// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2009 Oracle. All rights reserved. */ #include #include #include #include "messages.h" #include "ctree.h" #include "delayed-ref.h" #include "transaction.h" #include "qgroup.h" #include "space-info.h" #include "tree-mod-log.h" #include "fs.h" struct kmem_cache *btrfs_delayed_ref_head_cachep; struct kmem_cache *btrfs_delayed_tree_ref_cachep; struct kmem_cache *btrfs_delayed_data_ref_cachep; struct kmem_cache *btrfs_delayed_extent_op_cachep; /* * delayed back reference update tracking. For subvolume trees * we queue up extent allocations and backref maintenance for * delayed processing. This avoids deep call chains where we * add extents in the middle of btrfs_search_slot, and it allows * us to buffer up frequently modified backrefs in an rb tree instead * of hammering updates on the extent allocation tree. */ bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info) { struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; bool ret = false; u64 reserved; spin_lock(&global_rsv->lock); reserved = global_rsv->reserved; spin_unlock(&global_rsv->lock); /* * Since the global reserve is just kind of magic we don't really want * to rely on it to save our bacon, so if our size is more than the * delayed_refs_rsv and the global rsv then it's time to think about * bailing. */ spin_lock(&delayed_refs_rsv->lock); reserved += delayed_refs_rsv->reserved; if (delayed_refs_rsv->size >= reserved) ret = true; spin_unlock(&delayed_refs_rsv->lock); return ret; } /* * Release a ref head's reservation. * * @fs_info: the filesystem * @nr_refs: number of delayed refs to drop * @nr_csums: number of csum items to drop * * Drops the delayed ref head's count from the delayed refs rsv and free any * excess reservation we had. */ void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr_refs, int nr_csums) { struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv; u64 num_bytes; u64 released; num_bytes = btrfs_calc_delayed_ref_bytes(fs_info, nr_refs); num_bytes += btrfs_calc_delayed_ref_csum_bytes(fs_info, nr_csums); released = btrfs_block_rsv_release(fs_info, block_rsv, num_bytes, NULL); if (released) trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", 0, released, 0); } /* * Adjust the size of the delayed refs rsv. * * This is to be called anytime we may have adjusted trans->delayed_ref_updates * or trans->delayed_ref_csum_deletions, it'll calculate the additional size and * add it to the delayed_refs_rsv. */ void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv; struct btrfs_block_rsv *local_rsv = &trans->delayed_rsv; u64 num_bytes; u64 reserved_bytes; num_bytes = btrfs_calc_delayed_ref_bytes(fs_info, trans->delayed_ref_updates); num_bytes += btrfs_calc_delayed_ref_csum_bytes(fs_info, trans->delayed_ref_csum_deletions); if (num_bytes == 0) return; /* * Try to take num_bytes from the transaction's local delayed reserve. * If not possible, try to take as much as it's available. If the local * reserve doesn't have enough reserved space, the delayed refs reserve * will be refilled next time btrfs_delayed_refs_rsv_refill() is called * by someone or if a transaction commit is triggered before that, the * global block reserve will be used. We want to minimize using the * global block reserve for cases we can account for in advance, to * avoid exhausting it and reach -ENOSPC during a transaction commit. */ spin_lock(&local_rsv->lock); reserved_bytes = min(num_bytes, local_rsv->reserved); local_rsv->reserved -= reserved_bytes; local_rsv->full = (local_rsv->reserved >= local_rsv->size); spin_unlock(&local_rsv->lock); spin_lock(&delayed_rsv->lock); delayed_rsv->size += num_bytes; delayed_rsv->reserved += reserved_bytes; delayed_rsv->full = (delayed_rsv->reserved >= delayed_rsv->size); spin_unlock(&delayed_rsv->lock); trans->delayed_ref_updates = 0; trans->delayed_ref_csum_deletions = 0; } /* * Adjust the size of the delayed refs block reserve for 1 block group item * insertion, used after allocating a block group. */ void btrfs_inc_delayed_refs_rsv_bg_inserts(struct btrfs_fs_info *fs_info) { struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv; spin_lock(&delayed_rsv->lock); /* * Inserting a block