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1/*
2 * Copyright (c) 2000-2003 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_bit.h"
21#include "xfs_log.h"
22#include "xfs_inum.h"
23#include "xfs_trans.h"
24#include "xfs_sb.h"
25#include "xfs_ag.h"
26#include "xfs_alloc.h"
27#include "xfs_quota.h"
28#include "xfs_mount.h"
29#include "xfs_bmap_btree.h"
30#include "xfs_inode.h"
31#include "xfs_bmap.h"
32#include "xfs_rtalloc.h"
33#include "xfs_error.h"
34#include "xfs_itable.h"
35#include "xfs_attr.h"
36#include "xfs_buf_item.h"
37#include "xfs_trans_space.h"
38#include "xfs_trans_priv.h"
39#include "xfs_qm.h"
40#include "xfs_trace.h"
41
42
43/*
44   LOCK ORDER
45
46   inode lock		    (ilock)
47   dquot hash-chain lock    (hashlock)
48   xqm dquot freelist lock  (freelistlock
49   mount's dquot list lock  (mplistlock)
50   user dquot lock - lock ordering among dquots is based on the uid or gid
51   group dquot lock - similar to udquots. Between the two dquots, the udquot
52		      has to be locked first.
53   pin lock - the dquot lock must be held to take this lock.
54   flush lock - ditto.
55*/
56
57#ifdef DEBUG
58xfs_buftarg_t *xfs_dqerror_target;
59int xfs_do_dqerror;
60int xfs_dqreq_num;
61int xfs_dqerror_mod = 33;
62#endif
63
64static struct lock_class_key xfs_dquot_other_class;
65
66/*
67 * Allocate and initialize a dquot. We don't always allocate fresh memory;
68 * we try to reclaim a free dquot if the number of incore dquots are above
69 * a threshold.
70 * The only field inside the core that gets initialized at this point
71 * is the d_id field. The idea is to fill in the entire q_core
72 * when we read in the on disk dquot.
73 */
74STATIC xfs_dquot_t *
75xfs_qm_dqinit(
76	xfs_mount_t  *mp,
77	xfs_dqid_t   id,
78	uint	     type)
79{
80	xfs_dquot_t	*dqp;
81	boolean_t	brandnewdquot;
82
83	brandnewdquot = xfs_qm_dqalloc_incore(&dqp);
84	dqp->dq_flags = type;
85	dqp->q_core.d_id = cpu_to_be32(id);
86	dqp->q_mount = mp;
87
88	/*
89	 * No need to re-initialize these if this is a reclaimed dquot.
90	 */
91	if (brandnewdquot) {
92		INIT_LIST_HEAD(&dqp->q_freelist);
93		mutex_init(&dqp->q_qlock);
94		init_waitqueue_head(&dqp->q_pinwait);
95
96		/*
97		 * Because we want to use a counting completion, complete
98		 * the flush completion once to allow a single access to
99		 * the flush completion without blocking.
100		 */
101		init_completion(&dqp->q_flush);
102		complete(&dqp->q_flush);
103
104		trace_xfs_dqinit(dqp);
105	} else {
106		/*
107		 * Only the q_core portion was zeroed in dqreclaim_one().
108		 * So, we need to reset others.
109		 */
110		dqp->q_nrefs = 0;
111		dqp->q_blkno = 0;
112		INIT_LIST_HEAD(&dqp->q_mplist);
113		INIT_LIST_HEAD(&dqp->q_hashlist);
114		dqp->q_bufoffset = 0;
115		dqp->q_fileoffset = 0;
116		dqp->q_transp = NULL;
117		dqp->q_gdquot = NULL;
118		dqp->q_res_bcount = 0;
119		dqp->q_res_icount = 0;
120		dqp->q_res_rtbcount = 0;
121		atomic_set(&dqp->q_pincount, 0);
122		dqp->q_hash = NULL;
123		ASSERT(list_empty(&dqp->q_freelist));
124
125		trace_xfs_dqreuse(dqp);
126	}
127
128	/*
129	 * In either case we need to make sure group quotas have a different
130	 * lock class than user quotas, to make sure lockdep knows we can
131	 * locks of one of each at the same time.
132	 */
133	if (!(type & XFS_DQ_USER))
134		lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
135
136	/*
137	 * log item gets initialized later
138	 */
139	return (dqp);
140}
141
142/*
143 * This is called to free all the memory associated with a dquot
144 */
145void
146xfs_qm_dqdestroy(
147	xfs_dquot_t	*dqp)
148{
149	ASSERT(list_empty(&dqp->q_freelist));
150
151	mutex_destroy(&dqp->q_qlock);
152	sv_destroy(&dqp->q_pinwait);
153	kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
154
155	atomic_dec(&xfs_Gqm->qm_totaldquots);
156}
157
158/*
159 * This is what a 'fresh' dquot inside a dquot chunk looks like on disk.
160 */
161STATIC void
162xfs_qm_dqinit_core(
163	xfs_dqid_t	id,
164	uint		type,
165	xfs_dqblk_t	*d)
166{
167	/*
168	 * Caller has zero'd the entire dquot 'chunk' already.
169	 */
170	d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
171	d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
172	d->dd_diskdq.d_id = cpu_to_be32(id);
173	d->dd_diskdq.d_flags = type;
174}
175
176/*
177 * If default limits are in force, push them into the dquot now.
178 * We overwrite the dquot limits only if they are zero and this
179 * is not the root dquot.
180 */
181void
182xfs_qm_adjust_dqlimits(
183	xfs_mount_t		*mp,
184	xfs_disk_dquot_t	*d)
185{
186	xfs_quotainfo_t		*q = mp->m_quotainfo;
187
188	ASSERT(d->d_id);
189
190	if (q->qi_bsoftlimit && !d->d_blk_softlimit)
191		d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
192	if (q->qi_bhardlimit && !d->d_blk_hardlimit)
193		d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
194	if (q->qi_isoftlimit && !d->d_ino_softlimit)
195		d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
196	if (q->qi_ihardlimit && !d->d_ino_hardlimit)
197		d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
198	if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
199		d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
200	if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
201		d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
202}
203
204/*
205 * Check the limits and timers of a dquot and start or reset timers
206 * if necessary.
207 * This gets called even when quota enforcement is OFF, which makes our
208 * life a little less complicated. (We just don't reject any quota
209 * reservations in that case, when enforcement is off).
210 * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
211 * enforcement's off.
212 * In contrast, warnings are a little different in that they don't
213 * 'automatically' get started when limits get exceeded.  They do
214 * get reset to zero, however, when we find the count to be under
215 * the soft limit (they are only ever set non-zero via userspace).
