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authorTejun Heo <tj@kernel.org>2013-12-05 12:28:04 -0500
committerTejun Heo <tj@kernel.org>2013-12-05 12:28:04 -0500
commit7da112792753d71aed44b918395892a1fc53048a (patch)
tree7b370245a961024428a9247f8999f0f4b51c2c4f /include/linux/cgroup.h
parent5d22444f427511fe7c4733b233680309af5b071c (diff)
cgroup: attach cgroup_open_file to all cgroup files
In preparation of conversion to kernfs, cgroup file handling is updated so that it can be easily mapped to kernfs. This patch attaches cgroup_open_file, which used to be attached to pidlist files, to all cgroup files, introduces seq_css/cft() accessors to determine the cgroup_subsys_state and cftype associated with a given cgroup seq_file, exports them as public interface. This doesn't cause any behavior changes but unifies cgroup file handling across different file types and will help converting them to kernfs seq_show() interface. v2: Li pointed out that the original patch was using single_open_size() incorrectly assuming that the size param is private data size. Fix it by allocating @of separately and passing it to single_open() and explicitly freeing it in the release path. This isn't the prettiest but this path is gonna be restructured by the following patches pretty soon. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'include/linux/cgroup.h')
-rw-r--r--include/linux/cgroup.h33
1 files changed, 33 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 53e11da6e357..c3d698a72e02 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -21,6 +21,7 @@
#include <linux/xattr.h>
#include <linux/fs.h>
#include <linux/percpu-refcount.h>
+#include <linux/seq_file.h>
#ifdef CONFIG_CGROUPS
@@ -490,6 +491,26 @@ struct cftype_set {
};
/*
+ * cgroupfs file entry, pointed to from leaf dentry->d_fsdata. Don't
+ * access directly.
+ */
+struct cfent {
+ struct list_head node;
+ struct dentry *dentry;
+ struct cftype *type;
+ struct cgroup_subsys_state *css;
+
+ /* file xattrs */
+ struct simple_xattrs xattrs;
+};
+
+/* seq_file->private points to the following, only ->priv is public */
+struct cgroup_open_file {
+ struct cfent *cfe;
+ void *priv;
+};
+
+/*
* See the comment above CGRP_ROOT_SANE_BEHAVIOR for details. This
* function can be called as long as @cgrp is accessible.
*/
@@ -504,6 +525,18 @@ static inline const char *cgroup_name(const struct cgroup *cgrp)
return rcu_dereference(cgrp->name)->name;
}
+static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq)
+{
+ struct cgroup_open_file *of = seq->private;
+ return of->cfe->css;
+}
+
+static inline struct cftype *seq_cft(struct seq_file *seq)
+{
+ struct cgroup_open_file *of = seq->private;
+ return of->cfe->type;
+}
+
int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_rm_cftypes(struct cftype *cfts);