Messages in this thread | | | Date | Thu, 20 Feb 2020 20:38:37 +0100 | From | Christian Brauner <> | Subject | Re: [PATCH net-next v3 3/9] sysfs: add sysfs_group{s}_change_owner() |
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On Thu, Feb 20, 2020 at 12:15:50PM +0100, Greg Kroah-Hartman wrote: > On Tue, Feb 18, 2020 at 05:29:37PM +0100, Christian Brauner wrote: > > Add helpers to change the owner of sysfs groups. > > This function will be used to correctly account for kobject ownership > > changes, e.g. when moving network devices between network namespaces. > > > > Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> > > --- > > /* v2 */ > > - Greg Kroah-Hartman <gregkh@linuxfoundation.org>: > > - Add comment how ownership of sysfs object is changed. > > > > /* v3 */ > > - Greg Kroah-Hartman <gregkh@linuxfoundation.org>: > > - Add explicit uid/gid parameters. > > - Christian Brauner <christian.brauner@ubuntu.com>: > > - Collapse groups ownership helper patches into a single patch. > > --- > > fs/sysfs/group.c | 117 ++++++++++++++++++++++++++++++++++++++++++ > > include/linux/sysfs.h | 20 ++++++++ > > 2 files changed, 137 insertions(+) > > > > diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c > > index c4ab045926b7..bae562d3cba1 100644 > > --- a/fs/sysfs/group.c > > +++ b/fs/sysfs/group.c > > @@ -13,6 +13,7 @@ > > #include <linux/dcache.h> > > #include <linux/namei.h> > > #include <linux/err.h> > > +#include <linux/fs.h> > > #include "sysfs.h" > > > > > > @@ -457,3 +458,119 @@ int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, > > return PTR_ERR_OR_ZERO(link); > > } > > EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj); > > + > > +static int sysfs_group_attrs_change_owner(struct kernfs_node *grp_kn, > > + const struct attribute_group *grp, > > + struct iattr *newattrs) > > +{ > > + struct kernfs_node *kn; > > + int error; > > + > > + if (grp->attrs) { > > + struct attribute *const *attr; > > + > > + for (attr = grp->attrs; *attr; attr++) { > > + kn = kernfs_find_and_get(grp_kn, (*attr)->name); > > + if (!kn) > > + return -ENOENT; > > + > > + error = kernfs_setattr(kn, newattrs); > > + kernfs_put(kn); > > + if (error) > > + return error; > > + } > > + } > > + > > + if (grp->bin_attrs) { > > + struct bin_attribute *const *bin_attr; > > + > > + for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) { > > + kn = kernfs_find_and_get(grp_kn, (*bin_attr)->attr.name); > > + if (!kn) > > + return -ENOENT; > > + > > + error = kernfs_setattr(kn, newattrs); > > + kernfs_put(kn); > > + if (error) > > + return error; > > + } > > + } > > + > > + return 0; > > +} > > + > > +/** > > + * sysfs_group_change_owner - change owner of an attribute group. > > + * @kobj: The kobject containing the group. > > + * @grp: The attribute group. > > + * @kuid: new owner's kuid > > + * @kgid: new owner's kgid > > + * > > + * Returns 0 on success or error code on failure. > > This is fine to document, just funny it's the only one documented about > the return value so far in this series.
I stuck to the documentation style common to the file. Most of the functions in fs/syfs/file.c did not mention return codes sysfs_remove_bin_file(), sysfs_create_bin_file(), sysfs_remove_file_from_group() etc. But I'll document all in this series with return codes now.
Thanks! Christian
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