Implement lockless resource limits.

Use the same scheme implemented to manage credentials.

Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.

Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.

3 files changed, 11 insertions, 5 deletions

diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 3e694e122cfd..e6c83b43940b 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -246,6 +246,7 @@ struct thread {
 	int		td_intr_nesting_level; /* (k) Interrupt recursion. */
 	int		td_pinned;	/* (k) Temporary cpu pin count. */
 	struct ucred	*td_ucred;	/* (k) Reference to credentials. */
+	struct plimit	*td_limit;	/* (k) Resource limits. */
 	u_int		td_estcpu;	/* (t) estimated cpu utilization */
 	int		td_slptick;	/* (t) Time at sleep. */
 	int		td_blktick;	/* (t) Time spent blocked. */
@@ -499,7 +500,7 @@ struct proc {
 	struct filedesc	*p_fd;		/* (b) Open files. */
 	struct filedesc_to_leader *p_fdtol; /* (b) Tracking node */
 	struct pstats	*p_stats;	/* (b) Accounting/statistics (CPU). */
-	struct plimit	*p_limit;	/* (c) Process limits. */
+	struct plimit	*p_limit;	/* (c) Resource limits. */
 	struct callout	p_limco;	/* (c) Limit callout handle */
 	struct sigacts	*p_sigacts;	/* (x) Signal actions, state (CPU). */
 
diff --git a/sys/sys/resourcevar.h b/sys/sys/resourcevar.h
index a07fdf8d2427..b4c707d5e130 100644
--- a/sys/sys/resourcevar.h
+++ b/sys/sys/resourcevar.h
@@ -130,13 +130,16 @@ int	 kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which,
 struct plimit
 	*lim_alloc(void);
 void	 lim_copy(struct plimit *dst, struct plimit *src);
-rlim_t	 lim_cur(struct proc *p, int which);
+rlim_t	 lim_cur(struct thread *td, int which);
+rlim_t	 lim_cur_proc(struct proc *p, int which);
 void	 lim_fork(struct proc *p1, struct proc *p2);
 void	 lim_free(struct plimit *limp);
 struct plimit
 	*lim_hold(struct plimit *limp);
-rlim_t	 lim_max(struct proc *p, int which);
-void	 lim_rlimit(struct proc *p, int which, struct rlimit *rlp);
+rlim_t	 lim_max(struct thread *td, int which);
+rlim_t	 lim_max_proc(struct proc *p, int which);
+void	 lim_rlimit(struct thread *td, int which, struct rlimit *rlp);
+void	 lim_rlimit_proc(struct proc *p, int which, struct rlimit *rlp);
 void	 ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
 	    struct rusage_ext *rux2);
 void	 rucollect(struct rusage *ru, struct rusage *ru2);
@@ -156,5 +159,7 @@ void	 ui_racct_foreach(void (*callback)(struct racct *racct,
 	    void *arg2, void *arg3), void *arg2, void *arg3);
 #endif
 
+void	lim_update_thread(struct thread *td);
+
 #endif /* _KERNEL */
 #endif /* !_SYS_RESOURCEVAR_H_ */
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index a30130fe4b79..36ef8af08e89 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -692,7 +692,7 @@ int	vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base,
 	    struct ucred *active_cred, struct ucred *file_cred, size_t *aresid,
 	    struct thread *td);
 int	vn_rlimit_fsize(const struct vnode *vn, const struct uio *uio,
-	    const struct thread *td);
+	    struct thread *td);
 int	vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred,
 	    struct ucred *file_cred, struct thread *td);
 int	vn_start_write(struct vnode *vp, struct mount **mpp, int flags);