diff options
| -rw-r--r-- | include/linux/cgroup.h | 27 | ||||
| -rw-r--r-- | kernel/cgroup.c | 14 |
2 files changed, 31 insertions, 10 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index c5f3684ef557..c5a170ca4a48 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -515,6 +515,15 @@ struct cftype { */ int (*trigger)(struct cgroup_subsys_state *css, unsigned int event); + /* + * write() is the generic write callback which maps directly to + * kernfs write operation and overrides all other operations. + * Maximum write size is determined by ->max_write_len. Use + * of_css/cft() to access the associated css and cft. + */ + ssize_t (*write)(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off); + #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lock_class_key lockdep_key; #endif @@ -552,14 +561,24 @@ static inline ino_t cgroup_ino(struct cgroup *cgrp) return 0; } -static inline struct cftype *seq_cft(struct seq_file *seq) +/* cft/css accessors for cftype->write() operation */ +static inline struct cftype *of_cft(struct kernfs_open_file *of) { - struct kernfs_open_file *of = seq->private; - return of->kn->priv; } -struct cgroup_subsys_state *seq_css(struct seq_file *seq); +struct cgroup_subsys_state *of_css(struct kernfs_open_file *of); + +/* cft/css accessors for cftype->seq_*() operations */ +static inline struct cftype *seq_cft(struct seq_file *seq) +{ + return of_cft(seq->private); +} + +static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq) +{ + return of_css(seq->private); +} /* * Name / path handling functions. All are thin wrappers around the kernfs diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 671d8a6dae37..a16f91d12f4e 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -283,11 +283,10 @@ static inline bool cgroup_is_dead(const struct cgroup *cgrp) return test_bit(CGRP_DEAD, &cgrp->flags); } -struct cgroup_subsys_state *seq_css(struct seq_file *seq) +struct cgroup_subsys_state *of_css(struct kernfs_open_file *of) { - struct kernfs_open_file *of = seq->private; struct cgroup *cgrp = of->kn->parent->priv; - struct cftype *cft = seq_cft(seq); + struct cftype *cft = of_cft(of); /* * This is open and unprotected implementation of cgroup_css(). @@ -302,7 +301,7 @@ struct cgroup_subsys_state *seq_css(struct seq_file *seq) else return &cgrp->dummy_css; } -EXPORT_SYMBOL_GPL(seq_css); +EXPORT_SYMBOL_GPL(of_css); /** * cgroup_is_descendant - test ancestry @@ -1035,8 +1034,8 @@ static umode_t cgroup_file_mode(const struct cftype *cft) if (cft->read_u64 || cft->read_s64 || cft->seq_show) mode |= S_IRUGO; - if (cft->write_u64 || cft->write_s64 || cft->write_string || - cft->trigger) + if (cft->write_u64 || cft->write_s64 || cft->write || + cft->write_string || cft->trigger) mode |= S_IWUSR; return mode; @@ -2726,6 +2725,9 @@ static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, struct cgroup_subsys_state *css; int ret; + if (cft->write) + return cft->write(of, buf, nbytes, off); + /* * kernfs guarantees that a file isn't deleted with operations in * flight, which means that the matching css is and stays alive and |