xref: /linux/fs/ocfs2/localalloc.c (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * localalloc.c
5  *
6  * Node local data allocation
7  *
8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  */
25 
26 #include <linux/fs.h>
27 #include <linux/types.h>
28 #include <linux/slab.h>
29 #include <linux/highmem.h>
30 #include <linux/bitops.h>
31 
32 #include <cluster/masklog.h>
33 
34 #include "ocfs2.h"
35 
36 #include "alloc.h"
37 #include "blockcheck.h"
38 #include "dlmglue.h"
39 #include "inode.h"
40 #include "journal.h"
41 #include "localalloc.h"
42 #include "suballoc.h"
43 #include "super.h"
44 #include "sysfile.h"
45 #include "ocfs2_trace.h"
46 
47 #include "buffer_head_io.h"
48 
49 #define OCFS2_LOCAL_ALLOC(dinode)	(&((dinode)->id2.i_lab))
50 
51 static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc);
52 
53 static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
54 					     struct ocfs2_dinode *alloc,
55 					     u32 *numbits,
56 					     struct ocfs2_alloc_reservation *resv);
57 
58 static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc);
59 
60 static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
61 				    handle_t *handle,
62 				    struct ocfs2_dinode *alloc,
63 				    struct inode *main_bm_inode,
64 				    struct buffer_head *main_bm_bh);
65 
66 static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
67 						struct ocfs2_alloc_context **ac,
68 						struct inode **bitmap_inode,
69 						struct buffer_head **bitmap_bh);
70 
71 static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
72 					handle_t *handle,
73 					struct ocfs2_alloc_context *ac);
74 
75 static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
76 					  struct inode *local_alloc_inode);
77 
78 /*
79  * ocfs2_la_default_mb() - determine a default size, in megabytes of
80  * the local alloc.
81  *
82  * Generally, we'd like to pick as large a local alloc as
83  * possible. Performance on large workloads tends to scale
84  * proportionally to la size. In addition to that, the reservations
85  * code functions more efficiently as it can reserve more windows for
86  * write.
87  *
88  * Some things work against us when trying to choose a large local alloc:
89  *
90  * - We need to ensure our sizing is picked to leave enough space in
91  *   group descriptors for other allocations (such as block groups,
92  *   etc). Picking default sizes which are a multiple of 4 could help
93  *   - block groups are allocated in 2mb and 4mb chunks.
94  *
95  * - Likewise, we don't want to starve other nodes of bits on small
96  *   file systems. This can easily be taken care of by limiting our
97  *   default to a reasonable size (256M) on larger cluster sizes.
98  *
99  * - Some file systems can't support very large sizes - 4k and 8k in
100  *   particular are limited to less than 128 and 256 megabytes respectively.
101  *
102  * The following reference table shows group descriptor and local
103  * alloc maximums at various cluster sizes (4k blocksize)
104  *
105  * csize: 4K	group: 126M	la: 121M
106  * csize: 8K	group: 252M	la: 243M
107  * csize: 16K	group: 504M	la: 486M
108  * csize: 32K	group: 1008M	la: 972M
109  * csize: 64K	group: 2016M	la: 1944M
110  * csize: 128K	group: 4032M	la: 3888M
111  * csize: 256K	group: 8064M	la: 7776M
112  * csize: 512K	group: 16128M	la: 15552M
113  * csize: 1024K	group: 32256M	la: 31104M
114  */
115 #define	OCFS2_LA_MAX_DEFAULT_MB	256
116 #define	OCFS2_LA_OLD_DEFAULT	8
117 unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
118 {
119 	unsigned int la_mb;
120 	unsigned int gd_mb;
121 	unsigned int la_max_mb;
122 	unsigned int megs_per_slot;
123 	struct super_block *sb = osb->sb;
124 
125 	gd_mb = ocfs2_clusters_to_megabytes(osb->sb,
126 		8 * ocfs2_group_bitmap_size(sb, 0, osb->s_feature_incompat));
127 
128 	/*
129 	 * This takes care of files systems with very small group
130 	 * descriptors - 512 byte blocksize at cluster sizes lower
131 	 * than 16K and also 1k blocksize with 4k cluster size.
132 	 */
133 	if ((sb->s_blocksize == 512 && osb->s_clustersize <= 8192)
134 	    || (sb->s_blocksize == 1024 && osb->s_clustersize == 4096))
135 		return OCFS2_LA_OLD_DEFAULT;
136 
137 	/*
138 	 * Leave enough room for some block groups and make the final
139 	 * value we work from a multiple of 4.
140 	 */
141 	gd_mb -= 16;
142 	gd_mb &= 0xFFFFFFFB;
143 
144 	la_mb = gd_mb;
145 
146 	/*
147 	 * Keep window sizes down to a reasonable default
148 	 */
149 	if (la_mb > OCFS2_LA_MAX_DEFAULT_MB) {
150 		/*
151 		 * Some clustersize / blocksize combinations will have
152 		 * given us a larger than OCFS2_LA_MAX_DEFAULT_MB
153 		 * default size, but get poor distribution when
154 		 * limited to exactly 256 megabytes.
155 		 *
156 		 * As an example, 16K clustersize at 4K blocksize
157 		 * gives us a cluster group size of 504M. Paring the
158 		 * local alloc size down to 256 however, would give us
159 		 * only one window and around 200MB left in the
160 		 * cluster group. Instead, find the first size below
161 		 * 256 which would give us an even distribution.
162 		 *
163 		 * Larger cluster group sizes actually work out pretty
164 		 * well when pared to 256, so we don't have to do this
165 		 * for any group that fits more than two
166 		 * OCFS2_LA_MAX_DEFAULT_MB windows.
