2 * Copyright (c) 2011-2018 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);
86 static struct krate krate_h2me = { .freq = 1 };
89 * Basic RBTree for chains (core->rbtree and core->dbtree). Chains cannot
90 * overlap in the RB trees. Deleted chains are moved from rbtree to either
93 * Chains in delete-duplicate sequences can always iterate through core_entry
94 * to locate the live version of the chain.
96 RB_GENERATE(hammer2_chain_tree, hammer2_chain, rbnode, hammer2_chain_cmp);
99 hammer2_chain_cmp(hammer2_chain_t *chain1, hammer2_chain_t *chain2)
101 hammer2_key_t c1_beg;
102 hammer2_key_t c1_end;
103 hammer2_key_t c2_beg;
104 hammer2_key_t c2_end;
107 * Compare chains. Overlaps are not supposed to happen and catch
108 * any software issues early we count overlaps as a match.
110 c1_beg = chain1->bref.key;
111 c1_end = c1_beg + ((hammer2_key_t)1 << chain1->bref.keybits) - 1;
112 c2_beg = chain2->bref.key;
113 c2_end = c2_beg + ((hammer2_key_t)1 << chain2->bref.keybits) - 1;
115 if (c1_end < c2_beg) /* fully to the left */
117 if (c1_beg > c2_end) /* fully to the right */
119 return(0); /* overlap (must not cross edge boundary) */
123 * Assert that a chain has no media data associated with it.
126 hammer2_chain_assert_no_data(hammer2_chain_t *chain)
128 KKASSERT(chain->dio == NULL);
129 if (chain->bref.type != HAMMER2_BREF_TYPE_VOLUME &&
130 chain->bref.type != HAMMER2_BREF_TYPE_FREEMAP &&
132 panic("hammer2_assert_no_data: chain %p still has data", chain);
137 * Make a chain visible to the flusher. The flusher operates using a top-down
138 * recursion based on the ONFLUSH flag. It locates MODIFIED and UPDATE chains,
139 * flushes them, and updates blocks back to the volume root.
141 * This routine sets the ONFLUSH flag upward from the triggering chain until
142 * it hits an inode root or the volume root. Inode chains serve as inflection
143 * points, requiring the flusher to bridge across trees. Inodes include
144 * regular inodes, PFS roots (pmp->iroot), and the media super root
148 hammer2_chain_setflush(hammer2_chain_t *chain)
150 hammer2_chain_t *parent;
152 if ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) {
153 hammer2_spin_sh(&chain->core.spin);
154 while ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) {
155 atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONFLUSH);
156 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE)
158 if ((parent = chain->parent) == NULL)
160 hammer2_spin_sh(&parent->core.spin);
161 hammer2_spin_unsh(&chain->core.spin);
164 hammer2_spin_unsh(&chain->core.spin);
169 * Allocate a new disconnected chain element representing the specified
170 * bref. chain->refs is set to 1 and the passed bref is copied to
171 * chain->bref. chain->bytes is derived from the bref.
173 * chain->pmp inherits pmp unless the chain is an inode (other than the
176 * NOTE: Returns a referenced but unlocked (because there is no core) chain.
179 hammer2_chain_alloc(hammer2_dev_t *hmp, hammer2_pfs_t *pmp,
180 hammer2_blockref_t *bref)
182 hammer2_chain_t *chain;
186 * Special case - radix of 0 indicates a chain that does not
187 * need a data reference (context is completely embedded in the
190 if ((int)(bref->data_off & HAMMER2_OFF_MASK_RADIX))
191 bytes = 1U << (int)(bref->data_off & HAMMER2_OFF_MASK_RADIX);
195 atomic_add_long(&hammer2_chain_allocs, 1);
198 * Construct the appropriate system structure.
201 case HAMMER2_BREF_TYPE_DIRENT:
202 case HAMMER2_BREF_TYPE_INODE:
203 case HAMMER2_BREF_TYPE_INDIRECT:
204 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
205 case HAMMER2_BREF_TYPE_DATA:
206 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
208 * Chain's are really only associated with the hmp but we
209 * maintain a pmp association for per-mount memory tracking
210 * purposes. The pmp can be NULL.
212 chain = kmalloc(sizeof(*chain), hmp->mchain, M_WAITOK | M_ZERO);
214 case HAMMER2_BREF_TYPE_VOLUME:
215 case HAMMER2_BREF_TYPE_FREEMAP:
217 * Only hammer2_chain_bulksnap() calls this function with these
220 chain = kmalloc(sizeof(*chain), hmp->mchain, M_WAITOK | M_ZERO);
224 panic("hammer2_chain_alloc: unrecognized blockref type: %d",
229 * Initialize the new chain structure. pmp must be set to NULL for
230 * chains belonging to the super-root topology of a device mount.
232 if (pmp == hmp->spmp)
239 chain->bytes = bytes;
241 chain->flags = HAMMER2_CHAIN_ALLOCATED;
242 lockinit(&chain->diolk, "chdio", 0, 0);
245 * Set the PFS boundary flag if this chain represents a PFS root.
247 if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT)
248 atomic_set_int(&chain->flags, HAMMER2_CHAIN_PFSBOUNDARY);
249 hammer2_chain_core_init(chain);
255 * Initialize a chain's core structure. This structure used to be allocated
256 * but is now embedded.
258 * The core is not locked. No additional refs on the chain are made.
259 * (trans) must not be NULL if (core) is not NULL.
262 hammer2_chain_core_init(hammer2_chain_t *chain)
265 * Fresh core under nchain (no multi-homing of ochain's
268 RB_INIT(&chain->core.rbtree); /* live chains */
269 hammer2_mtx_init(&chain->lock, "h2chain");
273 * Add a reference to a chain element, preventing its destruction.
275 * (can be called with spinlock held)
278 hammer2_chain_ref(hammer2_chain_t *chain)
280 if (atomic_fetchadd_int(&chain->refs, 1) == 0) {
282 * Just flag that the chain was used and should be recycled
283 * on the LRU if it encounters it later.
285 if (chain->flags & HAMMER2_CHAIN_ONLRU)
286 atomic_set_int(&chain->flags, HAMMER2_CHAIN_LRUHINT);
290 * REMOVED - reduces contention, lru_list is more heuristical
293 * 0->non-zero transition must ensure that chain is removed
296 * NOTE: Already holding lru_spin here so we cannot call
297 * hammer2_chain_ref() to get it off lru_list, do
300 if (chain->flags & HAMMER2_CHAIN_ONLRU) {
301 hammer2_pfs_t *pmp = chain->pmp;
302 hammer2_spin_ex(&pmp->lru_spin);
303 if (chain->flags & HAMMER2_CHAIN_ONLRU) {
304 atomic_add_int(&pmp->lru_count, -1);
305 atomic_clear_int(&chain->flags,
306 HAMMER2_CHAIN_ONLRU);
307 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
309 hammer2_spin_unex(&pmp->lru_spin);
316 * Ref a locked chain and force the data to be held across an unlock.
317 * Chain must be currently locked. The user of the chain who desires
318 * to release the hold must call hammer2_chain_lock_unhold() to relock
319 * and unhold the chain, then unlock normally, or may simply call
320 * hammer2_chain_drop_unhold() (which is safer against deadlocks).
323 hammer2_chain_ref_hold(hammer2_chain_t *chain)
325 atomic_add_int(&chain->lockcnt, 1);
326 hammer2_chain_ref(chain);
330 * Insert the chain in the core rbtree.
332 * Normal insertions are placed in the live rbtree. Insertion of a deleted
333 * chain is a special case used by the flush code that is placed on the
334 * unstaged deleted list to avoid confusing the live view.
336 #define HAMMER2_CHAIN_INSERT_SPIN 0x0001
337 #define HAMMER2_CHAIN_INSERT_LIVE 0x0002
338 #define HAMMER2_CHAIN_INSERT_RACE 0x0004
342 hammer2_chain_insert(hammer2_chain_t *parent, hammer2_chain_t *chain,
343 int flags, int generation)
345 hammer2_chain_t *xchain;
348 if (flags & HAMMER2_CHAIN_INSERT_SPIN)
349 hammer2_spin_ex(&parent->core.spin);
352 * Interlocked by spinlock, check for race
354 if ((flags & HAMMER2_CHAIN_INSERT_RACE) &&
355 parent->core.generation != generation) {
356 error = HAMMER2_ERROR_EAGAIN;
363 xchain = RB_INSERT(hammer2_chain_tree, &parent->core.rbtree, chain);
364 KASSERT(xchain == NULL,
365 ("hammer2_chain_insert: collision %p %p (key=%016jx)",
366 chain, xchain, chain->bref.key));
367 atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE);
368 chain->parent = parent;
369 ++parent->core.chain_count;
370 ++parent->core.generation; /* XXX incs for _get() too, XXX */
373 * We have to keep track of the effective live-view blockref count
374 * so the create code knows when to push an indirect block.
376 if (flags & HAMMER2_CHAIN_INSERT_LIVE)
377 atomic_add_int(&parent->core.live_count, 1);
379 if (flags & HAMMER2_CHAIN_INSERT_SPIN)
380 hammer2_spin_unex(&parent->core.spin);
385 * Drop the caller's reference to the chain. When the ref count drops to
386 * zero this function will try to disassociate the chain from its parent and
387 * deallocate it, then recursely drop the parent using the implied ref
388 * from the chain's chain->parent.
390 * Nobody should own chain's mutex on the 1->0 transition, unless this drop
391 * races an acquisition by another cpu. Therefore we can loop if we are
392 * unable to acquire the mutex, and refs is unlikely to be 1 unless we again
393 * race against another drop.
395 static hammer2_chain_t *hammer2_chain_lastdrop(hammer2_chain_t *chain,
397 static void hammer2_chain_lru_flush(hammer2_pfs_t *pmp);
400 hammer2_chain_drop(hammer2_chain_t *chain)
404 if (hammer2_debug & 0x200000)
407 KKASSERT(chain->refs > 0);
415 if (hammer2_mtx_ex_try(&chain->lock) == 0)
416 chain = hammer2_chain_lastdrop(chain, 0);
417 /* retry the same chain, or chain from lastdrop */
419 if (atomic_cmpset_int(&chain->refs, refs, refs - 1))
421 /* retry the same chain */
428 * Unhold a held and probably not-locked chain, ensure that the data is
429 * dropped on the 1->0 transition of lockcnt by obtaining an exclusive
430 * lock and then simply unlocking the chain.
433 hammer2_chain_unhold(hammer2_chain_t *chain)
439 lockcnt = chain->lockcnt;
442 if (atomic_cmpset_int(&chain->lockcnt,
443 lockcnt, lockcnt - 1)) {
446 } else if (hammer2_mtx_ex_try(&chain->lock) == 0) {
447 hammer2_chain_unlock(chain);
451 * This situation can easily occur on SMP due to
452 * the gap inbetween the 1->0 transition and the
453 * final unlock. We cannot safely block on the
454 * mutex because lockcnt might go above 1.
456 * XXX Sleep for one tick if it takes too long.
459 if (iter > 1000 + hz) {
460 kprintf("hammer2: h2race1 %p\n", chain);
463 tsleep(&iter, 0, "h2race1", 1);
471 hammer2_chain_drop_unhold(hammer2_chain_t *chain)
473 hammer2_chain_unhold(chain);
474 hammer2_chain_drop(chain);
478 hammer2_chain_rehold(hammer2_chain_t *chain)
480 hammer2_chain_lock(chain, HAMMER2_RESOLVE_SHARED);
481 atomic_add_int(&chain->lockcnt, 1);
482 hammer2_chain_unlock(chain);
486 * Handles the (potential) last drop of chain->refs from 1->0. Called with
487 * the mutex exclusively locked, refs == 1, and lockcnt 0. SMP races are
488 * possible against refs and lockcnt. We must dispose of the mutex on chain.
490 * This function returns an unlocked chain for recursive drop or NULL. It
491 * can return the same chain if it determines it has raced another ref.
495 * When two chains need to be recursively dropped we use the chain we
496 * would otherwise free to placehold the additional chain. It's a bit
497 * convoluted but we can't just recurse without potentially blowing out
500 * The chain cannot be freed if it has any children.
501 * The chain cannot be freed if flagged MODIFIED unless we can dispose of it.
502 * The chain cannot be freed if flagged UPDATE unless we can dispose of it.
503 * Any dedup registration can remain intact.
505 * The core spinlock is allowed to nest child-to-parent (not parent-to-child).
509 hammer2_chain_lastdrop(hammer2_chain_t *chain, int depth)
513 hammer2_chain_t *parent;
514 hammer2_chain_t *rdrop;
517 * We need chain's spinlock to interlock the sub-tree test.
518 * We already have chain's mutex, protecting chain->parent.
520 * Remember that chain->refs can be in flux.
522 hammer2_spin_ex(&chain->core.spin);
524 if (chain->parent != NULL) {
526 * If the chain has a parent the UPDATE bit prevents scrapping
527 * as the chain is needed to properly flush the parent. Try
528 * to complete the 1->0 transition and return NULL. Retry
529 * (return chain) if we are unable to complete the 1->0
530 * transition, else return NULL (nothing more to do).
532 * If the chain has a parent the MODIFIED bit prevents
535 * Chains with UPDATE/MODIFIED are *not* put on the LRU list!
537 if (chain->flags & (HAMMER2_CHAIN_UPDATE |
538 HAMMER2_CHAIN_MODIFIED)) {
539 if (atomic_cmpset_int(&chain->refs, 1, 0)) {
540 hammer2_spin_unex(&chain->core.spin);
541 hammer2_chain_assert_no_data(chain);
542 hammer2_mtx_unlock(&chain->lock);
545 hammer2_spin_unex(&chain->core.spin);
546 hammer2_mtx_unlock(&chain->lock);
550 /* spinlock still held */
551 } else if (chain->bref.type == HAMMER2_BREF_TYPE_VOLUME ||
552 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP) {
554 * Retain the static vchain and fchain. Clear bits that
555 * are not relevant. Do not clear the MODIFIED bit,
556 * and certainly do not put it on the delayed-flush queue.
558 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
561 * The chain has no parent and can be flagged for destruction.
562 * Since it has no parent, UPDATE can also be cleared.
564 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY);
565 if (chain->flags & HAMMER2_CHAIN_UPDATE)
566 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
569 * If the chain has children we must propagate the DESTROY
570 * flag downward and rip the disconnected topology apart.
571 * This is accomplished by calling hammer2_flush() on the
574 * Any dedup is already handled by the underlying DIO, so
575 * we do not have to specifically flush it here.
577 if (chain->core.chain_count) {
578 hammer2_spin_unex(&chain->core.spin);
579 hammer2_flush(chain, HAMMER2_FLUSH_TOP |
581 hammer2_mtx_unlock(&chain->lock);
583 return(chain); /* retry drop */
587 * Otherwise we can scrap the MODIFIED bit if it is set,
588 * and continue along the freeing path.
590 * Be sure to clean-out any dedup bits. Without a parent
591 * this chain will no longer be visible to the flush code.
592 * Easy check data_off to avoid the volume root.
594 if (chain->flags & HAMMER2_CHAIN_MODIFIED) {
595 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED);
596 atomic_add_long(&hammer2_count_modified_chains, -1);
598 hammer2_pfs_memory_wakeup(chain->pmp);
600 /* spinlock still held */
603 /* spinlock still held */
606 * If any children exist we must leave the chain intact with refs == 0.
607 * They exist because chains are retained below us which have refs or
608 * may require flushing.
610 * Retry (return chain) if we fail to transition the refs to 0, else
611 * return NULL indication nothing more to do.
613 * Chains with children are NOT put on the LRU list.
615 if (chain->core.chain_count) {
616 if (atomic_cmpset_int(&chain->refs, 1, 0)) {
617 hammer2_spin_unex(&chain->core.spin);
618 hammer2_chain_assert_no_data(chain);
619 hammer2_mtx_unlock(&chain->lock);
622 hammer2_spin_unex(&chain->core.spin);
623 hammer2_mtx_unlock(&chain->lock);
627 /* spinlock still held */
628 /* no chains left under us */
631 * chain->core has no children left so no accessors can get to our
632 * chain from there. Now we have to lock the parent core to interlock
633 * remaining possible accessors that might bump chain's refs before
634 * we can safely drop chain's refs with intent to free the chain.
637 pmp = chain->pmp; /* can be NULL */
640 parent = chain->parent;
643 * WARNING! chain's spin lock is still held here, and other spinlocks
644 * will be acquired and released in the code below. We
645 * cannot be making fancy procedure calls!
649 * We can cache the chain if it is associated with a pmp
650 * and not flagged as being destroyed or requesting a full
651 * release. In this situation the chain is not removed
652 * from its parent, i.e. it can still be looked up.
654 * We intentionally do not cache DATA chains because these
655 * were likely used to load data into the logical buffer cache
656 * and will not be accessed again for some time.
659 (HAMMER2_CHAIN_DESTROY | HAMMER2_CHAIN_RELEASE)) == 0 &&
661 chain->bref.type != HAMMER2_BREF_TYPE_DATA) {
663 hammer2_spin_ex(&parent->core.spin);
664 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) {
666 * 1->0 transition failed, retry. Do not drop
667 * the chain's data yet!
670 hammer2_spin_unex(&parent->core.spin);
671 hammer2_spin_unex(&chain->core.spin);
672 hammer2_mtx_unlock(&chain->lock);
680 hammer2_chain_assert_no_data(chain);
683 * Make sure we are on the LRU list, clean up excessive
684 * LRU entries. We can only really drop one but there might
685 * be other entries that we can remove from the lru_list
688 * NOTE: HAMMER2_CHAIN_ONLRU may only be safely set when
689 * chain->core.spin AND pmp->lru_spin are held, but
690 * can be safely cleared only holding pmp->lru_spin.
692 if ((chain->flags & HAMMER2_CHAIN_ONLRU) == 0) {
693 hammer2_spin_ex(&pmp->lru_spin);
694 if ((chain->flags & HAMMER2_CHAIN_ONLRU) == 0) {
695 atomic_set_int(&chain->flags,
696 HAMMER2_CHAIN_ONLRU);
697 TAILQ_INSERT_TAIL(&pmp->lru_list,
699 atomic_add_int(&pmp->lru_count, 1);
701 if (pmp->lru_count < HAMMER2_LRU_LIMIT)
702 depth = 1; /* disable lru_list flush */
703 hammer2_spin_unex(&pmp->lru_spin);
705 /* disable lru flush */
710 hammer2_spin_unex(&parent->core.spin);
711 parent = NULL; /* safety */
713 hammer2_spin_unex(&chain->core.spin);
714 hammer2_mtx_unlock(&chain->lock);
717 * lru_list hysteresis (see above for depth overrides).
718 * Note that depth also prevents excessive lastdrop recursion.
721 hammer2_chain_lru_flush(pmp);
728 * Make sure we are not on the LRU list.
730 if (chain->flags & HAMMER2_CHAIN_ONLRU) {
731 hammer2_spin_ex(&pmp->lru_spin);
732 if (chain->flags & HAMMER2_CHAIN_ONLRU) {
733 atomic_add_int(&pmp->lru_count, -1);
734 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
735 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
737 hammer2_spin_unex(&pmp->lru_spin);
741 * Spinlock the parent and try to drop the last ref on chain.
742 * On success determine if we should dispose of the chain
743 * (remove the chain from its parent, etc).
745 * (normal core locks are top-down recursive but we define
746 * core spinlocks as bottom-up recursive, so this is safe).
749 hammer2_spin_ex(&parent->core.spin);
750 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) {
752 * 1->0 transition failed, retry.
754 hammer2_spin_unex(&parent->core.spin);
755 hammer2_spin_unex(&chain->core.spin);
756 hammer2_mtx_unlock(&chain->lock);
762 * 1->0 transition successful, parent spin held to prevent
763 * new lookups, chain spinlock held to protect parent field.
764 * Remove chain from the parent.
766 * If the chain is being removed from the parent's btree but
767 * is not bmapped, we have to adjust live_count downward. If
768 * it is bmapped then the blockref is retained in the parent
769 * as is its associated live_count. This case can occur when
770 * a chain added to the topology is unable to flush and is
771 * then later deleted.
773 if (chain->flags & HAMMER2_CHAIN_ONRBTREE) {
774 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) &&
775 (chain->flags & HAMMER2_CHAIN_BMAPPED) == 0) {
776 atomic_add_int(&parent->core.live_count, -1);
778 RB_REMOVE(hammer2_chain_tree,
779 &parent->core.rbtree, chain);
780 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE);
781 --parent->core.chain_count;
782 chain->parent = NULL;
786 * If our chain was the last chain in the parent's core the
787 * core is now empty and its parent might have to be
788 * re-dropped if it has 0 refs.
790 if (parent->core.chain_count == 0) {
792 atomic_add_int(&rdrop->refs, 1);
794 if (atomic_cmpset_int(&rdrop->refs, 0, 1) == 0)
798 hammer2_spin_unex(&parent->core.spin);
799 parent = NULL; /* safety */
805 if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) {
807 * 1->0 transition failed, retry.
809 hammer2_spin_unex(&parent->core.spin);
810 hammer2_spin_unex(&chain->core.spin);
811 hammer2_mtx_unlock(&chain->lock);
818 * Successful 1->0 transition, no parent, no children... no way for
819 * anyone to ref this chain any more. We can clean-up and free it.
821 * We still have the core spinlock, and core's chain_count is 0.
