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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
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+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;
+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;
+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);
+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]) {
+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();
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