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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
ocfs2_la_default_mb(struct ocfs2_super * osb)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 
ocfs2_la_set_sizes(struct ocfs2_super * osb,int requested_mb)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 
ocfs2_la_state_enabled(struct ocfs2_super * osb)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 
ocfs2_local_alloc_seen_free_bits(struct ocfs2_super * osb,unsigned int num_clusters)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 
ocfs2_la_enable_worker(struct work_struct * work)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  */
ocfs2_alloc_should_use_local(struct ocfs2_super * osb,u64 bits)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 
ocfs2_load_local_alloc(struct ocfs2_super * osb)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 	if (inode)
362 		iput(inode);
363 
364 	trace_ocfs2_load_local_alloc(osb->local_alloc_bits);
365 
366 	if (status)
367 		mlog_errno(status);
368 	return status;
369 }
370 
371 /*
372  * return any unused bits to the bitmap and write out a clean
373  * local_alloc.
374  *
375  * local_alloc_bh is optional. If not passed, we will simply use the
376  * one off osb. If you do pass it however, be warned that it *will* be
377  * returned brelse'd and NULL'd out.*/
ocfs2_shutdown_local_alloc(struct ocfs2_super * osb)378 void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb)
379 {
380 	int status;
381 	handle_t *handle;
382 	struct inode *local_alloc_inode = NULL;
383 	struct buffer_head *bh = NULL;
384 	struct buffer_head *main_bm_bh = NULL;
385 	struct inode *main_bm_inode = NULL;
386 	struct ocfs2_dinode *alloc_copy = NULL;
387 	struct ocfs2_dinode *alloc = NULL;
388 
389 	cancel_delayed_work(&osb->la_enable_wq);
390 	flush_workqueue(ocfs2_wq);
391 
392 	if (osb->local_alloc_state == OCFS2_LA_UNUSED)
393 		goto out;
394 
395 	local_alloc_inode =
396 		ocfs2_get_system_file_inode(osb,
397 					    LOCAL_ALLOC_SYSTEM_INODE,
398 					    osb->slot_num);
399 	if (!local_alloc_inode) {
400 		status = -ENOENT;
401 		mlog_errno(status);
402 		goto out;
403 	}
404 
405 	osb->local_alloc_state = OCFS2_LA_DISABLED;
406 
407 	ocfs2_resmap_uninit(&osb->osb_la_resmap);
408 
409 	main_bm_inode = ocfs2_get_system_file_inode(osb,
410 						    GLOBAL_BITMAP_SYSTEM_INODE,
411 						    OCFS2_INVALID_SLOT);
412 	if (!main_bm_inode) {
413 		status = -EINVAL;
414 		mlog_errno(status);
415 		goto out;
416 	}
417 
418 	mutex_lock(&main_bm_inode->i_mutex);
419 
420 	status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
421 	if (status < 0) {
422 		mlog_errno(status);
423 		goto out_mutex;
424 	}
425 
426 	/* WINDOW_MOVE_CREDITS is a bit heavy... */
427 	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
428 	if (IS_ERR(handle)) {
429 		mlog_errno(PTR_ERR(handle));
430 		handle = NULL;
431 		goto out_unlock;
432 	}
433 
434 	bh = osb->local_alloc_bh;
435 	alloc = (struct ocfs2_dinode *) bh->b_data;
436 
437 	alloc_copy = kmalloc(bh->b_size, GFP_NOFS);
438 	if (!alloc_copy) {
439 		status = -ENOMEM;
440 		goto out_commit;
441 	}
442 	memcpy(alloc_copy, alloc, bh->b_size);
443 
444 	status = ocfs2_journal_access_di(handle, INODE_CACHE(local_alloc_inode),
445 					 bh, OCFS2_JOURNAL_ACCESS_WRITE);
446 	if (status < 0) {
447 		mlog_errno(status);
448 		goto out_commit;
449 	}
450 
451 	ocfs2_clear_local_alloc(alloc);
452 	ocfs2_journal_dirty(handle, bh);
453 
454 	brelse(bh);
455 	osb->local_alloc_bh = NULL;
456 	osb->local_alloc_state = OCFS2_LA_UNUSED;
457 
458 	status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
459 					  main_bm_inode, main_bm_bh);
460 	if (status < 0)
461 		mlog_errno(status);
462 
463 out_commit:
464 	ocfs2_commit_trans(osb, handle);
465 
466 out_unlock:
467 	brelse(main_bm_bh);
468 
469 	ocfs2_inode_unlock(main_bm_inode, 1);
470 
471 out_mutex:
472 	mutex_unlock(&main_bm_inode->i_mutex);
473 	iput(main_bm_inode);
474 
475 out:
476 	if (local_alloc_inode)
477 		iput(local_alloc_inode);