822 * Any parent spinlock is gone.
824 hammer2_spin_unex(&chain->core.spin);
825 hammer2_chain_assert_no_data(chain);
826 hammer2_mtx_unlock(&chain->lock);
827 KKASSERT(RB_EMPTY(&chain->core.rbtree) &&
828 chain->core.chain_count == 0);
831 * All locks are gone, no pointers remain to the chain, finish
834 KKASSERT((chain->flags & (HAMMER2_CHAIN_UPDATE |
835 HAMMER2_CHAIN_MODIFIED)) == 0);
838 * Once chain resources are gone we can use the now dead chain
839 * structure to placehold what might otherwise require a recursive
840 * drop, because we have potentially two things to drop and can only
841 * return one directly.
843 if (chain->flags & HAMMER2_CHAIN_ALLOCATED) {
844 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ALLOCATED);
846 kfree(chain, hmp->mchain);
850 * Possible chaining loop when parent re-drop needed.
856 * Heuristical flush of the LRU, try to reduce the number of entries
857 * on the LRU to (HAMMER2_LRU_LIMIT * 2 / 3). This procedure is called
858 * only when lru_count exceeds HAMMER2_LRU_LIMIT.
862 hammer2_chain_lru_flush(hammer2_pfs_t *pmp)
864 hammer2_chain_t *chain;
868 hammer2_spin_ex(&pmp->lru_spin);
869 while (pmp->lru_count > HAMMER2_LRU_LIMIT * 2 / 3) {
871 * Pick a chain off the lru_list, just recycle it quickly
872 * if LRUHINT is set (the chain was ref'd but left on
873 * the lru_list, so cycle to the end).
875 chain = TAILQ_FIRST(&pmp->lru_list);
876 TAILQ_REMOVE(&pmp->lru_list, chain, lru_node);
878 if (chain->flags & HAMMER2_CHAIN_LRUHINT) {
879 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_LRUHINT);
880 TAILQ_INSERT_TAIL(&pmp->lru_list, chain, lru_node);
886 * Ok, we are off the LRU. We must adjust refs before we
887 * can safely clear the ONLRU flag.
889 atomic_add_int(&pmp->lru_count, -1);
890 if (atomic_cmpset_int(&chain->refs, 0, 1)) {
891 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
892 atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
895 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONLRU);
898 hammer2_spin_unex(&pmp->lru_spin);
903 * If we picked a chain off the lru list we may be able to lastdrop
904 * it. Use a depth of 1 to prevent excessive lastdrop recursion.
914 if (hammer2_mtx_ex_try(&chain->lock) == 0)
915 chain = hammer2_chain_lastdrop(chain, 1);
916 /* retry the same chain, or chain from lastdrop */
918 if (atomic_cmpset_int(&chain->refs, refs, refs - 1))
920 /* retry the same chain */
928 * On last lock release.
930 static hammer2_io_t *
931 hammer2_chain_drop_data(hammer2_chain_t *chain)
935 if ((dio = chain->dio) != NULL) {
939 switch(chain->bref.type) {
940 case HAMMER2_BREF_TYPE_VOLUME:
941 case HAMMER2_BREF_TYPE_FREEMAP:
944 if (chain->data != NULL) {
945 hammer2_spin_unex(&chain->core.spin);
946 panic("chain data not null: "
947 "chain %p bref %016jx.%02x "
948 "refs %d parent %p dio %p data %p",
949 chain, chain->bref.data_off,
950 chain->bref.type, chain->refs,
952 chain->dio, chain->data);
954 KKASSERT(chain->data == NULL);
962 * Lock a referenced chain element, acquiring its data with I/O if necessary,
963 * and specify how you would like the data to be resolved.
965 * If an I/O or other fatal error occurs, chain->error will be set to non-zero.
967 * The lock is allowed to recurse, multiple locking ops will aggregate
968 * the requested resolve types. Once data is assigned it will not be
969 * removed until the last unlock.
971 * HAMMER2_RESOLVE_NEVER - Do not resolve the data element.
972 * (typically used to avoid device/logical buffer
975 * HAMMER2_RESOLVE_MAYBE - Do not resolve data elements for chains in
976 * the INITIAL-create state (indirect blocks only).
978 * Do not resolve data elements for DATA chains.
979 * (typically used to avoid device/logical buffer
982 * HAMMER2_RESOLVE_ALWAYS- Always resolve the data element.
984 * HAMMER2_RESOLVE_SHARED- (flag) The chain is locked shared, otherwise
985 * it will be locked exclusive.
987 * HAMMER2_RESOLVE_NONBLOCK- (flag) The chain is locked non-blocking. If
988 * the lock fails, EAGAIN is returned.
990 * NOTE: Embedded elements (volume header, inodes) are always resolved
993 * NOTE: Specifying HAMMER2_RESOLVE_ALWAYS on a newly-created non-embedded
994 * element will instantiate and zero its buffer, and flush it on
997 * NOTE: (data) elements are normally locked RESOLVE_NEVER or RESOLVE_MAYBE
998 * so as not to instantiate a device buffer, which could alias against
999 * a logical file buffer. However, if ALWAYS is specified the
1000 * device buffer will be instantiated anyway.
1002 * NOTE: The return value is always 0 unless NONBLOCK is specified, in which
1003 * case it can be either 0 or EAGAIN.
1005 * WARNING! This function blocks on I/O if data needs to be fetched. This
1006 * blocking can run concurrent with other compatible lock holders
1007 * who do not need data returning. The lock is not upgraded to
1008 * exclusive during a data fetch, a separate bit is used to
1009 * interlock I/O. However, an exclusive lock holder can still count
1010 * on being interlocked against an I/O fetch managed by a shared
1014 hammer2_chain_lock(hammer2_chain_t *chain, int how)
1016 KKASSERT(chain->refs > 0);
1018 if (how & HAMMER2_RESOLVE_NONBLOCK) {
1020 * We still have to bump lockcnt before acquiring the lock,
1021 * even for non-blocking operation, because the unlock code
1022 * live-loops on lockcnt == 1 when dropping the last lock.
1024 * If the non-blocking operation fails we have to use an
1025 * unhold sequence to undo the mess.
1027 * NOTE: LOCKAGAIN must always succeed without blocking,
1028 * even if NONBLOCK is specified.
1030 atomic_add_int(&chain->lockcnt, 1);
1031 if (how & HAMMER2_RESOLVE_SHARED) {
1032 if (how & HAMMER2_RESOLVE_LOCKAGAIN) {
1033 hammer2_mtx_sh_again(&chain->lock);
1035 if (hammer2_mtx_sh_try(&chain->lock) != 0) {
1036 hammer2_chain_unhold(chain);
1041 if (hammer2_mtx_ex_try(&chain->lock) != 0) {
1042 hammer2_chain_unhold(chain);
1046 ++curthread->td_tracker;
1049 * Get the appropriate lock. If LOCKAGAIN is flagged with
1050 * SHARED the caller expects a shared lock to already be
1051 * present and we are giving it another ref. This case must
1052 * importantly not block if there is a pending exclusive lock
1055 atomic_add_int(&chain->lockcnt, 1);
1056 if (how & HAMMER2_RESOLVE_SHARED) {
1057 if (how & HAMMER2_RESOLVE_LOCKAGAIN) {
1058 hammer2_mtx_sh_again(&chain->lock);
1060 hammer2_mtx_sh(&chain->lock);
1063 hammer2_mtx_ex(&chain->lock);
1065 ++curthread->td_tracker;
1069 * If we already have a valid data pointer make sure the data is
1070 * synchronized to the current cpu, and then no further action is
1075 hammer2_io_bkvasync(chain->dio);
1080 * Do we have to resolve the data? This is generally only
1081 * applicable to HAMMER2_BREF_TYPE_DATA which is special-cased.
1082 * Other BREF types expects the data to be there.
1084 switch(how & HAMMER2_RESOLVE_MASK) {
1085 case HAMMER2_RESOLVE_NEVER:
1087 case HAMMER2_RESOLVE_MAYBE:
1088 if (chain->flags & HAMMER2_CHAIN_INITIAL)
1090 if (chain->bref.type == HAMMER2_BREF_TYPE_DATA)
1093 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE)
1095 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF)
1099 case HAMMER2_RESOLVE_ALWAYS:
1105 * Caller requires data
1107 hammer2_chain_load_data(chain);
1113 * Lock the chain, retain the hold, and drop the data persistence count.
1114 * The data should remain valid because we never transitioned lockcnt
1118 hammer2_chain_lock_unhold(hammer2_chain_t *chain, int how)
1120 hammer2_chain_lock(chain, how);
1121 atomic_add_int(&chain->lockcnt, -1);
1126 * Downgrade an exclusive chain lock to a shared chain lock.
1128 * NOTE: There is no upgrade equivalent due to the ease of
1129 * deadlocks in that direction.
1132 hammer2_chain_lock_downgrade(hammer2_chain_t *chain)
1134 hammer2_mtx_downgrade(&chain->lock);
1139 * Issue I/O and install chain->data. Caller must hold a chain lock, lock
1140 * may be of any type.
1142 * Once chain->data is set it cannot be disposed of until all locks are
1145 * Make sure the data is synchronized to the current cpu.
1148 hammer2_chain_load_data(hammer2_chain_t *chain)
1150 hammer2_blockref_t *bref;
1157 * Degenerate case, data already present, or chain has no media
1158 * reference to load.
1160 KKASSERT(chain->lock.mtx_lock & MTX_MASK);
1163 hammer2_io_bkvasync(chain->dio);
1166 if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0)
1170 KKASSERT(hmp != NULL);
1173 * Gain the IOINPROG bit, interlocked block.
1179 oflags = chain->flags;
1181 if (oflags & HAMMER2_CHAIN_IOINPROG) {
1182 nflags = oflags | HAMMER2_CHAIN_IOSIGNAL;
1183 tsleep_interlock(&chain->flags, 0);
1184 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) {
1185 tsleep(&chain->flags, PINTERLOCKED,
1190 nflags = oflags | HAMMER2_CHAIN_IOINPROG;
1191 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) {
1199 * We own CHAIN_IOINPROG
1201 * Degenerate case if we raced another load.
1205 hammer2_io_bkvasync(chain->dio);
1210 * We must resolve to a device buffer, either by issuing I/O or
1211 * by creating a zero-fill element. We do not mark the buffer
1212 * dirty when creating a zero-fill element (the hammer2_chain_modify()
1213 * API must still be used to do that).
1215 * The device buffer is variable-sized in powers of 2 down
1216 * to HAMMER2_MIN_ALLOC (typically 1K). A 64K physical storage
1217 * chunk always contains buffers of the same size. (XXX)
1219 * The minimum physical IO size may be larger than the variable
1222 bref = &chain->bref;
1225 * The getblk() optimization can only be used on newly created
1226 * elements if the physical block size matches the request.
1228 if (chain->flags & HAMMER2_CHAIN_INITIAL) {
1229 error = hammer2_io_new(hmp, bref->type,
1230 bref->data_off, chain->bytes,
1233 error = hammer2_io_bread(hmp, bref->type,
1234 bref->data_off, chain->bytes,
1236 hammer2_adjreadcounter(&chain->bref, chain->bytes);
1239 chain->error = HAMMER2_ERROR_EIO;
1240 kprintf("hammer2_chain_lock: I/O error %016jx: %d\n",
1241 (intmax_t)bref->data_off, error);
1242 hammer2_io_bqrelse(&chain->dio);
1248 * This isn't perfect and can be ignored on OSs which do not have
1249 * an indication as to whether a buffer is coming from cache or
1250 * if I/O was actually issued for the read. TESTEDGOOD will work
1251 * pretty well without the B_IOISSUED logic because chains are
1252 * cached, but in that situation (without B_IOISSUED) it will not
1253 * detect whether a re-read via I/O is corrupted verses the original
1256 * We can't re-run the CRC on every fresh lock. That would be
1257 * insanely expensive.
1259 * If the underlying kernel buffer covers the entire chain we can
1260 * use the B_IOISSUED indication to determine if we have to re-run
1261 * the CRC on chain data for chains that managed to stay cached
1262 * across the kernel disposal of the original buffer.
1264 if ((dio = chain->dio) != NULL && dio->bp) {
1265 struct buf *bp = dio->bp;
1267 if (dio->psize == chain->bytes &&
1268 (bp->b_flags & B_IOISSUED)) {
1269 atomic_clear_int(&chain->flags,
1270 HAMMER2_CHAIN_TESTEDGOOD);
1271 bp->b_flags &= ~B_IOISSUED;
1276 * NOTE: A locked chain's data cannot be modified without first
1277 * calling hammer2_chain_modify().
1281 * Clear INITIAL. In this case we used io_new() and the buffer has
1282 * been zero'd and marked dirty.
1284 * NOTE: hammer2_io_data() call issues bkvasync()
1286 bdata = hammer2_io_data(chain->dio, chain->bref.data_off);
1288 if (chain->flags & HAMMER2_CHAIN_INITIAL) {
1289 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1290 chain->bref.flags |= HAMMER2_BREF_FLAG_ZERO;
1291 } else if (chain->flags & HAMMER2_CHAIN_MODIFIED) {
1293 * check data not currently synchronized due to
1294 * modification. XXX assumes data stays in the buffer
1295 * cache, which might not be true (need biodep on flush
1296 * to calculate crc? or simple crc?).
1298 } else if ((chain->flags & HAMMER2_CHAIN_TESTEDGOOD) == 0) {
1299 if (hammer2_chain_testcheck(chain, bdata) == 0) {
1300 chain->error = HAMMER2_ERROR_CHECK;
1302 atomic_set_int(&chain->flags, HAMMER2_CHAIN_TESTEDGOOD);
1307 * Setup the data pointer, either pointing it to an embedded data
1308 * structure and copying the data from the buffer, or pointing it
1311 * The buffer is not retained when copying to an embedded data
1312 * structure in order to avoid potential deadlocks or recursions
1313 * on the same physical buffer.
1315 * WARNING! Other threads can start using the data the instant we
1316 * set chain->data non-NULL.
1318 switch (bref->type) {
1319 case HAMMER2_BREF_TYPE_VOLUME:
1320 case HAMMER2_BREF_TYPE_FREEMAP:
1322 * Copy data from bp to embedded buffer
1324 panic("hammer2_chain_load_data: unresolved volume header");
1326 case HAMMER2_BREF_TYPE_DIRENT:
1327 KKASSERT(chain->bytes != 0);
1329 case HAMMER2_BREF_TYPE_INODE:
1330 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
1331 case HAMMER2_BREF_TYPE_INDIRECT:
1332 case HAMMER2_BREF_TYPE_DATA:
1333 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1336 * Point data at the device buffer and leave dio intact.
1338 chain->data = (void *)bdata;
1343 * Release HAMMER2_CHAIN_IOINPROG and signal waiters if requested.
1350 oflags = chain->flags;
1351 nflags = oflags & ~(HAMMER2_CHAIN_IOINPROG |
1352 HAMMER2_CHAIN_IOSIGNAL);
1353 KKASSERT(oflags & HAMMER2_CHAIN_IOINPROG);
1354 if (atomic_cmpset_int(&chain->flags, oflags, nflags)) {
1355 if (oflags & HAMMER2_CHAIN_IOSIGNAL)
1356 wakeup(&chain->flags);
1363 * Unlock and deref a chain element.
1365 * Remember that the presence of children under chain prevent the chain's
1366 * destruction but do not add additional references, so the dio will still
1370 hammer2_chain_unlock(hammer2_chain_t *chain)
1376 --curthread->td_tracker;
1379 * If multiple locks are present (or being attempted) on this
1380 * particular chain we can just unlock, drop refs, and return.
1382 * Otherwise fall-through on the 1->0 transition.
1385 lockcnt = chain->lockcnt;
1386 KKASSERT(lockcnt > 0);
1389 if (atomic_cmpset_int(&chain->lockcnt,
1390 lockcnt, lockcnt - 1)) {
1391 hammer2_mtx_unlock(&chain->lock);
1394 } else if (hammer2_mtx_upgrade_try(&chain->lock) == 0) {
1395 /* while holding the mutex exclusively */
1396 if (atomic_cmpset_int(&chain->lockcnt, 1, 0))
1400 * This situation can easily occur on SMP due to
1401 * the gap inbetween the 1->0 transition and the
1402 * final unlock. We cannot safely block on the
1403 * mutex because lockcnt might go above 1.
1405 * XXX Sleep for one tick if it takes too long.
1407 if (++iter > 1000) {
1408 if (iter > 1000 + hz) {
1409 kprintf("hammer2: h2race2 %p\n", chain);
1412 tsleep(&iter, 0, "h2race2", 1);
1420 * Last unlock / mutex upgraded to exclusive. Drop the data
1423 dio = hammer2_chain_drop_data(chain);
1425 hammer2_io_bqrelse(&dio);
1426 hammer2_mtx_unlock(&chain->lock);
1430 * Unlock and hold chain data intact
1433 hammer2_chain_unlock_hold(hammer2_chain_t *chain)
1435 atomic_add_int(&chain->lockcnt, 1);
1436 hammer2_chain_unlock(chain);
1440 * Helper to obtain the blockref[] array base and count for a chain.
1442 * XXX Not widely used yet, various use cases need to be validated and
1443 * converted to use this function.
1446 hammer2_blockref_t *
1447 hammer2_chain_base_and_count(hammer2_chain_t *parent, int *countp)
1449 hammer2_blockref_t *base;
1452 if (parent->flags & HAMMER2_CHAIN_INITIAL) {
1455 switch(parent->bref.type) {
1456 case HAMMER2_BREF_TYPE_INODE:
1457 count = HAMMER2_SET_COUNT;
1459 case HAMMER2_BREF_TYPE_INDIRECT:
1460 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1461 count = parent->bytes / sizeof(hammer2_blockref_t);
1463 case HAMMER2_BREF_TYPE_VOLUME:
1464 count = HAMMER2_SET_COUNT;
1466 case HAMMER2_BREF_TYPE_FREEMAP:
1467 count = HAMMER2_SET_COUNT;
1470 panic("hammer2_chain_create_indirect: "
1471 "unrecognized blockref type: %d",
1477 switch(parent->bref.type) {
1478 case HAMMER2_BREF_TYPE_INODE:
1479 base = &parent->data->ipdata.u.blockset.blockref[0];
1480 count = HAMMER2_SET_COUNT;
1482 case HAMMER2_BREF_TYPE_INDIRECT:
1483 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1484 base = &parent->data->npdata[0];
1485 count = parent->bytes / sizeof(hammer2_blockref_t);
1487 case HAMMER2_BREF_TYPE_VOLUME:
1488 base = &parent->data->voldata.
1489 sroot_blockset.blockref[0];
1490 count = HAMMER2_SET_COUNT;
1492 case HAMMER2_BREF_TYPE_FREEMAP:
1493 base = &parent->data->blkset.blockref[0];
1494 count = HAMMER2_SET_COUNT;
1497 panic("hammer2_chain_create_indirect: "
1498 "unrecognized blockref type: %d",
1510 * This counts the number of live blockrefs in a block array and
1511 * also calculates the point at which all remaining blockrefs are empty.
1512 * This routine can only be called on a live chain.
1514 * Caller holds the chain locked, but possibly with a shared lock. We
1515 * must use an exclusive spinlock to prevent corruption.
1517 * NOTE: Flag is not set until after the count is complete, allowing
1518 * callers to test the flag without holding the spinlock.
1520 * NOTE: If base is NULL the related chain is still in the INITIAL
1521 * state and there are no blockrefs to count.
1523 * NOTE: live_count may already have some counts accumulated due to
1524 * creation and deletion and could even be initially negative.
1527 hammer2_chain_countbrefs(hammer2_chain_t *chain,
1528 hammer2_blockref_t *base, int count)
1530 hammer2_spin_ex(&chain->core.spin);
1531 if ((chain->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) {
1533 while (--count >= 0) {
1534 if (base[count].type)
1537 chain->core.live_zero = count + 1;
1538 while (count >= 0) {
1539 if (base[count].type)
1540 atomic_add_int(&chain->core.live_count,
1545 chain->core.live_zero = 0;
1547 /* else do not modify live_count */
1548 atomic_set_int(&chain->flags, HAMMER2_CHAIN_COUNTEDBREFS);
1550 hammer2_spin_unex(&chain->core.spin);
1554 * Resize the chain's physical storage allocation in-place. This function does
1555 * not usually adjust the data pointer and must be followed by (typically) a
1556 * hammer2_chain_modify() call to copy any old data over and adjust the
1559 * Chains can be resized smaller without reallocating the storage. Resizing
1560 * larger will reallocate the storage. Excess or prior storage is reclaimed
1561 * asynchronously at a later time.
1563 * An nradix value of 0 is special-cased to mean that the storage should
1564 * be disassociated, that is the chain is being resized to 0 bytes (not 1
1567 * Must be passed an exclusively locked parent and chain.
1569 * This function is mostly used with DATA blocks locked RESOLVE_NEVER in order
1570 * to avoid instantiating a device buffer that conflicts with the vnode data
1571 * buffer. However, because H2 can compress or encrypt data, the chain may
1572 * have a dio assigned to it in those situations, and they do not conflict.
1574 * XXX return error if cannot resize.
1577 hammer2_chain_resize(hammer2_chain_t *chain,
1578 hammer2_tid_t mtid, hammer2_off_t dedup_off,
1579 int nradix, int flags)
1589 * Only data and indirect blocks can be resized for now.
