1099 lines
30 KiB
C
1099 lines
30 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include <linux/fs.h>
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#include <linux/sched.h>
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#include <linux/writeback.h>
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#include <linux/pagemap.h>
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#include <linux/blkdev.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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#include "locking.h"
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#include "ref-cache.h"
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#include "tree-log.h"
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extern struct kmem_cache *btrfs_trans_handle_cachep;
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extern struct kmem_cache *btrfs_transaction_cachep;
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#define BTRFS_ROOT_TRANS_TAG 0
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static noinline void put_transaction(struct btrfs_transaction *transaction)
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{
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WARN_ON(transaction->use_count == 0);
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transaction->use_count--;
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if (transaction->use_count == 0) {
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list_del_init(&transaction->list);
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memset(transaction, 0, sizeof(*transaction));
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kmem_cache_free(btrfs_transaction_cachep, transaction);
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}
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}
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/*
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* either allocate a new transaction or hop into the existing one
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*/
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static noinline int join_transaction(struct btrfs_root *root)
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{
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struct btrfs_transaction *cur_trans;
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cur_trans = root->fs_info->running_transaction;
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if (!cur_trans) {
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cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
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GFP_NOFS);
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BUG_ON(!cur_trans);
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root->fs_info->generation++;
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root->fs_info->last_alloc = 0;
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root->fs_info->last_data_alloc = 0;
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cur_trans->num_writers = 1;
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cur_trans->num_joined = 0;
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cur_trans->transid = root->fs_info->generation;
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init_waitqueue_head(&cur_trans->writer_wait);
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init_waitqueue_head(&cur_trans->commit_wait);
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cur_trans->in_commit = 0;
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cur_trans->blocked = 0;
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cur_trans->use_count = 1;
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cur_trans->commit_done = 0;
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cur_trans->start_time = get_seconds();
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INIT_LIST_HEAD(&cur_trans->pending_snapshots);
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list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
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extent_io_tree_init(&cur_trans->dirty_pages,
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root->fs_info->btree_inode->i_mapping,
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GFP_NOFS);
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spin_lock(&root->fs_info->new_trans_lock);
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root->fs_info->running_transaction = cur_trans;
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spin_unlock(&root->fs_info->new_trans_lock);
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} else {
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cur_trans->num_writers++;
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cur_trans->num_joined++;
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}
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return 0;
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}
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/*
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* this does all the record keeping required to make sure that a
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* reference counted root is properly recorded in a given transaction.
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* This is required to make sure the old root from before we joined the transaction
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* is deleted when the transaction commits
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*/
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noinline int btrfs_record_root_in_trans(struct btrfs_root *root)
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{
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struct btrfs_dirty_root *dirty;
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u64 running_trans_id = root->fs_info->running_transaction->transid;
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if (root->ref_cows && root->last_trans < running_trans_id) {
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WARN_ON(root == root->fs_info->extent_root);
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if (root->root_item.refs != 0) {
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radix_tree_tag_set(&root->fs_info->fs_roots_radix,
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(unsigned long)root->root_key.objectid,
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BTRFS_ROOT_TRANS_TAG);
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dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
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BUG_ON(!dirty);
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dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
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BUG_ON(!dirty->root);
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dirty->latest_root = root;
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INIT_LIST_HEAD(&dirty->list);
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root->commit_root = btrfs_root_node(root);
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memcpy(dirty->root, root, sizeof(*root));
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spin_lock_init(&dirty->root->node_lock);
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spin_lock_init(&dirty->root->list_lock);
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mutex_init(&dirty->root->objectid_mutex);
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mutex_init(&dirty->root->log_mutex);
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INIT_LIST_HEAD(&dirty->root->dead_list);
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dirty->root->node = root->commit_root;
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dirty->root->commit_root = NULL;
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spin_lock(&root->list_lock);
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list_add(&dirty->root->dead_list, &root->dead_list);
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spin_unlock(&root->list_lock);
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root->dirty_root = dirty;
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} else {
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WARN_ON(1);
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}
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root->last_trans = running_trans_id;
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}
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return 0;
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}
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/* wait for commit against the current transaction to become unblocked
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* when this is done, it is safe to start a new transaction, but the current
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* transaction might not be fully on disk.
