[Qemu-devel] [RFC PATCH 25/36] mirror: add support for on_source_error/on_target_error

[Paolo Bonzini <pbonzini@redhat.com>]

(Mostly untested).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 block/mirror.c   |   50 +++++++++++++++++++++++++++++++++++++++++---------
 block_int.h      |    4 ++++
 blockdev.c       |   14 ++++++++++++--
 hmp.c            |    3 ++-
 qapi-schema.json |    7 ++++++-
 qmp-commands.hx  |    8 +++++++-
 6 files changed, 72 insertions(+), 14 deletions(-)

diff --git a/block/mirror.c b/block/mirror.c
index 4c1582d..bdcbe3e 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -32,11 +32,14 @@ typedef struct MirrorBlockJob {
     RateLimit limit;
     BlockDriverState *target;
     MirrorSyncMode mode;
+    BlockdevOnError on_source_error, on_target_error;
+    bool synced;
     int64_t sector_num;
     void *buf;
 } MirrorBlockJob;
 
-static int coroutine_fn mirror_iteration(MirrorBlockJob *s)
+static int coroutine_fn mirror_iteration(MirrorBlockJob *s,
+                                         BlockErrorAction *p_action)
 {
     BlockDriverState *source = s->common.bs;
     BlockDriverState *target = s->target;
@@ -58,9 +61,23 @@ static int coroutine_fn mirror_iteration(MirrorBlockJob *s)
 
     ret = bdrv_co_readv(source, s->sector_num, nb_sectors, &qiov);
     if (ret < 0) {
-        return ret;
+        *p_action = block_job_error_action(&s->common, source,
+                                           s->on_source_error, true, -ret);
+        goto fail;
     }
-    return bdrv_co_writev(target, s->sector_num, nb_sectors, &qiov);
+    ret = bdrv_co_writev(target, s->sector_num, nb_sectors, &qiov);
+    if (ret < 0) {
+        *p_action = block_job_error_action(&s->common, target,
+                                           s->on_target_error, false, -ret);
+        s->synced = false;
+        goto fail;
+    }
+    return 0;
+
+fail:
+    /* Try again later.  */
+    bdrv_set_dirty(source, s->sector_num, nb_sectors);
+    return ret;
 }
 
 static void coroutine_fn mirror_run(void *opaque)
@@ -70,7 +87,6 @@ static void coroutine_fn mirror_run(void *opaque)
     int64_t sector_num, end;
     int ret = 0;
     int n;
-    bool synced = false;
 
     if (block_job_is_cancelled(&s->common)) {
         goto immediate_exit;
@@ -116,8 +132,9 @@ static void coroutine_fn mirror_run(void *opaque)
         bool should_complete;
 
         if (bdrv_get_dirty_count(bs) != 0) {
-            ret = mirror_iteration(s);
-            if (ret < 0) {
+            BlockErrorAction action = BDRV_ACTION_REPORT;
+            ret = mirror_iteration(s, &action);
+            if (ret < 0 && action == BDRV_ACTION_REPORT) {
                 break;
             }
         }
@@ -128,11 +145,11 @@ static void coroutine_fn mirror_run(void *opaque)
              * I/O and report completion, so that drive-reopen can be
              * used to pivot to the mirroring target.
              */
-            synced = true;
+            s->synced = true;
             s->common.offset = end * BDRV_SECTOR_SIZE;
         }
 
-        should_complete = synced && block_job_is_cancelled(&s->common);
+        should_complete = s->synced && block_job_is_cancelled(&s->common);
         if (should_complete) {
             /* The dirty bitmap is not updated while operations are pending.
              * If we're about to exit, wait for pending operations before
@@ -147,7 +164,7 @@ static void coroutine_fn mirror_run(void *opaque)
 
         ret = 0;
         cnt = bdrv_get_dirty_count(bs);
-        if (synced) {
+        if (s->synced) {
             if (!should_complete) {
                 delay_ns = (cnt == 0 ? SLICE_TIME : 0);
                 block_job_sleep_ns(&s->common, rt_clock, delay_ns);
@@ -185,6 +202,7 @@ static void coroutine_fn mirror_run(void *opaque)
 immediate_exit:
     g_free(s->buf);
     bdrv_set_dirty_tracking(bs, false);
+    bdrv_iostatus_disable(s->target);
     bdrv_close(s->target);
     bdrv_delete(s->target);
     block_job_completed(&s->common, ret);
@@ -201,6 +219,13 @@ static void mirror_set_speed(BlockJob *job, int64_t speed, Error **errp)
     ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME);
 }
 
+static void mirror_iostatus_reset(BlockJob *job)
+{
+    MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
+
+    bdrv_iostatus_reset(s->target);
+}
+
 static void mirror_query(BlockJob *job, BlockJobInfo *info)
 {
     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
@@ -215,11 +240,14 @@ static BlockJobType mirror_job_type = {
     .instance_size = sizeof(MirrorBlockJob),
     .job_type      = "mirror",
     .set_speed     = mirror_set_speed,
+    .iostatus_reset= mirror_iostatus_reset,
     .query         = mirror_query,
 };
 
 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
                   int64_t speed, MirrorSyncMode mode,
+                  BlockdevOnError on_source_error,
+                  BlockdevOnError on_target_error,
                   BlockDriverCompletionFunc *cb,
                   void *opaque, Error **errp)
 {
@@ -230,9 +258,13 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target,
         return;
     }
 
