1 /*
2 * Copyright (c) 2010 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Ilya Dryomov <idryomov@gmail.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include "hammer.h"
36
37 static __inline int validate_zone(hammer_off_t data_offset);
38
39 int
40 hammer_ioc_dedup(hammer_transaction_t trans, hammer_inode_t ip,
41 struct hammer_ioc_dedup *dedup)
42 {
43 struct hammer_cursor cursor1, cursor2;
44 int error;
45 int seq;
46
47 /*
48 * Enforce hammer filesystem version requirements
49 */
50 if (trans->hmp->version < HAMMER_VOL_VERSION_FIVE) {
51 kprintf("hammer: Filesystem must be upgraded to v5 "
52 "before you can run dedup\n");
53 return (EOPNOTSUPP);
54 }
55
56 /*
57 * Cursor1, return an error -> candidate goes to pass2 list
58 */
59 error = hammer_init_cursor(trans, &cursor1, NULL, NULL);
60 if (error)
61 goto done_cursor;
62 cursor1.key_beg = dedup->elm1;
63 cursor1.flags |= HAMMER_CURSOR_BACKEND;
64
65 error = hammer_btree_lookup(&cursor1);
66 if (error)
67 goto done_cursor;
68 error = hammer_btree_extract(&cursor1, HAMMER_CURSOR_GET_LEAF |
69 HAMMER_CURSOR_GET_DATA);
70 if (error)
71 goto done_cursor;
72
73 /*
74 * Cursor2, return an error -> candidate goes to pass2 list
75 */
76 error = hammer_init_cursor(trans, &cursor2, NULL, NULL);
77 if (error)
78 goto done_cursors;
79 cursor2.key_beg = dedup->elm2;
80 cursor2.flags |= HAMMER_CURSOR_BACKEND;
81
82 error = hammer_btree_lookup(&cursor2);
83 if (error)
84 goto done_cursors;
85 error = hammer_btree_extract(&cursor2, HAMMER_CURSOR_GET_LEAF |
86 HAMMER_CURSOR_GET_DATA);
87 if (error)
88 goto done_cursors;
89
90 /*
91 * Zone validation. We can't de-dup any of the other zones
92 * (BTREE or META) or bad things will happen.
93 *
94 * Return with error = 0, but set an INVALID_ZONE flag.
95 */
96 error = validate_zone(cursor1.leaf->data_offset) +
97 validate_zone(cursor2.leaf->data_offset);
98 if (error) {
99 dedup->head.flags |= HAMMER_IOC_DEDUP_INVALID_ZONE;
100 error = 0;
101 goto done_cursors;
102 }
103
104 /*
105 * Comparison checks
106 *
107 * If zones don't match or data_len fields aren't the same
108 * we consider it to be a comparison failure.
109 *
110 * Return with error = 0, but set a CMP_FAILURE flag.
111 */
112 if ((cursor1.leaf->data_offset & HAMMER_OFF_ZONE_MASK) !=
113 (cursor2.leaf->data_offset & HAMMER_OFF_ZONE_MASK)) {
114 dedup->head.flags |= HAMMER_IOC_DEDUP_CMP_FAILURE;
115 goto done_cursors;
116 }
117 if (cursor1.leaf->data_len != cursor2.leaf->data_len) {
118 dedup->head.flags |= HAMMER_IOC_DEDUP_CMP_FAILURE;
119 goto done_cursors;
120 }
121
122 /* byte-by-byte comparison to be sure */
123 if (bcmp(cursor1.data, cursor2.data, cursor1.leaf->data_len)) {
124 dedup->head.flags |= HAMMER_IOC_DEDUP_CMP_FAILURE;
125 goto done_cursors;
126 }
127
128 /*
129 * Upgrade both cursors together to an exclusive lock
130 *
131 * Return an error -> candidate goes to pass2 list
132 */
133 hammer_sync_lock_sh(trans);
134 error = hammer_cursor_upgrade2(&cursor1, &cursor2);
135 if (error) {
136 hammer_sync_unlock(trans);
137 goto done_cursors;
138 }
139
140 error = hammer_blockmap_dedup(cursor1.trans,
141 cursor1.leaf->data_offset, cursor1.leaf->data_len);
142 if (error) {
143 if (error == ERANGE) {
144 /*
145 * Return with error = 0, but set an UNDERFLOW flag
146 */
147 dedup->head.flags |= HAMMER_IOC_DEDUP_UNDERFLOW;
148 error = 0;
149 goto downgrade_cursors;
150 } else {
151 /*
152 * Return an error -> block goes to pass2 list
153 */
154 goto downgrade_cursors;
155 }
156 }
157
158 /*
159 * The cursor2's cache must be invalidated before calling
160 * hammer_blockmap_free(), otherwise it will not be able to
161 * invalidate the underlying data buffer.