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*/
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static void wait_current_trans(struct btrfs_root *root)
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{
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struct btrfs_transaction *cur_trans;
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cur_trans = root->fs_info->running_transaction;
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if (cur_trans && cur_trans->blocked) {
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DEFINE_WAIT(wait);
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cur_trans->use_count++;
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while(1) {
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prepare_to_wait(&root->fs_info->transaction_wait, &wait,
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TASK_UNINTERRUPTIBLE);
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if (cur_trans->blocked) {
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mutex_unlock(&root->fs_info->trans_mutex);
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schedule();
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mutex_lock(&root->fs_info->trans_mutex);
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finish_wait(&root->fs_info->transaction_wait,
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&wait);
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} else {
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finish_wait(&root->fs_info->transaction_wait,
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&wait);
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break;
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}
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}
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put_transaction(cur_trans);
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}
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}
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static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
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int num_blocks, int wait)
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{
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struct btrfs_trans_handle *h =
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kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
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int ret;
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mutex_lock(&root->fs_info->trans_mutex);
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if (!root->fs_info->log_root_recovering &&
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((wait == 1 && !root->fs_info->open_ioctl_trans) || wait == 2))
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wait_current_trans(root);
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ret = join_transaction(root);
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BUG_ON(ret);
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btrfs_record_root_in_trans(root);
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h->transid = root->fs_info->running_transaction->transid;
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h->transaction = root->fs_info->running_transaction;
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h->blocks_reserved = num_blocks;
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h->blocks_used = 0;
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h->block_group = NULL;
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h->alloc_exclude_nr = 0;
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h->alloc_exclude_start = 0;
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root->fs_info->running_transaction->use_count++;
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mutex_unlock(&root->fs_info->trans_mutex);
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return h;
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}
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struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
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int num_blocks)
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{
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return start_transaction(root, num_blocks, 1);
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}
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struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
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int num_blocks)
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{
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return start_transaction(root, num_blocks, 0);
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}
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struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
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int num_blocks)
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{
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return start_transaction(r, num_blocks, 2);
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}
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/* wait for a transaction commit to be fully complete */
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static noinline int wait_for_commit(struct btrfs_root *root,
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struct btrfs_transaction *commit)
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{
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DEFINE_WAIT(wait);
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mutex_lock(&root->fs_info->trans_mutex);
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while(!commit->commit_done) {
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prepare_to_wait(&commit->commit_wait, &wait,
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TASK_UNINTERRUPTIBLE);
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if (commit->commit_done)
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break;
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mutex_unlock(&root->fs_info->trans_mutex);
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schedule();
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mutex_lock(&root->fs_info->trans_mutex);
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}
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mutex_unlock(&root->fs_info->trans_mutex);
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finish_wait(&commit->commit_wait, &wait);
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return 0;
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}
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/*
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* rate limit against the drop_snapshot code. This helps to slow down new operations
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* if the drop_snapshot code isn't able to keep up.
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*/
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static void throttle_on_drops(struct btrfs_root *root)
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{
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struct btrfs_fs_info *info = root->fs_info;
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int harder_count = 0;
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harder:
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if (atomic_read(&info->throttles)) {
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DEFINE_WAIT(wait);
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int thr;
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thr = atomic_read(&info->throttle_gen);
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do {
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prepare_to_wait(&info->transaction_throttle,
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&wait, TASK_UNINTERRUPTIBLE);
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if (!atomic_read(&info->throttles)) {
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finish_wait(&info->transaction_throttle, &wait);
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break;
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}
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schedule();
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finish_wait(&info->transaction_throttle, &wait);
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} while (thr == atomic_read(&info->throttle_gen));
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harder_count++;
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if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 &&
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harder_count < 2)
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goto harder;
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if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 &&
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harder_count < 10)
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goto harder;
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if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 &&
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harder_count < 20)
