1
2#include <linux/ceph/ceph_debug.h>
3
4#include <linux/sort.h>
5#include <linux/slab.h>
6#include <linux/iversion.h>
7#include "super.h"
8#include "mds_client.h"
9#include <linux/ceph/decode.h>
10
11
12#define CEPH_SNAPID_MAP_TIMEOUT (5 * 60 * HZ)
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64
65void ceph_get_snap_realm(struct ceph_mds_client *mdsc,
66 struct ceph_snap_realm *realm)
67{
68 lockdep_assert_held(&mdsc->snap_rwsem);
69
70
71
72
73
74
75
76 if (atomic_inc_not_zero(&realm->nref))
77 return;
78
79 spin_lock(&mdsc->snap_empty_lock);
80 if (atomic_inc_return(&realm->nref) == 1)
81 list_del_init(&realm->empty_item);
82 spin_unlock(&mdsc->snap_empty_lock);
83}
84
85static void __insert_snap_realm(struct rb_root *root,
86 struct ceph_snap_realm *new)
87{
88 struct rb_node **p = &root->rb_node;
89 struct rb_node *parent = NULL;
90 struct ceph_snap_realm *r = NULL;
91
92 while (*p) {
93 parent = *p;
94 r = rb_entry(parent, struct ceph_snap_realm, node);
95 if (new->ino < r->ino)
96 p = &(*p)->rb_left;
97 else if (new->ino > r->ino)
98 p = &(*p)->rb_right;
99 else
100 BUG();
101 }
102
103 rb_link_node(&new->node, parent, p);
104 rb_insert_color(&new->node, root);
105}
106
107
108
109
110
111
112static struct ceph_snap_realm *ceph_create_snap_realm(
113 struct ceph_mds_client *mdsc,
114 u64 ino)
115{
116 struct ceph_snap_realm *realm;
117
118 lockdep_assert_held_write(&mdsc->snap_rwsem);
119
120 realm = kzalloc(sizeof(*realm), GFP_NOFS);
121 if (!realm)
122 return ERR_PTR(-ENOMEM);
123
124 atomic_set(&realm->nref, 1);
125 realm->ino = ino;
126 INIT_LIST_HEAD(&realm->children);
127 INIT_LIST_HEAD(&realm->child_item);
128 INIT_LIST_HEAD(&realm->empty_item);
129 INIT_LIST_HEAD(&realm->dirty_item);
130 INIT_LIST_HEAD(&realm->inodes_with_caps);
131 spin_lock_init(&realm->inodes_with_caps_lock);
132 __insert_snap_realm(&mdsc->snap_realms, realm);
133 mdsc->num_snap_realms++;
134
135 dout("create_snap_realm %llx %p\n", realm->ino, realm);
136 return realm;
137}
138
139
140
141
142
143
144static struct ceph_snap_realm *__lookup_snap_realm(struct ceph_mds_client *mdsc,
145 u64 ino)
146{
147 struct rb_node *n = mdsc->snap_realms.rb_node;
148 struct ceph_snap_realm *r;
149
150 lockdep_assert_held(&mdsc->snap_rwsem);
151
152 while (n) {
153 r = rb_entry(n, struct ceph_snap_realm, node);
154 if (ino < r->ino)
155 n = n->rb_left;
156 else if (ino > r->ino)
157 n = n->rb_right;
158 else {
159 dout("lookup_snap_realm %llx %p\n", r->ino, r);
160 return r;
161 }
162 }
163 return NULL;
164}
165
166struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc,
167 u64 ino)
168{
169 struct ceph_snap_realm *r;
170 r = __lookup_snap_realm(mdsc, ino);
171 if (r)
172 ceph_get_snap_realm(mdsc, r);
173 return r;
174}
175
176static void __put_snap_realm(struct ceph_mds_client *mdsc,
177 struct ceph_snap_realm *realm);
178
179
180
181
182static void __destroy_snap_realm(struct ceph_mds_client *mdsc,
183 struct ceph_snap_realm *realm)
184{
185 lockdep_assert_held_write(&mdsc->snap_rwsem);
186
187 dout("__destroy_snap_realm %p %llx\n", realm, realm->ino);
188
189 rb_erase(&realm->node, &mdsc->snap_realms);
190 mdsc->num_snap_realms--;
191
192 if (realm->parent) {
193 list_del_init(&realm->child_item);
194 __put_snap_realm(mdsc, realm->parent);
195 }
196
197 kfree(realm->prior_parent_snaps);
198 kfree(realm->snaps);
199 ceph_put_snap_context(realm->cached_context);
