1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2000-2003 Silicon Graphics, Inc.
   4 * All Rights Reserved.
   5 */
   6#include "xfs.h"
   7#include "xfs_fs.h"
   8#include "xfs_format.h"
   9#include "xfs_log_format.h"
  10#include "xfs_shared.h"
  11#include "xfs_trans_resv.h"
  12#include "xfs_bit.h"
  13#include "xfs_mount.h"
  14#include "xfs_defer.h"
  15#include "xfs_inode.h"
  16#include "xfs_bmap.h"
  17#include "xfs_quota.h"
  18#include "xfs_trans.h"
  19#include "xfs_buf_item.h"
  20#include "xfs_trans_space.h"
  21#include "xfs_trans_priv.h"
  22#include "xfs_qm.h"
  23#include "xfs_trace.h"
  24#include "xfs_log.h"
  25#include "xfs_bmap_btree.h"
  26#include "xfs_error.h"
  27
  28/*
  29 * Lock order:
  30 *
  31 * ip->i_lock
  32 *   qi->qi_tree_lock
  33 *     dquot->q_qlock (xfs_dqlock() and friends)
  34 *       dquot->q_flush (xfs_dqflock() and friends)
  35 *       qi->qi_lru_lock
  36 *
  37 * If two dquots need to be locked the order is user before group/project,
  38 * otherwise by the lowest id first, see xfs_dqlock2.
  39 */
  40
  41struct kmem_cache		*xfs_dqtrx_cache;
  42static struct kmem_cache	*xfs_dquot_cache;
  43
  44static struct lock_class_key xfs_dquot_group_class;
  45static struct lock_class_key xfs_dquot_project_class;
  46
  47/*
  48 * This is called to free all the memory associated with a dquot
  49 */
  50void
  51xfs_qm_dqdestroy(
  52	struct xfs_dquot	*dqp)
  53{
  54	ASSERT(list_empty(&dqp->q_lru));
  55
  56	kmem_free(dqp->q_logitem.qli_item.li_lv_shadow);
  57	mutex_destroy(&dqp->q_qlock);
  58
  59	XFS_STATS_DEC(dqp->q_mount, xs_qm_dquot);
  60	kmem_cache_free(xfs_dquot_cache, dqp);
  61}
  62
  63/*
  64 * If default limits are in force, push them into the dquot now.
  65 * We overwrite the dquot limits only if they are zero and this
  66 * is not the root dquot.
  67 */
  68void
  69xfs_qm_adjust_dqlimits(
  70	struct xfs_dquot	*dq)
  71{
  72	struct xfs_mount	*mp = dq->q_mount;
  73	struct xfs_quotainfo	*q = mp->m_quotainfo;
  74	struct xfs_def_quota	*defq;
  75	int			prealloc = 0;
  76
  77	ASSERT(dq->q_id);
  78	defq = xfs_get_defquota(q, xfs_dquot_type(dq));
  79
  80	if (!dq->q_blk.softlimit) {
  81		dq->q_blk.softlimit = defq->blk.soft;
  82		prealloc = 1;
  83	}
  84	if (!dq->q_blk.hardlimit) {
  85		dq->q_blk.hardlimit = defq->blk.hard;
  86		prealloc = 1;
  87	}
  88	if (!dq->q_ino.softlimit)
  89		dq->q_ino.softlimit = defq->ino.soft;
  90	if (!dq->q_ino.hardlimit)
  91		dq->q_ino.hardlimit = defq->ino.hard;
  92	if (!dq->q_rtb.softlimit)
  93		dq->q_rtb.softlimit = defq->rtb.soft;
  94	if (!dq->q_rtb.hardlimit)
  95		dq->q_rtb.hardlimit = defq->rtb.hard;
  96
  97	if (prealloc)
  98		xfs_dquot_set_prealloc_limits(dq);
  99}
 100
 101/* Set the expiration time of a quota's grace period. */
 102time64_t
 103xfs_dquot_set_timeout(
 104	struct xfs_mount	*mp,
 105	time64_t		timeout)
 106{
 107	struct xfs_quotainfo	*qi = mp->m_quotainfo;
 108
 109	return clamp_t(time64_t, timeout, qi->qi_expiry_min,
 110					  qi->qi_expiry_max);
 111}
 112
 113/* Set the length of the default grace period. */
 114time64_t
 115xfs_dquot_set_grace_period(
 116	time64_t		grace)
 117{
 118	return clamp_t(time64_t, grace, XFS_DQ_GRACE_MIN, XFS_DQ_GRACE_MAX);
 119}
 120
 121/*
 122 * Determine if this quota counter is over either limit and set the quota
 123 * timers as appropriate.
 124 */
 125static inline void
 126xfs_qm_adjust_res_timer(
 127	struct xfs_mount	*mp,
 128	struct xfs_dquot_res	*res,
 129	struct xfs_quota_limits	*qlim)
 130{
 131	ASSERT(res->hardlimit == 0 || res->softlimit <= res->hardlimit);
 132
 133	if ((res->softlimit && res->count > res->softlimit) ||
 134	    (res->hardlimit && res->count > res->hardlimit)) {
 135		if (res->timer == 0)
 136			res->timer = xfs_dquot_set_timeout(mp,
 137					ktime_get_real_seconds() + qlim->time);
 138	} else {
 139		res->timer = 0;
 140	}
 141}
 142
 143/*
 144 * Check the limits and timers of a dquot and start or reset timers
 145 * if necessary.
 146 * This gets called even when quota enforcement is OFF, which makes our
 147 * life a little less complicated. (We just don't reject any quota
 148 * reservations in that case, when enforcement is off).
 149 * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
 150 * enforcement's off.
 151 * In contrast, warnings are a little different in that they don't
 152 * 'automatically' get started when limits get exceeded.  They do
 153 * get reset to zero, however, when we find the count to be under
 154 * the soft limit (they are only ever set non-zero via userspace).