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goto harder;
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}
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}
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void btrfs_throttle(struct btrfs_root *root)
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{
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mutex_lock(&root->fs_info->trans_mutex);
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if (!root->fs_info->open_ioctl_trans)
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wait_current_trans(root);
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mutex_unlock(&root->fs_info->trans_mutex);
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throttle_on_drops(root);
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}
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static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, int throttle)
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{
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struct btrfs_transaction *cur_trans;
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struct btrfs_fs_info *info = root->fs_info;
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mutex_lock(&info->trans_mutex);
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cur_trans = info->running_transaction;
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WARN_ON(cur_trans != trans->transaction);
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WARN_ON(cur_trans->num_writers < 1);
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cur_trans->num_writers--;
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if (waitqueue_active(&cur_trans->writer_wait))
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wake_up(&cur_trans->writer_wait);
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put_transaction(cur_trans);
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mutex_unlock(&info->trans_mutex);
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memset(trans, 0, sizeof(*trans));
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kmem_cache_free(btrfs_trans_handle_cachep, trans);
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if (throttle)
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throttle_on_drops(root);
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return 0;
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}
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int btrfs_end_transaction(struct btrfs_trans_handle *trans,
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struct btrfs_root *root)
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{
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return __btrfs_end_transaction(trans, root, 0);
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}
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int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
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struct btrfs_root *root)
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{
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return __btrfs_end_transaction(trans, root, 1);
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}
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/*
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* when btree blocks are allocated, they have some corresponding bits set for
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* them in one of two extent_io trees. This is used to make sure all of
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* those extents are on disk for transaction or log commit
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*/
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int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
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struct extent_io_tree *dirty_pages)
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{
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int ret;
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int err = 0;
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int werr = 0;
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struct page *page;
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struct inode *btree_inode = root->fs_info->btree_inode;
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u64 start = 0;
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u64 end;
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unsigned long index;
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while(1) {
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ret = find_first_extent_bit(dirty_pages, start, &start, &end,
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EXTENT_DIRTY);
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if (ret)
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break;
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while(start <= end) {
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cond_resched();
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index = start >> PAGE_CACHE_SHIFT;
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start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
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page = find_get_page(btree_inode->i_mapping, index);
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if (!page)
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continue;
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btree_lock_page_hook(page);
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if (!page->mapping) {
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unlock_page(page);
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page_cache_release(page);
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continue;
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}
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if (PageWriteback(page)) {
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if (PageDirty(page))
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wait_on_page_writeback(page);
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else {
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unlock_page(page);
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page_cache_release(page);
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continue;
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}
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}
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err = write_one_page(page, 0);
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if (err)
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werr = err;
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page_cache_release(page);
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}
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}
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while(1) {
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ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
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EXTENT_DIRTY);
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if (ret)
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break;
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clear_extent_dirty(dirty_pages, start, end, GFP_NOFS);
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while(start <= end) {
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index = start >> PAGE_CACHE_SHIFT;
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start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
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page = find_get_page(btree_inode->i_mapping, index);
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if (!page)
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continue;
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if (PageDirty(page)) {
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btree_lock_page_hook(page);
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wait_on_page_writeback(page);
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err = write_one_page(page, 0);
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if (err)
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werr = err;
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}
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wait_on_page_writeback(page);
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page_cache_release(page);
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cond_resched();
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}
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}
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if (err)
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werr = err;
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return werr;
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}
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int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
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struct btrfs_root *root)
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{
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if (!trans || !trans->transaction) {
