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;