200 kfree(realm);
201}
202
203
204
205
206static void __put_snap_realm(struct ceph_mds_client *mdsc,
207 struct ceph_snap_realm *realm)
208{
209 lockdep_assert_held_write(&mdsc->snap_rwsem);
210
211
212
213
214
215 if (atomic_dec_and_test(&realm->nref))
216 __destroy_snap_realm(mdsc, realm);
217}
218
219
220
221
222void ceph_put_snap_realm(struct ceph_mds_client *mdsc,
223 struct ceph_snap_realm *realm)
224{
225 if (!atomic_dec_and_lock(&realm->nref, &mdsc->snap_empty_lock))
226 return;
227
228 if (down_write_trylock(&mdsc->snap_rwsem)) {
229 spin_unlock(&mdsc->snap_empty_lock);
230 __destroy_snap_realm(mdsc, realm);
231 up_write(&mdsc->snap_rwsem);
232 } else {
233 list_add(&realm->empty_item, &mdsc->snap_empty);
234 spin_unlock(&mdsc->snap_empty_lock);
235 }
236}
237
238
239
240
241
242
243
244
245static void __cleanup_empty_realms(struct ceph_mds_client *mdsc)
246{
247 struct ceph_snap_realm *realm;
248
249 lockdep_assert_held_write(&mdsc->snap_rwsem);
250
251 spin_lock(&mdsc->snap_empty_lock);
252 while (!list_empty(&mdsc->snap_empty)) {
253 realm = list_first_entry(&mdsc->snap_empty,
254 struct ceph_snap_realm, empty_item);
255 list_del(&realm->empty_item);
256 spin_unlock(&mdsc->snap_empty_lock);
257 __destroy_snap_realm(mdsc, realm);
258 spin_lock(&mdsc->snap_empty_lock);
259 }
260 spin_unlock(&mdsc->snap_empty_lock);
261}
262
263void ceph_cleanup_empty_realms(struct ceph_mds_client *mdsc)
264{
265 down_write(&mdsc->snap_rwsem);
266 __cleanup_empty_realms(mdsc);
267 up_write(&mdsc->snap_rwsem);
268}
269
270
271
272
273
274
275
276
277
278static int adjust_snap_realm_parent(struct ceph_mds_client *mdsc,
279 struct ceph_snap_realm *realm,
280 u64 parentino)
281{
282 struct ceph_snap_realm *parent;
283
284 lockdep_assert_held_write(&mdsc->snap_rwsem);
285
286 if (realm->parent_ino == parentino)
287 return 0;
288
289 parent = ceph_lookup_snap_realm(mdsc, parentino);
290 if (!parent) {
291 parent = ceph_create_snap_realm(mdsc, parentino);
292 if (IS_ERR(parent))
293 return PTR_ERR(parent);
294 }
295 dout("adjust_snap_realm_parent %llx %p: %llx %p -> %llx %p\n",
296 realm->ino, realm, realm->parent_ino, realm->parent,
297 parentino, parent);
298 if (realm->parent) {
299 list_del_init(&realm->child_item);
300 ceph_put_snap_realm(mdsc, realm->parent);
301 }
302 realm->parent_ino = parentino;
303 realm->parent = parent;
304 list_add(&realm->child_item, &parent->children);
305 return 1;
306}
307
308
309static int cmpu64_rev(const void *a, const void *b)
310{
311 if (*(u64 *)a < *(u64 *)b)
312 return 1;
313 if (*(u64 *)a > *(u64 *)b)
314 return -1;
315 return 0;
316}
317
318
319
320
321
322static int build_snap_context(struct ceph_snap_realm *realm,
323 struct list_head* dirty_realms)
324{
325 struct ceph_snap_realm *parent = realm->parent;
326 struct ceph_snap_context *snapc;
327 int err = 0;
328 u32 num = realm->num_prior_parent_snaps + realm->num_snaps;
329
330
331
332
333
334
335 if (parent) {
336 if (!parent->cached_context) {
337 err = build_snap_context(parent, dirty_realms);
338 if (err)
339 goto fail;
340 }
341 num += parent->cached_context->num_snaps;
342 }
343
344
345
346
347
348 if (realm->cached_context &&
349 realm->cached_context->seq == realm->seq &&
350 (!parent ||
351 realm->cached_context->seq >= parent->cached_context->seq)) {
352 dout("build_snap_context %llx %p: %p seq %lld (%u snaps)"
