Commit e3712395 authored by Paul Menage's avatar Paul Menage Committed by Linus Torvalds

cgroup files: remove cpuset_common_file_write()

This patch tweaks the signatures of the update_cpumask() and
update_nodemask() functions so that they can be called directly as
handlers for the new cgroups write_string() method.

This allows cpuset_common_file_write() to be removed.
Signed-off-by: default avatarPaul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent af351026
......@@ -227,10 +227,6 @@ static struct cpuset top_cpuset = {
* The task_struct fields mems_allowed and mems_generation may only
* be accessed in the context of that task, so require no locks.
*
* The cpuset_common_file_write handler for operations that modify
* the cpuset hierarchy holds cgroup_mutex across the entire operation,
* single threading all such cpuset modifications across the system.
*
* The cpuset_common_file_read() handlers only hold callback_mutex across
* small pieces of code, such as when reading out possibly multi-word
* cpumasks and nodemasks.
......@@ -772,7 +768,7 @@ static void cpuset_change_cpumask(struct task_struct *tsk,
* @cs: the cpuset to consider
* @buf: buffer of cpu numbers written to this cpuset
*/
static int update_cpumask(struct cpuset *cs, char *buf)
static int update_cpumask(struct cpuset *cs, const char *buf)
{
struct cpuset trialcs;
struct cgroup_scanner scan;
......@@ -792,7 +788,6 @@ static int update_cpumask(struct cpuset *cs, char *buf)
* that parsing. The validate_change() call ensures that cpusets
* with tasks have cpus.
*/
buf = strstrip(buf);
if (!*buf) {
cpus_clear(trialcs.cpus_allowed);
} else {
......@@ -902,7 +897,7 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
static void *cpuset_being_rebound;
static int update_nodemask(struct cpuset *cs, char *buf)
static int update_nodemask(struct cpuset *cs, const char *buf)
{
struct cpuset trialcs;
nodemask_t oldmem;
......@@ -929,7 +924,6 @@ static int update_nodemask(struct cpuset *cs, char *buf)
* that parsing. The validate_change() call ensures that cpusets
* with tasks have memory.
*/
buf = strstrip(buf);
if (!*buf) {
nodes_clear(trialcs.mems_allowed);
} else {
......@@ -1256,72 +1250,14 @@ typedef enum {
FILE_SPREAD_SLAB,
} cpuset_filetype_t;
static ssize_t cpuset_common_file_write(struct cgroup *cont,
struct cftype *cft,
struct file *file,
const char __user *userbuf,
size_t nbytes, loff_t *unused_ppos)
{
struct cpuset *cs = cgroup_cs(cont);
cpuset_filetype_t type = cft->private;
char *buffer;
int retval = 0;
/* Crude upper limit on largest legitimate cpulist user might write. */
if (nbytes > 100U + 6 * max(NR_CPUS, MAX_NUMNODES))
return -E2BIG;
/* +1 for nul-terminator */
buffer = kmalloc(nbytes + 1, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
if (copy_from_user(buffer, userbuf, nbytes)) {
retval = -EFAULT;
goto out1;
}
buffer[nbytes] = 0; /* nul-terminate */
cgroup_lock();
if (cgroup_is_removed(cont)) {
retval = -ENODEV;
goto out2;
}
switch (type) {
case FILE_CPULIST:
retval = update_cpumask(cs, buffer);
break;
case FILE_MEMLIST:
retval = update_nodemask(cs, buffer);
break;
default:
retval = -EINVAL;
goto out2;
}
if (retval == 0)
retval = nbytes;
out2:
cgroup_unlock();
out1:
kfree(buffer);
return retval;
}
static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
{
int retval = 0;
struct cpuset *cs = cgroup_cs(cgrp);
cpuset_filetype_t type = cft->private;
cgroup_lock();
if (cgroup_is_removed(cgrp)) {
cgroup_unlock();
if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
}
switch (type) {
case FILE_CPU_EXCLUSIVE:
......@@ -1367,12 +1303,9 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
struct cpuset *cs = cgroup_cs(cgrp);
cpuset_filetype_t type = cft->private;
cgroup_lock();
if (cgroup_is_removed(cgrp)) {
cgroup_unlock();
if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
}
switch (type) {
case FILE_SCHED_RELAX_DOMAIN_LEVEL:
retval = update_relax_domain_level(cs, val);
......@@ -1385,6 +1318,32 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
return retval;
}
/*
* 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)
{
int retval = 0;
if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
switch (cft->private) {
case FILE_CPULIST:
retval = update_cpumask(cgroup_cs(cgrp), buf);
break;
case FILE_MEMLIST:
retval = update_nodemask(cgroup_cs(cgrp), buf);
break;
default:
retval = -EINVAL;
break;
}
cgroup_unlock();
return retval;
}
/*
* These ascii lists should be read in a single call, by using a user
* buffer large enough to hold the entire map. If read in smaller
......@@ -1504,14 +1463,16 @@ static struct cftype files[] = {
{
.name = "cpus",
.read = cpuset_common_file_read,
.write = cpuset_common_file_write,
.write_string = cpuset_write_resmask,
.max_write_len = (100U + 6 * NR_CPUS),
.private = FILE_CPULIST,
},
{
.name = "mems",
.read = cpuset_common_file_read,
.write = cpuset_common_file_write,
.write_string = cpuset_write_resmask,
.max_write_len = (100U + 6 * MAX_NUMNODES),
.private = FILE_MEMLIST,
},
......
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