pve-qemu-qoup/debian/patches/bitmap-mirror/0001-drive-mirror-add-support-for-sync-bitmap-mode-never.patch
Fiona Ebner f1eed34ac7 update submodule and patches to QEMU 8.2.2
This version includes both the AioContext lock and the block graph
lock, so there might be some deadlocks lurking. It's not possible to
disable the block graph lock like was done in QEMU 8.1, because there
are no changes like the function bdrv_schedule_unref() that require
it. QEMU 9.0 will finally get rid of the AioContext locking.

During live-restore with a VirtIO SCSI drive with iothread there is a
known racy deadlock related to the AioContext lock. Not new [1], but
not sure if more likely now. Should be fixed in QEMU 9.0.

The block graph lock comes with annotations that can be checked by
clang's TSA. This required changes to the block drivers, i.e.
alloc-track, pbs, zeroinit as well as taking the appropriate locks
in pve-backup, savevm-async, vma-reader.

Local variable shadowing is prohibited via a compiler flag now,
required slight adaptation in vma.c.

Major changes only affect alloc-track:

* It is not possible to call a generated co-wrapper like
  bdrv_get_info() while holding the block graph lock exclusively [0],
  which does happen during initialization of alloc-track when the
  backing hd is set and the refresh_limits driver callback is invoked.

  The bdrv_get_info() call to get the cluster size is moved to
  directly after opening the file child in track_open().

  The important thing is that at least the request alignment for the
  write target is used, because then the RMW cycle in bdrv_pwritev
  will gather enough data from the backing file. Partial cluster
  allocations in the target are not a fundamental issue, because the
  driver returns its allocation status based on the bitmap, so any
  other data that maps to the same cluster will still be copied later
  by a stream job (or during writes to that cluster).

* Replacing the node cannot be done in the
  track_co_change_backing_file() callback, because it is a coroutine
  and cannot hold the block graph lock exclusively. So it is moved to
  the stream job itself with the auto-remove option not having an
  effect anymore (qemu-server would always set it anyways).

  In the future, there could either be a special option for the stream
  job, or maybe the upcoming blockdev-replace QMP command can be used.

  Replacing the backing child is actually already done in the stream
  job, so no need to do it in the track_co_change_backing_file()
  callback. It also cannot be called from a coroutine. Looking at the
  implementation in the qcow2 driver, it doesn't seem to be intended
  to change the backing child itself, just update driver-internal
  state.

Other changes:

* alloc-track: Error out early when used without auto-remove. Since
  replacing the node now happens in the stream job, where the option
  cannot be read from (it's internal to the driver), it will always be
  treated as 'on'. Makes sure to have users beside qemu-server notice
  the change (should they even exist). The option can be fully dropped
  in the future while adding a version guard in qemu-server.

* alloc-track: Avoid seemingly superfluous child permission update.
  Doesn't seem necessary nowadays (maybe after commit "alloc-track:
  fix deadlock during drop" where the dropping is not rescheduled and
  delayed anymore or some upstream change). Replacing the block node
  will already update the permissions of the new node (which was the
  file child before). Should there really be some issue, instead of
  having a drop state, this could also be just based off the fact
  whether there is still a backing child.

  Dumping the cumulative (shared) permissions for the BDS with a debug
  print yields the same values after this patch and with QEMU 8.1,
  namely 3 and 5.

* PBS block driver: compile unconditionally. Proxmox VE always needs
  it and something in the build process changed to make it not enabled
  by default. Probably would need to move the build option to meson
  otherwise.

* backup: job unreferencing during cleanup needs to happen outside of
  coroutine, so it was moved to before invoking the clean

* mirror: Cherry-pick stable fix to avoid potential deadlock.

* savevm-async: migrate_init now can fail, so propagate potential
  error.

* savevm-async: compression counters are not accessible outside
  migration/ram-compress now, so drop code that prophylactically set
  it to zero.