167 		 */
168 		if (gd_mb > (2 * OCFS2_LA_MAX_DEFAULT_MB))
169 			la_mb = 256;
170 		else {
171 			unsigned int gd_mult = gd_mb;
172 
173 			while (gd_mult > 256)
174 				gd_mult = gd_mult >> 1;
175 
176 			la_mb = gd_mult;
177 		}
178 	}
179 
180 	megs_per_slot = osb->osb_clusters_at_boot / osb->max_slots;
181 	megs_per_slot = ocfs2_clusters_to_megabytes(osb->sb, megs_per_slot);
182 	/* Too many nodes, too few disk clusters. */
183 	if (megs_per_slot < la_mb)
184 		la_mb = megs_per_slot;
185 
186 	/* We can't store more bits than we can in a block. */
187 	la_max_mb = ocfs2_clusters_to_megabytes(osb->sb,
188 						ocfs2_local_alloc_size(sb) * 8);
189 	if (la_mb > la_max_mb)
190 		la_mb = la_max_mb;
191 
192 	return la_mb;
193 }
194 
195 void ocfs2_la_set_sizes(struct ocfs2_super *osb, int requested_mb)
196 {
197 	struct super_block *sb = osb->sb;
198 	unsigned int la_default_mb = ocfs2_la_default_mb(osb);
199 	unsigned int la_max_mb;
200 
201 	la_max_mb = ocfs2_clusters_to_megabytes(sb,
202 						ocfs2_local_alloc_size(sb) * 8);
203 
204 	trace_ocfs2_la_set_sizes(requested_mb, la_max_mb, la_default_mb);
205 
206 	if (requested_mb == -1) {
207 		/* No user request - use defaults */
208 		osb->local_alloc_default_bits =
209 			ocfs2_megabytes_to_clusters(sb, la_default_mb);
210 	} else if (requested_mb > la_max_mb) {
211 		/* Request is too big, we give the maximum available */
212 		osb->local_alloc_default_bits =
213 			ocfs2_megabytes_to_clusters(sb, la_max_mb);
214 	} else {
215 		osb->local_alloc_default_bits =
216 			ocfs2_megabytes_to_clusters(sb, requested_mb);
217 	}
218 
219 	osb->local_alloc_bits = osb->local_alloc_default_bits;
220 }
221 
222 static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb)
223 {
224 	return (osb->local_alloc_state == OCFS2_LA_THROTTLED ||
225 		osb->local_alloc_state == OCFS2_LA_ENABLED);
226 }
227 
228 void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb,
229 				      unsigned int num_clusters)
230 {
231 	spin_lock(&osb->osb_lock);
232 	if (osb->local_alloc_state == OCFS2_LA_DISABLED ||
233 	    osb->local_alloc_state == OCFS2_LA_THROTTLED)
234 		if (num_clusters >= osb->local_alloc_default_bits) {
235 			cancel_delayed_work(&osb->la_enable_wq);
236 			osb->local_alloc_state = OCFS2_LA_ENABLED;
237 		}
238 	spin_unlock(&osb->osb_lock);
239 }
240 
241 void ocfs2_la_enable_worker(struct work_struct *work)
242 {
243 	struct ocfs2_super *osb =
244 		container_of(work, struct ocfs2_super,
245 			     la_enable_wq.work);
246 	spin_lock(&osb->osb_lock);
247 	osb->local_alloc_state = OCFS2_LA_ENABLED;
248 	spin_unlock(&osb->osb_lock);
249 }
250 
251 /*
252  * Tell us whether a given allocation should use the local alloc
253  * file. Otherwise, it has to go to the main bitmap.
254  *
255  * This function does semi-dirty reads of local alloc size and state!
256  * This is ok however, as the values are re-checked once under mutex.
257  */
258 int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
259 {
260 	int ret = 0;
261 	int la_bits;
262 
263 	spin_lock(&osb->osb_lock);
264 	la_bits = osb->local_alloc_bits;
265 
266 	if (!ocfs2_la_state_enabled(osb))
267 		goto bail;
268 
269 	/* la_bits should be at least twice the size (in clusters) of
270 	 * a new block group. We want to be sure block group
271 	 * allocations go through the local alloc, so allow an
272 	 * allocation to take up to half the bitmap. */
273 	if (bits > (la_bits / 2))
274 		goto bail;
275 
276 	ret = 1;
277 bail:
278 	trace_ocfs2_alloc_should_use_local(
279 	     (unsigned long long)bits, osb->local_alloc_state, la_bits, ret);
280 	spin_unlock(&osb->osb_lock);
281 	return ret;
282 }
283 
284 int ocfs2_load_local_alloc(struct ocfs2_super *osb)
285 {
286 	int status = 0;
287 	struct ocfs2_dinode *alloc = NULL;
288 	struct buffer_head *alloc_bh = NULL;
289 	u32 num_used;
290 	struct inode *inode = NULL;
291 	struct ocfs2_local_alloc *la;
292 
293 	if (osb->local_alloc_bits == 0)
294 		goto bail;
295 
296 	if (osb->local_alloc_bits >= osb->bitmap_cpg) {
297 		mlog(ML_NOTICE, "Requested local alloc window %d is larger "
298 		     "than max possible %u. Using defaults.\n",
299 		     osb->local_alloc_bits, (osb->bitmap_cpg - 1));
300 		osb->local_alloc_bits =
301 			ocfs2_megabytes_to_clusters(osb->sb,
302 						    ocfs2_la_default_mb(osb));
303 	}
304 
305 	/* read the alloc off disk */
306 	inode = ocfs2_get_system_file_inode(osb, LOCAL_ALLOC_SYSTEM_INODE,
307 					    osb->slot_num);
308 	if (!inode) {
309 		status = -EINVAL;
310 		mlog_errno(status);
311 		goto bail;
312 	}
313 
314 	status = ocfs2_read_inode_block_full(inode, &alloc_bh,
315 					     OCFS2_BH_IGNORE_CACHE);
316 	if (status < 0) {
317 		mlog_errno(status);
318 		goto bail;
319 	}
320 
321 	alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
322 	la = OCFS2_LOCAL_ALLOC(alloc);
323 
324 	if (!(le32_to_cpu(alloc->i_flags) &
325 	    (OCFS2_LOCAL_ALLOC_FL|OCFS2_BITMAP_FL))) {
326 		mlog(ML_ERROR, "Invalid local alloc inode, %llu\n",
327 		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
328 		status = -EINVAL;
329 		goto bail;
330 	}
331 
332 	if ((la->la_size == 0) ||
333 	    (le16_to_cpu(la->la_size) > ocfs2_local_alloc_size(inode->i_sb))) {
334 		mlog(ML_ERROR, "Local alloc size is invalid (la_size = %u)\n",
335 		     le16_to_cpu(la->la_size));
336 		status = -EINVAL;
337 		goto bail;
338 	}
339 
340 	/* do a little verification. */
341 	num_used = ocfs2_local_alloc_count_bits(alloc);
342 
343 	/* hopefully the local alloc has always been recovered before
344 	 * we load it. */
345 	if (num_used
346 	    || alloc->id1.bitmap1.i_used
347 	    || alloc->id1.bitmap1.i_total
348 	    || la->la_bm_off)
349 		mlog(ML_ERROR, "Local alloc hasn't been recovered!\n"
350 		     "found = %u, set = %u, taken = %u, off = %u\n",
351 		     num_used, le32_to_cpu(alloc->id1.bitmap1.i_used),
352 		     le32_to_cpu(alloc->id1.bitmap1.i_total),
353 		     OCFS2_LOCAL_ALLOC(alloc)->la_bm_off);
354 
355 	osb->local_alloc_bh = alloc_bh;
356 	osb->local_alloc_state = OCFS2_LA_ENABLED;
357 
358 bail:
359 	if (status < 0)
360 		brelse(alloc_bh);
361 	iput(inode);
362 
363 	trace_ocfs2_load_local_alloc(osb->local_alloc_bits);
364 
365 	if (status)
366 		mlog_errno(status);
367 	return status;
368 }
369 
370 /*
371  * return any unused bits to the bitmap and write out a clean
372  * local_alloc.
