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959ef981 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
0cf6f686 DW |
2 | /* |
3 | * Copyright (C) 2018 Oracle. All Rights Reserved. | |
0cf6f686 | 4 | * Author: Darrick J. Wong <darrick.wong@oracle.com> |
0cf6f686 | 5 | */ |
a440f877 | 6 | #include "xfs.h" |
0cf6f686 DW |
7 | #include <stdint.h> |
8 | #include <stdlib.h> | |
0cf6f686 | 9 | #include <assert.h> |
0cf6f686 DW |
10 | #include <pthread.h> |
11 | #include "platform_defs.h" | |
12 | #include "avl64.h" | |
13 | #include "list.h" | |
14 | #include "bitmap.h" | |
15 | ||
16 | /* | |
17 | * Space Efficient Bitmap | |
18 | * | |
19 | * Implements a space-efficient bitmap. We use an AVL tree to manage | |
20 | * extent records that tell us which ranges are set; the bitmap key is | |
21 | * an arbitrary uint64_t. The usual bitmap operations (set, clear, | |
22 | * test, test and set) are supported, plus we can iterate set ranges. | |
23 | */ | |
24 | ||
25 | #define avl_for_each_range_safe(pos, n, l, first, last) \ | |
26 | for (pos = (first), n = pos->avl_nextino, l = (last)->avl_nextino; pos != (l); \ | |
27 | pos = n, n = pos ? pos->avl_nextino : NULL) | |
28 | ||
29 | #define avl_for_each_safe(tree, pos, n) \ | |
30 | for (pos = (tree)->avl_firstino, n = pos ? pos->avl_nextino : NULL; \ | |
31 | pos != NULL; \ | |
32 | pos = n, n = pos ? pos->avl_nextino : NULL) | |
33 | ||
34 | #define avl_for_each(tree, pos) \ | |
35 | for (pos = (tree)->avl_firstino; pos != NULL; pos = pos->avl_nextino) | |
36 | ||
37 | struct bitmap_node { | |
38 | struct avl64node btn_node; | |
39 | uint64_t btn_start; | |
40 | uint64_t btn_length; | |
41 | }; | |
42 | ||
43 | static uint64_t | |
44 | extent_start( | |
45 | struct avl64node *node) | |
46 | { | |
47 | struct bitmap_node *btn; | |
48 | ||
49 | btn = container_of(node, struct bitmap_node, btn_node); | |
50 | return btn->btn_start; | |
51 | } | |
52 | ||
53 | static uint64_t | |
54 | extent_end( | |
55 | struct avl64node *node) | |
56 | { | |
57 | struct bitmap_node *btn; | |
58 | ||
59 | btn = container_of(node, struct bitmap_node, btn_node); | |
60 | return btn->btn_start + btn->btn_length; | |
61 | } | |
62 | ||
63 | static struct avl64ops bitmap_ops = { | |
64 | extent_start, | |
65 | extent_end, | |
66 | }; | |
67 | ||
68 | /* Initialize a bitmap. */ | |
93ab49dd | 69 | int |
0cf6f686 DW |
70 | bitmap_init( |
71 | struct bitmap **bmapp) | |
72 | { | |
73 | struct bitmap *bmap; | |
74 | ||
75 | bmap = calloc(1, sizeof(struct bitmap)); | |
76 | if (!bmap) | |
93ab49dd | 77 | return -ENOMEM; |
0cf6f686 DW |
78 | bmap->bt_tree = malloc(sizeof(struct avl64tree_desc)); |
79 | if (!bmap->bt_tree) { | |
80 | free(bmap); | |
93ab49dd | 81 | return -ENOMEM; |
0cf6f686 DW |
82 | } |
83 | ||
84 | pthread_mutex_init(&bmap->bt_lock, NULL); | |
85 | avl64_init_tree(bmap->bt_tree, &bitmap_ops); | |
86 | *bmapp = bmap; | |
87 | ||
93ab49dd | 88 | return 0; |
0cf6f686 DW |
89 | } |
90 | ||
91 | /* Free a bitmap. */ | |
92 | void | |