1590 * (The volu root, inodes, and freemap elements use a fixed size).
1592 KKASSERT(chain != &hmp->vchain);
1593 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA ||
1594 chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT ||
1595 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT);
1598 * Nothing to do if the element is already the proper size
1600 obytes = chain->bytes;
1601 nbytes = (nradix) ? (1U << nradix) : 0;
1602 if (obytes == nbytes)
1603 return (chain->error);
1606 * Make sure the old data is instantiated so we can copy it. If this
1607 * is a data block, the device data may be superfluous since the data
1608 * might be in a logical block, but compressed or encrypted data is
1611 * NOTE: The modify will set BMAPUPD for us if BMAPPED is set.
1613 error = hammer2_chain_modify(chain, mtid, dedup_off, 0);
1618 * Relocate the block, even if making it smaller (because different
1619 * block sizes may be in different regions).
1621 * NOTE: Operation does not copy the data and may only be used
1622 * to resize data blocks in-place, or directory entry blocks
1623 * which are about to be modified in some manner.
1625 error = hammer2_freemap_alloc(chain, nbytes);
1629 chain->bytes = nbytes;
1632 * We don't want the followup chain_modify() to try to copy data
1633 * from the old (wrong-sized) buffer. It won't know how much to
1634 * copy. This case should only occur during writes when the
1635 * originator already has the data to write in-hand.
1638 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA ||
1639 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT);
1640 hammer2_io_brelse(&chain->dio);
1643 return (chain->error);
1647 * Set the chain modified so its data can be changed by the caller, or
1648 * install deduplicated data. The caller must call this routine for each
1649 * set of modifications it makes, even if the chain is already flagged
1652 * Sets bref.modify_tid to mtid only if mtid != 0. Note that bref.modify_tid
1653 * is a CLC (cluster level change) field and is not updated by parent
1654 * propagation during a flush.
1656 * Returns an appropriate HAMMER2_ERROR_* code, which will generally reflect
1657 * chain->error except for HAMMER2_ERROR_ENOSPC. If the allocation fails
1658 * due to no space available, HAMMER2_ERROR_ENOSPC is returned and the chain
1659 * remains unmodified with its old data ref intact and chain->error
1664 * If the DEDUPABLE flag is set in the chain the storage must be reallocated
1665 * even if the chain is still flagged MODIFIED. In this case the chain's
1666 * DEDUPABLE flag will be cleared once the new storage has been assigned.
1668 * If the caller passes a non-zero dedup_off we will use it to assign the
1669 * new storage. The MODIFIED flag will be *CLEARED* in this case, and
1670 * DEDUPABLE will be set (NOTE: the UPDATE flag is always set). The caller
1671 * must not modify the data content upon return.
1674 hammer2_chain_modify(hammer2_chain_t *chain, hammer2_tid_t mtid,
1675 hammer2_off_t dedup_off, int flags)
1677 hammer2_blockref_t obref;
1688 obref = chain->bref;
1689 KKASSERT((chain->flags & HAMMER2_CHAIN_FICTITIOUS) == 0);
1690 KKASSERT(chain->lock.mtx_lock & MTX_EXCLUSIVE);
1693 * Data is not optional for freemap chains (we must always be sure
1694 * to copy the data on COW storage allocations).
1696 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
1697 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
1698 KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) ||
1699 (flags & HAMMER2_MODIFY_OPTDATA) == 0);
1703 * Data must be resolved if already assigned, unless explicitly
1704 * flagged otherwise. If we cannot safety load the data the
1705 * modification fails and we return early.
1707 if (chain->data == NULL && chain->bytes != 0 &&
1708 (flags & HAMMER2_MODIFY_OPTDATA) == 0 &&
1709 (chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX)) {
1710 hammer2_chain_load_data(chain);
1712 return (chain->error);
1717 * Set MODIFIED to indicate that the chain has been modified. A new
1718 * allocation is required when modifying a chain.
1720 * Set UPDATE to ensure that the blockref is updated in the parent.
1722 * If MODIFIED is already set determine if we can reuse the assigned
1723 * data block or if we need a new data block.
1725 if ((chain->flags & HAMMER2_CHAIN_MODIFIED) == 0) {
1727 * Must set modified bit.
1729 atomic_add_long(&hammer2_count_modified_chains, 1);
1730 atomic_set_int(&chain->flags, HAMMER2_CHAIN_MODIFIED);
1731 hammer2_pfs_memory_inc(chain->pmp); /* can be NULL */
1735 * We may be able to avoid a copy-on-write if the chain's
1736 * check mode is set to NONE and the chain's current
1737 * modify_tid is beyond the last explicit snapshot tid.
1739 * This implements HAMMER2's overwrite-in-place feature.
1741 * NOTE! This data-block cannot be used as a de-duplication
1742 * source when the check mode is set to NONE.
1744 if ((chain->bref.type == HAMMER2_BREF_TYPE_DATA ||
1745 chain->bref.type == HAMMER2_BREF_TYPE_DIRENT) &&
1746 (chain->flags & HAMMER2_CHAIN_INITIAL) == 0 &&
1747 (chain->flags & HAMMER2_CHAIN_DEDUPABLE) == 0 &&
1748 HAMMER2_DEC_CHECK(chain->bref.methods) ==
1749 HAMMER2_CHECK_NONE &&
1751 chain->bref.modify_tid >
1752 chain->pmp->iroot->meta.pfs_lsnap_tid) {
1754 * Sector overwrite allowed.
1759 * Sector overwrite not allowed, must copy-on-write.
1763 } else if (chain->flags & HAMMER2_CHAIN_DEDUPABLE) {
1765 * If the modified chain was registered for dedup we need
1766 * a new allocation. This only happens for delayed-flush
1767 * chains (i.e. which run through the front-end buffer
1774 * Already flagged modified, no new allocation is needed.
1781 * Flag parent update required.
1783 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0) {
1784 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
1791 * The XOP code returns held but unlocked focus chains. This
1792 * prevents the chain from being destroyed but does not prevent
1793 * it from being modified. diolk is used to interlock modifications
1794 * against XOP frontend accesses to the focus.
1796 * This allows us to theoretically avoid deadlocking the frontend
1797 * if one of the backends lock up by not formally locking the
1798 * focused chain in the frontend. In addition, the synchronization
1799 * code relies on this mechanism to avoid deadlocking concurrent
1800 * synchronization threads.
1802 lockmgr(&chain->diolk, LK_EXCLUSIVE);
1805 * The modification or re-modification requires an allocation and
1806 * possible COW. If an error occurs, the previous content and data
1807 * reference is retained and the modification fails.
1809 * If dedup_off is non-zero, the caller is requesting a deduplication
1810 * rather than a modification. The MODIFIED bit is not set and the
1811 * data offset is set to the deduplication offset. The data cannot
1814 * NOTE: The dedup offset is allowed to be in a partially free state
1815 * and we must be sure to reset it to a fully allocated state
1816 * to force two bulkfree passes to free it again.
1818 * NOTE: Only applicable when chain->bytes != 0.
1820 * XXX can a chain already be marked MODIFIED without a data
1821 * assignment? If not, assert here instead of testing the case.
1823 if (chain != &hmp->vchain && chain != &hmp->fchain &&
1825 if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0 ||
1829 * NOTE: We do not have to remove the dedup
1830 * registration because the area is still
1831 * allocated and the underlying DIO will
1835 chain->bref.data_off = dedup_off;
1836 chain->bytes = 1 << (dedup_off &
1837 HAMMER2_OFF_MASK_RADIX);
1839 atomic_clear_int(&chain->flags,
1840 HAMMER2_CHAIN_MODIFIED);
1841 atomic_add_long(&hammer2_count_modified_chains,
1844 hammer2_pfs_memory_wakeup(chain->pmp);
1845 hammer2_freemap_adjust(hmp, &chain->bref,
1846 HAMMER2_FREEMAP_DORECOVER);
1847 atomic_set_int(&chain->flags,
1848 HAMMER2_CHAIN_DEDUPABLE);
1850 error = hammer2_freemap_alloc(chain,
1852 atomic_clear_int(&chain->flags,
1853 HAMMER2_CHAIN_DEDUPABLE);
1859 * Stop here if error. We have to undo any flag bits we might
1864 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED);
1865 atomic_add_long(&hammer2_count_modified_chains, -1);
1867 hammer2_pfs_memory_wakeup(chain->pmp);
1870 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
1872 lockmgr(&chain->diolk, LK_RELEASE);
1878 * Update mirror_tid and modify_tid. modify_tid is only updated
1879 * if not passed as zero (during flushes, parent propagation passes
1882 * NOTE: chain->pmp could be the device spmp.
1884 chain->bref.mirror_tid = hmp->voldata.mirror_tid + 1;
1886 chain->bref.modify_tid = mtid;
1889 * Set BMAPUPD to tell the flush code that an existing blockmap entry
1890 * requires updating as well as to tell the delete code that the
1891 * chain's blockref might not exactly match (in terms of physical size
1892 * or block offset) the one in the parent's blocktable. The base key
1893 * of course will still match.
1895 if (chain->flags & HAMMER2_CHAIN_BMAPPED)
1896 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPUPD);
1899 * Short-cut data blocks which the caller does not need an actual
1900 * data reference to (aka OPTDATA), as long as the chain does not
1901 * already have a data pointer to the data. This generally means
1902 * that the modifications are being done via the logical buffer cache.
1903 * The INITIAL flag relates only to the device data buffer and thus
1904 * remains unchange in this situation.
1906 * This code also handles bytes == 0 (most dirents).
1908 if (chain->bref.type == HAMMER2_BREF_TYPE_DATA &&
1909 (flags & HAMMER2_MODIFY_OPTDATA) &&
1910 chain->data == NULL) {
1911 KKASSERT(chain->dio == NULL);
1916 * Clearing the INITIAL flag (for indirect blocks) indicates that
1917 * we've processed the uninitialized storage allocation.
1919 * If this flag is already clear we are likely in a copy-on-write
1920 * situation but we have to be sure NOT to bzero the storage if
1921 * no data is present.
1923 if (chain->flags & HAMMER2_CHAIN_INITIAL) {
1924 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1931 * Instantiate data buffer and possibly execute COW operation
1933 switch(chain->bref.type) {
1934 case HAMMER2_BREF_TYPE_VOLUME:
1935 case HAMMER2_BREF_TYPE_FREEMAP:
1937 * The data is embedded, no copy-on-write operation is
1940 KKASSERT(chain->dio == NULL);
1942 case HAMMER2_BREF_TYPE_DIRENT:
1944 * The data might be fully embedded.
1946 if (chain->bytes == 0) {
1947 KKASSERT(chain->dio == NULL);
1951 case HAMMER2_BREF_TYPE_INODE:
1952 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
1953 case HAMMER2_BREF_TYPE_DATA:
1954 case HAMMER2_BREF_TYPE_INDIRECT:
1955 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
1957 * Perform the copy-on-write operation
1959 * zero-fill or copy-on-write depending on whether
1960 * chain->data exists or not and set the dirty state for
1961 * the new buffer. hammer2_io_new() will handle the
1964 * If a dedup_off was supplied this is an existing block
1965 * and no COW, copy, or further modification is required.
1967 KKASSERT(chain != &hmp->vchain && chain != &hmp->fchain);
1969 if (wasinitial && dedup_off == 0) {
1970 error = hammer2_io_new(hmp, chain->bref.type,
1971 chain->bref.data_off,
1972 chain->bytes, &dio);
1974 error = hammer2_io_bread(hmp, chain->bref.type,
1975 chain->bref.data_off,
1976 chain->bytes, &dio);
1978 hammer2_adjreadcounter(&chain->bref, chain->bytes);
1981 * If an I/O error occurs make sure callers cannot accidently
1982 * modify the old buffer's contents and corrupt the filesystem.
1984 * NOTE: hammer2_io_data() call issues bkvasync()
1987 kprintf("hammer2_chain_modify: hmp=%p I/O error\n",
1989 chain->error = HAMMER2_ERROR_EIO;
1990 hammer2_io_brelse(&dio);
1991 hammer2_io_brelse(&chain->dio);
1996 bdata = hammer2_io_data(dio, chain->bref.data_off);
2000 * COW (unless a dedup).
2002 KKASSERT(chain->dio != NULL);
2003 if (chain->data != (void *)bdata && dedup_off == 0) {
2004 bcopy(chain->data, bdata, chain->bytes);
2006 } else if (wasinitial == 0) {
2008 * We have a problem. We were asked to COW but
2009 * we don't have any data to COW with!
2011 panic("hammer2_chain_modify: having a COW %p\n",
2016 * Retire the old buffer, replace with the new. Dirty or
2017 * redirty the new buffer.
2019 * WARNING! The system buffer cache may have already flushed
2020 * the buffer, so we must be sure to [re]dirty it
2021 * for further modification.
2023 * If dedup_off was supplied, the caller is not
2024 * expected to make any further modification to the
2027 * WARNING! hammer2_get_gdata() assumes dio never transitions
2028 * through NULL in order to optimize away unnecessary
2034 if ((tio = chain->dio) != NULL)
2035 hammer2_io_bqrelse(&tio);
2036 chain->data = (void *)bdata;
2039 hammer2_io_setdirty(dio);
2043 panic("hammer2_chain_modify: illegal non-embedded type %d",
2050 * setflush on parent indicating that the parent must recurse down
2051 * to us. Do not call on chain itself which might already have it
2055 hammer2_chain_setflush(chain->parent);
2056 lockmgr(&chain->diolk, LK_RELEASE);
2058 return (chain->error);
2062 * Modify the chain associated with an inode.
2065 hammer2_chain_modify_ip(hammer2_inode_t *ip, hammer2_chain_t *chain,
2066 hammer2_tid_t mtid, int flags)
2070 hammer2_inode_modify(ip);
2071 error = hammer2_chain_modify(chain, mtid, 0, flags);
2077 * Volume header data locks
2080 hammer2_voldata_lock(hammer2_dev_t *hmp)
2082 lockmgr(&hmp->vollk, LK_EXCLUSIVE);
2086 hammer2_voldata_unlock(hammer2_dev_t *hmp)
2088 lockmgr(&hmp->vollk, LK_RELEASE);
2092 hammer2_voldata_modify(hammer2_dev_t *hmp)
2094 if ((hmp->vchain.flags & HAMMER2_CHAIN_MODIFIED) == 0) {
2095 atomic_add_long(&hammer2_count_modified_chains, 1);
2096 atomic_set_int(&hmp->vchain.flags, HAMMER2_CHAIN_MODIFIED);
2097 hammer2_pfs_memory_inc(hmp->vchain.pmp);
2102 * This function returns the chain at the nearest key within the specified
2103 * range. The returned chain will be referenced but not locked.
2105 * This function will recurse through chain->rbtree as necessary and will
2106 * return a *key_nextp suitable for iteration. *key_nextp is only set if
2107 * the iteration value is less than the current value of *key_nextp.
2109 * The caller should use (*key_nextp) to calculate the actual range of
2110 * the returned element, which will be (key_beg to *key_nextp - 1), because
2111 * there might be another element which is superior to the returned element
2114 * (*key_nextp) can be passed as key_beg in an iteration only while non-NULL
2115 * chains continue to be returned. On EOF (*key_nextp) may overflow since
2116 * it will wind up being (key_end + 1).
2118 * WARNING! Must be called with child's spinlock held. Spinlock remains
2119 * held through the operation.
2121 struct hammer2_chain_find_info {
2122 hammer2_chain_t *best;
2123 hammer2_key_t key_beg;
2124 hammer2_key_t key_end;
2125 hammer2_key_t key_next;
2128 static int hammer2_chain_find_cmp(hammer2_chain_t *child, void *data);
2129 static int hammer2_chain_find_callback(hammer2_chain_t *child, void *data);
2133 hammer2_chain_find(hammer2_chain_t *parent, hammer2_key_t *key_nextp,
2134 hammer2_key_t key_beg, hammer2_key_t key_end)
2136 struct hammer2_chain_find_info info;
2139 info.key_beg = key_beg;
2140 info.key_end = key_end;
2141 info.key_next = *key_nextp;
2143 RB_SCAN(hammer2_chain_tree, &parent->core.rbtree,
2144 hammer2_chain_find_cmp, hammer2_chain_find_callback,
2146 *key_nextp = info.key_next;
2148 kprintf("chain_find %p %016jx:%016jx next=%016jx\n",
2149 parent, key_beg, key_end, *key_nextp);
2157 hammer2_chain_find_cmp(hammer2_chain_t *child, void *data)
2159 struct hammer2_chain_find_info *info = data;
2160 hammer2_key_t child_beg;
2161 hammer2_key_t child_end;
2163 child_beg = child->bref.key;
2164 child_end = child_beg + ((hammer2_key_t)1 << child->bref.keybits) - 1;
2166 if (child_end < info->key_beg)
2168 if (child_beg > info->key_end)
2175 hammer2_chain_find_callback(hammer2_chain_t *child, void *data)
2177 struct hammer2_chain_find_info *info = data;
2178 hammer2_chain_t *best;
2179 hammer2_key_t child_end;
2182 * WARNING! Layerq is scanned forwards, exact matches should keep
2183 * the existing info->best.
2185 if ((best = info->best) == NULL) {
2187 * No previous best. Assign best
2190 } else if (best->bref.key <= info->key_beg &&
2191 child->bref.key <= info->key_beg) {
2196 /*info->best = child;*/
2197 } else if (child->bref.key < best->bref.key) {
2199 * Child has a nearer key and best is not flush with key_beg.
2200 * Set best to child. Truncate key_next to the old best key.
2203 if (info->key_next > best->bref.key || info->key_next == 0)
2204 info->key_next = best->bref.key;
2205 } else if (child->bref.key == best->bref.key) {
2207 * If our current best is flush with the child then this
2208 * is an illegal overlap.
2210 * key_next will automatically be limited to the smaller of
2211 * the two end-points.
2217 * Keep the current best but truncate key_next to the child's
2220 * key_next will also automatically be limited to the smaller
2221 * of the two end-points (probably not necessary for this case
2222 * but we do it anyway).
2224 if (info->key_next > child->bref.key || info->key_next == 0)
2225 info->key_next = child->bref.key;
2229 * Always truncate key_next based on child's end-of-range.
2231 child_end = child->bref.key + ((hammer2_key_t)1 << child->bref.keybits);
2232 if (child_end && (info->key_next > child_end || info->key_next == 0))
2233 info->key_next = child_end;
2239 * Retrieve the specified chain from a media blockref, creating the
2240 * in-memory chain structure which reflects it. The returned chain is
2241 * held and locked according to (how) (HAMMER2_RESOLVE_*). The caller must
2242 * handle crc-checks and so forth, and should check chain->error before
2243 * assuming that the data is good.
2245 * To handle insertion races pass the INSERT_RACE flag along with the
2246 * generation number of the core. NULL will be returned if the generation
2247 * number changes before we have a chance to insert the chain. Insert
2248 * races can occur because the parent might be held shared.
2250 * Caller must hold the parent locked shared or exclusive since we may
2251 * need the parent's bref array to find our block.
2253 * WARNING! chain->pmp is always set to NULL for any chain representing
2254 * part of the super-root topology.
2257 hammer2_chain_get(hammer2_chain_t *parent, int generation,
2258 hammer2_blockref_t *bref, int how)
2260 hammer2_dev_t *hmp = parent->hmp;
2261 hammer2_chain_t *chain;
2265 * Allocate a chain structure representing the existing media
2266 * entry. Resulting chain has one ref and is not locked.
2268 if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT)
2269 chain = hammer2_chain_alloc(hmp, NULL, bref);
2271 chain = hammer2_chain_alloc(hmp, parent->pmp, bref);
2272 /* ref'd chain returned */
2275 * Flag that the chain is in the parent's blockmap so delete/flush
2276 * knows what to do with it.
2278 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPPED);
2281 * chain must be locked to avoid unexpected ripouts
2283 hammer2_chain_lock(chain, how);
2286 * Link the chain into its parent. A spinlock is required to safely
2287 * access the RBTREE, and it is possible to collide with another
2288 * hammer2_chain_get() operation because the caller might only hold
2289 * a shared lock on the parent.
2291 * NOTE: Get races can occur quite often when we distribute
2292 * asynchronous read-aheads across multiple threads.
2294 KKASSERT(parent->refs > 0);
2295 error = hammer2_chain_insert(parent, chain,
2296 HAMMER2_CHAIN_INSERT_SPIN |
2297 HAMMER2_CHAIN_INSERT_RACE,
2300 KKASSERT((chain->flags & HAMMER2_CHAIN_ONRBTREE) == 0);
2301 /*kprintf("chain %p get race\n", chain);*/
2302 hammer2_chain_unlock(chain);
2303 hammer2_chain_drop(chain);
2306 KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE);
2310 * Return our new chain referenced but not locked, or NULL if
2317 * Lookup initialization/completion API
2320 hammer2_chain_lookup_init(hammer2_chain_t *parent, int flags)
2322 hammer2_chain_ref(parent);
2323 if (flags & HAMMER2_LOOKUP_SHARED) {
2324 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS |
2325 HAMMER2_RESOLVE_SHARED);
2327 hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
2333 hammer2_chain_lookup_done(hammer2_chain_t *parent)
2336 hammer2_chain_unlock(parent);
2337 hammer2_chain_drop(parent);
2342 * Take the locked chain and return a locked parent. The chain remains
2343 * locked on return, but may have to be temporarily unlocked to acquire
2344 * the parent. Because of this, (chain) must be stable and cannot be
2345 * deleted while it was temporarily unlocked (typically means that (chain)
2348 * Pass HAMMER2_RESOLVE_* flags in flags.