 155 */
 156void
 157xfs_qm_adjust_dqtimers(
 158	struct xfs_dquot	*dq)
 159{
 160	struct xfs_mount	*mp = dq->q_mount;
 161	struct xfs_quotainfo	*qi = mp->m_quotainfo;
 162	struct xfs_def_quota	*defq;
 163
 164	ASSERT(dq->q_id);
 165	defq = xfs_get_defquota(qi, xfs_dquot_type(dq));
 166
 167	xfs_qm_adjust_res_timer(dq->q_mount, &dq->q_blk, &defq->blk);
 168	xfs_qm_adjust_res_timer(dq->q_mount, &dq->q_ino, &defq->ino);
 169	xfs_qm_adjust_res_timer(dq->q_mount, &dq->q_rtb, &defq->rtb);
 170}
 171
 172/*
 173 * initialize a buffer full of dquots and log the whole thing
 174 */
 175STATIC void
 176xfs_qm_init_dquot_blk(
 177	struct xfs_trans	*tp,
 178	struct xfs_mount	*mp,
 179	xfs_dqid_t		id,
 180	xfs_dqtype_t		type,
 181	struct xfs_buf		*bp)
 182{
 
 183	struct xfs_quotainfo	*q = mp->m_quotainfo;
 184	struct xfs_dqblk	*d;
 185	xfs_dqid_t		curid;
 186	unsigned int		qflag;
 187	unsigned int		blftype;
 188	int			i;
 189
 190	ASSERT(tp);
 191	ASSERT(xfs_buf_islocked(bp));
 192
 193	switch (type) {
 194	case XFS_DQTYPE_USER:
 195		qflag = XFS_UQUOTA_CHKD;
 196		blftype = XFS_BLF_UDQUOT_BUF;
 197		break;
 198	case XFS_DQTYPE_PROJ:
 199		qflag = XFS_PQUOTA_CHKD;
 200		blftype = XFS_BLF_PDQUOT_BUF;
 201		break;
 202	case XFS_DQTYPE_GROUP:
 203		qflag = XFS_GQUOTA_CHKD;
 204		blftype = XFS_BLF_GDQUOT_BUF;
 205		break;
 206	default:
 207		ASSERT(0);
 208		return;
 209	}
 210
 211	d = bp->b_addr;
 212
 213	/*
 214	 * ID of the first dquot in the block - id's are zero based.
 215	 */
 216	curid = id - (id % q->qi_dqperchunk);
 217	memset(d, 0, BBTOB(q->qi_dqchunklen));
 218	for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) {
 219		d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 220		d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 221		d->dd_diskdq.d_id = cpu_to_be32(curid);
 222		d->dd_diskdq.d_type = type;
 223		if (curid > 0 && xfs_has_bigtime(mp))
 224			d->dd_diskdq.d_type |= XFS_DQTYPE_BIGTIME;
 225		if (xfs_has_crc(mp)) {
 226			uuid_copy(&d->dd_uuid, &mp->m_sb.sb_meta_uuid);
 227			xfs_update_cksum((char *)d, sizeof(struct xfs_dqblk),
 228					 XFS_DQUOT_CRC_OFF);
 229		}
 230	}
 231
 232	xfs_trans_dquot_buf(tp, bp, blftype);
 233
 234	/*
 235	 * quotacheck uses delayed writes to update all the dquots on disk in an
 236	 * efficient manner instead of logging the individual dquot changes as
 237	 * they are made. However if we log the buffer allocated here and crash
 238	 * after quotacheck while the logged initialisation is still in the
 239	 * active region of the log, log recovery can replay the dquot buffer
 240	 * initialisation over the top of the checked dquots and corrupt quota
 241	 * accounting.
 242	 *
 243	 * To avoid this problem, quotacheck cannot log the initialised buffer.
 244	 * We must still dirty the buffer and write it back before the
 245	 * allocation transaction clears the log. Therefore, mark the buffer as
 246	 * ordered instead of logging it directly. This is safe for quotacheck
 247	 * because it detects and repairs allocated but initialized dquot blocks
 248	 * in the quota inodes.
 249	 */
 250	if (!(mp->m_qflags & qflag))
 251		xfs_trans_ordered_buf(tp, bp);
 252	else
 253		xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
 254}
 255
 256/*
 257 * Initialize the dynamic speculative preallocation thresholds. The lo/hi
 258 * watermarks correspond to the soft and hard limits by default. If a soft limit
 259 * is not specified, we use 95% of the hard limit.
 260 */
 261void
 262xfs_dquot_set_prealloc_limits(struct xfs_dquot *dqp)
 263{
 264	uint64_t space;
 265
 266	dqp->q_prealloc_hi_wmark = dqp->q_blk.hardlimit;
 267	dqp->q_prealloc_lo_wmark = dqp->q_blk.softlimit;
 268	if (!dqp->q_prealloc_lo_wmark) {
 269		dqp->q_prealloc_lo_wmark = dqp->q_prealloc_hi_wmark;
 270		do_div(dqp->q_prealloc_lo_wmark, 100);
 271		dqp->q_prealloc_lo_wmark *= 95;
 272	}
 273
 274	space = dqp->q_prealloc_hi_wmark;
 275
 276	do_div(space, 100);
 277	dqp->q_low_space[XFS_QLOWSP_1_PCNT] = space;
 278	dqp->q_low_space[XFS_QLOWSP_3_PCNT] = space * 3;
 279	dqp->q_low_space[XFS_QLOWSP_5_PCNT] = space * 5;
 280}
 281
 282/*
 283 * Ensure that the given in-core dquot has a buffer on disk backing it, and
 284 * return the buffer locked and held. This is called when the bmapi finds a
 285 * hole.
 286 */
 287STATIC int
 288xfs_dquot_disk_alloc(
 289	struct xfs_dquot	*dqp,
 290	struct xfs_buf		**bpp)
 291{
 292	struct xfs_bmbt_irec	map;
 293	struct xfs_trans	*tp;
 294	struct xfs_mount	*mp = dqp->q_mount;
 295	struct xfs_buf		*bp;
 296	xfs_dqtype_t		qtype = xfs_dquot_type(dqp);
 297	struct xfs_inode	*quotip = xfs_quota_inode(mp, qtype);
 298	int			nmaps = 1;
 299	int			error;
 300
 301	trace_xfs_dqalloc(dqp);
 302
 303	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_dqalloc,
 304			XFS_QM_DQALLOC_SPACE_RES(mp), 0, 0, &tp);
 305	if (error)
 306		return error;
 307
 308	xfs_ilock(quotip, XFS_ILOCK_EXCL);
 309	xfs_trans_ijoin(tp, quotip, 0);
 310
 311	if (!xfs_this_quota_on(dqp->q_mount, qtype)) {
 312		/*
 313		 * Return if this type of quotas is turned off while we didn't
 314		 * have an inode lock
 315		 */
 316		error = -ESRCH;
 317		goto err_cancel;
 318	}
 319
 320	error = xfs_iext_count_may_overflow(quotip, XFS_DATA_FORK,
 321			XFS_IEXT_ADD_NOSPLIT_CNT);
 322	if (error == -EFBIG)
 323		error = xfs_iext_count_upgrade(tp, quotip,
 324				XFS_IEXT_ADD_NOSPLIT_CNT);
 325	if (error)
 326		goto err_cancel;
 327
 328	/* Create the block mapping. */
 329	error = xfs_bmapi_write(tp, quotip, dqp->q_fileoffset,
 330			XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA, 0, &map,
 331			&nmaps);
 332	if (error)
 333		goto err_cancel;
 334
 335	ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
 336	ASSERT(nmaps == 1);
 337	ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 338	       (map.br_startblock != HOLESTARTBLOCK));
 339
 340	/*
 341	 * Keep track of the blkno to save a lookup later
 342	 */
 343	dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 344
 345	/* now we can just get the buffer (there's nothing to read yet) */
 346	error = xfs_trans_get_buf(tp, mp->m_ddev_targp, dqp->q_blkno,
 347			mp->m_quotainfo->qi_dqchunklen, 0, &bp);
 348	if (error)
 349		goto err_cancel;
 350	bp->b_ops = &xfs_dquot_buf_ops;
 351
 352	/*
 353	 * Make a chunk of dquots out of this buffer and log
 354	 * the entire thing.
