5 * All Rights Reserved.
   6 */
   7#include "xfs.h"
   8#include "xfs_fs.h"
   9#include "xfs_shared.h"
  10#include "xfs_format.h"
  11#include "xfs_log_format.h"
  12#include "xfs_trans_resv.h"
  13#include "xfs_mount.h"
  14#include "xfs_extent_busy.h"
  15#include "xfs_quota.h"
  16#include "xfs_trans.h"
  17#include "xfs_trans_priv.h"
  18#include "xfs_log.h"
  19#include "xfs_log_priv.h"
  20#include "xfs_trace.h"
  21#include "xfs_error.h"
  22#include "xfs_defer.h"
  23#include "xfs_inode.h"
  24#include "xfs_dquot_item.h"
  25#include "xfs_dquot.h"
  26#include "xfs_icache.h"
  27#include "xfs_rtbitmap.h"
  28
  29struct kmem_cache	*xfs_trans_cache;
  30
  31#if defined(CONFIG_TRACEPOINTS)
  32static void
  33xfs_trans_trace_reservations(
  34	struct xfs_mount	*mp)
  35{
  36	struct xfs_trans_res	*res;
  37	struct xfs_trans_res	*end_res;
  38	int			i;
  39
  40	res = (struct xfs_trans_res *)M_RES(mp);
  41	end_res = (struct xfs_trans_res *)(M_RES(mp) + 1);
  42	for (i = 0; res < end_res; i++, res++)
  43		trace_xfs_trans_resv_calc(mp, i, res);
  44}
  45#else
  46# define xfs_trans_trace_reservations(mp)
  47#endif
  48
  49/*
  50 * Initialize the precomputed transaction reservation values
  51 * in the mount structure.
  52 */
  53void
  54xfs_trans_init(
  55	struct xfs_mount	*mp)
  56{
  57	xfs_trans_resv_calc(mp, M_RES(mp));
  58	xfs_trans_trace_reservations(mp);
  59}
  60
  61/*
  62 * Free the transaction structure.  If there is more clean up
  63 * to do when the structure is freed, add it here.
  64 */
  65STATIC void
  66xfs_trans_free(
  67	struct xfs_trans	*tp)
  68{
  69	xfs_extent_busy_sort(&tp->t_busy);
  70	xfs_extent_busy_clear(tp->t_mountp, &tp->t_busy, false);
  71
  72	trace_xfs_trans_free(tp, _RET_IP_);
  73	xfs_trans_clear_context(tp);
  74	if (!(tp->t_flags & XFS_TRANS_NO_WRITECOUNT))
  75		sb_end_intwrite(tp->t_mountp->m_super);
  76	xfs_trans_free_dqinfo(tp);
  77	kmem_cache_free(xfs_trans_cache, tp);
  78}
  79
  80/*
  81 * This is called to create a new transaction which will share the
  82 * permanent log reservation of the given transaction.  The remaining
  83 * unused block and rt extent reservations are also inherited.  This
  84 * implies that the original transaction is no longer allowed to allocate
  85 * blocks.  Locks and log items, however, are no inherited.  They must
  86 * be added to the new transaction explicitly.
  87 */
  88STATIC struct xfs_trans *
  89xfs_trans_dup(
  90	struct xfs_trans	*tp)
  91{
  92	struct xfs_trans	*ntp;
  93
  94	trace_xfs_trans_dup(tp, _RET_IP_);
  95
  96	ntp = kmem_cache_zalloc(xfs_trans_cache, GFP_KERNEL | __GFP_NOFAIL);
  97
  98	/*
  99	 * Initialize the new transaction structure.
 100	 */
 101	ntp->t_magic = XFS_TRANS_HEADER_MAGIC;
 102	ntp->t_mountp = tp->t_mountp;
 103	INIT_LIST_HEAD(&ntp->t_items);
 104	INIT_LIST_HEAD(&ntp->t_busy);
 105	INIT_LIST_HEAD(&ntp->t_dfops);
 106	ntp->t_highest_agno = NULLAGNUMBER;
 107
 108	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
 109	ASSERT(tp->t_ticket != NULL);
 110
 111	ntp->t_flags = XFS_TRANS_PERM_LOG_RES |
 112		       (tp->t_flags & XFS_TRANS_RESERVE) |
 113		       (tp->t_flags & XFS_TRANS_NO_WRITECOUNT) |
 114		       (tp->t_flags & XFS_TRANS_RES_FDBLKS);
 115	/* We gave our writer reference to the new transaction */
 116	tp->t_flags |= XFS_TRANS_NO_WRITECOUNT;
 117	ntp->t_ticket = xfs_log_ticket_get(tp->t_ticket);
 118
 119	ASSERT(tp->t_blk_res >= tp->t_blk_res_used);
 120	ntp->t_blk_res = tp->t_blk_res - tp->t_blk_res_used;
 121	tp->t_blk_res = tp->t_blk_res_used;
 122
 123	ntp->t_rtx_res = tp->t_rtx_res - tp->t_rtx_res_used;
 124	tp->t_rtx_res = tp->t_rtx_res_used;
 125
 126	xfs_trans_switch_context(tp, ntp);
 127
 128	/* move deferred ops over to the new tp */
 129	xfs_defer_move(ntp, tp);
 130
 131	xfs_trans_dup_dqinfo(tp, ntp);
 132	return ntp;
 133}
 134
 135/*
 136 * This is called to reserve free disk blocks and log space for the
 137 * given transaction.  This must be done before allocating any resources
 138 * within the transaction.
 139 *
 140 * This will return ENOSPC if there are not enough blocks available.
 141 * It will sleep waiting for available log space.
 142 * The only valid value for the flags parameter is XFS_RES_LOG_PERM, which
 143 * is used by long running transactions.  If any one of the reservations
 144 * fails then they will all be backed out.
 145 *
 146 * This does not do quota reservations. That typically is done by the
 147 * caller afterwards.
 148 */
 149static int
 150xfs_trans_reserve(
 151	struct xfs_trans	*tp,
 152	struct xfs_trans_res	*resp,
 153	uint			blocks,
 154	uint			rtextents)
 155{
 156	struct xfs_mount	*mp = tp->t_mountp;
 157	int			error = 0;
 158	bool			rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
 159
 160	/*
 161	 * Attempt to reserve the needed disk blocks by decrementing
 162	 * the number needed from the number available.  This will
 163	 * fail if the count would go below zero.
 164	 */
 165	if (blocks > 0) {
 166		error = xfs_mod_fdblocks(mp, -((int64_t)blocks), rsvd);
 167		if (error != 0)
 168			return -ENOSPC;
 169		tp->t_blk_res += blocks;
 170	}
 171
 172	/*
 173	 * Reserve the log space needed for this transaction.