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struct inode *btree_inode;
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btree_inode = root->fs_info->btree_inode;
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return filemap_write_and_wait(btree_inode->i_mapping);
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}
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return btrfs_write_and_wait_marked_extents(root,
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&trans->transaction->dirty_pages);
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}
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/*
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* this is used to update the root pointer in the tree of tree roots.
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*
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* But, in the case of the extent allocation tree, updating the root
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* pointer may allocate blocks which may change the root of the extent
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* allocation tree.
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*
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* So, this loops and repeats and makes sure the cowonly root didn't
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* change while the root pointer was being updated in the metadata.
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*/
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static int update_cowonly_root(struct btrfs_trans_handle *trans,
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struct btrfs_root *root)
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{
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int ret;
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u64 old_root_bytenr;
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struct btrfs_root *tree_root = root->fs_info->tree_root;
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btrfs_extent_post_op(trans, root);
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btrfs_write_dirty_block_groups(trans, root);
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btrfs_extent_post_op(trans, root);
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while(1) {
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old_root_bytenr = btrfs_root_bytenr(&root->root_item);
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if (old_root_bytenr == root->node->start)
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break;
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btrfs_set_root_bytenr(&root->root_item,
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root->node->start);
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btrfs_set_root_level(&root->root_item,
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btrfs_header_level(root->node));
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btrfs_set_root_generation(&root->root_item, trans->transid);
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|
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btrfs_extent_post_op(trans, root);
|
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|
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ret = btrfs_update_root(trans, tree_root,
|
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&root->root_key,
|
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&root->root_item);
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BUG_ON(ret);
|
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btrfs_write_dirty_block_groups(trans, root);
|
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btrfs_extent_post_op(trans, root);
|
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}
|
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return 0;
|
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}
|
|
|
|
/*
|
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* update all the cowonly tree roots on disk
|
|
*/
|
|
int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
|
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struct btrfs_root *root)
|
|
{
|
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struct btrfs_fs_info *fs_info = root->fs_info;
|
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struct list_head *next;
|
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struct extent_buffer *eb;
|
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|
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btrfs_extent_post_op(trans, fs_info->tree_root);
|
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|
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eb = btrfs_lock_root_node(fs_info->tree_root);
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btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb, 0);
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btrfs_tree_unlock(eb);
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free_extent_buffer(eb);
|
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|
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btrfs_extent_post_op(trans, fs_info->tree_root);
|
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|
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while(!list_empty(&fs_info->dirty_cowonly_roots)) {
|
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next = fs_info->dirty_cowonly_roots.next;
|
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list_del_init(next);
|
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root = list_entry(next, struct btrfs_root, dirty_list);
|
|
|
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update_cowonly_root(trans, root);
|
|
}
|
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return 0;
|
|
}
|
|
|
|
/*
|
|
* dead roots are old snapshots that need to be deleted. This allocates
|
|
* a dirty root struct and adds it into the list of dead roots that need to
|
|
* be deleted
|
|
*/
|
|
int btrfs_add_dead_root(struct btrfs_root *root, struct btrfs_root *latest)
|
|
{
|
|
struct btrfs_dirty_root *dirty;
|
|
|
|
dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
|
|
if (!dirty)
|
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return -ENOMEM;
|
|
dirty->root = root;
|
|
dirty->latest_root = latest;
|
|
|
|
mutex_lock(&root->fs_info->trans_mutex);
|
|
list_add(&dirty->list, &latest->fs_info->dead_roots);
|
|
mutex_unlock(&root->fs_info->trans_mutex);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* at transaction commit time we need to schedule the old roots for
|
|
* deletion via btrfs_drop_snapshot. This runs through all the
|
|
* reference counted roots that were modified in the current
|
|
* transaction and puts them into the drop list
|
|
*/
|
|
static noinline int add_dirty_roots(struct btrfs_trans_handle *trans,
|
|
struct radix_tree_root *radix,
|
|
struct list_head *list)
|
|
{
|
|
struct btrfs_dirty_root *dirty;
|
|
struct btrfs_root *gang[8];
|
|
struct btrfs_root *root;
|
|
int i;
|
|
int ret;
|
|
int err = 0;
|
|
u32 refs;
|
|
|
|
while(1) {
|
|
ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
|
|
ARRAY_SIZE(gang),
|
|
BTRFS_ROOT_TRANS_TAG);
|
|
if (ret == 0)
|
|
break;
|
|
for (i = 0; i < ret; i++) {
|
|
root = gang[i];
|
|
radix_tree_tag_clear(radix,
|
|
(unsigned long)root->root_key.objectid,
|
|
BTRFS_ROOT_TRANS_TAG);
|
|
|
|
BUG_ON(!root->ref_tree);
|
|
dirty = root->dirty_root;
|
|
|
|
btrfs_free_log(trans, root);
|
|
btrfs_free_reloc_root(trans, root);
|
|
|
|
if (root->commit_root == root->node) {
|
|
WARN_ON(root->node->start !=
|
|
btrfs_root_bytenr(&root->root_item));
|
|
|
|
free_extent_buffer(root->commit_root);
|
|
root->commit_root = NULL;
|
|
root->dirty_root = NULL;
|
|
|
|
spin_lock(&root->list_lock);
|
|
list_del_init(&dirty->root->dead_list);
|
|
spin_unlock(&root->list_lock);
|
|
|
|
kfree(dirty->root);
|
|
kfree(dirty);
|
|
|
|
/* make sure to update the root on disk
|
|
* so we get any updates to the block used
|
|
* counts
|
|
*/
|
|
err = btrfs_update_root(trans,
|
|
root->fs_info->tree_root,
|
|
&root->root_key,
|
|
&root->root_item);
|
|
continue;
|
|
}
|
|
|
|
memset(&root->root_item.drop_progress, 0,
|
|
sizeof(struct btrfs_disk_key));
|
|
root->root_item.drop_level = 0;
|
|
root->commit_root = NULL;
|
|
root->dirty_root = NULL;
|
|
root->root_key.offset = root->fs_info->generation;
|
|
btrfs_set_root_bytenr(&root->root_item,
|
|
root->node->start);
|
|
btrfs_set_root_level(&root->root_item,
|
|
btrfs_header_level(root->node));
|
|
btrfs_set_root_generation(&root->root_item,
|
|
root->root_key.offset);
|
|
|
|
err = btrfs_insert_root(trans, root->fs_info->tree_root,
|
|
&root->root_key,
|
|
&root->root_item);
|
|
if (err)
|
|
break;
|
|
|
|
refs = btrfs_root_refs(&dirty->root->root_item);
|
|
btrfs_set_root_refs(&dirty->root->root_item, refs - 1);
|
|
err = btrfs_update_root(trans, root->fs_info->tree_root,
|
|
&dirty->root->root_key,
|
|
&dirty->root->root_item);
|
|
|
|
BUG_ON(err);
|
|
if (refs == 1) {
|
|
list_add(&dirty->list, list);
|
|
} else {
|
|
WARN_ON(1);
|
|
free_extent_buffer(dirty->root->node);
|
|
kfree(dirty->root);
|
|
kfree(dirty);
|
|
}
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* defrag a given btree. If cacheonly == 1, this won't read from the disk,
|
|
* otherwise every leaf in the btree is read and defragged.
