X-Git-Url: https://bbs.cooldavid.org/git/?a=blobdiff_plain;f=fs%2Fioprio.c;h=2f7d05c899220e06d99ac9ecc9f8047903faa3a0;hb=24b7ea9f6c9787fad885442ed0cc010f1aa69cca;hp=748cfb92dcc6203897c62d87ee113876f197a28b;hpb=d9c5841e22231e4e49fd0a1004164e6fce59b7a6;p=net-next-2.6.git

diff --git a/fs/ioprio.c b/fs/ioprio.c
index 748cfb92dcc..2f7d05c8992 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -111,12 +111,14 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
 	read_lock(&tasklist_lock);
 	switch (which) {
 		case IOPRIO_WHO_PROCESS:
+			rcu_read_lock();
 			if (!who)
 				p = current;
 			else
 				p = find_task_by_vpid(who);
 			if (p)
 				ret = set_task_ioprio(p, ioprio);
+			rcu_read_unlock();
 			break;
 		case IOPRIO_WHO_PGRP:
 			if (!who)
@@ -139,7 +141,12 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
 				break;
 
 			do_each_thread(g, p) {
-				if (__task_cred(p)->uid != who)
+				int match;
+
+				rcu_read_lock();
+				match = __task_cred(p)->uid == who;
+				rcu_read_unlock();
+				if (!match)
 					continue;
 				ret = set_task_ioprio(p, ioprio);
 				if (ret)
@@ -200,12 +207,14 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
 	read_lock(&tasklist_lock);
 	switch (which) {
 		case IOPRIO_WHO_PROCESS:
+			rcu_read_lock();
 			if (!who)
 				p = current;
 			else
 				p = find_task_by_vpid(who);
 			if (p)
 				ret = get_task_ioprio(p);
+			rcu_read_unlock();
 			break;
 		case IOPRIO_WHO_PGRP:
 			if (!who)
@@ -232,7 +241,12 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
 				break;
 
 			do_each_thread(g, p) {
-				if (__task_cred(p)->uid != user->uid)
+				int match;
+
+				rcu_read_lock();
+				match = __task_cred(p)->uid == user->uid;
+				rcu_read_unlock();
+				if (!match)
 					continue;
 				tmpio = get_task_ioprio(p);
 				if (tmpio < 0)