filesys.c

T-kernel 的extension源代码

		/* Already connected: Obtain the connection information from FsInfo. */
		err = CheckFS(dev, omode, pinfo);
		if ( err < E_OK ) {
			goto err_ret1;
		}

		/* It must work in exclusive of the file system task. */
		Lock(&(*fs)->lock);

		diskid    = (*fs)->dskid;
		*diskinfo = (*fs)->dskInfo;
	}

	return diskid;

err_ret2:
	(void)DetachFS(diskid, NULL, FALSE);
err_ret1:
	DEBUG_PRINT(("attachDevice err = %d\n", err));
	return err;
}

/*
 * Disconnect the disk device.
 *	When fs != NULL, perform only the lock release of the file system task.
 */
LOCAL ER detachDevice( ID diskid, FsInfo *fs )
{
	ER	err;

	if ( fs == NULL ) {
		/* Disconnect */
		err = DetachFS(diskid, NULL, FALSE);
		if ( err < E_OK ) {
			goto err_ret;
		}
	} else {
		/* Lock release */
		Unlock(&fs->lock);
	}

	return E_OK;

err_ret:
	DEBUG_PRINT(("detachDevice err = %d\n", err));
	return err;
}

/*
 * Check the file header ID of the root file.
 */
LOCAL ER checkRootFileHeaderID( DfSystemHeader *sh, DiskMapInfo *dmInfo )
{
	DfFileHeader	*fh;
	ID		mid;
	W		chk;
	ER		err;

	/* Map the header of the root file. */
	fh = fmcMapRootFileHeader(sh, dmInfo, &mid);
	if ( fh == NULL ) {
		err = (ER)mid;
		goto err_ret;
	}

	/* Check the file header ID. */
	chk = ( (fmConvEndianW(fh->startid, dmInfo->big) == FileHeaderTopID)
	     && (fmConvEndianW(fh->endid,   dmInfo->big) == FileHeaderEndID) )?
							E_OK: E_ILFMT;

	err = fmcUnmapDisk(mid, MD_RDONLY);
	if ( err < E_OK ) {
		goto err_ret;
	}

	return chk;

err_ret:
	DEBUG_PRINT(("checkRootFileHeaderID err = %d\n", err));
	return err;
}

/*
 * Read the file system management information.
 */
LOCAL void getFileSystemStatus( FS_STATE *fs, DfSystemHeader *sh, BOOL big )
{
	/* Obtain the management information. */
	fs->fs_bsize = fmConvEndianH(sh->sblk, big);
	fs->fs_nfile = fmConvEndianH(sh->nfmax, big);
	fs->fs_lang  = (H)fmConvEndianH((UH)sh->lang, big);
	fs->fs_level = (H)fmConvEndianH((UH)sh->acclv, big);
	fs->fs_nblk  = (W)fmConvEndianW((UW)sh->nlb, big);
	fs->fs_nfree = (W)fmConvEndianW((UW)sh->nflb, big);
	fs->fs_mtime = (W)fmConvEndianW((UW)sh->mtime, big);
	fs->fs_ctime = (W)fmConvEndianW((UW)sh->ctime, big);
	(void)fmConvEndianTC(fs->fs_name,  (TC*)sh->fsnm,  L_FSNM, big);
	(void)fmConvEndianTC(fs->fs_locat, (TC*)sh->devnm, L_DLNM, big);
}

/*
 * fls_sts: Obtain the file system management information.
 */
EXPORT void fmcGetFileSystemStatus( FmCmdPkt *pkt )
{
	FM_FLS_STS_PARA	*cmdPara = (FM_FLS_STS_PARA*)pkt->cmd.para;
	DiskMapInfo	dmInfo;
	FsInfo		*fs;
	DfSystemHeader	*sh;
	ID		mid;
	ER		err;

	/* Parameter check */
	err = CheckStrSpaceR(cmdPara->dev, DevNameLen);
	if ( err < E_OK ) {
		goto err_ret1;
	}

	err = CheckSpaceRW(cmdPara->buff, sizeof(FS_STATE));
	if ( err < E_OK ) {
		goto err_ret1;
	}

