| /* |
| * Copyright (C) 2009 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/sort.h> |
| #include "ctree.h" |
| #include "delayed-ref.h" |
| #include "transaction.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. |
| */ |
| |
| /* |
| * compare two delayed tree backrefs with same bytenr and type |
| */ |
| static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2, |
| struct btrfs_delayed_tree_ref *ref1, int type) |
| { |
| if (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 *ref2, |
| struct btrfs_delayed_data_ref *ref1) |
| { |
| 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; |
| } |
| |
| /* |
| * entries in the rb tree are ordered by the byte number of the extent, |
| * type of the delayed backrefs and content of delayed backrefs. |
| */ |
| static int comp_entry(struct btrfs_delayed_ref_node *ref2, |
| struct btrfs_delayed_ref_node *ref1, |
| bool compare_seq) |
| { |
| if (ref1->bytenr < ref2->bytenr) |
| return -1; |
| if (ref1->bytenr > ref2->bytenr) |
| return 1; |
| if (ref1->is_head && ref2->is_head) |
| return 0; |
| if (ref2->is_head) |
| return -1; |
| if (ref1->is_head) |
| return 1; |
| if (ref1->type < ref2->type) |
| return -1; |
| if (ref1->type > ref2->type) |
| return 1; |
| /* merging of sequenced refs is not allowed */ |
| if (compare_seq) { |
| if (ref1->seq < ref2->seq) |
| return -1; |
| if (ref1->seq > ref2->seq) |
| return 1; |
| } |
| if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY || |
| ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) { |
| return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2), |
| btrfs_delayed_node_to_tree_ref(ref1), |
| ref1->type); |
| } else if (ref1->type == BTRFS_EXTENT_DATA_REF_KEY || |
| ref1->type == BTRFS_SHARED_DATA_REF_KEY) { |
| return comp_data_refs(btrfs_delayed_node_to_data_ref(ref2), |
| btrfs_delayed_node_to_data_ref(ref1)); |
| } |
| BUG(); |
| return 0; |
| } |
| |
| /* |
| * insert a new ref into the rbtree. This returns any existing refs |
| * for the same (bytenr,parent) tuple, or NULL if the new node was properly |
| * inserted. |
| */ |
| static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root, |
| struct rb_node *node) |
| { |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent_node = NULL; |
| struct btrfs_delayed_ref_node *entry; |
| struct btrfs_delayed_ref_node *ins; |
| int cmp; |
| |
| ins = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); |
| while (*p) { |
| parent_node = *p; |
| entry = rb_entry(parent_node, struct btrfs_delayed_ref_node, |
| rb_node); |
| |
| cmp = comp_entry(entry, ins, 1); |
| if (cmp < 0) |
| p = &(*p)->rb_left; |
| else if (cmp > 0) |
| p = &(*p)->rb_right; |
| else |
| return entry; |
| } |
| |
| rb_link_node(node, parent_node, p); |
| rb_insert_color(node, root); |
| return NULL; |
| } |
| |
| /* insert a new ref to head ref rbtree */ |
| static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root, |
| struct rb_node *node) |
| { |
| struct rb_node **p = &root->rb_node; |
| struct rb_node *parent_node = NULL; |
| struct btrfs_delayed_ref_head *entry; |
| struct btrfs_delayed_ref_head *ins; |
| u64 bytenr; |
| |
| ins = rb_entry(node, struct btrfs_delayed_ref_head, href_node); |
| bytenr = ins->node.bytenr; |
| while (*p) { |
| parent_node = *p; |
| entry = rb_entry(parent_node, struct btrfs_delayed_ref_head, |
| href_node); |
| |
| if (bytenr < entry->node.bytenr) |
| p = &(*p)->rb_left; |
| else if (bytenr > entry->node.bytenr) |
| p = &(*p)->rb_right; |
| else |
| return entry; |
| } |
| |
| rb_link_node(node, parent_node, p); |
| rb_insert_color(node, root); |
| return NULL; |
| } |
| |
| /* |
| * find an 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 rb_root *root, u64 bytenr, |