373  *
374  * local_alloc_bh is optional. If not passed, we will simply use the
375  * one off osb. If you do pass it however, be warned that it *will* be
376  * returned brelse'd and NULL'd out.*/
377 void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb)
378 {
379 	int status;
380 	handle_t *handle;
381 	struct inode *local_alloc_inode = NULL;
382 	struct buffer_head *bh = NULL;
383 	struct buffer_head *main_bm_bh = NULL;
384 	struct inode *main_bm_inode = NULL;
385 	struct ocfs2_dinode *alloc_copy = NULL;
386 	struct ocfs2_dinode *alloc = NULL;
387 
388 	cancel_delayed_work(&osb->la_enable_wq);
389 	flush_workqueue(osb->ocfs2_wq);
390 
391 	if (osb->local_alloc_state == OCFS2_LA_UNUSED)
392 		goto out;
393 
394 	local_alloc_inode =
395 		ocfs2_get_system_file_inode(osb,
396 					    LOCAL_ALLOC_SYSTEM_INODE,
397 					    osb->slot_num);
398 	if (!local_alloc_inode) {
399 		status = -ENOENT;
400 		mlog_errno(status);
401 		goto out;
402 	}
403 
404 	osb->local_alloc_state = OCFS2_LA_DISABLED;
405 
406 	ocfs2_resmap_uninit(&osb->osb_la_resmap);
407 
408 	main_bm_inode = ocfs2_get_system_file_inode(osb,
409 						    GLOBAL_BITMAP_SYSTEM_INODE,
410 						    OCFS2_INVALID_SLOT);
411 	if (!main_bm_inode) {
412 		status = -EINVAL;
413 		mlog_errno(status);
414 		goto out;
415 	}
416 
417 	inode_lock(main_bm_inode);
418 
419 	status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
420 	if (status < 0) {
421 		mlog_errno(status);
422 		goto out_mutex;
423 	}
424 
425 	/* WINDOW_MOVE_CREDITS is a bit heavy... */
426 	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
427 	if (IS_ERR(handle)) {
428 		mlog_errno(PTR_ERR(handle));
429 		handle = NULL;
430 		goto out_unlock;
431 	}
432 
433 	bh = osb->local_alloc_bh;
434 	alloc = (struct ocfs2_dinode *) bh->b_data;
435 
436 	alloc_copy = kmalloc(bh->b_size, GFP_NOFS);
437 	if (!alloc_copy) {
438 		status = -ENOMEM;
439 		goto out_commit;
440 	}
441 	memcpy(alloc_copy, alloc, bh->b_size);
442 
443 	status = ocfs2_journal_access_di(handle, INODE_CACHE(local_alloc_inode),
444 					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
445 	if (status < 0) {
446 		mlog_errno(status);
447 		goto out_commit;
448 	}
449 
450 	ocfs2_clear_local_alloc(alloc);
451 	ocfs2_journal_dirty(handle, bh);
452 
453 	brelse(bh);
454 	osb->local_alloc_bh = NULL;
455 	osb->local_alloc_state = OCFS2_LA_UNUSED;
456 
457 	status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
458 					  main_bm_inode, main_bm_bh);
459 	if (status < 0)
460 		mlog_errno(status);
461 
462 out_commit:
463 	ocfs2_commit_trans(osb, handle);
464 
465 out_unlock:
466 	brelse(main_bm_bh);
467 
468 	ocfs2_inode_unlock(main_bm_inode, 1);
469 
470 out_mutex:
471 	inode_unlock(main_bm_inode);
472 	iput(main_bm_inode);
473 
474 out:
475 	iput(local_alloc_inode);
476 
477 	kfree(alloc_copy);
478 }
479 
480 /*
481  * We want to free the bitmap bits outside of any recovery context as
482  * we'll need a cluster lock to do so, but we must clear the local
483  * alloc before giving up the recovered nodes journal. To solve this,
484  * we kmalloc a copy of the local alloc before it's change for the
485  * caller to process with ocfs2_complete_local_alloc_recovery
486  */
487 int ocfs2_begin_local_alloc_recovery(struct ocfs2_super *osb,
488 				     int slot_num,
489 				     struct ocfs2_dinode **alloc_copy)
490 {
491 	int status = 0;
492 	struct buffer_head *alloc_bh = NULL;
493 	struct inode *inode = NULL;
494 	struct ocfs2_dinode *alloc;
495 
496 	trace_ocfs2_begin_local_alloc_recovery(slot_num);
497 
498 	*alloc_copy = NULL;
499 
500 	inode = ocfs2_get_system_file_inode(osb,
501 					    LOCAL_ALLOC_SYSTEM_INODE,
502 					    slot_num);
503 	if (!inode) {
504 		status = -EINVAL;
505 		mlog_errno(status);
506 		goto bail;
507 	}
508 
509 	inode_lock(inode);
510 
511 	status = ocfs2_read_inode_block_full(inode, &alloc_bh,
512 					     OCFS2_BH_IGNORE_CACHE);
513 	if (status < 0) {
514 		mlog_errno(status);
515 		goto bail;
516 	}
517 
518 	*alloc_copy = kmalloc(alloc_bh->b_size, GFP_KERNEL);
519 	if (!(*alloc_copy)) {
520 		status = -ENOMEM;
521 		goto bail;
522 	}
523 	memcpy((*alloc_copy), alloc_bh->b_data, alloc_bh->b_size);
524 
525 	alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
526 	ocfs2_clear_local_alloc(alloc);
527 
528 	ocfs2_compute_meta_ecc(osb->sb, alloc_bh->b_data, &alloc->i_check);
