[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;

#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;
		list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
	}
	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;
	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)
{
	filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
	return 0;
}

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));
	}
	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);
	}
	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;
};

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;
}

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;
}
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
0f7d52f4 CM	11	#define BTRFS_ROOT_TRANS_TAG 0
0f7d52f4 CM	12
2c90e5d6	13	#define TRANS_MAGIC 0xE1E10E
79154b1b CM	14	static void put_transaction(struct btrfs_transaction *transaction)
79154b1b CM	15	{
2c90e5d6	16	WARN_ON(transaction->use_count == 0);
79154b1b	17	transaction->use_count--;
2c90e5d6	18	WARN_ON(transaction->magic != TRANS_MAGIC);
78fae27e CM	19	if (transaction->use_count == 0) {
	20	WARN_ON(total_trans == 0);
	21	total_trans--;
8fd17795	22	list_del_init(&transaction->list);
2c90e5d6 CM	23	memset(transaction, 0, sizeof(*transaction));
2c90e5d6 CM	24	kmem_cache_free(btrfs_transaction_cachep, transaction);
78fae27e	25	}
79154b1b CM	26	}
	27
	28	static int join_transaction(struct btrfs_root *root)
	29	{
	30	struct btrfs_transaction *cur_trans;
	31	cur_trans = root->fs_info->running_transaction;
	32	if (!cur_trans) {
2c90e5d6 CM	33	cur_trans = kmem_cache_alloc(btrfs_transaction_cachep,
2c90e5d6 CM	34	GFP_NOFS);
78fae27e	35	total_trans++;
79154b1b	36	BUG_ON(!cur_trans);
0f7d52f4	37	root->fs_info->generation++;
79154b1b CM	38	root->fs_info->running_transaction = cur_trans;
79154b1b CM	39	cur_trans->num_writers = 0;
0f7d52f4	40	cur_trans->transid = root->fs_info->generation;
79154b1b CM	41	init_waitqueue_head(&cur_trans->writer_wait);
79154b1b CM	42	init_waitqueue_head(&cur_trans->commit_wait);
2c90e5d6	43	cur_trans->magic = TRANS_MAGIC;
79154b1b	44	cur_trans->in_commit = 0;
d5719762	45	cur_trans->use_count = 1;
79154b1b	46	cur_trans->commit_done = 0;
8fd17795	47	list_add_tail(&cur_trans->list, &root->fs_info->trans_list);
79154b1b CM	48	}
	49	cur_trans->num_writers++;
	50	return 0;
	51	}
	52
	53	struct btrfs_trans_handle btrfs_start_transaction(struct btrfs_root root,
	54	int num_blocks)
	55	{
2c90e5d6 CM	56	struct btrfs_trans_handle *h =
2c90e5d6 CM	57	kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
79154b1b	58	int ret;
0f7d52f4	59	u64 running_trans_id;
79154b1b CM	60
	61	mutex_lock(&root->fs_info->trans_mutex);
	62	ret = join_transaction(root);
	63	BUG_ON(ret);
0f7d52f4 CM	64	running_trans_id = root->fs_info->running_transaction->transid;
	65
	66	if (root != root->fs_info->tree_root && root->last_trans <
	67	running_trans_id) {
	68	radix_tree_tag_set(&root->fs_info->fs_roots_radix,
2619ba1f CM	69	(unsigned long)root->root_key.objectid,
2619ba1f CM	70	BTRFS_ROOT_TRANS_TAG);
0f7d52f4 CM	71	root->commit_root = root->node;
	72	get_bh(root->node);
	73	}
	74	root->last_trans = running_trans_id;
	75	h->transid = running_trans_id;
79154b1b CM	76	h->transaction = root->fs_info->running_transaction;
	77	h->blocks_reserved = num_blocks;
	78	h->blocks_used = 0;
	79	root->fs_info->running_transaction->use_count++;
	80	mutex_unlock(&root->fs_info->trans_mutex);
2c90e5d6	81	h->magic = h->magic2 = TRANS_MAGIC;
79154b1b CM	82	return h;
	83	}
	84
	85	int btrfs_end_transaction(struct btrfs_trans_handle *trans,
	86	struct btrfs_root *root)
	87	{
	88	struct btrfs_transaction *cur_trans;
d6e4a428	89
2c90e5d6 CM	90	WARN_ON(trans->magic != TRANS_MAGIC);
2c90e5d6 CM	91	WARN_ON(trans->magic2 != TRANS_MAGIC);
79154b1b CM	92	mutex_lock(&root->fs_info->trans_mutex);