[0]: https://lore.kernel.org/qemu-devel/220be383-3b0d-4938-b584-69ad214e5d5d@proxmox.com/
[1]: https://lore.kernel.org/qemu-devel/e13b488e-bf13-44f2-acca-e724d14f43fd@proxmox.com/

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2024-04-26 14:14:06 +02:00

438 lines
19 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
Date: Mon, 6 Apr 2020 12:17:03 +0200
Subject: [PATCH] drive-mirror: add support for sync=bitmap mode=never
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This patch adds support for the "BITMAP" sync mode to drive-mirror and
blockdev-mirror. It adds support only for the BitmapSyncMode "never,"
because it's the simplest mode.
This mode simply uses a user-provided bitmap as an initial copy
manifest, and then does not clear any bits in the bitmap at the
conclusion of the operation.
Any new writes dirtied during the operation are copied out, in contrast
to backup. Note that whether these writes are reflected in the bitmap
at the conclusion of the operation depends on whether that bitmap is
actually recording!
This patch was originally based on one by Ma Haocong, but it has since
been modified pretty heavily.
Suggested-by: Ma Haocong <mahaocong@didichuxing.com>
Signed-off-by: Ma Haocong <mahaocong@didichuxing.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
[FE: rebased for 8.2.2]
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
block/mirror.c | 99 ++++++++++++++++++++------
blockdev.c | 38 +++++++++-
include/block/block_int-global-state.h | 4 +-
qapi/block-core.json | 25 ++++++-
tests/unit/test-block-iothread.c | 4 +-
5 files changed, 142 insertions(+), 28 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index abbddb39e4..ed14c8b498 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -51,7 +51,7 @@ typedef struct MirrorBlockJob {
BlockDriverState *to_replace;
/* Used to block operations on the drive-mirror-replace target */
Error *replace_blocker;
- bool is_none_mode;
+ MirrorSyncMode sync_mode;
BlockMirrorBackingMode backing_mode;
/* Whether the target image requires explicit zero-initialization */
bool zero_target;
@@ -73,6 +73,8 @@ typedef struct MirrorBlockJob {
size_t buf_size;
int64_t bdev_length;
unsigned long *cow_bitmap;
+ BdrvDirtyBitmap *sync_bitmap;
+ BitmapSyncMode bitmap_mode;
BdrvDirtyBitmap *dirty_bitmap;
BdrvDirtyBitmapIter *dbi;
uint8_t *buf;
@@ -724,7 +726,8 @@ static int mirror_exit_common(Job *job)
&error_abort);
if (!abort && s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
- BlockDriverState *backing = s->is_none_mode ? src : s->base;
+ BlockDriverState *backing;
+ backing = s->sync_mode == MIRROR_SYNC_MODE_NONE ? src : s->base;
BlockDriverState *unfiltered_target = bdrv_skip_filters(target_bs);
if (bdrv_cow_bs(unfiltered_target) != backing) {
@@ -831,6 +834,16 @@ static void mirror_abort(Job *job)
assert(ret == 0);
}
+/* Always called after commit/abort. */
+static void mirror_clean(Job *job)
+{
+ MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
+
+ if (s->sync_bitmap) {
+ bdrv_dirty_bitmap_set_busy(s->sync_bitmap, false);
+ }
+}
+
static void coroutine_fn mirror_throttle(MirrorBlockJob *s)
{
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
@@ -1027,7 +1040,8 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
mirror_free_init(s);
s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
- if (!s->is_none_mode) {
+ if ((s->sync_mode == MIRROR_SYNC_MODE_TOP) ||
+ (s->sync_mode == MIRROR_SYNC_MODE_FULL)) {
ret = mirror_dirty_init(s);
if (ret < 0 || job_is_cancelled(&s->common.job)) {
goto immediate_exit;
@@ -1323,6 +1337,7 @@ static const BlockJobDriver mirror_job_driver = {
.run = mirror_run,
.prepare = mirror_prepare,
.abort = mirror_abort,
+ .clean = mirror_clean,
.pause = mirror_pause,
.complete = mirror_complete,