529 	status = ocfs2_write_block(osb, alloc_bh, INODE_CACHE(inode));
530 	if (status < 0)
531 		mlog_errno(status);
532 
533 bail:
534 	if (status < 0) {
535 		kfree(*alloc_copy);
536 		*alloc_copy = NULL;
537 	}
538 
539 	brelse(alloc_bh);
540 
541 	if (inode) {
542 		inode_unlock(inode);
543 		iput(inode);
544 	}
545 
546 	if (status)
547 		mlog_errno(status);
548 	return status;
549 }
550 
551 /*
552  * Step 2: By now, we've completed the journal recovery, we've stamped
553  * a clean local alloc on disk and dropped the node out of the
554  * recovery map. Dlm locks will no longer stall, so lets clear out the
555  * main bitmap.
556  */
557 int ocfs2_complete_local_alloc_recovery(struct ocfs2_super *osb,
558 					struct ocfs2_dinode *alloc)
559 {
560 	int status;
561 	handle_t *handle;
562 	struct buffer_head *main_bm_bh = NULL;
563 	struct inode *main_bm_inode;
564 
565 	main_bm_inode = ocfs2_get_system_file_inode(osb,
566 						    GLOBAL_BITMAP_SYSTEM_INODE,
567 						    OCFS2_INVALID_SLOT);
568 	if (!main_bm_inode) {
569 		status = -EINVAL;
570 		mlog_errno(status);
571 		goto out;
572 	}
573 
574 	inode_lock(main_bm_inode);
575 
576 	status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
577 	if (status < 0) {
578 		mlog_errno(status);
579 		goto out_mutex;
580 	}
581 
582 	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
583 	if (IS_ERR(handle)) {
584 		status = PTR_ERR(handle);
585 		handle = NULL;
586 		mlog_errno(status);
587 		goto out_unlock;
588 	}
589 
590 	/* we want the bitmap change to be recorded on disk asap */
591 	handle->h_sync = 1;
592 
593 	status = ocfs2_sync_local_to_main(osb, handle, alloc,
594 					  main_bm_inode, main_bm_bh);
595 	if (status < 0)
596 		mlog_errno(status);
597 
598 	ocfs2_commit_trans(osb, handle);
599 
600 out_unlock:
601 	ocfs2_inode_unlock(main_bm_inode, 1);
602 
603 out_mutex:
604 	inode_unlock(main_bm_inode);
605 
606 	brelse(main_bm_bh);
607 
608 	iput(main_bm_inode);
609 
610 out:
611 	if (!status)
612 		ocfs2_init_steal_slots(osb);
613 	if (status)
614 		mlog_errno(status);
615 	return status;
616 }
617 
618 /*
619  * make sure we've got at least bits_wanted contiguous bits in the
620  * local alloc. You lose them when you drop i_mutex.
621  *
622  * We will add ourselves to the transaction passed in, but may start
623  * our own in order to shift windows.
624  */
625 int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
626 				   u32 bits_wanted,
627 				   struct ocfs2_alloc_context *ac)
628 {
629 	int status;
630 	struct ocfs2_dinode *alloc;
631 	struct inode *local_alloc_inode;
632 	unsigned int free_bits;
633 
634 	BUG_ON(!ac);
635 
636 	local_alloc_inode =
637 		ocfs2_get_system_file_inode(osb,
638 					    LOCAL_ALLOC_SYSTEM_INODE,
639 					    osb->slot_num);
640 	if (!local_alloc_inode) {
641 		status = -ENOENT;
642 		mlog_errno(status);
643 		goto bail;
644 	}
645 
646 	inode_lock(local_alloc_inode);
647 
648 	/*
649 	 * We must double check state and allocator bits because
650 	 * another process may have changed them while holding i_mutex.
651 	 */
652 	spin_lock(&osb->osb_lock);
653 	if (!ocfs2_la_state_enabled(osb) ||
654 	    (bits_wanted > osb->local_alloc_bits)) {
655 		spin_unlock(&osb->osb_lock);
656 		status = -ENOSPC;
657 		goto bail;
658 	}
659 	spin_unlock(&osb->osb_lock);
660 
661 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
662 
663 #ifdef CONFIG_OCFS2_DEBUG_FS
664 	if (le32_to_cpu(alloc->id1.bitmap1.i_used) !=
665 	    ocfs2_local_alloc_count_bits(alloc)) {
666 		ocfs2_error(osb->sb, "local alloc inode %llu says it has %u used bits, but a count shows %u\n",
667 			    (unsigned long long)le64_to_cpu(alloc->i_blkno),
668 			    le32_to_cpu(alloc->id1.bitmap1.i_used),
669 			    ocfs2_local_alloc_count_bits(alloc));
670 		status = -EIO;
671 		goto bail;
672 	}
673 #endif
674 
675 	free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
676 		le32_to_cpu(alloc->id1.bitmap1.i_used);
677 	if (bits_wanted > free_bits) {
678 		/* uhoh, window change time. */
679 		status =
680 			ocfs2_local_alloc_slide_window(osb, local_alloc_inode);
681 		if (status < 0) {
682 			if (status != -ENOSPC)
683 				mlog_errno(status);
684 			goto bail;
685 		}
686 
687 		/*
688 		 * Under certain conditions, the window slide code
689 		 * might have reduced the number of bits available or
690 		 * disabled the the local alloc entirely. Re-check
691 		 * here and return -ENOSPC if necessary.
