xref: /openbmc/linux/fs/xfs/xfs_dquot.c (revision 7490ca1e)
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  * Lock order:
44  *
45  * ip->i_lock
46  *   qh->qh_lock
47  *     qi->qi_dqlist_lock
48  *       dquot->q_qlock (xfs_dqlock() and friends)
49  *         dquot->q_flush (xfs_dqflock() and friends)
50  *         xfs_Gqm->qm_dqfrlist_lock
51  *
52  * If two dquots need to be locked the order is user before group/project,
53  * otherwise by the lowest id first, see xfs_dqlock2.
54  */
55 
56 #ifdef DEBUG
57 xfs_buftarg_t *xfs_dqerror_target;
58 int xfs_do_dqerror;
59 int xfs_dqreq_num;
60 int xfs_dqerror_mod = 33;
61 #endif
62 
63 static struct lock_class_key xfs_dquot_other_class;
64 
65 /*
66  * This is called to free all the memory associated with a dquot
67  */
68 void
69 xfs_qm_dqdestroy(
70 	xfs_dquot_t	*dqp)
71 {
72 	ASSERT(list_empty(&dqp->q_freelist));
73 
74 	mutex_destroy(&dqp->q_qlock);
75 	kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
76 
77 	atomic_dec(&xfs_Gqm->qm_totaldquots);
78 }
79 
80 /*
81  * If default limits are in force, push them into the dquot now.
82  * We overwrite the dquot limits only if they are zero and this
83  * is not the root dquot.
84  */
85 void
86 xfs_qm_adjust_dqlimits(
87 	xfs_mount_t		*mp,
88 	xfs_disk_dquot_t	*d)
89 {
90 	xfs_quotainfo_t		*q = mp->m_quotainfo;
91 
92 	ASSERT(d->d_id);
93 
94 	if (q->qi_bsoftlimit && !d->d_blk_softlimit)
95 		d->d_blk_softlimit = cpu_to_be64(q->qi_bsoftlimit);
96 	if (q->qi_bhardlimit && !d->d_blk_hardlimit)
97 		d->d_blk_hardlimit = cpu_to_be64(q->qi_bhardlimit);
98 	if (q->qi_isoftlimit && !d->d_ino_softlimit)
99 		d->d_ino_softlimit = cpu_to_be64(q->qi_isoftlimit);
100 	if (q->qi_ihardlimit && !d->d_ino_hardlimit)
101 		d->d_ino_hardlimit = cpu_to_be64(q->qi_ihardlimit);
102 	if (q->qi_rtbsoftlimit && !d->d_rtb_softlimit)
103 		d->d_rtb_softlimit = cpu_to_be64(q->qi_rtbsoftlimit);
104 	if (q->qi_rtbhardlimit && !d->d_rtb_hardlimit)
105 		d->d_rtb_hardlimit = cpu_to_be64(q->qi_rtbhardlimit);
106 }
107 
108 /*
109  * Check the limits and timers of a dquot and start or reset timers
110  * if necessary.
111  * This gets called even when quota enforcement is OFF, which makes our
112  * life a little less complicated. (We just don't reject any quota
113  * reservations in that case, when enforcement is off).
114  * We also return 0 as the values of the timers in Q_GETQUOTA calls, when
115  * enforcement's off.
116  * In contrast, warnings are a little different in that they don't
117  * 'automatically' get started when limits get exceeded.  They do
118  * get reset to zero, however, when we find the count to be under
119  * the soft limit (they are only ever set non-zero via userspace).
120  */
121 void
122 xfs_qm_adjust_dqtimers(
123 	xfs_mount_t		*mp,
124 	xfs_disk_dquot_t	*d)
125 {
126 	ASSERT(d->d_id);
127 
128 #ifdef DEBUG
129 	if (d->d_blk_hardlimit)
130 		ASSERT(be64_to_cpu(d->d_blk_softlimit) <=
131 		       be64_to_cpu(d->d_blk_hardlimit));
132 	if (d->d_ino_hardlimit)
133 		ASSERT(be64_to_cpu(d->d_ino_softlimit) <=
134 		       be64_to_cpu(d->d_ino_hardlimit));
135 	if (d->d_rtb_hardlimit)
136 		ASSERT(be64_to_cpu(d->d_rtb_softlimit) <=
137 		       be64_to_cpu(d->d_rtb_hardlimit));
138 #endif
139 
140 	if (!d->d_btimer) {
141 		if ((d->d_blk_softlimit &&
142 		     (be64_to_cpu(d->d_bcount) >
143 		      be64_to_cpu(d->d_blk_softlimit))) ||
144 		    (d->d_blk_hardlimit &&
145 		     (be64_to_cpu(d->d_bcount) >
146 		      be64_to_cpu(d->d_blk_hardlimit)))) {
147 			d->d_btimer = cpu_to_be32(get_seconds() +
148 					mp->m_quotainfo->qi_btimelimit);
149 		} else {
150 			d->d_bwarns = 0;
151 		}
152 	} else {
153 		if ((!d->d_blk_softlimit ||
154 		     (be64_to_cpu(d->d_bcount) <=
155 		      be64_to_cpu(d->d_blk_softlimit))) &&
156 		    (!d->d_blk_hardlimit ||
157 		    (be64_to_cpu(d->d_bcount) <=
158 		     be64_to_cpu(d->d_blk_hardlimit)))) {
159 			d->d_btimer = 0;
160 		}
161 	}
162 
163 	if (!d->d_itimer) {
164 		if ((d->d_ino_softlimit &&
165 		     (be64_to_cpu(d->d_icount) >
166 		      be64_to_cpu(d->d_ino_softlimit))) ||
167 		    (d->d_ino_hardlimit &&
168 		     (be64_to_cpu(d->d_icount) >
169 		      be64_to_cpu(d->d_ino_hardlimit)))) {
170 			d->d_itimer = cpu_to_be32(get_seconds() +
171 					mp->m_quotainfo->qi_itimelimit);
172 		} else {
173 			d->d_iwarns = 0;
174 		}
175 	} else {
176 		if ((!d->d_ino_softlimit ||