216 */
217void
218xfs_qm_adjust_dqtimers(
219	xfs_mount_t		*mp,
220	xfs_disk_dquot_t	*d)
221{
222	ASSERT(d->d_id);
223
224#ifdef QUOTADEBUG
225	if (d->d_blk_hardlimit)
226		ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
227		       be64_to_cpu(d->d_blk_hardlimit));
228	if (d->d_ino_hardlimit)
229		ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
230		       be64_to_cpu(d->d_ino_hardlimit));
231	if (d->d_rtb_hardlimit)
232		ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
233		       be64_to_cpu(d->d_rtb_hardlimit));
234#endif
235	if (!d->d_btimer) {
236		if ((d->d_blk_softlimit &&
237		     (be64_to_cpu(d->d_bcount) >=
238		      be64_to_cpu(d->d_blk_softlimit))) ||
239		    (d->d_blk_hardlimit &&
240		     (be64_to_cpu(d->d_bcount) >=
241		      be64_to_cpu(d->d_blk_hardlimit)))) {
242			d->d_btimer = cpu_to_be32(get_seconds() +
243					mp->m_quotainfo->qi_btimelimit);
244		} else {
245			d->d_bwarns = 0;
246		}
247	} else {
248		if ((!d->d_blk_softlimit ||
249		     (be64_to_cpu(d->d_bcount) <
250		      be64_to_cpu(d->d_blk_softlimit))) &&
251		    (!d->d_blk_hardlimit ||
252		    (be64_to_cpu(d->d_bcount) <
253		     be64_to_cpu(d->d_blk_hardlimit)))) {
254			d->d_btimer = 0;
255		}
256	}
257
258	if (!d->d_itimer) {
259		if ((d->d_ino_softlimit &&
260		     (be64_to_cpu(d->d_icount) >=
261		      be64_to_cpu(d->d_ino_softlimit))) ||
262		    (d->d_ino_hardlimit &&
263		     (be64_to_cpu(d->d_icount) >=
264		      be64_to_cpu(d->d_ino_hardlimit)))) {
265			d->d_itimer = cpu_to_be32(get_seconds() +
266					mp->m_quotainfo->qi_itimelimit);
267		} else {
268			d->d_iwarns = 0;
269		}
270	} else {
271		if ((!d->d_ino_softlimit ||
272		     (be64_to_cpu(d->d_icount) <
273		      be64_to_cpu(d->d_ino_softlimit)))  &&
274		    (!d->d_ino_hardlimit ||
275		     (be64_to_cpu(d->d_icount) <
276		      be64_to_cpu(d->d_ino_hardlimit)))) {
277			d->d_itimer = 0;
278		}
279	}
280
281	if (!d->d_rtbtimer) {
282		if ((d->d_rtb_softlimit &&
283		     (be64_to_cpu(d->d_rtbcount) >=
284		      be64_to_cpu(d->d_rtb_softlimit))) ||
285		    (d->d_rtb_hardlimit &&
286		     (be64_to_cpu(d->d_rtbcount) >=
287		      be64_to_cpu(d->d_rtb_hardlimit)))) {
288			d->d_rtbtimer = cpu_to_be32(get_seconds() +
289					mp->m_quotainfo->qi_rtbtimelimit);
290		} else {
291			d->d_rtbwarns = 0;
292		}
293	} else {
294		if ((!d->d_rtb_softlimit ||
295		     (be64_to_cpu(d->d_rtbcount) <
296		      be64_to_cpu(d->d_rtb_softlimit))) &&
297		    (!d->d_rtb_hardlimit ||
298		     (be64_to_cpu(d->d_rtbcount) <
299		      be64_to_cpu(d->d_rtb_hardlimit)))) {
300			d->d_rtbtimer = 0;
301		}
302	}
303}
304
305/*
306 * initialize a buffer full of dquots and log the whole thing
307 */
308STATIC void
309xfs_qm_init_dquot_blk(
310	xfs_trans_t	*tp,
311	xfs_mount_t	*mp,
312	xfs_dqid_t	id,
313	uint		type,
314	xfs_buf_t	*bp)
315{
316	struct xfs_quotainfo	*q = mp->m_quotainfo;
317	xfs_dqblk_t	*d;
318	int		curid, i;
319
320	ASSERT(tp);
321	ASSERT(XFS_BUF_ISBUSY(bp));
322	ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
323
324	d = (xfs_dqblk_t *)XFS_BUF_PTR(bp);
325
326	/*
327	 * ID of the first dquot in the block - id's are zero based.
328	 */
329	curid = id - (id % q->qi_dqperchunk);
330	ASSERT(curid >= 0);
331	memset(d, 0, BBTOB(q->qi_dqchunklen));
332	for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++)
333		xfs_qm_dqinit_core(curid, type, d);
334	xfs_trans_dquot_buf(tp, bp,
335			    (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
336			    ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
337			     XFS_BLF_GDQUOT_BUF)));
338	xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
339}
340
341
342
343/*
344 * Allocate a block and fill it with dquots.
345 * This is called when the bmapi finds a hole.
346 */
347STATIC int
348xfs_qm_dqalloc(
349	xfs_trans_t	**tpp,
350	xfs_mount_t	*mp,
351	xfs_dquot_t	*dqp,
352	xfs_inode_t	*quotip,
353	xfs_fileoff_t	offset_fsb,
354	xfs_buf_t	**O_bpp)
355{
356	xfs_fsblock_t	firstblock;
357	xfs_bmap_free_t flist;
358	xfs_bmbt_irec_t map;
359	int		nmaps, error, committed;
360	xfs_buf_t	*bp;
361	xfs_trans_t	*tp = *tpp;
362
363	ASSERT(tp != NULL);
364
365	trace_xfs_dqalloc(dqp);
366
367	/*
368	 * Initialize the bmap freelist prior to calling bmapi code.
369	 */
370	xfs_bmap_init(&flist, &firstblock);
371	xfs_ilock(quotip, XFS_ILOCK_EXCL);
372	/*
373	 * Return if this type of quotas is turned off while we didn't
374	 * have an inode lock
375	 */
376	if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
377		xfs_iunlock(quotip, XFS_ILOCK_EXCL);
378		return (ESRCH);
379	}
380
381	xfs_trans_ijoin_ref(tp, quotip, XFS_ILOCK_EXCL);
382	nmaps = 1;
383	if ((error = xfs_bmapi(tp, quotip,
384			      offset_fsb, XFS_DQUOT_CLUSTER_SIZE_FSB,
385			      XFS_BMAPI_METADATA | XFS_BMAPI_WRITE,
386			      &firstblock,
387			      XFS_QM_DQALLOC_SPACE_RES(mp),
388			      &map, &nmaps, &flist))) {
389		goto error0;
390	}
391	ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
392	ASSERT(nmaps == 1);
393	ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
394	       (map.br_startblock != HOLESTARTBLOCK));
395
396	/*
397	 * Keep track of the blkno to save a lookup later
398	 */
399	dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
400
401	/* now we can just get the buffer (there's nothing to read yet) */
402	bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
403			       dqp->q_blkno,
404			       mp->m_quotainfo->qi_dqchunklen,
405			       0);
406	if (!bp || (error = XFS_BUF_GETERROR(bp)))
407		goto error1;
408	/*
409	 * Make a chunk of dquots out of this buffer and log
410	 * the entire thing.
