xref: /openbmc/linux/fs/xfs/xfs_trans.c (revision b34e08d5)
1 /*
2  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
3  * Copyright (C) 2010 Red Hat, Inc.
4  * All Rights Reserved.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it would be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write the Free Software Foundation,
17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18  */
19 #include "xfs.h"
20 #include "xfs_fs.h"
21 #include "xfs_shared.h"
22 #include "xfs_format.h"
23 #include "xfs_log_format.h"
24 #include "xfs_trans_resv.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_mount.h"
28 #include "xfs_inode.h"
29 #include "xfs_extent_busy.h"
30 #include "xfs_quota.h"
31 #include "xfs_trans.h"
32 #include "xfs_trans_priv.h"
33 #include "xfs_log.h"
34 #include "xfs_trace.h"
35 #include "xfs_error.h"
36 
37 kmem_zone_t	*xfs_trans_zone;
38 kmem_zone_t	*xfs_log_item_desc_zone;
39 
40 /*
41  * Initialize the precomputed transaction reservation values
42  * in the mount structure.
43  */
44 void
45 xfs_trans_init(
46 	struct xfs_mount	*mp)
47 {
48 	xfs_trans_resv_calc(mp, M_RES(mp));
49 }
50 
51 /*
52  * This routine is called to allocate a transaction structure.
53  * The type parameter indicates the type of the transaction.  These
54  * are enumerated in xfs_trans.h.
55  *
56  * Dynamically allocate the transaction structure from the transaction
57  * zone, initialize it, and return it to the caller.
58  */
59 xfs_trans_t *
60 xfs_trans_alloc(
61 	xfs_mount_t	*mp,
62 	uint		type)
63 {
64 	xfs_trans_t     *tp;
65 
66 	sb_start_intwrite(mp->m_super);
67 	tp = _xfs_trans_alloc(mp, type, KM_SLEEP);
68 	tp->t_flags |= XFS_TRANS_FREEZE_PROT;
69 	return tp;
70 }
71 
72 xfs_trans_t *
73 _xfs_trans_alloc(
74 	xfs_mount_t	*mp,
75 	uint		type,
76 	xfs_km_flags_t	memflags)
77 {
78 	xfs_trans_t	*tp;
79 
80 	WARN_ON(mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
81 	atomic_inc(&mp->m_active_trans);
82 
83 	tp = kmem_zone_zalloc(xfs_trans_zone, memflags);
84 	tp->t_magic = XFS_TRANS_HEADER_MAGIC;
85 	tp->t_type = type;
86 	tp->t_mountp = mp;
87 	INIT_LIST_HEAD(&tp->t_items);
88 	INIT_LIST_HEAD(&tp->t_busy);
89 	return tp;
90 }
91 
92 /*
93  * Free the transaction structure.  If there is more clean up
94  * to do when the structure is freed, add it here.
95  */
96 STATIC void
97 xfs_trans_free(
98 	struct xfs_trans	*tp)
99 {
100 	xfs_extent_busy_sort(&tp->t_busy);
101 	xfs_extent_busy_clear(tp->t_mountp, &tp->t_busy, false);
102 
103 	atomic_dec(&tp->t_mountp->m_active_trans);
104 	if (tp->t_flags & XFS_TRANS_FREEZE_PROT)
105 		sb_end_intwrite(tp->t_mountp->m_super);
106 	xfs_trans_free_dqinfo(tp);
107 	kmem_zone_free(xfs_trans_zone, tp);
108 }
109 
110 /*
111  * This is called to create a new transaction which will share the
112  * permanent log reservation of the given transaction.  The remaining
113  * unused block and rt extent reservations are also inherited.  This
114  * implies that the original transaction is no longer allowed to allocate
115  * blocks.  Locks and log items, however, are no inherited.  They must
116  * be added to the new transaction explicitly.
117  */
118 xfs_trans_t *
119 xfs_trans_dup(
120 	xfs_trans_t	*tp)
121 {
122 	xfs_trans_t	*ntp;
123 
124 	ntp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP);
125 
126 	/*
127 	 * Initialize the new transaction structure.
128 	 */
129 	ntp->t_magic = XFS_TRANS_HEADER_MAGIC;
130 	ntp->t_type = tp->t_type;
131 	ntp->t_mountp = tp->t_mountp;
132 	INIT_LIST_HEAD(&ntp->t_items);
133 	INIT_LIST_HEAD(&ntp->t_busy);
134 
135 	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
136 	ASSERT(tp->t_ticket != NULL);
137 
138 	ntp->t_flags = XFS_TRANS_PERM_LOG_RES |
139 		       (tp->t_flags & XFS_TRANS_RESERVE) |
140 		       (tp->t_flags & XFS_TRANS_FREEZE_PROT);
141 	/* We gave our writer reference to the new transaction */
142 	tp->t_flags &= ~XFS_TRANS_FREEZE_PROT;
143 	ntp->t_ticket = xfs_log_ticket_get(tp->t_ticket);
144 	ntp->t_blk_res = tp->t_blk_res - tp->t_blk_res_used;
145 	tp->t_blk_res = tp->t_blk_res_used;
146 	ntp->t_rtx_res = tp->t_rtx_res - tp->t_rtx_res_used;
147 	tp->t_rtx_res = tp->t_rtx_res_used;
148 	ntp->t_pflags = tp->t_pflags;
149 
150 	xfs_trans_dup_dqinfo(tp, ntp);
151 
152 	atomic_inc(&tp->t_mountp->m_active_trans);
153 	return ntp;
154 }
155 
156 /*
157  * This is called to reserve free disk blocks and log space for the
158  * given transaction.  This must be done before allocating any resources
159  * within the transaction.