group item does not require changing the free space * tree, only the extent tree or the block group tree, so this is all we * need. */ delayed_rsv->size += btrfs_calc_insert_metadata_size(fs_info, 1); delayed_rsv->full = false; spin_unlock(&delayed_rsv->lock); } /* * Adjust the size of the delayed refs block reserve to release space for 1 * block group item insertion. */ void btrfs_dec_delayed_refs_rsv_bg_inserts(struct btrfs_fs_info *fs_info) { struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv; const u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1); u64 released; released = btrfs_block_rsv_release(fs_info, delayed_rsv, num_bytes, NULL); if (released > 0) trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", 0, released, 0); } /* * Adjust the size of the delayed refs block reserve for 1 block group item * update. */ void btrfs_inc_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info) { struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv; spin_lock(&delayed_rsv->lock); /* * Updating a block group item does not result in new nodes/leaves and * does not require changing the free space tree, only the extent tree * or the block group tree, so this is all we need. */ delayed_rsv->size += btrfs_calc_metadata_size(fs_info, 1); delayed_rsv->full = false; spin_unlock(&delayed_rsv->lock); } /* * Adjust the size of the delayed refs block reserve to release space for 1 * block group item update. */ void btrfs_dec_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info) { struct btrfs_block_rsv *delayed_rsv = &fs_info->delayed_refs_rsv; const u64 num_bytes = btrfs_calc_metadata_size(fs_info, 1); u64 released; released = btrfs_block_rsv_release(fs_info, delayed_rsv, num_bytes, NULL); if (released > 0) trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", 0, released, 0); } /* * Transfer bytes to our delayed refs rsv. * * @fs_info: the filesystem * @num_bytes: number of bytes to transfer * * This transfers up to the num_bytes amount, previously reserved, to the * delayed_refs_rsv. Any extra bytes are returned to the space info. */ void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info, u64 num_bytes) { struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; u64 to_free = 0; spin_lock(&delayed_refs_rsv->lock); if (delayed_refs_rsv->size > delayed_refs_rsv->reserved) { u64 delta = delayed_refs_rsv->size - delayed_refs_rsv->reserved; if (num_bytes > delta) { to_free = num_bytes - delta; num_bytes = delta; } } else { to_free = num_bytes; num_bytes = 0; } if (num_bytes) delayed_refs_rsv->reserved += num_bytes; if (delayed_refs_rsv->reserved >= delayed_refs_rsv->size) delayed_refs_rsv->full = true; spin_unlock(&delayed_refs_rsv->lock); if (num_bytes) trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", 0, num_bytes, 1); if (to_free) btrfs_space_info_free_bytes_may_use(fs_info, delayed_refs_rsv->space_info, to_free); } /* * Refill based on our delayed refs usage. * * @fs_info: the filesystem * @flush: control how we can flush for this reservation. * * This will refill the delayed block_rsv up to 1 items size worth of space and * will return -ENOSPC if we can't make the reservation. */ int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info, enum btrfs_reserve_flush_enum flush) { struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv; struct btrfs_space_info *space_info = block_rsv->space_info; u64 limit = btrfs_calc_delayed_ref_bytes(fs_info, 1); u64 num_bytes = 0; u64 refilled_bytes; u64 to_free; int ret = -ENOSPC; spin_lock(&block_rsv->lock); if (block_rsv->reserved < block_rsv->size) { num_bytes = block_rsv->size - block_rsv->reserved; num_bytes = min(num_bytes, limit); } spin_unlock(&block_rsv->lock); if (!num_bytes) return 0; ret = btrfs_reserve_metadata_bytes(fs_info, space_info, num_bytes, flush); if (ret) return ret; /* * We may have raced with someone else, so check again if we the block * reserve is still not full and release any excess space. */ spin_lock(&block_rsv->lock); if (block_rsv->reserved < block_rsv->size) { u64 needed = block_rsv->size - block_rsv->reserved; if (num_bytes >= needed) { block_rsv->reserved += needed; block_rsv->full = true; to_free = num_bytes - needed; refilled_bytes = needed; } else { block_rsv->reserved += num_bytes; to_free = 0; refilled_bytes = num_bytes; } } else { to_free = num_bytes; refilled_bytes = 0; } spin_unlock(&block_rsv->lock); if (to_free > 0) btrfs_space_info_free_bytes_may_use(fs_info, space_info, to_free); if (refilled_bytes > 0) trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", 0, refilled_bytes, 1); return 0; } /* * compare two delayed tree backrefs with same bytenr and type */ static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref1, struct btrfs_delayed_tree_ref *ref2) { if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) { if (ref1->root < ref2->root) return -1; if (ref1->root > ref2->root) return 1; } else { if (ref1->parent < ref2->parent) return -1; if (ref1->parent > ref2->parent) return 1; } return 0; } /* * compare two delayed data backrefs with same bytenr and type */ static int comp_data_refs(struct btrfs_delayed_data_ref *ref1, struct btrfs_delayed_data_ref *ref2) { if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) { if (ref1->root < ref2->root) return -1; if (ref1->root > ref2->root) return 1; if (ref1->objectid < ref2->objectid) return -1; if (ref1->objectid > ref2->objectid) return 1; if (ref1->offset < ref2->offset) return -1; if (ref1->offset > ref2->offset) return 1; } else { if (ref1->parent < ref2->parent) return -1; if (ref1->parent > ref2->parent) return 1; } return 0; } static int comp_refs(struct btrfs_delayed_ref_node *ref1, struct btrfs_delayed_ref_node *ref2, bool check_seq) { int ret = 0; if (ref1->type < ref2->type) return -1; if (ref1->type > ref2->type) return 1; if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY || ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) ret = comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref1), btrfs_delayed_node_to_tree_ref(ref2)); else ret = comp_data_refs(btrfs_delayed_node_to_data_ref(ref1), btrfs_delayed_node_to_data_ref(ref2)); if (ret) return ret; if (check_seq) { if (ref1->seq < ref2->seq) return -1; if (ref1->seq > ref2->seq) return 1; } return 0; } /* insert a new ref to head ref rbtree */ static struct btrfs_delayed_ref_head *htree_insert(struct rb_root_cached *root, struct rb_node *node) { struct rb_node **p = &root->rb_root.rb_node; struct rb_node *parent_node = NULL; struct btrfs_delayed_ref_head *entry; struct btrfs_delayed_ref_head *ins; u64 bytenr; bool leftmost = true; ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node); bytenr = ins->bytenr; while (*p) { parent_node = *p; entry = rb_entry(parent_node, struct btrfs_delayed_ref_head, href_node); if (bytenr < entry->bytenr) { p = &(*p)->rb_left; } else if (bytenr > entry->bytenr) { p = &(*p)->rb_right; leftmost = false; } else { return entry; } } rb_link_node(node, parent_node, p); rb_insert_color_cached(node, root, leftmost); return NULL; } static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root, struct btrfs_delayed_ref_node *ins) { struct rb_node **p = &root->rb_root.rb_node; struct rb_node *node = &ins->ref_node; struct rb_node *parent_node = NULL; struct btrfs_delayed_ref_node *entry; bool leftmost = true; while (*p) { int comp; parent_node = *p; entry = rb_entry(parent_node, struct btrfs_delayed_ref_node, ref_node); comp = comp_refs(ins, entry, true); if (comp < 0) { p = &(*p)->rb_left; } else if (comp > 0) { p = &(*p)->rb_right; leftmost = false; } else { return entry; } } rb_link_node(node, parent_node, p); rb_insert_color_cached(node, root, leftmost); return NULL; } static struct btrfs_delayed_ref_head *find_first_ref_head( struct btrfs_delayed_ref_root *dr) { struct rb_node *n; struct btrfs_delayed_ref_head *entry; n = rb_first_cached(&dr->href_root); if (!n) return NULL; entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node); return entry; } /* * Find a head entry based on bytenr. This returns the delayed ref head if it * was able to find one, or NULL if nothing was in that spot. If return_bigger * is given, the next bigger entry is returned if no exact match is found. */ static struct btrfs_delayed_ref_head *find_ref_head( struct btrfs_delayed_ref_root *dr, u64 bytenr, bool return_bigger) { struct rb_root *root = &dr->href_root.rb_root; struct rb_node *n; struct