1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * uptodate.c
5  *
6  * Tracking the up-to-date-ness of a local buffer_head with respect to
7  * the cluster.
8  *
9  * Copyright (C) 2002, 2004, 2005 Oracle.  All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public
13  * License as published by the Free Software Foundation; either
14  * version 2 of the License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public
22  * License along with this program; if not, write to the
23  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24  * Boston, MA 021110-1307, USA.
25  *
26  * Standard buffer head caching flags (uptodate, etc) are insufficient
27  * in a clustered environment - a buffer may be marked up to date on
28  * our local node but could have been modified by another cluster
29  * member. As a result an additional (and performant) caching scheme
30  * is required. A further requirement is that we consume as little
31  * memory as possible - we never pin buffer_head structures in order
32  * to cache them.
33  *
34  * We track the existence of up to date buffers on the inodes which
35  * are associated with them. Because we don't want to pin
36  * buffer_heads, this is only a (strong) hint and several other checks
37  * are made in the I/O path to ensure that we don't use a stale or
38  * invalid buffer without going to disk:
39  *	- buffer_jbd is used liberally - if a bh is in the journal on
40  *	  this node then it *must* be up to date.
41  *	- the standard buffer_uptodate() macro is used to detect buffers
42  *	  which may be invalid (even if we have an up to date tracking
43  * 	  item for them)
44  *
45  * For a full understanding of how this code works together, one
46  * should read the callers in dlmglue.c, the I/O functions in
47  * buffer_head_io.c and ocfs2_journal_access in journal.c
48  */
49 
50 #include <linux/fs.h>
51 #include <linux/types.h>
52 #include <linux/slab.h>
53 #include <linux/highmem.h>
54 #include <linux/buffer_head.h>
55 #include <linux/rbtree.h>
56 
57 #include <cluster/masklog.h>
58 
59 #include "ocfs2.h"
60 
61 #include "inode.h"
62 #include "uptodate.h"
63 #include "ocfs2_trace.h"
64 
65 struct ocfs2_meta_cache_item {
66 	struct rb_node	c_node;
67 	sector_t	c_block;
68 };
69 
70 static struct kmem_cache *ocfs2_uptodate_cachep;
71 
ocfs2_metadata_cache_owner(struct ocfs2_caching_info * ci)72 u64 ocfs2_metadata_cache_owner(struct ocfs2_caching_info *ci)
73 {
74 	BUG_ON(!ci || !ci->ci_ops);
75 
76 	return ci->ci_ops->co_owner(ci);
77 }
78 
ocfs2_metadata_cache_get_super(struct ocfs2_caching_info * ci)79 struct super_block *ocfs2_metadata_cache_get_super(struct ocfs2_caching_info *ci)
80 {
81 	BUG_ON(!ci || !ci->ci_ops);
82 
83 	return ci->ci_ops->co_get_super(ci);
84 }
85 
ocfs2_metadata_cache_lock(struct ocfs2_caching_info * ci)86 static void ocfs2_metadata_cache_lock(struct ocfs2_caching_info *ci)
87 {
88 	BUG_ON(!ci || !ci->ci_ops);
89 
90 	ci->ci_ops->co_cache_lock(ci);
91 }
92 
ocfs2_metadata_cache_unlock(struct ocfs2_caching_info * ci)93 static void ocfs2_metadata_cache_unlock(struct ocfs2_caching_info *ci)
94 {
95 	BUG_ON(!ci || !ci->ci_ops);
96 
97 	ci->ci_ops->co_cache_unlock(ci);
98 }
99 
ocfs2_metadata_cache_io_lock(struct ocfs2_caching_info * ci)100 void ocfs2_metadata_cache_io_lock(struct ocfs2_caching_info *ci)
101 {
102 	BUG_ON(!ci || !ci->ci_ops);
103 
104 	ci->ci_ops->co_io_lock(ci);
