From: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
To: qemu devel <qemu-devel@nongnu.org>,
Stefan Hajnoczi <stefanha@redhat.com>,
Fam Zheng <famz@redhat.com>, Max Reitz <mreitz@redhat.com>,
Kevin Wolf <kwolf@redhat.com>, Jeff Cody <jcody@redhat.com>
Cc: qemu block <qemu-block@nongnu.org>,
Paolo Bonzini <pbonzini@redhat.com>, John Snow <jsnow@redhat.com>,
Eric Blake <eblake@redhat.com>,
Markus Armbruster <armbru@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Dong Eddie <eddie.dong@intel.com>,
Jiang Yunhong <yunhong.jiang@intel.com>,
zhanghailiang <zhang.zhanghailiang@huawei.com>,
Gonglei <arei.gonglei@huawei.com>,
Wen Congyang <wency@cn.fujitsu.com>,
Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Subject: [Qemu-devel] [PATCH v19 03/10] Backup: export interfaces for extra serialization
Date: Fri, 20 May 2016 15:36:13 +0800 [thread overview]
Message-ID: <1463729780-31982-4-git-send-email-xiecl.fnst@cn.fujitsu.com> (raw)
In-Reply-To: <1463729780-31982-1-git-send-email-xiecl.fnst@cn.fujitsu.com>
Normal backup(sync='none') workflow:
step 1. NBD peformance I/O write from client to server
qcow2_co_writev
bdrv_co_writev
...
bdrv_aligned_pwritev
notifier_with_return_list_notify -> backup_do_cow
bdrv_driver_pwritev // write new contents
step 2. drive-backup sync=none
backup_do_cow
{
wait_for_overlapping_requests
cow_request_begin
for(; start < end; start++) {
bdrv_co_readv_no_serialising //read old contents from Secondary disk
bdrv_co_writev // write old contents to hidden-disk
}
cow_request_end
}
step 3. Then roll back to "step 1" to write new contents to Secondary disk.
And for replication, we must make sure that we only read the old contents from
Secondary disk in order to keep contents consistent.
1) Replication workflow of Secondary
virtio-blk
^
-------> 1 NBD |
|| server 3 replication
|| ^ ^
|| | backing backing |
|| Secondary disk 6<-------- hidden-disk 5 <-------- active-disk 4
|| | ^
|| '-------------------------'
|| drive-backup sync=none 2
Hence, we need these interfaces to implement coarse-grained serialization between
COW of Secondary disk and the read operation of replication.
Example codes about how to use them:
*#include "block/block_backup.h"
static coroutine_fn int xxx_co_readv()
{
CowRequest req;
BlockJob *job = secondary_disk->bs->job;
if (job) {
backup_wait_for_overlapping_requests(job, start, end);
backup_cow_request_begin(&req, job, start, end);
ret = bdrv_co_readv();
backup_cow_request_end(&req);
goto out;
}
ret = bdrv_co_readv();
out:
return ret;
}
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
block/backup.c | 41 ++++++++++++++++++++++++++++++++++-------
include/block/block_backup.h | 14 ++++++++++++++
2 files changed, 48 insertions(+), 7 deletions(-)
diff --git a/block/backup.c b/block/backup.c
index 93bfd4c..57bcfa3 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -28,13 +28,6 @@
#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
#define SLICE_TIME 100000000ULL /* ns */
-typedef struct CowRequest {
- int64_t start;
- int64_t end;
- QLIST_ENTRY(CowRequest) list;
- CoQueue wait_queue; /* coroutines blocked on this request */
-} CowRequest;
-
typedef struct BackupBlockJob {
BlockJob common;
BlockDriverState *target;
@@ -268,6 +261,40 @@ void backup_do_checkpoint(BlockJob *job, Error **errp)
bitmap_zero(backup_job->done_bitmap, len);
}
+void backup_wait_for_overlapping_requests(BlockJob *job, int64_t sector_num,
+ int nb_sectors)
+{
+ BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
+ int64_t sectors_per_cluster = cluster_size_sectors(backup_job);
+ int64_t start, end;
+
+ assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
+
+ start = sector_num / sectors_per_cluster;
+ end = DIV_ROUND_UP(sector_num + nb_sectors, sectors_per_cluster);
+ wait_for_overlapping_requests(backup_job, start, end);
