2 * Copyright (c) 2011-2019 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@dragonflybsd.org>
6 * and Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
18 * 3. Neither the name of The DragonFly Project nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific, prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * This subsystem implements most of the core support functions for
37 * the hammer2_chain structure.
39 * Chains are the in-memory version on media objects (volume header, inodes,
40 * indirect blocks, data blocks, etc). Chains represent a portion of the
43 * Chains are no-longer delete-duplicated. Instead, the original in-memory
44 * chain will be moved along with its block reference (e.g. for things like
45 * renames, hardlink operations, modifications, etc), and will be indexed
46 * on a secondary list for flush handling instead of propagating a flag
49 * Concurrent front-end operations can still run against backend flushes
50 * as long as they do not cross the current flush boundary. An operation
51 * running above the current flush (in areas not yet flushed) can become
52 * part of the current flush while ano peration running below the current
53 * flush can become part of the next flush.
55 #include <sys/cdefs.h>
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/types.h>
60 #include <sys/kern_syscall.h>
63 #include <crypto/sha2/sha2.h>
67 static hammer2_chain_t *hammer2_chain_create_indirect(
68 hammer2_chain_t *parent,
69 hammer2_key_t key, int keybits,
70 hammer2_tid_t mtid, int for_type, int *errorp);
71 static void hammer2_chain_rename_obref(hammer2_chain_t **parentp,
72 hammer2_chain_t *chain, hammer2_tid_t mtid,
73 int flags, hammer2_blockref_t *obref);
74 static int hammer2_chain_delete_obref(hammer2_chain_t *parent,
75 hammer2_chain_t *chain,
76 hammer2_tid_t mtid, int flags,
77 hammer2_blockref_t *obref);
78 static hammer2_io_t *hammer2_chain_drop_data(hammer2_chain_t *chain);
79 static hammer2_chain_t *hammer2_combined_find(
80 hammer2_chain_t *parent,
81 hammer2_blockref_t *base, int count,
82 hammer2_key_t *key_nextp,
83 hammer2_key_t key_beg, hammer2_key_t key_end,
84 hammer2_blockref_t **bresp);
87 * There are many degenerate situations where an extreme rate of console
88 * output can occur from warnings and errors. Make sure this output does
89 * not impede operations.
91 static struct krate krate_h2chk = { .freq = 5 };
92 static struct krate krate_h2me = { .freq = 1 };
93 static struct krate krate_h2em = { .freq = 1 };
96 * Basic RBTree for chains (core.rbtree).
98 RB_GENERATE(hammer2_chain_tree, hammer2_chain, rbnode, hammer2_chain_cmp);
101 hammer2_chain_cmp(hammer2_chain_t *chain1, hammer2_chain_t *chain2)
103 hammer2_key_t c1_beg;
104 hammer2_key_t c1_end;
105 hammer2_key_t c2_beg;
106 hammer2_key_t c2_end;
109 * Compare chains. Overlaps are not supposed to happen and catch
110 * any software issues early we count overlaps as a match.
112 c1_beg = chain1->bref.key;
113 c1_end = c1_beg + ((hammer2_key_t)1 << chain1->bref.keybits) - 1;
114 c2_beg = chain2->bref.key;
115 c2_end = c2_beg + ((hammer2_key_t)1 << chain2->bref.keybits) - 1;
117 if (c1_end < c2_beg) /* fully to the left */
119 if (c1_beg > c2_end) /* fully to the right */
121 return(0); /* overlap (must not cross edge boundary) */
125 * Assert that a chain has no media data associated with it.
128 hammer2_chain_assert_no_data(hammer2_chain_t *chain)
130 KKASSERT(chain->dio == NULL);
131 if (chain->bref.type != HAMMER2_BREF_TYPE_VOLUME &&
132 chain->bref.type != HAMMER2_BREF_TYPE_FREEMAP &&
134 panic("hammer2_chain_assert_no_data: chain %p still has data",
140 * Make a chain visible to the flusher. The flusher operates using a top-down
141 * recursion based on the ONFLUSH flag. It locates MODIFIED and UPDATE chains,
142 * flushes them, and updates blocks back to the volume root.
144 * This routine sets the ONFLUSH flag upward from the triggering chain until
145 * it hits an inode root or the volume root. Inode chains serve as inflection
146 * points, requiring the flusher to bridge across trees. Inodes include
147 * regular inodes, PFS roots (pmp->iroot), and the media super root
151 hammer2_chain_setflush(hammer2_chain_t *chain)
153 hammer2_chain_t *parent;
155 if ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) {
156 hammer2_spin_sh(&chain->core.spin);
157 while ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) {
158 atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONFLUSH);
159 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE)
161 if ((parent = chain->parent) == NULL)
163 hammer2_spin_sh(&parent->core.spin);
164 hammer2_spin_unsh(&chain->core.spin);
167 hammer2_spin_unsh(&chain->core.spin);
172 * Allocate a new disconnected chain element representing the specified
173 * bref. chain->refs is set to 1 and the passed bref is copied to
174 * chain->bref. chain->bytes is derived from the bref.
176 * chain->pmp inherits pmp unless the chain is an inode (other than the
179 * NOTE: Returns a referenced but unlocked (because there is no core) chain.
182 hammer2_chain_alloc(hammer2_dev_t *hmp, hammer2_pfs_t *pmp,
183 hammer2_blockref_t *bref)
185 hammer2_chain_t *chain;
189 * Special case - radix of 0 indicates a chain that does not
190 * need a data reference (context is completely embedded in the
193 if ((int)(bref->data_off & HAMMER2_OFF_MASK_RADIX))
194 bytes = 1U << (int)(bref->data_off & HAMMER2_OFF_MASK_RADIX);
198 atomic_add_long(&hammer2_chain_allocs, 1);
201 * Construct the appropriate system structure.
204 case HAMMER2_BREF_TYPE_DIRENT:
205 case HAMMER2_BREF_TYPE_INODE:
206 case HAMMER2_BREF_TYPE_INDIRECT:
207 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
208 case HAMMER2_BREF_TYPE_DATA:
209 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
210 chain = kmalloc(sizeof(*chain), hmp->mchain, M_WAITOK | M_ZERO);
212 case HAMMER2_BREF_TYPE_VOLUME:
213 case HAMMER2_BREF_TYPE_FREEMAP:
215 * Only hammer2_chain_bulksnap() calls this function with these
218 chain = kmalloc(sizeof(*chain), hmp->mchain, M_WAITOK | M_ZERO);
222 panic("hammer2_chain_alloc: unrecognized blockref type: %d",
227 * Initialize the new chain structure. pmp must be set to NULL for
228 * chains belonging to the super-root topology of a device mount.
230 if (pmp == hmp->spmp)
237 chain->bytes = bytes;
239 chain->flags = HAMMER2_CHAIN_ALLOCATED;
240 lockinit(&chain->diolk, "chdio", 0, 0);
243 * Set the PFS boundary flag if this chain represents a PFS root.
245 if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT)
246 atomic_set_int(&chain->flags, HAMMER2_CHAIN_PFSBOUNDARY);
247 hammer2_chain_core_init(chain);
253 * Initialize a chain's core structure. This structure used to be allocated
254 * but is now embedded.
256 * The core is not locked. No additional refs on the chain are made.
257 * (trans) must not be NULL if (core) is not NULL.
260 hammer2_chain_core_init(hammer2_chain_t *chain)
263 * Fresh core under nchain (no multi-homing of ochain's
266 RB_INIT(&chain->core.rbtree); /* live chains */
267 hammer2_mtx_init(&chain->lock, "h2chain");
271 * Add a reference to a chain element, preventing its destruction.
273 * (can be called with spinlock held)
276 hammer2_chain_ref(hammer2_chain_t *chain)
278 if (atomic_fetchadd_int(&chain->refs, 1) == 0) {
280 * Just flag that the chain was used and should be recycled
281 * on the LRU if it encounters it later.
283 if (chain->flags & HAMMER2_CHAIN_ONLRU)
284 atomic_set_int(&chain->flags, HAMMER2_CHAIN_LRUHINT);
288 * REMOVED - reduces contention, lru_list is more heuristical
291 * 0->non-zero transition must ensure that chain is removed
294 * NOTE: Already holding lru_spin here so we cannot call
295 * hammer2_chain_ref() to get it off lru_list, do
298 if (chain->flags & HAMMER2_CHAIN_ONLRU) {
299 hammer2_pfs_t *pmp = chain->pmp;
300 hammer2_spin_ex(&pmp->lru_spin);
301 if (chain->flags & HAMMER2_CHAIN_ONLRU) {
302 atomic_add_int(&pmp->lru_count, -1);
303 atomic_clear_int(&chain->flags,
304 HAMMER2_CHAIN_ONLRU);
305 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
307 hammer2_spin_unex(&pmp->lru_spin);
314 * Ref a locked chain and force the data to be held across an unlock.
315 * Chain must be currently locked. The user of the chain who desires
316 * to release the hold must call hammer2_chain_lock_unhold() to relock
317 * and unhold the chain, then unlock normally, or may simply call
318 * hammer2_chain_drop_unhold() (which is safer against deadlocks).
321 hammer2_chain_ref_hold(hammer2_chain_t *chain)
323 atomic_add_int(&chain->lockcnt, 1);
324 hammer2_chain_ref(chain);
328 * Insert the chain in the core rbtree.
330 * Normal insertions are placed in the live rbtree. Insertion of a deleted
331 * chain is a special case used by the flush code that is placed on the
332 * unstaged deleted list to avoid confusing the live view.
334 #define HAMMER2_CHAIN_INSERT_SPIN 0x0001
335 #define HAMMER2_CHAIN_INSERT_LIVE 0x0002
336 #define HAMMER2_CHAIN_INSERT_RACE 0x0004
340 hammer2_chain_insert(hammer2_chain_t *parent, hammer2_chain_t *chain,
341 int flags, int generation)
343 hammer2_chain_t *xchain;
346 if (flags & HAMMER2_CHAIN_INSERT_SPIN)
347 hammer2_spin_ex(&parent->core.spin);
350 * Interlocked by spinlock, check for race
352 if ((flags & HAMMER2_CHAIN_INSERT_RACE) &&
353 parent->core.generation != generation) {
354 error = HAMMER2_ERROR_EAGAIN;
361 xchain = RB_INSERT(hammer2_chain_tree, &parent->core.rbtree, chain);
362 KASSERT(xchain == NULL,
363 ("hammer2_chain_insert: collision %p %p (key=%016jx)",
364 chain, xchain, chain->bref.key));
365 atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE);
366 chain->parent = parent;
367 ++parent->core.chain_count;
368 ++parent->core.generation; /* XXX incs for _get() too, XXX */
371 * We have to keep track of the effective live-view blockref count
372 * so the create code knows when to push an indirect block.
374 if (flags & HAMMER2_CHAIN_INSERT_LIVE)
375 atomic_add_int(&parent->core.live_count, 1);
377 if (flags & HAMMER2_CHAIN_INSERT_SPIN)
378 hammer2_spin_unex(&parent->core.spin);
383 * Drop the caller's reference to the chain. When the ref count drops to
384 * zero this function will try to disassociate the chain from its parent and
385 * deallocate it, then recursely drop the parent using the implied ref
386 * from the chain's chain->parent.
388 * Nobody should own chain's mutex on the 1->0 transition, unless this drop
389 * races an acquisition by another cpu. Therefore we can loop if we are
390 * unable to acquire the mutex, and refs is unlikely to be 1 unless we again
391 * race against another drop.
393 static hammer2_chain_t *hammer2_chain_lastdrop(hammer2_chain_t *chain,
395 static void hammer2_chain_lru_flush(hammer2_pfs_t *pmp);
398 hammer2_chain_drop(hammer2_chain_t *chain)
402 if (hammer2_debug & 0x200000)
405 KKASSERT(chain->refs > 0);
413 if (hammer2_mtx_ex_try(&chain->lock) == 0)
414 chain = hammer2_chain_lastdrop(chain, 0);
415 /* retry the same chain, or chain from lastdrop */
417 if (atomic_cmpset_int(&chain->refs, refs, refs - 1))
419 /* retry the same chain */
426 * Unhold a held and probably not-locked chain, ensure that the data is
427 * dropped on the 1->0 transition of lockcnt by obtaining an exclusive
428 * lock and then simply unlocking the chain.
431 hammer2_chain_unhold(hammer2_chain_t *chain)
437 lockcnt = chain->lockcnt;
440 if (atomic_cmpset_int(&chain->lockcnt,
441 lockcnt, lockcnt - 1)) {
444 } else if (hammer2_mtx_ex_try(&chain->lock) == 0) {
445 hammer2_chain_unlock(chain);
449 * This situation can easily occur on SMP due to
450 * the gap inbetween the 1->0 transition and the
451 * final unlock. We cannot safely block on the
452 * mutex because lockcnt might go above 1.
454 * XXX Sleep for one tick if it takes too long.
457 if (iter > 1000 + hz) {
458 kprintf("hammer2: h2race1 %p\n", chain);
461 tsleep(&iter, 0, "h2race1", 1);
469 hammer2_chain_drop_unhold(hammer2_chain_t *chain)
471 hammer2_chain_unhold(chain);
472 hammer2_chain_drop(chain);
476 hammer2_chain_rehold(hammer2_chain_t *chain)
478 hammer2_chain_lock(chain, HAMMER2_RESOLVE_SHARED);
479 atomic_add_int(&chain->lockcnt, 1);
480 hammer2_chain_unlock(chain);
484 * Handles the (potential) last drop of chain->refs from 1->0. Called with
485 * the mutex exclusively locked, refs == 1, and lockcnt 0. SMP races are
486 * possible against refs and lockcnt. We must dispose of the mutex on chain.
488 * This function returns an unlocked chain for recursive drop or NULL. It
489 * can return the same chain if it determines it has raced another ref.
493 * When two chains need to be recursively dropped we use the chain we
494 * would otherwise free to placehold the additional chain. It's a bit
495 * convoluted but we can't just recurse without potentially blowing out
498 * The chain cannot be freed if it has any children.
499 * The chain cannot be freed if flagged MODIFIED unless we can dispose of it.
500 * The chain cannot be freed if flagged UPDATE unless we can dispose of it.
501 * Any dedup registration can remain intact.
503 * The core spinlock is allowed to nest child-to-parent (not parent-to-child).
507 hammer2_chain_lastdrop(hammer2_chain_t *chain, int depth)
511 hammer2_chain_t *parent;
512 hammer2_chain_t *rdrop;
515 * We need chain's spinlock to interlock the sub-tree test.
516 * We already have chain's mutex, protecting chain->parent.
518 * Remember that chain->refs can be in flux.
520 hammer2_spin_ex(&chain->core.spin);
522 if (chain->parent != NULL) {
524 * If the chain has a parent the UPDATE bit prevents scrapping
525 * as the chain is needed to properly flush the parent. Try
526 * to complete the 1->0 transition and return NULL. Retry
527 * (return chain) if we are unable to complete the 1->0
528 * transition, else return NULL (nothing more to do).
530 * If the chain has a parent the MODIFIED bit prevents
533 * Chains with UPDATE/MODIFIED are *not* put on the LRU list!
535 if (chain->flags & (HAMMER2_CHAIN_UPDATE |
536 HAMMER2_CHAIN_MODIFIED)) {
537 if (atomic_cmpset_int(&chain->refs, 1, 0)) {
538 hammer2_spin_unex(&chain->core.spin);
539 hammer2_chain_assert_no_data(chain);
540 hammer2_mtx_unlock(&chain->lock);
543 hammer2_spin_unex(&chain->core.spin);
544 hammer2_mtx_unlock(&chain->lock);
548 /* spinlock still held */
549 } else if (chain->bref.type == HAMMER2_BREF_TYPE_VOLUME ||
550 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP) {
552 * Retain the static vchain and fchain. Clear bits that
553 * are not relevant. Do not clear the MODIFIED bit,
554 * and certainly do not put it on the delayed-flush queue.
556 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
559 * The chain has no parent and can be flagged for destruction.
560 * Since it has no parent, UPDATE can also be cleared.
562 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY);
563 if (chain->flags & HAMMER2_CHAIN_UPDATE)
564 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
567 * If the chain has children we must propagate the DESTROY
568 * flag downward and rip the disconnected topology apart.
569 * This is accomplished by calling hammer2_flush() on the
572 * Any dedup is already handled by the underlying DIO, so
573 * we do not have to specifically flush it here.
575 if (chain->core.chain_count) {
576 hammer2_spin_unex(&chain->core.spin);
577 hammer2_flush(chain, HAMMER2_FLUSH_TOP |
579 hammer2_mtx_unlock(&chain->lock);
581 return(chain); /* retry drop */
585 * Otherwise we can scrap the MODIFIED bit if it is set,
586 * and continue along the freeing path.
588 * Be sure to clean-out any dedup bits. Without a parent
589 * this chain will no longer be visible to the flush code.
590 * Easy check data_off to avoid the volume root.
592 if (chain->flags & HAMMER2_CHAIN_MODIFIED) {
593 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED);
594 atomic_add_long(&hammer2_count_modified_chains, -1);
596 hammer2_pfs_memory_wakeup(chain->pmp, -1);
598 /* spinlock still held */
601 /* spinlock still held */
604 * If any children exist we must leave the chain intact with refs == 0.
605 * They exist because chains are retained below us which have refs or
606 * may require flushing.
608 * Retry (return chain) if we fail to transition the refs to 0, else
609 * return NULL indication nothing more to do.
611 * Chains with children are NOT put on the LRU list.
613 if (chain->core.chain_count) {
614 if (atomic_cmpset_int(&chain->refs, 1, 0)) {
615 hammer2_spin_unex(&chain->core.spin);
616 hammer2_chain_assert_no_data(chain);
617 hammer2_mtx_unlock(&chain->lock);
620 hammer2_spin_unex(&chain->core.spin);
621 hammer2_mtx_unlock(&chain->lock);
625 /* spinlock still held */
626 /* no chains left under us */
629 * chain->core has no children left so no accessors can get to our
630 * chain from there. Now we have to lock the parent core to interlock
631 * remaining possible accessors that might bump chain's refs before
632 * we can safely drop chain's refs with intent to free the chain.
635 pmp = chain->pmp; /* can be NULL */
638 parent = chain->parent;
641 * WARNING! chain's spin lock is still held here, and other spinlocks
642 * will be acquired and released in the code below. We
643 * cannot be making fancy procedure calls!
647 * We can cache the chain if it is associated with a pmp
648 * and not flagged as being destroyed or requesting a full
649 * release. In this situation the chain is not removed
650 * from its parent, i.e. it can still be looked up.
652 * We intentionally do not cache DATA chains because these
653 * were likely used to load data into the logical buffer cache
654 * and will not be accessed again for some time.
657 (HAMMER2_CHAIN_DESTROY | HAMMER2_CHAIN_RELEASE)) == 0 &&
659 chain->bref.type != HAMMER2_BREF_TYPE_DATA) {
661 hammer2_spin_ex(&parent->core.spin);
662 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) {
664 * 1->0 transition failed, retry. Do not drop
665 * the chain's data yet!
668 hammer2_spin_unex(&parent->core.spin);
669 hammer2_spin_unex(&chain->core.spin);
670 hammer2_mtx_unlock(&chain->lock);
678 hammer2_chain_assert_no_data(chain);
681 * Make sure we are on the LRU list, clean up excessive
682 * LRU entries. We can only really drop one but there might
683 * be other entries that we can remove from the lru_list
686 * NOTE: HAMMER2_CHAIN_ONLRU may only be safely set when
687 * chain->core.spin AND pmp->lru_spin are held, but
688 * can be safely cleared only holding pmp->lru_spin.
690 if ((chain->flags & HAMMER2_CHAIN_ONLRU) == 0) {
691 hammer2_spin_ex(&pmp->lru_spin);
692 if ((chain->flags & HAMMER2_CHAIN_ONLRU) == 0) {
693 atomic_set_int(&chain->flags,
694 HAMMER2_CHAIN_ONLRU);
695 TAILQ_INSERT_TAIL(&pmp->lru_list,
697 atomic_add_int(&pmp->lru_count, 1);
699 if (pmp->lru_count < HAMMER2_LRU_LIMIT)
700 depth = 1; /* disable lru_list flush */
701 hammer2_spin_unex(&pmp->lru_spin);
703 /* disable lru flush */
708 hammer2_spin_unex(&parent->core.spin);
709 parent = NULL; /* safety */
711 hammer2_spin_unex(&chain->core.spin);
712 hammer2_mtx_unlock(&chain->lock);
715 * lru_list hysteresis (see above for depth overrides).
716 * Note that depth also prevents excessive lastdrop recursion.
719 hammer2_chain_lru_flush(pmp);
726 * Make sure we are not on the LRU list.
728 if (chain->flags & HAMMER2_CHAIN_ONLRU) {
729 hammer2_spin_ex(&pmp->lru_spin);
730 if (chain->flags & HAMMER2_CHAIN_ONLRU) {
731 atomic_add_int(&pmp->lru_count, -1);
732 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
733 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
735 hammer2_spin_unex(&pmp->lru_spin);
739 * Spinlock the parent and try to drop the last ref on chain.
740 * On success determine if we should dispose of the chain
741 * (remove the chain from its parent, etc).
743 * (normal core locks are top-down recursive but we define
744 * core spinlocks as bottom-up recursive, so this is safe).
747 hammer2_spin_ex(&parent->core.spin);
748 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) {
750 * 1->0 transition failed, retry.
752 hammer2_spin_unex(&parent->core.spin);
753 hammer2_spin_unex(&chain->core.spin);
754 hammer2_mtx_unlock(&chain->lock);
760 * 1->0 transition successful, parent spin held to prevent
761 * new lookups, chain spinlock held to protect parent field.
762 * Remove chain from the parent.