105 }
106 
ocfs2_metadata_cache_io_unlock(struct ocfs2_caching_info * ci)107 void ocfs2_metadata_cache_io_unlock(struct ocfs2_caching_info *ci)
108 {
109 	BUG_ON(!ci || !ci->ci_ops);
110 
111 	ci->ci_ops->co_io_unlock(ci);
112 }
113 
114 
ocfs2_metadata_cache_reset(struct ocfs2_caching_info * ci,int clear)115 static void ocfs2_metadata_cache_reset(struct ocfs2_caching_info *ci,
116 				       int clear)
117 {
118 	ci->ci_flags |= OCFS2_CACHE_FL_INLINE;
119 	ci->ci_num_cached = 0;
120 
121 	if (clear) {
122 		ci->ci_created_trans = 0;
123 		ci->ci_last_trans = 0;
124 	}
125 }
126 
ocfs2_metadata_cache_init(struct ocfs2_caching_info * ci,const struct ocfs2_caching_operations * ops)127 void ocfs2_metadata_cache_init(struct ocfs2_caching_info *ci,
128 			       const struct ocfs2_caching_operations *ops)
129 {
130 	BUG_ON(!ops);
131 
132 	ci->ci_ops = ops;
133 	ocfs2_metadata_cache_reset(ci, 1);
134 }
135 
ocfs2_metadata_cache_exit(struct ocfs2_caching_info * ci)136 void ocfs2_metadata_cache_exit(struct ocfs2_caching_info *ci)
137 {
138 	ocfs2_metadata_cache_purge(ci);
139 	ocfs2_metadata_cache_reset(ci, 1);
140 }
141 
142 
143 /* No lock taken here as 'root' is not expected to be visible to other
144  * processes. */
ocfs2_purge_copied_metadata_tree(struct rb_root * root)145 static unsigned int ocfs2_purge_copied_metadata_tree(struct rb_root *root)
146 {
147 	unsigned int purged = 0;
148 	struct rb_node *node;
149 	struct ocfs2_meta_cache_item *item;
150 
151 	while ((node = rb_last(root)) != NULL) {
152 		item = rb_entry(node, struct ocfs2_meta_cache_item, c_node);
153 
154 		trace_ocfs2_purge_copied_metadata_tree(
155 					(unsigned long long) item->c_block);
156 
157 		rb_erase(&item->c_node, root);
158 		kmem_cache_free(ocfs2_uptodate_cachep, item);
159 
160 		purged++;
161 	}
162 	return purged;
163 }
164 
165 /* Called from locking and called from ocfs2_clear_inode. Dump the
166  * cache for a given inode.
167  *
168  * This function is a few more lines longer than necessary due to some
169  * accounting done here, but I think it's worth tracking down those
170  * bugs sooner -- Mark */
ocfs2_metadata_cache_purge(struct ocfs2_caching_info * ci)171 void ocfs2_metadata_cache_purge(struct ocfs2_caching_info *ci)
172 {
173 	unsigned int tree, to_purge, purged;
174 	struct rb_root root = RB_ROOT;
175 
176 	BUG_ON(!ci || !ci->ci_ops);
177 
178 	ocfs2_metadata_cache_lock(ci);
179 	tree = !(ci->ci_flags & OCFS2_CACHE_FL_INLINE);
180 	to_purge = ci->ci_num_cached;
181 
182 	trace_ocfs2_metadata_cache_purge(
183 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
184 		to_purge, tree);
185 
186 	/* If we're a tree, save off the root so that we can safely
187 	 * initialize the cache. We do the work to free tree members
188 	 * without the spinlock. */
189 	if (tree)
190 		root = ci->ci_cache.ci_tree;
191 
192 	ocfs2_metadata_cache_reset(ci, 0);
193 	ocfs2_metadata_cache_unlock(ci);
194 
195 	purged = ocfs2_purge_copied_metadata_tree(&root);
196 	/* If possible, track the number wiped so that we can more
197 	 * easily detect counting errors. Unfortunately, this is only
198 	 * meaningful for trees. */
199 	if (tree && purged != to_purge)
200 		mlog(ML_ERROR, "Owner %llu, count = %u, purged = %u\n",
201 		     (unsigned long long)ocfs2_metadata_cache_owner(ci),
202 		     to_purge, purged);
203 }
204 
205 /* Returns the index in the cache array, -1 if not found.