411	 */
412	xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
413			      dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
414
415	/*
416	 * xfs_bmap_finish() may commit the current transaction and
417	 * start a second transaction if the freelist is not empty.
418	 *
419	 * Since we still want to modify this buffer, we need to
420	 * ensure that the buffer is not released on commit of
421	 * the first transaction and ensure the buffer is added to the
422	 * second transaction.
423	 *
424	 * If there is only one transaction then don't stop the buffer
425	 * from being released when it commits later on.
426	 */
427
428	xfs_trans_bhold(tp, bp);
429
430	if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
431		goto error1;
432	}
433
434	if (committed) {
435		tp = *tpp;
436		xfs_trans_bjoin(tp, bp);
437	} else {
438		xfs_trans_bhold_release(tp, bp);
439	}
440
441	*O_bpp = bp;
442	return 0;
443
444      error1:
445	xfs_bmap_cancel(&flist);
446      error0:
447	xfs_iunlock(quotip, XFS_ILOCK_EXCL);
448
449	return (error);
450}
451
452/*
453 * Maps a dquot to the buffer containing its on-disk version.
454 * This returns a ptr to the buffer containing the on-disk dquot
455 * in the bpp param, and a ptr to the on-disk dquot within that buffer
456 */
457STATIC int
458xfs_qm_dqtobp(
459	xfs_trans_t		**tpp,
460	xfs_dquot_t		*dqp,
461	xfs_disk_dquot_t	**O_ddpp,
462	xfs_buf_t		**O_bpp,
463	uint			flags)
464{
465	xfs_bmbt_irec_t map;
466	int		nmaps, error;
467	xfs_buf_t	*bp;
468	xfs_inode_t	*quotip;
469	xfs_mount_t	*mp;
470	xfs_disk_dquot_t *ddq;
471	xfs_dqid_t	id;
472	boolean_t	newdquot;
473	xfs_trans_t	*tp = (tpp ? *tpp : NULL);
474
475	mp = dqp->q_mount;
476	id = be32_to_cpu(dqp->q_core.d_id);
477	nmaps = 1;
478	newdquot = B_FALSE;
479
480	/*
481	 * If we don't know where the dquot lives, find out.
482	 */
483	if (dqp->q_blkno == (xfs_daddr_t) 0) {
484		/* We use the id as an index */
485		dqp->q_fileoffset = (xfs_fileoff_t)id /
486					mp->m_quotainfo->qi_dqperchunk;
487		nmaps = 1;
488		quotip = XFS_DQ_TO_QIP(dqp);
489		xfs_ilock(quotip, XFS_ILOCK_SHARED);
490		/*
491		 * Return if this type of quotas is turned off while we didn't
492		 * have an inode lock
493		 */
494		if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
495			xfs_iunlock(quotip, XFS_ILOCK_SHARED);
496			return (ESRCH);
497		}
498		/*
499		 * Find the block map; no allocations yet
500		 */
501		error = xfs_bmapi(NULL, quotip, dqp->q_fileoffset,
502				  XFS_DQUOT_CLUSTER_SIZE_FSB,
503				  XFS_BMAPI_METADATA,
504				  NULL, 0, &map, &nmaps, NULL);
505
506		xfs_iunlock(quotip, XFS_ILOCK_SHARED);
507		if (error)
508			return (error);
509		ASSERT(nmaps == 1);
510		ASSERT(map.br_blockcount == 1);
511
512		/*
513		 * offset of dquot in the (fixed sized) dquot chunk.
514		 */
515		dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
516			sizeof(xfs_dqblk_t);
517		if (map.br_startblock == HOLESTARTBLOCK) {
518			/*
519			 * We don't allocate unless we're asked to
520			 */
521			if (!(flags & XFS_QMOPT_DQALLOC))
522				return (ENOENT);
523
524			ASSERT(tp);
525			if ((error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
526						dqp->q_fileoffset, &bp)))
527				return (error);
528			tp = *tpp;
529			newdquot = B_TRUE;
530		} else {
531			/*
532			 * store the blkno etc so that we don't have to do the
533			 * mapping all the time
534			 */
535			dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
536		}
537	}
538	ASSERT(dqp->q_blkno != DELAYSTARTBLOCK);
539	ASSERT(dqp->q_blkno != HOLESTARTBLOCK);
540
541	/*
542	 * Read in the buffer, unless we've just done the allocation
543	 * (in which case we already have the buf).
544	 */
545	if (!newdquot) {
546		trace_xfs_dqtobp_read(dqp);
547
548		error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
549					   dqp->q_blkno,
550					   mp->m_quotainfo->qi_dqchunklen,
551					   0, &bp);
552		if (error || !bp)
553			return XFS_ERROR(error);
554	}
555	ASSERT(XFS_BUF_ISBUSY(bp));
556	ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
557
558	/*
559	 * calculate the location of the dquot inside the buffer.
560	 */
561	ddq = (xfs_disk_dquot_t *)((char *)XFS_BUF_PTR(bp) + dqp->q_bufoffset);
562
563	/*
564	 * A simple sanity check in case we got a corrupted dquot...
565	 */
566	if (xfs_qm_dqcheck(ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES,
567			   flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN),
568			   "dqtobp")) {
569		if (!(flags & XFS_QMOPT_DQREPAIR)) {
570			xfs_trans_brelse(tp, bp);
571			return XFS_ERROR(EIO);
572		}
573		XFS_BUF_BUSY(bp); /* We dirtied this */
574	}
575
576	*O_bpp = bp;
577	*O_ddpp = ddq;
578
579	return (0);
580}
581
582
583/*
584 * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
585 * and release the buffer immediately.
586 *
587 */
588/* ARGSUSED */
589STATIC int
590xfs_qm_dqread(
591	xfs_trans_t	**tpp,
592	xfs_dqid_t	id,
593	xfs_dquot_t	*dqp,	/* dquot to get filled in */
594	uint		flags)
595{
596	xfs_disk_dquot_t *ddqp;
597	xfs_buf_t	 *bp;
598	int		 error;
599	xfs_trans_t	 *tp;
600
601	ASSERT(tpp);
602
603	trace_xfs_dqread(dqp);
604
605	/*
606	 * get a pointer to the on-disk dquot and the buffer containing it
607	 * dqp already knows its own type (GROUP/USER).
