inode.c

来自「基于组件方式开发操作系统的OSKIT源代码」· C语言 代码 · 共 662 行 · 第 1/2 页

		goal = bh->b_blocknr + uspi->s_fpb;
	tmp = ufs_new_fragments (inode, p, ufs_blknum(new_fragment), goal, uspi->s_fpb, err);
	if (!tmp) {
		if (SWAB32(*p)) {
			goto repeat;
		}
		else {
			return NULL;
		}
	}		
	result = getblk (bh->b_dev, tmp + blockoff, sb->s_blocksize);
	mark_buffer_dirty(bh, 1);
	if (IS_SYNC(inode)) {
		ll_rw_block (WRITE, 1, &bh);
		wait_on_buffer (bh);
	}
	inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(inode);
	brelse (bh);
	UFSD(("EXIT, result %u\n", tmp + blockoff))
	return result;
}

struct buffer_head * ufs_getfrag (struct inode * inode, unsigned fragment,
	int create, int * err)
{
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct buffer_head * bh;
	unsigned f;
	unsigned swab;
	
	sb = inode->i_sb;
	uspi = sb->u.ufs_sb.s_uspi;
	swab = sb->u.ufs_sb.s_swab;
	*err = -EIO;

	UFSD(("ENTER, ino %lu, fragment %u\n", inode->i_ino, fragment))
	if (fragment > ((UFS_NDADDR + uspi->s_apb + uspi->s_2apb + uspi->s_3apb) << uspi->s_fpbshift)) {
		ufs_warning (sb, "ufs_getblk", "block > big");
		return NULL;
	}

	*err = -ENOSPC;
	f = fragment;
	  
	/*
	 * Direct fragment
	 */
	if (fragment < UFS_NDIR_FRAGMENT)
		return ufs_inode_getfrag (inode, fragment, fragment, create, 1, err);
	/*
	 * Indirect fragment
	 */
	fragment -= UFS_NDIR_FRAGMENT;
	if (fragment < (1 << (uspi->s_apbshift + uspi->s_fpbshift))) {
		bh = ufs_inode_getfrag (inode, 
			UFS_IND_FRAGMENT + (fragment >> uspi->s_apbshift),
			f, create, uspi->s_fpb, err);
		return ufs_block_getfrag (inode, bh, 
			fragment & uspi->s_apbmask,
			f, create, sb->s_blocksize, err);
	}
	/*
	 * Dindirect fragment
	 */
	fragment -= 1 << (uspi->s_apbshift + uspi->s_fpbshift);
	if ( fragment < (1 << (uspi->s_2apbshift + uspi->s_fpbshift))) {
		bh = ufs_inode_getfrag (inode,
			UFS_DIND_FRAGMENT + (fragment >> uspi->s_2apbshift), 
			f, create, uspi->s_fpb, err);
		bh = ufs_block_getfrag (inode, bh,
			(fragment >> uspi->s_apbshift) & uspi->s_apbmask, 
			f, create, sb->s_blocksize, err);
		return ufs_block_getfrag (inode, bh, 
			fragment & uspi->s_apbmask,
			f, create, sb->s_blocksize, err);
	}
	/*
	 * Tindirect fragment
	 */
	fragment -= 1 << (uspi->s_2apbshift + uspi->s_fpbshift);
	bh = ufs_inode_getfrag (inode,
		UFS_TIND_FRAGMENT + (fragment >> uspi->s_3apbshift), 
		f, create, uspi->s_fpb, err);
	bh = ufs_block_getfrag (inode, bh,
		(fragment >> uspi->s_2apbshift) & uspi->s_apbmask,
		f, create, sb->s_blocksize, err);
	bh = ufs_block_getfrag (inode, bh,
		(fragment >> uspi->s_apbshift) & uspi->s_apbmask, 
		f, create, sb->s_blocksize, err);
	return ufs_block_getfrag (inode, bh,
		fragment & uspi->s_apbmask, 
		f, create, sb->s_blocksize, err);
}



struct buffer_head * ufs_bread (struct inode * inode, unsigned fragment,
	int create, int * err)
{
	struct buffer_head * bh;

	UFSD(("ENTER, ino %lu, fragment %u\n", inode->i_ino, fragment))
	bh = ufs_getfrag (inode, fragment, create, err);
	if (!bh || buffer_uptodate(bh)) 		
		return bh;
	ll_rw_block (READ, 1, &bh);
	wait_on_buffer (bh);
	if (buffer_uptodate(bh))
		return bh;
	brelse (bh);
	*err = -EIO;
	return NULL;
}

void ufs_read_inode (struct inode * inode)
{
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct ufs_inode * ufs_inode;	
	struct buffer_head * bh;
	unsigned i;
	unsigned flags, swab;
	
