inode.c

Linux中使用的苹果的Macintosh文件系统源代码

/*
 *  linux/fs/hfs/inode.c
 *
 * Copyright (C) 1995-1997  Paul H. Hargrove
 * (C) 2003 Ardis Technologies <[e-mail]>
 * This file may be distributed under the terms of the GNU General Public License.
 *
 * This file contains inode-related functions which do not depend on
 * which scheme is being used to represent forks.
 *
 * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
 */

#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/sched.h>

#include "hfs_fs.h"
#include "btree.h"

static const struct file_operations hfs_file_operations;
static const struct inode_operations hfs_file_inode_operations;

/*================ Variable-like macros ================*/

#define HFS_VALID_MODE_BITS  (S_IFREG | S_IFDIR | S_IRWXUGO)

static int hfs_writepage(struct page *page, struct writeback_control *wbc)
{
	return block_write_full_page(page, hfs_get_block, wbc);
}

static int hfs_readpage(struct file *file, struct page *page)
{
	return block_read_full_page(page, hfs_get_block);
}

static int hfs_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
{
	*pagep = NULL;
	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
				hfs_get_block,
				&HFS_I(mapping->host)->phys_size);
}

static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping, block, hfs_get_block);
}

static int hfs_releasepage(struct page *page, gfp_t mask)
{
	struct inode *inode = page->mapping->host;
	struct super_block *sb = inode->i_sb;
	struct hfs_btree *tree;
	struct hfs_bnode *node;
	u32 nidx;
	int i, res = 1;

	switch (inode->i_ino) {
	case HFS_EXT_CNID:
		tree = HFS_SB(sb)->ext_tree;
		break;
	case HFS_CAT_CNID:
		tree = HFS_SB(sb)->cat_tree;
		break;
	default:
		BUG();
		return 0;
	}
	if (tree->node_size >= PAGE_CACHE_SIZE) {
		nidx = page->index >> (tree->node_size_shift - PAGE_CACHE_SHIFT);
		spin_lock(&tree->hash_lock);
		node = hfs_bnode_findhash(tree, nidx);
		if (!node)
			;
		else if (atomic_read(&node->refcnt))
			res = 0;
		if (res && node) {
			hfs_bnode_unhash(node);
			hfs_bnode_free(node);
		}
		spin_unlock(&tree->hash_lock);
	} else {
		nidx = page->index << (PAGE_CACHE_SHIFT - tree->node_size_shift);
		i = 1 << (PAGE_CACHE_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 = 0;
				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(page) : 0;
}

static ssize_t hfs_direct_IO(int rw, struct kiocb *iocb,
		const struct iovec *iov, loff_t offset, unsigned long nr_segs)
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;

	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
				  offset, nr_segs, hfs_get_block, NULL);
}

static int hfs_writepages(struct address_space *mapping,
			  struct writeback_control *wbc)
{
	return mpage_writepages(mapping, wbc, hfs_get_block);
}

const struct address_space_operations hfs_btree_aops = {
	.readpage	= hfs_readpage,
	.writepage	= hfs_writepage,
	.sync_page	= block_sync_page,
	.write_begin	= hfs_write_begin,
	.write_end	= generic_write_end,
	.bmap		= hfs_bmap,
	.releasepage	= hfs_releasepage,
};

const struct address_space_operations hfs_aops = {
	.readpage	= hfs_readpage,
	.writepage	= hfs_writepage,
	.sync_page	= block_sync_page,
	.write_begin	= hfs_write_begin,
	.write_end	= generic_write_end,
	.bmap		= hfs_bmap,
	.direct_IO	= hfs_direct_IO,
	.writepages	= hfs_writepages,
};

