1 files changed, 131 insertions, 0 deletions
diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c
index 195e735..6fd4b97 100644
--- a/sys/kern/vfs_default.c
+++ b/sys/kern/vfs_default.c
@@ -99,6 +99,7 @@ struct vop_vector default_vnodeops = {
 	.vop_advlock =		vop_stdadvlock,
 	.vop_advlockasync =	vop_stdadvlockasync,
 	.vop_advlockpurge =	vop_stdadvlockpurge,
+	.vop_allocate =		vop_stdallocate,
 	.vop_bmap =		vop_stdbmap,
 	.vop_close =		VOP_NULL,
 	.vop_fsync =		VOP_NULL,
@@ -855,6 +856,136 @@ out:
 	return (error);
 }
 
+int
+vop_stdallocate(struct vop_allocate_args *ap)
+{
+#ifdef __notyet__
+	struct statfs sfs;
+#endif
+	struct iovec aiov;
+	struct vattr vattr, *vap;
+	struct uio auio;
+	off_t len, cur, offset;
+	uint8_t *buf;
+	struct thread *td;
+	struct vnode *vp;
+	size_t iosize;
+	int error, locked;
+
+	buf = NULL;
+	error = 0;
+	locked = 1;
+	td = curthread;
+	vap = &vattr;
+	vp = ap->a_vp;
+	len = ap->a_len;
+	offset = ap->a_offset;
+
+	error = VOP_GETATTR(vp, vap, td->td_ucred);
+	if (error != 0)
+		goto out;
+	iosize = vap->va_blocksize;
+	if (iosize == 0)
+		iosize = BLKDEV_IOSIZE;
+	if (iosize > MAXPHYS)
+		iosize = MAXPHYS;
+	buf = malloc(iosize, M_TEMP, M_WAITOK);
+
+#ifdef __notyet__
+	/*
+	 * Check if the filesystem sets f_maxfilesize; if not use
+	 * VOP_SETATTR to perform the check.
+	 */
+	error = VFS_STATFS(vp->v_mount, &sfs, td);
+	if (error != 0)
+		goto out;
+	if (sfs.f_maxfilesize) {
+		if (offset > sfs.f_maxfilesize || len > sfs.f_maxfilesize ||
+		    offset + len > sfs.f_maxfilesize) {
+			error = EFBIG;
+			goto out;
+		}
+	} else
+#endif
+	if (offset + len > vap->va_size) {
+		VATTR_NULL(vap);
+		vap->va_size = offset + len;
+		error = VOP_SETATTR(vp, vap, td->td_ucred);
+		if (error != 0)
+			goto out;
+	}
+
+	while (len > 0) {
+		if (should_yield()) {
+			VOP_UNLOCK(vp, 0);
+			locked = 0;
+			kern_yield(-1);
+			error = vn_lock(vp, LK_EXCLUSIVE);
+			if (error != 0)
+				break;
+			locked = 1;
+			error = VOP_GETATTR(vp, vap, td->td_ucred);
+			if (error != 0)
+				break;
+		}
+
+		/*
+		 * Read and write back anything below the nominal file
+		 * size.  There's currently no way outside the filesystem
+		 * to know whether this area is sparse or not.
+		 */
+		cur = iosize;
+		if ((offset % iosize) != 0)
+			cur -= (offset % iosize);
+		if (cur > len)
+			cur = len;
+		if (offset < vap->va_size) {
+			aiov.iov_base = buf;
+			aiov.iov_len = cur;
+			auio.uio_iov = &aiov;
+			auio.uio_iovcnt = 1;
+			auio.uio_offset = offset;
+			auio.uio_resid = cur;
+			auio.uio_segflg = UIO_SYSSPACE;
+			auio.uio_rw = UIO_READ;
+			auio.uio_td = td;
+			error = VOP_READ(vp, &auio, 0, td->td_ucred);
+			if (error != 0)
+				break;
+			if (auio.uio_resid > 0) {
+				bzero(buf + cur - auio.uio_resid,
+				    auio.uio_resid);
+			}
+		} else {
+			bzero(buf, cur);
+		}
+
+		aiov.iov_base = buf;
+		aiov.iov_len = cur;
+		auio.uio_iov = &aiov;
+		auio.uio_iovcnt = 1;
+		auio.uio_offset = offset;
+		auio.uio_resid = cur;
+		auio.uio_segflg = UIO_SYSSPACE;
+		auio.uio_rw = UIO_WRITE;
+		auio.uio_td = td;
+
+		error = VOP_WRITE(vp, &auio, 0, td->td_ucred);
+		if (error != 0)
+			break;
+
+		len -= cur;
+		offset += cur;
+	}
+
+ out:
+	KASSERT(locked || error != 0, ("How'd I get unlocked with no error?"));
+	if (locked && error != 0)
+		VOP_UNLOCK(vp, 0);
+	free(buf, M_TEMP);
+	return (error);
+}
+
 /*
  * vfs default ops
  * used to fill the vfs function table to get reasonable default return values.