206  * Requires ip_lock. */
ocfs2_search_cache_array(struct ocfs2_caching_info * ci,sector_t item)207 static int ocfs2_search_cache_array(struct ocfs2_caching_info *ci,
208 				    sector_t item)
209 {
210 	int i;
211 
212 	for (i = 0; i < ci->ci_num_cached; i++) {
213 		if (item == ci->ci_cache.ci_array[i])
214 			return i;
215 	}
216 
217 	return -1;
218 }
219 
220 /* Returns the cache item if found, otherwise NULL.
221  * Requires ip_lock. */
222 static struct ocfs2_meta_cache_item *
ocfs2_search_cache_tree(struct ocfs2_caching_info * ci,sector_t block)223 ocfs2_search_cache_tree(struct ocfs2_caching_info *ci,
224 			sector_t block)
225 {
226 	struct rb_node * n = ci->ci_cache.ci_tree.rb_node;
227 	struct ocfs2_meta_cache_item *item = NULL;
228 
229 	while (n) {
230 		item = rb_entry(n, struct ocfs2_meta_cache_item, c_node);
231 
232 		if (block < item->c_block)
233 			n = n->rb_left;
234 		else if (block > item->c_block)
235 			n = n->rb_right;
236 		else
237 			return item;
238 	}
239 
240 	return NULL;
241 }
242 
ocfs2_buffer_cached(struct ocfs2_caching_info * ci,struct buffer_head * bh)243 static int ocfs2_buffer_cached(struct ocfs2_caching_info *ci,
244 			       struct buffer_head *bh)
245 {
246 	int index = -1;
247 	struct ocfs2_meta_cache_item *item = NULL;
248 
249 	ocfs2_metadata_cache_lock(ci);
250 
251 	trace_ocfs2_buffer_cached_begin(
252 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
253 		(unsigned long long) bh->b_blocknr,
254 		!!(ci->ci_flags & OCFS2_CACHE_FL_INLINE));
255 
256 	if (ci->ci_flags & OCFS2_CACHE_FL_INLINE)
257 		index = ocfs2_search_cache_array(ci, bh->b_blocknr);
258 	else
259 		item = ocfs2_search_cache_tree(ci, bh->b_blocknr);
260 
261 	ocfs2_metadata_cache_unlock(ci);
262 
263 	trace_ocfs2_buffer_cached_end(index, item);
264 
265 	return (index != -1) || (item != NULL);
266 }
267 
268 /* Warning: even if it returns true, this does *not* guarantee that
269  * the block is stored in our inode metadata cache.
270  *
271  * This can be called under lock_buffer()
272  */
ocfs2_buffer_uptodate(struct ocfs2_caching_info * ci,struct buffer_head * bh)273 int ocfs2_buffer_uptodate(struct ocfs2_caching_info *ci,
274 			  struct buffer_head *bh)
275 {
276 	/* Doesn't matter if the bh is in our cache or not -- if it's
277 	 * not marked uptodate then we know it can't have correct
278 	 * data. */
279 	if (!buffer_uptodate(bh))
280 		return 0;
281 
282 	/* OCFS2 does not allow multiple nodes to be changing the same
283 	 * block at the same time. */
284 	if (buffer_jbd(bh))
285 		return 1;
286 
287 	/* Ok, locally the buffer is marked as up to date, now search
288 	 * our cache to see if we can trust that. */
289 	return ocfs2_buffer_cached(ci, bh);
290 }
291 
292 /*
293  * Determine whether a buffer is currently out on a read-ahead request.
294  * ci_io_sem should be held to serialize submitters with the logic here.
