Re: [PATCH 1/9] btrfs: switch BTRFS_FS_STATE_* to enums

[Omar Sandoval <osandov@osandov.com>]

On Tue, Nov 27, 2018 at 08:53:41PM +0100, David Sterba wrote:
> We can use simple enum for values that are not part of on-disk format:
> global filesystem states.

Reviewed-by: Omar Sandoval <osandov@fb.com>

Some typos/wording suggestions below.

> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
>  fs/btrfs/ctree.h | 25 +++++++++++++++++++------
>  1 file changed, 19 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index a98507fa9192..f82ec5e41b0c 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -109,13 +109,26 @@ static inline unsigned long btrfs_chunk_item_size(int num_stripes)
>  }
>  
>  /*
> - * File system states
> + * Runtime (in-memory) states of filesystem
>   */
> -#define BTRFS_FS_STATE_ERROR		0
> -#define BTRFS_FS_STATE_REMOUNTING	1
> -#define BTRFS_FS_STATE_TRANS_ABORTED	2
> -#define BTRFS_FS_STATE_DEV_REPLACING	3
> -#define BTRFS_FS_STATE_DUMMY_FS_INFO	4
> +enum {
> +	/* Global indicator of serious filesysystem errors */

filesysystem -> filesystem

> +	BTRFS_FS_STATE_ERROR,
> +	/*
> +	 * Filesystem is being remounted, allow to skip some operations, like
> +	 * defrag
> +	 */
> +	BTRFS_FS_STATE_REMOUNTING,
> +	/* Track if the transaction abort has been reported */

Which one is "the" transaction abort? This gives me the impression that
this is a flag on the transaction, but it's actually filesystem state.
Maybe "Track if a transaction abort has been reported on this
filesystem"?

> +	BTRFS_FS_STATE_TRANS_ABORTED,
> +	/*
> +	 * Indicate that replace source or target device state is changed and
> +	 * allow to block bio operations
> +	 */

Again, this makes it sound like it's device state, but it's actually
filesystem state. How about "Bio operations should be blocked on this
filesystem because a source or target device is being destroyed as part
of a device replace"?

> +	BTRFS_FS_STATE_DEV_REPLACING,
> +	/* The btrfs_fs_info created for self-tests */
> +	BTRFS_FS_STATE_DUMMY_FS_INFO,
> +};
>  
>  #define BTRFS_BACKREF_REV_MAX		256
>  #define BTRFS_BACKREF_REV_SHIFT		56
> -- 
> 2.19.1
>