]>
git.proxmox.com Git - mirror_zfs.git/blob - module/zfs/space_map.c
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.
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.
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]
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 #include <sys/zfs_context.h>
30 #include <sys/space_map.h>
32 static kmem_cache_t
*space_seg_cache
;
37 ASSERT(space_seg_cache
== NULL
);
38 space_seg_cache
= kmem_cache_create("space_seg_cache",
39 sizeof (space_seg_t
), 0, NULL
, NULL
, NULL
, NULL
, NULL
, 0);
45 kmem_cache_destroy(space_seg_cache
);
46 space_seg_cache
= NULL
;
51 * NOTE: caller is responsible for all locking.
54 space_map_seg_compare(const void *x1
, const void *x2
)
56 const space_seg_t
*s1
= x1
;
57 const space_seg_t
*s2
= x2
;
59 if (s1
->ss_start
< s2
->ss_start
) {
60 if (s1
->ss_end
> s2
->ss_start
)
64 if (s1
->ss_start
> s2
->ss_start
) {
65 if (s1
->ss_start
< s2
->ss_end
)
73 space_map_create(space_map_t
*sm
, uint64_t start
, uint64_t size
, uint8_t shift
,
76 bzero(sm
, sizeof (*sm
));
78 cv_init(&sm
->sm_load_cv
, NULL
, CV_DEFAULT
, NULL
);
80 avl_create(&sm
->sm_root
, space_map_seg_compare
,
81 sizeof (space_seg_t
), offsetof(struct space_seg
, ss_node
));
90 space_map_destroy(space_map_t
*sm
)
92 ASSERT(!sm
->sm_loaded
&& !sm
->sm_loading
);
93 VERIFY3U(sm
->sm_space
, ==, 0);
94 avl_destroy(&sm
->sm_root
);
95 cv_destroy(&sm
->sm_load_cv
);
99 space_map_add(space_map_t
*sm
, uint64_t start
, uint64_t size
)
102 space_seg_t ssearch
, *ss_before
, *ss_after
, *ss
;
103 uint64_t end
= start
+ size
;
104 int merge_before
, merge_after
;
106 ASSERT(MUTEX_HELD(sm
->sm_lock
));
108 VERIFY3U(start
, >=, sm
->sm_start
);
109 VERIFY3U(end
, <=, sm
->sm_start
+ sm
->sm_size
);
110 VERIFY(sm
->sm_space
+ size
<= sm
->sm_size
);
111 VERIFY(P2PHASE(start
, 1ULL << sm
->sm_shift
) == 0);
112 VERIFY(P2PHASE(size
, 1ULL << sm
->sm_shift
) == 0);
114 ssearch
.ss_start
= start
;
115 ssearch
.ss_end
= end
;
116 ss
= avl_find(&sm
->sm_root
, &ssearch
, &where
);
118 if (ss
!= NULL
&& ss
->ss_start
<= start
&& ss
->ss_end
>= end
) {
119 zfs_panic_recover("zfs: allocating allocated segment"
120 "(offset=%llu size=%llu)\n",
121 (longlong_t
)start
, (longlong_t
)size
);
125 /* Make sure we don't overlap with either of our neighbors */
128 ss_before
= avl_nearest(&sm
->sm_root
, where
, AVL_BEFORE
);
129 ss_after
= avl_nearest(&sm
->sm_root
, where
, AVL_AFTER
);
131 merge_before
= (ss_before
!= NULL
&& ss_before
->ss_end
== start
);
132 merge_after
= (ss_after
!= NULL
&& ss_after
->ss_start
== end
);
134 if (merge_before
&& merge_after
) {
135 avl_remove(&sm
->sm_root
, ss_before
);
136 if (sm
->sm_pp_root
) {
137 avl_remove(sm
->sm_pp_root
, ss_before
);
138 avl_remove(sm
->sm_pp_root
, ss_after
);
140 ss_after
->ss_start
= ss_before
->ss_start
;
141 kmem_cache_free(space_seg_cache
, ss_before
);
143 } else if (merge_before