295  */
ocfs2_buffer_read_ahead(struct ocfs2_caching_info * ci,struct buffer_head * bh)296 int ocfs2_buffer_read_ahead(struct ocfs2_caching_info *ci,
297 			    struct buffer_head *bh)
298 {
299 	return buffer_locked(bh) && ocfs2_buffer_cached(ci, bh);
300 }
301 
302 /* Requires ip_lock */
ocfs2_append_cache_array(struct ocfs2_caching_info * ci,sector_t block)303 static void ocfs2_append_cache_array(struct ocfs2_caching_info *ci,
304 				     sector_t block)
305 {
306 	BUG_ON(ci->ci_num_cached >= OCFS2_CACHE_INFO_MAX_ARRAY);
307 
308 	trace_ocfs2_append_cache_array(
309 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
310 		(unsigned long long)block, ci->ci_num_cached);
311 
312 	ci->ci_cache.ci_array[ci->ci_num_cached] = block;
313 	ci->ci_num_cached++;
314 }
315 
316 /* By now the caller should have checked that the item does *not*
317  * exist in the tree.
318  * Requires ip_lock. */
__ocfs2_insert_cache_tree(struct ocfs2_caching_info * ci,struct ocfs2_meta_cache_item * new)319 static void __ocfs2_insert_cache_tree(struct ocfs2_caching_info *ci,
320 				      struct ocfs2_meta_cache_item *new)
321 {
322 	sector_t block = new->c_block;
323 	struct rb_node *parent = NULL;
324 	struct rb_node **p = &ci->ci_cache.ci_tree.rb_node;
325 	struct ocfs2_meta_cache_item *tmp;
326 
327 	trace_ocfs2_insert_cache_tree(
328 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
329 		(unsigned long long)block, ci->ci_num_cached);
330 
331 	while(*p) {
332 		parent = *p;
333 
334 		tmp = rb_entry(parent, struct ocfs2_meta_cache_item, c_node);
335 
336 		if (block < tmp->c_block)
337 			p = &(*p)->rb_left;
338 		else if (block > tmp->c_block)
339 			p = &(*p)->rb_right;
340 		else {
341 			/* This should never happen! */
342 			mlog(ML_ERROR, "Duplicate block %llu cached!\n",
343 			     (unsigned long long) block);
344 			BUG();
345 		}
346 	}
347 
348 	rb_link_node(&new->c_node, parent, p);
349 	rb_insert_color(&new->c_node, &ci->ci_cache.ci_tree);
350 	ci->ci_num_cached++;
351 }
352 
353 /* co_cache_lock() must be held */
ocfs2_insert_can_use_array(struct ocfs2_caching_info * ci)354 static inline int ocfs2_insert_can_use_array(struct ocfs2_caching_info *ci)
355 {
356 	return (ci->ci_flags & OCFS2_CACHE_FL_INLINE) &&
357 		(ci->ci_num_cached < OCFS2_CACHE_INFO_MAX_ARRAY);
358 }
359 
360 /* tree should be exactly OCFS2_CACHE_INFO_MAX_ARRAY wide. NULL the
361  * pointers in tree after we use them - this allows caller to detect
362  * when to free in case of error.