2350 * This will work even if the chain is errored, and the caller can check
2351 * parent->error on return if desired since the parent will be locked.
2353 * This function handles the lock order reversal.
2356 hammer2_chain_getparent(hammer2_chain_t *chain, int flags)
2358 hammer2_chain_t *parent;
2361 * Be careful of order, chain must be unlocked before parent
2362 * is locked below to avoid a deadlock. Try it trivially first.
2364 parent = chain->parent;
2366 panic("hammer2_chain_getparent: no parent");
2367 hammer2_chain_ref(parent);
2368 if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0)
2372 hammer2_chain_unlock(chain);
2373 hammer2_chain_lock(parent, flags);
2374 hammer2_chain_lock(chain, flags);
2377 * Parent relinking races are quite common. We have to get
2378 * it right or we will blow up the block table.
2380 if (chain->parent == parent)
2382 hammer2_chain_unlock(parent);
2383 hammer2_chain_drop(parent);
2385 parent = chain->parent;
2387 panic("hammer2_chain_getparent: no parent");
2388 hammer2_chain_ref(parent);
2394 * Take the locked chain and return a locked parent. The chain is unlocked
2395 * and dropped. *chainp is set to the returned parent as a convenience.
2396 * Pass HAMMER2_RESOLVE_* flags in flags.
2398 * This will work even if the chain is errored, and the caller can check
2399 * parent->error on return if desired since the parent will be locked.
2401 * The chain does NOT need to be stable. We use a tracking structure
2402 * to track the expected parent if the chain is deleted out from under us.
2404 * This function handles the lock order reversal.
2407 hammer2_chain_repparent(hammer2_chain_t **chainp, int flags)
2409 hammer2_chain_t *chain;
2410 hammer2_chain_t *parent;
2411 struct hammer2_reptrack reptrack;
2412 struct hammer2_reptrack **repp;
2415 * Be careful of order, chain must be unlocked before parent
2416 * is locked below to avoid a deadlock. Try it trivially first.
2419 parent = chain->parent;
2420 if (parent == NULL) {
2421 hammer2_spin_unex(&chain->core.spin);
2422 panic("hammer2_chain_repparent: no parent");
2424 hammer2_chain_ref(parent);
2425 if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0) {
2426 hammer2_chain_unlock(chain);
2427 hammer2_chain_drop(chain);
2434 * Ok, now it gets a bit nasty. There are multiple situations where
2435 * the parent might be in the middle of a deletion, or where the child
2436 * (chain) might be deleted the instant we let go of its lock.
2437 * We can potentially end up in a no-win situation!
2439 * In particular, the indirect_maintenance() case can cause these
2442 * To deal with this we install a reptrack structure in the parent
2443 * This reptrack structure 'owns' the parent ref and will automatically
2444 * migrate to the parent's parent if the parent is deleted permanently.
2446 hammer2_spin_init(&reptrack.spin, "h2reptrk");
2447 reptrack.chain = parent;
2448 hammer2_chain_ref(parent); /* for the reptrack */
2450 hammer2_spin_ex(&parent->core.spin);
2451 reptrack.next = parent->core.reptrack;
2452 parent->core.reptrack = &reptrack;
2453 hammer2_spin_unex(&parent->core.spin);
2455 hammer2_chain_unlock(chain);
2456 hammer2_chain_drop(chain);
2457 chain = NULL; /* gone */
2460 * At the top of this loop, chain is gone and parent is refd both
2461 * by us explicitly AND via our reptrack. We are attempting to
2465 hammer2_chain_lock(parent, flags);
2467 if (reptrack.chain == parent)
2469 hammer2_chain_unlock(parent);
2470 hammer2_chain_drop(parent);
2472 kprintf("hammer2: debug REPTRACK %p->%p\n",
2473 parent, reptrack.chain);
2474 hammer2_spin_ex(&reptrack.spin);
2475 parent = reptrack.chain;
2476 hammer2_chain_ref(parent);
2477 hammer2_spin_unex(&reptrack.spin);
2481 * Once parent is locked and matches our reptrack, our reptrack
2482 * will be stable and we have our parent. We can unlink our
2485 * WARNING! Remember that the chain lock might be shared. Chains
2486 * locked shared have stable parent linkages.
2488 hammer2_spin_ex(&parent->core.spin);
2489 repp = &parent->core.reptrack;
2490 while (*repp != &reptrack)
2491 repp = &(*repp)->next;
2492 *repp = reptrack.next;
2493 hammer2_spin_unex(&parent->core.spin);
2495 hammer2_chain_drop(parent); /* reptrack ref */
2496 *chainp = parent; /* return parent lock+ref */
2502 * Dispose of any linked reptrack structures in (chain) by shifting them to
2503 * (parent). Both (chain) and (parent) must be exclusively locked.
2505 * This is interlocked against any children of (chain) on the other side.
2506 * No children so remain as-of when this is called so we can test
2507 * core.reptrack without holding the spin-lock.
2509 * Used whenever the caller intends to permanently delete chains related
2510 * to topological recursions (BREF_TYPE_INDIRECT, BREF_TYPE_FREEMAP_NODE),
2511 * where the chains underneath the node being deleted are given a new parent
2512 * above the node being deleted.
2516 hammer2_chain_repchange(hammer2_chain_t *parent, hammer2_chain_t *chain)
2518 struct hammer2_reptrack *reptrack;
2520 KKASSERT(chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree));
2521 while (chain->core.reptrack) {
2522 hammer2_spin_ex(&parent->core.spin);
2523 hammer2_spin_ex(&chain->core.spin);
2524 reptrack = chain->core.reptrack;
2525 if (reptrack == NULL) {
2526 hammer2_spin_unex(&chain->core.spin);
2527 hammer2_spin_unex(&parent->core.spin);
2530 hammer2_spin_ex(&reptrack->spin);
2531 chain->core.reptrack = reptrack->next;
2532 reptrack->chain = parent;
2533 reptrack->next = parent->core.reptrack;
2534 parent->core.reptrack = reptrack;
2535 hammer2_chain_ref(parent); /* reptrack */
2537 hammer2_spin_unex(&chain->core.spin);
2538 hammer2_spin_unex(&parent->core.spin);
2539 kprintf("hammer2: debug repchange %p %p->%p\n",
2540 reptrack, chain, parent);
2541 hammer2_chain_drop(chain); /* reptrack */
2546 * Locate the first chain whos key range overlaps (key_beg, key_end) inclusive.
2547 * (*parentp) typically points to an inode but can also point to a related
2548 * indirect block and this function will recurse upwards and find the inode
2549 * or the nearest undeleted indirect block covering the key range.
2551 * This function unconditionally sets *errorp, replacing any previous value.
2553 * (*parentp) must be exclusive or shared locked (depending on flags) and
2554 * referenced and can be an inode or an existing indirect block within the
2557 * If (*parent) is errored out, this function will not attempt to recurse
2558 * the radix tree and will return NULL along with an appropriate *errorp.
2559 * If NULL is returned and *errorp is 0, the requested lookup could not be
2562 * On return (*parentp) will be modified to point at the deepest parent chain
2563 * element encountered during the search, as a helper for an insertion or
2566 * The new (*parentp) will be locked shared or exclusive (depending on flags),
2567 * and referenced, and the old will be unlocked and dereferenced (no change
2568 * if they are both the same). This is particularly important if the caller
2569 * wishes to insert a new chain, (*parentp) will be set properly even if NULL
2570 * is returned, as long as no error occurred.
2572 * The matching chain will be returned locked according to flags.
2576 * NULL is returned if no match was found, but (*parentp) will still
2577 * potentially be adjusted.
2579 * On return (*key_nextp) will point to an iterative value for key_beg.
2580 * (If NULL is returned (*key_nextp) is set to (key_end + 1)).
2582 * This function will also recurse up the chain if the key is not within the
2583 * current parent's range. (*parentp) can never be set to NULL. An iteration
2584 * can simply allow (*parentp) to float inside the loop.
2586 * NOTE! chain->data is not always resolved. By default it will not be
2587 * resolved for BREF_TYPE_DATA, FREEMAP_NODE, or FREEMAP_LEAF. Use
2588 * HAMMER2_LOOKUP_ALWAYS to force resolution (but be careful w/
2589 * BREF_TYPE_DATA as the device buffer can alias the logical file
2594 hammer2_chain_lookup(hammer2_chain_t **parentp, hammer2_key_t *key_nextp,
2595 hammer2_key_t key_beg, hammer2_key_t key_end,
2596 int *errorp, int flags)
2599 hammer2_chain_t *parent;
2600 hammer2_chain_t *chain;
2601 hammer2_blockref_t *base;
2602 hammer2_blockref_t *bref;
2603 hammer2_blockref_t bcopy;
2604 hammer2_key_t scan_beg;
2605 hammer2_key_t scan_end;
2607 int how_always = HAMMER2_RESOLVE_ALWAYS;
2608 int how_maybe = HAMMER2_RESOLVE_MAYBE;
2611 int maxloops = 300000;
2612 volatile hammer2_mtx_t save_mtx;
2614 if (flags & HAMMER2_LOOKUP_ALWAYS) {
2615 how_maybe = how_always;
2616 how = HAMMER2_RESOLVE_ALWAYS;
2617 } else if (flags & HAMMER2_LOOKUP_NODATA) {
2618 how = HAMMER2_RESOLVE_NEVER;
2620 how = HAMMER2_RESOLVE_MAYBE;
2622 if (flags & HAMMER2_LOOKUP_SHARED) {
2623 how_maybe |= HAMMER2_RESOLVE_SHARED;
2624 how_always |= HAMMER2_RESOLVE_SHARED;
2625 how |= HAMMER2_RESOLVE_SHARED;
2629 * Recurse (*parentp) upward if necessary until the parent completely
2630 * encloses the key range or we hit the inode.
2632 * Handle races against the flusher deleting indirect nodes on its
2633 * way back up by continuing to recurse upward past the deletion.
2639 while (parent->bref.type == HAMMER2_BREF_TYPE_INDIRECT ||
2640 parent->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2641 scan_beg = parent->bref.key;
2642 scan_end = scan_beg +
2643 ((hammer2_key_t)1 << parent->bref.keybits) - 1;
2644 if ((parent->flags & HAMMER2_CHAIN_DELETED) == 0) {
2645 if (key_beg >= scan_beg && key_end <= scan_end)
2648 parent = hammer2_chain_repparent(parentp, how_maybe);
2651 if (--maxloops == 0)
2652 panic("hammer2_chain_lookup: maxloops");
2654 * Locate the blockref array. Currently we do a fully associative
2655 * search through the array.
2657 switch(parent->bref.type) {
2658 case HAMMER2_BREF_TYPE_INODE:
2660 * Special shortcut for embedded data returns the inode
2661 * itself. Callers must detect this condition and access
2662 * the embedded data (the strategy code does this for us).
2664 * This is only applicable to regular files and softlinks.
2666 * We need a second lock on parent. Since we already have
2667 * a lock we must pass LOCKAGAIN to prevent unexpected
2668 * blocking (we don't want to block on a second shared
2669 * ref if an exclusive lock is pending)
2671 if (parent->data->ipdata.meta.op_flags &
2672 HAMMER2_OPFLAG_DIRECTDATA) {
2673 if (flags & HAMMER2_LOOKUP_NODIRECT) {
2675 *key_nextp = key_end + 1;
2678 hammer2_chain_ref(parent);
2679 hammer2_chain_lock(parent, how_always |
2680 HAMMER2_RESOLVE_LOCKAGAIN);
2681 *key_nextp = key_end + 1;
2684 base = &parent->data->ipdata.u.blockset.blockref[0];
2685 count = HAMMER2_SET_COUNT;
2687 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
2688 case HAMMER2_BREF_TYPE_INDIRECT:
2690 * Handle MATCHIND on the parent
2692 if (flags & HAMMER2_LOOKUP_MATCHIND) {
2693 scan_beg = parent->bref.key;
2694 scan_end = scan_beg +
2695 ((hammer2_key_t)1 << parent->bref.keybits) - 1;
2696 if (key_beg == scan_beg && key_end == scan_end) {
2698 hammer2_chain_ref(chain);
2699 hammer2_chain_lock(chain, how_maybe);
2700 *key_nextp = scan_end + 1;
2706 * Optimize indirect blocks in the INITIAL state to avoid
2709 if (parent->flags & HAMMER2_CHAIN_INITIAL) {
2712 if (parent->data == NULL) {
2713 kprintf("parent->data is NULL %p\n", parent);
2715 tsleep(parent, 0, "xxx", 0);
2717 base = &parent->data->npdata[0];
2719 count = parent->bytes / sizeof(hammer2_blockref_t);
2721 case HAMMER2_BREF_TYPE_VOLUME:
2722 base = &parent->data->voldata.sroot_blockset.blockref[0];
2723 count = HAMMER2_SET_COUNT;
2725 case HAMMER2_BREF_TYPE_FREEMAP:
2726 base = &parent->data->blkset.blockref[0];
2727 count = HAMMER2_SET_COUNT;
2730 kprintf("hammer2_chain_lookup: unrecognized "
2731 "blockref(B) type: %d",
2734 tsleep(&base, 0, "dead", 0);
2735 panic("hammer2_chain_lookup: unrecognized "
2736 "blockref(B) type: %d",
2738 base = NULL; /* safety */
2739 count = 0; /* safety */
2743 * No lookup is possible if the parent is errored. We delayed
2744 * this check as long as we could to ensure that the parent backup,
2745 * embedded data, and MATCHIND code could still execute.
2747 if (parent->error) {
2748 *errorp = parent->error;
2753 * Merged scan to find next candidate.
2755 * hammer2_base_*() functions require the parent->core.live_* fields
2756 * to be synchronized.
2758 * We need to hold the spinlock to access the block array and RB tree
2759 * and to interlock chain creation.
2761 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0)
2762 hammer2_chain_countbrefs(parent, base, count);
2767 hammer2_spin_ex(&parent->core.spin);
2768 chain = hammer2_combined_find(parent, base, count,
2772 generation = parent->core.generation;
2775 * Exhausted parent chain, iterate.
2778 KKASSERT(chain == NULL);
2779 hammer2_spin_unex(&parent->core.spin);
2780 if (key_beg == key_end) /* short cut single-key case */
2784 * Stop if we reached the end of the iteration.
2786 if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT &&
2787 parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2792 * Calculate next key, stop if we reached the end of the
2793 * iteration, otherwise go up one level and loop.
2795 key_beg = parent->bref.key +
2796 ((hammer2_key_t)1 << parent->bref.keybits);
2797 if (key_beg == 0 || key_beg > key_end)
2799 parent = hammer2_chain_repparent(parentp, how_maybe);
2804 * Selected from blockref or in-memory chain.
2807 if (chain == NULL) {
2808 hammer2_spin_unex(&parent->core.spin);
2809 if (bcopy.type == HAMMER2_BREF_TYPE_INDIRECT ||
2810 bcopy.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2811 chain = hammer2_chain_get(parent, generation,
2814 chain = hammer2_chain_get(parent, generation,
2820 hammer2_chain_ref(chain);
2821 hammer2_spin_unex(&parent->core.spin);
2824 * chain is referenced but not locked. We must lock the
2825 * chain to obtain definitive state.
2827 if (bcopy.type == HAMMER2_BREF_TYPE_INDIRECT ||
2828 bcopy.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2829 hammer2_chain_lock(chain, how_maybe);
2831 hammer2_chain_lock(chain, how);
2833 KKASSERT(chain->parent == parent);
2835 if (bcmp(&bcopy, &chain->bref, sizeof(bcopy)) ||
2836 chain->parent != parent) {
2837 hammer2_chain_unlock(chain);
2838 hammer2_chain_drop(chain);
2839 chain = NULL; /* SAFETY */
2845 * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX)
2847 * NOTE: Chain's key range is not relevant as there might be
2848 * one-offs within the range that are not deleted.
2850 * NOTE: Lookups can race delete-duplicate because
2851 * delete-duplicate does not lock the parent's core
2852 * (they just use the spinlock on the core).
2854 if (chain->flags & HAMMER2_CHAIN_DELETED) {
2855 kprintf("skip deleted chain %016jx.%02x key=%016jx\n",
2856 chain->bref.data_off, chain->bref.type,
2858 hammer2_chain_unlock(chain);
2859 hammer2_chain_drop(chain);
2860 chain = NULL; /* SAFETY */
2861 key_beg = *key_nextp;
2862 if (key_beg == 0 || key_beg > key_end)
2868 * If the chain element is an indirect block it becomes the new
2869 * parent and we loop on it. We must maintain our top-down locks
2870 * to prevent the flusher from interfering (i.e. doing a
2871 * delete-duplicate and leaving us recursing down a deleted chain).
2873 * The parent always has to be locked with at least RESOLVE_MAYBE
2874 * so we can access its data. It might need a fixup if the caller
2875 * passed incompatible flags. Be careful not to cause a deadlock
2876 * as a data-load requires an exclusive lock.
2878 * If HAMMER2_LOOKUP_MATCHIND is set and the indirect block's key
2879 * range is within the requested key range we return the indirect
2880 * block and do NOT loop. This is usually only used to acquire
2883 if (chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT ||
2884 chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2885 save_mtx = parent->lock;
2886 hammer2_chain_unlock(parent);
2887 hammer2_chain_drop(parent);
2888 *parentp = parent = chain;
2889 chain = NULL; /* SAFETY */
2894 * All done, return the locked chain.
2896 * If the caller does not want a locked chain, replace the lock with
2897 * a ref. Perhaps this can eventually be optimized to not obtain the
2898 * lock in the first place for situations where the data does not
2899 * need to be resolved.
2901 * NOTE! A chain->error must be tested by the caller upon return.
2902 * *errorp is only set based on issues which occur while
2903 * trying to reach the chain.
2909 * After having issued a lookup we can iterate all matching keys.
2911 * If chain is non-NULL we continue the iteration from just after it's index.
2913 * If chain is NULL we assume the parent was exhausted and continue the
2914 * iteration at the next parent.
2916 * If a fatal error occurs (typically an I/O error), a dummy chain is
2917 * returned with chain->error and error-identifying information set. This
2918 * chain will assert if you try to do anything fancy with it.
2920 * XXX Depending on where the error occurs we should allow continued iteration.
2922 * parent must be locked on entry and remains locked throughout. chain's
2923 * lock status must match flags. Chain is always at least referenced.
2925 * WARNING! The MATCHIND flag does not apply to this function.
2928 hammer2_chain_next(hammer2_chain_t **parentp, hammer2_chain_t *chain,
2929 hammer2_key_t *key_nextp,
2930 hammer2_key_t key_beg, hammer2_key_t key_end,
2931 int *errorp, int flags)
2933 hammer2_chain_t *parent;
2937 * Calculate locking flags for upward recursion.
2939 how_maybe = HAMMER2_RESOLVE_MAYBE;
2940 if (flags & HAMMER2_LOOKUP_SHARED)
2941 how_maybe |= HAMMER2_RESOLVE_SHARED;
2947 * Calculate the next index and recalculate the parent if necessary.
2950 key_beg = chain->bref.key +
2951 ((hammer2_key_t)1 << chain->bref.keybits);
2952 hammer2_chain_unlock(chain);
2953 hammer2_chain_drop(chain);
2956 * chain invalid past this point, but we can still do a
2957 * pointer comparison w/parent.
2959 * Any scan where the lookup returned degenerate data embedded
2960 * in the inode has an invalid index and must terminate.
2962 if (chain == parent)
2964 if (key_beg == 0 || key_beg > key_end)
2967 } else if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT &&
2968 parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) {
2970 * We reached the end of the iteration.
2975 * Continue iteration with next parent unless the current
2976 * parent covers the range.
2978 * (This also handles the case of a deleted, empty indirect
2981 key_beg = parent->bref.key +
2982 ((hammer2_key_t)1 << parent->bref.keybits);
2983 if (key_beg == 0 || key_beg > key_end)
2985 parent = hammer2_chain_repparent(parentp, how_maybe);
2991 return (hammer2_chain_lookup(parentp, key_nextp,
2997 * Caller wishes to iterate chains under parent, loading new chains into
2998 * chainp. Caller must initialize *chainp to NULL and *firstp to 1, and
2999 * then call hammer2_chain_scan() repeatedly until a non-zero return.
3000 * During the scan, *firstp will be set to 0 and (*chainp) will be replaced
3001 * with the returned chain for the scan. The returned *chainp will be
3002 * locked and referenced. Any prior contents will be unlocked and dropped.
3004 * Caller should check the return value. A normal scan EOF will return
3005 * exactly HAMMER2_ERROR_EOF. Any other non-zero value indicates an
3006 * error trying to access parent data. Any error in the returned chain
3007 * must be tested separately by the caller.
3009 * (*chainp) is dropped on each scan, but will only be set if the returned
3010 * element itself can recurse. Leaf elements are NOT resolved, loaded, or
3011 * returned via *chainp. The caller will get their bref only.
3013 * The raw scan function is similar to lookup/next but does not seek to a key.
3014 * Blockrefs are iterated via first_bref = (parent, NULL) and
3015 * next_chain = (parent, bref).