btrfs_delayed_ref_head *entry; n = root->rb_node; entry = NULL; while (n) { entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node); if (bytenr < entry->bytenr) n = n->rb_left; else if (bytenr > entry->bytenr) n = n->rb_right; else return entry; } if (entry && return_bigger) { if (bytenr > entry->bytenr) { n = rb_next(&entry->href_node); if (!n) return NULL; entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node); } return entry; } return NULL; } int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs, struct btrfs_delayed_ref_head *head) { lockdep_assert_held(&delayed_refs->lock); if (mutex_trylock(&head->mutex)) return 0; refcount_inc(&head->refs); spin_unlock(&delayed_refs->lock); mutex_lock(&head->mutex); spin_lock(&delayed_refs->lock); if (RB_EMPTY_NODE(&head->href_node)) { mutex_unlock(&head->mutex); btrfs_put_delayed_ref_head(head); return -EAGAIN; } btrfs_put_delayed_ref_head(head); return 0; } static inline void drop_delayed_ref(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_root *delayed_refs, struct btrfs_delayed_ref_head *head, struct btrfs_delayed_ref_node *ref) { lockdep_assert_held(&head->lock); rb_erase_cached(&ref->ref_node, &head->ref_tree); RB_CLEAR_NODE(&ref->ref_node); if (!list_empty(&ref->add_list)) list_del(&ref->add_list); btrfs_put_delayed_ref(ref); atomic_dec(&delayed_refs->num_entries); btrfs_delayed_refs_rsv_release(fs_info, 1, 0); } static bool merge_ref(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_root *delayed_refs, struct btrfs_delayed_ref_head *head, struct btrfs_delayed_ref_node *ref, u64 seq) { struct btrfs_delayed_ref_node *next; struct rb_node *node = rb_next(&ref->ref_node); bool done = false; while (!done && node) { int mod; next = rb_entry(node, struct btrfs_delayed_ref_node, ref_node); node = rb_next(node); if (seq && next->seq >= seq) break; if (comp_refs(ref, next, false)) break; if (ref->action == next->action) { mod = next->ref_mod; } else { if (ref->ref_mod < next->ref_mod) { swap(ref, next); done = true; } mod = -next->ref_mod; } drop_delayed_ref(fs_info, delayed_refs, head, next); ref->ref_mod += mod; if (ref->ref_mod == 0) { drop_delayed_ref(fs_info, delayed_refs, head, ref); done = true; } else { /* * Can't have multiples of the same ref on a tree block. */ WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY || ref->type == BTRFS_SHARED_BLOCK_REF_KEY); } } return done; } void btrfs_merge_delayed_refs(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_root *delayed_refs, struct btrfs_delayed_ref_head *head) { struct btrfs_delayed_ref_node *ref; struct rb_node *node; u64 seq = 0; lockdep_assert_held(&head->lock); if (RB_EMPTY_ROOT(&head->ref_tree.rb_root)) return; /* We don't have too many refs to merge for data. */ if (head->is_data) return; seq = btrfs_tree_mod_log_lowest_seq(fs_info); again: for (node = rb_first_cached(&head->ref_tree); node; node = rb_next(node)) { ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node); if (seq && ref->seq >= seq) continue; if (merge_ref(fs_info, delayed_refs, head, ref, seq)) goto again; } } int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq) { int ret = 0; u64 min_seq = btrfs_tree_mod_log_lowest_seq(fs_info); if (min_seq != 0 && seq >= min_seq) { btrfs_debug(fs_info, "holding back delayed_ref %llu, lowest is %llu", seq, min_seq); ret = 1; } return ret; } struct btrfs_delayed_ref_head *btrfs_select_ref_head( struct btrfs_delayed_ref_root *delayed_refs) { struct btrfs_delayed_ref_head *head; lockdep_assert_held(&delayed_refs->lock); again: head = find_ref_head(delayed_refs, delayed_refs->run_delayed_start, true); if (!head && delayed_refs->run_delayed_start != 0) { delayed_refs->run_delayed_start = 0; head = find_first_ref_head(delayed_refs); } if (!head) return NULL; while (head->processing) { struct rb_node *node; node = rb_next(&head->href_node); if (!node) { if (delayed_refs->run_delayed_start == 0) return NULL; delayed_refs->run_delayed_start = 0; goto again; } head = rb_entry(node, struct btrfs_delayed_ref_head, href_node); } head->processing = true; WARN_ON(delayed_refs->num_heads_ready == 0); delayed_refs->num_heads_ready--; delayed_refs->run_delayed_start = head->bytenr + head->num_bytes; return