 355	 */
 356	xfs_qm_init_dquot_blk(tp, mp, dqp->q_id, qtype, bp);
 357	xfs_buf_set_ref(bp, XFS_DQUOT_REF);
 358
 359	/*
 360	 * Hold the buffer and join it to the dfops so that we'll still own
 361	 * the buffer when we return to the caller.  The buffer disposal on
 362	 * error must be paid attention to very carefully, as it has been
 363	 * broken since commit efa092f3d4c6 "[XFS] Fixes a bug in the quota
 364	 * code when allocating a new dquot record" in 2005, and the later
 365	 * conversion to xfs_defer_ops in commit 310a75a3c6c747 failed to keep
 366	 * the buffer locked across the _defer_finish call.  We can now do
 367	 * this correctly with xfs_defer_bjoin.
 368	 *
 369	 * Above, we allocated a disk block for the dquot information and used
 370	 * get_buf to initialize the dquot. If the _defer_finish fails, the old
 371	 * transaction is gone but the new buffer is not joined or held to any
 372	 * transaction, so we must _buf_relse it.
 373	 *
 374	 * If everything succeeds, the caller of this function is returned a
 375	 * buffer that is locked and held to the transaction.  The caller
 376	 * is responsible for unlocking any buffer passed back, either
 377	 * manually or by committing the transaction.  On error, the buffer is
 378	 * released and not passed back.
 379	 *
 380	 * Keep the quota inode ILOCKed until after the transaction commit to
 381	 * maintain the atomicity of bmap/rmap updates.
 382	 */
 383	xfs_trans_bhold(tp, bp);
 384	error = xfs_trans_commit(tp);
 385	xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 386	if (error) {
 387		xfs_buf_relse(bp);
 388		return error;
 389	}
 390
 391	*bpp = bp;
 392	return 0;
 393
 394err_cancel:
 395	xfs_trans_cancel(tp);
 396	xfs_iunlock(quotip, XFS_ILOCK_EXCL);
 397	return error;
 398}
 399
 400/*
 401 * Read in the in-core dquot's on-disk metadata and return the buffer.
 402 * Returns ENOENT to signal a hole.
 403 */
 404STATIC int
 405xfs_dquot_disk_read(
 406	struct xfs_mount	*mp,
 407	struct xfs_dquot	*dqp,
 408	struct xfs_buf		**bpp)
 409{
 410	struct xfs_bmbt_irec	map;
 411	struct xfs_buf		*bp;
 412	xfs_dqtype_t		qtype = xfs_dquot_type(dqp);
 413	struct xfs_inode	*quotip = xfs_quota_inode(mp, qtype);
 414	uint			lock_mode;
 415	int			nmaps = 1;
 416	int			error;
 417
 418	lock_mode = xfs_ilock_data_map_shared(quotip);
 419	if (!xfs_this_quota_on(mp, qtype)) {
 420		/*
 421		 * Return if this type of quotas is turned off while we
 422		 * didn't have the quota inode lock.
 423		 */
 424		xfs_iunlock(quotip, lock_mode);
 425		return -ESRCH;
 426	}
 427
 428	/*
 429	 * Find the block map; no allocations yet
 430	 */
 431	error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
 432			XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
 433	xfs_iunlock(quotip, lock_mode);
 434	if (error)
 435		return error;
 436
 437	ASSERT(nmaps == 1);
 438	ASSERT(map.br_blockcount >= 1);
 439	ASSERT(map.br_startblock != DELAYSTARTBLOCK);
 440	if (map.br_startblock == HOLESTARTBLOCK)
 441		return -ENOENT;
 442
 443	trace_xfs_dqtobp_read(dqp);
 444
 445	/*
 446	 * store the blkno etc so that we don't have to do the
 447	 * mapping all the time
 448	 */
 449	dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
 450
 451	error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
 452			mp->m_quotainfo->qi_dqchunklen, 0, &bp,
 453			&xfs_dquot_buf_ops);
 454	if (error) {
 455		ASSERT(bp == NULL);
 456		return error;
 457	}
 458
 459	ASSERT(xfs_buf_islocked(bp));
 460	xfs_buf_set_ref(bp, XFS_DQUOT_REF);
 461	*bpp = bp;
 462
 463	return 0;
 464}
 465
 466/* Allocate and initialize everything we need for an incore dquot. */
 467STATIC struct xfs_dquot *
 468xfs_dquot_alloc(
 469	struct xfs_mount	*mp,
 470	xfs_dqid_t		id,
 471	xfs_dqtype_t		type)
 472{
 473	struct xfs_dquot	*dqp;
 474
 475	dqp = kmem_cache_zalloc(xfs_dquot_cache, GFP_KERNEL | __GFP_NOFAIL);
 476
 477	dqp->q_type = type;
 478	dqp->q_id = id;
 479	dqp->q_mount = mp;
 480	INIT_LIST_HEAD(&dqp->q_lru);
 481	mutex_init(&dqp->q_qlock);
 482	init_waitqueue_head(&dqp->q_pinwait);
 483	dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
 484	/*
 485	 * Offset of dquot in the (fixed sized) dquot chunk.
 486	 */
 487	dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
 488			sizeof(struct xfs_dqblk);
 489
 490	/*
 491	 * Because we want to use a counting completion, complete
 492	 * the flush completion once to allow a single access to
 493	 * the flush completion without blocking.
 494	 */
 495	init_completion(&dqp->q_flush);
 496	complete(&dqp->q_flush);
 497
 498	/*
 499	 * Make sure group quotas have a different lock class than user
 500	 * quotas.
