Re: [PATCH 1/4] fs: remove the unused fs_lookup_param function

[Al Viro <viro@zeniv.linux.org.uk>]

On Sat, Sep 26, 2020 at 11:20:48AM +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  Documentation/filesystems/mount_api.rst | 18 +-------
>  fs/fs_parser.c                          | 56 -------------------------
>  include/linux/fs_parser.h               |  5 ---
>  3 files changed, 2 insertions(+), 77 deletions(-)
> 
> diff --git a/Documentation/filesystems/mount_api.rst b/Documentation/filesystems/mount_api.rst
> index 29c169c68961f3..dbff847986da47 100644
> --- a/Documentation/filesystems/mount_api.rst
> +++ b/Documentation/filesystems/mount_api.rst
> @@ -254,8 +254,8 @@ manage the filesystem context.  They are as follows:
>       will have been weeded out and fc->sb_flags updated in the context.
>       Security options will also have been weeded out and fc->security updated.
>  
> -     The parameter can be parsed with fs_parse() and fs_lookup_param().  Note
> -     that the source(s) are presented as parameters named "source".
> +     The parameter can be parsed with fs_parse().  Note that the source(s) are
> +     presented as parameters named "source".

Umm...  Not sure - I'm not too fond of fs_lookup_param(), but AFAIK there are
efforts to convert more filesystems to new mount API and I don't know if any
of those are currently using it - this work has moved to individual fs trees
now, so it's hard to keep track of.

Generally I would say "if it's out of tree, it's not our problem", but the new
API is fairly recent and conversions of in-tree filesystems aree still in
progress.  And they are likely to stay in topical branches in the regular
git trees of those in-tree filesystems while they are being developed, so
right now I would rather be careful with removals in that area, short of
serious problem with the primitive itself.  Being able to make lookup_filename()
static is obviously nice, but considering the changes done later in the series...
Let's hold it back for now.