608	 */
609	if ((error = xfs_qm_dqtobp(tpp, dqp, &ddqp, &bp, flags))) {
610		return (error);
611	}
612	tp = *tpp;
613
614	/* copy everything from disk dquot to the incore dquot */
615	memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
616	ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
617	xfs_qm_dquot_logitem_init(dqp);
618
619	/*
620	 * Reservation counters are defined as reservation plus current usage
621	 * to avoid having to add everytime.
622	 */
623	dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
624	dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
625	dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
626
627	/* Mark the buf so that this will stay incore a little longer */
628	XFS_BUF_SET_VTYPE_REF(bp, B_FS_DQUOT, XFS_DQUOT_REF);
629
630	/*
631	 * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
632	 * So we need to release with xfs_trans_brelse().
633	 * The strategy here is identical to that of inodes; we lock
634	 * the dquot in xfs_qm_dqget() before making it accessible to
635	 * others. This is because dquots, like inodes, need a good level of
636	 * concurrency, and we don't want to take locks on the entire buffers
637	 * for dquot accesses.
638	 * Note also that the dquot buffer may even be dirty at this point, if
639	 * this particular dquot was repaired. We still aren't afraid to
640	 * brelse it because we have the changes incore.
641	 */
642	ASSERT(XFS_BUF_ISBUSY(bp));
643	ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
644	xfs_trans_brelse(tp, bp);
645
646	return (error);
647}
648
649
650/*
651 * allocate an incore dquot from the kernel heap,
652 * and fill its core with quota information kept on disk.
653 * If XFS_QMOPT_DQALLOC is set, it'll allocate a dquot on disk
654 * if it wasn't already allocated.
655 */
656STATIC int
657xfs_qm_idtodq(
658	xfs_mount_t	*mp,
659	xfs_dqid_t	id,	 /* gid or uid, depending on type */
660	uint		type,	 /* UDQUOT or GDQUOT */
661	uint		flags,	 /* DQALLOC, DQREPAIR */
662	xfs_dquot_t	**O_dqpp)/* OUT : incore dquot, not locked */
663{
664	xfs_dquot_t	*dqp;
665	int		error;
666	xfs_trans_t	*tp;
667	int		cancelflags=0;
668
669	dqp = xfs_qm_dqinit(mp, id, type);
670	tp = NULL;
671	if (flags & XFS_QMOPT_DQALLOC) {
672		tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
673		error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp),
674				XFS_WRITE_LOG_RES(mp) +
675				BBTOB(mp->m_quotainfo->qi_dqchunklen) - 1 +
676				128,
677				0,
678				XFS_TRANS_PERM_LOG_RES,
679				XFS_WRITE_LOG_COUNT);
680		if (error) {
681			cancelflags = 0;
682			goto error0;
683		}
684		cancelflags = XFS_TRANS_RELEASE_LOG_RES;
685	}
686
687	/*
688	 * Read it from disk; xfs_dqread() takes care of
689	 * all the necessary initialization of dquot's fields (locks, etc)
690	 */
691	if ((error = xfs_qm_dqread(&tp, id, dqp, flags))) {
692		/*
693		 * This can happen if quotas got turned off (ESRCH),
694		 * or if the dquot didn't exist on disk and we ask to
695		 * allocate (ENOENT).
696		 */
697		trace_xfs_dqread_fail(dqp);
698		cancelflags |= XFS_TRANS_ABORT;
699		goto error0;
700	}
701	if (tp) {
702		if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES)))
703			goto error1;
704	}
705
706	*O_dqpp = dqp;
707	return (0);
708
709 error0:
710	ASSERT(error);
711	if (tp)
712		xfs_trans_cancel(tp, cancelflags);
713 error1:
714	xfs_qm_dqdestroy(dqp);
715	*O_dqpp = NULL;
716	return (error);
717}
718
719/*
720 * Lookup a dquot in the incore dquot hashtable. We keep two separate
721 * hashtables for user and group dquots; and, these are global tables
722 * inside the XQM, not per-filesystem tables.
723 * The hash chain must be locked by caller, and it is left locked
724 * on return. Returning dquot is locked.
725 */
726STATIC int
727xfs_qm_dqlookup(
728	xfs_mount_t		*mp,
729	xfs_dqid_t		id,
730	xfs_dqhash_t		*qh,
731	xfs_dquot_t		**O_dqpp)
732{
733	xfs_dquot_t		*dqp;
734	uint			flist_locked;
735
736	ASSERT(mutex_is_locked(&qh->qh_lock));
737
738	flist_locked = B_FALSE;
739
740	/*
741	 * Traverse the hashchain looking for a match
742	 */
743	list_for_each_entry(dqp, &qh->qh_list, q_hashlist) {
744		/*
745		 * We already have the hashlock. We don't need the
746		 * dqlock to look at the id field of the dquot, since the
747		 * id can't be modified without the hashlock anyway.
748		 */
749		if (be32_to_cpu(dqp->q_core.d_id) == id && dqp->q_mount == mp) {
750			trace_xfs_dqlookup_found(dqp);
751
752			/*
753			 * All in core dquots must be on the dqlist of mp
754			 */
755			ASSERT(!list_empty(&dqp->q_mplist));
756
757			xfs_dqlock(dqp);
758			if (dqp->q_nrefs == 0) {
759				ASSERT(!list_empty(&dqp->q_freelist));
760				if (!mutex_trylock(&xfs_Gqm->qm_dqfrlist_lock)) {
761					trace_xfs_dqlookup_want(dqp);
762
763					/*
764					 * We may have raced with dqreclaim_one()
765					 * (and lost). So, flag that we don't
766					 * want the dquot to be reclaimed.
767					 */
768					dqp->dq_flags |= XFS_DQ_WANT;
769					xfs_dqunlock(dqp);
770					mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
771					xfs_dqlock(dqp);
772					dqp->dq_flags &= ~(XFS_DQ_WANT);
773				}
774				flist_locked = B_TRUE;
775			}
776
777			/*
778			 * id couldn't have changed; we had the hashlock all
779			 * along
780			 */
781			ASSERT(be32_to_cpu(dqp->q_core.d_id) == id);
782
783			if (flist_locked) {
784				if (dqp->q_nrefs != 0) {
785					mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
786					flist_locked = B_FALSE;
787				} else {
788					/* take it off the freelist */
789					trace_xfs_dqlookup_freelist(dqp);
790					list_del_init(&dqp->q_freelist);
791					xfs_Gqm->qm_dqfrlist_cnt--;
792				}
793			}
794
795			XFS_DQHOLD(dqp);
796
797			if (flist_locked)
798				mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
799			/*
800			 * move the dquot to the front of the hashchain
801			 */
802			ASSERT(mutex_is_locked(&qh->qh_lock));
803			list_move(&dqp->q_hashlist, &qh->qh_list);
804			trace_xfs_dqlookup_done(dqp);
805			*O_dqpp = dqp;
806			return 0;
807		}
808	}
809
810	*O_dqpp = NULL;
811	ASSERT(mutex_is_locked(&qh->qh_lock));
812	return (1);
813}
814
815/*
816 * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
817 * a locked dquot, doing an allocation (if requested) as needed.