 501	 */
 502	switch (type) {
 503	case XFS_DQTYPE_USER:
 504		/* uses the default lock class */
 505		break;
 506	case XFS_DQTYPE_GROUP:
 507		lockdep_set_class(&dqp->q_qlock, &xfs_dquot_group_class);
 508		break;
 509	case XFS_DQTYPE_PROJ:
 510		lockdep_set_class(&dqp->q_qlock, &xfs_dquot_project_class);
 511		break;
 512	default:
 513		ASSERT(0);
 514		break;
 515	}
 516
 517	xfs_qm_dquot_logitem_init(dqp);
 518
 519	XFS_STATS_INC(mp, xs_qm_dquot);
 520	return dqp;
 521}
 522
 523/* Check the ondisk dquot's id and type match what the incore dquot expects. */
 524static bool
 525xfs_dquot_check_type(
 526	struct xfs_dquot	*dqp,
 527	struct xfs_disk_dquot	*ddqp)
 528{
 529	uint8_t			ddqp_type;
 530	uint8_t			dqp_type;
 531
 532	ddqp_type = ddqp->d_type & XFS_DQTYPE_REC_MASK;
 533	dqp_type = xfs_dquot_type(dqp);
 534
 535	if (be32_to_cpu(ddqp->d_id) != dqp->q_id)
 536		return false;
 537
 538	/*
 539	 * V5 filesystems always expect an exact type match.  V4 filesystems
 540	 * expect an exact match for user dquots and for non-root group and
 541	 * project dquots.
 542	 */
 543	if (xfs_has_crc(dqp->q_mount) ||
 544	    dqp_type == XFS_DQTYPE_USER || dqp->q_id != 0)
 545		return ddqp_type == dqp_type;
 546
 547	/*
 548	 * V4 filesystems support either group or project quotas, but not both
 549	 * at the same time.  The non-user quota file can be switched between
 550	 * group and project quota uses depending on the mount options, which
 551	 * means that we can encounter the other type when we try to load quota
 552	 * defaults.  Quotacheck will soon reset the entire quota file
 553	 * (including the root dquot) anyway, but don't log scary corruption
 554	 * reports to dmesg.
 555	 */
 556	return ddqp_type == XFS_DQTYPE_GROUP || ddqp_type == XFS_DQTYPE_PROJ;
 557}
 558
 559/* Copy the in-core quota fields in from the on-disk buffer. */
 560STATIC int
 561xfs_dquot_from_disk(
 562	struct xfs_dquot	*dqp,
 563	struct xfs_buf		*bp)
 564{
 565	struct xfs_disk_dquot	*ddqp = bp->b_addr + dqp->q_bufoffset;
 
 566
 567	/*
 568	 * Ensure that we got the type and ID we were looking for.
 569	 * Everything else was checked by the dquot buffer verifier.
 570	 */
 571	if (!xfs_dquot_check_type(dqp, ddqp)) {
 572		xfs_alert_tag(bp->b_mount, XFS_PTAG_VERIFIER_ERROR,
 573			  "Metadata corruption detected at %pS, quota %u",
 574			  __this_address, dqp->q_id);
 575		xfs_alert(bp->b_mount, "Unmount and run xfs_repair");
 576		return -EFSCORRUPTED;
 577	}
 578
 579	/* copy everything from disk dquot to the incore dquot */
 580	dqp->q_type = ddqp->d_type;
 581	dqp->q_blk.hardlimit = be64_to_cpu(ddqp->d_blk_hardlimit);
 582	dqp->q_blk.softlimit = be64_to_cpu(ddqp->d_blk_softlimit);
 583	dqp->q_ino.hardlimit = be64_to_cpu(ddqp->d_ino_hardlimit);
 584	dqp->q_ino.softlimit = be64_to_cpu(ddqp->d_ino_softlimit);
 585	dqp->q_rtb.hardlimit = be64_to_cpu(ddqp->d_rtb_hardlimit);
 586	dqp->q_rtb.softlimit = be64_to_cpu(ddqp->d_rtb_softlimit);
 587
 588	dqp->q_blk.count = be64_to_cpu(ddqp->d_bcount);
 589	dqp->q_ino.count = be64_to_cpu(ddqp->d_icount);
 590	dqp->q_rtb.count = be64_to_cpu(ddqp->d_rtbcount);
 591
 592	dqp->q_blk.timer = xfs_dquot_from_disk_ts(ddqp, ddqp->d_btimer);
 593	dqp->q_ino.timer = xfs_dquot_from_disk_ts(ddqp, ddqp->d_itimer);
 594	dqp->q_rtb.timer = xfs_dquot_from_disk_ts(ddqp, ddqp->d_rtbtimer);
 595
 596	/*
 597	 * Reservation counters are defined as reservation plus current usage
 598	 * to avoid having to add every time.
 599	 */
 600	dqp->q_blk.reserved = dqp->q_blk.count;
 601	dqp->q_ino.reserved = dqp->q_ino.count;
 602	dqp->q_rtb.reserved = dqp->q_rtb.count;
 603
 604	/* initialize the dquot speculative prealloc thresholds */
 605	xfs_dquot_set_prealloc_limits(dqp);
 606	return 0;
 607}
 608
 609/* Copy the in-core quota fields into the on-disk buffer. */
 610void
 611xfs_dquot_to_disk(
 612	struct xfs_disk_dquot	*ddqp,
 613	struct xfs_dquot	*dqp)
 614{
 615	ddqp->d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 616	ddqp->d_version = XFS_DQUOT_VERSION;
 617	ddqp->d_type = dqp->q_type;
 618	ddqp->d_id = cpu_to_be32(dqp->q_id);
 619	ddqp->d_pad0 = 0;
 620	ddqp->d_pad = 0;
 621
 622	ddqp->d_blk_hardlimit = cpu_to_be64(dqp->q_blk.hardlimit);
 623	ddqp->d_blk_softlimit = cpu_to_be64(dqp->q_blk.softlimit);
 624	ddqp->d_ino_hardlimit = cpu_to_be64(dqp->q_ino.hardlimit);
 625	ddqp->d_ino_softlimit = cpu_to_be64(dqp->q_ino.softlimit);
 626	ddqp->d_rtb_hardlimit = cpu_to_be64(dqp->q_rtb.hardlimit);
 627	ddqp->d_rtb_softlimit = cpu_to_be64(dqp->q_rtb.softlimit);
 628
 629	ddqp->d_bcount = cpu_to_be64(dqp->q_blk.count);
 630	ddqp->d_icount = cpu_to_be64(dqp->q_ino.count);
 631	ddqp->d_rtbcount = cpu_to_be64(dqp->q_rtb.count);
 632
 633	ddqp->d_bwarns = 0;
 634	ddqp->d_iwarns = 0;
 635	ddqp->d_rtbwarns = 0;
 636
 637	ddqp->d_btimer = xfs_dquot_to_disk_ts(dqp, dqp->q_blk.timer);
 638	ddqp->d_itimer = xfs_dquot_to_disk_ts(dqp, dqp->q_ino.timer);
 639	ddqp->d_rtbtimer = xfs_dquot_to_disk_ts(dqp, dqp->q_rtb.timer);
 640}
 641
 642/*
 643 * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
 644 * and release the buffer immediately.  If @can_alloc is true, fill any
 645 * holes in the on-disk metadata.