.cancel = mirror_cancel,
@@ -1341,6 +1356,7 @@ static const BlockJobDriver commit_active_job_driver = {
.run = mirror_run,
.prepare = mirror_prepare,
.abort = mirror_abort,
+ .clean = mirror_clean,
.pause = mirror_pause,
.complete = mirror_complete,
.cancel = commit_active_cancel,
@@ -1733,7 +1749,10 @@ static BlockJob *mirror_start_job(
BlockCompletionFunc *cb,
void *opaque,
const BlockJobDriver *driver,
- bool is_none_mode, BlockDriverState *base,
+ MirrorSyncMode sync_mode,
+ BdrvDirtyBitmap *bitmap,
+ BitmapSyncMode bitmap_mode,
+ BlockDriverState *base,
bool auto_complete, const char *filter_node_name,
bool is_mirror, MirrorCopyMode copy_mode,
Error **errp)
@@ -1747,10 +1766,39 @@ static BlockJob *mirror_start_job(
GLOBAL_STATE_CODE();
- if (granularity == 0) {
- granularity = bdrv_get_default_bitmap_granularity(target);
+ if (sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
+ error_setg(errp, "Sync mode '%s' not supported",
+ MirrorSyncMode_str(sync_mode));
+ return NULL;
+ } else if (sync_mode == MIRROR_SYNC_MODE_BITMAP) {
+ if (!bitmap) {
+ error_setg(errp, "Must provide a valid bitmap name for '%s'"
+ " sync mode",
+ MirrorSyncMode_str(sync_mode));
+ return NULL;
+ } else if (bitmap_mode != BITMAP_SYNC_MODE_NEVER) {
+ error_setg(errp,
+ "Bitmap Sync Mode '%s' is not supported by Mirror",
+ BitmapSyncMode_str(bitmap_mode));
+ }
+ } else if (bitmap) {
+ error_setg(errp,
+ "sync mode '%s' is not compatible with bitmaps",
+ MirrorSyncMode_str(sync_mode));
+ return NULL;
}
+ if (bitmap) {
+ if (granularity) {
+ error_setg(errp, "granularity (%d)"
+ "cannot be specified when a bitmap is provided",
+ granularity);
+ return NULL;
+ }
+ granularity = bdrv_dirty_bitmap_granularity(bitmap);
+ } else if (granularity == 0) {
+ granularity = bdrv_get_default_bitmap_granularity(target);
+ }
assert(is_power_of_2(granularity));
if (buf_size < 0) {
@@ -1890,7 +1938,9 @@ static BlockJob *mirror_start_job(
s->replaces = g_strdup(replaces);
s->on_source_error = on_source_error;
s->on_target_error = on_target_error;
- s->is_none_mode = is_none_mode;
+ s->sync_mode = sync_mode;
+ s->sync_bitmap = bitmap;
+ s->bitmap_mode = bitmap_mode;
s->backing_mode = backing_mode;
s->zero_target = zero_target;
qatomic_set(&s->copy_mode, copy_mode);
@@ -1916,6 +1966,18 @@ static BlockJob *mirror_start_job(
*/
bdrv_disable_dirty_bitmap(s->dirty_bitmap);
+ if (s->sync_bitmap) {
+ bdrv_dirty_bitmap_set_busy(s->sync_bitmap, true);
+ }
+
+ if (s->sync_mode == MIRROR_SYNC_MODE_BITMAP) {
+ bdrv_merge_dirty_bitmap(s->dirty_bitmap, s->sync_bitmap,
+ NULL, &local_err);
+ if (local_err) {
+ goto fail;
+ }
+ }
+
bdrv_graph_wrlock(bs);
ret = block_job_add_bdrv(&s->common, "source", bs, 0,
BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE |
@@ -1998,6 +2060,9 @@ fail:
if (s->dirty_bitmap) {
bdrv_release_dirty_bitmap(s->dirty_bitmap);
}
+ if (s->sync_bitmap) {
+ bdrv_dirty_bitmap_set_busy(s->sync_bitmap, false);
+ }
job_early_fail(&s->common.job);
}
@@ -2020,35 +2085,28 @@ void mirror_start(const char *job_id, BlockDriverState *bs,
BlockDriverState *target, const char *replaces,
int creation_flags, int64_t speed,
uint32_t granularity, int64_t buf_size,
- MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
+ MirrorSyncMode mode, BdrvDirtyBitmap *bitmap,
+ BitmapSyncMode bitmap_mode,
+ BlockMirrorBackingMode backing_mode,
bool zero_target,
BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
bool unmap, const char *filter_node_name,
MirrorCopyMode copy_mode, Error **errp)
{
- bool is_none_mode;
BlockDriverState *base;
GLOBAL_STATE_CODE();
- if ((mode == MIRROR_SYNC_MODE_INCREMENTAL) ||
- (mode == MIRROR_SYNC_MODE_BITMAP)) {
- error_setg(errp, "Sync mode '%s' not supported",
- MirrorSyncMode_str(mode));
- return;
- }
-
