From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57592) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WG92u-00034O-Mk for qemu-devel@nongnu.org; Wed, 19 Feb 2014 10:26:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WG92p-0007qB-87 for qemu-devel@nongnu.org; Wed, 19 Feb 2014 10:26:48 -0500 Received: from lnantes-156-75-100-125.w80-12.abo.wanadoo.fr ([80.12.84.125]:50329 helo=paradis.irqsave.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WG92o-0007q4-VT for qemu-devel@nongnu.org; Wed, 19 Feb 2014 10:26:43 -0500 Date: Wed, 19 Feb 2014 16:26:42 +0100 From: =?iso-8859-1?Q?Beno=EEt?= Canet Message-ID: <20140219152642.GC20622@irqsave.net> References: <1392817351-22148-1-git-send-email-famz@redhat.com> <1392817351-22148-4-git-send-email-famz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <1392817351-22148-4-git-send-email-famz@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v14 03/14] block: Replace in_use with operation blocker List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: kwolf@redhat.com, benoit.canet@irqsave.net, armbru@redhat.com, qemu-devel@nongnu.org, rjones@redhat.com, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com The Wednesday 19 Feb 2014 =E0 21:42:20 (+0800), Fam Zheng wrote : > This drops BlockDriverState.in_use with op_blockers: >=20 > - Call bdrv_op_block_all in place of bdrv_set_in_use(bs, 1). > - Call bdrv_op_unblock_all in place of bdrv_set_in_use(bs, 0). > - Check bdrv_op_is_blocked() in place of bdrv_in_use(bs). > The specific types are used, e.g. in place of starting block backup= , > bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP, ...). > - Check bdrv_op_blocker_is_empty() in place of assert(!bs->in_use). >=20 > Note: there is only bdrv_op_block_all and bdrv_op_unblock_all callers a= t > this moment. So although the checks are specific to op types, this > changes can still be seen as identical logic with previously with > in_use. The difference is error message are improved because of blocker > error info. >=20 > Signed-off-by: Fam Zheng > --- > block-migration.c | 7 +++++-- > block.c | 24 +++++++----------------- > blockdev.c | 15 ++++++--------- > blockjob.c | 14 +++++++++----- > hw/block/dataplane/virtio-blk.c | 19 ++++++++++++------- > include/block/block.h | 2 -- > include/block/block_int.h | 1 - > include/block/blockjob.h | 3 +++ > 8 files changed, 42 insertions(+), 43 deletions(-) >=20 > diff --git a/block-migration.c b/block-migration.c > index 897fdba..bf9a25f 100644 > --- a/block-migration.c > +++ b/block-migration.c > @@ -59,6 +59,7 @@ typedef struct BlkMigDevState { > unsigned long *aio_bitmap; > int64_t completed_sectors; > BdrvDirtyBitmap *dirty_bitmap; > + Error *blocker; > } BlkMigDevState; > =20 > typedef struct BlkMigBlock { > @@ -346,7 +347,8 @@ static void init_blk_migration_it(void *opaque, Blo= ckDriverState *bs) > bmds->completed_sectors =3D 0; > bmds->shared_base =3D block_mig_state.shared_base; > alloc_aio_bitmap(bmds); > - bdrv_set_in_use(bs, 1); > + error_setg(&bmds->blocker, "block device is in use by migratio= n"); > + bdrv_op_block_all(bs, bmds->blocker); > bdrv_ref(bs); > =20 > block_mig_state.total_sector_sum +=3D sectors; > @@ -584,7 +586,8 @@ static void blk_mig_cleanup(void) > blk_mig_lock(); > while ((bmds =3D QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) !=3D = NULL) { > QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry); > - bdrv_set_in_use(bmds->bs, 0); > + bdrv_op_unblock_all(bmds->bs, bmds->blocker); > + error_free(bmds->blocker); > bdrv_unref(bmds->bs); > g_free(bmds->aio_bitmap); > g_free(bmds); > diff --git a/block.c b/block.c > index 485d4f0..b5cb0c7 100644 > --- a/block.c > +++ b/block.c > @@ -1843,7 +1843,6 @@ static void bdrv_move_feature_fields(BlockDriverS= tate *bs_dest, > bs_dest->refcnt =3D bs_src->refcnt; > =20 > /* job */ > - bs_dest->in_use =3D bs_src->in_use; > bs_dest->job =3D bs_src->job; > =20 > /* keep the same entry in bdrv_states */ > @@ -1880,7 +1879,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDri= verState *bs_old) > assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); > assert(bs_new->job =3D=3D NULL); > assert(bs_new->dev =3D=3D