Re: [Qemu-devel] [RFC V8 03/13] quorum: Add quorum_aio_writev and its dependencies.

2013-09-30 Thread Benoît Canet 
Le Friday 27 Sep 2013 à 12:03:07 (+0200), Kevin Wolf a écrit :
 Am 26.09.2013 um 18:29 hat Benoît Canet geschrieben:
  Le Friday 08 Feb 2013 à 11:38:38 (+0100), Kevin Wolf a écrit :
   Am 28.01.2013 18:07, schrieb Benoît Canet:
Signed-off-by: Benoit Canet ben...@irqsave.net
---
 block/quorum.c |  111 

 1 file changed, 111 insertions(+)

diff --git a/block/quorum.c b/block/quorum.c
index d8fffbe..5d8470b 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -52,11 +52,122 @@ struct QuorumAIOCB {
 int vote_ret;
 };
 
+static void quorum_aio_cancel(BlockDriverAIOCB *blockacb)
+{
+QuorumAIOCB *acb = container_of(blockacb, QuorumAIOCB, common);
+bool finished = false;
+
+/* Wait for the request to finish */
+acb-finished = finished;
+while (!finished) {
+qemu_aio_wait();
+}
+}
+
+static AIOCBInfo quorum_aiocb_info = {
+.aiocb_size = sizeof(QuorumAIOCB),
+.cancel = quorum_aio_cancel,
+};
+
+static void quorum_aio_bh(void *opaque)
+{
+QuorumAIOCB *acb = opaque;
+BDRVQuorumState *s = acb-bqs;
+int ret;
+
+ret = s-threshold = acb-success_count ? 0 : -EIO;
   
   It would be very much preferable if you stored the actual error code
   instead of turning everything into -EIO.
   
+
+qemu_bh_delete(acb-bh);
+acb-common.cb(acb-common.opaque, ret);
+if (acb-finished) {
+*acb-finished = true;
+}
+g_free(acb-aios);
+qemu_aio_release(acb);
+}
   
   Move this down so that it's next to the function using the bottom half.
   
+
+static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s,
+   BlockDriverState *bs,
+   QEMUIOVector *qiov,
+   uint64_t sector_num,
+   int nb_sectors,
+   BlockDriverCompletionFunc *cb,
+   void *opaque)
+{
+QuorumAIOCB *acb = qemu_aio_get(quorum_aiocb_info, bs, cb, 
opaque);
+int i;
+
+acb-aios = g_new0(QuorumSingleAIOCB, s-total);
+
+acb-bqs = s;
+acb-qiov = qiov;
+acb-bh = NULL;
+acb-count = 0;
+acb-success_count = 0;
+acb-sector_num = sector_num;
+acb-nb_sectors = nb_sectors;
+acb-vote = NULL;
+acb-vote_ret = 0;
+acb-finished = NULL;
+
+for (i = 0; i  s-total; i++) {
+acb-aios[i].buf = NULL;
+acb-aios[i].ret = 0;
+acb-aios[i].parent = acb;
+}
   
   Would you mind to reorder the initialisation of the fields according to
   the order that is used in the struct definition?
   
+
+return acb;
+}
+
+static void quorum_aio_cb(void *opaque, int ret)
+{
+QuorumSingleAIOCB *sacb = opaque;
+QuorumAIOCB *acb = sacb-parent;
+BDRVQuorumState *s = acb-bqs;
+
+sacb-ret = ret;
+acb-count++;
+if (ret == 0) {
+acb-success_count++;
+}
+assert(acb-count = s-total);
+assert(acb-success_count = s-total);
+if (acb-count  s-total) {
+return;
+}
+
+acb-bh = qemu_bh_new(quorum_aio_bh, acb);
+qemu_bh_schedule(acb-bh);
   
   What's the reason for using a bottom half here? Worth a comment?
   
   multiwrite_cb() in block.c doesn't use one to achieve something similar.
   Is it buggy when you need one here?
   
  
  I tried the code without bh and it doesn't work.
 
 It's long ago tbat I wrote that comment, but the remark about
 multiwrite_cb() concerns me. Do you know _why_ it doesn't work without
 the BH, and whether the same problem affects multiwrite_cb()? I'd prefer
 if we understood what we're doing over just basing the code on
 experiments.

Tried to do the conversion again. It seems to works fine.

Best regards

Benoît
 
 Kevin

Re: [Qemu-devel] [RFC V8 03/13] quorum: Add quorum_aio_writev and its dependencies.