	/* Connect the file system. */
	err = attachDevice(cmdPara->dev, D_ATTACH|D_WEXCL, pkt->wrk.pinfo,
							&dmInfo.dskInfo, &fs);
	if ( err < E_OK ) {
		goto err_ret1;
	}
	dmInfo.dskid = (ID)err;

	/* Map the system header. */
	sh = fmcMapFileSystemHeader(&dmInfo, fs, &mid);
	if ( sh == NULL ) {
		err = (ER)mid;
		goto err_ret2;
	}

	/* Check the file header ID of the root file. */
	err = checkRootFileHeaderID(sh, &dmInfo);
	if ( err < E_OK ) {
		goto err_ret3;
	}

	/* Obtain the management information. */
	getFileSystemStatus(cmdPara->buff, sh, (BOOL)dmInfo.big);

	err = fmcUnmapDisk(mid, MD_RDONLY);
	if ( err < E_OK ) {
		goto err_ret2;
	}

	/* Disconnect the file system. */
	err = detachDevice(dmInfo.dskid, fs);
	if ( err < E_OK ) {
		goto err_ret1;
	}

	pkt->cmd.ret = ( dmInfo.dskInfo.protect != 0 )? 1: 0;
	return;

err_ret3:
	(void)fmcUnmapDisk(mid, MD_RDONLY);
err_ret2:
	(void)detachDevice(dmInfo.dskid, fs);
err_ret1:
	DEBUG_PRINT(("fmcGetFileSystemStatus err = %d\n", err));
	pkt->cmd.ret = err;
	return;
}

/*
 * Change the root file name.
 */
LOCAL ER changeRootFileName( FileName fname,
				DfSystemHeader *sh, DiskMapInfo *dmInfo )
{
	DfFileHeader	*fh;
	DfShortName	*sn;
	STIME		now;
	ID		mid;
	ER		err;

	/* Map the header of the root file. */
	fh = fmcMapRootFileHeader(sh, dmInfo, &mid);
	if ( fh == NULL ) {
		err = (ER)mid;
		goto err_ret;
	}

	/* Change the file name. */
	(void)fmConvEndianTC((TC*)fh->name, fname, FileNameLen, dmInfo->big);

	/* Update the date/time of access. */
	now = fmGetTime();
	fh->atime = (W)fmConvEndianW((UW)now, dmInfo->big);

	err = fmcUnmapDisk(mid, MD_WRITE);
	if ( err < E_OK ) {
		goto err_ret;
	}

	/* Map the root file abbreviated name. */
	sn = fmcMapRootFileShortName(sh, dmInfo, &mid);
	if ( sn == NULL ) {
		err = (ER)mid;
		goto err_ret;
	}

	/* Change the file abbreviated name. */
	*sn = fmConvEndianW(fmShortFileName(fname), dmInfo->big);

	err = fmcUnmapDisk(mid, MD_WRITE);
	if ( err < E_OK ) {
		goto err_ret;
	}
	return E_OK;

err_ret:
	DEBUG_PRINT(("changeRootFileName err = %d\n", err));
	return err;
}

/*
 * Change the file system information.
 *	When the system block is changed (written), return MD_WRITE to *mdflg.
 *	If not changed, the contents of *mdflg are not changed.
 */
LOCAL ER changeFileSystemInfo( TC *fsnm, TC *dlnm, FsInfo *fs,
			DfSystemHeader *sh, DiskMapInfo *dmInfo, UW *mdflg )
{
	UW		mflag = MD_RDONLY;
	STIME		now;
	ER		err;

	/* File system name */
	if ( fsnm != NULL ) {
		FsInfo	*p;

		/* Check the file system name. */
		err = CheckStrSpaceR(fsnm, L_FSNM);
		if ( err < E_OK ) {
			goto err_ret;
		}

		err = fmCheckFileName(fsnm, L_FSNM);
		if ( err < E_OK ) {
			goto err_ret;
		}

		/* Whether the file system of the same name is connected. */
		p = fmSelectFileSystemOfFsName(fsnm);
		if ( (p != NULL) && (p != fs) ) {
			err = E_OBJ;
			goto err_ret;
		}