353 " (unchanged)\n",
354 realm->ino, realm, realm->cached_context,
355 realm->cached_context->seq,
356 (unsigned int)realm->cached_context->num_snaps);
357 return 0;
358 }
359
360
361 err = -ENOMEM;
362 if (num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64))
363 goto fail;
364 snapc = ceph_create_snap_context(num, GFP_NOFS);
365 if (!snapc)
366 goto fail;
367
368
369 num = 0;
370 snapc->seq = realm->seq;
371 if (parent) {
372 u32 i;
373
374
375
376 for (i = 0; i < parent->cached_context->num_snaps; i++)
377 if (parent->cached_context->snaps[i] >=
378 realm->parent_since)
379 snapc->snaps[num++] =
380 parent->cached_context->snaps[i];
381 if (parent->cached_context->seq > snapc->seq)
382 snapc->seq = parent->cached_context->seq;
383 }
384 memcpy(snapc->snaps + num, realm->snaps,
385 sizeof(u64)*realm->num_snaps);
386 num += realm->num_snaps;
387 memcpy(snapc->snaps + num, realm->prior_parent_snaps,
388 sizeof(u64)*realm->num_prior_parent_snaps);
389 num += realm->num_prior_parent_snaps;
390
391 sort(snapc->snaps, num, sizeof(u64), cmpu64_rev, NULL);
392 snapc->num_snaps = num;
393 dout("build_snap_context %llx %p: %p seq %lld (%u snaps)\n",
394 realm->ino, realm, snapc, snapc->seq,
395 (unsigned int) snapc->num_snaps);
396
397 ceph_put_snap_context(realm->cached_context);
398 realm->cached_context = snapc;
399
400 list_add_tail(&realm->dirty_item, dirty_realms);
401 return 0;
402
403fail:
404
405
406
407
408 if (realm->cached_context) {
409 ceph_put_snap_context(realm->cached_context);
410 realm->cached_context = NULL;
411 }
412 pr_err("build_snap_context %llx %p fail %d\n", realm->ino,
413 realm, err);
414 return err;
415}
416
417
418
419
420static void rebuild_snap_realms(struct ceph_snap_realm *realm,
421 struct list_head *dirty_realms)
422{
423 struct ceph_snap_realm *child;
424
425 dout("rebuild_snap_realms %llx %p\n", realm->ino, realm);
426 build_snap_context(realm, dirty_realms);
427
428 list_for_each_entry(child, &realm->children, child_item)
429 rebuild_snap_realms(child, dirty_realms);
430}
431
432
433
434
435
436
437static int dup_array(u64 **dst, __le64 *src, u32 num)
438{
439 u32 i;
440
441 kfree(*dst);
442 if (num) {
443 *dst = kcalloc(num, sizeof(u64), GFP_NOFS);
444 if (!*dst)
445 return -ENOMEM;
446 for (i = 0; i < num; i++)
447 (*dst)[i] = get_unaligned_le64(src + i);
448 } else {
449 *dst = NULL;
450 }
451 return 0;
452}
453
454static bool has_new_snaps(struct ceph_snap_context *o,
455 struct ceph_snap_context *n)
456{
457 if (n->num_snaps == 0)
458 return false;
459
460 return n->snaps[0] > o->seq;
461}
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477static void ceph_queue_cap_snap(struct ceph_inode_info *ci)
478{
479 struct inode *inode = &ci->vfs_inode;
480 struct ceph_cap_snap *capsnap;
481 struct ceph_snap_context *old_snapc, *new_snapc;
482 struct ceph_buffer *old_blob = NULL;
483 int used, dirty;
484
485 capsnap = kzalloc(sizeof(*capsnap), GFP_NOFS);
486 if (!capsnap) {
487 pr_err("ENOMEM allocating ceph_cap_snap on %p\n", inode);
488 return;
489 }
490 capsnap->cap_flush.is_capsnap = true;
491 INIT_LIST_HEAD(&capsnap->cap_flush.i_list);
492 INIT_LIST_HEAD(&capsnap->cap_flush.g_list);
493
494 spin_lock(&ci->i_ceph_lock);
495 used = __ceph_caps_used(ci);
496 dirty = __ceph_caps_dirty(ci);
497
498 old_snapc = ci->i_head_snapc;
499 new_snapc = ci->i_snap_realm->cached_context;
500
501
502
