/* * Copyright (c) 2011-2020 The DragonFly Project. All rights reserved. * * This code is derived from software contributed to The DragonFly Project * by Matthew Dillon * and Venkatesh Srinivas * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name of The DragonFly Project nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific, prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * This subsystem implements most of the core support functions for * the hammer2_chain structure. * * Chains are the in-memory version on media objects (volume header, inodes, * indirect blocks, data blocks, etc). Chains represent a portion of the * HAMMER2 topology. * * Chains are no-longer delete-duplicated. Instead, the original in-memory * chain will be moved along with its block reference (e.g. for things like * renames, hardlink operations, modifications, etc), and will be indexed * on a secondary list for flush handling instead of propagating a flag * upward to the root. * * Concurrent front-end operations can still run against backend flushes * as long as they do not cross the current flush boundary. An operation * running above the current flush (in areas not yet flushed) can become * part of the current flush while ano peration running below the current * flush can become part of the next flush. */ #include #include #include #include #include #include #include #include "hammer2.h" static hammer2_chain_t *hammer2_chain_create_indirect( hammer2_chain_t *parent, hammer2_key_t key, int keybits, hammer2_tid_t mtid, int for_type, int *errorp); static int hammer2_chain_delete_obref(hammer2_chain_t *parent, hammer2_chain_t *chain, hammer2_tid_t mtid, int flags, hammer2_blockref_t *obref); static hammer2_chain_t *hammer2_combined_find( hammer2_chain_t *parent, hammer2_blockref_t *base, int count, hammer2_key_t *key_nextp, hammer2_key_t key_beg, hammer2_key_t key_end, hammer2_blockref_t **brefp); static hammer2_chain_t *hammer2_chain_lastdrop(hammer2_chain_t *chain, int depth); /* * There are many degenerate situations where an extreme rate of console * output can occur from warnings and errors. Make sure this output does * not impede operations. */ static struct krate krate_h2chk = { .freq = 5 }; static struct krate krate_h2me = { .freq = 1 }; static struct krate krate_h2em = { .freq = 1 }; /* * Basic RBTree for chains (core.rbtree). */ RB_GENERATE(hammer2_chain_tree, hammer2_chain, rbnode, hammer2_chain_cmp); int hammer2_chain_cmp(hammer2_chain_t *chain1, hammer2_chain_t *chain2) { hammer2_key_t c1_beg; hammer2_key_t c1_end; hammer2_key_t c2_beg; hammer2_key_t c2_end; /* * Compare chains. Overlaps are not supposed to happen and catch * any software issues early we count overlaps as a match. */ c1_beg = chain1->bref.key; c1_end = c1_beg + ((hammer2_key_t)1 << chain1->bref.keybits) - 1; c2_beg = chain2->bref.key; c2_end = c2_beg + ((hammer2_key_t)1 << chain2->bref.keybits) - 1; if (c1_end < c2_beg) /* fully to the left */ return(-1); if (c1_beg > c2_end) /* fully to the right */ return(1); return(0); /* overlap (must not cross edge boundary) */ } /* * Assert that a chain has no media data associated with it. */ static __inline void hammer2_chain_assert_no_data(hammer2_chain_t *chain) { KKASSERT(chain->dio == NULL); if (chain->bref.type != HAMMER2_BREF_TYPE_VOLUME && chain->bref.type != HAMMER2_BREF_TYPE_FREEMAP && chain->data) { panic("hammer2_chain_assert_no_data: chain %p still has data", chain); } } /* * Make a chain visible to the flusher. The flusher operates using a top-down * recursion based on the ONFLUSH flag. It locates MODIFIED and UPDATE chains, * flushes them, and updates blocks back to the volume root. * * This routine sets the ONFLUSH flag upward from the triggering chain until * it hits an inode root or the volume root. Inode chains serve as inflection * points, requiring the flusher to bridge across trees. Inodes include * regular inodes, PFS roots (pmp->iroot), and the media super root * (spmp->iroot). */ void hammer2_chain_setflush(hammer2_chain_t *chain) { hammer2_chain_t *parent; if ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) { hammer2_spin_sh(&chain->core.spin); while ((chain->flags & HAMMER2_CHAIN_ONFLUSH) == 0) { atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONFLUSH); if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) break; if ((parent = chain->parent) == NULL) break; hammer2_spin_sh(&parent->core.spin); hammer2_spin_unsh(&chain->core.spin); chain = parent; } hammer2_spin_unsh(&chain->core.spin); } } /* * Allocate a new disconnected chain element representing the specified * bref. chain->refs is set to 1 and the passed bref is copied to * chain->bref. chain->bytes is derived from the bref. * * chain->pmp inherits pmp unless the chain is an inode (other than the * super-root inode). * * NOTE: Returns a referenced but unlocked (because there is no core) chain. */ hammer2_chain_t * hammer2_chain_alloc(hammer2_dev_t *hmp, hammer2_pfs_t *pmp, hammer2_blockref_t *bref) { hammer2_chain_t *chain; u_int bytes; /* * Special case - radix of 0 indicates a chain that does not * need a data reference (context is completely embedded in the * bref). */ if ((int)(bref->data_off & HAMMER2_OFF_MASK_RADIX)) bytes = 1U << (int)(bref->data_off & HAMMER2_OFF_MASK_RADIX); else bytes = 0; switch(bref->type) { case HAMMER2_BREF_TYPE_INODE: case HAMMER2_BREF_TYPE_INDIRECT: case HAMMER2_BREF_TYPE_DATA: case HAMMER2_BREF_TYPE_DIRENT: case HAMMER2_BREF_TYPE_FREEMAP_NODE: case HAMMER2_BREF_TYPE_FREEMAP_LEAF: case HAMMER2_BREF_TYPE_FREEMAP: case HAMMER2_BREF_TYPE_VOLUME: chain = kmalloc_obj(sizeof(*chain), hmp->mchain, M_WAITOK | M_ZERO); atomic_add_long(&hammer2_chain_allocs, 1); break; case HAMMER2_BREF_TYPE_EMPTY: default: panic("hammer2_chain_alloc: unrecognized blockref type: %d", bref->type); break; } /* * Initialize the new chain structure. pmp must be set to NULL for * chains belonging to the super-root topology of a device mount. */ if (pmp == hmp->spmp) chain->pmp = NULL; else chain->pmp = pmp; chain->hmp = hmp; chain->bref = *bref; chain->bytes = bytes; chain->refs = 1; chain->flags = HAMMER2_CHAIN_ALLOCATED; /* * Set the PFS boundary flag if this chain represents a PFS root. */ if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT) atomic_set_int(&chain->flags, HAMMER2_CHAIN_PFSBOUNDARY); hammer2_chain_init(chain); return (chain); } /* * A common function to initialize chains including fchain and vchain. */ void hammer2_chain_init(hammer2_chain_t *chain) { RB_INIT(&chain->core.rbtree); /* live chains */ hammer2_mtx_init(&chain->lock, "h2chain"); hammer2_spin_init(&chain->core.spin, "h2chain"); lockinit(&chain->diolk, "chdio", 0, 0); } /* * Add a reference to a chain element, preventing its destruction. * Undone via hammer2_chain_drop() * * (can be called with spinlock held) */ void hammer2_chain_ref(hammer2_chain_t *chain) { if (atomic_fetchadd_int(&chain->refs, 1) == 0) { /* NOP */ } } /* * Ref a locked chain and force the data to be held across an unlock. * Chain must be currently locked. The user of the chain who desires * to release the hold must call hammer2_chain_lock_unhold() to relock * and unhold the chain, then unlock normally, or may simply call * hammer2_chain_drop_unhold() (which is safer against deadlocks). */ void hammer2_chain_ref_hold(hammer2_chain_t *chain) { atomic_add_int(&chain->lockcnt, 1); hammer2_chain_ref(chain); } /* * Insert the chain in the core rbtree. * * Normal insertions are placed in the live rbtree. Insertion of a deleted * chain is a special case used by the flush code that is placed on the * unstaged deleted list to avoid confusing the live view. */ #define HAMMER2_CHAIN_INSERT_SPIN 0x0001 #define HAMMER2_CHAIN_INSERT_LIVE 0x0002 #define HAMMER2_CHAIN_INSERT_RACE 0x0004 static int hammer2_chain_insert(hammer2_chain_t *parent, hammer2_chain_t *chain, int flags, int generation) { hammer2_chain_t *xchain __debugvar; int error = 0; if (flags & HAMMER2_CHAIN_INSERT_SPIN) hammer2_spin_ex(&parent->core.spin); /* * Interlocked by spinlock, check for race */ if ((flags & HAMMER2_CHAIN_INSERT_RACE) && parent->core.generation != generation) { error = HAMMER2_ERROR_EAGAIN; goto failed; } /* * Insert chain */ xchain = RB_INSERT(hammer2_chain_tree, &parent->core.rbtree, chain); KASSERT(xchain == NULL, ("hammer2_chain_insert: collision %p %p (key=%016jx)", chain, xchain, chain->bref.key)); atomic_set_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); chain->parent = parent; ++parent->core.chain_count; ++parent->core.generation; /* XXX incs for _get() too, XXX */ /* * We have to keep track of the effective live-view blockref count * so the create code knows when to push an indirect block. */ if (flags & HAMMER2_CHAIN_INSERT_LIVE) atomic_add_int(&parent->core.live_count, 1); failed: if (flags & HAMMER2_CHAIN_INSERT_SPIN) hammer2_spin_unex(&parent->core.spin); return error; } /* * Drop the caller's reference to the chain. When the ref count drops to * zero this function will try to disassociate the chain from its parent and * deallocate it, then recursely drop the parent using the implied ref * from the chain's chain->parent. * * Nobody should own chain's mutex on the 1->0 transition, unless this drop * races an acquisition by another cpu. Therefore we can loop if we are * unable to acquire the mutex, and refs is unlikely to be 1 unless we again * race against another drop. */ void hammer2_chain_drop(hammer2_chain_t *chain) { u_int refs; KKASSERT(chain->refs > 0); while (chain) { refs = chain->refs; cpu_ccfence(); KKASSERT(refs > 0); if (refs == 1) { if (hammer2_mtx_ex_try(&chain->lock) == 0) chain = hammer2_chain_lastdrop(chain, 0); /* retry the same chain, or chain from lastdrop */ } else { if (atomic_cmpset_int(&chain->refs, refs, refs - 1)) break; /* retry the same chain */ } cpu_pause(); } } /* * Unhold a held and probably not-locked chain, ensure that the data is * dropped on the 1->0 transition of lockcnt by obtaining an exclusive * lock and then simply unlocking the chain. */ void hammer2_chain_unhold(hammer2_chain_t *chain) { u_int lockcnt; int iter = 0; for (;;) { lockcnt = chain->lockcnt; cpu_ccfence(); if (lockcnt > 1) { if (atomic_cmpset_int(&chain->lockcnt, lockcnt, lockcnt - 1)) { break; } } else if (hammer2_mtx_ex_try(&chain->lock) == 0) { hammer2_chain_unlock(chain); break; } else { /* * This situation can easily occur on SMP due to * the gap inbetween the 1->0 transition and the * final unlock. We cannot safely block on the * mutex because lockcnt might go above 1. * * XXX Sleep for one tick if it takes too long. */ if (++iter > 1000) { if (iter > 1000 + hz) { kprintf("hammer2: h2race1 %p\n", chain); iter = 1000; } tsleep(&iter, 0, "h2race1", 1); } cpu_pause(); } } } void hammer2_chain_drop_unhold(hammer2_chain_t *chain) { hammer2_chain_unhold(chain); hammer2_chain_drop(chain); } void hammer2_chain_rehold(hammer2_chain_t *chain) { hammer2_chain_lock(chain, HAMMER2_RESOLVE_SHARED); atomic_add_int(&chain->lockcnt, 1); hammer2_chain_unlock(chain); } /* * Handles the (potential) last drop of chain->refs from 1->0. Called with * the mutex exclusively locked, refs == 1, and lockcnt 0. SMP races are * possible against refs and lockcnt. We must dispose of the mutex on chain. * * This function returns an unlocked chain for recursive drop or NULL. It * can return the same chain if it determines it has raced another ref. * * -- * * When two chains need to be recursively dropped we use the chain we * would otherwise free to placehold the additional chain. It's a bit * convoluted but we can't just recurse without potentially blowing out * the kernel stack. * * The chain cannot be freed if it has any children. * The chain cannot be freed if flagged MODIFIED unless we can dispose of it. * The chain cannot be freed if flagged UPDATE unless we can dispose of it. * Any dedup registration can remain intact. * * The core spinlock is allowed to nest child-to-parent (not parent-to-child). */ static hammer2_chain_t * hammer2_chain_lastdrop(hammer2_chain_t *chain, int depth) { hammer2_dev_t *hmp; hammer2_chain_t *parent; hammer2_chain_t *rdrop; /* * We need chain's spinlock to interlock the sub-tree test. * We already have chain's mutex, protecting chain->parent. * * Remember that chain->refs can be in flux. */ hammer2_spin_ex(&chain->core.spin); if (chain->parent != NULL) { /* * If the chain has a parent the UPDATE bit prevents scrapping * as the chain is needed to properly flush the parent. Try * to complete the 1->0 transition and return NULL. Retry * (return chain) if we are unable to complete the 1->0 * transition, else return NULL (nothing more to do). * * If the chain has a parent the MODIFIED bit prevents * scrapping. */ if (chain->flags & (HAMMER2_CHAIN_UPDATE | HAMMER2_CHAIN_MODIFIED)) { if (atomic_cmpset_int(&chain->refs, 1, 0)) { hammer2_spin_unex(&chain->core.spin); hammer2_chain_assert_no_data(chain); hammer2_mtx_unlock(&chain->lock); chain = NULL; } else { hammer2_spin_unex(&chain->core.spin); hammer2_mtx_unlock(&chain->lock); } return (chain); } /* spinlock still held */ } else if (chain->bref.type == HAMMER2_BREF_TYPE_VOLUME || chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP) { /* * Retain the static vchain and fchain. Clear bits that * are not relevant. Do not clear the MODIFIED bit, * and certainly do not put it on the delayed-flush queue. */ atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); } else { /* * The chain has no parent and can be flagged for destruction. * Since it has no parent, UPDATE can also be cleared. */ atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); if (chain->flags & HAMMER2_CHAIN_UPDATE) atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); /* * If the chain has children we must propagate the DESTROY * flag downward and rip the disconnected topology apart. * This is accomplished by calling hammer2_flush() on the * chain. * * Any dedup is already handled by the underlying DIO, so * we do not have to specifically flush it here. */ if (chain->core.chain_count) { hammer2_spin_unex(&chain->core.spin); hammer2_flush(chain, HAMMER2_FLUSH_TOP | HAMMER2_FLUSH_ALL); hammer2_mtx_unlock(&chain->lock); return(chain); /* retry drop */ } /* * Otherwise we can scrap the MODIFIED bit if it is set, * and continue along the freeing path. * * Be sure to clean-out any dedup bits. Without a parent * this chain will no longer be visible to the flush code. * Easy check data_off to avoid the volume root. */ if (chain->flags & HAMMER2_CHAIN_MODIFIED) { atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); atomic_add_long(&hammer2_count_modified_chains, -1); if (chain->pmp) hammer2_pfs_memory_wakeup(chain->pmp, -1); } /* spinlock still held */ } /* spinlock still held */ /* * If any children exist we must leave the chain intact with refs == 0. * They exist because chains are retained below us which have refs or * may require flushing. * * Retry (return chain) if we fail to transition the refs to 0, else * return NULL indication nothing more to do. */ if (chain->core.chain_count) { if (atomic_cmpset_int(&chain->refs, 1, 0)) { hammer2_spin_unex(&chain->core.spin); hammer2_chain_assert_no_data(chain); hammer2_mtx_unlock(&chain->lock); chain = NULL; } else { hammer2_spin_unex(&chain->core.spin); hammer2_mtx_unlock(&chain->lock); } return (chain); } /* spinlock still held */ /* no chains left under us */ /* * chain->core has no children left so no accessors can get to our * chain from there. Now we have to lock the parent core to interlock * remaining possible accessors that might bump chain's refs before * we can safely drop chain's refs with intent to free the chain. */ hmp = chain->hmp; rdrop = NULL; parent = chain->parent; /* * WARNING! chain's spin lock is still held here, and other spinlocks * will be acquired and released in the code below. We * cannot be making fancy procedure calls! */ /* * Spinlock the parent and try to drop the last ref on chain. * On success determine if we should dispose of the chain * (remove the chain from its parent, etc). * * (normal core locks are top-down recursive but we define * core spinlocks as bottom-up recursive, so this is safe). */ if (parent) { hammer2_spin_ex(&parent->core.spin); if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) { /* * 1->0 transition failed, retry. */ hammer2_spin_unex(&parent->core.spin); hammer2_spin_unex(&chain->core.spin); hammer2_mtx_unlock(&chain->lock); return(chain); } /* * 1->0 transition successful, parent spin held to prevent * new lookups, chain spinlock held to protect parent field. * Remove chain from the parent. * * If the chain is being removed from the parent's rbtree but * is not blkmapped, we have to adjust live_count downward. If * it is blkmapped then the blockref is retained in the parent * as is its associated live_count. This case can occur when * a chain added to the topology is unable to flush and is * then later deleted. */ if (chain->flags & HAMMER2_CHAIN_ONRBTREE) { if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) && (chain->flags & HAMMER2_CHAIN_BLKMAPPED) == 0) { atomic_add_int(&parent->core.live_count, -1); } RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain); atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); --parent->core.chain_count; chain->parent = NULL; } /* * If our chain was the last chain in the parent's core the * core is now empty and its parent might have to be * re-dropped if it has 0 refs. */ if (parent->core.chain_count == 0) { rdrop = parent; atomic_add_int(&rdrop->refs, 1); /* if (atomic_cmpset_int(&rdrop->refs, 0, 1) == 0) rdrop = NULL; */ } hammer2_spin_unex(&parent->core.spin); parent = NULL; /* safety */ /* FALL THROUGH */ } else { /* * No-parent case. */ if (atomic_cmpset_int(&chain->refs, 1, 0) == 0) { /* * 1->0 transition failed, retry. */ hammer2_spin_unex(&parent->core.spin); hammer2_spin_unex(&chain->core.spin); hammer2_mtx_unlock(&chain->lock); return(chain); } } /* * Successful 1->0 transition, no parent, no children... no way for * anyone to ref this chain any more. We can clean-up and free it. * * We still have the core spinlock, and core's chain_count is 0. * Any parent spinlock is gone. */ hammer2_spin_unex(&chain->core.spin); hammer2_chain_assert_no_data(chain); hammer2_mtx_unlock(&chain->lock); KKASSERT(RB_EMPTY(&chain->core.rbtree) && chain->core.chain_count == 0); /* * All locks are gone, no pointers remain to the chain, finish * freeing it. */ KKASSERT((chain->flags & (HAMMER2_CHAIN_UPDATE | HAMMER2_CHAIN_MODIFIED)) == 0); /* * Once chain resources are gone we can use the now dead chain * structure to placehold what might otherwise require a recursive * drop, because we have potentially two things to drop and can only * return one directly. */ if (chain->flags & HAMMER2_CHAIN_ALLOCATED) { atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ALLOCATED); chain->hmp = NULL; kfree_obj(chain, hmp->mchain); atomic_add_long(&hammer2_chain_allocs, -1); } /* * Possible chaining loop when parent re-drop needed. */ return(rdrop); } /* * On last lock release. */ static hammer2_io_t * hammer2_chain_drop_data(hammer2_chain_t *chain) { hammer2_io_t *dio; if ((dio = chain->dio) != NULL) { chain->dio = NULL; chain->data = NULL; } else { switch(chain->bref.type) { case HAMMER2_BREF_TYPE_VOLUME: case HAMMER2_BREF_TYPE_FREEMAP: break; default: if (chain->data != NULL) { hammer2_spin_unex(&chain->core.spin); panic("chain data not null: " "chain %p bref %016jx.