79154b1b CM	93	cur_trans = root->fs_info->running_transaction;
d5719762	94	WARN_ON(cur_trans->num_writers < 1);
79154b1b CM	95	if (waitqueue_active(&cur_trans->writer_wait))
	96	wake_up(&cur_trans->writer_wait);
	97	cur_trans->num_writers--;
	98	put_transaction(cur_trans);
	99	mutex_unlock(&root->fs_info->trans_mutex);
d6025579	100	memset(trans, 0, sizeof(*trans));
2c90e5d6	101	kmem_cache_free(btrfs_trans_handle_cachep, trans);
79154b1b CM	102	return 0;
	103	}
	104
	105
	106	int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
	107	struct btrfs_root *root)
	108	{
7cfcc17e	109	filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
79154b1b CM	110	return 0;
	111	}
	112
	113	int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
	114	struct btrfs_root *root)
	115	{
	116	int ret;
	117	u64 old_extent_block;
	118	struct btrfs_fs_info *fs_info = root->fs_info;
	119	struct btrfs_root *tree_root = fs_info->tree_root;
	120	struct btrfs_root *extent_root = fs_info->extent_root;
8352d8a4	121	struct btrfs_root *dev_root = fs_info->dev_root;
79154b1b	122
8352d8a4 CM	123	if (btrfs_super_device_root(fs_info->disk_super) !=
	124	bh_blocknr(dev_root->node)) {
	125	btrfs_set_super_device_root(fs_info->disk_super,
	126	bh_blocknr(dev_root->node));
	127	}
79154b1b CM	128	while(1) {
79154b1b CM	129	old_extent_block = btrfs_root_blocknr(&extent_root->root_item);
7eccb903	130	if (old_extent_block == bh_blocknr(extent_root->node))
79154b1b CM	131	break;
79154b1b CM	132	btrfs_set_root_blocknr(&extent_root->root_item,
7eccb903	133	bh_blocknr(extent_root->node));
79154b1b CM	134	ret = btrfs_update_root(trans, tree_root,
	135	&extent_root->root_key,
	136	&extent_root->root_item);
	137	BUG_ON(ret);
	138	}
	139	return 0;
	140	}
	141
	142	static int wait_for_commit(struct btrfs_root *root,
	143	struct btrfs_transaction *commit)
	144	{
	145	DEFINE_WAIT(wait);
79154b1b CM	146	while(!commit->commit_done) {
	147	prepare_to_wait(&commit->commit_wait, &wait,
	148	TASK_UNINTERRUPTIBLE);
	149	if (commit->commit_done)
	150	break;
	151	mutex_unlock(&root->fs_info->trans_mutex);
	152	schedule();
	153	mutex_lock(&root->fs_info->trans_mutex);
	154	}
	155	finish_wait(&commit->commit_wait, &wait);
	156	return 0;
	157	}
	158
0f7d52f4 CM	159	struct dirty_root {
	160	struct list_head list;
	161	struct btrfs_key snap_key;
	162	struct buffer_head *commit_root;
	163	struct btrfs_root *root;
	164	};
	165
	166	int add_dirty_roots(struct btrfs_trans_handle *trans,
	167	struct radix_tree_root radix, struct list_head list)
	168	{
	169	struct dirty_root *dirty;
	170	struct btrfs_root *gang[8];
	171	struct btrfs_root *root;
	172	int i;
	173	int ret;
	174	int err;
0f7d52f4 CM	175	while(1) {
	176	ret = radix_tree_gang_lookup_tag(radix, (void **)gang, 0,
	177	ARRAY_SIZE(gang),
	178	BTRFS_ROOT_TRANS_TAG);
	179	if (ret == 0)
	180	break;
	181	for (i = 0; i < ret; i++) {
	182	root = gang[i];
2619ba1f CM	183	radix_tree_tag_clear(radix,
	184	(unsigned long)root->root_key.objectid,
	185	BTRFS_ROOT_TRANS_TAG);
0f7d52f4	186	if (root->commit_root == root->node) {
7eccb903	187	WARN_ON(bh_blocknr(root->node) !=
0f7d52f4 CM	188	btrfs_root_blocknr(&root->root_item));
	189	brelse(root->commit_root);
	190	root->commit_root = NULL;
	191	continue;
	192	}
	193	dirty = kmalloc(sizeof(*dirty), GFP_NOFS);
	194	BUG_ON(!dirty);
	195	memcpy(&dirty->snap_key, &root->root_key,
	196	sizeof(root->root_key));
	197	dirty->commit_root = root->commit_root;
	198	root->commit_root = NULL;
	199	dirty->root = root;
0f7d52f4 CM	200	root->root_key.offset = root->fs_info->generation;
0f7d52f4 CM	201	btrfs_set_root_blocknr(&root->root_item,
7eccb903	202	bh_blocknr(root->node));
0f7d52f4 CM	203	err = btrfs_insert_root(trans, root->fs_info->tree_root,
	204	&root->root_key,
	205	&root->root_item);
	206	BUG_ON(err);
	207	list_add(&dirty->list, list);
	208	}
	209	}
0f7d52f4 CM	210	return 0;
	211	}
	212