 174	 */
 175	if (resp->tr_logres > 0) {
 176		bool	permanent = false;
 177
 178		ASSERT(tp->t_log_res == 0 ||
 179		       tp->t_log_res == resp->tr_logres);
 180		ASSERT(tp->t_log_count == 0 ||
 181		       tp->t_log_count == resp->tr_logcount);
 182
 183		if (resp->tr_logflags & XFS_TRANS_PERM_LOG_RES) {
 184			tp->t_flags |= XFS_TRANS_PERM_LOG_RES;
 185			permanent = true;
 186		} else {
 187			ASSERT(tp->t_ticket == NULL);
 188			ASSERT(!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
 189		}
 190
 191		if (tp->t_ticket != NULL) {
 192			ASSERT(resp->tr_logflags & XFS_TRANS_PERM_LOG_RES);
 193			error = xfs_log_regrant(mp, tp->t_ticket);
 194		} else {
 195			error = xfs_log_reserve(mp, resp->tr_logres,
 196						resp->tr_logcount,
 197						&tp->t_ticket, permanent);
 198		}
 199
 200		if (error)
 201			goto undo_blocks;
 202
 203		tp->t_log_res = resp->tr_logres;
 204		tp->t_log_count = resp->tr_logcount;
 205	}
 206
 207	/*
 208	 * Attempt to reserve the needed realtime extents by decrementing
 209	 * the number needed from the number available.  This will
 210	 * fail if the count would go below zero.
 211	 */
 212	if (rtextents > 0) {
 213		error = xfs_mod_frextents(mp, -((int64_t)rtextents));
 214		if (error) {
 215			error = -ENOSPC;
 216			goto undo_log;
 217		}
 218		tp->t_rtx_res += rtextents;
 219	}
 220
 221	return 0;
 222
 223	/*
 224	 * Error cases jump to one of these labels to undo any
 225	 * reservations which have already been performed.
 226	 */
 227undo_log:
 228	if (resp->tr_logres > 0) {
 229		xfs_log_ticket_ungrant(mp->m_log, tp->t_ticket);
 230		tp->t_ticket = NULL;
 231		tp->t_log_res = 0;
 232		tp->t_flags &= ~XFS_TRANS_PERM_LOG_RES;
 233	}
 234
 235undo_blocks:
 236	if (blocks > 0) {
 237		xfs_mod_fdblocks(mp, (int64_t)blocks, rsvd);
 238		tp->t_blk_res = 0;
 239	}
 240	return error;
 241}
 242
 243int
 244xfs_trans_alloc(
 245	struct xfs_mount	*mp,
 246	struct xfs_trans_res	*resp,
 247	uint			blocks,
 248	uint			rtextents,
 249	uint			flags,
 250	struct xfs_trans	**tpp)
 251{
 252	struct xfs_trans	*tp;
 253	bool			want_retry = true;
 254	int			error;
 255
 256	/*
 257	 * Allocate the handle before we do our freeze accounting and setting up
 258	 * GFP_NOFS allocation context so that we avoid lockdep false positives
 259	 * by doing GFP_KERNEL allocations inside sb_start_intwrite().
 260	 */
 261retry:
 262	tp = kmem_cache_zalloc(xfs_trans_cache, GFP_KERNEL | __GFP_NOFAIL);
 263	if (!(flags & XFS_TRANS_NO_WRITECOUNT))
 264		sb_start_intwrite(mp->m_super);
 265	xfs_trans_set_context(tp);
 266
 267	/*
 268	 * Zero-reservation ("empty") transactions can't modify anything, so
 269	 * they're allowed to run while we're frozen.
 270	 */
 271	WARN_ON(resp->tr_logres > 0 &&
 272		mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
 273	ASSERT(!(flags & XFS_TRANS_RES_FDBLKS) ||
 274	       xfs_has_lazysbcount(mp));
 275
 276	tp->t_magic = XFS_TRANS_HEADER_MAGIC;
 277	tp->t_flags = flags;
 278	tp->t_mountp = mp;
 279	INIT_LIST_HEAD(&tp->t_items);
 280	INIT_LIST_HEAD(&tp->t_busy);
 281	INIT_LIST_HEAD(&tp->t_dfops);
 282	tp->t_highest_agno = NULLAGNUMBER;
 283
 284	error = xfs_trans_reserve(tp, resp, blocks, rtextents);
 285	if (error == -ENOSPC && want_retry) {
 286		xfs_trans_cancel(tp);
 287
 288		/*
 289		 * We weren't able to reserve enough space for the transaction.
 290		 * Flush the other speculative space allocations to free space.
 291		 * Do not perform a synchronous scan because callers can hold
 292		 * other locks.
 293		 */
 294		error = xfs_blockgc_flush_all(mp);
 295		if (error)
 296			return error;
 297		want_retry = false;
 298		goto retry;
 299	}
 300	if (error) {
 301		xfs_trans_cancel(tp);
 302		return error;
 303	}
 304
 305	trace_xfs_trans_alloc(tp, _RET_IP_);
 306
 307	*tpp = tp;
 308	return 0;
 309}
 310
 311/*
 312 * Create an empty transaction with no reservation.  This is a defensive
 313 * mechanism for routines that query metadata without actually modifying them --
 314 * if the metadata being queried is somehow cross-linked (think a btree block
 315 * pointer that points higher in the tree), we risk deadlock.  However, blocks
 316 * grabbed as part of a transaction can be re-grabbed.  The verifiers will
 317 * notice the corrupt block and the operation will fail back to userspace
 318 * without deadlocking.
 319 *
 320 * Note the zero-length reservation; this transaction MUST be cancelled without
 321 * any dirty data.
 322 *
 323 * Callers should obtain freeze protection to avoid a conflict with fs freezing
 324 * where we can be grabbing buffers at the same time that freeze is trying to
 325 * drain the buffer LRU list.
 326 */
 327int
 328xfs_trans_alloc_empty(
 329	struct xfs_mount		*mp,
 330	struct xfs_trans		**tpp)
 331{
 332	struct xfs_trans_res		resv = {0};
 333
 334	return xfs_trans_alloc(mp, &resv, 0, 0, XFS_TRANS_NO_WRITECOUNT, tpp);
 335}
 336
 337/*
 338 * Record the indicated change to the given field for application
 339 * to the file system's superblock when the transaction commits.
 340 * For now, just store the change in the transaction structure.
 341 *
 342 * Mark the transaction structure to indicate that the superblock
 343 * needs to be updated before committing.
 344 *
 345 * Because we may not be keeping track of allocated/free inodes and
 346 * used filesystem blocks in the superblock, we do not mark the
 347 * superblock dirty in this transaction if we modify these fields.
 348 * We still need to update the transaction deltas so that they get
 349 * applied to the incore superblock, but we don't want them to
 350 * cause the superblock to get locked and logged if these are the
 351 * only fields in the superblock that the transaction modifies.
 352 */
 353void
 354xfs_trans_mod_sb(
 355	xfs_trans_t	*tp,
 356	uint		field,
 357	int64_t		delta)
 358{
 359	uint32_t	flags = (XFS_TRANS_DIRTY|XFS_TRANS_SB_DIRTY);
 360	xfs_mount_t	*mp = tp->t_mountp;
 361
 362	switch (field) {
 363	case XFS_TRANS_SB_ICOUNT:
 364		tp->t_icount_delta += delta;
 365		if (xfs_has_lazysbcount(mp))
 366			flags &= ~XFS_TRANS_SB_DIRTY;
 367		break;
 368	case XFS_TRANS_SB_IFREE:
 369		tp->t_ifree_delta += delta;
 370		if (xfs_has_lazysbcount(mp))
 371			flags &= ~XFS_TRANS_SB_DIRTY;
 372		break;
 373	case XFS_TRANS_SB_FDBLOCKS:
 374		/*
 375		 * Track the number of blocks allocated in the transaction.
 376		 * Make sure it does not exceed the number reserved. If so,
 377		 * shutdown as this can lead to accounting inconsistency.