160  *
161  * This will return ENOSPC if there are not enough blocks available.
162  * It will sleep waiting for available log space.
163  * The only valid value for the flags parameter is XFS_RES_LOG_PERM, which
164  * is used by long running transactions.  If any one of the reservations
165  * fails then they will all be backed out.
166  *
167  * This does not do quota reservations. That typically is done by the
168  * caller afterwards.
169  */
170 int
171 xfs_trans_reserve(
172 	struct xfs_trans	*tp,
173 	struct xfs_trans_res	*resp,
174 	uint			blocks,
175 	uint			rtextents)
176 {
177 	int		error = 0;
178 	int		rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
179 
180 	/* Mark this thread as being in a transaction */
181 	current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
182 
183 	/*
184 	 * Attempt to reserve the needed disk blocks by decrementing
185 	 * the number needed from the number available.  This will
186 	 * fail if the count would go below zero.
187 	 */
188 	if (blocks > 0) {
189 		error = xfs_icsb_modify_counters(tp->t_mountp, XFS_SBS_FDBLOCKS,
190 					  -((int64_t)blocks), rsvd);
191 		if (error != 0) {
192 			current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
193 			return (XFS_ERROR(ENOSPC));
194 		}
195 		tp->t_blk_res += blocks;
196 	}
197 
198 	/*
199 	 * Reserve the log space needed for this transaction.
200 	 */
201 	if (resp->tr_logres > 0) {
202 		bool	permanent = false;
203 
204 		ASSERT(tp->t_log_res == 0 ||
205 		       tp->t_log_res == resp->tr_logres);
206 		ASSERT(tp->t_log_count == 0 ||
207 		       tp->t_log_count == resp->tr_logcount);
208 
209 		if (resp->tr_logflags & XFS_TRANS_PERM_LOG_RES) {
210 			tp->t_flags |= XFS_TRANS_PERM_LOG_RES;
211 			permanent = true;
212 		} else {
213 			ASSERT(tp->t_ticket == NULL);
214 			ASSERT(!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
215 		}
216 
217 		if (tp->t_ticket != NULL) {
218 			ASSERT(resp->tr_logflags & XFS_TRANS_PERM_LOG_RES);
219 			error = xfs_log_regrant(tp->t_mountp, tp->t_ticket);
220 		} else {
221 			error = xfs_log_reserve(tp->t_mountp,
222 						resp->tr_logres,
223 						resp->tr_logcount,
224 						&tp->t_ticket, XFS_TRANSACTION,
225 						permanent, tp->t_type);
226 		}
227 
228 		if (error)
229 			goto undo_blocks;
230 
231 		tp->t_log_res = resp->tr_logres;
232 		tp->t_log_count = resp->tr_logcount;
233 	}
234 
235 	/*
236 	 * Attempt to reserve the needed realtime extents by decrementing
237 	 * the number needed from the number available.  This will
238 	 * fail if the count would go below zero.
239 	 */
240 	if (rtextents > 0) {
241 		error = xfs_mod_incore_sb(tp->t_mountp, XFS_SBS_FREXTENTS,
242 					  -((int64_t)rtextents), rsvd);
243 		if (error) {
244 			error = XFS_ERROR(ENOSPC);
245 			goto undo_log;
246 		}
247 		tp->t_rtx_res += rtextents;
248 	}
249 
250 	return 0;
251 
252 	/*
253 	 * Error cases jump to one of these labels to undo any
254 	 * reservations which have already been performed.
255 	 */
256 undo_log:
257 	if (resp->tr_logres > 0) {
258 		int		log_flags;
259 
260 		if (resp->tr_logflags & XFS_TRANS_PERM_LOG_RES) {
261 			log_flags = XFS_LOG_REL_PERM_RESERV;
262 		} else {
263 			log_flags = 0;
264 		}
265 		xfs_log_done(tp->t_mountp, tp->t_ticket, NULL, log_flags);
266 		tp->t_ticket = NULL;
267 		tp->t_log_res = 0;
268 		tp->t_flags &= ~XFS_TRANS_PERM_LOG_RES;
269 	}
270 
271 undo_blocks:
272 	if (blocks > 0) {
273 		xfs_icsb_modify_counters(tp->t_mountp, XFS_SBS_FDBLOCKS,
274 					 (int64_t)blocks, rsvd);
275 		tp->t_blk_res = 0;
276 	}
277 
278 	current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
279 
280 	return error;
281 }
282 
283 /*
284  * Record the indicated change to the given field for application
285  * to the file system's superblock when the transaction commits.
286  * For now, just store the change in the transaction structure.
