From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33258) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bXhCx-0002Vw-Qz for qemu-devel@nongnu.org; Thu, 11 Aug 2016 00:03:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bXhCt-0007C6-Kv for qemu-devel@nongnu.org; Thu, 11 Aug 2016 00:03:02 -0400 From: Reda Sallahi Date: Thu, 11 Aug 2016 06:02:32 +0200 Message-Id: <20160811040232.30905-1-fullmanet@gmail.com> Subject: [Qemu-devel] [PATCH] qemu-img: change opening method for the output in dd List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Kevin Wolf , Max Reitz , Fam Zheng , Stefan Hajnoczi , Reda Sallahi dd was creating an output image regardless of whether there was one already created. With this patch we try to open first the output image and resize it if necessary. Signed-off-by: Reda Sallahi --- Depends on: [PATCH v2] qemu-img: add conv=notrunc option to dd qemu-img.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 76 insertions(+), 15 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index 7c546c1..dfa0e63 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3919,6 +3919,8 @@ static int img_dd(int argc, char **argv) char *tmp; BlockDriver *drv = NULL, *proto_drv = NULL; BlockBackend *blk1 = NULL, *blk2 = NULL; + BlockDriverState *bs = NULL; + QDict *qoptions = NULL; QemuOpts *opts = NULL; QemuOptsList *create_opts = NULL; Error *local_err = NULL; @@ -4080,22 +4082,60 @@ static int img_dd(int argc, char **argv) size = dd.count * in.bsz; } - /* Overflow means the specified offset is beyond input image's size */ - if (dd.flags & C_SKIP && (in.offset > INT64_MAX / in.bsz || - size < in.bsz * in.offset)) { - qemu_opt_set_number(opts, BLOCK_OPT_SIZE, 0, &error_abort); - } else { - qemu_opt_set_number(opts, BLOCK_OPT_SIZE, - size - in.bsz * in.offset, &error_abort); - } + qoptions = qdict_new(); + qdict_put(qoptions, "driver", qstring_from_str(out_fmt)); - ret = bdrv_create(drv, out.filename, opts, &local_err); - if (ret < 0) { - error_reportf_err(local_err, - "%s: error while creating output image: ", - out.filename); - ret = -1; - goto out; + bs = bdrv_open(out.filename, NULL, qoptions, BDRV_O_RDWR, &local_err); + + if (!bs) { + drv = bdrv_find_format(out_fmt); + if (!drv) { + error_report("Unknown file format"); + ret = -1; + goto out; + } + proto_drv = bdrv_find_protocol(out.filename, true, &local_err); + + if (!proto_drv) { + error_report_err(local_err); + ret = -1; + goto out; + } + if (!drv->create_opts) { + error_report("Format driver '%s' does not support image creation", + drv->format_name); + ret = -1; + goto out; + } + if (!proto_drv->create_opts) { + error_report("Protocol driver '%s' does not support image creation", + proto_drv->format_name); + ret = -1; + goto out; + } + create_opts = qemu_opts_append(create_opts, drv->create_opts); + create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); + + opts = qemu_opts_create(create_opts, NULL, 0, &error_abort); + + /* Overflow means the specified offset is beyond input image's size */ + if (dd.flags & C_SKIP && (in.offset > INT64_MAX / in.bsz || + size < in.offset * in.bsz)) { + qemu_opt_set_number(opts, BLOCK_OPT_SIZE, + 0, &error_abort); + } else { + qemu_opt_set_number(opts, BLOCK_OPT_SIZE, + size - in.offset * in.bsz, &error_abort); + } + + ret = bdrv_create(drv, out.filename, opts, &local_err); + if (ret < 0) { + error_reportf_err(local_err, + "%s: error while creating output image: ", + out.filename); + ret = -1; + goto out; + } } blk2 = img_open(image_opts, out.filename, out_fmt, BDRV_O_RDWR, @@ -4117,6 +4157,26 @@ static int img_dd(int argc, char **argv) in_pos = in.offset * in.bsz; } + if (bs) { + int64_t blk2sz = blk_getlength(blk2); + if (blk2sz < 0) { + error_report("Failed to get size for '%s'", in.filename); + ret = -1; + goto out; + } + + if (!(dd.conv & C_NOTRUNC)) { + blk_truncate(blk2, 0); + } + if (!(dd.flags & C_SKIP) || (in.offset <= INT64_MAX / in.bsz && + size >= in.offset * in.bsz)) { + if (!(dd.conv & C_NOTRUNC) || + blk2sz < size - in.offset * in.bsz) { + blk_truncate(blk2, size - in.offset * in.bsz); + } + } + } + in.buf = g_new(uint8_t, in.bsz); for (out_pos = 0; in_pos < size; block_count++) { @@ -4152,6 +4212,7 @@ out: qemu_opts_free(create_opts); blk_unref(blk1); blk_unref(blk2); + bdrv_unref(bs); g_free(in.filename); g_free(out.filename); g_free(in.buf); -- 2.9.2