[linux-2.6-block.git] / fs / btrfs / transaction.c

#include <linux/module.h>
#include <linux/fs.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 TRANS_MAGIC 0xE1E10E
static void put_transaction(struct btrfs_transaction *transaction)
{
	WARN_ON(transaction->use_count == 0);
	transaction->use_count--;
	WARN_ON(transaction->magic != TRANS_MAGIC);
	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 = 0;
		cur_trans->transid = root->fs_info->generation;
		init_waitqueue_head(&cur_trans->writer_wait);
		init_waitqueue_head(&cur_trans->commit_wait);
		cur_trans->magic = TRANS_MAGIC;
		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);
		init_bit_radix(&cur_trans->dirty_pages);
	}
	cur_trans->num_writers++;
	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;
	u64 running_trans_id;

	mutex_lock(&root->fs_info->trans_mutex);
	ret = join_transaction(root);
	BUG_ON(ret);
	running_trans_id = root->fs_info->running_transaction->transid;

	if (root != root->fs_info->tree_root && root->last_trans <
	    running_trans_id) {
		radix_tree_tag_set(&root->fs_info->fs_roots_radix,
				   (unsigned long)root->root_key.objectid,
				   BTRFS_ROOT_TRANS_TAG);
		root->commit_root = root->node;
		get_bh(root->node);
	}
	root->last_trans = running_trans_id;
	h->transid = running_trans_id;
	h->transaction = root->fs_info->running_transaction;
	h->blocks_reserved = num_blocks;
	h->blocks_used = 0;
	h->block_group = NULL;
	root->fs_info->running_transaction->use_count++;
	mutex_unlock(&root->fs_info->trans_mutex);
	h->magic = h->magic2 = TRANS_MAGIC;
	return h;
}

int btrfs_end_transaction(struct btrfs_trans_handle *trans,
			  struct btrfs_root *root)
{
	struct btrfs_transaction *cur_trans;

	WARN_ON(trans->magic != TRANS_MAGIC);
	WARN_ON(trans->magic2 != TRANS_MAGIC);
	mutex_lock(&root->fs_info->trans_mutex);
	cur_trans = root->fs_info->running_transaction;
	WARN_ON(cur_trans->num_writers < 1);
	if (waitqueue_active(&cur_trans->writer_wait))
		wake_up(&cur_trans->writer_wait);
	cur_trans->num_writers--;
	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)
{
	unsigned long gang[16];
	int ret;
	int i;
	int err;
	int werr = 0;
	struct page *page;
	struct radix_tree_root *dirty_pages;
	struct inode *btree_inode = root->fs_info->btree_inode;

	if (!trans || !trans->transaction) {
		return filemap_write_and_wait(btree_inode->i_mapping);
	}
	dirty_pages = &trans->transaction->dirty_pages;
	while(1) {
		ret = find_first_radix_bit(dirty_pages, gang,
					   0, ARRAY_SIZE(gang));
		if (!ret)
			break;
		for (i = 0; i < ret; i++) {
			/* FIXME EIO */
			clear_radix_bit(dirty_pages, gang[i]);
			page = find_lock_page(btree_inode->i_mapping,
					      gang[i]);
			if (!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;
	struct btrfs_root *dev_root = fs_info->dev_root;

	if (btrfs_super_device_root(fs_info->disk_super) !=
	    bh_blocknr(dev_root->node)) {
		btrfs_set_super_device_root(fs_info->disk_super,
					    bh_blocknr(dev_root->node));
	}
	btrfs_write_dirty_block_groups(trans, extent_root);
	while(1) {
		old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
		if (old_extent_block == bh_blocknr(extent_root->node))
			break;
		btrfs_set_root_blocknr(&extent_root->root_item,
				       bh_blocknr(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);
	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);
	}
	finish_wait(&commit->commit_wait, &wait);
	return 0;
}

struct dirty_root {
	struct list_head list;
	struct btrfs_key snap_key;
	struct buffer_head *commit_root;
	struct btrfs_root *root;
};

