From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Fabian Ebner Date: Mon, 7 Feb 2022 14:21:01 +0100 Subject: [PATCH] qemu-img dd: add -l option for loading a snapshot Signed-off-by: Fiona Ebner Signed-off-by: Thomas Lamprecht --- docs/tools/qemu-img.rst | 6 +++--- qemu-img-cmds.hx | 4 ++-- qemu-img.c | 33 +++++++++++++++++++++++++++++++-- 3 files changed, 36 insertions(+), 7 deletions(-) diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst index c6bc902182..fe2241856e 100644 --- a/docs/tools/qemu-img.rst +++ b/docs/tools/qemu-img.rst @@ -496,10 +496,10 @@ Command description: it doesn't need to be specified separately in this case. -.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [-n] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] if=INPUT of=OUTPUT +.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [-n] [-l SNAPSHOT_PARAM] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] if=INPUT of=OUTPUT - dd copies from *INPUT* file to *OUTPUT* file converting it from - *FMT* format to *OUTPUT_FMT* format. + dd copies from *INPUT* file or snapshot *SNAPSHOT_PARAM* to *OUTPUT* file + converting it from *FMT* format to *OUTPUT_FMT* format. The data is by default read and written using blocks of 512 bytes but can be modified by specifying *BLOCK_SIZE*. If count=\ *BLOCKS* is specified diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx index 32749b416e..40ee9c0ed8 100644 --- a/qemu-img-cmds.hx +++ b/qemu-img-cmds.hx @@ -58,9 +58,9 @@ SRST ERST DEF("dd", img_dd, - "dd [--image-opts] [-U] [-f fmt] [-O output_fmt] [-n] [bs=block_size] [count=blocks] [skip=blocks] [osize=output_size] if=input of=output") + "dd [--image-opts] [-U] [-f fmt] [-O output_fmt] [-n] [-l snapshot_param] [bs=block_size] [count=blocks] [skip=blocks] [osize=output_size] if=input of=output") SRST -.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [-n] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] [osize=OUTPUT_SIZE] if=INPUT of=OUTPUT +.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [-n] [-l SNAPSHOT_PARAM] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] [osize=OUTPUT_SIZE] if=INPUT of=OUTPUT ERST DEF("info", img_info, diff --git a/qemu-img.c b/qemu-img.c index 4acdf75879..a9632b5951 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -5114,6 +5114,7 @@ static int img_dd(int argc, char **argv) BlockDriver *drv = NULL, *proto_drv = NULL; BlockBackend *blk1 = NULL, *blk2 = NULL; QemuOpts *opts = NULL; + QemuOpts *sn_opts = NULL; QemuOptsList *create_opts = NULL; Error *local_err = NULL; bool image_opts = false; @@ -5123,6 +5124,7 @@ static int img_dd(int argc, char **argv) int64_t size = 0, readsize = 0; int64_t out_pos, in_pos; bool force_share = false, skip_create = false; + const char *snapshot_name = NULL; struct DdInfo dd = { .flags = 0, .count = 0, @@ -5160,7 +5162,7 @@ static int img_dd(int argc, char **argv) { 0, 0, 0, 0 } }; - while ((c = getopt_long(argc, argv, ":hf:O:Un", long_options, NULL))) { + while ((c = getopt_long(argc, argv, ":hf:O:l:Un", long_options, NULL))) { if (c == EOF) { break; } @@ -5183,6 +5185,19 @@ static int img_dd(int argc, char **argv) case 'n': skip_create = true; break; + case 'l': + if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { + sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts, + optarg, false); + if (!sn_opts) { + error_report("Failed in parsing snapshot param '%s'", + optarg); + goto out; + } + } else { + snapshot_name = optarg; + } + break; case 'U': force_share = true; break; @@ -5242,11 +5257,24 @@ static int img_dd(int argc, char **argv) if (dd.flags & C_IF) { blk1 = img_open(image_opts, in.filename, fmt, 0, false, false, force_share); - if (!blk1) { ret = -1; goto out; } + if (sn_opts) { + bdrv_snapshot_load_tmp(blk_bs(blk1), + qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), + qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), + &local_err); + } else if (snapshot_name != NULL) { + bdrv_snapshot_load_tmp_by_id_or_name(blk_bs(blk1), snapshot_name, + &local_err); + } + if (local_err) { + error_reportf_err(local_err, "Failed to load snapshot: "); + ret = -1; + goto out; + } } if (dd.flags & C_OSIZE) { @@ -5401,6 +5429,7 @@ static int img_dd(int argc, char **argv) out: g_free(arg); qemu_opts_del(opts); + qemu_opts_del(sn_opts); qemu_opts_free(create_opts); blk_unref(blk1); blk_unref(blk2);