[Qemu-devel] [PATCH v3 1/1] drive-mirror: add incremental mode

[mahaocong <mahaocong_work@163.com>]

From: mahaocong <mahaocong@didichuxing.com>

Signed-off-by: mahaocong <mahaocong@didichuxing.com>
---
 block/mirror.c            | 46 ++++++++++++++++++++++++++++++++++------------
 blockdev.c                | 37 +++++++++++++++++++++++++++++++++++--
 include/block/block_int.h |  3 ++-
 qapi/block-core.json      |  7 ++++++-
 4 files changed, 77 insertions(+), 16 deletions(-)

diff --git a/block/mirror.c b/block/mirror.c
index ab59ad77e8..c59aefe9f0 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -50,6 +50,7 @@ typedef struct MirrorBlockJob {
     /* Used to block operations on the drive-mirror-replace target */
     Error *replace_blocker;
     bool is_none_mode;
+    BdrvDirtyBitmap *src_bitmap;
     BlockMirrorBackingMode backing_mode;
     MirrorCopyMode copy_mode;
     BlockdevOnError on_source_error, on_target_error;
@@ -814,6 +815,15 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
     return 0;
 }
 
+/*
+ * init dirty bitmap by using user bitmap. usr->hbitmap will be copy to
+ * mirror bitmap->hbitmap instead of reuse it.
+ */
+static void coroutine_fn mirror_dirty_init_incremental(MirrorBlockJob *s, Error **errp)
+{
+    bdrv_merge_dirty_bitmap(s->dirty_bitmap, s->src_bitmap, NULL, errp);
+}
+
 /* Called when going out of the streaming phase to flush the bulk of the
  * data to the medium, or just before completing.
  */
@@ -839,6 +849,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
     char backing_filename[2]; /* we only need 2 characters because we are only
                                  checking for a NULL string */
     int ret = 0;
+    Error *local_err = NULL;
 
     if (job_is_cancelled(&s->common.job)) {
         goto immediate_exit;
@@ -913,9 +924,19 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
 
     s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
     if (!s->is_none_mode) {
-        ret = mirror_dirty_init(s);
-        if (ret < 0 || job_is_cancelled(&s->common.job)) {
-            goto immediate_exit;
+        /* incremental mode */
+        if (s->src_bitmap) {
+            mirror_dirty_init_incremental(s, &local_err);
+            if (local_err) {
+                error_propagate(errp, local_err);
+                ret = -1;
+                goto immediate_exit;
+            }
+        } else {
+            ret = mirror_dirty_init(s);
+            if (ret < 0 || job_is_cancelled(&s->common.job)) {
+                goto immediate_exit;
+            }
         }
     }
 
@@ -1484,7 +1505,8 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs,
                              BlockCompletionFunc *cb,
                              void *opaque,
                              const BlockJobDriver *driver,
-                             bool is_none_mode, BlockDriverState *base,
+                             bool is_none_mode, BdrvDirtyBitmap *src_bitmap,
+                             BlockDriverState *base,
                              bool auto_complete, const char *filter_node_name,
                              bool is_mirror, MirrorCopyMode copy_mode,
                              Error **errp)
@@ -1598,6 +1620,7 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs,
     s->on_source_error = on_source_error;
     s->on_target_error = on_target_error;
     s->is_none_mode = is_none_mode;
+    s->src_bitmap = src_bitmap;
     s->backing_mode = backing_mode;
     s->copy_mode = copy_mode;
     s->base = base;
@@ -1664,7 +1687,8 @@ 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 *src_bitmap,
+                  BlockMirrorBackingMode backing_mode,
                   BlockdevOnError on_source_error,
                   BlockdevOnError on_target_error,
                   bool unmap, const char *filter_node_name,
@@ -1673,17 +1697,14 @@ void mirror_start(const char *job_id, BlockDriverState *bs,
     bool is_none_mode;
     BlockDriverState *base;
 
-    if (mode == MIRROR_SYNC_MODE_INCREMENTAL) {
-        error_setg(errp, "Sync mode 'incremental' not supported");
-        return;
-    }
     is_none_mode = mode == MIRROR_SYNC_MODE_NONE;
     base = mode == MIRROR_SYNC_MODE_TOP ? backing_bs(bs) : NULL;
     mirror_start_job(job_id, bs, creation_flags, target, replaces,
                      speed, granularity, buf_size, backing_mode,
                      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, is_none_mode,
+                     src_bitmap, base, false, filter_node_name, true,
+                     copy_mode, errp);
 }
 
