cgroup subsystems may find the O_APPEND and O_NONBLOCK flags useful
in determining the way they handle writes. For now only pass these
flags through the write_string op.
A subsequent patch will make use of the O_NONBLOCK flag in the
cgroup freezer write_string op.
Signed-off-by: Matt Helsley <matthltc@xxxxxxxxxx>
Cc: Nathan Lynch <ntl@xxxxxxxxx>
Cc: Paul Menage <menage@xxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
(Cc'ing mem controller maintainers in case they find this useful..)
Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
include/linux/cgroup.h | 3 ++-
kernel/cgroup.c | 5 +++--
kernel/cgroup_freezer.c | 5 ++---
kernel/cpuset.c | 2 +-
mm/memcontrol.c | 2 +-
security/device_cgroup.c | 2 +-
6 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 90bba9e..627da35 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -315,8 +315,9 @@ struct cftype {
* buffer of maximum length determined by max_write_len.
* Returns 0 or -ve error code.
*/
+#define CFTYPE_F_FLAGS (O_APPEND|O_NONBLOCK)
int (*write_string)(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer);
+ unsigned int f_flags, const char *buffer);
/*
* trigger() callback can be used to get some kick from the
* userspace, when the actual string written is not important
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index b6eadfe..af07d05 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1449,7 +1449,7 @@ bool cgroup_lock_live_group(struct cgroup *cgrp)
}
static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer)
+ unsigned int f_flags, const char *buffer)
{
BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
if (!cgroup_lock_live_group(cgrp))
@@ -1534,7 +1534,8 @@ static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft,
buffer[nbytes] = 0; /* nul-terminate */
strstrip(buffer);
- retval = cft->write_string(cgrp, cft, buffer);
+ retval = cft->write_string(cgrp, cft, file->f_flags & CFTYPE_F_FLAGS,
+ buffer);
if (!retval)
retval = nbytes;
out:
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 7925850..c97680f 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -343,9 +343,8 @@ out:
return retval;
}
-static int freezer_write(struct cgroup *cgroup,
- struct cftype *cft,
- const char *buffer)
+static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
+ unsigned int f_flags, const char *buffer)
{
int retval;
enum freezer_state goal_state;
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 7e75a41..de7f397 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1470,7 +1470,7 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
* Common handling for a write to a "cpus" or "mems" file.
*/
static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
- const char *buf)
+ unsigned int f_flags, const char *buf)
{
int retval = 0;
struct cpuset *cs = cgroup_cs(cgrp);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fd4529d..fd9c737 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2072,7 +2072,7 @@ static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
* RES_LIMIT.
*/
static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
- const char *buffer)
+ unsigned int f_flags, const char *buffer)
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
int type, name;
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index b8186ba..65d32ce 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -428,7 +428,7 @@ handle:
}
static int devcgroup_access_write(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer)
+ unsigned int f_flags, const char *buffer)
{
int retval;
--
1.5.6.3
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