|
|
*/
|
|
int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
|
|
{
|
|
struct btrfs_fs_info *info = root->fs_info;
|
|
int ret;
|
|
struct btrfs_trans_handle *trans;
|
|
unsigned long nr;
|
|
|
|
smp_mb();
|
|
if (root->defrag_running)
|
|
return 0;
|
|
trans = btrfs_start_transaction(root, 1);
|
|
while (1) {
|
|
root->defrag_running = 1;
|
|
ret = btrfs_defrag_leaves(trans, root, cacheonly);
|
|
nr = trans->blocks_used;
|
|
btrfs_end_transaction(trans, root);
|
|
btrfs_btree_balance_dirty(info->tree_root, nr);
|
|
cond_resched();
|
|
|
|
trans = btrfs_start_transaction(root, 1);
|
|
if (root->fs_info->closing || ret != -EAGAIN)
|
|
break;
|
|
}
|
|
root->defrag_running = 0;
|
|
smp_mb();
|
|
btrfs_end_transaction(trans, root);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Given a list of roots that need to be deleted, call btrfs_drop_snapshot on
|
|
* all of them
|
|
*/
|
|
static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
|
|
struct list_head *list)
|
|
{
|
|
struct btrfs_dirty_root *dirty;
|
|
struct btrfs_trans_handle *trans;
|
|
unsigned long nr;
|
|
u64 num_bytes;
|
|
u64 bytes_used;
|
|
u64 max_useless;
|
|
int ret = 0;
|
|
int err;
|
|
|
|
while(!list_empty(list)) {
|
|
struct btrfs_root *root;
|
|
|
|
dirty = list_entry(list->prev, struct btrfs_dirty_root, list);
|
|
list_del_init(&dirty->list);
|
|
|
|
num_bytes = btrfs_root_used(&dirty->root->root_item);
|
|
root = dirty->latest_root;
|
|
atomic_inc(&root->fs_info->throttles);
|
|
|
|
while(1) {
|
|
trans = btrfs_start_transaction(tree_root, 1);
|
|
mutex_lock(&root->fs_info->drop_mutex);
|
|
ret = btrfs_drop_snapshot(trans, dirty->root);
|
|
if (ret != -EAGAIN) {
|
|
break;
|
|
}
|
|
mutex_unlock(&root->fs_info->drop_mutex);
|
|
|
|
err = btrfs_update_root(trans,
|
|
tree_root,
|
|
&dirty->root->root_key,
|
|
&dirty->root->root_item);
|
|
if (err)
|
|
ret = err;
|
|
nr = trans->blocks_used;
|
|
ret = btrfs_end_transaction(trans, tree_root);
|
|
BUG_ON(ret);
|
|
|
|
btrfs_btree_balance_dirty(tree_root, nr);
|
|
cond_resched();
|
|
}
|
|
BUG_ON(ret);
|
|
atomic_dec(&root->fs_info->throttles);
|
|
wake_up(&root->fs_info->transaction_throttle);
|
|
|
|
num_bytes -= btrfs_root_used(&dirty->root->root_item);
|
|
bytes_used = btrfs_root_used(&root->root_item);
|
|
if (num_bytes) {
|
|
btrfs_record_root_in_trans(root);
|
|
btrfs_set_root_used(&root->root_item,
|
|
bytes_used - num_bytes);
|
|
}
|
|
|
|
ret = btrfs_del_root(trans, tree_root, &dirty->root->root_key);
|
|
if (ret) {
|
|
BUG();
|
|
break;
|
|
}
|
|
mutex_unlock(&root->fs_info->drop_mutex);
|
|
|
|
spin_lock(&root->list_lock);
|
|
list_del_init(&dirty->root->dead_list);
|
|
if (!list_empty(&root->dead_list)) {
|
|
struct btrfs_root *oldest;
|
|
oldest = list_entry(root->dead_list.prev,
|
|
struct btrfs_root, dead_list);
|
|
max_useless = oldest->root_key.offset - 1;
|
|
} else {
|
|
max_useless = root->root_key.offset - 1;
|
|
}
|
|
spin_unlock(&root->list_lock);
|
|
|
|
nr = trans->blocks_used;
|
|
ret = btrfs_end_transaction(trans, tree_root);
|
|
BUG_ON(ret);
|
|
|
|
ret = btrfs_remove_leaf_refs(root, max_useless, 0);
|
|
BUG_ON(ret);
|
|
|
|
free_extent_buffer(dirty->root->node);
|
|
kfree(dirty->root);
|
|
kfree(dirty);
|
|
|
|
btrfs_btree_balance_dirty(tree_root, nr);
|
|
cond_resched();
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* new snapshots need to be created at a very specific time in the
|
|
* transaction commit. This does the actual creation
|
|
*/
|
|
static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
|
|
struct btrfs_fs_info *fs_info,
|
|