 378		 */
 379		if (delta < 0) {
 380			tp->t_blk_res_used += (uint)-delta;
 381			if (tp->t_blk_res_used > tp->t_blk_res)
 382				xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
 383		} else if (delta > 0 && (tp->t_flags & XFS_TRANS_RES_FDBLKS)) {
 384			int64_t	blkres_delta;
 385
 386			/*
 387			 * Return freed blocks directly to the reservation
 388			 * instead of the global pool, being careful not to
 389			 * overflow the trans counter. This is used to preserve
 390			 * reservation across chains of transaction rolls that
 391			 * repeatedly free and allocate blocks.
 392			 */
 393			blkres_delta = min_t(int64_t, delta,
 394					     UINT_MAX - tp->t_blk_res);
 395			tp->t_blk_res += blkres_delta;
 396			delta -= blkres_delta;
 397		}
 398		tp->t_fdblocks_delta += delta;
 399		if (xfs_has_lazysbcount(mp))
 400			flags &= ~XFS_TRANS_SB_DIRTY;
 401		break;
 402	case XFS_TRANS_SB_RES_FDBLOCKS:
 403		/*
 404		 * The allocation has already been applied to the
 405		 * in-core superblock's counter.  This should only
 406		 * be applied to the on-disk superblock.
 407		 */
 408		tp->t_res_fdblocks_delta += delta;
 409		if (xfs_has_lazysbcount(mp))
 410			flags &= ~XFS_TRANS_SB_DIRTY;
 411		break;
 412	case XFS_TRANS_SB_FREXTENTS:
 413		/*
 414		 * Track the number of blocks allocated in the
 415		 * transaction.  Make sure it does not exceed the
 416		 * number reserved.
 417		 */
 418		if (delta < 0) {
 419			tp->t_rtx_res_used += (uint)-delta;
 420			ASSERT(tp->t_rtx_res_used <= tp->t_rtx_res);
 421		}
 422		tp->t_frextents_delta += delta;
 423		break;
 424	case XFS_TRANS_SB_RES_FREXTENTS:
 425		/*
 426		 * The allocation has already been applied to the
 427		 * in-core superblock's counter.  This should only
 428		 * be applied to the on-disk superblock.
 429		 */
 430		ASSERT(delta < 0);
 431		tp->t_res_frextents_delta += delta;
 432		break;
 433	case XFS_TRANS_SB_DBLOCKS:
 434		tp->t_dblocks_delta += delta;
 435		break;
 436	case XFS_TRANS_SB_AGCOUNT:
 437		ASSERT(delta > 0);
 438		tp->t_agcount_delta += delta;
 439		break;
 440	case XFS_TRANS_SB_IMAXPCT:
 441		tp->t_imaxpct_delta += delta;
 442		break;
 443	case XFS_TRANS_SB_REXTSIZE:
 444		tp->t_rextsize_delta += delta;
 445		break;
 446	case XFS_TRANS_SB_RBMBLOCKS:
 447		tp->t_rbmblocks_delta += delta;
 448		break;
 449	case XFS_TRANS_SB_RBLOCKS:
 450		tp->t_rblocks_delta += delta;
 451		break;
 452	case XFS_TRANS_SB_REXTENTS:
 453		tp->t_rextents_delta += delta;
 454		break;
 455	case XFS_TRANS_SB_REXTSLOG:
 456		tp->t_rextslog_delta += delta;
 457		break;
 458	default:
 459		ASSERT(0);
 460		return;
 461	}
 462
 463	tp->t_flags |= flags;
 464}
 465
 466/*
 467 * xfs_trans_apply_sb_deltas() is called from the commit code
 468 * to bring the superblock buffer into the current transaction
 469 * and modify it as requested by earlier calls to xfs_trans_mod_sb().
 470 *
 471 * For now we just look at each field allowed to change and change
 472 * it if necessary.
 473 */
 474STATIC void
 475xfs_trans_apply_sb_deltas(
 476	xfs_trans_t	*tp)
 477{
 478	struct xfs_dsb	*sbp;
 479	struct xfs_buf	*bp;
 480	int		whole = 0;
 481
 482	bp = xfs_trans_getsb(tp);
 483	sbp = bp->b_addr;
 484
 485	/*
 486	 * Only update the superblock counters if we are logging them
 487	 */
 488	if (!xfs_has_lazysbcount((tp->t_mountp))) {
 489		if (tp->t_icount_delta)
 490			be64_add_cpu(&sbp->sb_icount, tp->t_icount_delta);
 491		if (tp->t_ifree_delta)
 492			be64_add_cpu(&sbp->sb_ifree, tp->t_ifree_delta);
 493		if (tp->t_fdblocks_delta)
 494			be64_add_cpu(&sbp->sb_fdblocks, tp->t_fdblocks_delta);
 495		if (tp->t_res_fdblocks_delta)
 496			be64_add_cpu(&sbp->sb_fdblocks, tp->t_res_fdblocks_delta);
 497	}
 498
 499	/*
 500	 * Updating frextents requires careful handling because it does not
 501	 * behave like the lazysb counters because we cannot rely on log
 502	 * recovery in older kenels to recompute the value from the rtbitmap.
 503	 * This means that the ondisk frextents must be consistent with the
 504	 * rtbitmap.
 505	 *
 506	 * Therefore, log the frextents change to the ondisk superblock and
 507	 * update the incore superblock so that future calls to xfs_log_sb
 508	 * write the correct value ondisk.
 509	 *
 510	 * Don't touch m_frextents because it includes incore reservations,
 511	 * and those are handled by the unreserve function.
 512	 */
 513	if (tp->t_frextents_delta || tp->t_res_frextents_delta) {
 514		struct xfs_mount	*mp = tp->t_mountp;
 515		int64_t			rtxdelta;
 516
 517		rtxdelta = tp->t_frextents_delta + tp->t_res_frextents_delta;
 518
 519		spin_lock(&mp->m_sb_lock);
 520		be64_add_cpu(&sbp->sb_frextents, rtxdelta);
 521		mp->m_sb.sb_frextents += rtxdelta;
 522		spin_unlock(&mp->m_sb_lock);
 523	}
 524
 525	if (tp->t_dblocks_delta) {
 526		be64_add_cpu(&sbp->sb_dblocks, tp->t_dblocks_delta);
 527		whole = 1;
 528	}
 529	if (tp->t_agcount_delta) {
 530		be32_add_cpu(&sbp->sb_agcount, tp->t_agcount_delta);
 531		whole = 1;
 532	}
 533	if (tp->t_imaxpct_delta) {
 534		sbp->sb_imax_pct += tp->t_imaxpct_delta;
 535		whole = 1;
 536	}
 537	if (tp->t_rextsize_delta) {
 538		be32_add_cpu(&sbp->sb_rextsize, tp->t_rextsize_delta);
 539		whole = 1;
 540	}
 541	if (tp->t_rbmblocks_delta) {
 542		be32_add_cpu(&sbp->sb_rbmblocks, tp->t_rbmblocks_delta);
 543		whole = 1;
 544	}
 545	if (tp->t_rblocks_delta) {
 546		be64_add_cpu(&sbp->sb_rblocks, tp->t_rblocks_delta);
 547		whole = 1;
 548	}
 549	if (tp->t_rextents_delta) {
 550		be64_add_cpu(&sbp->sb_rextents, tp->t_rextents_delta);
 551		whole = 1;
 552	}
 553	if (tp->t_rextslog_delta) {
 554		sbp->sb_rextslog += tp->t_rextslog_delta;
 555		whole = 1;
 556	}
 557
 558	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
 559	if (whole)
 560		/*
 561		 * Log the whole thing, the fields are noncontiguous.
