diff options
Diffstat (limited to '')
| -rw-r--r-- | fs/btrfs/delayed-ref.c | 1171 |
1 files changed, 1171 insertions, 0 deletions
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c new file mode 100644 index 000000000..e08e3852c --- /dev/null +++ b/fs/btrfs/delayed-ref.c @@ -0,0 +1,1171 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2009 Oracle. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/sort.h> +#include "ctree.h" +#include "delayed-ref.h" +#include "transaction.h" +#include "qgroup.h" +#include "space-info.h" +#include "tree-mod-log.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; +} + +int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans) +{ + u64 num_entries = + atomic_read(&trans->transaction->delayed_refs.num_entries); + u64 avg_runtime; + u64 val; + + smp_mb(); + avg_runtime = trans->fs_info->avg_delayed_ref_runtime; + val = num_entries * avg_runtime; + if (val >= NSEC_PER_SEC) + return 1; + if (val >= NSEC_PER_SEC / 2) + return 2; + + return btrfs_check_space_for_delayed_refs(trans->fs_info); +} + +/** + * Release a ref head's reservation + * + * @fs_info: the filesystem + * @nr: number of items to drop + * + * This drops the delayed ref head's count from the delayed refs rsv and frees + * any excess reservation we had. + */ +void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr) +{ + struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv; + u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, nr); + u64 released = 0; + + /* + * We have to check the mount option here because we could be enabling + * the free space tree for the first time and don't have the compat_ro + * option set yet. + * + * We need extra reservations if we have the free space tree because + * we'll have to modify that tree as well. + */ + if (btrfs_test_opt(fs_info, FREE_SPACE_TREE)) + num_bytes *= 2; + + 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); +} + +/* + * btrfs_update_delayed_refs_rsv - adjust the size of the delayed refs rsv + * @trans - the trans that may have generated delayed refs + * + * This is to be called anytime we may have adjusted trans->delayed_ref_updates, + * 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; + u64 num_bytes; + + if (!trans->delayed_ref_updates) + return; + + num_bytes = btrfs_calc_insert_metadata_size(fs_info, + trans->delayed_ref_updates); + /* + * We have to check the mount option here because we could be enabling + * the free space tree for the first time and don't have the compat_ro + * option set yet. + * + * We need extra reservations if we have the free space tree because + * we'll have to modify that tree as well. + */ + if (btrfs_test_opt(fs_info, FREE_SPACE_TREE)) + num_bytes *= 2; + + spin_lock(&delayed_rsv->lock); + delayed_rsv->size += num_bytes; + delayed_rsv->full = false; + spin_unlock(&delayed_rsv->lock); + trans->delayed_ref_updates = 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; + u64 limit = btrfs_calc_insert_metadata_size(fs_info, 1); + u64 num_bytes = 0; + 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, block_rsv, num_bytes, flush); + if (ret) + return ret; + btrfs_block_rsv_add_bytes(block_rsv, num_bytes, 0); + trace_btrfs_space_reservation(fs_info, "delayed_refs_rsv", + 0, num_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_trans_handle *trans, + 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); + ref->in_tree = 0; + btrfs_put_delayed_ref(ref); + atomic_dec(&delayed_refs->num_entries); +} + +static bool merge_ref(struct btrfs_trans_handle *trans, + 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(trans, delayed_refs, head, next); + ref->ref_mod += mod; + if (ref->ref_mod == 0) { + drop_delayed_ref(trans, 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_trans_handle *trans, + struct btrfs_delayed_ref_root *delayed_refs, + struct btrfs_delayed_ref_head *head) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + 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(trans, 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; + +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 = 1; + 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 == 0) + delayed_refs->num_heads_ready--; +} + +/* + * Helper to insert the ref_node to the tail or merge with tail. + * + * Return 0 for insert. + * Return >0 for merge. + */ +static int insert_delayed_ref(struct btrfs_trans_handle *trans, + struct btrfs_delayed_ref_root *root, + struct btrfs_delayed_ref_head *href, + struct btrfs_delayed_ref_node *ref) +{ + struct btrfs_delayed_ref_node *exist; + int mod; + int ret = 0; + + spin_lock(&href->lock); + exist = tree_insert(&href->ref_tree, ref); + if (!exist) + goto inserted; + + /* Now we are sure we can merge */ + ret = 1; + 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, root, href, exist); + spin_unlock(&href->lock); + return ret; +inserted: + 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); + return ret; +} + +/* + * 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); + 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; + + /* + * 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. + */ + 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, csum_leaves); + } + if (existing->total_ref_mod < 0 && old_ref_mod >= 0) { + delayed_refs->pending_csums += existing->num_bytes; + trans->delayed_ref_updates += 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) +{ + int count_mod = 1; + int must_insert_reserved = 0; + + /* If reserved is provided, it must be a data extent. */ + BUG_ON(!is_data && reserved); + + /* + * The head node stores the sum of all the mods, so dropping a ref + * should drop the sum in the head node by one. + */ + if (action == BTRFS_UPDATE_DELAYED_HEAD) + count_mod = 0; + else if (action == BTRFS_DROP_DELAYED_REF) + count_mod = -1; + + /* + * 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. + */ + if (action == BTRFS_ADD_DELAYED_EXTENT) + must_insert_reserved = 1; + else + must_insert_reserved = 0; + + refcount_set(&head_ref->refs, 1); + head_ref->bytenr = bytenr; + head_ref->num_bytes = num_bytes; + head_ref->ref_mod = count_mod; + head_ref->must_insert_reserved = must_insert_reserved; + 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 = 0; + 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, int *qrecord_inserted_ret) +{ + struct btrfs_delayed_ref_head *existing; + struct btrfs_delayed_ref_root *delayed_refs; + int qrecord_inserted = 0; + + 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 = 1; + } + + 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 { + if (head_ref->is_data && head_ref->ref_mod < 0) { + delayed_refs->pending_csums += head_ref->num_bytes; + trans->delayed_ref_updates += + 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); + trans->delayed_ref_updates++; + } + if (qrecord_inserted_ret) + *qrecord_inserted_ret = qrecord_inserted; + + return head_ref; +} + +/* + * init_delayed_ref_common - 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->is_head = 0; + ref->in_tree = 1; + 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; + int qrecord_inserted; + bool is_system; + int action = generic_ref->action; + int level = generic_ref->tree_ref.level; + int ret; + 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.owning_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 (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) && + !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.owning_root, action, + ref_type); + ref->root = generic_ref->tree_ref.owning_root; + ref->parent = parent; + ref->level = level; + + init_delayed_ref_head(head_ref, record, bytenr, num_bytes, + generic_ref->tree_ref.owning_root, 0, action, + false, is_system); + 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); + + ret = insert_delayed_ref(trans, delayed_refs, 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 (ret > 0) + 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; + int qrecord_inserted; + int action = generic_ref->action; + int ret; + u64 bytenr = generic_ref->bytenr; + u64 num_bytes = generic_ref->len; + u64 parent = generic_ref->parent; + u64 ref_root = generic_ref->data_ref.owning_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 (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) && + !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); + 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); + + ret = insert_delayed_ref(trans, delayed_refs, 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 (ret > 0) + 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); + 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; +} |