2013-09-27 Thread Kevin Wolf 
Am 26.09.2013 um 18:16 hat Benoît Canet geschrieben:
   +static void quorum_aio_bh(void *opaque)
   +{
   +QuorumAIOCB *acb = opaque;
   +BDRVQuorumState *s = acb-bqs;
   +int ret;
   +
   +ret = s-threshold = acb-success_count ? 0 : -EIO;
  
  It would be very much preferable if you stored the actual error code
  instead of turning everything into -EIO.
 
 I am turning everything into -EIO because multiple errors can happen at the 
 same
 time.

Picking simply the first error code seems better than throwing all
information away. In the common case, I guess, you only have one error
at a time anyway. And if you do have multiple errors, you can still fix
one after another.

Kevin

Re: [Qemu-devel] [RFC V8 03/13] quorum: Add quorum_aio_writev and its dependencies.

2013-09-27 Thread Kevin Wolf 
Am 26.09.2013 um 18:29 hat Benoît Canet geschrieben:
 Le Friday 08 Feb 2013 à 11:38:38 (+0100), Kevin Wolf a écrit :
  Am 28.01.2013 18:07, schrieb Benoît Canet:
   Signed-off-by: Benoit Canet ben...@irqsave.net
   ---
block/quorum.c |  111 
   
1 file changed, 111 insertions(+)
   
   diff --git a/block/quorum.c b/block/quorum.c
   index d8fffbe..5d8470b 100644
   --- a/block/quorum.c
   +++ b/block/quorum.c
   @@ -52,11 +52,122 @@ struct QuorumAIOCB {
int vote_ret;
};

   +static void quorum_aio_cancel(BlockDriverAIOCB *blockacb)
   +{
   +QuorumAIOCB *acb = container_of(blockacb, QuorumAIOCB, common);
   +bool finished = false;
   +
   +/* Wait for the request to finish */
   +acb-finished = finished;
   +while (!finished) {
   +qemu_aio_wait();
   +}
   +}
   +
   +static AIOCBInfo quorum_aiocb_info = {
   +.aiocb_size = sizeof(QuorumAIOCB),
   +.cancel = quorum_aio_cancel,
   +};
   +
   +static void quorum_aio_bh(void *opaque)
   +{
   +QuorumAIOCB *acb = opaque;
   +BDRVQuorumState *s = acb-bqs;
   +int ret;
   +
   +ret = s-threshold = acb-success_count ? 0 : -EIO;
  
  It would be very much preferable if you stored the actual error code
  instead of turning everything into -EIO.
  
   +
   +qemu_bh_delete(acb-bh);
   +acb-common.cb(acb-common.opaque, ret);
   +if (acb-finished) {
   +*acb-finished = true;
   +}
   +g_free(acb-aios);
   +qemu_aio_release(acb);
   +}
  
  Move this down so that it's next to the function using the bottom half.
  
   +
   +static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s,
   +   BlockDriverState *bs,
   +   QEMUIOVector *qiov,
   +   uint64_t sector_num,
   +   int nb_sectors,
   +   BlockDriverCompletionFunc *cb,
   +   void *opaque)
   +{
   +QuorumAIOCB *acb = qemu_aio_get(quorum_aiocb_info, bs, cb, opaque);
   +int i;
   +
   +acb-aios = g_new0(QuorumSingleAIOCB, s-total);
   +
   +acb-bqs = s;
   +acb-qiov = qiov;
   +acb-bh = NULL;
   +acb-count = 0;
   +acb-success_count = 0;
   +acb-sector_num = sector_num;
   +acb-nb_sectors = nb_sectors;
   +acb-vote = NULL;
   +acb-vote_ret = 0;
   +acb-finished = NULL;
   +
   +for (i = 0; i  s-total; i++) {
   +acb-aios[i].buf = NULL;
   +acb-aios[i].ret = 0;
   +acb-aios[i].parent = acb;
   +}
  
  Would you mind to reorder the initialisation of the fields according to
  the order that is used in the struct definition?
  
