pve-qemu-qoup/debian/patches/pve/0031-PVE-Backup-Add-dirty-bitmap-tracking-for-incremental.patch
Fiona Ebner 5b15e2ecaf update submodule and patches to 7.1.0
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
  savevm-async, because the previously used QEMUFileOps was dropped.

  Changes to the current implementation:

  * Switch to vector based methods as required for an IO channel. For
    short reads the passed-in IO vector is stuffed with zeroes at the
    end, just to be sure.

  * For reading: The documentation in include/io/channel.h states that
    at least one byte should be read, so also error out when whe are
    at the very end instead of returning 0.

  * For reading: Fix off-by-one error when request goes beyond end.

    The wrong code piece was:
    if ((pos + size) > maxlen) {
        size = maxlen - pos - 1;
    }

    Previously, the last byte would not be read. It's actually
    possible to get a snapshot .raw file that has content all the way
    up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
    trailing zero bytes (I wrote a script to do it).

    Luckily, it didn't cause a real issue, because qemu_loadvm_state()
    is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
    section. The buffer for reading it is simply freed up afterwards
    and the function will assume that it read the whole section, even
    if that's not the case.

  * For writing: Make use of the generated blk_pwritev() wrapper
    instead of manually wrapping the coroutine to simplify and save a
    few lines.

* Adapt to changed interfaces for blk_{pread,pwrite}:
  * a9262f551e ("block: Change blk_{pread,pwrite}() param order")
  * 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
  * bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
  Those changes especially affected the qemu-img dd patches, because
  the context also changed, but also some of our block drivers used
  the functions.

* Drop qemu-common.h include: it got renamed after essentially
  everything was moved to other headers. The only remaining user I
  could find for things dropped from the header between 7.0 and 7.1
  was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
  already includes the header to which the function was moved.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2022-10-14 14:52:29 +02:00