%02x " "refs %d parent %p dio %p data %p", chain, chain->bref.data_off, chain->bref.type, chain->refs, chain->parent, chain->dio, chain->data); } KKASSERT(chain->data == NULL); break; } } return dio; } /* * Lock a referenced chain element, acquiring its data with I/O if necessary, * and specify how you would like the data to be resolved. * * If an I/O or other fatal error occurs, chain->error will be set to non-zero. * * The lock is allowed to recurse, multiple locking ops will aggregate * the requested resolve types. Once data is assigned it will not be * removed until the last unlock. * * HAMMER2_RESOLVE_NEVER - Do not resolve the data element. * (typically used to avoid device/logical buffer * aliasing for data) * * HAMMER2_RESOLVE_MAYBE - Do not resolve data elements for chains in * the INITIAL-create state (indirect blocks only). * * Do not resolve data elements for DATA chains. * (typically used to avoid device/logical buffer * aliasing for data) * * HAMMER2_RESOLVE_ALWAYS- Always resolve the data element. * * HAMMER2_RESOLVE_SHARED- (flag) The chain is locked shared, otherwise * it will be locked exclusive. * * HAMMER2_RESOLVE_NONBLOCK- (flag) The chain is locked non-blocking. If * the lock fails, EAGAIN is returned. * * NOTE: Embedded elements (volume header, inodes) are always resolved * regardless. * * NOTE: Specifying HAMMER2_RESOLVE_ALWAYS on a newly-created non-embedded * element will instantiate and zero its buffer, and flush it on * release. * * NOTE: (data) elements are normally locked RESOLVE_NEVER or RESOLVE_MAYBE * so as not to instantiate a device buffer, which could alias against * a logical file buffer. However, if ALWAYS is specified the * device buffer will be instantiated anyway. * * NOTE: The return value is always 0 unless NONBLOCK is specified, in which * case it can be either 0 or EAGAIN. * * WARNING! This function blocks on I/O if data needs to be fetched. This * blocking can run concurrent with other compatible lock holders * who do not need data returning. The lock is not upgraded to * exclusive during a data fetch, a separate bit is used to * interlock I/O. However, an exclusive lock holder can still count * on being interlocked against an I/O fetch managed by a shared * lock holder. */ int hammer2_chain_lock(hammer2_chain_t *chain, int how) { KKASSERT(chain->refs > 0); if (how & HAMMER2_RESOLVE_NONBLOCK) { /* * We still have to bump lockcnt before acquiring the lock, * even for non-blocking operation, because the unlock code * live-loops on lockcnt == 1 when dropping the last lock. * * If the non-blocking operation fails we have to use an * unhold sequence to undo the mess. * * NOTE: LOCKAGAIN must always succeed without blocking, * even if NONBLOCK is specified. */ atomic_add_int(&chain->lockcnt, 1); if (how & HAMMER2_RESOLVE_SHARED) { if (how & HAMMER2_RESOLVE_LOCKAGAIN) { hammer2_mtx_sh_again(&chain->lock); } else { if (hammer2_mtx_sh_try(&chain->lock) != 0) { hammer2_chain_unhold(chain); return EAGAIN; } } } else { if (hammer2_mtx_ex_try(&chain->lock) != 0) { hammer2_chain_unhold(chain); return EAGAIN; } } } else { /* * Get the appropriate lock. If LOCKAGAIN is flagged with * SHARED the caller expects a shared lock to already be * present and we are giving it another ref. This case must * importantly not block if there is a pending exclusive lock * request. */ atomic_add_int(&chain->lockcnt, 1); if (how & HAMMER2_RESOLVE_SHARED) { if (how & HAMMER2_RESOLVE_LOCKAGAIN) { hammer2_mtx_sh_again(&chain->lock); } else { hammer2_mtx_sh(&chain->lock); } } else { hammer2_mtx_ex(&chain->lock); } } /* * If we already have a valid data pointer make sure the data is * synchronized to the current cpu, and then no further action is * necessary. */ if (chain->data) { if (chain->dio) hammer2_io_bkvasync(chain->dio); return 0; } /* * Do we have to resolve the data? This is generally only * applicable to HAMMER2_BREF_TYPE_DATA which is special-cased. * Other BREF types expects the data to be there. */ switch(how & HAMMER2_RESOLVE_MASK) { case HAMMER2_RESOLVE_NEVER: return 0; case HAMMER2_RESOLVE_MAYBE: if (chain->flags & HAMMER2_CHAIN_INITIAL) return 0; if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) return 0; #if 0 if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) return 0; if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) return 0; #endif /* fall through */ case HAMMER2_RESOLVE_ALWAYS: default: break; } /* * Caller requires data */ hammer2_chain_load_data(chain); return 0; } #if 0 /* * Lock the chain, retain the hold, and drop the data persistence count. * The data should remain valid because we never transitioned lockcnt * through 0. */ void hammer2_chain_lock_unhold(hammer2_chain_t *chain, int how) { hammer2_chain_lock(chain, how); atomic_add_int(&chain->lockcnt, -1); } /* * Downgrade an exclusive chain lock to a shared chain lock. * * NOTE: There is no upgrade equivalent due to the ease of * deadlocks in that direction. */ void hammer2_chain_lock_downgrade(hammer2_chain_t *chain) { hammer2_mtx_downgrade(&chain->lock); } #endif /* * Issue I/O and install chain->data. Caller must hold a chain lock, lock * may be of any type. * * Once chain->data is set it cannot be disposed of until all locks are * released. * * Make sure the data is synchronized to the current cpu. */ void hammer2_chain_load_data(hammer2_chain_t *chain) { hammer2_blockref_t *bref; hammer2_dev_t *hmp; hammer2_io_t *dio; char *bdata; int error; /* * Degenerate case, data already present, or chain has no media * reference to load. */ KKASSERT(chain->lock.mtx_lock & MTX_MASK); if (chain->data) { if (chain->dio) hammer2_io_bkvasync(chain->dio); return; } if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0) return; hmp = chain->hmp; KKASSERT(hmp != NULL); /* * Gain the IOINPROG bit, interlocked block. */ for (;;) { u_int oflags; u_int nflags; oflags = chain->flags; cpu_ccfence(); if (oflags & HAMMER2_CHAIN_IOINPROG) { nflags = oflags | HAMMER2_CHAIN_IOSIGNAL; tsleep_interlock(&chain->flags, 0); if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { tsleep(&chain->flags, PINTERLOCKED, "h2iocw", 0); } /* retry */ } else { nflags = oflags | HAMMER2_CHAIN_IOINPROG; if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { break; } /* retry */ } } /* * We own CHAIN_IOINPROG * * Degenerate case if we raced another load. */ if (chain->data) { if (chain->dio) hammer2_io_bkvasync(chain->dio); goto done; } /* * We must resolve to a device buffer, either by issuing I/O or * by creating a zero-fill element. We do not mark the buffer * dirty when creating a zero-fill element (the hammer2_chain_modify() * API must still be used to do that). */ bref = &chain->bref; /* * The getblk() optimization can only be used on newly created * elements if the physical block size matches the request. */ if (chain->flags & HAMMER2_CHAIN_INITIAL) { error = hammer2_io_new(hmp, bref->type, bref->data_off, chain->bytes, &chain->dio); } else { error = hammer2_io_bread(hmp, bref->type, bref->data_off, chain->bytes, &chain->dio); hammer2_adjreadcounter(chain->bref.type, chain->bytes); } if (error) { chain->error = HAMMER2_ERROR_EIO; kprintf("hammer2_chain_load_data: I/O error %016jx: %d\n", (intmax_t)bref->data_off, error); hammer2_io_bqrelse(&chain->dio); goto done; } chain->error = 0; /* * This isn't perfect and can be ignored on OSs which do not have * an indication as to whether a buffer is coming from cache or * if I/O was actually issued for the read. TESTEDGOOD will work * pretty well without the B_IOISSUED logic because chains are * cached, but in that situation (without B_IOISSUED) it will not * detect whether a re-read via I/O is corrupted verses the original * read. * * We can't re-run the CRC on every fresh lock. That would be * insanely expensive. * * If the underlying kernel buffer covers the entire chain we can * use the B_IOISSUED indication to determine if we have to re-run * the CRC on chain data for chains that managed to stay cached * across the kernel disposal of the original buffer. */ if ((dio = chain->dio) != NULL && dio->bp) { struct buf *bp = dio->bp; if (dio->psize == chain->bytes && (bp->b_flags & B_IOISSUED)) { atomic_clear_int(&chain->flags, HAMMER2_CHAIN_TESTEDGOOD); bp->b_flags &= ~B_IOISSUED; } } /* * NOTE: A locked chain's data cannot be modified without first * calling hammer2_chain_modify(). */ /* * NOTE: hammer2_io_data() call issues bkvasync() */ bdata = hammer2_io_data(chain->dio, chain->bref.data_off); if (chain->flags & HAMMER2_CHAIN_INITIAL) { /* * Clear INITIAL. In this case we used io_new() and the * buffer has been zero'd and marked dirty. * * CHAIN_MODIFIED has not been set yet, and we leave it * that way for now. Set a temporary CHAIN_NOTTESTED flag * to prevent hammer2_chain_testcheck() from trying to match * a check code that has not yet been generated. This bit * should NOT end up on the actual media. */ atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL); atomic_set_int(&chain->flags, HAMMER2_CHAIN_NOTTESTED); } else if (chain->flags & HAMMER2_CHAIN_MODIFIED) { /* * check data not currently synchronized due to * modification. XXX assumes data stays in the buffer * cache, which might not be true (need biodep on flush * to calculate crc? or simple crc?). */ } else if ((chain->flags & HAMMER2_CHAIN_TESTEDGOOD) == 0) { if (hammer2_chain_testcheck(chain, bdata) == 0) { chain->error = HAMMER2_ERROR_CHECK; } else { atomic_set_int(&chain->flags, HAMMER2_CHAIN_TESTEDGOOD); } } /* * Setup the data pointer by pointing it into the buffer. * WARNING! Other threads can start using the data the instant we * set chain->data non-NULL. */ switch (bref->type) { case HAMMER2_BREF_TYPE_VOLUME: case HAMMER2_BREF_TYPE_FREEMAP: panic("hammer2_chain_load_data: unresolved volume header"); break; case HAMMER2_BREF_TYPE_DIRENT: KKASSERT(chain->bytes != 0); /* fall through */ case HAMMER2_BREF_TYPE_INODE: case HAMMER2_BREF_TYPE_FREEMAP_LEAF: case HAMMER2_BREF_TYPE_INDIRECT: case HAMMER2_BREF_TYPE_DATA: case HAMMER2_BREF_TYPE_FREEMAP_NODE: default: /* * Point data at the device buffer and leave dio intact. */ chain->data = (void *)bdata; break; } /* * Release HAMMER2_CHAIN_IOINPROG and signal waiters if requested. */ done: for (;;) { u_int oflags; u_int nflags; oflags = chain->flags; nflags = oflags & ~(HAMMER2_CHAIN_IOINPROG | HAMMER2_CHAIN_IOSIGNAL); KKASSERT(oflags & HAMMER2_CHAIN_IOINPROG); if (atomic_cmpset_int(&chain->flags, oflags, nflags)) { if (oflags & HAMMER2_CHAIN_IOSIGNAL) wakeup(&chain->flags); break; } } } /* * Unlock and deref a chain element. * * Remember that the presence of children under chain prevent the chain's * destruction but do not add additional references, so the dio will still * be dropped. */ void hammer2_chain_unlock(hammer2_chain_t *chain) { hammer2_io_t *dio; u_int lockcnt; int iter = 0; /* * If multiple locks are present (or being attempted) on this * particular chain we can just unlock, drop refs, and return. * * Otherwise fall-through on the 1->0 transition. */ for (;;) { lockcnt = chain->lockcnt; KKASSERT(lockcnt > 0); cpu_ccfence(); if (lockcnt > 1) { if (atomic_cmpset_int(&chain->lockcnt, lockcnt, lockcnt - 1)) { hammer2_mtx_unlock(&chain->lock); return; } } else if (hammer2_mtx_upgrade_try(&chain->lock) == 0) { /* while holding the mutex exclusively */ if (atomic_cmpset_int(&chain->lockcnt, 1, 0)) break; } else { /* * This situation can easily occur on SMP due to * the gap inbetween the 1->0 transition and the * final unlock. We cannot safely block on the * mutex because lockcnt might go above 1. * * XXX Sleep for one tick if it takes too long. */ if (++iter > 1000) { if (iter > 1000 + hz) { kprintf("hammer2: h2race2 %p\n", chain); iter = 1000; } tsleep(&iter, 0, "h2race2", 1); } cpu_pause(); } /* retry */ } /* * Last unlock / mutex upgraded to exclusive. Drop the data * reference. */ dio = hammer2_chain_drop_data(chain); if (dio) hammer2_io_bqrelse(&dio); hammer2_mtx_unlock(&chain->lock); } #if 0 /* * Unlock and hold chain data intact */ void hammer2_chain_unlock_hold(hammer2_chain_t *chain) { atomic_add_int(&chain->lockcnt, 1); hammer2_chain_unlock(chain); } #endif /* * Helper to obtain the blockref[] array base and count for a chain. * * XXX Not widely used yet, various use cases need to be validated and * converted to use this function. */ static hammer2_blockref_t * hammer2_chain_base_and_count(hammer2_chain_t *parent, int *countp) { hammer2_blockref_t *base; int count; if (parent->flags & HAMMER2_CHAIN_INITIAL) { base = NULL; switch(parent->bref.type) { case HAMMER2_BREF_TYPE_INODE: count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_INDIRECT: case HAMMER2_BREF_TYPE_FREEMAP_NODE: count = parent->bytes / sizeof(hammer2_blockref_t); break; case HAMMER2_BREF_TYPE_VOLUME: count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP: count = HAMMER2_SET_COUNT; break; default: panic("hammer2_chain_base_and_count: " "unrecognized blockref type: %d", parent->bref.type); count = 0; break; } } else { switch(parent->bref.type) { case HAMMER2_BREF_TYPE_INODE: base = &parent->data->ipdata.u.blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_INDIRECT: case HAMMER2_BREF_TYPE_FREEMAP_NODE: base = &parent->data->npdata[0]; count = parent->bytes / sizeof(hammer2_blockref_t); break; case HAMMER2_BREF_TYPE_VOLUME: base = &parent->data->voldata. sroot_blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP: base = &parent->data->blkset.blockref[0]; count = HAMMER2_SET_COUNT; break; default: panic("hammer2_chain_base_and_count: " "unrecognized blockref type: %d", parent->bref.type); base = NULL; count = 0; break; } } *countp = count; return base; } /* * This counts the number of live blockrefs in a block array and * also calculates the point at which all remaining blockrefs are empty. * This routine can only be called on a live chain. * * Caller holds the chain locked, but possibly with a shared lock. We * must use an exclusive spinlock to prevent corruption. * * NOTE: Flag is not set until after the count is complete, allowing * callers to test the flag without holding the spinlock. * * NOTE: If base is NULL the related chain is still in the INITIAL * state and there are no blockrefs to count. * * NOTE: live_count may already have some counts accumulated due to * creation and deletion and could even be initially negative. */ void hammer2_chain_countbrefs(hammer2_chain_t *chain, hammer2_blockref_t *base, int count) { hammer2_spin_ex(&chain->core.spin); if ((chain->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) { if (base) { while (--count >= 0) { if (base[count].type != HAMMER2_BREF_TYPE_EMPTY) break; } chain->core.live_zero = count + 1; while (count >= 0) { if (base[count].type != HAMMER2_BREF_TYPE_EMPTY) atomic_add_int(&chain->core.live_count, 1); --count; } } else { chain->core.live_zero = 0; } /* else do not modify live_count */ atomic_set_int(&chain->flags, HAMMER2_CHAIN_COUNTEDBREFS); } hammer2_spin_unex(&chain->core.spin); } /* * Resize the chain's physical storage allocation in-place. This function does * not usually adjust the data pointer and must be followed by (typically) a * hammer2_chain_modify() call to copy any old data over and adjust the * data pointer. * * Chains can be resized smaller without reallocating the storage. Resizing * larger will reallocate the storage. Excess or prior storage is reclaimed * asynchronously at a later time. * * An nradix value of 0 is special-cased to mean that the storage should * be disassociated, that is the chain is being resized to 0 bytes (not 1 * byte). * * Must be passed an exclusively locked parent and chain. * * This function is mostly used with DATA blocks locked RESOLVE_NEVER in order * to avoid instantiating a device buffer that conflicts with the vnode data * buffer. However, because H2 can compress or encrypt data, the chain may * have a dio assigned to it in those situations, and they do not conflict. * * XXX return error if cannot resize. */ int hammer2_chain_resize(hammer2_chain_t *chain, hammer2_tid_t mtid, hammer2_off_t dedup_off, int nradix, int flags) { hammer2_dev_t *hmp; size_t obytes; size_t nbytes; int error; hmp = chain->hmp; /* * Only data and indirect blocks can be resized for now. * (The volu root, inodes, and freemap elements use a fixed size). */ KKASSERT(chain != &hmp->vchain); KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA || chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT || chain->bref.type == HAMMER2_BREF_TYPE_DIRENT); /* * Nothing to do if the element is already the proper size */ obytes = chain->bytes; nbytes = (nradix) ? (1U << nradix) : 0; if (obytes == nbytes) return (chain->error); /* * Make sure the old data is instantiated so we can copy it. If this * is a data block, the device data may be superfluous since the data * might be in a logical block, but compressed or encrypted data is * another matter. * * NOTE: The modify will set BLKMAPUPD for us if BLKMAPPED is set. */ error = hammer2_chain_modify(chain, mtid, dedup_off, 0); if (error) return error; /* * Reallocate the block, even if making it smaller (because different * block sizes may be in different regions). * * NOTE: Operation does not copy the data and may only be used * to resize data blocks in-place, or directory entry blocks * which are about to be modified in some manner. */ error = hammer2_freemap_alloc(chain, nbytes); if (error) return error; chain->bytes = nbytes; /* * We don't want the followup chain_modify() to try to copy data * from the old (wrong-sized) buffer. It won't know how much to * copy. This case should only occur during writes when the * originator already has the data to write in-hand. */ if (chain->dio) { KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_DATA || chain->bref.type == HAMMER2_BREF_TYPE_DIRENT); hammer2_io_brelse(&chain->dio); chain->data = NULL; } return (chain->error); } /* * Set the chain modified so its data can be changed by the caller, or * install deduplicated data. The caller must call this routine for each * set of modifications it makes, even if the chain is already flagged * MODIFIED. * * Sets bref.modify_tid to mtid only if mtid != 0. Note that bref.modify_tid * is a CLC (cluster level change) field and is not updated by parent * propagation during a flush. * * Returns an appropriate HAMMER2_ERROR_* code, which will generally reflect * chain->error except for HAMMER2_ERROR_ENOSPC. If the allocation fails * due to no space available, HAMMER2_ERROR_ENOSPC is returned and the chain * remains unmodified with its old data ref intact and chain->error * unchanged. * * Dedup Handling * * If the DEDUPABLE flag is set in the chain the storage must be reallocated * even if the chain is still flagged MODIFIED. In this case the chain's * DEDUPABLE flag will be cleared once the new storage has been assigned. * * If the caller passes a non-zero dedup_off we will use it to assign the * new storage. The MODIFIED flag will be *CLEARED* in this case, and * DEDUPABLE will be set (NOTE: the UPDATE flag is always set). The caller * must not modify the data content upon return. */ int hammer2_chain_modify(hammer2_chain_t *chain, hammer2_tid_t mtid, hammer2_off_t dedup_off, int flags) { hammer2_dev_t *hmp; hammer2_io_t *dio; int error; int wasinitial; int setmodified; int setupdate; int newmod; char *bdata; hmp = chain->hmp; KKASSERT(chain->lock.mtx_lock & MTX_EXCLUSIVE); /* * Data is not optional for freemap chains (we must always be sure * to copy the data on COW storage allocations). */ if (chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE || chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) || (flags & HAMMER2_MODIFY_OPTDATA) == 