287  *
288  * Mark the transaction structure to indicate that the superblock
289  * needs to be updated before committing.
290  *
291  * Because we may not be keeping track of allocated/free inodes and
292  * used filesystem blocks in the superblock, we do not mark the
293  * superblock dirty in this transaction if we modify these fields.
294  * We still need to update the transaction deltas so that they get
295  * applied to the incore superblock, but we don't want them to
296  * cause the superblock to get locked and logged if these are the
297  * only fields in the superblock that the transaction modifies.
298  */
299 void
300 xfs_trans_mod_sb(
301 	xfs_trans_t	*tp,
302 	uint		field,
303 	int64_t		delta)
304 {
305 	uint32_t	flags = (XFS_TRANS_DIRTY|XFS_TRANS_SB_DIRTY);
306 	xfs_mount_t	*mp = tp->t_mountp;
307 
308 	switch (field) {
309 	case XFS_TRANS_SB_ICOUNT:
310 		tp->t_icount_delta += delta;
311 		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
312 			flags &= ~XFS_TRANS_SB_DIRTY;
313 		break;
314 	case XFS_TRANS_SB_IFREE:
315 		tp->t_ifree_delta += delta;
316 		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
317 			flags &= ~XFS_TRANS_SB_DIRTY;
318 		break;
319 	case XFS_TRANS_SB_FDBLOCKS:
320 		/*
321 		 * Track the number of blocks allocated in the
322 		 * transaction.  Make sure it does not exceed the
323 		 * number reserved.
324 		 */
325 		if (delta < 0) {
326 			tp->t_blk_res_used += (uint)-delta;
327 			ASSERT(tp->t_blk_res_used <= tp->t_blk_res);
328 		}
329 		tp->t_fdblocks_delta += delta;
330 		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
331 			flags &= ~XFS_TRANS_SB_DIRTY;
332 		break;
333 	case XFS_TRANS_SB_RES_FDBLOCKS:
334 		/*
335 		 * The allocation has already been applied to the
336 		 * in-core superblock's counter.  This should only
337 		 * be applied to the on-disk superblock.
338 		 */
339 		ASSERT(delta < 0);
340 		tp->t_res_fdblocks_delta += delta;
341 		if (xfs_sb_version_haslazysbcount(&mp->m_sb))
342 			flags &= ~XFS_TRANS_SB_DIRTY;
343 		break;
344 	case XFS_TRANS_SB_FREXTENTS:
345 		/*
346 		 * Track the number of blocks allocated in the
347 		 * transaction.  Make sure it does not exceed the
348 		 * number reserved.
349 		 */
350 		if (delta < 0) {
351 			tp->t_rtx_res_used += (uint)-delta;
352 			ASSERT(tp->t_rtx_res_used <= tp->t_rtx_res);
353 		}
354 		tp->t_frextents_delta += delta;
355 		break;
356 	case XFS_TRANS_SB_RES_FREXTENTS:
357 		/*
358 		 * The allocation has already been applied to the
359 		 * in-core superblock's counter.  This should only
360 		 * be applied to the on-disk superblock.
361 		 */
362 		ASSERT(delta < 0);
363 		tp->t_res_frextents_delta += delta;
364 		break;
365 	case XFS_TRANS_SB_DBLOCKS:
366 		ASSERT(delta > 0);
367 		tp->t_dblocks_delta += delta;
368 		break;
369 	case XFS_TRANS_SB_AGCOUNT:
370 		ASSERT(delta > 0);
371 		tp->t_agcount_delta += delta;
372 		break;
373 	case XFS_TRANS_SB_IMAXPCT:
374 		tp->t_imaxpct_delta += delta;
375 		break;
376 	case XFS_TRANS_SB_REXTSIZE:
377 		tp->t_rextsize_delta += delta;
378 		break;
379 	case XFS_TRANS_SB_RBMBLOCKS:
380 		tp->t_rbmblocks_delta += delta;
381 		break;
382 	case XFS_TRANS_SB_RBLOCKS:
383 		tp->t_rblocks_delta += delta;
384 		break;
385 	case XFS_TRANS_SB_REXTENTS:
386 		tp->t_rextents_delta += delta;
387 		break;
388 	case XFS_TRANS_SB_REXTSLOG:
389 		tp->t_rextslog_delta += delta;
390 		break;
391 	default:
392 		ASSERT(0);
393 		return;
394 	}
395 
396 	tp->t_flags |= flags;
397 }
398 
399 /*
400  * xfs_trans_apply_sb_deltas() is called from the commit code
401  * to bring the superblock buffer into the current transaction
402  * and modify it as requested by earlier calls to xfs_trans_mod_sb().
403  *
404  * For now we just look at each field allowed to change and change
405  * it if necessary.
406  */
407 STATIC void
408 xfs_trans_apply_sb_deltas(
409 	xfs_trans_t	*tp)
410 {
411 	xfs_dsb_t	*sbp;
412 	xfs_buf_t	*bp;
413 	int		whole = 0;
414 
415 	bp = xfs_trans_getsb(tp, tp->t_mountp, 0);
416 	sbp = XFS_BUF_TO_SBP(bp);
417 
418 	/*
419 	 * Check that superblock mods match the mods made to AGF counters.
