cgroup: rename cgroup_css_from_dir() to css_from_dir() and update its syntax
cgroup_css_from_dir() will grow another user. In preparation, make
the following changes.
* All css functions are prefixed with just "css_", rename it to
css_from_dir().
* Take dentry * instead of file * as dentry is what ultimately
identifies a cgroup and file may not always be available. Note that
the function now checkes whether @dentry->d_inode is NULL as the
caller now may specify a negative dentry.
* Make it take cgroup_subsys * instead of integer subsys_id. This
simplifies the function and allows specifying no subsystem for
cgroup->dummy_css.
* Make return section a bit less verbose.
This patch doesn't introduce any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index b685955..21ba298 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -903,7 +903,8 @@
/* Get id and depth of css */
unsigned short css_id(struct cgroup_subsys_state *css);
-struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id);
+struct cgroup_subsys_state *css_from_dir(struct dentry *dentry,
+ struct cgroup_subsys *ss);
#else /* !CONFIG_CGROUPS */