) {
144 ss_before
->ss_end
= end
;
146 avl_remove(sm
->sm_pp_root
, ss_before
);
148 } else if (merge_after
) {
149 ss_after
->ss_start
= start
;
151 avl_remove(sm
->sm_pp_root
, ss_after
);
154 ss
= kmem_cache_alloc(space_seg_cache
, KM_PUSHPAGE
);
155 ss
->ss_start
= start
;
157 avl_insert(&sm
->sm_root
, ss
, where
);
161 avl_add(sm
->sm_pp_root
, ss
);
163 sm
->sm_space
+= size
;
167 space_map_remove(space_map_t
*sm
, uint64_t start
, uint64_t size
)
170 space_seg_t ssearch
, *ss
, *newseg
;
171 uint64_t end
= start
+ size
;
172 int left_over
, right_over
;
174 ASSERT(MUTEX_HELD(sm
->sm_lock
));
176 VERIFY(P2PHASE(start
, 1ULL << sm
->sm_shift
) == 0);
177 VERIFY(P2PHASE(size
, 1ULL << sm
->sm_shift
) == 0);
179 ssearch
.ss_start
= start
;
180 ssearch
.ss_end
= end
;
181 ss
= avl_find(&sm
->sm_root
, &ssearch
, &where
);
183 /* Make sure we completely overlap with someone */
185 zfs_panic_recover("zfs: freeing free segment "
186 "(offset=%llu size=%llu)",
187 (longlong_t
)start
, (longlong_t
)size
);
190 VERIFY3U(ss
->ss_start
, <=, start
);
191 VERIFY3U(ss
->ss_end
, >=, end
);
192 VERIFY(sm
->sm_space
- size
<= sm
->sm_size
);
194 left_over
= (ss
->ss_start
!= start
);
195 right_over
= (ss
->ss_end
!= end
);
198 avl_remove(sm
->sm_pp_root
, ss
);
200 if (left_over
&& right_over
) {
201 newseg
= kmem_cache_alloc(space_seg_cache
, KM_PUSHPAGE
);
202 newseg
->ss_start
= end
;
203 newseg
->ss_end
= ss
->ss_end
;
205 avl_insert_here(&sm
->sm_root
, newseg
, ss
, AVL_AFTER
);
207 avl_add(sm
->sm_pp_root
, newseg
);
208 } else if (left_over
) {
210 } else if (right_over
) {
213 avl_remove(&sm
->sm_root
, ss
);
214 kmem_cache_free(space_seg_cache
, ss
);
218 if (sm
->sm_pp_root
&& ss
!= NULL
)
219 avl_add(sm
->sm_pp_root
, ss
);
221 sm
->sm_space
-= size
;
225 space_map_contains(space_map_t
*sm
, uint64_t start
, uint64_t size
)
228 space_seg_t ssearch
, *ss
;
229 uint64_t end
= start
+ size
;
231 ASSERT(MUTEX_HELD(sm
->sm_lock
));
233 VERIFY(P2PHASE(start
, 1ULL << sm
->sm_shift
) == 0);
234 VERIFY(P2PHASE(size
, 1ULL << sm
->sm_shift
) == 0);
236 ssearch
.ss_start
= start
;
237 ssearch
.ss_end
= end
;
238 ss
= avl_find(&sm
->sm_root
, &ssearch
, &where
);
240 return (ss
!= NULL
&& ss
->ss_start
<= start
&& ss
->ss_end
>= end
);
244 space_map_vacate(space_map_t
*sm
, space_map_func_t
*func
, space_map_t
*mdest
)
249 ASSERT(MUTEX_HELD(sm
->sm_lock
));
251 while ((ss
= avl_destroy_nodes(&sm
->sm_root
, &cookie
)) != NULL
) {
253 func(mdest
, ss
->ss_start
, ss
->ss_end
- ss
->ss_start
);
254 kmem_cache_free(space_seg_cache
, ss
);
260 space_map_walk(space_map_t
*sm
, space_map_func_t
*func
, space_map_t
*mdest
)
264 ASSERT(MUTEX_HELD(sm
->sm_lock
));
266 for (ss
= avl_first(&sm
->sm_root
); ss
; ss
= AVL_NEXT(&sm
->sm_root
, ss
))
267 func(mdest
, ss
->ss_start
, ss
->ss_end
- ss
->ss_start
);
271 * Wait for any in-progress space_map_load() to complete.