162 */
163 hammer_cursor_invalidate_cache(&cursor2);
164 hammer_blockmap_free(cursor2.trans,
165 cursor2.leaf->data_offset, cursor2.leaf->data_len);
166
167 hammer_modify_node(cursor2.trans, cursor2.node,
168 &cursor2.leaf->data_offset, sizeof(hammer_off_t));
169 cursor2.leaf->data_offset = cursor1.leaf->data_offset;
170 hammer_modify_node_done(cursor2.node);
171
172 downgrade_cursors:
173 hammer_cursor_downgrade2(&cursor1, &cursor2);
174 hammer_sync_unlock(trans);
175 done_cursors:
176 hammer_done_cursor(&cursor2);
177 done_cursor:
178 hammer_done_cursor(&cursor1);
179
180 /*
181 * Avoid deadlocking the buffer cache
182 */
183 seq = trans->hmp->flusher.done;
184 while (hammer_flusher_meta_halflimit(trans->hmp) ||
185 hammer_flusher_undo_exhausted(trans, 2)) {
186 hammer_flusher_wait(trans->hmp, seq);
187 seq = hammer_flusher_async_one(trans->hmp);
188 }
189 return (error);
190 }
191
192 static __inline int
193 validate_zone(hammer_off_t data_offset)
194 {
195 switch(data_offset & HAMMER_OFF_ZONE_MASK) {
196 case HAMMER_ZONE_LARGE_DATA:
197 case HAMMER_ZONE_SMALL_DATA:
198 return (0);
199 default:
200 return (1);
201 }
202 }
203
204 /************************************************************************
205 * LIVE DEDUP *
206 ************************************************************************
207 *
208 * HAMMER Live Dedup (aka as efficient cp(1) implementation)
209 *
210 * The dedup cache is operated in a LRU fashion and destroyed on
211 * unmount, so essentially this is a live dedup on a cached dataset and
212 * not a full-fledged fs-wide one - we have a batched dedup for that.
213 * We allow duplicate entries in the buffer cache, data blocks are
214 * deduplicated only on their way to media. By default the cache is
215 * populated on reads only, but it can be populated on writes too.
216 *
217 * The main implementation gotcha is on-media requirement - in order for
218 * a data block to be added to a dedup cache it has to be present on
219 * disk. This simplifies cache logic a lot - once data is laid out on
220 * media it remains valid on media all the way up to the point where the
221 * related big block the data was stored in is freed - so there is only
222 * one place we need to bother with invalidation code.