93 | bitmap_free( | |
94 | struct bitmap **bmapp) | |
95 | { | |
96 | struct bitmap *bmap; | |
97 | struct avl64node *node; | |
98 | struct avl64node *n; | |
99 | struct bitmap_node *ext; | |
100 | ||
101 | bmap = *bmapp; | |
102 | avl_for_each_safe(bmap->bt_tree, node, n) { | |
103 | ext = container_of(node, struct bitmap_node, btn_node); | |
104 | free(ext); | |
105 | } | |
106 | free(bmap->bt_tree); | |
b0956ceb | 107 | free(bmap); |
0cf6f686 DW |
108 | *bmapp = NULL; |
109 | } | |
110 | ||
111 | /* Create a new bitmap extent node. */ | |
112 | static struct bitmap_node * | |
113 | bitmap_node_init( | |
114 | uint64_t start, | |
115 | uint64_t len) | |
116 | { | |
117 | struct bitmap_node *ext; | |
118 | ||
119 | ext = malloc(sizeof(struct bitmap_node)); | |
120 | if (!ext) | |
121 | return NULL; | |
122 | ||
123 | ext->btn_node.avl_nextino = NULL; | |
124 | ext->btn_start = start; | |
125 | ext->btn_length = len; | |
126 | ||
127 | return ext; | |
128 | } | |
129 | ||
93ab49dd DW |
130 | /* Create a new bitmap node and insert it. */ |
131 | static inline int | |
132 | __bitmap_insert( | |
133 | struct bitmap *bmap, | |
134 | uint64_t start, | |
135 | uint64_t length) | |
136 | { | |
137 | struct bitmap_node *ext; | |
138 | struct avl64node *node; | |
139 | ||
140 | ext = bitmap_node_init(start, length); | |
141 | if (!ext) | |
142 | return -ENOMEM; | |
143 | ||
144 | node = avl64_insert(bmap->bt_tree, &ext->btn_node); | |
145 | if (node == NULL) { | |
146 | free(ext); | |
147 | return -EEXIST; | |
148 | } | |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
0cf6f686 | 153 | /* Set a region of bits (locked). */ |
93ab49dd | 154 | static int |
0cf6f686 DW |
155 | __bitmap_set( |
156 | struct bitmap *bmap, | |
157 | uint64_t start, | |
158 | uint64_t length) | |
159 | { | |
160 | struct avl64node *firstn; | |
161 | struct avl64node *lastn; | |
162 | struct avl64node *pos; | |
163 | struct avl64node *n; | |
164 | struct avl64node *l; | |
165 | struct bitmap_node *ext; | |
166 | uint64_t new_start; | |
167 | uint64_t new_length; | |
0cf6f686 DW |
168 | |
169 | /* Find any existing nodes adjacent or within that range. */ | |
170 | avl64_findranges(bmap->bt_tree, start - 1, start + length + 1, | |
171 | &firstn, &lastn); | |
172 | ||
173 | /* Nothing, just insert a new extent. */ | |
93ab49dd DW |
174 | if (firstn == NULL && lastn == NULL) |
175 | return __bitmap_insert(bmap, start, length); | |
0cf6f686 DW |
176 | |
177 | assert(firstn != NULL && lastn != NULL); | |
178 | new_start = start; | |
179 | new_length = length; | |
180 | ||
181 | avl_for_each_range_safe(pos, n, l, firstn, lastn) { | |
182 | ext = container_of(pos, struct bitmap_node, btn_node); | |
183 | ||
184 | /* Bail if the new extent is contained within an old one. */ | |
185 | if (ext->btn_start <= start && | |
186 | ext->btn_start + ext->btn_length >= start + length) | |
93ab49dd | 187 | return 0; |
0cf6f686 DW |
188 | |
189 | /* Check for overlapping and adjacent extents. */ | |
190 | if (ext->btn_start + ext->btn_length >= start || | |