764 * If the chain is being removed from the parent's btree but
765 * is not bmapped, we have to adjust live_count downward. If
766 * it is bmapped then the blockref is retained in the parent
767 * as is its associated live_count. This case can occur when
768 * a chain added to the topology is unable to flush and is
769 * then later deleted.
771 if (chain->flags & HAMMER2_CHAIN_ONRBTREE) {
772 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) &&
773 (chain->flags & HAMMER2_CHAIN_BMAPPED) == 0) {
774 atomic_add_int(&parent->core.live_count, -1);
776 RB_REMOVE(hammer2_chain_tree,
777 &parent->core.rbtree, chain);
778 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE);
779 --parent->core.chain_count;
780 chain->parent = NULL;
784 * If our chain was the last chain in the parent's core the
785 * core is now empty and its parent might have to be
786 * re-dropped if it has 0 refs.
788 if (parent->core.chain_count == 0) {
790 atomic_add_int(&rdrop->refs, 1);
792 if (atomic_cmpset_int(&rdrop->refs, 0, 1) == 0)
796 hammer2_spin_unex(&parent->core.spin);
797 parent = NULL; /* safety */
803 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) {
805 * 1->0 transition failed, retry.
807 hammer2_spin_unex(&parent->core.spin);
808 hammer2_spin_unex(&chain->core.spin);
809 hammer2_mtx_unlock(&chain->lock);
816 * Successful 1->0 transition, no parent, no children... no way for
817 * anyone to ref this chain any more. We can clean-up and free it.
819 * We still have the core spinlock, and core's chain_count is 0.
820 * Any parent spinlock is gone.
822 hammer2_spin_unex(&chain->core.spin);
823 hammer2_chain_assert_no_data(chain);
824 hammer2_mtx_unlock(&chain->lock);
825 KKASSERT(RB_EMPTY(&chain->core.rbtree) &&
826 chain->core.chain_count == 0);
829 * All locks are gone, no pointers remain to the chain, finish
832 KKASSERT((chain->flags & (HAMMER2_CHAIN_UPDATE |
833 HAMMER2_CHAIN_MODIFIED)) == 0);
836 * Once chain resources are gone we can use the now dead chain
837 * structure to placehold what might otherwise require a recursive
838 * drop, because we have potentially two things to drop and can only
839 * return one directly.
841 if (chain->flags & HAMMER2_CHAIN_ALLOCATED) {
842 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ALLOCATED);
844 kfree(chain, hmp->mchain);
848 * Possible chaining loop when parent re-drop needed.
854 * Heuristical flush of the LRU, try to reduce the number of entries
855 * on the LRU to (HAMMER2_LRU_LIMIT * 2 / 3). This procedure is called
856 * only when lru_count exceeds HAMMER2_LRU_LIMIT.
860 hammer2_chain_lru_flush(hammer2_pfs_t *pmp)
862 hammer2_chain_t *chain;
866 hammer2_spin_ex(&pmp->lru_spin);
867 while (pmp->lru_count > HAMMER2_LRU_LIMIT * 2 / 3) {
869 * Pick a chain off the lru_list, just recycle it quickly
870 * if LRUHINT is set (the chain was ref'd but left on
871 * the lru_list, so cycle to the end).
873 chain = TAILQ_FIRST(&pmp->lru_list);
874 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
876 if (chain->flags & HAMMER2_CHAIN_LRUHINT) {
877 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_LRUHINT);
878 TAILQ_INSERT_TAIL(&pmp->lru_list, chain, lru_node);
884 * Ok, we are off the LRU. We must adjust refs before we
885 * can safely clear the ONLRU flag.
887 atomic_add_int(&pmp->lru_count, -1);
888 if (atomic_cmpset_int(&chain->refs, 0, 1)) {
889 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
890 atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
893 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
896 hammer2_spin_unex(&pmp->lru_spin);
901 * If we picked a chain off the lru list we may be able to lastdrop
902 * it. Use a depth of 1 to prevent excessive lastdrop recursion.
912 if (hammer2_mtx_ex_try(&chain->lock) == 0)
913 chain = hammer2_chain_lastdrop(chain, 1);
914 /* retry the same chain, or chain from lastdrop */
916 if (atomic_cmpset_int(&chain->refs, refs, refs - 1))
918 /* retry the same chain */
926 * On last lock release.
928 static hammer2_io_t *
929 hammer2_chain_drop_data(hammer2_chain_t *chain)
933 if ((dio = chain->dio) != NULL) {
937 switch(chain->bref.type) {
938 case HAMMER2_BREF_TYPE_VOLUME:
939 case HAMMER2_BREF_TYPE_FREEMAP:
942 if (chain->data != NULL) {
943 hammer2_spin_unex(&chain->core.spin);
944 panic("chain data not null: "
945 "chain %p bref %016jx.%02x "
946 "refs %d parent %p dio %p data %p",
947 chain, chain->bref.data_off,
948 chain->bref.type, chain->refs,
950 chain->dio, chain->data);
952 KKASSERT(chain->data == NULL);
960 * Lock a referenced chain element, acquiring its data with I/O if necessary,
961 * and specify how you would like the data to be resolved.
963 * If an I/O or other fatal error occurs, chain->error will be set to non-zero.
965 * The lock is allowed to recurse, multiple locking ops will aggregate
966 * the requested resolve types. Once data is assigned it will not be
967 * removed until the last unlock.
969 * HAMMER2_RESOLVE_NEVER - Do not resolve the data element.
970 * (typically used to avoid device/logical buffer
973 * HAMMER2_RESOLVE_MAYBE - Do not resolve data elements for chains in
974 * the INITIAL-create state (indirect blocks only).
976 * Do not resolve data elements for DATA chains.
977 * (typically used to avoid device/logical buffer
980 * HAMMER2_RESOLVE_ALWAYS- Always resolve the data element.
982 * HAMMER2_RESOLVE_SHARED- (flag) The chain is locked shared, otherwise
983 * it will be locked exclusive.
985 * HAMMER2_RESOLVE_NONBLOCK- (flag) The chain is locked non-blocking. If
986 * the lock fails, EAGAIN is returned.
988 * NOTE: Embedded elements (volume header, inodes) are always resolved
991 * NOTE: Specifying HAMMER2_RESOLVE_ALWAYS on a newly-created non-embedded
992 * element will instantiate and zero its buffer, and flush it on
995 * NOTE: (data) elements are normally locked RESOLVE_NEVER or RESOLVE_MAYBE
996 * so as not to instantiate a device buffer, which could alias against
997 * a logical file buffer. However, if ALWAYS is specified the
998 * device buffer will be instantiated anyway.
1000 * NOTE: The return value is always 0 unless NONBLOCK is specified, in which
1001 * case it can be either 0 or EAGAIN.
1003 * WARNING! This function blocks on I/O if data needs to be fetched. This
1004 * blocking can run concurrent with other compatible lock holders
1005 * who do not need data returning. The lock is not upgraded to
1006 * exclusive during a data fetch, a separate bit is used to
1007 * interlock I/O. However, an exclusive lock holder can still count
1008 * on being interlocked against an I/O fetch managed by a shared
1012 hammer2_chain_lock(hammer2_chain_t *chain, int how)
1014 KKASSERT(chain->refs > 0);
1016 if (how & HAMMER2_RESOLVE_NONBLOCK) {
1018 * We still have to bump lockcnt before acquiring the lock,
1019 * even for non-blocking operation, because the unlock code
1020 * live-loops on lockcnt == 1 when dropping the last lock.
1022 * If the non-blocking operation fails we have to use an
1023 * unhold sequence to undo the mess.
1025 * NOTE: LOCKAGAIN must always succeed without blocking,
1026 * even if NONBLOCK is specified.
1028 atomic_add_int(&chain->lockcnt, 1);
1029 if (how & HAMMER2_RESOLVE_SHARED) {
1030 if (how & HAMMER2_RESOLVE_LOCKAGAIN) {
1031 hammer2_mtx_sh_again(&chain->lock);
1033 if (hammer2_mtx_sh_try(&chain->lock) != 0) {
1034 hammer2_chain_unhold(chain);
1039 if (hammer2_mtx_ex_try(&chain->lock) != 0) {
1040 hammer2_chain_unhold(chain);
1046 * Get the appropriate lock. If LOCKAGAIN is flagged with
1047 * SHARED the caller expects a shared lock to already be
1048 * present and we are giving it another ref. This case must
1049 * importantly not block if there is a pending exclusive lock
1052 atomic_add_int(&chain->lockcnt, 1);
1053 if (how & HAMMER2_RESOLVE_SHARED) {
1054 if (how & HAMMER2_RESOLVE_LOCKAGAIN) {
1055 hammer2_mtx_sh_again(&chain->lock);
1057 hammer2_mtx_sh(&chain->lock);
1060 hammer2_mtx_ex(&chain->lock);
1065 * If we already have a valid data pointer make sure the data is
1066 * synchronized to the current cpu, and then no further action is
1071 hammer2_io_bkvasync(chain->dio);
1076 * Do we have to resolve the data? This is generally only
1077 * applicable to HAMMER2_BREF_TYPE_DATA which is special-cased.
1078 * Other BREF types expects the data to be there.
1080 switch(how & HAMMER2_RESOLVE_MASK) {
1081 case HAMMER2_RESOLVE_NEVER:
1083 case HAMMER2_RESOLVE_MAYBE:
1084 if (chain->flags & HAMMER2_CHAIN_INITIAL)
1086 if (chain->bref.type == HAMMER2_BREF_TYPE_DATA)
1089 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE)
1091 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF)
1095 case HAMMER2_RESOLVE_ALWAYS:
1101 * Caller requires data
1103 hammer2_chain_load_data(chain);
1109 * Lock the chain, retain the hold, and drop the data persistence count.
1110 * The data should remain valid because we never transitioned lockcnt
1114 hammer2_chain_lock_unhold(hammer2_chain_t *chain, int how)
1116 hammer2_chain_lock(chain, how);
1117 atomic_add_int(&chain->lockcnt, -1);
1122 * Downgrade an exclusive chain lock to a shared chain lock.
1124 * NOTE: There is no upgrade equivalent due to the ease of
1125 * deadlocks in that direction.
1128 hammer2_chain_lock_downgrade(hammer2_chain_t *chain)
1130 hammer2_mtx_downgrade(&chain->lock);
1135 * Issue I/O and install chain->data. Caller must hold a chain lock, lock
1136 * may be of any type.
1138 * Once chain->data is set it cannot be disposed of until all locks are
1141 * Make sure the data is synchronized to the current cpu.
1144 hammer2_chain_load_data(hammer2_chain_t *chain)
1146 hammer2_blockref_t *bref;
1153 * Degenerate case, data already present, or chain has no media
1154 * reference to load.
1156 KKASSERT(chain->lock.mtx_lock & MTX_MASK);
1159 hammer2_io_bkvasync(chain->dio);
1162 if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0)
1166 KKASSERT(hmp != NULL);
1169 * Gain the IOINPROG bit, interlocked block.
1175 oflags = chain->flags;
1177 if (oflags & HAMMER2_CHAIN_IOINPROG) {
1178 nflags = oflags | HAMMER2_CHAIN_IOSIGNAL;
1179 tsleep_interlock(&chain->flags, 0);
1180 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) {
1181 tsleep(&chain->flags, PINTERLOCKED,
1186 nflags = oflags | HAMMER2_CHAIN_IOINPROG;
1187 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) {
1195 * We own CHAIN_IOINPROG
1197 * Degenerate case if we raced another load.
1201 hammer2_io_bkvasync(chain->dio);
1206 * We must resolve to a device buffer, either by issuing I/O or
1207 * by creating a zero-fill element. We do not mark the buffer
1208 * dirty when creating a zero-fill element (the hammer2_chain_modify()
1209 * API must still be used to do that).
1211 * The device buffer is variable-sized in powers of 2 down
1212 * to HAMMER2_MIN_ALLOC (typically 1K). A 64K physical storage
1213 * chunk always contains buffers of the same size. (XXX)
1215 * The minimum physical IO size may be larger than the variable
1218 bref = &chain->bref;
1221 * The getblk() optimization can only be used on newly created
1222 * elements if the physical block size matches the request.
1224 if (chain->flags & HAMMER2_CHAIN_INITIAL) {
1225 error = hammer2_io_new(hmp, bref->type,
1226 bref->data_off, chain->bytes,
1229 error = hammer2_io_bread(hmp, bref->type,
1230 bref->data_off, chain->bytes,
1232 hammer2_adjreadcounter(&chain->bref, chain->bytes);
1235 chain->error = HAMMER2_ERROR_EIO;
1236 kprintf("hammer2_chain_lock: I/O error %016jx: %d\n",
1237 (intmax_t)bref->data_off, error);
1238 hammer2_io_bqrelse(&chain->dio);
1244 * This isn't perfect and can be ignored on OSs which do not have
1245 * an indication as to whether a buffer is coming from cache or
1246 * if I/O was actually issued for the read. TESTEDGOOD will work
1247 * pretty well without the B_IOISSUED logic because chains are
1248 * cached, but in that situation (without B_IOISSUED) it will not
1249 * detect whether a re-read via I/O is corrupted verses the original
1252 * We can't re-run the CRC on every fresh lock. That would be
1253 * insanely expensive.
1255 * If the underlying kernel buffer covers the entire chain we can
1256 * use the B_IOISSUED indication to determine if we have to re-run
1257 * the CRC on chain data for chains that managed to stay cached
1258 * across the kernel disposal of the original buffer.
1260 if ((dio = chain->dio) != NULL && dio->bp) {
1261 struct buf *bp = dio->bp;
1263 if (dio->psize == chain->bytes &&
1264 (bp->b_flags & B_IOISSUED)) {
1265 atomic_clear_int(&chain->flags,
1266 HAMMER2_CHAIN_TESTEDGOOD);
1267 bp->b_flags &= ~B_IOISSUED;
1272 * NOTE: A locked chain's data cannot be modified without first
1273 * calling hammer2_chain_modify().
1277 * Clear INITIAL. In this case we used io_new() and the buffer has
1278 * been zero'd and marked dirty.
1280 * NOTE: hammer2_io_data() call issues bkvasync()
1282 bdata = hammer2_io_data(chain->dio, chain->bref.data_off);
1284 if (chain->flags & HAMMER2_CHAIN_INITIAL) {
1285 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1286 chain->bref.flags |= HAMMER2_BREF_FLAG_ZERO;
1287 } else if (chain->flags & HAMMER2_CHAIN_MODIFIED) {
1289 * check data not currently synchronized due to
1290 * modification. XXX assumes data stays in the buffer
1291 * cache, which might not be true (need biodep on flush
1292 * to calculate crc? or simple crc?).
1294 } else if ((chain->flags & HAMMER2_CHAIN_TESTEDGOOD) == 0) {
1295 if (hammer2_chain_testcheck(chain, bdata) == 0) {
1296 chain->error = HAMMER2_ERROR_CHECK;
1298 atomic_set_int(&chain->flags, HAMMER2_CHAIN_TESTEDGOOD);
1303 * Setup the data pointer, either pointing it to an embedded data
1304 * structure and copying the data from the buffer, or pointing it
1307 * The buffer is not retained when copying to an embedded data
1308 * structure in order to avoid potential deadlocks or recursions
1309 * on the same physical buffer.
1311 * WARNING! Other threads can start using the data the instant we
1312 * set chain->data non-NULL.
1314 switch (bref->type) {
1315 case HAMMER2_BREF_TYPE_VOLUME:
1316 case HAMMER2_BREF_TYPE_FREEMAP:
1318 * Copy data from bp to embedded buffer
1320 panic("hammer2_chain_load_data: unresolved volume header");
1322 case HAMMER2_BREF_TYPE_DIRENT:
1323 KKASSERT(chain->bytes != 0);
1325 case HAMMER2_BREF_TYPE_INODE:
1326 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
1327 case HAMMER2_BREF_TYPE_INDIRECT:
1328 case HAMMER2_BREF_TYPE_DATA:
1329 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1332 * Point data at the device buffer and leave dio intact.
1334 chain->data = (void *)bdata;
1339 * Release HAMMER2_CHAIN_IOINPROG and signal waiters if requested.
1346 oflags = chain->flags;
1347 nflags = oflags & ~(HAMMER2_CHAIN_IOINPROG |
1348 HAMMER2_CHAIN_IOSIGNAL);
1349 KKASSERT(oflags & HAMMER2_CHAIN_IOINPROG);
1350 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) {
1351 if (oflags & HAMMER2_CHAIN_IOSIGNAL)
1352 wakeup(&chain->flags);
1359 * Unlock and deref a chain element.
1361 * Remember that the presence of children under chain prevent the chain's
1362 * destruction but do not add additional references, so the dio will still
1366 hammer2_chain_unlock(hammer2_chain_t *chain)
1373 * If multiple locks are present (or being attempted) on this
1374 * particular chain we can just unlock, drop refs, and return.
1376 * Otherwise fall-through on the 1->0 transition.
1379 lockcnt = chain->lockcnt;
1380 KKASSERT(lockcnt > 0);
1383 if (atomic_cmpset_int(&chain->lockcnt,
1384 lockcnt, lockcnt - 1)) {
1385 hammer2_mtx_unlock(&chain->lock);
1388 } else if (hammer2_mtx_upgrade_try(&chain->lock) == 0) {
1389 /* while holding the mutex exclusively */
1390 if (atomic_cmpset_int(&chain->lockcnt, 1, 0))
1394 * This situation can easily occur on SMP due to
1395 * the gap inbetween the 1->0 transition and the
1396 * final unlock. We cannot safely block on the
1397 * mutex because lockcnt might go above 1.
1399 * XXX Sleep for one tick if it takes too long.
1401 if (++iter > 1000) {
1402 if (iter > 1000 + hz) {
1403 kprintf("hammer2: h2race2 %p\n", chain);
1406 tsleep(&iter, 0, "h2race2", 1);
1414 * Last unlock / mutex upgraded to exclusive. Drop the data
1417 dio = hammer2_chain_drop_data(chain);
1419 hammer2_io_bqrelse(&dio);
1420 hammer2_mtx_unlock(&chain->lock);
1424 * Unlock and hold chain data intact
1427 hammer2_chain_unlock_hold(hammer2_chain_t *chain)
1429 atomic_add_int(&chain->lockcnt, 1);
1430 hammer2_chain_unlock(chain);
1434 * Helper to obtain the blockref[] array base and count for a chain.
1436 * XXX Not widely used yet, various use cases need to be validated and
1437 * converted to use this function.
1440 hammer2_blockref_t *
1441 hammer2_chain_base_and_count(hammer2_chain_t *parent, int *countp)
1443 hammer2_blockref_t *base;
1446 if (parent->flags & HAMMER2_CHAIN_INITIAL) {
1449 switch(parent->bref.type) {
1450 case HAMMER2_BREF_TYPE_INODE:
1451 count = HAMMER2_SET_COUNT;
1453 case HAMMER2_BREF_TYPE_INDIRECT:
1454 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1455 count = parent->bytes / sizeof(hammer2_blockref_t);
1457 case HAMMER2_BREF_TYPE_VOLUME:
1458 count = HAMMER2_SET_COUNT;
1460 case HAMMER2_BREF_TYPE_FREEMAP:
1461 count = HAMMER2_SET_COUNT;
1464 panic("hammer2_chain_base_and_count: "
1465 "unrecognized blockref type: %d",
1471 switch(parent->bref.type) {
1472 case HAMMER2_BREF_TYPE_INODE:
1473 base = &parent->data->ipdata.u.blockset.blockref[0];
1474 count = HAMMER2_SET_COUNT;
1476 case HAMMER2_BREF_TYPE_INDIRECT:
1477 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1478 base = &parent->data->npdata[0];
1479 count = parent->bytes / sizeof(hammer2_blockref_t);
1481 case HAMMER2_BREF_TYPE_VOLUME:
1482 base = &parent->data->voldata.
1483 sroot_blockset.blockref[0];
1484 count = HAMMER2_SET_COUNT;
1486 case HAMMER2_BREF_TYPE_FREEMAP:
1487 base = &parent->data->blkset.blockref[0];
1488 count = HAMMER2_SET_COUNT;
1491 panic("hammer2_chain_base_and_count: "
1492 "unrecognized blockref type: %d",
1504 * This counts the number of live blockrefs in a block array and
1505 * also calculates the point at which all remaining blockrefs are empty.
1506 * This routine can only be called on a live chain.
1508 * Caller holds the chain locked, but possibly with a shared lock. We
1509 * must use an exclusive spinlock to prevent corruption.
1511 * NOTE: Flag is not set until after the count is complete, allowing
1512 * callers to test the flag without holding the spinlock.
1514 * NOTE: If base is NULL the related chain is still in the INITIAL
1515 * state and there are no blockrefs to count.
1517 * NOTE: live_count may already have some counts accumulated due to
1518 * creation and deletion and could even be initially negative.
1521 hammer2_chain_countbrefs(hammer2_chain_t *chain,
1522 hammer2_blockref_t *base, int count)
1524 hammer2_spin_ex(&chain->core.spin);
1525 if ((chain->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) {
1527 while (--count >= 0) {
1528 if (base[count].type != HAMMER2_BREF_TYPE_EMPTY)
1531 chain->core.live_zero = count + 1;
1532 while (count >= 0) {
1533 if (base[count].type != HAMMER2_BREF_TYPE_EMPTY)
1534 atomic_add_int(&chain->core.live_count,
1539 chain->core.live_zero = 0;
1541 /* else do not modify live_count */
1542 atomic_set_int(&chain->flags, HAMMER2_CHAIN_COUNTEDBREFS);
1544 hammer2_spin_unex(&chain->core.spin);
1548 * Resize the chain's physical storage allocation in-place. This function does
1549 * not usually adjust the data pointer and must be followed by (typically) a
1550 * hammer2_chain_modify() call to copy any old data over and adjust the
1553 * Chains can be resized smaller without reallocating the storage. Resizing
1554 * larger will reallocate the storage. Excess or prior storage is reclaimed
1555 * asynchronously at a later time.