363  *
364  * The co_cache_lock() must be held. */
ocfs2_expand_cache(struct ocfs2_caching_info * ci,struct ocfs2_meta_cache_item ** tree)365 static void ocfs2_expand_cache(struct ocfs2_caching_info *ci,
366 			       struct ocfs2_meta_cache_item **tree)
367 {
368 	int i;
369 
370 	mlog_bug_on_msg(ci->ci_num_cached != OCFS2_CACHE_INFO_MAX_ARRAY,
371 			"Owner %llu, num cached = %u, should be %u\n",
372 			(unsigned long long)ocfs2_metadata_cache_owner(ci),
373 			ci->ci_num_cached, OCFS2_CACHE_INFO_MAX_ARRAY);
374 	mlog_bug_on_msg(!(ci->ci_flags & OCFS2_CACHE_FL_INLINE),
375 			"Owner %llu not marked as inline anymore!\n",
376 			(unsigned long long)ocfs2_metadata_cache_owner(ci));
377 
378 	/* Be careful to initialize the tree members *first* because
379 	 * once the ci_tree is used, the array is junk... */
380 	for (i = 0; i < OCFS2_CACHE_INFO_MAX_ARRAY; i++)
381 		tree[i]->c_block = ci->ci_cache.ci_array[i];
382 
383 	ci->ci_flags &= ~OCFS2_CACHE_FL_INLINE;
384 	ci->ci_cache.ci_tree = RB_ROOT;
385 	/* this will be set again by __ocfs2_insert_cache_tree */
386 	ci->ci_num_cached = 0;
387 
388 	for (i = 0; i < OCFS2_CACHE_INFO_MAX_ARRAY; i++) {
389 		__ocfs2_insert_cache_tree(ci, tree[i]);
390 		tree[i] = NULL;
391 	}
392 
393 	trace_ocfs2_expand_cache(
394 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
395 		ci->ci_flags, ci->ci_num_cached);
396 }
397 
398 /* Slow path function - memory allocation is necessary. See the
399  * comment above ocfs2_set_buffer_uptodate for more information. */
__ocfs2_set_buffer_uptodate(struct ocfs2_caching_info * ci,sector_t block,int expand_tree)400 static void __ocfs2_set_buffer_uptodate(struct ocfs2_caching_info *ci,
401 					sector_t block,
402 					int expand_tree)
403 {
404 	int i;
405 	struct ocfs2_meta_cache_item *new = NULL;
406 	struct ocfs2_meta_cache_item *tree[OCFS2_CACHE_INFO_MAX_ARRAY] =
407 		{ NULL, };
408 
409 	trace_ocfs2_set_buffer_uptodate(
410 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
411 		(unsigned long long)block, expand_tree);
412 
413 	new = kmem_cache_alloc(ocfs2_uptodate_cachep, GFP_NOFS);
414 	if (!new) {
415 		mlog_errno(-ENOMEM);
416 		return;
417 	}
418 	new->c_block = block;
419 
420 	if (expand_tree) {
421 		/* Do *not* allocate an array here - the removal code
422 		 * has no way of tracking that. */
423 		for (i = 0; i < OCFS2_CACHE_INFO_MAX_ARRAY; i++) {
424 			tree[i] = kmem_cache_alloc(ocfs2_uptodate_cachep,
425 						   GFP_NOFS);
426 			if (!tree[i]) {
427 				mlog_errno(-ENOMEM);
428 				goto out_free;
429 			}
430 
431 			/* These are initialized in ocfs2_expand_cache! */
432 		}
433 	}
434 
435 	ocfs2_metadata_cache_lock(ci);
436 	if (ocfs2_insert_can_use_array(ci)) {
437 		/* Ok, items were removed from the cache in between
438 		 * locks. Detect this and revert back to the fast path */
439 		ocfs2_append_cache_array(ci, block);
440 		ocfs2_metadata_cache_unlock(ci);
441 		goto out_free;
442 	}
443 
444 	if (expand_tree)
445 		ocfs2_expand_cache(ci, tree);
446 
447 	__ocfs2_insert_cache_tree(ci, new);
448 	ocfs2_metadata_cache_unlock(ci);
449 
450 	new = NULL;
451 out_free:
452 	if (new)
453 		kmem_cache_free(ocfs2_uptodate_cachep, new);
454 
455 	/* If these were used, then ocfs2_expand_cache re-set them to
456 	 * NULL for us. */
457 	if (tree[0]) {
458 		for (i = 0; i < OCFS2_CACHE_INFO_MAX_ARRAY; i++)
459 			if (tree[i])
460 				kmem_cache_free(ocfs2_uptodate_cachep,
461 						tree[i]);
462 	}
463 }
464 
465 /* Item insertion is guarded by co_io_lock(), so the insertion path takes
466  * advantage of this by not rechecking for a duplicate insert during
467  * the slow case. Additionally, if the cache needs to be bumped up to
468  * a tree, the code will not recheck after acquiring the lock --
469  * multiple paths cannot be expanding to a tree at the same time.