bdrv_graph_rdlock_main_loop();
- is_none_mode = mode == MIRROR_SYNC_MODE_NONE;
base = mode == MIRROR_SYNC_MODE_TOP ? bdrv_backing_chain_next(bs) : NULL;
bdrv_graph_rdunlock_main_loop();
mirror_start_job(job_id, bs, creation_flags, target, replaces,
speed, granularity, buf_size, backing_mode, zero_target,
on_source_error, on_target_error, unmap, NULL, NULL,
- &mirror_job_driver, is_none_mode, base, false,
- filter_node_name, true, copy_mode, errp);
+ &mirror_job_driver, mode, bitmap, bitmap_mode, base,
+ false, filter_node_name, true, copy_mode, errp);
}
BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs,
@@ -2075,7 +2133,8 @@ BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs,
job_id, bs, creation_flags, base, NULL, speed, 0, 0,
MIRROR_LEAVE_BACKING_CHAIN, false,
on_error, on_error, true, cb, opaque,
- &commit_active_job_driver, false, base, auto_complete,
+ &commit_active_job_driver, MIRROR_SYNC_MODE_FULL,
+ NULL, 0, base, auto_complete,
filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND,
errp);
if (!job) {
diff --git a/blockdev.c b/blockdev.c
index c91f49e7b6..8c8e8b604a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2903,6 +2903,9 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
BlockDriverState *target,
const char *replaces,
enum MirrorSyncMode sync,
+ const char *bitmap_name,
+ bool has_bitmap_mode,
+ BitmapSyncMode bitmap_mode,
BlockMirrorBackingMode backing_mode,
bool zero_target,
bool has_speed, int64_t speed,
@@ -2921,6 +2924,7 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
{
BlockDriverState *unfiltered_bs;
int job_flags = JOB_DEFAULT;
+ BdrvDirtyBitmap *bitmap = NULL;
GLOBAL_STATE_CODE();
GRAPH_RDLOCK_GUARD_MAINLOOP();
@@ -2975,6 +2979,29 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
sync = MIRROR_SYNC_MODE_FULL;
}
+ if (bitmap_name) {
+ if (granularity) {
+ error_setg(errp, "Granularity and bitmap cannot both be set");
+ return;
+ }
+
+ if (!has_bitmap_mode) {
+ error_setg(errp, "bitmap-mode must be specified if"
+ " a bitmap is provided");
+ return;
+ }
+
+ bitmap = bdrv_find_dirty_bitmap(bs, bitmap_name);
+ if (!bitmap) {
+ error_setg(errp, "Dirty bitmap '%s' not found", bitmap_name);
+ return;
+ }
+
+ if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_ALLOW_RO, errp)) {
+ return;
+ }
+ }
+
if (!replaces) {
/* We want to mirror from @bs, but keep implicit filters on top */
unfiltered_bs = bdrv_skip_implicit_filters(bs);
@@ -3030,8 +3057,8 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
* and will allow to check whether the node still exist at mirror completion
*/
mirror_start(job_id, bs, target,
- replaces, job_flags,
- speed, granularity, buf_size, sync, backing_mode, zero_target,
+ replaces, job_flags, speed, granularity, buf_size, sync,
+ bitmap, bitmap_mode, backing_mode, zero_target,
on_source_error, on_target_error, unmap, filter_node_name,
copy_mode, errp);
}
@@ -3189,6 +3216,8 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)
blockdev_mirror_common(arg->job_id, bs, target_bs,
arg->replaces, arg->sync,
+ arg->bitmap,
+ arg->has_bitmap_mode, arg->bitmap_mode,
backing_mode, zero_target,
arg->has_speed, arg->speed,
arg->has_granularity, arg->granularity,
@@ -3210,6 +3239,8 @@ void qmp_blockdev_mirror(const char *job_id,
const char *device, const char *target,
const char *replaces,
MirrorSyncMode sync,
+ const char *bitmap,
+ bool has_bitmap_mode, BitmapSyncMode bitmap_mode,
bool has_speed, int64_t speed,
bool has_granularity, uint32_t granularity,
bool has_buf_size, int64_t buf_size,
@@ -3258,7 +3289,8 @@ void qmp_blockdev_mirror(const char *job_id,
}
blockdev_mirror_common(job_id, bs, target_bs,
- replaces, sync, backing_mode,
+ replaces, sync,
+ bitmap, has_bitmap_mode, bitmap_mode, backing_mode,
zero_target, has_speed, speed,
