* See also Documentation/block/ioprio.txt
*
*/
+#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/ioprio.h>
#include <linux/blkdev.h>
#include <linux/security.h>
#include <linux/pid_namespace.h>
-static int set_task_ioprio(struct task_struct *task, int ioprio)
+int set_task_ioprio(struct task_struct *task, int ioprio)
{
int err;
struct io_context *ioc;
+ const struct cred *cred = current_cred(), *tcred;
- if (task->uid != current->euid &&
- task->uid != current->uid && !capable(CAP_SYS_NICE))
+ rcu_read_lock();
+ tcred = __task_cred(task);
+ if (tcred->uid != cred->euid &&
+ tcred->uid != cred->uid && !capable(CAP_SYS_NICE)) {
+ rcu_read_unlock();
return -EPERM;
+ }
+ rcu_read_unlock();
err = security_task_setioprio(task, ioprio);
if (err)
return err;
task_lock(task);
+ do {
+ ioc = task->io_context;
+ /* see wmb() in current_io_context() */
+ smp_read_barrier_depends();
+ if (ioc)
+ break;
- task->ioprio = ioprio;
-
- ioc = task->io_context;
- /* see wmb() in current_io_context() */
- smp_read_barrier_depends();
+ ioc = alloc_io_context(GFP_ATOMIC, -1);
+ if (!ioc) {
+ err = -ENOMEM;
+ break;
+ }
+ task->io_context = ioc;
+ } while (1);
- if (ioc)
+ if (!err) {
+ ioc->ioprio = ioprio;
ioc->ioprio_changed = 1;
+ }
task_unlock(task);
- return 0;
+ return err;
}
+EXPORT_SYMBOL_GPL(set_task_ioprio);
-asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
+SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
{
int class = IOPRIO_PRIO_CLASS(ioprio);
int data = IOPRIO_PRIO_DATA(ioprio);
break;
case IOPRIO_CLASS_IDLE:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
+ break;
+ case IOPRIO_CLASS_NONE:
+ if (data)
+ return -EINVAL;
break;
default:
return -EINVAL;
if (!who)
p = current;
else
- p = find_task_by_pid_ns(who,
- current->nsproxy->pid_ns);
+ p = find_task_by_vpid(who);
if (p)
ret = set_task_ioprio(p, ioprio);
break;
pgrp = task_pgrp(current);
else
pgrp = find_vpid(who);
- do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
+ do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
ret = set_task_ioprio(p, ioprio);
if (ret)
break;
- } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
+ } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
if (!who)
- user = current->user;
+ user = current_user();
else
user = find_user(who);
break;
do_each_thread(g, p) {
- if (p->uid != who)
+ if (__task_cred(p)->uid != who)
continue;
ret = set_task_ioprio(p, ioprio);
if (ret)
ret = security_task_getioprio(p);
if (ret)
goto out;
- ret = p->ioprio;
+ ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM);
+ if (p->io_context)
+ ret = p->io_context->ioprio;
out:
return ret;
}
return aprio;
}
-asmlinkage long sys_ioprio_get(int which, int who)
+SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
{
struct task_struct *g, *p;
struct user_struct *user;
if (!who)
p = current;
else
- p = find_task_by_pid_ns(who,
- current->nsproxy->pid_ns);
+ p = find_task_by_vpid(who);
if (p)
ret = get_task_ioprio(p);
break;
pgrp = task_pgrp(current);
else
pgrp = find_vpid(who);
- do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
+ do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
tmpio = get_task_ioprio(p);
if (tmpio < 0)
continue;
ret = tmpio;
else
ret = ioprio_best(ret, tmpio);
- } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
+ } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
if (!who)
- user = current->user;
+ user = current_user();
else
user = find_user(who);
break;
do_each_thread(g, p) {
- if (p->uid != user->uid)
+ if (__task_cred(p)->uid != user->uid)
continue;
tmpio = get_task_ioprio(p);
if (tmpio < 0)
read_unlock(&tasklist_lock);
return ret;
}
-