ext4: Configure dentry operations at dentry-creation time

This was already the case for case-insensitive before commit
bb9cd91 ("fscrypt: Have filesystems handle their d_ops"), but it
was changed to set at lookup-time to facilitate the integration with
fscrypt.  But it's a problem because dentries that don't get created
through ->lookup() won't have any visibility of the operations.

Since fscrypt now also supports configuring dentry operations at
creation-time, do it for any encrypted and/or casefold volume,
simplifying the implementation across these features.

Acked-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-8-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>

Author: krisman

fs/ext4/namei.c

@@ -1762,7 +1762,6 @@ static struct buffer_head *ext4_lookup_entry(struct inode *dir,
 	struct buffer_head *bh;
 
 	err = ext4_fname_prepare_lookup(dir, dentry, &fname);
-	generic_set_encrypted_ci_d_ops(dentry);
 	if (err == -ENOENT)
 		return NULL;
 	if (err)

fs/ext4/super.c

@@ -5484,6 +5484,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
 		goto failed_mount4;
 	}
 
+	generic_set_sb_d_ops(sb);
 	sb->s_root = d_make_root(root);
 	if (!sb->s_root) {
 		ext4_msg(sb, KERN_ERR, "get root dentry failed");