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Thu, 23 May 2019 15:45:04 +0000 Received: from abhmp0018.oracle.com (abhmp0018.oracle.com [141.146.116.24]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x4NFj3rr024548; Thu, 23 May 2019 15:45:03 GMT Received: from nexus.ravello.local (/213.57.127.2) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 23 May 2019 15:45:02 +0000 From: Sam Eiderman To: kwolf@redhat.com, qemu-block@nongnu.org, qemu-devel@nongnu.org, mreitz@redhat.com Date: Thu, 23 May 2019 18:44:44 +0300 Message-Id: <20190523154444.28783-4-shmuel.eiderman@oracle.com> X-Mailer: git-send-email 2.13.3 In-Reply-To: <20190523154444.28783-1-shmuel.eiderman@oracle.com> References: <20190523154444.28783-1-shmuel.eiderman@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9265 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905230107 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9265 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905230107 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 156.151.31.85 Subject: [Qemu-devel] [PATCH v4 3/3] qemu-img: rebase: Reuse in-chain BlockDriverState X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: eyal.moscovici@oracle.com, arbel.moshe@oracle.com, liran.alon@oracle.com, shmuel.eiderman@oracle.com, sagi.amit@oracle.com, karl.heubaum@oracle.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP If a chain was detected, don't open a new BlockBackend from the target backing file which will create a new BlockDriverState. Instead, create an empty BlockBackend and attach the already open BlockDriverState. Permissions for blk_new() were copied from blk_new_open() when flags = 0. Reviewed-by: Karl Heubaum Reviewed-by: Eyal Moscovici Signed-off-by: Sagi Amit Co-developed-by: Sagi Amit Signed-off-by: Sam Eiderman Reviewed-by: Max Reitz --- qemu-img.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index e6fd8e1a98..b3a1c76fb6 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3358,16 +3358,29 @@ static int img_rebase(int argc, char **argv) * in its chain. */ prefix_chain_bs = bdrv_find_backing_image(bs, out_real_path); - - blk_new_backing = blk_new_open(out_real_path, NULL, - options, src_flags, &local_err); - g_free(out_real_path); - if (!blk_new_backing) { - error_reportf_err(local_err, - "Could not open new backing file '%s': ", - out_baseimg); - ret = -1; - goto out; + if (prefix_chain_bs) { + g_free(out_real_path); + blk_new_backing = blk_new(BLK_PERM_CONSISTENT_READ, + BLK_PERM_ALL); + ret = blk_insert_bs(blk_new_backing, prefix_chain_bs, + &local_err); + if (ret < 0) { + error_reportf_err(local_err, + "Could not reuse backing file '%s': ", + out_baseimg); + goto out; + } + } else { + blk_new_backing = blk_new_open(out_real_path, NULL, + options, src_flags, &local_err); + g_free(out_real_path); + if (!blk_new_backing) { + error_reportf_err(local_err, + "Could not open new backing file '%s': ", + out_baseimg); + ret = -1; + goto out; + } } } }