 646 */
 647static int
 648xfs_qm_dqread(
 649	struct xfs_mount	*mp,
 650	xfs_dqid_t		id,
 651	xfs_dqtype_t		type,
 652	bool			can_alloc,
 653	struct xfs_dquot	**dqpp)
 654{
 655	struct xfs_dquot	*dqp;
 656	struct xfs_buf		*bp;
 657	int			error;
 658
 659	dqp = xfs_dquot_alloc(mp, id, type);
 660	trace_xfs_dqread(dqp);
 661
 662	/* Try to read the buffer, allocating if necessary. */
 663	error = xfs_dquot_disk_read(mp, dqp, &bp);
 664	if (error == -ENOENT && can_alloc)
 665		error = xfs_dquot_disk_alloc(dqp, &bp);
 666	if (error)
 667		goto err;
 668
 669	/*
 670	 * At this point we should have a clean locked buffer.  Copy the data
 671	 * to the incore dquot and release the buffer since the incore dquot
 672	 * has its own locking protocol so we needn't tie up the buffer any
 673	 * further.
 674	 */
 675	ASSERT(xfs_buf_islocked(bp));
 676	error = xfs_dquot_from_disk(dqp, bp);
 677	xfs_buf_relse(bp);
 678	if (error)
 679		goto err;
 680
 681	*dqpp = dqp;
 682	return error;
 683
 684err:
 685	trace_xfs_dqread_fail(dqp);
 686	xfs_qm_dqdestroy(dqp);
 687	*dqpp = NULL;
 688	return error;
 689}
 690
 691/*
 692 * Advance to the next id in the current chunk, or if at the
 693 * end of the chunk, skip ahead to first id in next allocated chunk
 694 * using the SEEK_DATA interface.
 695 */
 696static int
 697xfs_dq_get_next_id(
 698	struct xfs_mount	*mp,
 699	xfs_dqtype_t		type,
 700	xfs_dqid_t		*id)
 701{
 702	struct xfs_inode	*quotip = xfs_quota_inode(mp, type);
 703	xfs_dqid_t		next_id = *id + 1; /* simple advance */
 704	uint			lock_flags;
 705	struct xfs_bmbt_irec	got;
 706	struct xfs_iext_cursor	cur;
 707	xfs_fsblock_t		start;
 708	int			error = 0;
 709
 710	/* If we'd wrap past the max ID, stop */
 711	if (next_id < *id)
 712		return -ENOENT;
 713
 714	/* If new ID is within the current chunk, advancing it sufficed */
 715	if (next_id % mp->m_quotainfo->qi_dqperchunk) {
 716		*id = next_id;
 717		return 0;
 718	}
 719
 720	/* Nope, next_id is now past the current chunk, so find the next one */
 721	start = (xfs_fsblock_t)next_id / mp->m_quotainfo->qi_dqperchunk;
 722
 723	lock_flags = xfs_ilock_data_map_shared(quotip);
 724	error = xfs_iread_extents(NULL, quotip, XFS_DATA_FORK);
 725	if (error)
 726		return error;
 727
 728	if (xfs_iext_lookup_extent(quotip, &quotip->i_df, start, &cur, &got)) {
 729		/* contiguous chunk, bump startoff for the id calculation */
 730		if (got.br_startoff < start)
 731			got.br_startoff = start;
 732		*id = got.br_startoff * mp->m_quotainfo->qi_dqperchunk;
 733	} else {
 734		error = -ENOENT;
 735	}
 736
 737	xfs_iunlock(quotip, lock_flags);
 738
 739	return error;
 740}
 741
 742/*
 743 * Look up the dquot in the in-core cache.  If found, the dquot is returned
 744 * locked and ready to go.
 745 */
 746static struct xfs_dquot *
 747xfs_qm_dqget_cache_lookup(
 748	struct xfs_mount	*mp,
 749	struct xfs_quotainfo	*qi,
 750	struct radix_tree_root	*tree,
 751	xfs_dqid_t		id)
 752{
 753	struct xfs_dquot	*dqp;
 754
 755restart:
 756	mutex_lock(&qi->qi_tree_lock);
 757	dqp = radix_tree_lookup(tree, id);
 758	if (!dqp) {
 759		mutex_unlock(&qi->qi_tree_lock);
 760		XFS_STATS_INC(mp, xs_qm_dqcachemisses);
 761		return NULL;
 762	}
 763
 764	xfs_dqlock(dqp);
 765	if (dqp->q_flags & XFS_DQFLAG_FREEING) {
 766		xfs_dqunlock(dqp);
 767		mutex_unlock(&qi->qi_tree_lock);
 768		trace_xfs_dqget_freeing(dqp);
 769		delay(1);
 770		goto restart;
 771	}
 772
 773	dqp->q_nrefs++;
 774	mutex_unlock(&qi->qi_tree_lock);
 775
 776	trace_xfs_dqget_hit(dqp);
 777	XFS_STATS_INC(mp, xs_qm_dqcachehits);
 778	return dqp;
 779}
 780
 781/*
 782 * Try to insert a new dquot into the in-core cache.  If an error occurs the
 783 * caller should throw away the dquot and start over.  Otherwise, the dquot
 784 * is returned locked (and held by the cache) as if there had been a cache
 785 * hit.
 786 */
 787static int
 788xfs_qm_dqget_cache_insert(
 789	struct xfs_mount	*mp,
 790	struct xfs_quotainfo	*qi,
 791	struct radix_tree_root	*tree,
 792	xfs_dqid_t		id,
 793	struct xfs_dquot	*dqp)
 794{
 795	int			error;
 796
 797	mutex_lock(&qi->qi_tree_lock);
 798	error = radix_tree_insert(tree, id, dqp);
 799	if (unlikely(error)) {
 800		/* Duplicate found!  Caller must try again. */
 801		WARN_ON(error != -EEXIST);
 802		mutex_unlock(&qi->qi_tree_lock);
 803		trace_xfs_dqget_dup(dqp);
 804		return error;
 805	}
 806
 807	/* Return a locked dquot to the caller, with a reference taken. */
 808	xfs_dqlock(dqp);
 809	dqp->q_nrefs = 1;
 810
 811	qi->qi_dquots++;
 812	mutex_unlock(&qi->qi_tree_lock);
 813
 814	return 0;
 815}
 816
 817/* Check our input parameters. */
 818static int
 819xfs_qm_dqget_checks(
 820	struct xfs_mount	*mp,
 821	xfs_dqtype_t		type)
 822{
 823	switch (type) {
 824	case XFS_DQTYPE_USER:
 825		if (!XFS_IS_UQUOTA_ON(mp))
 826			return -ESRCH;
 827		return 0;
 828	case XFS_DQTYPE_GROUP:
 829		if (!XFS_IS_GQUOTA_ON(mp))
 830			return -ESRCH;
 831		return 0;
 832	case XFS_DQTYPE_PROJ:
 833		if (!XFS_IS_PQUOTA_ON(mp))
 834			return -ESRCH;
 835		return 0;
 836	default:
 837		WARN_ON_ONCE(0);
 838		return -EINVAL;
 839	}
 840}
 841
 842/*
 843 * Given the file system, id, and type (UDQUOT/GDQUOT/PDQUOT), return a
 844 * locked dquot, doing an allocation (if requested) as needed.