818 * When both an inode and an id are given, the inode's id takes precedence.
819 * That is, if the id changes while we don't hold the ilock inside this
820 * function, the new dquot is returned, not necessarily the one requested
821 * in the id argument.
822 */
823int
824xfs_qm_dqget(
825	xfs_mount_t	*mp,
826	xfs_inode_t	*ip,	  /* locked inode (optional) */
827	xfs_dqid_t	id,	  /* uid/projid/gid depending on type */
828	uint		type,	  /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
829	uint		flags,	  /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
830	xfs_dquot_t	**O_dqpp) /* OUT : locked incore dquot */
831{
832	xfs_dquot_t	*dqp;
833	xfs_dqhash_t	*h;
834	uint		version;
835	int		error;
836
837	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
838	if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
839	    (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
840	    (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
841		return (ESRCH);
842	}
843	h = XFS_DQ_HASH(mp, id, type);
844
845#ifdef DEBUG
846	if (xfs_do_dqerror) {
847		if ((xfs_dqerror_target == mp->m_ddev_targp) &&
848		    (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
849			cmn_err(CE_DEBUG, "Returning error in dqget");
850			return (EIO);
851		}
852	}
853#endif
854
855 again:
856
857#ifdef DEBUG
858	ASSERT(type == XFS_DQ_USER ||
859	       type == XFS_DQ_PROJ ||
860	       type == XFS_DQ_GROUP);
861	if (ip) {
862		ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
863		if (type == XFS_DQ_USER)
864			ASSERT(ip->i_udquot == NULL);
865		else
866			ASSERT(ip->i_gdquot == NULL);
867	}
868#endif
869	mutex_lock(&h->qh_lock);
870
871	/*
872	 * Look in the cache (hashtable).
873	 * The chain is kept locked during lookup.
874	 */
875	if (xfs_qm_dqlookup(mp, id, h, O_dqpp) == 0) {
876		XQM_STATS_INC(xqmstats.xs_qm_dqcachehits);
877		/*
878		 * The dquot was found, moved to the front of the chain,
879		 * taken off the freelist if it was on it, and locked
880		 * at this point. Just unlock the hashchain and return.
881		 */
882		ASSERT(*O_dqpp);
883		ASSERT(XFS_DQ_IS_LOCKED(*O_dqpp));
884		mutex_unlock(&h->qh_lock);
885		trace_xfs_dqget_hit(*O_dqpp);
886		return (0);	/* success */
887	}
888	XQM_STATS_INC(xqmstats.xs_qm_dqcachemisses);
889
890	/*
891	 * Dquot cache miss. We don't want to keep the inode lock across
892	 * a (potential) disk read. Also we don't want to deal with the lock
893	 * ordering between quotainode and this inode. OTOH, dropping the inode
894	 * lock here means dealing with a chown that can happen before
895	 * we re-acquire the lock.
896	 */
897	if (ip)
898		xfs_iunlock(ip, XFS_ILOCK_EXCL);
899	/*
900	 * Save the hashchain version stamp, and unlock the chain, so that
901	 * we don't keep the lock across a disk read
902	 */
903	version = h->qh_version;
904	mutex_unlock(&h->qh_lock);
905
906	/*
907	 * Allocate the dquot on the kernel heap, and read the ondisk
908	 * portion off the disk. Also, do all the necessary initialization
909	 * This can return ENOENT if dquot didn't exist on disk and we didn't
910	 * ask it to allocate; ESRCH if quotas got turned off suddenly.
911	 */
912	if ((error = xfs_qm_idtodq(mp, id, type,
913				  flags & (XFS_QMOPT_DQALLOC|XFS_QMOPT_DQREPAIR|
914					   XFS_QMOPT_DOWARN),
915				  &dqp))) {
916		if (ip)
917			xfs_ilock(ip, XFS_ILOCK_EXCL);
918		return (error);
919	}
920
921	/*
922	 * See if this is mount code calling to look at the overall quota limits
923	 * which are stored in the id == 0 user or group's dquot.
924	 * Since we may not have done a quotacheck by this point, just return
925	 * the dquot without attaching it to any hashtables, lists, etc, or even
926	 * taking a reference.
927	 * The caller must dqdestroy this once done.
928	 */
929	if (flags & XFS_QMOPT_DQSUSER) {
930		ASSERT(id == 0);
931		ASSERT(! ip);
932		goto dqret;
933	}
934
935	/*
936	 * Dquot lock comes after hashlock in the lock ordering
937	 */
938	if (ip) {
939		xfs_ilock(ip, XFS_ILOCK_EXCL);
940
941		/*
942		 * A dquot could be attached to this inode by now, since
943		 * we had dropped the ilock.
944		 */
945		if (type == XFS_DQ_USER) {
946			if (!XFS_IS_UQUOTA_ON(mp)) {
947				/* inode stays locked on return */
948				xfs_qm_dqdestroy(dqp);
949				return XFS_ERROR(ESRCH);
950			}
951			if (ip->i_udquot) {
952				xfs_qm_dqdestroy(dqp);
953				dqp = ip->i_udquot;
954				xfs_dqlock(dqp);
955				goto dqret;
956			}
957		} else {
958			if (!XFS_IS_OQUOTA_ON(mp)) {
959				/* inode stays locked on return */
960				xfs_qm_dqdestroy(dqp);
961				return XFS_ERROR(ESRCH);
962			}
963			if (ip->i_gdquot) {
964				xfs_qm_dqdestroy(dqp);
965				dqp = ip->i_gdquot;
966				xfs_dqlock(dqp);
967				goto dqret;
968			}
969		}
970	}
971
972	/*
973	 * Hashlock comes after ilock in lock order
974	 */
975	mutex_lock(&h->qh_lock);
976	if (version != h->qh_version) {
977		xfs_dquot_t *tmpdqp;
978		/*
979		 * Now, see if somebody else put the dquot in the
980		 * hashtable before us. This can happen because we didn't
981		 * keep the hashchain lock. We don't have to worry about
982		 * lock order between the two dquots here since dqp isn't
983		 * on any findable lists yet.
984		 */
985		if (xfs_qm_dqlookup(mp, id, h, &tmpdqp) == 0) {
986			/*
987			 * Duplicate found. Just throw away the new dquot
988			 * and start over.
