? sys/atomic.h
Index: kern/kern_prot.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/kern_prot.c,v
retrieving revision 1.67
diff -c -r1.67 kern_prot.c
*** kern/kern_prot.c	2000/11/10 23:57:48	1.67
--- kern/kern_prot.c	2000/11/26 21:29:46
***************
*** 1131,1139 ****
  {
  	register struct ucred *cr;
  
! 	MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK);
! 	bzero((caddr_t)cr, sizeof(*cr));
  	cr->cr_ref = 1;
  	return (cr);
  }
  
--- 1131,1139 ----
  {
  	register struct ucred *cr;
  
! 	MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK|M_ZERO);
  	cr->cr_ref = 1;
+ 	mtx_init(&cr->cr_mtx, "ucred", MTX_DEF);
  	return (cr);
  }
  
***************
*** 1145,1151 ****
--- 1145,1154 ----
  crfree(cr)
  	struct ucred *cr;
  {
+ 
+ 	mtx_enter(&cr->cr_mtx, MTX_DEF);
  	if (--cr->cr_ref == 0) {
+ 		mtx_destroy(&cr->cr_mtx);
  		/*
  		 * Some callers of crget(), such as nfs_statfs(),
  		 * allocate a temporary credential, but don't
***************
*** 1154,1159 ****
--- 1157,1164 ----
  		if (cr->cr_uidinfo != NULL)
  			uifree(cr->cr_uidinfo);
  		FREE((caddr_t)cr, M_CRED);
+ 	} else {
+ 		mtx_exit(&cr->cr_mtx, MTX_DEF);
  	}
  }
  
***************
*** 1166,1178 ****
  {
  	struct ucred *newcr;
  
! 	if (cr->cr_ref == 1)
  		return (cr);
! 	newcr = crget();
! 	*newcr = *cr;
! 	uihold(newcr->cr_uidinfo);
  	crfree(cr);
- 	newcr->cr_ref = 1;
  	return (newcr);
  }
  
--- 1171,1184 ----
  {
  	struct ucred *newcr;
  
! 	mtx_enter(&cr->cr_mtx, MTX_DEF);
! 	if (cr->cr_ref == 1) {
! 		mtx_exit(&cr->cr_mtx, MTX_DEF);
  		return (cr);
! 	}
! 	mtx_exit(&cr->cr_mtx, MTX_DEF);
! 	newcr = crdup(cr);
  	crfree(cr);
  	return (newcr);
  }
  
***************
*** 1185,1192 ****
  {
  	struct ucred *newcr;
  
! 	newcr = crget();
  	*newcr = *cr;
  	uihold(newcr->cr_uidinfo);
  	newcr->cr_ref = 1;
  	return (newcr);
--- 1191,1199 ----
  {
  	struct ucred *newcr;
  
! 	MALLOC(newcr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK);
  	*newcr = *cr;
+ 	mtx_init(&newcr->cr_mtx, "ucred", MTX_DEF);
  	uihold(newcr->cr_uidinfo);
  	newcr->cr_ref = 1;
  	return (newcr);
Index: sys/ucred.h
===================================================================
RCS file: /home/ncvs/src/sys/sys/ucred.h,v
retrieving revision 1.17
diff -c -r1.17 ucred.h
*** sys/ucred.h	2000/10/26 15:49:35	1.17
--- sys/ucred.h	2000/11/26 21:29:48
***************
*** 37,42 ****
--- 37,44 ----
  #ifndef _SYS_UCRED_H_
  #define	_SYS_UCRED_H_
  
+ #include <sys/mutex.h>
+ 
  /*
   * Credentials.
   *
***************
*** 44,50 ****
   * Only the suser()/suser_xxx() function should be used for this.
   */
  struct ucred {
! 	u_short	cr_ref;			/* reference count */
  	uid_t	cr_uid;			/* effective user id */
  	short	cr_ngroups;		/* number of groups */
  	gid_t	cr_groups[NGROUPS];	/* groups */
--- 46,53 ----
   * Only the suser()/suser_xxx() function should be used for this.
   */
  struct ucred {
! 	struct	mtx cr_mtx;		/* protect refcount */
! 	u_int	cr_ref;			/* reference count */
  	uid_t	cr_uid;			/* effective user id */
  	short	cr_ngroups;		/* number of groups */
  	gid_t	cr_groups[NGROUPS];	/* groups */
***************
*** 55,61 ****
  #define FSCRED ((struct ucred *)-1)	/* filesystem credential */
  
  #ifdef _KERNEL
! #define	crhold(cr)	(cr)->cr_ref++
  
  struct proc;
  
--- 58,69 ----
  #define FSCRED ((struct ucred *)-1)	/* filesystem credential */
  
  #ifdef _KERNEL
! #define	crhold(cr) \
! 	do {						\
! 		mtx_enter(&(cr)->cr_mtx, MTX_DEF);	\
! 		(cr)->cr_ref++;				\
! 		mtx_exit(&(cr)->cr_mtx, MTX_DEF);	\
! 	} while (0)
  
  struct proc;