Re: [RFC PATCH 17/20] famfs: Add module stuff

John Groves
2024-02-27T22:15:24Z

On 24/02/26 01:47PM, Jonathan Cameron wrote:
> On Fri, 23 Feb 2024 11:42:01 -0600
> John Groves <John@Groves.net> wrote:
>
> > This commit introduces the module init and exit machinery for famfs.
> >
> > Signed-off-by: John Groves <john@groves.net>
> I'd prefer to see this from the start with the functionality of the module
> built up as you go + build logic in place. Makes it easy to spot places
> where the patches aren't appropriately self constrained.
> > ---
> > fs/famfs/famfs_inode.c | 44 ++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 44 insertions(+)
> >
> > diff --git a/fs/famfs/famfs_inode.c b/fs/famfs/famfs_inode.c
> > index ab46ec50b70d..0d659820e8ff 100644
> > --- a/fs/famfs/famfs_inode.c
> > +++ b/fs/famfs/famfs_inode.c
> > @@ -462,4 +462,48 @@ static struct file_system_type famfs_fs_type = {
> > .fs_flags = FS_USERNS_MOUNT,
> > };
> >
> > +/*****************************************************************************************
> > + * Module stuff
>
> I'd drop these drivers structure comments. They add little beyond
> a high possibility of being wrong after the code has evolved a bit.

Probably will do with the module-ops-up refactor for v2

>
> > + */
> > +static struct kobject *famfs_kobj;
> > +
> > +static int __init init_famfs_fs(void)
> > +{
> > + int rc;
> > +
> > +#if defined(CONFIG_DEV_DAX_IOMAP)
> > + pr_notice("%s: Your kernel supports famfs on /dev/dax\n", __func__);
> > +#else
> > + pr_notice("%s: Your kernel does not support famfs on /dev/dax\n", __func__);
> > +#endif
> > + famfs_kobj = kobject_create_and_add(MODULE_NAME, fs_kobj);
> > + if (!famfs_kobj) {
> > + pr_warn("Failed to create kobject\n");
> > + return -ENOMEM;
> > + }
> > +
> > + rc = sysfs_create_group(famfs_kobj, &famfs_attr_group);
> > + if (rc) {
> > + kobject_put(famfs_kobj);
> > + pr_warn("%s: Failed to create sysfs group\n", __func__);
> > + return rc;
> > + }
> > +
> > + return register_filesystem(&famfs_fs_type);
>
> If this fails, do we not leak the kobj and sysfs groups?

Good catch, thanks! Fixed for now- but the kobj is also likely to go away. Will
endeavor to get it right...

Thanks,
John