Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

===================================================================
RCS file: /ftp/cvs/cvsroot/src/sys/ufs/ufs/ufs_inode.c,v
rcsdiff: /ftp/cvs/cvsroot/src/sys/ufs/ufs/ufs_inode.c,v: warning: Unknown phrases like `commitid ...;' are present.
retrieving revision 1.13
retrieving revision 1.13.4.4
diff -u -p -r1.13 -r1.13.4.4
--- src/sys/ufs/ufs/ufs_inode.c	1999/03/05 21:09:50	1.13
+++ src/sys/ufs/ufs/ufs_inode.c	1999/08/06 12:50:27	1.13.4.4
@@ -1,4 +1,4 @@
-/*	$NetBSD: ufs_inode.c,v 1.13 1999/03/05 21:09:50 mycroft Exp $	*/
+/*	$NetBSD: ufs_inode.c,v 1.13.4.4 1999/08/06 12:50:27 chs Exp $	*/
 
 /*
  * Copyright (c) 1991, 1993
@@ -55,6 +55,8 @@
 #include <ufs/ufs/ufsmount.h>
 #include <ufs/ufs/ufs_extern.h>
 
+#include <uvm/uvm.h>
+
 /*
  * Last reference to an inode.  If necessary, write or delete it.
  */
@@ -146,3 +148,112 @@ ufs_reclaim(vp, p)
 #endif
 	return (0);
 }
+
+/*
+ * allocate a range of blocks in a file.
+ * after this function returns, any page entirely contained within the range
+ * will map to invalid data and thus must be overwritten before it is made
+ * accessible to others.
+ */
+
+int
+ufs_balloc_range(vp, off, len, cred, flags)
+	struct vnode *vp;
+	off_t off, len;
+	struct ucred *cred;
+	int flags;
+{
+	off_t eof, pagestart, pageend;
+	struct uvm_object *uobj;
+	struct inode *ip = VTOI(vp);
+	int i, delta, error, npages1, npages2;
+	int bshift = vp->v_mount->mnt_fs_bshift;
+	int bsize = 1 << bshift;
+	int ppb = max(bsize >> PAGE_SHIFT, 1);
+	struct vm_page *pgs1[ppb], *pgs2[ppb];
+	UVMHIST_FUNC("ufs_balloc_range"); UVMHIST_CALLED(ubchist);
+	UVMHIST_LOG(ubchist, "vp %p off 0x%x len 0x%x u_size 0x%x",
+		    vp, (int)off, (int)len, (int)vp->v_uvm.u_size);
+
+	/*
+	 * if the range does not start on a page and block boundary,
+	 * cache the first block if the file so the page(s) will contain
+	 * the correct data.  hold the page(s) busy while we allocate
+	 * the backing store for the range.
+	 */
+
+	uobj = &vp->v_uvm.u_obj;
+	eof = max(vp->v_uvm.u_size, off + len);
+	vp->v_uvm.u_size = eof;
+	UVMHIST_LOG(ubchist, "new eof 0x%x", (int)eof,0,0,0);
+	error = 0;
+	pgs1[0] = pgs2[0] = NULL;
+	pagestart = trunc_page(off) & ~(bsize - 1);
+	if (off != pagestart) {
+		npages1 = min(ppb, (round_page(eof) - pagestart) >>
+			      PAGE_SHIFT);
+		memset(pgs1, 0, npages1);
+		simple_lock(&uobj->vmobjlock);
+		error = VOP_GETPAGES(vp, pagestart, pgs1, &npages1, 0,
+				     VM_PROT_READ, 0, PGO_SYNCIO);
+		if (error) {
+			goto errout;
+		}
+		for (i = 0; i < npages1; i++) {
+			UVMHIST_LOG(ubchist, "got pgs1[%d] %p", i, pgs1[i],0,0);
+		}
+	}
+
+	/*
+	 * similarly if the range does not end on a page and block boundary.
+	 */
+
+	pageend = trunc_page(off + len) & ~(bsize - 1);
+	if (off + len < ip->i_ffs_size &&
+	    off + len != pageend &&
+	    pagestart != pageend) {
+		npages2 = min(ppb, (round_page(eof) - pageend) >>
+			      PAGE_SHIFT);
+		memset(pgs2, 0, npages2);
+		simple_lock(&uobj->vmobjlock);
+		error = VOP_GETPAGES(vp, pageend, pgs2, &npages2, 0,
+				     VM_PROT_READ, 0, PGO_SYNCIO);
+		if (error) {
+			goto errout;
+		}
+		for (i = 0; i < npages2; i++) {
+			UVMHIST_LOG(ubchist, "got pgs2[%d] %p", i, pgs2[i],0,0);
+		}
+	}
+
+	/*
+	 * adjust off to be block-aligned.
+	 */
+
+	delta = off & (bsize - 1);
+	off -= delta;
+	len += delta;
+
+	/*
+	 * now allocate the range.
+	 */
+
+	if ((error = VOP_BALLOC(vp, off, len, cred, flags))) {
+		goto errout;
+	}
+
+	/*
+	 * unbusy any pages we are holding.
+	 */
+
+errout:
+	simple_lock(&uobj->vmobjlock);
+	if (pgs1[0] != NULL) {
+		uvm_page_unbusy(pgs1, npages1);
+	}
+	if (pgs2[0] != NULL) {
+		uvm_page_unbusy(pgs2, npages2);
+	}
+	simple_unlock(&uobj->vmobjlock);
+	return error;
+}