Commit a74a4b97 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Replace the transaction work queue with kthreads 



This creates one kthread for commits and one kthread for
deleting old snapshots.  All the work queues are removed.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 89ce8a63

fs/btrfs/ctree.c

+4 −1
Original line number Diff line number Diff line
@@ -1352,6 +1352,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root 
						free_extent_buffer(tmp);

					goto again;

				} else {

					if (tmp)

						free_extent_buffer(tmp);

					b = read_node_slot(root, b, slot);

				}

			}
@@ -3048,6 +3050,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) 
		free_extent_buffer(c);

		path->nodes[level] = next;

		path->slots[level] = 0;

		if (!path->skip_locking)

			path->locks[level] = 1;

		if (!level)

			break;

fs/btrfs/ctree.h

+4 −9
Original line number Diff line number Diff line
@@ -23,7 +23,6 @@ 
#include <linux/mm.h>

#include <linux/highmem.h>

#include <linux/fs.h>

#include <linux/workqueue.h>

#include <linux/completion.h>

#include <linux/backing-dev.h>

#include <asm/kmap_types.h>
@@ -519,15 +518,14 @@ struct btrfs_fs_info { 
	struct backing_dev_info bdi;

	spinlock_t hash_lock;

	struct mutex trans_mutex;

	struct mutex transaction_kthread_mutex;

	struct mutex cleaner_mutex;

	struct mutex alloc_mutex;

	struct mutex chunk_mutex;

	struct mutex drop_mutex;

	struct list_head trans_list;

	struct list_head hashers;

	struct list_head dead_roots;

	struct list_head end_io_work_list;

	struct work_struct end_io_work;

	spinlock_t end_io_work_lock;

	atomic_t nr_async_submits;



	/*
@@ -543,13 +541,10 @@ struct btrfs_fs_info { 
	struct btrfs_workers workers;

	struct btrfs_workers endio_workers;

	struct btrfs_workers submit_workers;

	struct task_struct *transaction_kthread;

	struct task_struct *cleaner_kthread;

	int thread_pool_size;



#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)

	struct work_struct trans_work;

#else

	struct delayed_work trans_work;

#endif

	struct kobject super_kobj;

	struct completion kobj_unregister;

	int do_barriers;

fs/btrfs/disk-io.c

+107 −9
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
 * Boston, MA 021110-1307, USA.

 */



#include <linux/version.h>

#include <linux/fs.h>

#include <linux/blkdev.h>

#include <linux/scatterlist.h>
@@ -24,6 +25,12 @@ 
#include <linux/writeback.h>

#include <linux/buffer_head.h> // for block_sync_page

#include <linux/workqueue.h>

#include <linux/kthread.h>

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)

# include <linux/freezer.h>

#else

# include <linux/sched.h>

#endif

#include "crc32c.h"

#include "ctree.h"

#include "disk-io.h"
@@ -1100,6 +1107,87 @@ static void end_workqueue_fn(struct btrfs_work *work) 
#endif

}



static int cleaner_kthread(void *arg)

{

	struct btrfs_root *root = arg;



	do {

		smp_mb();

		if (root->fs_info->closing)

			break;



		vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);

		mutex_lock(&root->fs_info->cleaner_mutex);

printk("cleaner awake\n");

		btrfs_clean_old_snapshots(root);

printk("cleaner done\n");

		mutex_unlock(&root->fs_info->cleaner_mutex);



		if (freezing(current)) {

			refrigerator();

		} else {

			smp_mb();

			if (root->fs_info->closing)

				break;

			set_current_state(TASK_INTERRUPTIBLE);

			schedule();

			__set_current_state(TASK_RUNNING);

		}

	} while (!kthread_should_stop());

	return 0;

}



static int transaction_kthread(void *arg)

{

	struct btrfs_root *root = arg;

	struct btrfs_trans_handle *trans;

	struct btrfs_transaction *cur;

	unsigned long now;

	unsigned long delay;

	int ret;



	do {

		smp_mb();

		if (root->fs_info->closing)

			break;



		delay = HZ * 30;

		vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);

		mutex_lock(&root->fs_info->transaction_kthread_mutex);



		mutex_lock(&root->fs_info->trans_mutex);

		cur = root->fs_info->running_transaction;

		if (!cur) {

			mutex_unlock(&root->fs_info->trans_mutex);

			goto sleep;

		}

		now = get_seconds();

		if (now < cur->start_time || now - cur->start_time < 30) {

			mutex_unlock(&root->fs_info->trans_mutex);

			delay = HZ * 5;

			goto sleep;

		}

		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);

sleep:

		wake_up_process(root->fs_info->cleaner_kthread);

		mutex_unlock(&root->fs_info->transaction_kthread_mutex);



		if (freezing(current)) {

			refrigerator();

		} else {

			if (root->fs_info->closing)

				break;

			set_current_state(TASK_INTERRUPTIBLE);

			schedule_timeout(delay);

			__set_current_state(TASK_RUNNING);

		}

	} while (!kthread_should_stop());

	return 0;

}



struct btrfs_root *open_ctree(struct super_block *sb,

			      struct btrfs_fs_devices *fs_devices,

			      char *options)
@@ -1189,11 +1277,6 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
			     fs_info->btree_inode->i_mapping, GFP_NOFS);

	fs_info->do_barriers = 1;



#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)

	INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);

#else

	INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);

