diff options
Diffstat (limited to 'fs/ioprio.c')
| -rw-r--r-- | fs/ioprio.c | 241 |
1 files changed, 0 insertions, 241 deletions
diff --git a/fs/ioprio.c b/fs/ioprio.c deleted file mode 100644 index e50170ca7c33..000000000000 --- a/fs/ioprio.c +++ /dev/null @@ -1,241 +0,0 @@ -/* - * fs/ioprio.c - * - * Copyright (C) 2004 Jens Axboe <axboe@kernel.dk> - * - * Helper functions for setting/querying io priorities of processes. The - * system calls closely mimmick getpriority/setpriority, see the man page for - * those. The prio argument is a composite of prio class and prio data, where - * the data argument has meaning within that class. The standard scheduling - * classes have 8 distinct prio levels, with 0 being the highest prio and 7 - * being the lowest. - * - * IOW, setting BE scheduling class with prio 2 is done ala: - * - * unsigned int prio = (IOPRIO_CLASS_BE << IOPRIO_CLASS_SHIFT) | 2; - * - * ioprio_set(PRIO_PROCESS, pid, prio); - * - * See also Documentation/block/ioprio.txt - * - */ -#include <linux/gfp.h> -#include <linux/kernel.h> -#include <linux/export.h> -#include <linux/ioprio.h> -#include <linux/blkdev.h> -#include <linux/capability.h> -#include <linux/syscalls.h> -#include <linux/security.h> -#include <linux/pid_namespace.h> - -int set_task_ioprio(struct task_struct *task, int ioprio) -{ - int err; - struct io_context *ioc; - const struct cred *cred = current_cred(), *tcred; - - rcu_read_lock(); - tcred = __task_cred(task); - if (!uid_eq(tcred->uid, cred->euid) && - !uid_eq(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; - - ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE); - if (ioc) { - ioc->ioprio = ioprio; - put_io_context(ioc); - } - - return err; -} -EXPORT_SYMBOL_GPL(set_task_ioprio); - -SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) -{ - int class = IOPRIO_PRIO_CLASS(ioprio); - int data = IOPRIO_PRIO_DATA(ioprio); - struct task_struct *p, *g; - struct user_struct *user; - struct pid *pgrp; - kuid_t uid; - int ret; - - switch (class) { - case IOPRIO_CLASS_RT: - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - /* fall through, rt has prio field too */ - case IOPRIO_CLASS_BE: - if (data >= IOPRIO_BE_NR || data < 0) - return -EINVAL; - - break; - case IOPRIO_CLASS_IDLE: - break; - case IOPRIO_CLASS_NONE: - if (data) - return -EINVAL; - break; - default: - return -EINVAL; - } - - ret = -ESRCH; - rcu_read_lock(); - switch (which) { - case IOPRIO_WHO_PROCESS: - if (!who) - p = current; - else - p = find_task_by_vpid(who); - if (p) - ret = set_task_ioprio(p, ioprio); - break; - case IOPRIO_WHO_PGRP: - if (!who) - pgrp = task_pgrp(current); - else - pgrp = find_vpid(who); - do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { - ret = set_task_ioprio(p, ioprio); - if (ret) - break; - } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); - break; - case IOPRIO_WHO_USER: - uid = make_kuid(current_user_ns(), who); - if (!uid_valid(uid)) - break; - if (!who) - user = current_user(); - else - user = find_user(uid); - - if (!user) - break; - - do_each_thread(g, p) { - if (!uid_eq(task_uid(p), uid)) - continue; - ret = set_task_ioprio(p, ioprio); - if (ret) - goto free_uid; - } while_each_thread(g, p); -free_uid: - if (who) - free_uid(user); - break; - default: - ret = -EINVAL; - } - - rcu_read_unlock(); - return ret; -} - -static int get_task_ioprio(struct task_struct *p) -{ - int ret; - - ret = security_task_getioprio(p); - if (ret) - goto out; - ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM); - if (p->io_context) - ret = p->io_context->ioprio; -out: - return ret; -} - -int ioprio_best(unsigned short aprio, unsigned short bprio) -{ - unsigned short aclass = IOPRIO_PRIO_CLASS(aprio); - unsigned short bclass = IOPRIO_PRIO_CLASS(bprio); - - if (aclass == IOPRIO_CLASS_NONE) - aclass = IOPRIO_CLASS_BE; - if (bclass == IOPRIO_CLASS_NONE) - bclass = IOPRIO_CLASS_BE; - - if (aclass == bclass) - return min(aprio, bprio); - if (aclass > bclass) - return bprio; - else - return aprio; -} - -SYSCALL_DEFINE2(ioprio_get, int, which, int, who) -{ - struct task_struct *g, *p; - struct user_struct *user; - struct pid *pgrp; - kuid_t uid; - int ret = -ESRCH; - int tmpio; - - rcu_read_lock(); - switch (which) { - case IOPRIO_WHO_PROCESS: - if (!who) - p = current; - else - p = find_task_by_vpid(who); - if (p) - ret = get_task_ioprio(p); - break; - case IOPRIO_WHO_PGRP: - if (!who) - pgrp = task_pgrp(current); - else - pgrp = find_vpid(who); - do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { - tmpio = get_task_ioprio(p); - if (tmpio < 0) - continue; - if (ret == -ESRCH) - ret = tmpio; - else - ret = ioprio_best(ret, tmpio); - } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); - break; - case IOPRIO_WHO_USER: - uid = make_kuid(current_user_ns(), who); - if (!who) - user = current_user(); - else - user = find_user(uid); - - if (!user) - break; - - do_each_thread(g, p) { - if (!uid_eq(task_uid(p), user->uid)) - continue; - tmpio = get_task_ioprio(p); - if (tmpio < 0) - continue; - if (ret == -ESRCH) - ret = tmpio; - else - ret = ioprio_best(ret, tmpio); - } while_each_thread(g, p); - - if (who) - free_uid(user); - break; - default: - ret = -EINVAL; - } - - rcu_read_unlock(); - return ret; -} |