forked from Minki/linux
8c2383c3dd
Signed-off-by: Chris Mason <chris.mason@oracle.com>
438 lines
12 KiB
C
438 lines
12 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/module.h>
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#include <linux/fs.h>
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#include <linux/sched.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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static int total_trans = 0;
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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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static struct workqueue_struct *trans_wq;
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#define BTRFS_ROOT_TRANS_TAG 0
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static 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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WARN_ON(total_trans == 0);
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total_trans--;
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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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static 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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total_trans++;
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BUG_ON(!cur_trans);
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root->fs_info->generation++;
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root->fs_info->running_transaction = cur_trans;
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cur_trans->num_writers = 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->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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list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
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init_bit_radix(&cur_trans->dirty_pages);
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}
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cur_trans->num_writers++;
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return 0;
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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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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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u64 running_trans_id;
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mutex_lock(&root->fs_info->trans_mutex);
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ret = join_transaction(root);
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BUG_ON(ret);
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running_trans_id = root->fs_info->running_transaction->transid;
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if (root != root->fs_info->tree_root && root->last_trans <
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running_trans_id) {
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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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root->commit_root = root->node;
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get_bh(root->node);
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}
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root->last_trans = running_trans_id;
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h->transid = running_trans_id;
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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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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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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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struct btrfs_transaction *cur_trans;
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mutex_lock(&root->fs_info->trans_mutex);
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cur_trans = root->fs_info->running_transaction;
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WARN_ON(cur_trans->num_writers < 1);
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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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cur_trans->num_writers--;
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put_transaction(cur_trans);
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mutex_unlock(&root->fs_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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return 0;
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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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unsigned long gang[16];
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int ret;
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int i;
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int err;
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int werr = 0;
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struct page *page;
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struct radix_tree_root *dirty_pages;
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struct inode *btree_inode = root->fs_info->btree_inode;
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if (!trans || !trans->transaction) {
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return filemap_write_and_wait(btree_inode->i_mapping);
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}
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dirty_pages = &trans->transaction->dirty_pages;
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while(1) {
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ret = find_first_radix_bit(dirty_pages, gang,
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0, ARRAY_SIZE(gang));
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if (!ret)
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break;
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for (i = 0; i < ret; i++) {
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/* FIXME EIO */
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clear_radix_bit(dirty_pages, gang[i]);
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page = find_lock_page(btree_inode->i_mapping,
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gang[i]);
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if (!page)
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continue;
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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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err = filemap_fdatawait(btree_inode->i_mapping);
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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_commit_tree_roots(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_extent_block;
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struct btrfs_fs_info *fs_info = root->fs_info;
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struct btrfs_root *tree_root = fs_info->tree_root;
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struct btrfs_root *extent_root = fs_info->extent_root;
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btrfs_write_dirty_block_groups(trans, extent_root);
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while(1) {
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old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
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if (old_extent_block == bh_blocknr(extent_root->node))
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break;
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btrfs_set_root_blocknr(&extent_root->root_item,
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bh_blocknr(extent_root->node));
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ret = btrfs_update_root(trans, tree_root,
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&extent_root->root_key,
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&extent_root->root_item);
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BUG_ON(ret);
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btrfs_write_dirty_block_groups(trans, extent_root);
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}
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return 0;
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}
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static 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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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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finish_wait(&commit->commit_wait, &wait);
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return 0;
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}
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struct dirty_root {
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struct list_head list;
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struct btrfs_key snap_key;
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struct buffer_head *commit_root;
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struct btrfs_root *root;
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};
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static int add_dirty_roots(struct btrfs_trans_handle *trans,
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struct radix_tree_root *radix,
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struct list_head *list)
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{
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struct dirty_root *dirty;
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struct btrfs_root *gang[8];
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struct btrfs_root *root;
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int i;
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int ret;
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int err;
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while(1) {
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ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
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ARRAY_SIZE(gang),
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BTRFS_ROOT_TRANS_TAG);
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if (ret == 0)
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break;
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for (i = 0; i < ret; i++) {
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root = gang[i];
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radix_tree_tag_clear(radix,
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(unsigned long)root->root_key.objectid,
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BTRFS_ROOT_TRANS_TAG);
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if (root->commit_root == root->node) {
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WARN_ON(bh_blocknr(root->node) !=
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btrfs_root_blocknr(&root->root_item));
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brelse(root->commit_root);
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root->commit_root = NULL;
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continue;
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}
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dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
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BUG_ON(!dirty);
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memcpy(&dirty->snap_key, &root->root_key,
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sizeof(root->root_key));
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dirty->commit_root = root->commit_root;
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root->commit_root = NULL;
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dirty->root = root;
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root->root_key.offset = root->fs_info->generation;
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btrfs_set_root_blocknr(&root->root_item,
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bh_blocknr(root->node));
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err = btrfs_insert_root(trans, root->fs_info->tree_root,
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&root->root_key,
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&root->root_item);
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BUG_ON(err);
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list_add(&dirty->list, list);
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}
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}
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return 0;
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}
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static int drop_dirty_roots(struct btrfs_root *tree_root,