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;
	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(bh_blocknr(root->node) !=
					btrfs_root_blocknr(&root->root_item));
				brelse(root->commit_root);
				root->commit_root = NULL;
				continue;
			}
			dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
			BUG_ON(!dirty);
			memcpy(&dirty->snap_key, &root->root_key,
			       sizeof(root->root_key));
			dirty->commit_root = root->commit_root;
			root->commit_root = NULL;
			dirty->root = root;
			root->root_key.offset = root->fs_info->generation;
			btrfs_set_root_blocknr(&root->root_item,
					       bh_blocknr(root->node));
			err = btrfs_insert_root(trans, root->fs_info->tree_root,
						&root->root_key,
						&root->root_item);
			BUG_ON(err);
			list_add(&dirty->list, list);
		}
	}
	return 0;
}

static int drop_dirty_roots(struct btrfs_root *tree_root,
			    struct list_head *list)
{
	struct dirty_root *dirty;
	struct btrfs_trans_handle *trans;
	int ret;

	while(!list_empty(list)) {
		dirty = list_entry(list->next, struct dirty_root, list);
		list_del_init(&dirty->list);
		trans = btrfs_start_transaction(tree_root, 1);
		ret = btrfs_drop_snapshot(trans, dirty->root,
					  dirty->commit_root);
		BUG_ON(ret);

		ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
		BUG_ON(ret);
		ret = btrfs_end_transaction(trans, tree_root);
		BUG_ON(ret);
		kfree(dirty);
	}
	return 0;
}

int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root)
{
	int ret = 0;
	struct btrfs_transaction *cur_trans;
	struct btrfs_transaction *prev_trans = NULL;
	struct list_head dirty_fs_roots;
	DEFINE_WAIT(wait);

	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++;
		btrfs_end_transaction(trans, root);
		ret = wait_for_commit(root, cur_trans);
		BUG_ON(ret);
		put_transaction(cur_trans);
		mutex_unlock(&root->fs_info->trans_mutex);
		return 0;
	}
	cur_trans = trans->transaction;
	trans->transaction->in_commit = 1;
	while (trans->transaction->num_writers > 1) {
		WARN_ON(cur_trans != trans->transaction);
		prepare_to_wait(&trans->transaction->writer_wait, &wait,
				TASK_UNINTERRUPTIBLE);
		if (trans->transaction->num_writers <= 1)
			break;
		mutex_unlock(&root->fs_info->trans_mutex);
		schedule();
		mutex_lock(&root->fs_info->trans_mutex);
		finish_wait(&trans->transaction->writer_wait, &wait);
	}
	finish_wait(&trans->transaction->writer_wait, &wait);
	WARN_ON(cur_trans != trans->transaction);
	add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
	ret = btrfs_commit_tree_roots(trans, root);
	BUG_ON(ret);
	cur_trans = root->fs_info->running_transaction;
	root->fs_info->running_transaction = NULL;
	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 = NULL;
		else
			prev_trans->use_count++;
	}
	mutex_unlock(&root->fs_info->trans_mutex);
	mutex_unlock(&root->fs_info->fs_mutex);
	ret = btrfs_write_and_wait_transaction(trans, root);
	if (prev_trans) {
		mutex_lock(&root->fs_info->trans_mutex);
		wait_for_commit(root, prev_trans);
		put_transaction(prev_trans);
		mutex_unlock(&root->fs_info->trans_mutex);
	}
	btrfs_set_super_generation(root->fs_info->disk_super,
				   cur_trans->transid);
	BUG_ON(ret);
	write_ctree_super(trans, root);

	mutex_lock(&root->fs_info->fs_mutex);
	btrfs_finish_extent_commit(trans, root);
	mutex_lock(&root->fs_info->trans_mutex);
	cur_trans->commit_done = 1;
	wake_up(&cur_trans->commit_wait);
	put_transaction(cur_trans);
	put_transaction(cur_trans);
	mutex_unlock(&root->fs_info->trans_mutex);
	kmem_cache_free(btrfs_trans_handle_cachep, trans);

	drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
	return ret;
}

void btrfs_transaction_cleaner(struct work_struct *work)
{
	struct btrfs_fs_info *fs_info = container_of(work,
						     struct btrfs_fs_info,
						     trans_work.work);