478 
479 	kfree(alloc_copy);
480 }
481 
482 /*
483  * We want to free the bitmap bits outside of any recovery context as
484  * we'll need a cluster lock to do so, but we must clear the local
485  * alloc before giving up the recovered nodes journal. To solve this,
486  * we kmalloc a copy of the local alloc before it's change for the
487  * caller to process with ocfs2_complete_local_alloc_recovery
488  */
ocfs2_begin_local_alloc_recovery(struct ocfs2_super * osb,int slot_num,struct ocfs2_dinode ** alloc_copy)489 int ocfs2_begin_local_alloc_recovery(struct ocfs2_super *osb,
490 				     int slot_num,
491 				     struct ocfs2_dinode **alloc_copy)
492 {
493 	int status = 0;
494 	struct buffer_head *alloc_bh = NULL;
495 	struct inode *inode = NULL;
496 	struct ocfs2_dinode *alloc;
497 
498 	trace_ocfs2_begin_local_alloc_recovery(slot_num);
499 
500 	*alloc_copy = NULL;
501 
502 	inode = ocfs2_get_system_file_inode(osb,
503 					    LOCAL_ALLOC_SYSTEM_INODE,
504 					    slot_num);
505 	if (!inode) {
506 		status = -EINVAL;
507 		mlog_errno(status);
508 		goto bail;
509 	}
510 
511 	mutex_lock(&inode->i_mutex);
512 
513 	status = ocfs2_read_inode_block_full(inode, &alloc_bh,
514 					     OCFS2_BH_IGNORE_CACHE);
515 	if (status < 0) {
516 		mlog_errno(status);
517 		goto bail;
518 	}
519 
520 	*alloc_copy = kmalloc(alloc_bh->b_size, GFP_KERNEL);
521 	if (!(*alloc_copy)) {
522 		status = -ENOMEM;
523 		goto bail;
524 	}
525 	memcpy((*alloc_copy), alloc_bh->b_data, alloc_bh->b_size);
526 
527 	alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
528 	ocfs2_clear_local_alloc(alloc);
529 
530 	ocfs2_compute_meta_ecc(osb->sb, alloc_bh->b_data, &alloc->i_check);
531 	status = ocfs2_write_block(osb, alloc_bh, INODE_CACHE(inode));
532 	if (status < 0)
533 		mlog_errno(status);
534 
535 bail:
536 	if (status < 0) {
537 		kfree(*alloc_copy);
538 		*alloc_copy = NULL;
539 	}
540 
541 	brelse(alloc_bh);
542 
543 	if (inode) {
544 		mutex_unlock(&inode->i_mutex);
545 		iput(inode);
546 	}
547 
548 	if (status)
549 		mlog_errno(status);
550 	return status;
551 }
552 
553 /*
554  * Step 2: By now, we've completed the journal recovery, we've stamped
555  * a clean local alloc on disk and dropped the node out of the
556  * recovery map. Dlm locks will no longer stall, so lets clear out the
557  * main bitmap.
558  */
ocfs2_complete_local_alloc_recovery(struct ocfs2_super * osb,struct ocfs2_dinode * alloc)559 int ocfs2_complete_local_alloc_recovery(struct ocfs2_super *osb,
560 					struct ocfs2_dinode *alloc)
561 {
562 	int status;
563 	handle_t *handle;
564 	struct buffer_head *main_bm_bh = NULL;
565 	struct inode *main_bm_inode;
566 
567 	main_bm_inode = ocfs2_get_system_file_inode(osb,
568 						    GLOBAL_BITMAP_SYSTEM_INODE,
569 						    OCFS2_INVALID_SLOT);
570 	if (!main_bm_inode) {
571 		status = -EINVAL;
572 		mlog_errno(status);
573 		goto out;
574 	}
575 
576 	mutex_lock(&main_bm_inode->i_mutex);
577 
578 	status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
579 	if (status < 0) {
580 		mlog_errno(status);
581 		goto out_mutex;
582 	}
583 
584 	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
585 	if (IS_ERR(handle)) {
586 		status = PTR_ERR(handle);
587 		handle = NULL;
588 		mlog_errno(status);
589 		goto out_unlock;
590 	}
591 
592 	/* we want the bitmap change to be recorded on disk asap */
593 	handle->h_sync = 1;
594 
595 	status = ocfs2_sync_local_to_main(osb, handle, alloc,
596 					  main_bm_inode, main_bm_bh);
597 	if (status < 0)
598 		mlog_errno(status);
599 
600 	ocfs2_commit_trans(osb, handle);
601 
602 out_unlock:
603 	ocfs2_inode_unlock(main_bm_inode, 1);
604 
605 out_mutex:
606 	mutex_unlock(&main_bm_inode->i_mutex);
607 
608 	brelse(main_bm_bh);
609 
610 	iput(main_bm_inode);
611 
612 out:
613 	if (!status)
614 		ocfs2_init_steal_slots(osb);
615 	if (status)
616 		mlog_errno(status);
617 	return status;
618 }
619 
620 /*
621  * make sure we've got at least bits_wanted contiguous bits in the
622  * local alloc. You lose them when you drop i_mutex.