453 lines
17 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Stefan Reiter <s.reiter@proxmox.com>
Date: Mon, 29 Jun 2020 11:06:03 +0200
Subject: [PATCH] PVE-Backup: Add dirty-bitmap tracking for incremental backups
Uses QEMU's existing MIRROR_SYNC_MODE_BITMAP and a dirty-bitmap on top
of all backed-up drives. This will only execute the data-write callback
for any changed chunks, the PBS rust code will reuse chunks from the
previous index for everything it doesn't receive if reuse_index is true.
On error or cancellation, remove all dirty bitmaps to ensure
consistency.
Add PBS/incremental specific information to query backup info QMP and
HMP commands.
Only supported for PBS backups.
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
---
block/monitor/block-hmp-cmds.c | 1 +
monitor/hmp-cmds.c | 45 ++++++++++----
proxmox-backup-client.c | 3 +-
proxmox-backup-client.h | 1 +
pve-backup.c | 103 ++++++++++++++++++++++++++++++---
qapi/block-core.json | 12 +++-
6 files changed, 142 insertions(+), 23 deletions(-)
diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c
index 89ca64444d..45da74d7a0 100644
--- a/block/monitor/block-hmp-cmds.c
+++ b/block/monitor/block-hmp-cmds.c
@@ -1042,6 +1042,7 @@ void hmp_backup(Monitor *mon, const QDict *qdict)
false, NULL, // PBS fingerprint
false, NULL, // PBS backup-id
false, 0, // PBS backup-time
+ false, false, // PBS incremental
true, dir ? BACKUP_FORMAT_DIR : BACKUP_FORMAT_VMA,
false, NULL, false, NULL, !!devlist,
devlist, qdict_haskey(qdict, "speed"), speed, &error);
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 1168773da7..4c1671e289 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -223,19 +223,42 @@ void hmp_info_backup(Monitor *mon, const QDict *qdict)
monitor_printf(mon, "End time: %s", ctime(&info->end_time));
}
- int per = (info->has_total && info->total &&
- info->has_transferred && info->transferred) ?
- (info->transferred * 100)/info->total : 0;
- int zero_per = (info->has_total && info->total &&
- info->has_zero_bytes && info->zero_bytes) ?
- (info->zero_bytes * 100)/info->total : 0;
monitor_printf(mon, "Backup file: %s\n", info->backup_file);
monitor_printf(mon, "Backup uuid: %s\n", info->uuid);
- monitor_printf(mon, "Total size: %zd\n", info->total);
- monitor_printf(mon, "Transferred bytes: %zd (%d%%)\n",
- info->transferred, per);
- monitor_printf(mon, "Zero bytes: %zd (%d%%)\n",
- info->zero_bytes, zero_per);
+
+ if (!(info->has_total && info->total)) {
+ // this should not happen normally
+ monitor_printf(mon, "Total size: %d\n", 0);
+ } else {
+ bool incremental = false;
+ size_t total_or_dirty = info->total;
+ if (info->has_transferred) {
+ if (info->has_dirty && info->dirty) {
+ if (info->dirty < info->total) {
+ total_or_dirty = info->dirty;
+ incremental = true;
+ }
+ }
+ }
+
+ int per = (info->transferred * 100)/total_or_dirty;
+
+ monitor_printf(mon, "Backup mode: %s\n", incremental ? "incremental" : "full");
+
+ int zero_per = (info->has_zero_bytes && info->zero_bytes) ?
+ (info->zero_bytes * 100)/info->total : 0;
+ monitor_printf(mon, "Total size: %zd\n", info->total);
+ monitor_printf(mon, "Transferred bytes: %zd (%d%%)\n",
+ info->transferred, per);
+ monitor_printf(mon, "Zero bytes: %zd (%d%%)\n",
+ info->zero_bytes, zero_per);
+
+ if (info->has_reused) {
+ int reused_per = (info->reused * 100)/total_or_dirty;
+ monitor_printf(mon, "Reused bytes: %zd (%d%%)\n",
+ info->reused, reused_per);
+ }
+ }
}
qapi_free_BackupStatus(info);
diff --git a/proxmox-backup-client.c b/proxmox-backup-client.c
index a8f6653a81..4ce7bc0b5e 100644
