[Qemu-devel] [PATCH 0/2] Forbid adding children to a Quorum in blkverify mode

[Qemu-devel] [PATCH 0/2] Forbid adding children to a Quorum in blkverify mode

[Alberto Garcia]

Hi,

as pointed out by Kevin, the Quorum driver should not allow adding new
children when running in blkverify mode.

This series fixes that and also adds a couple of basic iotests for the
x-blockdev-change QMP command.

Berto

Alberto Garcia (2):
  quorum: Forbid adding children in blkverify mode
  iotest: Test x-blockdev-change on a Quorum

 block/quorum.c             |  8 +++++
 tests/qemu-iotests/081     | 86 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/081.out | 54 +++++++++++++++++++++++++++++
 3 files changed, 148 insertions(+)

-- 
2.11.0

[Qemu-devel] [PATCH 1/2] quorum: Forbid adding children in blkverify mode

[Alberto Garcia]

The blkverify mode of Quorum only works when the number of children is
exactly two, so any attempt to add a new one must return an error.

quorum_del_child() on the other hand doesn't need any additional check
because decreasing the number of children would make it go under the
vote threshold.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reported-by: Kevin Wolf <kwolf@redhat.com>
---
 block/quorum.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/block/quorum.c b/block/quorum.c
index 6188ff6666..16b3c8067c 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -992,6 +992,11 @@ static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs,
     char indexstr[32];
     int ret;
 
+    if (s->is_blkverify) {
+        error_setg(errp, "Cannot add a child to a quorum in blkverify mode");
+        return;
+    }
+
     assert(s->num_children <= INT_MAX / sizeof(BdrvChild *));
     if (s->num_children == INT_MAX / sizeof(BdrvChild *) ||
         s->next_child_index == UINT_MAX) {
@@ -1046,6 +1051,9 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child,
         return;
     }
 
+    /* We know now that num_children > threshold, so blkverify must be false */
+    assert(!s->is_blkverify);
+
     bdrv_drained_begin(bs);
 
     /* We can safely remove this child now */
-- 
2.11.0

[Qemu-devel] [PATCH 2/2] iotest: Test x-blockdev-change on a Quorum

[Alberto Garcia]

This patch tests that you can add and remove drives from a Quorum
using the x-blockdev-change command.

Signed-off-by: Alberto Garcia <berto@igalia.com>
---
 tests/qemu-iotests/081     | 86 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/081.out | 54 +++++++++++++++++++++++++++++
 2 files changed, 140 insertions(+)

diff --git a/tests/qemu-iotests/081 b/tests/qemu-iotests/081
index 0ea010afbf..7a441f9300 100755
--- a/tests/qemu-iotests/081
+++ b/tests/qemu-iotests/081
@@ -198,6 +198,92 @@ quorum="$quorum,file.children.2.driver=raw"
 
 $QEMU_IO -c "open -o $quorum" | _filter_qemu_io
 
+echo
+echo "== dinamically adding a child to a quorum =="
+
+for verify in false true; do
+    run_qemu <<EOF
+    { "execute": "qmp_capabilities" }
+    { "execute": "blockdev-add",
+        "arguments": {
+            "driver": "quorum",
+            "node-name": "drive0-quorum",
+            "vote-threshold": 2,
+            "blkverify": ${verify},
+            "children": [
+                {
+                    "driver": "$IMGFMT",
+                    "file": {
+                        "driver": "file",
+                        "filename": "$TEST_DIR/1.raw"
+                    }
+                },
+                {
+                    "driver": "$IMGFMT",
+                    "file": {
+                        "driver": "file",
+                        "filename": "$TEST_DIR/2.raw"
+                    }
+                }
+            ]
+        }
+    }
+    { "execute": "blockdev-add",
+        "arguments": {
+            "node-name": "drive3",
+            "driver": "$IMGFMT",
+            "file": {
+                "driver": "file",
+                "filename": "$TEST_DIR/2.raw"
+            }
+        }
+    }
+    { "execute": "x-blockdev-change",
+      "arguments": { "parent": "drive0-quorum",
+                     "node": "drive3" } }
+    { "execute": "quit" }
+EOF
+done
+
+echo
+echo "== dinamically removing a child from a quorum =="
+
+for verify in false true; do
+    for vote_threshold in 1 2; do
+        run_qemu <<EOF
+        { "execute": "qmp_capabilities" }
+        { "execute": "blockdev-add",
+            "arguments": {
+                "driver": "quorum",
+                "node-name": "drive0-quorum",
+                "vote-threshold": ${vote_threshold},
+                "blkverify": ${verify},
+                "children": [
+                    {
+                        "driver": "$IMGFMT",
+                        "file": {
+                            "driver": "file",
+                            "filename": "$TEST_DIR/1.raw"
+                        }
+                    },
+                    {
+                        "driver": "$IMGFMT",
+                        "file": {
+                            "driver": "file",
+                            "filename": "$TEST_DIR/2.raw"
+                        }
+                    }
+                ]
+            }
+        }
+        { "execute": "x-blockdev-change",
+          "arguments": { "parent": "drive0-quorum",
+                         "child": "children.1" } }
+        { "execute": "quit" }
+EOF
+    done
+done
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/081.out b/tests/qemu-iotests/081.out
index 2f12c890e9..909f3fba3b 100644
--- a/tests/qemu-iotests/081.out
+++ b/tests/qemu-iotests/081.out
@@ -71,4 +71,58 @@ read 10485760/10485760 bytes at offset 0
 
 == checking the blkverify mode with invalid settings ==
 can't open: blkverify=on can only be set if there are exactly two files and vote-threshold is 2
+
+== dinamically adding a child to a quorum ==
+Testing:
+QMP_VERSION
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}}
+
+Testing:
+QMP_VERSION
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"error": {"class": "GenericError", "desc": "Cannot add a child to a quorum in blkverify mode"}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}}
+
+
+== dinamically removing a child from a quorum ==
+Testing:
+QMP_VERSION
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}}
+
+Testing:
+QMP_VERSION
+{"return": {}}
+{"return": {}}
+{"error": {"class": "GenericError", "desc": "The number of children cannot be lower than the vote threshold 2"}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}}
+
+Testing:
+QMP_VERSION
+{"return": {}}
+{"error": {"class": "GenericError", "desc": "blkverify=on can only be set if there are exactly two files and vote-threshold is 2"}}
+{"error": {"class": "GenericError", "desc": "Cannot find device=drive0-quorum nor node_name=drive0-quorum"}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}}
+
+Testing:
+QMP_VERSION
+{"return": {}}
+{"return": {}}
+{"error": {"class": "GenericError", "desc": "The number of children cannot be lower than the vote threshold 2"}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false}}
+
 *** done
-- 
2.11.0

Re: [Qemu-devel] [PATCH 2/2] iotest: Test x-blockdev-change on a Quorum

[Kevin Wolf]

Am 18.10.2018 um 10:59 hat Alberto Garcia geschrieben:
> This patch tests that you can add and remove drives from a Quorum
> using the x-blockdev-change command.
> 
> Signed-off-by: Alberto Garcia <berto@igalia.com>

> --- a/tests/qemu-iotests/081
> +++ b/tests/qemu-iotests/081
> @@ -198,6 +198,92 @@ quorum="$quorum,file.children.2.driver=raw"
>  
>  $QEMU_IO -c "open -o $quorum" | _filter_qemu_io
>  
> +echo
> +echo "== dinamically adding a child to a quorum =="

s/dinamically/dynamically/ (and in three more instances)

Thanks, fixed the typo and applied the series to the block branch.

Kevin