0); } /* * Data must be resolved if already assigned, unless explicitly * flagged otherwise. If we cannot safety load the data the * modification fails and we return early. */ if (chain->data == NULL && chain->bytes != 0 && (flags & HAMMER2_MODIFY_OPTDATA) == 0 && (chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX)) { hammer2_chain_load_data(chain); if (chain->error) return (chain->error); } error = 0; /* * Set MODIFIED to indicate that the chain has been modified. A new * allocation is required when modifying a chain. * * Set UPDATE to ensure that the blockref is updated in the parent. * * If MODIFIED is already set determine if we can reuse the assigned * data block or if we need a new data block. */ if ((chain->flags & HAMMER2_CHAIN_MODIFIED) == 0) { /* * Must set modified bit. */ atomic_add_long(&hammer2_count_modified_chains, 1); atomic_set_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); hammer2_pfs_memory_inc(chain->pmp); /* can be NULL */ setmodified = 1; /* * We may be able to avoid a copy-on-write if the chain's * check mode is set to NONE and the chain's current * modify_tid is beyond the last explicit snapshot tid. * * This implements HAMMER2's overwrite-in-place feature. * * NOTE! This data-block cannot be used as a de-duplication * source when the check mode is set to NONE. */ if ((chain->bref.type == HAMMER2_BREF_TYPE_DATA || chain->bref.type == HAMMER2_BREF_TYPE_DIRENT) && (chain->flags & HAMMER2_CHAIN_INITIAL) == 0 && (chain->flags & HAMMER2_CHAIN_DEDUPABLE) == 0 && HAMMER2_DEC_CHECK(chain->bref.methods) == HAMMER2_CHECK_NONE && chain->pmp && chain->bref.modify_tid > chain->pmp->iroot->meta.pfs_lsnap_tid) { /* * Sector overwrite allowed. */ newmod = 0; } else if ((hmp->hflags & HMNT2_EMERG) && chain->pmp && chain->bref.modify_tid > chain->pmp->iroot->meta.pfs_lsnap_tid) { /* * If in emergency delete mode then do a modify-in- * place on any chain type belonging to the PFS as * long as it doesn't mess up a snapshot. We might * be forced to do this anyway a little further down * in the code if the allocation fails. * * Also note that in emergency mode, these modify-in- * place operations are NOT SAFE. A storage failure, * power failure, or panic can corrupt the filesystem. */ newmod = 0; } else { /* * Sector overwrite not allowed, must copy-on-write. */ newmod = 1; } } else if (chain->flags & HAMMER2_CHAIN_DEDUPABLE) { /* * If the modified chain was registered for dedup we need * a new allocation. This only happens for delayed-flush * chains (i.e. which run through the front-end buffer * cache). */ newmod = 1; setmodified = 0; } else { /* * Already flagged modified, no new allocation is needed. */ newmod = 0; setmodified = 0; } /* * Flag parent update required. */ if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0) { atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); setupdate = 1; } else { setupdate = 0; } /* * The XOP code returns held but unlocked focus chains. This * prevents the chain from being destroyed but does not prevent * it from being modified. diolk is used to interlock modifications * against XOP frontend accesses to the focus. * * This allows us to theoretically avoid deadlocking the frontend * if one of the backends lock up by not formally locking the * focused chain in the frontend. In addition, the synchronization * code relies on this mechanism to avoid deadlocking concurrent * synchronization threads. */ lockmgr(&chain->diolk, LK_EXCLUSIVE); /* * The modification or re-modification requires an allocation and * possible COW. If an error occurs, the previous content and data * reference is retained and the modification fails. * * If dedup_off is non-zero, the caller is requesting a deduplication * rather than a modification. The MODIFIED bit is not set and the * data offset is set to the deduplication offset. The data cannot * be modified. * * NOTE: The dedup offset is allowed to be in a partially free state * and we must be sure to reset it to a fully allocated state * to force two bulkfree passes to free it again. * * NOTE: Only applicable when chain->bytes != 0. * * XXX can a chain already be marked MODIFIED without a data * assignment? If not, assert here instead of testing the case. */ if (chain != &hmp->vchain && chain != &hmp->fchain && chain->bytes) { if ((chain->bref.data_off & ~HAMMER2_OFF_MASK_RADIX) == 0 || newmod ) { /* * NOTE: We do not have to remove the dedup * registration because the area is still * allocated and the underlying DIO will * still be flushed. */ if (dedup_off) { chain->bref.data_off = dedup_off; if ((int)(dedup_off & HAMMER2_OFF_MASK_RADIX)) chain->bytes = 1 << (int)(dedup_off & HAMMER2_OFF_MASK_RADIX); else chain->bytes = 0; chain->error = 0; atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); atomic_add_long(&hammer2_count_modified_chains, -1); if (chain->pmp) { hammer2_pfs_memory_wakeup( chain->pmp, -1); } hammer2_freemap_adjust(hmp, &chain->bref, HAMMER2_FREEMAP_DORECOVER); atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEDUPABLE); } else { error = hammer2_freemap_alloc(chain, chain->bytes); atomic_clear_int(&chain->flags, HAMMER2_CHAIN_DEDUPABLE); /* * If we are unable to allocate a new block * but we are in emergency mode, issue a * warning to the console and reuse the same * block. * * We behave as if the allocation were * successful. * * THIS IS IMPORTANT: These modifications * are virtually guaranteed to corrupt any * snapshots related to this filesystem. */ if (error && (hmp->hflags & HMNT2_EMERG)) { error = 0; chain->bref.flags |= HAMMER2_BREF_FLAG_EMERG_MIP; krateprintf(&krate_h2em, "hammer2: Emergency Mode WARNING: " "Operation will likely corrupt " "related snapshot: " "%016jx.%02x key=%016jx\n", chain->bref.data_off, chain->bref.type, chain->bref.key); } else if (error == 0) { chain->bref.flags &= ~HAMMER2_BREF_FLAG_EMERG_MIP; } } } } /* * Stop here if error. We have to undo any flag bits we might * have set above. */ if (error) { if (setmodified) { atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED); atomic_add_long(&hammer2_count_modified_chains, -1); if (chain->pmp) hammer2_pfs_memory_wakeup(chain->pmp, -1); } if (setupdate) { atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); } lockmgr(&chain->diolk, LK_RELEASE); return error; } /* * Update mirror_tid and modify_tid. modify_tid is only updated * if not passed as zero (during flushes, parent propagation passes * the value 0). * * NOTE: chain->pmp could be the device spmp. */ chain->bref.mirror_tid = hmp->voldata.mirror_tid + 1; if (mtid) chain->bref.modify_tid = mtid; /* * Set BLKMAPUPD to tell the flush code that an existing blockmap entry * requires updating as well as to tell the delete code that the * chain's blockref might not exactly match (in terms of physical size * or block offset) the one in the parent's blocktable. The base key * of course will still match. */ if (chain->flags & HAMMER2_CHAIN_BLKMAPPED) atomic_set_int(&chain->flags, HAMMER2_CHAIN_BLKMAPUPD); /* * Short-cut data block handling when the caller does not need an * actual data reference to (aka OPTDATA), as long as the chain does * not already have a data pointer to the data and no de-duplication * occurred. * * This generally means that the modifications are being done via the * logical buffer cache. * * NOTE: If deduplication occurred we have to run through the data * stuff to clear INITIAL, and the caller will likely want to * assign the check code anyway. Leaving INITIAL set on a * dedup can be deadly (it can cause the block to be zero'd!). * * This code also handles bytes == 0 (most dirents). */ if (chain->bref.type == HAMMER2_BREF_TYPE_DATA && (flags & HAMMER2_MODIFY_OPTDATA) && chain->data == NULL) { if (dedup_off == 0) { KKASSERT(chain->dio == NULL); goto skip2; } } /* * Clearing the INITIAL flag (for indirect blocks) indicates that * we've processed the uninitialized storage allocation. * * If this flag is already clear we are likely in a copy-on-write * situation but we have to be sure NOT to bzero the storage if * no data is present. * * Clearing of NOTTESTED is allowed if the MODIFIED bit is set, */ if (chain->flags & HAMMER2_CHAIN_INITIAL) { atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL); wasinitial = 1; } else { wasinitial = 0; } /* * Instantiate data buffer and possibly execute COW operation */ switch(chain->bref.type) { case HAMMER2_BREF_TYPE_VOLUME: case HAMMER2_BREF_TYPE_FREEMAP: /* * The data is embedded, no copy-on-write operation is * needed. */ KKASSERT(chain->dio == NULL); break; case HAMMER2_BREF_TYPE_DIRENT: /* * The data might be fully embedded. */ if (chain->bytes == 0) { KKASSERT(chain->dio == NULL); break; } /* fall through */ case HAMMER2_BREF_TYPE_INODE: case HAMMER2_BREF_TYPE_FREEMAP_LEAF: case HAMMER2_BREF_TYPE_DATA: case HAMMER2_BREF_TYPE_INDIRECT: case HAMMER2_BREF_TYPE_FREEMAP_NODE: /* * Perform the copy-on-write operation * * zero-fill or copy-on-write depending on whether * chain->data exists or not and set the dirty state for * the new buffer. hammer2_io_new() will handle the * zero-fill. * * If a dedup_off was supplied this is an existing block * and no COW, copy, or further modification is required. */ KKASSERT(chain != &hmp->vchain && chain != &hmp->fchain); if (wasinitial && dedup_off == 0) { error = hammer2_io_new(hmp, chain->bref.type, chain->bref.data_off, chain->bytes, &dio); } else { error = hammer2_io_bread(hmp, chain->bref.type, chain->bref.data_off, chain->bytes, &dio); } hammer2_adjreadcounter(chain->bref.type, chain->bytes); /* * If an I/O error occurs make sure callers cannot accidently * modify the old buffer's contents and corrupt the filesystem. * * NOTE: hammer2_io_data() call issues bkvasync() */ if (error) { kprintf("hammer2_chain_modify: hmp=%p I/O error\n", hmp); chain->error = HAMMER2_ERROR_EIO; hammer2_io_brelse(&dio); hammer2_io_brelse(&chain->dio); chain->data = NULL; break; } chain->error = 0; bdata = hammer2_io_data(dio, chain->bref.data_off); if (chain->data) { /* * COW (unless a dedup). */ KKASSERT(chain->dio != NULL); if (chain->data != (void *)bdata && dedup_off == 0) { bcopy(chain->data, bdata, chain->bytes); } } else if (wasinitial == 0 && dedup_off == 0) { /* * We have a problem. We were asked to COW but * we don't have any data to COW with! */ panic("hammer2_chain_modify: having a COW %p\n", chain); } /* * Retire the old buffer, replace with the new. Dirty or * redirty the new buffer. * * WARNING! The system buffer cache may have already flushed * the buffer, so we must be sure to [re]dirty it * for further modification. * * If dedup_off was supplied, the caller is not * expected to make any further modification to the * buffer. * * WARNING! hammer2_get_gdata() assumes dio never transitions * through NULL in order to optimize away unnecessary * diolk operations. */ { hammer2_io_t *tio; if ((tio = chain->dio) != NULL) hammer2_io_bqrelse(&tio); chain->data = (void *)bdata; chain->dio = dio; if (dedup_off == 0) hammer2_io_setdirty(dio); } break; default: panic("hammer2_chain_modify: illegal non-embedded type %d", chain->bref.type); break; } skip2: /* * setflush on parent indicating that the parent must recurse down * to us. Do not call on chain itself which might already have it * set. */ if (chain->parent) hammer2_chain_setflush(chain->parent); lockmgr(&chain->diolk, LK_RELEASE); return (chain->error); } /* * Modify the chain associated with an inode. */ int hammer2_chain_modify_ip(hammer2_inode_t *ip, hammer2_chain_t *chain, hammer2_tid_t mtid, int flags) { int error; hammer2_inode_modify(ip); error = hammer2_chain_modify(chain, mtid, 0, flags); return error; } /* * This function returns the chain at the nearest key within the specified * range. The returned chain will be referenced but not locked. * * This function will recurse through chain->rbtree as necessary and will * return a *key_nextp suitable for iteration. *key_nextp is only set if * the iteration value is less than the current value of *key_nextp. * * The caller should use (*key_nextp) to calculate the actual range of * the returned element, which will be (key_beg to *key_nextp - 1), because * there might be another element which is superior to the returned element * and overlaps it. * * (*key_nextp) can be passed as key_beg in an iteration only while non-NULL * chains continue to be returned. On EOF (*key_nextp) may overflow since * it will wind up being (key_end + 1). * * WARNING! Must be called with child's spinlock held. Spinlock remains * held through the operation. */ struct hammer2_chain_find_info { hammer2_chain_t *best; hammer2_key_t key_beg; hammer2_key_t key_end; hammer2_key_t key_next; }; static int hammer2_chain_find_cmp(hammer2_chain_t *child, void *data); static int hammer2_chain_find_callback(hammer2_chain_t *child, void *data); static hammer2_chain_t * hammer2_chain_find(hammer2_chain_t *parent, hammer2_key_t *key_nextp, hammer2_key_t key_beg, hammer2_key_t key_end) { struct hammer2_chain_find_info info; info.best = NULL; info.key_beg = key_beg; info.key_end = key_end; info.key_next = *key_nextp; RB_SCAN(hammer2_chain_tree, &parent->core.rbtree, hammer2_chain_find_cmp, hammer2_chain_find_callback, &info); *key_nextp = info.key_next; #if 0 kprintf("chain_find %p %016jx:%016jx next=%016jx\n", parent, key_beg, key_end, *key_nextp); #endif return (info.best); } static int hammer2_chain_find_cmp(hammer2_chain_t *child, void *data) { struct hammer2_chain_find_info *info = data; hammer2_key_t child_beg; hammer2_key_t child_end; child_beg = child->bref.key; child_end = child_beg + ((hammer2_key_t)1 << child->bref.keybits) - 1; if (child_end < info->key_beg) return(-1); if (child_beg > info->key_end) return(1); return(0); } static int hammer2_chain_find_callback(hammer2_chain_t *child, void *data) { struct hammer2_chain_find_info *info = data; hammer2_chain_t *best; hammer2_key_t child_end; if ((best = info->best) == NULL) { /* * No previous best. Assign best */ info->best = child; } else if (best->bref.key <= info->key_beg && child->bref.key <= info->key_beg) { /* * Illegal overlap. */ KKASSERT(0); /*info->best = child;*/ } else if (child->bref.key < best->bref.key) { /* * Child has a nearer key and best is not flush with key_beg. * Set best to child. Truncate key_next to the old best key. */ info->best = child; if (info->key_next > best->bref.key || info->key_next == 0) info->key_next = best->bref.key; } else if (child->bref.key == best->bref.key) { /* * If our current best is flush with the child then this * is an illegal overlap. * * key_next will automatically be limited to the smaller of * the two end-points. */ KKASSERT(0); info->best = child; } else { /* * Keep the current best but truncate key_next to the child's * base. * * key_next will also automatically be limited to the smaller * of the two end-points (probably not necessary for this case * but we do it anyway). */ if (info->key_next > child->bref.key || info->key_next == 0) info->key_next = child->bref.key; } /* * Always truncate key_next based on child's end-of-range. */ child_end = child->bref.key + ((hammer2_key_t)1 << child->bref.keybits); if (child_end && (info->key_next > child_end || info->key_next == 0)) info->key_next = child_end; return(0); } /* * Retrieve the specified chain from a media blockref, creating the * in-memory chain structure which reflects it. The returned chain is * held and locked according to (how) (HAMMER2_RESOLVE_*). The caller must * handle crc-checks and so forth, and should check chain->error before * assuming that the data is good. * * To handle insertion races pass the INSERT_RACE flag along with the * generation number of the core. NULL will be returned if the generation * number changes before we have a chance to insert the chain. Insert * races can occur because the parent might be held shared. * * Caller must hold the parent locked shared or exclusive since we may * need the parent's bref array to find our block. * * WARNING! chain->pmp is always set to NULL for any chain representing * part of the super-root topology. */ hammer2_chain_t * hammer2_chain_get(hammer2_chain_t *parent, int generation, hammer2_blockref_t *bref, int how) { hammer2_dev_t *hmp = parent->hmp; hammer2_chain_t *chain; int error; /* * Allocate a chain structure representing the existing media * entry. Resulting chain has one ref and is not locked. */ if (bref->flags & HAMMER2_BREF_FLAG_PFSROOT) chain = hammer2_chain_alloc(hmp, NULL, bref); else chain = hammer2_chain_alloc(hmp, parent->pmp, bref); /* ref'd chain returned */ /* * Flag that the chain is in the parent's blockmap so delete/flush * knows what to do with it. */ atomic_set_int(&chain->flags, HAMMER2_CHAIN_BLKMAPPED); /* * chain must be locked to avoid unexpected ripouts */ hammer2_chain_lock(chain, how); /* * Link the chain into its parent. A spinlock is required to safely * access the RBTREE, and it is possible to collide with another * hammer2_chain_get() operation because the caller might only hold * a shared lock on the parent. * * NOTE: Get races can occur quite often when we distribute * asynchronous read-aheads across multiple threads. */ KKASSERT(parent->refs > 0); error = hammer2_chain_insert(parent, chain, HAMMER2_CHAIN_INSERT_SPIN | HAMMER2_CHAIN_INSERT_RACE, generation); if (error) { KKASSERT((chain->flags & HAMMER2_CHAIN_ONRBTREE) == 0); /*kprintf("chain %p get race\n", chain);*/ hammer2_chain_unlock(chain); hammer2_chain_drop(chain); chain = NULL; } else { KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE); } /* * Return our new chain referenced but not locked, or NULL if * a race occurred. */ return (chain); } /* * Lookup initialization/completion API */ hammer2_chain_t * hammer2_chain_lookup_init(hammer2_chain_t *parent, int flags) { hammer2_chain_ref(parent); if (flags & HAMMER2_LOOKUP_SHARED) { hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS | HAMMER2_RESOLVE_SHARED); } else { hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS); } return (parent); } void hammer2_chain_lookup_done(hammer2_chain_t *parent) { if (parent) { hammer2_chain_unlock(parent); hammer2_chain_drop(parent); } } /* * Take the locked chain and return a locked parent. The chain remains * locked on return, but may have to be temporarily unlocked to acquire * the parent. Because of this, (chain) must be stable and cannot be * deleted while it was temporarily unlocked (typically means that (chain) * is an inode). * * Pass HAMMER2_RESOLVE_* flags in flags. * * This will work even if the chain is errored, and the caller can check * parent->error on return if desired since the parent will be locked. * * This function handles the lock order reversal. */ hammer2_chain_t * hammer2_chain_getparent(hammer2_chain_t *chain, int flags) { hammer2_chain_t *parent; /* * Be careful of order, chain must be unlocked before parent * is locked below to avoid a deadlock. Try it trivially first. */ parent = chain->parent; if (parent == NULL) panic("hammer2_chain_getparent: no parent"); hammer2_chain_ref(parent); if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0) return parent; for (;;) { hammer2_chain_unlock(chain); hammer2_chain_lock(parent, flags); hammer2_chain_lock(chain, flags); /* * Parent relinking races are quite common. We have to get * it right or we will blow up the block table. */ if (chain->parent == parent) break; hammer2_chain_unlock(parent); hammer2_chain_drop(parent); cpu_ccfence(); parent = chain->parent; if (parent == NULL) panic("hammer2_chain_getparent: no parent"); hammer2_chain_ref(parent); } return parent; } /* * Take the locked chain