Date: Sat, 2 Apr 2016 08:36:25 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r297509 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs Message-ID: <201604020836.u328aPZY009355@repo.freebsd.org>
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Author: mav Date: Sat Apr 2 08:36:24 2016 New Revision: 297509 URL: https://svnweb.freebsd.org/changeset/base/297509 Log: MFV r297506: 6738 zfs send stream padding needs documentation Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: Dan Kimmel <dan.kimmel@delphix.com> Reviewed by: Paul Dagnelie <pcd@delphix.com> Reviewed by: Dan McDonald <danmcd@omniti.com> Approved by: Robert Mustacchi <rm@joyent.com> Author: Eli Rosenthal <eli.rosenthal@delphix.com> illumos/illumos-gate@c20404ff77119516354b0d112d28b7ea0dadd303 Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c Directory Properties: head/sys/cddl/contrib/opensolaris/ (props changed) Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c Sat Apr 2 08:34:15 2016 (r297508) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c Sat Apr 2 08:36:24 2016 (r297509) @@ -107,6 +107,19 @@ dump_bytes(dmu_sendarg_t *dsp, void *buf dsl_dataset_t *ds = dmu_objset_ds(dsp->dsa_os); struct uio auio; struct iovec aiov; + + /* + * The code does not rely on this (len being a multiple of 8). We keep + * this assertion because of the corresponding assertion in + * receive_read(). Keeping this assertion ensures that we do not + * inadvertently break backwards compatibility (causing the assertion + * in receive_read() to trigger on old software). + * + * Removing the assertions could be rolled into a new feature that uses + * data that isn't 8-byte aligned; if the assertions were removed, a + * feature flag would have to be added. + */ + ASSERT0(len % 8); aiov.iov_base = buf; @@ -1824,7 +1837,10 @@ receive_read(struct receive_arg *ra, int { int done = 0; - /* some things will require 8-byte alignment, so everything must */ + /* + * The code doesn't rely on this (lengths being multiples of 8). See + * comment in dump_bytes. + */ ASSERT0(len % 8); while (done < len) {
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