1557 * An nradix value of 0 is special-cased to mean that the storage should
1558 * be disassociated, that is the chain is being resized to 0 bytes (not 1
1561 * Must be passed an exclusively locked parent and chain.
1563 * This function is mostly used with DATA blocks locked RESOLVE_NEVER in order
1564 * to avoid instantiating a device buffer that conflicts with the vnode data
1565 * buffer. However, because H2 can compress or encrypt data, the chain may
1566 * have a dio assigned to it in those situations, and they do not conflict.
1568 * XXX return error if cannot resize.
1571 hammer2_chain_resize(hammer2_chain_t *chain,
1572 hammer2_tid_t mtid, hammer2_off_t dedup_off,
1573 int nradix, int flags)
1583 * Only data and indirect blocks can be resized for now.
1584 * (The volu root, inodes, and freemap elements use a fixed size).
1586 KKASSERT(chain != &hmp->vchain);
1587 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA ||
1588 chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT ||
1589 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT);
1592 * Nothing to do if the element is already the proper size
1594 obytes = chain->bytes;
1595 nbytes = (nradix) ? (1U << nradix) : 0;
1596 if (obytes == nbytes)
1597 return (chain->error);
1600 * Make sure the old data is instantiated so we can copy it. If this
1601 * is a data block, the device data may be superfluous since the data
1602 * might be in a logical block, but compressed or encrypted data is
1605 * NOTE: The modify will set BMAPUPD for us if BMAPPED is set.
1607 error = hammer2_chain_modify(chain, mtid, dedup_off, 0);
1612 * Relocate the block, even if making it smaller (because different
1613 * block sizes may be in different regions).
1615 * NOTE: Operation does not copy the data and may only be used
1616 * to resize data blocks in-place, or directory entry blocks
1617 * which are about to be modified in some manner.
1619 error = hammer2_freemap_alloc(chain, nbytes);
1623 chain->bytes = nbytes;
1626 * We don't want the followup chain_modify() to try to copy data
1627 * from the old (wrong-sized) buffer. It won't know how much to
1628 * copy. This case should only occur during writes when the
1629 * originator already has the data to write in-hand.
1632 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA ||
1633 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT);
1634 hammer2_io_brelse(&chain->dio);
1637 return (chain->error);
1641 * Set the chain modified so its data can be changed by the caller, or
1642 * install deduplicated data. The caller must call this routine for each
1643 * set of modifications it makes, even if the chain is already flagged
1646 * Sets bref.modify_tid to mtid only if mtid != 0. Note that bref.modify_tid
1647 * is a CLC (cluster level change) field and is not updated by parent
1648 * propagation during a flush.
1650 * Returns an appropriate HAMMER2_ERROR_* code, which will generally reflect
1651 * chain->error except for HAMMER2_ERROR_ENOSPC. If the allocation fails
1652 * due to no space available, HAMMER2_ERROR_ENOSPC is returned and the chain
1653 * remains unmodified with its old data ref intact and chain->error
1658 * If the DEDUPABLE flag is set in the chain the storage must be reallocated
1659 * even if the chain is still flagged MODIFIED. In this case the chain's
1660 * DEDUPABLE flag will be cleared once the new storage has been assigned.
1662 * If the caller passes a non-zero dedup_off we will use it to assign the
1663 * new storage. The MODIFIED flag will be *CLEARED* in this case, and
1664 * DEDUPABLE will be set (NOTE: the UPDATE flag is always set). The caller
1665 * must not modify the data content upon return.
1668 hammer2_chain_modify(hammer2_chain_t *chain, hammer2_tid_t mtid,
1669 hammer2_off_t dedup_off, int flags)
1671 hammer2_blockref_t obref;
1682 obref = chain->bref;
1683 KKASSERT((chain->flags & HAMMER2_CHAIN_FICTITIOUS) == 0);
1684 KKASSERT(chain->lock.mtx_lock & MTX_EXCLUSIVE);
1687 * Data is not optional for freemap chains (we must always be sure
1688 * to copy the data on COW storage allocations).
1690 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
1691 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
1692 KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) ||
1693 (flags & HAMMER2_MODIFY_OPTDATA) == 0);
1697 * Data must be resolved if already assigned, unless explicitly
1698 * flagged otherwise. If we cannot safety load the data the
1699 * modification fails and we return early.
1701 if (chain->data == NULL && chain->bytes != 0 &&
1702 (flags & HAMMER2_MODIFY_OPTDATA) == 0 &&
1703 (chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX)) {
1704 hammer2_chain_load_data(chain);
1706 return (chain->error);
1711 * Set MODIFIED to indicate that the chain has been modified. A new
1712 * allocation is required when modifying a chain.
1714 * Set UPDATE to ensure that the blockref is updated in the parent.
1716 * If MODIFIED is already set determine if we can reuse the assigned
1717 * data block or if we need a new data block.
1719 if ((chain->flags & HAMMER2_CHAIN_MODIFIED) == 0) {
1721 * Must set modified bit.
1723 atomic_add_long(&hammer2_count_modified_chains, 1);
1724 atomic_set_int(&chain->flags, HAMMER2_CHAIN_MODIFIED);
1725 hammer2_pfs_memory_inc(chain->pmp); /* can be NULL */
1729 * We may be able to avoid a copy-on-write if the chain's
1730 * check mode is set to NONE and the chain's current
1731 * modify_tid is beyond the last explicit snapshot tid.
1733 * This implements HAMMER2's overwrite-in-place feature.
1735 * NOTE! This data-block cannot be used as a de-duplication
1736 * source when the check mode is set to NONE.
1738 if ((chain->bref.type == HAMMER2_BREF_TYPE_DATA ||
1739 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT) &&
1740 (chain->flags & HAMMER2_CHAIN_INITIAL) == 0 &&
1741 (chain->flags & HAMMER2_CHAIN_DEDUPABLE) == 0 &&
1742 HAMMER2_DEC_CHECK(chain->bref.methods) ==
1743 HAMMER2_CHECK_NONE &&
1745 chain->bref.modify_tid >
1746 chain->pmp->iroot->meta.pfs_lsnap_tid) {
1748 * Sector overwrite allowed.
1751 } else if ((hmp->hflags & HMNT2_EMERG) &&
1753 chain->bref.modify_tid >
1754 chain->pmp->iroot->meta.pfs_lsnap_tid) {
1756 * If in emergency delete mode then do a modify-in-
1757 * place on any chain type belonging to the PFS as
1758 * long as it doesn't mess up a snapshot. We might
1759 * be forced to do this anyway a little further down
1760 * in the code if the allocation fails.
1762 * Also note that in emergency mode, these modify-in-
1763 * place operations are NOT SAFE. A storage failure,
1764 * power failure, or panic can corrupt the filesystem.
1769 * Sector overwrite not allowed, must copy-on-write.
1773 } else if (chain->flags & HAMMER2_CHAIN_DEDUPABLE) {
1775 * If the modified chain was registered for dedup we need
1776 * a new allocation. This only happens for delayed-flush
1777 * chains (i.e. which run through the front-end buffer
1784 * Already flagged modified, no new allocation is needed.
1791 * Flag parent update required.
1793 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0) {
1794 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
1801 * The XOP code returns held but unlocked focus chains. This
1802 * prevents the chain from being destroyed but does not prevent
1803 * it from being modified. diolk is used to interlock modifications
1804 * against XOP frontend accesses to the focus.
1806 * This allows us to theoretically avoid deadlocking the frontend
1807 * if one of the backends lock up by not formally locking the
1808 * focused chain in the frontend. In addition, the synchronization
1809 * code relies on this mechanism to avoid deadlocking concurrent
1810 * synchronization threads.
1812 lockmgr(&chain->diolk, LK_EXCLUSIVE);
1815 * The modification or re-modification requires an allocation and
1816 * possible COW. If an error occurs, the previous content and data
1817 * reference is retained and the modification fails.
1819 * If dedup_off is non-zero, the caller is requesting a deduplication
1820 * rather than a modification. The MODIFIED bit is not set and the
1821 * data offset is set to the deduplication offset. The data cannot
1824 * NOTE: The dedup offset is allowed to be in a partially free state
1825 * and we must be sure to reset it to a fully allocated state
1826 * to force two bulkfree passes to free it again.
1828 * NOTE: Only applicable when chain->bytes != 0.
1830 * XXX can a chain already be marked MODIFIED without a data
1831 * assignment? If not, assert here instead of testing the case.
1833 if (chain != &hmp->vchain && chain != &hmp->fchain &&
1835 if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0 ||
1839 * NOTE: We do not have to remove the dedup
1840 * registration because the area is still
1841 * allocated and the underlying DIO will
1845 chain->bref.data_off = dedup_off;
1846 chain->bytes = 1 << (dedup_off &
1847 HAMMER2_OFF_MASK_RADIX);
1849 atomic_clear_int(&chain->flags,
1850 HAMMER2_CHAIN_MODIFIED);
1851 atomic_add_long(&hammer2_count_modified_chains,
1854 hammer2_pfs_memory_wakeup(
1857 hammer2_freemap_adjust(hmp, &chain->bref,
1858 HAMMER2_FREEMAP_DORECOVER);
1859 atomic_set_int(&chain->flags,
1860 HAMMER2_CHAIN_DEDUPABLE);
1862 error = hammer2_freemap_alloc(chain,
1864 atomic_clear_int(&chain->flags,
1865 HAMMER2_CHAIN_DEDUPABLE);
1868 * If we are unable to allocate a new block
1869 * but we are in emergency mode, issue a
1870 * warning to the console and reuse the same
1873 * We behave as if the allocation were
1876 * THIS IS IMPORTANT: These modifications
1877 * are virtually guaranteed to corrupt any
1878 * snapshots related to this filesystem.
1880 if (error && (hmp->hflags & HMNT2_EMERG)) {
1882 chain->bref.flags |=
1883 HAMMER2_BREF_FLAG_EMERG_MIP;
1885 krateprintf(&krate_h2em,
1886 "hammer2: Emergency Mode WARNING: "
1887 "Operation will likely corrupt "
1888 "related snapshot: "
1889 "%016jx.%02x key=%016jx\n",
1890 chain->bref.data_off,
1893 } else if (error == 0) {
1894 chain->bref.flags &=
1895 ~HAMMER2_BREF_FLAG_EMERG_MIP;
1902 * Stop here if error. We have to undo any flag bits we might
1907 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED);
1908 atomic_add_long(&hammer2_count_modified_chains, -1);
1910 hammer2_pfs_memory_wakeup(chain->pmp, -1);
1913 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
1915 lockmgr(&chain->diolk, LK_RELEASE);
1921 * Update mirror_tid and modify_tid. modify_tid is only updated
1922 * if not passed as zero (during flushes, parent propagation passes
1925 * NOTE: chain->pmp could be the device spmp.
1927 chain->bref.mirror_tid = hmp->voldata.mirror_tid + 1;
1929 chain->bref.modify_tid = mtid;
1932 * Set BMAPUPD to tell the flush code that an existing blockmap entry
1933 * requires updating as well as to tell the delete code that the
1934 * chain's blockref might not exactly match (in terms of physical size
1935 * or block offset) the one in the parent's blocktable. The base key
1936 * of course will still match.
1938 if (chain->flags & HAMMER2_CHAIN_BMAPPED)
1939 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPUPD);
1942 * Short-cut data blocks which the caller does not need an actual
1943 * data reference to (aka OPTDATA), as long as the chain does not
1944 * already have a data pointer to the data. This generally means
1945 * that the modifications are being done via the logical buffer cache.
1946 * The INITIAL flag relates only to the device data buffer and thus
1947 * remains unchange in this situation.
1949 * This code also handles bytes == 0 (most dirents).
1951 if (chain->bref.type == HAMMER2_BREF_TYPE_DATA &&
1952 (flags & HAMMER2_MODIFY_OPTDATA) &&
1953 chain->data == NULL) {
1954 KKASSERT(chain->dio == NULL);
1959 * Clearing the INITIAL flag (for indirect blocks) indicates that
1960 * we've processed the uninitialized storage allocation.
1962 * If this flag is already clear we are likely in a copy-on-write
1963 * situation but we have to be sure NOT to bzero the storage if
1964 * no data is present.
1966 if (chain->flags & HAMMER2_CHAIN_INITIAL) {
1967 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1974 * Instantiate data buffer and possibly execute COW operation
1976 switch(chain->bref.type) {
1977 case HAMMER2_BREF_TYPE_VOLUME:
1978 case HAMMER2_BREF_TYPE_FREEMAP:
1980 * The data is embedded, no copy-on-write operation is
1983 KKASSERT(chain->dio == NULL);
1985 case HAMMER2_BREF_TYPE_DIRENT:
1987 * The data might be fully embedded.
1989 if (chain->bytes == 0) {
1990 KKASSERT(chain->dio == NULL);
1994 case HAMMER2_BREF_TYPE_INODE:
1995 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
1996 case HAMMER2_BREF_TYPE_DATA:
1997 case HAMMER2_BREF_TYPE_INDIRECT:
1998 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2000 * Perform the copy-on-write operation
2002 * zero-fill or copy-on-write depending on whether
2003 * chain->data exists or not and set the dirty state for
2004 * the new buffer. hammer2_io_new() will handle the
2007 * If a dedup_off was supplied this is an existing block
2008 * and no COW, copy, or further modification is required.
2010 KKASSERT(chain != &hmp->vchain && chain != &hmp->fchain);
2012 if (wasinitial && dedup_off == 0) {
2013 error = hammer2_io_new(hmp, chain->bref.type,
2014 chain->bref.data_off,
2015 chain->bytes, &dio);
2017 error = hammer2_io_bread(hmp, chain->bref.type,
2018 chain->bref.data_off,
2019 chain->bytes, &dio);
2021 hammer2_adjreadcounter(&chain->bref, chain->bytes);
2024 * If an I/O error occurs make sure callers cannot accidently
2025 * modify the old buffer's contents and corrupt the filesystem.
2027 * NOTE: hammer2_io_data() call issues bkvasync()
2030 kprintf("hammer2_chain_modify: hmp=%p I/O error\n",
2032 chain->error = HAMMER2_ERROR_EIO;
2033 hammer2_io_brelse(&dio);
2034 hammer2_io_brelse(&chain->dio);
2039 bdata = hammer2_io_data(dio, chain->bref.data_off);
2043 * COW (unless a dedup).
2045 KKASSERT(chain->dio != NULL);
2046 if (chain->data != (void *)bdata && dedup_off == 0) {
2047 bcopy(chain->data, bdata, chain->bytes);
2049 } else if (wasinitial == 0) {
2051 * We have a problem. We were asked to COW but
2052 * we don't have any data to COW with!
2054 panic("hammer2_chain_modify: having a COW %p\n",
2059 * Retire the old buffer, replace with the new. Dirty or
2060 * redirty the new buffer.
2062 * WARNING! The system buffer cache may have already flushed
2063 * the buffer, so we must be sure to [re]dirty it
2064 * for further modification.
2066 * If dedup_off was supplied, the caller is not
2067 * expected to make any further modification to the
2070 * WARNING! hammer2_get_gdata() assumes dio never transitions
2071 * through NULL in order to optimize away unnecessary
2077 if ((tio = chain->dio) != NULL)
2078 hammer2_io_bqrelse(&tio);
2079 chain->data = (void *)bdata;
2082 hammer2_io_setdirty(dio);
2086 panic("hammer2_chain_modify: illegal non-embedded type %d",
2093 * setflush on parent indicating that the parent must recurse down
2094 * to us. Do not call on chain itself which might already have it
2098 hammer2_chain_setflush(chain->parent);
2099 lockmgr(&chain->diolk, LK_RELEASE);
2101 return (chain->error);
2105 * Modify the chain associated with an inode.
2108 hammer2_chain_modify_ip(hammer2_inode_t *ip, hammer2_chain_t *chain,
2109 hammer2_tid_t mtid, int flags)
2113 hammer2_inode_modify(ip);
2114 error = hammer2_chain_modify(chain, mtid, 0, flags);
2120 * Volume header data locks
2123 hammer2_voldata_lock(hammer2_dev_t *hmp)
2125 lockmgr(&hmp->vollk, LK_EXCLUSIVE);
2129 hammer2_voldata_unlock(hammer2_dev_t *hmp)
2131 lockmgr(&hmp->vollk, LK_RELEASE);
2135 hammer2_voldata_modify(hammer2_dev_t *hmp)
2137 if ((hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) == 0) {
2138 atomic_add_long(&hammer2_count_modified_chains, 1);
2139 atomic_set_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
2140 hammer2_pfs_memory_inc(hmp->vchain.pmp);
2145 * This function returns the chain at the nearest key within the specified
2146 * range. The returned chain will be referenced but not locked.
2148 * This function will recurse through chain->rbtree as necessary and will
2149 * return a *key_nextp suitable for iteration. *key_nextp is only set if
2150 * the iteration value is less than the current value of *key_nextp.
2152 * The caller should use (*key_nextp) to calculate the actual range of
2153 * the returned element, which will be (key_beg to *key_nextp - 1), because
2154 * there might be another element which is superior to the returned element
2157 * (*key_nextp) can be passed as key_beg in an iteration only while non-NULL
2158 * chains continue to be returned. On EOF (*key_nextp) may overflow since
2159 * it will wind up being (key_end + 1).
2161 * WARNING! Must be called with child's spinlock held. Spinlock remains
2162 * held through the operation.
2164 struct hammer2_chain_find_info {
2165 hammer2_chain_t *best;
2166 hammer2_key_t key_beg;
2167 hammer2_key_t key_end;
2168 hammer2_key_t key_next;
2171 static int hammer2_chain_find_cmp(hammer2_chain_t *child, void *data);
2172 static int hammer2_chain_find_callback(hammer2_chain_t *child, void *data);
2176 hammer2_chain_find(hammer2_chain_t *parent, hammer2_key_t *key_nextp,
2177 hammer2_key_t key_beg, hammer2_key_t key_end)
2179 struct hammer2_chain_find_info info;
2182 info.key_beg = key_beg;
2183 info.key_end = key_end;
2184 info.key_next = *key_nextp;
2186 RB_SCAN(hammer2_chain_tree, &parent->core.rbtree,
2187 hammer2_chain_find_cmp, hammer2_chain_find_callback,
2189 *key_nextp = info.key_next;
2191 kprintf("chain_find %p %016jx:%016jx next=%016jx\n",
2192 parent, key_beg, key_end, *key_nextp);
2200 hammer2_chain_find_cmp(hammer2_chain_t *child, void *data)
2202 struct hammer2_chain_find_info *info = data;
2203 hammer2_key_t child_beg;
2204 hammer2_key_t child_end;
2206 child_beg = child->bref.key;
2207 child_end = child_beg + ((hammer2_key_t)1 << child->bref.keybits) - 1;
2209 if (child_end < info->key_beg)
2211 if (child_beg > info->key_end)
2218 hammer2_chain_find_callback(hammer2_chain_t *child, void *data)
2220 struct hammer2_chain_find_info *info = data;
2221 hammer2_chain_t *best;
2222 hammer2_key_t child_end;
2225 * WARNING! Layerq is scanned forwards, exact matches should keep
2226 * the existing info->best.
2228 if ((best = info->best) == NULL) {
2230 * No previous best. Assign best
2233 } else if (best->bref.key <= info->key_beg &&
2234 child->bref.key <= info->key_beg) {
2239 /*info->best = child;*/
2240 } else if (child->bref.key < best->bref.key) {
2242 * Child has a nearer key and best is not flush with key_beg.
2243 * Set best to child. Truncate key_next to the old best key.
2246 if (info->key_next > best->bref.key || info->key_next == 0)
2247 info->key_next = best->bref.key;
2248 } else if (child->bref.key == best->bref.key) {
2250 * If our current best is flush with the child then this
2251 * is an illegal overlap.
2253 * key_next will automatically be limited to the smaller of
2254 * the two end-points.
2260 * Keep the current best but truncate key_next to the child's
2263 * key_next will also automatically be limited to the smaller
2264 * of the two end-points (probably not necessary for this case
2265 * but we do it anyway).
2267 if (info->key_next > child->bref.key || info->key_next == 0)
2268 info->key_next = child->bref.key;
2272 * Always truncate key_next based on child's end-of-range.
2274 child_end = child->bref.key + ((hammer2_key_t)1 << child->bref.keybits);
2275 if (child_end && (info->key_next > child_end || info->key_next == 0))
2276 info->key_next = child_end;
2282 * Retrieve the specified chain from a media blockref, creating the
2283 * in-memory chain structure which reflects it. The returned chain is
2284 * held and locked according to (how) (HAMMER2_RESOLVE_*). The caller must
2285 * handle crc-checks and so forth, and should check chain->error before
2286 * assuming that the data is good.
2288 * To handle insertion races pass the INSERT_RACE flag along with the
2289 * generation number of the core. NULL will be returned if the generation
2290 * number changes before we have a chance to insert the chain. Insert
2291 * races can occur because the parent might be held shared.
2293 * Caller must hold the parent locked shared or exclusive since we may
2294 * need the parent's bref array to find our block.
2296 * WARNING! chain->pmp is always set to NULL for any chain representing
2297 * part of the super-root topology.
2300 hammer2_chain_get(hammer2_chain_t *parent, int generation,
2301 hammer2_blockref_t *bref, int how)
2303 hammer2_dev_t *hmp = parent->hmp;
2304 hammer2_chain_t *chain;
2308 * Allocate a chain structure representing the existing media
2309 * entry. Resulting chain has one ref and is not locked.
2311 if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT)
2312 chain = hammer2_chain_alloc(hmp, NULL, bref);
2314 chain = hammer2_chain_alloc(hmp, parent->pmp, bref);
2315 /* ref'd chain returned */
2318 * Flag that the chain is in the parent's blockmap so delete/flush
2319 * knows what to do with it.