 562		 */
 563		xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb) - 1);
 564	else
 565		/*
 566		 * Since all the modifiable fields are contiguous, we
 567		 * can get away with this.
 568		 */
 569		xfs_trans_log_buf(tp, bp, offsetof(struct xfs_dsb, sb_icount),
 570				  offsetof(struct xfs_dsb, sb_frextents) +
 571				  sizeof(sbp->sb_frextents) - 1);
 572}
 573
 574/*
 575 * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations and
 576 * apply superblock counter changes to the in-core superblock.  The
 577 * t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT
 578 * applied to the in-core superblock.  The idea is that that has already been
 579 * done.
 580 *
 581 * If we are not logging superblock counters, then the inode allocated/free and
 582 * used block counts are not updated in the on disk superblock. In this case,
 583 * XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we
 584 * still need to update the incore superblock with the changes.
 585 *
 586 * Deltas for the inode count are +/-64, hence we use a large batch size of 128
 587 * so we don't need to take the counter lock on every update.
 588 */
 589#define XFS_ICOUNT_BATCH	128
 590
 591void
 592xfs_trans_unreserve_and_mod_sb(
 593	struct xfs_trans	*tp)
 594{
 595	struct xfs_mount	*mp = tp->t_mountp;
 596	bool			rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
 597	int64_t			blkdelta = 0;
 598	int64_t			rtxdelta = 0;
 599	int64_t			idelta = 0;
 600	int64_t			ifreedelta = 0;
 601	int			error;
 602
 603	/* calculate deltas */
 604	if (tp->t_blk_res > 0)
 605		blkdelta = tp->t_blk_res;
 606	if ((tp->t_fdblocks_delta != 0) &&
 607	    (xfs_has_lazysbcount(mp) ||
 608	     (tp->t_flags & XFS_TRANS_SB_DIRTY)))
 609	        blkdelta += tp->t_fdblocks_delta;
 610
 611	if (tp->t_rtx_res > 0)
 612		rtxdelta = tp->t_rtx_res;
 613	if ((tp->t_frextents_delta != 0) &&
 614	    (tp->t_flags & XFS_TRANS_SB_DIRTY))
 615		rtxdelta += tp->t_frextents_delta;
 616
 617	if (xfs_has_lazysbcount(mp) ||
 618	     (tp->t_flags & XFS_TRANS_SB_DIRTY)) {
 619		idelta = tp->t_icount_delta;
 620		ifreedelta = tp->t_ifree_delta;
 621	}
 622
 623	/* apply the per-cpu counters */
 624	if (blkdelta) {
 625		error = xfs_mod_fdblocks(mp, blkdelta, rsvd);
 626		ASSERT(!error);
 627	}
 628
 629	if (idelta)
 630		percpu_counter_add_batch(&mp->m_icount, idelta,
 631					 XFS_ICOUNT_BATCH);
 632
 633	if (ifreedelta)
 634		percpu_counter_add(&mp->m_ifree, ifreedelta);
 635
 636	if (rtxdelta) {
 637		error = xfs_mod_frextents(mp, rtxdelta);
 638		ASSERT(!error);
 639	}
 640
 641	if (!(tp->t_flags & XFS_TRANS_SB_DIRTY))
 642		return;
 643
 644	/* apply remaining deltas */
 645	spin_lock(&mp->m_sb_lock);
 646	mp->m_sb.sb_fdblocks += tp->t_fdblocks_delta + tp->t_res_fdblocks_delta;
 647	mp->m_sb.sb_icount += idelta;
 648	mp->m_sb.sb_ifree += ifreedelta;
 649	/*
 650	 * Do not touch sb_frextents here because we are dealing with incore
 651	 * reservation.  sb_frextents is not part of the lazy sb counters so it
 652	 * must be consistent with the ondisk rtbitmap and must never include
 653	 * incore reservations.
 654	 */
 655	mp->m_sb.sb_dblocks += tp->t_dblocks_delta;
 656	mp->m_sb.sb_agcount += tp->t_agcount_delta;
 657	mp->m_sb.sb_imax_pct += tp->t_imaxpct_delta;
 658	mp->m_sb.sb_rextsize += tp->t_rextsize_delta;
 659	if (tp->t_rextsize_delta) {
 660		mp->m_rtxblklog = log2_if_power2(mp->m_sb.sb_rextsize);
 661		mp->m_rtxblkmask = mask64_if_power2(mp->m_sb.sb_rextsize);
 662	}
 663	mp->m_sb.sb_rbmblocks += tp->t_rbmblocks_delta;
 664	mp->m_sb.sb_rblocks += tp->t_rblocks_delta;
 665	mp->m_sb.sb_rextents += tp->t_rextents_delta;
 666	mp->m_sb.sb_rextslog += tp->t_rextslog_delta;
 667	spin_unlock(&mp->m_sb_lock);
 668
 669	/*
 670	 * Debug checks outside of the spinlock so they don't lock up the
 671	 * machine if they fail.
 672	 */
 673	ASSERT(mp->m_sb.sb_imax_pct >= 0);
 674	ASSERT(mp->m_sb.sb_rextslog >= 0);
 675	return;
 676}
 677
 678/* Add the given log item to the transaction's list of log items. */
 679void
 680xfs_trans_add_item(
 681	struct xfs_trans	*tp,
 682	struct xfs_log_item	*lip)
 683{
 684	ASSERT(lip->li_log == tp->t_mountp->m_log);
 685	ASSERT(lip->li_ailp == tp->t_mountp->m_ail);
 686	ASSERT(list_empty(&lip->li_trans));
 687	ASSERT(!test_bit(XFS_LI_DIRTY, &lip->li_flags));
 688
 689	list_add_tail(&lip->li_trans, &tp->t_items);
 690	trace_xfs_trans_add_item(tp, _RET_IP_);
 691}
 692
 693/*
 694 * Unlink the log item from the transaction. the log item is no longer
 695 * considered dirty in this transaction, as the linked transaction has
 696 * finished, either by abort or commit completion.
 697 */
 698void
 699xfs_trans_del_item(
 700	struct xfs_log_item	*lip)
 701{
 702	clear_bit(XFS_LI_DIRTY, &lip->li_flags);
 703	list_del_init(&lip->li_trans);
 704}
 705
 706/* Detach and unlock all of the items in a transaction */
 707static void
 708xfs_trans_free_items(
 709	struct xfs_trans	*tp,
 710	bool			abort)
 711{
 712	struct xfs_log_item	*lip, *next;
 713
 714	trace_xfs_trans_free_items(tp, _RET_IP_);
 715
 716	list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) {
 717		xfs_trans_del_item(lip);
 718		if (abort)
 719			set_bit(XFS_LI_ABORTED, &lip->li_flags);
 720		if (lip->li_ops->iop_release)
 721			lip->li_ops->iop_release(lip);
 722	}
 723}
 724
 725static inline void
 726xfs_log_item_batch_insert(
 727	struct xfs_ail		*ailp,
 728	struct xfs_ail_cursor	*cur,
 729	struct xfs_log_item	**log_items,
 730	int			nr_items,
 731	xfs_lsn_t		commit_lsn)
 732{
 733	int	i;
 734
 735	spin_lock(&ailp->ail_lock);
 736	/* xfs_trans_ail_update_bulk drops ailp->ail_lock */
 737	xfs_trans_ail_update_bulk(ailp, cur, log_items, nr_items, commit_lsn);
 738
 739	for (i = 0; i < nr_items; i++) {
 740		struct xfs_log_item *lip = log_items[i];
 741
 742		if (lip->li_ops->iop_unpin)
 743			lip->li_ops->iop_unpin(lip, 0);
 744	}
 745}
 746
 747/*
 748 * Bulk operation version of xfs_trans_committed that takes a log vector of
 749 * items to insert into the AIL. This uses bulk AIL insertion techniques to
 750 * minimise lock traffic.