623  *
624  * We will add ourselves to the transaction passed in, but may start
625  * our own in order to shift windows.
626  */
ocfs2_reserve_local_alloc_bits(struct ocfs2_super * osb,u32 bits_wanted,struct ocfs2_alloc_context * ac)627 int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
628 				   u32 bits_wanted,
629 				   struct ocfs2_alloc_context *ac)
630 {
631 	int status;
632 	struct ocfs2_dinode *alloc;
633 	struct inode *local_alloc_inode;
634 	unsigned int free_bits;
635 
636 	BUG_ON(!ac);
637 
638 	local_alloc_inode =
639 		ocfs2_get_system_file_inode(osb,
640 					    LOCAL_ALLOC_SYSTEM_INODE,
641 					    osb->slot_num);
642 	if (!local_alloc_inode) {
643 		status = -ENOENT;
644 		mlog_errno(status);
645 		goto bail;
646 	}
647 
648 	mutex_lock(&local_alloc_inode->i_mutex);
649 
650 	/*
651 	 * We must double check state and allocator bits because
652 	 * another process may have changed them while holding i_mutex.
653 	 */
654 	spin_lock(&osb->osb_lock);
655 	if (!ocfs2_la_state_enabled(osb) ||
656 	    (bits_wanted > osb->local_alloc_bits)) {
657 		spin_unlock(&osb->osb_lock);
658 		status = -ENOSPC;
659 		goto bail;
660 	}
661 	spin_unlock(&osb->osb_lock);
662 
663 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
664 
665 #ifdef CONFIG_OCFS2_DEBUG_FS
666 	if (le32_to_cpu(alloc->id1.bitmap1.i_used) !=
667 	    ocfs2_local_alloc_count_bits(alloc)) {
668 		ocfs2_error(osb->sb, "local alloc inode %llu says it has "
669 			    "%u free bits, but a count shows %u",
670 			    (unsigned long long)le64_to_cpu(alloc->i_blkno),
671 			    le32_to_cpu(alloc->id1.bitmap1.i_used),
672 			    ocfs2_local_alloc_count_bits(alloc));
673 		status = -EIO;
674 		goto bail;
675 	}
676 #endif
677 
678 	free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
679 		le32_to_cpu(alloc->id1.bitmap1.i_used);
680 	if (bits_wanted > free_bits) {
681 		/* uhoh, window change time. */
682 		status =
683 			ocfs2_local_alloc_slide_window(osb, local_alloc_inode);
684 		if (status < 0) {
685 			if (status != -ENOSPC)
686 				mlog_errno(status);
687 			goto bail;
688 		}
689 
690 		/*
691 		 * Under certain conditions, the window slide code
692 		 * might have reduced the number of bits available or
693 		 * disabled the the local alloc entirely. Re-check
694 		 * here and return -ENOSPC if necessary.
695 		 */
696 		status = -ENOSPC;
697 		if (!ocfs2_la_state_enabled(osb))
698 			goto bail;
699 
700 		free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
701 			le32_to_cpu(alloc->id1.bitmap1.i_used);
702 		if (bits_wanted > free_bits)
703 			goto bail;
704 	}
705 
706 	ac->ac_inode = local_alloc_inode;
707 	/* We should never use localalloc from another slot */
708 	ac->ac_alloc_slot = osb->slot_num;
709 	ac->ac_which = OCFS2_AC_USE_LOCAL;
710 	get_bh(osb->local_alloc_bh);
711 	ac->ac_bh = osb->local_alloc_bh;
712 	status = 0;
713 bail:
714 	if (status < 0 && local_alloc_inode) {
715 		mutex_unlock(&local_alloc_inode->i_mutex);
716 		iput(local_alloc_inode);
717 	}
718 
719 	trace_ocfs2_reserve_local_alloc_bits(
720 		(unsigned long long)ac->ac_max_block,
721 		bits_wanted, osb->slot_num, status);
722 
723 	if (status)
724 		mlog_errno(status);
725 	return status;
726 }
727 
ocfs2_claim_local_alloc_bits(struct ocfs2_super * osb,handle_t * handle,struct ocfs2_alloc_context * ac,u32 bits_wanted,u32 * bit_off,u32 * num_bits)728 int ocfs2_claim_local_alloc_bits(struct ocfs2_super *osb,
729 				 handle_t *handle,
730 				 struct ocfs2_alloc_context *ac,
731 				 u32 bits_wanted,
732 				 u32 *bit_off,
733 				 u32 *num_bits)
734 {
735 	int status, start;
736 	struct inode *local_alloc_inode;
737 	void *bitmap;
738 	struct ocfs2_dinode *alloc;
739 	struct ocfs2_local_alloc *la;
740 
741 	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);
742 
