In order to unlock flock(2), make writes to the f_iflags field of struct

file atomic. This also gets rid of the last kernel lock protected field
in the scope of struct file.

ok mpi@ visa@

4 files changed, 11 insertions, 12 deletions

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 059a62120a0..1b79eefaf7d 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_descrip.c,v 1.200 2020/02/26 13:54:52 visa Exp $	*/
+/*	$OpenBSD: kern_descrip.c,v 1.201 2020/03/13 10:07:01 anton Exp $	*/
 /*	$NetBSD: kern_descrip.c,v 1.42 1996/03/30 22:24:38 christos Exp $	*/
 
 /*
@@ -707,7 +707,7 @@ fdinsert(struct filedesc *fdp, int fd, int flags, struct file *fp)
 
 	mtx_enter(&fhdlk);
 	if ((fp->f_iflags & FIF_INSERTED) == 0) {
-		fp->f_iflags |= FIF_INSERTED;
+		atomic_setbits_int(&fp->f_iflags, FIF_INSERTED);
 		if ((fq = fdp->fd_ofiles[0]) != NULL) {
 			LIST_INSERT_AFTER(fq, fp, f_list);
 		} else {
@@ -1317,7 +1317,7 @@ sys_flock(struct proc *p, void *v, register_t *retval)
 	lf.l_len = 0;
 	if (how & LOCK_UN) {
 		lf.l_type = F_UNLCK;
-		fp->f_iflags &= ~FIF_HASLOCK;
+		atomic_clearbits_int(&fp->f_iflags, FIF_HASLOCK);
 		error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
 		goto out;
 	}
@@ -1329,7 +1329,7 @@ sys_flock(struct proc *p, void *v, register_t *retval)
 		error = EINVAL;
 		goto out;
 	}
-	fp->f_iflags |= FIF_HASLOCK;
+	atomic_setbits_int(&fp->f_iflags, FIF_HASLOCK);
 	if (how & LOCK_NB)
 		error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK);
 	else
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index 34dc786d60f..3a8c9208f9e 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_syscalls.c,v 1.342 2020/01/30 15:36:11 visa Exp $	*/
+/*	$OpenBSD: vfs_syscalls.c,v 1.343 2020/03/13 10:07:01 anton Exp $	*/
 /*	$NetBSD: vfs_syscalls.c,v 1.71 1996/04/23 10:29:02 mycroft Exp $	*/
 
 /*
@@ -1188,7 +1188,7 @@ doopenat(struct proc *p, int fd, const char *path, int oflags, mode_t mode,
 			goto out;
 		}
 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
-		fp->f_iflags |= FIF_HASLOCK;
+		atomic_setbits_int(&fp->f_iflags, FIF_HASLOCK);
 	}
 	if (localtrunc) {
 		if ((fp->f_flag & FWRITE) == 0)
@@ -1457,7 +1457,7 @@ sys_fhopen(struct proc *p, void *v, register_t *retval)
 			goto bad;
 		}
 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
-		fp->f_iflags |= FIF_HASLOCK;
+		atomic_setbits_int(&fp->f_iflags, FIF_HASLOCK);
 	}
 	VOP_UNLOCK(vp);
 	*retval = indx;
diff --git a/sys/sys/file.h b/sys/sys/file.h
index c52d9c8e089..f638c1507b6 100644
--- a/sys/sys/file.h
+++ b/sys/sys/file.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: file.h,v 1.60 2020/02/01 08:57:27 anton Exp $	*/
+/*	$OpenBSD: file.h,v 1.61 2020/03/13 10:07:01 anton Exp $	*/
 /*	$NetBSD: file.h,v 1.11 1995/03/26 20:24:13 jtc Exp $	*/
 
 /*
@@ -75,7 +75,6 @@ struct	fileops {
  *	a	atomic operations
  *	f	per file `f_mtx'
  *	v	vnode lock
- *	k	kernel lock
  */
 struct file {
 	LIST_ENTRY(file) f_list;/* [F] list of active files */
@@ -86,7 +85,7 @@ struct file {
 #define	DTYPE_PIPE	3	/* pipe */
 #define	DTYPE_KQUEUE	4	/* event queue */
 #define	DTYPE_DMABUF	5	/* DMA buffer (for DRM) */
-	int	f_iflags;	/* [k] internal flags */
+	u_int	f_iflags;	/* [a] internal flags */
 	int	f_type;		/* [I] descriptor type */
 	u_int	f_count;	/* [a] reference count */
 	struct	ucred *f_cred;	/* [I] credentials associated with descriptor */
diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h
index 7848b7059be..9e2fc55ce52 100644
--- a/sys/sys/sysctl.h
+++ b/sys/sys/sysctl.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sysctl.h,v 1.204 2020/02/16 07:55:30 anton Exp $	*/
+/*	$OpenBSD: sysctl.h,v 1.205 2020/03/13 10:07:01 anton Exp $	*/
 /*	$NetBSD: sysctl.h,v 1.16 1996/04/09 20:55:36 cgd Exp $	*/
 
 /*
@@ -735,7 +735,7 @@ do {									\
 struct kinfo_file {
 	uint64_t	f_fileaddr;	/* PTR: address of struct file */
 	uint32_t	f_flag;		/* UINT: flags (see fcntl.h) */
-	uint32_t	f_iflags;	/* INT: internal flags */
+	uint32_t	f_iflags;	/* UINT: internal flags */
 	uint32_t	f_type;		/* INT: descriptor type */
 	uint32_t	f_count;	/* UINT: reference count */
 	uint32_t	f_msgcount;	/* UINT: references from msg queue */