191 | ext->btn_start <= start + length) { | |
192 | if (ext->btn_start < start) { | |
193 | new_start = ext->btn_start; | |
194 | new_length += ext->btn_length; | |
195 | } | |
196 | ||
197 | if (ext->btn_start + ext->btn_length > | |
198 | new_start + new_length) | |
199 | new_length = ext->btn_start + ext->btn_length - | |
200 | new_start; | |
201 | ||
202 | avl64_delete(bmap->bt_tree, pos); | |
203 | free(ext); | |
204 | } | |
205 | } | |
206 | ||
93ab49dd | 207 | return __bitmap_insert(bmap, new_start, new_length); |
0cf6f686 DW |
208 | } |
209 | ||
210 | /* Set a region of bits. */ | |
93ab49dd | 211 | int |
0cf6f686 DW |
212 | bitmap_set( |
213 | struct bitmap *bmap, | |
214 | uint64_t start, | |
215 | uint64_t length) | |
216 | { | |
93ab49dd | 217 | int res; |
0cf6f686 DW |
218 | |
219 | pthread_mutex_lock(&bmap->bt_lock); | |
220 | res = __bitmap_set(bmap, start, length); | |
221 | pthread_mutex_unlock(&bmap->bt_lock); | |
222 | ||
223 | return res; | |
224 | } | |
225 | ||
226 | #if 0 /* Unused, provided for completeness. */ | |
227 | /* Clear a region of bits. */ | |
228 | bool | |
229 | bitmap_clear( | |
230 | struct bitmap *bmap, | |
231 | uint64_t start, | |
232 | uint64_t len) | |
233 | { | |
234 | struct avl64node *firstn; | |
235 | struct avl64node *lastn; | |
236 | struct avl64node *pos; | |
237 | struct avl64node *n; | |
238 | struct avl64node *l; | |
239 | struct bitmap_node *ext; | |
240 | uint64_t new_start; | |
241 | uint64_t new_length; | |
242 | struct avl64node *node; | |
243 | int stat; | |
244 | ||
245 | pthread_mutex_lock(&bmap->bt_lock); | |
246 | /* Find any existing nodes over that range. */ | |
247 | avl64_findranges(bmap->bt_tree, start, start + len, &firstn, &lastn); | |
248 | ||
249 | /* Nothing, we're done. */ | |
250 | if (firstn == NULL && lastn == NULL) { | |
251 | pthread_mutex_unlock(&bmap->bt_lock); | |
252 | return true; | |
253 | } | |
254 | ||
255 | assert(firstn != NULL && lastn != NULL); | |
256 | ||
257 | /* Delete or truncate everything in sight. */ | |
258 | avl_for_each_range_safe(pos, n, l, firstn, lastn) { | |
259 | ext = container_of(pos, struct bitmap_node, btn_node); | |
260 | ||
261 | stat = 0; | |
262 | if (ext->btn_start < start) | |
263 | stat |= 1; | |
264 | if (ext->btn_start + ext->btn_length > start + len) | |
265 | stat |= 2; | |
266 | switch (stat) { | |
267 | case 0: | |
268 | /* Extent totally within range; delete. */ | |
269 | avl64_delete(bmap->bt_tree, pos); | |
270 | free(ext); | |
271 | break; | |
272 | case 1: | |
273 | /* Extent is left-adjacent; truncate. */ | |
274 | ext->btn_length = start - ext->btn_start; | |
275 | break; | |
276 | case 2: | |
277 | /* Extent is right-adjacent; move it. */ | |
278 | ext->btn_length = ext->btn_start + ext->btn_length - | |
279 | (start + len); | |
280 | ext->btn_start = start + len; | |
281 | break; | |
282 | case 3: | |
283 | /* Extent overlaps both ends. */ | |
284 | ext->btn_length = start - ext->btn_start; | |
285 | new_start = start + len; | |