2321 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPPED);
2324 * chain must be locked to avoid unexpected ripouts
2326 hammer2_chain_lock(chain, how);
2329 * Link the chain into its parent. A spinlock is required to safely
2330 * access the RBTREE, and it is possible to collide with another
2331 * hammer2_chain_get() operation because the caller might only hold
2332 * a shared lock on the parent.
2334 * NOTE: Get races can occur quite often when we distribute
2335 * asynchronous read-aheads across multiple threads.
2337 KKASSERT(parent->refs > 0);
2338 error = hammer2_chain_insert(parent, chain,
2339 HAMMER2_CHAIN_INSERT_SPIN |
2340 HAMMER2_CHAIN_INSERT_RACE,
2343 KKASSERT((chain->flags & HAMMER2_CHAIN_ONRBTREE) == 0);
2344 /*kprintf("chain %p get race\n", chain);*/
2345 hammer2_chain_unlock(chain);
2346 hammer2_chain_drop(chain);
2349 KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE);
2353 * Return our new chain referenced but not locked, or NULL if
2360 * Lookup initialization/completion API
2363 hammer2_chain_lookup_init(hammer2_chain_t *parent, int flags)
2365 hammer2_chain_ref(parent);
2366 if (flags & HAMMER2_LOOKUP_SHARED) {
2367 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS |
2368 HAMMER2_RESOLVE_SHARED);
2370 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2376 hammer2_chain_lookup_done(hammer2_chain_t *parent)
2379 hammer2_chain_unlock(parent);
2380 hammer2_chain_drop(parent);
2385 * Take the locked chain and return a locked parent. The chain remains
2386 * locked on return, but may have to be temporarily unlocked to acquire
2387 * the parent. Because of this, (chain) must be stable and cannot be
2388 * deleted while it was temporarily unlocked (typically means that (chain)
2391 * Pass HAMMER2_RESOLVE_* flags in flags.
2393 * This will work even if the chain is errored, and the caller can check
2394 * parent->error on return if desired since the parent will be locked.
2396 * This function handles the lock order reversal.
2399 hammer2_chain_getparent(hammer2_chain_t *chain, int flags)
2401 hammer2_chain_t *parent;
2404 * Be careful of order, chain must be unlocked before parent
2405 * is locked below to avoid a deadlock. Try it trivially first.
2407 parent = chain->parent;
2409 panic("hammer2_chain_getparent: no parent");
2410 hammer2_chain_ref(parent);
2411 if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0)
2415 hammer2_chain_unlock(chain);
2416 hammer2_chain_lock(parent, flags);
2417 hammer2_chain_lock(chain, flags);
2420 * Parent relinking races are quite common. We have to get
2421 * it right or we will blow up the block table.
2423 if (chain->parent == parent)
2425 hammer2_chain_unlock(parent);
2426 hammer2_chain_drop(parent);
2428 parent = chain->parent;
2430 panic("hammer2_chain_getparent: no parent");
2431 hammer2_chain_ref(parent);
2437 * Take the locked chain and return a locked parent. The chain is unlocked
2438 * and dropped. *chainp is set to the returned parent as a convenience.
2439 * Pass HAMMER2_RESOLVE_* flags in flags.
2441 * This will work even if the chain is errored, and the caller can check
2442 * parent->error on return if desired since the parent will be locked.
2444 * The chain does NOT need to be stable. We use a tracking structure
2445 * to track the expected parent if the chain is deleted out from under us.
2447 * This function handles the lock order reversal.
2450 hammer2_chain_repparent(hammer2_chain_t **chainp, int flags)
2452 hammer2_chain_t *chain;
2453 hammer2_chain_t *parent;
2454 struct hammer2_reptrack reptrack;
2455 struct hammer2_reptrack **repp;
2458 * Be careful of order, chain must be unlocked before parent
2459 * is locked below to avoid a deadlock. Try it trivially first.
2462 parent = chain->parent;
2463 if (parent == NULL) {
2464 hammer2_spin_unex(&chain->core.spin);
2465 panic("hammer2_chain_repparent: no parent");
2467 hammer2_chain_ref(parent);
2468 if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0) {
2469 hammer2_chain_unlock(chain);
2470 hammer2_chain_drop(chain);
2477 * Ok, now it gets a bit nasty. There are multiple situations where
2478 * the parent might be in the middle of a deletion, or where the child
2479 * (chain) might be deleted the instant we let go of its lock.
2480 * We can potentially end up in a no-win situation!
2482 * In particular, the indirect_maintenance() case can cause these
2485 * To deal with this we install a reptrack structure in the parent
2486 * This reptrack structure 'owns' the parent ref and will automatically
2487 * migrate to the parent's parent if the parent is deleted permanently.
2489 hammer2_spin_init(&reptrack.spin, "h2reptrk");
2490 reptrack.chain = parent;
2491 hammer2_chain_ref(parent); /* for the reptrack */
2493 hammer2_spin_ex(&parent->core.spin);
2494 reptrack.next = parent->core.reptrack;
2495 parent->core.reptrack = &reptrack;
2496 hammer2_spin_unex(&parent->core.spin);
2498 hammer2_chain_unlock(chain);
2499 hammer2_chain_drop(chain);
2500 chain = NULL; /* gone */
2503 * At the top of this loop, chain is gone and parent is refd both
2504 * by us explicitly AND via our reptrack. We are attempting to
2508 hammer2_chain_lock(parent, flags);
2510 if (reptrack.chain == parent)
2512 hammer2_chain_unlock(parent);
2513 hammer2_chain_drop(parent);
2515 kprintf("hammer2: debug REPTRACK %p->%p\n",
2516 parent, reptrack.chain);
2517 hammer2_spin_ex(&reptrack.spin);
2518 parent = reptrack.chain;
2519 hammer2_chain_ref(parent);
2520 hammer2_spin_unex(&reptrack.spin);
2524 * Once parent is locked and matches our reptrack, our reptrack
2525 * will be stable and we have our parent. We can unlink our
2528 * WARNING! Remember that the chain lock might be shared. Chains
2529 * locked shared have stable parent linkages.
2531 hammer2_spin_ex(&parent->core.spin);
2532 repp = &parent->core.reptrack;
2533 while (*repp != &reptrack)
2534 repp = &(*repp)->next;
2535 *repp = reptrack.next;
2536 hammer2_spin_unex(&parent->core.spin);
2538 hammer2_chain_drop(parent); /* reptrack ref */
2539 *chainp = parent; /* return parent lock+ref */
2545 * Dispose of any linked reptrack structures in (chain) by shifting them to
2546 * (parent). Both (chain) and (parent) must be exclusively locked.
2548 * This is interlocked against any children of (chain) on the other side.
2549 * No children so remain as-of when this is called so we can test
2550 * core.reptrack without holding the spin-lock.
2552 * Used whenever the caller intends to permanently delete chains related
2553 * to topological recursions (BREF_TYPE_INDIRECT, BREF_TYPE_FREEMAP_NODE),
2554 * where the chains underneath the node being deleted are given a new parent
2555 * above the node being deleted.
2559 hammer2_chain_repchange(hammer2_chain_t *parent, hammer2_chain_t *chain)
2561 struct hammer2_reptrack *reptrack;
2563 KKASSERT(chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree));
2564 while (chain->core.reptrack) {
2565 hammer2_spin_ex(&parent->core.spin);
2566 hammer2_spin_ex(&chain->core.spin);
2567 reptrack = chain->core.reptrack;
2568 if (reptrack == NULL) {
2569 hammer2_spin_unex(&chain->core.spin);
2570 hammer2_spin_unex(&parent->core.spin);
2573 hammer2_spin_ex(&reptrack->spin);
2574 chain->core.reptrack = reptrack->next;
2575 reptrack->chain = parent;
2576 reptrack->next = parent->core.reptrack;
2577 parent->core.reptrack = reptrack;
2578 hammer2_chain_ref(parent); /* reptrack */
2580 hammer2_spin_unex(&chain->core.spin);
2581 hammer2_spin_unex(&parent->core.spin);
2582 kprintf("hammer2: debug repchange %p %p->%p\n",
2583 reptrack, chain, parent);
2584 hammer2_chain_drop(chain); /* reptrack */
2589 * Locate the first chain whos key range overlaps (key_beg, key_end) inclusive.
2590 * (*parentp) typically points to an inode but can also point to a related
2591 * indirect block and this function will recurse upwards and find the inode
2592 * or the nearest undeleted indirect block covering the key range.
2594 * This function unconditionally sets *errorp, replacing any previous value.
2596 * (*parentp) must be exclusive or shared locked (depending on flags) and
2597 * referenced and can be an inode or an existing indirect block within the
2600 * If (*parent) is errored out, this function will not attempt to recurse
2601 * the radix tree and will return NULL along with an appropriate *errorp.
2602 * If NULL is returned and *errorp is 0, the requested lookup could not be
2605 * On return (*parentp) will be modified to point at the deepest parent chain
2606 * element encountered during the search, as a helper for an insertion or
2609 * The new (*parentp) will be locked shared or exclusive (depending on flags),
2610 * and referenced, and the old will be unlocked and dereferenced (no change
2611 * if they are both the same). This is particularly important if the caller
2612 * wishes to insert a new chain, (*parentp) will be set properly even if NULL
2613 * is returned, as long as no error occurred.
2615 * The matching chain will be returned locked according to flags.
2619 * NULL is returned if no match was found, but (*parentp) will still
2620 * potentially be adjusted.
2622 * On return (*key_nextp) will point to an iterative value for key_beg.
2623 * (If NULL is returned (*key_nextp) is set to (key_end + 1)).
2625 * This function will also recurse up the chain if the key is not within the
2626 * current parent's range. (*parentp) can never be set to NULL. An iteration
2627 * can simply allow (*parentp) to float inside the loop.
2629 * NOTE! chain->data is not always resolved. By default it will not be
2630 * resolved for BREF_TYPE_DATA, FREEMAP_NODE, or FREEMAP_LEAF. Use
2631 * HAMMER2_LOOKUP_ALWAYS to force resolution (but be careful w/
2632 * BREF_TYPE_DATA as the device buffer can alias the logical file
2637 hammer2_chain_lookup(hammer2_chain_t **parentp, hammer2_key_t *key_nextp,
2638 hammer2_key_t key_beg, hammer2_key_t key_end,
2639 int *errorp, int flags)
2642 hammer2_chain_t *parent;
2643 hammer2_chain_t *chain;
2644 hammer2_blockref_t *base;
2645 hammer2_blockref_t *bref;
2646 hammer2_blockref_t bsave;
2647 hammer2_key_t scan_beg;
2648 hammer2_key_t scan_end;
2650 int how_always = HAMMER2_RESOLVE_ALWAYS;
2651 int how_maybe = HAMMER2_RESOLVE_MAYBE;
2654 int maxloops = 300000;
2655 volatile hammer2_mtx_t save_mtx;
2657 if (flags & HAMMER2_LOOKUP_ALWAYS) {
2658 how_maybe = how_always;
2659 how = HAMMER2_RESOLVE_ALWAYS;
2660 } else if (flags & HAMMER2_LOOKUP_NODATA) {
2661 how = HAMMER2_RESOLVE_NEVER;
2663 how = HAMMER2_RESOLVE_MAYBE;
2665 if (flags & HAMMER2_LOOKUP_SHARED) {
2666 how_maybe |= HAMMER2_RESOLVE_SHARED;
2667 how_always |= HAMMER2_RESOLVE_SHARED;
2668 how |= HAMMER2_RESOLVE_SHARED;
2672 * Recurse (*parentp) upward if necessary until the parent completely
2673 * encloses the key range or we hit the inode.
2675 * Handle races against the flusher deleting indirect nodes on its
2676 * way back up by continuing to recurse upward past the deletion.
2682 while (parent->bref.type == HAMMER2_BREF_TYPE_INDIRECT ||
2683 parent->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2684 scan_beg = parent->bref.key;
2685 scan_end = scan_beg +
2686 ((hammer2_key_t)1 << parent->bref.keybits) - 1;
2687 if ((parent->flags & HAMMER2_CHAIN_DELETED) == 0) {
2688 if (key_beg >= scan_beg && key_end <= scan_end)
2691 parent = hammer2_chain_repparent(parentp, how_maybe);
2694 if (--maxloops == 0)
2695 panic("hammer2_chain_lookup: maxloops");
2698 * MATCHIND case that does not require parent->data (do prior to
2699 * parent->error check).
2701 switch(parent->bref.type) {
2702 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2703 case HAMMER2_BREF_TYPE_INDIRECT:
2704 if (flags & HAMMER2_LOOKUP_MATCHIND) {
2705 scan_beg = parent->bref.key;
2706 scan_end = scan_beg +
2707 ((hammer2_key_t)1 << parent->bref.keybits) - 1;
2708 if (key_beg == scan_beg && key_end == scan_end) {
2710 hammer2_chain_ref(chain);
2711 hammer2_chain_lock(chain, how_maybe);
2712 *key_nextp = scan_end + 1;
2722 * No lookup is possible if the parent is errored. We delayed
2723 * this check as long as we could to ensure that the parent backup,
2724 * embedded data, and MATCHIND code could still execute.
2726 if (parent->error) {
2727 *errorp = parent->error;
2732 * Locate the blockref array. Currently we do a fully associative
2733 * search through the array.
2735 switch(parent->bref.type) {
2736 case HAMMER2_BREF_TYPE_INODE:
2738 * Special shortcut for embedded data returns the inode
2739 * itself. Callers must detect this condition and access
2740 * the embedded data (the strategy code does this for us).
2742 * This is only applicable to regular files and softlinks.
2744 * We need a second lock on parent. Since we already have
2745 * a lock we must pass LOCKAGAIN to prevent unexpected
2746 * blocking (we don't want to block on a second shared
2747 * ref if an exclusive lock is pending)
2749 if (parent->data->ipdata.meta.op_flags &
2750 HAMMER2_OPFLAG_DIRECTDATA) {
2751 if (flags & HAMMER2_LOOKUP_NODIRECT) {
2753 *key_nextp = key_end + 1;
2756 hammer2_chain_ref(parent);
2757 hammer2_chain_lock(parent, how_always |
2758 HAMMER2_RESOLVE_LOCKAGAIN);
2759 *key_nextp = key_end + 1;
2762 base = &parent->data->ipdata.u.blockset.blockref[0];
2763 count = HAMMER2_SET_COUNT;
2765 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2766 case HAMMER2_BREF_TYPE_INDIRECT:
2768 * Optimize indirect blocks in the INITIAL state to avoid
2771 * Debugging: Enter permanent wait state instead of
2772 * panicing on unexpectedly NULL data for the moment.
2774 if (parent->flags & HAMMER2_CHAIN_INITIAL) {
2777 if (parent->data == NULL) {
2778 kprintf("hammer2: unexpected NULL data "
2781 tsleep(parent, 0, "xxx", 0);
2783 base = &parent->data->npdata[0];
2785 count = parent->bytes / sizeof(hammer2_blockref_t);
2787 case HAMMER2_BREF_TYPE_VOLUME:
2788 base = &parent->data->voldata.sroot_blockset.blockref[0];
2789 count = HAMMER2_SET_COUNT;
2791 case HAMMER2_BREF_TYPE_FREEMAP:
2792 base = &parent->data->blkset.blockref[0];
2793 count = HAMMER2_SET_COUNT;
2796 kprintf("hammer2_chain_lookup: unrecognized "
2797 "blockref(B) type: %d",
2800 tsleep(&base, 0, "dead", 0);
2801 panic("hammer2_chain_lookup: unrecognized "
2802 "blockref(B) type: %d",
2804 base = NULL; /* safety */
2805 count = 0; /* safety */
2809 * Merged scan to find next candidate.
2811 * hammer2_base_*() functions require the parent->core.live_* fields
2812 * to be synchronized.
2814 * We need to hold the spinlock to access the block array and RB tree
2815 * and to interlock chain creation.
2817 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0)
2818 hammer2_chain_countbrefs(parent, base, count);
2823 hammer2_spin_ex(&parent->core.spin);
2824 chain = hammer2_combined_find(parent, base, count,
2828 generation = parent->core.generation;
2831 * Exhausted parent chain, iterate.
2834 KKASSERT(chain == NULL);
2835 hammer2_spin_unex(&parent->core.spin);
2836 if (key_beg == key_end) /* short cut single-key case */
2840 * Stop if we reached the end of the iteration.
2842 if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT &&
2843 parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2848 * Calculate next key, stop if we reached the end of the
2849 * iteration, otherwise go up one level and loop.
2851 key_beg = parent->bref.key +
2852 ((hammer2_key_t)1 << parent->bref.keybits);
2853 if (key_beg == 0 || key_beg > key_end)
2855 parent = hammer2_chain_repparent(parentp, how_maybe);
2860 * Selected from blockref or in-memory chain.
2863 if (chain == NULL) {
2864 hammer2_spin_unex(&parent->core.spin);
2865 if (bsave.type == HAMMER2_BREF_TYPE_INDIRECT ||
2866 bsave.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2867 chain = hammer2_chain_get(parent, generation,
2870 chain = hammer2_chain_get(parent, generation,
2876 hammer2_chain_ref(chain);
2877 hammer2_spin_unex(&parent->core.spin);
2880 * chain is referenced but not locked. We must lock the
2881 * chain to obtain definitive state.
2883 if (bsave.type == HAMMER2_BREF_TYPE_INDIRECT ||
2884 bsave.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2885 hammer2_chain_lock(chain, how_maybe);
2887 hammer2_chain_lock(chain, how);
2889 KKASSERT(chain->parent == parent);
2891 if (bcmp(&bsave, &chain->bref, sizeof(bsave)) ||
2892 chain->parent != parent) {
2893 hammer2_chain_unlock(chain);
2894 hammer2_chain_drop(chain);
2895 chain = NULL; /* SAFETY */
2901 * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX)
2903 * NOTE: Chain's key range is not relevant as there might be
2904 * one-offs within the range that are not deleted.
2906 * NOTE: Lookups can race delete-duplicate because
2907 * delete-duplicate does not lock the parent's core
2908 * (they just use the spinlock on the core).
2910 if (chain->flags & HAMMER2_CHAIN_DELETED) {
2911 kprintf("skip deleted chain %016jx.%02x key=%016jx\n",
2912 chain->bref.data_off, chain->bref.type,
2914 hammer2_chain_unlock(chain);
2915 hammer2_chain_drop(chain);
2916 chain = NULL; /* SAFETY */
2917 key_beg = *key_nextp;
2918 if (key_beg == 0 || key_beg > key_end)
2924 * If the chain element is an indirect block it becomes the new
2925 * parent and we loop on it. We must maintain our top-down locks
2926 * to prevent the flusher from interfering (i.e. doing a
2927 * delete-duplicate and leaving us recursing down a deleted chain).
2929 * The parent always has to be locked with at least RESOLVE_MAYBE
2930 * so we can access its data. It might need a fixup if the caller
2931 * passed incompatible flags. Be careful not to cause a deadlock
2932 * as a data-load requires an exclusive lock.
2934 * If HAMMER2_LOOKUP_MATCHIND is set and the indirect block's key
2935 * range is within the requested key range we return the indirect
2936 * block and do NOT loop. This is usually only used to acquire
2939 if (chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT ||
2940 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2941 save_mtx = parent->lock;
2942 hammer2_chain_unlock(parent);
2943 hammer2_chain_drop(parent);
2944 *parentp = parent = chain;
2945 chain = NULL; /* SAFETY */
2950 * All done, return the locked chain.
2952 * If the caller does not want a locked chain, replace the lock with
2953 * a ref. Perhaps this can eventually be optimized to not obtain the
2954 * lock in the first place for situations where the data does not
2955 * need to be resolved.
2957 * NOTE! A chain->error must be tested by the caller upon return.
2958 * *errorp is only set based on issues which occur while
2959 * trying to reach the chain.
2965 * After having issued a lookup we can iterate all matching keys.
2967 * If chain is non-NULL we continue the iteration from just after it's index.
2969 * If chain is NULL we assume the parent was exhausted and continue the
2970 * iteration at the next parent.
2972 * If a fatal error occurs (typically an I/O error), a dummy chain is
2973 * returned with chain->error and error-identifying information set. This
2974 * chain will assert if you try to do anything fancy with it.
2976 * XXX Depending on where the error occurs we should allow continued iteration.
2978 * parent must be locked on entry and remains locked throughout. chain's
2979 * lock status must match flags. Chain is always at least referenced.
2981 * WARNING! The MATCHIND flag does not apply to this function.
2984 hammer2_chain_next(hammer2_chain_t **parentp, hammer2_chain_t *chain,
2985 hammer2_key_t *key_nextp,
2986 hammer2_key_t key_beg, hammer2_key_t key_end,
2987 int *errorp, int flags)
2989 hammer2_chain_t *parent;
2993 * Calculate locking flags for upward recursion.
2995 how_maybe = HAMMER2_RESOLVE_MAYBE;
2996 if (flags & HAMMER2_LOOKUP_SHARED)
2997 how_maybe |= HAMMER2_RESOLVE_SHARED;
3003 * Calculate the next index and recalculate the parent if necessary.
3006 key_beg = chain->bref.key +
3007 ((hammer2_key_t)1 << chain->bref.keybits);
3008 hammer2_chain_unlock(chain);
3009 hammer2_chain_drop(chain);
3012 * chain invalid past this point, but we can still do a
3013 * pointer comparison w/parent.
3015 * Any scan where the lookup returned degenerate data embedded
3016 * in the inode has an invalid index and must terminate.
3018 if (chain == parent)
3020 if (key_beg == 0 || key_beg > key_end)
3023 } else if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT &&
3024 parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) {
3026 * We reached the end of the iteration.
