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author | Tejun Heo <tj@kernel.org> | 2013-12-05 12:28:04 -0500 |
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committer | Tejun Heo <tj@kernel.org> | 2013-12-05 12:28:04 -0500 |
commit | 7da112792753d71aed44b918395892a1fc53048a (patch) | |
tree | 7b370245a961024428a9247f8999f0f4b51c2c4f /include/linux/cgroup.h | |
parent | 5d22444f427511fe7c4733b233680309af5b071c (diff) | |
download | linux-stable-7da112792753d71aed44b918395892a1fc53048a.tar.gz linux-stable-7da112792753d71aed44b918395892a1fc53048a.tar.bz2 linux-stable-7da112792753d71aed44b918395892a1fc53048a.zip |
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.h | 33 |
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); |