989			 */
990			xfs_qm_dqput(tmpdqp);
991			mutex_unlock(&h->qh_lock);
992			xfs_qm_dqdestroy(dqp);
993			XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
994			goto again;
995		}
996	}
997
998	/*
999	 * Put the dquot at the beginning of the hash-chain and mp's list
1000	 * LOCK ORDER: hashlock, freelistlock, mplistlock, udqlock, gdqlock ..
1001	 */
1002	ASSERT(mutex_is_locked(&h->qh_lock));
1003	dqp->q_hash = h;
1004	list_add(&dqp->q_hashlist, &h->qh_list);
1005	h->qh_version++;
1006
1007	/*
1008	 * Attach this dquot to this filesystem's list of all dquots,
1009	 * kept inside the mount structure in m_quotainfo field
1010	 */
1011	mutex_lock(&mp->m_quotainfo->qi_dqlist_lock);
1012
1013	/*
1014	 * We return a locked dquot to the caller, with a reference taken
1015	 */
1016	xfs_dqlock(dqp);
1017	dqp->q_nrefs = 1;
1018
1019	list_add(&dqp->q_mplist, &mp->m_quotainfo->qi_dqlist);
1020	mp->m_quotainfo->qi_dquots++;
1021	mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
1022	mutex_unlock(&h->qh_lock);
1023 dqret:
1024	ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
1025	trace_xfs_dqget_miss(dqp);
1026	*O_dqpp = dqp;
1027	return (0);
1028}
1029
1030
1031/*
1032 * Release a reference to the dquot (decrement ref-count)
1033 * and unlock it. If there is a group quota attached to this
1034 * dquot, carefully release that too without tripping over
1035 * deadlocks'n'stuff.
1036 */
1037void
1038xfs_qm_dqput(
1039	xfs_dquot_t	*dqp)
1040{
1041	xfs_dquot_t	*gdqp;
1042
1043	ASSERT(dqp->q_nrefs > 0);
1044	ASSERT(XFS_DQ_IS_LOCKED(dqp));
1045
1046	trace_xfs_dqput(dqp);
1047
1048	if (dqp->q_nrefs != 1) {
1049		dqp->q_nrefs--;
1050		xfs_dqunlock(dqp);
1051		return;
1052	}
1053
1054	/*
1055	 * drop the dqlock and acquire the freelist and dqlock
1056	 * in the right order; but try to get it out-of-order first
1057	 */
1058	if (!mutex_trylock(&xfs_Gqm->qm_dqfrlist_lock)) {
1059		trace_xfs_dqput_wait(dqp);
1060		xfs_dqunlock(dqp);
1061		mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
1062		xfs_dqlock(dqp);
1063	}
1064
1065	while (1) {
1066		gdqp = NULL;
1067
1068		/* We can't depend on nrefs being == 1 here */
1069		if (--dqp->q_nrefs == 0) {
1070			trace_xfs_dqput_free(dqp);
1071
1072			list_add_tail(&dqp->q_freelist, &xfs_Gqm->qm_dqfrlist);
1073			xfs_Gqm->qm_dqfrlist_cnt++;
1074
1075			/*
1076			 * If we just added a udquot to the freelist, then
1077			 * we want to release the gdquot reference that
1078			 * it (probably) has. Otherwise it'll keep the
1079			 * gdquot from getting reclaimed.
1080			 */
1081			if ((gdqp = dqp->q_gdquot)) {
1082				/*
1083				 * Avoid a recursive dqput call
1084				 */
1085				xfs_dqlock(gdqp);
1086				dqp->q_gdquot = NULL;
1087			}
1088		}
1089		xfs_dqunlock(dqp);
1090
1091		/*
1092		 * If we had a group quota inside the user quota as a hint,
1093		 * release it now.
1094		 */
1095		if (! gdqp)
1096			break;
1097		dqp = gdqp;
1098	}
1099	mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
1100}
1101
1102/*
1103 * Release a dquot. Flush it if dirty, then dqput() it.
1104 * dquot must not be locked.
1105 */
1106void
1107xfs_qm_dqrele(
1108	xfs_dquot_t	*dqp)
1109{
1110	if (!dqp)
1111		return;
1112
1113	trace_xfs_dqrele(dqp);
1114
1115	xfs_dqlock(dqp);
1116	/*
1117	 * We don't care to flush it if the dquot is dirty here.
1118	 * That will create stutters that we want to avoid.
1119	 * Instead we do a delayed write when we try to reclaim
1120	 * a dirty dquot. Also xfs_sync will take part of the burden...
1121	 */
1122	xfs_qm_dqput(dqp);
1123}
1124
1125/*
1126 * This is the dquot flushing I/O completion routine.  It is called
1127 * from interrupt level when the buffer containing the dquot is
1128 * flushed to disk.  It is responsible for removing the dquot logitem
1129 * from the AIL if it has not been re-logged, and unlocking the dquot's
1130 * flush lock. This behavior is very similar to that of inodes..
1131 */
1132STATIC void
1133xfs_qm_dqflush_done(
1134	struct xfs_buf		*bp,
1135	struct xfs_log_item	*lip)
1136{
1137	xfs_dq_logitem_t	*qip = (struct xfs_dq_logitem *)lip;
1138	xfs_dquot_t		*dqp = qip->qli_dquot;
1139	struct xfs_ail		*ailp = lip->li_ailp;
1140
1141	/*
1142	 * We only want to pull the item from the AIL if its
1143	 * location in the log has not changed since we started the flush.
1144	 * Thus, we only bother if the dquot's lsn has
1145	 * not changed. First we check the lsn outside the lock
1146	 * since it's cheaper, and then we recheck while
1147	 * holding the lock before removing the dquot from the AIL.
1148	 */
1149	if ((lip->li_flags & XFS_LI_IN_AIL) &&
1150	    lip->li_lsn == qip->qli_flush_lsn) {
1151
1152		/* xfs_trans_ail_delete() drops the AIL lock. */
1153		spin_lock(&ailp->xa_lock);
1154		if (lip->li_lsn == qip->qli_flush_lsn)
1155			xfs_trans_ail_delete(ailp, lip);
1156		else
1157			spin_unlock(&ailp->xa_lock);
1158	}
1159
1160	/*
1161	 * Release the dq's flush lock since we're done with it.
1162	 */
1163	xfs_dqfunlock(dqp);
1164}
1165
1166/*
1167 * Write a modified dquot to disk.
1168 * The dquot must be locked and the flush lock too taken by caller.
1169 * The flush lock will not be unlocked until the dquot reaches the disk,
1170 * but the dquot is free to be unlocked and modified by the caller
1171 * in the interim. Dquot is still locked on return. This behavior is
1172 * identical to that of inodes.