struct btrfs_pending_snapshot *pending)
|
|
{
|
|
struct btrfs_key key;
|
|
struct btrfs_root_item *new_root_item;
|
|
struct btrfs_root *tree_root = fs_info->tree_root;
|
|
struct btrfs_root *root = pending->root;
|
|
struct extent_buffer *tmp;
|
|
struct extent_buffer *old;
|
|
int ret;
|
|
u64 objectid;
|
|
|
|
new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
|
|
if (!new_root_item) {
|
|
ret = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
|
|
if (ret)
|
|
goto fail;
|
|
|
|
btrfs_record_root_in_trans(root);
|
|
btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
|
|
memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
|
|
|
|
key.objectid = objectid;
|
|
key.offset = trans->transid;
|
|
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
|
|
|
|
old = btrfs_lock_root_node(root);
|
|
btrfs_cow_block(trans, root, old, NULL, 0, &old, 0);
|
|
|
|
btrfs_copy_root(trans, root, old, &tmp, objectid);
|
|
btrfs_tree_unlock(old);
|
|
free_extent_buffer(old);
|
|
|
|
btrfs_set_root_bytenr(new_root_item, tmp->start);
|
|
btrfs_set_root_level(new_root_item, btrfs_header_level(tmp));
|
|
btrfs_set_root_generation(new_root_item, trans->transid);
|
|
ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
|
|
new_root_item);
|
|
btrfs_tree_unlock(tmp);
|
|
free_extent_buffer(tmp);
|
|
if (ret)
|
|
goto fail;
|
|
|
|
key.offset = (u64)-1;
|
|
memcpy(&pending->root_key, &key, sizeof(key));
|
|
fail:
|
|
kfree(new_root_item);
|
|
return ret;
|
|
}
|
|
|
|
static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_pending_snapshot *pending)
|
|
{
|
|
int ret;
|
|
int namelen;
|
|
u64 index = 0;
|
|
struct btrfs_trans_handle *trans;
|
|
struct inode *parent_inode;
|
|
struct inode *inode;
|
|
struct btrfs_root *parent_root;
|
|
|
|
parent_inode = pending->dentry->d_parent->d_inode;
|
|
parent_root = BTRFS_I(parent_inode)->root;
|
|
trans = btrfs_start_transaction(parent_root, 1);
|
|
|
|
/*
|
|
* insert the directory item
|
|
*/
|
|
namelen = strlen(pending->name);
|
|
ret = btrfs_set_inode_index(parent_inode, &index);
|
|
ret = btrfs_insert_dir_item(trans, parent_root,
|
|
pending->name, namelen,
|
|
parent_inode->i_ino,
|
|
&pending->root_key, BTRFS_FT_DIR, index);
|
|
|
|
if (ret)
|
|
goto fail;
|
|
|
|
/* add the backref first */
|
|
ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
|
|
pending->root_key.objectid,
|
|
BTRFS_ROOT_BACKREF_KEY,
|
|
parent_root->root_key.objectid,
|
|
parent_inode->i_ino, index, pending->name,
|
|
namelen);
|
|
|
|
BUG_ON(ret);
|
|
|
|
/* now add the forward ref */
|
|
ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
|
|
parent_root->root_key.objectid,
|
|
BTRFS_ROOT_REF_KEY,
|
|
pending->root_key.objectid,
|
|
parent_inode->i_ino, index, pending->name,
|
|
namelen);
|
|
|
|
inode = btrfs_lookup_dentry(parent_inode, pending->dentry);
|
|
d_instantiate(pending->dentry, inode);
|
|
fail:
|
|
btrfs_end_transaction(trans, fs_info->fs_root);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* create all the snapshots we've scheduled for creation
|
|
*/
|
|
static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
|
|
struct btrfs_fs_info *fs_info)
|
|
{
|
|
struct btrfs_pending_snapshot *pending;
|
|
struct list_head *head = &trans->transaction->pending_snapshots;
|
|
struct list_head *cur;
|
|
int ret;
|
|
|
|
list_for_each(cur, head) {
|
|
pending = list_entry(cur, struct btrfs_pending_snapshot, list);
|
|
ret = create_pending_snapshot(trans, fs_info, pending);
|
|
BUG_ON(ret);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static noinline int finish_pending_snapshots(struct btrfs_trans_handle *trans,