3017 * The passed-in parent must be locked and its data resolved. The function
3018 * nominally returns a locked and referenced *chainp != NULL for chains
3019 * the caller might need to recurse on (and will dipose of any *chainp passed
3020 * in). The caller must check the chain->bref.type either way.
3023 hammer2_chain_scan(hammer2_chain_t *parent, hammer2_chain_t **chainp,
3024 hammer2_blockref_t *bref, int *firstp,
3028 hammer2_blockref_t *base;
3029 hammer2_blockref_t *bref_ptr;
3031 hammer2_key_t next_key;
3032 hammer2_chain_t *chain = NULL;
3034 int how_always = HAMMER2_RESOLVE_ALWAYS;
3035 int how_maybe = HAMMER2_RESOLVE_MAYBE;
3038 int maxloops = 300000;
3045 * Scan flags borrowed from lookup.
3047 if (flags & HAMMER2_LOOKUP_ALWAYS) {
3048 how_maybe = how_always;
3049 how = HAMMER2_RESOLVE_ALWAYS;
3050 } else if (flags & HAMMER2_LOOKUP_NODATA) {
3051 how = HAMMER2_RESOLVE_NEVER;
3053 how = HAMMER2_RESOLVE_MAYBE;
3055 if (flags & HAMMER2_LOOKUP_SHARED) {
3056 how_maybe |= HAMMER2_RESOLVE_SHARED;
3057 how_always |= HAMMER2_RESOLVE_SHARED;
3058 how |= HAMMER2_RESOLVE_SHARED;
3062 * Calculate key to locate first/next element, unlocking the previous
3063 * element as we go. Be careful, the key calculation can overflow.
3065 * (also reset bref to NULL)
3071 key = bref->key + ((hammer2_key_t)1 << bref->keybits);
3072 if ((chain = *chainp) != NULL) {
3074 hammer2_chain_unlock(chain);
3075 hammer2_chain_drop(chain);
3079 error |= HAMMER2_ERROR_EOF;
3085 if (parent->error) {
3086 error = parent->error;
3089 if (--maxloops == 0)
3090 panic("hammer2_chain_scan: maxloops");
3093 * Locate the blockref array. Currently we do a fully associative
3094 * search through the array.
3096 switch(parent->bref.type) {
3097 case HAMMER2_BREF_TYPE_INODE:
3099 * An inode with embedded data has no sub-chains.
3101 * WARNING! Bulk scan code may pass a static chain marked
3102 * as BREF_TYPE_INODE with a copy of the volume
3103 * root blockset to snapshot the volume.
3105 if (parent->data->ipdata.meta.op_flags &
3106 HAMMER2_OPFLAG_DIRECTDATA) {
3107 error |= HAMMER2_ERROR_EOF;
3110 base = &parent->data->ipdata.u.blockset.blockref[0];
3111 count = HAMMER2_SET_COUNT;
3113 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3114 case HAMMER2_BREF_TYPE_INDIRECT:
3116 * Optimize indirect blocks in the INITIAL state to avoid
3119 if (parent->flags & HAMMER2_CHAIN_INITIAL) {
3122 if (parent->data == NULL)
3123 panic("parent->data is NULL");
3124 base = &parent->data->npdata[0];
3126 count = parent->bytes / sizeof(hammer2_blockref_t);
3128 case HAMMER2_BREF_TYPE_VOLUME:
3129 base = &parent->data->voldata.sroot_blockset.blockref[0];
3130 count = HAMMER2_SET_COUNT;
3132 case HAMMER2_BREF_TYPE_FREEMAP:
3133 base = &parent->data->blkset.blockref[0];
3134 count = HAMMER2_SET_COUNT;
3137 panic("hammer2_chain_lookup: unrecognized blockref type: %d",
3139 base = NULL; /* safety */
3140 count = 0; /* safety */
3144 * Merged scan to find next candidate.
3146 * hammer2_base_*() functions require the parent->core.live_* fields
3147 * to be synchronized.
3149 * We need to hold the spinlock to access the block array and RB tree
3150 * and to interlock chain creation.
3152 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0)
3153 hammer2_chain_countbrefs(parent, base, count);
3157 hammer2_spin_ex(&parent->core.spin);
3158 chain = hammer2_combined_find(parent, base, count,
3160 key, HAMMER2_KEY_MAX,
3162 generation = parent->core.generation;
3165 * Exhausted parent chain, we're done.
3167 if (bref_ptr == NULL) {
3168 hammer2_spin_unex(&parent->core.spin);
3169 KKASSERT(chain == NULL);
3170 error |= HAMMER2_ERROR_EOF;
3175 * Copy into the supplied stack-based blockref.
3180 * Selected from blockref or in-memory chain.
3182 if (chain == NULL) {
3183 switch(bref->type) {
3184 case HAMMER2_BREF_TYPE_INODE:
3185 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3186 case HAMMER2_BREF_TYPE_INDIRECT:
3187 case HAMMER2_BREF_TYPE_VOLUME:
3188 case HAMMER2_BREF_TYPE_FREEMAP:
3190 * Recursion, always get the chain
3192 hammer2_spin_unex(&parent->core.spin);
3193 chain = hammer2_chain_get(parent, generation,
3200 * No recursion, do not waste time instantiating
3201 * a chain, just iterate using the bref.
3203 hammer2_spin_unex(&parent->core.spin);
3208 * Recursion or not we need the chain in order to supply
3211 hammer2_chain_ref(chain);
3212 hammer2_spin_unex(&parent->core.spin);
3213 hammer2_chain_lock(chain, how);
3216 (bcmp(bref, &chain->bref, sizeof(*bref)) ||
3217 chain->parent != parent)) {
3218 hammer2_chain_unlock(chain);
3219 hammer2_chain_drop(chain);
3225 * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX)
3227 * NOTE: chain's key range is not relevant as there might be
3228 * one-offs within the range that are not deleted.
3230 * NOTE: XXX this could create problems with scans used in
3231 * situations other than mount-time recovery.
3233 * NOTE: Lookups can race delete-duplicate because
3234 * delete-duplicate does not lock the parent's core
3235 * (they just use the spinlock on the core).
3237 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
3238 hammer2_chain_unlock(chain);
3239 hammer2_chain_drop(chain);
3244 error |= HAMMER2_ERROR_EOF;
3252 * All done, return the bref or NULL, supply chain if necessary.
3260 * Create and return a new hammer2 system memory structure of the specified
3261 * key, type and size and insert it under (*parentp). This is a full
3262 * insertion, based on the supplied key/keybits, and may involve creating
3263 * indirect blocks and moving other chains around via delete/duplicate.
3265 * This call can be made with parent == NULL as long as a non -1 methods
3266 * is supplied. hmp must also be supplied in this situation (otherwise
3267 * hmp is extracted from the supplied parent). The chain will be detached
3268 * from the topology. A later call with both parent and chain can be made
3271 * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (*parentp) TO THE INSERTION
3272 * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING
3273 * FULL. This typically means that the caller is creating the chain after
3274 * doing a hammer2_chain_lookup().
3276 * (*parentp) must be exclusive locked and may be replaced on return
3277 * depending on how much work the function had to do.
3279 * (*parentp) must not be errored or this function will assert.
3281 * (*chainp) usually starts out NULL and returns the newly created chain,
3282 * but if the caller desires the caller may allocate a disconnected chain
3283 * and pass it in instead.
3285 * This function should NOT be used to insert INDIRECT blocks. It is
3286 * typically used to create/insert inodes and data blocks.
3288 * Caller must pass-in an exclusively locked parent the new chain is to
3289 * be inserted under, and optionally pass-in a disconnected, exclusively
3290 * locked chain to insert (else we create a new chain). The function will
3291 * adjust (*parentp) as necessary, create or connect the chain, and
3292 * return an exclusively locked chain in *chainp.
3294 * When creating a PFSROOT inode under the super-root, pmp is typically NULL
3295 * and will be reassigned.
3297 * NOTE: returns HAMMER_ERROR_* flags
3300 hammer2_chain_create(hammer2_chain_t **parentp, hammer2_chain_t **chainp,
3301 hammer2_dev_t *hmp, hammer2_pfs_t *pmp, int methods,
3302 hammer2_key_t key, int keybits, int type, size_t bytes,
3303 hammer2_tid_t mtid, hammer2_off_t dedup_off, int flags)
3305 hammer2_chain_t *chain;
3306 hammer2_chain_t *parent;
3307 hammer2_blockref_t *base;
3308 hammer2_blockref_t dummy;
3312 int maxloops = 300000;
3315 * Topology may be crossing a PFS boundary.
3319 KKASSERT(hammer2_mtx_owned(&parent->lock));
3320 KKASSERT(parent->error == 0);
3325 if (chain == NULL) {
3327 * First allocate media space and construct the dummy bref,
3328 * then allocate the in-memory chain structure. Set the
3329 * INITIAL flag for fresh chains which do not have embedded
3332 * XXX for now set the check mode of the child based on
3333 * the parent or, if the parent is an inode, the
3334 * specification in the inode.
3336 bzero(&dummy, sizeof(dummy));
3339 dummy.keybits = keybits;
3340 dummy.data_off = hammer2_getradix(bytes);
3343 * Inherit methods from parent by default. Primarily used
3344 * for BREF_TYPE_DATA. Non-data types *must* be set to
3345 * a non-NONE check algorithm.
3348 dummy.methods = parent->bref.methods;
3350 dummy.methods = (uint8_t)methods;
3352 if (type != HAMMER2_BREF_TYPE_DATA &&
3353 HAMMER2_DEC_CHECK(dummy.methods) == HAMMER2_CHECK_NONE) {
3355 HAMMER2_ENC_CHECK(HAMMER2_CHECK_DEFAULT);
3358 chain = hammer2_chain_alloc(hmp, pmp, &dummy);
3361 * Lock the chain manually, chain_lock will load the chain
3362 * which we do NOT want to do. (note: chain->refs is set
3363 * to 1 by chain_alloc() for us, but lockcnt is not).
3366 hammer2_mtx_ex(&chain->lock);
3368 ++curthread->td_tracker;
3371 * Set INITIAL to optimize I/O. The flag will generally be
3372 * processed when we call hammer2_chain_modify().
3374 * Recalculate bytes to reflect the actual media block
3375 * allocation. Handle special case radix 0 == 0 bytes.
3377 bytes = (size_t)(chain->bref.data_off & HAMMER2_OFF_MASK_RADIX);
3379 bytes = (hammer2_off_t)1 << bytes;
3380 chain->bytes = bytes;
3383 case HAMMER2_BREF_TYPE_VOLUME:
3384 case HAMMER2_BREF_TYPE_FREEMAP:
3385 panic("hammer2_chain_create: called with volume type");
3387 case HAMMER2_BREF_TYPE_INDIRECT:
3388 panic("hammer2_chain_create: cannot be used to"
3389 "create indirect block");
3391 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3392 panic("hammer2_chain_create: cannot be used to"
3393 "create freemap root or node");
3395 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
3396 KKASSERT(bytes == sizeof(chain->data->bmdata));
3398 case HAMMER2_BREF_TYPE_DIRENT:
3399 case HAMMER2_BREF_TYPE_INODE:
3400 case HAMMER2_BREF_TYPE_DATA:
3403 * leave chain->data NULL, set INITIAL
3405 KKASSERT(chain->data == NULL);
3406 atomic_set_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
3411 * We are reattaching a previously deleted chain, possibly
3412 * under a new parent and possibly with a new key/keybits.
3413 * The chain does not have to be in a modified state. The
3414 * UPDATE flag will be set later on in this routine.
3416 * Do NOT mess with the current state of the INITIAL flag.
3418 chain->bref.key = key;
3419 chain->bref.keybits = keybits;
3420 if (chain->flags & HAMMER2_CHAIN_DELETED)
3421 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_DELETED);
3422 KKASSERT(chain->parent == NULL);
3426 * Set the appropriate bref flag if requested.
3428 * NOTE! Callers can call this function to move chains without
3429 * knowing about special flags, so don't clear bref flags
3432 if (flags & HAMMER2_INSERT_PFSROOT)
3433 chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT;
3439 * Calculate how many entries we have in the blockref array and
3440 * determine if an indirect block is required when inserting into
3444 if (--maxloops == 0)
3445 panic("hammer2_chain_create: maxloops");
3447 switch(parent->bref.type) {
3448 case HAMMER2_BREF_TYPE_INODE:
3449 if ((parent->data->ipdata.meta.op_flags &
3450 HAMMER2_OPFLAG_DIRECTDATA) != 0) {
3451 kprintf("hammer2: parent set for direct-data! "
3452 "pkey=%016jx ckey=%016jx\n",
3456 KKASSERT((parent->data->ipdata.meta.op_flags &
3457 HAMMER2_OPFLAG_DIRECTDATA) == 0);
3458 KKASSERT(parent->data != NULL);
3459 base = &parent->data->ipdata.u.blockset.blockref[0];
3460 count = HAMMER2_SET_COUNT;
3462 case HAMMER2_BREF_TYPE_INDIRECT:
3463 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3464 if (parent->flags & HAMMER2_CHAIN_INITIAL)
3467 base = &parent->data->npdata[0];
3468 count = parent->bytes / sizeof(hammer2_blockref_t);
3470 case HAMMER2_BREF_TYPE_VOLUME:
3471 KKASSERT(parent->data != NULL);
3472 base = &parent->data->voldata.sroot_blockset.blockref[0];
3473 count = HAMMER2_SET_COUNT;
3475 case HAMMER2_BREF_TYPE_FREEMAP:
3476 KKASSERT(parent->data != NULL);
3477 base = &parent->data->blkset.blockref[0];
3478 count = HAMMER2_SET_COUNT;
3481 panic("hammer2_chain_create: unrecognized blockref type: %d",
3489 * Make sure we've counted the brefs
3491 if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0)
3492 hammer2_chain_countbrefs(parent, base, count);
3494 KASSERT(parent->core.live_count >= 0 &&
3495 parent->core.live_count <= count,
3496 ("bad live_count %d/%d (%02x, %d)",
3497 parent->core.live_count, count,
3498 parent->bref.type, parent->bytes));
3501 * If no free blockref could be found we must create an indirect
3502 * block and move a number of blockrefs into it. With the parent
3503 * locked we can safely lock each child in order to delete+duplicate
3504 * it without causing a deadlock.
3506 * This may return the new indirect block or the old parent depending
3507 * on where the key falls. NULL is returned on error.
3509 if (parent->core.live_count == count) {
3510 hammer2_chain_t *nparent;
3512 KKASSERT((flags & HAMMER2_INSERT_SAMEPARENT) == 0);
3514 nparent = hammer2_chain_create_indirect(parent, key, keybits,
3515 mtid, type, &error);
3516 if (nparent == NULL) {
3518 hammer2_chain_drop(chain);
3522 if (parent != nparent) {
3523 hammer2_chain_unlock(parent);
3524 hammer2_chain_drop(parent);
3525 parent = *parentp = nparent;
3531 * fall through if parent, or skip to here if no parent.
3534 if (chain->flags & HAMMER2_CHAIN_DELETED)
3535 kprintf("Inserting deleted chain @%016jx\n",
3539 * Link the chain into its parent.
3541 if (chain->parent != NULL)
3542 panic("hammer2: hammer2_chain_create: chain already connected");
3543 KKASSERT(chain->parent == NULL);
3545 KKASSERT(parent->core.live_count < count);
3546 hammer2_chain_insert(parent, chain,
3547 HAMMER2_CHAIN_INSERT_SPIN |
3548 HAMMER2_CHAIN_INSERT_LIVE,
3554 * Mark the newly created chain modified. This will cause
3555 * UPDATE to be set and process the INITIAL flag.
3557 * Device buffers are not instantiated for DATA elements
3558 * as these are handled by logical buffers.
3560 * Indirect and freemap node indirect blocks are handled
3561 * by hammer2_chain_create_indirect() and not by this
3564 * Data for all other bref types is expected to be
3565 * instantiated (INODE, LEAF).
3567 switch(chain->bref.type) {
3568 case HAMMER2_BREF_TYPE_DATA:
3569 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
3570 case HAMMER2_BREF_TYPE_DIRENT:
3571 case HAMMER2_BREF_TYPE_INODE:
3572 error = hammer2_chain_modify(chain, mtid, dedup_off,
3573 HAMMER2_MODIFY_OPTDATA);
3577 * Remaining types are not supported by this function.
3578 * In particular, INDIRECT and LEAF_NODE types are
3579 * handled by create_indirect().
3581 panic("hammer2_chain_create: bad type: %d",
3588 * When reconnecting a chain we must set UPDATE and
3589 * setflush so the flush recognizes that it must update
3590 * the bref in the parent.
3592 if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0)
3593 atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
3597 * We must setflush(parent) to ensure that it recurses through to
3598 * chain. setflush(chain) might not work because ONFLUSH is possibly
3599 * already set in the chain (so it won't recurse up to set it in the
3603 hammer2_chain_setflush(parent);
3612 * Move the chain from its old parent to a new parent. The chain must have
3613 * already been deleted or already disconnected (or never associated) with
3614 * a parent. The chain is reassociated with the new parent and the deleted
3615 * flag will be cleared (no longer deleted). The chain's modification state
3618 * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (parent) TO THE INSERTION
3619 * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING
3620 * FULL. This typically means that the caller is creating the chain after
3621 * doing a hammer2_chain_lookup().
3623 * Neither (parent) or (chain) can be errored.
3625 * If (parent) is non-NULL then the chain is inserted under the parent.
3627 * If (parent) is NULL then the newly duplicated chain is not inserted
3628 * anywhere, similar to if it had just been chain_alloc()'d (suitable for
3629 * passing into hammer2_chain_create() after this function returns).
3631 * WARNING! This function calls create which means it can insert indirect
3632 * blocks. This can cause other unrelated chains in the parent to
3633 * be moved to a newly inserted indirect block in addition to the
3637 hammer2_chain_rename(hammer2_chain_t **parentp, hammer2_chain_t *chain,
3638 hammer2_tid_t mtid, int flags)
3640 hammer2_blockref_t *bref;
3642 hammer2_chain_t *parent;
3646 * WARNING! We should never resolve DATA to device buffers
3647 * (XXX allow it if the caller did?), and since
3648 * we currently do not have the logical buffer cache
3649 * buffer in-hand to fix its cached physical offset
3650 * we also force the modify code to not COW it. XXX
3652 * NOTE! We allow error'd chains to be renamed. The bref itself
3653 * is good and can be renamed. The content, however, may
3657 KKASSERT(chain->parent == NULL);
3658 /*KKASSERT(chain->error == 0); allow */
3661 * Now create a duplicate of the chain structure, associating
3662 * it with the same core, making it the same size, pointing it
3663 * to the same bref (the same media block).
3665 * NOTE: Handle special radix == 0 case (means 0 bytes).
3667 bref = &chain->bref;
3668 bytes = (size_t)(bref->data_off & HAMMER2_OFF_MASK_RADIX);
3670 bytes = (hammer2_off_t)1 << bytes;
3673 * If parent is not NULL the duplicated chain will be entered under
3674 * the parent and the UPDATE bit set to tell flush to update
3677 * We must setflush(parent) to ensure that it recurses through to
3678 * chain. setflush(chain) might not work because ONFLUSH is possibly
3679 * already set in the chain (so it won't recurse up to set it in the
3682 * Having both chains locked is extremely important for atomicy.
3684 if (parentp && (parent = *parentp) != NULL) {
3685 KKASSERT(hammer2_mtx_owned(&parent->lock));
3686 KKASSERT(parent->refs > 0);
3687 KKASSERT(parent->error == 0);
3689 hammer2_chain_create(parentp, &chain, NULL, chain->pmp,
3690 HAMMER2_METH_DEFAULT,
3691 bref->key, bref->keybits, bref->type,
3692 chain->bytes, mtid, 0, flags);
3693 KKASSERT(chain->flags & HAMMER2_CHAIN_UPDATE);
3694 hammer2_chain_setflush(*parentp);
3699 * This works in tandem with delete_obref() to install a blockref in
3700 * (typically) an indirect block that is associated with the chain being
3701 * moved to *parentp.
3703 * The reason we need this function is that the caller needs to maintain
3704 * the blockref as it was, and not generate a new blockref for what might
3705 * be a modified chain. Otherwise stuff will leak into the flush that
3706 * the flush code's FLUSH_INODE_STOP flag is unable to catch.
3708 * It is EXTREMELY important that we properly set CHAIN_BMAPUPD and
3709 * CHAIN_UPDATE. We must set BMAPUPD if the bref does not match, and
3710 * we must clear CHAIN_UPDATE (that was likely set by the chain_rename) if
3711 * it does. Otherwise we can end up in a situation where H2 is unable to
3712 * clean up the in-memory chain topology.
3714 * The reason for this is that flushes do not generally flush through
3715 * BREF_TYPE_INODE chains and depend on a hammer2_inode_t queued to syncq
3716 * or sideq to properly flush and dispose of the related inode chain's flags.
3717 * Situations where the inode is not actually modified by the frontend,
3718 * but where we have to move the related chains around as we insert or cleanup
3719 * indirect blocks, can leave us with a 'dirty' (non-disposable) in-memory
3720 * inode chain that does not have a hammer2_inode_t associated with it.