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struct list_head *list)
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{
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struct dirty_root *dirty;
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struct btrfs_trans_handle *trans;
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int ret;
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while(!list_empty(list)) {
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mutex_lock(&tree_root->fs_info->fs_mutex);
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dirty = list_entry(list->next, struct dirty_root, list);
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list_del_init(&dirty->list);
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trans = btrfs_start_transaction(tree_root, 1);
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ret = btrfs_drop_snapshot(trans, dirty->root,
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dirty->commit_root);
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BUG_ON(ret);
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ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
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BUG_ON(ret);
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ret = btrfs_end_transaction(trans, tree_root);
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BUG_ON(ret);
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kfree(dirty);
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mutex_unlock(&tree_root->fs_info->fs_mutex);
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btrfs_btree_balance_dirty(tree_root);
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}
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return 0;
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}
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int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
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struct btrfs_root *root)
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{
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int ret = 0;
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struct btrfs_transaction *cur_trans;
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struct btrfs_transaction *prev_trans = NULL;
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struct list_head dirty_fs_roots;
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DEFINE_WAIT(wait);
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INIT_LIST_HEAD(&dirty_fs_roots);
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mutex_lock(&root->fs_info->trans_mutex);
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if (trans->transaction->in_commit) {
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cur_trans = trans->transaction;
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trans->transaction->use_count++;
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btrfs_end_transaction(trans, root);
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ret = wait_for_commit(root, cur_trans);
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BUG_ON(ret);
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put_transaction(cur_trans);
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mutex_unlock(&root->fs_info->trans_mutex);
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return 0;
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}
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cur_trans = trans->transaction;
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trans->transaction->in_commit = 1;
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while (trans->transaction->num_writers > 1) {
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WARN_ON(cur_trans != trans->transaction);
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prepare_to_wait(&trans->transaction->writer_wait, &wait,
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TASK_UNINTERRUPTIBLE);
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if (trans->transaction->num_writers <= 1)
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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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finish_wait(&trans->transaction->writer_wait, &wait);
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}
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finish_wait(&trans->transaction->writer_wait, &wait);
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WARN_ON(cur_trans != trans->transaction);
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add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
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ret = btrfs_commit_tree_roots(trans, root);
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BUG_ON(ret);
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cur_trans = root->fs_info->running_transaction;
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root->fs_info->running_transaction = NULL;
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if (cur_trans->list.prev != &root->fs_info->trans_list) {
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prev_trans = list_entry(cur_trans->list.prev,
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struct btrfs_transaction, list);
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if (prev_trans->commit_done)
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prev_trans = NULL;
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else
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prev_trans->use_count++;
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}
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mutex_unlock(&root->fs_info->trans_mutex);
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mutex_unlock(&root->fs_info->fs_mutex);
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ret = btrfs_write_and_wait_transaction(trans, root);
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if (prev_trans) {
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mutex_lock(&root->fs_info->trans_mutex);
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wait_for_commit(root, prev_trans);
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put_transaction(prev_trans);
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mutex_unlock(&root->fs_info->trans_mutex);
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}
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btrfs_set_super_generation(root->fs_info->disk_super,
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cur_trans->transid);
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BUG_ON(ret);
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write_ctree_super(trans, root);
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mutex_lock(&root->fs_info->fs_mutex);
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btrfs_finish_extent_commit(trans, root);
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mutex_lock(&root->fs_info->trans_mutex);
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cur_trans->commit_done = 1;
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wake_up(&cur_trans->commit_wait);
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put_transaction(cur_trans);
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put_transaction(cur_trans);
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if (root->fs_info->closing)
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list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
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else
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list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
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mutex_unlock(&root->fs_info->trans_mutex);
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kmem_cache_free(btrfs_trans_handle_cachep, trans);
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if (root->fs_info->closing) {
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mutex_unlock(&root->fs_info->fs_mutex);
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drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
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mutex_lock(&root->fs_info->fs_mutex);
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}
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return ret;
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}
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void btrfs_transaction_cleaner(struct work_struct *work)
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{
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struct btrfs_fs_info *fs_info = container_of(work,
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struct btrfs_fs_info,
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trans_work.work);
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struct btrfs_root *root = fs_info->tree_root;
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struct btrfs_transaction *cur;
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struct btrfs_trans_handle *trans;
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struct list_head dirty_roots;
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unsigned long now;
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unsigned long delay = HZ * 30;
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int ret;
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INIT_LIST_HEAD(&dirty_roots);
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mutex_lock(&root->fs_info->fs_mutex);
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mutex_lock(&root->fs_info->trans_mutex);
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cur = root->fs_info->running_transaction;
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if (!cur) {
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mutex_unlock(&root->fs_info->trans_mutex);
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goto out;
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}
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now = get_seconds();
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if (now < cur->start_time || now - cur->start_time < 30) {
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mutex_unlock(&root->fs_info->trans_mutex);
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delay = HZ * 5;
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goto out;
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}
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mutex_unlock(&root->fs_info->trans_mutex);
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trans = btrfs_start_transaction(root, 1);
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ret = btrfs_commit_transaction(trans, root);
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out:
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mutex_unlock(&root->fs_info->fs_mutex);
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mutex_lock(&root->fs_info->trans_mutex);
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list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
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mutex_unlock(&root->fs_info->trans_mutex);
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if (!list_empty(&dirty_roots)) {
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drop_dirty_roots(root, &dirty_roots);
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}
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btrfs_transaction_queue_work(root, delay);
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}
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void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
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{
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queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
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}
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void btrfs_transaction_flush_work(struct btrfs_root *root)
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{
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cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
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flush_workqueue(trans_wq);
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}
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void __init btrfs_init_transaction_sys(void)
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{
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trans_wq = create_workqueue("btrfs");
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}
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void __exit btrfs_exit_transaction_sys(void)
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{
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destroy_workqueue(trans_wq);
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}
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