|
|
struct btrfs_fs_info *fs_info)
|
|
{
|
|
struct btrfs_pending_snapshot *pending;
|
|
struct list_head *head = &trans->transaction->pending_snapshots;
|
|
int ret;
|
|
|
|
while(!list_empty(head)) {
|
|
pending = list_entry(head->next,
|
|
struct btrfs_pending_snapshot, list);
|
|
ret = finish_pending_snapshot(fs_info, pending);
|
|
BUG_ON(ret);
|
|
list_del(&pending->list);
|
|
kfree(pending->name);
|
|
kfree(pending);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root)
|
|
{
|
|
unsigned long joined = 0;
|
|
unsigned long timeout = 1;
|
|
struct btrfs_transaction *cur_trans;
|
|
struct btrfs_transaction *prev_trans = NULL;
|
|
struct btrfs_root *chunk_root = root->fs_info->chunk_root;
|
|
struct list_head dirty_fs_roots;
|
|
struct extent_io_tree *pinned_copy;
|
|
DEFINE_WAIT(wait);
|
|
int ret;
|
|
|
|
INIT_LIST_HEAD(&dirty_fs_roots);
|
|
mutex_lock(&root->fs_info->trans_mutex);
|
|
if (trans->transaction->in_commit) {
|
|
cur_trans = trans->transaction;
|
|
trans->transaction->use_count++;
|
|
mutex_unlock(&root->fs_info->trans_mutex);
|
|
btrfs_end_transaction(trans, root);
|
|
|
|
ret = wait_for_commit(root, cur_trans);
|
|
BUG_ON(ret);
|
|
|
|
mutex_lock(&root->fs_info->trans_mutex);
|
|
put_transaction(cur_trans);
|
|
mutex_unlock(&root->fs_info->trans_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
pinned_copy = kmalloc(sizeof(*pinned_copy), GFP_NOFS);
|
|
if (!pinned_copy)
|
|
return -ENOMEM;
|
|
|
|
extent_io_tree_init(pinned_copy,
|
|
root->fs_info->btree_inode->i_mapping, GFP_NOFS);
|
|
|
|
trans->transaction->in_commit = 1;
|
|
trans->transaction->blocked = 1;
|
|
cur_trans = trans->transaction;
|
|
if (cur_trans->list.prev != &root->fs_info->trans_list) {
|
|
prev_trans = list_entry(cur_trans->list.prev,
|
|
struct btrfs_transaction, list);
|
|
if (!prev_trans->commit_done) {
|
|
prev_trans->use_count++;
|
|
mutex_unlock(&root->fs_info->trans_mutex);
|
|
|
|
wait_for_commit(root, prev_trans);
|
|
|
|
mutex_lock(&root->fs_info->trans_mutex);
|
|
put_transaction(prev_trans);
|
|
}
|
|
}
|
|
|
|
do {
|
|
int snap_pending = 0;
|
|
joined = cur_trans->num_joined;
|
|
if (!list_empty(&trans->transaction->pending_snapshots))
|
|
snap_pending = 1;
|
|
|
|
WARN_ON(cur_trans != trans->transaction);
|
|
prepare_to_wait(&cur_trans->writer_wait, &wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
|
|
if (cur_trans->num_writers > 1)
|
|
timeout = MAX_SCHEDULE_TIMEOUT;
|
|
else
|
|
timeout = 1;
|
|
|
|
mutex_unlock(&root->fs_info->trans_mutex);
|
|
|
|
if (snap_pending) {
|
|
ret = btrfs_wait_ordered_extents(root, 1);
|
|
BUG_ON(ret);
|
|
}
|
|
|
|
schedule_timeout(timeout);
|
|
|
|
mutex_lock(&root->fs_info->trans_mutex);
|
|
finish_wait(&cur_trans->writer_wait, &wait);
|
|
} while (cur_trans->num_writers > 1 ||
|
|
(cur_trans->num_joined != joined));
|
|
|
|
ret = create_pending_snapshots(trans, root->fs_info);
|
|
BUG_ON(ret);
|
|
|
|
WARN_ON(cur_trans != trans->transaction);
|
|
|
|
/* btrfs_commit_tree_roots is responsible for getting the
|
|
* various roots consistent with each other. Every pointer
|
|
* in the tree of tree roots has to point to the most up to date
|
|
* root for every subvolume and other tree. So, we have to keep
|
|
* the tree logging code from jumping in and changing any
|
|
* of the trees.
|
|
*
|
|
* At this point in the commit, there can't be any tree-log
|
|
* writers, but a little lower down we drop the trans mutex
|
|
* and let new people in. By holding the tree_log_mutex
|
|
* from now until after the super is written, we avoid races
|
|
* with the tree-log code.