692 		 */
693 		status = -ENOSPC;
694 		if (!ocfs2_la_state_enabled(osb))
695 			goto bail;
696 
697 		free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
698 			le32_to_cpu(alloc->id1.bitmap1.i_used);
699 		if (bits_wanted > free_bits)
700 			goto bail;
701 	}
702 
703 	ac->ac_inode = local_alloc_inode;
704 	/* We should never use localalloc from another slot */
705 	ac->ac_alloc_slot = osb->slot_num;
706 	ac->ac_which = OCFS2_AC_USE_LOCAL;
707 	get_bh(osb->local_alloc_bh);
708 	ac->ac_bh = osb->local_alloc_bh;
709 	status = 0;
710 bail:
711 	if (status < 0 && local_alloc_inode) {
712 		inode_unlock(local_alloc_inode);
713 		iput(local_alloc_inode);
714 	}
715 
716 	trace_ocfs2_reserve_local_alloc_bits(
717 		(unsigned long long)ac->ac_max_block,
718 		bits_wanted, osb->slot_num, status);
719 
720 	if (status)
721 		mlog_errno(status);
722 	return status;
723 }
724 
725 int ocfs2_claim_local_alloc_bits(struct ocfs2_super *osb,
726 				 handle_t *handle,
727 				 struct ocfs2_alloc_context *ac,
728 				 u32 bits_wanted,
729 				 u32 *bit_off,
730 				 u32 *num_bits)
731 {
732 	int status, start;
733 	struct inode *local_alloc_inode;
734 	void *bitmap;
735 	struct ocfs2_dinode *alloc;
736 	struct ocfs2_local_alloc *la;
737 
738 	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);
739 
740 	local_alloc_inode = ac->ac_inode;
741 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
742 	la = OCFS2_LOCAL_ALLOC(alloc);
743 
744 	start = ocfs2_local_alloc_find_clear_bits(osb, alloc, &bits_wanted,
745 						  ac->ac_resv);
746 	if (start == -1) {
747 		/* TODO: Shouldn't we just BUG here? */
748 		status = -ENOSPC;
749 		mlog_errno(status);
750 		goto bail;
751 	}
752 
753 	bitmap = la->la_bitmap;
754 	*bit_off = le32_to_cpu(la->la_bm_off) + start;
755 	*num_bits = bits_wanted;
756 
757 	status = ocfs2_journal_access_di(handle,
758 					 INODE_CACHE(local_alloc_inode),
759 					 osb->local_alloc_bh,
760 					 OCFS2_JOURNAL_ACCESS_WRITE);
761 	if (status < 0) {
762 		mlog_errno(status);
763 		goto bail;
764 	}
765 
766 	ocfs2_resmap_claimed_bits(&osb->osb_la_resmap, ac->ac_resv, start,
767 				  bits_wanted);
768 
769 	while(bits_wanted--)
770 		ocfs2_set_bit(start++, bitmap);
771 
772 	le32_add_cpu(&alloc->id1.bitmap1.i_used, *num_bits);
773 	ocfs2_journal_dirty(handle, osb->local_alloc_bh);
774 
775 bail:
776 	if (status)
777 		mlog_errno(status);
778 	return status;
779 }
780 
781 int ocfs2_free_local_alloc_bits(struct ocfs2_super *osb,
782 				handle_t *handle,
783 				struct ocfs2_alloc_context *ac,
784 				u32 bit_off,
785 				u32 num_bits)
786 {
787 	int status, start;
788 	u32 clear_bits;
789 	struct inode *local_alloc_inode;
790 	void *bitmap;
791 	struct ocfs2_dinode *alloc;
792 	struct ocfs2_local_alloc *la;
793 
794 	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);
795 
796 	local_alloc_inode = ac->ac_inode;
797 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
798 	la = OCFS2_LOCAL_ALLOC(alloc);
799 
800 	bitmap = la->la_bitmap;
801 	start = bit_off - le32_to_cpu(la->la_bm_off);
802 	clear_bits = num_bits;
803 
804 	status = ocfs2_journal_access_di(handle,
805 			INODE_CACHE(local_alloc_inode),
806 			osb->local_alloc_bh,
807 			OCFS2_JOURNAL_ACCESS_WRITE);
808 	if (status < 0) {
809 		mlog_errno(status);
810 		goto bail;
811 	}
812 
813 	while (clear_bits--)
814 		ocfs2_clear_bit(start++, bitmap);
815 
816 	le32_add_cpu(&alloc->id1.bitmap1.i_used, -num_bits);
817 	ocfs2_journal_dirty(handle, osb->local_alloc_bh);
818 
819 bail:
820 	return status;
821 }
822 
823 static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc)
824 {
825 	u32 count;
826 	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
827 
828 	count = memweight(la->la_bitmap, le16_to_cpu(la->la_size));
829 
830 	trace_ocfs2_local_alloc_count_bits(count);
831 	return count;
832 }
833 
834 static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
835 				     struct ocfs2_dinode *alloc,
836 				     u32 *numbits,
837 				     struct ocfs2_alloc_reservation *resv)
838 {
839 	int numfound = 0, bitoff, left, startoff, lastzero;
840 	int local_resv = 0;
841 	struct ocfs2_alloc_reservation r;
842 	void *bitmap = NULL;
843 	struct ocfs2_reservation_map *resmap = &osb->osb_la_resmap;
844 
845 	if (!alloc->id1.bitmap1.i_total) {
846 		bitoff = -1;
847 		goto bail;
848 	}
849 
850 	if (!resv) {
851 		local_resv = 1;
852 		ocfs2_resv_init_once(&r);
853 		ocfs2_resv_set_type(&r, OCFS2_RESV_FLAG_TMP);
854 		resv = &r;
855 	}
856 
857 	numfound = *numbits;
858 	if (ocfs2_resmap_resv_bits(resmap, resv, &bitoff, &numfound) == 0) {
859 		if (numfound < *numbits)
860 			*numbits = numfound;
861 		goto bail;
862 	}
863 
864 	/*
865 	 * Code error. While reservations are enabled, local
866 	 * allocation should _always_ go through them.