3031 * Continue iteration with next parent unless the current
3032 * parent covers the range.
3034 * (This also handles the case of a deleted, empty indirect
3037 key_beg = parent->bref.key +
3038 ((hammer2_key_t)1 << parent->bref.keybits);
3039 if (key_beg == 0 || key_beg > key_end)
3041 parent = hammer2_chain_repparent(parentp, how_maybe);
3047 return (hammer2_chain_lookup(parentp, key_nextp,
3053 * Caller wishes to iterate chains under parent, loading new chains into
3054 * chainp. Caller must initialize *chainp to NULL and *firstp to 1, and
3055 * then call hammer2_chain_scan() repeatedly until a non-zero return.
3056 * During the scan, *firstp will be set to 0 and (*chainp) will be replaced
3057 * with the returned chain for the scan. The returned *chainp will be
3058 * locked and referenced. Any prior contents will be unlocked and dropped.
3060 * Caller should check the return value. A normal scan EOF will return
3061 * exactly HAMMER2_ERROR_EOF. Any other non-zero value indicates an
3062 * error trying to access parent data. Any error in the returned chain
3063 * must be tested separately by the caller.
3065 * (*chainp) is dropped on each scan, but will only be set if the returned
3066 * element itself can recurse. Leaf elements are NOT resolved, loaded, or
3067 * returned via *chainp. The caller will get their bref only.
3069 * The raw scan function is similar to lookup/next but does not seek to a key.
3070 * Blockrefs are iterated via first_bref = (parent, NULL) and
3071 * next_chain = (parent, bref).
3073 * The passed-in parent must be locked and its data resolved. The function
3074 * nominally returns a locked and referenced *chainp != NULL for chains
3075 * the caller might need to recurse on (and will dipose of any *chainp passed
3076 * in). The caller must check the chain->bref.type either way.
3079 hammer2_chain_scan(hammer2_chain_t *parent, hammer2_chain_t **chainp,
3080 hammer2_blockref_t *bref, int *firstp,
3084 hammer2_blockref_t *base;
3085 hammer2_blockref_t *bref_ptr;
3087 hammer2_key_t next_key;
3088 hammer2_chain_t *chain = NULL;
3090 int how_always = HAMMER2_RESOLVE_ALWAYS;
3091 int how_maybe = HAMMER2_RESOLVE_MAYBE;
3094 int maxloops = 300000;
3101 * Scan flags borrowed from lookup.
3103 if (flags & HAMMER2_LOOKUP_ALWAYS) {
3104 how_maybe = how_always;
3105 how = HAMMER2_RESOLVE_ALWAYS;
3106 } else if (flags & HAMMER2_LOOKUP_NODATA) {
3107 how = HAMMER2_RESOLVE_NEVER;
3109 how = HAMMER2_RESOLVE_MAYBE;
3111 if (flags & HAMMER2_LOOKUP_SHARED) {
3112 how_maybe |= HAMMER2_RESOLVE_SHARED;
3113 how_always |= HAMMER2_RESOLVE_SHARED;
3114 how |= HAMMER2_RESOLVE_SHARED;
3118 * Calculate key to locate first/next element, unlocking the previous
3119 * element as we go. Be careful, the key calculation can overflow.
3121 * (also reset bref to NULL)
3127 key = bref->key + ((hammer2_key_t)1 << bref->keybits);
3128 if ((chain = *chainp) != NULL) {
3130 hammer2_chain_unlock(chain);
3131 hammer2_chain_drop(chain);
3135 error |= HAMMER2_ERROR_EOF;
3141 if (parent->error) {
3142 error = parent->error;
3145 if (--maxloops == 0)
3146 panic("hammer2_chain_scan: maxloops");
3149 * Locate the blockref array. Currently we do a fully associative
3150 * search through the array.
3152 switch(parent->bref.type) {
3153 case HAMMER2_BREF_TYPE_INODE:
3155 * An inode with embedded data has no sub-chains.
3157 * WARNING! Bulk scan code may pass a static chain marked
3158 * as BREF_TYPE_INODE with a copy of the volume
3159 * root blockset to snapshot the volume.
3161 if (parent->data->ipdata.meta.op_flags &
3162 HAMMER2_OPFLAG_DIRECTDATA) {
3163 error |= HAMMER2_ERROR_EOF;
3166 base = &parent->data->ipdata.u.blockset.blockref[0];
3167 count = HAMMER2_SET_COUNT;
3169 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3170 case HAMMER2_BREF_TYPE_INDIRECT:
3172 * Optimize indirect blocks in the INITIAL state to avoid
3175 if (parent->flags & HAMMER2_CHAIN_INITIAL) {
3178 if (parent->data == NULL)
3179 panic("parent->data is NULL");
3180 base = &parent->data->npdata[0];
3182 count = parent->bytes / sizeof(hammer2_blockref_t);
3184 case HAMMER2_BREF_TYPE_VOLUME:
3185 base = &parent->data->voldata.sroot_blockset.blockref[0];
3186 count = HAMMER2_SET_COUNT;
3188 case HAMMER2_BREF_TYPE_FREEMAP:
3189 base = &parent->data->blkset.blockref[0];
3190 count = HAMMER2_SET_COUNT;
3193 panic("hammer2_chain_scan: unrecognized blockref type: %d",
3195 base = NULL; /* safety */
3196 count = 0; /* safety */
3200 * Merged scan to find next candidate.
3202 * hammer2_base_*() functions require the parent->core.live_* fields
3203 * to be synchronized.
3205 * We need to hold the spinlock to access the block array and RB tree
3206 * and to interlock chain creation.
3208 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0)
3209 hammer2_chain_countbrefs(parent, base, count);
3213 hammer2_spin_ex(&parent->core.spin);
3214 chain = hammer2_combined_find(parent, base, count,
3216 key, HAMMER2_KEY_MAX,
3218 generation = parent->core.generation;
3221 * Exhausted parent chain, we're done.
3223 if (bref_ptr == NULL) {
3224 hammer2_spin_unex(&parent->core.spin);
3225 KKASSERT(chain == NULL);
3226 error |= HAMMER2_ERROR_EOF;
3231 * Copy into the supplied stack-based blockref.
3236 * Selected from blockref or in-memory chain.
3238 if (chain == NULL) {
3239 switch(bref->type) {
3240 case HAMMER2_BREF_TYPE_INODE:
3241 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3242 case HAMMER2_BREF_TYPE_INDIRECT:
3243 case HAMMER2_BREF_TYPE_VOLUME:
3244 case HAMMER2_BREF_TYPE_FREEMAP:
3246 * Recursion, always get the chain
3248 hammer2_spin_unex(&parent->core.spin);
3249 chain = hammer2_chain_get(parent, generation,
3256 * No recursion, do not waste time instantiating
3257 * a chain, just iterate using the bref.
3259 hammer2_spin_unex(&parent->core.spin);
3264 * Recursion or not we need the chain in order to supply
3267 hammer2_chain_ref(chain);
3268 hammer2_spin_unex(&parent->core.spin);
3269 hammer2_chain_lock(chain, how);
3272 (bcmp(bref, &chain->bref, sizeof(*bref)) ||
3273 chain->parent != parent)) {
3274 hammer2_chain_unlock(chain);
3275 hammer2_chain_drop(chain);
3281 * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX)
3283 * NOTE: chain's key range is not relevant as there might be
3284 * one-offs within the range that are not deleted.
3286 * NOTE: XXX this could create problems with scans used in
3287 * situations other than mount-time recovery.
3289 * NOTE: Lookups can race delete-duplicate because
3290 * delete-duplicate does not lock the parent's core
3291 * (they just use the spinlock on the core).
3293 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
3294 hammer2_chain_unlock(chain);
3295 hammer2_chain_drop(chain);
3300 error |= HAMMER2_ERROR_EOF;
3308 * All done, return the bref or NULL, supply chain if necessary.
3316 * Create and return a new hammer2 system memory structure of the specified
3317 * key, type and size and insert it under (*parentp). This is a full
3318 * insertion, based on the supplied key/keybits, and may involve creating
3319 * indirect blocks and moving other chains around via delete/duplicate.
3321 * This call can be made with parent == NULL as long as a non -1 methods
3322 * is supplied. hmp must also be supplied in this situation (otherwise
3323 * hmp is extracted from the supplied parent). The chain will be detached
3324 * from the topology. A later call with both parent and chain can be made
3327 * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (*parentp) TO THE INSERTION
3328 * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING
3329 * FULL. This typically means that the caller is creating the chain after
3330 * doing a hammer2_chain_lookup().
3332 * (*parentp) must be exclusive locked and may be replaced on return
3333 * depending on how much work the function had to do.
3335 * (*parentp) must not be errored or this function will assert.
3337 * (*chainp) usually starts out NULL and returns the newly created chain,
3338 * but if the caller desires the caller may allocate a disconnected chain
3339 * and pass it in instead.
3341 * This function should NOT be used to insert INDIRECT blocks. It is
3342 * typically used to create/insert inodes and data blocks.
3344 * Caller must pass-in an exclusively locked parent the new chain is to
3345 * be inserted under, and optionally pass-in a disconnected, exclusively
3346 * locked chain to insert (else we create a new chain). The function will
3347 * adjust (*parentp) as necessary, create or connect the chain, and
3348 * return an exclusively locked chain in *chainp.
3350 * When creating a PFSROOT inode under the super-root, pmp is typically NULL
3351 * and will be reassigned.
3353 * NOTE: returns HAMMER_ERROR_* flags
3356 hammer2_chain_create(hammer2_chain_t **parentp, hammer2_chain_t **chainp,
3357 hammer2_dev_t *hmp, hammer2_pfs_t *pmp, int methods,
3358 hammer2_key_t key, int keybits, int type, size_t bytes,
3359 hammer2_tid_t mtid, hammer2_off_t dedup_off, int flags)
3361 hammer2_chain_t *chain;
3362 hammer2_chain_t *parent;
3363 hammer2_blockref_t *base;
3364 hammer2_blockref_t dummy;
3368 int maxloops = 300000;
3371 * Topology may be crossing a PFS boundary.
3375 KKASSERT(hammer2_mtx_owned(&parent->lock));
3376 KKASSERT(parent->error == 0);
3381 if (chain == NULL) {
3383 * First allocate media space and construct the dummy bref,
3384 * then allocate the in-memory chain structure. Set the
3385 * INITIAL flag for fresh chains which do not have embedded
3388 * XXX for now set the check mode of the child based on
3389 * the parent or, if the parent is an inode, the
3390 * specification in the inode.
3392 bzero(&dummy, sizeof(dummy));
3395 dummy.keybits = keybits;
3396 dummy.data_off = hammer2_getradix(bytes);
3399 * Inherit methods from parent by default. Primarily used
3400 * for BREF_TYPE_DATA. Non-data types *must* be set to
3401 * a non-NONE check algorithm.
3404 dummy.methods = parent->bref.methods;
3406 dummy.methods = (uint8_t)methods;
3408 if (type != HAMMER2_BREF_TYPE_DATA &&
3409 HAMMER2_DEC_CHECK(dummy.methods) == HAMMER2_CHECK_NONE) {
3411 HAMMER2_ENC_CHECK(HAMMER2_CHECK_DEFAULT);
3414 chain = hammer2_chain_alloc(hmp, pmp, &dummy);
3417 * Lock the chain manually, chain_lock will load the chain
3418 * which we do NOT want to do. (note: chain->refs is set
3419 * to 1 by chain_alloc() for us, but lockcnt is not).
3422 hammer2_mtx_ex(&chain->lock);
3426 * Set INITIAL to optimize I/O. The flag will generally be
3427 * processed when we call hammer2_chain_modify().
3429 * Recalculate bytes to reflect the actual media block
3430 * allocation. Handle special case radix 0 == 0 bytes.
3432 bytes = (size_t)(chain->bref.data_off & HAMMER2_OFF_MASK_RADIX);
3434 bytes = (hammer2_off_t)1 << bytes;
3435 chain->bytes = bytes;
3438 case HAMMER2_BREF_TYPE_VOLUME:
3439 case HAMMER2_BREF_TYPE_FREEMAP:
3440 panic("hammer2_chain_create: called with volume type");
3442 case HAMMER2_BREF_TYPE_INDIRECT:
3443 panic("hammer2_chain_create: cannot be used to"
3444 "create indirect block");
3446 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3447 panic("hammer2_chain_create: cannot be used to"
3448 "create freemap root or node");
3450 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
3451 KKASSERT(bytes == sizeof(chain->data->bmdata));
3453 case HAMMER2_BREF_TYPE_DIRENT:
3454 case HAMMER2_BREF_TYPE_INODE:
3455 case HAMMER2_BREF_TYPE_DATA:
3458 * leave chain->data NULL, set INITIAL
3460 KKASSERT(chain->data == NULL);
3461 atomic_set_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
3466 * We are reattaching a previously deleted chain, possibly
3467 * under a new parent and possibly with a new key/keybits.
3468 * The chain does not have to be in a modified state. The
3469 * UPDATE flag will be set later on in this routine.
3471 * Do NOT mess with the current state of the INITIAL flag.
3473 chain->bref.key = key;
3474 chain->bref.keybits = keybits;
3475 if (chain->flags & HAMMER2_CHAIN_DELETED)
3476 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_DELETED);
3477 KKASSERT(chain->parent == NULL);
3481 * Set the appropriate bref flag if requested.
3483 * NOTE! Callers can call this function to move chains without
3484 * knowing about special flags, so don't clear bref flags
3487 if (flags & HAMMER2_INSERT_PFSROOT)
3488 chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT;
3494 * Calculate how many entries we have in the blockref array and
3495 * determine if an indirect block is required when inserting into
3499 if (--maxloops == 0)
3500 panic("hammer2_chain_create: maxloops");
3502 switch(parent->bref.type) {
3503 case HAMMER2_BREF_TYPE_INODE:
3504 if ((parent->data->ipdata.meta.op_flags &
3505 HAMMER2_OPFLAG_DIRECTDATA) != 0) {
3506 kprintf("hammer2: parent set for direct-data! "
3507 "pkey=%016jx ckey=%016jx\n",
3511 KKASSERT((parent->data->ipdata.meta.op_flags &
3512 HAMMER2_OPFLAG_DIRECTDATA) == 0);
3513 KKASSERT(parent->data != NULL);
3514 base = &parent->data->ipdata.u.blockset.blockref[0];
3515 count = HAMMER2_SET_COUNT;
3517 case HAMMER2_BREF_TYPE_INDIRECT:
3518 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3519 if (parent->flags & HAMMER2_CHAIN_INITIAL)
3522 base = &parent->data->npdata[0];
3523 count = parent->bytes / sizeof(hammer2_blockref_t);
3525 case HAMMER2_BREF_TYPE_VOLUME:
3526 KKASSERT(parent->data != NULL);
3527 base = &parent->data->voldata.sroot_blockset.blockref[0];
3528 count = HAMMER2_SET_COUNT;
3530 case HAMMER2_BREF_TYPE_FREEMAP:
3531 KKASSERT(parent->data != NULL);
3532 base = &parent->data->blkset.blockref[0];
3533 count = HAMMER2_SET_COUNT;
3536 panic("hammer2_chain_create: unrecognized blockref type: %d",
3544 * Make sure we've counted the brefs
3546 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0)
3547 hammer2_chain_countbrefs(parent, base, count);
3549 KASSERT(parent->core.live_count >= 0 &&
3550 parent->core.live_count <= count,
3551 ("bad live_count %d/%d (%02x, %d)",
3552 parent->core.live_count, count,
3553 parent->bref.type, parent->bytes));
3556 * If no free blockref could be found we must create an indirect
3557 * block and move a number of blockrefs into it. With the parent
3558 * locked we can safely lock each child in order to delete+duplicate
3559 * it without causing a deadlock.
3561 * This may return the new indirect block or the old parent depending
3562 * on where the key falls. NULL is returned on error.
3564 if (parent->core.live_count == count) {
3565 hammer2_chain_t *nparent;
3567 KKASSERT((flags & HAMMER2_INSERT_SAMEPARENT) == 0);
3569 nparent = hammer2_chain_create_indirect(parent, key, keybits,
3570 mtid, type, &error);
3571 if (nparent == NULL) {
3573 hammer2_chain_drop(chain);
3577 if (parent != nparent) {
3578 hammer2_chain_unlock(parent);
3579 hammer2_chain_drop(parent);
3580 parent = *parentp = nparent;
3586 * fall through if parent, or skip to here if no parent.
3589 if (chain->flags & HAMMER2_CHAIN_DELETED)
3590 kprintf("Inserting deleted chain @%016jx\n",
3594 * Link the chain into its parent.
3596 if (chain->parent != NULL)
3597 panic("hammer2: hammer2_chain_create: chain already connected");
3598 KKASSERT(chain->parent == NULL);
3600 KKASSERT(parent->core.live_count < count);
3601 hammer2_chain_insert(parent, chain,
3602 HAMMER2_CHAIN_INSERT_SPIN |
3603 HAMMER2_CHAIN_INSERT_LIVE,
3609 * Mark the newly created chain modified. This will cause
3610 * UPDATE to be set and process the INITIAL flag.
3612 * Device buffers are not instantiated for DATA elements
3613 * as these are handled by logical buffers.
3615 * Indirect and freemap node indirect blocks are handled
3616 * by hammer2_chain_create_indirect() and not by this
3619 * Data for all other bref types is expected to be
3620 * instantiated (INODE, LEAF).
3622 switch(chain->bref.type) {
3623 case HAMMER2_BREF_TYPE_DATA:
3624 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
3625 case HAMMER2_BREF_TYPE_DIRENT:
3626 case HAMMER2_BREF_TYPE_INODE:
3627 error = hammer2_chain_modify(chain, mtid, dedup_off,
3628 HAMMER2_MODIFY_OPTDATA);
3632 * Remaining types are not supported by this function.
3633 * In particular, INDIRECT and LEAF_NODE types are
3634 * handled by create_indirect().
3636 panic("hammer2_chain_create: bad type: %d",
3643 * When reconnecting a chain we must set UPDATE and
3644 * setflush so the flush recognizes that it must update
3645 * the bref in the parent.
3647 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0)
3648 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
3652 * We must setflush(parent) to ensure that it recurses through to
3653 * chain. setflush(chain) might not work because ONFLUSH is possibly
3654 * already set in the chain (so it won't recurse up to set it in the
3658 hammer2_chain_setflush(parent);
3667 * Move the chain from its old parent to a new parent. The chain must have
3668 * already been deleted or already disconnected (or never associated) with
3669 * a parent. The chain is reassociated with the new parent and the deleted
3670 * flag will be cleared (no longer deleted). The chain's modification state
3673 * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (parent) TO THE INSERTION
3674 * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING
3675 * FULL. This typically means that the caller is creating the chain after
3676 * doing a hammer2_chain_lookup().
3678 * Neither (parent) or (chain) can be errored.
3680 * If (parent) is non-NULL then the chain is inserted under the parent.
3682 * If (parent) is NULL then the newly duplicated chain is not inserted
3683 * anywhere, similar to if it had just been chain_alloc()'d (suitable for
3684 * passing into hammer2_chain_create() after this function returns).
3686 * WARNING! This function calls create which means it can insert indirect
3687 * blocks. This can cause other unrelated chains in the parent to
3688 * be moved to a newly inserted indirect block in addition to the
3692 hammer2_chain_rename(hammer2_chain_t **parentp, hammer2_chain_t *chain,
3693 hammer2_tid_t mtid, int flags)
3695 hammer2_blockref_t *bref;
3697 hammer2_chain_t *parent;
3701 * WARNING! We should never resolve DATA to device buffers
3702 * (XXX allow it if the caller did?), and since
3703 * we currently do not have the logical buffer cache
3704 * buffer in-hand to fix its cached physical offset
3705 * we also force the modify code to not COW it. XXX
3707 * NOTE! We allow error'd chains to be renamed. The bref itself
3708 * is good and can be renamed. The content, however, may
3712 KKASSERT(chain->parent == NULL);
3713 /*KKASSERT(chain->error == 0); allow */
3716 * Now create a duplicate of the chain structure, associating
3717 * it with the same core, making it the same size, pointing it
3718 * to the same bref (the same media block).
3720 * NOTE: Handle special radix == 0 case (means 0 bytes).
3722 bref = &chain->bref;
3723 bytes = (size_t)(bref->data_off & HAMMER2_OFF_MASK_RADIX);
3725 bytes = (hammer2_off_t)1 << bytes;
3728 * If parent is not NULL the duplicated chain will be entered under
3729 * the parent and the UPDATE bit set to tell flush to update
3732 * We must setflush(parent) to ensure that it recurses through to
3733 * chain. setflush(chain) might not work because ONFLUSH is possibly
3734 * already set in the chain (so it won't recurse up to set it in the
3737 * Having both chains locked is extremely important for atomicy.
3739 if (parentp && (parent = *parentp) != NULL) {
3740 KKASSERT(hammer2_mtx_owned(&parent->lock));
3741 KKASSERT(parent->refs > 0);
3742 KKASSERT(parent->error == 0);
3744 hammer2_chain_create(parentp, &chain, NULL, chain->pmp,
3745 HAMMER2_METH_DEFAULT,
3746 bref->key, bref->keybits, bref->type,
3747 chain->bytes, mtid, 0, flags);
3748 KKASSERT(chain->flags & HAMMER2_CHAIN_UPDATE);
3749 hammer2_chain_setflush(*parentp);
3754 * This works in tandem with delete_obref() to install a blockref in
3755 * (typically) an indirect block that is associated with the chain being
3756 * moved to *parentp.
3758 * The reason we need this function is that the caller needs to maintain
3759 * the blockref as it was, and not generate a new blockref for what might
3760 * be a modified chain. Otherwise stuff will leak into the flush that
3761 * the flush code's FLUSH_INODE_STOP flag is unable to catch.