503
504
505
506 if (used & CEPH_CAP_FILE_WR)
507 dirty |= CEPH_CAP_FILE_WR;
508
509 if (__ceph_have_pending_cap_snap(ci)) {
510
511
512
513
514 dout("queue_cap_snap %p already pending\n", inode);
515 goto update_snapc;
516 }
517 if (ci->i_wrbuffer_ref_head == 0 &&
518 !(dirty & (CEPH_CAP_ANY_EXCL|CEPH_CAP_FILE_WR))) {
519 dout("queue_cap_snap %p nothing dirty|writing\n", inode);
520 goto update_snapc;
521 }
522
523 BUG_ON(!old_snapc);
524
525
526
527
528
529
530
531
532
533 if (has_new_snaps(old_snapc, new_snapc)) {
534 if (dirty & (CEPH_CAP_ANY_EXCL|CEPH_CAP_FILE_WR))
535 capsnap->need_flush = true;
536 } else {
537 if (!(used & CEPH_CAP_FILE_WR) &&
538 ci->i_wrbuffer_ref_head == 0) {
539 dout("queue_cap_snap %p "
540 "no new_snap|dirty_page|writing\n", inode);
541 goto update_snapc;
542 }
543 }
544
545 dout("queue_cap_snap %p cap_snap %p queuing under %p %s %s\n",
546 inode, capsnap, old_snapc, ceph_cap_string(dirty),
547 capsnap->need_flush ? "" : "no_flush");
548 ihold(inode);
549
550 refcount_set(&capsnap->nref, 1);
551 INIT_LIST_HEAD(&capsnap->ci_item);
552
553 capsnap->follows = old_snapc->seq;
554 capsnap->issued = __ceph_caps_issued(ci, NULL);
555 capsnap->dirty = dirty;
556
557 capsnap->mode = inode->i_mode;
558 capsnap->uid = inode->i_uid;
559 capsnap->gid = inode->i_gid;
560
561 if (dirty & CEPH_CAP_XATTR_EXCL) {
562 old_blob = __ceph_build_xattrs_blob(ci);
563 capsnap->xattr_blob =
564 ceph_buffer_get(ci->i_xattrs.blob);
565 capsnap->xattr_version = ci->i_xattrs.version;
566 } else {
567 capsnap->xattr_blob = NULL;
568 capsnap->xattr_version = 0;
569 }
570
571 capsnap->inline_data = ci->i_inline_version != CEPH_INLINE_NONE;
572
573
574
575
576 capsnap->dirty_pages = ci->i_wrbuffer_ref_head;
577 ci->i_wrbuffer_ref_head = 0;
578 capsnap->context = old_snapc;
579 list_add_tail(&capsnap->ci_item, &ci->i_cap_snaps);
580
581 if (used & CEPH_CAP_FILE_WR) {
582 dout("queue_cap_snap %p cap_snap %p snapc %p"
583 " seq %llu used WR, now pending\n", inode,
584 capsnap, old_snapc, old_snapc->seq);
585 capsnap->writing = 1;
586 } else {
587
588 __ceph_finish_cap_snap(ci, capsnap);
589 }
590 capsnap = NULL;
591 old_snapc = NULL;
592
593update_snapc:
594 if (ci->i_wrbuffer_ref_head == 0 &&
595 ci->i_wr_ref == 0 &&
596 ci->i_dirty_caps == 0 &&
597 ci->i_flushing_caps == 0) {
598 ci->i_head_snapc = NULL;
599 } else {
600 ci->i_head_snapc = ceph_get_snap_context(new_snapc);
601 dout(" new snapc is %p\n", new_snapc);
602 }
603 spin_unlock(&ci->i_ceph_lock);
604
605 ceph_buffer_put(old_blob);
606 kfree(capsnap);
607 ceph_put_snap_context(old_snapc);
608}
609
610
611
612
613
614
615
616
617
618int __ceph_finish_cap_snap(struct ceph_inode_info *ci,
619 struct ceph_cap_snap *capsnap)
620{
621 struct inode *inode = &ci->vfs_inode;
622 struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb);
623
624 BUG_ON(capsnap->writing);
625 capsnap->size = i_size_read(inode);
626 capsnap->mtime = inode->i_mtime;
627 capsnap->atime = inode->i_atime;
628 capsnap->ctime = inode->i_ctime;
629 capsnap->btime = ci->i_btime;
630 capsnap->change_attr = inode_peek_iversion_raw(inode);
631 capsnap->time_warp_seq = ci->i_time_warp_seq;
632 capsnap->truncate_size = ci->i_truncate_size;
633 capsnap->truncate_seq = ci->i_truncate_seq;
634 if (capsnap->dirty_pages) {
635 dout("finish_cap_snap %p cap_snap %p snapc %p %llu %s s=%llu "
636 "still has %d dirty pages\n", inode, capsnap,
