1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25 /*
26 * Copyright (c) 2013 by Delphix. All rights reserved.
27 */
28
29 #include <sys/zfs_context.h>
30 #include <sys/spa.h>
31 #include <sys/dmu.h>
32 #include <sys/dnode.h>
33 #include <sys/zio.h>
34 #include <sys/range_tree.h>
35
36 static kmem_cache_t *range_seg_cache;
37
38 void
39 range_tree_init(void)
40 {
41 ASSERT(range_seg_cache == NULL);
42 range_seg_cache = kmem_cache_create("range_seg_cache",
43 sizeof (range_seg_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
44 }
45
46 void
47 range_tree_fini(void)
48 {
49 kmem_cache_destroy(range_seg_cache);
50 range_seg_cache = NULL;
51 }
52
53 void
54 range_tree_stat_verify(range_tree_t *rt)
55 {
56 range_seg_t *rs;
57 uint64_t hist[RANGE_TREE_HISTOGRAM_SIZE] = { 0 };
58 int i;
59
60 for (rs = avl_first(&rt->rt_root); rs != NULL;
61 rs = AVL_NEXT(&rt->rt_root, rs)) {
62 uint64_t size = rs->rs_end - rs->rs_start;
63 int idx = highbit(size) - 1;
64
65 hist[idx]++;
66 ASSERT3U(hist[idx], !=, 0);
67 }
68
69 for (i = 0; i < RANGE_TREE_HISTOGRAM_SIZE; i++) {
70 if (hist[i] != rt->rt_histogram[i]) {
71 zfs_dbgmsg("i=%d, hist=%p, hist=%llu, rt_hist=%llu",
72 i, hist, hist[i], rt->rt_histogram[i]);
73 }
74 VERIFY3U(hist[i], ==, rt->rt_histogram[i]);
75 }
76 }
77
78 static void
79 range_tree_stat_incr(range_tree_t *rt, range_seg_t *rs)
80 {
81 uint64_t size = rs->rs_end - rs->rs_start;
82 int idx = highbit(size) - 1;
83
84 ASSERT3U(idx, <,
85 sizeof (rt->rt_histogram) / sizeof (*rt->rt_histogram));
86
87 ASSERT(MUTEX_HELD(rt->rt_lock));
88 rt->rt_histogram[idx]++;
89 ASSERT3U(rt->rt_histogram[idx], !=, 0);
90 }
91
92 static void
93 range_tree_stat_decr(range_tree_t *rt, range_seg_t *rs)
94 {
95 uint64_t size = rs->rs_end - rs->rs_start;
96 int idx = highbit(size) - 1;
97
98 ASSERT3U(idx, <,
99 sizeof (rt->rt_histogram) / sizeof (*rt->rt_histogram));
100
101 ASSERT(MUTEX_HELD(rt->rt_lock));
102 ASSERT3U(rt->rt_histogram[idx], !=, 0);
103 rt->rt_histogram[idx]--;
104 }
105
106 /*
107 * NOTE: caller is responsible for all locking.
108 */
109 static int
110 range_tree_seg_compare(const void *x1, const void *x2)
111 {
112 const range_seg_t *r1 = x1;
113 const range_seg_t *r2 = x2;
114
115 if (r1->rs_start < r2->rs_start) {
116 if (r1->rs_end > r2->rs_start)
117 return (0);
118 return (-1);
119 }
120 if (r1->rs_start > r2->rs_start) {
121 if (r1->rs_start < r2->rs_end)
122 return (0);
123 return (1);
124 }
125 return (0);
126 }
127
128 range_tree_t *
129 range_tree_create(range_tree_ops_t *ops, void *arg, kmutex_t *lp)
130 {
131 range_tree_t *rt;
132
133 rt = kmem_zalloc(sizeof (range_tree_t), KM_SLEEP);
134
135 avl_create(&rt->rt_root, range_tree_seg_compare,
136 sizeof (range_seg_t), offsetof(range_seg_t, rs_node));
137
138 rt->rt_lock = lp;
139 rt->rt_ops = ops;
140 rt->rt_arg = arg;
141
142 if (rt->rt_ops != NULL)
143 rt->rt_ops->rtop_create(rt, rt->rt_arg);
144
145 return (rt);
146 }
147
148 void
149 range_tree_destroy(range_tree_t *rt)
150 {
151 VERIFY0(rt->rt_space);
152
153 if (rt->rt_ops != NULL)
154 rt->rt_ops->rtop_destroy(rt, rt->rt_arg);