867 	 */
868 	BUG_ON(osb->osb_resv_level != 0);
869 
870 	/*
871 	 * Reservations are disabled. Handle this the old way.
872 	 */
873 
874 	bitmap = OCFS2_LOCAL_ALLOC(alloc)->la_bitmap;
875 
876 	numfound = bitoff = startoff = 0;
877 	lastzero = -1;
878 	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
879 	while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
880 		if (bitoff == left) {
881 			/* mlog(0, "bitoff (%d) == left", bitoff); */
882 			break;
883 		}
884 		/* mlog(0, "Found a zero: bitoff = %d, startoff = %d, "
885 		   "numfound = %d\n", bitoff, startoff, numfound);*/
886 
887 		/* Ok, we found a zero bit... is it contig. or do we
888 		 * start over?*/
889 		if (bitoff == startoff) {
890 			/* we found a zero */
891 			numfound++;
892 			startoff++;
893 		} else {
894 			/* got a zero after some ones */
895 			numfound = 1;
896 			startoff = bitoff+1;
897 		}
898 		/* we got everything we needed */
899 		if (numfound == *numbits) {
900 			/* mlog(0, "Found it all!\n"); */
901 			break;
902 		}
903 	}
904 
905 	trace_ocfs2_local_alloc_find_clear_bits_search_bitmap(bitoff, numfound);
906 
907 	if (numfound == *numbits)
908 		bitoff = startoff - numfound;
909 	else
910 		bitoff = -1;
911 
912 bail:
913 	if (local_resv)
914 		ocfs2_resv_discard(resmap, resv);
915 
916 	trace_ocfs2_local_alloc_find_clear_bits(*numbits,
917 		le32_to_cpu(alloc->id1.bitmap1.i_total),
918 		bitoff, numfound);
919 
920 	return bitoff;
921 }
922 
923 static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc)
924 {
925 	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
926 	int i;
927 
928 	alloc->id1.bitmap1.i_total = 0;
929 	alloc->id1.bitmap1.i_used = 0;
930 	la->la_bm_off = 0;
931 	for(i = 0; i < le16_to_cpu(la->la_size); i++)
932 		la->la_bitmap[i] = 0;
933 }
934 
935 #if 0
936 /* turn this on and uncomment below to aid debugging window shifts. */
937 static void ocfs2_verify_zero_bits(unsigned long *bitmap,
938 				   unsigned int start,
939 				   unsigned int count)
940 {
941 	unsigned int tmp = count;
942 	while(tmp--) {
943 		if (ocfs2_test_bit(start + tmp, bitmap)) {
944 			printk("ocfs2_verify_zero_bits: start = %u, count = "
945 			       "%u\n", start, count);
946 			printk("ocfs2_verify_zero_bits: bit %u is set!",
947 			       start + tmp);
948 			BUG();
949 		}
950 	}
951 }
952 #endif
953 
954 /*
955  * sync the local alloc to main bitmap.
956  *
957  * assumes you've already locked the main bitmap -- the bitmap inode
958  * passed is used for caching.
959  */
960 static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
961 				    handle_t *handle,
962 				    struct ocfs2_dinode *alloc,
963 				    struct inode *main_bm_inode,
964 				    struct buffer_head *main_bm_bh)
965 {
966 	int status = 0;
967 	int bit_off, left, count, start;
968 	u64 la_start_blk;
969 	u64 blkno;
970 	void *bitmap;
971 	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
972 
973 	trace_ocfs2_sync_local_to_main(
974 	     le32_to_cpu(alloc->id1.bitmap1.i_total),
975 	     le32_to_cpu(alloc->id1.bitmap1.i_used));
976 
977 	if (!alloc->id1.bitmap1.i_total) {
978 		goto bail;
979 	}
980 
981 	if (le32_to_cpu(alloc->id1.bitmap1.i_used) ==
982 	    le32_to_cpu(alloc->id1.bitmap1.i_total)) {
983 		goto bail;
984 	}
985 
986 	la_start_blk = ocfs2_clusters_to_blocks(osb->sb,
987 						le32_to_cpu(la->la_bm_off));
988 	bitmap = la->la_bitmap;
989 	start = count = bit_off = 0;
990 	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
991 
992 	while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))
993 	       != -1) {
994 		if ((bit_off < left) && (bit_off == start)) {
995 			count++;
996 			start++;
997 			continue;
998 		}
999 		if (count) {
1000 			blkno = la_start_blk +
1001 				ocfs2_clusters_to_blocks(osb->sb,
1002 							 start - count);
1003 
1004 			trace_ocfs2_sync_local_to_main_free(
1005 			     count, start - count,
1006 			     (unsigned long long)la_start_blk,
1007 			     (unsigned long long)blkno);
1008 
1009 			status = ocfs2_release_clusters(handle,
1010 							main_bm_inode,
1011 							main_bm_bh, blkno,
1012 							count);
1013 			if (status < 0) {
1014 				mlog_errno(status);
1015 				goto bail;
1016 			}
1017 		}
1018 		if (bit_off >= left)
1019 			break;
1020 		count = 1;
1021 		start = bit_off + 1;
1022 	}
1023 
1024 bail:
1025 	if (status)
1026 		mlog_errno(status);
1027 	return status;
1028 }
1029 
1030 enum ocfs2_la_event {
1031 	OCFS2_LA_EVENT_SLIDE,		/* Normal window slide. */
1032 	OCFS2_LA_EVENT_FRAGMENTED,	/* The global bitmap has
1033 					 * enough bits theoretically
1034 					 * free, but a contiguous
1035 					 * allocation could not be
1036 					 * found. */
1037 	OCFS2_LA_EVENT_ENOSPC,		/* Global bitmap doesn't have
1038 					 * enough bits free to satisfy
1039 					 * our request. */
1040 };
1041 #define OCFS2_LA_ENABLE_INTERVAL (30 * HZ)
1042 /*
1043  * Given an event, calculate the size of our next local alloc window.