743 	local_alloc_inode = ac->ac_inode;
744 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
745 	la = OCFS2_LOCAL_ALLOC(alloc);
746 
747 	start = ocfs2_local_alloc_find_clear_bits(osb, alloc, &bits_wanted,
748 						  ac->ac_resv);
749 	if (start == -1) {
750 		/* TODO: Shouldn't we just BUG here? */
751 		status = -ENOSPC;
752 		mlog_errno(status);
753 		goto bail;
754 	}
755 
756 	bitmap = la->la_bitmap;
757 	*bit_off = le32_to_cpu(la->la_bm_off) + start;
758 	*num_bits = bits_wanted;
759 
760 	status = ocfs2_journal_access_di(handle,
761 					 INODE_CACHE(local_alloc_inode),
762 					 osb->local_alloc_bh,
763 					 OCFS2_JOURNAL_ACCESS_WRITE);
764 	if (status < 0) {
765 		mlog_errno(status);
766 		goto bail;
767 	}
768 
769 	ocfs2_resmap_claimed_bits(&osb->osb_la_resmap, ac->ac_resv, start,
770 				  bits_wanted);
771 
772 	while(bits_wanted--)
773 		ocfs2_set_bit(start++, bitmap);
774 
775 	le32_add_cpu(&alloc->id1.bitmap1.i_used, *num_bits);
776 	ocfs2_journal_dirty(handle, osb->local_alloc_bh);
777 
778 bail:
779 	if (status)
780 		mlog_errno(status);
781 	return status;
782 }
783 
ocfs2_free_local_alloc_bits(struct ocfs2_super * osb,handle_t * handle,struct ocfs2_alloc_context * ac,u32 bit_off,u32 num_bits)784 int ocfs2_free_local_alloc_bits(struct ocfs2_super *osb,
785 				handle_t *handle,
786 				struct ocfs2_alloc_context *ac,
787 				u32 bit_off,
788 				u32 num_bits)
789 {
790 	int status, start;
791 	u32 clear_bits;
792 	struct inode *local_alloc_inode;
793 	void *bitmap;
794 	struct ocfs2_dinode *alloc;
795 	struct ocfs2_local_alloc *la;
796 
797 	BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);
798 
799 	local_alloc_inode = ac->ac_inode;
800 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
801 	la = OCFS2_LOCAL_ALLOC(alloc);
802 
803 	bitmap = la->la_bitmap;
804 	start = bit_off - le32_to_cpu(la->la_bm_off);
805 	clear_bits = num_bits;
806 
807 	status = ocfs2_journal_access_di(handle,
808 			INODE_CACHE(local_alloc_inode),
809 			osb->local_alloc_bh,
810 			OCFS2_JOURNAL_ACCESS_WRITE);
811 	if (status < 0) {
812 		mlog_errno(status);
813 		goto bail;
814 	}
815 
816 	while (clear_bits--)
817 		ocfs2_clear_bit(start++, bitmap);
818 
819 	le32_add_cpu(&alloc->id1.bitmap1.i_used, -num_bits);
820 	ocfs2_journal_dirty(handle, osb->local_alloc_bh);
821 
822 bail:
823 	return status;
824 }
825 
ocfs2_local_alloc_count_bits(struct ocfs2_dinode * alloc)826 static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc)
827 {
828 	u32 count;
829 	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
830 
831 	count = memweight(la->la_bitmap, le16_to_cpu(la->la_size));
832 
833 	trace_ocfs2_local_alloc_count_bits(count);
834 	return count;
835 }
836 
ocfs2_local_alloc_find_clear_bits(struct ocfs2_super * osb,struct ocfs2_dinode * alloc,u32 * numbits,struct ocfs2_alloc_reservation * resv)837 static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
838 				     struct ocfs2_dinode *alloc,
839 				     u32 *numbits,
840 				     struct ocfs2_alloc_reservation *resv)
841 {
842 	int numfound, bitoff, left, startoff, lastzero;
843 	int local_resv = 0;
844 	struct ocfs2_alloc_reservation r;
845 	void *bitmap = NULL;
846 	struct ocfs2_reservation_map *resmap = &osb->osb_la_resmap;
847 
848 	if (!alloc->id1.bitmap1.i_total) {
849 		bitoff = -1;
850 		goto bail;
851 	}
852 
853 	if (!resv) {
854 		local_resv = 1;
855 		ocfs2_resv_init_once(&r);
856 		ocfs2_resv_set_type(&r, OCFS2_RESV_FLAG_TMP);
857 		resv = &r;
858 	}
859 
860 	numfound = *numbits;
861 	if (ocfs2_resmap_resv_bits(resmap, resv, &bitoff, &numfound) == 0) {
862 		if (numfound < *numbits)
863 			*numbits = numfound;
864 		goto bail;
865 	}
866 
867 	/*
868 	 * Code error. While reservations are enabled, local
869 	 * allocation should _always_ go through them.