155
156 avl_destroy(&rt->rt_root);
157 kmem_free(rt, sizeof (*rt));
158 }
159
160 void
161 range_tree_add(void *arg, uint64_t start, uint64_t size)
162 {
163 range_tree_t *rt = arg;
164 avl_index_t where;
165 range_seg_t rsearch, *rs_before, *rs_after, *rs;
166 uint64_t end = start + size;
167 boolean_t merge_before, merge_after;
168
169 ASSERT(MUTEX_HELD(rt->rt_lock));
170 VERIFY(size != 0);
171
172 rsearch.rs_start = start;
173 rsearch.rs_end = end;
174 rs = avl_find(&rt->rt_root, &rsearch, &where);
175
176 if (rs != NULL && rs->rs_start <= start && rs->rs_end >= end) {
177 zfs_panic_recover("zfs: allocating allocated segment"
178 "(offset=%llu size=%llu)\n",
179 (longlong_t)start, (longlong_t)size);
180 return;
181 }
182
183 /* Make sure we don't overlap with either of our neighbors */
184 VERIFY(rs == NULL);
185
186 rs_before = avl_nearest(&rt->rt_root, where, AVL_BEFORE);
187 rs_after = avl_nearest(&rt->rt_root, where, AVL_AFTER);
188
189 merge_before = (rs_before != NULL && rs_before->rs_end == start);
190 merge_after = (rs_after != NULL && rs_after->rs_start == end);
191
192 if (merge_before && merge_after) {
193 avl_remove(&rt->rt_root, rs_before);
194 if (rt->rt_ops != NULL) {
195 rt->rt_ops->rtop_remove(rt, rs_before, rt->rt_arg);
196 rt->rt_ops->rtop_remove(rt, rs_after, rt->rt_arg);
197 }
198
199 range_tree_stat_decr(rt, rs_before);
200 range_tree_stat_decr(rt, rs_after);
201
202 rs_after->rs_start = rs_before->rs_start;
203 kmem_cache_free(range_seg_cache, rs_before);
204 rs = rs_after;
205 } else if (merge_before) {
206 if (rt->rt_ops != NULL)
207 rt->rt_ops->rtop_remove(rt, rs_before, rt->rt_arg);
208
209 range_tree_stat_decr(rt, rs_before);
210
211 rs_before->rs_end = end;
212 rs = rs_before;
213 } else if (merge_after) {
214 if (rt->rt_ops != NULL)
215 rt->rt_ops->rtop_remove(rt, rs_after, rt->rt_arg);
216
217 range_tree_stat_decr(rt, rs_after);
218
219 rs_after->rs_start = start;
220 rs = rs_after;
221 } else {
222 rs = kmem_cache_alloc(range_seg_cache, KM_SLEEP);
223 rs->rs_start = start;
224 rs->rs_end = end;
225 avl_insert(&rt->rt_root, rs, where);
226 }
227
228 if (rt->rt_ops != NULL)
229 rt->rt_ops->rtop_add(rt, rs, rt->rt_arg);
230
231 range_tree_stat_incr(rt, rs);
232 rt->rt_space += size;
233 }
234
235 void
236 range_tree_remove(void *arg, uint64_t start, uint64_t size)
237 {
238 range_tree_t *rt = arg;
239 avl_index_t where;
240 range_seg_t rsearch, *rs, *newseg;
241 uint64_t end = start + size;
242 boolean_t left_over, right_over;
243
244 ASSERT(MUTEX_HELD(rt->rt_lock));
245 VERIFY3U(size, !=, 0);
246 VERIFY3U(size, <=, rt->rt_space);
247
248 rsearch.rs_start = start;
249 rsearch.rs_end = end;
250 rs = avl_find(&rt->rt_root, &rsearch, &where);
251
252 /* Make sure we completely overlap with someone */
253 if (rs == NULL) {
254 zfs_panic_recover("zfs: freeing free segment "
255 "(offset=%llu size=%llu)",
256 (longlong_t)start, (longlong_t)size);
257 return;
258 }
259 VERIFY3U(rs->rs_start, <=, start);
260 VERIFY3U(rs->rs_end, >=, end);
261
262 left_over = (rs->rs_start != start);
263 right_over = (rs->rs_end != end);
264