| struct btrfs_delayed_ref_head **last, int return_bigger) |
| { |
| struct rb_node *n; |
| struct btrfs_delayed_ref_head *entry; |
| int cmp = 0; |
| |
| again: |
| n = root->rb_node; |
| entry = NULL; |
| while (n) { |
| entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node); |
| if (last) |
| *last = entry; |
| |
| if (bytenr < entry->node.bytenr) |
| cmp = -1; |
| else if (bytenr > entry->node.bytenr) |
| cmp = 1; |
| else |
| cmp = 0; |
| |
| if (cmp < 0) |
| n = n->rb_left; |
| else if (cmp > 0) |
| n = n->rb_right; |
| else |
| return entry; |
| } |
| if (entry && return_bigger) { |
| if (cmp > 0) { |
| n = rb_next(&entry->href_node); |
| if (!n) |
| n = rb_first(root); |
| entry = rb_entry(n, struct btrfs_delayed_ref_head, |
| href_node); |
| bytenr = entry->node.bytenr; |
| return_bigger = 0; |
| goto again; |
| } |
| return entry; |
| } |
| return NULL; |
| } |
| |
| int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans, |
| struct btrfs_delayed_ref_head *head) |
| { |
| struct btrfs_delayed_ref_root *delayed_refs; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| assert_spin_locked(&delayed_refs->lock); |
| if (mutex_trylock(&head->mutex)) |
| return 0; |
| |
| atomic_inc(&head->node.refs); |
| spin_unlock(&delayed_refs->lock); |
| |
| mutex_lock(&head->mutex); |
| spin_lock(&delayed_refs->lock); |
| if (!head->node.in_tree) { |
| mutex_unlock(&head->mutex); |
| btrfs_put_delayed_ref(&head->node); |
| return -EAGAIN; |
| } |
| btrfs_put_delayed_ref(&head->node); |
| return 0; |
| } |
| |
| static inline void drop_delayed_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_delayed_ref_root *delayed_refs, |
| struct btrfs_delayed_ref_node *ref) |
| { |
| rb_erase(&ref->rb_node, &delayed_refs->root); |
| if (btrfs_delayed_ref_is_head(ref)) { |
| struct btrfs_delayed_ref_head *head; |
| |
| head = btrfs_delayed_node_to_head(ref); |
| rb_erase(&head->href_node, &delayed_refs->href_root); |
| } |
| ref->in_tree = 0; |
| btrfs_put_delayed_ref(ref); |
| delayed_refs->num_entries--; |
| if (trans->delayed_ref_updates) |
| trans->delayed_ref_updates--; |
| } |
| |
| static int merge_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_delayed_ref_root *delayed_refs, |
| struct btrfs_delayed_ref_node *ref, u64 seq) |
| { |
| struct rb_node *node; |
| int merged = 0; |
| int mod = 0; |
| int done = 0; |
| |
| node = rb_prev(&ref->rb_node); |
| while (node) { |
| struct btrfs_delayed_ref_node *next; |
| |
| next = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); |
| node = rb_prev(node); |
| if (next->bytenr != ref->bytenr) |
| break; |
| if (seq && next->seq >= seq) |
| break; |
| if (comp_entry(ref, next, 0)) |
| continue; |
| |
| if (ref->action == next->action) { |
| mod = next->ref_mod; |
| } else { |
| if (ref->ref_mod < next->ref_mod) { |
| struct btrfs_delayed_ref_node *tmp; |
| |
| tmp = ref; |
| ref = next; |
| next = tmp; |
| done = 1; |
| } |
| mod = -next->ref_mod; |
| } |
| |
| merged++; |
| drop_delayed_ref(trans, delayed_refs, next); |
| ref->ref_mod += mod; |
| if (ref->ref_mod == 0) { |
| drop_delayed_ref(trans, delayed_refs, ref); |
| break; |
| } else { |
| /* |
| * You 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); |
| } |
| |
| if (done) |
| break; |
| node = rb_prev(&ref->rb_node); |
| } |
| |
| return merged; |
| } |
| |
| void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans, |
| struct btrfs_fs_info *fs_info, |
| struct btrfs_delayed_ref_root *delayed_refs, |
| struct btrfs_delayed_ref_head *head) |
| { |
| struct rb_node *node; |
| u64 seq = 0; |
| |
| /* |
| * We don't have too much refs to merge in the case of delayed data |
