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bh=qKXUZmlru6pmYggmL/tjU9HOqkL962sW3qnltYaDw5U=; b=FHSF/nxSPHNu/klvUb3yLqN+rmXNrhHjW2rbPFXBxepie/h5Nb9eFYCksoY2sCqZGnHoRE JwDUfFXmISKhHkFA/z63Gdtd/uBLESR3a53cdGc9iiv91NtO7WWsnoTr8MUKsYLgYEDLNu 92qU+hWmznFxpbSjOsetV2oUSjtXkw0= X-MC-Unique: JdqBXKGvNvyj_4wADwKdxQ-1 From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PATCH v4 6/9] file-posix: Support BDRV_REQ_ZERO_WRITE for truncate Date: Mon, 20 Apr 2020 15:32:11 +0200 Message-Id: <20200420133214.28921-7-kwolf@redhat.com> In-Reply-To: <20200420133214.28921-1-kwolf@redhat.com> References: <20200420133214.28921-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable 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=205.139.110.120; envelope-from=kwolf@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs1p.gnu.org: First seen = 2020/04/20 04:32:42 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, berto@igalia.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" For regular files, we always get BDRV_REQ_ZERO_WRITE behaviour from the OS, so we can advertise the flag and just ignore it. Signed-off-by: Kevin Wolf Reviewed-by: Alberto Garcia Reviewed-by: Vladimir Sementsov-Ogievskiy --- block/file-posix.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/file-posix.c b/block/file-posix.c index 53f475ed61..1dca220a81 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -702,6 +702,10 @@ static int raw_open_common(BlockDriverState *bs, QDict= *options, #endif =20 bs->supported_zero_flags =3D BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK; + if (S_ISREG(st.st_mode)) { + /* When extending regular files, we get zeros from the OS */ + bs->supported_truncate_flags =3D BDRV_REQ_ZERO_WRITE; + } ret =3D 0; fail: if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) { --=20 2.20.1