420 	 */
421 	ASSERT((tp->t_fdblocks_delta + tp->t_res_fdblocks_delta) ==
422 	       (tp->t_ag_freeblks_delta + tp->t_ag_flist_delta +
423 		tp->t_ag_btree_delta));
424 
425 	/*
426 	 * Only update the superblock counters if we are logging them
427 	 */
428 	if (!xfs_sb_version_haslazysbcount(&(tp->t_mountp->m_sb))) {
429 		if (tp->t_icount_delta)
430 			be64_add_cpu(&sbp->sb_icount, tp->t_icount_delta);
431 		if (tp->t_ifree_delta)
432 			be64_add_cpu(&sbp->sb_ifree, tp->t_ifree_delta);
433 		if (tp->t_fdblocks_delta)
434 			be64_add_cpu(&sbp->sb_fdblocks, tp->t_fdblocks_delta);
435 		if (tp->t_res_fdblocks_delta)
436 			be64_add_cpu(&sbp->sb_fdblocks, tp->t_res_fdblocks_delta);
437 	}
438 
439 	if (tp->t_frextents_delta)
440 		be64_add_cpu(&sbp->sb_frextents, tp->t_frextents_delta);
441 	if (tp->t_res_frextents_delta)
442 		be64_add_cpu(&sbp->sb_frextents, tp->t_res_frextents_delta);
443 
444 	if (tp->t_dblocks_delta) {
445 		be64_add_cpu(&sbp->sb_dblocks, tp->t_dblocks_delta);
446 		whole = 1;
447 	}
448 	if (tp->t_agcount_delta) {
449 		be32_add_cpu(&sbp->sb_agcount, tp->t_agcount_delta);
450 		whole = 1;
451 	}
452 	if (tp->t_imaxpct_delta) {
453 		sbp->sb_imax_pct += tp->t_imaxpct_delta;
454 		whole = 1;
455 	}
456 	if (tp->t_rextsize_delta) {
457 		be32_add_cpu(&sbp->sb_rextsize, tp->t_rextsize_delta);
458 		whole = 1;
459 	}
460 	if (tp->t_rbmblocks_delta) {
461 		be32_add_cpu(&sbp->sb_rbmblocks, tp->t_rbmblocks_delta);
462 		whole = 1;
463 	}
464 	if (tp->t_rblocks_delta) {
465 		be64_add_cpu(&sbp->sb_rblocks, tp->t_rblocks_delta);
466 		whole = 1;
467 	}
468 	if (tp->t_rextents_delta) {
469 		be64_add_cpu(&sbp->sb_rextents, tp->t_rextents_delta);
470 		whole = 1;
471 	}
472 	if (tp->t_rextslog_delta) {
473 		sbp->sb_rextslog += tp->t_rextslog_delta;
474 		whole = 1;
475 	}
476 
477 	if (whole)
478 		/*
479 		 * Log the whole thing, the fields are noncontiguous.
480 		 */
481 		xfs_trans_log_buf(tp, bp, 0, sizeof(xfs_dsb_t) - 1);
482 	else
483 		/*
484 		 * Since all the modifiable fields are contiguous, we
485 		 * can get away with this.
486 		 */
487 		xfs_trans_log_buf(tp, bp, offsetof(xfs_dsb_t, sb_icount),
488 				  offsetof(xfs_dsb_t, sb_frextents) +
489 				  sizeof(sbp->sb_frextents) - 1);
490 }
491 
492 /*
493  * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations
494  * and apply superblock counter changes to the in-core superblock.  The
495  * t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT
496  * applied to the in-core superblock.  The idea is that that has already been
497  * done.
498  *
499  * This is done efficiently with a single call to xfs_mod_incore_sb_batch().
500  * However, we have to ensure that we only modify each superblock field only
501  * once because the application of the delta values may not be atomic. That can
502  * lead to ENOSPC races occurring if we have two separate modifcations of the
503  * free space counter to put back the entire reservation and then take away
504  * what we used.
505  *
506  * If we are not logging superblock counters, then the inode allocated/free and
507  * used block counts are not updated in the on disk superblock. In this case,
508  * XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we
509  * still need to update the incore superblock with the changes.
