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Commit | Line | Data |
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342d847d TT |
1 | /* |
2 | * ea_refcount.c | |
efc6f628 | 3 | * |
342d847d TT |
4 | * Copyright (C) 2001 Theodore Ts'o. This file may be |
5 | * redistributed under the terms of the GNU Public License. | |
6 | */ | |
7 | ||
d1154eb4 | 8 | #include "config.h" |
342d847d TT |
9 | #if HAVE_UNISTD_H |
10 | #include <unistd.h> | |
11 | #endif | |
12 | #include <string.h> | |
13 | #include <stdio.h> | |
14 | ||
0eeec8ac TT |
15 | #ifdef TEST_PROGRAM |
16 | #undef ENABLE_NLS | |
17 | #endif | |
342d847d TT |
18 | #include "e2fsck.h" |
19 | ||
20 | /* | |
21 | * The strategy we use for keeping track of EA refcounts is as | |
22 | * follows. We keep a sorted array of first EA blocks and its | |
23 | * reference counts. Once the refcount has dropped to zero, it is | |
24 | * removed from the array to save memory space. Once the EA block is | |
efc6f628 | 25 | * checked, its bit is set in the block_ea_map bitmap. |
342d847d TT |
26 | */ |
27 | struct ea_refcount_el { | |
130e961a | 28 | blk64_t ea_blk; |
342d847d TT |
29 | int ea_count; |
30 | }; | |
31 | ||
32 | struct ea_refcount { | |
33 | blk_t count; | |
34 | blk_t size; | |
54434927 | 35 | blk_t cursor; |
342d847d TT |
36 | struct ea_refcount_el *list; |
37 | }; | |
38 | ||
39 | void ea_refcount_free(ext2_refcount_t refcount) | |
40 | { | |
41 | if (!refcount) | |
42 | return; | |
43 | ||
44 | if (refcount->list) | |
c4e3d3f3 TT |
45 | ext2fs_free_mem(&refcount->list); |
46 | ext2fs_free_mem(&refcount); | |
342d847d TT |
47 | } |
48 | ||
49 | errcode_t ea_refcount_create(int size, ext2_refcount_t *ret) | |
50 | { | |
51 | ext2_refcount_t refcount; | |
52 | errcode_t retval; | |
53 | size_t bytes; | |
342d847d | 54 | |
c4e3d3f3 | 55 | retval = ext2fs_get_mem(sizeof(struct ea_refcount), &refcount); |
342d847d TT |
56 | if (retval) |
57 | return retval; | |
58 | memset(refcount, 0, sizeof(struct ea_refcount)); | |
59 | ||
60 | if (!size) | |
61 | size = 500; | |
62 | refcount->size = size; | |
63 | bytes = (size_t) (size * sizeof(struct ea_refcount_el)); | |
64 | #ifdef DEBUG | |
65 | printf("Refcount allocated %d entries, %d bytes.\n", | |
66 | refcount->size, bytes); | |
67 | #endif | |
c4e3d3f3 | 68 | retval = ext2fs_get_mem(bytes, &refcount->list); |
342d847d TT |
69 | if (retval) |
70 | goto errout; | |
71 | memset(refcount->list, 0, bytes); | |
72 | ||
73 | refcount->count = 0; | |
74 | refcount->cursor = 0; | |
75 | ||
76 | *ret = refcount; | |
77 | return 0; | |
78 | ||
79 | errout: | |
80 | ea_refcount_free(refcount); | |
81 | return(retval); | |
82 | } | |
83 | ||
84 | /* | |
85 | * collapse_refcount() --- go through the refcount array, and get rid | |
86 | * of any count == zero entries | |
87 | */ | |
88 | static void refcount_collapse(ext2_refcount_t refcount) | |
89 | { | |
54434927 | 90 | unsigned int i, j; |