and return a locked parent. The chain is unlocked * and dropped. *chainp is set to the returned parent as a convenience. * Pass HAMMER2_RESOLVE_* flags in flags. * * This will work even if the chain is errored, and the caller can check * parent->error on return if desired since the parent will be locked. * * The chain does NOT need to be stable. We use a tracking structure * to track the expected parent if the chain is deleted out from under us. * * This function handles the lock order reversal. */ hammer2_chain_t * hammer2_chain_repparent(hammer2_chain_t **chainp, int flags) { hammer2_chain_t *chain; hammer2_chain_t *parent; struct hammer2_reptrack reptrack; struct hammer2_reptrack **repp; /* * Be careful of order, chain must be unlocked before parent * is locked below to avoid a deadlock. Try it trivially first. */ chain = *chainp; parent = chain->parent; if (parent == NULL) { hammer2_spin_unex(&chain->core.spin); panic("hammer2_chain_repparent: no parent"); } hammer2_chain_ref(parent); if (hammer2_chain_lock(parent, flags|HAMMER2_RESOLVE_NONBLOCK) == 0) { hammer2_chain_unlock(chain); hammer2_chain_drop(chain); *chainp = parent; return parent; } /* * Ok, now it gets a bit nasty. There are multiple situations where * the parent might be in the middle of a deletion, or where the child * (chain) might be deleted the instant we let go of its lock. * We can potentially end up in a no-win situation! * * In particular, the indirect_maintenance() case can cause these * situations. * * To deal with this we install a reptrack structure in the parent * This reptrack structure 'owns' the parent ref and will automatically * migrate to the parent's parent if the parent is deleted permanently. */ hammer2_spin_init(&reptrack.spin, "h2reptrk"); reptrack.chain = parent; hammer2_chain_ref(parent); /* for the reptrack */ hammer2_spin_ex(&parent->core.spin); reptrack.next = parent->core.reptrack; parent->core.reptrack = &reptrack; hammer2_spin_unex(&parent->core.spin); hammer2_chain_unlock(chain); hammer2_chain_drop(chain); chain = NULL; /* gone */ /* * At the top of this loop, chain is gone and parent is refd both * by us explicitly AND via our reptrack. We are attempting to * lock parent. */ for (;;) { hammer2_chain_lock(parent, flags); if (reptrack.chain == parent) break; hammer2_chain_unlock(parent); hammer2_chain_drop(parent); kprintf("hammer2: debug REPTRACK %p->%p\n", parent, reptrack.chain); hammer2_spin_ex(&reptrack.spin); parent = reptrack.chain; hammer2_chain_ref(parent); hammer2_spin_unex(&reptrack.spin); } /* * Once parent is locked and matches our reptrack, our reptrack * will be stable and we have our parent. We can unlink our * reptrack. * * WARNING! Remember that the chain lock might be shared. Chains * locked shared have stable parent linkages. */ hammer2_spin_ex(&parent->core.spin); repp = &parent->core.reptrack; while (*repp != &reptrack) repp = &(*repp)->next; *repp = reptrack.next; hammer2_spin_unex(&parent->core.spin); hammer2_chain_drop(parent); /* reptrack ref */ *chainp = parent; /* return parent lock+ref */ return parent; } /* * Dispose of any linked reptrack structures in (chain) by shifting them to * (parent). Both (chain) and (parent) must be exclusively locked. * * This is interlocked against any children of (chain) on the other side. * No children so remain as-of when this is called so we can test * core.reptrack without holding the spin-lock. * * Used whenever the caller intends to permanently delete chains related * to topological recursions (BREF_TYPE_INDIRECT, BREF_TYPE_FREEMAP_NODE), * where the chains underneath the node being deleted are given a new parent * above the node being deleted. */ static void hammer2_chain_repchange(hammer2_chain_t *parent, hammer2_chain_t *chain) { struct hammer2_reptrack *reptrack; KKASSERT(chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree)); while (chain->core.reptrack) { hammer2_spin_ex(&parent->core.spin); hammer2_spin_ex(&chain->core.spin); reptrack = chain->core.reptrack; if (reptrack == NULL) { hammer2_spin_unex(&chain->core.spin); hammer2_spin_unex(&parent->core.spin); break; } hammer2_spin_ex(&reptrack->spin); chain->core.reptrack = reptrack->next; reptrack->chain = parent; reptrack->next = parent->core.reptrack; parent->core.reptrack = reptrack; hammer2_chain_ref(parent); /* reptrack */ hammer2_spin_unex(&chain->core.spin); hammer2_spin_unex(&parent->core.spin); kprintf("hammer2: debug repchange %p %p->%p\n", reptrack, chain, parent); hammer2_chain_drop(chain); /* reptrack */ } } /* * Locate the first chain whos key range overlaps (key_beg, key_end) inclusive. * (*parentp) typically points to an inode but can also point to a related * indirect block and this function will recurse upwards and find the inode * or the nearest undeleted indirect block covering the key range. * * This function unconditionally sets *errorp, replacing any previous value. * * (*parentp) must be exclusive or shared locked (depending on flags) and * referenced and can be an inode or an existing indirect block within the * inode. * * If (*parent) is errored out, this function will not attempt to recurse * the radix tree and will return NULL along with an appropriate *errorp. * If NULL is returned and *errorp is 0, the requested lookup could not be * located. * * On return (*parentp) will be modified to point at the deepest parent chain * element encountered during the search, as a helper for an insertion or * deletion. * * The new (*parentp) will be locked shared or exclusive (depending on flags), * and referenced, and the old will be unlocked and dereferenced (no change * if they are both the same). This is particularly important if the caller * wishes to insert a new chain, (*parentp) will be set properly even if NULL * is returned, as long as no error occurred. * * The matching chain will be returned locked according to flags. * * -- * * NULL is returned if no match was found, but (*parentp) will still * potentially be adjusted. * * On return (*key_nextp) will point to an iterative value for key_beg. * (If NULL is returned (*key_nextp) is set to (key_end + 1)). * * This function will also recurse up the chain if the key is not within the * current parent's range. (*parentp) can never be set to NULL. An iteration * can simply allow (*parentp) to float inside the loop. * * NOTE! chain->data is not always resolved. By default it will not be * resolved for BREF_TYPE_DATA, FREEMAP_NODE, or FREEMAP_LEAF. Use * HAMMER2_LOOKUP_ALWAYS to force resolution (but be careful w/ * BREF_TYPE_DATA as the device buffer can alias the logical file * buffer). */ hammer2_chain_t * hammer2_chain_lookup(hammer2_chain_t **parentp, hammer2_key_t *key_nextp, hammer2_key_t key_beg, hammer2_key_t key_end, int *errorp, int flags) { hammer2_chain_t *parent; hammer2_chain_t *chain; hammer2_blockref_t *base; hammer2_blockref_t *bref; hammer2_blockref_t bsave; hammer2_key_t scan_beg; hammer2_key_t scan_end; int count = 0; int how_always = HAMMER2_RESOLVE_ALWAYS; int how_maybe = HAMMER2_RESOLVE_MAYBE; int how; int generation; int maxloops = 300000; if (flags & HAMMER2_LOOKUP_ALWAYS) { how_maybe = how_always; how = HAMMER2_RESOLVE_ALWAYS; } else if (flags & HAMMER2_LOOKUP_NODATA) { how = HAMMER2_RESOLVE_NEVER; } else { how = HAMMER2_RESOLVE_MAYBE; } if (flags & HAMMER2_LOOKUP_SHARED) { how_maybe |= HAMMER2_RESOLVE_SHARED; how_always |= HAMMER2_RESOLVE_SHARED; how |= HAMMER2_RESOLVE_SHARED; } /* * Recurse (*parentp) upward if necessary until the parent completely * encloses the key range or we hit the inode. * * Handle races against the flusher deleting indirect nodes on its * way back up by continuing to recurse upward past the deletion. */ parent = *parentp; *errorp = 0; while (parent->bref.type == HAMMER2_BREF_TYPE_INDIRECT || parent->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { scan_beg = parent->bref.key; scan_end = scan_beg + ((hammer2_key_t)1 << parent->bref.keybits) - 1; if ((parent->flags & HAMMER2_CHAIN_DELETED) == 0) { if (key_beg >= scan_beg && key_end <= scan_end) break; } parent = hammer2_chain_repparent(parentp, how_maybe); } again: if (--maxloops == 0) panic("hammer2_chain_lookup: maxloops"); /* * MATCHIND case that does not require parent->data (do prior to * parent->error check). */ switch(parent->bref.type) { case HAMMER2_BREF_TYPE_FREEMAP_NODE: case HAMMER2_BREF_TYPE_INDIRECT: if (flags & HAMMER2_LOOKUP_MATCHIND) { scan_beg = parent->bref.key; scan_end = scan_beg + ((hammer2_key_t)1 << parent->bref.keybits) - 1; if (key_beg == scan_beg && key_end == scan_end) { chain = parent; hammer2_chain_ref(chain); hammer2_chain_lock(chain, how_maybe); *key_nextp = scan_end + 1; goto done; } } break; default: break; } /* * No lookup is possible if the parent is errored. We delayed * this check as long as we could to ensure that the parent backup, * embedded data, and MATCHIND code could still execute. */ if (parent->error) { *errorp = parent->error; return NULL; } /* * Locate the blockref array. Currently we do a fully associative * search through the array. */ switch(parent->bref.type) { case HAMMER2_BREF_TYPE_INODE: /* * Special shortcut for embedded data returns the inode * itself. Callers must detect this condition and access * the embedded data (the strategy code does this for us). * * This is only applicable to regular files and softlinks. * * We need a second lock on parent. Since we already have * a lock we must pass LOCKAGAIN to prevent unexpected * blocking (we don't want to block on a second shared * ref if an exclusive lock is pending) */ if (parent->data->ipdata.meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) { if (flags & HAMMER2_LOOKUP_NODIRECT) { chain = NULL; *key_nextp = key_end + 1; goto done; } hammer2_chain_ref(parent); hammer2_chain_lock(parent, how_always | HAMMER2_RESOLVE_LOCKAGAIN); *key_nextp = key_end + 1; return (parent); } base = &parent->data->ipdata.u.blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP_NODE: case HAMMER2_BREF_TYPE_INDIRECT: /* * Optimize indirect blocks in the INITIAL state to avoid * I/O. * * Debugging: Enter permanent wait state instead of * panicing on unexpectedly NULL data for the moment. */ if (parent->flags & HAMMER2_CHAIN_INITIAL) { base = NULL; } else { if (parent->data == NULL) { kprintf("hammer2: unexpected NULL data " "on %p\n", parent); while (1) tsleep(parent, 0, "xxx", 0); } base = &parent->data->npdata[0]; } count = parent->bytes / sizeof(hammer2_blockref_t); break; case HAMMER2_BREF_TYPE_VOLUME: base = &parent->data->voldata.sroot_blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP: base = &parent->data->blkset.blockref[0]; count = HAMMER2_SET_COUNT; break; default: panic("hammer2_chain_lookup: unrecognized " "blockref(B) type: %d", parent->bref.type); base = NULL; /* safety */ count = 0; /* safety */ break; } /* * Merged scan to find next candidate. * * hammer2_base_*() functions require the parent->core.live_* fields * to be synchronized. * * We need to hold the spinlock to access the block array and RB tree * and to interlock chain creation. */ if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) hammer2_chain_countbrefs(parent, base, count); /* * Combined search */ hammer2_spin_ex(&parent->core.spin); chain = hammer2_combined_find(parent, base, count, key_nextp, key_beg, key_end, &bref); generation = parent->core.generation; /* * Exhausted parent chain, iterate. */ if (bref == NULL) { KKASSERT(chain == NULL); hammer2_spin_unex(&parent->core.spin); if (key_beg == key_end) /* short cut single-key case */ return (NULL); /* * Stop if we reached the end of the iteration. */ if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT && parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) { return (NULL); } /* * Calculate next key, stop if we reached the end of the * iteration, otherwise go up one level and loop. */ key_beg = parent->bref.key + ((hammer2_key_t)1 << parent->bref.keybits); if (key_beg == 0 || key_beg > key_end) return (NULL); parent = hammer2_chain_repparent(parentp, how_maybe); goto again; } /* * Selected from blockref or in-memory chain. */ bsave = *bref; if (chain == NULL) { hammer2_spin_unex(&parent->core.spin); if (bsave.type == HAMMER2_BREF_TYPE_INDIRECT || bsave.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { chain = hammer2_chain_get(parent, generation, &bsave, how_maybe); } else { chain = hammer2_chain_get(parent, generation, &bsave, how); } if (chain == NULL) goto again; } else { hammer2_chain_ref(chain); hammer2_spin_unex(&parent->core.spin); /* * chain is referenced but not locked. We must lock the * chain to obtain definitive state. */ if (bsave.type == HAMMER2_BREF_TYPE_INDIRECT || bsave.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { hammer2_chain_lock(chain, how_maybe); } else { hammer2_chain_lock(chain, how); } KKASSERT(chain->parent == parent); } if (bcmp(&bsave, &chain->bref, sizeof(bsave)) || chain->parent != parent) { hammer2_chain_unlock(chain); hammer2_chain_drop(chain); chain = NULL; /* SAFETY */ goto again; } /* * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX) * * NOTE: Chain's key range is not relevant as there might be * one-offs within the range that are not deleted. * * NOTE: Lookups can race delete-duplicate because * delete-duplicate does not lock the parent's core * (they just use the spinlock on the core). */ if (chain->flags & HAMMER2_CHAIN_DELETED) { kprintf("skip deleted chain %016jx.%02x key=%016jx\n", chain->bref.data_off, chain->bref.type, chain->bref.key); hammer2_chain_unlock(chain); hammer2_chain_drop(chain); chain = NULL; /* SAFETY */ key_beg = *key_nextp; if (key_beg == 0 || key_beg > key_end) return(NULL); goto again; } /* * If the chain element is an indirect block it becomes the new * parent and we loop on it. We must maintain our top-down locks * to prevent the flusher from interfering (i.e. doing a * delete-duplicate and leaving us recursing down a deleted chain). * * The parent always has to be locked with at least RESOLVE_MAYBE * so we can access its data. It might need a fixup if the caller * passed incompatible flags. Be careful not to cause a deadlock * as a data-load requires an exclusive lock. * * If HAMMER2_LOOKUP_MATCHIND is set and the indirect block's key * range is within the requested key range we return the indirect * block and do NOT loop. This is usually only used to acquire * freemap nodes. */ if (chain->bref.type == HAMMER2_BREF_TYPE_INDIRECT || chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_NODE) { hammer2_chain_unlock(parent); hammer2_chain_drop(parent); *parentp = parent = chain; chain = NULL; /* SAFETY */ goto again; } done: /* * All done, return the locked chain. * * If the caller does not want a locked chain, replace the lock with * a ref. Perhaps this can eventually be optimized to not obtain the * lock in the first place for situations where the data does not * need to be resolved. * * NOTE! A chain->error must be tested by the caller upon return. * *errorp is only set based on issues which occur while * trying to reach the chain. */ return (chain); } /* * After having issued a lookup we can iterate all matching keys. * * If chain is non-NULL we continue the iteration from just after it's index. * * If chain is NULL we assume the parent was exhausted and continue the * iteration at the next parent. * * If a fatal error occurs (typically an I/O error), a dummy chain is * returned with chain->error and error-identifying information set. This * chain will assert if you try to do anything fancy with it. * * XXX Depending on where the error occurs we should allow continued iteration. * * parent must be locked on entry and remains locked throughout. chain's * lock status must match flags. Chain is always at least referenced. * * WARNING! The MATCHIND flag does not apply to this function. */ hammer2_chain_t * hammer2_chain_next(hammer2_chain_t **parentp, hammer2_chain_t *chain, hammer2_key_t *key_nextp, hammer2_key_t key_beg, hammer2_key_t key_end, int *errorp, int flags) { hammer2_chain_t *parent; int how_maybe; /* * Calculate locking flags for upward recursion. */ how_maybe = HAMMER2_RESOLVE_MAYBE; if (flags & HAMMER2_LOOKUP_SHARED) how_maybe |= HAMMER2_RESOLVE_SHARED; parent = *parentp; *errorp = 0; /* * Calculate the next index and recalculate the parent if necessary. */ if (chain) { key_beg = chain->bref.key + ((hammer2_key_t)1 << chain->bref.keybits); hammer2_chain_unlock(chain); hammer2_chain_drop(chain); /* * chain invalid past this point, but we can still do a * pointer comparison w/parent. * * Any scan where the lookup returned degenerate data embedded * in the inode has an invalid index and must terminate. */ if (chain == parent) return(NULL); if (key_beg == 0 || key_beg > key_end) return(NULL); chain = NULL; } else if (parent->bref.type != HAMMER2_BREF_TYPE_INDIRECT && parent->bref.type != HAMMER2_BREF_TYPE_FREEMAP_NODE) { /* * We reached the end of the iteration. */ return (NULL); } else { /* * Continue iteration with next parent unless the current * parent covers the range. * * (This also handles the case of a deleted, empty indirect * node). */ key_beg = parent->bref.key + ((hammer2_key_t)1 << parent->bref.keybits); if (key_beg == 0 || key_beg > key_end) return (NULL); parent = hammer2_chain_repparent(parentp, how_maybe); } /* * And execute */ return (hammer2_chain_lookup(parentp, key_nextp, key_beg, key_end, errorp, flags)); } /* * Caller wishes to iterate chains under parent, loading new chains into * chainp. Caller must initialize *chainp to NULL and *firstp to 1, and * then call hammer2_chain_scan() repeatedly until a non-zero return. * During the scan, *firstp will be set to 0 and (*chainp) will be replaced * with the returned chain for the scan. The returned *chainp will be * locked and referenced. Any prior contents will be unlocked and dropped. * * Caller should check the return value. A normal scan EOF will return * exactly HAMMER2_ERROR_EOF. Any other non-zero value indicates an * error trying to access parent data. Any error in the returned chain * must be tested separately by the caller. * * (*chainp) is dropped on each scan, but will only be set if the returned * element itself can recurse. Leaf elements are NOT resolved, loaded, or * returned via *chainp. The caller will get their bref only. * * The raw scan function is similar to lookup/next but does not seek to a key. * Blockrefs are iterated via first_bref = (parent, NULL) and * next_chain = (parent, bref). * * The passed-in parent must be locked and its data resolved. The function * nominally returns a locked and referenced *chainp != NULL for chains * the caller might need to recurse on (and will dipose of any *chainp passed * in). The caller must check the chain->bref.type either way. */ int hammer2_chain_scan(hammer2_chain_t *parent, hammer2_chain_t **chainp, hammer2_blockref_t *bref, int *firstp, int flags) { hammer2_blockref_t *base; hammer2_blockref_t *bref_ptr; hammer2_key_t key; hammer2_key_t next_key; hammer2_chain_t *chain = NULL; int count = 0; int how; int generation; int maxloops = 300000; int error; error = 0; /* * Scan flags borrowed from lookup. */ if (flags & HAMMER2_LOOKUP_ALWAYS) { how = HAMMER2_RESOLVE_ALWAYS; } else if (flags & HAMMER2_LOOKUP_NODATA) { how = HAMMER2_RESOLVE_NEVER; } else { how = HAMMER2_RESOLVE_MAYBE; } if (flags & HAMMER2_LOOKUP_SHARED) { how |= HAMMER2_RESOLVE_SHARED; } /* * Calculate key to locate first/next element, unlocking the previous * element as we go. Be careful, the key calculation can overflow. * * (also reset bref to NULL) */ if (*firstp) { key = 0; *firstp = 0; } else { key = bref->key + ((hammer2_key_t)1 << bref->keybits); if ((chain = *chainp) != NULL) { *chainp = NULL; hammer2_chain_unlock(chain); hammer2_chain_drop(chain); chain = NULL; } if (key == 0) { error |= HAMMER2_ERROR_EOF; goto done; } } again: if (parent->error) { error = parent->error; goto done; } if (--maxloops == 0) panic("hammer2_chain_scan: maxloops"); /* * Locate the blockref array. Currently we do a fully associative * search through the array. */ switch(parent->bref.type) { case HAMMER2_BREF_TYPE_INODE: /* * An inode with embedded data has no sub-chains. * * WARNING! Bulk scan code may pass a static chain marked * as BREF_TYPE_INODE with a copy of the volume * root blockset to snapshot the volume. */ if (parent->data->ipdata.meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) { error |= HAMMER2_ERROR_EOF; goto done; } base = &parent->data->ipdata.u.blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP_NODE: case HAMMER2_BREF_TYPE_INDIRECT: /* * Optimize indirect blocks in the INITIAL state to avoid * I/O. */ if (parent->flags & HAMMER2_CHAIN_INITIAL) { base = NULL; } else { if (parent->data == NULL) panic("parent->data is NULL"); base = &parent->data->npdata[0]; } count = parent->bytes / sizeof(hammer2_blockref_t); break; case HAMMER2_BREF_TYPE_VOLUME: base = &parent->data->voldata.sroot_blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP: base = &parent->data->blkset.blockref[0]; count = HAMMER2_SET_COUNT; break; default: panic("hammer2_chain_scan: unrecognized blockref type: %d", parent->bref.type); base = NULL; /* safety */ count = 0; /* safety */ break; } /* * Merged scan to find next candidate. * * hammer2_base_*() functions require the parent->core.live_* fields * to be synchronized. * * We need to hold the spinlock to access the block array and RB tree * and to interlock chain creation. */ if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) hammer2_chain_countbrefs(parent, base, count); next_key = 0; bref_ptr = NULL; hammer2_spin_ex(&parent->core.spin); chain = hammer2_combined_find(parent, base, count, &next_key, key, HAMMER2_KEY_MAX, &bref_ptr); generation = parent->core.generation; /* * Exhausted parent chain, we're done. */ if (bref_ptr == NULL) { hammer2_spin_unex(&parent->core.spin); KKASSERT(chain == NULL); error |= HAMMER2_ERROR_EOF; goto done; } /* * Copy into the supplied stack-based blockref. */ *bref = *bref_ptr; /* * Selected from blockref or in-memory chain. */ if (chain == NULL) { switch(bref->type) { case HAMMER2_BREF_TYPE_INODE: case HAMMER2_BREF_TYPE_FREEMAP_NODE: case HAMMER2_BREF_TYPE_INDIRECT: case HAMMER2_BREF_TYPE_VOLUME: case HAMMER2_BREF_TYPE_FREEMAP: /* * Recursion, always get the chain */ hammer2_spin_unex(&parent->core.spin); chain = hammer2_chain_get(parent, generation, bref, how); if (chain == NULL) goto again; break; default: /* * No recursion, do not waste time instantiating * a chain, just iterate using the bref. */ hammer2_spin_unex(&parent->core.spin); break; } } else { /* * Recursion or not we need the chain in order to supply * the bref. */ hammer2_chain_ref(chain); hammer2_spin_unex(&parent->core.spin); hammer2_chain_lock(chain, how); } if (chain && (bcmp(bref, &chain->bref, sizeof(*bref)) || chain->parent != parent)) { hammer2_chain_unlock(chain); hammer2_chain_drop(chain); chain = NULL; goto again; } /* * Skip deleted chains (XXX cache 'i' end-of-block-array? XXX) * * NOTE: chain's key range is not relevant as there might be * one-offs within the range that are not deleted. * * NOTE: XXX this could create problems with scans used in * situations other than mount-time recovery. * * NOTE: Lookups can race delete-duplicate because * delete-duplicate does not lock the parent's core * (they just use the spinlock on the core). */ if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { hammer2_chain_unlock(chain); hammer2_chain_drop(chain); chain = NULL; key = next_key; if (key == 0) { error |= HAMMER2_ERROR_EOF; goto done; } goto again; } done: /* * All done, return the bref or NULL, supply chain if necessary. */ if (chain) *chainp = chain; return (error); } /* * Create and return a new hammer2 system memory structure of the specified * key, type and size and insert it under (*parentp). This is a full * insertion, based on the supplied key/keybits, and may involve creating * indirect blocks and moving other chains around via delete/duplicate. * * This call can be made with parent == NULL as long as a non -1 methods * is supplied. hmp must also be supplied in this situation (otherwise * hmp is extracted from the supplied parent). The chain will be detached * from the topology. A later call with both parent and chain can be made * to attach it. * * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (*parentp) TO THE INSERTION * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING * FULL. This typically means that the caller is creating the chain after * doing a hammer2_chain_lookup(). * * (*parentp) must be exclusive locked and may be replaced on return * depending on how much work the function had to do. * * (*parentp) must not be errored or this function will assert. * * (*chainp) usually starts out NULL and returns the newly created chain, * but if the caller desires the caller may allocate a disconnected chain * and pass it in instead. * * This function should NOT be used to insert INDIRECT blocks. It is * typically used to create/insert inodes and data blocks. * * Caller must pass-in an exclusively locked parent the new chain is to * be inserted under, and optionally pass-in a disconnected, exclusively * locked chain to insert (else we create a new chain). The function will * adjust (*parentp) as necessary, create or connect the chain, and * return an exclusively locked chain in *chainp. * * When creating a PFSROOT inode under the super-root, pmp is typically NULL * and will be reassigned. * * NOTE: returns HAMMER_ERROR_* flags */ int hammer2_chain_create(hammer2_chain_t **parentp, hammer2_chain_t **chainp, hammer2_dev_t *hmp, hammer2_pfs_t *pmp, int methods, hammer2_key_t key, int keybits, int type, size_t bytes, hammer2_tid_t mtid, hammer2_off_t dedup_off, int flags) { hammer2_chain_t *chain; hammer2_chain_t *parent; hammer2_blockref_t *base; hammer2_blockref_t dummy; int allocated = 0; int error = 0; int count; int maxloops = 300000; /* * Topology may be crossing a PFS boundary. */ parent = *parentp; if (parent) { KKASSERT(hammer2_mtx_owned(&parent->lock)); KKASSERT(parent->error == 0); hmp = parent->hmp; } chain = *chainp; if (chain == NULL) { /* * First allocate media space and construct the dummy bref, * then allocate the in-memory chain structure. Set the * INITIAL flag for fresh chains which do not have embedded * data. */ bzero(&dummy, sizeof(dummy)); dummy.type = type; dummy.key = key; dummy.keybits = keybits; dummy.data_off = hammer2_getradix(bytes); /* * Inherit methods from parent by default. Primarily used * for BREF_TYPE_DATA. Non-data types *must* be set to * a non-NONE check algorithm. */ if (methods == HAMMER2_METH_DEFAULT) dummy.methods = parent->bref.methods; else dummy.methods = (uint8_t)methods; if (type != HAMMER2_BREF_TYPE_DATA && HAMMER2_DEC_CHECK(dummy.methods) == HAMMER2_CHECK_NONE) { dummy.methods |= HAMMER2_ENC_CHECK(HAMMER2_CHECK_DEFAULT); } chain = hammer2_chain_alloc(hmp, pmp, &dummy); /* * Lock the chain manually, chain_lock will load the chain * which we do NOT want to do. (note: chain->refs is set * to 1 by chain_alloc() for us, but lockcnt is not). */ chain->lockcnt = 1; hammer2_mtx_ex(&chain->lock); allocated = 1; /* * Set INITIAL to optimize I/O. The flag will generally be * processed when we call hammer2_chain_modify(). */ switch(type) { case HAMMER2_BREF_TYPE_VOLUME: case HAMMER2_BREF_TYPE_FREEMAP: panic("hammer2_chain_create: called with volume type"); break; case HAMMER2_BREF_TYPE_INDIRECT: panic("hammer2_chain_create: cannot be used to" "create indirect block"); break; case HAMMER2_BREF_TYPE_FREEMAP_NODE: panic("hammer2_chain_create: cannot be used to" "create freemap root or node"); break; case HAMMER2_BREF_TYPE_FREEMAP_LEAF: KKASSERT(bytes == sizeof(chain->data->bmdata)); /* fall through */ case HAMMER2_BREF_TYPE_DIRENT: case HAMMER2_BREF_TYPE_INODE: case HAMMER2_BREF_TYPE_DATA: default: /* * leave chain->data NULL, set INITIAL */ KKASSERT(chain->data == NULL); atomic_set_int(&chain->flags, HAMMER2_CHAIN_INITIAL); break; } } else { /* * We are reattaching a previously deleted chain, possibly * under a new parent and possibly with a new key/keybits. * The chain does not have to be in a modified state. The * UPDATE flag will be set later on in this routine. * * Do NOT mess with the current state of the INITIAL flag. */ chain->bref.key = key; chain->bref.keybits = keybits; if (chain->flags & HAMMER2_CHAIN_DELETED) atomic_clear_int(&chain->flags, HAMMER2_CHAIN_DELETED); KKASSERT(chain->parent == NULL); } /* * Set the appropriate bref flag if requested. * * NOTE! Callers can call this function to move chains without * knowing about special flags, so don't clear bref flags * here! */ if (flags & HAMMER2_INSERT_PFSROOT) chain->bref.flags |= HAMMER2_BREF_FLAG_PFSROOT; if (parent == NULL) goto skip; /* * Calculate how many entries we have in the blockref array and * determine if an indirect block is required when inserting into * the parent. */ again: if (--maxloops == 0) panic("hammer2_chain_create: maxloops"); switch(parent->bref.type) { case HAMMER2_BREF_TYPE_INODE: if ((parent->data->ipdata.meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) != 0) { kprintf("hammer2: parent set for direct-data! " "pkey=%016jx ckey=%016jx\n", parent->bref.key, chain->bref.key); } KKASSERT((parent->data->ipdata.meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) == 0); KKASSERT(parent->data != NULL); base = &parent->data->ipdata.u.blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_INDIRECT: case HAMMER2_BREF_TYPE_FREEMAP_NODE: if (parent->flags & HAMMER2_CHAIN_INITIAL) base = NULL; else base = &parent->data->npdata[0]; count = parent->bytes / sizeof(hammer2_blockref_t); break; case HAMMER2_BREF_TYPE_VOLUME: KKASSERT(parent->data != NULL); base = &parent->data->voldata.sroot_blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP: KKASSERT(parent->data != NULL); base = &parent->data->blkset.blockref[0]; count = HAMMER2_SET_COUNT; break; default: panic("hammer2_chain_create: unrecognized blockref type: %d", parent->bref.type); base = NULL; count = 0; break; } /* * Make sure we've counted the brefs */ if ((parent->flags & HAMMER2_CHAIN_COUNTEDBREFS) == 0) hammer2_chain_countbrefs(parent, base, count); KASSERT(parent->core.live_count >= 0 && parent->core.live_count <= count, ("bad live_count %d/%d (%02x, %d)", parent->core.live_count, count, parent->bref.type, parent->bytes)); /* * If no free blockref could be found we must create an indirect * block and move a number of blockrefs into it. With the parent * locked we can safely lock each child in order to delete+duplicate * it without causing a deadlock. * * This may return the new indirect block or the old parent depending * on where the key falls. NULL is returned on error. */ if (parent->core.live_count == count) { hammer2_chain_t *nparent; KKASSERT((flags & HAMMER2_INSERT_SAMEPARENT) == 0); nparent = hammer2_chain_create_indirect(parent, key, keybits, mtid, type, &error); if (nparent == NULL) { if (allocated) hammer2_chain_drop(chain); chain = NULL; goto done; } if (parent != nparent) { hammer2_chain_unlock(parent); hammer2_chain_drop(parent); parent = *parentp = nparent; } goto again; } /* * fall through if parent, or skip to here if no parent. */ skip: if (chain->flags & HAMMER2_CHAIN_DELETED) kprintf("Inserting deleted chain @%016jx\n", chain->bref.key); /* * Link the chain into its parent. */ if (chain->parent != NULL) panic("hammer2: hammer2_chain_create: chain already connected"); KKASSERT(chain->parent == NULL); if (parent) { KKASSERT(parent->core.live_count < count); hammer2_chain_insert(parent, chain, HAMMER2_CHAIN_INSERT_SPIN | HAMMER2_CHAIN_INSERT_LIVE, 0); } if (allocated) { /* * Mark the newly created chain modified. This will cause * UPDATE to be set and process the INITIAL flag. * * Device buffers are not instantiated for DATA elements * as these are handled by logical buffers. * * Indirect and freemap node indirect blocks are handled * by hammer2_chain_create_indirect() and not by this * function. * * Data for all other bref types is expected to be * instantiated (INODE, LEAF). */ switch(chain->bref.type) { case HAMMER2_BREF_TYPE_DATA: case HAMMER2_BREF_TYPE_FREEMAP_LEAF: case HAMMER2_BREF_TYPE_DIRENT: case HAMMER2_BREF_TYPE_INODE: error = hammer2_chain_modify(chain, mtid, dedup_off, HAMMER2_MODIFY_OPTDATA); break; default: /* * Remaining types are not supported by this function. * In particular, INDIRECT and LEAF_NODE types are * handled by create_indirect(). */ panic("hammer2_chain_create: bad type: %d", chain->bref.type); /* NOT REACHED */ break; } } else { /* * When reconnecting a chain we must set UPDATE and * setflush so the flush recognizes that it must update * the bref in the parent. */ if ((chain->flags & HAMMER2_CHAIN_UPDATE) == 0) atomic_set_int(&chain->flags, HAMMER2_CHAIN_UPDATE); } /* * We must setflush(parent) to ensure that it recurses through to * chain. setflush(chain) might not work because ONFLUSH is possibly * already set in the chain (so it won't recurse up to set it in the * parent). */ if (parent) hammer2_chain_setflush(parent); done: *chainp = chain; return (error); } /* * Move the chain from its old parent to a new parent. The chain must have * already been deleted or already disconnected (or never associated) with * a parent. The chain is reassociated with the new parent and the deleted * flag will be cleared (no longer deleted). The chain's modification state * is not altered. * * THE CALLER MUST HAVE ALREADY PROPERLY SEEKED (parent) TO THE INSERTION * POINT SANS ANY REQUIRED INDIRECT BLOCK CREATIONS DUE TO THE ARRAY BEING * FULL. This typically means that the caller is creating the chain after * doing a hammer2_chain_lookup(). * * Neither (parent) or (chain) can be errored. * * If (parent) is non-NULL then the chain is inserted under the parent. * * If (parent) is NULL then the newly duplicated chain is not inserted * anywhere, similar to if it had just been chain_alloc()'d (suitable for * passing into hammer2_chain_create() after this function returns). * * WARNING! This function calls create which means it can insert indirect * blocks. This can cause other unrelated chains in the parent to * be moved to a newly inserted indirect block in addition to the * specific chain. */ void hammer2_chain_rename(hammer2_chain_t **parentp, hammer2_chain_t *chain, hammer2_tid_t mtid, int flags) { hammer2_blockref_t *bref; hammer2_chain_t *parent; /* * WARNING! We should never resolve DATA to device buffers * (XXX allow it if the caller did?), and since * we currently do not have the logical buffer cache * buffer in-hand to fix its cached physical offset * we also force the modify code to not COW it. XXX * * NOTE! We allow error'd chains to be renamed. The bref itself * is good and can be renamed. The content, however, may * be inaccessible. */ KKASSERT(chain->parent == NULL); /*KKASSERT(chain->error == 0); allow */ bref = &chain->bref; /* * If parent is not NULL the duplicated chain will be entered under * the parent and the UPDATE bit set to tell flush to update * the blockref. * * We must setflush(parent) to ensure that it recurses through to * chain. setflush(chain) might not work because ONFLUSH is possibly * already set in the chain (so it won't recurse up to set it in the * parent). * * Having both chains locked is extremely important for atomicy. */ if (parentp && (parent = *parentp) != NULL) { KKASSERT(hammer2_mtx_owned(&parent->lock)); KKASSERT(parent->refs > 0); KKASSERT(parent->error == 0); hammer2_chain_create(parentp, &chain, NULL, chain->pmp, HAMMER2_METH_DEFAULT, bref->key, bref->keybits, bref->type, chain->bytes, mtid, 0, flags); KKASSERT(chain->flags & HAMMER2_CHAIN_UPDATE); hammer2_chain_setflush(*parentp); } } /* * This works in tandem with delete_obref() to install a blockref in * (typically) an indirect block that is associated with the chain being * moved to *parentp. * * The reason we need this function is that the caller needs to maintain * the blockref as it was, and not generate a new blockref for what might * be a modified chain. Otherwise stuff will leak into the flush that * the flush code's FLUSH_INODE_STOP flag is unable to catch. * * It is EXTREMELY important that we properly set CHAIN_BLKMAPUPD and * CHAIN_UPDATE. We must set BLKMAPUPD if the bref does not match, and * we must clear CHAIN_UPDATE (that was likely set by the chain_rename) if * it does. Otherwise we can end up in a situation where H2 is unable to * clean up the in-memory chain topology. * * The reason for this is that flushes do not generally flush through * BREF_TYPE_INODE chains and depend on a hammer2_inode_t queued to syncq * or sideq to properly flush and dispose of the related inode chain's flags. * Situations where the inode is not actually modified by the frontend, * but where we have to move the related chains around as we insert or cleanup * indirect blocks, can leave us with a 'dirty' (non-disposable) in-memory * inode chain that does not have a hammer2_inode_t associated with it. */ static void hammer2_chain_rename_obref(hammer2_chain_t **parentp, hammer2_chain_t *chain, hammer2_tid_t mtid, int flags, hammer2_blockref_t *obref) { hammer2_chain_rename(parentp, chain, mtid, flags); if (obref->type != HAMMER2_BREF_TYPE_EMPTY) { hammer2_blockref_t *tbase; int tcount; KKASSERT((chain->flags & HAMMER2_CHAIN_BLKMAPPED) == 0); hammer2_chain_modify(*parentp, mtid, 0, 0); tbase = hammer2_chain_base_and_count(*parentp, &tcount); hammer2_base_insert(*parentp, tbase, tcount, chain, obref); if (bcmp(obref, &chain->bref, sizeof(chain->bref))) { atomic_set_int(&chain->flags, HAMMER2_CHAIN_BLKMAPUPD | HAMMER2_CHAIN_UPDATE); } else { atomic_clear_int(&chain->flags, HAMMER2_CHAIN_UPDATE); } } } /* * Helper function for deleting chains. * * The chain is removed from the live view (the RBTREE) as well as the parent's * blockmap. Both chain and its parent must be locked. * * parent may not be errored. chain can be errored. */ static int _hammer2_chain_delete_helper(hammer2_chain_t *parent, hammer2_chain_t *chain, hammer2_tid_t mtid, int flags, hammer2_blockref_t *obref) { int error = 0; KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0); KKASSERT(chain->parent == parent); if (chain->flags & HAMMER2_CHAIN_BLKMAPPED) { /* * Chain is blockmapped, so there must be a parent. * Atomically remove the chain from the parent and remove * the blockmap entry. The parent must be set modified * to remove the blockmap entry. */ hammer2_blockref_t *base; int count; KKASSERT(parent != NULL); KKASSERT(parent->error == 0); KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0); error = hammer2_chain_modify(parent, mtid, 0, 0); if (error) goto done; /* * Calculate blockmap pointer */ KKASSERT(chain->flags & HAMMER2_CHAIN_ONRBTREE); hammer2_spin_ex(&chain->core.spin); hammer2_spin_ex(&parent->core.spin); atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); atomic_add_int(&parent->core.live_count, -1); ++parent->core.generation; RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain); atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); --parent->core.chain_count; chain->parent = NULL; switch(parent->bref.type) { case HAMMER2_BREF_TYPE_INODE: /* * Access the inode's block array. However, there * is no block array if the inode is flagged * DIRECTDATA. */ if (parent->data && (parent->data->ipdata.meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) == 0) { base = &parent->data->ipdata.u.blockset.blockref[0]; } else { base = NULL; } count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_INDIRECT: case HAMMER2_BREF_TYPE_FREEMAP_NODE: if (parent->data) base = &parent->data->npdata[0]; else base = NULL; count = parent->bytes / sizeof(hammer2_blockref_t); break; case HAMMER2_BREF_TYPE_VOLUME: base = &parent->data->voldata. sroot_blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP: base = &parent->data->blkset.blockref[0]; count = HAMMER2_SET_COUNT; break; default: base = NULL; count = 0; panic("_hammer2_chain_delete_helper: " "unrecognized blockref type: %d", parent->bref.type); break; } /* * delete blockmapped chain from its parent. */ if (base) { hammer2_base_delete(parent, base, count, chain, obref); } hammer2_spin_unex(&parent->core.spin); hammer2_spin_unex(&chain->core.spin); } else if (chain->flags & HAMMER2_CHAIN_ONRBTREE) { /* * Chain is not blockmapped but a parent is present. * Atomically remove the chain from the parent. There is * no blockmap entry to remove. */ hammer2_spin_ex(&chain->core.spin); hammer2_spin_ex(&parent->core.spin); atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); atomic_add_int(&parent->core.live_count, -1); ++parent->core.generation; RB_REMOVE(hammer2_chain_tree, &parent->core.rbtree, chain); atomic_clear_int(&chain->flags, HAMMER2_CHAIN_ONRBTREE); --parent->core.chain_count; chain->parent = NULL; hammer2_spin_unex(&parent->core.spin); hammer2_spin_unex(&chain->core.spin); } else { /* * Chain is not blockmapped and has no parent. This * is a degenerate case. */ atomic_set_int(&chain->flags, HAMMER2_CHAIN_DELETED); } done: return error; } /* * Create an indirect block that covers one or more of the elements in the * current parent. Either returns the existing parent with no locking or * ref changes or returns the new indirect block locked and referenced * and leaving the original parent lock/ref intact as well. * * If an error occurs, NULL is returned and *errorp is set to the H2 error. * * The returned chain depends on where the specified key falls. * * The key/keybits for the indirect mode only needs to follow three rules: * * (1) That all elements underneath it fit within its key space and * * (2) That all elements outside it are outside its key space. * * (3) When creating the new indirect block any elements in the current * parent that fit within the new indirect block's keyspace must be * moved into the new indirect block. * * (4) The keyspace chosen for the inserted indirect block CAN cover a wider * keyspace the the current parent, but lookup/iteration rules will * ensure (and must ensure) that rule (2) for all parents leading up * to the nearest inode or the root volume header is adhered to. This * is accomplished by always recursing through matching keyspaces in * the hammer2_chain_lookup() and hammer2_chain_next() API. * * The current implementation calculates the current worst-case keyspace by * iterating the current parent and then divides it into two halves, choosing * whichever half has the most elements (not necessarily the half containing * the requested key). * * We can also opt to use the half with the least number of elements. This * causes lower-numbered keys (aka logical file offsets) to recurse through * fewer indirect blocks and higher-numbered keys to recurse through more. * This also has the risk of not moving enough elements to the new indirect * block and being forced to create several indirect blocks before the element * can be inserted. * * Must be called with an exclusively locked parent. * * NOTE: *errorp set to HAMMER_ERROR_* flags */ static int hammer2_chain_indkey_freemap(hammer2_chain_t *parent, hammer2_key_t *keyp, int keybits, hammer2_blockref_t *base, int count); static int hammer2_chain_indkey_file(hammer2_chain_t *parent, hammer2_key_t *keyp, int keybits, hammer2_blockref_t *base, int count, int ncount); static int hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp, int keybits, hammer2_blockref_t *base, int count, int ncount); static hammer2_chain_t * hammer2_chain_create_indirect(hammer2_chain_t *parent, hammer2_key_t create_key, int create_bits, hammer2_tid_t mtid, int for_type, int *errorp) { hammer2_dev_t *hmp; hammer2_blockref_t *base; hammer2_blockref_t *bref; hammer2_blockref_t bsave; hammer2_blockref_t dummy; hammer2_chain_t *chain; hammer2_chain_t *ichain; hammer2_key_t key = create_key; hammer2_key_t key_beg; hammer2_key_t key_end; hammer2_key_t key_next; int keybits = create_bits; int count; int ncount; int nbytes; int loops; int error; int reason; int generation; int maxloops = 300000; /* * Calculate the base blockref pointer or NULL if the chain * is known to be empty. We need to calculate the array count * for RB lookups either way. */ hmp = parent->hmp; KKASSERT(hammer2_mtx_owned(&parent->lock)); /* * Pre-modify the parent now to avoid having to deal with error * processing if we tried to later (in the middle of our loop). * * We are going to be moving bref's around, the indirect blocks * cannot be in an initial state. Do not pass MODIFY_OPTDATA. */ *errorp = hammer2_chain_modify(parent, mtid, 0, 0); if (*errorp) { kprintf("hammer2_chain_create_indirect: error %08x %s\n", *errorp, hammer2_error_str(*errorp)); return NULL; } KKASSERT((parent->flags & HAMMER2_CHAIN_INITIAL) == 0); /*hammer2_chain_modify(&parent, HAMMER2_MODIFY_OPTDATA);*/ base = hammer2_chain_base_and_count(parent, &count); /* * How big should our new indirect block be? It has to be at least * as large as its parent for splits to work properly. * * The freemap uses a specific indirect block size. The number of * levels are built dynamically and ultimately depend on the size * volume. Because freemap blocks are taken from the reserved areas * of the volume our goal is efficiency (fewer levels) and not so * much to save disk space. * * The first indirect block level for a directory usually uses * HAMMER2_IND_BYTES_MIN (4KB = 32 directory entries). Due to * the hash mechanism, this typically gives us a nominal * 32 * 4 entries with one level of indirection. * * We use HAMMER2_IND_BYTES_NOM (16KB = 128 blockrefs) for FILE * indirect blocks. The initial 4 entries in the inode gives us * 256KB. Up to 4 indirect blocks gives us 32MB. Three levels * of indirection gives us 137GB, and so forth. H2 can support * huge file sizes but they are not typical, so we try to stick * with compactness and do not use a larger indirect block size. * * We could use 64KB (PBUFSIZE), giving us 512 blockrefs, but * due to the way indirect blocks are created this usually winds * up being extremely inefficient for small files. Even though * 16KB requires more levels of indirection for very large files, * the 16KB records can be ganged together into 64KB DIOs. */ if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE || for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { nbytes = HAMMER2_FREEMAP_LEVELN_PSIZE; } else if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) { if (parent->data->ipdata.meta.type == HAMMER2_OBJTYPE_DIRECTORY) nbytes = HAMMER2_IND_BYTES_MIN; /* 4KB = 32 entries */ else nbytes = HAMMER2_IND_BYTES_NOM; /* 16KB = ~8MB file */ } else { nbytes = HAMMER2_IND_BYTES_NOM; } if (nbytes < count * sizeof(hammer2_blockref_t)) { KKASSERT(for_type != HAMMER2_BREF_TYPE_FREEMAP_NODE && for_type != HAMMER2_BREF_TYPE_FREEMAP_LEAF); nbytes = count * sizeof(hammer2_blockref_t); } ncount = nbytes / sizeof(hammer2_blockref_t); /* * When creating an indirect block for a freemap node or leaf * the key/keybits must be fitted to static radix levels because * particular radix levels use particular reserved blocks in the * related zone. * * This routine calculates the key/radix of the indirect block * we need to create, and whether it is on the high-side or the * low-side. */ switch(for_type) { case HAMMER2_BREF_TYPE_FREEMAP_NODE: case HAMMER2_BREF_TYPE_FREEMAP_LEAF: keybits = hammer2_chain_indkey_freemap(parent, &key, keybits, base, count); break; case HAMMER2_BREF_TYPE_DATA: keybits = hammer2_chain_indkey_file(parent, &key, keybits, base, count, ncount); break; case HAMMER2_BREF_TYPE_DIRENT: case HAMMER2_BREF_TYPE_INODE: keybits = hammer2_chain_indkey_dir(parent, &key, keybits, base, count, ncount); break; default: panic("illegal indirect block for bref type %d", for_type); break; } /* * Normalize the key for the radix being represented, keeping the * high bits and throwing away the low bits. */ key &= ~(((hammer2_key_t)1 << keybits) - 1); /* * Ok, create our new indirect block */ bzero(&dummy, sizeof(dummy)); if (for_type == HAMMER2_BREF_TYPE_FREEMAP_NODE || for_type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) { dummy.type = HAMMER2_BREF_TYPE_FREEMAP_NODE; } else { dummy.type = HAMMER2_BREF_TYPE_INDIRECT; } dummy.key = key; dummy.keybits = keybits; dummy.data_off = hammer2_getradix(nbytes); dummy.methods = HAMMER2_ENC_CHECK(HAMMER2_DEC_CHECK(parent->bref.methods)) | HAMMER2_ENC_COMP(HAMMER2_COMP_NONE); ichain = hammer2_chain_alloc(hmp, parent->pmp, &dummy); atomic_set_int(&ichain->flags, HAMMER2_CHAIN_INITIAL); hammer2_chain_lock(ichain, HAMMER2_RESOLVE_MAYBE); /* ichain has one ref at this point */ /* * We have to mark it modified to allocate its block, but use * OPTDATA to allow it to remain in the INITIAL state. Otherwise * it won't be acted upon by the flush code. * * XXX remove OPTDATA, we need a fully initialized indirect block to * be able to move the original blockref. */ *errorp = hammer2_chain_modify(ichain, mtid, 0, 0); if (*errorp) { kprintf("hammer2_chain_create_indirect: error %08x %s\n", *errorp, hammer2_error_str(*errorp)); hammer2_chain_unlock(ichain); hammer2_chain_drop(ichain); return NULL; } KKASSERT((ichain->flags & HAMMER2_CHAIN_INITIAL) == 0); /* * Iterate the original parent and move the matching brefs into * the new indirect block. * * XXX handle flushes. */ key_beg = 0; key_end = HAMMER2_KEY_MAX; key_next = 0; /* avoid gcc warnings */ hammer2_spin_ex(&parent->core.spin); loops = 0; reason = 0; for (;;) { /* * Parent may have been modified, relocating its block array. * Reload the base pointer. */ base = hammer2_chain_base_and_count(parent, &count); if (++loops > 100000) { hammer2_spin_unex(&parent->core.spin); panic("excessive loops r=%d p=%p base/count %p:%d %016jx\n", reason, parent, base, count, key_next); } /* * NOTE: spinlock stays intact, returned chain (if not NULL) * is not referenced or locked which means that we * cannot safely check its flagged / deletion status * until we lock it. */ chain = hammer2_combined_find(parent, base, count, &key_next, key_beg, key_end, &bref); generation = parent->core.generation; if (bref == NULL) break; key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); /* * Skip keys that are not within the key/radix of the new * indirect block. They stay in the parent. */ if (rounddown2(key ^ bref->key, (hammer2_key_t)1 << keybits) != 0) { goto next_key_spinlocked; } /* * Load the new indirect block by acquiring the related * chains (potentially from media as it might not be * in-memory). Then move it to the new parent (ichain). * * chain is referenced but not locked. We must lock the * chain to obtain definitive state. */ bsave = *bref; if (chain) { /* * Use chain already present in the RBTREE */ hammer2_chain_ref(chain); hammer2_spin_unex(&parent->core.spin); hammer2_chain_lock(chain, HAMMER2_RESOLVE_NEVER); } else { /* * Get chain for blockref element. _get returns NULL * on insertion race. */ hammer2_spin_unex(&parent->core.spin); chain = hammer2_chain_get(parent, generation, &bsave, HAMMER2_RESOLVE_NEVER); if (chain == NULL) { reason = 1; hammer2_spin_ex(&parent->core.spin); continue; } } /* * This is always live so if the chain has been deleted * we raced someone and we have to retry. * * NOTE: Lookups can race delete-duplicate because * delete-duplicate does not lock the parent's core * (they just use the spinlock on the core). * * (note reversed logic for this one) */ if (bcmp(&bsave, &chain->bref, sizeof(bsave)) || chain->parent != parent || (chain->flags & HAMMER2_CHAIN_DELETED)) { hammer2_chain_unlock(chain); hammer2_chain_drop(chain); if (hammer2_debug & 0x0040) { kprintf("LOST PARENT RETRY " "RETRY (%p,%p)->%p %08x\n", parent, chain->parent, chain, chain->flags); } hammer2_spin_ex(&parent->core.spin); continue; } /* * Shift the chain to the indirect block. * * WARNING! The (parent, chain) deletion may modify the parent * and invalidate the base pointer. * * WARNING! Parent must already be marked modified, so we * can assume that chain_delete always suceeds. * * WARNING! hammer2_chain_repchange() does not have to be * called (and doesn't work anyway because we are * only doing a partial shift). A recursion that is * in-progress can continue at the current parent * and will be able to properly find its next key. */ error = hammer2_chain_delete_obref(parent, chain, mtid, 0, &bsave); KKASSERT(error == 0); hammer2_chain_rename_obref(&ichain, chain, mtid, 0, &bsave); hammer2_chain_unlock(chain); hammer2_chain_drop(chain); KKASSERT(parent->refs > 0); chain = NULL; base = NULL; /* safety */ hammer2_spin_ex(&parent->core.spin); next_key_spinlocked: if (--maxloops == 0) panic("hammer2_chain_create_indirect: maxloops"); reason = 4; if (key_next == 0 || key_next > key_end) break; key_beg = key_next; /* loop */ } hammer2_spin_unex(&parent->core.spin); /* * Insert the new indirect block into the parent now that we've * cleared out some entries in the parent. We calculated a good * insertion index in the loop above (ichain->index). * * We don't have to set UPDATE here because we mark ichain * modified down below (so the normal modified -> flush -> set-moved * sequence applies). * * The insertion shouldn't race as this is a completely new block * and the parent is locked. */ base = NULL; /* safety, parent modify may change address */ KKASSERT((ichain->flags & HAMMER2_CHAIN_ONRBTREE) == 0); KKASSERT(parent->core.live_count < count); hammer2_chain_insert(parent, ichain, HAMMER2_CHAIN_INSERT_SPIN | HAMMER2_CHAIN_INSERT_LIVE, 0); /* * Make sure flushes propogate after our manual insertion. */ hammer2_chain_setflush(ichain); hammer2_chain_setflush(parent); /* * Figure out what to return. */ if (rounddown2(create_key ^ key, (hammer2_key_t)1 << keybits) != 0) { /* * Key being created is outside the key range, * return the original parent. */ hammer2_chain_unlock(ichain); hammer2_chain_drop(ichain); } else { /* * Otherwise its in the range, return the new parent. * (leave both the new and old parent locked). */ parent = ichain; } return(parent); } /* * Do maintenance on an indirect chain. Both parent and chain are locked. * * Returns non-zero if (chain) is deleted, either due to being empty or * because its children were safely moved into the parent. */ int hammer2_chain_indirect_maintenance(hammer2_chain_t *parent, hammer2_chain_t *chain) { hammer2_blockref_t *chain_base; hammer2_blockref_t *base; hammer2_blockref_t *bref; hammer2_blockref_t bsave; hammer2_key_t key_next; hammer2_key_t key_beg; hammer2_key_t key_end; hammer2_chain_t *sub; int chain_count; int count; int error; int generation; /* * Make sure we have an accurate live_count */ if ((chain->flags & (HAMMER2_CHAIN_INITIAL | HAMMER2_CHAIN_COUNTEDBREFS)) == 0) { base = &chain->data->npdata[0]; count = chain->bytes / sizeof(hammer2_blockref_t); hammer2_chain_countbrefs(chain, base, count); } /* * If the indirect block is empty we can delete it. * (ignore deletion error) */ if (chain->core.live_count == 0 && RB_EMPTY(&chain->core.rbtree)) { hammer2_chain_delete(parent, chain, chain->bref.modify_tid, HAMMER2_DELETE_PERMANENT); hammer2_chain_repchange(parent, chain); return 1; } base = hammer2_chain_base_and_count(parent, &count); if ((parent->flags & (HAMMER2_CHAIN_INITIAL | HAMMER2_CHAIN_COUNTEDBREFS)) == 0) { hammer2_chain_countbrefs(parent, base, count); } /* * Determine if we can collapse chain into parent, calculate * hysteresis for chain emptiness. */ if (parent->core.live_count + chain->core.live_count - 1 > count) return 0; chain_count = chain->bytes / sizeof(hammer2_blockref_t); if (chain->core.live_count > chain_count * 3 / 4) return 0; /* * Ok, theoretically we can collapse chain's contents into * parent. chain is locked, but any in-memory children of chain * are not. For this to work, we must be able to dispose of any * in-memory children of chain. * * For now require that there are no in-memory children of chain. * * WARNING! Both chain and parent must remain locked across this * entire operation. */ /* * Parent must be marked modified. Don't try to collapse it if we * can't mark it modified. Once modified, destroy chain to make room * and to get rid of what will be a conflicting key (this is included * in the calculation above). Finally, move the children of chain * into chain's parent. * * This order creates an accounting problem for bref.embed.stats * because we destroy chain before we remove its children. Any * elements whos blockref is already synchronized will be counted * twice. To deal with the problem we clean out chain's stats prior * to deleting it. */ error = hammer2_chain_modify(parent, 0, 0, 0); if (error) { krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n", hammer2_error_str(error)); return 0; } error = hammer2_chain_modify(chain, chain->bref.modify_tid, 0, 0); if (error) { krateprintf(&krate_h2me, "hammer2: indirect_maint: %s\n", hammer2_error_str(error)); return 0; } chain->bref.embed.stats.inode_count = 0; chain->bref.embed.stats.data_count = 0; error = hammer2_chain_delete(parent, chain, chain->bref.modify_tid, HAMMER2_DELETE_PERMANENT); KKASSERT(error == 0); /* * The combined_find call requires core.spin to be held. One would * think there wouldn't be any conflicts since we hold chain * exclusively locked, but the caching mechanism for 0-ref children * does not require a chain lock. */ hammer2_spin_ex(&chain->core.spin); key_next = 0; key_beg = 0; key_end = HAMMER2_KEY_MAX; for (;;) { chain_base = &chain->data->npdata[0]; chain_count = chain->bytes / sizeof(hammer2_blockref_t); sub = hammer2_combined_find(chain, chain_base, chain_count, &key_next, key_beg, key_end, &bref); generation = chain->core.generation; if (bref == NULL) break; key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); bsave = *bref; if (sub) { hammer2_chain_ref(sub); hammer2_spin_unex(&chain->core.spin); hammer2_chain_lock(sub, HAMMER2_RESOLVE_NEVER); } else { hammer2_spin_unex(&chain->core.spin); sub = hammer2_chain_get(chain, generation, &bsave, HAMMER2_RESOLVE_NEVER); if (sub == NULL) { hammer2_spin_ex(&chain->core.spin); continue; } } if (bcmp(&bsave, &sub->bref, sizeof(bsave)) || sub->parent != chain || (sub->flags & HAMMER2_CHAIN_DELETED)) { hammer2_chain_unlock(sub); hammer2_chain_drop(sub); hammer2_spin_ex(&chain->core.spin); sub = NULL; /* safety */ continue; } error = hammer2_chain_delete_obref(chain, sub, sub->bref.modify_tid, 0, &bsave); KKASSERT(error == 0); hammer2_chain_rename_obref(&parent, sub, sub->bref.modify_tid, HAMMER2_INSERT_SAMEPARENT, &bsave); hammer2_chain_unlock(sub); hammer2_chain_drop(sub); hammer2_spin_ex(&chain->core.spin); if (key_next == 0) break; key_beg = key_next; } hammer2_spin_unex(&chain->core.spin); hammer2_chain_repchange(parent, chain); return 