1044  *
1045  * This should always be called under i_mutex of the local alloc inode
1046  * so that local alloc disabling doesn't race with processes trying to
1047  * use the allocator.
1048  *
1049  * Returns the state which the local alloc was left in. This value can
1050  * be ignored by some paths.
1051  */
1052 static int ocfs2_recalc_la_window(struct ocfs2_super *osb,
1053 				  enum ocfs2_la_event event)
1054 {
1055 	unsigned int bits;
1056 	int state;
1057 
1058 	spin_lock(&osb->osb_lock);
1059 	if (osb->local_alloc_state == OCFS2_LA_DISABLED) {
1060 		WARN_ON_ONCE(osb->local_alloc_state == OCFS2_LA_DISABLED);
1061 		goto out_unlock;
1062 	}
1063 
1064 	/*
1065 	 * ENOSPC and fragmentation are treated similarly for now.
1066 	 */
1067 	if (event == OCFS2_LA_EVENT_ENOSPC ||
1068 	    event == OCFS2_LA_EVENT_FRAGMENTED) {
1069 		/*
1070 		 * We ran out of contiguous space in the primary
1071 		 * bitmap. Drastically reduce the number of bits used
1072 		 * by local alloc until we have to disable it.
1073 		 */
1074 		bits = osb->local_alloc_bits >> 1;
1075 		if (bits > ocfs2_megabytes_to_clusters(osb->sb, 1)) {
1076 			/*
1077 			 * By setting state to THROTTLED, we'll keep
1078 			 * the number of local alloc bits used down
1079 			 * until an event occurs which would give us
1080 			 * reason to assume the bitmap situation might
1081 			 * have changed.
1082 			 */
1083 			osb->local_alloc_state = OCFS2_LA_THROTTLED;
1084 			osb->local_alloc_bits = bits;
1085 		} else {
1086 			osb->local_alloc_state = OCFS2_LA_DISABLED;
1087 		}
1088 		queue_delayed_work(osb->ocfs2_wq, &osb->la_enable_wq,
1089 				   OCFS2_LA_ENABLE_INTERVAL);
1090 		goto out_unlock;
1091 	}
1092 
1093 	/*
1094 	 * Don't increase the size of the local alloc window until we
1095 	 * know we might be able to fulfill the request. Otherwise, we
1096 	 * risk bouncing around the global bitmap during periods of
1097 	 * low space.
1098 	 */
1099 	if (osb->local_alloc_state != OCFS2_LA_THROTTLED)
1100 		osb->local_alloc_bits = osb->local_alloc_default_bits;
1101 
1102 out_unlock:
1103 	state = osb->local_alloc_state;
1104 	spin_unlock(&osb->osb_lock);
1105 
1106 	return state;
1107 }
1108 
1109 static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
1110 						struct ocfs2_alloc_context **ac,
1111 						struct inode **bitmap_inode,
1112 						struct buffer_head **bitmap_bh)
1113 {
1114 	int status;
1115 
1116 	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1117 	if (!(*ac)) {
1118 		status = -ENOMEM;
1119 		mlog_errno(status);
1120 		goto bail;
1121 	}
1122 
1123 retry_enospc:
1124 	(*ac)->ac_bits_wanted = osb->local_alloc_bits;
1125 	status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1126 	if (status == -ENOSPC) {
1127 		if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_ENOSPC) ==
1128 		    OCFS2_LA_DISABLED)
1129 			goto bail;
1130 
1131 		ocfs2_free_ac_resource(*ac);
1132 		memset(*ac, 0, sizeof(struct ocfs2_alloc_context));
1133 		goto retry_enospc;
1134 	}
1135 	if (status < 0) {
1136 		mlog_errno(status);
1137 		goto bail;
1138 	}
1139 
1140 	*bitmap_inode = (*ac)->ac_inode;
1141 	igrab(*bitmap_inode);
1142 	*bitmap_bh = (*ac)->ac_bh;
1143 	get_bh(*bitmap_bh);
1144 	status = 0;
1145 bail:
1146 	if ((status < 0) && *ac) {
1147 		ocfs2_free_alloc_context(*ac);
1148 		*ac = NULL;
1149 	}
1150 
1151 	if (status)
1152 		mlog_errno(status);
1153 	return status;
1154 }
1155 
1156 /*
1157  * pass it the bitmap lock in lock_bh if you have it.