+    s->on_source_error = on_source_error;
+    s->on_target_error = on_target_error;
     s->target = target;
     s->mode = mode;
     bdrv_set_dirty_tracking(bs, true);
+    bdrv_set_on_error(s->target, on_target_error, on_target_error);
+    bdrv_iostatus_enable(s->target);
     s->common.co = qemu_coroutine_create(mirror_run);
     trace_mirror_start(bs, s, s->common.co, opaque);
     qemu_coroutine_enter(s->common.co, s);
diff --git a/block_int.h b/block_int.h
index d7e1928..599eb37 100644
--- a/block_int.h
+++ b/block_int.h
@@ -312,6 +312,8 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base,
  * @target: Block device to write to.
  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
  * @mode: Whether to collapse all images in the chain to the target.
+ * @on_source_error: The action to take upon error reading from the source.
+ * @on_target_error: The action to take upon error writing to the target.
  * @cb: Completion function for the job.
  * @opaque: Opaque pointer value passed to @cb.
  * @errp: Error object.
@@ -323,6 +325,8 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base,
  */
 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
                   int64_t speed, MirrorSyncMode mode,
+                  BlockdevOnError on_source_error,
+                  BlockdevOnError on_target_error,
                   BlockDriverCompletionFunc *cb,
                   void *opaque, Error **errp);
 
diff --git a/blockdev.c b/blockdev.c
index 29ecadc..4000d16 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -835,7 +835,10 @@ void qmp_drive_mirror(const char *device, const char *target,
                       bool has_format, const char *format,
                       enum MirrorSyncMode sync,
                       bool has_mode, enum NewImageMode mode,
-                      bool has_speed, int64_t speed, Error **errp)
+                      bool has_speed, int64_t speed,
+                      bool has_on_source_error, BlockdevOnError on_source_error,
+                      bool has_on_target_error, BlockdevOnError on_target_error,
+                      Error **errp)
 {
     BlockDriverState *bs;
     BlockDriverState *source, *target_bs;
@@ -846,6 +849,12 @@ void qmp_drive_mirror(const char *device, const char *target,
     uint64_t size;
     int ret;
 
+    if (!has_on_source_error) {
+        on_source_error = BLOCKDEV_ON_ERROR_REPORT;
+    }
+    if (!has_on_target_error) {
+        on_target_error = BLOCKDEV_ON_ERROR_REPORT;
+    }
     if (!has_mode) {
         mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
     }
@@ -929,7 +938,8 @@ void qmp_drive_mirror(const char *device, const char *target,
         return;
     }
 
-    mirror_start(bs, target_bs, speed, sync, block_job_cb, bs, &local_err);
+    mirror_start(bs, target_bs, speed, sync, on_source_error, on_target_error,
+                 block_job_cb, bs, &local_err);
     if (local_err != NULL) {
         bdrv_delete(target_bs);
         error_propagate(errp, local_err);
diff --git a/hmp.c b/hmp.c
index 2dfc477..ce0d040 100644
--- a/hmp.c
+++ b/hmp.c
@@ -717,7 +717,8 @@ void hmp_drive_mirror(Monitor *mon, const QDict *qdict)
 
     qmp_drive_mirror(device, filename, !!format, format,
                      full ? MIRROR_SYNC_MODE_FULL : MIRROR_SYNC_MODE_TOP,
-                     true, mode, false, 0, &errp);
+                     true, mode, false, 0,
+                     false, 0, false, 0, &errp);
     hmp_handle_error(mon, &errp);
 }
 
diff --git a/qapi-schema.json b/qapi-schema.json
index 7b619e9..2ee988b 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1379,6 +1379,10 @@
 #        (all the disk, only the sectors allocated in the topmost image, or
 #        only new I/O).
 #
+# @on_source_error: #optional the action to take on an error on the source
+#
+# @on_target_error: #optional the action to take on an error on the target
+#
 # Returns: nothing on success
 #          If @device is not a valid block device, DeviceNotFound
 #          If @target can't be opened, OpenFileFailed
@@ -1389,7 +1393,8 @@
 { 'command': 'drive-mirror',
   'data': { 'device': 'str', 'target': 'str', '*format': 'str',
             'sync': 'MirrorSyncMode', '*mode': 'NewImageMode',
-            '*speed': 'int' } }
+            '*speed': 'int', '*on_source_error': 'BlockdevOnError',
+            '*on_target_error': 'BlockdevOnError' } }
 
 ##
 # @migrate_cancel
diff --git a/qmp-commands.hx b/qmp-commands.hx
index cccea2f..aff1660 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -833,7 +833,8 @@ EQMP
 
     {
         .name       = "drive-mirror",
-        .args_type  = "sync:s,device:B,target:s,sync:s?,format:s?",
+        .args_type  = "sync:s,device:B,target:s,sync:s?,format:s?,"
+                      "on_source_error:s?,on_target_error:s?",
         .mhandler.cmd_new = qmp_marshal_input_drive_mirror,
     },
 
@@ -860,6 +861,11 @@ Arguments:
   possibilities include "full" for all the disk, "top" for only the sectors
   allocated in the topmost image, or "none" to only replicate new I/O
   (MirrorSyncMode).
+- "on_source_error": the action to take on an error on the source
+  (BlockdevOnError)
+- "on_target_error": the action to take on an error on the target
+  (BlockdevOnError)
+
 
 
 Example:
-- 
1.7.10.2