 845 */
 846int
 847xfs_qm_dqget(
 848	struct xfs_mount	*mp,
 849	xfs_dqid_t		id,
 850	xfs_dqtype_t		type,
 851	bool			can_alloc,
 852	struct xfs_dquot	**O_dqpp)
 853{
 854	struct xfs_quotainfo	*qi = mp->m_quotainfo;
 855	struct radix_tree_root	*tree = xfs_dquot_tree(qi, type);
 856	struct xfs_dquot	*dqp;
 857	int			error;
 858
 859	error = xfs_qm_dqget_checks(mp, type);
 860	if (error)
 861		return error;
 862
 863restart:
 864	dqp = xfs_qm_dqget_cache_lookup(mp, qi, tree, id);
 865	if (dqp) {
 866		*O_dqpp = dqp;
 867		return 0;
 868	}
 869
 870	error = xfs_qm_dqread(mp, id, type, can_alloc, &dqp);
 871	if (error)
 872		return error;
 873
 874	error = xfs_qm_dqget_cache_insert(mp, qi, tree, id, dqp);
 875	if (error) {
 876		/*
 877		 * Duplicate found. Just throw away the new dquot and start
 878		 * over.
 879		 */
 880		xfs_qm_dqdestroy(dqp);
 881		XFS_STATS_INC(mp, xs_qm_dquot_dups);
 882		goto restart;
 883	}
 884
 885	trace_xfs_dqget_miss(dqp);
 886	*O_dqpp = dqp;
 887	return 0;
 888}
 889
 890/*
 891 * Given a dquot id and type, read and initialize a dquot from the on-disk
 892 * metadata.  This function is only for use during quota initialization so
 893 * it ignores the dquot cache assuming that the dquot shrinker isn't set up.
 894 * The caller is responsible for _qm_dqdestroy'ing the returned dquot.
 895 */
 896int
 897xfs_qm_dqget_uncached(
 898	struct xfs_mount	*mp,
 899	xfs_dqid_t		id,
 900	xfs_dqtype_t		type,
 901	struct xfs_dquot	**dqpp)
 902{
 903	int			error;
 904
 905	error = xfs_qm_dqget_checks(mp, type);
 906	if (error)
 907		return error;
 908
 909	return xfs_qm_dqread(mp, id, type, 0, dqpp);
 910}
 911
 912/* Return the quota id for a given inode and type. */
 913xfs_dqid_t
 914xfs_qm_id_for_quotatype(
 915	struct xfs_inode	*ip,
 916	xfs_dqtype_t		type)
 917{
 918	switch (type) {
 919	case XFS_DQTYPE_USER:
 920		return i_uid_read(VFS_I(ip));
 921	case XFS_DQTYPE_GROUP:
 922		return i_gid_read(VFS_I(ip));
 923	case XFS_DQTYPE_PROJ:
 924		return ip->i_projid;
 925	}
 926	ASSERT(0);
 927	return 0;
 928}
 929
 930/*
 931 * Return the dquot for a given inode and type.  If @can_alloc is true, then
 932 * allocate blocks if needed.  The inode's ILOCK must be held and it must not
 933 * have already had an inode attached.
 934 */
 935int
 936xfs_qm_dqget_inode(
 937	struct xfs_inode	*ip,
 938	xfs_dqtype_t		type,
 939	bool			can_alloc,
 940	struct xfs_dquot	**O_dqpp)
 941{
 942	struct xfs_mount	*mp = ip->i_mount;
 943	struct xfs_quotainfo	*qi = mp->m_quotainfo;
 944	struct radix_tree_root	*tree = xfs_dquot_tree(qi, type);
 945	struct xfs_dquot	*dqp;
 946	xfs_dqid_t		id;
 947	int			error;
 948
 949	error = xfs_qm_dqget_checks(mp, type);
 950	if (error)
 951		return error;
 952
 953	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 954	ASSERT(xfs_inode_dquot(ip, type) == NULL);
 955
 956	id = xfs_qm_id_for_quotatype(ip, type);
 957
 958restart:
 959	dqp = xfs_qm_dqget_cache_lookup(mp, qi, tree, id);
 960	if (dqp) {
 961		*O_dqpp = dqp;
 962		return 0;
 963	}
 964
 965	/*
 966	 * Dquot cache miss. We don't want to keep the inode lock across
 967	 * a (potential) disk read. Also we don't want to deal with the lock
 968	 * ordering between quotainode and this inode. OTOH, dropping the inode
 969	 * lock here means dealing with a chown that can happen before
 970	 * we re-acquire the lock.
 971	 */
 972	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 973	error = xfs_qm_dqread(mp, id, type, can_alloc, &dqp);
 974	xfs_ilock(ip, XFS_ILOCK_EXCL);
 975	if (error)
 976		return error;
 977
 978	/*
 979	 * A dquot could be attached to this inode by now, since we had
 980	 * dropped the ilock.
 981	 */
 982	if (xfs_this_quota_on(mp, type)) {
 983		struct xfs_dquot	*dqp1;
 984
 985		dqp1 = xfs_inode_dquot(ip, type);
 986		if (dqp1) {
 987			xfs_qm_dqdestroy(dqp);
 988			dqp = dqp1;
 989			xfs_dqlock(dqp);
 990			goto dqret;
 991		}
 992	} else {
 993		/* inode stays locked on return */
 994		xfs_qm_dqdestroy(dqp);
 995		return -ESRCH;
 996	}
 997
 998	error = xfs_qm_dqget_cache_insert(mp, qi, tree, id, dqp);
 999	if (error) {
1000		/*
1001		 * Duplicate found. Just throw away the new dquot and start
1002		 * over.
1003		 */
1004		xfs_qm_dqdestroy(dqp);
1005		XFS_STATS_INC(mp, xs_qm_dquot_dups);
1006		goto restart;
1007	}
1008
1009dqret:
1010	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
1011	trace_xfs_dqget_miss(dqp);
1012	*O_dqpp = dqp;
1013	return 0;
1014}
1015
1016/*
1017 * Starting at @id and progressing upwards, look for an initialized incore
1018 * dquot, lock it, and return it.