   +
   +return acb;
   +}
   +
   +static void quorum_aio_cb(void *opaque, int ret)
   +{
   +QuorumSingleAIOCB *sacb = opaque;
   +QuorumAIOCB *acb = sacb-parent;
   +BDRVQuorumState *s = acb-bqs;
   +
   +sacb-ret = ret;
   +acb-count++;
   +if (ret == 0) {
   +acb-success_count++;
   +}
   +assert(acb-count = s-total);
   +assert(acb-success_count = s-total);
   +if (acb-count  s-total) {
   +return;
   +}
   +
   +acb-bh = qemu_bh_new(quorum_aio_bh, acb);
   +qemu_bh_schedule(acb-bh);
  
  What's the reason for using a bottom half here? Worth a comment?
  
  multiwrite_cb() in block.c doesn't use one to achieve something similar.
  Is it buggy when you need one here?
  
 
 I tried the code without bh and it doesn't work.

It's long ago tbat I wrote that comment, but the remark about
multiwrite_cb() concerns me. Do you know _why_ it doesn't work without
the BH, and whether the same problem affects multiwrite_cb()? I'd prefer
if we understood what we're doing over just basing the code on
experiments.

Kevin

Re: [Qemu-devel] [RFC V8 03/13] quorum: Add quorum_aio_writev and its dependencies.

2013-09-26 Thread Benoît Canet 
Le Friday 08 Feb 2013 à 11:38:38 (+0100), Kevin Wolf a écrit :
 Am 28.01.2013 18:07, schrieb Benoît Canet:
  Signed-off-by: Benoit Canet ben...@irqsave.net
  ---
   block/quorum.c |  111 
  
   1 file changed, 111 insertions(+)
  
  diff --git a/block/quorum.c b/block/quorum.c
  index d8fffbe..5d8470b 100644
  --- a/block/quorum.c
  +++ b/block/quorum.c
  @@ -52,11 +52,122 @@ struct QuorumAIOCB {
   int vote_ret;
   };
   
  +static void quorum_aio_cancel(BlockDriverAIOCB *blockacb)
  +{
  +QuorumAIOCB *acb = container_of(blockacb, QuorumAIOCB, common);
  +bool finished = false;
  +
  +/* Wait for the request to finish */
  +acb-finished = finished;
  +while (!finished) {
  +qemu_aio_wait();
  +}
  +}
  +
  +static AIOCBInfo quorum_aiocb_info = {
  +.aiocb_size = sizeof(QuorumAIOCB),
  +.cancel = quorum_aio_cancel,
  +};
  +
  +static void quorum_aio_bh(void *opaque)
  +{
  +QuorumAIOCB *acb = opaque;
  +BDRVQuorumState *s = acb-bqs;
  +int ret;
  +
  +ret = s-threshold = acb-success_count ? 0 : -EIO;
 
 It would be very much preferable if you stored the actual error code
 instead of turning everything into -EIO.
 
  +
  +qemu_bh_delete(acb-bh);
  +acb-common.cb(acb-common.opaque, ret);
  +if (acb-finished) {
  +*acb-finished = true;
  +}
  +g_free(acb-aios);
  +qemu_aio_release(acb);
  +}
 
 Move this down so that it's next to the function using the bottom half.
 
  +
  +static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s,
  +   BlockDriverState *bs,
  +   QEMUIOVector *qiov,
  +   uint64_t sector_num,
  +   int nb_sectors,
  +   BlockDriverCompletionFunc *cb,
  +   void *opaque)
  +{
  +QuorumAIOCB *acb = qemu_aio_get(quorum_aiocb_info, bs, cb, opaque);
  +int i;
  +
  +acb-aios = g_new0(QuorumSingleAIOCB, s-total);
  +
  +acb-bqs = s;
  +acb-qiov = qiov;
  +acb-bh = NULL;
  +acb-count = 0;
  +acb-success_count = 0;
  +acb-sector_num = sector_num;
  +acb-nb_sectors = nb_sectors;
  +acb-vote = NULL;
  +acb-vote_ret = 0;
  +acb-finished = NULL;
  +
  +for (i = 0; i  s-total; i++) {
  +acb-aios[i].buf = NULL;
  +acb-aios[i].ret = 0;
  +acb-aios[i].parent = acb;
  +}
 
 Would you mind to reorder the initialisation of the fields according to
 the order that is used in the struct definition?
 
  +
  +return acb;
  +}
  +
  +static void quorum_aio_cb(void *opaque, int ret)
  +{
  +QuorumSingleAIOCB *sacb = opaque;
  +QuorumAIOCB *acb = sacb-parent;
  +BDRVQuorumState *s = acb-bqs;
  +
  +sacb-ret = ret;
  +acb-count++;
  +if (ret == 0) {
  +acb-success_count++;
  +}
  +assert(acb-count = s-total);
  +assert(acb-success_count = s-total);
  +if (acb-count  s-total) {
  +return;
  +}
  +
  +acb-bh = qemu_bh_new(quorum_aio_bh, acb);
  +qemu_bh_schedule(acb-bh);
 
 What's the reason for using a bottom half here? Worth a comment?
 
 multiwrite_cb() in block.c doesn't use one to achieve something similar.
 Is it buggy when you need one here?
It think I get the bottom half by largely taking inspiration reading Marcello
blkmirror code.