	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;

printk("btrfs transaction cleaner\n");
	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);
printk("forcing commit\n");
	trans = btrfs_start_transaction(root, 1);
	ret = btrfs_commit_transaction(trans, root);
out:
	mutex_unlock(&root->fs_info->fs_mutex);
	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 __exit btrfs_exit_transaction_sys(void)
{
	destroy_workqueue(trans_wq);
}
Commit	Line	Data
79154b1b CM	1	#include <linux/module.h>
	2	#include <linux/fs.h>
	3	#include "ctree.h"
	4	#include "disk-io.h"
	5	#include "transaction.h"
	6
78fae27e	7	static int total_trans = 0;
2c90e5d6 CM	8	extern struct kmem_cache *btrfs_trans_handle_cachep;
	9	extern struct kmem_cache *btrfs_transaction_cachep;
	10
08607c1b CM	11	static struct workqueue_struct *trans_wq;
08607c1b CM	12
0f7d52f4 CM	13	#define BTRFS_ROOT_TRANS_TAG 0
0f7d52f4 CM	14
2c90e5d6	15	#define TRANS_MAGIC 0xE1E10E
79154b1b CM	16	static void put_transaction(struct btrfs_transaction *transaction)
79154b1b CM	17	{
2c90e5d6	18	WARN_ON(transaction->use_count == 0);
79154b1b	19	transaction->use_count--;
2c90e5d6	20	WARN_ON(transaction->magic != TRANS_MAGIC);
78fae27e CM	21	if (transaction->use_count == 0) {
	22	WARN_ON(total_trans == 0);
	23	total_trans--;
8fd17795	24	list_del_init(&transaction->list);
2c90e5d6 CM	25	memset(transaction, 0, sizeof(*transaction));
2c90e5d6 CM	26	kmem_cache_free(btrfs_transaction_cachep, transaction);
78fae27e	27	}
79154b1b CM	28	}
	29
	30	static int join_transaction(struct btrfs_root *root)
	31	{
	32	struct btrfs_transaction *cur_trans;
	33	cur_trans = root->fs_info->running_transaction;
	34	if (!cur_trans) {
2c90e5d6 CM	35	cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
2c90e5d6 CM	36	GFP_NOFS);
78fae27e	37	total_trans++;
79154b1b	38	BUG_ON(!cur_trans);
0f7d52f4	39	root->fs_info->generation++;
79154b1b CM	40	root->fs_info->running_transaction = cur_trans;
79154b1b CM	41	cur_trans->num_writers = 0;
0f7d52f4	42	cur_trans->transid = root->fs_info->generation;
79154b1b CM	43	init_waitqueue_head(&cur_trans->writer_wait);
79154b1b CM	44	init_waitqueue_head(&cur_trans->commit_wait);
2c90e5d6	45	cur_trans->magic = TRANS_MAGIC;
79154b1b	46	cur_trans->in_commit = 0;
d5719762	47	cur_trans->use_count = 1;
79154b1b	48	cur_trans->commit_done = 0;
08607c1b	49	cur_trans->start_time = get_seconds();
8fd17795	50	list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
7c4452b9	51	init_bit_radix(&cur_trans->dirty_pages);
79154b1b CM	52	}
	53	cur_trans->num_writers++;
	54	return 0;
	55	}
	56
	57	struct btrfs_trans_handle btrfs_start_transaction(struct btrfs_root root,
	58	int num_blocks)
	59	{
2c90e5d6 CM	60	struct btrfs_trans_handle *h =
2c90e5d6 CM	61	kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
79154b1b	62	int ret;
0f7d52f4	63	u64 running_trans_id;
79154b1b CM	64
	65	mutex_lock(&root->fs_info->trans_mutex);