| * refs. |
| */ |
| if (head->is_data) |
| return; |
| |
| spin_lock(&fs_info->tree_mod_seq_lock); |
| if (!list_empty(&fs_info->tree_mod_seq_list)) { |
| struct seq_list *elem; |
| |
| elem = list_first_entry(&fs_info->tree_mod_seq_list, |
| struct seq_list, list); |
| seq = elem->seq; |
| } |
| spin_unlock(&fs_info->tree_mod_seq_lock); |
| |
| node = rb_prev(&head->node.rb_node); |
| while (node) { |
| struct btrfs_delayed_ref_node *ref; |
| |
| ref = rb_entry(node, struct btrfs_delayed_ref_node, |
| rb_node); |
| if (ref->bytenr != head->node.bytenr) |
| break; |
| |
| /* We can't merge refs that are outside of our seq count */ |
| if (seq && ref->seq >= seq) |
| break; |
| if (merge_ref(trans, delayed_refs, ref, seq)) |
| node = rb_prev(&head->node.rb_node); |
| else |
| node = rb_prev(node); |
| } |
| } |
| |
| int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, |
| struct btrfs_delayed_ref_root *delayed_refs, |
| u64 seq) |
| { |
| struct seq_list *elem; |
| int ret = 0; |
| |
| spin_lock(&fs_info->tree_mod_seq_lock); |
| if (!list_empty(&fs_info->tree_mod_seq_list)) { |
| elem = list_first_entry(&fs_info->tree_mod_seq_list, |
| struct seq_list, list); |
| if (seq >= elem->seq) { |
| pr_debug("holding back delayed_ref %#x.%x, lowest is %#x.%x (%p)\n", |
| (u32)(seq >> 32), (u32)seq, |
| (u32)(elem->seq >> 32), (u32)elem->seq, |
| delayed_refs); |
| ret = 1; |
| } |
| } |
| |
| spin_unlock(&fs_info->tree_mod_seq_lock); |
| return ret; |
| } |
| |
| int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans, |
| struct list_head *cluster, u64 start) |
| { |
| int count = 0; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| struct rb_node *node; |
| struct btrfs_delayed_ref_head *head = NULL; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| node = rb_first(&delayed_refs->href_root); |
| |
| if (start) { |
| find_ref_head(&delayed_refs->href_root, start + 1, &head, 1); |
| if (head) |
| node = &head->href_node; |
| } |
| again: |
| while (node && count < 32) { |
| head = rb_entry(node, struct btrfs_delayed_ref_head, href_node); |
| if (list_empty(&head->cluster)) { |
| list_add_tail(&head->cluster, cluster); |
| delayed_refs->run_delayed_start = |
| head->node.bytenr; |
| count++; |
| |
| WARN_ON(delayed_refs->num_heads_ready == 0); |
| delayed_refs->num_heads_ready--; |
| } else if (count) { |
| /* the goal of the clustering is to find extents |
| * that are likely to end up in the same extent |
| * leaf on disk. So, we don't want them spread |
| * all over the tree. Stop now if we've hit |
| * a head that was already in use |
| */ |
| break; |
| } |
| node = rb_next(node); |
| } |
| if (count) { |
| return 0; |
| } else if (start) { |
| /* |
| * we've gone to the end of the rbtree without finding any |
| * clusters. start from the beginning and try again |
| */ |
| start = 0; |
| node = rb_first(&delayed_refs->href_root); |
| goto again; |
| } |
| return 1; |
| } |
| |
| void btrfs_release_ref_cluster(struct list_head *cluster) |
| { |
| struct list_head *pos, *q; |
| |
| list_for_each_safe(pos, q, cluster) |
| list_del_init(pos); |
| } |
| |
| /* |
| * helper function to update an extent delayed ref in the |
| * rbtree. existing and update must both have the same |
| * bytenr and parent |
| * |
| * This may free existing if the update cancels out whatever |
| * operation it was doing. |
| */ |
| static noinline void |
| update_existing_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_delayed_ref_root *delayed_refs, |
| struct btrfs_delayed_ref_node *existing, |
| struct btrfs_delayed_ref_node *update) |
| { |
| if (update->action != existing->action) { |
| /* |