 751 *
 752 * If we are called with the aborted flag set, it is because a log write during
 753 * a CIL checkpoint commit has failed. In this case, all the items in the
 754 * checkpoint have already gone through iop_committed and iop_committing, which
 755 * means that checkpoint commit abort handling is treated exactly the same
 756 * as an iclog write error even though we haven't started any IO yet. Hence in
 757 * this case all we need to do is iop_committed processing, followed by an
 758 * iop_unpin(aborted) call.
 759 *
 760 * The AIL cursor is used to optimise the insert process. If commit_lsn is not
 761 * at the end of the AIL, the insert cursor avoids the need to walk
 762 * the AIL to find the insertion point on every xfs_log_item_batch_insert()
 763 * call. This saves a lot of needless list walking and is a net win, even
 764 * though it slightly increases that amount of AIL lock traffic to set it up
 765 * and tear it down.
 766 */
 767void
 768xfs_trans_committed_bulk(
 769	struct xfs_ail		*ailp,
 770	struct list_head	*lv_chain,
 771	xfs_lsn_t		commit_lsn,
 772	bool			aborted)
 773{
 774#define LOG_ITEM_BATCH_SIZE	32
 775	struct xfs_log_item	*log_items[LOG_ITEM_BATCH_SIZE];
 776	struct xfs_log_vec	*lv;
 777	struct xfs_ail_cursor	cur;
 778	int			i = 0;
 779
 780	spin_lock(&ailp->ail_lock);
 781	xfs_trans_ail_cursor_last(ailp, &cur, commit_lsn);
 782	spin_unlock(&ailp->ail_lock);
 783
 784	/* unpin all the log items */
 785	list_for_each_entry(lv, lv_chain, lv_list) {
 786		struct xfs_log_item	*lip = lv->lv_item;
 787		xfs_lsn_t		item_lsn;
 788
 789		if (aborted)
 790			set_bit(XFS_LI_ABORTED, &lip->li_flags);
 791
 792		if (lip->li_ops->flags & XFS_ITEM_RELEASE_WHEN_COMMITTED) {
 793			lip->li_ops->iop_release(lip);
 794			continue;
 795		}
 796
 797		if (lip->li_ops->iop_committed)
 798			item_lsn = lip->li_ops->iop_committed(lip, commit_lsn);
 799		else
 800			item_lsn = commit_lsn;
 801
 802		/* item_lsn of -1 means the item needs no further processing */
 803		if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0)
 804			continue;
 805
 806		/*
 807		 * if we are aborting the operation, no point in inserting the
 808		 * object into the AIL as we are in a shutdown situation.
 809		 */
 810		if (aborted) {
 811			ASSERT(xlog_is_shutdown(ailp->ail_log));
 812			if (lip->li_ops->iop_unpin)
 813				lip->li_ops->iop_unpin(lip, 1);
 814			continue;
 815		}
 816
 817		if (item_lsn != commit_lsn) {
 818
 819			/*
 820			 * Not a bulk update option due to unusual item_lsn.
 821			 * Push into AIL immediately, rechecking the lsn once
 822			 * we have the ail lock. Then unpin the item. This does
 823			 * not affect the AIL cursor the bulk insert path is
 824			 * using.
 825			 */
 826			spin_lock(&ailp->ail_lock);
 827			if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0)
 828				xfs_trans_ail_update(ailp, lip, item_lsn);
 829			else
 830				spin_unlock(&ailp->ail_lock);
 831			if (lip->li_ops->iop_unpin)
 832				lip->li_ops->iop_unpin(lip, 0);
 833			continue;
 834		}
 835
 836		/* Item is a candidate for bulk AIL insert.  */
 837		log_items[i++] = lv->lv_item;
 838		if (i >= LOG_ITEM_BATCH_SIZE) {
 839			xfs_log_item_batch_insert(ailp, &cur, log_items,
 840					LOG_ITEM_BATCH_SIZE, commit_lsn);
 841			i = 0;
 842		}
 843	}
 844
 845	/* make sure we insert the remainder! */
 846	if (i)
 847		xfs_log_item_batch_insert(ailp, &cur, log_items, i, commit_lsn);
 848
 849	spin_lock(&ailp->ail_lock);
 850	xfs_trans_ail_cursor_done(&cur);
 851	spin_unlock(&ailp->ail_lock);
 852}
 853
 854/*
 855 * Sort transaction items prior to running precommit operations. This will
 856 * attempt to order the items such that they will always be locked in the same
 857 * order. Items that have no sort function are moved to the end of the list
 858 * and so are locked last.
 859 *
 860 * This may need refinement as different types of objects add sort functions.
 861 *
 862 * Function is more complex than it needs to be because we are comparing 64 bit
 863 * values and the function only returns 32 bit values.
 864 */
 865static int
 866xfs_trans_precommit_sort(
 867	void			*unused_arg,
 868	const struct list_head	*a,
 869	const struct list_head	*b)
 870{
 871	struct xfs_log_item	*lia = container_of(a,
 872					struct xfs_log_item, li_trans);
 873	struct xfs_log_item	*lib = container_of(b,
 874					struct xfs_log_item, li_trans);
 875	int64_t			diff;
 876
 877	/*
 878	 * If both items are non-sortable, leave them alone. If only one is
 879	 * sortable, move the non-sortable item towards the end of the list.
 880	 */
 881	if (!lia->li_ops->iop_sort && !lib->li_ops->iop_sort)
 882		return 0;
 883	if (!lia->li_ops->iop_sort)
 884		return 1;
 885	if (!lib->li_ops->iop_sort)
 886		return -1;
 887
 888	diff = lia->li_ops->iop_sort(lia) - lib->li_ops->iop_sort(lib);
 889	if (diff < 0)
 890		return -1;
 891	if (diff > 0)
 892		return 1;
 893	return 0;
 894}
 895
 896/*
 897 * Run transaction precommit functions.
 898 *
 899 * If there is an error in any of the callouts, then stop immediately and
 900 * trigger a shutdown to abort the transaction. There is no recovery possible
 901 * from errors at this point as the transaction is dirty....
 902 */
 903static int
 904xfs_trans_run_precommits(
 905	struct xfs_trans	*tp)
 906{
 907	struct xfs_mount	*mp = tp->t_mountp;
 908	struct xfs_log_item	*lip, *n;
 909	int			error = 0;
 910
 911	/*
 912	 * Sort the item list to avoid ABBA deadlocks with other transactions
 913	 * running precommit operations that lock multiple shared items such as
 914	 * inode cluster buffers.