510  */
511 void
512 xfs_trans_unreserve_and_mod_sb(
513 	xfs_trans_t	*tp)
514 {
515 	xfs_mod_sb_t	msb[9];	/* If you add cases, add entries */
516 	xfs_mod_sb_t	*msbp;
517 	xfs_mount_t	*mp = tp->t_mountp;
518 	/* REFERENCED */
519 	int		error;
520 	int		rsvd;
521 	int64_t		blkdelta = 0;
522 	int64_t		rtxdelta = 0;
523 	int64_t		idelta = 0;
524 	int64_t		ifreedelta = 0;
525 
526 	msbp = msb;
527 	rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
528 
529 	/* calculate deltas */
530 	if (tp->t_blk_res > 0)
531 		blkdelta = tp->t_blk_res;
532 	if ((tp->t_fdblocks_delta != 0) &&
533 	    (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
534 	     (tp->t_flags & XFS_TRANS_SB_DIRTY)))
535 	        blkdelta += tp->t_fdblocks_delta;
536 
537 	if (tp->t_rtx_res > 0)
538 		rtxdelta = tp->t_rtx_res;
539 	if ((tp->t_frextents_delta != 0) &&
540 	    (tp->t_flags & XFS_TRANS_SB_DIRTY))
541 		rtxdelta += tp->t_frextents_delta;
542 
543 	if (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
544 	     (tp->t_flags & XFS_TRANS_SB_DIRTY)) {
545 		idelta = tp->t_icount_delta;
546 		ifreedelta = tp->t_ifree_delta;
547 	}
548 
549 	/* apply the per-cpu counters */
550 	if (blkdelta) {
551 		error = xfs_icsb_modify_counters(mp, XFS_SBS_FDBLOCKS,
552 						 blkdelta, rsvd);
553 		if (error)
554 			goto out;
555 	}
556 
557 	if (idelta) {
558 		error = xfs_icsb_modify_counters(mp, XFS_SBS_ICOUNT,
559 						 idelta, rsvd);
560 		if (error)
561 			goto out_undo_fdblocks;
562 	}
563 
564 	if (ifreedelta) {
565 		error = xfs_icsb_modify_counters(mp, XFS_SBS_IFREE,
566 						 ifreedelta, rsvd);
567 		if (error)
568 			goto out_undo_icount;
569 	}
570 
571 	/* apply remaining deltas */
572 	if (rtxdelta != 0) {
573 		msbp->msb_field = XFS_SBS_FREXTENTS;
574 		msbp->msb_delta = rtxdelta;
575 		msbp++;
576 	}
577 
578 	if (tp->t_flags & XFS_TRANS_SB_DIRTY) {
579 		if (tp->t_dblocks_delta != 0) {
580 			msbp->msb_field = XFS_SBS_DBLOCKS;
581 			msbp->msb_delta = tp->t_dblocks_delta;
582 			msbp++;
583 		}
584 		if (tp->t_agcount_delta != 0) {
585 			msbp->msb_field = XFS_SBS_AGCOUNT;
586 			msbp->msb_delta = tp->t_agcount_delta;
587 			msbp++;
588 		}
589 		if (tp->t_imaxpct_delta != 0) {
590 			msbp->msb_field = XFS_SBS_IMAX_PCT;
591 			msbp->msb_delta = tp->t_imaxpct_delta;
592 			msbp++;
593 		}
594 		if (tp->t_rextsize_delta != 0) {
595 			msbp->msb_field = XFS_SBS_REXTSIZE;
596 			msbp->msb_delta = tp->t_rextsize_delta;
597 			msbp++;
598 		}
599 		if (tp->t_rbmblocks_delta != 0) {
600 			msbp->msb_field = XFS_SBS_RBMBLOCKS;
601 			msbp->msb_delta = tp->t_rbmblocks_delta;
602 			msbp++;
603 		}
604 		if (tp->t_rblocks_delta != 0) {
605 			msbp->msb_field = XFS_SBS_RBLOCKS;
606 			msbp->msb_delta = tp->t_rblocks_delta;
607 			msbp++;
608 		}
609 		if (tp->t_rextents_delta != 0) {
610 			msbp->msb_field = XFS_SBS_REXTENTS;
611 			msbp->msb_delta = tp->t_rextents_delta;
612 			msbp++;
613 		}
614 		if (tp->t_rextslog_delta != 0) {
615 			msbp->msb_field = XFS_SBS_REXTSLOG;
616 			msbp->msb_delta = tp->t_rextslog_delta;
617 			msbp++;
618 		}
619 	}
620 
621 	/*
622 	 * If we need to change anything, do it.
623 	 */
624 	if (msbp > msb) {
625 		error = xfs_mod_incore_sb_batch(tp->t_mountp, msb,
626 			(uint)(msbp - msb), rsvd);
627 		if (error)
628 			goto out_undo_ifreecount;
629 	}
630 
631 	return;
632 
633 out_undo_ifreecount:
634 	if (ifreedelta)
635 		xfs_icsb_modify_counters(mp, XFS_SBS_IFREE, -ifreedelta, rsvd);
636 out_undo_icount:
637 	if (idelta)
638 		xfs_icsb_modify_counters(mp, XFS_SBS_ICOUNT, -idelta, rsvd);
639 out_undo_fdblocks:
640 	if (blkdelta)
641 		xfs_icsb_modify_counters(mp, XFS_SBS_FDBLOCKS, -blkdelta, rsvd);
642 out:
643 	ASSERT(error == 0);
644 	return;
645 }
646 
647 /*
648  * Add the given log item to the transaction's list of log items.
649  *
650  * The log item will now point to its new descriptor with its li_desc field.