	66	ret = join_transaction(root);
	67	BUG_ON(ret);
0f7d52f4 CM	68	running_trans_id = root->fs_info->running_transaction->transid;
	69
	70	if (root != root->fs_info->tree_root && root->last_trans <
	71	running_trans_id) {
	72	radix_tree_tag_set(&root->fs_info->fs_roots_radix,
2619ba1f CM	73	(unsigned long)root->root_key.objectid,
2619ba1f CM	74	BTRFS_ROOT_TRANS_TAG);
0f7d52f4 CM	75	root->commit_root = root->node;
	76	get_bh(root->node);
	77	}
	78	root->last_trans = running_trans_id;
	79	h->transid = running_trans_id;
79154b1b CM	80	h->transaction = root->fs_info->running_transaction;
	81	h->blocks_reserved = num_blocks;
	82	h->blocks_used = 0;
31f3c99b	83	h->block_group = NULL;
79154b1b CM	84	root->fs_info->running_transaction->use_count++;
79154b1b CM	85	mutex_unlock(&root->fs_info->trans_mutex);
2c90e5d6	86	h->magic = h->magic2 = TRANS_MAGIC;
79154b1b CM	87	return h;
	88	}
	89
	90	int btrfs_end_transaction(struct btrfs_trans_handle *trans,
	91	struct btrfs_root *root)
	92	{
	93	struct btrfs_transaction *cur_trans;
d6e4a428	94
2c90e5d6 CM	95	WARN_ON(trans->magic != TRANS_MAGIC);
2c90e5d6 CM	96	WARN_ON(trans->magic2 != TRANS_MAGIC);
79154b1b CM	97	mutex_lock(&root->fs_info->trans_mutex);
79154b1b CM	98	cur_trans = root->fs_info->running_transaction;
d5719762	99	WARN_ON(cur_trans->num_writers < 1);
79154b1b CM	100	if (waitqueue_active(&cur_trans->writer_wait))
	101	wake_up(&cur_trans->writer_wait);
	102	cur_trans->num_writers--;
	103	put_transaction(cur_trans);
	104	mutex_unlock(&root->fs_info->trans_mutex);
d6025579	105	memset(trans, 0, sizeof(*trans));
2c90e5d6	106	kmem_cache_free(btrfs_trans_handle_cachep, trans);
79154b1b CM	107	return 0;
	108	}
	109
	110
	111	int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
	112	struct btrfs_root *root)
	113	{
7c4452b9 CM	114	unsigned long gang[16];
	115	int ret;
	116	int i;
	117	int err;
	118	int werr = 0;
	119	struct page *page;
	120	struct radix_tree_root *dirty_pages;
	121	struct inode *btree_inode = root->fs_info->btree_inode;
	122
	123	if (!trans \|\| !trans->transaction) {
	124	return filemap_write_and_wait(btree_inode->i_mapping);
	125	}
	126	dirty_pages = &trans->transaction->dirty_pages;
	127	while(1) {
e37c9e69 CM	128	ret = find_first_radix_bit(dirty_pages, gang,
e37c9e69 CM	129	0, ARRAY_SIZE(gang));
7c4452b9 CM	130	if (!ret)
	131	break;
	132	for (i = 0; i < ret; i++) {
	133	/* FIXME EIO */
	134	clear_radix_bit(dirty_pages, gang[i]);
	135	page = find_lock_page(btree_inode->i_mapping,
	136	gang[i]);
	137	if (!page)
	138	continue;
	139	err = write_one_page(page, 0);
	140	if (err)
	141	werr = err;
	142	page_cache_release(page);
	143	}
	144	}
	145	err = filemap_fdatawait(btree_inode->i_mapping);
	146	if (err)
	147	werr = err;
	148	return werr;
79154b1b CM	149	}
	150
	151	int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
	152	struct btrfs_root *root)
	153	{
	154	int ret;
	155	u64 old_extent_block;
	156	struct btrfs_fs_info *fs_info = root->fs_info;