274 space_map_load_wait(space_map_t
*sm
)
276 ASSERT(MUTEX_HELD(sm
->sm_lock
));
278 while (sm
->sm_loading
) {
279 ASSERT(!sm
->sm_loaded
);
280 cv_wait(&sm
->sm_load_cv
, sm
->sm_lock
);
285 * Note: space_map_load() will drop sm_lock across dmu_read() calls.
286 * The caller must be OK with this.
289 space_map_load(space_map_t
*sm
, space_map_ops_t
*ops
, uint8_t maptype
,
290 space_map_obj_t
*smo
, objset_t
*os
)
292 uint64_t *entry
, *entry_map
, *entry_map_end
;
293 uint64_t bufsize
, size
, offset
, end
, space
;
294 uint64_t mapstart
= sm
->sm_start
;
297 ASSERT(MUTEX_HELD(sm
->sm_lock
));
298 ASSERT(!sm
->sm_loaded
);
299 ASSERT(!sm
->sm_loading
);
301 sm
->sm_loading
= B_TRUE
;
302 end
= smo
->smo_objsize
;
303 space
= smo
->smo_alloc
;
305 ASSERT(sm
->sm_ops
== NULL
);
306 VERIFY3U(sm
->sm_space
, ==, 0);
308 if (maptype
== SM_FREE
) {
309 space_map_add(sm
, sm
->sm_start
, sm
->sm_size
);
310 space
= sm
->sm_size
- space
;
313 bufsize
= 1ULL << SPACE_MAP_BLOCKSHIFT
;
314 entry_map
= zio_buf_alloc(bufsize
);
316 mutex_exit(sm
->sm_lock
);
318 dmu_prefetch(os
, smo
->smo_object
, bufsize
, end
- bufsize
);
319 mutex_enter(sm
->sm_lock
);
321 for (offset
= 0; offset
< end
; offset
+= bufsize
) {
322 size
= MIN(end
- offset
, bufsize
);
323 VERIFY(P2PHASE(size
, sizeof (uint64_t)) == 0);
326 dprintf("object=%llu offset=%llx size=%llx\n",
327 smo
->smo_object
, offset
, size
);
329 mutex_exit(sm
->sm_lock
);
330 error
= dmu_read(os
, smo
->smo_object
, offset
, size
, entry_map
,
332 mutex_enter(sm
->sm_lock
);
336 entry_map_end
= entry_map
+ (size
/ sizeof (uint64_t));
337 for (entry
= entry_map
; entry
< entry_map_end
; entry
++) {
340 if (SM_DEBUG_DECODE(e
)) /* Skip debug entries */
343 (SM_TYPE_DECODE(e
) == maptype
?
344 space_map_add
: space_map_remove
)(sm
,
345 (SM_OFFSET_DECODE(e
) << sm
->sm_shift
) + mapstart
,
346 SM_RUN_DECODE(e
) << sm
->sm_shift
);
351 VERIFY3U(sm
->sm_space
, ==, space
);
353 sm
->sm_loaded
= B_TRUE
;
358 space_map_vacate(sm
, NULL
, NULL
);
361 zio_buf_free(entry_map
, bufsize
);
363 sm
->sm_loading
= B_FALSE
;
365 cv_broadcast(&sm
->sm_load_cv
);
371 space_map_unload(space_map_t
*sm
)
373 ASSERT(MUTEX_HELD(sm
->sm_lock
));
375 if (sm
->sm_loaded
&& sm
->sm_ops
!= NULL
)
376 sm
->sm_ops
->smop_unload(sm
);
378 sm
->sm_loaded
= B_FALSE
;
381 space_map_vacate(sm
, NULL
, NULL
);
385 space_map_maxsize(space_map_t
*sm
)
387 ASSERT(sm
->sm_ops
!= NULL
);
388 return (sm
->sm_ops
->smop_max(sm
));
392 space_map_alloc(space_map_t
*sm
, uint64_t size
)
396 start
= sm
->sm_ops
->smop_alloc(sm
, size
);
398 space_map_remove(sm
, start
, size
);
403 space_map_claim(space_map_t
*sm
, uint64_t start
, uint64_t size
)
405 sm
->sm_ops
->smop_claim(sm
, start
, size
);
406 space_map_remove(sm
, start
, size
);
410 space_map_free(space_map_t
*sm
, uint64_t start
, uint64_t size
)
412 space_map_add(sm
, start
, size
);
413 sm
->sm_ops
->smop_free(sm
, start
, size
);
417 * Note: space_map_sync() will drop sm_lock across dmu_write() calls.