 void commit_active_start(const char *job_id, BlockDriverState *bs,
@@ -1707,7 +1728,8 @@ void commit_active_start(const char *job_id, BlockDriverState *bs,
     mirror_start_job(job_id, bs, creation_flags, base, NULL, speed, 0, 0,
                      MIRROR_LEAVE_BACKING_CHAIN,
                      on_error, on_error, true, cb, opaque,
-                     &commit_active_job_driver, false, base, auto_complete,
+                     &commit_active_job_driver, false,
+                     NULL, base, auto_complete,
                      filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND,
                      &local_err);
     if (local_err) {
diff --git a/blockdev.c b/blockdev.c
index a6f71f9d83..969362d36a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3661,6 +3661,8 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
                                    BlockDriverState *target,
                                    bool has_replaces, const char *replaces,
                                    enum MirrorSyncMode sync,
+                                   bool has_bitmap,
+                                   const char *bitmap_name,
                                    BlockMirrorBackingMode backing_mode,
                                    bool has_speed, int64_t speed,
                                    bool has_granularity, uint32_t granularity,
@@ -3678,6 +3680,7 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
                                    Error **errp)
 {
     int job_flags = JOB_DEFAULT;
+    BdrvDirtyBitmap *src_bitmap = NULL;
 
     if (!has_speed) {
         speed = 0;
@@ -3700,6 +3703,24 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
     if (!has_filter_node_name) {
         filter_node_name = NULL;
     }
+    if (!has_bitmap) {
+        bitmap_name = NULL;
+    }
+    /*
+     * In incremental mode, we should create null name bitmap by
+     * using user bitmap's granularity.
+     */
+    if (sync == MIRROR_SYNC_MODE_INCREMENTAL) {
+        assert(bitmap_name);
+        src_bitmap = bdrv_find_dirty_bitmap(bs, bitmap_name);
+        if (!src_bitmap) {
+            error_setg(errp, "Error: can't find dirty bitmap "
+                       "before start incremental drive-mirror");
+            return;
+        }
+        granularity = bdrv_dirty_bitmap_granularity(src_bitmap);
+    }
+
     if (!has_copy_mode) {
         copy_mode = MIRROR_COPY_MODE_BACKGROUND;
     }
@@ -3737,7 +3758,7 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
      */
     mirror_start(job_id, bs, target,
                  has_replaces ? replaces : NULL, job_flags,
-                 speed, granularity, buf_size, sync, backing_mode,
+                 speed, granularity, buf_size, sync, src_bitmap, backing_mode,
                  on_source_error, on_target_error, unmap, filter_node_name,
                  copy_mode, errp);
 }
@@ -3784,6 +3805,16 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)
     if (arg->sync == MIRROR_SYNC_MODE_NONE) {
         source = bs;
     }
+    if ((arg->sync == MIRROR_SYNC_MODE_INCREMENTAL) &&
+        (!arg->has_bitmap)) {
+        error_setg(errp, "incremental mode must specify the bitmap name");
+        goto out;
+    }
+    if ((arg->sync == MIRROR_SYNC_MODE_INCREMENTAL) &&
+        (arg->has_granularity)) {
+        error_setg(errp, "incremental mode can not set bitmap granularity");
+        goto out;
+    }
 
     size = bdrv_getlength(bs);
     if (size < 0) {
@@ -3878,6 +3909,7 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp)
 
     blockdev_mirror_common(arg->has_job_id ? arg->job_id : NULL, bs, target_bs,
                            arg->has_replaces, arg->replaces, arg->sync,
+                           arg->has_bitmap, arg->bitmap,
                            backing_mode, arg->has_speed, arg->speed,
                            arg->has_granularity, arg->granularity,
                            arg->has_buf_size, arg->buf_size,
@@ -3935,7 +3967,8 @@ void qmp_blockdev_mirror(bool has_job_id, const char *job_id,
     bdrv_set_aio_context(target_bs, aio_context);
 
     blockdev_mirror_common(has_job_id ? job_id : NULL, bs, target_bs,
-                           has_replaces, replaces, sync, backing_mode,
+                           has_replaces, replaces, sync, false, NULL,
+                           backing_mode,
                            has_speed, speed,
                            has_granularity, granularity,
                            has_buf_size, buf_size,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index f605622216..57a441f992 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -1054,7 +1054,8 @@ 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 *src_bitmap,
+                  BlockMirrorBackingMode backing_mode,
                   BlockdevOnError on_source_error,
                   BlockdevOnError on_target_error,
                   bool unmap, const char *filter_node_name,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 762000f31f..058bafca65 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1727,6 +1727,11 @@
 #        (all the disk, only the sectors allocated in the topmost image, or
 #        only new I/O).
 #
+# @bitmap: the name of user-created-bitmap which is used on incremental mode
+#          drive-mirror. If user select incremental mode, bitmap should not be
+#          null, and can not set granularity, because the mirror bitmap should
+#          have the same granularity with user-created-bitmap.
+#
 # @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
@@ -1768,7 +1773,7 @@
 { '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', '*mode': 'NewImageMode',
             '*speed': 'int', '*granularity': 'uint32',
             '*buf-size': 'int', '*on-source-error': 'BlockdevOnError',
             '*on-target-error': 'BlockdevOnError',
-- 
2.14.1