1019 */
1020int
1021xfs_qm_dqget_next(
1022	struct xfs_mount	*mp,
1023	xfs_dqid_t		id,
1024	xfs_dqtype_t		type,
1025	struct xfs_dquot	**dqpp)
1026{
1027	struct xfs_dquot	*dqp;
1028	int			error = 0;
1029
1030	*dqpp = NULL;
1031	for (; !error; error = xfs_dq_get_next_id(mp, type, &id)) {
1032		error = xfs_qm_dqget(mp, id, type, false, &dqp);
1033		if (error == -ENOENT)
1034			continue;
1035		else if (error != 0)
1036			break;
1037
1038		if (!XFS_IS_DQUOT_UNINITIALIZED(dqp)) {
1039			*dqpp = dqp;
1040			return 0;
1041		}
1042
1043		xfs_qm_dqput(dqp);
1044	}
1045
1046	return error;
1047}
1048
1049/*
1050 * Release a reference to the dquot (decrement ref-count) and unlock it.
1051 *
1052 * If there is a group quota attached to this dquot, carefully release that
1053 * too without tripping over deadlocks'n'stuff.
1054 */
1055void
1056xfs_qm_dqput(
1057	struct xfs_dquot	*dqp)
1058{
1059	ASSERT(dqp->q_nrefs > 0);
1060	ASSERT(XFS_DQ_IS_LOCKED(dqp));
1061
1062	trace_xfs_dqput(dqp);
1063
1064	if (--dqp->q_nrefs == 0) {
1065		struct xfs_quotainfo	*qi = dqp->q_mount->m_quotainfo;
1066		trace_xfs_dqput_free(dqp);
1067
1068		if (list_lru_add(&qi->qi_lru, &dqp->q_lru))
1069			XFS_STATS_INC(dqp->q_mount, xs_qm_dquot_unused);
1070	}
1071	xfs_dqunlock(dqp);
1072}
1073
1074/*
1075 * Release a dquot. Flush it if dirty, then dqput() it.
1076 * dquot must not be locked.
1077 */
1078void
1079xfs_qm_dqrele(
1080	struct xfs_dquot	*dqp)
1081{
1082	if (!dqp)
1083		return;
1084
1085	trace_xfs_dqrele(dqp);
1086
1087	xfs_dqlock(dqp);
1088	/*
1089	 * We don't care to flush it if the dquot is dirty here.
1090	 * That will create stutters that we want to avoid.
1091	 * Instead we do a delayed write when we try to reclaim
1092	 * a dirty dquot. Also xfs_sync will take part of the burden...
1093	 */
1094	xfs_qm_dqput(dqp);
1095}
1096
1097/*
1098 * This is the dquot flushing I/O completion routine.  It is called
1099 * from interrupt level when the buffer containing the dquot is
1100 * flushed to disk.  It is responsible for removing the dquot logitem
1101 * from the AIL if it has not been re-logged, and unlocking the dquot's
1102 * flush lock. This behavior is very similar to that of inodes..
1103 */
1104static void
1105xfs_qm_dqflush_done(
1106	struct xfs_log_item	*lip)
1107{
1108	struct xfs_dq_logitem	*qip = (struct xfs_dq_logitem *)lip;
1109	struct xfs_dquot	*dqp = qip->qli_dquot;
1110	struct xfs_ail		*ailp = lip->li_ailp;
1111	xfs_lsn_t		tail_lsn;
1112
1113	/*
1114	 * We only want to pull the item from the AIL if its
1115	 * location in the log has not changed since we started the flush.
1116	 * Thus, we only bother if the dquot's lsn has
1117	 * not changed. First we check the lsn outside the lock
1118	 * since it's cheaper, and then we recheck while
1119	 * holding the lock before removing the dquot from the AIL.
1120	 */
1121	if (test_bit(XFS_LI_IN_AIL, &lip->li_flags) &&
1122	    ((lip->li_lsn == qip->qli_flush_lsn) ||
1123	     test_bit(XFS_LI_FAILED, &lip->li_flags))) {
1124
1125		spin_lock(&ailp->ail_lock);
1126		xfs_clear_li_failed(lip);
1127		if (lip->li_lsn == qip->qli_flush_lsn) {
1128			/* xfs_ail_update_finish() drops the AIL lock */
1129			tail_lsn = xfs_ail_delete_one(ailp, lip);
1130			xfs_ail_update_finish(ailp, tail_lsn);
1131		} else {
1132			spin_unlock(&ailp->ail_lock);
1133		}
1134	}
1135
1136	/*
1137	 * Release the dq's flush lock since we're done with it.
1138	 */
1139	xfs_dqfunlock(dqp);
1140}
1141
1142void
1143xfs_buf_dquot_iodone(
1144	struct xfs_buf		*bp)
1145{
1146	struct xfs_log_item	*lip, *n;
1147
1148	list_for_each_entry_safe(lip, n, &bp->b_li_list, li_bio_list) {
1149		list_del_init(&lip->li_bio_list);
1150		xfs_qm_dqflush_done(lip);
1151	}
1152}
1153
1154void
1155xfs_buf_dquot_io_fail(
1156	struct xfs_buf		*bp)
1157{
1158	struct xfs_log_item	*lip;
1159
1160	spin_lock(&bp->b_mount->m_ail->ail_lock);
1161	list_for_each_entry(lip, &bp->b_li_list, li_bio_list)
1162		xfs_set_li_failed(lip, bp);
1163	spin_unlock(&bp->b_mount->m_ail->ail_lock);
1164}
1165
1166/* Check incore dquot for errors before we flush. */
1167static xfs_failaddr_t
1168xfs_qm_dqflush_check(
1169	struct xfs_dquot	*dqp)
1170{
1171	xfs_dqtype_t		type = xfs_dquot_type(dqp);
1172
1173	if (type != XFS_DQTYPE_USER &&
1174	    type != XFS_DQTYPE_GROUP &&
1175	    type != XFS_DQTYPE_PROJ)
1176		return __this_address;
1177
1178	if (dqp->q_id == 0)
1179		return NULL;
1180
1181	if (dqp->q_blk.softlimit && dqp->q_blk.count > dqp->q_blk.softlimit &&
1182	    !dqp->q_blk.timer)
1183		return __this_address;
1184
1185	if (dqp->q_ino.softlimit && dqp->q_ino.count > dqp->q_ino.softlimit &&
1186	    !dqp->q_ino.timer)
1187		return __this_address;
1188
1189	if (dqp->q_rtb.softlimit && dqp->q_rtb.count > dqp->q_rtb.softlimit &&
1190	    !dqp->q_rtb.timer)
1191		return __this_address;
1192
1193	/* bigtime flag should never be set on root dquots */
1194	if (dqp->q_type & XFS_DQTYPE_BIGTIME) {
1195		if (!xfs_has_bigtime(dqp->q_mount))
1196			return __this_address;
1197		if (dqp->q_id == 0)
1198			return __this_address;
1199	}
1200
1201	return NULL;
1202}
1203
1204/*
1205 * Write a modified dquot to disk.
1206 * The dquot must be locked and the flush lock too taken by caller.