|
|
*/
|
|
mutex_lock(&root->fs_info->tree_log_mutex);
|
|
/*
|
|
* keep tree reloc code from adding new reloc trees
|
|
*/
|
|
mutex_lock(&root->fs_info->tree_reloc_mutex);
|
|
|
|
|
|
ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
|
|
&dirty_fs_roots);
|
|
BUG_ON(ret);
|
|
|
|
/* add_dirty_roots gets rid of all the tree log roots, it is now
|
|
* safe to free the root of tree log roots
|
|
*/
|
|
btrfs_free_log_root_tree(trans, root->fs_info);
|
|
|
|
ret = btrfs_commit_tree_roots(trans, root);
|
|
BUG_ON(ret);
|
|
|
|
cur_trans = root->fs_info->running_transaction;
|
|
spin_lock(&root->fs_info->new_trans_lock);
|
|
root->fs_info->running_transaction = NULL;
|
|
spin_unlock(&root->fs_info->new_trans_lock);
|
|
btrfs_set_super_generation(&root->fs_info->super_copy,
|
|
cur_trans->transid);
|
|
btrfs_set_super_root(&root->fs_info->super_copy,
|
|
root->fs_info->tree_root->node->start);
|
|
btrfs_set_super_root_level(&root->fs_info->super_copy,
|
|
btrfs_header_level(root->fs_info->tree_root->node));
|
|
|
|
btrfs_set_super_chunk_root(&root->fs_info->super_copy,
|
|
chunk_root->node->start);
|
|
btrfs_set_super_chunk_root_level(&root->fs_info->super_copy,
|
|
btrfs_header_level(chunk_root->node));
|
|
btrfs_set_super_chunk_root_generation(&root->fs_info->super_copy,
|
|
btrfs_header_generation(chunk_root->node));
|
|
|
|
if (!root->fs_info->log_root_recovering) {
|
|
btrfs_set_super_log_root(&root->fs_info->super_copy, 0);
|
|
btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0);
|
|
}
|
|
|
|
memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
|
|
sizeof(root->fs_info->super_copy));
|
|
|
|
btrfs_copy_pinned(root, pinned_copy);
|
|
|
|
trans->transaction->blocked = 0;
|
|
wake_up(&root->fs_info->transaction_throttle);
|
|
wake_up(&root->fs_info->transaction_wait);
|
|
|
|
mutex_unlock(&root->fs_info->trans_mutex);
|
|
ret = btrfs_write_and_wait_transaction(trans, root);
|
|
BUG_ON(ret);
|
|
write_ctree_super(trans, root, 0);
|
|
|
|
/*
|
|
* the super is written, we can safely allow the tree-loggers
|
|
* to go about their business
|
|
*/
|
|
mutex_unlock(&root->fs_info->tree_log_mutex);
|
|
|
|
btrfs_finish_extent_commit(trans, root, pinned_copy);
|
|
kfree(pinned_copy);
|
|
|
|
btrfs_drop_dead_reloc_roots(root);
|
|
mutex_unlock(&root->fs_info->tree_reloc_mutex);
|
|
|
|
/* do the directory inserts of any pending snapshot creations */
|
|
finish_pending_snapshots(trans, root->fs_info);
|
|
|
|
mutex_lock(&root->fs_info->trans_mutex);
|
|
|
|
cur_trans->commit_done = 1;
|
|
root->fs_info->last_trans_committed = cur_trans->transid;
|
|
wake_up(&cur_trans->commit_wait);
|
|
|
|
put_transaction(cur_trans);
|
|
put_transaction(cur_trans);
|
|
|
|
list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
|
|
if (root->fs_info->closing)
|
|
list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
|
|
|
|
mutex_unlock(&root->fs_info->trans_mutex);
|
|
|
|
kmem_cache_free(btrfs_trans_handle_cachep, trans);
|
|
|
|
if (root->fs_info->closing) {
|
|
drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* interface function to delete all the snapshots we have scheduled for deletion
|
|
*/
|
|
int btrfs_clean_old_snapshots(struct btrfs_root *root)
|
|
{
|
|
struct list_head dirty_roots;
|
|
INIT_LIST_HEAD(&dirty_roots);
|
|
again:
|
|
mutex_lock(&root->fs_info->trans_mutex);
|
|
list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
|
|
mutex_unlock(&root->fs_info->trans_mutex);
|
|
|
|
if (!list_empty(&dirty_roots)) {
|
|
drop_dirty_roots(root, &dirty_roots);
|
|
goto again;
|
|
}
|
|
return 0;
|
|
}
|