265 range_tree_stat_decr(rt, rs);
266
267 if (rt->rt_ops != NULL)
268 rt->rt_ops->rtop_remove(rt, rs, rt->rt_arg);
269
270 if (left_over && right_over) {
271 newseg = kmem_cache_alloc(range_seg_cache, KM_SLEEP);
272 newseg->rs_start = end;
273 newseg->rs_end = rs->rs_end;
274 range_tree_stat_incr(rt, newseg);
275
276 rs->rs_end = start;
277
278 avl_insert_here(&rt->rt_root, newseg, rs, AVL_AFTER);
279 if (rt->rt_ops != NULL)
280 rt->rt_ops->rtop_add(rt, newseg, rt->rt_arg);
281 } else if (left_over) {
282 rs->rs_end = start;
283 } else if (right_over) {
284 rs->rs_start = end;
285 } else {
286 avl_remove(&rt->rt_root, rs);
287 kmem_cache_free(range_seg_cache, rs);
288 rs = NULL;
289 }
290
291 if (rs != NULL) {
292 range_tree_stat_incr(rt, rs);
293
294 if (rt->rt_ops != NULL)
295 rt->rt_ops->rtop_add(rt, rs, rt->rt_arg);
296 }
297
298 rt->rt_space -= size;
299 }
300
301 static range_seg_t *
302 range_tree_find(range_tree_t *rt, uint64_t start, uint64_t size,
303 avl_index_t *wherep)
304 {
305 range_seg_t rsearch, *rs;
306 uint64_t end = start + size;
307
308 ASSERT(MUTEX_HELD(rt->rt_lock));
309 VERIFY(size != 0);
310
311 rsearch.rs_start = start;
312 rsearch.rs_end = end;
313 rs = avl_find(&rt->rt_root, &rsearch, wherep);
314
315 if (rs != NULL && rs->rs_start <= start && rs->rs_end >= end)
316 return (rs);
317 return (NULL);
318 }
319
320 void
321 range_tree_verify(range_tree_t *rt, uint64_t off, uint64_t size)
322 {
323 range_seg_t *rs;
324 avl_index_t where;
325
326 mutex_enter(rt->rt_lock);
327 rs = range_tree_find(rt, off, size, &where);
328 if (rs != NULL)
329 panic("freeing free block; rs=%p", (void *)rs);
330 mutex_exit(rt->rt_lock);
331 }
332
333 boolean_t
334 range_tree_contains(range_tree_t *rt, uint64_t start, uint64_t size)
335 {
336 avl_index_t where;
337
338 return (range_tree_find(rt, start, size, &where) != NULL);
339 }
340
341 void
342 range_tree_swap(range_tree_t **rtsrc, range_tree_t **rtdst)
343 {
344 range_tree_t *rt;
345
346 ASSERT(MUTEX_HELD((*rtsrc)->rt_lock));
347 ASSERT0(range_tree_space(*rtdst));
348 ASSERT0(avl_numnodes(&(*rtdst)->rt_root));
349
350 rt = *rtsrc;
351 *rtsrc = *rtdst;
352 *rtdst = rt;
353 }
354
355 void
356 range_tree_vacate(range_tree_t *rt, range_tree_func_t *func, void *arg)
357 {
358 range_seg_t *rs;
359 void *cookie = NULL;
360
361 ASSERT(MUTEX_HELD(rt->rt_lock));
362
363 if (rt->rt_ops != NULL)
364 rt->rt_ops->rtop_vacate(rt, rt->rt_arg);
365
366 while ((rs = avl_destroy_nodes(&rt->rt_root, &cookie)) != NULL) {
367 if (func != NULL)
368 func(arg, rs->rs_start, rs->rs_end - rs->rs_start);
369 kmem_cache_free(range_seg_cache, rs);
370 }
371
372 bzero(rt->rt_histogram, sizeof (rt->rt_histogram));
373 rt->rt_space = 0;
374 }
375
376 void
377 range_tree_walk(range_tree_t *rt, range_tree_func_t *func, void *arg)
378 {
379 range_seg_t *rs;
380
381 ASSERT(MUTEX_HELD(rt->rt_lock));
382
383 for (rs = avl_first(&rt->rt_root); rs; rs = AVL_NEXT(&rt->rt_root, rs))
384 func(arg, rs->rs_start, rs->rs_end - rs->rs_start);
385 }
386
387 uint64_t
388 range_tree_space(range_tree_t *rt)
389 {
390 return (rt->rt_space);
391 }