286 | new_length = ext->btn_start + ext->btn_length - | |
287 | new_start; | |
288 | ||
289 | ext = bitmap_node_init(new_start, new_length); | |
290 | if (!ext) | |
291 | return false; | |
292 | ||
293 | node = avl64_insert(bmap->bt_tree, &ext->btn_node); | |
294 | if (node == NULL) { | |
295 | errno = EEXIST; | |
296 | return false; | |
297 | } | |
298 | break; | |
299 | } | |
300 | } | |
301 | ||
302 | pthread_mutex_unlock(&bmap->bt_lock); | |
303 | return true; | |
304 | } | |
305 | #endif | |
306 | ||
307 | #ifdef DEBUG | |
308 | /* Iterate the set regions of this bitmap. */ | |
93ab49dd | 309 | int |
0cf6f686 DW |
310 | bitmap_iterate( |
311 | struct bitmap *bmap, | |
93ab49dd | 312 | int (*fn)(uint64_t, uint64_t, void *), |
0cf6f686 DW |
313 | void *arg) |
314 | { | |
315 | struct avl64node *node; | |
316 | struct bitmap_node *ext; | |
93ab49dd | 317 | int error = 0; |
0cf6f686 DW |
318 | |
319 | pthread_mutex_lock(&bmap->bt_lock); | |
320 | avl_for_each(bmap->bt_tree, node) { | |
321 | ext = container_of(node, struct bitmap_node, btn_node); | |
93ab49dd DW |
322 | error = fn(ext->btn_start, ext->btn_length, arg); |
323 | if (error) | |
0cf6f686 DW |
324 | break; |
325 | } | |
326 | pthread_mutex_unlock(&bmap->bt_lock); | |
327 | ||
93ab49dd | 328 | return error; |
0cf6f686 DW |
329 | } |
330 | #endif | |
331 | ||
332 | /* Do any bitmap extents overlap the given one? (locked) */ | |
333 | static bool | |
334 | __bitmap_test( | |
335 | struct bitmap *bmap, | |
336 | uint64_t start, | |
337 | uint64_t len) | |
338 | { | |
339 | struct avl64node *firstn; | |
340 | struct avl64node *lastn; | |
341 | ||
342 | /* Find any existing nodes over that range. */ | |
343 | avl64_findranges(bmap->bt_tree, start, start + len, &firstn, &lastn); | |
344 | ||
345 | return firstn != NULL && lastn != NULL; | |
346 | } | |
347 | ||
348 | /* Is any part of this range set? */ | |
349 | bool | |
350 | bitmap_test( | |
351 | struct bitmap *bmap, | |
352 | uint64_t start, | |
353 | uint64_t len) | |
354 | { | |
355 | bool res; | |
356 | ||
357 | pthread_mutex_lock(&bmap->bt_lock); | |
358 | res = __bitmap_test(bmap, start, len); | |
359 | pthread_mutex_unlock(&bmap->bt_lock); | |
360 | ||
361 | return res; | |
362 | } | |
363 | ||
364 | /* Are none of the bits set? */ | |
365 | bool | |
366 | bitmap_empty( | |
367 | struct bitmap *bmap) | |
368 | { | |
369 | return bmap->bt_tree->avl_firstino == NULL; | |
370 | } | |
371 | ||
372 | #ifdef DEBUG | |
93ab49dd | 373 | static int |
0cf6f686 DW |
374 | bitmap_dump_fn( |
375 | uint64_t startblock, | |
376 | uint64_t blockcount, | |
377 | void *arg) | |
378 | { | |
379 | printf("%"PRIu64":%"PRIu64"\n", startblock, blockcount); | |
93ab49dd | 380 | return 0; |
0cf6f686 DW |
381 | } |
382 | ||
383 | /* Dump bitmap. */ | |
384 | void | |
385 | bitmap_dump( | |
386 | struct bitmap *bmap) | |
387 | { | |
388 | printf("BITMAP DUMP %p\n", bmap); | |
389 | bitmap_iterate(bmap, bitmap_dump_fn, NULL); | |
390 | printf("BITMAP DUMP DONE\n"); | |
391 | } | |
392 | #endif |