From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42778) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y1M14-0008S9-02 for qemu-devel@nongnu.org; Wed, 17 Dec 2014 16:20:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y1M0x-0004Di-R0 for qemu-devel@nongnu.org; Wed, 17 Dec 2014 16:20:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51706) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y1M0x-0004Dc-Ic for qemu-devel@nongnu.org; Wed, 17 Dec 2014 16:20:11 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sBHLKASg024415 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Wed, 17 Dec 2014 16:20:10 -0500 Message-ID: <5491F387.3030708@redhat.com> Date: Wed, 17 Dec 2014 16:20:07 -0500 From: John Snow MIME-Version: 1.0 References: <1418820703-17179-1-git-send-email-famz@redhat.com> <1418820703-17179-4-git-send-email-famz@redhat.com> In-Reply-To: <1418820703-17179-4-git-send-email-famz@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v5 3/4] block: Add blockdev-backup to transaction List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: "kwolf >> Kevin Wolf" , "mrei >> Max Reitz" , qemu-devel , stefan Hajnoczi , "arm >> Markus Armbruster" On 12/17/2014 07:51 AM, Fam Zheng wrote: > Signed-off-by: Fam Zheng > --- > blockdev.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > qapi-schema.json | 2 ++ > 2 files changed, 81 insertions(+) > > diff --git a/blockdev.c b/blockdev.c > index dbbab1d..9f9ae88 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -1559,6 +1559,79 @@ static void drive_backup_clean(BlkTransactionState *common) > } > } > > +typedef struct BlockdevBackupState { > + BlkTransactionState common; > + BlockDriverState *bs; > + BlockJob *job; > + AioContext *aio_context; > +} BlockdevBackupState; > + > +static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp) > +{ > + BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common); > + BlockdevBackup *backup; > + BlockDriverState *bs, *target; > + Error *local_err = NULL; > + > + assert(common->action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP); > + backup = common->action->blockdev_backup; > + > + bs = bdrv_find(backup->device); > + if (!bs) { > + error_set(errp, QERR_DEVICE_NOT_FOUND, backup->device); > + return; > + } > + > + target = bdrv_find(backup->target); > + if (!target) { > + error_set(errp, QERR_DEVICE_NOT_FOUND, backup->target); > + return; > + } > + > + /* AioContext is released in .clean() */ > + state->aio_context = bdrv_get_aio_context(bs); > + if (state->aio_context != bdrv_get_aio_context(target)) { > + state->aio_context = NULL; > + error_setg(errp, "Backup between two IO threads is not implemented"); > + return; > + } > + aio_context_acquire(state->aio_context); > + > + qmp_blockdev_backup(backup->device, backup->target, > + backup->sync, > + backup->has_speed, backup->speed, > + backup->has_on_source_error, backup->on_source_error, > + backup->has_on_target_error, backup->on_target_error, > + &local_err); > + if (local_err) { > + error_propagate(errp, local_err); > + return; > + } > + > + state->bs = bdrv_find(backup->device); Just some questions: why not use 'bs' instead of calling the function again? Granted, it should work a second time if it worked once. > + state->job = state->bs->job; Why stash both bs and bs->job? Can the BDS change what its job member points to between .prepare() and .abort() ? > +} > + > +static void blockdev_backup_abort(BlkTransactionState *common) > +{ > + BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common); > + BlockDriverState *bs = state->bs; > + > + /* Only cancel if it's the job we started */ > + if (bs && bs->job && bs->job == state->job) { > + block_job_cancel_sync(bs->job); > + } > +} > + > +static void blockdev_backup_clean(BlkTransactionState *common) > +{ > + BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common); > + > + if (state->aio_context) { > + aio_context_release(state->aio_context); > + } > +} > + > static void abort_prepare(BlkTransactionState *common, Error **errp) > { > error_setg(errp, "Transaction aborted using Abort action"); > @@ -1582,6 +1655,12 @@ static const BdrvActionOps actions[] = { > .abort = drive_backup_abort, > .clean = drive_backup_clean, > }, > + [TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP] = { > + .instance_size = sizeof(BlockdevBackupState), > + .prepare = blockdev_backup_prepare, > + .abort = blockdev_backup_abort, > + .clean = blockdev_backup_clean, > + }, > [TRANSACTION_ACTION_KIND_ABORT] = { > .instance_size = sizeof(BlkTransactionState), > .prepare = abort_prepare, > diff --git a/qapi-schema.json b/qapi-schema.json > index 47d99cf..fbfc52f 100644 > --- a/qapi-schema.json > +++ b/qapi-schema.json > @@ -1260,11 +1260,13 @@ > # drive-backup since 1.6 > # abort since 1.6 > # blockdev-snapshot-internal-sync since 1.7 > +# blockdev-backup since 2.3 > ## > { 'union': 'TransactionAction', > 'data': { > 'blockdev-snapshot-sync': 'BlockdevSnapshot', > 'drive-backup': 'DriveBackup', > + 'blockdev-backup': 'BlockdevBackup', > 'abort': 'Abort', > 'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal' > } } > At any rate, regardless of the answers to my questions: Reviewed-by: John Snow