637 capsnap->context, capsnap->context->seq,
638 ceph_cap_string(capsnap->dirty), capsnap->size,
639 capsnap->dirty_pages);
640 return 0;
641 }
642
643
644 if (ci->i_wb_ref) {
645 dout("finish_cap_snap %p cap_snap %p snapc %p %llu %s s=%llu "
646 "used WRBUFFER, delaying\n", inode, capsnap,
647 capsnap->context, capsnap->context->seq,
648 ceph_cap_string(capsnap->dirty), capsnap->size);
649 capsnap->writing = 1;
650 return 0;
651 }
652
653 ci->i_ceph_flags |= CEPH_I_FLUSH_SNAPS;
654 dout("finish_cap_snap %p cap_snap %p snapc %p %llu %s s=%llu\n",
655 inode, capsnap, capsnap->context,
656 capsnap->context->seq, ceph_cap_string(capsnap->dirty),
657 capsnap->size);
658
659 spin_lock(&mdsc->snap_flush_lock);
660 if (list_empty(&ci->i_snap_flush_item))
661 list_add_tail(&ci->i_snap_flush_item, &mdsc->snap_flush_list);
662 spin_unlock(&mdsc->snap_flush_lock);
663 return 1;
664}
665
666
667
668
669
670static void queue_realm_cap_snaps(struct ceph_snap_realm *realm)
671{
672 struct ceph_inode_info *ci;
673 struct inode *lastinode = NULL;
674
675 dout("queue_realm_cap_snaps %p %llx inodes\n", realm, realm->ino);
676
677 spin_lock(&realm->inodes_with_caps_lock);
678 list_for_each_entry(ci, &realm->inodes_with_caps, i_snap_realm_item) {
679 struct inode *inode = igrab(&ci->vfs_inode);
680 if (!inode)
681 continue;
682 spin_unlock(&realm->inodes_with_caps_lock);
683 iput(lastinode);
684 lastinode = inode;
685 ceph_queue_cap_snap(ci);
686 spin_lock(&realm->inodes_with_caps_lock);
687 }
688 spin_unlock(&realm->inodes_with_caps_lock);
689 iput(lastinode);
690
691 dout("queue_realm_cap_snaps %p %llx done\n", realm, realm->ino);
692}
693
694
695
696
697
698
699
700
701int ceph_update_snap_trace(struct ceph_mds_client *mdsc,
702 void *p, void *e, bool deletion,
703 struct ceph_snap_realm **realm_ret)
704{
705 struct ceph_mds_snap_realm *ri;
706 __le64 *snaps;
707 __le64 *prior_parent_snaps;
708 struct ceph_snap_realm *realm = NULL;
709 struct ceph_snap_realm *first_realm = NULL;
710 int invalidate = 0;
711 int err = -ENOMEM;
712 LIST_HEAD(dirty_realms);
713
714 lockdep_assert_held_write(&mdsc->snap_rwsem);
715
716 dout("update_snap_trace deletion=%d\n", deletion);
717more:
718 ceph_decode_need(&p, e, sizeof(*ri), bad);
719 ri = p;
720 p += sizeof(*ri);
721 ceph_decode_need(&p, e, sizeof(u64)*(le32_to_cpu(ri->num_snaps) +
722 le32_to_cpu(ri->num_prior_parent_snaps)), bad);
723 snaps = p;
724 p += sizeof(u64) * le32_to_cpu(ri->num_snaps);
725 prior_parent_snaps = p;
726 p += sizeof(u64) * le32_to_cpu(ri->num_prior_parent_snaps);
727
728 realm = ceph_lookup_snap_realm(mdsc, le64_to_cpu(ri->ino));
729 if (!realm) {
730 realm = ceph_create_snap_realm(mdsc, le64_to_cpu(ri->ino));
731 if (IS_ERR(realm)) {
732 err = PTR_ERR(realm);
733 goto fail;
734 }
735 }
736
737
738 err = adjust_snap_realm_parent(mdsc, realm, le64_to_cpu(ri->parent));
739 if (err < 0)
740 goto fail;
741 invalidate += err;
742
743 if (le64_to_cpu(ri->seq) > realm->seq) {
744 dout("update_snap_trace updating %llx %p %lld -> %lld\n",
745 realm->ino, realm, realm->seq, le64_to_cpu(ri->seq));
746
747 realm->seq = le64_to_cpu(ri->seq);
748 realm->created = le64_to_cpu(ri->created);
749 realm->parent_since = le64_to_cpu(ri->parent_since);
750
751 realm->num_snaps = le32_to_cpu(ri->num_snaps);
752 err = dup_array(&realm->snaps, snaps, realm->num_snaps);
753 if (err < 0)
