diff options
| -rw-r--r-- | include/linux/cgroup.h | 4 | ||||
| -rw-r--r-- | kernel/cgroup.c | 21 |
2 files changed, 14 insertions, 11 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index e78377a91a74..cc59d3a21d87 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -21,11 +21,13 @@ struct cgroupfs_root; struct cgroup_subsys; struct inode; +struct cgroup; extern int cgroup_init_early(void); extern int cgroup_init(void); extern void cgroup_init_smp(void); extern void cgroup_lock(void); +extern bool cgroup_lock_live_group(struct cgroup *cgrp); extern void cgroup_unlock(void); extern void cgroup_fork(struct task_struct *p); extern void cgroup_fork_callbacks(struct task_struct *p); @@ -295,8 +297,6 @@ int cgroup_add_files(struct cgroup *cgrp, int cgroup_is_removed(const struct cgroup *cgrp); -int cgroup_lock_live_group(struct cgroup *cgrp); - int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen); int cgroup_task_count(const struct cgroup *cgrp); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 0120b5d67a73..a14122ecaa5e 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1329,10 +1329,10 @@ enum cgroup_filetype { * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive. * @cgrp: the cgroup to be checked for liveness * - * Returns true (with lock held) on success, or false (with no lock - * held) on failure. + * On success, returns true; the lock should be later released with + * cgroup_unlock(). On failure returns false with no lock held. */ -int cgroup_lock_live_group(struct cgroup *cgrp) +bool cgroup_lock_live_group(struct cgroup *cgrp) { mutex_lock(&cgroup_mutex); if (cgroup_is_removed(cgrp)) { @@ -1349,7 +1349,7 @@ static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft, if (!cgroup_lock_live_group(cgrp)) return -ENODEV; strcpy(cgrp->root->release_agent_path, buffer); - mutex_unlock(&cgroup_mutex); + cgroup_unlock(); return 0; } @@ -1360,16 +1360,19 @@ static int cgroup_release_agent_show(struct cgroup *cgrp, struct cftype *cft, return -ENODEV; seq_puts(seq, cgrp->root->release_agent_path); seq_putc(seq, '\n'); - mutex_unlock(&cgroup_mutex); + cgroup_unlock(); return 0; } +/* A buffer size big enough for numbers or short strings */ +#define CGROUP_LOCAL_BUFFER_SIZE 64 + static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft, struct file *file, const char __user *userbuf, size_t nbytes, loff_t *unused_ppos) { - char buffer[64]; + char buffer[CGROUP_LOCAL_BUFFER_SIZE]; int retval = 0; char *end; @@ -1403,7 +1406,7 @@ static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft, const char __user *userbuf, size_t nbytes, loff_t *unused_ppos) { - char local_buffer[64]; + char local_buffer[CGROUP_LOCAL_BUFFER_SIZE]; int retval = 0; size_t max_bytes = cft->max_write_len; char *buffer = local_buffer; @@ -1518,7 +1521,7 @@ static ssize_t cgroup_read_u64(struct cgroup *cgrp, struct cftype *cft, char __user *buf, size_t nbytes, loff_t *ppos) { - char tmp[64]; + char tmp[CGROUP_LOCAL_BUFFER_SIZE]; u64 val = cft->read_u64(cgrp, cft); int len = sprintf(tmp, "%llu\n", (unsigned long long) val); @@ -1530,7 +1533,7 @@ static ssize_t cgroup_read_s64(struct cgroup *cgrp, struct cftype *cft, char __user *buf, size_t nbytes, loff_t *ppos) { - char tmp[64]; + char tmp[CGROUP_LOCAL_BUFFER_SIZE]; s64 val = cft->read_s64(cgrp, cft); int len = sprintf(tmp, "%lld\n", (long long) val); |