177 		     (be64_to_cpu(d->d_icount) <=
178 		      be64_to_cpu(d->d_ino_softlimit)))  &&
179 		    (!d->d_ino_hardlimit ||
180 		     (be64_to_cpu(d->d_icount) <=
181 		      be64_to_cpu(d->d_ino_hardlimit)))) {
182 			d->d_itimer = 0;
183 		}
184 	}
185 
186 	if (!d->d_rtbtimer) {
187 		if ((d->d_rtb_softlimit &&
188 		     (be64_to_cpu(d->d_rtbcount) >
189 		      be64_to_cpu(d->d_rtb_softlimit))) ||
190 		    (d->d_rtb_hardlimit &&
191 		     (be64_to_cpu(d->d_rtbcount) >
192 		      be64_to_cpu(d->d_rtb_hardlimit)))) {
193 			d->d_rtbtimer = cpu_to_be32(get_seconds() +
194 					mp->m_quotainfo->qi_rtbtimelimit);
195 		} else {
196 			d->d_rtbwarns = 0;
197 		}
198 	} else {
199 		if ((!d->d_rtb_softlimit ||
200 		     (be64_to_cpu(d->d_rtbcount) <=
201 		      be64_to_cpu(d->d_rtb_softlimit))) &&
202 		    (!d->d_rtb_hardlimit ||
203 		     (be64_to_cpu(d->d_rtbcount) <=
204 		      be64_to_cpu(d->d_rtb_hardlimit)))) {
205 			d->d_rtbtimer = 0;
206 		}
207 	}
208 }
209 
210 /*
211  * initialize a buffer full of dquots and log the whole thing
212  */
213 STATIC void
214 xfs_qm_init_dquot_blk(
215 	xfs_trans_t	*tp,
216 	xfs_mount_t	*mp,
217 	xfs_dqid_t	id,
218 	uint		type,
219 	xfs_buf_t	*bp)
220 {
221 	struct xfs_quotainfo	*q = mp->m_quotainfo;
222 	xfs_dqblk_t	*d;
223 	int		curid, i;
224 
225 	ASSERT(tp);
226 	ASSERT(xfs_buf_islocked(bp));
227 
228 	d = bp->b_addr;
229 
230 	/*
231 	 * ID of the first dquot in the block - id's are zero based.
232 	 */
233 	curid = id - (id % q->qi_dqperchunk);
234 	ASSERT(curid >= 0);
235 	memset(d, 0, BBTOB(q->qi_dqchunklen));
236 	for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) {
237 		d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
238 		d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
239 		d->dd_diskdq.d_id = cpu_to_be32(curid);
240 		d->dd_diskdq.d_flags = type;
241 	}
242 
243 	xfs_trans_dquot_buf(tp, bp,
244 			    (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
245 			    ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
246 			     XFS_BLF_GDQUOT_BUF)));
247 	xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
248 }
249 
250 
251 
252 /*
253  * Allocate a block and fill it with dquots.
254  * This is called when the bmapi finds a hole.
255  */
256 STATIC int
257 xfs_qm_dqalloc(
258 	xfs_trans_t	**tpp,
259 	xfs_mount_t	*mp,
260 	xfs_dquot_t	*dqp,
261 	xfs_inode_t	*quotip,
262 	xfs_fileoff_t	offset_fsb,
263 	xfs_buf_t	**O_bpp)
264 {
265 	xfs_fsblock_t	firstblock;
266 	xfs_bmap_free_t flist;
267 	xfs_bmbt_irec_t map;
268 	int		nmaps, error, committed;
269 	xfs_buf_t	*bp;
270 	xfs_trans_t	*tp = *tpp;
271 
272 	ASSERT(tp != NULL);
273 
274 	trace_xfs_dqalloc(dqp);
275 
276 	/*
277 	 * Initialize the bmap freelist prior to calling bmapi code.
278 	 */
279 	xfs_bmap_init(&flist, &firstblock);
280 	xfs_ilock(quotip, XFS_ILOCK_EXCL);
281 	/*
282 	 * Return if this type of quotas is turned off while we didn't
283 	 * have an inode lock
284 	 */
285 	if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
286 		xfs_iunlock(quotip, XFS_ILOCK_EXCL);
287 		return (ESRCH);
288 	}
289 
290 	xfs_trans_ijoin(tp, quotip, XFS_ILOCK_EXCL);
291 	nmaps = 1;
292 	error = xfs_bmapi_write(tp, quotip, offset_fsb,
293 				XFS_DQUOT_CLUSTER_SIZE_FSB, XFS_BMAPI_METADATA,
294 				&firstblock, XFS_QM_DQALLOC_SPACE_RES(mp),
295 				&map, &nmaps, &flist);
296 	if (error)
297 		goto error0;
298 	ASSERT(map.br_blockcount == XFS_DQUOT_CLUSTER_SIZE_FSB);
299 	ASSERT(nmaps == 1);
300 	ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
301 	       (map.br_startblock != HOLESTARTBLOCK));
302 
303 	/*
304 	 * Keep track of the blkno to save a lookup later
305 	 */
306 	dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
307 
308 	/* now we can just get the buffer (there's nothing to read yet) */
309 	bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
310 			       dqp->q_blkno,
311 			       mp->m_quotainfo->qi_dqchunklen,
312 			       0);
313 
314 	error = xfs_buf_geterror(bp);
315 	if (error)
316 		goto error1;
317 
318 	/*
319 	 * Make a chunk of dquots out of this buffer and log
320 	 * the entire thing.
321 	 */
322 	xfs_qm_init_dquot_blk(tp, mp, be32_to_cpu(dqp->q_core.d_id),
323 			      dqp->dq_flags & XFS_DQ_ALLTYPES, bp);
324 
325 	/*
326 	 * xfs_bmap_finish() may commit the current transaction and
327 	 * start a second transaction if the freelist is not empty.
