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Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c21
1 files changed, 12 insertions, 9 deletions
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);