 915	 */
 916	list_sort(NULL, &tp->t_items, xfs_trans_precommit_sort);
 917
 918	/*
 919	 * Precommit operations can remove the log item from the transaction
 920	 * if the log item exists purely to delay modifications until they
 921	 * can be ordered against other operations. Hence we have to use
 922	 * list_for_each_entry_safe() here.
 923	 */
 924	list_for_each_entry_safe(lip, n, &tp->t_items, li_trans) {
 925		if (!test_bit(XFS_LI_DIRTY, &lip->li_flags))
 926			continue;
 927		if (lip->li_ops->iop_precommit) {
 928			error = lip->li_ops->iop_precommit(tp, lip);
 929			if (error)
 930				break;
 931		}
 932	}
 933	if (error)
 934		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
 935	return error;
 936}
 937
 938/*
 939 * Commit the given transaction to the log.
 940 *
 941 * XFS disk error handling mechanism is not based on a typical
 942 * transaction abort mechanism. Logically after the filesystem
 943 * gets marked 'SHUTDOWN', we can't let any new transactions
 944 * be durable - ie. committed to disk - because some metadata might
 945 * be inconsistent. In such cases, this returns an error, and the
 946 * caller may assume that all locked objects joined to the transaction
 947 * have already been unlocked as if the commit had succeeded.
 948 * Do not reference the transaction structure after this call.
 949 */
 950static int
 951__xfs_trans_commit(
 952	struct xfs_trans	*tp,
 953	bool			regrant)
 954{
 955	struct xfs_mount	*mp = tp->t_mountp;
 956	struct xlog		*log = mp->m_log;
 957	xfs_csn_t		commit_seq = 0;
 958	int			error = 0;
 959	int			sync = tp->t_flags & XFS_TRANS_SYNC;
 960
 961	trace_xfs_trans_commit(tp, _RET_IP_);
 962
 963	error = xfs_trans_run_precommits(tp);
 964	if (error) {
 965		if (tp->t_flags & XFS_TRANS_PERM_LOG_RES)
 966			xfs_defer_cancel(tp);
 967		goto out_unreserve;
 968	}
 969
 970	/*
 971	 * Finish deferred items on final commit. Only permanent transactions
 972	 * should ever have deferred ops.
 973	 */
 974	WARN_ON_ONCE(!list_empty(&tp->t_dfops) &&
 975		     !(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
 976	if (!regrant && (tp->t_flags & XFS_TRANS_PERM_LOG_RES)) {
 977		error = xfs_defer_finish_noroll(&tp);
 978		if (error)
 979			goto out_unreserve;
 980
 981		/* Run precommits from final tx in defer chain. */
 982		error = xfs_trans_run_precommits(tp);
 983		if (error)
 984			goto out_unreserve;
 985	}
 986
 987	/*
 988	 * If there is nothing to be logged by the transaction,
 989	 * then unlock all of the items associated with the
 990	 * transaction and free the transaction structure.
 991	 * Also make sure to return any reserved blocks to
 992	 * the free pool.
 993	 */
 994	if (!(tp->t_flags & XFS_TRANS_DIRTY))
 995		goto out_unreserve;
 996
 997	/*
 998	 * We must check against log shutdown here because we cannot abort log
 999	 * items and leave them dirty, inconsistent and unpinned in memory while
1000	 * the log is active. This leaves them open to being written back to
1001	 * disk, and that will lead to on-disk corruption.
1002	 */
1003	if (xlog_is_shutdown(log)) {
1004		error = -EIO;
1005		goto out_unreserve;
1006	}
1007
1008	ASSERT(tp->t_ticket != NULL);
1009
1010	/*
1011	 * If we need to update the superblock, then do it now.
1012	 */
1013	if (tp->t_flags & XFS_TRANS_SB_DIRTY)
1014		xfs_trans_apply_sb_deltas(tp);
1015	xfs_trans_apply_dquot_deltas(tp);
1016
1017	xlog_cil_commit(log, tp, &commit_seq, regrant);
1018
1019	xfs_trans_free(tp);
1020
1021	/*
1022	 * If the transaction needs to be synchronous, then force the
1023	 * log out now and wait for it.
1024	 */
1025	if (sync) {
1026		error = xfs_log_force_seq(mp, commit_seq, XFS_LOG_SYNC, NULL);
1027		XFS_STATS_INC(mp, xs_trans_sync);
1028	} else {
1029		XFS_STATS_INC(mp, xs_trans_async);
1030	}
1031
1032	return error;
1033
1034out_unreserve:
1035	xfs_trans_unreserve_and_mod_sb(tp);
1036
1037	/*
1038	 * It is indeed possible for the transaction to be not dirty but
1039	 * the dqinfo portion to be.  All that means is that we have some
1040	 * (non-persistent) quota reservations that need to be unreserved.
1041	 */
1042	xfs_trans_unreserve_and_mod_dquots(tp);
1043	if (tp->t_ticket) {
1044		if (regrant && !xlog_is_shutdown(log))
1045			xfs_log_ticket_regrant(log, tp->t_ticket);
1046		else
1047			xfs_log_ticket_ungrant(log, tp->t_ticket);
1048		tp->t_ticket = NULL;
1049	}
1050	xfs_trans_free_items(tp, !!error);
1051	xfs_trans_free(tp);
1052
1053	XFS_STATS_INC(mp, xs_trans_empty);
1054	return error;
1055}
1056
1057int
1058xfs_trans_commit(
1059	struct xfs_trans	*tp)
1060{
1061	return __xfs_trans_commit(tp, false);
1062}
1063
1064/*
1065 * Unlock all of the transaction's items and free the transaction.  If the
1066 * transaction is dirty, we must shut down the filesystem because there is no
1067 * way to restore them to their previous state.
1068 *
1069 * If the transaction has made a log reservation, make sure to release it as
1070 * well.
1071 *
1072 * This is a high level function (equivalent to xfs_trans_commit()) and so can
1073 * be called after the transaction has effectively been aborted due to the mount
1074 * being shut down. However, if the mount has not been shut down and the
1075 * transaction is dirty we will shut the mount down and, in doing so, that
1076 * guarantees that the log is shut down, too. Hence we don't need to be as
1077 * careful with shutdown state and dirty items here as we need to be in
1078 * xfs_trans_commit().
1079 */
1080void
1081xfs_trans_cancel(
1082	struct xfs_trans	*tp)
1083{
1084	struct xfs_mount	*mp = tp->t_mountp;
1085	struct xlog		*log = mp->m_log;
1086	bool			dirty = (tp->t_flags & XFS_TRANS_DIRTY);
1087
1088	trace_xfs_trans_cancel(tp, _RET_IP_);
1089
1090	/*
1091	 * It's never valid to cancel a transaction with deferred ops attached,
1092	 * because the transaction is effectively dirty.  Complain about this
1093	 * loudly before freeing the in-memory defer items and shutting down the
1094	 * filesystem.
1095	 */
1096	if (!list_empty(&tp->t_dfops)) {
 
1097		ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
1098		dirty = true;
1099		xfs_defer_cancel(tp);
1100	}
1101
1102	/*
1103	 * See if the caller is relying on us to shut down the filesystem. We
1104	 * only want an error report if there isn't already a shutdown in
1105	 * progress, so we only need to check against the mount shutdown state
1106	 * here.