328 	 *
329 	 * Since we still want to modify this buffer, we need to
330 	 * ensure that the buffer is not released on commit of
331 	 * the first transaction and ensure the buffer is added to the
332 	 * second transaction.
333 	 *
334 	 * If there is only one transaction then don't stop the buffer
335 	 * from being released when it commits later on.
336 	 */
337 
338 	xfs_trans_bhold(tp, bp);
339 
340 	if ((error = xfs_bmap_finish(tpp, &flist, &committed))) {
341 		goto error1;
342 	}
343 
344 	if (committed) {
345 		tp = *tpp;
346 		xfs_trans_bjoin(tp, bp);
347 	} else {
348 		xfs_trans_bhold_release(tp, bp);
349 	}
350 
351 	*O_bpp = bp;
352 	return 0;
353 
354       error1:
355 	xfs_bmap_cancel(&flist);
356       error0:
357 	xfs_iunlock(quotip, XFS_ILOCK_EXCL);
358 
359 	return (error);
360 }
361 
362 /*
363  * Maps a dquot to the buffer containing its on-disk version.
364  * This returns a ptr to the buffer containing the on-disk dquot
365  * in the bpp param, and a ptr to the on-disk dquot within that buffer
366  */
367 STATIC int
368 xfs_qm_dqtobp(
369 	xfs_trans_t		**tpp,
370 	xfs_dquot_t		*dqp,
371 	xfs_disk_dquot_t	**O_ddpp,
372 	xfs_buf_t		**O_bpp,
373 	uint			flags)
374 {
375 	xfs_bmbt_irec_t map;
376 	int		nmaps = 1, error;
377 	xfs_buf_t	*bp;
378 	xfs_inode_t	*quotip = XFS_DQ_TO_QIP(dqp);
379 	xfs_mount_t	*mp = dqp->q_mount;
380 	xfs_disk_dquot_t *ddq;
381 	xfs_dqid_t	id = be32_to_cpu(dqp->q_core.d_id);
382 	xfs_trans_t	*tp = (tpp ? *tpp : NULL);
383 
384 	dqp->q_fileoffset = (xfs_fileoff_t)id / mp->m_quotainfo->qi_dqperchunk;
385 
386 	xfs_ilock(quotip, XFS_ILOCK_SHARED);
387 	if (XFS_IS_THIS_QUOTA_OFF(dqp)) {
388 		/*
389 		 * Return if this type of quotas is turned off while we
390 		 * didn't have the quota inode lock.
391 		 */
392 		xfs_iunlock(quotip, XFS_ILOCK_SHARED);
393 		return ESRCH;
394 	}
395 
396 	/*
397 	 * Find the block map; no allocations yet
398 	 */
399 	error = xfs_bmapi_read(quotip, dqp->q_fileoffset,
400 			       XFS_DQUOT_CLUSTER_SIZE_FSB, &map, &nmaps, 0);
401 
402 	xfs_iunlock(quotip, XFS_ILOCK_SHARED);
403 	if (error)
404 		return error;
405 
406 	ASSERT(nmaps == 1);
407 	ASSERT(map.br_blockcount == 1);
408 
409 	/*
410 	 * Offset of dquot in the (fixed sized) dquot chunk.
411 	 */
412 	dqp->q_bufoffset = (id % mp->m_quotainfo->qi_dqperchunk) *
413 		sizeof(xfs_dqblk_t);
414 
415 	ASSERT(map.br_startblock != DELAYSTARTBLOCK);
416 	if (map.br_startblock == HOLESTARTBLOCK) {
417 		/*
418 		 * We don't allocate unless we're asked to
419 		 */
420 		if (!(flags & XFS_QMOPT_DQALLOC))
421 			return ENOENT;
422 
423 		ASSERT(tp);
424 		error = xfs_qm_dqalloc(tpp, mp, dqp, quotip,
425 					dqp->q_fileoffset, &bp);
426 		if (error)
427 			return error;
428 		tp = *tpp;
429 	} else {
430 		trace_xfs_dqtobp_read(dqp);
431 
432 		/*
433 		 * store the blkno etc so that we don't have to do the
434 		 * mapping all the time
435 		 */
436 		dqp->q_blkno = XFS_FSB_TO_DADDR(mp, map.br_startblock);
437 
438 		error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
439 					   dqp->q_blkno,
440 					   mp->m_quotainfo->qi_dqchunklen,
441 					   0, &bp);
442 		if (error || !bp)
443 			return XFS_ERROR(error);
444 	}
445 
446 	ASSERT(xfs_buf_islocked(bp));
447 
448 	/*
449 	 * calculate the location of the dquot inside the buffer.
450 	 */
451 	ddq = bp->b_addr + dqp->q_bufoffset;
452 
453 	/*
454 	 * A simple sanity check in case we got a corrupted dquot...
455 	 */
456 	error = xfs_qm_dqcheck(mp, ddq, id, dqp->dq_flags & XFS_DQ_ALLTYPES,
457 			   flags & (XFS_QMOPT_DQREPAIR|XFS_QMOPT_DOWARN),
458 			   "dqtobp");
459 	if (error) {
460 		if (!(flags & XFS_QMOPT_DQREPAIR)) {
461 			xfs_trans_brelse(tp, bp);
462 			return XFS_ERROR(EIO);
463 		}
464 	}
465 
466 	*O_bpp = bp;
467 	*O_ddpp = ddq;
468 
469 	return (0);
470 }
471 
472 
473 /*
474  * Read in the ondisk dquot using dqtobp() then copy it to an incore version,
475  * and release the buffer immediately.
476  *
477  * If XFS_QMOPT_DQALLOC is set, allocate a dquot on disk if it needed.
