From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 6 May 2009 03:48:50 +0000 (-0400)
Subject: Make sure that all callers of remount hold s_umount exclusive
X-Git-Tag: v2.6.31-rc1~375^2~49
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=443b94baaa16771e98b29ca7c24f1e305738ffca;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git

Make sure that all callers of remount hold s_umount exclusive

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/super.c b/fs/super.c
index cb19fff..49f670c 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -579,7 +579,7 @@ static void do_emergency_remount(struct work_struct *work)
 	list_for_each_entry(sb, &super_blocks, s_list) {
 		sb->s_count++;
 		spin_unlock(&sb_lock);
-		down_read(&sb->s_umount);
+		down_write(&sb->s_umount);
 		if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) {
 			/*
 			 * ->remount_fs needs lock_kernel().
@@ -590,7 +590,8 @@ static void do_emergency_remount(struct work_struct *work)
 			do_remount_sb(sb, MS_RDONLY, NULL, 1);
 			unlock_kernel();
 		}
-		drop_super(sb);
+		up_write(&sb->s_umount);
+		put_super(sb);
 		spin_lock(&sb_lock);
 	}
 	spin_unlock(&sb_lock);