342d847d TT |
91 | struct ea_refcount_el *list; |
92 | ||
93 | list = refcount->list; | |
94 | for (i = 0, j = 0; i < refcount->count; i++) { | |
95 | if (list[i].ea_count) { | |
96 | if (i != j) | |
97 | list[j] = list[i]; | |
98 | j++; | |
99 | } | |
100 | } | |
101 | #if defined(DEBUG) || defined(TEST_PROGRAM) | |
102 | printf("Refcount_collapse: size was %d, now %d\n", | |
103 | refcount->count, j); | |
104 | #endif | |
105 | refcount->count = j; | |
106 | } | |
107 | ||
108 | ||
109 | /* | |
110 | * insert_refcount_el() --- Insert a new entry into the sorted list at a | |
111 | * specified position. | |
112 | */ | |
113 | static struct ea_refcount_el *insert_refcount_el(ext2_refcount_t refcount, | |
130e961a | 114 | blk64_t blk, int pos) |
342d847d TT |
115 | { |
116 | struct ea_refcount_el *el; | |
117 | errcode_t retval; | |
118 | blk_t new_size = 0; | |
119 | int num; | |
120 | ||
121 | if (refcount->count >= refcount->size) { | |
122 | new_size = refcount->size + 100; | |
123 | #ifdef DEBUG | |
124 | printf("Reallocating refcount %d entries...\n", new_size); | |
efc6f628 | 125 | #endif |
342d847d TT |
126 | retval = ext2fs_resize_mem((size_t) refcount->size * |
127 | sizeof(struct ea_refcount_el), | |
128 | (size_t) new_size * | |
129 | sizeof(struct ea_refcount_el), | |
c4e3d3f3 | 130 | &refcount->list); |
342d847d TT |
131 | if (retval) |
132 | return 0; | |
133 | refcount->size = new_size; | |
134 | } | |
135 | num = (int) refcount->count - pos; | |
136 | if (num < 0) | |
137 | return 0; /* should never happen */ | |
138 | if (num) { | |
139 | memmove(&refcount->list[pos+1], &refcount->list[pos], | |
140 | sizeof(struct ea_refcount_el) * num); | |
141 | } | |
142 | refcount->count++; | |
143 | el = &refcount->list[pos]; | |
144 | el->ea_count = 0; | |
145 | el->ea_blk = blk; | |
146 | return el; | |
147 | } | |
148 | ||
149 | ||
150 | /* | |
151 | * get_refcount_el() --- given an block number, try to find refcount | |
152 | * information in the sorted list. If the create flag is set, | |
153 | * and we can't find an entry, create one in the sorted list. | |
154 | */ | |
155 | static struct ea_refcount_el *get_refcount_el(ext2_refcount_t refcount, | |
130e961a | 156 | blk64_t blk, int create) |
342d847d | 157 | { |
342d847d | 158 | int low, high, mid; |
342d847d TT |
159 | |
160 | if (!refcount || !refcount->list) | |
161 | return 0; | |
162 | retry: | |
163 | low = 0; | |
164 | high = (int) refcount->count-1; | |
165 | if (create && ((refcount->count == 0) || | |
166 | (blk > refcount->list[high].ea_blk))) { | |
167 | if (refcount->count >= refcount->size) | |
168 | refcount_collapse(refcount); | |
169 | ||
170 | return insert_refcount_el(refcount, blk, | |
171 | (unsigned) refcount->count); | |
172 | } | |
173 | if (refcount->count == 0) | |
174 | return 0; | |
efc6f628 | 175 | |
342d847d TT |
176 | if (refcount->cursor >= refcount->count) |
177 | refcount->cursor = 0; | |
