[Qemu-devel] [PULL 0/4] Block layer patches for 2.6

[Qemu-devel] [PULL 0/4] Block layer patches for 2.6

[Kevin Wolf]

The following changes since commit 2e3a76ae3e47d502f9f0c4424b719945fba9d459:

  Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20160404' into staging (2016-04-04 17:43:39 +0100)

are available in the git repository at:


  git://repo.or.cz/qemu/kevin.git tags/for-upstream

for you to fetch changes up to 6a5c357fdbd4c91c5142f1b7ccf4658664b52ea2:

  Merge remote-tracking branch 'mreitz/tags/pull-block-for-kevin-2016-04-05' into queue-block (2016-04-05 17:31:20 +0200)

----------------------------------------------------------------

Block layer patches for 2.6

----------------------------------------------------------------
Eric Blake (1):
      crypto: Avoid memory leak on failure

Fam Zheng (1):
      qemu-iotests: 149: Use "/usr/bin/env python"

Kevin Wolf (2):
      block: Forbid I/O throttling on nodes with multiple parents for 2.6
      Merge remote-tracking branch 'mreitz/tags/pull-block-for-kevin-2016-04-05' into queue-block

Paolo Bonzini (1):
      block: forbid x-blockdev-del from acting on DriveInfo

 block.c                |  7 +++++++
 block/crypto.c         | 12 ++++++------
 blockdev.c             | 12 ++++++++++++
 tests/qemu-iotests/149 |  2 +-
 4 files changed, 26 insertions(+), 7 deletions(-)

[Qemu-devel] [PULL 1/4] block: forbid x-blockdev-del from acting on DriveInfo

[Kevin Wolf]

From: Paolo Bonzini <pbonzini@redhat.com>

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: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index e50e8ea..332068a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -4027,6 +4027,11 @@ void qmp_x_blockdev_del(bool has_id, const char *id,
             error_setg(errp, "Cannot find block backend %s", id);
             return;
         }
+        if (blk_legacy_dinfo(blk)) {
+            error_setg(errp, "Deleting block backend added with drive-add"
+                       " is not supported");
+            return;
+        }
         if (blk_get_refcnt(blk) > 1) {
             error_setg(errp, "Block backend %s is in use", id);
             return;
-- 
1.8.3.1

[Qemu-devel] [PULL 2/4] block: Forbid I/O throttling on nodes with multiple parents for 2.6

[Kevin Wolf]

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: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block.c    | 7 +++++++
 blockdev.c | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/block.c b/block.c
index d36eb75..d4939b4 100644
--- a/block.c
+++ b/block.c
@@ -1526,6 +1526,13 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename,
         if (!bs) {
             return -ENODEV;
         }
+
+        if (bs->throttle_state) {
+            error_setg(errp, "Cannot reference an existing block device for "
+                       "which I/O throttling is enabled");
+            return -EINVAL;
+        }
+
         bdrv_ref(bs);
         *pbs = bs;
         return 0;
diff --git a/blockdev.c b/blockdev.c
index 332068a..f1f520a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2661,6 +2661,13 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
         goto out;
     }
 
+    /* The BlockBackend must be the only parent */
+    assert(QLIST_FIRST(&bs->parents));
+    if (QLIST_NEXT(QLIST_FIRST(&bs->parents), next_parent)) {
+        error_setg(errp, "Cannot throttle device with multiple parents");
+        goto out;
+    }
+
     throttle_config_init(&cfg);
     cfg.buckets[THROTTLE_BPS_TOTAL].avg = bps;
     cfg.buckets[THROTTLE_BPS_READ].avg  = bps_rd;
-- 
1.8.3.1

[Qemu-devel] [PULL 3/4] qemu-iotests: 149: Use "/usr/bin/env python"

[Kevin Wolf]

From: Fam Zheng <famz@redhat.com>

Do the same as other scripts, to pick the correct interpreter between
python2 and python3 from the environment.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1459504593-2692-1-git-send-email-famz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/149 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/qemu-iotests/149 b/tests/qemu-iotests/149
index bb5811d..52e23d2 100755
--- a/tests/qemu-iotests/149
+++ b/tests/qemu-iotests/149
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 #
 # Copyright (C) 2016 Red Hat, Inc.
 #
-- 
1.8.3.1

[Qemu-devel] [PULL 4/4] crypto: Avoid memory leak on failure

[Kevin Wolf]

From: Eric Blake <eblake@redhat.com>

Commit 7836857 introduced a memory leak due to invalid use of
Error vs. visit_type_end().  If visiting the intermediate
members fails, we clear the error and unconditionally use
visit_end_struct() on the same error object; but if that
cleanup succeeds, we then skip the qapi_free call.

Until a later patch adds visit_check_struct(), the only safe
approach is to use two separate error objects.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1459526222-30052-1-git-send-email-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/crypto.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/block/crypto.c b/block/crypto.c
index be34985..1903e84 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -196,6 +196,7 @@ block_crypto_open_opts_init(QCryptoBlockFormat format,
     OptsVisitor *ov;
     QCryptoBlockOpenOptions *ret = NULL;
     Error *local_err = NULL;
+    Error *end_err = NULL;
 
     ret = g_new0(QCryptoBlockOpenOptions, 1);
     ret->format = format;
@@ -218,10 +219,9 @@ block_crypto_open_opts_init(QCryptoBlockFormat format,
         error_setg(&local_err, "Unsupported block format %d", format);
         break;
     }
-    error_propagate(errp, local_err);
-    local_err = NULL;
 
-    visit_end_struct(opts_get_visitor(ov), &local_err);
+    visit_end_struct(opts_get_visitor(ov), &end_err);
+    error_propagate(&local_err, end_err);
 
  out:
     if (local_err) {
@@ -242,6 +242,7 @@ block_crypto_create_opts_init(QCryptoBlockFormat format,
     OptsVisitor *ov;
     QCryptoBlockCreateOptions *ret = NULL;
     Error *local_err = NULL;
+    Error *end_err = NULL;
 
     ret = g_new0(QCryptoBlockCreateOptions, 1);
     ret->format = format;
@@ -264,10 +265,9 @@ block_crypto_create_opts_init(QCryptoBlockFormat format,
         error_setg(&local_err, "Unsupported block format %d", format);
         break;
     }
-    error_propagate(errp, local_err);
-    local_err = NULL;
 
-    visit_end_struct(opts_get_visitor(ov), &local_err);
+    visit_end_struct(opts_get_visitor(ov), &end_err);
+    error_propagate(&local_err, end_err);
 
  out:
     if (local_err) {
-- 
1.8.3.1

Re: [Qemu-devel] [PULL 0/4] Block layer patches for 2.6

[Peter Maydell]

On 5 April 2016 at 16:41, Kevin Wolf <kwolf@redhat.com> wrote:
> The following changes since commit 2e3a76ae3e47d502f9f0c4424b719945fba9d459:
>
>   Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20160404' into staging (2016-04-04 17:43:39 +0100)
>
> are available in the git repository at:
>
>
>   git://repo.or.cz/qemu/kevin.git tags/for-upstream
>
> for you to fetch changes up to 6a5c357fdbd4c91c5142f1b7ccf4658664b52ea2:
>
>   Merge remote-tracking branch 'mreitz/tags/pull-block-for-kevin-2016-04-05' into queue-block (2016-04-05 17:31:20 +0200)
>
> ----------------------------------------------------------------
>
> Block layer patches for 2.6
>
> ----------------------------------------------------------------

Applied, thanks.

-- PMM