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

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

kernel/cpuset.c

+35 −74
Original line number Diff line number Diff line
@@ -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,

	},