223 */
224
225 /*
226 * RB-Tree support for dedup cache structures
227 */
228 RB_GENERATE2(hammer_dedup_crc_rb_tree, hammer_dedup_cache, crc_entry,
229 hammer_dedup_crc_rb_compare, hammer_crc_t, crc);
230 RB_GENERATE2(hammer_dedup_off_rb_tree, hammer_dedup_cache, off_entry,
231 hammer_dedup_off_rb_compare, hammer_off_t, data_offset);
232
233 struct hammer_dedup_inval {
234 struct hammer_mount *hmp;
235 hammer_off_t base_offset;
236 };
237
238 static int hammer_dedup_scancmp(hammer_dedup_cache_t dc, void *data);
239 static int hammer_dedup_cache_inval_callback(hammer_dedup_cache_t dc,
240 void *data);
241 static __inline int _vnode_validate(hammer_dedup_cache_t dcp, void *data,
242 int *errorp);
243 static __inline int _dev_validate(hammer_dedup_cache_t dcp, void *data,
244 int *errorp);
245
246 int
247 hammer_dedup_crc_rb_compare(hammer_dedup_cache_t dc1,
248 hammer_dedup_cache_t dc2)
249 {
250 if (dc1->crc < dc2->crc)
251 return (-1);
252 if (dc1->crc > dc2->crc)
253 return (1);
254
255 return (0);
256 }
257
258 int
259 hammer_dedup_off_rb_compare(hammer_dedup_cache_t dc1,
260 hammer_dedup_cache_t dc2)
261 {
262 if (dc1->data_offset < dc2->data_offset)
263 return (-1);
264 if (dc1->data_offset > dc2->data_offset)
265 return (1);
266
267 return (0);
268 }
269
270 static int
271 hammer_dedup_scancmp(hammer_dedup_cache_t dc, void *data)
272 {
273 hammer_off_t off = ((struct hammer_dedup_inval *)data)->base_offset;
274
275 if (dc->data_offset < off)
276 return (-1);
277 if (dc->data_offset >= off + HAMMER_LARGEBLOCK_SIZE)
278 return (1);
279
280 return (0);
281 }
282
283 static int
284 hammer_dedup_cache_inval_callback(hammer_dedup_cache_t dc, void *data)
285 {
286 hammer_mount_t hmp = ((struct hammer_dedup_inval *)data)->hmp;
287
288 RB_REMOVE(hammer_dedup_crc_rb_tree, &hmp->rb_dedup_crc_root, dc);
289 RB_REMOVE(hammer_dedup_off_rb_tree, &hmp->rb_dedup_off_root, dc);
290 TAILQ_REMOVE(&hmp->dedup_lru_list, dc, lru_entry);
291
292 --hmp->dedup_cache_count;
293 kfree(dc, hmp->m_misc);
294
295 return (0);
296 }
297
298 hammer_dedup_cache_t
299 hammer_dedup_cache_add(hammer_inode_t ip, hammer_btree_leaf_elm_t leaf)
300 {
301 hammer_dedup_cache_t dcp, tmp;
302 hammer_mount_t hmp = ip->hmp;
303
304 if (hmp->dedup_free_cache == NULL) {
305 tmp = kmalloc(sizeof(*tmp), hmp->m_misc, M_WAITOK | M_ZERO);
306 if (hmp->dedup_free_cache == NULL)
307 hmp->dedup_free_cache = tmp;
308 else
309 kfree(tmp, hmp->m_misc);
310 }
311
312 KKASSERT(leaf != NULL);
313
314 dcp = RB_LOOKUP(hammer_dedup_crc_rb_tree,
315 &hmp->rb_dedup_crc_root, leaf->data_crc);
316 if (dcp != NULL) {
317 RB_REMOVE(hammer_dedup_off_rb_tree,
318 &hmp->rb_dedup_off_root, dcp);
319 TAILQ_REMOVE(&hmp->dedup_lru_list, dcp, lru_entry);
320 goto populate;
321 }
322
323 if (hmp->dedup_cache_count < hammer_live_dedup_cache_size) {
324 dcp = hmp->dedup_free_cache;
325 hmp->dedup_free_cache = NULL;
326 ++hmp->dedup_cache_count;
