linux/fs/btrfs/transaction.c

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/*
* Copyright (C) 2007 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/fs.h>
#include <linux/sched.h>
#include <linux/writeback.h>
#include <linux/pagemap.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
static int total_trans = 0;
extern struct kmem_cache *btrfs_trans_handle_cachep;
extern struct kmem_cache *btrfs_transaction_cachep;
static struct workqueue_struct *trans_wq;
#define BTRFS_ROOT_TRANS_TAG 0
#define BTRFS_ROOT_DEFRAG_TAG 1
static void put_transaction(struct btrfs_transaction *transaction)
{
WARN_ON(transaction->use_count == 0);
transaction->use_count--;
if (transaction->use_count == 0) {
WARN_ON(total_trans == 0);
total_trans--;
list_del_init(&transaction->list);
memset(transaction, 0, sizeof(*transaction));
kmem_cache_free(btrfs_transaction_cachep, transaction);
}
}
static int join_transaction(struct btrfs_root *root)
{
struct btrfs_transaction *cur_trans;
cur_trans = root->fs_info->running_transaction;
if (!cur_trans) {
cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
GFP_NOFS);
total_trans++;
BUG_ON(!cur_trans);
root->fs_info->generation++;
root->fs_info->running_transaction = cur_trans;
cur_trans->num_writers = 1;
cur_trans->num_joined = 0;
cur_trans->transid = root->fs_info->generation;
init_waitqueue_head(&cur_trans->writer_wait);
init_waitqueue_head(&cur_trans->commit_wait);
cur_trans->in_commit = 0;
cur_trans->use_count = 1;
cur_trans->commit_done = 0;
cur_trans->start_time = get_seconds();
list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
btrfs_ordered_inode_tree_init(&cur_trans->ordered_inode_tree);
extent_map_tree_init(&cur_trans->dirty_pages,
root->fs_info->btree_inode->i_mapping,
GFP_NOFS);
} else {
cur_trans->num_writers++;
cur_trans->num_joined++;
}
return 0;
}
static int record_root_in_trans(struct btrfs_root *root)
{
u64 running_trans_id = root->fs_info->running_transaction->transid;
if (root->ref_cows && root->last_trans < running_trans_id) {
WARN_ON(root == root->fs_info->extent_root);
if (root->root_item.refs != 0) {
radix_tree_tag_set(&root->fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid,
BTRFS_ROOT_TRANS_TAG);
radix_tree_tag_set(&root->fs_info->fs_roots_radix,
(unsigned long)root->root_key.objectid,
BTRFS_ROOT_DEFRAG_TAG);
root->commit_root = root->node;
extent_buffer_get(root->node);
} else {
WARN_ON(1);
}
root->last_trans = running_trans_id;
}
return 0;
}
struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
int num_blocks)
{
struct btrfs_trans_handle *h =
kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
int ret;
mutex_lock(&root->fs_info->trans_mutex);
ret = join_transaction(root);
BUG_ON(ret);
record_root_in_trans(root);
h->transid = root->fs_info->running_transaction->transid;
h->transaction = root->fs_info->running_transaction;
h->blocks_reserved = num_blocks;
h->blocks_used = 0;
h->block_group = NULL;
h->alloc_exclude_nr = 0;
h->alloc_exclude_start = 0;
root->fs_info->running_transaction->use_count++;
mutex_unlock(&root->fs_info->trans_mutex);
return h;
}
int btrfs_end_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_transaction *cur_trans;
mutex_lock(&root->fs_info->trans_mutex);
cur_trans = root->fs_info->running_transaction;
WARN_ON(cur_trans != trans->transaction);
WARN_ON(cur_trans->num_writers < 1);
cur_trans->num_writers--;
if (waitqueue_active(&cur_trans->writer_wait))
wake_up(&cur_trans->writer_wait);
put_transaction(cur_trans);
mutex_unlock(&root->fs_info->trans_mutex);
memset(trans, 0, sizeof(*trans));
kmem_cache_free(btrfs_trans_handle_cachep, trans);
return 0;
}
int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
int err;
int werr = 0;
struct extent_map_tree *dirty_pages;
struct page *page;
struct inode *btree_inode = root->fs_info->btree_inode;
u64 start;
u64 end;
unsigned long index;
if (!trans || !trans->transaction) {
return filemap_write_and_wait(btree_inode->i_mapping);
}
dirty_pages = &trans->transaction->dirty_pages;
while(1) {
ret = find_first_extent_bit(dirty_pages, 0, &start, &end,
EXTENT_DIRTY);
if (ret)
break;
clear_extent_dirty(dirty_pages, start, end, GFP_NOFS);
while(start <= end) {
index = start >> PAGE_CACHE_SHIFT;
start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
page = find_lock_page(btree_inode->i_mapping, index);
if (!page)
continue;
if (PageWriteback(page)) {
if (PageDirty(page))
wait_on_page_writeback(page);
else {
unlock_page(page);
page_cache_release(page);
continue;
}
}
err = write_one_page(page, 0);
if (err)
werr = err;
page_cache_release(page);
}
}
err = filemap_fdatawait(btree_inode->i_mapping);
if (err)
werr = err;
return werr;
}
int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
u64 old_extent_block;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *tree_root = fs_info->tree_root;
struct btrfs_root *extent_root = fs_info->extent_root;