420 space_map_sync(space_map_t
*sm
, uint8_t maptype
,
421 space_map_obj_t
*smo
, objset_t
*os
, dmu_tx_t
*tx
)
423 spa_t
*spa
= dmu_objset_spa(os
);
426 uint64_t bufsize
, start
, size
, run_len
, delta
, sm_space
;
427 uint64_t *entry
, *entry_map
, *entry_map_end
;
429 ASSERT(MUTEX_HELD(sm
->sm_lock
));
431 if (sm
->sm_space
== 0)
434 dprintf("object %4llu, txg %llu, pass %d, %c, count %lu, space %llx\n",
435 smo
->smo_object
, dmu_tx_get_txg(tx
), spa_sync_pass(spa
),
436 maptype
== SM_ALLOC
? 'A' : 'F', avl_numnodes(&sm
->sm_root
),
439 if (maptype
== SM_ALLOC
)
440 smo
->smo_alloc
+= sm
->sm_space
;
442 smo
->smo_alloc
-= sm
->sm_space
;
444 bufsize
= (8 + avl_numnodes(&sm
->sm_root
)) * sizeof (uint64_t);
445 bufsize
= MIN(bufsize
, 1ULL << SPACE_MAP_BLOCKSHIFT
);
446 entry_map
= zio_buf_alloc(bufsize
);
447 entry_map_end
= entry_map
+ (bufsize
/ sizeof (uint64_t));
450 *entry
++ = SM_DEBUG_ENCODE(1) |
451 SM_DEBUG_ACTION_ENCODE(maptype
) |
452 SM_DEBUG_SYNCPASS_ENCODE(spa_sync_pass(spa
)) |
453 SM_DEBUG_TXG_ENCODE(dmu_tx_get_txg(tx
));
456 sm_space
= sm
->sm_space
;
457 while ((ss
= avl_destroy_nodes(&sm
->sm_root
, &cookie
)) != NULL
) {
458 size
= ss
->ss_end
- ss
->ss_start
;
459 start
= (ss
->ss_start
- sm
->sm_start
) >> sm
->sm_shift
;
462 size
>>= sm
->sm_shift
;
465 run_len
= MIN(size
, SM_RUN_MAX
);
467 if (entry
== entry_map_end
) {
468 mutex_exit(sm
->sm_lock
);
469 dmu_write(os
, smo
->smo_object
, smo
->smo_objsize
,
470 bufsize
, entry_map
, tx
);
471 mutex_enter(sm
->sm_lock
);
472 smo
->smo_objsize
+= bufsize
;
476 *entry
++ = SM_OFFSET_ENCODE(start
) |
477 SM_TYPE_ENCODE(maptype
) |
478 SM_RUN_ENCODE(run_len
);
483 kmem_cache_free(space_seg_cache
, ss
);
486 if (entry
!= entry_map
) {
487 size
= (entry
- entry_map
) * sizeof (uint64_t);
488 mutex_exit(sm
->sm_lock
);
489 dmu_write(os
, smo
->smo_object
, smo
->smo_objsize
,
490 size
, entry_map
, tx
);
491 mutex_enter(sm
->sm_lock
);
492 smo
->smo_objsize
+= size
;
496 * Ensure that the space_map's accounting wasn't changed
497 * while we were in the middle of writing it out.
