This is the kernel Lite/2 commit. There are some requisite userland

changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.

The system boots and can mount UFS filesystems.

Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
		Mount_std mounts will not work until the getfsent
		library routine is changed.

Reviewed by:	various people
Submitted by:	Jeffery Hsu <hsu@freebsd.org>

1 files changed, 57 insertions, 21 deletions

diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 0ba5c45..98842c6 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -96,10 +96,11 @@ vn_open(ndp, fmode, cmode)
 			VATTR_NULL(vap);
 			vap->va_type = VREG;
 			vap->va_mode = cmode;
-			LEASE_CHECK(ndp->ni_dvp, p, cred, LEASE_WRITE);
-			error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
-			    &ndp->ni_cnd, vap);
-			if (error)
+			if (fmode & O_EXCL)
+				vap->va_vaflags |= VA_EXCLUSIVE;
+			VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE);
+			if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
+			    &ndp->ni_cnd, vap))
 				return (error);
 			fmode &= ~O_TRUNC;
 			vp = ndp->ni_vp;
@@ -149,9 +150,9 @@ vn_open(ndp, fmode, cmode)
 		}
 	}
 	if (fmode & O_TRUNC) {
-		VOP_UNLOCK(vp);				/* XXX */
-		LEASE_CHECK(vp, p, cred, LEASE_WRITE);
-		VOP_LOCK(vp);				/* XXX */
+		VOP_UNLOCK(vp, 0, p);				/* XXX */
+		VOP_LEASE(vp, p, cred, LEASE_WRITE);
+		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);	/* XXX */
 		VATTR_NULL(vap);
 		vap->va_size = 0;
 		error = VOP_SETATTR(vp, vap, cred, p);
@@ -179,8 +180,7 @@ bad:
 
 /*
  * Check for write permissions on the specified vnode.
- * The read-only status of the file system is checked.
- * Also, prototype text segments cannot be written.
+ * Prototype text segments cannot be written.
  */
 int
 vn_writechk(vp)
@@ -237,7 +237,7 @@ vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p)
 	int error;
 
 	if ((ioflg & IO_NODELOCKED) == 0)
-		VOP_LOCK(vp);
+		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
 	auio.uio_iov = &aiov;
 	auio.uio_iovcnt = 1;
 	aiov.iov_base = base;
@@ -258,7 +258,7 @@ vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p)
 		if (auio.uio_resid && error == 0)
 			error = EIO;
 	if ((ioflg & IO_NODELOCKED) == 0)
-		VOP_UNLOCK(vp);
+		VOP_UNLOCK(vp, 0, p);
 	return (error);
 }
 
@@ -271,12 +271,13 @@ vn_read(fp, uio, cred)
 	struct uio *uio;
 	struct ucred *cred;
 {
-	register struct vnode *vp = (struct vnode *)fp->f_data;
+	struct vnode *vp = (struct vnode *)fp->f_data;
+	struct proc *p = uio->uio_procp;
 	int count, error;
 	int flag, seq;
 
-	LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_READ);
-	VOP_LOCK(vp);
+	VOP_LEASE(vp, p, cred, LEASE_READ);
+	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
 	uio->uio_offset = fp->f_offset;
 	count = uio->uio_resid;
 	flag = 0;
@@ -313,7 +314,7 @@ vn_read(fp, uio, cred)
 	error = VOP_READ(vp, uio, flag, cred);
 	fp->f_offset += count - uio->uio_resid;
 	fp->f_nextread = fp->f_offset;
-	VOP_UNLOCK(vp);
+	VOP_UNLOCK(vp, 0, p);
 	return (error);
 }
 
@@ -326,15 +327,19 @@ vn_write(fp, uio, cred)
 	struct uio *uio;
 	struct ucred *cred;
 {
-	register struct vnode *vp = (struct vnode *)fp->f_data;
-	int count, error, ioflag = 0;
+	struct vnode *vp = (struct vnode *)fp->f_data;
+	struct proc *p = uio->uio_procp;
+	int count, error, ioflag = IO_UNIT;
 
 	if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
 		ioflag |= IO_APPEND;
 	if (fp->f_flag & FNONBLOCK)
 		ioflag |= IO_NDELAY;
-	LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_WRITE);
-	VOP_LOCK(vp);
+	if ((fp->f_flag & O_FSYNC) ||
+	    (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
+		ioflag |= IO_SYNC;
+	VOP_LEASE(vp, p, cred, LEASE_WRITE);
+	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
 	uio->uio_offset = fp->f_offset;
 	count = uio->uio_resid;
 	error = VOP_WRITE(vp, uio, ioflag, cred);
@@ -342,7 +347,7 @@ vn_write(fp, uio, cred)
 		fp->f_offset = uio->uio_offset;
 	else
 		fp->f_offset += count - uio->uio_resid;
-	VOP_UNLOCK(vp);
+	VOP_UNLOCK(vp, 0, p);
 	return (error);
 }
 
@@ -402,7 +407,7 @@ vn_stat(vp, sb, p)
 	sb->st_rdev = vap->va_rdev;
 	sb->st_size = vap->va_size;
 	sb->st_atimespec = vap->va_atime;
-	sb->st_mtimespec= vap->va_mtime;
+	sb->st_mtimespec = vap->va_mtime;
 	sb->st_ctimespec = vap->va_ctime;
 	sb->st_blksize = vap->va_blocksize;
 	sb->st_flags = vap->va_flags;
@@ -495,3 +500,34 @@ vn_closefile(fp, p)
 	return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
 		fp->f_cred, p));
 }
+
+/*
+ * Check that the vnode is still valid, and if so
+ * acquire requested lock.
+ */
+int
+vn_lock(vp, flags, p)
+	struct vnode *vp;
+	int flags;
+	struct proc *p;
+{
+	int error;
+	
+	do {
+		if ((flags & LK_INTERLOCK) == 0) {
+			simple_lock(&vp->v_interlock);
+		}
+		if (vp->v_flag & VXLOCK) {
+			vp->v_flag |= VXWANT;
+			simple_unlock(&vp->v_interlock);
+			tsleep((caddr_t)vp, PINOD, "vn_lock", 0);
+			error = ENOENT;
+		} else {
+			error = VOP_LOCK(vp, flags | LK_INTERLOCK, p);
+			if (error == 0)
+				return (error);
+		}
+		flags &= ~LK_INTERLOCK;
+	} while (flags & LK_RETRY);
+	return (error);
+}