870 	 */
871 	BUG_ON(osb->osb_resv_level != 0);
872 
873 	/*
874 	 * Reservations are disabled. Handle this the old way.
875 	 */
876 
877 	bitmap = OCFS2_LOCAL_ALLOC(alloc)->la_bitmap;
878 
879 	numfound = bitoff = startoff = 0;
880 	lastzero = -1;
881 	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
882 	while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
883 		if (bitoff == left) {
884 			/* mlog(0, "bitoff (%d) == left", bitoff); */
885 			break;
886 		}
887 		/* mlog(0, "Found a zero: bitoff = %d, startoff = %d, "
888 		   "numfound = %d\n", bitoff, startoff, numfound);*/
889 
890 		/* Ok, we found a zero bit... is it contig. or do we
891 		 * start over?*/
892 		if (bitoff == startoff) {
893 			/* we found a zero */
894 			numfound++;
895 			startoff++;
896 		} else {
897 			/* got a zero after some ones */
898 			numfound = 1;
899 			startoff = bitoff+1;
900 		}
901 		/* we got everything we needed */
902 		if (numfound == *numbits) {
903 			/* mlog(0, "Found it all!\n"); */
904 			break;
905 		}
906 	}
907 
908 	trace_ocfs2_local_alloc_find_clear_bits_search_bitmap(bitoff, numfound);
909 
910 	if (numfound == *numbits)
911 		bitoff = startoff - numfound;
912 	else
913 		bitoff = -1;
914 
915 bail:
916 	if (local_resv)
917 		ocfs2_resv_discard(resmap, resv);
918 
919 	trace_ocfs2_local_alloc_find_clear_bits(*numbits,
920 		le32_to_cpu(alloc->id1.bitmap1.i_total),
921 		bitoff, numfound);
922 
923 	return bitoff;
924 }
925 
ocfs2_clear_local_alloc(struct ocfs2_dinode * alloc)926 static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc)
927 {
928 	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
929 	int i;
930 
931 	alloc->id1.bitmap1.i_total = 0;
932 	alloc->id1.bitmap1.i_used = 0;
933 	la->la_bm_off = 0;
934 	for(i = 0; i < le16_to_cpu(la->la_size); i++)
935 		la->la_bitmap[i] = 0;
936 }
937 
938 #if 0
939 /* turn this on and uncomment below to aid debugging window shifts. */
940 static void ocfs2_verify_zero_bits(unsigned long *bitmap,
941 				   unsigned int start,
942 				   unsigned int count)
943 {
944 	unsigned int tmp = count;
945 	while(tmp--) {
946 		if (ocfs2_test_bit(start + tmp, bitmap)) {
947 			printk("ocfs2_verify_zero_bits: start = %u, count = "
948 			       "%u\n", start, count);
949 			printk("ocfs2_verify_zero_bits: bit %u is set!",
950 			       start + tmp);
951 			BUG();
952 		}
953 	}
954 }
955 #endif
956 
957 /*
958  * sync the local alloc to main bitmap.
959  *
960  * assumes you've already locked the main bitmap -- the bitmap inode
961  * passed is used for caching.