499 VERIFY3U(sm
->sm_space
, ==, sm_space
);
501 zio_buf_free(entry_map
, bufsize
);
503 sm
->sm_space
-= delta
;
504 VERIFY3U(sm
->sm_space
, ==, 0);
508 space_map_truncate(space_map_obj_t
*smo
, objset_t
*os
, dmu_tx_t
*tx
)
510 VERIFY(dmu_free_range(os
, smo
->smo_object
, 0, -1ULL, tx
) == 0);
512 smo
->smo_objsize
= 0;
517 * Space map reference trees.
519 * A space map is a collection of integers. Every integer is either
520 * in the map, or it's not. A space map reference tree generalizes
521 * the idea: it allows its members to have arbitrary reference counts,
522 * as opposed to the implicit reference count of 0 or 1 in a space map.
523 * This representation comes in handy when computing the union or
524 * intersection of multiple space maps. For example, the union of
525 * N space maps is the subset of the reference tree with refcnt >= 1.
526 * The intersection of N space maps is the subset with refcnt >= N.
528 * [It's very much like a Fourier transform. Unions and intersections
529 * are hard to perform in the 'space map domain', so we convert the maps
530 * into the 'reference count domain', where it's trivial, then invert.]
532 * vdev_dtl_reassess() uses computations of this form to determine
533 * DTL_MISSING and DTL_OUTAGE for interior vdevs -- e.g. a RAID-Z vdev
534 * has an outage wherever refcnt >= vdev_nparity + 1, and a mirror vdev
535 * has an outage wherever refcnt >= vdev_children.
538 space_map_ref_compare(const void *x1
, const void *x2
)
540 const space_ref_t
*sr1
= x1
;
541 const space_ref_t
*sr2
= x2
;
543 if (sr1
->sr_offset
< sr2
->sr_offset
)
545 if (sr1
->sr_offset
> sr2
->sr_offset
)
557 space_map_ref_create(avl_tree_t
*t
)
559 avl_create(t
, space_map_ref_compare
,
560 sizeof (space_ref_t
), offsetof(space_ref_t
, sr_node
));
564 space_map_ref_destroy(avl_tree_t
*t
)
569 while ((sr
= avl_destroy_nodes(t
, &cookie
)) != NULL
)
570 kmem_free(sr
, sizeof (*sr
));
576 space_map_ref_add_node(avl_tree_t
*t
, uint64_t offset
, int64_t refcnt
)
580 sr
= kmem_alloc(sizeof (*sr
), KM_PUSHPAGE
);
581 sr
->sr_offset
= offset
;
582 sr
->sr_refcnt
= refcnt
;
588 space_map_ref_add_seg(avl_tree_t
*t
, uint64_t start
, uint64_t end
,
591 space_map_ref_add_node(t
, start
, refcnt
);
592 space_map_ref_add_node(t
, end
, -refcnt
);
596 * Convert (or add) a space map into a reference tree.
599 space_map_ref_add_map(avl_tree_t
*t
, space_map_t
*sm
, int64_t refcnt
)
603 ASSERT(MUTEX_HELD(sm
->sm_lock
));
605 for (ss
= avl_first(&sm
->sm_root
); ss
; ss
= AVL_NEXT(&sm
->sm_root
, ss
))
606 space_map_ref_add_seg(t
, ss
->ss_start
, ss
->ss_end
, refcnt
);
610 * Convert a reference tree into a space map. The space map will contain
611 * all members of the reference tree for which refcnt >= minref.
614 space_map_ref_generate_map(avl_tree_t
*t
, space_map_t
*sm
, int64_t minref
)
616 uint64_t start
= -1ULL;
620 ASSERT(MUTEX_HELD(sm
->sm_lock
));
622 space_map_vacate(sm
, NULL
, NULL
);
624 for (sr
= avl_first(t
); sr
!= NULL
; sr
= AVL_NEXT(t
, sr
)) {
625 refcnt
+= sr
->sr_refcnt
;
626 if (refcnt
>= minref
) {
627 if (start
== -1ULL) {
628 start
= sr
->sr_offset
;
631 if (start
!= -1ULL) {
632 uint64_t end
= sr
->sr_offset
;
633 ASSERT(start
<= end
);
635 space_map_add(sm
, start
, end
- start
);
641 ASSERT(start
== -1ULL);