478  */
479 int
480 xfs_qm_dqread(
481 	struct xfs_mount	*mp,
482 	xfs_dqid_t		id,
483 	uint			type,
484 	uint			flags,
485 	struct xfs_dquot	**O_dqpp)
486 {
487 	struct xfs_dquot	*dqp;
488 	struct xfs_disk_dquot	*ddqp;
489 	struct xfs_buf		*bp;
490 	struct xfs_trans	*tp = NULL;
491 	int			error;
492 	int			cancelflags = 0;
493 
494 
495 	dqp = kmem_zone_zalloc(xfs_Gqm->qm_dqzone, KM_SLEEP);
496 
497 	dqp->dq_flags = type;
498 	dqp->q_core.d_id = cpu_to_be32(id);
499 	dqp->q_mount = mp;
500 	INIT_LIST_HEAD(&dqp->q_freelist);
501 	mutex_init(&dqp->q_qlock);
502 	init_waitqueue_head(&dqp->q_pinwait);
503 
504 	/*
505 	 * Because we want to use a counting completion, complete
506 	 * the flush completion once to allow a single access to
507 	 * the flush completion without blocking.
508 	 */
509 	init_completion(&dqp->q_flush);
510 	complete(&dqp->q_flush);
511 
512 	/*
513 	 * Make sure group quotas have a different lock class than user
514 	 * quotas.
515 	 */
516 	if (!(type & XFS_DQ_USER))
517 		lockdep_set_class(&dqp->q_qlock, &xfs_dquot_other_class);
518 
519 	atomic_inc(&xfs_Gqm->qm_totaldquots);
520 
521 	trace_xfs_dqread(dqp);
522 
523 	if (flags & XFS_QMOPT_DQALLOC) {
524 		tp = xfs_trans_alloc(mp, XFS_TRANS_QM_DQALLOC);
525 		error = xfs_trans_reserve(tp, XFS_QM_DQALLOC_SPACE_RES(mp),
526 				XFS_WRITE_LOG_RES(mp) +
527 				/*
528 				 * Round the chunklen up to the next multiple
529 				 * of 128 (buf log item chunk size)).
530 				 */
531 				BBTOB(mp->m_quotainfo->qi_dqchunklen) - 1 + 128,
532 				0,
533 				XFS_TRANS_PERM_LOG_RES,
534 				XFS_WRITE_LOG_COUNT);
535 		if (error)
536 			goto error1;
537 		cancelflags = XFS_TRANS_RELEASE_LOG_RES;
538 	}
539 
540 	/*
541 	 * get a pointer to the on-disk dquot and the buffer containing it
542 	 * dqp already knows its own type (GROUP/USER).
543 	 */
544 	error = xfs_qm_dqtobp(&tp, dqp, &ddqp, &bp, flags);
545 	if (error) {
546 		/*
547 		 * This can happen if quotas got turned off (ESRCH),
548 		 * or if the dquot didn't exist on disk and we ask to
549 		 * allocate (ENOENT).
550 		 */
551 		trace_xfs_dqread_fail(dqp);
552 		cancelflags |= XFS_TRANS_ABORT;
553 		goto error1;
554 	}
555 
556 	/* copy everything from disk dquot to the incore dquot */
557 	memcpy(&dqp->q_core, ddqp, sizeof(xfs_disk_dquot_t));
558 	xfs_qm_dquot_logitem_init(dqp);
559 
560 	/*
561 	 * Reservation counters are defined as reservation plus current usage
562 	 * to avoid having to add every time.
563 	 */
564 	dqp->q_res_bcount = be64_to_cpu(ddqp->d_bcount);
565 	dqp->q_res_icount = be64_to_cpu(ddqp->d_icount);
566 	dqp->q_res_rtbcount = be64_to_cpu(ddqp->d_rtbcount);
567 
568 	/* Mark the buf so that this will stay incore a little longer */
569 	xfs_buf_set_ref(bp, XFS_DQUOT_REF);
570 
571 	/*
572 	 * We got the buffer with a xfs_trans_read_buf() (in dqtobp())
573 	 * So we need to release with xfs_trans_brelse().
574 	 * The strategy here is identical to that of inodes; we lock
575 	 * the dquot in xfs_qm_dqget() before making it accessible to
576 	 * others. This is because dquots, like inodes, need a good level of
577 	 * concurrency, and we don't want to take locks on the entire buffers
578 	 * for dquot accesses.
579 	 * Note also that the dquot buffer may even be dirty at this point, if
580 	 * this particular dquot was repaired. We still aren't afraid to
581 	 * brelse it because we have the changes incore.
582 	 */
583 	ASSERT(xfs_buf_islocked(bp));
584 	xfs_trans_brelse(tp, bp);
585 
586 	if (tp) {
587 		error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
588 		if (error)
589 			goto error0;
590 	}
591 
592 	*O_dqpp = dqp;
593 	return error;
594 
595 error1:
596 	if (tp)
597 		xfs_trans_cancel(tp, cancelflags);
598 error0:
599 	xfs_qm_dqdestroy(dqp);
600 	*O_dqpp = NULL;
601 	return error;
602 }
603 
604 /*
605  * Lookup a dquot in the incore dquot hashtable. We keep two separate
606  * hashtables for user and group dquots; and, these are global tables
607  * inside the XQM, not per-filesystem tables.
608  * The hash chain must be locked by caller, and it is left locked
609  * on return. Returning dquot is locked.
610  */
611 STATIC int
612 xfs_qm_dqlookup(
613 	xfs_mount_t		*mp,
614 	xfs_dqid_t		id,
615 	xfs_dqhash_t		*qh,
616 	xfs_dquot_t		**O_dqpp)
617 {
618 	xfs_dquot_t		*dqp;
619 
620 	ASSERT(mutex_is_locked(&qh->qh_lock));
621 
622 	/*
623 	 * Traverse the hashchain looking for a match
624 	 */
625 	list_for_each_entry(dqp, &qh->qh_list, q_hashlist) {
626 		/*
627 		 * We already have the hashlock. We don't need the
628 		 * dqlock to look at the id field of the dquot, since the
629 		 * id can't be modified without the hashlock anyway.