651  */
652 void
653 xfs_trans_add_item(
654 	struct xfs_trans	*tp,
655 	struct xfs_log_item	*lip)
656 {
657 	struct xfs_log_item_desc *lidp;
658 
659 	ASSERT(lip->li_mountp == tp->t_mountp);
660 	ASSERT(lip->li_ailp == tp->t_mountp->m_ail);
661 
662 	lidp = kmem_zone_zalloc(xfs_log_item_desc_zone, KM_SLEEP | KM_NOFS);
663 
664 	lidp->lid_item = lip;
665 	lidp->lid_flags = 0;
666 	list_add_tail(&lidp->lid_trans, &tp->t_items);
667 
668 	lip->li_desc = lidp;
669 }
670 
671 STATIC void
672 xfs_trans_free_item_desc(
673 	struct xfs_log_item_desc *lidp)
674 {
675 	list_del_init(&lidp->lid_trans);
676 	kmem_zone_free(xfs_log_item_desc_zone, lidp);
677 }
678 
679 /*
680  * Unlink and free the given descriptor.
681  */
682 void
683 xfs_trans_del_item(
684 	struct xfs_log_item	*lip)
685 {
686 	xfs_trans_free_item_desc(lip->li_desc);
687 	lip->li_desc = NULL;
688 }
689 
690 /*
691  * Unlock all of the items of a transaction and free all the descriptors
692  * of that transaction.
693  */
694 void
695 xfs_trans_free_items(
696 	struct xfs_trans	*tp,
697 	xfs_lsn_t		commit_lsn,
698 	int			flags)
699 {
700 	struct xfs_log_item_desc *lidp, *next;
701 
702 	list_for_each_entry_safe(lidp, next, &tp->t_items, lid_trans) {
703 		struct xfs_log_item	*lip = lidp->lid_item;
704 
705 		lip->li_desc = NULL;
706 
707 		if (commit_lsn != NULLCOMMITLSN)
708 			lip->li_ops->iop_committing(lip, commit_lsn);
709 		if (flags & XFS_TRANS_ABORT)
710 			lip->li_flags |= XFS_LI_ABORTED;
711 		lip->li_ops->iop_unlock(lip);
712 
713 		xfs_trans_free_item_desc(lidp);
714 	}
715 }
716 
717 static inline void
718 xfs_log_item_batch_insert(
719 	struct xfs_ail		*ailp,
720 	struct xfs_ail_cursor	*cur,
721 	struct xfs_log_item	**log_items,
722 	int			nr_items,
723 	xfs_lsn_t		commit_lsn)
724 {
725 	int	i;
726 
727 	spin_lock(&ailp->xa_lock);
728 	/* xfs_trans_ail_update_bulk drops ailp->xa_lock */
729 	xfs_trans_ail_update_bulk(ailp, cur, log_items, nr_items, commit_lsn);
730 
731 	for (i = 0; i < nr_items; i++) {
732 		struct xfs_log_item *lip = log_items[i];
733 
734 		lip->li_ops->iop_unpin(lip, 0);
735 	}
736 }
737 
738 /*
739  * Bulk operation version of xfs_trans_committed that takes a log vector of
740  * items to insert into the AIL. This uses bulk AIL insertion techniques to
741  * minimise lock traffic.
742  *
743  * If we are called with the aborted flag set, it is because a log write during
744  * a CIL checkpoint commit has failed. In this case, all the items in the
745  * checkpoint have already gone through iop_commited and iop_unlock, which
746  * means that checkpoint commit abort handling is treated exactly the same
747  * as an iclog write error even though we haven't started any IO yet. Hence in
748  * this case all we need to do is iop_committed processing, followed by an
749  * iop_unpin(aborted) call.
750  *
751  * The AIL cursor is used to optimise the insert process. If commit_lsn is not
752  * at the end of the AIL, the insert cursor avoids the need to walk
753  * the AIL to find the insertion point on every xfs_log_item_batch_insert()
754  * call. This saves a lot of needless list walking and is a net win, even
755  * though it slightly increases that amount of AIL lock traffic to set it up
756  * and tear it down.
757  */
758 void
759 xfs_trans_committed_bulk(
760 	struct xfs_ail		*ailp,
761 	struct xfs_log_vec	*log_vector,
762 	xfs_lsn_t		commit_lsn,
763 	int			aborted)
764 {
765 #define LOG_ITEM_BATCH_SIZE	32
766 	struct xfs_log_item	*log_items[LOG_ITEM_BATCH_SIZE];
767 	struct xfs_log_vec	*lv;
768 	struct xfs_ail_cursor	cur;
769 	int			i = 0;
770 
771 	spin_lock(&ailp->xa_lock);
772 	xfs_trans_ail_cursor_last(ailp, &cur, commit_lsn);
773 	spin_unlock(&ailp->xa_lock);
774 
775 	/* unpin all the log items */
776 	for (lv = log_vector; lv; lv = lv->lv_next ) {
777 		struct xfs_log_item	*lip = lv->lv_item;
778 		xfs_lsn_t		item_lsn;
779 
780 		if (aborted)
781 			lip->li_flags |= XFS_LI_ABORTED;
782 		item_lsn = lip->li_ops->iop_committed(lip, commit_lsn);
783 
784 		/* item_lsn of -1 means the item needs no further processing */
785 		if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0)
786 			continue;
787 
788 		/*
789 		 * if we are aborting the operation, no point in inserting the
790 		 * object into the AIL as we are in a shutdown situation.