178 | if (blk == refcount->list[refcount->cursor].ea_blk) | |
179 | return &refcount->list[refcount->cursor++]; | |
180 | #ifdef DEBUG | |
181 | printf("Non-cursor get_refcount_el: %u\n", blk); | |
182 | #endif | |
183 | while (low <= high) { | |
342d847d | 184 | mid = (low+high)/2; |
342d847d TT |
185 | if (blk == refcount->list[mid].ea_blk) { |
186 | refcount->cursor = mid+1; | |
187 | return &refcount->list[mid]; | |
188 | } | |
189 | if (blk < refcount->list[mid].ea_blk) | |
190 | high = mid-1; | |
191 | else | |
192 | low = mid+1; | |
193 | } | |
194 | /* | |
195 | * If we need to create a new entry, it should be right at | |
196 | * low (where high will be left at low-1). | |
197 | */ | |
198 | if (create) { | |
199 | if (refcount->count >= refcount->size) { | |
200 | refcount_collapse(refcount); | |
201 | if (refcount->count < refcount->size) | |
202 | goto retry; | |
203 | } | |
204 | return insert_refcount_el(refcount, blk, low); | |
205 | } | |
206 | return 0; | |
207 | } | |
208 | ||
130e961a | 209 | errcode_t ea_refcount_fetch(ext2_refcount_t refcount, blk64_t blk, |
342d847d TT |
210 | int *ret) |
211 | { | |
212 | struct ea_refcount_el *el; | |
efc6f628 | 213 | |
342d847d TT |
214 | el = get_refcount_el(refcount, blk, 0); |
215 | if (!el) { | |
216 | *ret = 0; | |
217 | return 0; | |
218 | } | |
219 | *ret = el->ea_count; | |
220 | return 0; | |
221 | } | |
222 | ||
130e961a | 223 | errcode_t ea_refcount_increment(ext2_refcount_t refcount, blk64_t blk, int *ret) |
342d847d TT |
224 | { |
225 | struct ea_refcount_el *el; | |
226 | ||
227 | el = get_refcount_el(refcount, blk, 1); | |
228 | if (!el) | |
229 | return EXT2_ET_NO_MEMORY; | |
230 | el->ea_count++; | |
231 | ||
232 | if (ret) | |
233 | *ret = el->ea_count; | |
234 | return 0; | |
235 | } | |
236 | ||
130e961a | 237 | errcode_t ea_refcount_decrement(ext2_refcount_t refcount, blk64_t blk, int *ret) |
342d847d TT |
238 | { |
239 | struct ea_refcount_el *el; | |
240 | ||
241 | el = get_refcount_el(refcount, blk, 0); | |
242 | if (!el || el->ea_count == 0) | |
243 | return EXT2_ET_INVALID_ARGUMENT; | |
244 | ||
245 | el->ea_count--; | |
246 | ||
247 | if (ret) | |
248 | *ret = el->ea_count; | |
249 | return 0; | |
250 | } | |
251 | ||
130e961a | 252 | errcode_t ea_refcount_store(ext2_refcount_t refcount, blk64_t blk, int count) |
342d847d TT |
253 | { |
254 | struct ea_refcount_el *el; | |
255 | ||
256 | /* | |
257 | * Get the refcount element | |
258 | */ | |
259 | el = get_refcount_el(refcount, blk, count ? 1 : 0); | |
260 | if (!el) | |
261 | return count ? EXT2_ET_NO_MEMORY : 0; | |
262 | el->ea_count = count; | |
263 | return 0; | |
264 | } | |
265 | ||
266 | blk_t ext2fs_get_refcount_size(ext2_refcount_t refcount) | |
267 | { | |
268 | if (!refcount) | |
269 | return 0; | |
270 | ||
271 | return refcount->size; | |
272 | } | |
273 | ||
274 | void ea_refcount_intr_begin(ext2_refcount_t refcount) | |