	UFSD(("ENTER, ino %lu\n", inode->i_ino))
	
	sb = inode->i_sb;
	uspi = sb->u.ufs_sb.s_uspi;
	flags = sb->u.ufs_sb.s_flags;
	swab = sb->u.ufs_sb.s_swab;

	if (inode->i_ino < UFS_ROOTINO || 
	    inode->i_ino > (uspi->s_ncg * uspi->s_ipg)) {
		ufs_warning (sb, "ufs_read_inode", "bad inode number (%lu)\n", inode->i_ino);
		return;
	}
	
	bh = bread (sb->s_dev, uspi->s_sbbase + ufs_inotofsba(inode->i_ino), sb->s_blocksize);
	if (!bh) {
		ufs_warning (sb, "ufs_read_inode", "unable to read inode %lu\n", inode->i_ino);
		return;
	}
	ufs_inode = (struct ufs_inode *) (bh->b_data + sizeof(struct ufs_inode) * ufs_inotofsbo(inode->i_ino));

	/*
	 * Copy data to the in-core inode.
	 */
	inode->i_mode = SWAB16(ufs_inode->ui_mode);
	inode->i_nlink = SWAB16(ufs_inode->ui_nlink);
	if (inode->i_nlink == 0)
		ufs_error (sb, "ufs_read_inode", "inode %lu has zero nlink\n", inode->i_ino);
	
	/*
	 * Linux has only 16-bit uid and gid, so we can't support EFT.
	 * Files are dynamically chown()ed to root.
	 */
	inode->i_uid = inode->u.ufs_i.i_uid = ufs_get_inode_uid(ufs_inode);
	inode->i_gid = inode->u.ufs_i.i_gid = ufs_get_inode_gid(ufs_inode);
	if (inode->u.ufs_i.i_uid >= UFS_USEEFT) {
		inode->i_uid = 0;
	}
	if (inode->u.ufs_i.i_gid >= UFS_USEEFT) {
		inode->i_gid = 0;
	}
	
	/*
	 * Linux i_size can be 32 on some architectures. We will mark 
	 * big files as read only and let user access first 32 bits.
	 */
	inode->u.ufs_i.i_size = SWAB64(ufs_inode->ui_size);
	inode->i_size = (off_t) inode->u.ufs_i.i_size;
	if (sizeof(off_t) == 4 && (inode->u.ufs_i.i_size >> 32))
		inode->i_size = (__u32)-1;

	inode->i_atime = SWAB32(ufs_inode->ui_atime.tv_sec);
	inode->i_ctime = SWAB32(ufs_inode->ui_ctime.tv_sec);
	inode->i_mtime = SWAB32(ufs_inode->ui_mtime.tv_sec);
	inode->i_blocks = SWAB32(ufs_inode->ui_blocks);
	inode->i_blksize = PAGE_SIZE;   /* This is the optimal IO size (for stat) */
	inode->i_version = ++event;

	inode->u.ufs_i.i_flags = SWAB32(ufs_inode->ui_flags);
	inode->u.ufs_i.i_gen = SWAB32(ufs_inode->ui_gen);
	inode->u.ufs_i.i_shadow = SWAB32(ufs_inode->ui_u3.ui_sun.ui_shadow);
	inode->u.ufs_i.i_oeftflag = SWAB32(ufs_inode->ui_u3.ui_sun.ui_oeftflag);
	inode->u.ufs_i.i_lastfrag = howmany (inode->i_size, uspi->s_fsize);
	
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		inode->i_rdev = to_kdev_t(SWAB32(ufs_inode->ui_u2.ui_addr.ui_db[0]));
	else if (inode->i_blocks) {
		for (i = 0; i < (UFS_NDADDR + UFS_NINDIR); i++)
			inode->u.ufs_i.i_u1.i_data[i] = ufs_inode->ui_u2.ui_addr.ui_db[i];
	}
	else {
		for (i = 0; i < (UFS_NDADDR + UFS_NINDIR) * 4; i++)
			inode->u.ufs_i.i_u1.i_symlink[i] = ufs_inode->ui_u2.ui_symlink[i];
	}

	brelse (bh);

	inode->i_op = NULL;

	if (S_ISREG(inode->i_mode))
		inode->i_op = &ufs_file_inode_operations;
	else if (S_ISDIR(inode->i_mode))
		inode->i_op = &ufs_dir_inode_operations;
	else if (S_ISLNK(inode->i_mode))
		inode->i_op = &ufs_symlink_inode_operations;
	else if (S_ISCHR(inode->i_mode))
		inode->i_op = &chrdev_inode_operations;
	else if (S_ISBLK(inode->i_mode))
		inode->i_op = &blkdev_inode_operations;
	else if (S_ISFIFO(inode->i_mode))
		init_fifo(inode);

