reiserfs: rework priv inode handling

Reiserfs is the only filesystem that removes IOP_XATTR without also
using a set of dedicated inode operations at the same time that nop all
xattr related inode operations. This means we need to have a IOP_XATTR
check in vfs_listxattr() instead of just being able to check for
->listxatt() being implemented.

Introduce a dedicated set of nop inode operations that are used when
IOP_XATTR is removed, allowing us to remove that check from
vfs_listxattr(). This in turn allows us to completely decouple POSIX ACLs from
IOP_XATTR.

Cc: reiserfs-devel@vger.kernel.org
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

fs/reiserfs/file.c

@@ -261,3 +261,10 @@ const struct inode_operations reiserfs_file_inode_operations = {
 	.fileattr_get = reiserfs_fileattr_get,
 	.fileattr_set = reiserfs_fileattr_set,
 };
+
+const struct inode_operations reiserfs_priv_file_inode_operations = {
+	.setattr = reiserfs_setattr,
+	.permission = reiserfs_permission,
+	.fileattr_get = reiserfs_fileattr_get,
+	.fileattr_set = reiserfs_fileattr_set,
+};

fs/reiserfs/inode.c

@@ -2087,10 +2087,8 @@ int reiserfs_new_inode(struct reiserfs_transaction_handle *th,
 	 * Mark it private if we're creating the privroot
 	 * or something under it.
 	 */
-	if (IS_PRIVATE(dir) || dentry == REISERFS_SB(sb)->priv_root) {
-		inode->i_flags |= S_PRIVATE;
-		inode->i_opflags &= ~IOP_XATTR;
-	}
+	if (IS_PRIVATE(dir) || dentry == REISERFS_SB(sb)->priv_root)
+		reiserfs_init_priv_inode(inode);
 
 	if (reiserfs_posixacl(inode->i_sb)) {
 		reiserfs_write_unlock(inode->i_sb);

fs/reiserfs/namei.c

@@ -378,13 +378,11 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
 
 		/*
 		 * Propagate the private flag so we know we're
-		 * in the priv tree.  Also clear IOP_XATTR
+		 * in the priv tree.  Also clear xattr support
 		 * since we don't have xattrs on xattr files.
 		 */
-		if (IS_PRIVATE(dir)) {
-			inode->i_flags |= S_PRIVATE;
-			inode->i_opflags &= ~IOP_XATTR;
-		}
+		if (IS_PRIVATE(dir))
+			reiserfs_init_priv_inode(inode);
 	}
 	reiserfs_write_unlock(dir->i_sb);
 	if (retval == IO_ERROR) {
@@ -1649,6 +1647,48 @@ static int reiserfs_rename(struct mnt_idmap *idmap,
 	return retval;
 }
 
+static const struct inode_operations reiserfs_priv_dir_inode_operations = {
+	.create = reiserfs_create,
+	.lookup = reiserfs_lookup,
+	.link = reiserfs_link,
+	.unlink = reiserfs_unlink,
+	.symlink = reiserfs_symlink,
+	.mkdir = reiserfs_mkdir,
+	.rmdir = reiserfs_rmdir,
+	.mknod = reiserfs_mknod,
+	.rename = reiserfs_rename,
+	.setattr = reiserfs_setattr,
+	.permission = reiserfs_permission,
+	.fileattr_get = reiserfs_fileattr_get,
+	.fileattr_set = reiserfs_fileattr_set,
+};
+
+static const struct inode_operations reiserfs_priv_symlink_inode_operations = {
+	.get_link	= page_get_link,
+	.setattr = reiserfs_setattr,
+	.permission = reiserfs_permission,
+};
+
+static const struct inode_operations reiserfs_priv_special_inode_operations = {
+	.setattr = reiserfs_setattr,
+	.permission = reiserfs_permission,
+};
+
+void reiserfs_init_priv_inode(struct inode *inode)
+{
+	inode->i_flags |= S_PRIVATE;
+	inode->i_opflags &= ~IOP_XATTR;
+
+	if (S_ISREG(inode->i_mode))
+		inode->i_op = &reiserfs_priv_file_inode_operations;
+	else if (S_ISDIR(inode->i_mode))
+		inode->i_op = &reiserfs_priv_dir_inode_operations;
+	else if (S_ISLNK(inode->i_mode))
+		inode->i_op = &reiserfs_priv_symlink_inode_operations;
+	else
+		inode->i_op = &reiserfs_priv_special_inode_operations;
+}
+
 /* directories can handle most operations...  */
 const struct inode_operations reiserfs_dir_inode_operations = {
 	.create = reiserfs_create,

fs/reiserfs/reiserfs.h

@@ -3106,6 +3106,7 @@ int reiserfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 int __reiserfs_write_begin(struct page *page, unsigned from, unsigned len);
 
 /* namei.c */
+void reiserfs_init_priv_inode(struct inode *inode);
 void set_de_name_and_namelen(struct reiserfs_dir_entry *de);
 int search_by_entry_key(struct super_block *sb, const struct cpu_key *key,
 			struct treepath *path, struct reiserfs_dir_entry *de);
@@ -3175,6 +3176,7 @@ void reiserfs_unmap_buffer(struct buffer_head *);
 
 /* file.c */
 extern const struct inode_operations reiserfs_file_inode_operations;
+extern const struct inode_operations reiserfs_priv_file_inode_operations;
 extern const struct file_operations reiserfs_file_operations;
 extern const struct address_space_operations reiserfs_address_space_operations;
 

fs/reiserfs/xattr.c

@@ -896,8 +896,7 @@ static int create_privroot(struct dentry *dentry)
 		return -EOPNOTSUPP;
 	}
 
-	d_inode(dentry)->i_flags |= S_PRIVATE;
-	d_inode(dentry)->i_opflags &= ~IOP_XATTR;
+	reiserfs_init_priv_inode(d_inode(dentry));
 	reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
 		      "storage.\n", PRIVROOT_NAME);
 
@@ -979,10 +978,8 @@ int reiserfs_lookup_privroot(struct super_block *s)
 	if (!IS_ERR(dentry)) {
 		REISERFS_SB(s)->priv_root = dentry;
 		d_set_d_op(dentry, &xattr_lookup_poison_ops);
-		if (d_really_is_positive(dentry)) {
-			d_inode(dentry)->i_flags |= S_PRIVATE;
-			d_inode(dentry)->i_opflags &= ~IOP_XATTR;
-		}
+		if (d_really_is_positive(dentry))
+			reiserfs_init_priv_inode(d_inode(dentry));
 	} else
 		err = PTR_ERR(dentry);
 	inode_unlock(d_inode(s->s_root));