Bug 12634

Description jhs 1999-07-14 00:10:01 UTC

I run a site of 10 hosts with many ports distfiles, NFS mounted on other hosts.
Here's my actual example of how I hit the barrier, shown so folk won't think
it's a contrived amount of links, it's simply my current site's NFS file system) :
  DIRECTORY			SYMBOLIC LINK (or file, in last line)
  /usr				ports -> /host/park/usr/ports
  /host				park -> /a/park
  /a/park/usr/ports		distfiles@ -> /pub/freebsd/distfiles/links
  /				pub -> public
  /				public -> site/public
  /site				public -> domain/public
  /site/domain			public -> this/public
  /site/domain			this -> jhs.no_domain
  /site/domain/jhs.no_domain	public -> ../../../host/flip/usr2/public
  /host				flip -> /a/flip
  /a/flip/usr2			public@ -> ftp/public
  /a/flip/usr2/ftp/public/freebsd/distfiles/links/	gv-3.5.8.tar.gz -> /usr/ports/distfiles/cd.3.2/./gv-3.5.8.tar.gz
  /usr				ports -> /host/park/usr/ports
  /host				park -> /a/park
  /a/park/usr/ports		distfiles@ -> /pub/freebsd/distfiles/links
  /				pub -> public
  /				public -> site/public
  /site				public -> domain/public
  /site/domain			public -> this/public
  /site/domain			this -> jhs.no_domain
  /site/domain/jhs.no_domain	public -> ../../../host/flip/usr2/public
  /host				flip -> /a/flip
  /a/flip/usr2			public@ -> ftp/public
  /a/flip/usr2/ftp/public/freebsd/distfiles/links/	cd.3.2 ../cd.3.2
  /a/flip/usr2/ftp/public/freebsd/distfiles		3.2-RELEASE/links
  /a/flip/usr2/ftp/public/freebsd/distfiles/3.2-RELEASE/links	gv-3.5.8.tar.gz@ -> ../d4/gv-3.5.8.tar.gz
  /a/flip/usr2/ftp/public/freebsd/distfiles/3.2-RELEASE		d4 -> link/d4
  /a/flip/usr2/ftp/public/freebsd/distfiles/3.2-RELEASE		link -> link.flip
  /a/flip/usr2/ftp/public/freebsd/distfiles/3.2-RELEASE		link.flip -> ../../../../../../usr1/ftp/public/freebsd/ref/3.2-RELEASE/distfiles
  /a/flip/usr1/ftp/public/freebsd/ref/3.2-RELEASE/distfiles/d4	gv-3.5.8.tar.gz [ The real file ]

Fix: Having searched all files in /usr/src for sysparam.h, I found just:
	sys/i386/boot/dosboot/fbsdboot.mak
	sys/i386/boot/dosboot/param.h:#include "sysparam.h"
& both had Control Ms in (for Dos), it thus seems highly likely this quote
	"A path name lookup involved more than 8 symbolic links."
was never correct, it should have read "32", & I've now increased it.



Background Info:
---
These can probably stay unchanged:
	sys/i386/boot/dosboot/sysparam.h:172	
		#define MAXSYMLINKS     8
	gnu/usr.bin/rcs/lib/conf.h:46
		#if has_readlink && !defined(MAXSYMLINKS)
		#	if has_sys_param_h
		#		include <sys/param.h>
		#	endif
		#	ifndef MAXSYMLINKS
		#		define MAXSYMLINKS 20 /* BSD; not standard yet */
		#	endif
		#endif
These use MAXSYMLINKS:
	gnu/usr.bin/rcs/lib/rcsedit.c	resolve_symlink(L)
	lib/libc/stdlib/realpath.c:	realpath(path, resolved)
	lib/libstand/nfs.c:		nfs_open(upath, f)
	lib/libstand/ufs.c:		ufs_open(upath, f)
	sys/kern/vfs_lookup.c:		namei(ndp)
	sys/nfs/nfs_subs.c:		nfs_namei(ndp, fhp, len, slp, nam, mdp, dposp, retdirp, p, kerbflag, pubflag)
These use ELOOP:
	lib/libc/gen/errlst.c:114	"Too many levels of symbolic links"
	lib/libc/gen/exec.c:275		case ELOOP:
	lib/libc/sys/intro.2:354	A path name lookup involved more than 8 symbolic links.
	share/examples/mdoc/example.3:	Too many levels of symbolic links.
	sys/sys/errno.h:		#define ELOOP 62
	lib/libc/stdlib/realpath.c	if (++symlinks > MAXSYMLINKS)
	) )--LBgkgox2pvUSLXLFBJZLsu9hcHoW9NYxV9Rogtt4alUkE1R0
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*** old/src/sys/sys/param.h	Sat May  8 23:55:42 1999
--- new/src/sys/sys/param.h	Tue Jul 13 23:10:21 1999
***************
*** 168,174 ****
   * infinite loops reasonably quickly.
   */
  #define	MAXPATHLEN	PATH_MAX
! #define MAXSYMLINKS	32
  
  /* Bit map related macros. */
  #define	setbit(a,i)	((a)[(i)/NBBY] |= 1<<((i)%NBBY))
--- 168,174 ----
   * infinite loops reasonably quickly.
   */
  #define	MAXPATHLEN	PATH_MAX
! #define MAXSYMLINKS	64
  
  /* Bit map related macros. */
  #define	setbit(a,i)	((a)[(i)/NBBY] |= 1<<((i)%NBBY))
How-To-Repeat: 
	I hit the problem doing 
		md5 /usr/ports/distfiles/gv-3.5.8.tar.gz
	with the above set of links.