[Qemu-devel] [PATCH v10 00/15] blockdev: BlockBackend and media

[Qemu-devel] [PATCH v10 00/15] blockdev: BlockBackend and media

[Max Reitz]

I'm sorry for having singlehandedly stalled the block pull request twice
now, and I sure hope everything is going to be fine this time.

v9 was missing a change to patch 13: While it did (probably?) fix
cocoa.m in patch 11 for patch 11, patch 13 changed the signature of the
function in question yet again, so with the whole series applied, it
still broke.

Just as v9, this series consists of the changed patch (patch 13) only.
The sole difference to v8/v9 is an added "false, 0," line in cocoa.m
(clang tells me that putting plain integers into enums is fine in Obj-C
(unlike in C++), so I hope it works).

“Third time's the charm”, that's what they say.


git-backport-diff against v9:

Key:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream
patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences,
respectively

001/15:[----] [--] 'block: Add blk_remove_bs()'
002/15:[----] [--] 'block: Make bdrv_states public'
003/15:[----] [--] 'block: Add functions for inheriting a BBRS'
004/15:[----] [--] 'blockdev: Add blockdev-open-tray'
005/15:[----] [--] 'blockdev: Add blockdev-close-tray'
006/15:[----] [--] 'blockdev: Add blockdev-remove-medium'
007/15:[----] [--] 'blockdev: Add blockdev-insert-medium'
008/15:[----] [--] 'blockdev: Implement eject with basic operations'
009/15:[----] [--] 'blockdev: Implement change with basic operations'
010/15:[----] [--] 'block: Inquire tray state before tray-moved events'
011/15:[----] [--] 'qmp: Introduce blockdev-change-medium'
012/15:[----] [--] 'hmp: Use blockdev-change-medium for change command'
013/15:[0001] [FC] 'blockdev: read-only-mode for blockdev-change-medium'
014/15:[----] [--] 'hmp: Add read-only-mode option to change command'
015/15:[----] [--] 'iotests: Add test for change-related QMP commands'


Max Reitz (15):
  block: Add blk_remove_bs()
  block: Make bdrv_states public
  block: Add functions for inheriting a BBRS
  blockdev: Add blockdev-open-tray
  blockdev: Add blockdev-close-tray
  blockdev: Add blockdev-remove-medium
  blockdev: Add blockdev-insert-medium
  blockdev: Implement eject with basic operations
  blockdev: Implement change with basic operations
  block: Inquire tray state before tray-moved events
  qmp: Introduce blockdev-change-medium
  hmp: Use blockdev-change-medium for change command
  blockdev: read-only-mode for blockdev-change-medium
  hmp: Add read-only-mode option to change command
  iotests: Add test for change-related QMP commands

 block.c                        |   3 +-
 block/block-backend.c          |  56 +++-
 blockdev.c                     | 286 ++++++++++++----
 hmp-commands.hx                |  20 +-
 hmp.c                          |  47 ++-
 include/block/block_int.h      |   2 +
 include/sysemu/block-backend.h |   3 +
 include/sysemu/blockdev.h      |   2 -
 qapi-schema.json               |   6 +-
 qapi/block-core.json           | 126 ++++++++
 qmp-commands.hx                | 218 +++++++++++++
 qmp.c                          |   3 +-
 tests/qemu-iotests/118         | 720 +++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/118.out     |   5 +
 tests/qemu-iotests/group       |   1 +
 ui/cocoa.m                     |  11 +-
 16 files changed, 1403 insertions(+), 106 deletions(-)
 create mode 100755 tests/qemu-iotests/118
 create mode 100644 tests/qemu-iotests/118.out

-- 
2.6.2

[Qemu-devel] [PATCH v10 13/15] blockdev: read-only-mode for blockdev-change-medium

[Max Reitz]

Add an option to qmp_blockdev_change_medium() which allows changing the
read-only status of the block device whose medium is changed.

Some drives do not have a inherently fixed read-only status; for
instance, floppy disks can be set read-only or writable independently of
the drive. Some users may find it useful to be able to therefore change
the read-only status of a block device when changing the medium.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 blockdev.c           | 22 ++++++++++++++++++++++
 hmp.c                |  2 +-
 qapi/block-core.json | 24 +++++++++++++++++++++++-
 qmp-commands.hx      | 24 +++++++++++++++++++++++-
 qmp.c                |  3 ++-
 ui/cocoa.m           |  1 +
 6 files changed, 72 insertions(+), 4 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index b3a958c..34f6e5b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2145,6 +2145,8 @@ void qmp_blockdev_insert_medium(const char *device, const char *node_name,
 
 void qmp_blockdev_change_medium(const char *device, const char *filename,
                                 bool has_format, const char *format,
+                                bool has_read_only,
+                                BlockdevChangeReadOnlyMode read_only,
                                 Error **errp)
 {
     BlockBackend *blk;
@@ -2166,6 +2168,26 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
 
     bdrv_flags = blk_get_open_flags_from_root_state(blk);
 