	157	struct btrfs_root *tree_root = fs_info->tree_root;
	158	struct btrfs_root *extent_root = fs_info->extent_root;
8352d8a4	159	struct btrfs_root *dev_root = fs_info->dev_root;
79154b1b	160
8352d8a4 CM	161	if (btrfs_super_device_root(fs_info->disk_super) !=
	162	bh_blocknr(dev_root->node)) {
	163	btrfs_set_super_device_root(fs_info->disk_super,
	164	bh_blocknr(dev_root->node));
	165	}
9078a3e1	166	btrfs_write_dirty_block_groups(trans, extent_root);
79154b1b CM	167	while(1) {
79154b1b CM	168	old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
7eccb903	169	if (old_extent_block == bh_blocknr(extent_root->node))
79154b1b CM	170	break;
79154b1b CM	171	btrfs_set_root_blocknr(&extent_root->root_item,
7eccb903	172	bh_blocknr(extent_root->node));
79154b1b CM	173	ret = btrfs_update_root(trans, tree_root,
	174	&extent_root->root_key,
	175	&extent_root->root_item);
	176	BUG_ON(ret);
9078a3e1	177	btrfs_write_dirty_block_groups(trans, extent_root);
79154b1b CM	178	}
	179	return 0;
	180	}
	181
	182	static int wait_for_commit(struct btrfs_root *root,
	183	struct btrfs_transaction *commit)
	184	{
	185	DEFINE_WAIT(wait);
79154b1b CM	186	while(!commit->commit_done) {
	187	prepare_to_wait(&commit->commit_wait, &wait,
	188	TASK_UNINTERRUPTIBLE);
	189	if (commit->commit_done)
	190	break;
	191	mutex_unlock(&root->fs_info->trans_mutex);
	192	schedule();
	193	mutex_lock(&root->fs_info->trans_mutex);
	194	}
	195	finish_wait(&commit->commit_wait, &wait);
	196	return 0;
	197	}
	198
0f7d52f4 CM	199	struct dirty_root {
	200	struct list_head list;
	201	struct btrfs_key snap_key;
	202	struct buffer_head *commit_root;
	203	struct btrfs_root *root;
	204	};
	205
35b7e476 CM	206	static int add_dirty_roots(struct btrfs_trans_handle *trans,
	207	struct radix_tree_root *radix,
	208	struct list_head *list)
0f7d52f4 CM	209	{
	210	struct dirty_root *dirty;
	211	struct btrfs_root *gang[8];
	212	struct btrfs_root *root;
	213	int i;
	214	int ret;
	215	int err;
0f7d52f4 CM	216	while(1) {
	217	ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
	218	ARRAY_SIZE(gang),
	219	BTRFS_ROOT_TRANS_TAG);
	220	if (ret == 0)
	221	break;
	222	for (i = 0; i < ret; i++) {
	223	root = gang[i];
2619ba1f CM	224	radix_tree_tag_clear(radix,
	225	(unsigned long)root->root_key.objectid,
	226	BTRFS_ROOT_TRANS_TAG);
0f7d52f4	227	if (root->commit_root == root->node) {
7eccb903	228	WARN_ON(bh_blocknr(root->node) !=
0f7d52f4 CM	229	btrfs_root_blocknr(&root->root_item));
	230	brelse(root->commit_root);
	231	root->commit_root = NULL;
	232	continue;
	233	}
	234	dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
	235	BUG_ON(!dirty);
	236	memcpy(&dirty->snap_key, &root->root_key,
	237	sizeof(root->root_key));
	238	dirty->commit_root = root->commit_root;
	239	root->commit_root = NULL;
	240	dirty->root = root;
0f7d52f4 CM	241	root->root_key.offset = root->fs_info->generation;
0f7d52f4 CM	242	btrfs_set_root_blocknr(&root->root_item,