/*
 * hfs_new_inode
 */
struct inode *hfs_new_inode(struct inode *dir, struct qstr *name, int mode)
{
	struct super_block *sb = dir->i_sb;
	struct inode *inode = new_inode(sb);
	if (!inode)
		return NULL;

	mutex_init(&HFS_I(inode)->extents_lock);
	INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
	hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
	inode->i_ino = HFS_SB(sb)->next_id++;
	inode->i_mode = mode;
	inode->i_uid = current_fsuid();
	inode->i_gid = current_fsgid();
	inode->i_nlink = 1;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
	HFS_I(inode)->flags = 0;
	HFS_I(inode)->rsrc_inode = NULL;
	HFS_I(inode)->fs_blocks = 0;
	if (S_ISDIR(mode)) {
		inode->i_size = 2;
		HFS_SB(sb)->folder_count++;
		if (dir->i_ino == HFS_ROOT_CNID)
			HFS_SB(sb)->root_dirs++;
		inode->i_op = &hfs_dir_inode_operations;
		inode->i_fop = &hfs_dir_operations;
		inode->i_mode |= S_IRWXUGO;
		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
	} else if (S_ISREG(mode)) {
		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
		HFS_SB(sb)->file_count++;
		if (dir->i_ino == HFS_ROOT_CNID)
			HFS_SB(sb)->root_files++;
		inode->i_op = &hfs_file_inode_operations;
		inode->i_fop = &hfs_file_operations;
		inode->i_mapping->a_ops = &hfs_aops;
		inode->i_mode |= S_IRUGO|S_IXUGO;
		if (mode & S_IWUSR)
			inode->i_mode |= S_IWUGO;
		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
		HFS_I(inode)->phys_size = 0;
		HFS_I(inode)->alloc_blocks = 0;
		HFS_I(inode)->first_blocks = 0;
		HFS_I(inode)->cached_start = 0;
		HFS_I(inode)->cached_blocks = 0;
		memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
		memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
	}
	insert_inode_hash(inode);
	mark_inode_dirty(inode);
	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
	sb->s_dirt = 1;

	return inode;
}

void hfs_delete_inode(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;

	dprint(DBG_INODE, "delete_inode: %lu\n", inode->i_ino);
	if (S_ISDIR(inode->i_mode)) {
		HFS_SB(sb)->folder_count--;
		if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
			HFS_SB(sb)->root_dirs--;
		set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
		sb->s_dirt = 1;
		return;
	}
	HFS_SB(sb)->file_count--;
	if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
		HFS_SB(sb)->root_files--;
	if (S_ISREG(inode->i_mode)) {
		if (!inode->i_nlink) {
			inode->i_size = 0;
			hfs_file_truncate(inode);
		}
	}
	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
	sb->s_dirt = 1;
}

void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
			 __be32 __log_size, __be32 phys_size, u32 clump_size)
{
	struct super_block *sb = inode->i_sb;
	u32 log_size = be32_to_cpu(__log_size);
	u16 count;
	int i;

	memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
	for (count = 0, i = 0; i < 3; i++)
		count += be16_to_cpu(ext[i].count);
	HFS_I(inode)->first_blocks = count;

	inode->i_size = HFS_I(inode)->phys_size = log_size;
	HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
	inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
	HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
				     HFS_SB(sb)->alloc_blksz;
	HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
	if (!HFS_I(inode)->clump_blocks)
		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
}

struct hfs_iget_data {
	struct hfs_cat_key *key;
	hfs_cat_rec *rec;
};

static int hfs_test_inode(struct inode *inode, void *data)
{
	struct hfs_iget_data *idata = data;
	hfs_cat_rec *rec;

	rec = idata->rec;
	switch (rec->type) {
	case HFS_CDR_DIR:
		return inode->i_ino == be32_to_cpu(rec->dir.DirID);
	case HFS_CDR_FIL:
		return inode->i_ino == be32_to_cpu(rec->file.FlNum);
	default:
		BUG();
		return 1;
	}
}

/*
 * hfs_read_inode
 */
static int hfs_read_inode(struct inode *inode, void *data)
{
	struct hfs_iget_data *idata = data;
	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
	hfs_cat_rec *rec;

	HFS_I(inode)->flags = 0;
	HFS_I(inode)->rsrc_inode = NULL;
	mutex_init(&HFS_I(inode)->extents_lock);
	INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);

	/* Initialize the inode */
	inode->i_uid = hsb->s_uid;
	inode->i_gid = hsb->s_gid;
	inode->i_nlink = 1;

	if (idata->key)
		HFS_I(inode)->cat_key = *idata->key;
	else
		HFS_I(inode)->flags |= HFS_FLG_RSRC;
	HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;

	rec = idata->rec;
	switch (rec->type) {
	case HFS_CDR_FIL:
		if (!HFS_IS_RSRC(inode)) {
			hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
					    rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
		} else {
			hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
					    rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
		}