754 goto fail;
755
756 realm->num_prior_parent_snaps =
757 le32_to_cpu(ri->num_prior_parent_snaps);
758 err = dup_array(&realm->prior_parent_snaps, prior_parent_snaps,
759 realm->num_prior_parent_snaps);
760 if (err < 0)
761 goto fail;
762
763 if (realm->seq > mdsc->last_snap_seq)
764 mdsc->last_snap_seq = realm->seq;
765
766 invalidate = 1;
767 } else if (!realm->cached_context) {
768 dout("update_snap_trace %llx %p seq %lld new\n",
769 realm->ino, realm, realm->seq);
770 invalidate = 1;
771 } else {
772 dout("update_snap_trace %llx %p seq %lld unchanged\n",
773 realm->ino, realm, realm->seq);
774 }
775
776 dout("done with %llx %p, invalidated=%d, %p %p\n", realm->ino,
777 realm, invalidate, p, e);
778
779
780 if (invalidate && p >= e)
781 rebuild_snap_realms(realm, &dirty_realms);
782
783 if (!first_realm)
784 first_realm = realm;
785 else
786 ceph_put_snap_realm(mdsc, realm);
787
788 if (p < e)
789 goto more;
790
791
792
793
794
795 while (!list_empty(&dirty_realms)) {
796 realm = list_first_entry(&dirty_realms, struct ceph_snap_realm,
797 dirty_item);
798 list_del_init(&realm->dirty_item);
799 queue_realm_cap_snaps(realm);
800 }
801
802 if (realm_ret)
803 *realm_ret = first_realm;
804 else
805 ceph_put_snap_realm(mdsc, first_realm);
806
807 __cleanup_empty_realms(mdsc);
808 return 0;
809
810bad:
811 err = -EIO;
812fail:
813 if (realm && !IS_ERR(realm))
814 ceph_put_snap_realm(mdsc, realm);
815 if (first_realm)
816 ceph_put_snap_realm(mdsc, first_realm);
817 pr_err("update_snap_trace error %d\n", err);
818 return err;
819}
820
821
822
823
824
825
826
827
828static void flush_snaps(struct ceph_mds_client *mdsc)
829{
830 struct ceph_inode_info *ci;
831 struct inode *inode;
832 struct ceph_mds_session *session = NULL;
833
834 dout("flush_snaps\n");
835 spin_lock(&mdsc->snap_flush_lock);
836 while (!list_empty(&mdsc->snap_flush_list)) {
837 ci = list_first_entry(&mdsc->snap_flush_list,
838 struct ceph_inode_info, i_snap_flush_item);
839 inode = &ci->vfs_inode;
840 ihold(inode);
841 spin_unlock(&mdsc->snap_flush_lock);
842 ceph_flush_snaps(ci, &session);
843 iput(inode);
844 spin_lock(&mdsc->snap_flush_lock);
845 }
846 spin_unlock(&mdsc->snap_flush_lock);
847
848 ceph_put_mds_session(session);
849 dout("flush_snaps done\n");
850}
851
852
853
854
855
856
857
858
859
860
861
862
863
864void ceph_handle_snap(struct ceph_mds_client *mdsc,
865 struct ceph_mds_session *session,
866 struct ceph_msg *msg)
867{
868 struct super_block *sb = mdsc->fsc->sb;
869 int mds = session->s_mds;
870 u64 split;
871 int op;
872 int trace_len;
873 struct ceph_snap_realm *realm = NULL;
874 void *p = msg->front.iov_base;
875 void *e = p + msg->front.iov_len;
876 struct ceph_mds_snap_head *h;
877 int num_split_inos, num_split_realms;
878 __le64 *split_inos = NULL, *split_realms = NULL;
879 int i;
880 int locked_rwsem = 0;
881
882
883 if (msg->front.iov_len < sizeof(*h))
884 goto bad;
885 h = p;
886 op = le32_to_cpu(h->op);
887 split = le64_to_cpu(h->split);
888
889 num_split_inos = le32_to_cpu(h->num_split_inos);
890 num_split_realms = le32_to_cpu(h->num_split_realms);
891 trace_len = le32_to_cpu(h->trace_len);
892 p += sizeof(*h);
893
894 dout("handle_snap from mds%d op %s split %llx tracelen %d\n", mds,
895 ceph_snap_op_name(op), split, trace_len);
896
897 mutex_lock(&session->s_mutex);
898 inc_session_sequence(session);
899 mutex_unlock(&session->s_mutex);
