pve-qemu-qoup/debian/patches/pve/0050-qemu-img-dd-add-l-option-for-loading-a-snapshot.patch
Fiona Ebner bf251437e9 update submodule and patches to QEMU 8.0.0
Many changes were necessary this time around:

* QAPI was changed to avoid redundant has_* variables, see commit
44ea9d9be3 ("qapi: Start to elide redundant has_FOO in generated C")
for details. This affected many QMP commands added by Proxmox too.

* Pending querying for migration got split into two functions, one to
estimate, one for exact value, see commit c8df4a7aef ("migration:
Split save_live_pending() into state_pending_*") for details. Relevant
for savevm-async and PBS dirty bitmap.

* Some block (driver) functions got converted to coroutines, so the
Proxmox block drivers needed to be adapted.

* Alloc track auto-detaching during PBS live restore got broken by
AioContext-related changes resulting in a deadlock. The current, hacky
method was replaced by a simpler one. Stefan apparently ran into a
problem with that when he wrote the driver, but there were
improvements in the stream job code since then and I didn't manage to
reproduce the issue. It's a separate patch "alloc-track: fix deadlock
during drop" for now, you can find the details there.

* Async snapshot-related changes:
  - The pending querying got adapted to the above-mentioned split and
  a patch is added to optimize it/make it more similar to what
  upstream code does.
  - Added initialization of the compression counters (for
    future-proofing).
  - It's necessary the hold the BQL (big QEMU lock = iothread mutex)
  during the setup phase, because block layer functions are used there
  and not doing so leads to racy, hard-to-debug crashes or hangs. It's
  necessary to change some upstream code too for this, a version of
  the patch "migration: for snapshots, hold the BQL during setup
  callbacks" is intended to be upstreamed.
  - Need to take the bdrv graph read lock before flushing.

* hmp_info_balloon was moved to a different file.

* Needed to include a new headers from time to time to still get the
correct functions.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-22 15:09:14 +02:00

131 lines
5.1 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Fabian Ebner <f.ebner@proxmox.com>
Date: Mon, 7 Feb 2022 14:21:01 +0100
Subject: [PATCH] qemu-img: dd: add -l option for loading a snapshot
Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
---
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 5e713e231d..9390d5e5cf 100644
--- a/docs/tools/qemu-img.rst
+++ b/docs/tools/qemu-img.rst
@@ -492,10 +492,10 @@ 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 b5b0bb4467..36f97e1f19 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 06d814e39c..e2c06c496d 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -5002,6 +5002,7 @@ 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;
@@ -5011,6 +5012,7 @@ 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,
@@ -5048,7 +5050,7 @@ 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;
}
@@ -5071,6 +5073,19 @@ 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;
@@ -5130,11 +5145,24 @@ 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) {
@@ -5289,6 +5317,7 @@ 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);