Re: [PATCH RFC 2/3] fs: add vfs_cmd_create()

[Christian Brauner <brauner@kernel.org>]

On Tue, Aug 01, 2023 at 05:43:33PM +0200, Christoph Hellwig wrote:
> On Tue, Aug 01, 2023 at 03:09:01PM +0200, Christian Brauner wrote:
> > Split the steps to create a superblock into a tiny helper. This will
> > make the next patch easier to follow.
> > 
> > Signed-off-by: Christian Brauner <brauner@kernel.org>
> > ---
> >  fs/fsopen.c | 45 +++++++++++++++++++++++++++++++--------------
> >  1 file changed, 31 insertions(+), 14 deletions(-)
> > 
> > diff --git a/fs/fsopen.c b/fs/fsopen.c
> > index fc9d2d9fd234..af2ff05dcee5 100644
> > --- a/fs/fsopen.c
> > +++ b/fs/fsopen.c
> > @@ -209,6 +209,36 @@ SYSCALL_DEFINE3(fspick, int, dfd, const char __user *, path, unsigned int, flags
> >  	return ret;
> >  }
> >  
> > +static int vfs_cmd_create(struct fs_context *fc)
> > +{
> > +	struct super_block *sb;
> > +	int ret;
> > +
> > +	if (fc->phase != FS_CONTEXT_CREATE_PARAMS)
> > +		return -EBUSY;
> > +
> > +	if (!mount_capable(fc))
> > +		return -EPERM;
> > +
> > +	fc->phase = FS_CONTEXT_CREATING;
> > +
> > +	ret = vfs_get_tree(fc);
> > +	if (ret)
> > +		return ret;
> 
> The error handling here now fails to set FS_CONTEXT_FAILED.
> 
> Also at a very minimum I'd also want a helper for the reconfigure
> case to mirror this one.  But I think the whole sys_fsconfig and

That's acceptable.