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  1. 06 7月, 2016 2 次提交
    • E
      qapi: Add new visit_complete() function · 3b098d56
      由 Eric Blake 提交于 
      Making each output visitor provide its own output collection
function was the only remaining reason for exposing visitor
sub-types to the rest of the code base.  Add a polymorphic
visit_complete() function which is a no-op for input visitors,
and which populates an opaque pointer for output visitors.  For
maximum type-safety, also add a parameter to the output visitor
constructors with a type-correct version of the output pointer,
and assert that the two uses match.

This approach was considered superior to either passing the
output parameter only during construction (action at a distance
during visit_free() feels awkward) or only during visit_complete()
(defeating type safety makes it easier to use incorrectly).

Most callers were function-local, and therefore a mechanical
conversion; the testsuite was a bit trickier, but the previous
cleanup patch minimized the churn here.

The visit_complete() function may be called at most once; doing
so lets us use transfer semantics rather than duplication or
ref-count semantics to get the just-built output back to the
caller, even though it means our behavior is not idempotent.

Generated code is simplified as follows for events:

|@@ -26,7 +26,7 @@ void qapi_event_send_acpi_device_ost(ACP
|     QDict *qmp;
|     Error *err = NULL;
|     QMPEventFuncEmit emit;
|-    QmpOutputVisitor *qov;
|+    QObject *obj;
|     Visitor *v;
|     q_obj_ACPI_DEVICE_OST_arg param = {
|         info
|@@ -39,8 +39,7 @@ void qapi_event_send_acpi_device_ost(ACP
|
|     qmp = qmp_event_build_dict("ACPI_DEVICE_OST");
|
|-    qov = qmp_output_visitor_new();
|-    v = qmp_output_get_visitor(qov);
|+    v = qmp_output_visitor_new(&obj);
|
|     visit_start_struct(v, "ACPI_DEVICE_OST", NULL, 0, &err);
|     if (err) {
|@@ -55,7 +54,8 @@ void qapi_event_send_acpi_device_ost(ACP
|         goto out;
|     }
|
|-    qdict_put_obj(qmp, "data", qmp_output_get_qobject(qov));
|+    visit_complete(v, &obj);
|+    qdict_put_obj(qmp, "data", obj);
|     emit(QAPI_EVENT_ACPI_DEVICE_OST, qmp, &err);

and for commands:

| {
|     Error *err = NULL;
|-    QmpOutputVisitor *qov = qmp_output_visitor_new();
|     Visitor *v;
|
|-    v = qmp_output_get_visitor(qov);
|+    v = qmp_output_visitor_new(ret_out);
|     visit_type_AddfdInfo(v, "unused", &ret_in, &err);
|-    if (err) {
|-        goto out;
|+    if (!err) {
|+        visit_complete(v, ret_out);
|     }
|-    *ret_out = qmp_output_get_qobject(qov);
|-
|-out:
|     error_propagate(errp, err);
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-13-git-send-email-eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
      3b098d56
    • E
      qmp-output-visitor: Favor new visit_free() function · 1830f22a
      由 Eric Blake 提交于 
      Now that we have a polymorphic visit_free(), we no longer need
qmp_output_visitor_cleanup(); however, we still need to
expose the subtype for qmp_output_get_qobject().
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <1465490926-28625-10-git-send-email-eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
      1830f22a
  3. 20 6月, 2016 2 次提交
  5. 16 6月, 2016 3 次提交
    • M
      block/mirror: Fix target backing BDS · 274fccee
      由 Max Reitz 提交于 
      Currently, we are trying to move the backing BDS from the source to the
target in bdrv_replace_in_backing_chain() which is called from
mirror_exit(). However, mirror_complete() already tries to open the
target's backing chain with a call to bdrv_open_backing_file().