1; } /* * Freemap indirect blocks * * Calculate the keybits and highside/lowside of the freemap node the * caller is creating. * * This routine will specify the next higher-level freemap key/radix * representing the lowest-ordered set. By doing so, eventually all * low-ordered sets will be moved one level down. * * We have to be careful here because the freemap reserves a limited * number of blocks for a limited number of levels. So we can't just * push indiscriminately. */ int hammer2_chain_indkey_freemap(hammer2_chain_t *parent, hammer2_key_t *keyp, int keybits, hammer2_blockref_t *base, int count) { hammer2_chain_t *chain; hammer2_blockref_t *bref; hammer2_key_t key; hammer2_key_t key_beg; hammer2_key_t key_end; hammer2_key_t key_next; int maxloops = 300000; key = *keyp; keybits = 64; /* * Calculate the range of keys in the array being careful to skip * slots which are overridden with a deletion. */ key_beg = 0; key_end = HAMMER2_KEY_MAX; hammer2_spin_ex(&parent->core.spin); for (;;) { if (--maxloops == 0) { panic("indkey_freemap shit %p %p:%d\n", parent, base, count); } chain = hammer2_combined_find(parent, base, count, &key_next, key_beg, key_end, &bref); /* * Exhausted search */ if (bref == NULL) break; /* * Skip deleted chains. */ if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { if (key_next == 0 || key_next > key_end) break; key_beg = key_next; continue; } /* * Use the full live (not deleted) element for the scan * iteration. HAMMER2 does not allow partial replacements. * * XXX should be built into hammer2_combined_find(). */ key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); if (keybits > bref->keybits) { key = bref->key; keybits = bref->keybits; } else if (keybits == bref->keybits && bref->key < key) { key = bref->key; } if (key_next == 0) break; key_beg = key_next; } hammer2_spin_unex(&parent->core.spin); /* * Return the keybits for a higher-level FREEMAP_NODE covering * this node. */ switch(keybits) { case HAMMER2_FREEMAP_LEVEL0_RADIX: keybits = HAMMER2_FREEMAP_LEVEL1_RADIX; break; case HAMMER2_FREEMAP_LEVEL1_RADIX: keybits = HAMMER2_FREEMAP_LEVEL2_RADIX; break; case HAMMER2_FREEMAP_LEVEL2_RADIX: keybits = HAMMER2_FREEMAP_LEVEL3_RADIX; break; case HAMMER2_FREEMAP_LEVEL3_RADIX: keybits = HAMMER2_FREEMAP_LEVEL4_RADIX; break; case HAMMER2_FREEMAP_LEVEL4_RADIX: keybits = HAMMER2_FREEMAP_LEVEL5_RADIX; break; case HAMMER2_FREEMAP_LEVEL5_RADIX: panic("hammer2_chain_indkey_freemap: level too high"); break; default: panic("hammer2_chain_indkey_freemap: bad radix"); break; } *keyp = key; return (keybits); } /* * File indirect blocks * * Calculate the key/keybits for the indirect block to create by scanning * existing keys. The key being created is also passed in *keyp and can be * inside or outside the indirect block. Regardless, the indirect block * must hold at least two keys in order to guarantee sufficient space. * * We use a modified version of the freemap's fixed radix tree, but taylored * for file data. Basically we configure an indirect block encompassing the * smallest key. */ static int hammer2_chain_indkey_file(hammer2_chain_t *parent, hammer2_key_t *keyp, int keybits, hammer2_blockref_t *base, int count, int ncount) { hammer2_chain_t *chain; hammer2_blockref_t *bref; hammer2_key_t key; hammer2_key_t key_beg; hammer2_key_t key_end; hammer2_key_t key_next; int nradix; int maxloops = 300000; key = *keyp; keybits = 64; /* * Calculate the range of keys in the array being careful to skip * slots which are overridden with a deletion. * * Locate the smallest key. */ key_beg = 0; key_end = HAMMER2_KEY_MAX; hammer2_spin_ex(&parent->core.spin); for (;;) { if (--maxloops == 0) { panic("indkey_freemap shit %p %p:%d\n", parent, base, count); } chain = hammer2_combined_find(parent, base, count, &key_next, key_beg, key_end, &bref); /* * Exhausted search */ if (bref == NULL) break; /* * Skip deleted chains. */ if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { if (key_next == 0 || key_next > key_end) break; key_beg = key_next; continue; } /* * Use the full live (not deleted) element for the scan * iteration. HAMMER2 does not allow partial replacements. * * XXX should be built into hammer2_combined_find(). */ key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); if (keybits > bref->keybits) { key = bref->key; keybits = bref->keybits; } else if (keybits == bref->keybits && bref->key < key) { key = bref->key; } if (key_next == 0) break; key_beg = key_next; } hammer2_spin_unex(&parent->core.spin); /* * Calculate the static keybits for a higher-level indirect block * that contains the key. */ *keyp = key; switch(ncount) { case HAMMER2_IND_COUNT_MIN: nradix = HAMMER2_IND_RADIX_MIN - HAMMER2_BLOCKREF_RADIX; break; case HAMMER2_IND_COUNT_NOM: nradix = HAMMER2_IND_RADIX_NOM - HAMMER2_BLOCKREF_RADIX; break; case HAMMER2_IND_COUNT_MAX: nradix = HAMMER2_IND_RADIX_MAX - HAMMER2_BLOCKREF_RADIX; break; default: panic("bad ncount %d\n", ncount); nradix = 0; break; } /* * The largest radix that can be returned for an indirect block is * 63 bits. (The largest practical indirect block radix is actually * 62 bits because the top-level inode or volume root contains four * entries, but allow 63 to be returned). */ if (nradix >= 64) nradix = 63; return keybits + nradix; } #if 1 /* * Directory indirect blocks. * * Covers both the inode index (directory of inodes), and directory contents * (filenames hardlinked to inodes). * * Because directory keys are hashed we generally try to cut the space in * half. We accomodate the inode index (which tends to have linearly * increasing inode numbers) by ensuring that the keyspace is at least large * enough to fill up the indirect block being created. */ static int hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp, int keybits, hammer2_blockref_t *base, int count, int ncount) { hammer2_blockref_t *bref; hammer2_chain_t *chain; hammer2_key_t key_beg; hammer2_key_t key_end; hammer2_key_t key_next; hammer2_key_t key; int nkeybits; int locount; int hicount; int maxloops = 300000; /* * NOTE: We can't take a shortcut here anymore for inodes because * the root directory can contain a mix of inodes and directory * entries (we used to just return 63 if parent->bref.type was * HAMMER2_BREF_TYPE_INODE. */ key = *keyp; locount = 0; hicount = 0; /* * Calculate the range of keys in the array being careful to skip * slots which are overridden with a deletion. */ key_beg = 0; key_end = HAMMER2_KEY_MAX; hammer2_spin_ex(&parent->core.spin); for (;;) { if (--maxloops == 0) { panic("indkey_freemap shit %p %p:%d\n", parent, base, count); } chain = hammer2_combined_find(parent, base, count, &key_next, key_beg, key_end, &bref); /* * Exhausted search */ if (bref == NULL) break; /* * Deleted object */ if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { if (key_next == 0 || key_next > key_end) break; key_beg = key_next; continue; } /* * Use the full live (not deleted) element for the scan * iteration. HAMMER2 does not allow partial replacements. * * XXX should be built into hammer2_combined_find(). */ key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); /* * Expand our calculated key range (key, keybits) to fit * the scanned key. nkeybits represents the full range * that we will later cut in half (two halves @ nkeybits - 1). */ nkeybits = keybits; if (nkeybits < bref->keybits) { if (bref->keybits > 64) { kprintf("bad bref chain %p bref %p\n", chain, bref); Debugger("fubar"); } nkeybits = bref->keybits; } while (nkeybits < 64 && rounddown2(key ^ bref->key, (hammer2_key_t)1 << nkeybits) != 0) { ++nkeybits; } /* * If the new key range is larger we have to determine * which side of the new key range the existing keys fall * under by checking the high bit, then collapsing the * locount into the hicount or vise-versa. */ if (keybits != nkeybits) { if (((hammer2_key_t)1 << (nkeybits - 1)) & key) { hicount += locount; locount = 0; } else { locount += hicount; hicount = 0; } keybits = nkeybits; } /* * The newly scanned key will be in the lower half or the * upper half of the (new) key range. */ if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key) ++hicount; else ++locount; if (key_next == 0) break; key_beg = key_next; } hammer2_spin_unex(&parent->core.spin); bref = NULL; /* now invalid (safety) */ /* * Adjust keybits to represent half of the full range calculated * above (radix 63 max) for our new indirect block. */ --keybits; /* * Expand keybits to hold at least ncount elements. ncount will be * a power of 2. This is to try to completely fill leaf nodes (at * least for keys which are not hashes). * * We aren't counting 'in' or 'out', we are counting 'high side' * and 'low side' based on the bit at (1LL << keybits). We want * everything to be inside in these cases so shift it all to * the low or high side depending on the new high bit. */ while (((hammer2_key_t)1 << keybits) < ncount) { ++keybits; if (key & ((hammer2_key_t)1 << keybits)) { hicount += locount; locount = 0; } else { locount += hicount; hicount = 0; } } if (hicount > locount) key |= (hammer2_key_t)1 << keybits; else key &= ~(hammer2_key_t)1 << keybits; *keyp = key; return (keybits); } #else /* * Directory indirect blocks. * * Covers both the inode index (directory of inodes), and directory contents * (filenames hardlinked to inodes). * * Because directory keys are hashed we generally try to cut the space in * half. We accomodate the inode index (which tends to have linearly * increasing inode numbers) by ensuring that the keyspace is at least large * enough to fill up the indirect block being created. */ static int hammer2_chain_indkey_dir(hammer2_chain_t *parent, hammer2_key_t *keyp, int keybits, hammer2_blockref_t *base, int count, int ncount) { hammer2_blockref_t *bref; hammer2_chain_t *chain; hammer2_key_t key_beg; hammer2_key_t key_end; hammer2_key_t key_next; hammer2_key_t key; int nkeybits; int locount; int hicount; int maxloops = 300000; /* * Shortcut if the parent is the inode. In this situation the * parent has 4+1 directory entries and we are creating an indirect * block capable of holding many more. */ if (parent->bref.type == HAMMER2_BREF_TYPE_INODE) { return 63; } key = *keyp; locount = 0; hicount = 0; /* * Calculate the range of keys in the array being careful to skip * slots which are overridden with a deletion. */ key_beg = 0; key_end = HAMMER2_KEY_MAX; hammer2_spin_ex(&parent->core.spin); for (;;) { if (--maxloops == 0) { panic("indkey_freemap shit %p %p:%d\n", parent, base, count); } chain = hammer2_combined_find(parent, base, count, &key_next, key_beg, key_end, &bref); /* * Exhausted search */ if (bref == NULL) break; /* * Deleted object */ if (chain && (chain->flags & HAMMER2_CHAIN_DELETED)) { if (key_next == 0 || key_next > key_end) break; key_beg = key_next; continue; } /* * Use the full live (not deleted) element for the scan * iteration. HAMMER2 does not allow partial replacements. * * XXX should be built into hammer2_combined_find(). */ key_next = bref->key + ((hammer2_key_t)1 << bref->keybits); /* * Expand our calculated key range (key, keybits) to fit * the scanned key. nkeybits represents the full range * that we will later cut in half (two halves @ nkeybits - 1). */ nkeybits = keybits; if (nkeybits < bref->keybits) { if (bref->keybits > 64) { kprintf("bad bref chain %p bref %p\n", chain, bref); Debugger("fubar"); } nkeybits = bref->keybits; } while (nkeybits < 64 && (~(((hammer2_key_t)1 << nkeybits) - 1) & (key ^ bref->key)) != 0) { ++nkeybits; } /* * If the new key range is larger we have to determine * which side of the new key range the existing keys fall * under by checking the high bit, then collapsing the * locount into the hicount or vise-versa. */ if (keybits != nkeybits) { if (((hammer2_key_t)1 << (nkeybits - 1)) & key) { hicount += locount; locount = 0; } else { locount += hicount; hicount = 0; } keybits = nkeybits; } /* * The newly scanned key will be in the lower half or the * upper half of the (new) key range. */ if (((hammer2_key_t)1 << (nkeybits - 1)) & bref->key) ++hicount; else ++locount; if (key_next == 0) break; key_beg = key_next; } hammer2_spin_unex(&parent->core.spin); bref = NULL; /* now invalid (safety) */ /* * Adjust keybits to represent half of the full range calculated * above (radix 63 max) for our new indirect block. */ --keybits; /* * Expand keybits to hold at least ncount elements. ncount will be * a power of 2. This is to try to completely fill leaf nodes (at * least for keys which are not hashes). * * We aren't counting 'in' or 'out', we are counting 'high side' * and 'low side' based on the bit at (1LL << keybits). We want * everything to be inside in these cases so shift it all to * the low or high side depending on the new high bit. */ while (((hammer2_key_t)1 << keybits) < ncount) { ++keybits; if (key & ((hammer2_key_t)1 << keybits)) { hicount += locount; locount = 0; } else { locount += hicount; hicount = 0; } } if (hicount > locount) key |= (hammer2_key_t)1 << keybits; else key &= ~(hammer2_key_t)1 << keybits; *keyp = key; return (keybits); } #endif /* * Sets CHAIN_DELETED and remove the chain's blockref from the parent if * it exists. * * Both parent and chain must be locked exclusively. * * This function will modify the parent if the blockref requires removal * from the parent's block table. * * This function is NOT recursive. Any entity already pushed into the * chain (such as an inode) may still need visibility into its contents, * as well as the ability to read and modify the contents. For example, * for an unlinked file which is still open. * * Also note that the flusher is responsible for cleaning up empty * indirect blocks. */ int hammer2_chain_delete(hammer2_chain_t *parent, hammer2_chain_t *chain, hammer2_tid_t mtid, int flags) { int error = 0; KKASSERT(hammer2_mtx_owned(&chain->lock)); /* * Nothing to do if already marked. * * We need the spinlock on the core whos RBTREE contains chain * to protect against races. */ if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) { KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 && chain->parent == parent); error = _hammer2_chain_delete_helper(parent, chain, mtid, flags, NULL); } /* * Permanent deletions mark the chain as destroyed. * * NOTE: We do not setflush the chain unless the deletion is * permanent, since the deletion of a chain does not actually * require it to be flushed. */ if (error == 0) { if (flags & HAMMER2_DELETE_PERMANENT) { atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); hammer2_chain_setflush(chain); } } return error; } static int hammer2_chain_delete_obref(hammer2_chain_t *parent, hammer2_chain_t *chain, hammer2_tid_t mtid, int flags, hammer2_blockref_t *obref) { int error = 0; KKASSERT(hammer2_mtx_owned(&chain->lock)); /* * Nothing to do if already marked. * * We need the spinlock on the core whos RBTREE contains chain * to protect against races. */ obref->type = HAMMER2_BREF_TYPE_EMPTY; if ((chain->flags & HAMMER2_CHAIN_DELETED) == 0) { KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0 && chain->parent == parent); error = _hammer2_chain_delete_helper(parent, chain, mtid, flags, obref); } /* * Permanent deletions mark the chain as destroyed. * * NOTE: We do not setflush the chain unless the deletion is * permanent, since the deletion of a chain does not actually * require it to be flushed. */ if (error == 0) { if (flags & HAMMER2_DELETE_PERMANENT) { atomic_set_int(&chain->flags, HAMMER2_CHAIN_DESTROY); hammer2_chain_setflush(chain); } } return error; } /* * Returns the index of the nearest element in the blockref array >= elm. * Returns (count) if no element could be found. * * Sets *key_nextp to the next key for loop purposes but does not modify * it if the next key would be higher than the current value of *key_nextp. * Note that *key_nexp can overflow to 0, which should be tested by the * caller. * * WARNING! Must be called with parent's spinlock held. Spinlock remains * held through the operation. */ static int hammer2_base_find(hammer2_chain_t *parent, hammer2_blockref_t *base, int count, hammer2_key_t *key_nextp, hammer2_key_t key_beg, hammer2_key_t key_end) { hammer2_blockref_t *scan; hammer2_key_t scan_end; int i; int limit; /* * Require the live chain's already have their core's counted * so we can optimize operations. */ KKASSERT(parent->flags & HAMMER2_CHAIN_COUNTEDBREFS); /* * Degenerate case */ if (count == 0 || base == NULL) return(count); /* * Sequential optimization using parent->cache_index. This is * the most likely scenario. * * We can avoid trailing empty entries on live chains, otherwise * we might have to check the whole block array. */ i = parent->cache_index; /* SMP RACE OK */ cpu_ccfence(); limit = parent->core.live_zero; if (i >= limit) i = limit - 1; if (i < 0) i = 0; KKASSERT(i < count); /* * Search backwards */ scan = &base[i]; while (i > 0 && (scan->type == HAMMER2_BREF_TYPE_EMPTY || scan->key > key_beg)) { --scan; --i; } parent->cache_index = i; /* * Search forwards, stop when we find a scan element which * encloses the key or until we know that there are no further * elements. */ while (i < count) { if (scan->type != HAMMER2_BREF_TYPE_EMPTY) { scan_end = scan->key + ((hammer2_key_t)1 << scan->keybits) - 1; if (scan->key > key_beg || scan_end >= key_beg) break; } if (i >= limit) return (count); ++scan; ++i; } if (i != count) { parent->cache_index = i; if (i >= limit) { i = count; } else { scan_end = scan->key + ((hammer2_key_t)1 << scan->keybits); if (scan_end && (*key_nextp > scan_end || *key_nextp == 0)) { *key_nextp = scan_end; } } } return (i); } /* * Do a combined search and return the next match either from the blockref * array or from the in-memory chain. Sets *brefp to the returned bref in * both cases, or sets it to NULL if the search exhausted. Only returns * a non-NULL chain if the search matched from the in-memory chain. * * When no in-memory chain has been found and a non-NULL bref is returned * in *brefp. * * * The returned chain is not locked or referenced. Use the returned bref * to determine if the search exhausted or not. Iterate if the base find * is chosen but matches a deleted chain. * * WARNING! Must be called with parent's spinlock held. Spinlock remains * held through the operation. */ static hammer2_chain_t * hammer2_combined_find(hammer2_chain_t *parent, hammer2_blockref_t *base, int count, hammer2_key_t *key_nextp, hammer2_key_t key_beg, hammer2_key_t key_end, hammer2_blockref_t **brefp) { hammer2_blockref_t *bref; hammer2_chain_t *chain; int i; /* * Lookup in block array and in rbtree. */ *key_nextp = key_end + 1; i = hammer2_base_find(parent, base, count, key_nextp, key_beg, key_end); chain = hammer2_chain_find(parent, key_nextp, key_beg, key_end); /* * Neither matched */ if (i == count && chain == NULL) { *brefp = NULL; return(NULL); } /* * Only chain matched. */ if (i == count) { bref = &chain->bref; goto found; } /* * Only blockref matched. */ if (chain == NULL) { bref = &base[i]; goto found; } /* * Both in-memory and blockref matched, select the nearer element. * * If both are flush with the left-hand side or both are the * same distance away, select the chain. In this situation the * chain must have been loaded from the matching blockmap. */ if ((chain->bref.key <= key_beg && base[i].key <= key_beg) || chain->bref.key == base[i].key) { KKASSERT(chain->bref.key == base[i].key); bref = &chain->bref; goto found; } /* * Select the nearer key */ if (chain->bref.key < base[i].key) { bref = &chain->bref; } else { bref = &base[i]; chain = NULL; } /* * If the