7eccb903	243	bh_blocknr(root->node));
0f7d52f4 CM	244	err = btrfs_insert_root(trans, root->fs_info->tree_root,
	245	&root->root_key,
	246	&root->root_item);
	247	BUG_ON(err);
	248	list_add(&dirty->list, list);
	249	}
	250	}
0f7d52f4 CM	251	return 0;
	252	}
	253
35b7e476 CM	254	static int drop_dirty_roots(struct btrfs_root *tree_root,
35b7e476 CM	255	struct list_head *list)
0f7d52f4 CM	256	{
	257	struct dirty_root *dirty;
	258	struct btrfs_trans_handle *trans;
	259	int ret;
	260
	261	while(!list_empty(list)) {
	262	dirty = list_entry(list->next, struct dirty_root, list);
	263	list_del_init(&dirty->list);
	264	trans = btrfs_start_transaction(tree_root, 1);
0f7d52f4 CM	265	ret = btrfs_drop_snapshot(trans, dirty->root,
	266	dirty->commit_root);
	267	BUG_ON(ret);
	268
0f7d52f4 CM	269	ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
	270	BUG_ON(ret);
	271	ret = btrfs_end_transaction(trans, tree_root);
	272	BUG_ON(ret);
	273	kfree(dirty);
	274	}
	275	return 0;
	276	}
	277
79154b1b CM	278	int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
	279	struct btrfs_root *root)
	280	{
	281	int ret = 0;
79154b1b	282	struct btrfs_transaction *cur_trans;
8fd17795	283	struct btrfs_transaction *prev_trans = NULL;
0f7d52f4	284	struct list_head dirty_fs_roots;
79154b1b CM	285	DEFINE_WAIT(wait);
79154b1b CM	286
0f7d52f4	287	INIT_LIST_HEAD(&dirty_fs_roots);
d6e4a428	288
79154b1b CM	289	mutex_lock(&root->fs_info->trans_mutex);
	290	if (trans->transaction->in_commit) {
	291	cur_trans = trans->transaction;
	292	trans->transaction->use_count++;
	293	btrfs_end_transaction(trans, root);
	294	ret = wait_for_commit(root, cur_trans);
	295	BUG_ON(ret);
	296	put_transaction(cur_trans);
	297	mutex_unlock(&root->fs_info->trans_mutex);
	298	return 0;
	299	}
2c90e5d6 CM	300	cur_trans = trans->transaction;
2c90e5d6 CM	301	trans->transaction->in_commit = 1;
79154b1b	302	while (trans->transaction->num_writers > 1) {
2c90e5d6	303	WARN_ON(cur_trans != trans->transaction);
79154b1b CM	304	prepare_to_wait(&trans->transaction->writer_wait, &wait,
	305	TASK_UNINTERRUPTIBLE);
	306	if (trans->transaction->num_writers <= 1)
	307	break;
	308	mutex_unlock(&root->fs_info->trans_mutex);
	309	schedule();
	310	mutex_lock(&root->fs_info->trans_mutex);
2c90e5d6	311	finish_wait(&trans->transaction->writer_wait, &wait);
79154b1b CM	312	}
79154b1b CM	313	finish_wait(&trans->transaction->writer_wait, &wait);
2c90e5d6	314	WARN_ON(cur_trans != trans->transaction);
0f7d52f4	315	add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
79154b1b CM	316	ret = btrfs_commit_tree_roots(trans, root);
79154b1b CM	317	BUG_ON(ret);
78fae27e CM	318	cur_trans = root->fs_info->running_transaction;
78fae27e CM	319	root->fs_info->running_transaction = NULL;
8fd17795 CM	320	if (cur_trans->list.prev != &root->fs_info->trans_list) {
	321	prev_trans = list_entry(cur_trans->list.prev,
	322	struct btrfs_transaction, list);
