X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fioprio.c;h=c7c0b28d7d2177c7c88d32f3f62856e97cfc7ff5;hb=f958a1320ff7a1e0e861d3c90de6da12a88839dc;hp=10d2c211d18b28414aa8b0f26dcfe489fa0ddfe9;hpb=41487c65bfcce9c8e4d123da1719fcfd8df6d4d0;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/ioprio.c b/fs/ioprio.c
index 10d2c21..c7c0b28 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -25,36 +25,54 @@
 #include <linux/capability.h>
 #include <linux/syscalls.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);
@@ -74,8 +92,10 @@ asmlinkage long sys_ioprio_set(int which, int who, int 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;
@@ -93,7 +113,7 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
 			if (!who)
 				p = current;
 			else
-				p = find_task_by_pid(who);
+				p = find_task_by_vpid(who);
 			if (p)
 				ret = set_task_ioprio(p, ioprio);
 			break;
@@ -101,16 +121,16 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
 			if (!who)
 				pgrp = task_pgrp(current);
 			else
-				pgrp = find_pid(who);
-			do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
+				pgrp = find_vpid(who);
+			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);
 
@@ -118,7 +138,7 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
 				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)
@@ -143,7 +163,9 @@ static int get_task_ioprio(struct task_struct *p)
 	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;
 }
@@ -166,7 +188,7 @@ int ioprio_best(unsigned short aprio, unsigned short bprio)
 		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;
@@ -180,7 +202,7 @@ asmlinkage long sys_ioprio_get(int which, int who)
 			if (!who)
 				p = current;
 			else
-				p = find_task_by_pid(who);
+				p = find_task_by_vpid(who);
 			if (p)
 				ret = get_task_ioprio(p);
 			break;
@@ -188,8 +210,8 @@ asmlinkage long sys_ioprio_get(int which, int who)
 			if (!who)
 				pgrp = task_pgrp(current);
 			else
-				pgrp = find_pid(who);
-			do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
+				pgrp = find_vpid(who);
+			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 				tmpio = get_task_ioprio(p);
 				if (tmpio < 0)
 					continue;
@@ -197,11 +219,11 @@ asmlinkage long sys_ioprio_get(int which, int who)
 					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);
 
@@ -209,7 +231,7 @@ asmlinkage long sys_ioprio_get(int which, int 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)
@@ -230,4 +252,3 @@ asmlinkage long sys_ioprio_get(int which, int who)
 	read_unlock(&tasklist_lock);
 	return ret;
 }
-