commit c29c1dd312f39ec18a3c6177c6da09a75e095d70
author Fam Zheng <famz@redhat.com> Thu Dec 18 18:37:05 2014 +0800
committer Stefan Hajnoczi <stefanha@redhat.com> Tue Jan 13 11:47:56 2015 +0000
tree 8be81941bacdac122ab360b1f6c9486add1e8ef9
parent b7b9d39a7a5bd3a7fe5968b7780c9868c3210a4d

qmp: Add command 'blockdev-backup'

Similar to drive-backup, but this command uses a device id as target
instead of creating/opening an image file.

Also add blocker on target bs, since the target is also a named device
now.

Add check and report error for bs == target which became possible but is
an illegal case with introduction of blockdev-backup.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1418899027-8445-3-git-send-email-famz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

block/backup.c

diff --git a/block/backup.c b/block/backup.c
index 792e655..1c535b1 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -360,6 +360,7 @@
     hbitmap_free(job->bitmap);
 
     bdrv_iostatus_disable(target);
+    bdrv_op_unblock_all(target, job->common.blocker);
 
     data = g_malloc(sizeof(*data));
     data->ret = ret;
@@ -379,6 +380,11 @@
     assert(target);
     assert(cb);
 
+    if (bs == target) {
+        error_setg(errp, "Source and target cannot be the same");
+        return;
+    }
+
     if ((on_source_error == BLOCKDEV_ON_ERROR_STOP ||
          on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
         !bdrv_iostatus_is_enabled(bs)) {
@@ -386,6 +392,26 @@
         return;
     }
 
+    if (!bdrv_is_inserted(bs)) {
+        error_setg(errp, "Device is not inserted: %s",
+                   bdrv_get_device_name(bs));
+        return;
+    }
+
+    if (!bdrv_is_inserted(target)) {
+        error_setg(errp, "Device is not inserted: %s",
+                   bdrv_get_device_name(target));
+        return;
+    }
+
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
+        return;
+    }
+
+    if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_BACKUP_TARGET, errp)) {
+        return;
+    }
+
     len = bdrv_getlength(bs);
     if (len < 0) {
         error_setg_errno(errp, -len, "unable to get length for '%s'",
@@ -399,6 +425,8 @@
         return;
     }
 
+    bdrv_op_block_all(target, job->common.blocker);
+
     job->on_source_error = on_source_error;
     job->on_target_error = on_target_error;
     job->target = target;