#ifdef UFS_INODE_DEBUG_MORE
	ufs_print_inode (inode);
#endif
	UFSD(("EXIT\n"))
}

static int ufs_update_inode(struct inode * inode, int do_sync)
{
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct buffer_head * bh;
	struct ufs_inode * ufs_inode;
	unsigned i;
	unsigned flags, swab;

	UFSD(("ENTER, ino %lu\n", inode->i_ino))

	sb = inode->i_sb;
	uspi = sb->u.ufs_sb.s_uspi;
	flags = sb->u.ufs_sb.s_flags;
	swab = sb->u.ufs_sb.s_swab;

	if (inode->i_ino < UFS_ROOTINO || 
	    inode->i_ino > (uspi->s_ncg * uspi->s_ipg)) {
		ufs_warning (sb, "ufs_read_inode", "bad inode number (%lu)\n", inode->i_ino);
		return -1;
	}

	bh = bread (sb->s_dev, ufs_inotofsba(inode->i_ino), sb->s_blocksize);
	if (!bh) {
		ufs_warning (sb, "ufs_read_inode", "unable to read inode %lu\n", inode->i_ino);
		return -1;
	}
	ufs_inode = (struct ufs_inode *) (bh->b_data + ufs_inotofsbo(inode->i_ino) * sizeof(struct ufs_inode));

	ufs_inode->ui_mode = SWAB16(inode->i_mode);
	ufs_inode->ui_nlink = SWAB16(inode->i_nlink);

	if (inode->i_uid == 0 && inode->u.ufs_i.i_uid >= UFS_USEEFT)
		ufs_set_inode_uid (ufs_inode, inode->u.ufs_i.i_uid);
	else
		ufs_set_inode_uid (ufs_inode, inode->i_uid);

	if (inode->i_gid == 0 && inode->u.ufs_i.i_gid >= UFS_USEEFT)
		ufs_set_inode_gid (ufs_inode, inode->u.ufs_i.i_gid);
	else
		ufs_set_inode_gid (ufs_inode, inode->i_gid);
		
	ufs_inode->ui_size = SWAB64((u64)inode->i_size);
	ufs_inode->ui_atime.tv_sec = SWAB32(inode->i_atime);
	ufs_inode->ui_atime.tv_usec = SWAB32(0);
	ufs_inode->ui_ctime.tv_sec = SWAB32(inode->i_ctime);
	ufs_inode->ui_ctime.tv_usec = SWAB32(0);
	ufs_inode->ui_mtime.tv_sec = SWAB32(inode->i_mtime);
	ufs_inode->ui_mtime.tv_usec = SWAB32(0);
	ufs_inode->ui_blocks = SWAB32(inode->i_blocks);
	ufs_inode->ui_flags = SWAB32(inode->u.ufs_i.i_flags);
	ufs_inode->ui_gen = SWAB32(inode->u.ufs_i.i_gen);

	if ((flags & UFS_UID_MASK) == UFS_UID_EFT) {
		ufs_inode->ui_u3.ui_sun.ui_shadow = SWAB32(inode->u.ufs_i.i_shadow);
		ufs_inode->ui_u3.ui_sun.ui_oeftflag = SWAB32(inode->u.ufs_i.i_oeftflag);
	}

	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		ufs_inode->ui_u2.ui_addr.ui_db[0] = SWAB32(kdev_t_to_nr(inode->i_rdev));
	else if (inode->i_blocks) {
		for (i = 0; i < (UFS_NDADDR + UFS_NINDIR); i++)
			ufs_inode->ui_u2.ui_addr.ui_db[i] = inode->u.ufs_i.i_u1.i_data[i];
	}
	else {
		for (i = 0; i < (UFS_NDADDR + UFS_NINDIR) * 4; i++)
			ufs_inode->ui_u2.ui_symlink[i] = inode->u.ufs_i.i_u1.i_symlink[i];
	}

	if (!inode->i_nlink)
		memset (ufs_inode, 0, sizeof(struct ufs_inode));
		
	mark_buffer_dirty(bh, 1);
	if (do_sync) {
		ll_rw_block (WRITE, 1, &bh);
		wait_on_buffer (bh);
	}
	brelse (bh);
	
	UFSD(("EXIT\n"))
	return 0;
}

void ufs_write_inode (struct inode * inode)
{
	ufs_update_inode (inode, 0);
}

int ufs_sync_inode (struct inode *inode)
{
	return ufs_update_inode (inode, 1);
}

void ufs_put_inode (struct inode * inode)
{
	UFSD(("ENTER & EXIT\n"))
}

void ufs_delete_inode (struct inode * inode)
{
	/*inode->u.ufs_i.i_dtime = CURRENT_TIME;*/
	mark_inode_dirty(inode);
	ufs_update_inode(inode, IS_SYNC(inode));
	inode->i_size = 0;
	if (inode->i_blocks)
		ufs_truncate (inode);
	ufs_free_inode (inode);
}