+    if (!has_read_only) {
+        read_only = BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN;
+    }
+
+    switch (read_only) {
+    case BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN:
+        break;
+
+    case BLOCKDEV_CHANGE_READ_ONLY_MODE_READ_ONLY:
+        bdrv_flags &= ~BDRV_O_RDWR;
+        break;
+
+    case BLOCKDEV_CHANGE_READ_ONLY_MODE_READ_WRITE:
+        bdrv_flags |= BDRV_O_RDWR;
+        break;
+
+    default:
+        abort();
+    }
+
     if (has_format) {
         options = qdict_new();
         qdict_put(options, "driver", qstring_from_str(format));
diff --git a/hmp.c b/hmp.c
index e5ad944..16006aa 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1355,7 +1355,7 @@ void hmp_change(Monitor *mon, const QDict *qdict)
         }
         qmp_change("vnc", target, !!arg, arg, &err);
     } else {
-        qmp_blockdev_change_medium(device, target, !!arg, arg, &err);
+        qmp_blockdev_change_medium(device, target, !!arg, arg, false, 0, &err);
         if (err &&
             error_get_class(err) == ERROR_CLASS_DEVICE_ENCRYPTED) {
             error_free(err);
diff --git a/qapi/block-core.json b/qapi/block-core.json
index e9fa649..fa08ba9 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1959,6 +1959,24 @@
 
 
 ##
+# @BlockdevChangeReadOnlyMode:
+#
+# Specifies the new read-only mode of a block device subject to the
+# @blockdev-change-medium command.
+#
+# @retain:      Retains the current read-only mode
+#
+# @read-only:   Makes the device read-only
+#
+# @read-write:  Makes the device writable
+#
+# Since: 2.3
+##
+{ 'enum': 'BlockdevChangeReadOnlyMode',
+  'data': ['retain', 'read-only', 'read-write'] }
+
+
+##
 # @blockdev-change-medium:
 #
 # Changes the medium inserted into a block device by ejecting the current medium
@@ -1973,12 +1991,16 @@
 # @format:          #optional, format to open the new image with (defaults to
 #                   the probed format)
 #
+# @read-only-mode:  #optional, change the read-only mode of the device; defaults
+#                   to 'retain'
+#
 # Since: 2.5
 ##
 { 'command': 'blockdev-change-medium',
   'data': { 'device': 'str',
             'filename': 'str',
-            '*format': 'str' } }
+            '*format': 'str',
+            '*read-only-mode': 'BlockdevChangeReadOnlyMode' } }
 
 
 ##
diff --git a/qmp-commands.hx b/qmp-commands.hx
index f6d9c25..39d6e25 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4183,7 +4183,7 @@ EQMP
 
     {
         .name       = "blockdev-change-medium",
-        .args_type  = "device:B,filename:F,format:s?",
+        .args_type  = "device:B,filename:F,format:s?,read-only-mode:s?",
         .mhandler.cmd_new = qmp_marshal_blockdev_change_medium,
     },
 
@@ -4199,6 +4199,8 @@ Arguments:
 - "device": device name (json-string)
 - "filename": filename of the new image (json-string)
 - "format": format of the new image (json-string, optional)
+- "read-only-mode": new read-only mode (json-string, optional)
+          - Possible values: "retain" (default), "read-only", "read-write"
 
 Examples:
 
@@ -4210,6 +4212,26 @@ Examples:
                             "format": "raw" } }
 <- { "return": {} }
 
+2. Load a read-only medium into a writable drive
+
+-> { "execute": "blockdev-change-medium",
+             "arguments": { "device": "isa-fd0",
+                            "filename": "/srv/images/ro.img",
+                            "format": "raw",
+                            "read-only-mode": "retain" } }
+
+<- { "error":
+     { "class": "GenericError",
+       "desc": "Could not open '/srv/images/ro.img': Permission denied" } }
+
+-> { "execute": "blockdev-change-medium",
+             "arguments": { "device": "isa-fd0",
+                            "filename": "/srv/images/ro.img",
+                            "format": "raw",
+                            "read-only-mode": "read-only" } }
+
+<- { "return": {} }
+
 EQMP
 
     {
diff --git a/qmp.c b/qmp.c
index 4e44f98..ddc63ea 100644
--- a/qmp.c
+++ b/qmp.c
@@ -414,7 +414,8 @@ void qmp_change(const char *device, const char *target,
     if (strcmp(device, "vnc") == 0) {
         qmp_change_vnc(target, has_arg, arg, errp);
     } else {
-        qmp_blockdev_change_medium(device, target, has_arg, arg, errp);
+        qmp_blockdev_change_medium(device, target, has_arg, arg, false, 0,
+                                   errp);
     }
 }
 
diff --git a/ui/cocoa.m b/ui/cocoa.m
index 2d8e4e2..1554331 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -1118,6 +1118,7 @@ QemuCocoaView *cocoaView;
                                    [file cStringUsingEncoding:
                                          NSASCIIStringEncoding],
                                    true, "raw",
+                                   false, 0,
                                    &err);
         handleAnyDeviceErrors(err);
     }
-- 
2.6.2