First, we should only set the target's backing BDS once. Second, the
mirroring block job has a better idea of what to set it to than the
generic code in bdrv_replace_in_backing_chain() (in fact, the latter's
conditions on when to move the backing BDS from source to target are not
really correct).

Therefore, remove that code from bdrv_replace_in_backing_chain() and
leave it to mirror_complete().

Depending on what kind of mirroring is performed, we furthermore want to
use different strategies to open the target's backing chain:

- If blockdev-mirror is used, we can assume the user made sure that the
  target already has the correct backing chain. In particular, we should
  not try to open a backing file if the target does not have any yet.

- If drive-mirror with mode=absolute-paths is used, we can and should
  reuse the already existing chain of nodes that the source BDS is in.
  In case of sync=full, no backing BDS is required; with sync=top, we
  just link the source's backing BDS to the target, and with sync=none,
  we use the source BDS as the target's backing BDS.
  We should not try to open these backing files anew because this would
  lead to two BDSs existing per physical file in the backing chain, and
  we would like to avoid such concurrent access.

- If drive-mirror with mode=existing is used, we have to use the
  information provided in the physical image file which means opening
  the target's backing chain completely anew, just as it has been done
  already.
  If the target's backing chain shares images with the source, this may
  lead to multiple BDSs per physical image file. But since we cannot
  reliably ascertain this case, there is nothing we can do about it.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-id: 20160610185750.30956-3-mreitz@redhat.com
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>
      274fccee
    • A
      block: use the block job list in qmp_query_block_jobs() · f0f55ded
      由 Alberto Garcia 提交于 
      qmp_query_block_jobs() uses bdrv_next() to look for block jobs, but
this function can only find those in top-level BlockDriverStates.

This patch uses block_job_next() instead.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Message-id: a8b7e5497b7c1fa67c12fcceae1630d01c3b1f96.1464346103.git.berto@igalia.com
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>
      f0f55ded
    • C
      blockdev: clarify error on attempt to open locked tray · 38a53d50
      由 Colin Lord 提交于 
      When opening a device with a locked tray, gives an error explaining the
device tray is locked and that the user should wait and try again. This
is less confusing than the previous error, which simply stated that the
tray was locked.
Signed-off-by: NColin Lord <clord@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      38a53d50
  7. 08 6月, 2016 1 次提交
  9. 07 6月, 2016 2 次提交
  11. 26 5月, 2016 6 次提交
  13. 19 5月, 2016 8 次提交
  15. 12 5月, 2016 2 次提交
  17. 05 4月, 2016 2 次提交
    • K
      block: Forbid I/O throttling on nodes with multiple parents for 2.6 · 76b22320
      由 Kevin Wolf 提交于 
      As the patches to move I/O throttling to BlockBackend didn't make it in
time for the 2.6 release, but the release adds new ways of configuring
VMs whose behaviour would change once the move is done, we need to
outlaw such configurations temporarily.

The problem exists whenever a BDS has more users than just its BB, for
example it is used as a backing file for another node. (This wasn't
possible in 2.5 yet as we introduced node references to specify a
backing file only recently.) In these cases, the throttling would
apply to these other users now, but after moving throttling to the
BlockBackend the other users wouldn't be throttled any more.

This patch prevents making new references to a throttled node as well as
using monitor commands to throttle a node with multiple parents.

Compared to 2.5 this changes behaviour in some corner cases where
references were allowed before, like bs->file or Quorum children. It
seems reasonable to assume that users didn't use I/O throttling on such
low level nodes. With the upcoming move of throttling into BlockBackend,
such configurations won't be possible anyway.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
      76b22320
    • P
      block: forbid x-blockdev-del from acting on DriveInfo · 5cf87fd6
      由 Paolo Bonzini 提交于 
      Failing on -drive/drive_add created BlockBackends was a
requirement for x-blockdev-del, but it sneaked through
the patch review.  Let's fix it now.

