switch fat to ->s_d_op, close exportfs races there

don't bother with lock_super() in fat_fill_super() callers, while
we are at it - there won't be any concurrency anyway.

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

1 files changed, 5 insertions, 8 deletions

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 206351a..86753fe 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -703,7 +703,6 @@ static struct dentry *fat_fh_to_dentry(struct super_block *sb,
 		struct fid *fid, int fh_len, int fh_type)
 {
 	struct inode *inode = NULL;
-	struct dentry *result;
 	u32 *fh = fid->raw;
 
 	if (fh_len < 5 || fh_type != 3)
@@ -748,10 +747,7 @@ static struct dentry *fat_fh_to_dentry(struct super_block *sb,
 	 * the fat_iget lookup again.  If that fails, then we are totally out
 	 * of luck.  But all that is for another day
 	 */
-	result = d_obtain_alias(inode);
-	if (!IS_ERR(result))
-		d_set_d_op(result, sb->s_root->d_op);
-	return result;
+	return d_obtain_alias(inode);
 }
 
 static int
@@ -799,8 +795,6 @@ static struct dentry *fat_get_parent(struct dentry *child)
 	brelse(bh);
 
 	parent = d_obtain_alias(inode);
-	if (!IS_ERR(parent))
-		d_set_d_op(parent, sb->s_root->d_op);
 out:
 	unlock_super(sb);
 
@@ -1244,7 +1238,8 @@ static int fat_read_root(struct inode *inode)
  * Read the super block of an MS-DOS FS.
  */
 int fat_fill_super(struct super_block *sb, void *data, int silent,
-		   const struct inode_operations *fs_dir_inode_ops, int isvfat)
+		   const struct inode_operations *fs_dir_inode_ops, int isvfat,
+		   void (*setup)(struct super_block *))
 {
 	struct inode *root_inode = NULL, *fat_inode = NULL;
 	struct buffer_head *bh;
@@ -1280,6 +1275,8 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 	if (error)
 		goto out_fail;
 
+	setup(sb); /* flavour-specific stuff that needs options */
+
 	error = -EIO;
 	sb_min_blocksize(sb, 512);
 	bh = sb_bread(sb, 0);