3763 * It is EXTREMELY important that we properly set CHAIN_BMAPUPD and
3764 * CHAIN_UPDATE. We must set BMAPUPD if the bref does not match, and
3765 * we must clear CHAIN_UPDATE (that was likely set by the chain_rename) if
3766 * it does. Otherwise we can end up in a situation where H2 is unable to
3767 * clean up the in-memory chain topology.
3769 * The reason for this is that flushes do not generally flush through
3770 * BREF_TYPE_INODE chains and depend on a hammer2_inode_t queued to syncq
3771 * or sideq to properly flush and dispose of the related inode chain's flags.
3772 * Situations where the inode is not actually modified by the frontend,
3773 * but where we have to move the related chains around as we insert or cleanup
3774 * indirect blocks, can leave us with a 'dirty' (non-disposable) in-memory
3775 * inode chain that does not have a hammer2_inode_t associated with it.
3778 hammer2_chain_rename_obref(hammer2_chain_t **parentp, hammer2_chain_t *chain,
3779 hammer2_tid_t mtid, int flags,
3780 hammer2_blockref_t *obref)
3782 hammer2_chain_rename(parentp, chain, mtid, flags);
3784 if (obref->type != HAMMER2_BREF_TYPE_EMPTY) {
3785 hammer2_blockref_t *tbase;
3788 KKASSERT((chain->flags & HAMMER2_CHAIN_BMAPPED) == 0);
3789 hammer2_chain_modify(*parentp, mtid, 0, 0);
3790 tbase = hammer2_chain_base_and_count(*parentp, &tcount);
3791 hammer2_base_insert(*parentp, tbase, tcount, chain, obref);
3792 if (bcmp(obref, &chain->bref, sizeof(chain->bref))) {
3793 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPUPD |
3794 HAMMER2_CHAIN_UPDATE);
3796 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
3802 * Helper function for deleting chains.
3804 * The chain is removed from the live view (the RBTREE) as well as the parent's
3805 * blockmap. Both chain and its parent must be locked.
3807 * parent may not be errored. chain can be errored.
3810 _hammer2_chain_delete_helper(hammer2_chain_t *parent, hammer2_chain_t *chain,
3811 hammer2_tid_t mtid, int flags,
3812 hammer2_blockref_t *obref)
3817 KKASSERT((chain->flags & (HAMMER2_CHAIN_DELETED |
3818 HAMMER2_CHAIN_FICTITIOUS)) == 0);
3819 KKASSERT(chain->parent == parent);
3822 if (chain->flags & HAMMER2_CHAIN_BMAPPED) {
3824 * Chain is blockmapped, so there must be a parent.
3825 * Atomically remove the chain from the parent and remove
3826 * the blockmap entry. The parent must be set modified
3827 * to remove the blockmap entry.
3829 hammer2_blockref_t *base;
3832 KKASSERT(parent != NULL);
3833 KKASSERT(parent->error == 0);
3834 KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0);
3835 error = hammer2_chain_modify(parent, mtid, 0, 0);
3840 * Calculate blockmap pointer
3842 KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE);
3843 hammer2_spin_ex(&chain->core.spin);
3844 hammer2_spin_ex(&parent->core.spin);
3846 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED);
3847 atomic_add_int(&parent->core.live_count, -1);
3848 ++parent->core.generation;
3849 RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain);
3850 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE);
3851 --parent->core.chain_count;
3852 chain->parent = NULL;
3854 switch(parent->bref.type) {
3855 case HAMMER2_BREF_TYPE_INODE:
3857 * Access the inode's block array. However, there
3858 * is no block array if the inode is flagged
3862 (parent->data->ipdata.meta.op_flags &
3863 HAMMER2_OPFLAG_DIRECTDATA) == 0) {
3865 &parent->data->ipdata.u.blockset.blockref[0];
3869 count = HAMMER2_SET_COUNT;
3871 case HAMMER2_BREF_TYPE_INDIRECT:
3872 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3874 base = &parent->data->npdata[0];
3877 count = parent->bytes / sizeof(hammer2_blockref_t);
3879 case HAMMER2_BREF_TYPE_VOLUME:
3880 base = &parent->data->voldata.
3881 sroot_blockset.blockref[0];
3882 count = HAMMER2_SET_COUNT;
3884 case HAMMER2_BREF_TYPE_FREEMAP:
3885 base = &parent->data->blkset.blockref[0];
3886 count = HAMMER2_SET_COUNT;
3891 panic("_hammer2_chain_delete_helper: "
3892 "unrecognized blockref type: %d",
3897 * delete blockmapped chain from its parent.
3899 * The parent is not affected by any statistics in chain
3900 * which are pending synchronization. That is, there is
3901 * nothing to undo in the parent since they have not yet
3902 * been incorporated into the parent.
3904 * The parent is affected by statistics stored in inodes.
3905 * Those have already been synchronized, so they must be
3906 * undone. XXX split update possible w/delete in middle?
3909 hammer2_base_delete(parent, base, count, chain, obref);
3911 hammer2_spin_unex(&parent->core.spin);
3912 hammer2_spin_unex(&chain->core.spin);
3913 } else if (chain->flags & HAMMER2_CHAIN_ONRBTREE) {
3915 * Chain is not blockmapped but a parent is present.
3916 * Atomically remove the chain from the parent. There is
3917 * no blockmap entry to remove.
3919 * Because chain was associated with a parent but not
3920 * synchronized, the chain's *_count_up fields contain
3921 * inode adjustment statistics which must be undone.
3923 hammer2_spin_ex(&chain->core.spin);
3924 hammer2_spin_ex(&parent->core.spin);
3925 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED);
3926 atomic_add_int(&parent->core.live_count, -1);
3927 ++parent->core.generation;
3928 RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain);
3929 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE);
3930 --parent->core.chain_count;
3931 chain->parent = NULL;
3932 hammer2_spin_unex(&parent->core.spin);
3933 hammer2_spin_unex(&chain->core.spin);
3936 * Chain is not blockmapped and has no parent. This
3937 * is a degenerate case.
3939 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED);
3946 * Create an indirect block that covers one or more of the elements in the
3947 * current parent. Either returns the existing parent with no locking or
3948 * ref changes or returns the new indirect block locked and referenced
3949 * and leaving the original parent lock/ref intact as well.
3951 * If an error occurs, NULL is returned and *errorp is set to the H2 error.
3953 * The returned chain depends on where the specified key falls.
3955 * The key/keybits for the indirect mode only needs to follow three rules:
3957 * (1) That all elements underneath it fit within its key space and
3959 * (2) That all elements outside it are outside its key space.
3961 * (3) When creating the new indirect block any elements in the current
3962 * parent that fit within the new indirect block's keyspace must be
3963 * moved into the new indirect block.
3965 * (4) The keyspace chosen for the inserted indirect block CAN cover a wider
3966 * keyspace the the current parent, but lookup/iteration rules will
3967 * ensure (and must ensure) that rule (2) for all parents leading up
3968 * to the nearest inode or the root volume header is adhered to. This
3969 * is accomplished by always recursing through matching keyspaces in
3970 * the hammer2_chain_lookup() and hammer2_chain_next() API.
3972 * The current implementation calculates the current worst-case keyspace by
3973 * iterating the current parent and then divides it into two halves, choosing
3974 * whichever half has the most elements (not necessarily the half containing
3975 * the requested key).
3977 * We can also opt to use the half with the least number of elements. This
3978 * causes lower-numbered keys (aka logical file offsets) to recurse through
3979 * fewer indirect blocks and higher-numbered keys to recurse through more.
3980 * This also has the risk of not moving enough elements to the new indirect
3981 * block and being forced to create several indirect blocks before the element
3984 * Must be called with an exclusively locked parent.
3986 * NOTE: *errorp set to HAMMER_ERROR_* flags
3988 static int hammer2_chain_indkey_freemap(hammer2_chain_t *parent,
3989 hammer2_key_t *keyp, int keybits,
3990 hammer2_blockref_t *base, int count);
3991 static int hammer2_chain_indkey_file(hammer2_chain_t *parent,
3992 hammer2_key_t *keyp, int keybits,
3993 hammer2_blockref_t *base, int count,
3995 static int hammer2_chain_indkey_dir(hammer2_chain_t *parent,
3996 hammer2_key_t *keyp, int keybits,
3997 hammer2_blockref_t *base, int count,
4001 hammer2_chain_create_indirect(hammer2_chain_t *parent,
4002 hammer2_key_t create_key, int create_bits,
4003 hammer2_tid_t mtid, int for_type, int *errorp)
4006 hammer2_blockref_t *base;
4007 hammer2_blockref_t *bref;
4008 hammer2_blockref_t bsave;
4009 hammer2_blockref_t dummy;
4010 hammer2_chain_t *chain;
4011 hammer2_chain_t *ichain;
4012 hammer2_key_t key = create_key;
4013 hammer2_key_t key_beg;
4014 hammer2_key_t key_end;
4015 hammer2_key_t key_next;
4016 int keybits = create_bits;
4024 int maxloops = 300000;
4027 * Calculate the base blockref pointer or NULL if the chain
4028 * is known to be empty. We need to calculate the array count
4029 * for RB lookups either way.
4032 KKASSERT(hammer2_mtx_owned(&parent->lock));
4035 * Pre-modify the parent now to avoid having to deal with error
4036 * processing if we tried to later (in the middle of our loop).
4038 * We are going to be moving bref's around, the indirect blocks
4039 * cannot be in an initial state. Do not pass MODIFY_OPTDATA.
4041 *errorp = hammer2_chain_modify(parent, mtid, 0, 0);
4043 kprintf("hammer2_create_indirect: error %08x %s\n",
4044 *errorp, hammer2_error_str(*errorp));
4047 KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0);
4049 /*hammer2_chain_modify(&parent, HAMMER2_MODIFY_OPTDATA);*/
4050 base = hammer2_chain_base_and_count(parent, &count);
4053 * How big should our new indirect block be? It has to be at least
4054 * as large as its parent for splits to work properly.
4056 * The freemap uses a specific indirect block size. The number of
4057 * levels are built dynamically and ultimately depend on the size
4058 * volume. Because freemap blocks are taken from the reserved areas
4059 * of the volume our goal is efficiency (fewer levels) and not so
4060 * much to save disk space.
4062 * The first indirect block level for a directory usually uses
4063 * HAMMER2_IND_BYTES_MIN (4KB = 32 directory entries). Due to
4064 * the hash mechanism, this typically gives us a nominal
4065 * 32 * 4 entries with one level of indirection.
4067 * We use HAMMER2_IND_BYTES_NOM (16KB = 128 blockrefs) for FILE
4068 * indirect blocks. The initial 4 entries in the inode gives us
4069 * 256KB. Up to 4 indirect blocks gives us 32MB. Three levels
4070 * of indirection gives us 137GB, and so forth. H2 can support
4071 * huge file sizes but they are not typical, so we try to stick
4072 * with compactness and do not use a larger indirect block size.
4074 * We could use 64KB (PBUFSIZE), giving us 512 blockrefs, but
4075 * due to the way indirect blocks are created this usually winds
4076 * up being extremely inefficient for small files. Even though
4077 * 16KB requires more levels of indirection for very large files,
4078 * the 16KB records can be ganged together into 64KB DIOs.
4080 if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
4081 for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
4082 nbytes = HAMMER2_FREEMAP_LEVELN_PSIZE;
4083 } else if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) {
4084 if (parent->data->ipdata.meta.type ==
4085 HAMMER2_OBJTYPE_DIRECTORY)
4086 nbytes = HAMMER2_IND_BYTES_MIN; /* 4KB = 32 entries */
4088 nbytes = HAMMER2_IND_BYTES_NOM; /* 16KB = ~8MB file */
4091 nbytes = HAMMER2_IND_BYTES_NOM;
4093 if (nbytes < count * sizeof(hammer2_blockref_t)) {
4094 KKASSERT(for_type != HAMMER2_BREF_TYPE_FREEMAP_NODE &&
4095 for_type != HAMMER2_BREF_TYPE_FREEMAP_LEAF);
4096 nbytes = count * sizeof(hammer2_blockref_t);
4098 ncount = nbytes / sizeof(hammer2_blockref_t);
4101 * When creating an indirect block for a freemap node or leaf
4102 * the key/keybits must be fitted to static radix levels because
4103 * particular radix levels use particular reserved blocks in the
4106 * This routine calculates the key/radix of the indirect block
4107 * we need to create, and whether it is on the high-side or the
4111 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
4112 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
4113 keybits = hammer2_chain_indkey_freemap(parent, &key, keybits,
4116 case HAMMER2_BREF_TYPE_DATA:
4117 keybits = hammer2_chain_indkey_file(parent, &key, keybits,
4118 base, count, ncount);
4120 case HAMMER2_BREF_TYPE_DIRENT:
4121 case HAMMER2_BREF_TYPE_INODE:
4122 keybits = hammer2_chain_indkey_dir(parent, &key, keybits,
4123 base, count, ncount);
4126 panic("illegal indirect block for bref type %d", for_type);
4131 * Normalize the key for the radix being represented, keeping the
4132 * high bits and throwing away the low bits.
4134 key &= ~(((hammer2_key_t)1 << keybits) - 1);
4137 * Ok, create our new indirect block
4139 bzero(&dummy, sizeof(dummy));
4140 if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
4141 for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
4142 dummy.type = HAMMER2_BREF_TYPE_FREEMAP_NODE;
4144 dummy.type = HAMMER2_BREF_TYPE_INDIRECT;
4147 dummy.keybits = keybits;
4148 dummy.data_off = hammer2_getradix(nbytes);
4150 HAMMER2_ENC_CHECK(HAMMER2_DEC_CHECK(parent->bref.methods)) |
4151 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
4153 ichain = hammer2_chain_alloc(hmp, parent->pmp, &dummy);
4154 atomic_set_int(&ichain->flags, HAMMER2_CHAIN_INITIAL);
4155 hammer2_chain_lock(ichain, HAMMER2_RESOLVE_MAYBE);
4156 /* ichain has one ref at this point */
4159 * We have to mark it modified to allocate its block, but use
4160 * OPTDATA to allow it to remain in the INITIAL state. Otherwise
4161 * it won't be acted upon by the flush code.
4163 * XXX remove OPTDATA, we need a fully initialized indirect block to
4164 * be able to move the original blockref.
4166 *errorp = hammer2_chain_modify(ichain, mtid, 0, 0);
4168 kprintf("hammer2_alloc_indirect: error %08x %s\n",
4169 *errorp, hammer2_error_str(*errorp));
4170 hammer2_chain_unlock(ichain);
4171 hammer2_chain_drop(ichain);
4174 KKASSERT((ichain->flags & HAMMER2_CHAIN_INITIAL) == 0);
4177 * Iterate the original parent and move the matching brefs into
4178 * the new indirect block.
4180 * XXX handle flushes.
4183 key_end = HAMMER2_KEY_MAX;
4184 key_next = 0; /* avoid gcc warnings */
4185 hammer2_spin_ex(&parent->core.spin);
4191 * Parent may have been modified, relocating its block array.
4192 * Reload the base pointer.
4194 base = hammer2_chain_base_and_count(parent, &count);
4196 if (++loops > 100000) {
4197 hammer2_spin_unex(&parent->core.spin);
4198 panic("excessive loops r=%d p=%p base/count %p:%d %016jx\n",
4199 reason, parent, base, count, key_next);
4203 * NOTE: spinlock stays intact, returned chain (if not NULL)
4204 * is not referenced or locked which means that we
4205 * cannot safely check its flagged / deletion status
4208 chain = hammer2_combined_find(parent, base, count,
4212 generation = parent->core.generation;
4215 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4218 * Skip keys that are not within the key/radix of the new
4219 * indirect block. They stay in the parent.
4221 if (rounddown2(key ^ bref->key, (hammer2_key_t)1 << keybits) != 0) {
4222 goto next_key_spinlocked;
4226 * Load the new indirect block by acquiring the related
4227 * chains (potentially from media as it might not be
4228 * in-memory). Then move it to the new parent (ichain).
4230 * chain is referenced but not locked. We must lock the
4231 * chain to obtain definitive state.
4236 * Use chain already present in the RBTREE
4238 hammer2_chain_ref(chain);
4239 hammer2_spin_unex(&parent->core.spin);
4240 hammer2_chain_lock(chain, HAMMER2_RESOLVE_NEVER);
4243 * Get chain for blockref element. _get returns NULL
4244 * on insertion race.
4246 hammer2_spin_unex(&parent->core.spin);
4247 chain = hammer2_chain_get(parent, generation, &bsave,
4248 HAMMER2_RESOLVE_NEVER);
4249 if (chain == NULL) {
4251 hammer2_spin_ex(&parent->core.spin);
4257 * This is always live so if the chain has been deleted
4258 * we raced someone and we have to retry.
4260 * NOTE: Lookups can race delete-duplicate because
4261 * delete-duplicate does not lock the parent's core
4262 * (they just use the spinlock on the core).
4264 * (note reversed logic for this one)
4266 if (bcmp(&bsave, &chain->bref, sizeof(bsave)) ||
4267 chain->parent != parent ||
4268 (chain->flags & HAMMER2_CHAIN_DELETED)) {
4269 hammer2_chain_unlock(chain);
4270 hammer2_chain_drop(chain);
4271 if (hammer2_debug & 0x0040) {
4272 kprintf("LOST PARENT RETRY "
4273 "RETRY (%p,%p)->%p %08x\n",
4274 parent, chain->parent, chain, chain->flags);
4276 hammer2_spin_ex(&parent->core.spin);
4281 * Shift the chain to the indirect block.
4283 * WARNING! No reason for us to load chain data, pass NOSTATS
4284 * to prevent delete/insert from trying to access
4285 * inode stats (and thus asserting if there is no
4286 * chain->data loaded).
4288 * WARNING! The (parent, chain) deletion may modify the parent
4289 * and invalidate the base pointer.
4291 * WARNING! Parent must already be marked modified, so we
4292 * can assume that chain_delete always suceeds.
4294 * WARNING! hammer2_chain_repchange() does not have to be
4295 * called (and doesn't work anyway because we are
4296 * only doing a partial shift). A recursion that is
4297 * in-progress can continue at the current parent
4298 * and will be able to properly find its next key.
4300 error = hammer2_chain_delete_obref(parent, chain, mtid, 0,
4302 KKASSERT(error == 0);
4303 hammer2_chain_rename_obref(&ichain, chain, mtid, 0, &bsave);
4304 hammer2_chain_unlock(chain);
4305 hammer2_chain_drop(chain);
4306 KKASSERT(parent->refs > 0);
4308 base = NULL; /* safety */
4309 hammer2_spin_ex(&parent->core.spin);
4310 next_key_spinlocked:
4311 if (--maxloops == 0)
4312 panic("hammer2_chain_create_indirect: maxloops");
4314 if (key_next == 0 || key_next > key_end)
4319 hammer2_spin_unex(&parent->core.spin);
4322 * Insert the new indirect block into the parent now that we've
4323 * cleared out some entries in the parent. We calculated a good
4324 * insertion index in the loop above (ichain->index).
4326 * We don't have to set UPDATE here because we mark ichain
4327 * modified down below (so the normal modified -> flush -> set-moved
4328 * sequence applies).
4330 * The insertion shouldn't race as this is a completely new block
4331 * and the parent is locked.
4333 base = NULL; /* safety, parent modify may change address */
4334 KKASSERT((ichain->flags & HAMMER2_CHAIN_ONRBTREE) == 0);
4335 KKASSERT(parent->core.live_count < count);
4336 hammer2_chain_insert(parent, ichain,
4337 HAMMER2_CHAIN_INSERT_SPIN |
4338 HAMMER2_CHAIN_INSERT_LIVE,
4342 * Make sure flushes propogate after our manual insertion.
4344 hammer2_chain_setflush(ichain);
4345 hammer2_chain_setflush(parent);
4348 * Figure out what to return.
4350 if (rounddown2(create_key ^ key, (hammer2_key_t)1 << keybits)) {
4352 * Key being created is outside the key range,
4353 * return the original parent.
4355 hammer2_chain_unlock(ichain);
4356 hammer2_chain_drop(ichain);
4359 * Otherwise its in the range, return the new parent.
4360 * (leave both the new and old parent locked).
4369 * Do maintenance on an indirect chain. Both parent and chain are locked.
4371 * Returns non-zero if (chain) is deleted, either due to being empty or
4372 * because its children were safely moved into the parent.
4375 hammer2_chain_indirect_maintenance(hammer2_chain_t *parent,
4376 hammer2_chain_t *chain)
4378 hammer2_blockref_t *chain_base;
4379 hammer2_blockref_t *base;
4380 hammer2_blockref_t *bref;
4381 hammer2_blockref_t bsave;
4382 hammer2_key_t key_next;
4383 hammer2_key_t key_beg;
4384 hammer2_key_t key_end;
4385 hammer2_chain_t *sub;
4392 * Make sure we have an accurate live_count
4394 if ((chain->flags & (HAMMER2_CHAIN_INITIAL |
4395 HAMMER2_CHAIN_COUNTEDBREFS)) == 0) {
4396 base = &chain->data->npdata[0];
4397 count = chain->bytes / sizeof(hammer2_blockref_t);
4398 hammer2_chain_countbrefs(chain, base, count);
4402 * If the indirect block is empty we can delete it.
4403 * (ignore deletion error)
4405 if (chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree)) {
4406 hammer2_chain_delete(parent, chain,
4407 chain->bref.modify_tid,
4408 HAMMER2_DELETE_PERMANENT);
4409 hammer2_chain_repchange(parent, chain);
4413 base = hammer2_chain_base_and_count(parent, &count);
4415 if ((parent->flags & (HAMMER2_CHAIN_INITIAL |
4416 HAMMER2_CHAIN_COUNTEDBREFS)) == 0) {
4417 hammer2_chain_countbrefs(parent, base, count);
4421 * Determine if we can collapse chain into parent, calculate
4422 * hysteresis for chain emptiness.