Example:

$ x86_64-softmmu/qemu-system-x86_64 -drive if=none,file=null-co://,id=null -qmp stdio
>> {'execute':'qmp_capabilities'}
<< {"return": {}}
>> {'execute':'x-blockdev-del','arguments':{'id':'null'}}
<< {"error": {"class": "GenericError", "desc": "Deleting block backend added with drive-add is not supported"}}

And without a DriveInfo:

>> { "execute": "blockdev-add", "arguments": { "options": { "driver":"null-co", "id":"null2"}}}
<< {"return": {}}
>> {'execute':'x-blockdev-del','arguments':{'id':'null2'}}
<< {"return": {}}
Suggested-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      5cf87fd6
  19. 30 3月, 2016 7 次提交
    • K
      block: Remove BDRV_O_CACHE_WB · 61de4c68
      由 Kevin Wolf 提交于 
      The previous patches have successively made blk->enable_write_cache the
true source for the information whether a writethrough mode must be
implemented. The corresponding BDRV_O_CACHE_WB is only useless baggage
we're carrying around, so now's the time to remove it.

At the same time, we remove the 'cache.writeback' option parsing on the
BDS level as the only effect was setting the BDRV_O_CACHE_WB flag.

This change requires test cases that explicitly enabled the option to
drop it. Other than that and the change of the error message when
writethrough is enabled on the BDS level (from "Can't set writethrough
mode" to "doesn't support the option"), there should be no change in
behaviour.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
      61de4c68
    • K
      block: Use bdrv_parse_cache_mode() in drive_init() · 04feb4a5
      由 Kevin Wolf 提交于 
      Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
      04feb4a5
    • K
      block: Always set writeback mode in blk_new_open() · 72e775c7
      由 Kevin Wolf 提交于 
      All callers of blk_new_open() either don't rely on the WCE bit set after
blk_new_open() because they explicitly set it anyway, or they pass
BDRV_O_CACHE_WB unconditionally.

This patch changes blk_new_open() so that it always enables writeback
mode and asserts that BDRV_O_CACHE_WB is clear. For those callers that
used to pass BDRV_O_CACHE_WB unconditionally, the flag is removed now.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
      72e775c7
    • K
      block: blockdev_init(): Call blk_set_enable_write_cache() explicitly · e4b24b49
      由 Kevin Wolf 提交于 
      Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
      e4b24b49
    • K
      block: Reject writethrough mode except at the root · 73ac451f
      由 Kevin Wolf 提交于 
      Writethrough mode is going to become a BlockBackend feature rather than
a BDS one, so forbid it in places where we won't be able to support it
when the code finally matches the envisioned design.

We only allowed setting the cache mode of non-root nodes after the 2.5
release, so we're still free to make this change.

The target of block jobs is now always opened in a writeback mode
because it doesn't have a BlockBackend attached. This makes more sense
anyway because block jobs know when to flush. If the graph is modified
on job completion, the original cache mode moves to the new root, so
for the guest device writethough always stays enabled if it was
configured this way.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
      73ac451f
    • K
      block: Remove copy-on-read from bdrv_move_feature_fields() · 4c844983
      由 Kevin Wolf 提交于 
      Ever since we first introduced bdrv_append() in commit 8802d1fd ('qapi:
Introduce blockdev-group-snapshot-sync command'), the copy-on-read flag
was moved to the new top layer when taking a snapshot. The only problem
is that it doesn't make a whole lot of sense.

The use case for manually enabled CoR is to avoid reading data twice
from a slow remote image, so we want to save it to a local overlay, say
an ISO image accessed via HTTP to a local qcow2 overlay. When taking a
snapshot, we end up with a backing chain like this:

    http <- local.qcow2 <- snap_overlay.qcow2

There is no point in doing CoR from local.qcow2 into snap_overlay.qcow2,
we just want to keep copying data from the remote source into
local.qcow2.

The other use case of CoR is in the context of streaming, which isn't
very interesting for bdrv_move_feature_fields() because op blockers
prevent this combination.

