From 608c35120c7e8026232a2c2b7083648fca20144d Mon Sep 17 00:00:00 2001

From: John Snow <jsnow@redhat.com>

Date: Wed, 27 Mar 2019 17:22:33 +0100

Subject: [PATCH 094/163] qemu-nbd: Add --bitmap=NAME option

RH-Author: John Snow <jsnow@redhat.com>

Message-id: <20190327172308.31077-21-jsnow@redhat.com>

Patchwork-id: 85200

O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH 20/55] qemu-nbd: Add --bitmap=NAME option

Bugzilla: 1691009

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Max Reitz <mreitz@redhat.com>

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: Eric Blake <eblake@redhat.com>

Having to fire up qemu, then use QMP commands for nbd-server-start

and nbd-server-add, just to expose a persistent dirty bitmap, is

rather tedious.  Make it possible to expose a dirty bitmap using

just qemu-nbd (of course, for now this only works when qemu-nbd is

visiting a BDS formatted as qcow2).

Of course, any good feature also needs unit testing, so expand

iotest 223 to cover it.

Signed-off-by: Eric Blake <eblake@redhat.com>

Message-Id: <20190111194720.15671-9-eblake@redhat.com>

(cherry picked from commit 636192c4b6052820ea126a5287c58a8f53f3c84f)

Signed-off-by: John Snow <jsnow@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 qemu-nbd.c                 | 10 ++++++++--

 qemu-nbd.texi              |  4 ++++

 tests/qemu-iotests/223     | 18 +++++++++++++++++-

 tests/qemu-iotests/223.out | 12 +++++++++++-

 4 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/qemu-nbd.c b/qemu-nbd.c

index ac4c958..0c92f62 100644

--- a/qemu-nbd.c

+++ b/qemu-nbd.c

@@ -95,6 +95,7 @@ static void usage(const char *name)

 "Exposing part of the image:\n"

 "  -o, --offset=OFFSET       offset into the image\n"

 "  -P, --partition=NUM       only expose partition NUM\n"

+"  -B, --bitmap=NAME         expose a persistent dirty bitmap\n"

 "\n"

 "General purpose options:\n"

 "  --object type,id=ID,...   define an object such as 'secret' for providing\n"

@@ -509,7 +510,7 @@ int main(int argc, char **argv)

     off_t fd_size;

     QemuOpts *sn_opts = NULL;

     const char *sn_id_or_name = NULL;

-    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:";

+    const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:";

     struct option lopt[] = {

         { "help", no_argument, NULL, 'h' },

         { "version", no_argument, NULL, 'V' },

@@ -519,6 +520,7 @@ int main(int argc, char **argv)

         { "offset", required_argument, NULL, 'o' },

         { "read-only", no_argument, NULL, 'r' },

         { "partition", required_argument, NULL, 'P' },

+        { "bitmap", required_argument, NULL, 'B' },

         { "connect", required_argument, NULL, 'c' },

         { "disconnect", no_argument, NULL, 'd' },

         { "snapshot", no_argument, NULL, 's' },

@@ -558,6 +560,7 @@ int main(int argc, char **argv)

     QDict *options = NULL;

     const char *export_name = ""; /* Default export name */

     const char *export_description = NULL;

+    const char *bitmap = NULL;

     const char *tlscredsid = NULL;

     bool imageOpts = false;

     bool writethrough = true;

@@ -695,6 +698,9 @@ int main(int argc, char **argv)

                 exit(EXIT_FAILURE);

             }

             break;

+        case 'B':

+            bitmap = optarg;

+            break;

         case 'k':

             sockpath = optarg;

             if (sockpath[0] != '/') {

@@ -1018,7 +1024,7 @@ int main(int argc, char **argv)