791 		 */
792 		if (aborted) {
793 			ASSERT(XFS_FORCED_SHUTDOWN(ailp->xa_mount));
794 			lip->li_ops->iop_unpin(lip, 1);
795 			continue;
796 		}
797 
798 		if (item_lsn != commit_lsn) {
799 
800 			/*
801 			 * Not a bulk update option due to unusual item_lsn.
802 			 * Push into AIL immediately, rechecking the lsn once
803 			 * we have the ail lock. Then unpin the item. This does
804 			 * not affect the AIL cursor the bulk insert path is
805 			 * using.
806 			 */
807 			spin_lock(&ailp->xa_lock);
808 			if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0)
809 				xfs_trans_ail_update(ailp, lip, item_lsn);
810 			else
811 				spin_unlock(&ailp->xa_lock);
812 			lip->li_ops->iop_unpin(lip, 0);
813 			continue;
814 		}
815 
816 		/* Item is a candidate for bulk AIL insert.  */
817 		log_items[i++] = lv->lv_item;
818 		if (i >= LOG_ITEM_BATCH_SIZE) {
819 			xfs_log_item_batch_insert(ailp, &cur, log_items,
820 					LOG_ITEM_BATCH_SIZE, commit_lsn);
821 			i = 0;
822 		}
823 	}
824 
825 	/* make sure we insert the remainder! */
826 	if (i)
827 		xfs_log_item_batch_insert(ailp, &cur, log_items, i, commit_lsn);
828 
829 	spin_lock(&ailp->xa_lock);
830 	xfs_trans_ail_cursor_done(ailp, &cur);
831 	spin_unlock(&ailp->xa_lock);
832 }
833 
834 /*
835  * Commit the given transaction to the log.
836  *
837  * XFS disk error handling mechanism is not based on a typical
838  * transaction abort mechanism. Logically after the filesystem
839  * gets marked 'SHUTDOWN', we can't let any new transactions
840  * be durable - ie. committed to disk - because some metadata might
841  * be inconsistent. In such cases, this returns an error, and the
842  * caller may assume that all locked objects joined to the transaction
843  * have already been unlocked as if the commit had succeeded.
844  * Do not reference the transaction structure after this call.
845  */
846 int
847 xfs_trans_commit(
848 	struct xfs_trans	*tp,
849 	uint			flags)
850 {
851 	struct xfs_mount	*mp = tp->t_mountp;
852 	xfs_lsn_t		commit_lsn = -1;
853 	int			error = 0;
854 	int			log_flags = 0;
855 	int			sync = tp->t_flags & XFS_TRANS_SYNC;
856 
857 	/*
858 	 * Determine whether this commit is releasing a permanent
859 	 * log reservation or not.
860 	 */
861 	if (flags & XFS_TRANS_RELEASE_LOG_RES) {
862 		ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
863 		log_flags = XFS_LOG_REL_PERM_RESERV;
864 	}
865 
866 	/*
867 	 * If there is nothing to be logged by the transaction,
868 	 * then unlock all of the items associated with the
869 	 * transaction and free the transaction structure.
870 	 * Also make sure to return any reserved blocks to
871 	 * the free pool.
872 	 */
873 	if (!(tp->t_flags & XFS_TRANS_DIRTY))
874 		goto out_unreserve;
875 
876 	if (XFS_FORCED_SHUTDOWN(mp)) {
877 		error = XFS_ERROR(EIO);
878 		goto out_unreserve;
879 	}
880 
881 	ASSERT(tp->t_ticket != NULL);
882 
883 	/*
884 	 * If we need to update the superblock, then do it now.
885 	 */
886 	if (tp->t_flags & XFS_TRANS_SB_DIRTY)
887 		xfs_trans_apply_sb_deltas(tp);
888 	xfs_trans_apply_dquot_deltas(tp);
889 
890 	xfs_log_commit_cil(mp, tp, &commit_lsn, flags);
891 
892 	current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
893 	xfs_trans_free(tp);
894 
895 	/*
896 	 * If the transaction needs to be synchronous, then force the
897 	 * log out now and wait for it.
898 	 */
899 	if (sync) {
900 		error = _xfs_log_force_lsn(mp, commit_lsn, XFS_LOG_SYNC, NULL);
901 		XFS_STATS_INC(xs_trans_sync);
902 	} else {
903 		XFS_STATS_INC(xs_trans_async);
904 	}
905 
906 	return error;
907 
908 out_unreserve:
909 	xfs_trans_unreserve_and_mod_sb(tp);
910 
911 	/*
912 	 * It is indeed possible for the transaction to be not dirty but
913 	 * the dqinfo portion to be.  All that means is that we have some
914 	 * (non-persistent) quota reservations that need to be unreserved.
915 	 */
916 	xfs_trans_unreserve_and_mod_dquots(tp);
917 	if (tp->t_ticket) {
918 		commit_lsn = xfs_log_done(mp, tp->t_ticket, NULL, log_flags);
919 		if (commit_lsn == -1 && !error)
920 			error = XFS_ERROR(EIO);
921 	}
922 	current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
923 	xfs_trans_free_items(tp, NULLCOMMITLSN, error ? XFS_TRANS_ABORT : 0);
924 	xfs_trans_free(tp);
925 
926 	XFS_STATS_INC(xs_trans_empty);
927 	return error;
928 }
929 
930 /*
931  * Unlock all of the transaction's items and free the transaction.