470  *
471  * The slow path takes into account that items can be removed
472  * (including the whole tree wiped and reset) when this process it out
473  * allocating memory. In those cases, it reverts back to the fast
474  * path.
475  *
476  * Note that this function may actually fail to insert the block if
477  * memory cannot be allocated. This is not fatal however (but may
478  * result in a performance penalty)
479  *
480  * Readahead buffers can be passed in here before the I/O request is
481  * completed.
482  */
ocfs2_set_buffer_uptodate(struct ocfs2_caching_info * ci,struct buffer_head * bh)483 void ocfs2_set_buffer_uptodate(struct ocfs2_caching_info *ci,
484 			       struct buffer_head *bh)
485 {
486 	int expand;
487 
488 	/* The block may very well exist in our cache already, so avoid
489 	 * doing any more work in that case. */
490 	if (ocfs2_buffer_cached(ci, bh))
491 		return;
492 
493 	trace_ocfs2_set_buffer_uptodate_begin(
494 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
495 		(unsigned long long)bh->b_blocknr);
496 
497 	/* No need to recheck under spinlock - insertion is guarded by
498 	 * co_io_lock() */
499 	ocfs2_metadata_cache_lock(ci);
500 	if (ocfs2_insert_can_use_array(ci)) {
501 		/* Fast case - it's an array and there's a free
502 		 * spot. */
503 		ocfs2_append_cache_array(ci, bh->b_blocknr);
504 		ocfs2_metadata_cache_unlock(ci);
505 		return;
506 	}
507 
508 	expand = 0;
509 	if (ci->ci_flags & OCFS2_CACHE_FL_INLINE) {
510 		/* We need to bump things up to a tree. */
511 		expand = 1;
512 	}
513 	ocfs2_metadata_cache_unlock(ci);
514 
515 	__ocfs2_set_buffer_uptodate(ci, bh->b_blocknr, expand);
516 }
517 
518 /* Called against a newly allocated buffer. Most likely nobody should
519  * be able to read this sort of metadata while it's still being
520  * allocated, but this is careful to take co_io_lock() anyway. */
ocfs2_set_new_buffer_uptodate(struct ocfs2_caching_info * ci,struct buffer_head * bh)521 void ocfs2_set_new_buffer_uptodate(struct ocfs2_caching_info *ci,
522 				   struct buffer_head *bh)
523 {
524 	/* This should definitely *not* exist in our cache */
525 	BUG_ON(ocfs2_buffer_cached(ci, bh));
526 
527 	set_buffer_uptodate(bh);
528 
529 	ocfs2_metadata_cache_io_lock(ci);
530 	ocfs2_set_buffer_uptodate(ci, bh);
531 	ocfs2_metadata_cache_io_unlock(ci);
532 }
533 
534 /* Requires ip_lock. */
ocfs2_remove_metadata_array(struct ocfs2_caching_info * ci,int index)535 static void ocfs2_remove_metadata_array(struct ocfs2_caching_info *ci,
536 					int index)
537 {
538 	sector_t *array = ci->ci_cache.ci_array;
539 	int bytes;
540 
541 	BUG_ON(index < 0 || index >= OCFS2_CACHE_INFO_MAX_ARRAY);
542 	BUG_ON(index >= ci->ci_num_cached);
543 	BUG_ON(!ci->ci_num_cached);
544 
545 	trace_ocfs2_remove_metadata_array(
546 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
547 		index, ci->ci_num_cached);
548 
549 	ci->ci_num_cached--;
550 
551 	/* don't need to copy if the array is now empty, or if we
552 	 * removed at the tail */