275 | { | |
276 | refcount->cursor = 0; | |
277 | } | |
278 | ||
279 | ||
130e961a | 280 | blk64_t ea_refcount_intr_next(ext2_refcount_t refcount, |
342d847d TT |
281 | int *ret) |
282 | { | |
283 | struct ea_refcount_el *list; | |
efc6f628 | 284 | |
342d847d TT |
285 | while (1) { |
286 | if (refcount->cursor >= refcount->count) | |
287 | return 0; | |
288 | list = refcount->list; | |
289 | if (list[refcount->cursor].ea_count) { | |
290 | if (ret) | |
291 | *ret = list[refcount->cursor].ea_count; | |
292 | return list[refcount->cursor++].ea_blk; | |
293 | } | |
294 | refcount->cursor++; | |
295 | } | |
296 | } | |
297 | ||
298 | ||
299 | #ifdef TEST_PROGRAM | |
300 | ||
301 | errcode_t ea_refcount_validate(ext2_refcount_t refcount, FILE *out) | |
302 | { | |
303 | errcode_t ret = 0; | |
304 | int i; | |
305 | const char *bad = "bad refcount"; | |
efc6f628 | 306 | |
342d847d TT |
307 | if (refcount->count > refcount->size) { |
308 | fprintf(out, "%s: count > size\n", bad); | |
309 | return EXT2_ET_INVALID_ARGUMENT; | |
310 | } | |
311 | for (i=1; i < refcount->count; i++) { | |
312 | if (refcount->list[i-1].ea_blk >= refcount->list[i].ea_blk) { | |
313 | fprintf(out, "%s: list[%d].blk=%u, list[%d].blk=%u\n", | |
314 | bad, i-1, refcount->list[i-1].ea_blk, | |
315 | i, refcount->list[i].ea_blk); | |
316 | ret = EXT2_ET_INVALID_ARGUMENT; | |
317 | } | |
318 | } | |
319 | return ret; | |
320 | } | |
321 | ||
322 | #define BCODE_END 0 | |
323 | #define BCODE_CREATE 1 | |
324 | #define BCODE_FREE 2 | |
325 | #define BCODE_STORE 3 | |
326 | #define BCODE_INCR 4 | |
327 | #define BCODE_DECR 5 | |
328 | #define BCODE_FETCH 6 | |
329 | #define BCODE_VALIDATE 7 | |
330 | #define BCODE_LIST 8 | |
331 | #define BCODE_COLLAPSE 9 | |
332 | ||
333 | int bcode_program[] = { | |
334 | BCODE_CREATE, 5, | |
335 | BCODE_STORE, 3, 3, | |
336 | BCODE_STORE, 4, 4, | |
337 | BCODE_STORE, 1, 1, | |
338 | BCODE_STORE, 8, 8, | |
339 | BCODE_STORE, 2, 2, | |
340 | BCODE_STORE, 4, 0, | |
341 | BCODE_STORE, 2, 0, | |
342 | BCODE_STORE, 6, 6, | |
343 | BCODE_VALIDATE, | |
344 | BCODE_STORE, 4, 4, | |
345 | BCODE_STORE, 2, 2, | |
346 | BCODE_FETCH, 1, | |
347 | BCODE_FETCH, 2, | |
348 | BCODE_INCR, 3, | |
349 | BCODE_INCR, 3, | |
350 | BCODE_DECR, 4, | |
351 | BCODE_STORE, 4, 4, | |
352 | BCODE_VALIDATE, | |
353 | BCODE_STORE, 20, 20, | |
354 | BCODE_STORE, 40, 40, | |
355 | BCODE_STORE, 30, 30, | |
356 | BCODE_STORE, 10, 10, | |
357 | BCODE_DECR, 30, | |
358 | BCODE_FETCH, 30, | |
359 | BCODE_DECR, 2, | |
360 | BCODE_DECR, 2, | |
361 | BCODE_COLLAPSE, | |
362 | BCODE_LIST, | |
363 | BCODE_VALIDATE, | |
364 | BCODE_FREE, | |
365 | BCODE_END | |
366 | }; | |
367 | ||
368 | int main(int argc, char **argv) | |
369 | { | |
370 | int i = 0; | |
371 | ext2_refcount_t refcount; | |
372 | int size, arg; | |
130e961a | 373 | blk64_t blk; |
342d847d TT |
374 | errcode_t retval; |
375 | ||
376 | while (1) { | |