		/* Change the root file name. */
		err = changeRootFileName(fsnm, sh, dmInfo);
		if ( err < E_OK ) {
			goto err_ret;
		}

		/* Change file system name. */
		(void)fmConvEndianTC((TC*)sh->fsnm, fsnm, L_FSNM, dmInfo->big);
		if ( fs != NULL ) {
			tc_strncpy(fs->fsName, fsnm, L_FSNM);
		}

		mflag = MD_WRITE;
	}

	/* Device location name */
	if ( dlnm != NULL ) {

		/* Check the device location name. */
		err = CheckStrSpaceR(dlnm, L_DLNM);
		if ( err < E_OK ) {
			goto err_ret;
		}

		/* Change the device location name. */
		(void)fmConvEndianTC((TC*)sh->devnm, dlnm, L_DLNM, dmInfo->big);

		mflag = MD_WRITE;
	}

	if ( mflag != MD_RDONLY ) {

		/* Update the date/time of system block update. */
		now = fmGetTime();
		sh->mtime = (W)fmConvEndianW((UW)now, dmInfo->big);

		*mdflg = mflag;
	}

	return E_OK;

err_ret:
	if ( mflag != MD_RDONLY ) {
		*mdflg = mflag;
	}
	DEBUG_PRINT(("changeFileSystemInfo err = %d\n", err));
	return err;
}

/*
 * chg_fls: Change the file system information.
 */
EXPORT void fmcChangeFileSystemInfo( FmCmdPkt *pkt )
{
	FM_CHG_FLS_PARA	*cmdPara = (FM_CHG_FLS_PARA*)pkt->cmd.para;
	DiskMapInfo	dmInfo;
	FsInfo		*fs;
	DfSystemHeader	*sh;
	ID		mid;
	UW		mflag = MD_RDONLY;
	ER		err;

	/* Parameter check */
	err = CheckStrSpaceR(cmdPara->dev, DevNameLen);
	if ( err < E_OK ) {
		goto err_ret1;
	}

	/* Connect the file system. */
	err = attachDevice(cmdPara->dev, D_ATTACH|D_WRITE|D_WEXCL,
					pkt->wrk.pinfo, &dmInfo.dskInfo, &fs);
	if ( err < E_OK ) {
		goto err_ret1;
	}
	dmInfo.dskid = (ID)err;

	/* Whether it is write protected. */
	if ( dmInfo.dskInfo.protect != 0 ) {
		err = E_RONLY;
		goto err_ret2;
	}

	/* Map the system header. */
	sh = fmcMapFileSystemHeader(&dmInfo, fs, &mid);
	if ( sh == NULL ) {
		err = (ER)mid;
		goto err_ret2;
	}

	/* Check the file header ID of the root file. */
	err = checkRootFileHeaderID(sh, &dmInfo);
	if ( err < E_OK ) {
		goto err_ret3;
	}

	/* Change the file system information. */
	err = changeFileSystemInfo(cmdPara->fs_name, cmdPara->fs_locate, fs,
							sh, &dmInfo, &mflag);
	if ( err < E_OK ) {
		goto err_ret3;
	}

	err = fmcUnmapDisk(mid, mflag);
	if ( err < E_OK ) {
		goto err_ret2;
	}

	/* Disconnect the file system. */
	err = detachDevice(dmInfo.dskid, fs);
	if ( err < E_OK ) {
		goto err_ret1;
	}

	pkt->cmd.ret = E_OK;
	return;

err_ret3:
	(void)fmcUnmapDisk(mid, mflag);
err_ret2:
	(void)detachDevice(dmInfo.dskid, fs);
err_ret1:
	DEBUG_PRINT(("fmcChangeFileSystemInfo err =%d\n", err));
	pkt->cmd.ret = err;
	return;
}