1173 */
1174int
1175xfs_qm_dqflush(
1176	xfs_dquot_t		*dqp,
1177	uint			flags)
1178{
1179	xfs_mount_t		*mp;
1180	xfs_buf_t		*bp;
1181	xfs_disk_dquot_t	*ddqp;
1182	int			error;
1183
1184	ASSERT(XFS_DQ_IS_LOCKED(dqp));
1185	ASSERT(!completion_done(&dqp->q_flush));
1186	trace_xfs_dqflush(dqp);
1187
1188	/*
1189	 * If not dirty, or it's pinned and we are not supposed to
1190	 * block, nada.
1191	 */
1192	if (!XFS_DQ_IS_DIRTY(dqp) ||
1193	    (!(flags & SYNC_WAIT) && atomic_read(&dqp->q_pincount) > 0)) {
1194		xfs_dqfunlock(dqp);
1195		return 0;
1196	}
1197	xfs_qm_dqunpin_wait(dqp);
1198
1199	/*
1200	 * This may have been unpinned because the filesystem is shutting
1201	 * down forcibly. If that's the case we must not write this dquot
1202	 * to disk, because the log record didn't make it to disk!
1203	 */
1204	if (XFS_FORCED_SHUTDOWN(dqp->q_mount)) {
1205		dqp->dq_flags &= ~(XFS_DQ_DIRTY);
1206		xfs_dqfunlock(dqp);
1207		return XFS_ERROR(EIO);
1208	}
1209
1210	/*
1211	 * Get the buffer containing the on-disk dquot
1212	 * We don't need a transaction envelope because we know that the
1213	 * the ondisk-dquot has already been allocated for.
1214	 */
1215	if ((error = xfs_qm_dqtobp(NULL, dqp, &ddqp, &bp, XFS_QMOPT_DOWARN))) {
1216		ASSERT(error != ENOENT);
1217		/*
1218		 * Quotas could have gotten turned off (ESRCH)
1219		 */
1220		xfs_dqfunlock(dqp);
1221		return (error);
1222	}
1223
1224	if (xfs_qm_dqcheck(&dqp->q_core, be32_to_cpu(ddqp->d_id),
1225			   0, XFS_QMOPT_DOWARN, "dqflush (incore copy)")) {
1226		xfs_force_shutdown(dqp->q_mount, SHUTDOWN_CORRUPT_INCORE);
1227		return XFS_ERROR(EIO);
1228	}
1229
1230	/* This is the only portion of data that needs to persist */
1231	memcpy(ddqp, &(dqp->q_core), sizeof(xfs_disk_dquot_t));
1232
1233	/*
1234	 * Clear the dirty field and remember the flush lsn for later use.
1235	 */
1236	dqp->dq_flags &= ~(XFS_DQ_DIRTY);
1237	mp = dqp->q_mount;
1238
1239	xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1240					&dqp->q_logitem.qli_item.li_lsn);
1241
1242	/*
1243	 * Attach an iodone routine so that we can remove this dquot from the
1244	 * AIL and release the flush lock once the dquot is synced to disk.
1245	 */
1246	xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1247				  &dqp->q_logitem.qli_item);
1248
1249	/*
1250	 * If the buffer is pinned then push on the log so we won't
1251	 * get stuck waiting in the write for too long.
1252	 */
1253	if (XFS_BUF_ISPINNED(bp)) {
1254		trace_xfs_dqflush_force(dqp);
1255		xfs_log_force(mp, 0);
1256	}
1257
1258	if (flags & SYNC_WAIT)
1259		error = xfs_bwrite(mp, bp);
1260	else
1261		xfs_bdwrite(mp, bp);
1262
1263	trace_xfs_dqflush_done(dqp);
1264
1265	/*
1266	 * dqp is still locked, but caller is free to unlock it now.
1267	 */
1268	return error;
1269
1270}
1271
1272int
1273xfs_qm_dqlock_nowait(
1274	xfs_dquot_t *dqp)
1275{
1276	return mutex_trylock(&dqp->q_qlock);
1277}
1278
1279void
1280xfs_dqlock(
1281	xfs_dquot_t *dqp)
1282{
1283	mutex_lock(&dqp->q_qlock);
1284}
1285
1286void
1287xfs_dqunlock(
1288	xfs_dquot_t *dqp)
1289{
1290	mutex_unlock(&(dqp->q_qlock));
1291	if (dqp->q_logitem.qli_dquot == dqp) {
1292		/* Once was dqp->q_mount, but might just have been cleared */
1293		xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_ailp,
1294					(xfs_log_item_t*)&(dqp->q_logitem));
1295	}
1296}
1297
1298
1299void
1300xfs_dqunlock_nonotify(
1301	xfs_dquot_t *dqp)
1302{
1303	mutex_unlock(&(dqp->q_qlock));
1304}
1305
1306/*
1307 * Lock two xfs_dquot structures.
1308 *
1309 * To avoid deadlocks we always lock the quota structure with
1310 * the lowerd id first.
1311 */
1312void
1313xfs_dqlock2(
1314	xfs_dquot_t	*d1,
1315	xfs_dquot_t	*d2)
1316{
1317	if (d1 && d2) {
1318		ASSERT(d1 != d2);
1319		if (be32_to_cpu(d1->q_core.d_id) >
1320		    be32_to_cpu(d2->q_core.d_id)) {
1321			mutex_lock(&d2->q_qlock);
1322			mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1323		} else {
1324			mutex_lock(&d1->q_qlock);
1325			mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1326		}
1327	} else if (d1) {
1328		mutex_lock(&d1->q_qlock);
1329	} else if (d2) {
1330		mutex_lock(&d2->q_qlock);
1331	}
1332}
1333
1334
1335/*
1336 * Take a dquot out of the mount's dqlist as well as the hashlist.
1337 * This is called via unmount as well as quotaoff, and the purge
1338 * will always succeed unless there are soft (temp) references
1339 * outstanding.
1340 *
1341 * This returns 0 if it was purged, 1 if it wasn't. It's not an error code
1342 * that we're returning! XXXsup - not cool.
1343 */
1344/* ARGSUSED */
1345int
1346xfs_qm_dqpurge(
1347	xfs_dquot_t	*dqp)
1348{
1349	xfs_dqhash_t	*qh = dqp->q_hash;
1350	xfs_mount_t	*mp = dqp->q_mount;
1351
1352	ASSERT(mutex_is_locked(&mp->m_quotainfo->qi_dqlist_lock));
1353	ASSERT(mutex_is_locked(&dqp->q_hash->qh_lock));
1354
1355	xfs_dqlock(dqp);
1356	/*
1357	 * We really can't afford to purge a dquot that is
1358	 * referenced, because these are hard refs.
1359	 * It shouldn't happen in general because we went thru _all_ inodes in
1360	 * dqrele_all_inodes before calling this and didn't let the mountlock go.
1361	 * However it is possible that we have dquots with temporary
1362	 * references that are not attached to an inode. e.g. see xfs_setattr().