3723 hammer2_chain_rename_obref(hammer2_chain_t **parentp, hammer2_chain_t *chain,
3724 hammer2_tid_t mtid, int flags,
3725 hammer2_blockref_t *obref)
3727 hammer2_chain_rename(parentp, chain, mtid, flags);
3730 hammer2_blockref_t *tbase;
3733 KKASSERT((chain->flags & HAMMER2_CHAIN_BMAPPED) == 0);
3734 hammer2_chain_modify(*parentp, mtid, 0, 0);
3735 tbase = hammer2_chain_base_and_count(*parentp, &tcount);
3736 hammer2_base_insert(*parentp, tbase, tcount, chain, obref);
3737 if (bcmp(obref, &chain->bref, sizeof(chain->bref))) {
3738 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPUPD |
3739 HAMMER2_CHAIN_UPDATE);
3741 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE);
3747 * Helper function for deleting chains.
3749 * The chain is removed from the live view (the RBTREE) as well as the parent's
3750 * blockmap. Both chain and its parent must be locked.
3752 * parent may not be errored. chain can be errored.
3755 _hammer2_chain_delete_helper(hammer2_chain_t *parent, hammer2_chain_t *chain,
3756 hammer2_tid_t mtid, int flags,
3757 hammer2_blockref_t *obref)
3762 KKASSERT((chain->flags & (HAMMER2_CHAIN_DELETED |
3763 HAMMER2_CHAIN_FICTITIOUS)) == 0);
3764 KKASSERT(chain->parent == parent);
3767 if (chain->flags & HAMMER2_CHAIN_BMAPPED) {
3769 * Chain is blockmapped, so there must be a parent.
3770 * Atomically remove the chain from the parent and remove
3771 * the blockmap entry. The parent must be set modified
3772 * to remove the blockmap entry.
3774 hammer2_blockref_t *base;
3777 KKASSERT(parent != NULL);
3778 KKASSERT(parent->error == 0);
3779 KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0);
3780 error = hammer2_chain_modify(parent, mtid, 0, 0);
3785 * Calculate blockmap pointer
3787 KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE);
3788 hammer2_spin_ex(&chain->core.spin);
3789 hammer2_spin_ex(&parent->core.spin);
3791 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED);
3792 atomic_add_int(&parent->core.live_count, -1);
3793 ++parent->core.generation;
3794 RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain);
3795 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE);
3796 --parent->core.chain_count;
3797 chain->parent = NULL;
3799 switch(parent->bref.type) {
3800 case HAMMER2_BREF_TYPE_INODE:
3802 * Access the inode's block array. However, there
3803 * is no block array if the inode is flagged
3807 (parent->data->ipdata.meta.op_flags &
3808 HAMMER2_OPFLAG_DIRECTDATA) == 0) {
3810 &parent->data->ipdata.u.blockset.blockref[0];
3814 count = HAMMER2_SET_COUNT;
3816 case HAMMER2_BREF_TYPE_INDIRECT:
3817 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
3819 base = &parent->data->npdata[0];
3822 count = parent->bytes / sizeof(hammer2_blockref_t);
3824 case HAMMER2_BREF_TYPE_VOLUME:
3825 base = &parent->data->voldata.
3826 sroot_blockset.blockref[0];
3827 count = HAMMER2_SET_COUNT;
3829 case HAMMER2_BREF_TYPE_FREEMAP:
3830 base = &parent->data->blkset.blockref[0];
3831 count = HAMMER2_SET_COUNT;
3836 panic("hammer2_flush_pass2: "
3837 "unrecognized blockref type: %d",
3842 * delete blockmapped chain from its parent.
3844 * The parent is not affected by any statistics in chain
3845 * which are pending synchronization. That is, there is
3846 * nothing to undo in the parent since they have not yet
3847 * been incorporated into the parent.
3849 * The parent is affected by statistics stored in inodes.
3850 * Those have already been synchronized, so they must be
3851 * undone. XXX split update possible w/delete in middle?
3854 hammer2_base_delete(parent, base, count, chain, obref);
3856 hammer2_spin_unex(&parent->core.spin);
3857 hammer2_spin_unex(&chain->core.spin);
3858 } else if (chain->flags & HAMMER2_CHAIN_ONRBTREE) {
3860 * Chain is not blockmapped but a parent is present.
3861 * Atomically remove the chain from the parent. There is
3862 * no blockmap entry to remove.
3864 * Because chain was associated with a parent but not
3865 * synchronized, the chain's *_count_up fields contain
3866 * inode adjustment statistics which must be undone.
3868 hammer2_spin_ex(&chain->core.spin);
3869 hammer2_spin_ex(&parent->core.spin);
3870 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED);
3871 atomic_add_int(&parent->core.live_count, -1);
3872 ++parent->core.generation;
3873 RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain);
3874 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE);
3875 --parent->core.chain_count;
3876 chain->parent = NULL;
3877 hammer2_spin_unex(&parent->core.spin);
3878 hammer2_spin_unex(&chain->core.spin);
3881 * Chain is not blockmapped and has no parent. This
3882 * is a degenerate case.
3884 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED);
3891 * Create an indirect block that covers one or more of the elements in the
3892 * current parent. Either returns the existing parent with no locking or
3893 * ref changes or returns the new indirect block locked and referenced
3894 * and leaving the original parent lock/ref intact as well.
3896 * If an error occurs, NULL is returned and *errorp is set to the H2 error.
3898 * The returned chain depends on where the specified key falls.
3900 * The key/keybits for the indirect mode only needs to follow three rules:
3902 * (1) That all elements underneath it fit within its key space and
3904 * (2) That all elements outside it are outside its key space.
3906 * (3) When creating the new indirect block any elements in the current
3907 * parent that fit within the new indirect block's keyspace must be
3908 * moved into the new indirect block.
3910 * (4) The keyspace chosen for the inserted indirect block CAN cover a wider
3911 * keyspace the the current parent, but lookup/iteration rules will
3912 * ensure (and must ensure) that rule (2) for all parents leading up
3913 * to the nearest inode or the root volume header is adhered to. This
3914 * is accomplished by always recursing through matching keyspaces in
3915 * the hammer2_chain_lookup() and hammer2_chain_next() API.
3917 * The current implementation calculates the current worst-case keyspace by
3918 * iterating the current parent and then divides it into two halves, choosing
3919 * whichever half has the most elements (not necessarily the half containing
3920 * the requested key).
3922 * We can also opt to use the half with the least number of elements. This
3923 * causes lower-numbered keys (aka logical file offsets) to recurse through
3924 * fewer indirect blocks and higher-numbered keys to recurse through more.
3925 * This also has the risk of not moving enough elements to the new indirect
3926 * block and being forced to create several indirect blocks before the element
3929 * Must be called with an exclusively locked parent.
3931 * NOTE: *errorp set to HAMMER_ERROR_* flags
3933 static int hammer2_chain_indkey_freemap(hammer2_chain_t *parent,
3934 hammer2_key_t *keyp, int keybits,
3935 hammer2_blockref_t *base, int count);
3936 static int hammer2_chain_indkey_file(hammer2_chain_t *parent,
3937 hammer2_key_t *keyp, int keybits,
3938 hammer2_blockref_t *base, int count,
3940 static int hammer2_chain_indkey_dir(hammer2_chain_t *parent,
3941 hammer2_key_t *keyp, int keybits,
3942 hammer2_blockref_t *base, int count,
3946 hammer2_chain_create_indirect(hammer2_chain_t *parent,
3947 hammer2_key_t create_key, int create_bits,
3948 hammer2_tid_t mtid, int for_type, int *errorp)
3951 hammer2_blockref_t *base;
3952 hammer2_blockref_t *bref;
3953 hammer2_blockref_t bcopy;
3954 hammer2_chain_t *chain;
3955 hammer2_chain_t *ichain;
3956 hammer2_chain_t dummy;
3957 hammer2_key_t key = create_key;
3958 hammer2_key_t key_beg;
3959 hammer2_key_t key_end;
3960 hammer2_key_t key_next;
3961 int keybits = create_bits;
3969 int maxloops = 300000;
3972 * Calculate the base blockref pointer or NULL if the chain
3973 * is known to be empty. We need to calculate the array count
3974 * for RB lookups either way.
3977 KKASSERT(hammer2_mtx_owned(&parent->lock));
3980 * Pre-modify the parent now to avoid having to deal with error
3981 * processing if we tried to later (in the middle of our loop).
3983 * We are going to be moving bref's around, the indirect blocks
3984 * cannot be in an initial state. Do not pass MODIFY_OPTDATA.
3986 *errorp = hammer2_chain_modify(parent, mtid, 0, 0);
3988 kprintf("hammer2_create_indirect: error %08x %s\n",
3989 *errorp, hammer2_error_str(*errorp));
3992 KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0);
3994 /*hammer2_chain_modify(&parent, HAMMER2_MODIFY_OPTDATA);*/
3995 base = hammer2_chain_base_and_count(parent, &count);
3998 * dummy used in later chain allocation (no longer used for lookups).
4000 bzero(&dummy, sizeof(dummy));
4003 * How big should our new indirect block be? It has to be at least
4004 * as large as its parent for splits to work properly.
4006 * The freemap uses a specific indirect block size. The number of
4007 * levels are built dynamically and ultimately depend on the size
4008 * volume. Because freemap blocks are taken from the reserved areas
4009 * of the volume our goal is efficiency (fewer levels) and not so
4010 * much to save disk space.
4012 * The first indirect block level for a directory usually uses
4013 * HAMMER2_IND_BYTES_MIN (4KB = 32 directory entries). Due to
4014 * the hash mechanism, this typically gives us a nominal
4015 * 32 * 4 entries with one level of indirection.
4017 * We use HAMMER2_IND_BYTES_NOM (16KB = 128 blockrefs) for FILE
4018 * indirect blocks. The initial 4 entries in the inode gives us
4019 * 256KB. Up to 4 indirect blocks gives us 32MB. Three levels
4020 * of indirection gives us 137GB, and so forth. H2 can support
4021 * huge file sizes but they are not typical, so we try to stick
4022 * with compactness and do not use a larger indirect block size.
4024 * We could use 64KB (PBUFSIZE), giving us 512 blockrefs, but
4025 * due to the way indirect blocks are created this usually winds
4026 * up being extremely inefficient for small files. Even though
4027 * 16KB requires more levels of indirection for very large files,
4028 * the 16KB records can be ganged together into 64KB DIOs.
4030 if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
4031 for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
4032 nbytes = HAMMER2_FREEMAP_LEVELN_PSIZE;
4033 } else if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) {
4034 if (parent->data->ipdata.meta.type ==
4035 HAMMER2_OBJTYPE_DIRECTORY)
4036 nbytes = HAMMER2_IND_BYTES_MIN; /* 4KB = 32 entries */
4038 nbytes = HAMMER2_IND_BYTES_NOM; /* 16KB = ~8MB file */
4041 nbytes = HAMMER2_IND_BYTES_NOM;
4043 if (nbytes < count * sizeof(hammer2_blockref_t)) {
4044 KKASSERT(for_type != HAMMER2_BREF_TYPE_FREEMAP_NODE &&
4045 for_type != HAMMER2_BREF_TYPE_FREEMAP_LEAF);
4046 nbytes = count * sizeof(hammer2_blockref_t);
4048 ncount = nbytes / sizeof(hammer2_blockref_t);
4051 * When creating an indirect block for a freemap node or leaf
4052 * the key/keybits must be fitted to static radix levels because
4053 * particular radix levels use particular reserved blocks in the
4056 * This routine calculates the key/radix of the indirect block
4057 * we need to create, and whether it is on the high-side or the
4061 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
4062 case HAMMER2_BREF_TYPE_FREEMAP_LEAF:
4063 keybits = hammer2_chain_indkey_freemap(parent, &key, keybits,
4066 case HAMMER2_BREF_TYPE_DATA:
4067 keybits = hammer2_chain_indkey_file(parent, &key, keybits,
4068 base, count, ncount);
4070 case HAMMER2_BREF_TYPE_DIRENT:
4071 case HAMMER2_BREF_TYPE_INODE:
4072 keybits = hammer2_chain_indkey_dir(parent, &key, keybits,
4073 base, count, ncount);
4076 panic("illegal indirect block for bref type %d", for_type);
4081 * Normalize the key for the radix being represented, keeping the
4082 * high bits and throwing away the low bits.
4084 key &= ~(((hammer2_key_t)1 << keybits) - 1);
4087 * Ok, create our new indirect block
4089 if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
4090 for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
4091 dummy.bref.type = HAMMER2_BREF_TYPE_FREEMAP_NODE;
4093 dummy.bref.type = HAMMER2_BREF_TYPE_INDIRECT;
4095 dummy.bref.key = key;
4096 dummy.bref.keybits = keybits;
4097 dummy.bref.data_off = hammer2_getradix(nbytes);
4098 dummy.bref.methods =
4099 HAMMER2_ENC_CHECK(HAMMER2_DEC_CHECK(parent->bref.methods)) |
4100 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE);
4102 ichain = hammer2_chain_alloc(hmp, parent->pmp, &dummy.bref);
4103 atomic_set_int(&ichain->flags, HAMMER2_CHAIN_INITIAL);
4104 hammer2_chain_lock(ichain, HAMMER2_RESOLVE_MAYBE);
4105 /* ichain has one ref at this point */
4108 * We have to mark it modified to allocate its block, but use
4109 * OPTDATA to allow it to remain in the INITIAL state. Otherwise
4110 * it won't be acted upon by the flush code.
4112 * XXX remove OPTDATA, we need a fully initialized indirect block to
4113 * be able to move the original blockref.
4115 *errorp = hammer2_chain_modify(ichain, mtid, 0, 0);
4117 kprintf("hammer2_alloc_indirect: error %08x %s\n",
4118 *errorp, hammer2_error_str(*errorp));
4119 hammer2_chain_unlock(ichain);
4120 hammer2_chain_drop(ichain);
4123 KKASSERT((ichain->flags & HAMMER2_CHAIN_INITIAL) == 0);
4126 * Iterate the original parent and move the matching brefs into
4127 * the new indirect block.
4129 * XXX handle flushes.
4132 key_end = HAMMER2_KEY_MAX;
4133 key_next = 0; /* avoid gcc warnings */
4134 hammer2_spin_ex(&parent->core.spin);
4140 * Parent may have been modified, relocating its block array.
4141 * Reload the base pointer.
4143 base = hammer2_chain_base_and_count(parent, &count);
4145 if (++loops > 100000) {
4146 hammer2_spin_unex(&parent->core.spin);
4147 panic("excessive loops r=%d p=%p base/count %p:%d %016jx\n",
4148 reason, parent, base, count, key_next);
4152 * NOTE: spinlock stays intact, returned chain (if not NULL)
4153 * is not referenced or locked which means that we
4154 * cannot safely check its flagged / deletion status
4157 chain = hammer2_combined_find(parent, base, count,
4161 generation = parent->core.generation;
4164 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4167 * Skip keys that are not within the key/radix of the new
4168 * indirect block. They stay in the parent.
4170 if ((~(((hammer2_key_t)1 << keybits) - 1) &
4171 (key ^ bref->key)) != 0) {
4172 goto next_key_spinlocked;
4176 * Load the new indirect block by acquiring the related
4177 * chains (potentially from media as it might not be
4178 * in-memory). Then move it to the new parent (ichain).
4180 * chain is referenced but not locked. We must lock the
4181 * chain to obtain definitive state.
4186 * Use chain already present in the RBTREE
4188 hammer2_chain_ref(chain);
4189 hammer2_spin_unex(&parent->core.spin);
4190 hammer2_chain_lock(chain, HAMMER2_RESOLVE_NEVER);
4193 * Get chain for blockref element. _get returns NULL
4194 * on insertion race.
4196 hammer2_spin_unex(&parent->core.spin);
4197 chain = hammer2_chain_get(parent, generation, &bcopy,
4198 HAMMER2_RESOLVE_NEVER);
4199 if (chain == NULL) {
4201 hammer2_spin_ex(&parent->core.spin);
4207 * This is always live so if the chain has been deleted
4208 * we raced someone and we have to retry.
4210 * NOTE: Lookups can race delete-duplicate because
4211 * delete-duplicate does not lock the parent's core
4212 * (they just use the spinlock on the core).
4214 * (note reversed logic for this one)
4216 if (bcmp(&bcopy, &chain->bref, sizeof(bcopy)) ||
4217 chain->parent != parent ||
4218 (chain->flags & HAMMER2_CHAIN_DELETED)) {
4219 hammer2_chain_unlock(chain);
4220 hammer2_chain_drop(chain);
4221 if (hammer2_debug & 0x0040) {
4222 kprintf("LOST PARENT RETRY "
4223 "RETRY (%p,%p)->%p %08x\n",
4224 parent, chain->parent, chain, chain->flags);
4226 hammer2_spin_ex(&parent->core.spin);
4231 * Shift the chain to the indirect block.
4233 * WARNING! No reason for us to load chain data, pass NOSTATS
4234 * to prevent delete/insert from trying to access
4235 * inode stats (and thus asserting if there is no
4236 * chain->data loaded).
4238 * WARNING! The (parent, chain) deletion may modify the parent
4239 * and invalidate the base pointer.
4241 * WARNING! Parent must already be marked modified, so we
4242 * can assume that chain_delete always suceeds.
4244 * WARNING! hammer2_chain_repchange() does not have to be
4245 * called (and doesn't work anyway because we are
4246 * only doing a partial shift). A recursion that is
4247 * in-progress can continue at the current parent
4248 * and will be able to properly find its next key.
4250 error = hammer2_chain_delete_obref(parent, chain, mtid, 0,
4252 KKASSERT(error == 0);
4253 hammer2_chain_rename_obref(&ichain, chain, mtid, 0, &bcopy);
4254 hammer2_chain_unlock(chain);
4255 hammer2_chain_drop(chain);
4256 KKASSERT(parent->refs > 0);
4258 base = NULL; /* safety */
4259 hammer2_spin_ex(&parent->core.spin);
4260 next_key_spinlocked:
4261 if (--maxloops == 0)
4262 panic("hammer2_chain_create_indirect: maxloops");
4264 if (key_next == 0 || key_next > key_end)
4269 hammer2_spin_unex(&parent->core.spin);
4272 * Insert the new indirect block into the parent now that we've
4273 * cleared out some entries in the parent. We calculated a good
4274 * insertion index in the loop above (ichain->index).
4276 * We don't have to set UPDATE here because we mark ichain
4277 * modified down below (so the normal modified -> flush -> set-moved
4278 * sequence applies).
4280 * The insertion shouldn't race as this is a completely new block
4281 * and the parent is locked.
4283 base = NULL; /* safety, parent modify may change address */
4284 KKASSERT((ichain->flags & HAMMER2_CHAIN_ONRBTREE) == 0);
4285 KKASSERT(parent->core.live_count < count);
4286 hammer2_chain_insert(parent, ichain,
4287 HAMMER2_CHAIN_INSERT_SPIN |
4288 HAMMER2_CHAIN_INSERT_LIVE,
4292 * Make sure flushes propogate after our manual insertion.
4294 hammer2_chain_setflush(ichain);
4295 hammer2_chain_setflush(parent);
4298 * Figure out what to return.
4300 if (~(((hammer2_key_t)1 << keybits) - 1) &
4301 (create_key ^ key)) {
4303 * Key being created is outside the key range,
4304 * return the original parent.
4306 hammer2_chain_unlock(ichain);
4307 hammer2_chain_drop(ichain);
4310 * Otherwise its in the range, return the new parent.
4311 * (leave both the new and old parent locked).
4320 * Do maintenance on an indirect chain. Both parent and chain are locked.
4322 * Returns non-zero if (chain) is deleted, either due to being empty or
4323 * because its children were safely moved into the parent.
4326 hammer2_chain_indirect_maintenance(hammer2_chain_t *parent,
4327 hammer2_chain_t *chain)
4329 hammer2_blockref_t *chain_base;
4330 hammer2_blockref_t *base;
4331 hammer2_blockref_t *bref;
4332 hammer2_blockref_t bcopy;
4333 hammer2_key_t key_next;
4334 hammer2_key_t key_beg;
4335 hammer2_key_t key_end;
4336 hammer2_chain_t *sub;
4343 * Make sure we have an accurate live_count
4345 if ((chain->flags & (HAMMER2_CHAIN_INITIAL |
4346 HAMMER2_CHAIN_COUNTEDBREFS)) == 0) {
4347 base = &chain->data->npdata[0];
4348 count = chain->bytes / sizeof(hammer2_blockref_t);
4349 hammer2_chain_countbrefs(chain, base, count);
4353 * If the indirect block is empty we can delete it.
4354 * (ignore deletion error)
4356 if (chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree)) {
4357 hammer2_chain_delete(parent, chain,
4358 chain->bref.modify_tid,
4359 HAMMER2_DELETE_PERMANENT);
4360 hammer2_chain_repchange(parent, chain);
4364 base = hammer2_chain_base_and_count(parent, &count);
4366 if ((parent->flags & (HAMMER2_CHAIN_INITIAL |
4367 HAMMER2_CHAIN_COUNTEDBREFS)) == 0) {
4368 hammer2_chain_countbrefs(parent, base, count);
4372 * Determine if we can collapse chain into parent, calculate
4373 * hysteresis for chain emptiness.