head; } void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs, struct btrfs_delayed_ref_head *head) { lockdep_assert_held(&delayed_refs->lock); lockdep_assert_held(&head->lock); rb_erase_cached(&head->href_node, &delayed_refs->href_root); RB_CLEAR_NODE(&head->href_node); atomic_dec(&delayed_refs->num_entries); delayed_refs->num_heads--; if (!head->processing) delayed_refs->num_heads_ready--; } /* * Helper to insert the ref_node to the tail or merge with tail. * * Return false if the ref was inserted. * Return true if the ref was merged into an existing one (and therefore can be * freed by the caller). */ static bool insert_delayed_ref(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *href, struct btrfs_delayed_ref_node *ref) { struct btrfs_delayed_ref_root *root = &trans->transaction->delayed_refs; struct btrfs_delayed_ref_node *exist; int mod; spin_lock(&href->lock); exist = tree_insert(&href->ref_tree, ref); if (!exist) { if (ref->action == BTRFS_ADD_DELAYED_REF) list_add_tail(&ref->add_list, &href->ref_add_list); atomic_inc(&root->num_entries); spin_unlock(&href->lock); trans->delayed_ref_updates++; return false; } /* Now we are sure we can merge */ if (exist->action == ref->action) { mod = ref->ref_mod; } else { /* Need to change action */ if (exist->ref_mod < ref->ref_mod) { exist->action = ref->action; mod = -exist->ref_mod; exist->ref_mod = ref->ref_mod; if (ref->action == BTRFS_ADD_DELAYED_REF) list_add_tail(&exist->add_list, &href->ref_add_list); else if (ref->action == BTRFS_DROP_DELAYED_REF) { ASSERT(!list_empty(&exist->add_list)); list_del(&exist->add_list); } else { ASSERT(0); } } else mod = -ref->ref_mod; } exist->ref_mod += mod; /* remove existing tail if its ref_mod is zero */ if (exist->ref_mod == 0) drop_delayed_ref(trans->fs_info, root, href, exist); spin_unlock(&href->lock); return true; } /* * helper function to update the accounting in the head ref * existing and update must have the same bytenr */ static noinline void update_existing_head_ref(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *existing, struct btrfs_delayed_ref_head *update) { struct btrfs_delayed_ref_root *delayed_refs = &trans->transaction->delayed_refs; struct btrfs_fs_info *fs_info = trans->fs_info; int old_ref_mod; BUG_ON(existing->is_data != update->is_data); spin_lock(&existing->lock); /* * When freeing an extent, we may not know the owning root when we * first create the head_ref. However, some deref before the last deref * will know it, so we just need to update the head_ref accordingly. */ if (!existing->owning_root) existing->owning_root = update->owning_root; if (update->must_insert_reserved) { /* if the extent was freed and then * reallocated before the delayed ref * entries were processed, we can end up * with an existing head ref without * the must_insert_reserved flag set. * Set it again here */ existing->must_insert_reserved = update->must_insert_reserved; existing->owning_root = update->owning_root; /* * update the num_bytes so we make sure the accounting * is done correctly */ existing->num_bytes = update->num_bytes; } if (update->extent_op) { if (!existing->extent_op) { existing->extent_op = update->extent_op; } else { if (update->extent_op->update_key) { memcpy(&existing->extent_op->key, &update->extent_op->key, sizeof(update->extent_op->key)); existing->extent_op->update_key = true; } if (update->extent_op->update_flags) { existing->extent_op->flags_to_set |= update->extent_op->flags_to_set; existing->extent_op->update_flags = true; } btrfs_free_delayed_extent_op(update->extent_op); } } /* * update the reference mod on the head to reflect this new operation, * only need the lock for this case cause we could be processing it * currently, for refs we just added we know we're a-ok. */ old_ref_mod = existing->total_ref_mod; existing->ref_mod += update->ref_mod; existing->total_ref_mod += update->ref_mod; /* * If we are going to from a positive ref mod to a negative or vice * versa we need to make sure to adjust pending_csums accordingly. * We reserve bytes for csum deletion when adding or updating a ref head * see add_delayed_ref_head() for more details. */ if (existing->is_data) { u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, existing->num_bytes); if (existing->total_ref_mod >= 0 && old_ref_mod < 0) { delayed_refs->pending_csums -= existing->num_bytes; btrfs_delayed_refs_rsv_release(fs_info, 0, csum_leaves); } if (existing->total_ref_mod < 0 && old_ref_mod >= 0) { delayed_refs->pending_csums += existing->num_bytes; trans->delayed_ref_csum_deletions += csum_leaves; } } spin_unlock(&existing->lock); } static void init_delayed_ref_head(struct btrfs_delayed_ref_head *head_ref, struct btrfs_qgroup_extent_record *qrecord, u64 bytenr, u64 num_bytes, u64 ref_root, u64 reserved, int action, bool is_data, bool is_system, u64 owning_root) { int count_mod = 1; bool must_insert_reserved = false; /* If reserved is provided, it must be a data extent. */ BUG_ON(!is_data && reserved); switch (action) { case BTRFS_UPDATE_DELAYED_HEAD: count_mod = 0; break; case BTRFS_DROP_DELAYED_REF: /* * The head node stores the sum of all the mods, so dropping a ref * should drop the sum in the head node by one. */ count_mod = -1; break; case BTRFS_ADD_DELAYED_EXTENT: /* * BTRFS_ADD_DELAYED_EXTENT means that we need to update the * reserved accounting when the extent is finally added, or if a * later modification deletes the delayed ref without ever * inserting the extent into the extent allocation tree. * ref->must_insert_reserved is the flag used to record that * accounting mods are required. * * Once we record must_insert_reserved, switch the action to * BTRFS_ADD_DELAYED_REF because other special casing is not * required. */ must_insert_reserved = true; break; } refcount_set(&head_ref->refs, 1); head_ref->bytenr = bytenr; head_ref->num_bytes = num_bytes; head_ref->ref_mod = count_mod; head_ref->reserved_bytes = reserved; head_ref->must_insert_reserved = must_insert_reserved; head_ref->owning_root = owning_root; head_ref->is_data = is_data; head_ref->is_system = is_system; head_ref->ref_tree = RB_ROOT_CACHED; INIT_LIST_HEAD(&head_ref->ref_add_list); RB_CLEAR_NODE(&head_ref->href_node); head_ref->processing = false; head_ref->total_ref_mod = count_mod; spin_lock_init(&head_ref->lock); mutex_init(&head_ref->mutex); if (qrecord) { if (ref_root && reserved) { qrecord->data_rsv = reserved; qrecord->data_rsv_refroot = ref_root; } qrecord->bytenr = bytenr; qrecord->num_bytes = num_bytes; qrecord->old_roots = NULL; } } /* * helper function to actually insert a head node into the rbtree. * this does all the dirty work in terms of maintaining the correct * overall modification count. */ static noinline struct btrfs_delayed_ref_head * add_delayed_ref_head(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *head_ref, struct btrfs_qgroup_extent_record *qrecord, int action, bool *qrecord_inserted_ret) { struct btrfs_delayed_ref_head *existing; struct btrfs_delayed_ref_root *delayed_refs; bool qrecord_inserted = false; delayed_refs = &trans->transaction->delayed_refs; /* Record qgroup extent info if provided */ if (qrecord) { if (btrfs_qgroup_trace_extent_nolock(trans->fs_info, delayed_refs, qrecord)) kfree(qrecord); else qrecord_inserted = true; } trace_add_delayed_ref_head(trans->fs_info, head_ref, action); existing = htree_insert(&delayed_refs->href_root, &head_ref->href_node); if (existing) { update_existing_head_ref(trans, existing, head_ref); /* * we've updated the existing ref, free the newly * allocated ref */ kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref); head_ref = existing; } else { /* * We reserve the amount of bytes needed to delete csums when * adding the ref head and not when adding individual drop refs * since the csum items are deleted only after running the last * delayed drop ref (the data extent's ref count drops to 0). */ if (head_ref->is_data && head_ref->ref_mod < 0) { delayed_refs->pending_csums += head_ref->num_bytes; trans->delayed_ref_csum_deletions += btrfs_csum_bytes_to_leaves(trans->fs_info, head_ref->num_bytes); } delayed_refs->num_heads++; delayed_refs->num_heads_ready++; atomic_inc(&delayed_refs->num_entries); } if (qrecord_inserted_ret) *qrecord_inserted_ret = qrecord_inserted; return head_ref; } /* * Initialize the structure which represents a modification to a an extent. * * @fs_info: Internal to the mounted filesystem mount