377 | switch (bcode_program[i++]) { | |
378 | case BCODE_END: | |
379 | exit(0); | |
380 | case BCODE_CREATE: | |
381 | size = bcode_program[i++]; | |
382 | retval = ea_refcount_create(size, &refcount); | |
383 | if (retval) { | |
6b56f3d9 AD |
384 | com_err("ea_refcount_create", retval, |
385 | "while creating size %d", size); | |
342d847d TT |
386 | exit(1); |
387 | } else | |
388 | printf("Creating refcount with size %d\n", | |
389 | size); | |
390 | break; | |
391 | case BCODE_FREE: | |
392 | ea_refcount_free(refcount); | |
393 | refcount = 0; | |
394 | printf("Freeing refcount\n"); | |
395 | break; | |
396 | case BCODE_STORE: | |
397 | blk = (blk_t) bcode_program[i++]; | |
398 | arg = bcode_program[i++]; | |
342d847d | 399 | printf("Storing blk %u with value %d\n", blk, arg); |
6b56f3d9 | 400 | retval = ea_refcount_store(refcount, blk, arg); |
342d847d | 401 | if (retval) |
6b56f3d9 AD |
402 | com_err("ea_refcount_store", retval, |
403 | "while storing blk %u", blk); | |
342d847d TT |
404 | break; |
405 | case BCODE_FETCH: | |
406 | blk = (blk_t) bcode_program[i++]; | |
407 | retval = ea_refcount_fetch(refcount, blk, &arg); | |
408 | if (retval) | |
6b56f3d9 AD |
409 | com_err("ea_refcount_fetch", retval, |
410 | "while fetching blk %u", blk); | |
342d847d TT |
411 | else |
412 | printf("bcode_fetch(%u) returns %d\n", | |
413 | blk, arg); | |
414 | break; | |
415 | case BCODE_INCR: | |
416 | blk = (blk_t) bcode_program[i++]; | |
6b56f3d9 | 417 | retval = ea_refcount_increment(refcount, blk, &arg); |
342d847d TT |
418 | if (retval) |
419 | com_err("ea_refcount_increment", retval, | |
6b56f3d9 | 420 | "while incrementing blk %u", blk); |
342d847d TT |
421 | else |
422 | printf("bcode_increment(%u) returns %d\n", | |
423 | blk, arg); | |
424 | break; | |
425 | case BCODE_DECR: | |
426 | blk = (blk_t) bcode_program[i++]; | |
6b56f3d9 | 427 | retval = ea_refcount_decrement(refcount, blk, &arg); |
342d847d TT |
428 | if (retval) |
429 | com_err("ea_refcount_decrement", retval, | |
430 | "while decrementing blk %u", blk); | |
431 | else | |
432 | printf("bcode_decrement(%u) returns %d\n", | |
433 | blk, arg); | |
434 | break; | |
435 | case BCODE_VALIDATE: | |
436 | retval = ea_refcount_validate(refcount, stderr); | |
437 | if (retval) | |
6b56f3d9 AD |
438 | com_err("ea_refcount_validate", retval, |
439 | "while validating"); | |
342d847d TT |
440 | else |
441 | printf("Refcount validation OK.\n"); | |
442 | break; | |
443 | case BCODE_LIST: | |
444 | ea_refcount_intr_begin(refcount); | |
445 | while (1) { | |
6b56f3d9 | 446 | blk = ea_refcount_intr_next(refcount, &arg); |
342d847d TT |
447 | if (!blk) |
448 | break; | |
6b56f3d9 | 449 | printf("\tblk=%u, count=%d\n", blk, arg); |
342d847d TT |
450 | } |
451 | break; | |
452 | case BCODE_COLLAPSE: | |
453 | refcount_collapse(refcount); | |
454 | break; | |
455 | } | |
efc6f628 | 456 | |
342d847d TT |
457 | } |
458 | } | |
459 | ||
460 | #endif |