1107	 */
1108	if (dirty && !xfs_is_shutdown(mp)) {
1109		XFS_ERROR_REPORT("xfs_trans_cancel", XFS_ERRLEVEL_LOW, mp);
1110		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1111	}
1112#ifdef DEBUG
1113	/* Log items need to be consistent until the log is shut down. */
1114	if (!dirty && !xlog_is_shutdown(log)) {
1115		struct xfs_log_item *lip;
1116
1117		list_for_each_entry(lip, &tp->t_items, li_trans)
1118			ASSERT(!xlog_item_is_intent_done(lip));
1119	}
1120#endif
1121	xfs_trans_unreserve_and_mod_sb(tp);
1122	xfs_trans_unreserve_and_mod_dquots(tp);
1123
1124	if (tp->t_ticket) {
1125		xfs_log_ticket_ungrant(log, tp->t_ticket);
1126		tp->t_ticket = NULL;
1127	}
1128
1129	xfs_trans_free_items(tp, dirty);
1130	xfs_trans_free(tp);
1131}
1132
1133/*
1134 * Roll from one trans in the sequence of PERMANENT transactions to
1135 * the next: permanent transactions are only flushed out when
1136 * committed with xfs_trans_commit(), but we still want as soon
1137 * as possible to let chunks of it go to the log. So we commit the
1138 * chunk we've been working on and get a new transaction to continue.
1139 */
1140int
1141xfs_trans_roll(
1142	struct xfs_trans	**tpp)
1143{
1144	struct xfs_trans	*trans = *tpp;
1145	struct xfs_trans_res	tres;
1146	int			error;
1147
1148	trace_xfs_trans_roll(trans, _RET_IP_);
1149
1150	/*
1151	 * Copy the critical parameters from one trans to the next.
1152	 */
1153	tres.tr_logres = trans->t_log_res;
1154	tres.tr_logcount = trans->t_log_count;
1155
1156	*tpp = xfs_trans_dup(trans);
1157
1158	/*
1159	 * Commit the current transaction.
1160	 * If this commit failed, then it'd just unlock those items that
1161	 * are not marked ihold. That also means that a filesystem shutdown
1162	 * is in progress. The caller takes the responsibility to cancel
1163	 * the duplicate transaction that gets returned.
1164	 */
1165	error = __xfs_trans_commit(trans, true);
1166	if (error)
1167		return error;
1168
1169	/*
1170	 * Reserve space in the log for the next transaction.
1171	 * This also pushes items in the "AIL", the list of logged items,
1172	 * out to disk if they are taking up space at the tail of the log
1173	 * that we want to use.  This requires that either nothing be locked
1174	 * across this call, or that anything that is locked be logged in
1175	 * the prior and the next transactions.
1176	 */
1177	tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
1178	return xfs_trans_reserve(*tpp, &tres, 0, 0);
1179}
1180
1181/*
1182 * Allocate an transaction, lock and join the inode to it, and reserve quota.
1183 *
1184 * The caller must ensure that the on-disk dquots attached to this inode have
1185 * already been allocated and initialized.  The caller is responsible for
1186 * releasing ILOCK_EXCL if a new transaction is returned.
1187 */
1188int
1189xfs_trans_alloc_inode(
1190	struct xfs_inode	*ip,
1191	struct xfs_trans_res	*resv,
1192	unsigned int		dblocks,
1193	unsigned int		rblocks,
1194	bool			force,
1195	struct xfs_trans	**tpp)
1196{
1197	struct xfs_trans	*tp;
1198	struct xfs_mount	*mp = ip->i_mount;
1199	bool			retried = false;
1200	int			error;
1201
1202retry:
1203	error = xfs_trans_alloc(mp, resv, dblocks,
1204			xfs_extlen_to_rtxlen(mp, rblocks),
1205			force ? XFS_TRANS_RESERVE : 0, &tp);
1206	if (error)
1207		return error;
1208
1209	xfs_ilock(ip, XFS_ILOCK_EXCL);
1210	xfs_trans_ijoin(tp, ip, 0);
1211
1212	error = xfs_qm_dqattach_locked(ip, false);
1213	if (error) {
1214		/* Caller should have allocated the dquots! */
1215		ASSERT(error != -ENOENT);
1216		goto out_cancel;
1217	}
1218
1219	error = xfs_trans_reserve_quota_nblks(tp, ip, dblocks, rblocks, force);
1220	if ((error == -EDQUOT || error == -ENOSPC) && !retried) {
1221		xfs_trans_cancel(tp);
1222		xfs_iunlock(ip, XFS_ILOCK_EXCL);
1223		xfs_blockgc_free_quota(ip, 0);
1224		retried = true;
1225		goto retry;
1226	}
1227	if (error)
1228		goto out_cancel;
1229
1230	*tpp = tp;
1231	return 0;
1232
1233out_cancel:
1234	xfs_trans_cancel(tp);
1235	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1236	return error;
1237}
1238
1239/*
1240 * Try to reserve more blocks for a transaction.
1241 *
1242 * This is for callers that need to attach resources to a transaction, scan
1243 * those resources to determine the space reservation requirements, and then
1244 * modify the attached resources.  In other words, online repair.  This can
1245 * fail due to ENOSPC, so the caller must be able to cancel the transaction
1246 * without shutting down the fs.
1247 */
1248int
1249xfs_trans_reserve_more(
1250	struct xfs_trans	*tp,
1251	unsigned int		blocks,
1252	unsigned int		rtextents)
1253{
1254	struct xfs_trans_res	resv = { };
1255
1256	return xfs_trans_reserve(tp, &resv, blocks, rtextents);
1257}
1258
1259/*
1260 * Try to reserve more blocks and file quota for a transaction.  Same
1261 * conditions of usage as xfs_trans_reserve_more.
1262 */
1263int
1264xfs_trans_reserve_more_inode(
1265	struct xfs_trans	*tp,
1266	struct xfs_inode	*ip,
1267	unsigned int		dblocks,
1268	unsigned int		rblocks,
1269	bool			force_quota)
1270{
1271	struct xfs_trans_res	resv = { };
1272	struct xfs_mount	*mp = ip->i_mount;
1273	unsigned int		rtx = xfs_extlen_to_rtxlen(mp, rblocks);
1274	int			error;
1275
1276	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1277
1278	error = xfs_trans_reserve(tp, &resv, dblocks, rtx);
1279	if (error)
1280		return error;
1281
1282	if (!XFS_IS_QUOTA_ON(mp) || xfs_is_quota_inode(&mp->m_sb, ip->i_ino))
1283		return 0;
1284
1285	if (tp->t_flags & XFS_TRANS_RESERVE)
1286		force_quota = true;
1287
1288	error = xfs_trans_reserve_quota_nblks(tp, ip, dblocks, rblocks,
1289			force_quota);
1290	if (!error)
1291		return 0;
1292
1293	/* Quota failed, give back the new reservation. */
1294	xfs_mod_fdblocks(mp, dblocks, tp->t_flags & XFS_TRANS_RESERVE);
1295	tp->t_blk_res -= dblocks;
1296	xfs_mod_frextents(mp, rtx);
1297	tp->t_rtx_res -= rtx;
1298	return error;
1299}
1300
1301/*
1302 * Allocate an transaction in preparation for inode creation by reserving quota
1303 * against the given dquots.  Callers are not required to hold any inode locks.