630 		 */
631 		if (be32_to_cpu(dqp->q_core.d_id) != id || dqp->q_mount != mp)
632 			continue;
633 
634 		trace_xfs_dqlookup_found(dqp);
635 
636 		xfs_dqlock(dqp);
637 		if (dqp->dq_flags & XFS_DQ_FREEING) {
638 			*O_dqpp = NULL;
639 			xfs_dqunlock(dqp);
640 			return -1;
641 		}
642 
643 		dqp->q_nrefs++;
644 
645 		/*
646 		 * move the dquot to the front of the hashchain
647 		 */
648 		list_move(&dqp->q_hashlist, &qh->qh_list);
649 		trace_xfs_dqlookup_done(dqp);
650 		*O_dqpp = dqp;
651 		return 0;
652 	}
653 
654 	*O_dqpp = NULL;
655 	return 1;
656 }
657 
658 /*
659  * Given the file system, inode OR id, and type (UDQUOT/GDQUOT), return a
660  * a locked dquot, doing an allocation (if requested) as needed.
661  * When both an inode and an id are given, the inode's id takes precedence.
662  * That is, if the id changes while we don't hold the ilock inside this
663  * function, the new dquot is returned, not necessarily the one requested
664  * in the id argument.
665  */
666 int
667 xfs_qm_dqget(
668 	xfs_mount_t	*mp,
669 	xfs_inode_t	*ip,	  /* locked inode (optional) */
670 	xfs_dqid_t	id,	  /* uid/projid/gid depending on type */
671 	uint		type,	  /* XFS_DQ_USER/XFS_DQ_PROJ/XFS_DQ_GROUP */
672 	uint		flags,	  /* DQALLOC, DQSUSER, DQREPAIR, DOWARN */
673 	xfs_dquot_t	**O_dqpp) /* OUT : locked incore dquot */
674 {
675 	xfs_dquot_t	*dqp;
676 	xfs_dqhash_t	*h;
677 	uint		version;
678 	int		error;
679 
680 	ASSERT(XFS_IS_QUOTA_RUNNING(mp));
681 	if ((! XFS_IS_UQUOTA_ON(mp) && type == XFS_DQ_USER) ||
682 	    (! XFS_IS_PQUOTA_ON(mp) && type == XFS_DQ_PROJ) ||
683 	    (! XFS_IS_GQUOTA_ON(mp) && type == XFS_DQ_GROUP)) {
684 		return (ESRCH);
685 	}
686 	h = XFS_DQ_HASH(mp, id, type);
687 
688 #ifdef DEBUG
689 	if (xfs_do_dqerror) {
690 		if ((xfs_dqerror_target == mp->m_ddev_targp) &&
691 		    (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
692 			xfs_debug(mp, "Returning error in dqget");
693 			return (EIO);
694 		}
695 	}
696 
697 	ASSERT(type == XFS_DQ_USER ||
698 	       type == XFS_DQ_PROJ ||
699 	       type == XFS_DQ_GROUP);
700 	if (ip) {
701 		ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
702 		if (type == XFS_DQ_USER)
703 			ASSERT(ip->i_udquot == NULL);
704 		else
705 			ASSERT(ip->i_gdquot == NULL);
706 	}
707 #endif
708 
709 restart:
710 	mutex_lock(&h->qh_lock);
711 
712 	/*
713 	 * Look in the cache (hashtable).
714 	 * The chain is kept locked during lookup.
715 	 */
716 	switch (xfs_qm_dqlookup(mp, id, h, O_dqpp)) {
717 	case -1:
718 		XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
719 		mutex_unlock(&h->qh_lock);
720 		delay(1);
721 		goto restart;
722 	case 0:
723 		XQM_STATS_INC(xqmstats.xs_qm_dqcachehits);
724 		/*
725 		 * The dquot was found, moved to the front of the chain,
726 		 * taken off the freelist if it was on it, and locked
727 		 * at this point. Just unlock the hashchain and return.
728 		 */
729 		ASSERT(*O_dqpp);
730 		ASSERT(XFS_DQ_IS_LOCKED(*O_dqpp));
731 		mutex_unlock(&h->qh_lock);
732 		trace_xfs_dqget_hit(*O_dqpp);
733 		return 0;	/* success */
734 	default:
735 		XQM_STATS_INC(xqmstats.xs_qm_dqcachemisses);
736 		break;
737 	}
738 
739 	/*
740 	 * Dquot cache miss. We don't want to keep the inode lock across
741 	 * a (potential) disk read. Also we don't want to deal with the lock
742 	 * ordering between quotainode and this inode. OTOH, dropping the inode
743 	 * lock here means dealing with a chown that can happen before
744 	 * we re-acquire the lock.
745 	 */
746 	if (ip)
747 		xfs_iunlock(ip, XFS_ILOCK_EXCL);
748 	/*
749 	 * Save the hashchain version stamp, and unlock the chain, so that
750 	 * we don't keep the lock across a disk read
751 	 */
752 	version = h->qh_version;
753 	mutex_unlock(&h->qh_lock);
754 
755 	error = xfs_qm_dqread(mp, id, type, flags, &dqp);
756 
757 	if (ip)
758 		xfs_ilock(ip, XFS_ILOCK_EXCL);
759 
760 	if (error)
761 		return error;
762 
763 	/*
764 	 * Dquot lock comes after hashlock in the lock ordering
765 	 */
766 	if (ip) {
767 		/*
768 		 * A dquot could be attached to this inode by now, since
769 		 * we had dropped the ilock.