962  */
ocfs2_sync_local_to_main(struct ocfs2_super * osb,handle_t * handle,struct ocfs2_dinode * alloc,struct inode * main_bm_inode,struct buffer_head * main_bm_bh)963 static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
964 				    handle_t *handle,
965 				    struct ocfs2_dinode *alloc,
966 				    struct inode *main_bm_inode,
967 				    struct buffer_head *main_bm_bh)
968 {
969 	int status = 0;
970 	int bit_off, left, count, start;
971 	u64 la_start_blk;
972 	u64 blkno;
973 	void *bitmap;
974 	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
975 
976 	trace_ocfs2_sync_local_to_main(
977 	     le32_to_cpu(alloc->id1.bitmap1.i_total),
978 	     le32_to_cpu(alloc->id1.bitmap1.i_used));
979 
980 	if (!alloc->id1.bitmap1.i_total) {
981 		goto bail;
982 	}
983 
984 	if (le32_to_cpu(alloc->id1.bitmap1.i_used) ==
985 	    le32_to_cpu(alloc->id1.bitmap1.i_total)) {
986 		goto bail;
987 	}
988 
989 	la_start_blk = ocfs2_clusters_to_blocks(osb->sb,
990 						le32_to_cpu(la->la_bm_off));
991 	bitmap = la->la_bitmap;
992 	start = count = bit_off = 0;
993 	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
994 
995 	while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))
996 	       != -1) {
997 		if ((bit_off < left) && (bit_off == start)) {
998 			count++;
999 			start++;
1000 			continue;
1001 		}
1002 		if (count) {
1003 			blkno = la_start_blk +
1004 				ocfs2_clusters_to_blocks(osb->sb,
1005 							 start - count);
1006 
1007 			trace_ocfs2_sync_local_to_main_free(
1008 			     count, start - count,
1009 			     (unsigned long long)la_start_blk,
1010 			     (unsigned long long)blkno);
1011 
1012 			status = ocfs2_release_clusters(handle,
1013 							main_bm_inode,
1014 							main_bm_bh, blkno,
1015 							count);
1016 			if (status < 0) {
1017 				mlog_errno(status);
1018 				goto bail;
1019 			}
1020 		}
1021 		if (bit_off >= left)
1022 			break;
1023 		count = 1;
1024 		start = bit_off + 1;
1025 	}
1026 
1027 bail:
1028 	if (status)
1029 		mlog_errno(status);
1030 	return status;
1031 }
1032 
1033 enum ocfs2_la_event {
1034 	OCFS2_LA_EVENT_SLIDE,		/* Normal window slide. */
1035 	OCFS2_LA_EVENT_FRAGMENTED,	/* The global bitmap has
1036 					 * enough bits theoretically
1037 					 * free, but a contiguous
1038 					 * allocation could not be
1039 					 * found. */
1040 	OCFS2_LA_EVENT_ENOSPC,		/* Global bitmap doesn't have
1041 					 * enough bits free to satisfy
1042 					 * our request. */
1043 };
1044 #define OCFS2_LA_ENABLE_INTERVAL (30 * HZ)
1045 /*
1046  * Given an event, calculate the size of our next local alloc window.
1047  *
1048  * This should always be called under i_mutex of the local alloc inode
1049  * so that local alloc disabling doesn't race with processes trying to
1050  * use the allocator.
1051  *
1052  * Returns the state which the local alloc was left in. This value can
1053  * be ignored by some paths.
1054  */
ocfs2_recalc_la_window(struct ocfs2_super * osb,enum ocfs2_la_event event)1055 static int ocfs2_recalc_la_window(struct ocfs2_super *osb,
1056 				  enum ocfs2_la_event event)
1057 {
1058 	unsigned int bits;
1059 	int state;
1060 
1061 	spin_lock(&osb->osb_lock);
1062 	if (osb->local_alloc_state == OCFS2_LA_DISABLED) {
1063 		WARN_ON_ONCE(osb->local_alloc_state == OCFS2_LA_DISABLED);
1064 		goto out_unlock;
1065 	}
1066 
1067 	/*
1068 	 * ENOSPC and fragmentation are treated similarly for now.
1069 	 */
1070 	if (event == OCFS2_LA_EVENT_ENOSPC ||
1071 	    event == OCFS2_LA_EVENT_FRAGMENTED) {
1072 		/*
1073 		 * We ran out of contiguous space in the primary
1074 		 * bitmap. Drastically reduce the number of bits used
1075 		 * by local alloc until we have to disable it.
1076 		 */
1077 		bits = osb->local_alloc_bits >> 1;
1078 		if (bits > ocfs2_megabytes_to_clusters(osb->sb, 1)) {
1079 			/*
1080 			 * By setting state to THROTTLED, we'll keep
1081 			 * the number of local alloc bits used down
1082 			 * until an event occurs which would give us
1083 			 * reason to assume the bitmap situation might
1084 			 * have changed.
1085 			 */
1086 			osb->local_alloc_state = OCFS2_LA_THROTTLED;
1087 			osb->local_alloc_bits = bits;
1088 		} else {
1089 			osb->local_alloc_state = OCFS2_LA_DISABLED;
1090 		}
1091 		queue_delayed_work(ocfs2_wq, &osb->la_enable_wq,
1092 				   OCFS2_LA_ENABLE_INTERVAL);
1093 		goto out_unlock;
1094 	}
1095 
1096 	/*
1097 	 * Don't increase the size of the local alloc window until we
1098 	 * know we might be able to fulfill the request. Otherwise, we
1099 	 * risk bouncing around the global bitmap during periods of
1100 	 * low space.
