linux/fs/btrfs/transaction.c
Chris Mason 925baeddc5 Btrfs: Start btree concurrency work.
The allocation trees and the chunk trees are serialized via their own
dedicated mutexes.  This means allocation location is still not very
fine grained.

The main FS btree is protected by locks on each block in the btree.  Locks
are taken top / down, and as processing finishes on a given level of the
tree, the lock is released after locking the lower level.

The end result of a search is now a path where only the lowest level
is locked.  Releasing or freeing the path drops any locks held.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00

873 lines
23 KiB
C

/*
* 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"
#include "locking.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 noinline 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 noinline 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->last_alloc = 0;
root->fs_info->last_data_alloc = 0;
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();
INIT_LIST_HEAD(&cur_trans->pending_snapshots);
list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
btrfs_ordered_inode_tree_init(&cur_trans->ordered_inode_tree);
extent_io_tree_init(&cur_trans->dirty_pages,
root->fs_info->btree_inode->i_mapping,
GFP_NOFS);
spin_lock(&root->fs_info->new_trans_lock);
root->fs_info->running_transaction = cur_trans;
spin_unlock(&root->fs_info->new_trans_lock);
} else {
cur_trans->num_writers++;
cur_trans->num_joined++;
}
return 0;
}
static noinline 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 = btrfs_root_node(root);
} 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_io_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;
}
static int update_cowonly_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
u64 old_root_bytenr;
struct btrfs_root *tree_root = root->fs_info->tree_root;
btrfs_write_dirty_block_groups(trans, root);
while(1) {
old_root_bytenr = btrfs_root_bytenr(&root->root_item);
if (old_root_bytenr == root->node->start)
break;
btrfs_set_root_bytenr(&root->root_item,
root->node->start);
btrfs_set_root_level(&root->root_item,
btrfs_header_level(root->node));
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
&root->root_item);
BUG_ON(ret);
btrfs_write_dirty_block_groups(trans, root);
}
return 0;
}
int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct list_head *next;
while(!list_empty(&fs_info->dirty_cowonly_roots)) {
next = fs_info->dirty_cowonly_roots.next;
list_del_init(next);
root = list_entry(next, struct btrfs_root, dirty_list);
update_cowonly_root(trans, root);
}
return 0;
}
static noinline 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 noinline 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 noinline 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;
root->fs_info->throttles++;
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);
root->fs_info->throttles--;
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;
int ret;
root->fs_info->throttles++;
while(1) {
ret = btrfs_find_first_ordered_inode(
&cur_trans->ordered_inode_tree,
&root_objectid, &objectid, &inode);
if (!ret)
break;
mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex);
if (S_ISREG(inode->i_mode)) {
atomic_inc(&BTRFS_I(inode)->ordered_writeback);
filemap_fdatawrite(inode->i_mapping);
atomic_dec(&BTRFS_I(inode)->ordered_writeback);
}
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, &inode);
if (!ret)
break;
mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex);
if (S_ISREG(inode->i_mode)) {
atomic_inc(&BTRFS_I(inode)->ordered_writeback);
filemap_write_and_wait(inode->i_mapping);
atomic_dec(&BTRFS_I(inode)->ordered_writeback);
}
atomic_dec(&inode->i_count);
iput(inode);
mutex_lock(&root->fs_info->fs_mutex);
mutex_lock(&root->fs_info->trans_mutex);
}
root->fs_info->throttles--;
return 0;
}
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;
int namelen;
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;
memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
key.objectid = objectid;
key.offset = 1;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
old = btrfs_lock_root_node(root);
btrfs_cow_block(trans, root, old, NULL, 0, &old);
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));
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;
/*
* insert the directory item
*/
key.offset = (u64)-1;
namelen = strlen(pending->name);
ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
pending->name, namelen,
root->fs_info->sb->s_root->d_inode->i_ino,
&key, BTRFS_FT_DIR);
if (ret)
goto fail;
ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
pending->name, strlen(pending->name), objectid,
root->fs_info->sb->s_root->d_inode->i_ino);
/* Invalidate existing dcache entry for new snapshot. */
btrfs_invalidate_dcache_root(root, pending->name, namelen);
fail:
kfree(new_root_item);
return ret;
}
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;
int ret;
while(!list_empty(head)) {
pending = list_entry(head->next,
struct btrfs_pending_snapshot, list);
ret = create_pending_snapshot(trans, 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);
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_io_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));
ret = create_pending_snapshots(trans, root->fs_info);
BUG_ON(ret);
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;
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));
memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy,
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);
if (root->fs_info->closing)
goto out;
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)
{
if (!root->fs_info->closing)
queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
}
void btrfs_transaction_flush_work(struct btrfs_root *root)
{
cancel_delayed_work(&root->fs_info->trans_work);
flush_workqueue(trans_wq);
}
void __init btrfs_init_transaction_sys(void)
{
trans_wq = create_workqueue("btrfs-transaction");
}
void btrfs_exit_transaction_sys(void)
{
destroy_workqueue(trans_wq);
}