;
;	File:		TFSRFN3.a
;
;	Contains:	This file contains file system utility routines which
;				use the volume block map.
;
;	Copyright:	© 1982-1991 by Apple Computer, Inc., all rights reserved.
;
;	Change History (most recent first):
;
;		 <2>	 9/12/91	JSM		Add a header.
;	   <1.1>	11/10/88	CCH		Fixed Header.
;	   <1.0>	 11/9/88	CCH		Adding to EASE.
;	   <1.0>	 2/11/88	BBM		Adding file for the first time into EASE…
;				 1/14/86	LAK		Changed interface (FileAlloc sets up D0 option first so
;									AllocContig entrypoint is no longer needed).
;				 1/14/86	LAK		Changed interface (FileAlloc sets up D0 option first so
;									AllocContig entrypoint is no longer needed).
;				 10/1/85	LAK		Minor cleanup. Removed Lg2Phys (only called by Cache).
;				 8/29/85	BB		Added support for contiguous allocation (AllocContig)
;				 6/19/85	PWD		Changed non-hardware internal errors to FSDSIntErr instead of
;									IOErr.
;				 4/25/85	PWD		Changed to convert all internal errors to IOErr.
;				 3/10/85	GJC		All new for TFS - old is now part of MFS compatibility routines
;				 3/10/85	GJC		Added TFS functionality.
;				 8/18/83	LAK		Fixed same bug again (3 more to go).
;				 8/15/83	LAK		Fixed bug in block allocation (last free block bug).
;				 1/17/83	LAK		Changes for alloc blks offset from diskette start.
;				 1/17/83	LAK		Changed for final volume format (alloc blks offset)
;				12/23/82	LAK		Added incr, decr of volume free block count in DAlBlks, Alloc;
;									mark volume dirty in these routines instead of SubMrk.
;				12/22/82	LAK		Rewrote to reflect new file system data structures; No
;									reclamation of space is now needed from undeleted files; always
;									checks number of free bytes available on the volume before
;									proceeding; now has 2 entry points.
;

;_______________________________________________________________________
;
; External Routines:
;
;
; Internal Routines: GtNxBlk,Alloc,DAlBlks,SubMrk
;
;_______________________________________________________________________

;_______________________________________________________________________
;
; Routine:		Alloc,AllocContig
; (c) 1983 Apple Computer Inc.
;
; Arguments:	  A2.L (input)	-- VCB ptr
;				  (A1,D1.W) (input) -- FCB pointer
;				  D4.L (input)	-- number of bytes extra to allocate
;				  D0.W (output) -- Error code, 0 if no error.
;									(only FXM error: dskfull - other errors can
;									 be passed up by VSM or BT)
;				  D6.L (output) -- number of bytes actually allocated (always
;									a multiple of 512-bytes).
;				  All other registers are preserved
; Called By:	FileWrite,SetEOF,FileAlloc
; Calls:		GtNxBlk,SubMrk
; Function: 	Allocate new blocks to a file.	(Does not check lock bits!)
;				Alloc entry point does nothing if it can't get all the bytes
;				requested.
;
; Modification History:
;  22 Dec 82  LAK  Rewrote to reflect new file system data structures;
;				   No reclamation of space is now needed from undeleted
;				   files; always checks number of free bytes available
;				   on the volume before proceeding; now has 2 entry points.
;  17 Jan 83  LAK  Changes for alloc blks offset from diskette start.
;  10 Mar 85  GJC  Added TFS functionality.
;  <14Jan86>  LAK  Changed interface (FileAlloc sets up D0 option first so
;					 AllocContig entrypoint is no longer needed).
;_______________________________________________________________________


			 BLANKS 	  ON
			 STRING 	  ASIS

Alloc		 BSR	TFSVolTst	   ; is it TFS or is it MFS
			 BNE	MFSAlloc	   ; MFS - then go handle it
			 MOVEQ	#kEFAll,D0	   ; get it all or give up (doesn't     <14Jan86>
								   ;  to be contiguous)

AllocTFS	 MOVE.L (SP)+,-(A6)    ; save return address				<14Jan86>
			 MOVE.L D3,-(A6)	   ; save D3							<14Jan86>
			 MOVE.W D0,D3		   ; pass options in D3 				<14Jan86>
			 JSR	Extendfile	   ; get the space
			 MOVE.L (A6)+,D3	   ; restore D3 						<29Aug85>
			 MOVE.L (A6)+,-(SP)    ; Restore return address
			 TST.W	D0			   ; Set condition codes
			 RTS