1101 	 */
1102 	if (osb->local_alloc_state != OCFS2_LA_THROTTLED)
1103 		osb->local_alloc_bits = osb->local_alloc_default_bits;
1104 
1105 out_unlock:
1106 	state = osb->local_alloc_state;
1107 	spin_unlock(&osb->osb_lock);
1108 
1109 	return state;
1110 }
1111 
ocfs2_local_alloc_reserve_for_window(struct ocfs2_super * osb,struct ocfs2_alloc_context ** ac,struct inode ** bitmap_inode,struct buffer_head ** bitmap_bh)1112 static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
1113 						struct ocfs2_alloc_context **ac,
1114 						struct inode **bitmap_inode,
1115 						struct buffer_head **bitmap_bh)
1116 {
1117 	int status;
1118 
1119 	*ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1120 	if (!(*ac)) {
1121 		status = -ENOMEM;
1122 		mlog_errno(status);
1123 		goto bail;
1124 	}
1125 
1126 retry_enospc:
1127 	(*ac)->ac_bits_wanted = osb->local_alloc_bits;
1128 	status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1129 	if (status == -ENOSPC) {
1130 		if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_ENOSPC) ==
1131 		    OCFS2_LA_DISABLED)
1132 			goto bail;
1133 
1134 		ocfs2_free_ac_resource(*ac);
1135 		memset(*ac, 0, sizeof(struct ocfs2_alloc_context));
1136 		goto retry_enospc;
1137 	}
1138 	if (status < 0) {
1139 		mlog_errno(status);
1140 		goto bail;
1141 	}
1142 
1143 	*bitmap_inode = (*ac)->ac_inode;
1144 	igrab(*bitmap_inode);
1145 	*bitmap_bh = (*ac)->ac_bh;
1146 	get_bh(*bitmap_bh);
1147 	status = 0;
1148 bail:
1149 	if ((status < 0) && *ac) {
1150 		ocfs2_free_alloc_context(*ac);
1151 		*ac = NULL;
1152 	}
1153 
1154 	if (status)
1155 		mlog_errno(status);
1156 	return status;
1157 }
1158 
1159 /*
1160  * pass it the bitmap lock in lock_bh if you have it.
1161  */
ocfs2_local_alloc_new_window(struct ocfs2_super * osb,handle_t * handle,struct ocfs2_alloc_context * ac)1162 static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
1163 					handle_t *handle,
1164 					struct ocfs2_alloc_context *ac)
1165 {
1166 	int status = 0;
1167 	u32 cluster_off, cluster_count;
1168 	struct ocfs2_dinode *alloc = NULL;
1169 	struct ocfs2_local_alloc *la;
1170 
1171 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
1172 	la = OCFS2_LOCAL_ALLOC(alloc);
1173 
1174 	trace_ocfs2_local_alloc_new_window(
1175 		le32_to_cpu(alloc->id1.bitmap1.i_total),
1176 		osb->local_alloc_bits);
1177 
1178 	/* Instruct the allocation code to try the most recently used
1179 	 * cluster group. We'll re-record the group used this pass
1180 	 * below. */
1181 	ac->ac_last_group = osb->la_last_gd;
1182 
1183 	/* we used the generic suballoc reserve function, but we set
1184 	 * everything up nicely, so there's no reason why we can't use
1185 	 * the more specific cluster api to claim bits. */
1186 	status = ocfs2_claim_clusters(handle, ac, osb->local_alloc_bits,
1187 				      &cluster_off, &cluster_count);
1188 	if (status == -ENOSPC) {
1189 retry_enospc:
1190 		/*
1191 		 * Note: We could also try syncing the journal here to
1192 		 * allow use of any free bits which the current
1193 		 * transaction can't give us access to. --Mark
1194 		 */
1195 		if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_FRAGMENTED) ==
1196 		    OCFS2_LA_DISABLED)
1197 			goto bail;
1198 
1199 		ac->ac_bits_wanted = osb->local_alloc_bits;
1200 		status = ocfs2_claim_clusters(handle, ac,
1201 					      osb->local_alloc_bits,
1202 					      &cluster_off,
1203 					      &cluster_count);
1204 		if (status == -ENOSPC)
1205 			goto retry_enospc;
1206 		/*
1207 		 * We only shrunk the *minimum* number of in our
1208 		 * request - it's entirely possible that the allocator
1209 		 * might give us more than we asked for.
