Re: [PATCH 06/15] btrfs: Cleanup num_tolerated_disk_barrier_failures

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

Hi Anand,

Would you please push patch 1~6 in your hot spare patchset to Chris first?

In my opinion, it will need some time before some details like whether 
to do hot-spare in kernel or in user-space are settled.

And all these 6 patches are quite independent from the hot spare patchset.
So it would be OK to push them into mainline in this or next merge windows.

Thanks,
Qu

On 11/09/2015 06:56 PM, Anand Jain wrote:
> From: Qu Wenruo <quwenruo@cn.fujitsu.com>
>
> As we use per-chunk degradable check, now the global
> num_tolerated_disk_barrier_failures is of no use. So cleanup it.
>
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
>
> [Btrfs: resolve conflict to apply 'btrfs: Cleanup num_tolerated_disk_barrier_failures']
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>   fs/btrfs/ctree.h   |  2 --
>   fs/btrfs/disk-io.c | 56 ------------------------------------------------------
>   fs/btrfs/disk-io.h |  2 --
>   fs/btrfs/volumes.c | 17 -----------------
>   4 files changed, 77 deletions(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index a86051e..dedd3e0 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -1753,8 +1753,6 @@ struct btrfs_fs_info {
>   	/* next backup root to be overwritten */
>   	int backup_root_index;
>
> -	int num_tolerated_disk_barrier_failures;
> -
>   	/* device replace state */
>   	struct btrfs_dev_replace dev_replace;
>
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index d3303f9..d10ef2e 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -2965,8 +2965,6 @@ retry_root_backup:
>   		printk(KERN_ERR "BTRFS: Failed to read block groups: %d\n", ret);
>   		goto fail_sysfs;
>   	}
> -	fs_info->num_tolerated_disk_barrier_failures =
> -		btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
>
>   	fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
>   					       "btrfs-cleaner");
> @@ -3498,60 +3496,6 @@ int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
>   	return 0;
>   }
>
> -int btrfs_calc_num_tolerated_disk_barrier_failures(
> -	struct btrfs_fs_info *fs_info)
> -{
> -	struct btrfs_ioctl_space_info space;
> -	struct btrfs_space_info *sinfo;
> -	u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
> -		       BTRFS_BLOCK_GROUP_SYSTEM,
> -		       BTRFS_BLOCK_GROUP_METADATA,
> -		       BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
> -	int i;
> -	int c;
> -	int num_tolerated_disk_barrier_failures =
> -		(int)fs_info->fs_devices->num_devices;
> -
> -	for (i = 0; i < ARRAY_SIZE(types); i++) {
> -		struct btrfs_space_info *tmp;
> -
> -		sinfo = NULL;
> -		rcu_read_lock();
> -		list_for_each_entry_rcu(tmp, &fs_info->space_info, list) {
> -			if (tmp->flags == types[i]) {
> -				sinfo = tmp;
> -				break;
> -			}
> -		}
> -		rcu_read_unlock();
> -
> -		if (!sinfo)
> -			continue;
> -
> -		down_read(&sinfo->groups_sem);
> -		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
> -			u64 flags;
> -
> -			if (list_empty(&sinfo->block_groups[c]))
> -				continue;
> -
> -			btrfs_get_block_group_info(&sinfo->block_groups[c],
> -						   &space);
> -			if (space.total_bytes == 0 || space.used_bytes == 0)
> -				continue;
> -			flags = space.flags;
> -
> -			num_tolerated_disk_barrier_failures = min(
> -				num_tolerated_disk_barrier_failures,
> -				btrfs_get_num_tolerated_disk_barrier_failures(
> -					flags));
> -		}
> -		up_read(&sinfo->groups_sem);
> -	}
> -
> -	return num_tolerated_disk_barrier_failures;
> -}
> -
>   static int write_all_supers(struct btrfs_root *root, int max_mirrors)
>   {
>   	struct list_head *head;
> diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
> index adeb318..6dc5fd3 100644
> --- a/fs/btrfs/disk-io.h
> +++ b/fs/btrfs/disk-io.h
> @@ -142,8 +142,6 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
>   int btree_lock_page_hook(struct page *page, void *data,
>   				void (*flush_fn)(void *));
>   int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
> -int btrfs_calc_num_tolerated_disk_barrier_failures(
> -	struct btrfs_fs_info *fs_info);
>   int __init btrfs_end_io_wq_init(void);
>   void btrfs_end_io_wq_exit(void);
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index a5262bf..33ad42e 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1782,9 +1782,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid)
>   		free_fs_devices(cur_devices);
>   	}
>
> -	root->fs_info->num_tolerated_disk_barrier_failures =
> -		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
> -
>   	/*
>   	 * at this point, the device is zero sized.  We want to
>   	 * remove it from the devices list and zero out the old super
> @@ -2289,8 +2286,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
>   		}
>   	}
>
> -	root->fs_info->num_tolerated_disk_barrier_failures =
> -		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
>   	ret = btrfs_commit_transaction(trans, root);
>
>   	if (seeding_dev) {
> @@ -3518,13 +3513,6 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
>   		}
>   	} while (read_seqretry(&fs_info->profiles_lock, seq));
>
> -	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
> -		fs_info->num_tolerated_disk_barrier_failures = min(
> -			btrfs_calc_num_tolerated_disk_barrier_failures(fs_info),
> -			btrfs_get_num_tolerated_disk_barrier_failures(
> -				bctl->sys.target));
> -	}
> -
>   	ret = insert_balance_item(fs_info->tree_root, bctl);
>   	if (ret && ret != -EEXIST)
>   		goto out;
> @@ -3547,11 +3535,6 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
>   	mutex_lock(&fs_info->balance_mutex);
>   	atomic_dec(&fs_info->balance_running);
>
> -	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
> -		fs_info->num_tolerated_disk_barrier_failures =
> -			btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
> -	}
> -
>   	if (bargs) {
>   		memset(bargs, 0, sizeof(*bargs));
>   		update_ioctl_balance_args(fs_info, 0, bargs);
>