| * this is effectively undoing either an add or a |
| * drop. We decrement the ref_mod, and if it goes |
| * down to zero we just delete the entry without |
| * every changing the extent allocation tree. |
| */ |
| existing->ref_mod--; |
| if (existing->ref_mod == 0) |
| drop_delayed_ref(trans, delayed_refs, existing); |
| else |
| WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY || |
| existing->type == BTRFS_SHARED_BLOCK_REF_KEY); |
| } else { |
| WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY || |
| existing->type == BTRFS_SHARED_BLOCK_REF_KEY); |
| /* |
| * the action on the existing ref matches |
| * the action on the ref we're trying to add. |
| * Bump the ref_mod by one so the backref that |
| * is eventually added/removed has the correct |
| * reference count |
| */ |
| existing->ref_mod += update->ref_mod; |
| } |
| } |
| |
| /* |
| * 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_delayed_ref_node *existing, |
| struct btrfs_delayed_ref_node *update) |
| { |
| struct btrfs_delayed_ref_head *existing_ref; |
| struct btrfs_delayed_ref_head *ref; |
| |
| existing_ref = btrfs_delayed_node_to_head(existing); |
| ref = btrfs_delayed_node_to_head(update); |
| BUG_ON(existing_ref->is_data != ref->is_data); |
| |
| if (ref->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_ref->must_insert_reserved = ref->must_insert_reserved; |
| |
| /* |
| * update the num_bytes so we make sure the accounting |
| * is done correctly |
| */ |
| existing->num_bytes = update->num_bytes; |
| |
| } |
| |
| if (ref->extent_op) { |
| if (!existing_ref->extent_op) { |
| existing_ref->extent_op = ref->extent_op; |
| } else { |
| if (ref->extent_op->update_key) { |
| memcpy(&existing_ref->extent_op->key, |
| &ref->extent_op->key, |
| sizeof(ref->extent_op->key)); |
| existing_ref->extent_op->update_key = 1; |
| } |
| if (ref->extent_op->update_flags) { |
| existing_ref->extent_op->flags_to_set |= |
| ref->extent_op->flags_to_set; |
| existing_ref->extent_op->update_flags = 1; |
| } |
| btrfs_free_delayed_extent_op(ref->extent_op); |
| } |
| } |
| /* |
| * update the reference mod on the head to reflect this new operation |
| */ |
| existing->ref_mod += update->ref_mod; |
| } |
| |
| /* |
| * 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 void add_delayed_ref_head(struct btrfs_fs_info *fs_info, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_delayed_ref_node *ref, |
| u64 bytenr, u64 num_bytes, |
| int action, int is_data) |
| { |
| struct btrfs_delayed_ref_node *existing; |
| struct btrfs_delayed_ref_head *head_ref = NULL; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| int count_mod = 1; |
| int must_insert_reserved = 0; |
| |
| /* |
| * 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; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| |
| /* first set the basic ref node struct up */ |
| atomic_set(&ref->refs, 1); |
| ref->bytenr = bytenr; |
| ref->num_bytes = num_bytes; |
| ref->ref_mod = count_mod; |
| ref->type = 0; |
| ref->action = 0; |
| ref->is_head = 1; |
| ref->in_tree = 1; |
| ref->seq = 0; |
| |
| head_ref = btrfs_delayed_node_to_head(ref); |
| head_ref->must_insert_reserved = must_insert_reserved; |
| head_ref->is_data = is_data; |
| |
| INIT_LIST_HEAD(&head_ref->cluster); |
| mutex_init(&head_ref->mutex); |
| |
| trace_add_delayed_ref_head(ref, head_ref, action); |
| |
| existing = tree_insert(&delayed_refs->root, &ref->rb_node); |
| |
| if (existing) { |
| update_existing_head_ref(existing, ref); |
| /* |
| * we've updated the existing ref, free the newly |
| * allocated ref |
| */ |
| kmem_cache_free(btrfs_delayed_ref_head_cachep, head_ref); |
| } else { |
| htree_insert(&delayed_refs->href_root, &head_ref->href_node); |