#endif

	BTRFS_I(fs_info->btree_inode)->root = tree_root;

	memset(&BTRFS_I(fs_info->btree_inode)->location, 0,

	       sizeof(struct btrfs_key));
@@ -1204,6 +1287,8 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	mutex_init(&fs_info->drop_mutex);

	mutex_init(&fs_info->alloc_mutex);

	mutex_init(&fs_info->chunk_mutex);

	mutex_init(&fs_info->transaction_kthread_mutex);

	mutex_init(&fs_info->cleaner_mutex);



#if 0

	ret = add_hasher(fs_info, "crc32c");
@@ -1247,7 +1332,6 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	btrfs_start_workers(&fs_info->submit_workers, 1);

	btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);





	err = -EINVAL;

	if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {

		printk("Btrfs: wanted %llu devices, but found %llu\n",
@@ -1341,9 +1425,22 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	fs_info->data_alloc_profile = (u64)-1;

	fs_info->metadata_alloc_profile = (u64)-1;

	fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;

	fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,

					       "btrfs-cleaner");

	if (!fs_info->cleaner_kthread)

		goto fail_extent_root;



	fs_info->transaction_kthread = kthread_run(transaction_kthread,

						   tree_root,

						   "btrfs-transaction");

	if (!fs_info->transaction_kthread)

		goto fail_trans_kthread;





	return tree_root;



fail_trans_kthread:

	kthread_stop(fs_info->cleaner_kthread);

fail_extent_root:

	free_extent_buffer(extent_root->node);

fail_tree_root:
@@ -1562,8 +1659,11 @@ int close_ctree(struct btrfs_root *root) 
	fs_info->closing = 1;

	smp_mb();



	btrfs_transaction_flush_work(root);

	kthread_stop(root->fs_info->transaction_kthread);

	kthread_stop(root->fs_info->cleaner_kthread);



	btrfs_defrag_dirty_roots(root->fs_info);

	btrfs_clean_old_snapshots(root);

	trans = btrfs_start_transaction(root, 1);

	ret = btrfs_commit_transaction(trans, root);

	/* run commit again to  drop the original snapshot */
@@ -1574,8 +1674,6 @@ int close_ctree(struct btrfs_root *root) 


	write_ctree_super(NULL, root);



	btrfs_transaction_flush_work(root);



	if (fs_info->delalloc_bytes) {

		printk("btrfs: at unmount delalloc count %Lu\n",

		       fs_info->delalloc_bytes);

fs/btrfs/extent-tree.c

+5 −5
Original line number Diff line number Diff line
@@ -1216,15 +1216,16 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans, 
	if (ret == -ENOSPC) {

printk("space info full %Lu\n", flags);

		space_info->full = 1;

		goto out;

		goto out_unlock;

	}

	BUG_ON(ret);



	ret = btrfs_make_block_group(trans, extent_root, 0, flags,

		     BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);

	BUG_ON(ret);

out:

out_unlock:

	mutex_unlock(&extent_root->fs_info->chunk_mutex);

out:

	return 0;

}
@@ -2274,6 +2275,7 @@ static int noinline walk_down_tree(struct btrfs_trans_handle *trans, 
			free_extent_buffer(next);

			mutex_unlock(&root->fs_info->alloc_mutex);



			if (path->slots[*level] == 0)

				reada_walk_down(root, cur, path->slots[*level]);



			next = read_tree_block(root, bytenr, blocksize,
@@ -2446,8 +2448,6 @@ int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root 
			break;

		if (wret < 0)

			ret = wret;

		ret = -EAGAIN;

		break;

	}

	for (i = 0; i <= orig_level; i++) {

		if (path->nodes[i]) {

fs/btrfs/super.c

+6 −10
Original line number Diff line number Diff line
@@ -340,7 +340,6 @@ static int btrfs_fill_super(struct super_block * sb, 
		goto fail_close;



	sb->s_root = root_dentry;

	btrfs_transaction_queue_work(tree_root, HZ * 30);



#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)

	save_mount_options(sb, data);
@@ -416,9 +415,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type, int flags, 
		goto error_free_subvol_name;



	bdev = fs_devices->latest_bdev;

	btrfs_lock_volumes();

	s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);

	btrfs_unlock_volumes();

	if (IS_ERR(s))

		goto error_s;
@@ -530,13 +527,15 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 
static void btrfs_write_super_lockfs(struct super_block *sb)

{

	struct btrfs_root *root = btrfs_sb(sb);

	btrfs_transaction_flush_work(root);

	mutex_lock(&root->fs_info->transaction_kthread_mutex);

	mutex_lock(&root->fs_info->cleaner_mutex);

}



static void btrfs_unlockfs(struct super_block *sb)

{

	struct btrfs_root *root = btrfs_sb(sb);

	btrfs_transaction_queue_work(root, HZ * 30);

	mutex_unlock(&root->fs_info->cleaner_mutex);

	mutex_unlock(&root->fs_info->transaction_kthread_mutex);

}



static struct super_operations btrfs_super_ops = {
@@ -589,10 +588,9 @@ static int __init init_btrfs_fs(void) 
	if (err)

		return err;



	btrfs_init_transaction_sys();

	err = btrfs_init_cachep();

	if (err)

		goto free_transaction_sys;

		goto free_sysfs;



	err = extent_io_init();

	if (err)
@@ -618,15 +616,13 @@ static int __init init_btrfs_fs(void) 
	extent_io_exit();

free_cachep:

	btrfs_destroy_cachep();

free_transaction_sys:

	btrfs_exit_transaction_sys();

free_sysfs:

	btrfs_exit_sysfs();

	return err;

}



static void __exit exit_btrfs_fs(void)

{

	btrfs_exit_transaction_sys();

	btrfs_destroy_cachep();

	extent_map_exit();

	extent_io_exit();