	213	int drop_dirty_roots(struct btrfs_root tree_root, struct list_head list)
	214	{
	215	struct dirty_root *dirty;
	216	struct btrfs_trans_handle *trans;
	217	int ret;
	218
	219	while(!list_empty(list)) {
	220	dirty = list_entry(list->next, struct dirty_root, list);
	221	list_del_init(&dirty->list);
	222	trans = btrfs_start_transaction(tree_root, 1);
0f7d52f4 CM	223	ret = btrfs_drop_snapshot(trans, dirty->root,
	224	dirty->commit_root);
	225	BUG_ON(ret);
	226
0f7d52f4 CM	227	ret = btrfs_del_root(trans, tree_root, &dirty->snap_key);
	228	BUG_ON(ret);
	229	ret = btrfs_end_transaction(trans, tree_root);
	230	BUG_ON(ret);
	231	kfree(dirty);
	232	}
	233	return 0;
	234	}
	235
79154b1b CM	236	int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
	237	struct btrfs_root *root)
	238	{
	239	int ret = 0;
79154b1b	240	struct btrfs_transaction *cur_trans;
8fd17795	241	struct btrfs_transaction *prev_trans = NULL;
0f7d52f4	242	struct list_head dirty_fs_roots;
79154b1b CM	243	DEFINE_WAIT(wait);
79154b1b CM	244
0f7d52f4	245	INIT_LIST_HEAD(&dirty_fs_roots);
d6e4a428	246
79154b1b CM	247	mutex_lock(&root->fs_info->trans_mutex);
	248	if (trans->transaction->in_commit) {
	249	cur_trans = trans->transaction;
	250	trans->transaction->use_count++;
	251	btrfs_end_transaction(trans, root);
	252	ret = wait_for_commit(root, cur_trans);
	253	BUG_ON(ret);
	254	put_transaction(cur_trans);
	255	mutex_unlock(&root->fs_info->trans_mutex);
	256	return 0;
	257	}
2c90e5d6 CM	258	cur_trans = trans->transaction;
2c90e5d6 CM	259	trans->transaction->in_commit = 1;
79154b1b	260	while (trans->transaction->num_writers > 1) {
2c90e5d6	261	WARN_ON(cur_trans != trans->transaction);
79154b1b CM	262	prepare_to_wait(&trans->transaction->writer_wait, &wait,
	263	TASK_UNINTERRUPTIBLE);
	264	if (trans->transaction->num_writers <= 1)
	265	break;
	266	mutex_unlock(&root->fs_info->trans_mutex);
	267	schedule();
	268	mutex_lock(&root->fs_info->trans_mutex);
2c90e5d6	269	finish_wait(&trans->transaction->writer_wait, &wait);
79154b1b CM	270	}
79154b1b CM	271	finish_wait(&trans->transaction->writer_wait, &wait);
2c90e5d6	272	WARN_ON(cur_trans != trans->transaction);
0f7d52f4	273	add_dirty_roots(trans, &root->fs_info->fs_roots_radix, &dirty_fs_roots);
79154b1b CM	274	ret = btrfs_commit_tree_roots(trans, root);
79154b1b CM	275	BUG_ON(ret);
78fae27e CM	276	cur_trans = root->fs_info->running_transaction;
78fae27e CM	277	root->fs_info->running_transaction = NULL;
8fd17795 CM	278	if (cur_trans->list.prev != &root->fs_info->trans_list) {
	279	prev_trans = list_entry(cur_trans->list.prev,
	280	struct btrfs_transaction, list);
	281	if (prev_trans->commit_done)
	282	prev_trans = NULL;
	283	else
	284	prev_trans->use_count++;
	285	}
78fae27e	286	mutex_unlock(&root->fs_info->trans_mutex);
8fd17795	287	mutex_unlock(&root->fs_info->fs_mutex);
79154b1b	288	ret = btrfs_write_and_wait_transaction(trans, root);
8fd17795 CM	289	if (prev_trans) {
	290	mutex_lock(&root->fs_info->trans_mutex);
	291	wait_for_commit(root, prev_trans);
	292	put_transaction(prev_trans);
	293	mutex_unlock(&root->fs_info->trans_mutex);
	294	}
	295	btrfs_set_super_generation(root->fs_info->disk_super,
	296	cur_trans->transid);
79154b1b	297	BUG_ON(ret);
79154b1b	298	write_ctree_super(trans, root);
8fd17795 CM	299
8fd17795 CM	300	mutex_lock(&root->fs_info->fs_mutex);
78fae27e CM	301	btrfs_finish_extent_commit(trans, root);
78fae27e CM	302	mutex_lock(&root->fs_info->trans_mutex);
2c90e5d6 CM	303	cur_trans->commit_done = 1;
2c90e5d6 CM	304	wake_up(&cur_trans->commit_wait);
78fae27e	305	put_transaction(cur_trans);
79154b1b	306	put_transaction(cur_trans);
78fae27e	307	mutex_unlock(&root->fs_info->trans_mutex);
2c90e5d6	308	kmem_cache_free(btrfs_trans_handle_cachep, trans);
79154b1b	309
0f7d52f4	310	drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
79154b1b CM	311	return ret;
	312	}
	313