4424 if (parent->core.live_count + chain->core.live_count - 1 > count)
4426 chain_count = chain->bytes / sizeof(hammer2_blockref_t);
4427 if (chain->core.live_count > chain_count * 3 / 4)
4431 * Ok, theoretically we can collapse chain's contents into
4432 * parent. chain is locked, but any in-memory children of chain
4433 * are not. For this to work, we must be able to dispose of any
4434 * in-memory children of chain.
4436 * For now require that there are no in-memory children of chain.
4438 * WARNING! Both chain and parent must remain locked across this
4443 * Parent must be marked modified. Don't try to collapse it if we
4444 * can't mark it modified. Once modified, destroy chain to make room
4445 * and to get rid of what will be a conflicting key (this is included
4446 * in the calculation above). Finally, move the children of chain
4447 * into chain's parent.
4449 * This order creates an accounting problem for bref.embed.stats
4450 * because we destroy chain before we remove its children. Any
4451 * elements whos blockref is already synchronized will be counted
4452 * twice. To deal with the problem we clean out chain's stats prior
4455 error = hammer2_chain_modify(parent, 0, 0, 0);
4457 krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n",
4458 hammer2_error_str(error));
4461 error = hammer2_chain_modify(chain, chain->bref.modify_tid, 0, 0);
4463 krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n",
4464 hammer2_error_str(error));
4468 chain->bref.embed.stats.inode_count = 0;
4469 chain->bref.embed.stats.data_count = 0;
4470 error = hammer2_chain_delete(parent, chain,
4471 chain->bref.modify_tid,
4472 HAMMER2_DELETE_PERMANENT);
4473 KKASSERT(error == 0);
4476 * The combined_find call requires core.spin to be held. One would
4477 * think there wouldn't be any conflicts since we hold chain
4478 * exclusively locked, but the caching mechanism for 0-ref children
4479 * does not require a chain lock.
4481 hammer2_spin_ex(&chain->core.spin);
4485 key_end = HAMMER2_KEY_MAX;
4487 chain_base = &chain->data->npdata[0];
4488 chain_count = chain->bytes / sizeof(hammer2_blockref_t);
4489 sub = hammer2_combined_find(chain, chain_base, chain_count,
4493 generation = chain->core.generation;
4496 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4500 hammer2_chain_ref(sub);
4501 hammer2_spin_unex(&chain->core.spin);
4502 hammer2_chain_lock(sub, HAMMER2_RESOLVE_NEVER);
4504 hammer2_spin_unex(&chain->core.spin);
4505 sub = hammer2_chain_get(chain, generation, &bsave,
4506 HAMMER2_RESOLVE_NEVER);
4508 hammer2_spin_ex(&chain->core.spin);
4512 if (bcmp(&bsave, &sub->bref, sizeof(bsave)) ||
4513 sub->parent != chain ||
4514 (sub->flags & HAMMER2_CHAIN_DELETED)) {
4515 hammer2_chain_unlock(sub);
4516 hammer2_chain_drop(sub);
4517 hammer2_spin_ex(&chain->core.spin);
4518 sub = NULL; /* safety */
4521 error = hammer2_chain_delete_obref(chain, sub,
4522 sub->bref.modify_tid, 0,
4524 KKASSERT(error == 0);
4525 hammer2_chain_rename_obref(&parent, sub,
4526 sub->bref.modify_tid,
4527 HAMMER2_INSERT_SAMEPARENT, &bsave);
4528 hammer2_chain_unlock(sub);
4529 hammer2_chain_drop(sub);
4530 hammer2_spin_ex(&chain->core.spin);
4536 hammer2_spin_unex(&chain->core.spin);
4538 hammer2_chain_repchange(parent, chain);
4544 * Freemap indirect blocks
4546 * Calculate the keybits and highside/lowside of the freemap node the
4547 * caller is creating.
4549 * This routine will specify the next higher-level freemap key/radix
4550 * representing the lowest-ordered set. By doing so, eventually all
4551 * low-ordered sets will be moved one level down.
4553 * We have to be careful here because the freemap reserves a limited
4554 * number of blocks for a limited number of levels. So we can't just
4555 * push indiscriminately.
4558 hammer2_chain_indkey_freemap(hammer2_chain_t *parent, hammer2_key_t *keyp,
4559 int keybits, hammer2_blockref_t *base, int count)
4561 hammer2_chain_t *chain;
4562 hammer2_blockref_t *bref;
4564 hammer2_key_t key_beg;
4565 hammer2_key_t key_end;
4566 hammer2_key_t key_next;
4569 int maxloops = 300000;
4577 * Calculate the range of keys in the array being careful to skip
4578 * slots which are overridden with a deletion.
4581 key_end = HAMMER2_KEY_MAX;
4582 hammer2_spin_ex(&parent->core.spin);
4585 if (--maxloops == 0) {
4586 panic("indkey_freemap shit %p %p:%d\n",
4587 parent, base, count);
4589 chain = hammer2_combined_find(parent, base, count,
4601 * Skip deleted chains.
4603 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
4604 if (key_next == 0 || key_next > key_end)
4611 * Use the full live (not deleted) element for the scan
4612 * iteration. HAMMER2 does not allow partial replacements.
4614 * XXX should be built into hammer2_combined_find().
4616 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4618 if (keybits > bref->keybits) {
4620 keybits = bref->keybits;
4621 } else if (keybits == bref->keybits && bref->key < key) {
4628 hammer2_spin_unex(&parent->core.spin);
4631 * Return the keybits for a higher-level FREEMAP_NODE covering
4635 case HAMMER2_FREEMAP_LEVEL0_RADIX:
4636 keybits = HAMMER2_FREEMAP_LEVEL1_RADIX;
4638 case HAMMER2_FREEMAP_LEVEL1_RADIX:
4639 keybits = HAMMER2_FREEMAP_LEVEL2_RADIX;
4641 case HAMMER2_FREEMAP_LEVEL2_RADIX:
4642 keybits = HAMMER2_FREEMAP_LEVEL3_RADIX;
4644 case HAMMER2_FREEMAP_LEVEL3_RADIX:
4645 keybits = HAMMER2_FREEMAP_LEVEL4_RADIX;
4647 case HAMMER2_FREEMAP_LEVEL4_RADIX:
4648 keybits = HAMMER2_FREEMAP_LEVEL5_RADIX;
4650 case HAMMER2_FREEMAP_LEVEL5_RADIX:
4651 panic("hammer2_chain_indkey_freemap: level too high");
4654 panic("hammer2_chain_indkey_freemap: bad radix");
4663 * File indirect blocks
4665 * Calculate the key/keybits for the indirect block to create by scanning
4666 * existing keys. The key being created is also passed in *keyp and can be
4667 * inside or outside the indirect block. Regardless, the indirect block
4668 * must hold at least two keys in order to guarantee sufficient space.
4670 * We use a modified version of the freemap's fixed radix tree, but taylored
4671 * for file data. Basically we configure an indirect block encompassing the
4675 hammer2_chain_indkey_file(hammer2_chain_t *parent, hammer2_key_t *keyp,
4676 int keybits, hammer2_blockref_t *base, int count,
4679 hammer2_chain_t *chain;
4680 hammer2_blockref_t *bref;
4682 hammer2_key_t key_beg;
4683 hammer2_key_t key_end;
4684 hammer2_key_t key_next;
4688 int maxloops = 300000;
4696 * Calculate the range of keys in the array being careful to skip
4697 * slots which are overridden with a deletion.
4699 * Locate the smallest key.
4702 key_end = HAMMER2_KEY_MAX;
4703 hammer2_spin_ex(&parent->core.spin);
4706 if (--maxloops == 0) {
4707 panic("indkey_freemap shit %p %p:%d\n",
4708 parent, base, count);
4710 chain = hammer2_combined_find(parent, base, count,
4722 * Skip deleted chains.
4724 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
4725 if (key_next == 0 || key_next > key_end)
4732 * Use the full live (not deleted) element for the scan
4733 * iteration. HAMMER2 does not allow partial replacements.
4735 * XXX should be built into hammer2_combined_find().
4737 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4739 if (keybits > bref->keybits) {
4741 keybits = bref->keybits;
4742 } else if (keybits == bref->keybits && bref->key < key) {
4749 hammer2_spin_unex(&parent->core.spin);
4752 * Calculate the static keybits for a higher-level indirect block
4753 * that contains the key.
4758 case HAMMER2_IND_BYTES_MIN / sizeof(hammer2_blockref_t):
4759 nradix = HAMMER2_IND_RADIX_MIN - HAMMER2_BLOCKREF_RADIX;
4761 case HAMMER2_IND_BYTES_NOM / sizeof(hammer2_blockref_t):
4762 nradix = HAMMER2_IND_RADIX_NOM - HAMMER2_BLOCKREF_RADIX;
4764 case HAMMER2_IND_BYTES_MAX / sizeof(hammer2_blockref_t):
4765 nradix = HAMMER2_IND_RADIX_MAX - HAMMER2_BLOCKREF_RADIX;
4768 panic("bad ncount %d\n", ncount);
4774 * The largest radix that can be returned for an indirect block is
4775 * 63 bits. (The largest practical indirect block radix is actually
4776 * 62 bits because the top-level inode or volume root contains four
4777 * entries, but allow 63 to be returned).
4782 return keybits + nradix;
4788 * Directory indirect blocks.
4790 * Covers both the inode index (directory of inodes), and directory contents
4791 * (filenames hardlinked to inodes).
4793 * Because directory keys are hashed we generally try to cut the space in
4794 * half. We accomodate the inode index (which tends to have linearly
4795 * increasing inode numbers) by ensuring that the keyspace is at least large
4796 * enough to fill up the indirect block being created.
4799 hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp,
4800 int keybits, hammer2_blockref_t *base, int count,
4803 hammer2_blockref_t *bref;
4804 hammer2_chain_t *chain;
4805 hammer2_key_t key_beg;
4806 hammer2_key_t key_end;
4807 hammer2_key_t key_next;
4812 int maxloops = 300000;
4815 * NOTE: We can't take a shortcut here anymore for inodes because
4816 * the root directory can contain a mix of inodes and directory
4817 * entries (we used to just return 63 if parent->bref.type was
4818 * HAMMER2_BREF_TYPE_INODE.
4825 * Calculate the range of keys in the array being careful to skip
4826 * slots which are overridden with a deletion.
4829 key_end = HAMMER2_KEY_MAX;
4830 hammer2_spin_ex(&parent->core.spin);
4833 if (--maxloops == 0) {
4834 panic("indkey_freemap shit %p %p:%d\n",
4835 parent, base, count);
4837 chain = hammer2_combined_find(parent, base, count,
4851 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
4852 if (key_next == 0 || key_next > key_end)
4859 * Use the full live (not deleted) element for the scan
4860 * iteration. HAMMER2 does not allow partial replacements.
4862 * XXX should be built into hammer2_combined_find().
4864 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4867 * Expand our calculated key range (key, keybits) to fit
4868 * the scanned key. nkeybits represents the full range
4869 * that we will later cut in half (two halves @ nkeybits - 1).
4872 if (nkeybits < bref->keybits) {
4873 if (bref->keybits > 64) {
4874 kprintf("bad bref chain %p bref %p\n",
4878 nkeybits = bref->keybits;
4880 while (nkeybits < 64 &&
4881 rounddown2(key ^ bref->key, (hammer2_key_t)1 << nkeybits) != 0) {
4886 * If the new key range is larger we have to determine
4887 * which side of the new key range the existing keys fall
4888 * under by checking the high bit, then collapsing the
4889 * locount into the hicount or vise-versa.
4891 if (keybits != nkeybits) {
4892 if (((hammer2_key_t)1 << (nkeybits - 1)) & key) {
4903 * The newly scanned key will be in the lower half or the
4904 * upper half of the (new) key range.
4906 if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key)
4915 hammer2_spin_unex(&parent->core.spin);
4916 bref = NULL; /* now invalid (safety) */
4919 * Adjust keybits to represent half of the full range calculated
4920 * above (radix 63 max) for our new indirect block.
4925 * Expand keybits to hold at least ncount elements. ncount will be
4926 * a power of 2. This is to try to completely fill leaf nodes (at
4927 * least for keys which are not hashes).
4929 * We aren't counting 'in' or 'out', we are counting 'high side'
4930 * and 'low side' based on the bit at (1LL << keybits). We want
4931 * everything to be inside in these cases so shift it all to
4932 * the low or high side depending on the new high bit.
4934 while (((hammer2_key_t)1 << keybits) < ncount) {
4936 if (key & ((hammer2_key_t)1 << keybits)) {
4945 if (hicount > locount)
4946 key |= (hammer2_key_t)1 << keybits;
4948 key &= ~(hammer2_key_t)1 << keybits;
4958 * Directory indirect blocks.
4960 * Covers both the inode index (directory of inodes), and directory contents
4961 * (filenames hardlinked to inodes).
4963 * Because directory keys are hashed we generally try to cut the space in
4964 * half. We accomodate the inode index (which tends to have linearly
4965 * increasing inode numbers) by ensuring that the keyspace is at least large
4966 * enough to fill up the indirect block being created.
4969 hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp,
4970 int keybits, hammer2_blockref_t *base, int count,
4973 hammer2_blockref_t *bref;
4974 hammer2_chain_t *chain;
4975 hammer2_key_t key_beg;
4976 hammer2_key_t key_end;
4977 hammer2_key_t key_next;
4982 int maxloops = 300000;
4985 * Shortcut if the parent is the inode. In this situation the
4986 * parent has 4+1 directory entries and we are creating an indirect
4987 * block capable of holding many more.
4989 if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) {
4998 * Calculate the range of keys in the array being careful to skip
4999 * slots which are overridden with a deletion.
5002 key_end = HAMMER2_KEY_MAX;
5003 hammer2_spin_ex(&parent->core.spin);
5006 if (--maxloops == 0) {
5007 panic("indkey_freemap shit %p %p:%d\n",
5008 parent, base, count);
5010 chain = hammer2_combined_find(parent, base, count,
5024 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
5025 if (key_next == 0 || key_next > key_end)
5032 * Use the full live (not deleted) element for the scan
5033 * iteration. HAMMER2 does not allow partial replacements.
5035 * XXX should be built into hammer2_combined_find().
5037 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
5040 * Expand our calculated key range (key, keybits) to fit
5041 * the scanned key. nkeybits represents the full range
5042 * that we will later cut in half (two halves @ nkeybits - 1).
5045 if (nkeybits < bref->keybits) {
5046 if (bref->keybits > 64) {
5047 kprintf("bad bref chain %p bref %p\n",
5051 nkeybits = bref->keybits;
5053 while (nkeybits < 64 &&
5054 (~(((hammer2_key_t)1 << nkeybits) - 1) &
5055 (key ^ bref->key)) != 0) {
5060 * If the new key range is larger we have to determine
5061 * which side of the new key range the existing keys fall
5062 * under by checking the high bit, then collapsing the
5063 * locount into the hicount or vise-versa.
5065 if (keybits != nkeybits) {
5066 if (((hammer2_key_t)1 << (nkeybits - 1)) & key) {
5077 * The newly scanned key will be in the lower half or the
5078 * upper half of the (new) key range.
5080 if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key)
5089 hammer2_spin_unex(&parent->core.spin);
5090 bref = NULL; /* now invalid (safety) */
5093 * Adjust keybits to represent half of the full range calculated
5094 * above (radix 63 max) for our new indirect block.
5099 * Expand keybits to hold at least ncount elements. ncount will be
5100 * a power of 2. This is to try to completely fill leaf nodes (at
5101 * least for keys which are not hashes).
5103 * We aren't counting 'in' or 'out', we are counting 'high side'
5104 * and 'low side' based on the bit at (1LL << keybits). We want
5105 * everything to be inside in these cases so shift it all to
5106 * the low or high side depending on the new high bit.
5108 while (((hammer2_key_t)1 << keybits) < ncount) {
5110 if (key & ((hammer2_key_t)1 << keybits)) {
5119 if (hicount > locount)
5120 key |= (hammer2_key_t)1 << keybits;
5122 key &= ~(hammer2_key_t)1 << keybits;
5132 * Sets CHAIN_DELETED and remove the chain's blockref from the parent if
5135 * Both parent and chain must be locked exclusively.
5137 * This function will modify the parent if the blockref requires removal
5138 * from the parent's block table.
5140 * This function is NOT recursive. Any entity already pushed into the
5141 * chain (such as an inode) may still need visibility into its contents,
5142 * as well as the ability to read and modify the contents. For example,
5143 * for an unlinked file which is still open.
5145 * Also note that the flusher is responsible for cleaning up empty
5149 hammer2_chain_delete(hammer2_chain_t *parent, hammer2_chain_t *chain,
5150 hammer2_tid_t mtid, int flags)
5154 KKASSERT(hammer2_mtx_owned(&chain->lock));
5157 * Nothing to do if already marked.
5159 * We need the spinlock on the core whos RBTREE contains chain
5160 * to protect against races.
5162 if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) {
5163 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 &&
5164 chain->parent == parent);
5165 error = _hammer2_chain_delete_helper(parent, chain,
5170 * Permanent deletions mark the chain as destroyed.
5172 * NOTE: We do not setflush the chain unless the deletion is
5173 * permanent, since the deletion of a chain does not actually
5174 * require it to be flushed.
5177 if (flags & HAMMER2_DELETE_PERMANENT) {
5178 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY);
5179 hammer2_chain_setflush(chain);
5187 hammer2_chain_delete_obref(hammer2_chain_t *parent, hammer2_chain_t *chain,
5188 hammer2_tid_t mtid, int flags,
5189 hammer2_blockref_t *obref)
5193 KKASSERT(hammer2_mtx_owned(&chain->lock));
5196 * Nothing to do if already marked.
5198 * We need the spinlock on the core whos RBTREE contains chain
5199 * to protect against races.
5201 obref->type = HAMMER2_BREF_TYPE_EMPTY;
5202 if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) {
5203 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 &&
5204 chain->parent == parent);
5205 error = _hammer2_chain_delete_helper(parent, chain,
5206 mtid, flags, obref);
5210 * Permanent deletions mark the chain as destroyed.
5212 * NOTE: We do not setflush the chain unless the deletion is
5213 * permanent, since the deletion of a chain does not actually
5214 * require it to be flushed.
5217 if (flags & HAMMER2_DELETE_PERMANENT) {
5218 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY);
5219 hammer2_chain_setflush(chain);
5227 * Returns the index of the nearest element in the blockref array >= elm.
5228 * Returns (count) if no element could be found.
5230 * Sets *key_nextp to the next key for loop purposes but does not modify
5231 * it if the next key would be higher than the current value of *key_nextp.
5232 * Note that *key_nexp can overflow to 0, which should be tested by the
5235 * WARNING! Must be called with parent's spinlock held. Spinlock remains
5236 * held through the operation.
5239 hammer2_base_find(hammer2_chain_t *parent,
5240 hammer2_blockref_t *base, int count,
5241 hammer2_key_t *key_nextp,
5242 hammer2_key_t key_beg, hammer2_key_t key_end)
5244 hammer2_blockref_t *scan;
5245 hammer2_key_t scan_end;
5250 * Require the live chain's already have their core's counted
5251 * so we can optimize operations.
5253 KKASSERT(parent->flags & HAMMER2_CHAIN_COUNTEDBREFS);
5258 if (count == 0 || base == NULL)
5262 * Sequential optimization using parent->cache_index. This is
5263 * the most likely scenario.
5265 * We can avoid trailing empty entries on live chains, otherwise
5266 * we might have to check the whole block array.
5268 i = parent->cache_index; /* SMP RACE OK */
5270 limit = parent->core.live_zero;
5275 KKASSERT(i < count);
5281 while (i > 0 && (scan->type == HAMMER2_BREF_TYPE_EMPTY ||
5282 scan->key > key_beg)) {
5286 parent->cache_index = i;
5289 * Search forwards, stop when we find a scan element which
5290 * encloses the key or until we know that there are no further
5294 if (scan->type != HAMMER2_BREF_TYPE_EMPTY) {
5295 scan_end = scan->key +
5296 ((hammer2_key_t)1 << scan->keybits) - 1;
5297 if (scan->key > key_beg || scan_end >= key_beg)
5306 parent->cache_index = i;
5310 scan_end = scan->key +
5311 ((hammer2_key_t)1 << scan->keybits);
5312 if (scan_end && (*key_nextp > scan_end ||
5314 *key_nextp = scan_end;
5322 * Do a combined search and return the next match either from the blockref
5323 * array or from the in-memory chain. Sets *bresp to the returned bref in
5324 * both cases, or sets it to NULL if the search exhausted. Only returns
5325 * a non-NULL chain if the search matched from the in-memory chain.
5327 * When no in-memory chain has been found and a non-NULL bref is returned
5331 * The returned chain is not locked or referenced. Use the returned bref
5332 * to determine if the search exhausted or not. Iterate if the base find
5333 * is chosen but matches a deleted chain.
5335 * WARNING! Must be called with parent's spinlock held. Spinlock remains
5336 * held through the operation.
5339 hammer2_combined_find(hammer2_chain_t *parent,
5340 hammer2_blockref_t *base, int count,
5341 hammer2_key_t *key_nextp,
5342 hammer2_key_t key_beg, hammer2_key_t key_end,
5343 hammer2_blockref_t **bresp)
5345 hammer2_blockref_t *bref;
5346 hammer2_chain_t *chain;
5350 * Lookup in block array and in rbtree.
5352 *key_nextp = key_end + 1;
5353 i = hammer2_base_find(parent, base, count, key_nextp,
5355 chain = hammer2_chain_find(parent, key_nextp, key_beg, key_end);
5360 if (i == count && chain == NULL) {
5366 * Only chain matched.