has_granularity, granularity,
has_buf_size, buf_size,
diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h
index ef31c58bb3..57265a617a 100644
--- a/include/block/block_int-global-state.h
+++ b/include/block/block_int-global-state.h
@@ -152,7 +152,9 @@ void mirror_start(const char *job_id, BlockDriverState *bs,
BlockDriverState *target, const char *replaces,
int creation_flags, int64_t speed,
uint32_t granularity, int64_t buf_size,
- MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
+ MirrorSyncMode mode, BdrvDirtyBitmap *bitmap,
+ BitmapSyncMode bitmap_mode,
+ BlockMirrorBackingMode backing_mode,
bool zero_target,
BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index ca390c5700..8db0986e9e 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2163,6 +2163,15 @@
# destination (all the disk, only the sectors allocated in the
# topmost image, or only new I/O).
#
+# @bitmap: The name of a bitmap to use for sync=bitmap mode. This
+# argument must be present for bitmap mode and absent otherwise.
+# The bitmap's granularity is used instead of @granularity (Since
+# 4.1).
+#
+# @bitmap-mode: Specifies the type of data the bitmap should contain
+# after the operation concludes. Must be present if sync is
+# "bitmap". Must NOT be present otherwise. (Since 4.1)
+#
# @granularity: granularity of the dirty bitmap, default is 64K if the
# image format doesn't have clusters, 4K if the clusters are
# smaller than that, else the cluster size. Must be a power of 2
@@ -2205,7 +2214,9 @@
{ 'struct': 'DriveMirror',
'data': { '*job-id': 'str', 'device': 'str', 'target': 'str',
'*format': 'str', '*node-name': 'str', '*replaces': 'str',
- 'sync': 'MirrorSyncMode', '*mode': 'NewImageMode',
+ 'sync': 'MirrorSyncMode', '*bitmap': 'str',
+ '*bitmap-mode': 'BitmapSyncMode',
+ '*mode': 'NewImageMode',
'*speed': 'int', '*granularity': 'uint32',
'*buf-size': 'int', '*on-source-error': 'BlockdevOnError',
'*on-target-error': 'BlockdevOnError',
@@ -2489,6 +2500,15 @@
# destination (all the disk, only the sectors allocated in the
# topmost image, or only new I/O).
#
+# @bitmap: The name of a bitmap to use for sync=bitmap mode. This
+# argument must be present for bitmap mode and absent otherwise.
+# The bitmap's granularity is used instead of @granularity (since
+# 4.1).
+#
+# @bitmap-mode: Specifies the type of data the bitmap should contain
+# after the operation concludes. Must be present if sync is
+# "bitmap". Must NOT be present otherwise. (Since 4.1)
+#
# @granularity: granularity of the dirty bitmap, default is 64K if the
# image format doesn't have clusters, 4K if the clusters are
# smaller than that, else the cluster size. Must be a power of 2
@@ -2539,7 +2559,8 @@
{ 'command': 'blockdev-mirror',
'data': { '*job-id': 'str', 'device': 'str', 'target': 'str',
'*replaces': 'str',
- 'sync': 'MirrorSyncMode',
+ 'sync': 'MirrorSyncMode', '*bitmap': 'str',
+ '*bitmap-mode': 'BitmapSyncMode',
'*speed': 'int', '*granularity': 'uint32',
'*buf-size': 'int', '*on-source-error': 'BlockdevOnError',
'*on-target-error': 'BlockdevOnError',
diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c
index 9b15d2768c..54acd47188 100644
--- a/tests/unit/test-block-iothread.c
+++ b/tests/unit/test-block-iothread.c
@@ -766,8 +766,8 @@ static void test_propagate_mirror(void)
/* Start a mirror job */
aio_context_acquire(main_ctx);
mirror_start("job0", src, target, NULL, JOB_DEFAULT, 0, 0, 0,
- MIRROR_SYNC_MODE_NONE, MIRROR_OPEN_BACKING_CHAIN, false,
- BLOCKDEV_ON_ERROR_REPORT, BLOCKDEV_ON_ERROR_REPORT,
+ MIRROR_SYNC_MODE_NONE, NULL, 0, MIRROR_OPEN_BACKING_CHAIN,
+ false, BLOCKDEV_ON_ERROR_REPORT, BLOCKDEV_ON_ERROR_REPORT,
false, "filter_node", MIRROR_COPY_MODE_BACKGROUND,
&error_abort);
aio_context_release(main_ctx);