| delayed_refs->num_heads++; |
| delayed_refs->num_heads_ready++; |
| delayed_refs->num_entries++; |
| trans->delayed_ref_updates++; |
| } |
| } |
| |
| /* |
| * helper to insert a delayed tree ref into the rbtree. |
| */ |
| static noinline void add_delayed_tree_ref(struct btrfs_fs_info *fs_info, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_delayed_ref_node *ref, |
| u64 bytenr, u64 num_bytes, u64 parent, |
| u64 ref_root, int level, int action, |
| int for_cow) |
| { |
| struct btrfs_delayed_ref_node *existing; |
| struct btrfs_delayed_tree_ref *full_ref; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| u64 seq = 0; |
| |
| if (action == BTRFS_ADD_DELAYED_EXTENT) |
| action = BTRFS_ADD_DELAYED_REF; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| |
| /* first set the basic ref node struct up */ |
| atomic_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; |
| |
| if (need_ref_seq(for_cow, ref_root)) |
| seq = btrfs_get_tree_mod_seq(fs_info, &trans->delayed_ref_elem); |
| ref->seq = seq; |
| |
| full_ref = btrfs_delayed_node_to_tree_ref(ref); |
| full_ref->parent = parent; |
| full_ref->root = ref_root; |
| if (parent) |
| ref->type = BTRFS_SHARED_BLOCK_REF_KEY; |
| else |
| ref->type = BTRFS_TREE_BLOCK_REF_KEY; |
| full_ref->level = level; |
| |
| trace_add_delayed_tree_ref(ref, full_ref, action); |
| |
| existing = tree_insert(&delayed_refs->root, &ref->rb_node); |
| |
| if (existing) { |
| update_existing_ref(trans, delayed_refs, existing, ref); |
| /* |
| * we've updated the existing ref, free the newly |
| * allocated ref |
| */ |
| kmem_cache_free(btrfs_delayed_tree_ref_cachep, full_ref); |
| } else { |
| delayed_refs->num_entries++; |
| trans->delayed_ref_updates++; |
| } |
| } |
| |
| /* |
| * helper to insert a delayed data ref into the rbtree. |
| */ |
| static noinline void add_delayed_data_ref(struct btrfs_fs_info *fs_info, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_delayed_ref_node *ref, |
| u64 bytenr, u64 num_bytes, u64 parent, |
| u64 ref_root, u64 owner, u64 offset, |
| int action, int for_cow) |
| { |
| struct btrfs_delayed_ref_node *existing; |
| struct btrfs_delayed_data_ref *full_ref; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| u64 seq = 0; |
| |
| if (action == BTRFS_ADD_DELAYED_EXTENT) |
| action = BTRFS_ADD_DELAYED_REF; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| |
| /* first set the basic ref node struct up */ |
| atomic_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; |
| |
| if (need_ref_seq(for_cow, ref_root)) |
| seq = btrfs_get_tree_mod_seq(fs_info, &trans->delayed_ref_elem); |
| ref->seq = seq; |
| |
| full_ref = btrfs_delayed_node_to_data_ref(ref); |
| full_ref->parent = parent; |
| full_ref->root = ref_root; |
| if (parent) |
| ref->type = BTRFS_SHARED_DATA_REF_KEY; |
| else |
| ref->type = BTRFS_EXTENT_DATA_REF_KEY; |
| |
| full_ref->objectid = owner; |
| full_ref->offset = offset; |
| |
| trace_add_delayed_data_ref(ref, full_ref, action); |
| |
| existing = tree_insert(&delayed_refs->root, &ref->rb_node); |
| |
| if (existing) { |
| update_existing_ref(trans, delayed_refs, existing, ref); |
| /* |
| * we've updated the existing ref, free the newly |
| * allocated ref |
| */ |
| kmem_cache_free(btrfs_delayed_data_ref_cachep, full_ref); |
| } else { |
| delayed_refs->num_entries++; |
| trans->delayed_ref_updates++; |
| } |
| } |
| |
| /* |
| * 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_fs_info *fs_info, |
| struct btrfs_trans_handle *trans, |
| u64 bytenr, u64 num_bytes, u64 parent, |
| u64 ref_root, int level, int action, |
| struct btrfs_delayed_extent_op *extent_op, |
| int for_cow) |
| { |