5369 bref = &chain->bref;
5374 * Only blockref matched.
5376 if (chain == NULL) {
5382 * Both in-memory and blockref matched, select the nearer element.
5384 * If both are flush with the left-hand side or both are the
5385 * same distance away, select the chain. In this situation the
5386 * chain must have been loaded from the matching blockmap.
5388 if ((chain->bref.key <= key_beg && base[i].key <= key_beg) ||
5389 chain->bref.key == base[i].key) {
5390 KKASSERT(chain->bref.key == base[i].key);
5391 bref = &chain->bref;
5396 * Select the nearer key
5398 if (chain->bref.key < base[i].key) {
5399 bref = &chain->bref;
5406 * If the bref is out of bounds we've exhausted our search.
5409 if (bref->key > key_end) {
5419 * Locate the specified block array element and delete it. The element
5422 * The spin lock on the related chain must be held.
5424 * NOTE: live_count was adjusted when the chain was deleted, so it does not
5425 * need to be adjusted when we commit the media change.
5428 hammer2_base_delete(hammer2_chain_t *parent,
5429 hammer2_blockref_t *base, int count,
5430 hammer2_chain_t *chain,
5431 hammer2_blockref_t *obref)
5433 hammer2_blockref_t *elm = &chain->bref;
5434 hammer2_blockref_t *scan;
5435 hammer2_key_t key_next;
5439 * Delete element. Expect the element to exist.
5441 * XXX see caller, flush code not yet sophisticated enough to prevent
5442 * re-flushed in some cases.
5444 key_next = 0; /* max range */
5445 i = hammer2_base_find(parent, base, count, &key_next,
5446 elm->key, elm->key);
5448 if (i == count || scan->type == HAMMER2_BREF_TYPE_EMPTY ||
5449 scan->key != elm->key ||
5450 ((chain->flags & HAMMER2_CHAIN_BMAPUPD) == 0 &&
5451 scan->keybits != elm->keybits)) {
5452 hammer2_spin_unex(&parent->core.spin);
5453 panic("delete base %p element not found at %d/%d elm %p\n",
5454 base, i, count, elm);
5459 * Update stats and zero the entry.
5461 * NOTE: Handle radix == 0 (0 bytes) case.
5463 if ((int)(scan->data_off & HAMMER2_OFF_MASK_RADIX)) {
5464 parent->bref.embed.stats.data_count -= (hammer2_off_t)1 <<
5465 (int)(scan->data_off & HAMMER2_OFF_MASK_RADIX);
5467 switch(scan->type) {
5468 case HAMMER2_BREF_TYPE_INODE:
5469 --parent->bref.embed.stats.inode_count;
5471 case HAMMER2_BREF_TYPE_DATA:
5472 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) {
5473 atomic_set_int(&chain->flags,
5474 HAMMER2_CHAIN_HINT_LEAF_COUNT);
5476 if (parent->bref.leaf_count)
5477 --parent->bref.leaf_count;
5480 case HAMMER2_BREF_TYPE_INDIRECT:
5481 if (scan->type != HAMMER2_BREF_TYPE_DATA) {
5482 parent->bref.embed.stats.data_count -=
5483 scan->embed.stats.data_count;
5484 parent->bref.embed.stats.inode_count -=
5485 scan->embed.stats.inode_count;
5487 if (scan->type == HAMMER2_BREF_TYPE_INODE)
5489 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) {
5490 atomic_set_int(&chain->flags,
5491 HAMMER2_CHAIN_HINT_LEAF_COUNT);
5493 if (parent->bref.leaf_count <= scan->leaf_count)
5494 parent->bref.leaf_count = 0;
5496 parent->bref.leaf_count -= scan->leaf_count;
5499 case HAMMER2_BREF_TYPE_DIRENT:
5500 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) {
5501 atomic_set_int(&chain->flags,
5502 HAMMER2_CHAIN_HINT_LEAF_COUNT);
5504 if (parent->bref.leaf_count)
5505 --parent->bref.leaf_count;
5513 bzero(scan, sizeof(*scan));
5516 * We can only optimize parent->core.live_zero for live chains.
5518 if (parent->core.live_zero == i + 1) {
5519 while (--i >= 0 && base[i].type == HAMMER2_BREF_TYPE_EMPTY)
5521 parent->core.live_zero = i + 1;
5525 * Clear appropriate blockmap flags in chain.
5527 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_BMAPPED |
5528 HAMMER2_CHAIN_BMAPUPD);
5532 * Insert the specified element. The block array must not already have the
5533 * element and must have space available for the insertion.
5535 * The spin lock on the related chain must be held.
5537 * NOTE: live_count was adjusted when the chain was deleted, so it does not
5538 * need to be adjusted when we commit the media change.
5541 hammer2_base_insert(hammer2_chain_t *parent,
5542 hammer2_blockref_t *base, int count,
5543 hammer2_chain_t *chain, hammer2_blockref_t *elm)
5545 hammer2_key_t key_next;
5554 * Insert new element. Expect the element to not already exist
5555 * unless we are replacing it.
5557 * XXX see caller, flush code not yet sophisticated enough to prevent
5558 * re-flushed in some cases.
5560 key_next = 0; /* max range */
5561 i = hammer2_base_find(parent, base, count, &key_next,
5562 elm->key, elm->key);
5565 * Shortcut fill optimization, typical ordered insertion(s) may not
5568 KKASSERT(i >= 0 && i <= count);
5571 * Set appropriate blockmap flags in chain (if not NULL)
5574 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPPED);
5577 * Update stats and zero the entry
5579 if ((int)(elm->data_off & HAMMER2_OFF_MASK_RADIX)) {
5580 parent->bref.embed.stats.data_count += (hammer2_off_t)1 <<
5581 (int)(elm->data_off & HAMMER2_OFF_MASK_RADIX);
5584 case HAMMER2_BREF_TYPE_INODE:
5585 ++parent->bref.embed.stats.inode_count;
5587 case HAMMER2_BREF_TYPE_DATA:
5588 if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX)
5589 ++parent->bref.leaf_count;
5591 case HAMMER2_BREF_TYPE_INDIRECT:
5592 if (elm->type != HAMMER2_BREF_TYPE_DATA) {
5593 parent->bref.embed.stats.data_count +=
5594 elm->embed.stats.data_count;
5595 parent->bref.embed.stats.inode_count +=
5596 elm->embed.stats.inode_count;
5598 if (elm->type == HAMMER2_BREF_TYPE_INODE)
5600 if (parent->bref.leaf_count + elm->leaf_count <
5601 HAMMER2_BLOCKREF_LEAF_MAX) {
5602 parent->bref.leaf_count += elm->leaf_count;
5604 parent->bref.leaf_count = HAMMER2_BLOCKREF_LEAF_MAX;
5607 case HAMMER2_BREF_TYPE_DIRENT:
5608 if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX)
5609 ++parent->bref.leaf_count;
5617 * We can only optimize parent->core.live_zero for live chains.
5619 if (i == count && parent->core.live_zero < count) {
5620 i = parent->core.live_zero++;
5625 xkey = elm->key + ((hammer2_key_t)1 << elm->keybits) - 1;
5626 if (i != count && (base[i].key < elm->key || xkey >= base[i].key)) {
5627 hammer2_spin_unex(&parent->core.spin);
5628 panic("insert base %p overlapping elements at %d elm %p\n",
5633 * Try to find an empty slot before or after.
5637 while (j > 0 || k < count) {
5639 if (j >= 0 && base[j].type == HAMMER2_BREF_TYPE_EMPTY) {
5643 bcopy(&base[j+1], &base[j],
5644 (i - j - 1) * sizeof(*base));
5650 if (k < count && base[k].type == HAMMER2_BREF_TYPE_EMPTY) {
5651 bcopy(&base[i], &base[i+1],
5652 (k - i) * sizeof(hammer2_blockref_t));
5656 * We can only update parent->core.live_zero for live
5659 if (parent->core.live_zero <= k)
5660 parent->core.live_zero = k + 1;
5665 panic("hammer2_base_insert: no room!");
5672 for (l = 0; l < count; ++l) {
5673 if (base[l].type != HAMMER2_BREF_TYPE_EMPTY) {
5674 key_next = base[l].key +
5675 ((hammer2_key_t)1 << base[l].keybits) - 1;
5679 while (++l < count) {
5680 if (base[l].type != HAMMER2_BREF_TYPE_EMPTY) {
5681 if (base[l].key <= key_next)
5682 panic("base_insert %d %d,%d,%d fail %p:%d", u, i, j, k, base, l);
5683 key_next = base[l].key +
5684 ((hammer2_key_t)1 << base[l].keybits) - 1;
5694 * Sort the blockref array for the chain. Used by the flush code to
5695 * sort the blockref[] array.
5697 * The chain must be exclusively locked AND spin-locked.
5699 typedef hammer2_blockref_t *hammer2_blockref_p;
5703 hammer2_base_sort_callback(const void *v1, const void *v2)
5705 hammer2_blockref_p bref1 = *(const hammer2_blockref_p *)v1;
5706 hammer2_blockref_p bref2 = *(const hammer2_blockref_p *)v2;
5709 * Make sure empty elements are placed at the end of the array
5711 if (bref1->type == HAMMER2_BREF_TYPE_EMPTY) {
5712 if (bref2->type == HAMMER2_BREF_TYPE_EMPTY)
5715 } else if (bref2->type == HAMMER2_BREF_TYPE_EMPTY) {
5722 if (bref1->key < bref2->key)
5724 if (bref1->key > bref2->key)
5730 hammer2_base_sort(hammer2_chain_t *chain)
5732 hammer2_blockref_t *base;
5735 switch(chain->bref.type) {
5736 case HAMMER2_BREF_TYPE_INODE:
5738 * Special shortcut for embedded data returns the inode
5739 * itself. Callers must detect this condition and access
5740 * the embedded data (the strategy code does this for us).
5742 * This is only applicable to regular files and softlinks.
5744 if (chain->data->ipdata.meta.op_flags &
5745 HAMMER2_OPFLAG_DIRECTDATA) {
5748 base = &chain->data->ipdata.u.blockset.blockref[0];
5749 count = HAMMER2_SET_COUNT;
5751 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
5752 case HAMMER2_BREF_TYPE_INDIRECT:
5754 * Optimize indirect blocks in the INITIAL state to avoid
5757 KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) == 0);
5758 base = &chain->data->npdata[0];
5759 count = chain->bytes / sizeof(hammer2_blockref_t);
5761 case HAMMER2_BREF_TYPE_VOLUME:
5762 base = &chain->data->voldata.sroot_blockset.blockref[0];
5763 count = HAMMER2_SET_COUNT;
5765 case HAMMER2_BREF_TYPE_FREEMAP:
5766 base = &chain->data->blkset.blockref[0];
5767 count = HAMMER2_SET_COUNT;
5770 kprintf("hammer2_chain_lookup: unrecognized "
5771 "blockref(A) type: %d",
5774 tsleep(&base, 0, "dead", 0);
5775 panic("hammer2_base_sort: unrecognized "
5776 "blockref(A) type: %d",
5778 base = NULL; /* safety */
5779 count = 0; /* safety */
5781 kqsort(base, count, sizeof(*base), hammer2_base_sort_callback);
5787 * Chain memory management
5790 hammer2_chain_wait(hammer2_chain_t *chain)
5792 tsleep(chain, 0, "chnflw", 1);
5795 const hammer2_media_data_t *
5796 hammer2_chain_rdata(hammer2_chain_t *chain)
5798 KKASSERT(chain->data != NULL);
5799 return (chain->data);
5802 hammer2_media_data_t *
5803 hammer2_chain_wdata(hammer2_chain_t *chain)
5805 KKASSERT(chain->data != NULL);
5806 return (chain->data);
5810 * Set the check data for a chain. This can be a heavy-weight operation
5811 * and typically only runs on-flush. For file data check data is calculated
5812 * when the logical buffers are flushed.
5815 hammer2_chain_setcheck(hammer2_chain_t *chain, void *bdata)
5817 chain->bref.flags &= ~HAMMER2_BREF_FLAG_ZERO;
5819 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
5820 case HAMMER2_CHECK_NONE:
5822 case HAMMER2_CHECK_DISABLED:
5824 case HAMMER2_CHECK_ISCSI32:
5825 chain->bref.check.iscsi32.value =
5826 hammer2_icrc32(bdata, chain->bytes);
5828 case HAMMER2_CHECK_XXHASH64:
5829 chain->bref.check.xxhash64.value =
5830 XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED);
5832 case HAMMER2_CHECK_SHA192:
5834 SHA256_CTX hash_ctx;
5836 uint8_t digest[SHA256_DIGEST_LENGTH];
5837 uint64_t digest64[SHA256_DIGEST_LENGTH/8];
5840 SHA256_Init(&hash_ctx);
5841 SHA256_Update(&hash_ctx, bdata, chain->bytes);
5842 SHA256_Final(u.digest, &hash_ctx);
5843 u.digest64[2] ^= u.digest64[3];
5845 chain->bref.check.sha192.data,
5846 sizeof(chain->bref.check.sha192.data));
5849 case HAMMER2_CHECK_FREEMAP:
5850 chain->bref.check.freemap.icrc32 =
5851 hammer2_icrc32(bdata, chain->bytes);
5854 kprintf("hammer2_chain_setcheck: unknown check type %02x\n",
5855 chain->bref.methods);
5861 * Characterize a failed check code and try to trace back to the inode.
5864 hammer2_characterize_failed_chain(hammer2_chain_t *chain, uint64_t check,
5867 hammer2_chain_t *lchain;
5868 hammer2_chain_t *ochain;
5871 did = krateprintf(&krate_h2chk,
5872 "chain %016jx.%02x (%s) meth=%02x CHECK FAIL "
5873 "(flags=%08x, bref/data ",
5874 chain->bref.data_off,
5876 hammer2_bref_type_str(&chain->bref),
5877 chain->bref.methods,
5883 kprintf("%08x/%08x)\n",
5884 chain->bref.check.iscsi32.value,
5887 kprintf("%016jx/%016jx)\n",
5888 chain->bref.check.xxhash64.value,
5893 * Run up the chains to try to find the governing inode so we
5896 * XXX This error reporting is not really MPSAFE
5900 while (chain && chain->bref.type != HAMMER2_BREF_TYPE_INODE) {
5902 chain = chain->parent;
5905 if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
5906 ((chain->bref.flags & HAMMER2_BREF_FLAG_PFSROOT) == 0 ||
5907 (lchain->bref.key & HAMMER2_DIRHASH_VISIBLE))) {
5908 kprintf(" Resides at/in inode %ld\n",
5910 } else if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
5911 kprintf(" Resides in inode index - CRITICAL!!!\n");
5913 kprintf(" Resides in root index - CRITICAL!!!\n");
5916 const char *pfsname = "UNKNOWN";
5920 for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
5921 if (ochain->pmp->pfs_hmps[i] == ochain->hmp &&
5922 ochain->pmp->pfs_names[i]) {
5923 pfsname = ochain->pmp->pfs_names[i];
5928 kprintf(" In pfs %s on device %s\n",
5929 pfsname, ochain->hmp->devrepname);
5934 * Returns non-zero on success, 0 on failure.
5937 hammer2_chain_testcheck(hammer2_chain_t *chain, void *bdata)
5943 if (chain->bref.flags & HAMMER2_BREF_FLAG_ZERO)
5946 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
5947 case HAMMER2_CHECK_NONE:
5950 case HAMMER2_CHECK_DISABLED:
5953 case HAMMER2_CHECK_ISCSI32:
5954 check32 = hammer2_icrc32(bdata, chain->bytes);
5955 r = (chain->bref.check.iscsi32.value == check32);
5957 hammer2_characterize_failed_chain(chain, check32, 32);
5959 hammer2_process_icrc32 += chain->bytes;
5961 case HAMMER2_CHECK_XXHASH64:
5962 check64 = XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED);
5963 r = (chain->bref.check.xxhash64.value == check64);
5965 hammer2_characterize_failed_chain(chain, check64, 64);
5967 hammer2_process_xxhash64 += chain->bytes;
5969 case HAMMER2_CHECK_SHA192:
5971 SHA256_CTX hash_ctx;
5973 uint8_t digest[SHA256_DIGEST_LENGTH];
5974 uint64_t digest64[SHA256_DIGEST_LENGTH/8];
5977 SHA256_Init(&hash_ctx);
5978 SHA256_Update(&hash_ctx, bdata, chain->bytes);
5979 SHA256_Final(u.digest, &hash_ctx);
5980 u.digest64[2] ^= u.digest64[3];
5982 chain->bref.check.sha192.data,
5983 sizeof(chain->bref.check.sha192.data)) == 0) {
5987 krateprintf(&krate_h2chk,
5988 "chain %016jx.%02x meth=%02x "
5990 chain->bref.data_off,
5992 chain->bref.methods);
5996 case HAMMER2_CHECK_FREEMAP:
5997 r = (chain->bref.check.freemap.icrc32 ==
5998 hammer2_icrc32(bdata, chain->bytes));
6002 did = krateprintf(&krate_h2chk,
6003 "chain %016jx.%02x meth=%02x "
6005 chain->bref.data_off,
6007 chain->bref.methods);
6009 kprintf("freemap.icrc %08x icrc32 %08x (%d)\n",
6010 chain->bref.check.freemap.icrc32,
6011 hammer2_icrc32(bdata, chain->bytes),
6014 kprintf("dio %p buf %016jx,%d "
6017 chain->dio->bp->b_loffset,
6018 chain->dio->bp->b_bufsize,
6020 chain->dio->bp->b_data);
6026 kprintf("hammer2_chain_setcheck: unknown check type %02x\n",
6027 chain->bref.methods);
6035 * Acquire the chain and parent representing the specified inode for the
6036 * device at the specified cluster index.
6038 * The flags passed in are LOOKUP flags, not RESOLVE flags.
6040 * If we are unable to locate the inode, HAMMER2_ERROR_EIO is returned and
6041 * *chainp will be NULL. *parentp may still be set error or not, or NULL
6042 * if the parent itself could not be resolved.
6044 * The caller may pass-in a locked *parentp and/or *chainp, or neither.
6045 * They will be unlocked and released by this function. The *parentp and
6046 * *chainp representing the located inode are returned locked.
6049 hammer2_chain_inode_find(hammer2_pfs_t *pmp, hammer2_key_t inum,
6050 int clindex, int flags,
6051 hammer2_chain_t **parentp, hammer2_chain_t **chainp)
6053 hammer2_chain_t *parent;
6054 hammer2_chain_t *rchain;
6055 hammer2_key_t key_dummy;
6056 hammer2_inode_t *ip;
6060 resolve_flags = (flags & HAMMER2_LOOKUP_SHARED) ?
6061 HAMMER2_RESOLVE_SHARED : 0;
6064 * Caller expects us to replace these.
6067 hammer2_chain_unlock(*chainp);
6068 hammer2_chain_drop(*chainp);
6072 hammer2_chain_unlock(*parentp);
6073 hammer2_chain_drop(*parentp);
6078 * Be very careful, this is a backend function and we CANNOT
6079 * lock any frontend inode structure we find. But we have to
6080 * look the inode up this way first in case it exists but is
6081 * detached from the radix tree.
6083 ip = hammer2_inode_lookup(pmp, inum);
6085 *chainp = hammer2_inode_chain_and_parent(ip, clindex,
6088 hammer2_inode_drop(ip);
6091 hammer2_chain_unlock(*chainp);
6092 hammer2_chain_drop(*chainp);
6095 hammer2_chain_unlock(*parentp);
6096 hammer2_chain_drop(*parentp);
6102 * Inodes hang off of the iroot (bit 63 is clear, differentiating
6103 * inodes from root directory entries in the key lookup).
6105 parent = hammer2_inode_chain(pmp->iroot, clindex, resolve_flags);
6108 rchain = hammer2_chain_lookup(&parent, &key_dummy,
6112 error = HAMMER2_ERROR_EIO;
6121 * Used by the bulkscan code to snapshot the synchronized storage for
6122 * a volume, allowing it to be scanned concurrently against normal
6126 hammer2_chain_bulksnap(hammer2_dev_t *hmp)
6128 hammer2_chain_t *copy;
6130 copy = hammer2_chain_alloc(hmp, hmp->spmp, &hmp->vchain.bref);
6131 copy->data = kmalloc(sizeof(copy->data->voldata),
6134 hammer2_voldata_lock(hmp);
6135 copy->data->voldata = hmp->volsync;
6136 hammer2_voldata_unlock(hmp);
6142 hammer2_chain_bulkdrop(hammer2_chain_t *copy)
6144 KKASSERT(copy->bref.type == HAMMER2_BREF_TYPE_VOLUME);
6145 KKASSERT(copy->data);
6146 kfree(copy->data, copy->hmp->mchain);
6148 atomic_add_long(&hammer2_chain_allocs, -1);
6149 hammer2_chain_drop(copy);
6153 * Returns non-zero if the chain (INODE or DIRENT) matches the
6157 hammer2_chain_dirent_test(hammer2_chain_t *chain, const char *name,
6160 const hammer2_inode_data_t *ripdata;
6161 const hammer2_dirent_head_t *den;
6163 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
6164 ripdata = &chain->data->ipdata;
6165 if (ripdata->meta.name_len == name_len &&
6166 bcmp(ripdata->filename, name, name_len) == 0) {
6170 if (chain->bref.type == HAMMER2_BREF_TYPE_DIRENT &&
6171 chain->bref.embed.dirent.namlen == name_len) {
6172 den = &chain->bref.embed.dirent;
6173 if (name_len > sizeof(chain->bref.check.buf) &&
6174 bcmp(chain->data->buf, name, name_len) == 0) {
6177 if (name_len <= sizeof(chain->bref.check.buf) &&
6178 bcmp(chain->bref.check.buf, name, name_len) == 0) {