1210 		 */
1211 		if (status == 0) {
1212 			spin_lock(&osb->osb_lock);
1213 			osb->local_alloc_bits = cluster_count;
1214 			spin_unlock(&osb->osb_lock);
1215 		}
1216 	}
1217 	if (status < 0) {
1218 		if (status != -ENOSPC)
1219 			mlog_errno(status);
1220 		goto bail;
1221 	}
1222 
1223 	osb->la_last_gd = ac->ac_last_group;
1224 
1225 	la->la_bm_off = cpu_to_le32(cluster_off);
1226 	alloc->id1.bitmap1.i_total = cpu_to_le32(cluster_count);
1227 	/* just in case... In the future when we find space ourselves,
1228 	 * we don't have to get all contiguous -- but we'll have to
1229 	 * set all previously used bits in bitmap and update
1230 	 * la_bits_set before setting the bits in the main bitmap. */
1231 	alloc->id1.bitmap1.i_used = 0;
1232 	memset(OCFS2_LOCAL_ALLOC(alloc)->la_bitmap, 0,
1233 	       le16_to_cpu(la->la_size));
1234 
1235 	ocfs2_resmap_restart(&osb->osb_la_resmap, cluster_count,
1236 			     OCFS2_LOCAL_ALLOC(alloc)->la_bitmap);
1237 
1238 	trace_ocfs2_local_alloc_new_window_result(
1239 		OCFS2_LOCAL_ALLOC(alloc)->la_bm_off,
1240 		le32_to_cpu(alloc->id1.bitmap1.i_total));
1241 
1242 bail:
1243 	if (status)
1244 		mlog_errno(status);
1245 	return status;
1246 }
1247 
1248 /* Note that we do *NOT* lock the local alloc inode here as
1249  * it's been locked already for us. */
ocfs2_local_alloc_slide_window(struct ocfs2_super * osb,struct inode * local_alloc_inode)1250 static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
1251 					  struct inode *local_alloc_inode)
1252 {
1253 	int status = 0;
1254 	struct buffer_head *main_bm_bh = NULL;
1255 	struct inode *main_bm_inode = NULL;
1256 	handle_t *handle = NULL;
1257 	struct ocfs2_dinode *alloc;
1258 	struct ocfs2_dinode *alloc_copy = NULL;
1259 	struct ocfs2_alloc_context *ac = NULL;
1260 
1261 	ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_SLIDE);
1262 
1263 	/* This will lock the main bitmap for us. */
1264 	status = ocfs2_local_alloc_reserve_for_window(osb,
1265 						      &ac,
1266 						      &main_bm_inode,
1267 						      &main_bm_bh);
1268 	if (status < 0) {
1269 		if (status != -ENOSPC)
1270 			mlog_errno(status);
1271 		goto bail;
1272 	}
1273 
1274 	handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
1275 	if (IS_ERR(handle)) {
1276 		status = PTR_ERR(handle);
1277 		handle = NULL;
1278 		mlog_errno(status);
1279 		goto bail;
1280 	}
1281 
1282 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
1283 
1284 	/* We want to clear the local alloc before doing anything
1285 	 * else, so that if we error later during this operation,
1286 	 * local alloc shutdown won't try to double free main bitmap
1287 	 * bits. Make a copy so the sync function knows which bits to
1288 	 * free. */
1289 	alloc_copy = kmalloc(osb->local_alloc_bh->b_size, GFP_NOFS);
1290 	if (!alloc_copy) {
1291 		status = -ENOMEM;
1292 		mlog_errno(status);
1293 		goto bail;
1294 	}
1295 	memcpy(alloc_copy, alloc, osb->local_alloc_bh->b_size);
1296 
1297 	status = ocfs2_journal_access_di(handle,
1298 					 INODE_CACHE(local_alloc_inode),
1299 					 osb->local_alloc_bh,
1300 					 OCFS2_JOURNAL_ACCESS_WRITE);
1301 	if (status < 0) {
1302 		mlog_errno(status);
1303 		goto bail;
1304 	}
1305 
1306 	ocfs2_clear_local_alloc(alloc);
1307 	ocfs2_journal_dirty(handle, osb->local_alloc_bh);
1308 
1309 	status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
1310 					  main_bm_inode, main_bm_bh);
1311 	if (status < 0) {
1312 		mlog_errno(status);
1313 		goto bail;
1314 	}
1315 
1316 	status = ocfs2_local_alloc_new_window(osb, handle, ac);
1317 	if (status < 0) {
1318 		if (status != -ENOSPC)
1319 			mlog_errno(status);
1320 		goto bail;
1321 	}
1322 
1323 	atomic_inc(&osb->alloc_stats.moves);
1324 
1325 bail:
1326 	if (handle)
1327 		ocfs2_commit_trans(osb, handle);
1328 
1329 	brelse(main_bm_bh);
1330 
1331 	if (main_bm_inode)
1332 		iput(main_bm_inode);
1333 
1334 	kfree(alloc_copy);
1335 
1336 	if (ac)
1337 		ocfs2_free_alloc_context(ac);
1338 
1339 	if (status)
1340 		mlog_errno(status);
1341 	return status;
1342 }
1343 
1344