From 4fb3a53860cee2aaaf81186c451b7da0b95b45c1 Mon Sep 17 00:00:00 2001
From: Dipankar Sarma <dipankar@in.ibm.com>
Date: Fri, 16 Sep 2005 19:28:13 -0700
Subject: [PATCH] files: fix preemption issues

With the new fdtable locking rules, you have to protect fdtable with either
->file_lock or rcu_read_lock/unlock().  There are some places where we
aren't doing either.  This patch fixes those places.

Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 fs/locks.c      | 3 +++
 fs/proc/array.c | 3 +++
 2 files changed, 6 insertions(+)

(limited to 'fs')

diff --git a/fs/locks.c b/fs/locks.c
index c2c09b4798d6..f7daa5f48949 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -124,6 +124,7 @@
 #include <linux/smp_lock.h>
 #include <linux/syscalls.h>
 #include <linux/time.h>
+#include <linux/rcupdate.h>
 
 #include <asm/semaphore.h>
 #include <asm/uaccess.h>
@@ -2205,6 +2206,7 @@ void steal_locks(fl_owner_t from)
 
 	lock_kernel();
 	j = 0;
+	rcu_read_lock();
 	fdt = files_fdtable(files);
 	for (;;) {
 		unsigned long set;
@@ -2222,6 +2224,7 @@ void steal_locks(fl_owner_t from)
 			set >>= 1;
 		}
 	}
+	rcu_read_unlock();
 	unlock_kernel();
 }
 EXPORT_SYMBOL(steal_locks);
diff --git a/fs/proc/array.c b/fs/proc/array.c
index d88d518d30f6..d84eecacbeaf 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -74,6 +74,7 @@
 #include <linux/file.h>
 #include <linux/times.h>
 #include <linux/cpuset.h>
+#include <linux/rcupdate.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -180,12 +181,14 @@ static inline char * task_state(struct task_struct *p, char *buffer)
 		p->gid, p->egid, p->sgid, p->fsgid);
 	read_unlock(&tasklist_lock);
 	task_lock(p);
+	rcu_read_lock();
 	if (p->files)
 		fdt = files_fdtable(p->files);
 	buffer += sprintf(buffer,
 		"FDSize:\t%d\n"
 		"Groups:\t",
 		fdt ? fdt->max_fds : 0);
+	rcu_read_unlock();
 
 	group_info = p->group_info;
 	get_group_info(group_info);
-- 
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