--- a/proxmox-backup-client.c
+++ b/proxmox-backup-client.c
@@ -89,6 +89,7 @@ proxmox_backup_co_register_image(
ProxmoxBackupHandle *pbs,
const char *device_name,
uint64_t size,
+ bool incremental,
Error **errp)
{
Coroutine *co = qemu_coroutine_self();
@@ -98,7 +99,7 @@ proxmox_backup_co_register_image(
int pbs_res = -1;
proxmox_backup_register_image_async(
- pbs, device_name, size ,proxmox_backup_schedule_wake, &waker, &pbs_res, &pbs_err);
+ pbs, device_name, size, incremental, proxmox_backup_schedule_wake, &waker, &pbs_res, &pbs_err);
qemu_coroutine_yield();
if (pbs_res < 0) {
if (errp) error_setg(errp, "backup register image failed: %s", pbs_err ? pbs_err : "unknown error");
diff --git a/proxmox-backup-client.h b/proxmox-backup-client.h
index 1dda8b7d8f..8cbf645b2c 100644
--- a/proxmox-backup-client.h
+++ b/proxmox-backup-client.h
@@ -32,6 +32,7 @@ proxmox_backup_co_register_image(
ProxmoxBackupHandle *pbs,
const char *device_name,
uint64_t size,
+ bool incremental,
Error **errp);
diff --git a/pve-backup.c b/pve-backup.c
index 88f5ee133f..1c49cd178d 100644
--- a/pve-backup.c
+++ b/pve-backup.c
@@ -28,6 +28,8 @@
*
*/
+const char *PBS_BITMAP_NAME = "pbs-incremental-dirty-bitmap";
+
static struct PVEBackupState {
struct {
// Everithing accessed from qmp_backup_query command is protected using lock
@@ -39,7 +41,9 @@ static struct PVEBackupState {
uuid_t uuid;
char uuid_str[37];
size_t total;
+ size_t dirty;
size_t transferred;
+ size_t reused;
size_t zero_bytes;
} stat;
int64_t speed;
@@ -66,6 +70,7 @@ typedef struct PVEBackupDevInfo {
uint8_t dev_id;
bool completed;
char targetfile[PATH_MAX];
+ BdrvDirtyBitmap *bitmap;
BlockDriverState *target;
} PVEBackupDevInfo;
@@ -105,11 +110,12 @@ static bool pvebackup_error_or_canceled(void)
return error_or_canceled;
}
-static void pvebackup_add_transfered_bytes(size_t transferred, size_t zero_bytes)
+static void pvebackup_add_transfered_bytes(size_t transferred, size_t zero_bytes, size_t reused)
{
qemu_mutex_lock(&backup_state.stat.lock);
backup_state.stat.zero_bytes += zero_bytes;
backup_state.stat.transferred += transferred;
+ backup_state.stat.reused += reused;
qemu_mutex_unlock(&backup_state.stat.lock);
}
@@ -148,7 +154,8 @@ pvebackup_co_dump_pbs_cb(
pvebackup_propagate_error(local_err);
return pbs_res;
} else {
- pvebackup_add_transfered_bytes(size, !buf ? size : 0);
+ size_t reused = (pbs_res == 0) ? size : 0;
+ pvebackup_add_transfered_bytes(size, !buf ? size : 0, reused);
}
return size;
@@ -208,11 +215,11 @@ pvebackup_co_dump_vma_cb(
} else {
if (remaining >= VMA_CLUSTER_SIZE) {
assert(ret == VMA_CLUSTER_SIZE);
- pvebackup_add_transfered_bytes(VMA_CLUSTER_SIZE, zero_bytes);
+ pvebackup_add_transfered_bytes(VMA_CLUSTER_SIZE, zero_bytes, 0);
remaining -= VMA_CLUSTER_SIZE;
} else {
assert(ret == remaining);
- pvebackup_add_transfered_bytes(remaining, zero_bytes);
+ pvebackup_add_transfered_bytes(remaining, zero_bytes, 0);
remaining = 0;
}
}
@@ -248,6 +255,18 @@ static void coroutine_fn pvebackup_co_cleanup(void *unused)
if (local_err != NULL) {
pvebackup_propagate_error(local_err);
}
+ } else {
+ // on error or cancel we cannot ensure synchronization of dirty
+ // bitmaps with backup server, so remove all and do full backup next
+ GList *l = backup_state.di_list;
+ while (l) {
+ PVEBackupDevInfo *di = (PVEBackupDevInfo *)l->data;
+ l = g_list_next(l);
+
+ if (di->bitmap) {
+ bdrv_release_dirty_bitmap(di->bitmap);
+ }
+ }
}
proxmox_backup_disconnect(backup_state.pbs);
@@ -303,6 +322,12 @@ static void pvebackup_complete_cb(void *opaque, int ret)