770 		 */
771 		if (type == XFS_DQ_USER) {
772 			if (!XFS_IS_UQUOTA_ON(mp)) {
773 				/* inode stays locked on return */
774 				xfs_qm_dqdestroy(dqp);
775 				return XFS_ERROR(ESRCH);
776 			}
777 			if (ip->i_udquot) {
778 				xfs_qm_dqdestroy(dqp);
779 				dqp = ip->i_udquot;
780 				xfs_dqlock(dqp);
781 				goto dqret;
782 			}
783 		} else {
784 			if (!XFS_IS_OQUOTA_ON(mp)) {
785 				/* inode stays locked on return */
786 				xfs_qm_dqdestroy(dqp);
787 				return XFS_ERROR(ESRCH);
788 			}
789 			if (ip->i_gdquot) {
790 				xfs_qm_dqdestroy(dqp);
791 				dqp = ip->i_gdquot;
792 				xfs_dqlock(dqp);
793 				goto dqret;
794 			}
795 		}
796 	}
797 
798 	/*
799 	 * Hashlock comes after ilock in lock order
800 	 */
801 	mutex_lock(&h->qh_lock);
802 	if (version != h->qh_version) {
803 		xfs_dquot_t *tmpdqp;
804 		/*
805 		 * Now, see if somebody else put the dquot in the
806 		 * hashtable before us. This can happen because we didn't
807 		 * keep the hashchain lock. We don't have to worry about
808 		 * lock order between the two dquots here since dqp isn't
809 		 * on any findable lists yet.
810 		 */
811 		switch (xfs_qm_dqlookup(mp, id, h, &tmpdqp)) {
812 		case 0:
813 		case -1:
814 			/*
815 			 * Duplicate found, either in cache or on its way out.
816 			 * Just throw away the new dquot and start over.
817 			 */
818 			if (tmpdqp)
819 				xfs_qm_dqput(tmpdqp);
820 			mutex_unlock(&h->qh_lock);
821 			xfs_qm_dqdestroy(dqp);
822 			XQM_STATS_INC(xqmstats.xs_qm_dquot_dups);
823 			goto restart;
824 		default:
825 			break;
826 		}
827 	}
828 
829 	/*
830 	 * Put the dquot at the beginning of the hash-chain and mp's list
831 	 * LOCK ORDER: hashlock, freelistlock, mplistlock, udqlock, gdqlock ..
832 	 */
833 	ASSERT(mutex_is_locked(&h->qh_lock));
834 	dqp->q_hash = h;
835 	list_add(&dqp->q_hashlist, &h->qh_list);
836 	h->qh_version++;
837 
838 	/*
839 	 * Attach this dquot to this filesystem's list of all dquots,
840 	 * kept inside the mount structure in m_quotainfo field
841 	 */
842 	mutex_lock(&mp->m_quotainfo->qi_dqlist_lock);
843 
844 	/*
845 	 * We return a locked dquot to the caller, with a reference taken
846 	 */
847 	xfs_dqlock(dqp);
848 	dqp->q_nrefs = 1;
849 
850 	list_add(&dqp->q_mplist, &mp->m_quotainfo->qi_dqlist);
851 	mp->m_quotainfo->qi_dquots++;
852 	mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
853 	mutex_unlock(&h->qh_lock);
854  dqret:
855 	ASSERT((ip == NULL) || xfs_isilocked(ip, XFS_ILOCK_EXCL));
856 	trace_xfs_dqget_miss(dqp);
857 	*O_dqpp = dqp;
858 	return (0);
859 }
860 
861 
862 /*
863  * Release a reference to the dquot (decrement ref-count)
864  * and unlock it. If there is a group quota attached to this
865  * dquot, carefully release that too without tripping over
866  * deadlocks'n'stuff.
867  */
868 void
869 xfs_qm_dqput(
870 	struct xfs_dquot	*dqp)
871 {
872 	struct xfs_dquot	*gdqp;
873 
874 	ASSERT(dqp->q_nrefs > 0);
875 	ASSERT(XFS_DQ_IS_LOCKED(dqp));
876 
877 	trace_xfs_dqput(dqp);
878 
879 recurse:
880 	if (--dqp->q_nrefs > 0) {
881 		xfs_dqunlock(dqp);
882 		return;
883 	}
884 
885 	trace_xfs_dqput_free(dqp);
886 
887 	mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
888 	if (list_empty(&dqp->q_freelist)) {
889 		list_add_tail(&dqp->q_freelist, &xfs_Gqm->qm_dqfrlist);
890 		xfs_Gqm->qm_dqfrlist_cnt++;
891 	}
892 	mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
893 
894 	/*
895 	 * If we just added a udquot to the freelist, then we want to release
896 	 * the gdquot reference that it (probably) has. Otherwise it'll keep
897 	 * the gdquot from getting reclaimed.
898 	 */
899 	gdqp = dqp->q_gdquot;
900 	if (gdqp) {
901 		xfs_dqlock(gdqp);
902 		dqp->q_gdquot = NULL;
903 	}
904 	xfs_dqunlock(dqp);
905 
906 	/*
907 	 * If we had a group quota hint, release it now.
908 	 */
909 	if (gdqp) {
910 		dqp = gdqp;
911 		goto recurse;
912 	}
913 }
914 
915 /*
916  * Release a dquot. Flush it if dirty, then dqput() it.
917  * dquot must not be locked.
918  */
919 void
920 xfs_qm_dqrele(
921 	xfs_dquot_t	*dqp)
922 {
923 	if (!dqp)
924 		return;
925 
926 	trace_xfs_dqrele(dqp);
927 
928 	xfs_dqlock(dqp);
929 	/*
930 	 * We don't care to flush it if the dquot is dirty here.
931 	 * That will create stutters that we want to avoid.
932 	 * Instead we do a delayed write when we try to reclaim
933 	 * a dirty dquot. Also xfs_sync will take part of the burden...
934 	 */
935 	xfs_qm_dqput(dqp);
936 }
937 
938 /*
939  * This is the dquot flushing I/O completion routine.  It is called
940  * from interrupt level when the buffer containing the dquot is
941  * flushed to disk.  It is responsible for removing the dquot logitem
942  * from the AIL if it has not been re-logged, and unlocking the dquot's
943  * flush lock. This behavior is very similar to that of inodes..