Best regards

Benoît


 
 Kevin

Re: [Qemu-devel] [RFC V8 03/13] quorum: Add quorum_aio_writev and its dependencies.

2013-09-26 Thread Benoît Canet 
  +static void quorum_aio_bh(void *opaque)
  +{
  +QuorumAIOCB *acb = opaque;
  +BDRVQuorumState *s = acb-bqs;
  +int ret;
  +
  +ret = s-threshold = acb-success_count ? 0 : -EIO;
 
 It would be very much preferable if you stored the actual error code
 instead of turning everything into -EIO.

I am turning everything into -EIO because multiple errors can happen at the same
time.

Best regards

Benoît

Re: [Qemu-devel] [RFC V8 03/13] quorum: Add quorum_aio_writev and its dependencies.

2013-09-26 Thread Benoît Canet 
Le Friday 08 Feb 2013 à 11:38:38 (+0100), Kevin Wolf a écrit :
 Am 28.01.2013 18:07, schrieb Benoît Canet:
  Signed-off-by: Benoit Canet ben...@irqsave.net
  ---
   block/quorum.c |  111 
  
   1 file changed, 111 insertions(+)
  
  diff --git a/block/quorum.c b/block/quorum.c
  index d8fffbe..5d8470b 100644
  --- a/block/quorum.c
  +++ b/block/quorum.c
  @@ -52,11 +52,122 @@ struct QuorumAIOCB {
   int vote_ret;
   };
   
  +static void quorum_aio_cancel(BlockDriverAIOCB *blockacb)
  +{
  +QuorumAIOCB *acb = container_of(blockacb, QuorumAIOCB, common);
  +bool finished = false;
  +
  +/* Wait for the request to finish */
  +acb-finished = finished;
  +while (!finished) {
  +qemu_aio_wait();
  +}
  +}
  +
  +static AIOCBInfo quorum_aiocb_info = {
  +.aiocb_size = sizeof(QuorumAIOCB),
  +.cancel = quorum_aio_cancel,
  +};
  +
  +static void quorum_aio_bh(void *opaque)
  +{
  +QuorumAIOCB *acb = opaque;
  +BDRVQuorumState *s = acb-bqs;
  +int ret;
  +
  +ret = s-threshold = acb-success_count ? 0 : -EIO;
 
 It would be very much preferable if you stored the actual error code
 instead of turning everything into -EIO.
 
  +
  +qemu_bh_delete(acb-bh);
  +acb-common.cb(acb-common.opaque, ret);
  +if (acb-finished) {
  +*acb-finished = true;
  +}
  +g_free(acb-aios);
  +qemu_aio_release(acb);
  +}
 
 Move this down so that it's next to the function using the bottom half.
 
  +
  +static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s,
  +   BlockDriverState *bs,
  +   QEMUIOVector *qiov,
  +   uint64_t sector_num,
  +   int nb_sectors,
  +   BlockDriverCompletionFunc *cb,
  +   void *opaque)
  +{
  +QuorumAIOCB *acb = qemu_aio_get(quorum_aiocb_info, bs, cb, opaque);
  +int i;
  +
  +acb-aios = g_new0(QuorumSingleAIOCB, s-total);
  +
  +acb-bqs = s;
  +acb-qiov = qiov;
  +acb-bh = NULL;
  +acb-count = 0;
  +acb-success_count = 0;
  +acb-sector_num = sector_num;
  +acb-nb_sectors = nb_sectors;
  +acb-vote = NULL;
  +acb-vote_ret = 0;
  +acb-finished = NULL;
  +
  +for (i = 0; i  s-total; i++) {
  +acb-aios[i].buf = NULL;
  +acb-aios[i].ret = 0;
  +acb-aios[i].parent = acb;
  +}
 
 Would you mind to reorder the initialisation of the fields according to
 the order that is used in the struct definition?
 