1304 */
1305int
1306xfs_trans_alloc_icreate(
1307	struct xfs_mount	*mp,
1308	struct xfs_trans_res	*resv,
1309	struct xfs_dquot	*udqp,
1310	struct xfs_dquot	*gdqp,
1311	struct xfs_dquot	*pdqp,
1312	unsigned int		dblocks,
1313	struct xfs_trans	**tpp)
1314{
1315	struct xfs_trans	*tp;
1316	bool			retried = false;
1317	int			error;
1318
1319retry:
1320	error = xfs_trans_alloc(mp, resv, dblocks, 0, 0, &tp);
1321	if (error)
1322		return error;
1323
1324	error = xfs_trans_reserve_quota_icreate(tp, udqp, gdqp, pdqp, dblocks);
1325	if ((error == -EDQUOT || error == -ENOSPC) && !retried) {
1326		xfs_trans_cancel(tp);
1327		xfs_blockgc_free_dquots(mp, udqp, gdqp, pdqp, 0);
1328		retried = true;
1329		goto retry;
1330	}
1331	if (error) {
1332		xfs_trans_cancel(tp);
1333		return error;
1334	}
1335
1336	*tpp = tp;
1337	return 0;
1338}
1339
1340/*
1341 * Allocate an transaction, lock and join the inode to it, and reserve quota
1342 * in preparation for inode attribute changes that include uid, gid, or prid
1343 * changes.
1344 *
1345 * The caller must ensure that the on-disk dquots attached to this inode have
1346 * already been allocated and initialized.  The ILOCK will be dropped when the
1347 * transaction is committed or cancelled.
1348 */
1349int
1350xfs_trans_alloc_ichange(
1351	struct xfs_inode	*ip,
1352	struct xfs_dquot	*new_udqp,
1353	struct xfs_dquot	*new_gdqp,
1354	struct xfs_dquot	*new_pdqp,
1355	bool			force,
1356	struct xfs_trans	**tpp)
1357{
1358	struct xfs_trans	*tp;
1359	struct xfs_mount	*mp = ip->i_mount;
1360	struct xfs_dquot	*udqp;
1361	struct xfs_dquot	*gdqp;
1362	struct xfs_dquot	*pdqp;
1363	bool			retried = false;
1364	int			error;
1365
1366retry:
1367	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
1368	if (error)
1369		return error;
1370
1371	xfs_ilock(ip, XFS_ILOCK_EXCL);
1372	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1373
1374	error = xfs_qm_dqattach_locked(ip, false);
1375	if (error) {
1376		/* Caller should have allocated the dquots! */
1377		ASSERT(error != -ENOENT);
1378		goto out_cancel;
1379	}
1380
1381	/*
1382	 * For each quota type, skip quota reservations if the inode's dquots
1383	 * now match the ones that came from the caller, or the caller didn't
1384	 * pass one in.  The inode's dquots can change if we drop the ILOCK to
1385	 * perform a blockgc scan, so we must preserve the caller's arguments.
1386	 */
1387	udqp = (new_udqp != ip->i_udquot) ? new_udqp : NULL;
1388	gdqp = (new_gdqp != ip->i_gdquot) ? new_gdqp : NULL;
1389	pdqp = (new_pdqp != ip->i_pdquot) ? new_pdqp : NULL;
1390	if (udqp || gdqp || pdqp) {
1391		unsigned int	qflags = XFS_QMOPT_RES_REGBLKS;
1392
1393		if (force)
1394			qflags |= XFS_QMOPT_FORCE_RES;
1395
1396		/*
1397		 * Reserve enough quota to handle blocks on disk and reserved
1398		 * for a delayed allocation.  We'll actually transfer the
1399		 * delalloc reservation between dquots at chown time, even
1400		 * though that part is only semi-transactional.
1401		 */
1402		error = xfs_trans_reserve_quota_bydquots(tp, mp, udqp, gdqp,
1403				pdqp, ip->i_nblocks + ip->i_delayed_blks,
1404				1, qflags);
1405		if ((error == -EDQUOT || error == -ENOSPC) && !retried) {
1406			xfs_trans_cancel(tp);
1407			xfs_blockgc_free_dquots(mp, udqp, gdqp, pdqp, 0);
1408			retried = true;
1409			goto retry;
1410		}
1411		if (error)
1412			goto out_cancel;
1413	}
1414
1415	*tpp = tp;
1416	return 0;
1417
1418out_cancel:
1419	xfs_trans_cancel(tp);
1420	return error;
1421}
1422
1423/*
1424 * Allocate an transaction, lock and join the directory and child inodes to it,
1425 * and reserve quota for a directory update.  If there isn't sufficient space,
1426 * @dblocks will be set to zero for a reservationless directory update and
1427 * @nospace_error will be set to a negative errno describing the space
1428 * constraint we hit.
1429 *
1430 * The caller must ensure that the on-disk dquots attached to this inode have
1431 * already been allocated and initialized.  The ILOCKs will be dropped when the
1432 * transaction is committed or cancelled.
1433 */
1434int
1435xfs_trans_alloc_dir(
1436	struct xfs_inode	*dp,
1437	struct xfs_trans_res	*resv,
1438	struct xfs_inode	*ip,
1439	unsigned int		*dblocks,
1440	struct xfs_trans	**tpp,
1441	int			*nospace_error)
1442{
1443	struct xfs_trans	*tp;
1444	struct xfs_mount	*mp = ip->i_mount;
1445	unsigned int		resblks;
1446	bool			retried = false;
1447	int			error;
1448
1449retry:
1450	*nospace_error = 0;
1451	resblks = *dblocks;
1452	error = xfs_trans_alloc(mp, resv, resblks, 0, 0, &tp);
1453	if (error == -ENOSPC) {
1454		*nospace_error = error;
1455		resblks = 0;
1456		error = xfs_trans_alloc(mp, resv, resblks, 0, 0, &tp);
1457	}
1458	if (error)
1459		return error;
1460
1461	xfs_lock_two_inodes(dp, XFS_ILOCK_EXCL, ip, XFS_ILOCK_EXCL);
1462
1463	xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
1464	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
1465
1466	error = xfs_qm_dqattach_locked(dp, false);
1467	if (error) {
1468		/* Caller should have allocated the dquots! */
1469		ASSERT(error != -ENOENT);
1470		goto out_cancel;
1471	}
1472
1473	error = xfs_qm_dqattach_locked(ip, false);
1474	if (error) {
1475		/* Caller should have allocated the dquots! */
1476		ASSERT(error != -ENOENT);
1477		goto out_cancel;
1478	}
1479
1480	if (resblks == 0)
1481		goto done;
1482
1483	error = xfs_trans_reserve_quota_nblks(tp, dp, resblks, 0, false);
1484	if (error == -EDQUOT || error == -ENOSPC) {
1485		if (!retried) {
1486			xfs_trans_cancel(tp);
1487			xfs_blockgc_free_quota(dp, 0);
1488			retried = true;
1489			goto retry;
1490		}
1491
1492		*nospace_error = error;
1493		resblks = 0;
1494		error = 0;
1495	}
1496	if (error)
1497		goto out_cancel;
1498
1499done:
1500	*tpp = tp;
1501	*dblocks = resblks;
1502	return 0;
1503
1504out_cancel:
1505	xfs_trans_cancel(tp);
1506	return error;
1507}