944  */
945 STATIC void
946 xfs_qm_dqflush_done(
947 	struct xfs_buf		*bp,
948 	struct xfs_log_item	*lip)
949 {
950 	xfs_dq_logitem_t	*qip = (struct xfs_dq_logitem *)lip;
951 	xfs_dquot_t		*dqp = qip->qli_dquot;
952 	struct xfs_ail		*ailp = lip->li_ailp;
953 
954 	/*
955 	 * We only want to pull the item from the AIL if its
956 	 * location in the log has not changed since we started the flush.
957 	 * Thus, we only bother if the dquot's lsn has
958 	 * not changed. First we check the lsn outside the lock
959 	 * since it's cheaper, and then we recheck while
960 	 * holding the lock before removing the dquot from the AIL.
961 	 */
962 	if ((lip->li_flags & XFS_LI_IN_AIL) &&
963 	    lip->li_lsn == qip->qli_flush_lsn) {
964 
965 		/* xfs_trans_ail_delete() drops the AIL lock. */
966 		spin_lock(&ailp->xa_lock);
967 		if (lip->li_lsn == qip->qli_flush_lsn)
968 			xfs_trans_ail_delete(ailp, lip);
969 		else
970 			spin_unlock(&ailp->xa_lock);
971 	}
972 
973 	/*
974 	 * Release the dq's flush lock since we're done with it.
975 	 */
976 	xfs_dqfunlock(dqp);
977 }
978 
979 /*
980  * Write a modified dquot to disk.
981  * The dquot must be locked and the flush lock too taken by caller.
982  * The flush lock will not be unlocked until the dquot reaches the disk,
983  * but the dquot is free to be unlocked and modified by the caller
984  * in the interim. Dquot is still locked on return. This behavior is
985  * identical to that of inodes.
986  */
987 int
988 xfs_qm_dqflush(
989 	xfs_dquot_t		*dqp,
990 	uint			flags)
991 {
992 	struct xfs_mount	*mp = dqp->q_mount;
993 	struct xfs_buf		*bp;
994 	struct xfs_disk_dquot	*ddqp;
995 	int			error;
996 
997 	ASSERT(XFS_DQ_IS_LOCKED(dqp));
998 	ASSERT(!completion_done(&dqp->q_flush));
999 
1000 	trace_xfs_dqflush(dqp);
1001 
1002 	/*
1003 	 * If not dirty, or it's pinned and we are not supposed to block, nada.
1004 	 */
1005 	if (!XFS_DQ_IS_DIRTY(dqp) ||
1006 	    ((flags & SYNC_TRYLOCK) && atomic_read(&dqp->q_pincount) > 0)) {
1007 		xfs_dqfunlock(dqp);
1008 		return 0;
1009 	}
1010 	xfs_qm_dqunpin_wait(dqp);
1011 
1012 	/*
1013 	 * This may have been unpinned because the filesystem is shutting
1014 	 * down forcibly. If that's the case we must not write this dquot
1015 	 * to disk, because the log record didn't make it to disk!
1016 	 */
1017 	if (XFS_FORCED_SHUTDOWN(mp)) {
1018 		dqp->dq_flags &= ~XFS_DQ_DIRTY;
1019 		xfs_dqfunlock(dqp);
1020 		return XFS_ERROR(EIO);
1021 	}
1022 
1023 	/*
1024 	 * Get the buffer containing the on-disk dquot
1025 	 */
1026 	error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
1027 				   mp->m_quotainfo->qi_dqchunklen, 0, &bp);
1028 	if (error) {
1029 		ASSERT(error != ENOENT);
1030 		xfs_dqfunlock(dqp);
1031 		return error;
1032 	}
1033 
1034 	/*
1035 	 * Calculate the location of the dquot inside the buffer.
1036 	 */
1037 	ddqp = bp->b_addr + dqp->q_bufoffset;
1038 
1039 	/*
1040 	 * A simple sanity check in case we got a corrupted dquot..
1041 	 */
1042 	error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
1043 			   XFS_QMOPT_DOWARN, "dqflush (incore copy)");
1044 	if (error) {
1045 		xfs_buf_relse(bp);
1046 		xfs_dqfunlock(dqp);
1047 		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1048 		return XFS_ERROR(EIO);
1049 	}
1050 
1051 	/* This is the only portion of data that needs to persist */
1052 	memcpy(ddqp, &dqp->q_core, sizeof(xfs_disk_dquot_t));
1053 
1054 	/*
1055 	 * Clear the dirty field and remember the flush lsn for later use.
1056 	 */
1057 	dqp->dq_flags &= ~XFS_DQ_DIRTY;
1058 
1059 	xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
1060 					&dqp->q_logitem.qli_item.li_lsn);
1061 
1062 	/*
1063 	 * Attach an iodone routine so that we can remove this dquot from the
1064 	 * AIL and release the flush lock once the dquot is synced to disk.
1065 	 */
1066 	xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
1067 				  &dqp->q_logitem.qli_item);
1068 
1069 	/*
1070 	 * If the buffer is pinned then push on the log so we won't
1071 	 * get stuck waiting in the write for too long.
1072 	 */
1073 	if (xfs_buf_ispinned(bp)) {
1074 		trace_xfs_dqflush_force(dqp);
1075 		xfs_log_force(mp, 0);
1076 	}
1077 
1078 	if (flags & SYNC_WAIT)
1079 		error = xfs_bwrite(bp);
1080 	else
1081 		xfs_buf_delwri_queue(bp);
1082 
1083 	xfs_buf_relse(bp);
1084 
1085 	trace_xfs_dqflush_done(dqp);
1086 
1087 	/*
1088 	 * dqp is still locked, but caller is free to unlock it now.
