Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!hplabs!hpl-opus!hpccc!culberts
From: culberts@hpccc.HP.COM (Bruce Culbertson)
Newsgroups: comp.os.minix
Subject: Re: getdents.c bug fix, fixes new ls also
Message-ID: <6910005@hpccc.HP.COM>
Date: 28 Aug 89 21:04:11 GMT
References: <6910004@hpccc.HP.COM>
Organization: Hewlett-Packard Co.
Lines: 79

I regret to say that the original bug fix I posted for getdents.c was
not entirely correct.  Previously I tested it with readdir(), which
unfortunately did not expose the problem which still existed.  I have
tested the new version with a good sampling of directory sizes and
buffer sizes.  I hope this will be my last message on this subject!
This cdif is relative to the original 1.4a version.

Bruce Culbertson
culberts@hplabs.hp.com
---------------------------------  cut  ----------------------------------
*** getdents.old	Thu Aug 24 09:04:24 1989
--- getdents.c	Thu Aug 24 18:28:17 1989
***************
*** 100,107 ****
  #endif
  
  #ifndef DIRBLKSIZ
! #define	DIRBLKSIZ	4096		/* directory file read buffer size */
  #endif
  
  #ifndef NULL
  #define	NULL	0
--- 100,117 ----
  #endif
  
  #ifndef DIRBLKSIZ
! /* directory file read buffer size
!  * For directory files with fixed sized records, this should be a
!  * multiple of the record size.  For variable sized records, this code
!  * is probably unreliable if the directory is larger than DIRBLKSIZ --
!  * so make DIRBLKSIZ big.
!  */
! #ifdef UFS
! #define	DIRBLKSIZ (64*sizeof(struct direct))
! #else
! #define	DIRBLKSIZ 4096
  #endif
+ #endif
  
  #ifndef NULL
  #define	NULL	0
***************
*** 109,114 ****
--- 119,125 ----
  
  #ifndef SEEK_CUR
  #define	SEEK_CUR	1
+ #define	SEEK_SET	0
  #endif
  
  #ifndef S_ISDIR				/* macro to test for directory file */
***************
*** 275,282 ****
  
  				if ( (char *)bp + reclen > &buf[nbyte] )
  					{
! 					errno = EINVAL;
! 					return -1;	/* buf too small */
  					}
  
  				bp->d_ino = dp->d_fileno;
--- 286,302 ----
  
  				if ( (char *)bp + reclen > &buf[nbyte] )
  					{
! 					/* buf too small, lseek so we get the
! 					 * rest on next call to getdents() 
! 					 */
! 					if (lseek (fildes,
! 					(long)((char *)dp-u.dblk+offset),
! 					SEEK_SET) < 0)
! 						{
! 						/* errno set by lseek */
! 						return -1;
! 						}
! 					break;
  					}
  
  				bp->d_ino = dp->d_fileno;