Re: [PATCH 2/3] btrfs: export currently executing exclusive operation via sysfs

[Nikolay Borisov <nborisov@suse.com>]

On 3.08.20 г. 23:29 ч., Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> /sys/fs/<fsid>/exclusive_operation contains the currently executing
> exclusive operation. Add a sysfs_notify() when operation end, so
> userspace can be notified of exclusive operation is finished.
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>  fs/btrfs/ioctl.c |  2 ++
>  fs/btrfs/sysfs.c | 25 +++++++++++++++++++++++++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 3352b4ffa5c6..664c02a5baf9 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -373,6 +373,8 @@ bool btrfs_exclop_start(struct btrfs_fs_info *fs_info, int type)
>  void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
>  {
>  	atomic_set(&fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
> +	sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL,
> +			"exclusive_operation");
>  }
>  
>  /*
> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
> index a39bff64ff24..71950c121588 100644
> --- a/fs/btrfs/sysfs.c
> +++ b/fs/btrfs/sysfs.c
> @@ -808,6 +808,30 @@ static ssize_t btrfs_checksum_show(struct kobject *kobj,
>  
>  BTRFS_ATTR(, checksum, btrfs_checksum_show);
>  
> +static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
> +		struct kobj_attribute *a, char *buf)
> +{
> +	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
> +	switch (atomic_read(&fs_info->exclusive_operation)) {
> +		case  BTRFS_EXCLOP_NONE:
> +			return scnprintf(buf, PAGE_SIZE, "none\n");
> +		case BTRFS_EXCLOP_BALANCE:
> +			return scnprintf(buf, PAGE_SIZE, "balance\n");
> +		case BTRFS_EXCLOP_DEV_ADD:
> +			return scnprintf(buf, PAGE_SIZE, "device add\n");
> +		case BTRFS_EXCLOP_DEV_REPLACE:
> +			return scnprintf(buf, PAGE_SIZE, "device replace\n");
> +		case BTRFS_EXCLOP_DEV_REMOVE:
> +			return scnprintf(buf, PAGE_SIZE, "device remove\n");
> +		case BTRFS_EXCLOP_SWAP_ACTIVATE:
> +			return scnprintf(buf, PAGE_SIZE, "swap activate\n");
> +		case BTRFS_EXCLOP_RESIZE:
> +			return scnprintf(buf, PAGE_SIZE, "resize\n");
> +	}
> +	return 0;
> +}
> +BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
> +
>  static const struct attribute *btrfs_attrs[] = {
>  	BTRFS_ATTR_PTR(, label),
>  	BTRFS_ATTR_PTR(, nodesize),
> @@ -816,6 +840,7 @@ static const struct attribute *btrfs_attrs[] = {
>  	BTRFS_ATTR_PTR(, quota_override),
>  	BTRFS_ATTR_PTR(, metadata_uuid),
>  	BTRFS_ATTR_PTR(, checksum),
> +	BTRFS_ATTR_PTR(, exclusive_operation),
>  	NULL,
>  };
>  
>