path: root/fs/hfsplus/inode.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hfsplus/inode.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Inode handling routines
 */

#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/uio.h>
#include <linux/fileattr.h>

#include "hfsplus_fs.h"
#include "hfsplus_raw.h"
#include "xattr.h"

static int hfsplus_read_folio(struct file *file, struct folio *folio)
{
	return block_read_full_folio(folio, hfsplus_get_block);
}

static void hfsplus_write_failed(struct address_space *mapping, loff_t to)
{
	struct inode *inode = mapping->host;

	if (to > inode->i_size) {
		truncate_pagecache(inode, inode->i_size);
		hfsplus_file_truncate(inode);
	}
}

int hfsplus_write_begin(const struct kiocb *iocb,
			struct address_space *mapping, loff_t pos,
			unsigned len, struct folio **foliop,
			void **fsdata)
{
	int ret;

	ret = cont_write_begin(iocb, mapping, pos, len, foliop, fsdata,
				hfsplus_get_block,
				&HFSPLUS_I(mapping->host)->phys_size);
	if (unlikely(ret))
		hfsplus_write_failed(mapping, pos + len);

	return ret;
}

static sector_t hfsplus_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping, block, hfsplus_get_block);
}

static bool hfsplus_release_folio(struct folio *folio, gfp_t mask)
{
	struct inode *inode = folio->mapping->host;
	struct super_block *sb = inode->i_sb;
	struct hfs_btree *tree;
	struct hfs_bnode *node;
	u32 nidx;
	int i;
	bool res = true;

	switch (inode->i_ino) {
	case HFSPLUS_EXT_CNID:
		tree = HFSPLUS_SB(sb)->ext_tree;
		break;
	case HFSPLUS_CAT_CNID:
		tree = HFSPLUS_SB(sb)->cat_tree;
		break;
	case HFSPLUS_ATTR_CNID:
		tree = HFSPLUS_SB(sb)->attr_tree;
		break;
	default:
		BUG();
		return false;
	}
	if (!tree)
		return false;
	if (tree->node_size >= PAGE_SIZE) {
		nidx = folio->index >>
			(tree->node_size_shift - PAGE_SHIFT);
		spin_lock(&tree->hash_lock);
		node = hfs_bnode_findhash(tree, nidx);
		if (!node)
			;
		else if (atomic_read(&node->refcnt))
			res = false;
		if (res && node) {
			hfs_bnode_unhash(node);
			hfs_bnode_free(node);
		}
		spin_unlock(&tree->hash_lock);
	} else {
		nidx = folio->index <<
			(PAGE_SHIFT - tree->node_size_shift);
		i = 1 << (PAGE_SHIFT - tree->node_size_shift);
		spin_lock(&tree->hash_lock);
		do {
			node = hfs_bnode_findhash(tree, nidx++);
			if (!node)
				continue;
			if (atomic_read(&node->refcnt)) {
				res = false;
				break;
			}
			hfs_bnode_unhash(node);
			hfs_bnode_free(node);
		} while (--i && nidx < tree->node_count);
		spin_unlock(&tree->hash_lock);
	}
	return res ? try_to_free_buffers(folio) : false;
}

static ssize_t hfsplus_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
	struct file *file = iocb->ki_filp;
	struct address_space *mapping = file->f_mapping;
	struct inode *inode = mapping->host;
	loff_t isize;
	size_t count = iov_iter_count(iter);
	loff_t end = iocb->ki_pos + count;
	ssize_t ret;

	/*
	 * The hfsplus_get_block() only allows creating the next sequential block.
	 * For direct writes beyond EOF, expand the file first.
	 */
	if (iov_iter_rw(iter) == WRITE && iocb->ki_pos > i_size_read(inode)) {
		loff_t start_off, end_off;
		loff_t start_page, end_page;

		isize = i_size_read(inode);

		/*
		 * Wait for any in-flight DIO on this inode to finish before
		 * calling generic_cont_expand_simple().
		 */
		inode_dio_wait(inode);

		ret = generic_cont_expand_simple(inode, iocb->ki_pos);
		if (ret)
			return ret;

		start_off = isize;
		end_off = (end > 0) ? end - 1 : end;

		ret = filemap_write_and_wait_range(mapping, start_off, end_off);
		if (ret)
			return ret;

		start_page = start_off >> PAGE_SHIFT;
		end_page = end_off >> PAGE_SHIFT;

		invalidate_inode_pages2_range(mapping, start_page, end_page);
	}

	ret = blockdev_direct_IO