// remove self from job queue
backup_state.di_list = g_list_remove(backup_state.di_list, di);
+ if (di->bitmap && ret < 0) {
+ // on error or cancel we cannot ensure synchronization of dirty
+ // bitmaps with backup server, so remove all and do full backup next
+ bdrv_release_dirty_bitmap(di->bitmap);
+ }
+
g_free(di);
qemu_mutex_unlock(&backup_state.backup_mutex);
@@ -472,12 +497,18 @@ static bool create_backup_jobs(void) {
assert(di->target != NULL);
+ MirrorSyncMode sync_mode = MIRROR_SYNC_MODE_FULL;
+ BitmapSyncMode bitmap_mode = BITMAP_SYNC_MODE_NEVER;
+ if (di->bitmap) {
+ sync_mode = MIRROR_SYNC_MODE_BITMAP;
+ bitmap_mode = BITMAP_SYNC_MODE_ON_SUCCESS;
+ }
AioContext *aio_context = bdrv_get_aio_context(di->bs);
aio_context_acquire(aio_context);
BlockJob *job = backup_job_create(
- NULL, di->bs, di->target, backup_state.speed, MIRROR_SYNC_MODE_FULL, NULL,
- BITMAP_SYNC_MODE_NEVER, false, NULL, &perf, BLOCKDEV_ON_ERROR_REPORT, BLOCKDEV_ON_ERROR_REPORT,
+ NULL, di->bs, di->target, backup_state.speed, sync_mode, di->bitmap,
+ bitmap_mode, false, NULL, &perf, BLOCKDEV_ON_ERROR_REPORT, BLOCKDEV_ON_ERROR_REPORT,
JOB_DEFAULT, pvebackup_complete_cb, di, NULL, &local_err);
aio_context_release(aio_context);
@@ -528,6 +559,8 @@ typedef struct QmpBackupTask {
const char *fingerprint;
bool has_fingerprint;
int64_t backup_time;
+ bool has_use_dirty_bitmap;
+ bool use_dirty_bitmap;
bool has_format;
BackupFormat format;
bool has_config_file;
@@ -619,6 +652,7 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
}
size_t total = 0;
+ size_t dirty = 0;
l = di_list;
while (l) {
@@ -656,6 +690,8 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
int dump_cb_block_size = PROXMOX_BACKUP_DEFAULT_CHUNK_SIZE; // Hardcoded (4M)
firewall_name = "fw.conf";
+ bool use_dirty_bitmap = task->has_use_dirty_bitmap && task->use_dirty_bitmap;
+
char *pbs_err = NULL;
pbs = proxmox_backup_new(
task->backup_file,
@@ -675,7 +711,8 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
goto err;
}
- if (proxmox_backup_co_connect(pbs, task->errp) < 0)
+ int connect_result = proxmox_backup_co_connect(pbs, task->errp);
+ if (connect_result < 0)
goto err;
/* register all devices */
@@ -686,9 +723,40 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
const char *devname = bdrv_get_device_name(di->bs);
- int dev_id = proxmox_backup_co_register_image(pbs, devname, di->size, task->errp);
- if (dev_id < 0)
+ BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(di->bs, PBS_BITMAP_NAME);
+ bool expect_only_dirty = false;
+
+ if (use_dirty_bitmap) {
+ if (bitmap == NULL) {
+ bitmap = bdrv_create_dirty_bitmap(di->bs, dump_cb_block_size, PBS_BITMAP_NAME, task->errp);
+ if (!bitmap) {
+ goto err;
+ }
+ } else {
+ expect_only_dirty = proxmox_backup_check_incremental(pbs, devname, di->size) != 0;
+ }
+
+ if (expect_only_dirty) {
+ dirty += bdrv_get_dirty_count(bitmap);
+ } else {
+ /* mark entire bitmap as dirty to make full backup */
+ bdrv_set_dirty_bitmap(bitmap, 0, di->size);
+ dirty += di->size;
+ }
+ di->bitmap = bitmap;
+ } else {
+ dirty += di->size;
+
+ /* after a full backup the old dirty bitmap is invalid anyway */
+ if (bitmap != NULL) {
+ bdrv_release_dirty_bitmap(bitmap);
+ }
+ }
+
+ int dev_id = proxmox_backup_co_register_image(pbs, devname, di->size, expect_only_dirty, task->errp);
+ if (dev_id < 0) {
goto err;
+ }
if (!(di->target = bdrv_backup_dump_create(dump_cb_block_size, di->size, pvebackup_co_dump_pbs_cb, di, task->errp))) {
goto err;
@@ -697,6 +765,8 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
di->dev_id = dev_id;
}