1207 * The flush lock will not be unlocked until the dquot reaches the disk,
1208 * but the dquot is free to be unlocked and modified by the caller
1209 * in the interim. Dquot is still locked on return. This behavior is
1210 * identical to that of inodes.
1211 */
1212int
1213xfs_qm_dqflush(
1214	struct xfs_dquot	*dqp,
1215	struct xfs_buf		**bpp)
1216{
1217	struct xfs_mount	*mp = dqp->q_mount;
1218	struct xfs_log_item	*lip = &dqp->q_logitem.qli_item;
1219	struct xfs_buf		*bp;
1220	struct xfs_dqblk	*dqblk;
1221	xfs_failaddr_t		fa;
1222	int			error;
1223
1224	ASSERT(XFS_DQ_IS_LOCKED(dqp));
1225	ASSERT(!completion_done(&dqp->q_flush));
1226
1227	trace_xfs_dqflush(dqp);
1228
1229	*bpp = NULL;
1230
1231	xfs_qm_dqunpin_wait(dqp);
1232
1233	/*
1234	 * Get the buffer containing the on-disk dquot
1235	 */
1236	error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1237				   mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK,
1238				   &bp, &xfs_dquot_buf_ops);
1239	if (error == -EAGAIN)
1240		goto out_unlock;
1241	if (error)
1242		goto out_abort;
1243
1244	fa = xfs_qm_dqflush_check(dqp);
1245	if (fa) {
1246		xfs_alert(mp, "corrupt dquot ID 0x%x in memory at %pS",
1247				dqp->q_id, fa);
1248		xfs_buf_relse(bp);
1249		error = -EFSCORRUPTED;
1250		goto out_abort;
1251	}
1252
1253	/* Flush the incore dquot to the ondisk buffer. */
1254	dqblk = bp->b_addr + dqp->q_bufoffset;
1255	xfs_dquot_to_disk(&dqblk->dd_diskdq, dqp);
1256
1257	/*
1258	 * Clear the dirty field and remember the flush lsn for later use.
1259	 */
1260	dqp->q_flags &= ~XFS_DQFLAG_DIRTY;
1261
1262	xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1263					&dqp->q_logitem.qli_item.li_lsn);
1264
1265	/*
1266	 * copy the lsn into the on-disk dquot now while we have the in memory
1267	 * dquot here. This can't be done later in the write verifier as we
1268	 * can't get access to the log item at that point in time.
1269	 *
1270	 * We also calculate the CRC here so that the on-disk dquot in the
1271	 * buffer always has a valid CRC. This ensures there is no possibility
1272	 * of a dquot without an up-to-date CRC getting to disk.
1273	 */
1274	if (xfs_has_crc(mp)) {
1275		dqblk->dd_lsn = cpu_to_be64(dqp->q_logitem.qli_item.li_lsn);
1276		xfs_update_cksum((char *)dqblk, sizeof(struct xfs_dqblk),
1277				 XFS_DQUOT_CRC_OFF);
1278	}
1279
1280	/*
1281	 * Attach the dquot to the buffer so that we can remove this dquot from
1282	 * the AIL and release the flush lock once the dquot is synced to disk.
1283	 */
1284	bp->b_flags |= _XBF_DQUOTS;
1285	list_add_tail(&dqp->q_logitem.qli_item.li_bio_list, &bp->b_li_list);
1286
1287	/*
1288	 * If the buffer is pinned then push on the log so we won't
1289	 * get stuck waiting in the write for too long.
1290	 */
1291	if (xfs_buf_ispinned(bp)) {
1292		trace_xfs_dqflush_force(dqp);
1293		xfs_log_force(mp, 0);
1294	}
1295
1296	trace_xfs_dqflush_done(dqp);
1297	*bpp = bp;
1298	return 0;
1299
1300out_abort:
1301	dqp->q_flags &= ~XFS_DQFLAG_DIRTY;
1302	xfs_trans_ail_delete(lip, 0);
1303	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1304out_unlock:
1305	xfs_dqfunlock(dqp);
1306	return error;
1307}
1308
1309/*
1310 * Lock two xfs_dquot structures.
1311 *
1312 * To avoid deadlocks we always lock the quota structure with
1313 * the lowerd id first.
1314 */
1315void
1316xfs_dqlock2(
1317	struct xfs_dquot	*d1,
1318	struct xfs_dquot	*d2)
1319{
1320	if (d1 && d2) {
1321		ASSERT(d1 != d2);
1322		if (d1->q_id > d2->q_id) {
1323			mutex_lock(&d2->q_qlock);
1324			mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1325		} else {
1326			mutex_lock(&d1->q_qlock);
1327			mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1328		}
1329	} else if (d1) {
1330		mutex_lock(&d1->q_qlock);
1331	} else if (d2) {
1332		mutex_lock(&d2->q_qlock);
1333	}
1334}
1335
1336int __init
1337xfs_qm_init(void)
1338{
1339	xfs_dquot_cache = kmem_cache_create("xfs_dquot",
1340					  sizeof(struct xfs_dquot),
1341					  0, 0, NULL);
1342	if (!xfs_dquot_cache)
1343		goto out;
1344
1345	xfs_dqtrx_cache = kmem_cache_create("xfs_dqtrx",
1346					     sizeof(struct xfs_dquot_acct),
1347					     0, 0, NULL);
1348	if (!xfs_dqtrx_cache)
1349		goto out_free_dquot_cache;
1350
1351	return 0;
1352
1353out_free_dquot_cache:
1354	kmem_cache_destroy(xfs_dquot_cache);
1355out:
1356	return -ENOMEM;
1357}
1358
1359void
1360xfs_qm_exit(void)
1361{
1362	kmem_cache_destroy(xfs_dqtrx_cache);
1363	kmem_cache_destroy(xfs_dquot_cache);
1364}
1365
1366/*
1367 * Iterate every dquot of a particular type.  The caller must ensure that the
1368 * particular quota type is active.  iter_fn can return negative error codes,
1369 * or -ECANCELED to indicate that it wants to stop iterating.
1370 */
1371int
1372xfs_qm_dqiterate(
1373	struct xfs_mount	*mp,
1374	xfs_dqtype_t		type,
1375	xfs_qm_dqiterate_fn	iter_fn,
1376	void			*priv)
1377{
1378	struct xfs_dquot	*dq;
1379	xfs_dqid_t		id = 0;
1380	int			error;
1381
1382	do {
1383		error = xfs_qm_dqget_next(mp, id, type, &dq);
1384		if (error == -ENOENT)
1385			return 0;
1386		if (error)
1387			return error;
1388
1389		error = iter_fn(dq, type, priv);
1390		id = dq->q_id;
1391		xfs_qm_dqput(dq);
1392	} while (error == 0 && id != 0);
1393
1394	return error;
1395}