327 } else {
328 dcp = TAILQ_FIRST(&hmp->dedup_lru_list);
329 RB_REMOVE(hammer_dedup_crc_rb_tree,
330 &hmp->rb_dedup_crc_root, dcp);
331 RB_REMOVE(hammer_dedup_off_rb_tree,
332 &hmp->rb_dedup_off_root, dcp);
333 TAILQ_REMOVE(&hmp->dedup_lru_list, dcp, lru_entry);
334 }
335
336 dcp->crc = leaf->data_crc;
337 tmp = RB_INSERT(hammer_dedup_crc_rb_tree, &hmp->rb_dedup_crc_root, dcp);
338 KKASSERT(tmp == NULL);
339
340 populate:
341 dcp->hmp = ip->hmp;
342 dcp->obj_id = ip->obj_id;
343 dcp->localization = ip->obj_localization;
344 dcp->file_offset = leaf->base.key - leaf->data_len;
345 dcp->bytes = leaf->data_len;
346 dcp->data_offset = leaf->data_offset;
347
348 tmp = RB_INSERT(hammer_dedup_off_rb_tree, &hmp->rb_dedup_off_root, dcp);
349 KKASSERT(tmp == NULL);
350 TAILQ_INSERT_TAIL(&hmp->dedup_lru_list, dcp, lru_entry);
351
352 return (dcp);
353 }
354
355 __inline hammer_dedup_cache_t
356 hammer_dedup_cache_lookup(hammer_mount_t hmp, hammer_crc_t crc)
357 {
358 hammer_dedup_cache_t dcp;
359
360 dcp = RB_LOOKUP(hammer_dedup_crc_rb_tree,
361 &hmp->rb_dedup_crc_root, crc);
362 return dcp;
363 }
364
365 void hammer_dedup_cache_inval(hammer_mount_t hmp, hammer_off_t base_offset)
366 {
367 struct hammer_dedup_inval di;
368
369 di.hmp = hmp;
370 di.base_offset = base_offset;
371
372 RB_SCAN(hammer_dedup_off_rb_tree, &hmp->rb_dedup_off_root,
373 hammer_dedup_scancmp, hammer_dedup_cache_inval_callback, &di);
374 }
375
376 void
377 hammer_destroy_dedup_cache(hammer_mount_t hmp)
378 {
379 hammer_dedup_cache_t dcp;
380
381 while ((dcp = TAILQ_FIRST(&hmp->dedup_lru_list)) != NULL) {
382 RB_REMOVE(hammer_dedup_crc_rb_tree, &hmp->rb_dedup_crc_root, dcp);
383 RB_REMOVE(hammer_dedup_off_rb_tree, &hmp->rb_dedup_off_root, dcp);
384 TAILQ_REMOVE(&hmp->dedup_lru_list, dcp, lru_entry);
385 --hmp->dedup_cache_count;
386 kfree(dcp, hmp->m_misc);
387 }
388
389 KKASSERT(RB_EMPTY(&hmp->rb_dedup_crc_root));
390 KKASSERT(RB_EMPTY(&hmp->rb_dedup_off_root));
391 KKASSERT(TAILQ_EMPTY(&hmp->dedup_lru_list));
392
393 KKASSERT(hmp->dedup_cache_count == 0);
394 }
395
396 int
397 hammer_dedup_validate(hammer_dedup_cache_t dcp, int zone, int bytes,
398 void *data)
399 {
400 int error;
401
402 /*
403 * Zone validation
404 */
405 if (HAMMER_ZONE_DECODE(dcp->data_offset) != zone)
406 return (0);
407
408 /*
409 * Block length validation
410 */
411 if (dcp->bytes != bytes)
412 return (0);
413
414 /*
415 * Byte-by-byte data comparison
416 *
417 * The data we need for validation may already be present in the
418 * buffer cache in two flavours: vnode-based buffer or
419 * block-device-based buffer. In case vnode-based buffer wasn't
420 * there or if a non-blocking attempt to acquire it failed use
421 * device-based buffer (for large-zone data blocks it will
422 * generate a separate read).
423 *
424 * XXX vnode-based checking is not MP safe so when live-dedup
425 * is turned on we must always use the device buffer.