} else if (format == BACKUP_FORMAT_VMA) {
+ dirty = total;
+
vmaw = vma_writer_create(task->backup_file, uuid, &local_err);
if (!vmaw) {
if (local_err) {
@@ -724,6 +794,8 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
}
}
} else if (format == BACKUP_FORMAT_DIR) {
+ dirty = total;
+
if (mkdir(task->backup_file, 0640) != 0) {
error_setg_errno(task->errp, errno, "can't create directory '%s'\n",
task->backup_file);
@@ -796,8 +868,10 @@ static void coroutine_fn pvebackup_co_prepare(void *opaque)
char *uuid_str = g_strdup(backup_state.stat.uuid_str);
backup_state.stat.total = total;
+ backup_state.stat.dirty = dirty;
backup_state.stat.transferred = 0;
backup_state.stat.zero_bytes = 0;
+ backup_state.stat.reused = format == BACKUP_FORMAT_PBS && dirty >= total ? 0 : total - dirty;
qemu_mutex_unlock(&backup_state.stat.lock);
@@ -821,6 +895,10 @@ err:
PVEBackupDevInfo *di = (PVEBackupDevInfo *)l->data;
l = g_list_next(l);
+ if (di->bitmap) {
+ bdrv_release_dirty_bitmap(di->bitmap);
+ }
+
if (di->target) {
bdrv_unref(di->target);
}
@@ -862,6 +940,7 @@ UuidInfo *qmp_backup(
bool has_fingerprint, const char *fingerprint,
bool has_backup_id, const char *backup_id,
bool has_backup_time, int64_t backup_time,
+ bool has_use_dirty_bitmap, bool use_dirty_bitmap,
bool has_format, BackupFormat format,
bool has_config_file, const char *config_file,
bool has_firewall_file, const char *firewall_file,
@@ -880,6 +959,8 @@ UuidInfo *qmp_backup(
.backup_id = backup_id,
.has_backup_time = has_backup_time,
.backup_time = backup_time,
+ .has_use_dirty_bitmap = has_use_dirty_bitmap,
+ .use_dirty_bitmap = use_dirty_bitmap,
.has_format = has_format,
.format = format,
.has_config_file = has_config_file,
@@ -948,10 +1029,14 @@ BackupStatus *qmp_query_backup(Error **errp)
info->has_total = true;
info->total = backup_state.stat.total;
+ info->has_dirty = true;
+ info->dirty = backup_state.stat.dirty;
info->has_zero_bytes = true;
info->zero_bytes = backup_state.stat.zero_bytes;
info->has_transferred = true;
info->transferred = backup_state.stat.transferred;
+ info->has_reused = true;
+ info->reused = backup_state.stat.reused;
qemu_mutex_unlock(&backup_state.stat.lock);
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 90ad07b7ee..3ad9eb5d1a 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -753,8 +753,13 @@
#
# @total: total amount of bytes involved in the backup process
#
+# @dirty: with incremental mode (PBS) this is the amount of bytes involved
+# in the backup process which are marked dirty.
+#
# @transferred: amount of bytes already backed up.
#
+# @reused: amount of bytes reused due to deduplication.
+#
# @zero-bytes: amount of 'zero' bytes detected.
#
# @start-time: time (epoch) when backup job started.
@@ -767,8 +772,8 @@
#
##
{ 'struct': 'BackupStatus',
- 'data': {'*status': 'str', '*errmsg': 'str', '*total': 'int',
- '*transferred': 'int', '*zero-bytes': 'int',
+ 'data': {'*status': 'str', '*errmsg': 'str', '*total': 'int', '*dirty': 'int',
+ '*transferred': 'int', '*zero-bytes': 'int', '*reused': 'int',
'*start-time': 'int', '*end-time': 'int',
'*backup-file': 'str', '*uuid': 'str' } }
@@ -811,6 +816,8 @@
#
# @backup-time: backup timestamp (Unix epoch, required for format 'pbs')
#
+# @use-dirty-bitmap: use dirty bitmap to detect incremental changes since last job (optional for format 'pbs')
+#
# Returns: the uuid of the backup job
#
##
@@ -821,6 +828,7 @@
'*fingerprint': 'str',
'*backup-id': 'str',
'*backup-time': 'int',
+ '*use-dirty-bitmap': 'bool',
'*format': 'BackupFormat',
'*config-file': 'str',
'*firewall-file': 'str',