fat: drop lock/unlock super

Removed lock/unlock super. Added a new private s_lock mutex.

Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index c1055e7..e2cfda9 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -208,7 +208,7 @@
 	struct inode *inode;
 	int err;
 
-	lock_super(sb);
+	mutex_lock(&MSDOS_SB(sb)->s_lock);
 	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 	switch (err) {
 	case -ENOENT:
@@ -221,7 +221,7 @@
 	default:
 		inode = ERR_PTR(err);
 	}
-	unlock_super(sb);
+	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 	return d_splice_alias(inode, dentry);
 }
 
@@ -273,7 +273,7 @@
 	unsigned char msdos_name[MSDOS_NAME];
 	int err, is_hid;
 
-	lock_super(sb);
+	mutex_lock(&MSDOS_SB(sb)->s_lock);
 
 	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 				msdos_name, &MSDOS_SB(sb)->options);
@@ -302,7 +302,7 @@
 
 	d_instantiate(dentry, inode);
 out:
-	unlock_super(sb);
+	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 	if (!err)
 		err = fat_flush_inodes(sb, dir, inode);
 	return err;
@@ -316,7 +316,7 @@
 	struct fat_slot_info sinfo;
 	int err;
 
-	lock_super(sb);
+	mutex_lock(&MSDOS_SB(sb)->s_lock);
 	/*
 	 * Check whether the directory is not in use, then check
 	 * whether it is empty.
@@ -337,7 +337,7 @@
 	inode->i_ctime = CURRENT_TIME_SEC;
 	fat_detach(inode);
 out:
-	unlock_super(sb);
+	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 	if (!err)
 		err = fat_flush_inodes(sb, dir, inode);
 
@@ -354,7 +354,7 @@
 	struct timespec ts;
 	int err, is_hid, cluster;
 
-	lock_super(sb);
+	mutex_lock(&MSDOS_SB(sb)->s_lock);
 
 	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 				msdos_name, &MSDOS_SB(sb)->options);
@@ -392,14 +392,14 @@
 
 	d_instantiate(dentry, inode);
 
-	unlock_super(sb);
+	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 	fat_flush_inodes(sb, dir, inode);
 	return 0;
 
 out_free:
 	fat_free_clusters(dir, cluster);
 out:
-	unlock_super(sb);
+	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 	return err;
 }
 
@@ -411,7 +411,7 @@
 	struct fat_slot_info sinfo;
 	int err;
 
-	lock_super(sb);
+	mutex_lock(&MSDOS_SB(sb)->s_lock);
 	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 	if (err)
 		goto out;
@@ -423,7 +423,7 @@
 	inode->i_ctime = CURRENT_TIME_SEC;
 	fat_detach(inode);
 out:
-	unlock_super(sb);
+	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 	if (!err)
 		err = fat_flush_inodes(sb, dir, inode);
 
@@ -606,7 +606,7 @@
 	unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 	int err, is_hid;
 
-	lock_super(sb);
+	mutex_lock(&MSDOS_SB(sb)->s_lock);
 
 	err = msdos_format_name(old_dentry->d_name.name,
 				old_dentry->d_name.len, old_msdos_name,
@@ -625,7 +625,7 @@
 	err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 			      new_dir, new_msdos_name, new_dentry, is_hid);
 out:
-	unlock_super(sb);
+	mutex_unlock(&MSDOS_SB(sb)->s_lock);
 	if (!err)
 		err = fat_flush_inodes(sb, old_dir, new_dir);
 	return err;