Messages in this thread | | | Date | Tue, 3 Mar 2009 10:08:27 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH 0/4] cgroups: show correct file mode |
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On Tue, 03 Mar 2009 09:08:23 +0800 Li Zefan <lizf@cn.fujitsu.com> wrote:
> Paul Menage wrote: > > On Sun, Mar 1, 2009 at 6:13 PM, Li Zefan <lizf@cn.fujitsu.com> wrote: > >> Now a cgroup subsystem can set default file mode of its control files, > >> so here is a patchset to correct file mode of each subsystem's files. > > > > I really think that we should be defaulting this based on whether the > > control file has read or write handlers. > > > > Sure, there are special cases like "tasks" that we'd need to set a > > manual value for, but most of these patches would be unnecessary. > > > > Those patches are small and trivial, but it's ok for me to do this > automatically. How about below patch. > > Note cpuset.memory_pressure is read-only though it has read handler. > Since if the read handler is removed, it'll return EINVAL instead of > the current EACCESS, I think it's better to leave as it is. > > ===================== > > cgroups: show correct file mode > > Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> > --- > include/linux/cgroup.h | 5 +++++ > kernel/cgroup.c | 30 ++++++++++++++++++++++++++++++ > kernel/cpuset.c | 1 + > 3 files changed, 36 insertions(+) > > diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h > index 6ad1989..af3c10f 100644 > --- a/include/linux/cgroup.h > +++ b/include/linux/cgroup.h > @@ -258,6 +258,11 @@ struct cftype { > */ > char name[MAX_CFTYPE_NAME]; > int private; > + /* > + * If not 0, file mode is set to this value, otherwise it will > + * be figured out automatically > + */ > + int mode; > > /* > * If non-zero, defines the maximum length of string that can > diff --git a/kernel/cgroup.c b/kernel/cgroup.c > index 379baa3..0b19204 100644 > --- a/kernel/cgroup.c > +++ b/kernel/cgroup.c > @@ -1750,6 +1750,33 @@ static int cgroup_create_dir(struct cgroup *cgrp, struct dentry *dentry, > return error; > } > > +/** > + * cgroup_file_mode - deduce file mode of a control file > + * @cft: the control file in question > + * > + * returns cftype->mode if ->mode is not 0 > + * returns 0644 if it has both a read and a write handler > + * returns 0444 if it has only a read handler > + * returns 0200 if it has only a write hander > + */ > +static int cgroup_file_mode(const struct cftype *cft) > +{ > + int mode = 0; > + > + if (cft->mode) > + return cft->mode; > + > + if (cft->read || cft->read_u64 || cft->read_s64 || > + cft->read_map || cft->read_seq_string) > + mode += 0444; > + > + if (cft->write || cft->write_u64 || cft->write_s64 || > + cft->write_string || cft->trigger) > + mode += 0200; > +
+= is not |=...
Thanks, -Kame
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