  +
  +return acb;
  +}
  +
  +static void quorum_aio_cb(void *opaque, int ret)
  +{
  +QuorumSingleAIOCB *sacb = opaque;
  +QuorumAIOCB *acb = sacb-parent;
  +BDRVQuorumState *s = acb-bqs;
  +
  +sacb-ret = ret;
  +acb-count++;
  +if (ret == 0) {
  +acb-success_count++;
  +}
  +assert(acb-count = s-total);
  +assert(acb-success_count = s-total);
  +if (acb-count  s-total) {
  +return;
  +}
  +
  +acb-bh = qemu_bh_new(quorum_aio_bh, acb);
  +qemu_bh_schedule(acb-bh);
 
 What's the reason for using a bottom half here? Worth a comment?
 
 multiwrite_cb() in block.c doesn't use one to achieve something similar.
 Is it buggy when you need one here?
 

I tried the code without bh and it doesn't work.

 Kevin

Re: [Qemu-devel] [RFC V8 03/13] quorum: Add quorum_aio_writev and its dependencies.

2013-02-08 Thread Kevin Wolf 
Am 28.01.2013 18:07, schrieb Benoît Canet:
 Signed-off-by: Benoit Canet ben...@irqsave.net
 ---
  block/quorum.c |  111 
 
  1 file changed, 111 insertions(+)
 
 diff --git a/block/quorum.c b/block/quorum.c
 index d8fffbe..5d8470b 100644
 --- a/block/quorum.c
 +++ b/block/quorum.c
 @@ -52,11 +52,122 @@ struct QuorumAIOCB {
  int vote_ret;
  };
  
 +static void quorum_aio_cancel(BlockDriverAIOCB *blockacb)
 +{
 +QuorumAIOCB *acb = container_of(blockacb, QuorumAIOCB, common);
 +bool finished = false;
 +
 +/* Wait for the request to finish */
 +acb-finished = finished;
 +while (!finished) {
 +qemu_aio_wait();
 +}
 +}
 +
 +static AIOCBInfo quorum_aiocb_info = {
 +.aiocb_size = sizeof(QuorumAIOCB),
 +.cancel = quorum_aio_cancel,
 +};
 +
 +static void quorum_aio_bh(void *opaque)
 +{
 +QuorumAIOCB *acb = opaque;
 +BDRVQuorumState *s = acb-bqs;
 +int ret;
 +
 +ret = s-threshold = acb-success_count ? 0 : -EIO;

It would be very much preferable if you stored the actual error code
instead of turning everything into -EIO.

 +
 +qemu_bh_delete(acb-bh);
 +acb-common.cb(acb-common.opaque, ret);
 +if (acb-finished) {
 +*acb-finished = true;
 +}
 +g_free(acb-aios);
 +qemu_aio_release(acb);
 +}

Move this down so that it's next to the function using the bottom half.

 +
 +static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s,
 +   BlockDriverState *bs,
 +   QEMUIOVector *qiov,
 +   uint64_t sector_num,
 +   int nb_sectors,
 +   BlockDriverCompletionFunc *cb,
 +   void *opaque)
 +{
 +QuorumAIOCB *acb = qemu_aio_get(quorum_aiocb_info, bs, cb, opaque);
 +int i;
 +
 +acb-aios = g_new0(QuorumSingleAIOCB, s-total);
 +
 +acb-bqs = s;
 +acb-qiov = qiov;
 +acb-bh = NULL;
 +acb-count = 0;
 +acb-success_count = 0;
 +acb-sector_num = sector_num;
 +acb-nb_sectors = nb_sectors;
 +acb-vote = NULL;
 +acb-vote_ret = 0;
 +acb-finished = NULL;
 +
 +for (i = 0; i  s-total; i++) {
 +acb-aios[i].buf = NULL;
 +acb-aios[i].ret = 0;
 +acb-aios[i].parent = acb;
 +}

Would you mind to reorder the initialisation of the fields according to
the order that is used in the struct definition?

 +
 +return acb;
 +}
 +
 +static void quorum_aio_cb(void *opaque, int ret)
 +{
 +QuorumSingleAIOCB *sacb = opaque;
 +QuorumAIOCB *acb = sacb-parent;
 +BDRVQuorumState *s = acb-bqs;
 +
 +sacb-ret = ret;
 +acb-count++;
 +if (ret == 0) {
 +acb-success_count++;
 +}
 +assert(acb-count = s-total);
 +assert(acb-success_count = s-total);
 +if (acb-count  s-total) {
 +return;
 +}
 +
 +acb-bh = qemu_bh_new(quorum_aio_bh, acb);
 +qemu_bh_schedule(acb-bh);

What's the reason for using a bottom half here? Worth a comment?

multiwrite_cb() in block.c doesn't use one to achieve something similar.
Is it buggy when you need one here?