932  * The transaction must not have modified any of its items, because
933  * there is no way to restore them to their previous state.
934  *
935  * If the transaction has made a log reservation, make sure to release
936  * it as well.
937  */
938 void
939 xfs_trans_cancel(
940 	xfs_trans_t		*tp,
941 	int			flags)
942 {
943 	int			log_flags;
944 	xfs_mount_t		*mp = tp->t_mountp;
945 
946 	/*
947 	 * See if the caller is being too lazy to figure out if
948 	 * the transaction really needs an abort.
949 	 */
950 	if ((flags & XFS_TRANS_ABORT) && !(tp->t_flags & XFS_TRANS_DIRTY))
951 		flags &= ~XFS_TRANS_ABORT;
952 	/*
953 	 * See if the caller is relying on us to shut down the
954 	 * filesystem.  This happens in paths where we detect
955 	 * corruption and decide to give up.
956 	 */
957 	if ((tp->t_flags & XFS_TRANS_DIRTY) && !XFS_FORCED_SHUTDOWN(mp)) {
958 		XFS_ERROR_REPORT("xfs_trans_cancel", XFS_ERRLEVEL_LOW, mp);
959 		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
960 	}
961 #ifdef DEBUG
962 	if (!(flags & XFS_TRANS_ABORT) && !XFS_FORCED_SHUTDOWN(mp)) {
963 		struct xfs_log_item_desc *lidp;
964 
965 		list_for_each_entry(lidp, &tp->t_items, lid_trans)
966 			ASSERT(!(lidp->lid_item->li_type == XFS_LI_EFD));
967 	}
968 #endif
969 	xfs_trans_unreserve_and_mod_sb(tp);
970 	xfs_trans_unreserve_and_mod_dquots(tp);
971 
972 	if (tp->t_ticket) {
973 		if (flags & XFS_TRANS_RELEASE_LOG_RES) {
974 			ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
975 			log_flags = XFS_LOG_REL_PERM_RESERV;
976 		} else {
977 			log_flags = 0;
978 		}
979 		xfs_log_done(mp, tp->t_ticket, NULL, log_flags);
980 	}
981 
982 	/* mark this thread as no longer being in a transaction */
983 	current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
984 
985 	xfs_trans_free_items(tp, NULLCOMMITLSN, flags);
986 	xfs_trans_free(tp);
987 }
988 
989 /*
990  * Roll from one trans in the sequence of PERMANENT transactions to
991  * the next: permanent transactions are only flushed out when
992  * committed with XFS_TRANS_RELEASE_LOG_RES, but we still want as soon
993  * as possible to let chunks of it go to the log. So we commit the
994  * chunk we've been working on and get a new transaction to continue.
995  */
996 int
997 xfs_trans_roll(
998 	struct xfs_trans	**tpp,
999 	struct xfs_inode	*dp)
1000 {
1001 	struct xfs_trans	*trans;
1002 	struct xfs_trans_res	tres;
1003 	int			error;
1004 
1005 	/*
1006 	 * Ensure that the inode is always logged.
1007 	 */
1008 	trans = *tpp;
1009 	xfs_trans_log_inode(trans, dp, XFS_ILOG_CORE);
1010 
1011 	/*
1012 	 * Copy the critical parameters from one trans to the next.
1013 	 */
1014 	tres.tr_logres = trans->t_log_res;
1015 	tres.tr_logcount = trans->t_log_count;
1016 	*tpp = xfs_trans_dup(trans);
1017 
1018 	/*
1019 	 * Commit the current transaction.
1020 	 * If this commit failed, then it'd just unlock those items that
1021 	 * are not marked ihold. That also means that a filesystem shutdown
1022 	 * is in progress. The caller takes the responsibility to cancel
1023 	 * the duplicate transaction that gets returned.
1024 	 */
1025 	error = xfs_trans_commit(trans, 0);
1026 	if (error)
1027 		return (error);
1028 
1029 	trans = *tpp;
1030 
1031 	/*
1032 	 * transaction commit worked ok so we can drop the extra ticket
1033 	 * reference that we gained in xfs_trans_dup()
1034 	 */
1035 	xfs_log_ticket_put(trans->t_ticket);
1036 
1037 
1038 	/*
1039 	 * Reserve space in the log for th next transaction.
1040 	 * This also pushes items in the "AIL", the list of logged items,
1041 	 * out to disk if they are taking up space at the tail of the log
1042 	 * that we want to use.  This requires that either nothing be locked
1043 	 * across this call, or that anything that is locked be logged in
1044 	 * the prior and the next transactions.
1045 	 */
1046 	tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
1047 	error = xfs_trans_reserve(trans, &tres, 0, 0);
1048 	/*
1049 	 *  Ensure that the inode is in the new transaction and locked.
1050 	 */
1051 	if (error)
1052 		return error;
1053 
1054 	xfs_trans_ijoin(trans, dp, 0);
1055 	return 0;
1056 }
1057