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bh=9wxyHHmtNJw/tCA3q+lIV5qOOTS+hWiwLY3VPrMUxm8=; b=NMCATKFhp6eYjP4N8kX1kU8183LGuVhkCPJ9sAErAczltKDSIjb5SamB/OGlBMTGPWIZ4i iK2x2XtXO9ELGlogv8xPc42ox0kbtIx3VR2oiKvsdtZ+dhv1yBwtfzY1xlJwWQMJGJsk0j RE/0Hz+LVtKAtb0+mNo6KkaPrrK0X04= X-MC-Unique: mvw270KPPl-QS2NgDy2C6w-1 From: Eric Blake To: qemu-devel@nongnu.org Cc: Vladimir Sementsov-Ogievskiy , Kevin Wolf , Hanna Reitz , qemu-block@nongnu.org (open list:qcow2) Subject: [PATCH] qcow2: Explicit mention of padding bytes Date: Mon, 22 May 2023 13:46:31 -0500 Message-Id: <20230522184631.47211-1-eblake@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1684781255784100002 Content-Type: text/plain; charset="utf-8" Although we already covered the need for padding bytes with our changes in commit 3ae3fcfa, commit 66fcbca5 (both v5.0.0) added one byte and relied on the rest of the text for implicitly covering 7 padding bytes. For consistency with other parts of the header (such as the header extension format listing padding from n - m, or the snapshot table entry listing variable padding), we might as well call out the remaining 7 bytes as padding until such time (as any) as they gain another meaning. Signed-off-by: Eric Blake CC: Vladimir Sementsov-Ogievskiy Reviewed-by: Vladimir Sementsov-Ogievskiy --- Spring cleaning my old branches. v3: reviving an old patch; v2 was: https://lists.gnu.org/archive/html/qemu-devel/2020-04/msg00687.html --- docs/interop/qcow2.txt | 1 + 1 file changed, 1 insertion(+) diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt index e7f036c286b..2c4618375ad 100644 --- a/docs/interop/qcow2.txt +++ b/docs/interop/qcow2.txt @@ -226,6 +226,7 @@ version 2. in QEMU. However, clusters wit= h the deflate compression type do not have zlib headers. + 105 - 111: Padding, contents defined below. =3D=3D=3D Header padding =3D=3D=3D --=20 2.40.1