4375 if (parent->core.live_count + chain->core.live_count - 1 > count)
4377 chain_count = chain->bytes / sizeof(hammer2_blockref_t);
4378 if (chain->core.live_count > chain_count * 3 / 4)
4382 * Ok, theoretically we can collapse chain's contents into
4383 * parent. chain is locked, but any in-memory children of chain
4384 * are not. For this to work, we must be able to dispose of any
4385 * in-memory children of chain.
4387 * For now require that there are no in-memory children of chain.
4389 * WARNING! Both chain and parent must remain locked across this
4394 * Parent must be marked modified. Don't try to collapse it if we
4395 * can't mark it modified. Once modified, destroy chain to make room
4396 * and to get rid of what will be a conflicting key (this is included
4397 * in the calculation above). Finally, move the children of chain
4398 * into chain's parent.
4400 * This order creates an accounting problem for bref.embed.stats
4401 * because we destroy chain before we remove its children. Any
4402 * elements whos blockref is already synchronized will be counted
4403 * twice. To deal with the problem we clean out chain's stats prior
4406 error = hammer2_chain_modify(parent, 0, 0, 0);
4408 krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n",
4409 hammer2_error_str(error));
4412 error = hammer2_chain_modify(chain, chain->bref.modify_tid, 0, 0);
4414 krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n",
4415 hammer2_error_str(error));
4419 chain->bref.embed.stats.inode_count = 0;
4420 chain->bref.embed.stats.data_count = 0;
4421 error = hammer2_chain_delete(parent, chain,
4422 chain->bref.modify_tid,
4423 HAMMER2_DELETE_PERMANENT);
4424 KKASSERT(error == 0);
4427 * The combined_find call requires core.spin to be held. One would
4428 * think there wouldn't be any conflicts since we hold chain
4429 * exclusively locked, but the caching mechanism for 0-ref children
4430 * does not require a chain lock.
4432 hammer2_spin_ex(&chain->core.spin);
4436 key_end = HAMMER2_KEY_MAX;
4438 chain_base = &chain->data->npdata[0];
4439 chain_count = chain->bytes / sizeof(hammer2_blockref_t);
4440 sub = hammer2_combined_find(chain, chain_base, chain_count,
4444 generation = chain->core.generation;
4447 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4451 hammer2_chain_ref(sub);
4452 hammer2_spin_unex(&chain->core.spin);
4453 hammer2_chain_lock(sub, HAMMER2_RESOLVE_NEVER);
4455 hammer2_spin_unex(&chain->core.spin);
4456 sub = hammer2_chain_get(chain, generation, &bcopy,
4457 HAMMER2_RESOLVE_NEVER);
4459 hammer2_spin_ex(&chain->core.spin);
4463 if (bcmp(&bcopy, &sub->bref, sizeof(bcopy)) ||
4464 sub->parent != chain ||
4465 (sub->flags & HAMMER2_CHAIN_DELETED)) {
4466 hammer2_chain_unlock(sub);
4467 hammer2_chain_drop(sub);
4468 hammer2_spin_ex(&chain->core.spin);
4469 sub = NULL; /* safety */
4472 error = hammer2_chain_delete_obref(chain, sub,
4473 sub->bref.modify_tid, 0,
4475 KKASSERT(error == 0);
4476 hammer2_chain_rename_obref(&parent, sub,
4477 sub->bref.modify_tid,
4478 HAMMER2_INSERT_SAMEPARENT, &bcopy);
4479 hammer2_chain_unlock(sub);
4480 hammer2_chain_drop(sub);
4481 hammer2_spin_ex(&chain->core.spin);
4487 hammer2_spin_unex(&chain->core.spin);
4489 hammer2_chain_repchange(parent, chain);
4495 * Freemap indirect blocks
4497 * Calculate the keybits and highside/lowside of the freemap node the
4498 * caller is creating.
4500 * This routine will specify the next higher-level freemap key/radix
4501 * representing the lowest-ordered set. By doing so, eventually all
4502 * low-ordered sets will be moved one level down.
4504 * We have to be careful here because the freemap reserves a limited
4505 * number of blocks for a limited number of levels. So we can't just
4506 * push indiscriminately.
4509 hammer2_chain_indkey_freemap(hammer2_chain_t *parent, hammer2_key_t *keyp,
4510 int keybits, hammer2_blockref_t *base, int count)
4512 hammer2_chain_t *chain;
4513 hammer2_blockref_t *bref;
4515 hammer2_key_t key_beg;
4516 hammer2_key_t key_end;
4517 hammer2_key_t key_next;
4520 int maxloops = 300000;
4528 * Calculate the range of keys in the array being careful to skip
4529 * slots which are overridden with a deletion.
4532 key_end = HAMMER2_KEY_MAX;
4533 hammer2_spin_ex(&parent->core.spin);
4536 if (--maxloops == 0) {
4537 panic("indkey_freemap shit %p %p:%d\n",
4538 parent, base, count);
4540 chain = hammer2_combined_find(parent, base, count,
4552 * Skip deleted chains.
4554 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
4555 if (key_next == 0 || key_next > key_end)
4562 * Use the full live (not deleted) element for the scan
4563 * iteration. HAMMER2 does not allow partial replacements.
4565 * XXX should be built into hammer2_combined_find().
4567 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4569 if (keybits > bref->keybits) {
4571 keybits = bref->keybits;
4572 } else if (keybits == bref->keybits && bref->key < key) {
4579 hammer2_spin_unex(&parent->core.spin);
4582 * Return the keybits for a higher-level FREEMAP_NODE covering
4586 case HAMMER2_FREEMAP_LEVEL0_RADIX:
4587 keybits = HAMMER2_FREEMAP_LEVEL1_RADIX;
4589 case HAMMER2_FREEMAP_LEVEL1_RADIX:
4590 keybits = HAMMER2_FREEMAP_LEVEL2_RADIX;
4592 case HAMMER2_FREEMAP_LEVEL2_RADIX:
4593 keybits = HAMMER2_FREEMAP_LEVEL3_RADIX;
4595 case HAMMER2_FREEMAP_LEVEL3_RADIX:
4596 keybits = HAMMER2_FREEMAP_LEVEL4_RADIX;
4598 case HAMMER2_FREEMAP_LEVEL4_RADIX:
4599 keybits = HAMMER2_FREEMAP_LEVEL5_RADIX;
4601 case HAMMER2_FREEMAP_LEVEL5_RADIX:
4602 panic("hammer2_chain_indkey_freemap: level too high");
4605 panic("hammer2_chain_indkey_freemap: bad radix");
4614 * File indirect blocks
4616 * Calculate the key/keybits for the indirect block to create by scanning
4617 * existing keys. The key being created is also passed in *keyp and can be
4618 * inside or outside the indirect block. Regardless, the indirect block
4619 * must hold at least two keys in order to guarantee sufficient space.
4621 * We use a modified version of the freemap's fixed radix tree, but taylored
4622 * for file data. Basically we configure an indirect block encompassing the
4626 hammer2_chain_indkey_file(hammer2_chain_t *parent, hammer2_key_t *keyp,
4627 int keybits, hammer2_blockref_t *base, int count,
4630 hammer2_chain_t *chain;
4631 hammer2_blockref_t *bref;
4633 hammer2_key_t key_beg;
4634 hammer2_key_t key_end;
4635 hammer2_key_t key_next;
4639 int maxloops = 300000;
4647 * Calculate the range of keys in the array being careful to skip
4648 * slots which are overridden with a deletion.
4650 * Locate the smallest key.
4653 key_end = HAMMER2_KEY_MAX;
4654 hammer2_spin_ex(&parent->core.spin);
4657 if (--maxloops == 0) {
4658 panic("indkey_freemap shit %p %p:%d\n",
4659 parent, base, count);
4661 chain = hammer2_combined_find(parent, base, count,
4673 * Skip deleted chains.
4675 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
4676 if (key_next == 0 || key_next > key_end)
4683 * Use the full live (not deleted) element for the scan
4684 * iteration. HAMMER2 does not allow partial replacements.
4686 * XXX should be built into hammer2_combined_find().
4688 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4690 if (keybits > bref->keybits) {
4692 keybits = bref->keybits;
4693 } else if (keybits == bref->keybits && bref->key < key) {
4700 hammer2_spin_unex(&parent->core.spin);
4703 * Calculate the static keybits for a higher-level indirect block
4704 * that contains the key.
4709 case HAMMER2_IND_BYTES_MIN / sizeof(hammer2_blockref_t):
4710 nradix = HAMMER2_IND_RADIX_MIN - HAMMER2_BLOCKREF_RADIX;
4712 case HAMMER2_IND_BYTES_NOM / sizeof(hammer2_blockref_t):
4713 nradix = HAMMER2_IND_RADIX_NOM - HAMMER2_BLOCKREF_RADIX;
4715 case HAMMER2_IND_BYTES_MAX / sizeof(hammer2_blockref_t):
4716 nradix = HAMMER2_IND_RADIX_MAX - HAMMER2_BLOCKREF_RADIX;
4719 panic("bad ncount %d\n", ncount);
4725 * The largest radix that can be returned for an indirect block is
4726 * 63 bits. (The largest practical indirect block radix is actually
4727 * 62 bits because the top-level inode or volume root contains four
4728 * entries, but allow 63 to be returned).
4733 return keybits + nradix;
4739 * Directory indirect blocks.
4741 * Covers both the inode index (directory of inodes), and directory contents
4742 * (filenames hardlinked to inodes).
4744 * Because directory keys are hashed we generally try to cut the space in
4745 * half. We accomodate the inode index (which tends to have linearly
4746 * increasing inode numbers) by ensuring that the keyspace is at least large
4747 * enough to fill up the indirect block being created.
4750 hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp,
4751 int keybits, hammer2_blockref_t *base, int count,
4754 hammer2_blockref_t *bref;
4755 hammer2_chain_t *chain;
4756 hammer2_key_t key_beg;
4757 hammer2_key_t key_end;
4758 hammer2_key_t key_next;
4763 int maxloops = 300000;
4766 * NOTE: We can't take a shortcut here anymore for inodes because
4767 * the root directory can contain a mix of inodes and directory
4768 * entries (we used to just return 63 if parent->bref.type was
4769 * HAMMER2_BREF_TYPE_INODE.
4776 * Calculate the range of keys in the array being careful to skip
4777 * slots which are overridden with a deletion.
4780 key_end = HAMMER2_KEY_MAX;
4781 hammer2_spin_ex(&parent->core.spin);
4784 if (--maxloops == 0) {
4785 panic("indkey_freemap shit %p %p:%d\n",
4786 parent, base, count);
4788 chain = hammer2_combined_find(parent, base, count,
4802 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
4803 if (key_next == 0 || key_next > key_end)
4810 * Use the full live (not deleted) element for the scan
4811 * iteration. HAMMER2 does not allow partial replacements.
4813 * XXX should be built into hammer2_combined_find().
4815 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4818 * Expand our calculated key range (key, keybits) to fit
4819 * the scanned key. nkeybits represents the full range
4820 * that we will later cut in half (two halves @ nkeybits - 1).
4823 if (nkeybits < bref->keybits) {
4824 if (bref->keybits > 64) {
4825 kprintf("bad bref chain %p bref %p\n",
4829 nkeybits = bref->keybits;
4831 while (nkeybits < 64 &&
4832 (~(((hammer2_key_t)1 << nkeybits) - 1) &
4833 (key ^ bref->key)) != 0) {
4838 * If the new key range is larger we have to determine
4839 * which side of the new key range the existing keys fall
4840 * under by checking the high bit, then collapsing the
4841 * locount into the hicount or vise-versa.
4843 if (keybits != nkeybits) {
4844 if (((hammer2_key_t)1 << (nkeybits - 1)) & key) {
4855 * The newly scanned key will be in the lower half or the
4856 * upper half of the (new) key range.
4858 if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key)
4867 hammer2_spin_unex(&parent->core.spin);
4868 bref = NULL; /* now invalid (safety) */
4871 * Adjust keybits to represent half of the full range calculated
4872 * above (radix 63 max) for our new indirect block.
4877 * Expand keybits to hold at least ncount elements. ncount will be
4878 * a power of 2. This is to try to completely fill leaf nodes (at
4879 * least for keys which are not hashes).
4881 * We aren't counting 'in' or 'out', we are counting 'high side'
4882 * and 'low side' based on the bit at (1LL << keybits). We want
4883 * everything to be inside in these cases so shift it all to
4884 * the low or high side depending on the new high bit.
4886 while (((hammer2_key_t)1 << keybits) < ncount) {
4888 if (key & ((hammer2_key_t)1 << keybits)) {
4897 if (hicount > locount)
4898 key |= (hammer2_key_t)1 << keybits;
4900 key &= ~(hammer2_key_t)1 << keybits;
4910 * Directory indirect blocks.
4912 * Covers both the inode index (directory of inodes), and directory contents
4913 * (filenames hardlinked to inodes).
4915 * Because directory keys are hashed we generally try to cut the space in
4916 * half. We accomodate the inode index (which tends to have linearly
4917 * increasing inode numbers) by ensuring that the keyspace is at least large
4918 * enough to fill up the indirect block being created.
4921 hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp,
4922 int keybits, hammer2_blockref_t *base, int count,
4925 hammer2_blockref_t *bref;
4926 hammer2_chain_t *chain;
4927 hammer2_key_t key_beg;
4928 hammer2_key_t key_end;
4929 hammer2_key_t key_next;
4934 int maxloops = 300000;
4937 * Shortcut if the parent is the inode. In this situation the
4938 * parent has 4+1 directory entries and we are creating an indirect
4939 * block capable of holding many more.
4941 if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) {
4950 * Calculate the range of keys in the array being careful to skip
4951 * slots which are overridden with a deletion.
4954 key_end = HAMMER2_KEY_MAX;
4955 hammer2_spin_ex(&parent->core.spin);
4958 if (--maxloops == 0) {
4959 panic("indkey_freemap shit %p %p:%d\n",
4960 parent, base, count);
4962 chain = hammer2_combined_find(parent, base, count,
4976 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) {
4977 if (key_next == 0 || key_next > key_end)
4984 * Use the full live (not deleted) element for the scan
4985 * iteration. HAMMER2 does not allow partial replacements.
4987 * XXX should be built into hammer2_combined_find().
4989 key_next = bref->key + ((hammer2_key_t)1 << bref->keybits);
4992 * Expand our calculated key range (key, keybits) to fit
4993 * the scanned key. nkeybits represents the full range
4994 * that we will later cut in half (two halves @ nkeybits - 1).
4997 if (nkeybits < bref->keybits) {
4998 if (bref->keybits > 64) {
4999 kprintf("bad bref chain %p bref %p\n",
5003 nkeybits = bref->keybits;
5005 while (nkeybits < 64 &&
5006 (~(((hammer2_key_t)1 << nkeybits) - 1) &
5007 (key ^ bref->key)) != 0) {
5012 * If the new key range is larger we have to determine
5013 * which side of the new key range the existing keys fall
5014 * under by checking the high bit, then collapsing the
5015 * locount into the hicount or vise-versa.
5017 if (keybits != nkeybits) {
5018 if (((hammer2_key_t)1 << (nkeybits - 1)) & key) {
5029 * The newly scanned key will be in the lower half or the
5030 * upper half of the (new) key range.
5032 if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key)
5041 hammer2_spin_unex(&parent->core.spin);
5042 bref = NULL; /* now invalid (safety) */
5045 * Adjust keybits to represent half of the full range calculated
5046 * above (radix 63 max) for our new indirect block.
5051 * Expand keybits to hold at least ncount elements. ncount will be
5052 * a power of 2. This is to try to completely fill leaf nodes (at
5053 * least for keys which are not hashes).
5055 * We aren't counting 'in' or 'out', we are counting 'high side'
5056 * and 'low side' based on the bit at (1LL << keybits). We want
5057 * everything to be inside in these cases so shift it all to
5058 * the low or high side depending on the new high bit.
5060 while (((hammer2_key_t)1 << keybits) < ncount) {
5062 if (key & ((hammer2_key_t)1 << keybits)) {
5071 if (hicount > locount)
5072 key |= (hammer2_key_t)1 << keybits;
5074 key &= ~(hammer2_key_t)1 << keybits;
5084 * Sets CHAIN_DELETED and remove the chain's blockref from the parent if
5087 * Both parent and chain must be locked exclusively.
5089 * This function will modify the parent if the blockref requires removal
5090 * from the parent's block table.
5092 * This function is NOT recursive. Any entity already pushed into the
5093 * chain (such as an inode) may still need visibility into its contents,
5094 * as well as the ability to read and modify the contents. For example,
5095 * for an unlinked file which is still open.
5097 * Also note that the flusher is responsible for cleaning up empty
5101 hammer2_chain_delete(hammer2_chain_t *parent, hammer2_chain_t *chain,
5102 hammer2_tid_t mtid, int flags)
5106 KKASSERT(hammer2_mtx_owned(&chain->lock));
5109 * Nothing to do if already marked.
5111 * We need the spinlock on the core whos RBTREE contains chain
5112 * to protect against races.
5114 if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) {
5115 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 &&
5116 chain->parent == parent);
5117 error = _hammer2_chain_delete_helper(parent, chain,
5122 * Permanent deletions mark the chain as destroyed.
5124 * NOTE: We do not setflush the chain unless the deletion is
5125 * permanent, since the deletion of a chain does not actually
5126 * require it to be flushed.
5129 if (flags & HAMMER2_DELETE_PERMANENT) {
5130 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY);
5131 hammer2_chain_setflush(chain);
5139 hammer2_chain_delete_obref(hammer2_chain_t *parent, hammer2_chain_t *chain,
5140 hammer2_tid_t mtid, int flags,
5141 hammer2_blockref_t *obref)
5145 KKASSERT(hammer2_mtx_owned(&chain->lock));
5148 * Nothing to do if already marked.
5150 * We need the spinlock on the core whos RBTREE contains chain
5151 * to protect against races.
5154 if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) {
5155 KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 &&
5156 chain->parent == parent);
5157 error = _hammer2_chain_delete_helper(parent, chain,
5158 mtid, flags, obref);
5162 * Permanent deletions mark the chain as destroyed.
5164 * NOTE: We do not setflush the chain unless the deletion is
5165 * permanent, since the deletion of a chain does not actually
5166 * require it to be flushed.
5169 if (flags & HAMMER2_DELETE_PERMANENT) {
5170 atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY);
5171 hammer2_chain_setflush(chain);
5179 * Returns the index of the nearest element in the blockref array >= elm.
5180 * Returns (count) if no element could be found.
5182 * Sets *key_nextp to the next key for loop purposes but does not modify
5183 * it if the next key would be higher than the current value of *key_nextp.
5184 * Note that *key_nexp can overflow to 0, which should be tested by the
5187 * WARNING! Must be called with parent's spinlock held. Spinlock remains
5188 * held through the operation.
5191 hammer2_base_find(hammer2_chain_t *parent,
5192 hammer2_blockref_t *base, int count,
5193 hammer2_key_t *key_nextp,
5194 hammer2_key_t key_beg, hammer2_key_t key_end)
5196 hammer2_blockref_t *scan;
5197 hammer2_key_t scan_end;
5202 * Require the live chain's already have their core's counted
5203 * so we can optimize operations.
5205 KKASSERT(parent->flags & HAMMER2_CHAIN_COUNTEDBREFS);
5210 if (count == 0 || base == NULL)
5214 * Sequential optimization using parent->cache_index. This is
5215 * the most likely scenario.
5217 * We can avoid trailing empty entries on live chains, otherwise
5218 * we might have to check the whole block array.
5220 i = parent->cache_index; /* SMP RACE OK */
5222 limit = parent->core.live_zero;
5227 KKASSERT(i < count);
5233 while (i > 0 && (scan->type == 0 || scan->key > key_beg)) {
5237 parent->cache_index = i;
5240 * Search forwards, stop when we find a scan element which
5241 * encloses the key or until we know that there are no further
5245 if (scan->type != 0) {
5246 scan_end = scan->key +
5247 ((hammer2_key_t)1 << scan->keybits) - 1;
5248 if (scan->key > key_beg || scan_end >= key_beg)
5257 parent->cache_index = i;
5261 scan_end = scan->key +
5262 ((hammer2_key_t)1 << scan->keybits);
5263 if (scan_end && (*key_nextp > scan_end ||
5265 *key_nextp = scan_end;
5273 * Do a combined search and return the next match either from the blockref
5274 * array or from the in-memory chain. Sets *bresp to the returned bref in
5275 * both cases, or sets it to NULL if the search exhausted. Only returns
5276 * a non-NULL chain if the search matched from the in-memory chain.
5278 * When no in-memory chain has been found and a non-NULL bref is returned
5282 * The returned chain is not locked or referenced. Use the returned bref
5283 * to determine if the search exhausted or not. Iterate if the base find
5284 * is chosen but matches a deleted chain.
5286 * WARNING! Must be called with parent's spinlock held. Spinlock remains
5287 * held through the operation.
5290 hammer2_combined_find(hammer2_chain_t *parent,
5291 hammer2_blockref_t *base, int count,
5292 hammer2_key_t *key_nextp,
5293 hammer2_key_t key_beg, hammer2_key_t key_end,
5294 hammer2_blockref_t **bresp)
5296 hammer2_blockref_t *bref;
5297 hammer2_chain_t *chain;
5301 * Lookup in block array and in rbtree.
5303 *key_nextp = key_end + 1;
5304 i = hammer2_base_find(parent, base, count, key_nextp,
5306 chain = hammer2_chain_find(parent, key_nextp, key_beg, key_end);
5311 if (i == count && chain == NULL) {
5317 * Only chain matched.