structure. * * @ref: The structure which is going to be initialized. * * @bytenr: The logical address of the extent for which a modification is * going to be recorded. * * @num_bytes: Size of the extent whose modification is being recorded. * * @ref_root: The id of the root where this modification has originated, this * can be either one of the well-known metadata trees or the * subvolume id which references this extent. * * @action: Can be one of BTRFS_ADD_DELAYED_REF/BTRFS_DROP_DELAYED_REF or * BTRFS_ADD_DELAYED_EXTENT * * @ref_type: Holds the type of the extent which is being recorded, can be * one of BTRFS_SHARED_BLOCK_REF_KEY/BTRFS_TREE_BLOCK_REF_KEY * when recording a metadata extent or BTRFS_SHARED_DATA_REF_KEY/ * BTRFS_EXTENT_DATA_REF_KEY when recording data extent */ static void init_delayed_ref_common(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_node *ref, u64 bytenr, u64 num_bytes, u64 ref_root, int action, u8 ref_type) { u64 seq = 0; if (action == BTRFS_ADD_DELAYED_EXTENT) action = BTRFS_ADD_DELAYED_REF; if (is_fstree(ref_root)) seq = atomic64_read(&fs_info->tree_mod_seq); refcount_set(&ref->refs, 1); ref->bytenr = bytenr; ref->num_bytes = num_bytes; ref->ref_mod = 1; ref->action = action; ref->seq = seq; ref->type = ref_type; RB_CLEAR_NODE(&ref->ref_node); INIT_LIST_HEAD(&ref->add_list); } /* * add a delayed tree ref. This does all of the accounting required * to make sure the delayed ref is eventually processed before this * transaction commits. */ int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans, struct btrfs_ref *generic_ref, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_delayed_tree_ref *ref; struct btrfs_delayed_ref_head *head_ref; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_qgroup_extent_record *record = NULL; bool qrecord_inserted; bool is_system; bool merged; int action = generic_ref->action; int level = generic_ref->tree_ref.level; u64 bytenr = generic_ref->bytenr; u64 num_bytes = generic_ref->len; u64 parent = generic_ref->parent; u8 ref_type; is_system = (generic_ref->tree_ref.ref_root == BTRFS_CHUNK_TREE_OBJECTID); ASSERT(generic_ref->type == BTRFS_REF_METADATA && generic_ref->action); ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS); if (!ref) return -ENOMEM; head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS); if (!head_ref) { kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref); return -ENOMEM; } if (btrfs_qgroup_full_accounting(fs_info) && !generic_ref->skip_qgroup) { record = kzalloc(sizeof(*record), GFP_NOFS); if (!record) { kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref); kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref); return -ENOMEM; } } if (parent) ref_type = BTRFS_SHARED_BLOCK_REF_KEY; else ref_type = BTRFS_TREE_BLOCK_REF_KEY; init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes, generic_ref->tree_ref.ref_root, action, ref_type); ref->root = generic_ref->tree_ref.ref_root; ref->parent = parent; ref->level = level; init_delayed_ref_head(head_ref, record, bytenr, num_bytes, generic_ref->tree_ref.ref_root, 0, action, false, is_system, generic_ref->owning_root); head_ref->extent_op = extent_op; delayed_refs = &trans->transaction->delayed_refs; spin_lock(&delayed_refs->lock); /* * insert both the head node and the new ref without dropping * the spin lock */ head_ref = add_delayed_ref_head(trans, head_ref, record, action, &qrecord_inserted); merged = insert_delayed_ref(trans, head_ref, &ref->node); spin_unlock(&delayed_refs->lock); /* * Need to update the delayed_refs_rsv with any changes we may have * made. */ btrfs_update_delayed_refs_rsv(trans); trace_add_delayed_tree_ref(fs_info, &ref->node, ref, action == BTRFS_ADD_DELAYED_EXTENT ? BTRFS_ADD_DELAYED_REF : action); if (merged) kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref); if (qrecord_inserted) btrfs_qgroup_trace_extent_post(trans, record); return 0; } /* * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref. */ int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans, struct btrfs_ref *generic_ref, u64 reserved) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_delayed_data_ref *ref; struct btrfs_delayed_ref_head *head_ref; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_qgroup_extent_record *record = NULL; bool qrecord_inserted; int action = generic_ref->action; bool merged; u64 bytenr = generic_ref->bytenr; u64 num_bytes = generic_ref->len; u64 parent = generic_ref->parent; u64 ref_root = generic_ref->data_ref.ref_root; u64 owner = generic_ref->data_ref.ino; u64 offset = generic_ref->data_ref.offset; u8 ref_type; ASSERT(generic_ref->type == BTRFS_REF_DATA && action); ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS); if (!ref) return -ENOMEM; if (parent) ref_type = BTRFS_SHARED_DATA_REF_KEY; else ref_type = BTRFS_EXTENT_DATA_REF_KEY; init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes, ref_root, action, ref_type); ref->root = ref_root; ref->parent = parent; ref->objectid = owner; ref->offset = offset; head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS); if (!head_ref) { kmem_cache_free(btrfs_delayed_data_ref_cachep, ref); return -ENOMEM; } if (btrfs_qgroup_full_accounting(fs_info) && !generic_ref->skip_qgroup) { record = kzalloc(sizeof(*record), GFP_NOFS); if (!record) { kmem_cache_free(btrfs_delayed_data_ref_cachep, ref); kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref); return -ENOMEM; } } init_delayed_ref_head(head_ref, record, bytenr, num_bytes, ref_root, reserved, action, true, false, generic_ref->owning_root); head_ref->extent_op = NULL; delayed_refs = &trans->transaction->delayed_refs; spin_lock(&delayed_refs->lock); /* * insert both the head node and the new ref without dropping * the spin lock */ head_ref = add_delayed_ref_head(trans, head_ref, record, action, &qrecord_inserted); merged = insert_delayed_ref(trans, head_ref, &ref->node); spin_unlock(&delayed_refs->lock); /* * Need to update the delayed_refs_rsv with any changes we may have * made. */ btrfs_update_delayed_refs_rsv(trans); trace_add_delayed_data_ref(trans->fs_info, &ref->node, ref, action == BTRFS_ADD_DELAYED_EXTENT ? BTRFS_ADD_DELAYED_REF : action); if (merged) kmem_cache_free(btrfs_delayed_data_ref_cachep, ref); if (qrecord_inserted) return btrfs_qgroup_trace_extent_post(trans, record); return 0; } int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_delayed_ref_head *head_ref; struct btrfs_delayed_ref_root *delayed_refs; head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS); if (!head_ref) return -ENOMEM; init_delayed_ref_head(head_ref, NULL, bytenr, num_bytes, 0, 0, BTRFS_UPDATE_DELAYED_HEAD, false, false, 0); head_ref->extent_op = extent_op; delayed_refs = &trans->transaction->delayed_refs; spin_lock(&delayed_refs->lock); add_delayed_ref_head(trans, head_ref, NULL, BTRFS_UPDATE_DELAYED_HEAD, NULL); spin_unlock(&delayed_refs->lock); /* * Need to update the delayed_refs_rsv with any changes we may have * made. */ btrfs_update_delayed_refs_rsv(trans); return 0; } /* * This does a simple search for the head node for a given extent. Returns the * head node if found, or NULL if not. */ struct btrfs_delayed_ref_head * btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr) { lockdep_assert_held(&delayed_refs->lock); return find_ref_head(delayed_refs, bytenr, false); } void __cold btrfs_delayed_ref_exit(void) { kmem_cache_destroy(btrfs_delayed_ref_head_cachep); kmem_cache_destroy(btrfs_delayed_tree_ref_cachep); kmem_cache_destroy(btrfs_delayed_data_ref_cachep); kmem_cache_destroy(btrfs_delayed_extent_op_cachep); } int __init btrfs_delayed_ref_init(void) { btrfs_delayed_ref_head_cachep = kmem_cache_create( "btrfs_delayed_ref_head", sizeof(struct btrfs_delayed_ref_head), 0, SLAB_MEM_SPREAD, NULL); if (!btrfs_delayed_ref_head_cachep) goto fail; btrfs_delayed_tree_ref_cachep = kmem_cache_create( "btrfs_delayed_tree_ref", sizeof(struct btrfs_delayed_tree_ref), 0, SLAB_MEM_SPREAD, NULL); if (!btrfs_delayed_tree_ref_cachep) goto fail; btrfs_delayed_data_ref_cachep = kmem_cache_create( "btrfs_delayed_data_ref", sizeof(struct btrfs_delayed_data_ref), 0, SLAB_MEM_SPREAD, NULL); if (!btrfs_delayed_data_ref_cachep) goto fail; btrfs_delayed_extent_op_cachep = kmem_cache_create( "btrfs_delayed_extent_op", sizeof(struct btrfs_delayed_extent_op), 0, SLAB_MEM_SPREAD, NULL); if (!btrfs_delayed_extent_op_cachep) goto fail; return 0; fail: btrfs_delayed_ref_exit(); return -ENOMEM; }