426 */
427 #if 0
428 if (hammer_double_buffer) {
429 error = 1;
430 } else if (_vnode_validate(dcp, data, &error)) {
431 hammer_live_dedup_vnode_bcmps++;
432 return (1);
433 } else {
434 if (error == 3)
435 hammer_live_dedup_findblk_failures++;
436 }
437
438 /*
439 * If there was an error previously or if double buffering is
440 * enabled.
441 */
442 if (error) {
443 if (_dev_validate(dcp, data, &error)) {
444 hammer_live_dedup_device_bcmps++;
445 return (1);
446 }
447 }
448 #endif
449 if (_dev_validate(dcp, data, &error)) {
450 hammer_live_dedup_device_bcmps++;
451 return (1);
452 }
453
454 return (0);
455 }
456
457 static __inline int
458 _vnode_validate(hammer_dedup_cache_t dcp, void *data, int *errorp)
459 {
460 struct hammer_transaction trans;
461 hammer_inode_t ip;
462 struct vnode *vp;
463 struct buf *bp;
464 off_t dooffset;
465 int result, error;
466
467 result = error = 0;
468 *errorp = 0;
469
470 hammer_simple_transaction(&trans, dcp->hmp);
471
472 ip = hammer_get_inode(&trans, NULL, dcp->obj_id, HAMMER_MAX_TID,
473 dcp->localization, 0, &error);
474 if (ip == NULL) {
475 kprintf("dedup: unable to find objid %016jx:%08x\n",
476 (intmax_t)dcp->obj_id, dcp->localization);
477 *errorp = 1;
478 goto failed2;
479 }
480
481 error = hammer_get_vnode(ip, &vp);
482 if (error) {
483 kprintf("dedup: unable to acquire vnode for %016jx:%08x\n",
484 (intmax_t)dcp->obj_id, dcp->localization);
485 *errorp = 2;
486 goto failed;
487 }
488
489 if ((bp = findblk(ip->vp, dcp->file_offset, FINDBLK_NBLOCK)) != NULL) {
490 bremfree(bp);
491
492 /* XXX if (mapped to userspace) goto done, *errorp = 4 */
493
494 if ((bp->b_flags & B_CACHE) == 0 || bp->b_flags & B_DIRTY) {
495 *errorp = 5;
496 goto done;
497 }
498
499 if (bp->b_bio2.bio_offset != dcp->data_offset) {
500 error = VOP_BMAP(ip->vp, dcp->file_offset, &dooffset,
501 NULL, NULL, BUF_CMD_READ);
502 if (error) {
503 *errorp = 6;
504 goto done;
505 }
506
507 if (dooffset != dcp->data_offset) {
508 *errorp = 7;
509 goto done;
510 }
511 hammer_live_dedup_bmap_saves++;
512 }
513
514 if (bcmp(data, bp->b_data, dcp->bytes) == 0)
515 result = 1;
516
517 done:
518 bqrelse(bp);
519 } else {
520 *errorp = 3;
521 }
522 vput(vp);
523
524 failed:
525 hammer_rel_inode(ip, 0);
526 failed2:
527 hammer_done_transaction(&trans);
528 return (result);
529 }
530
531 static __inline int
532 _dev_validate(hammer_dedup_cache_t dcp, void *data, int *errorp)
533 {
534 hammer_buffer_t buffer = NULL;
535 void *ondisk_data;
536 int result, error;
537
538 result = error = 0;
539 *errorp = 0;
540
541 ondisk_data = hammer_bread_ext(dcp->hmp, dcp->data_offset,
542 dcp->bytes, &error, &buffer);
543 if (error) {
544 *errorp = 1;
545 goto failed;
546 }
547
548 if (bcmp(data, ondisk_data, dcp->bytes) == 0)
549 result = 1;
550
551 failed:
552 if (buffer)
553 hammer_rel_buffer(buffer, 0);
554
555 return (result);
556 }
Cache object: b6369616524e6c75d992e2251cd225da
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