     }

     export = nbd_export_new(bs, dev_offset, fd_size, export_name,

-                            export_description, NULL, nbdflags,

+                            export_description, bitmap, nbdflags,

                             nbd_export_closed, writethrough, NULL,

                             &error_fatal);

diff --git a/qemu-nbd.texi b/qemu-nbd.texi

index 9a84e81..96b1546 100644

--- a/qemu-nbd.texi

+++ b/qemu-nbd.texi

@@ -45,6 +45,10 @@ auto-detecting

 Export the disk as read-only

 @item -P, --partition=@var{num}

 Only expose partition @var{num}

+@item -B, --bitmap=@var{name}

+If @var{filename} has a qcow2 persistent bitmap @var{name}, expose

+that bitmap via the ``qemu:dirty-bitmap:@var{name}'' context

+accessible through NBD_OPT_SET_META_CONTEXT.

 @item -s, --snapshot

 Use @var{filename} as an external snapshot, create a temporary

 file with backing_file=@var{filename}, redirect the write to

diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223

index 0bcc98a..773892d 100755

--- a/tests/qemu-iotests/223

+++ b/tests/qemu-iotests/223

@@ -25,6 +25,7 @@ status=1 # failure is the default!

 _cleanup()

 {

+    nbd_server_stop

     _cleanup_test_img

     _cleanup_qemu

     rm -f "$TEST_DIR/nbd"

@@ -35,6 +36,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15

 . ./common.rc

 . ./common.filter

 . ./common.qemu

+. ./common.nbd

 _supported_fmt qcow2

 _supported_proto file # uses NBD as well

@@ -163,7 +165,7 @@ $QEMU_IMG map --output=json --image-opts \

   "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b2" | _filter_qemu_img_map

 echo

-echo "=== End NBD server ==="

+echo "=== End qemu NBD server ==="

 echo

 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-remove",

@@ -176,6 +178,20 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "return"

 _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-stop"}' "error" # Again

 _send_qemu_cmd $QEMU_HANDLE '{"execute":"quit"}' "return"

+echo

+echo "=== Use qemu-nbd as server ==="

+echo

+

+nbd_server_start_unix_socket -r -f $IMGFMT -B b "$TEST_IMG"

+IMG="driver=nbd,server.type=unix,server.path=$nbd_unix_socket"

+$QEMU_IMG map --output=json --image-opts \

+  "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b" | _filter_qemu_img_map

+

+nbd_server_start_unix_socket -f $IMGFMT -B b2 "$TEST_IMG"

+IMG="driver=nbd,server.type=unix,server.path=$nbd_unix_socket"

+$QEMU_IMG map --output=json --image-opts \

+  "$IMG,x-dirty-bitmap=qemu:dirty-bitmap:b2" | _filter_qemu_img_map

+

 # success, all done

 echo '*** done'

 rm -f $seq.full

diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out

index a0c2dec..4012bb0 100644

--- a/tests/qemu-iotests/223.out

+++ b/tests/qemu-iotests/223.out

@@ -61,7 +61,7 @@ read 2097152/2097152 bytes at offset 2097152

 { "start": 1024, "length": 2096128, "depth": 0, "zero": false, "data": true},

 { "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]

-=== End NBD server ===

+=== End qemu NBD server ===

 {"return": {}}

 {"return": {}}

@@ -69,4 +69,14 @@ read 2097152/2097152 bytes at offset 2097152

 {"return": {}}

 {"error": {"class": "GenericError", "desc": "NBD server not running"}}

 {"return": {}}

+

+=== Use qemu-nbd as server ===

+

+[{ "start": 0, "length": 65536, "depth": 0, "zero": false, "data": false},

+{ "start": 65536, "length": 2031616, "depth": 0, "zero": false, "data": true},

+{ "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]

+[{ "start": 0, "length": 512, "depth": 0, "zero": false, "data": true},

+{ "start": 512, "length": 512, "depth": 0, "zero": false, "data": false},

+{ "start": 1024, "length": 2096128, "depth": 0, "zero": false, "data": true},

+{ "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]

 *** done

-- 

1.8.3.1