553 	if (ci->ci_num_cached && index < ci->ci_num_cached) {
554 		bytes = sizeof(sector_t) * (ci->ci_num_cached - index);
555 		memmove(&array[index], &array[index + 1], bytes);
556 	}
557 }
558 
559 /* Requires ip_lock. */
ocfs2_remove_metadata_tree(struct ocfs2_caching_info * ci,struct ocfs2_meta_cache_item * item)560 static void ocfs2_remove_metadata_tree(struct ocfs2_caching_info *ci,
561 				       struct ocfs2_meta_cache_item *item)
562 {
563 	trace_ocfs2_remove_metadata_tree(
564 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
565 		(unsigned long long)item->c_block);
566 
567 	rb_erase(&item->c_node, &ci->ci_cache.ci_tree);
568 	ci->ci_num_cached--;
569 }
570 
ocfs2_remove_block_from_cache(struct ocfs2_caching_info * ci,sector_t block)571 static void ocfs2_remove_block_from_cache(struct ocfs2_caching_info *ci,
572 					  sector_t block)
573 {
574 	int index;
575 	struct ocfs2_meta_cache_item *item = NULL;
576 
577 	ocfs2_metadata_cache_lock(ci);
578 	trace_ocfs2_remove_block_from_cache(
579 		(unsigned long long)ocfs2_metadata_cache_owner(ci),
580 		(unsigned long long) block, ci->ci_num_cached,
581 		ci->ci_flags);
582 
583 	if (ci->ci_flags & OCFS2_CACHE_FL_INLINE) {
584 		index = ocfs2_search_cache_array(ci, block);
585 		if (index != -1)
586 			ocfs2_remove_metadata_array(ci, index);
587 	} else {
588 		item = ocfs2_search_cache_tree(ci, block);
589 		if (item)
590 			ocfs2_remove_metadata_tree(ci, item);
591 	}
592 	ocfs2_metadata_cache_unlock(ci);
593 
594 	if (item)
595 		kmem_cache_free(ocfs2_uptodate_cachep, item);
596 }
597 
598 /*
599  * Called when we remove a chunk of metadata from an inode. We don't
600  * bother reverting things to an inlined array in the case of a remove
601  * which moves us back under the limit.
602  */
ocfs2_remove_from_cache(struct ocfs2_caching_info * ci,struct buffer_head * bh)603 void ocfs2_remove_from_cache(struct ocfs2_caching_info *ci,
604 			     struct buffer_head *bh)
605 {
606 	sector_t block = bh->b_blocknr;
607 
608 	ocfs2_remove_block_from_cache(ci, block);
609 }
610 
611 /* Called when we remove xattr clusters from an inode. */
ocfs2_remove_xattr_clusters_from_cache(struct ocfs2_caching_info * ci,sector_t block,u32 c_len)612 void ocfs2_remove_xattr_clusters_from_cache(struct ocfs2_caching_info *ci,
613 					    sector_t block,
614 					    u32 c_len)
615 {
616 	struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
617 	unsigned int i, b_len = ocfs2_clusters_to_blocks(sb, 1) * c_len;
618 
619 	for (i = 0; i < b_len; i++, block++)
620 		ocfs2_remove_block_from_cache(ci, block);
621 }
622 
init_ocfs2_uptodate_cache(void)623 int __init init_ocfs2_uptodate_cache(void)
624 {
625 	ocfs2_uptodate_cachep = kmem_cache_create("ocfs2_uptodate",
626 				  sizeof(struct ocfs2_meta_cache_item),
627 				  0, SLAB_HWCACHE_ALIGN, NULL);
628 	if (!ocfs2_uptodate_cachep)
629 		return -ENOMEM;
630 
631 	return 0;
632 }
633 
exit_ocfs2_uptodate_cache(void)634 void exit_ocfs2_uptodate_cache(void)
635 {
636 	kmem_cache_destroy(ocfs2_uptodate_cachep);
637 }
638