+}
+
+void backup_cow_request_begin(CowRequest *req, BlockJob *job,
+ int64_t sector_num,
+ int nb_sectors)
+{
+ BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
+ int64_t sectors_per_cluster = cluster_size_sectors(backup_job);
+ int64_t start, end;
+
+ assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
+
+ start = sector_num / sectors_per_cluster;
+ end = DIV_ROUND_UP(sector_num + nb_sectors, sectors_per_cluster);
+ cow_request_begin(req, backup_job, start, end);
+}
+
+void backup_cow_request_end(CowRequest *req)
+{
+ cow_request_end(req);
+}
+
static const BlockJobDriver backup_job_driver = {
.instance_size = sizeof(BackupBlockJob),
.job_type = BLOCK_JOB_TYPE_BACKUP,
diff --git a/include/block/block_backup.h b/include/block/block_backup.h
index 3753bcb..e0e7ce6 100644
--- a/include/block/block_backup.h
+++ b/include/block/block_backup.h
@@ -1,3 +1,17 @@
#include "block/block_int.h"
+typedef struct CowRequest {
+ int64_t start;
+ int64_t end;
+ QLIST_ENTRY(CowRequest) list;
+ CoQueue wait_queue; /* coroutines blocked on this request */
+} CowRequest;
+
+void backup_wait_for_overlapping_requests(BlockJob *job, int64_t sector_num,
+ int nb_sectors);
+void backup_cow_request_begin(CowRequest *req, BlockJob *job,
+ int64_t sector_num,
+ int nb_sectors);
+void backup_cow_request_end(CowRequest *req);
+
void backup_do_checkpoint(BlockJob *job, Error **errp);
--
1.9.3
next prev parent reply other threads:[~2016-05-20 7:33 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-20 7:36 [Qemu-devel] [PATCH v19 00/10] Block replication for continuous checkpoints Changlong Xie
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 01/10] unblock backup operations in backing file Changlong Xie
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 02/10] Backup: clear all bitmap when doing block checkpoint Changlong Xie
2016-05-20 7:36 ` Changlong Xie [this message]
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 04/10] Link backup into block core Changlong Xie
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 05/10] docs: block replication's description Changlong Xie
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 06/10] auto complete active commit Changlong Xie
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 07/10] Introduce new APIs to do replication operation Changlong Xie
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 08/10] Implement new driver for block replication Changlong Xie
2016-05-30 18:14 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2016-05-31 1:20 ` Changlong Xie
2016-06-07 4:59 ` [Qemu-devel] " Changlong Xie
2016-06-07 5:36 ` Changlong Xie
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 09/10] tests: add unit test case for replication Changlong Xie
2016-05-27 1:46 ` Changlong Xie
2016-05-30 17:34 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2016-05-31 10:21 ` Changlong Xie
2016-05-20 7:36 ` [Qemu-devel] [PATCH v19 10/10] support replication driver in blockdev-add Changlong Xie
2016-05-27 1:59 ` [Qemu-devel] [PATCH v19 00/10] Block replication for continuous checkpoints Changlong Xie
2016-05-27 7:23 ` Fam Zheng
2016-05-30 18:20 ` [Qemu-devel] [Qemu-block] " Stefan Hajnoczi
2016-05-31 10:25 ` Changlong Xie
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1463729780-31982-4-git-send-email-xiecl.fnst@cn.fujitsu.com \
--to=xiecl.fnst@cn.fujitsu.com \
--cc=arei.gonglei@huawei.com \
--cc=armbru@redhat.com \
--cc=dgilbert@redhat.com \
--cc=eblake@redhat.com \
--cc=eddie.dong@intel.com \
--cc=famz@redhat.com \
--cc=jcody@redhat.com \
--cc=jsnow@redhat.com \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.com \
--cc=wency@cn.fujitsu.com \
--cc=yunhong.jiang@intel.com \
--cc=zhang.zhanghailiang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.