This patch makes the copy-on-read flag stay on the image for which it
was originally set and prevents it from being propagated to the new
overlay. It is no longer intended to move CoR to the BlockBackend level.
In order for this to make sense, we also need to keep the respective
image read-write.

As a side effect of these changes, creating a live snapshot image (as
opposed to using an existing externally created one) on top of a COR
block device works now. It used to fail because it tried to open its
backing file both read-only and with COR.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
      4c844983
    • K
      block: Remove bdrv_make_anon() · 63eaaae0
      由 Kevin Wolf 提交于 
      The call in hmp_drive_del() is dead code because blk_remove_bs() is
called a few lines above. The only other remaining user is
bdrv_delete(), which only abuses bdrv_make_anon() to remove it from the
named nodes list. This path inlines the list entry removal into
bdrv_delete() and removes bdrv_make_anon().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
      63eaaae0
  21. 23 3月, 2016 1 次提交
  23. 18 3月, 2016 1 次提交
    • E
      qapi: Don't special-case simple union wrappers · 32bafa8f
      由 Eric Blake 提交于 
      Simple unions were carrying a special case that hid their 'data'
QMP member from the resulting C struct, via the hack method
QAPISchemaObjectTypeVariant.simple_union_type().  But by using
the work we started by unboxing flat union and alternate
branches, coupled with the ability to visit the members of an
implicit type, we can now expose the simple union's implicit
type in qapi-types.h:

| struct q_obj_ImageInfoSpecificQCow2_wrapper {
|     ImageInfoSpecificQCow2 *data;
| };
|
| struct q_obj_ImageInfoSpecificVmdk_wrapper {
|     ImageInfoSpecificVmdk *data;
| };
...
| struct ImageInfoSpecific {
|     ImageInfoSpecificKind type;
|     union { /* union tag is @type */
|         void *data;
|-        ImageInfoSpecificQCow2 *qcow2;
|-        ImageInfoSpecificVmdk *vmdk;
|+        q_obj_ImageInfoSpecificQCow2_wrapper qcow2;
|+        q_obj_ImageInfoSpecificVmdk_wrapper vmdk;
|     } u;
| };

Doing this removes asymmetry between QAPI's QMP side and its
C side (both sides now expose 'data'), and means that the
treatment of a simple union as sugar for a flat union is now
equivalent in both languages (previously the two approaches used
a different layer of dereferencing, where the simple union could
be converted to a flat union with equivalent C layout but
different {} on the wire, or to an equivalent QMP wire form
but with different C representation).  Using the implicit type
also lets us get rid of the simple_union_type() hack.

Of course, now all clients of simple unions have to adjust from
using su->u.member to using su->u.member.data; while this touches
a number of files in the tree, some earlier cleanup patches
helped minimize the change to the initialization of a temporary
variable rather than every single member access.  The generated
qapi-visit.c code is also affected by the layout change:

|@@ -7393,10 +7393,10 @@ void visit_type_ImageInfoSpecific_member
|     }
|     switch (obj->type) {
|     case IMAGE_INFO_SPECIFIC_KIND_QCOW2:
|-        visit_type_ImageInfoSpecificQCow2(v, "data", &obj->u.qcow2, &err);
|+        visit_type_q_obj_ImageInfoSpecificQCow2_wrapper_members(v, &obj->u.qcow2, &err);
|         break;
|     case IMAGE_INFO_SPECIFIC_KIND_VMDK:
|-        visit_type_ImageInfoSpecificVmdk(v, "data", &obj->u.vmdk, &err);
|+        visit_type_q_obj_ImageInfoSpecificVmdk_wrapper_members(v, &obj->u.vmdk, &err);
|         break;
|     default:
|         abort();
Signed-off-by: NEric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-13-git-send-email-eblake@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
      32bafa8f
  25. 17 3月, 2016 3 次提交