900
901 down_write(&mdsc->snap_rwsem);
902 locked_rwsem = 1;
903
904 if (op == CEPH_SNAP_OP_SPLIT) {
905 struct ceph_mds_snap_realm *ri;
906
907
908
909
910
911
912
913 split_inos = p;
914 p += sizeof(u64) * num_split_inos;
915 split_realms = p;
916 p += sizeof(u64) * num_split_realms;
917 ceph_decode_need(&p, e, sizeof(*ri), bad);
918
919
920
921 ri = p;
922
923 realm = ceph_lookup_snap_realm(mdsc, split);
924 if (!realm) {
925 realm = ceph_create_snap_realm(mdsc, split);
926 if (IS_ERR(realm))
927 goto out;
928 }
929
930 dout("splitting snap_realm %llx %p\n", realm->ino, realm);
931 for (i = 0; i < num_split_inos; i++) {
932 struct ceph_vino vino = {
933 .ino = le64_to_cpu(split_inos[i]),
934 .snap = CEPH_NOSNAP,
935 };
936 struct inode *inode = ceph_find_inode(sb, vino);
937 struct ceph_inode_info *ci;
938 struct ceph_snap_realm *oldrealm;
939
940 if (!inode)
941 continue;
942 ci = ceph_inode(inode);
943
944 spin_lock(&ci->i_ceph_lock);
945 if (!ci->i_snap_realm)
946 goto skip_inode;
947
948
949
950
951
952
953
954 if (ci->i_snap_realm->created >
955 le64_to_cpu(ri->created)) {
956 dout(" leaving %p in newer realm %llx %p\n",
957 inode, ci->i_snap_realm->ino,
958 ci->i_snap_realm);
959 goto skip_inode;
960 }
961 dout(" will move %p to split realm %llx %p\n",
962 inode, realm->ino, realm);
963
964
965
966 oldrealm = ci->i_snap_realm;
967 spin_lock(&oldrealm->inodes_with_caps_lock);
968 list_del_init(&ci->i_snap_realm_item);
969 spin_unlock(&oldrealm->inodes_with_caps_lock);
970
971 spin_lock(&realm->inodes_with_caps_lock);
972 list_add(&ci->i_snap_realm_item,
973 &realm->inodes_with_caps);
974 ci->i_snap_realm = realm;
975 if (realm->ino == ci->i_vino.ino)
976 realm->inode = inode;
977 spin_unlock(&realm->inodes_with_caps_lock);
978
979 spin_unlock(&ci->i_ceph_lock);
980
981 ceph_get_snap_realm(mdsc, realm);
982 ceph_put_snap_realm(mdsc, oldrealm);
983
984 iput(inode);
985 continue;
986
987skip_inode:
988 spin_unlock(&ci->i_ceph_lock);
989 iput(inode);
990 }
991
992
993 for (i = 0; i < num_split_realms; i++) {
994 struct ceph_snap_realm *child =
995 __lookup_snap_realm(mdsc,
996 le64_to_cpu(split_realms[i]));
997 if (!child)
998 continue;
999 adjust_snap_realm_parent(mdsc, child, realm->ino);
1000 }
1001 }
1002
1003
1004
1005
1006
1007 ceph_update_snap_trace(mdsc, p, e,
1008 op == CEPH_SNAP_OP_DESTROY, NULL);
1009
1010 if (op == CEPH_SNAP_OP_SPLIT)
1011
1012 ceph_put_snap_realm(mdsc, realm);
1013
1014 __cleanup_empty_realms(mdsc);
1015
1016 up_write(&mdsc->snap_rwsem);
1017
1018 flush_snaps(mdsc);
1019 return;
1020
1021bad:
1022 pr_err("corrupt snap message from mds%d\n", mds);
1023 ceph_msg_dump(msg);
1024out:
1025 if (locked_rwsem)
1026 up_write(&mdsc->snap_rwsem);
1027 return;
1028}
1029
1030struct ceph_snapid_map* ceph_get_snapid_map(struct ceph_mds_client *mdsc,
1031 u64 snap)
1032{
1033 struct ceph_snapid_map *sm, *exist;
1034 struct rb_node **p, *parent;
1035 int ret;
1036
1037 exist = NULL;
1038 spin_lock(&mdsc->snapid_map_lock);
1039 p = &mdsc->snapid_map_tree.rb_node;
1040 while (*p) {
1041 exist = rb_entry(*p, struct ceph_snapid_map, node);
1042 if (snap > exist->snap) {
1043 p = &(*p)->rb_left;
1044 } else if (snap < exist->snap) {
1045 p = &(*p)->rb_right;
1046 } else {
1047 if (atomic_inc_return(&exist->ref) == 1)
1048 list_del_init(&exist->lru);
1049 break;
1050 }
1051 exist = NULL;
1052 }