btrfs_write_dirty_block_groups(trans, extent_root);
while(1) {
old_extent_block = btrfs_root_bytenr(&extent_root->root_item);
if (old_extent_block == extent_root->node->start)
break;
btrfs_set_root_bytenr(&extent_root->root_item,
extent_root->node->start);
btrfs_set_root_level(&extent_root->root_item,
btrfs_header_level(extent_root->node));
ret = btrfs_update_root(trans, tree_root,
&extent_root->root_key,
&extent_root->root_item);
BUG_ON(ret);
btrfs_write_dirty_block_groups(trans, extent_root);
}
return 0;
}
static int wait_for_commit(struct btrfs_root *root,
struct btrfs_transaction *commit)
{
DEFINE_WAIT(wait);
mutex_lock(&root->fs_info->trans_mutex);
while(!commit->commit_done) {
prepare_to_wait(&commit->commit_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (commit->commit_done)
break;
mutex_unlock(&root->fs_info->trans_mutex);
schedule();
mutex_lock(&root->fs_info->trans_mutex);
}
mutex_unlock(&root->fs_info->trans_mutex);
finish_wait(&commit->commit_wait, &wait);
return 0;
}
struct dirty_root {
struct list_head list;
struct btrfs_root *root;
struct btrfs_root *latest_root;
};
int btrfs_add_dead_root(struct btrfs_root *root,
struct btrfs_root *latest,
struct list_head *dead_list)
{
struct dirty_root *dirty;
dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
if (!dirty)
return -ENOMEM;
dirty->root = root;
dirty->latest_root = latest;
list_add(&dirty->list, dead_list);
return 0;
}
static int add_dirty_roots(struct btrfs_trans_handle *trans,
struct radix_tree_root *radix,
struct list_head *list)
{
struct 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);
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;
/* 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;
}
dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
BUG_ON(!dirty);
dirty->root = kmalloc(sizeof(*dirty->root), GFP_NOFS);
BUG_ON(!dirty->root);
memset(&root->root_item.drop_progress, 0,
sizeof(struct btrfs_disk_key));
root->root_item.drop_level = 0;
memcpy(dirty->root, root, sizeof(*root));
dirty->root->node = root->commit_root;
dirty->latest_root = root;
root->commit_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));
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);
kfree(dirty->root);
kfree(dirty);
}
}
}
return err;
}
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;
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);
mutex_unlock(&info->fs_mutex);
btrfs_btree_balance_dirty(info->tree_root, nr);
cond_resched();
mutex_lock(&info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
if (ret != -EAGAIN)
break;
}
root->defrag_running = 0;
radix_tree_tag_clear(&info->fs_roots_radix,
(unsigned long)root->root_key.objectid,
BTRFS_ROOT_DEFRAG_TAG);
btrfs_end_transaction(trans, root);
return 0;
}
int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info)
{
struct btrfs_root *gang[1];
struct btrfs_root *root;
int i;
int ret;
int err = 0;
u64 last = 0;
while(1) {
ret = radix_tree_gang_lookup_tag(&info->fs_roots_radix,
(void **)gang, last,
ARRAY_SIZE(gang),
BTRFS_ROOT_DEFRAG_TAG);
if (ret == 0)
break;
for (i = 0; i < ret; i++) {
root = gang[i];
last = root->root_key.objectid + 1;
btrfs_defrag_root(root, 1);
}
}
btrfs_defrag_root(info->extent_root, 1);
return err;
}
static int drop_dirty_roots(struct btrfs_root *tree_root,
struct list_head *list)
{
struct dirty_root *dirty;
struct btrfs_trans_handle *trans;
unsigned long nr;
u64 num_bytes;
u64 bytes_used;
int ret = 0;
int err;
while(!list_empty(list)) {
struct btrfs_root *root;
mutex_lock(&tree_root->fs_info->fs_mutex);
dirty = list_entry(list->next, struct dirty_root, list);
list_del_init(&dirty->list);
num_bytes = btrfs_root_used(&dirty->root->root_item);
root = dirty->latest_root;
while(1) {
trans = btrfs_start_transaction(tree_root, 1);
ret = btrfs_drop_snapshot(trans, dirty->root);
if (ret != -EAGAIN) {
break;
}
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);
mutex_unlock(&tree_root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(tree_root, nr);
cond_resched();
mutex_lock(&tree_root->fs_info->fs_mutex);
}
BUG_ON(ret);
num_bytes -= btrfs_root_used(&dirty->root->root_item);
bytes_used = btrfs_root_used(&root->root_item);
if (num_bytes) {
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;
}
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, tree_root);
BUG_ON(ret);
free_extent_buffer(dirty->root->node);
kfree(dirty->root);
kfree(dirty);
mutex_unlock(&tree_root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(tree_root, nr);
cond_resched();
}
return ret;
}
int btrfs_write_ordered_inodes(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_transaction *cur_trans = trans->transaction;
struct inode *inode;
u64 root_objectid = 0;
u64 objectid = 0;
u64 transid = trans->transid;
int ret;
printk("write ordered trans %Lu\n", transid);
while(1) {
ret = btrfs_find_first_ordered_inode(
&cur_trans->ordered_inode_tree,
&root_objectid, &objectid);
if (!ret)
break;
mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex);
inode = btrfs_ilookup(root->fs_info->sb, objectid,
root_objectid);
if (inode) {
if (S_ISREG(inode->i_mode))
filemap_fdatawrite(inode->i_mapping);
iput(inode);
}
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
}
while(1) {
root_objectid = 0;
objectid = 0;
ret = btrfs_find_del_first_ordered_inode(
&cur_trans->ordered_inode_tree,
&root_objectid, &objectid);
if (!ret)
break;
mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex);
inode = btrfs_ilookup(root->fs_info->sb, objectid,
root_objectid);
if (inode) {
if (S_ISREG(inode->i_mode))
filemap_write_and_wait(inode->i_mapping);
iput(inode);
}
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
}
printk("done write ordered trans %Lu\n", transid);
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 list_head dirty_fs_roots;
struct extent_map_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);
mutex_unlock(&root->fs_info->fs_mutex);
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);
mutex_lock(&root->fs_info->fs_mutex);
return 0;
}
pinned_copy = kmalloc(sizeof(*pinned_copy), GFP_NOFS);
if (!pinned_copy)
return -ENOMEM;
extent_map_tree_init(pinned_copy,
root->fs_info->btree_inode->i_mapping, GFP_NOFS);
trans->transaction->in_commit = 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->fs_mutex);
mutex_unlock(&root->fs_info->trans_mutex);
wait_for_commit(root, prev_trans);
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
put_transaction(prev_trans);
}
}
do {
joined = cur_trans->num_joined;
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->fs_mutex);
mutex_unlock(&root->fs_info->trans_mutex);
schedule_timeout(timeout);
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
finish_wait(&cur_trans->writer_wait, &wait);
ret = btrfs_write_ordered_inodes(trans, root);
} while (cur_trans->num_writers > 1 ||
(cur_trans->num_joined != joined));
WARN_ON(cur_trans != trans->transaction);
ret = add_dirty_roots(trans, &root->fs_info->fs_roots_radix,
&dirty_fs_roots);
BUG_ON(ret);
ret = btrfs_commit_tree_roots(trans, root);
BUG_ON(ret);
cur_trans = root->fs_info->running_transaction;
root->fs_info->running_transaction = NULL;
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));
write_extent_buffer(root->fs_info->sb_buffer,
&root->fs_info->super_copy, 0,
sizeof(root->fs_info->super_copy));
btrfs_copy_pinned(root, pinned_copy);
mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex);
ret = btrfs_write_and_wait_transaction(trans, root);
BUG_ON(ret);
write_ctree_super(trans, root);
mutex_lock(&root->fs_info->fs_mutex);
btrfs_finish_extent_commit(trans, root, pinned_copy);
mutex_lock(&root->fs_info->trans_mutex);
kfree(pinned_copy);
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);
if (root->fs_info->closing)
list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
else
list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
mutex_unlock(&root->fs_info->trans_mutex);
kmem_cache_free(btrfs_trans_handle_cachep, trans);
if (root->fs_info->closing) {
mutex_unlock(&root->fs_info->fs_mutex);
drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
mutex_lock(&root->fs_info->fs_mutex);
}
return ret;
}
int btrfs_clean_old_snapshots(struct btrfs_root *root)
{
struct list_head dirty_roots;
INIT_LIST_HEAD(&dirty_roots);
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);
}
return 0;
}
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
void btrfs_transaction_cleaner(void *p)
#else
void btrfs_transaction_cleaner(struct work_struct *work)
#endif
{
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
struct btrfs_fs_info *fs_info = p;
#else
struct btrfs_fs_info *fs_info = container_of(work,
struct btrfs_fs_info,
trans_work.work);
#endif
struct btrfs_root *root = fs_info->tree_root;
struct btrfs_transaction *cur;
struct btrfs_trans_handle *trans;
unsigned long now;
unsigned long delay = HZ * 30;
int ret;
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
cur = root->fs_info->running_transaction;
if (!cur) {
mutex_unlock(&root->fs_info->trans_mutex);
goto out;
}
now = get_seconds();
if (now < cur->start_time || now - cur->start_time < 30) {
mutex_unlock(&root->fs_info->trans_mutex);
delay = HZ * 5;
goto out;
}
mutex_unlock(&root->fs_info->trans_mutex);
btrfs_defrag_dirty_roots(root->fs_info);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
out:
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_clean_old_snapshots(root);
btrfs_transaction_queue_work(root, delay);
}
void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
{
queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
}
void btrfs_transaction_flush_work(struct btrfs_root *root)
{
cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
flush_workqueue(trans_wq);
}
void __init btrfs_init_transaction_sys(void)
{
trans_wq = create_workqueue("btrfs");
}
void btrfs_exit_transaction_sys(void)
{
destroy_workqueue(trans_wq);
}