5320 bref = &chain->bref;
5325 * Only blockref matched.
5327 if (chain == NULL) {
5333 * Both in-memory and blockref matched, select the nearer element.
5335 * If both are flush with the left-hand side or both are the
5336 * same distance away, select the chain. In this situation the
5337 * chain must have been loaded from the matching blockmap.
5339 if ((chain->bref.key <= key_beg && base[i].key <= key_beg) ||
5340 chain->bref.key == base[i].key) {
5341 KKASSERT(chain->bref.key == base[i].key);
5342 bref = &chain->bref;
5347 * Select the nearer key
5349 if (chain->bref.key < base[i].key) {
5350 bref = &chain->bref;
5357 * If the bref is out of bounds we've exhausted our search.
5360 if (bref->key > key_end) {
5370 * Locate the specified block array element and delete it. The element
5373 * The spin lock on the related chain must be held.
5375 * NOTE: live_count was adjusted when the chain was deleted, so it does not
5376 * need to be adjusted when we commit the media change.
5379 hammer2_base_delete(hammer2_chain_t *parent,
5380 hammer2_blockref_t *base, int count,
5381 hammer2_chain_t *chain,
5382 hammer2_blockref_t *obref)
5384 hammer2_blockref_t *elm = &chain->bref;
5385 hammer2_blockref_t *scan;
5386 hammer2_key_t key_next;
5390 * Delete element. Expect the element to exist.
5392 * XXX see caller, flush code not yet sophisticated enough to prevent
5393 * re-flushed in some cases.
5395 key_next = 0; /* max range */
5396 i = hammer2_base_find(parent, base, count, &key_next,
5397 elm->key, elm->key);
5399 if (i == count || scan->type == 0 ||
5400 scan->key != elm->key ||
5401 ((chain->flags & HAMMER2_CHAIN_BMAPUPD) == 0 &&
5402 scan->keybits != elm->keybits)) {
5403 hammer2_spin_unex(&parent->core.spin);
5404 panic("delete base %p element not found at %d/%d elm %p\n",
5405 base, i, count, elm);
5410 * Update stats and zero the entry.
5412 * NOTE: Handle radix == 0 (0 bytes) case.
5414 if ((int)(scan->data_off & HAMMER2_OFF_MASK_RADIX)) {
5415 parent->bref.embed.stats.data_count -= (hammer2_off_t)1 <<
5416 (int)(scan->data_off & HAMMER2_OFF_MASK_RADIX);
5418 switch(scan->type) {
5419 case HAMMER2_BREF_TYPE_INODE:
5420 --parent->bref.embed.stats.inode_count;
5422 case HAMMER2_BREF_TYPE_DATA:
5423 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) {
5424 atomic_set_int(&chain->flags,
5425 HAMMER2_CHAIN_HINT_LEAF_COUNT);
5427 if (parent->bref.leaf_count)
5428 --parent->bref.leaf_count;
5431 case HAMMER2_BREF_TYPE_INDIRECT:
5432 if (scan->type != HAMMER2_BREF_TYPE_DATA) {
5433 parent->bref.embed.stats.data_count -=
5434 scan->embed.stats.data_count;
5435 parent->bref.embed.stats.inode_count -=
5436 scan->embed.stats.inode_count;
5438 if (scan->type == HAMMER2_BREF_TYPE_INODE)
5440 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) {
5441 atomic_set_int(&chain->flags,
5442 HAMMER2_CHAIN_HINT_LEAF_COUNT);
5444 if (parent->bref.leaf_count <= scan->leaf_count)
5445 parent->bref.leaf_count = 0;
5447 parent->bref.leaf_count -= scan->leaf_count;
5450 case HAMMER2_BREF_TYPE_DIRENT:
5451 if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) {
5452 atomic_set_int(&chain->flags,
5453 HAMMER2_CHAIN_HINT_LEAF_COUNT);
5455 if (parent->bref.leaf_count)
5456 --parent->bref.leaf_count;
5464 bzero(scan, sizeof(*scan));
5467 * We can only optimize parent->core.live_zero for live chains.
5469 if (parent->core.live_zero == i + 1) {
5470 while (--i >= 0 && base[i].type == 0)
5472 parent->core.live_zero = i + 1;
5476 * Clear appropriate blockmap flags in chain.
5478 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_BMAPPED |
5479 HAMMER2_CHAIN_BMAPUPD);
5483 * Insert the specified element. The block array must not already have the
5484 * element and must have space available for the insertion.
5486 * The spin lock on the related chain must be held.
5488 * NOTE: live_count was adjusted when the chain was deleted, so it does not
5489 * need to be adjusted when we commit the media change.
5492 hammer2_base_insert(hammer2_chain_t *parent,
5493 hammer2_blockref_t *base, int count,
5494 hammer2_chain_t *chain, hammer2_blockref_t *elm)
5496 hammer2_key_t key_next;
5505 * Insert new element. Expect the element to not already exist
5506 * unless we are replacing it.
5508 * XXX see caller, flush code not yet sophisticated enough to prevent
5509 * re-flushed in some cases.
5511 key_next = 0; /* max range */
5512 i = hammer2_base_find(parent, base, count, &key_next,
5513 elm->key, elm->key);
5516 * Shortcut fill optimization, typical ordered insertion(s) may not
5519 KKASSERT(i >= 0 && i <= count);
5522 * Set appropriate blockmap flags in chain (if not NULL)
5525 atomic_set_int(&chain->flags, HAMMER2_CHAIN_BMAPPED);
5528 * Update stats and zero the entry
5530 if ((int)(elm->data_off & HAMMER2_OFF_MASK_RADIX)) {
5531 parent->bref.embed.stats.data_count += (hammer2_off_t)1 <<
5532 (int)(elm->data_off & HAMMER2_OFF_MASK_RADIX);
5535 case HAMMER2_BREF_TYPE_INODE:
5536 ++parent->bref.embed.stats.inode_count;
5538 case HAMMER2_BREF_TYPE_DATA:
5539 if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX)
5540 ++parent->bref.leaf_count;
5542 case HAMMER2_BREF_TYPE_INDIRECT:
5543 if (elm->type != HAMMER2_BREF_TYPE_DATA) {
5544 parent->bref.embed.stats.data_count +=
5545 elm->embed.stats.data_count;
5546 parent->bref.embed.stats.inode_count +=
5547 elm->embed.stats.inode_count;
5549 if (elm->type == HAMMER2_BREF_TYPE_INODE)
5551 if (parent->bref.leaf_count + elm->leaf_count <
5552 HAMMER2_BLOCKREF_LEAF_MAX) {
5553 parent->bref.leaf_count += elm->leaf_count;
5555 parent->bref.leaf_count = HAMMER2_BLOCKREF_LEAF_MAX;
5558 case HAMMER2_BREF_TYPE_DIRENT:
5559 if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX)
5560 ++parent->bref.leaf_count;
5568 * We can only optimize parent->core.live_zero for live chains.
5570 if (i == count && parent->core.live_zero < count) {
5571 i = parent->core.live_zero++;
5576 xkey = elm->key + ((hammer2_key_t)1 << elm->keybits) - 1;
5577 if (i != count && (base[i].key < elm->key || xkey >= base[i].key)) {
5578 hammer2_spin_unex(&parent->core.spin);
5579 panic("insert base %p overlapping elements at %d elm %p\n",
5584 * Try to find an empty slot before or after.
5588 while (j > 0 || k < count) {
5590 if (j >= 0 && base[j].type == 0) {
5594 bcopy(&base[j+1], &base[j],
5595 (i - j - 1) * sizeof(*base));
5601 if (k < count && base[k].type == 0) {
5602 bcopy(&base[i], &base[i+1],
5603 (k - i) * sizeof(hammer2_blockref_t));
5607 * We can only update parent->core.live_zero for live
5610 if (parent->core.live_zero <= k)
5611 parent->core.live_zero = k + 1;
5616 panic("hammer2_base_insert: no room!");
5623 for (l = 0; l < count; ++l) {
5625 key_next = base[l].key +
5626 ((hammer2_key_t)1 << base[l].keybits) - 1;
5630 while (++l < count) {
5632 if (base[l].key <= key_next)
5633 panic("base_insert %d %d,%d,%d fail %p:%d", u, i, j, k, base, l);
5634 key_next = base[l].key +
5635 ((hammer2_key_t)1 << base[l].keybits) - 1;
5645 * Sort the blockref array for the chain. Used by the flush code to
5646 * sort the blockref[] array.
5648 * The chain must be exclusively locked AND spin-locked.
5650 typedef hammer2_blockref_t *hammer2_blockref_p;
5654 hammer2_base_sort_callback(const void *v1, const void *v2)
5656 hammer2_blockref_p bref1 = *(const hammer2_blockref_p *)v1;
5657 hammer2_blockref_p bref2 = *(const hammer2_blockref_p *)v2;
5660 * Make sure empty elements are placed at the end of the array
5662 if (bref1->type == 0) {
5663 if (bref2->type == 0)
5666 } else if (bref2->type == 0) {
5673 if (bref1->key < bref2->key)
5675 if (bref1->key > bref2->key)
5681 hammer2_base_sort(hammer2_chain_t *chain)
5683 hammer2_blockref_t *base;
5686 switch(chain->bref.type) {
5687 case HAMMER2_BREF_TYPE_INODE:
5689 * Special shortcut for embedded data returns the inode
5690 * itself. Callers must detect this condition and access
5691 * the embedded data (the strategy code does this for us).
5693 * This is only applicable to regular files and softlinks.
5695 if (chain->data->ipdata.meta.op_flags &
5696 HAMMER2_OPFLAG_DIRECTDATA) {
5699 base = &chain->data->ipdata.u.blockset.blockref[0];
5700 count = HAMMER2_SET_COUNT;
5702 case HAMMER2_BREF_TYPE_FREEMAP_NODE:
5703 case HAMMER2_BREF_TYPE_INDIRECT:
5705 * Optimize indirect blocks in the INITIAL state to avoid
5708 KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) == 0);
5709 base = &chain->data->npdata[0];
5710 count = chain->bytes / sizeof(hammer2_blockref_t);
5712 case HAMMER2_BREF_TYPE_VOLUME:
5713 base = &chain->data->voldata.sroot_blockset.blockref[0];
5714 count = HAMMER2_SET_COUNT;
5716 case HAMMER2_BREF_TYPE_FREEMAP:
5717 base = &chain->data->blkset.blockref[0];
5718 count = HAMMER2_SET_COUNT;
5721 kprintf("hammer2_chain_lookup: unrecognized "
5722 "blockref(A) type: %d",
5725 tsleep(&base, 0, "dead", 0);
5726 panic("hammer2_chain_lookup: unrecognized "
5727 "blockref(A) type: %d",
5729 base = NULL; /* safety */
5730 count = 0; /* safety */
5732 kqsort(base, count, sizeof(*base), hammer2_base_sort_callback);
5738 * Chain memory management
5741 hammer2_chain_wait(hammer2_chain_t *chain)
5743 tsleep(chain, 0, "chnflw", 1);
5746 const hammer2_media_data_t *
5747 hammer2_chain_rdata(hammer2_chain_t *chain)
5749 KKASSERT(chain->data != NULL);
5750 return (chain->data);
5753 hammer2_media_data_t *
5754 hammer2_chain_wdata(hammer2_chain_t *chain)
5756 KKASSERT(chain->data != NULL);
5757 return (chain->data);
5761 * Set the check data for a chain. This can be a heavy-weight operation
5762 * and typically only runs on-flush. For file data check data is calculated
5763 * when the logical buffers are flushed.
5766 hammer2_chain_setcheck(hammer2_chain_t *chain, void *bdata)
5768 chain->bref.flags &= ~HAMMER2_BREF_FLAG_ZERO;
5770 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
5771 case HAMMER2_CHECK_NONE:
5773 case HAMMER2_CHECK_DISABLED:
5775 case HAMMER2_CHECK_ISCSI32:
5776 chain->bref.check.iscsi32.value =
5777 hammer2_icrc32(bdata, chain->bytes);
5779 case HAMMER2_CHECK_XXHASH64:
5780 chain->bref.check.xxhash64.value =
5781 XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED);
5783 case HAMMER2_CHECK_SHA192:
5785 SHA256_CTX hash_ctx;
5787 uint8_t digest[SHA256_DIGEST_LENGTH];
5788 uint64_t digest64[SHA256_DIGEST_LENGTH/8];
5791 SHA256_Init(&hash_ctx);
5792 SHA256_Update(&hash_ctx, bdata, chain->bytes);
5793 SHA256_Final(u.digest, &hash_ctx);
5794 u.digest64[2] ^= u.digest64[3];
5796 chain->bref.check.sha192.data,
5797 sizeof(chain->bref.check.sha192.data));
5800 case HAMMER2_CHECK_FREEMAP:
5801 chain->bref.check.freemap.icrc32 =
5802 hammer2_icrc32(bdata, chain->bytes);
5805 kprintf("hammer2_chain_setcheck: unknown check type %02x\n",
5806 chain->bref.methods);
5812 * Characterize a failed check code and try to trace back to the inode.
5815 hammer2_characterize_failed_chain(hammer2_chain_t *chain, uint64_t check,
5818 hammer2_chain_t *lchain;
5819 hammer2_chain_t *ochain;
5821 kprintf("chain %016jx.%02x (%s) meth=%02x CHECK FAIL "
5822 "(flags=%08x, bref/data ",
5823 chain->bref.data_off,
5825 hammer2_bref_type_str(&chain->bref),
5826 chain->bref.methods,
5829 kprintf("%08x/%08x)\n",
5830 chain->bref.check.iscsi32.value,
5833 kprintf("%016jx/%016jx)\n",
5834 chain->bref.check.xxhash64.value,
5839 * Run up the chains to try to find the governing inode so we
5842 * XXX This error reporting is not really MPSAFE
5846 while (chain && chain->bref.type != HAMMER2_BREF_TYPE_INODE) {
5848 chain = chain->parent;
5851 if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
5852 ((chain->bref.flags & HAMMER2_BREF_FLAG_PFSROOT) == 0 ||
5853 (lchain->bref.key & HAMMER2_DIRHASH_VISIBLE))) {
5854 kprintf(" Resides at/in inode %ld\n",
5856 } else if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
5857 kprintf(" Resides in inode index - CRITICAL!!!\n");
5859 kprintf(" Resides in root index - CRITICAL!!!\n");
5862 const char *pfsname = "UNKNOWN";
5866 for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) {
5867 if (ochain->pmp->pfs_hmps[i] == ochain->hmp &&
5868 ochain->pmp->pfs_names[i]) {
5869 pfsname = ochain->pmp->pfs_names[i];
5874 kprintf(" In pfs %s on device %s\n",
5875 pfsname, ochain->hmp->devrepname);
5880 hammer2_chain_testcheck(hammer2_chain_t *chain, void *bdata)
5886 if (chain->bref.flags & HAMMER2_BREF_FLAG_ZERO)
5889 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
5890 case HAMMER2_CHECK_NONE:
5893 case HAMMER2_CHECK_DISABLED:
5896 case HAMMER2_CHECK_ISCSI32:
5897 check32 = hammer2_icrc32(bdata, chain->bytes);
5898 r = (chain->bref.check.iscsi32.value == check32);
5900 hammer2_characterize_failed_chain(chain, check32, 32);
5902 hammer2_process_icrc32 += chain->bytes;
5904 case HAMMER2_CHECK_XXHASH64:
5905 check64 = XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED);
5906 r = (chain->bref.check.xxhash64.value == check64);
5908 hammer2_characterize_failed_chain(chain, check64, 64);
5910 hammer2_process_xxhash64 += chain->bytes;
5912 case HAMMER2_CHECK_SHA192:
5914 SHA256_CTX hash_ctx;
5916 uint8_t digest[SHA256_DIGEST_LENGTH];
5917 uint64_t digest64[SHA256_DIGEST_LENGTH/8];
5920 SHA256_Init(&hash_ctx);
5921 SHA256_Update(&hash_ctx, bdata, chain->bytes);
5922 SHA256_Final(u.digest, &hash_ctx);
5923 u.digest64[2] ^= u.digest64[3];
5925 chain->bref.check.sha192.data,
5926 sizeof(chain->bref.check.sha192.data)) == 0) {
5930 kprintf("chain %016jx.%02x meth=%02x "
5932 chain->bref.data_off,
5934 chain->bref.methods);
5938 case HAMMER2_CHECK_FREEMAP:
5939 r = (chain->bref.check.freemap.icrc32 ==
5940 hammer2_icrc32(bdata, chain->bytes));
5942 kprintf("chain %016jx.%02x meth=%02x "
5944 chain->bref.data_off,
5946 chain->bref.methods);
5947 kprintf("freemap.icrc %08x icrc32 %08x (%d)\n",
5948 chain->bref.check.freemap.icrc32,
5949 hammer2_icrc32(bdata, chain->bytes),
5952 kprintf("dio %p buf %016jx,%d bdata %p/%p\n",
5953 chain->dio, chain->dio->bp->b_loffset,
5954 chain->dio->bp->b_bufsize, bdata,
5955 chain->dio->bp->b_data);
5960 kprintf("hammer2_chain_setcheck: unknown check type %02x\n",
5961 chain->bref.methods);
5969 * Acquire the chain and parent representing the specified inode for the
5970 * device at the specified cluster index.
5972 * The flags passed in are LOOKUP flags, not RESOLVE flags.
5974 * If we are unable to locate the inode, HAMMER2_ERROR_EIO is returned and
5975 * *chainp will be NULL. *parentp may still be set error or not, or NULL
5976 * if the parent itself could not be resolved.
5978 * The caller may pass-in a locked *parentp and/or *chainp, or neither.
5979 * They will be unlocked and released by this function. The *parentp and
5980 * *chainp representing the located inode are returned locked.
5983 hammer2_chain_inode_find(hammer2_pfs_t *pmp, hammer2_key_t inum,
5984 int clindex, int flags,
5985 hammer2_chain_t **parentp, hammer2_chain_t **chainp)
5987 hammer2_chain_t *parent;
5988 hammer2_chain_t *rchain;
5989 hammer2_key_t key_dummy;
5990 hammer2_inode_t *ip;
5994 resolve_flags = (flags & HAMMER2_LOOKUP_SHARED) ?
5995 HAMMER2_RESOLVE_SHARED : 0;
5998 * Caller expects us to replace these.
6001 hammer2_chain_unlock(*chainp);
6002 hammer2_chain_drop(*chainp);
6006 hammer2_chain_unlock(*parentp);
6007 hammer2_chain_drop(*parentp);
6012 * Be very careful, this is a backend function and we CANNOT
6013 * lock any frontend inode structure we find. But we have to
6014 * look the inode up this way first in case it exists but is
6015 * detached from the radix tree.
6017 ip = hammer2_inode_lookup(pmp, inum);
6019 *chainp = hammer2_inode_chain_and_parent(ip, clindex,
6022 hammer2_inode_drop(ip);
6025 hammer2_chain_unlock(*chainp);
6026 hammer2_chain_drop(*chainp);
6029 hammer2_chain_unlock(*parentp);
6030 hammer2_chain_drop(*parentp);
6036 * Inodes hang off of the iroot (bit 63 is clear, differentiating
6037 * inodes from root directory entries in the key lookup).
6039 parent = hammer2_inode_chain(pmp->iroot, clindex, resolve_flags);
6042 rchain = hammer2_chain_lookup(&parent, &key_dummy,
6046 error = HAMMER2_ERROR_EIO;
6055 * Used by the bulkscan code to snapshot the synchronized storage for
6056 * a volume, allowing it to be scanned concurrently against normal
6060 hammer2_chain_bulksnap(hammer2_dev_t *hmp)
6062 hammer2_chain_t *copy;
6064 copy = hammer2_chain_alloc(hmp, hmp->spmp, &hmp->vchain.bref);
6065 copy->data = kmalloc(sizeof(copy->data->voldata),
6068 hammer2_voldata_lock(hmp);
6069 copy->data->voldata = hmp->volsync;
6070 hammer2_voldata_unlock(hmp);
6076 hammer2_chain_bulkdrop(hammer2_chain_t *copy)
6078 KKASSERT(copy->bref.type == HAMMER2_BREF_TYPE_VOLUME);
6079 KKASSERT(copy->data);
6080 kfree(copy->data, copy->hmp->mchain);
6082 atomic_add_long(&hammer2_chain_allocs, -1);
6083 hammer2_chain_drop(copy);
6087 * Returns non-zero if the chain (INODE or DIRENT) matches the
6091 hammer2_chain_dirent_test(hammer2_chain_t *chain, const char *name,
6094 const hammer2_inode_data_t *ripdata;
6095 const hammer2_dirent_head_t *den;
6097 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
6098 ripdata = &chain->data->ipdata;
6099 if (ripdata->meta.name_len == name_len &&
6100 bcmp(ripdata->filename, name, name_len) == 0) {
6104 if (chain->bref.type == HAMMER2_BREF_TYPE_DIRENT &&
6105 chain->bref.embed.dirent.namlen == name_len) {
6106 den = &chain->bref.embed.dirent;
6107 if (name_len > sizeof(chain->bref.check.buf) &&
6108 bcmp(chain->data->buf, name, name_len) == 0) {
6111 if (name_len <= sizeof(chain->bref.check.buf) &&
6112 bcmp(chain->bref.check.buf, name, name_len) == 0) {