Module Name: src
Committed By: manu
Date: Sun Oct 5 07:53:22 UTC 2014
Modified Files:
src/sys/fs/puffs: puffs_vnops.c
Log Message:
If we truncate the file, make sure we zero-fill the end of the last
page, otherwise if the file is later truncated to a larger size
(creating a hole), that area will not return zeroes as it should.
To generate a diff of this commit:
cvs rdiff -u -r1.187 -r1.188 src/sys/fs/puffs/puffs_vnops.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/fs/puffs/puffs_vnops.c
diff -u src/sys/fs/puffs/puffs_vnops.c:1.187 src/sys/fs/puffs/puffs_vnops.c:1.188
--- src/sys/fs/puffs/puffs_vnops.c:1.187 Tue Sep 30 10:15:03 2014
+++ src/sys/fs/puffs/puffs_vnops.c Sun Oct 5 07:53:22 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: puffs_vnops.c,v 1.187 2014/09/30 10:15:03 hannken Exp $ */
+/* $NetBSD: puffs_vnops.c,v 1.188 2014/10/05 07:53:22 manu Exp $ */
/*
* Copyright (c) 2005, 2006, 2007 Antti Kantee. All Rights Reserved.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: puffs_vnops.c,v 1.187 2014/09/30 10:15:03 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: puffs_vnops.c,v 1.188 2014/10/05 07:53:22 manu Exp $");
#include <sys/param.h>
#include <sys/buf.h>
@@ -1130,6 +1130,38 @@ puffs_vnop_getattr(void *v)
return error;
}
+static void
+zerofill_lastpage(struct vnode *vp, voff_t off)
+{
+ char zbuf[PAGE_SIZE];
+ struct iovec iov;
+ struct uio uio;
+ vsize_t len;
+ int error;
+
+ if (trunc_page(off) == off)
+ return;
+
+ len = round_page(off) - off;
+ memset(zbuf, 0, len);
+
+ iov.iov_base = zbuf;
+ iov.iov_len = len;
+ UIO_SETUP_SYSSPACE(&uio);
+ uio.uio_iov = &iov;
+ uio.uio_iovcnt = 1;
+ uio.uio_offset = off;
+ uio.uio_resid = len;
+ uio.uio_rw = UIO_WRITE;
+
+ error = ubc_uiomove(&vp->v_uobj, &uio, len,
+ UVM_ADV_SEQUENTIAL, UBC_WRITE|UBC_UNMAP_FLAG(vp));
+ if (error)
+ DPRINTF(("zero-fill 0x%lx@0x%llx => %d\n", len, off, error));
+
+ return;
+}
+
static int
dosetattr(struct vnode *vp, struct vattr *vap, kauth_cred_t cred, int flags)
{
@@ -1191,6 +1223,17 @@ dosetattr(struct vnode *vp, struct vattr
if ((flags & SETATTR_ASYNC) == 0)
error = puffs_msg_wait2(pmp, park_setattr, vp->v_data, NULL);
+ /*
+ * If we truncate the file, make sure we zero-fill
+ * the end of the last page, otherwise if the file
+ * is later truncated to a larger size (creating a
+ * a hole), that area will not return zeroes as it
+ * should.
+ */
+ if ((error == 0) && (flags & SETATTR_CHSIZE) &&
+ (vap->va_size != VNOVAL) && (vap->va_size < vp->v_size))
+ zerofill_lastpage(vp, vap->va_size);
+
if ((error == 0) && PUFFS_USE_FS_TTL(pmp)) {
struct timespec *va_ttl = &setattr_msg->pvnr_va_ttl;
struct vattr *rvap = &setattr_msg->pvnr_va;