1053 spin_unlock(&mdsc->snapid_map_lock);
1054 if (exist) {
1055 dout("found snapid map %llx -> %x\n", exist->snap, exist->dev);
1056 return exist;
1057 }
1058
1059 sm = kmalloc(sizeof(*sm), GFP_NOFS);
1060 if (!sm)
1061 return NULL;
1062
1063 ret = get_anon_bdev(&sm->dev);
1064 if (ret < 0) {
1065 kfree(sm);
1066 return NULL;
1067 }
1068
1069 INIT_LIST_HEAD(&sm->lru);
1070 atomic_set(&sm->ref, 1);
1071 sm->snap = snap;
1072
1073 exist = NULL;
1074 parent = NULL;
1075 p = &mdsc->snapid_map_tree.rb_node;
1076 spin_lock(&mdsc->snapid_map_lock);
1077 while (*p) {
1078 parent = *p;
1079 exist = rb_entry(*p, struct ceph_snapid_map, node);
1080 if (snap > exist->snap)
1081 p = &(*p)->rb_left;
1082 else if (snap < exist->snap)
1083 p = &(*p)->rb_right;
1084 else
1085 break;
1086 exist = NULL;
1087 }
1088 if (exist) {
1089 if (atomic_inc_return(&exist->ref) == 1)
1090 list_del_init(&exist->lru);
1091 } else {
1092 rb_link_node(&sm->node, parent, p);
1093 rb_insert_color(&sm->node, &mdsc->snapid_map_tree);
1094 }
1095 spin_unlock(&mdsc->snapid_map_lock);
1096 if (exist) {
1097 free_anon_bdev(sm->dev);
1098 kfree(sm);
1099 dout("found snapid map %llx -> %x\n", exist->snap, exist->dev);
1100 return exist;
1101 }
1102
1103 dout("create snapid map %llx -> %x\n", sm->snap, sm->dev);
1104 return sm;
1105}
1106
1107void ceph_put_snapid_map(struct ceph_mds_client* mdsc,
1108 struct ceph_snapid_map *sm)
1109{
1110 if (!sm)
1111 return;
1112 if (atomic_dec_and_lock(&sm->ref, &mdsc->snapid_map_lock)) {
1113 if (!RB_EMPTY_NODE(&sm->node)) {
1114 sm->last_used = jiffies;
1115 list_add_tail(&sm->lru, &mdsc->snapid_map_lru);
1116 spin_unlock(&mdsc->snapid_map_lock);
1117 } else {
1118
1119
1120 spin_unlock(&mdsc->snapid_map_lock);
1121 kfree(sm);
1122 }
1123 }
1124}
1125
1126void ceph_trim_snapid_map(struct ceph_mds_client *mdsc)
1127{
1128 struct ceph_snapid_map *sm;
1129 unsigned long now;
1130 LIST_HEAD(to_free);
1131
1132 spin_lock(&mdsc->snapid_map_lock);
1133 now = jiffies;
1134
1135 while (!list_empty(&mdsc->snapid_map_lru)) {
1136 sm = list_first_entry(&mdsc->snapid_map_lru,
1137 struct ceph_snapid_map, lru);
1138 if (time_after(sm->last_used + CEPH_SNAPID_MAP_TIMEOUT, now))
1139 break;
1140
1141 rb_erase(&sm->node, &mdsc->snapid_map_tree);
1142 list_move(&sm->lru, &to_free);
1143 }
1144 spin_unlock(&mdsc->snapid_map_lock);
1145
1146 while (!list_empty(&to_free)) {
1147 sm = list_first_entry(&to_free, struct ceph_snapid_map, lru);
1148 list_del(&sm->lru);
1149 dout("trim snapid map %llx -> %x\n", sm->snap, sm->dev);
1150 free_anon_bdev(sm->dev);
1151 kfree(sm);
1152 }
1153}
1154
1155void ceph_cleanup_snapid_map(struct ceph_mds_client *mdsc)
1156{
1157 struct ceph_snapid_map *sm;
1158 struct rb_node *p;
1159 LIST_HEAD(to_free);
1160
1161 spin_lock(&mdsc->snapid_map_lock);
1162 while ((p = rb_first(&mdsc->snapid_map_tree))) {
1163 sm = rb_entry(p, struct ceph_snapid_map, node);
1164 rb_erase(p, &mdsc->snapid_map_tree);
1165 RB_CLEAR_NODE(p);
1166 list_move(&sm->lru, &to_free);
1167 }
1168 spin_unlock(&mdsc->snapid_map_lock);
1169
1170 while (!list_empty(&to_free)) {
1171 sm = list_first_entry(&to_free, struct ceph_snapid_map, lru);
1172 list_del(&sm->lru);
1173 free_anon_bdev(sm->dev);
1174 if (WARN_ON_ONCE(atomic_read(&sm->ref))) {
1175 pr_err("snapid map %llx -> %x still in use\n",
1176 sm->snap, sm->dev);
1177 }
1178 kfree(sm);
1179 }
1180}
1181