1089 	 */
1090 	return error;
1091 
1092 }
1093 
1094 void
1095 xfs_dqunlock(
1096 	xfs_dquot_t *dqp)
1097 {
1098 	xfs_dqunlock_nonotify(dqp);
1099 	if (dqp->q_logitem.qli_dquot == dqp) {
1100 		xfs_trans_unlocked_item(dqp->q_logitem.qli_item.li_ailp,
1101 					&dqp->q_logitem.qli_item);
1102 	}
1103 }
1104 
1105 /*
1106  * Lock two xfs_dquot structures.
1107  *
1108  * To avoid deadlocks we always lock the quota structure with
1109  * the lowerd id first.
1110  */
1111 void
1112 xfs_dqlock2(
1113 	xfs_dquot_t	*d1,
1114 	xfs_dquot_t	*d2)
1115 {
1116 	if (d1 && d2) {
1117 		ASSERT(d1 != d2);
1118 		if (be32_to_cpu(d1->q_core.d_id) >
1119 		    be32_to_cpu(d2->q_core.d_id)) {
1120 			mutex_lock(&d2->q_qlock);
1121 			mutex_lock_nested(&d1->q_qlock, XFS_QLOCK_NESTED);
1122 		} else {
1123 			mutex_lock(&d1->q_qlock);
1124 			mutex_lock_nested(&d2->q_qlock, XFS_QLOCK_NESTED);
1125 		}
1126 	} else if (d1) {
1127 		mutex_lock(&d1->q_qlock);
1128 	} else if (d2) {
1129 		mutex_lock(&d2->q_qlock);
1130 	}
1131 }
1132 
1133 /*
1134  * Take a dquot out of the mount's dqlist as well as the hashlist.  This is
1135  * called via unmount as well as quotaoff, and the purge will always succeed.
1136  */
1137 void
1138 xfs_qm_dqpurge(
1139 	struct xfs_dquot	*dqp)
1140 {
1141 	struct xfs_mount	*mp = dqp->q_mount;
1142 	struct xfs_dqhash	*qh = dqp->q_hash;
1143 
1144 	xfs_dqlock(dqp);
1145 
1146 	/*
1147 	 * If we're turning off quotas, we have to make sure that, for
1148 	 * example, we don't delete quota disk blocks while dquots are
1149 	 * in the process of getting written to those disk blocks.
1150 	 * This dquot might well be on AIL, and we can't leave it there
1151 	 * if we're turning off quotas. Basically, we need this flush
1152 	 * lock, and are willing to block on it.
1153 	 */
1154 	if (!xfs_dqflock_nowait(dqp)) {
1155 		/*
1156 		 * Block on the flush lock after nudging dquot buffer,
1157 		 * if it is incore.
1158 		 */
1159 		xfs_dqflock_pushbuf_wait(dqp);
1160 	}
1161 
1162 	/*
1163 	 * If we are turning this type of quotas off, we don't care
1164 	 * about the dirty metadata sitting in this dquot. OTOH, if
1165 	 * we're unmounting, we do care, so we flush it and wait.
1166 	 */
1167 	if (XFS_DQ_IS_DIRTY(dqp)) {
1168 		int	error;
1169 
1170 		/*
1171 		 * We don't care about getting disk errors here. We need
1172 		 * to purge this dquot anyway, so we go ahead regardless.
1173 		 */
1174 		error = xfs_qm_dqflush(dqp, SYNC_WAIT);
1175 		if (error)
1176 			xfs_warn(mp, "%s: dquot %p flush failed",
1177 				__func__, dqp);
1178 		xfs_dqflock(dqp);
1179 	}
1180 
1181 	ASSERT(atomic_read(&dqp->q_pincount) == 0);
1182 	ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
1183 	       !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));
1184 
1185 	xfs_dqfunlock(dqp);
1186 	xfs_dqunlock(dqp);
1187 
1188 	mutex_lock(&qh->qh_lock);
1189 	list_del_init(&dqp->q_hashlist);
1190 	qh->qh_version++;
1191 	mutex_unlock(&qh->qh_lock);
1192 
1193 	mutex_lock(&mp->m_quotainfo->qi_dqlist_lock);
1194 	list_del_init(&dqp->q_mplist);
1195 	mp->m_quotainfo->qi_dqreclaims++;
1196 	mp->m_quotainfo->qi_dquots--;
1197 	mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
1198 
1199 	/*
1200 	 * We move dquots to the freelist as soon as their reference count
1201 	 * hits zero, so it really should be on the freelist here.
1202 	 */
1203 	mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
1204 	ASSERT(!list_empty(&dqp->q_freelist));
1205 	list_del_init(&dqp->q_freelist);
1206 	xfs_Gqm->qm_dqfrlist_cnt--;
1207 	mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
1208 
1209 	xfs_qm_dqdestroy(dqp);
1210 }
1211 
1212 /*
1213  * Give the buffer a little push if it is incore and
1214  * wait on the flush lock.
1215  */
1216 void
1217 xfs_dqflock_pushbuf_wait(
1218 	xfs_dquot_t	*dqp)
1219 {
1220 	xfs_mount_t	*mp = dqp->q_mount;
1221 	xfs_buf_t	*bp;
1222 
1223 	/*
1224 	 * Check to see if the dquot has been flushed delayed
1225 	 * write.  If so, grab its buffer and send it
1226 	 * out immediately.  We'll be able to acquire
1227 	 * the flush lock when the I/O completes.
1228 	 */
1229 	bp = xfs_incore(mp->m_ddev_targp, dqp->q_blkno,
1230 			mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);
1231 	if (!bp)
1232 		goto out_lock;
1233 
1234 	if (XFS_BUF_ISDELAYWRITE(bp)) {
1235 		if (xfs_buf_ispinned(bp))
1236 			xfs_log_force(mp, 0);
1237 		xfs_buf_delwri_promote(bp);
1238 		wake_up_process(bp->b_target->bt_task);
1239 	}
1240 	xfs_buf_relse(bp);
1241 out_lock:
1242 	xfs_dqflock(dqp);
1243 }
1244