	323	if (prev_trans->commit_done)
	324	prev_trans = NULL;
	325	else
	326	prev_trans->use_count++;
	327	}
78fae27e	328	mutex_unlock(&root->fs_info->trans_mutex);
8fd17795	329	mutex_unlock(&root->fs_info->fs_mutex);
79154b1b	330	ret = btrfs_write_and_wait_transaction(trans, root);
8fd17795 CM	331	if (prev_trans) {
	332	mutex_lock(&root->fs_info->trans_mutex);
	333	wait_for_commit(root, prev_trans);
	334	put_transaction(prev_trans);
	335	mutex_unlock(&root->fs_info->trans_mutex);
	336	}
	337	btrfs_set_super_generation(root->fs_info->disk_super,
	338	cur_trans->transid);
79154b1b	339	BUG_ON(ret);
79154b1b	340	write_ctree_super(trans, root);
8fd17795 CM	341
8fd17795 CM	342	mutex_lock(&root->fs_info->fs_mutex);
78fae27e CM	343	btrfs_finish_extent_commit(trans, root);
78fae27e CM	344	mutex_lock(&root->fs_info->trans_mutex);
2c90e5d6 CM	345	cur_trans->commit_done = 1;
2c90e5d6 CM	346	wake_up(&cur_trans->commit_wait);
78fae27e	347	put_transaction(cur_trans);
79154b1b	348	put_transaction(cur_trans);
78fae27e	349	mutex_unlock(&root->fs_info->trans_mutex);
2c90e5d6	350	kmem_cache_free(btrfs_trans_handle_cachep, trans);
79154b1b	351
0f7d52f4	352	drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
79154b1b CM	353	return ret;
	354	}
	355
08607c1b CM	356	void btrfs_transaction_cleaner(struct work_struct *work)
	357	{
	358	struct btrfs_fs_info *fs_info = container_of(work,
	359	struct btrfs_fs_info,
	360	trans_work.work);
	361
	362	struct btrfs_root *root = fs_info->tree_root;
	363	struct btrfs_transaction *cur;
	364	struct btrfs_trans_handle *trans;
	365	unsigned long now;
	366	unsigned long delay = HZ * 30;
	367	int ret;
	368
	369	printk("btrfs transaction cleaner\n");
	370	mutex_lock(&root->fs_info->fs_mutex);
	371	mutex_lock(&root->fs_info->trans_mutex);
	372	cur = root->fs_info->running_transaction;
	373	if (!cur) {
	374	mutex_unlock(&root->fs_info->trans_mutex);
	375	goto out;
	376	}
	377	now = get_seconds();
	378	if (now < cur->start_time \|\| now - cur->start_time < 30) {
	379	mutex_unlock(&root->fs_info->trans_mutex);
	380	delay = HZ * 5;
	381	goto out;
	382	}
	383	mutex_unlock(&root->fs_info->trans_mutex);
	384	printk("forcing commit\n");
	385	trans = btrfs_start_transaction(root, 1);
	386	ret = btrfs_commit_transaction(trans, root);
	387	out:
	388	mutex_unlock(&root->fs_info->fs_mutex);
	389	btrfs_transaction_queue_work(root, delay);
	390	}
	391
	392	void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
	393	{
	394	queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
	395	}
	396
	397	void btrfs_transaction_flush_work(struct btrfs_root *root)
	398	{
	399	cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
	400	flush_workqueue(trans_wq);
	401	}
	402
	403	void __init btrfs_init_transaction_sys(void)
	404	{
	405	trans_wq = create_workqueue("btrfs");
	406	}
	407
	408	void __exit btrfs_exit_transaction_sys(void)
	409	{
	410	destroy_workqueue(trans_wq);
	411	}
	412