1158  */
1159 static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
1160 					handle_t *handle,
1161 					struct ocfs2_alloc_context *ac)
1162 {
1163 	int status = 0;
1164 	u32 cluster_off, cluster_count;
1165 	struct ocfs2_dinode *alloc = NULL;
1166 	struct ocfs2_local_alloc *la;
1167 
1168 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
1169 	la = OCFS2_LOCAL_ALLOC(alloc);
1170 
1171 	trace_ocfs2_local_alloc_new_window(
1172 		le32_to_cpu(alloc->id1.bitmap1.i_total),
1173 		osb->local_alloc_bits);
1174 
1175 	/* Instruct the allocation code to try the most recently used
1176 	 * cluster group. We'll re-record the group used this pass
1177 	 * below. */
1178 	ac->ac_last_group = osb->la_last_gd;
1179 
1180 	/* we used the generic suballoc reserve function, but we set
1181 	 * everything up nicely, so there's no reason why we can't use
1182 	 * the more specific cluster api to claim bits. */
1183 	status = ocfs2_claim_clusters(handle, ac, osb->local_alloc_bits,
1184 				      &cluster_off, &cluster_count);
1185 	if (status == -ENOSPC) {
1186 retry_enospc:
1187 		/*
1188 		 * Note: We could also try syncing the journal here to
1189 		 * allow use of any free bits which the current
1190 		 * transaction can't give us access to. --Mark
1191 		 */
1192 		if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_FRAGMENTED) ==
1193 		    OCFS2_LA_DISABLED)
1194 			goto bail;
1195 
1196 		ac->ac_bits_wanted = osb->local_alloc_bits;
1197 		status = ocfs2_claim_clusters(handle, ac,
1198 					      osb->local_alloc_bits,
1199 					      &cluster_off,
1200 					      &cluster_count);
1201 		if (status == -ENOSPC)
1202 			goto retry_enospc;
1203 		/*
1204 		 * We only shrunk the *minimum* number of in our
1205 		 * request - it's entirely possible that the allocator
1206 		 * might give us more than we asked for.
1207 		 */
1208 		if (status == 0) {
1209 			spin_lock(&osb->osb_lock);
1210 			osb->local_alloc_bits = cluster_count;
1211 			spin_unlock(&osb->osb_lock);
1212 		}
1213 	}
1214 	if (status < 0) {
1215 		if (status != -ENOSPC)
1216 			mlog_errno(status);
1217 		goto bail;
1218 	}
1219 
1220 	osb->la_last_gd = ac->ac_last_group;
1221 
1222 	la->la_bm_off = cpu_to_le32(cluster_off);
1223 	alloc->id1.bitmap1.i_total = cpu_to_le32(cluster_count);
1224 	/* just in case... In the future when we find space ourselves,
1225 	 * we don't have to get all contiguous -- but we'll have to
1226 	 * set all previously used bits in bitmap and update
1227 	 * la_bits_set before setting the bits in the main bitmap. */
1228 	alloc->id1.bitmap1.i_used = 0;
1229 	memset(OCFS2_LOCAL_ALLOC(alloc)->la_bitmap, 0,
1230 	       le16_to_cpu(la->la_size));
1231 
1232 	ocfs2_resmap_restart(&osb->osb_la_resmap, cluster_count,
1233 			     OCFS2_LOCAL_ALLOC(alloc)->la_bitmap);
1234 
1235 	trace_ocfs2_local_alloc_new_window_result(
1236 		OCFS2_LOCAL_ALLOC(alloc)->la_bm_off,
1237 		le32_to_cpu(alloc->id1.bitmap1.i_total));
1238 
1239 bail:
1240 	if (status)
1241 		mlog_errno(status);
1242 	return status;
1243 }
1244 
1245 /* Note that we do *NOT* lock the local alloc inode here as
1246  * it's been locked already for us. */
1247 static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
1248 					  struct inode *local_alloc_inode)
1249 {
1250 	int status = 0;
1251 	struct buffer_head *main_bm_bh = NULL;
1252 	struct inode *main_bm_inode = NULL;
1253 	handle_t *handle = NULL;
1254 	struct ocfs2_dinode *alloc;
1255 	struct ocfs2_dinode *alloc_copy = NULL;
1256 	struct ocfs2_alloc_context *ac = NULL;
1257 
1258 	ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_SLIDE);
1259 
1260 	/* This will lock the main bitmap for us. */
1261 	status = ocfs2_local_alloc_reserve_for_window(osb,
1262 						      &ac,
1263 						      &main_bm_inode,
1264 						      &main_bm_bh);
1265 	if (status < 0) {
1266 		if (status != -ENOSPC)
1267 			mlog_errno(status);
1268 		goto bail;
1269 	}
1270 
1271 	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
1272 	if (IS_ERR(handle)) {
1273 		status = PTR_ERR(handle);
1274 		handle = NULL;
1275 		mlog_errno(status);
1276 		goto bail;
1277 	}
1278 
1279 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
1280 
1281 	/* We want to clear the local alloc before doing anything
1282 	 * else, so that if we error later during this operation,
1283 	 * local alloc shutdown won't try to double free main bitmap
1284 	 * bits. Make a copy so the sync function knows which bits to
1285 	 * free. */
1286 	alloc_copy = kmalloc(osb->local_alloc_bh->b_size, GFP_NOFS);
1287 	if (!alloc_copy) {
1288 		status = -ENOMEM;
1289 		mlog_errno(status);
1290 		goto bail;
1291 	}
1292 	memcpy(alloc_copy, alloc, osb->local_alloc_bh->b_size);
1293 
1294 	status = ocfs2_journal_access_di(handle,
1295 					 INODE_CACHE(local_alloc_inode),
1296 					 osb->local_alloc_bh,
1297 					 OCFS2_JOURNAL_ACCESS_WRITE);
1298 	if (status < 0) {
1299 		mlog_errno(status);
1300 		goto bail;
1301 	}
1302 
1303 	ocfs2_clear_local_alloc(alloc);
1304 	ocfs2_journal_dirty(handle, osb->local_alloc_bh);
1305 
1306 	status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
1307 					  main_bm_inode, main_bm_bh);
1308 	if (status < 0) {
1309 		mlog_errno(status);
1310 		goto bail;
1311 	}
1312 
1313 	status = ocfs2_local_alloc_new_window(osb, handle, ac);
1314 	if (status < 0) {
1315 		if (status != -ENOSPC)
1316 			mlog_errno(status);
1317 		goto bail;
1318 	}
1319 
1320 	atomic_inc(&osb->alloc_stats.moves);
1321 
1322 bail:
1323 	if (handle)
1324 		ocfs2_commit_trans(osb, handle);
1325 
1326 	brelse(main_bm_bh);
1327 
1328 	iput(main_bm_inode);
1329 	kfree(alloc_copy);
1330 
1331 	if (ac)
1332 		ocfs2_free_alloc_context(ac);
1333 
1334 	if (status)
1335 		mlog_errno(status);
1336 	return status;
1337 }
1338 
1339