| struct btrfs_delayed_tree_ref *ref; |
| struct btrfs_delayed_ref_head *head_ref; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| |
| BUG_ON(extent_op && extent_op->is_data); |
| 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; |
| } |
| |
| 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 |
| */ |
| add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr, |
| num_bytes, action, 0); |
| |
| add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr, |
| num_bytes, parent, ref_root, level, action, |
| for_cow); |
| spin_unlock(&delayed_refs->lock); |
| if (need_ref_seq(for_cow, ref_root)) |
| btrfs_qgroup_record_ref(trans, &ref->node, extent_op); |
| |
| return 0; |
| } |
| |
| /* |
| * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref. |
| */ |
| int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, |
| struct btrfs_trans_handle *trans, |
| u64 bytenr, u64 num_bytes, |
| u64 parent, u64 ref_root, |
| u64 owner, u64 offset, int action, |
| struct btrfs_delayed_extent_op *extent_op, |
| int for_cow) |
| { |
| struct btrfs_delayed_data_ref *ref; |
| struct btrfs_delayed_ref_head *head_ref; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| |
| BUG_ON(extent_op && !extent_op->is_data); |
| ref = kmem_cache_alloc(btrfs_delayed_data_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_data_ref_cachep, ref); |
| return -ENOMEM; |
| } |
| |
| 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 |
| */ |
| add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr, |
| num_bytes, action, 1); |
| |
| add_delayed_data_ref(fs_info, trans, &ref->node, bytenr, |
| num_bytes, parent, ref_root, owner, offset, |
| action, for_cow); |
| spin_unlock(&delayed_refs->lock); |
| if (need_ref_seq(for_cow, ref_root)) |
| btrfs_qgroup_record_ref(trans, &ref->node, extent_op); |
| |
| return 0; |
| } |
| |
| int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info, |
| 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; |
| |
| head_ref->extent_op = extent_op; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| spin_lock(&delayed_refs->lock); |
| |
| add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr, |
| num_bytes, BTRFS_UPDATE_DELAYED_HEAD, |
| extent_op->is_data); |
| |
| spin_unlock(&delayed_refs->lock); |
| return 0; |
| } |
| |
| /* |
| * this does a simple search for the head node for a given extent. |
| * It must be called with the delayed ref spinlock held, and it returns |
| * the head node if any where found, or NULL if not. |
| */ |
| struct btrfs_delayed_ref_head * |
| btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr) |
| { |
| struct btrfs_delayed_ref_root *delayed_refs; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| return find_ref_head(&delayed_refs->href_root, bytenr, NULL, 0); |
| } |
| |
| void btrfs_delayed_ref_exit(void) |
| { |
| if (btrfs_delayed_ref_head_cachep) |
| kmem_cache_destroy(btrfs_delayed_ref_head_cachep); |
| if (btrfs_delayed_tree_ref_cachep) |
| kmem_cache_destroy(btrfs_delayed_tree_ref_cachep); |
| if (btrfs_delayed_data_ref_cachep) |
| kmem_cache_destroy(btrfs_delayed_data_ref_cachep); |
| if (btrfs_delayed_extent_op_cachep) |
| kmem_cache_destroy(btrfs_delayed_extent_op_cachep); |
| } |
| |
| int 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_RECLAIM_ACCOUNT | 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_RECLAIM_ACCOUNT | 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_RECLAIM_ACCOUNT | 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_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); |
| if (!btrfs_delayed_extent_op_cachep) |
| goto fail; |
| |
| return 0; |
| fail: |
| btrfs_delayed_ref_exit(); |
| return -ENOMEM; |
| } |