bref is out of bounds we've exhausted our search. */ found: if (bref->key > key_end) { *brefp = NULL; chain = NULL; } else { *brefp = bref; } return(chain); } /* * Locate the specified block array element and delete it. The element * must exist. * * The spin lock on the related chain must be held. * * NOTE: live_count was adjusted when the chain was deleted, so it does not * need to be adjusted when we commit the media change. */ void hammer2_base_delete(hammer2_chain_t *parent, hammer2_blockref_t *base, int count, hammer2_chain_t *chain, hammer2_blockref_t *obref) { hammer2_blockref_t *elm = &chain->bref; hammer2_blockref_t *scan; hammer2_key_t key_next; int i; /* * Delete element. Expect the element to exist. * * XXX see caller, flush code not yet sophisticated enough to prevent * re-flushed in some cases. */ key_next = 0; /* max range */ i = hammer2_base_find(parent, base, count, &key_next, elm->key, elm->key); scan = &base[i]; if (i == count || scan->type == HAMMER2_BREF_TYPE_EMPTY || scan->key != elm->key || ((chain->flags & HAMMER2_CHAIN_BLKMAPUPD) == 0 && scan->keybits != elm->keybits)) { hammer2_spin_unex(&parent->core.spin); panic("delete base %p element not found at %d/%d elm %p\n", base, i, count, elm); return; } /* * Update stats and zero the entry. * * NOTE: Handle radix == 0 (0 bytes) case. */ if ((int)(scan->data_off & HAMMER2_OFF_MASK_RADIX)) { parent->bref.embed.stats.data_count -= (hammer2_off_t)1 << (int)(scan->data_off & HAMMER2_OFF_MASK_RADIX); } switch(scan->type) { case HAMMER2_BREF_TYPE_INODE: --parent->bref.embed.stats.inode_count; /* fall through */ case HAMMER2_BREF_TYPE_DATA: if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { atomic_set_int(&chain->flags, HAMMER2_CHAIN_HINT_LEAF_COUNT); } else { if (parent->bref.leaf_count) --parent->bref.leaf_count; } /* fall through */ case HAMMER2_BREF_TYPE_INDIRECT: if (scan->type != HAMMER2_BREF_TYPE_DATA) { parent->bref.embed.stats.data_count -= scan->embed.stats.data_count; parent->bref.embed.stats.inode_count -= scan->embed.stats.inode_count; } if (scan->type == HAMMER2_BREF_TYPE_INODE) break; if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { atomic_set_int(&chain->flags, HAMMER2_CHAIN_HINT_LEAF_COUNT); } else { if (parent->bref.leaf_count <= scan->leaf_count) parent->bref.leaf_count = 0; else parent->bref.leaf_count -= scan->leaf_count; } break; case HAMMER2_BREF_TYPE_DIRENT: if (parent->bref.leaf_count == HAMMER2_BLOCKREF_LEAF_MAX) { atomic_set_int(&chain->flags, HAMMER2_CHAIN_HINT_LEAF_COUNT); } else { if (parent->bref.leaf_count) --parent->bref.leaf_count; } default: break; } if (obref) *obref = *scan; bzero(scan, sizeof(*scan)); /* * We can only optimize parent->core.live_zero for live chains. */ if (parent->core.live_zero == i + 1) { while (--i >= 0 && base[i].type == HAMMER2_BREF_TYPE_EMPTY) ; parent->core.live_zero = i + 1; } /* * Clear appropriate blockmap flags in chain. */ atomic_clear_int(&chain->flags, HAMMER2_CHAIN_BLKMAPPED | HAMMER2_CHAIN_BLKMAPUPD); } /* * Insert the specified element. The block array must not already have the * element and must have space available for the insertion. * * The spin lock on the related chain must be held. * * NOTE: live_count was adjusted when the chain was deleted, so it does not * need to be adjusted when we commit the media change. */ void hammer2_base_insert(hammer2_chain_t *parent, hammer2_blockref_t *base, int count, hammer2_chain_t *chain, hammer2_blockref_t *elm) { hammer2_key_t key_next; hammer2_key_t xkey; int i; int j; int k; int l; int u = 1; /* * Insert new element. Expect the element to not already exist * unless we are replacing it. * * XXX see caller, flush code not yet sophisticated enough to prevent * re-flushed in some cases. */ key_next = 0; /* max range */ i = hammer2_base_find(parent, base, count, &key_next, elm->key, elm->key); /* * Shortcut fill optimization, typical ordered insertion(s) may not * require a search. */ KKASSERT(i >= 0 && i <= count); /* * Set appropriate blockmap flags in chain (if not NULL) */ if (chain) atomic_set_int(&chain->flags, HAMMER2_CHAIN_BLKMAPPED); /* * Update stats and zero the entry */ if ((int)(elm->data_off & HAMMER2_OFF_MASK_RADIX)) { parent->bref.embed.stats.data_count += (hammer2_off_t)1 << (int)(elm->data_off & HAMMER2_OFF_MASK_RADIX); } switch(elm->type) { case HAMMER2_BREF_TYPE_INODE: ++parent->bref.embed.stats.inode_count; /* fall through */ case HAMMER2_BREF_TYPE_DATA: if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX) ++parent->bref.leaf_count; /* fall through */ case HAMMER2_BREF_TYPE_INDIRECT: if (elm->type != HAMMER2_BREF_TYPE_DATA) { parent->bref.embed.stats.data_count += elm->embed.stats.data_count; parent->bref.embed.stats.inode_count += elm->embed.stats.inode_count; } if (elm->type == HAMMER2_BREF_TYPE_INODE) break; if (parent->bref.leaf_count + elm->leaf_count < HAMMER2_BLOCKREF_LEAF_MAX) { parent->bref.leaf_count += elm->leaf_count; } else { parent->bref.leaf_count = HAMMER2_BLOCKREF_LEAF_MAX; } break; case HAMMER2_BREF_TYPE_DIRENT: if (parent->bref.leaf_count != HAMMER2_BLOCKREF_LEAF_MAX) ++parent->bref.leaf_count; break; default: break; } /* * We can only optimize parent->core.live_zero for live chains. */ if (i == count && parent->core.live_zero < count) { i = parent->core.live_zero++; base[i] = *elm; return; } xkey = elm->key + ((hammer2_key_t)1 << elm->keybits) - 1; if (i != count && (base[i].key < elm->key || xkey >= base[i].key)) { hammer2_spin_unex(&parent->core.spin); panic("insert base %p overlapping elements at %d elm %p\n", base, i, elm); } /* * Try to find an empty slot before or after. */ j = i; k = i; while (j > 0 || k < count) { --j; if (j >= 0 && base[j].type == HAMMER2_BREF_TYPE_EMPTY) { if (j == i - 1) { base[j] = *elm; } else { bcopy(&base[j+1], &base[j], (i - j - 1) * sizeof(*base)); base[i - 1] = *elm; } goto validate; } ++k; if (k < count && base[k].type == HAMMER2_BREF_TYPE_EMPTY) { bcopy(&base[i], &base[i+1], (k - i) * sizeof(hammer2_blockref_t)); base[i] = *elm; /* * We can only update parent->core.live_zero for live * chains. */ if (parent->core.live_zero <= k) parent->core.live_zero = k + 1; u = 2; goto validate; } } panic("hammer2_base_insert: no room!"); /* * Debugging */ validate: key_next = 0; for (l = 0; l < count; ++l) { if (base[l].type != HAMMER2_BREF_TYPE_EMPTY) { key_next = base[l].key + ((hammer2_key_t)1 << base[l].keybits) - 1; break; } } while (++l < count) { if (base[l].type != HAMMER2_BREF_TYPE_EMPTY) { if (base[l].key <= key_next) panic("base_insert %d %d,%d,%d fail %p:%d", u, i, j, k, base, l); key_next = base[l].key + ((hammer2_key_t)1 << base[l].keybits) - 1; } } } #if 0 /* * Sort the blockref array for the chain. Used by the flush code to * sort the blockref[] array. * * The chain must be exclusively locked AND spin-locked. */ typedef hammer2_blockref_t *hammer2_blockref_p; static int hammer2_base_sort_callback(const void *v1, const void *v2) { hammer2_blockref_p bref1 = *(const hammer2_blockref_p *)v1; hammer2_blockref_p bref2 = *(const hammer2_blockref_p *)v2; /* * Make sure empty elements are placed at the end of the array */ if (bref1->type == HAMMER2_BREF_TYPE_EMPTY) { if (bref2->type == HAMMER2_BREF_TYPE_EMPTY) return(0); return(1); } else if (bref2->type == HAMMER2_BREF_TYPE_EMPTY) { return(-1); } /* * Sort by key */ if (bref1->key < bref2->key) return(-1); if (bref1->key > bref2->key) return(1); return(0); } void hammer2_base_sort(hammer2_chain_t *chain) { hammer2_blockref_t *base; int count; switch(chain->bref.type) { case HAMMER2_BREF_TYPE_INODE: /* * Special shortcut for embedded data returns the inode * itself. Callers must detect this condition and access * the embedded data (the strategy code does this for us). * * This is only applicable to regular files and softlinks. */ if (chain->data->ipdata.meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA) { return; } base = &chain->data->ipdata.u.blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP_NODE: case HAMMER2_BREF_TYPE_INDIRECT: /* * Optimize indirect blocks in the INITIAL state to avoid * I/O. */ KKASSERT((chain->flags & HAMMER2_CHAIN_INITIAL) == 0); base = &chain->data->npdata[0]; count = chain->bytes / sizeof(hammer2_blockref_t); break; case HAMMER2_BREF_TYPE_VOLUME: base = &chain->data->voldata.sroot_blockset.blockref[0]; count = HAMMER2_SET_COUNT; break; case HAMMER2_BREF_TYPE_FREEMAP: base = &chain->data->blkset.blockref[0]; count = HAMMER2_SET_COUNT; break; default: panic("hammer2_base_sort: unrecognized " "blockref(A) type: %d", chain->bref.type); base = NULL; /* safety */ count = 0; /* safety */ break; } kqsort(base, count, sizeof(*base), hammer2_base_sort_callback); } #endif /* * Set the check data for a chain. This can be a heavy-weight operation * and typically only runs on-flush. For file data check data is calculated * when the logical buffers are flushed. */ void hammer2_chain_setcheck(hammer2_chain_t *chain, void *bdata) { atomic_clear_int(&chain->flags, HAMMER2_CHAIN_NOTTESTED); switch(HAMMER2_DEC_CHECK(chain->bref.methods)) { case HAMMER2_CHECK_NONE: break; case HAMMER2_CHECK_DISABLED: break; case HAMMER2_CHECK_ISCSI32: chain->bref.check.iscsi32.value = hammer2_icrc32(bdata, chain->bytes); break; case HAMMER2_CHECK_XXHASH64: chain->bref.check.xxhash64.value = XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED); break; case HAMMER2_CHECK_SHA192: { SHA256_CTX hash_ctx; union { uint8_t digest[SHA256_DIGEST_LENGTH]; uint64_t digest64[SHA256_DIGEST_LENGTH/8]; } u; SHA256_Init(&hash_ctx); SHA256_Update(&hash_ctx, bdata, chain->bytes); SHA256_Final(u.digest, &hash_ctx); u.digest64[2] ^= u.digest64[3]; bcopy(u.digest, chain->bref.check.sha192.data, sizeof(chain->bref.check.sha192.data)); } break; case HAMMER2_CHECK_FREEMAP: chain->bref.check.freemap.icrc32 = hammer2_icrc32(bdata, chain->bytes); break; default: kprintf("hammer2_chain_setcheck: unknown check type %02x\n", chain->bref.methods); break; } } /* * Characterize a failed check code and try to trace back to the inode. */ static void hammer2_characterize_failed_chain(hammer2_chain_t *chain, uint64_t check, int bits) { hammer2_chain_t *lchain; hammer2_chain_t *ochain; int did; did = krateprintf(&krate_h2chk, "chain %016jx.%02x (%s) meth=%02x CHECK FAIL " "(flags=%08x, bref/data ", chain->bref.data_off, chain->bref.type, hammer2_bref_type_str(chain->bref.type), chain->bref.methods, chain->flags); if (did == 0) return; if (bits == 32) { kprintf("%08x/%08x)\n", chain->bref.check.iscsi32.value, (uint32_t)check); } else { kprintf("%016jx/%016jx)\n", chain->bref.check.xxhash64.value, check); } /* * Run up the chains to try to find the governing inode so we * can report it. * * XXX This error reporting is not really MPSAFE */ ochain = chain; lchain = chain; while (chain && chain->bref.type != HAMMER2_BREF_TYPE_INODE) { lchain = chain; chain = chain->parent; } if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE && ((chain->bref.flags & HAMMER2_BREF_FLAG_PFSROOT) == 0 || (lchain->bref.key & HAMMER2_DIRHASH_VISIBLE))) { kprintf(" Resides at/in inode %ld\n", (long)chain->bref.key); } else if (chain && chain->bref.type == HAMMER2_BREF_TYPE_INODE) { kprintf(" Resides in inode index - CRITICAL!!!\n"); } else { kprintf(" Resides in root index - CRITICAL!!!\n"); } if (ochain->hmp) { const char *pfsname = "UNKNOWN"; int i; if (ochain->pmp) { for (i = 0; i < HAMMER2_MAXCLUSTER; ++i) { if (ochain->pmp->pfs_hmps[i] == ochain->hmp && ochain->pmp->pfs_names[i]) { pfsname = ochain->pmp->pfs_names[i]; break; } } } kprintf(" In pfs %s on device %s\n", pfsname, ochain->hmp->devrepname); } } /* * Returns non-zero on success, 0 on failure. */ int hammer2_chain_testcheck(hammer2_chain_t *chain, void *bdata) { uint32_t check32; uint64_t check64; int r; if (chain->flags & HAMMER2_CHAIN_NOTTESTED) return 1; switch(HAMMER2_DEC_CHECK(chain->bref.methods)) { case HAMMER2_CHECK_NONE: r = 1; break; case HAMMER2_CHECK_DISABLED: r = 1; break; case HAMMER2_CHECK_ISCSI32: check32 = hammer2_icrc32(bdata, chain->bytes); r = (chain->bref.check.iscsi32.value == check32); if (r == 0) { hammer2_characterize_failed_chain(chain, check32, 32); } hammer2_process_icrc32 += chain->bytes; break; case HAMMER2_CHECK_XXHASH64: check64 = XXH64(bdata, chain->bytes, XXH_HAMMER2_SEED); r = (chain->bref.check.xxhash64.value == check64); if (r == 0) { hammer2_characterize_failed_chain(chain, check64, 64); } hammer2_process_xxhash64 += chain->bytes; break; case HAMMER2_CHECK_SHA192: { SHA256_CTX hash_ctx; union { uint8_t digest[SHA256_DIGEST_LENGTH]; uint64_t digest64[SHA256_DIGEST_LENGTH/8]; } u; SHA256_Init(&hash_ctx); SHA256_Update(&hash_ctx, bdata, chain->bytes); SHA256_Final(u.digest, &hash_ctx); u.digest64[2] ^= u.digest64[3]; if (bcmp(u.digest, chain->bref.check.sha192.data, sizeof(chain->bref.check.sha192.data)) == 0) { r = 1; } else { r = 0; krateprintf(&krate_h2chk, "chain %016jx.%02x meth=%02x " "CHECK FAIL\n", chain->bref.data_off, chain->bref.type, chain->bref.methods); } } break; case HAMMER2_CHECK_FREEMAP: r = (chain->bref.check.freemap.icrc32 == hammer2_icrc32(bdata, chain->bytes)); if (r == 0) { int did; did = krateprintf(&krate_h2chk, "chain %016jx.%02x meth=%02x " "CHECK FAIL\n", chain->bref.data_off, chain->bref.type, chain->bref.methods); if (did) { kprintf("freemap.icrc %08x icrc32 %08x (%d)\n", chain->bref.check.freemap.icrc32, hammer2_icrc32(bdata, chain->bytes), chain->bytes); if (chain->dio) { kprintf("dio %p buf %016jx,%d " "bdata %p/%p\n", chain->dio, (intmax_t)chain->dio->bp->b_loffset, chain->dio->bp->b_bufsize, bdata, chain->dio->bp->b_data); } } } break; default: kprintf("hammer2_chain_testcheck: unknown check type %02x\n", chain->bref.methods); r = 1; break; } return r; } /* * Acquire the chain and parent representing the specified inode for the * device at the specified cluster index. * * The flags passed in are LOOKUP flags, not RESOLVE flags. * * If we are unable to locate the inode, HAMMER2_ERROR_EIO or HAMMER2_ERROR_CHECK * is returned. In case of error, *chainp and/or *parentp may still be returned * non-NULL. * * The caller may pass-in a locked *parentp and/or *chainp, or neither. * They will be unlocked and released by this function. The *parentp and * *chainp representing the located inode are returned locked. * * The returned error includes any error on the returned chain in addition to * errors incurred while trying to lookup the inode. However, a chain->error * might not be recognized if HAMMER2_LOOKUP_NODATA is passed. This flag may * not be passed to this function. */ int hammer2_chain_inode_find(hammer2_pfs_t *pmp, hammer2_key_t inum, int clindex, int flags, hammer2_chain_t **parentp, hammer2_chain_t **chainp) { hammer2_chain_t *parent; hammer2_chain_t *rchain; hammer2_key_t key_dummy; hammer2_inode_t *ip; int resolve_flags; int error; KKASSERT((flags & HAMMER2_LOOKUP_NODATA) == 0); resolve_flags = (flags & HAMMER2_LOOKUP_SHARED) ? HAMMER2_RESOLVE_SHARED : 0; /* * Caller expects us to replace these. */ if (*chainp) { hammer2_chain_unlock(*chainp); hammer2_chain_drop(*chainp); *chainp = NULL; } if (*parentp) { hammer2_chain_unlock(*parentp); hammer2_chain_drop(*parentp); *parentp = NULL; } /* * Be very careful, this is a backend function and we CANNOT * lock any frontend inode structure we find. But we have to * look the inode up this way first in case it exists but is * detached from the radix tree. */ ip = hammer2_inode_lookup(pmp, inum); if (ip) { *chainp = hammer2_inode_chain_and_parent(ip, clindex, parentp, resolve_flags); hammer2_inode_drop(ip); if (*chainp) return (*chainp)->error; hammer2_chain_unlock(*chainp); hammer2_chain_drop(*chainp); *chainp = NULL; if (*parentp) { hammer2_chain_unlock(*parentp); hammer2_chain_drop(*parentp); *parentp = NULL; } } /* * Inodes hang off of the iroot (bit 63 is clear, differentiating * inodes from root directory entries in the key lookup). */ parent = hammer2_inode_chain(pmp->iroot, clindex, resolve_flags); rchain = NULL; if (parent) { /* * NOTE: rchain can be returned as NULL even if error == 0 * (i.e. not found) */ rchain = hammer2_chain_lookup(&parent, &key_dummy, inum, inum, &error, flags); /* * Propagate a chain-specific error to caller. * * If the chain is not errored, we must still validate that the inode * number is correct, because all hell will break loose if it isn't * correct. It should always be correct so print to the console and * simulate a CHECK error if it is not. */ if (error == 0 && rchain) { error = rchain->error; if (error == 0 && rchain->data) { if (inum != rchain->data->ipdata.meta.inum) { kprintf("hammer2_chain_inode_find: lookup inum %ld, " "got valid inode but with inum %ld\n", (long)inum, (long)rchain->data->ipdata.meta.inum); error = HAMMER2_ERROR_CHECK; rchain->error = error; } } } } else { error = HAMMER2_ERROR_EIO; } *parentp = parent; *chainp = rchain; return error; } /* * Used by the bulkscan code to snapshot the synchronized storage for * a volume, allowing it to be scanned concurrently against normal * operation. */ hammer2_chain_t * hammer2_chain_bulksnap(hammer2_dev_t *hmp) { hammer2_chain_t *copy; copy = hammer2_chain_alloc(hmp, hmp->spmp, &hmp->vchain.bref); copy->data = kmalloc(sizeof(copy->data->voldata), hmp->mmsg, M_WAITOK | M_ZERO); hammer2_voldata_lock(hmp); copy->data->voldata = hmp->volsync; hammer2_voldata_unlock(hmp); return copy; } void hammer2_chain_bulkdrop(hammer2_chain_t *copy) { KKASSERT(copy->bref.type == HAMMER2_BREF_TYPE_VOLUME); KKASSERT(copy->data); kfree(copy->data, copy->hmp->mmsg); copy->data = NULL; hammer2_chain_drop(copy); } /* * Returns non-zero if the chain (INODE or DIRENT) matches the * filename. */ int hammer2_chain_dirent_test(hammer2_chain_t *chain, const char *name, size_t name_len) { const hammer2_inode_data_t *ripdata; if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) { ripdata = &chain->data->ipdata; if (ripdata->meta.name_len == name_len && bcmp(ripdata->filename, name, name_len) == 0) { return 1; } } if (chain->bref.type == HAMMER2_BREF_TYPE_DIRENT && chain->bref.embed.dirent.namlen == name_len) { if (name_len > sizeof(chain->bref.check.buf) && bcmp(chain->data->buf, name, name_len) == 0) { return 1; } if (name_len <= sizeof(chain->bref.check.buf) && bcmp(chain->bref.check.buf, name, name_len) == 0) { return 1; } } return 0; } /* * Debugging */ void hammer2_dump_chain(hammer2_chain_t *chain, int tab, int bi, int *countp, char pfx, u_int flags) { hammer2_chain_t *scan; hammer2_chain_t *parent; --*countp; if (*countp == 0) { kprintf("%*.*s...\n", tab, tab, ""); return; } if (*countp < 0) return; kprintf("%*.*s%c-chain %p %s.%-3d %016jx %016jx/%-2d mir=%016jx\n", tab, tab, "", pfx, chain, hammer2_bref_type_str(chain->bref.type), bi, chain->bref.data_off, chain->bref.key, chain->bref.keybits, chain->bref.mirror_tid); kprintf("%*.*s [%08x] (%s) refs=%d", tab, tab, "", chain->flags, ((chain->bref.type == HAMMER2_BREF_TYPE_INODE && chain->data) ? (char *)chain->data->ipdata.filename : "?"), chain->refs); parent = chain->parent; if (parent) kprintf("\n%*.*s p=%p [pflags %08x prefs %d]", tab, tab, "", parent, parent->flags, parent->refs); if (RB_EMPTY(&chain->core.rbtree)) { kprintf("\n"); } else { int bi = 0; kprintf(" {\n"); RB_FOREACH(scan, hammer2_chain_tree, &chain->core.rbtree) { if ((scan->flags & flags) || flags == (u_int)-1) { hammer2_dump_chain(scan, tab + 4, bi, countp, 'a', flags); } bi++; } if (chain->bref.type == HAMMER2_BREF_TYPE_INODE && chain->data) kprintf("%*.*s}(%s)\n", tab, tab, "", chain->data->ipdata.filename); else kprintf("%*.*s}\n", tab, tab, ""); } }