1363	 */
1364	if (dqp->q_nrefs != 0) {
1365		xfs_dqunlock(dqp);
1366		mutex_unlock(&dqp->q_hash->qh_lock);
1367		return (1);
1368	}
1369
1370	ASSERT(!list_empty(&dqp->q_freelist));
1371
1372	/*
1373	 * If we're turning off quotas, we have to make sure that, for
1374	 * example, we don't delete quota disk blocks while dquots are
1375	 * in the process of getting written to those disk blocks.
1376	 * This dquot might well be on AIL, and we can't leave it there
1377	 * if we're turning off quotas. Basically, we need this flush
1378	 * lock, and are willing to block on it.
1379	 */
1380	if (!xfs_dqflock_nowait(dqp)) {
1381		/*
1382		 * Block on the flush lock after nudging dquot buffer,
1383		 * if it is incore.
1384		 */
1385		xfs_qm_dqflock_pushbuf_wait(dqp);
1386	}
1387
1388	/*
1389	 * XXXIf we're turning this type of quotas off, we don't care
1390	 * about the dirty metadata sitting in this dquot. OTOH, if
1391	 * we're unmounting, we do care, so we flush it and wait.
1392	 */
1393	if (XFS_DQ_IS_DIRTY(dqp)) {
1394		int	error;
1395
1396		/* dqflush unlocks dqflock */
1397		/*
1398		 * Given that dqpurge is a very rare occurrence, it is OK
1399		 * that we're holding the hashlist and mplist locks
1400		 * across the disk write. But, ... XXXsup
1401		 *
1402		 * We don't care about getting disk errors here. We need
1403		 * to purge this dquot anyway, so we go ahead regardless.
1404		 */
1405		error = xfs_qm_dqflush(dqp, SYNC_WAIT);
1406		if (error)
1407			xfs_fs_cmn_err(CE_WARN, mp,
1408				"xfs_qm_dqpurge: dquot %p flush failed", dqp);
1409		xfs_dqflock(dqp);
1410	}
1411	ASSERT(atomic_read(&dqp->q_pincount) == 0);
1412	ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
1413	       !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
1414
1415	list_del_init(&dqp->q_hashlist);
1416	qh->qh_version++;
1417	list_del_init(&dqp->q_mplist);
1418	mp->m_quotainfo->qi_dqreclaims++;
1419	mp->m_quotainfo->qi_dquots--;
1420	ASSERT(!list_empty(&dqp->q_freelist));
1421
1422	dqp->q_mount = NULL;
1423	dqp->q_hash = NULL;
1424	dqp->dq_flags = XFS_DQ_INACTIVE;
1425	memset(&dqp->q_core, 0, sizeof(dqp->q_core));
1426	xfs_dqfunlock(dqp);
1427	xfs_dqunlock(dqp);
1428	mutex_unlock(&qh->qh_lock);
1429	return (0);
1430}
1431
1432
1433#ifdef QUOTADEBUG
1434void
1435xfs_qm_dqprint(xfs_dquot_t *dqp)
1436{
1437	cmn_err(CE_DEBUG, "-----------KERNEL DQUOT----------------");
1438	cmn_err(CE_DEBUG, "---- dquotID =  %d",
1439		(int)be32_to_cpu(dqp->q_core.d_id));
1440	cmn_err(CE_DEBUG, "---- type    =  %s", DQFLAGTO_TYPESTR(dqp));
1441	cmn_err(CE_DEBUG, "---- fs      =  0x%p", dqp->q_mount);
1442	cmn_err(CE_DEBUG, "---- blkno   =  0x%x", (int) dqp->q_blkno);
1443	cmn_err(CE_DEBUG, "---- boffset =  0x%x", (int) dqp->q_bufoffset);
1444	cmn_err(CE_DEBUG, "---- blkhlimit =  %Lu (0x%x)",
1445		be64_to_cpu(dqp->q_core.d_blk_hardlimit),
1446		(int)be64_to_cpu(dqp->q_core.d_blk_hardlimit));
1447	cmn_err(CE_DEBUG, "---- blkslimit =  %Lu (0x%x)",
1448		be64_to_cpu(dqp->q_core.d_blk_softlimit),
1449		(int)be64_to_cpu(dqp->q_core.d_blk_softlimit));
1450	cmn_err(CE_DEBUG, "---- inohlimit =  %Lu (0x%x)",
1451		be64_to_cpu(dqp->q_core.d_ino_hardlimit),
1452		(int)be64_to_cpu(dqp->q_core.d_ino_hardlimit));
1453	cmn_err(CE_DEBUG, "---- inoslimit =  %Lu (0x%x)",
1454		be64_to_cpu(dqp->q_core.d_ino_softlimit),
1455		(int)be64_to_cpu(dqp->q_core.d_ino_softlimit));
1456	cmn_err(CE_DEBUG, "---- bcount  =  %Lu (0x%x)",
1457		be64_to_cpu(dqp->q_core.d_bcount),
1458		(int)be64_to_cpu(dqp->q_core.d_bcount));
1459	cmn_err(CE_DEBUG, "---- icount  =  %Lu (0x%x)",
1460		be64_to_cpu(dqp->q_core.d_icount),
1461		(int)be64_to_cpu(dqp->q_core.d_icount));
1462	cmn_err(CE_DEBUG, "---- btimer  =  %d",
1463		(int)be32_to_cpu(dqp->q_core.d_btimer));
1464	cmn_err(CE_DEBUG, "---- itimer  =  %d",
1465		(int)be32_to_cpu(dqp->q_core.d_itimer));
1466	cmn_err(CE_DEBUG, "---------------------------");
1467}
1468#endif
1469
1470/*
1471 * Give the buffer a little push if it is incore and
1472 * wait on the flush lock.
1473 */
1474void
1475xfs_qm_dqflock_pushbuf_wait(
1476	xfs_dquot_t	*dqp)
1477{
1478	xfs_mount_t	*mp = dqp->q_mount;
1479	xfs_buf_t	*bp;
1480
1481	/*
1482	 * Check to see if the dquot has been flushed delayed
1483	 * write.  If so, grab its buffer and send it
1484	 * out immediately.  We'll be able to acquire
1485	 * the flush lock when the I/O completes.
1486	 */
1487	bp = xfs_incore(mp->m_ddev_targp, dqp->q_blkno,
1488			mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);
1489	if (!bp)
1490		goto out_lock;
1491
1492	if (XFS_BUF_ISDELAYWRITE(bp)) {
1493		if (XFS_BUF_ISPINNED(bp))
1494			xfs_log_force(mp, 0);
1495		xfs_buf_delwri_promote(bp);
1496		wake_up_process(bp->b_target->bt_task);
1497	}
1498	xfs_buf_relse(bp);
1499out_lock:
1500	xfs_dqflock(dqp);
1501}
1502