Kevin

[Qemu-devel] [RFC V8 03/13] quorum: Add quorum_aio_writev and its dependencies.

2013-01-28 Thread Benoît Canet 
Signed-off-by: Benoit Canet ben...@irqsave.net
---
 block/quorum.c |  111 
 1 file changed, 111 insertions(+)

diff --git a/block/quorum.c b/block/quorum.c
index d8fffbe..5d8470b 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -52,11 +52,122 @@ struct QuorumAIOCB {
 int vote_ret;
 };
 
+static void quorum_aio_cancel(BlockDriverAIOCB *blockacb)
+{
+QuorumAIOCB *acb = container_of(blockacb, QuorumAIOCB, common);
+bool finished = false;
+
+/* Wait for the request to finish */
+acb-finished = finished;
+while (!finished) {
+qemu_aio_wait();
+}
+}
+
+static AIOCBInfo quorum_aiocb_info = {
+.aiocb_size = sizeof(QuorumAIOCB),
+.cancel = quorum_aio_cancel,
+};
+
+static void quorum_aio_bh(void *opaque)
+{
+QuorumAIOCB *acb = opaque;
+BDRVQuorumState *s = acb-bqs;
+int ret;
+
+ret = s-threshold = acb-success_count ? 0 : -EIO;
+
+qemu_bh_delete(acb-bh);
+acb-common.cb(acb-common.opaque, ret);
+if (acb-finished) {
+*acb-finished = true;
+}
+g_free(acb-aios);
+qemu_aio_release(acb);
+}
+
+static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s,
+   BlockDriverState *bs,
+   QEMUIOVector *qiov,
+   uint64_t sector_num,
+   int nb_sectors,
+   BlockDriverCompletionFunc *cb,
+   void *opaque)
+{
+QuorumAIOCB *acb = qemu_aio_get(quorum_aiocb_info, bs, cb, opaque);
+int i;
+
+acb-aios = g_new0(QuorumSingleAIOCB, s-total);
+
+acb-bqs = s;
+acb-qiov = qiov;
+acb-bh = NULL;
+acb-count = 0;
+acb-success_count = 0;
+acb-sector_num = sector_num;
+acb-nb_sectors = nb_sectors;
+acb-vote = NULL;
+acb-vote_ret = 0;
+acb-finished = NULL;
+
+for (i = 0; i  s-total; i++) {
+acb-aios[i].buf = NULL;
+acb-aios[i].ret = 0;
+acb-aios[i].parent = acb;
+}
+
+return acb;
+}
+
+static void quorum_aio_cb(void *opaque, int ret)
+{
+QuorumSingleAIOCB *sacb = opaque;
+QuorumAIOCB *acb = sacb-parent;
+BDRVQuorumState *s = acb-bqs;
+
+sacb-ret = ret;
+acb-count++;
+if (ret == 0) {
+acb-success_count++;
+}
+assert(acb-count = s-total);
+assert(acb-success_count = s-total);
+if (acb-count  s-total) {
+return;
+}
+
+acb-bh = qemu_bh_new(quorum_aio_bh, acb);
+qemu_bh_schedule(acb-bh);
+}
+
+static BlockDriverAIOCB *quorum_aio_writev(BlockDriverState *bs,
+  int64_t sector_num,
+  QEMUIOVector *qiov,
+  int nb_sectors,
+  BlockDriverCompletionFunc *cb,
+  void *opaque)
+{
+BDRVQuorumState *s = bs-opaque;
+QuorumAIOCB *acb = quorum_aio_get(s, bs, qiov, sector_num, nb_sectors,
+  cb, opaque);
+int i;
+
+for (i = 0; i  s-total; i++) {
+acb-aios[i].aiocb = bdrv_aio_writev(s-bs[i], sector_num, qiov,
+ nb_sectors, quorum_aio_cb,
+ acb-aios[i]);
+}
+
+return acb-common;
+}
+
 static BlockDriver bdrv_quorum = {
 .format_name= quorum,
 .protocol_name  = quorum,
 
 .instance_size  = sizeof(BDRVQuorumState),
+
+.bdrv_aio_writev= quorum_aio_writev,
 };
 
 static void bdrv_quorum_init(void)
-- 
1.7.10.4