NULL); > - assert(bs_new->in_use =3D=3D 0); > + assert(bdrv_op_blocker_is_empty(bs_new)); > assert(bs_new->io_limits_enabled =3D=3D false); > assert(!throttle_have_timer(&bs_new->throttle_state)); > =20 > @@ -1899,7 +1898,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDri= verState *bs_old) > /* Check a few fields that should remain attached to the device */ > assert(bs_new->dev =3D=3D NULL); > assert(bs_new->job =3D=3D NULL); > - assert(bs_new->in_use =3D=3D 0); > + assert(bdrv_op_blocker_is_empty(bs_new)); > assert(bs_new->io_limits_enabled =3D=3D false); > assert(!throttle_have_timer(&bs_new->throttle_state)); > =20 > @@ -1936,7 +1935,7 @@ static void bdrv_delete(BlockDriverState *bs) > { > assert(!bs->dev); > assert(!bs->job); > - assert(!bs->in_use); > + assert(bdrv_op_blocker_is_empty(bs)); > assert(!bs->refcnt); > assert(QLIST_EMPTY(&bs->dirty_bitmaps)); > =20 > @@ -2118,7 +2117,8 @@ int bdrv_commit(BlockDriverState *bs) > return -ENOTSUP; > } > =20 > - if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) { > + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, NULL) || > + bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, NULL)= ) { > return -EBUSY; > } > =20 > @@ -3353,8 +3353,9 @@ int bdrv_truncate(BlockDriverState *bs, int64_t o= ffset) > return -ENOTSUP; > if (bs->read_only) > return -EACCES; > - if (bdrv_in_use(bs)) > + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) { > return -EBUSY; > + } > ret =3D drv->bdrv_truncate(bs, offset); > if (ret =3D=3D 0) { > ret =3D refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); > @@ -5205,17 +5206,6 @@ bool bdrv_op_blocker_is_empty(BlockDriverState *= bs) > return true; > } > =20 > -void bdrv_set_in_use(BlockDriverState *bs, int in_use) > -{ > - assert(bs->in_use !=3D in_use); > - bs->in_use =3D in_use; > -} > - > -int bdrv_in_use(BlockDriverState *bs) > -{ > - return bs->in_use; > -} > - > void bdrv_iostatus_enable(BlockDriverState *bs) > { > bs->iostatus_enabled =3D true; > diff --git a/blockdev.c b/blockdev.c > index f083612..53dce70 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -1289,8 +1289,8 @@ static void external_snapshot_prepare(BlkTransact= ionState *common, > return; > } > =20 > - if (bdrv_in_use(state->old_bs)) { > - error_set(errp, QERR_DEVICE_IN_USE, device); > + if (bdrv_op_is_blocked(state->old_bs, > + BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) { > return; > } > =20 > @@ -1512,8 +1512,7 @@ exit: > =20 > static void eject_device(BlockDriverState *bs, int force, Error **errp= ) > { > - if (bdrv_in_use(bs)) { > - error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs)); > + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_EJECT, errp)) { > return; > } > if (!bdrv_dev_has_removable_media(bs)) { > @@ -1719,7 +1718,7 @@ int do_drive_del(Monitor *mon, const QDict *qdict= , QObject **ret_data) > qerror_report(QERR_DEVICE_NOT_FOUND, id); > return -1; > } > - if (bdrv_in_use(bs)) { > + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, NULL)) { > qerror_report(QERR_DEVICE_IN_USE, id); > return -1; > } > @@ -1972,8 +1971,7 @@ void qmp_drive_backup(const char *device, const c= har *target, > } > } > =20 > - if (bdrv_in_use(bs)) { > - error_set(errp, QERR_DEVICE_IN_USE, device); > + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) { > return; > } > =20 > @@ -2106,8 +2104,7 @@ void qmp_drive_mirror(const char *device, const c= har *target, > } > } > =20 > - if (bdrv_in_use(bs)) { > - error_set(errp, QERR_DEVICE_IN_USE, device); > + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_MIRROR, errp)) { > return; > } > =20 > diff --git a/blockjob.c b/blockjob.c > index 9e5fd5c..f1ff036 100644 > --- a/blockjob.c > +++ b/blockjob.c > @@ -41,14 +41,16 @@ void *block_job_create(const BlockJobDriver *driver= , BlockDriverState *bs, > { > BlockJob *job; > =20 > - if (bs->job || bdrv_in_use(bs)) { > + if (bs->job || !bdrv_op_blocker_is_empty(bs)) { > error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs)); > return NULL; > } > bdrv_ref(bs); > - bdrv_set_in_use(bs, 1); > - > job =3D g_malloc0(driver->instance_size); > + error_setg(&job->blocker, "block device is in use by block job: %s= ", > + BlockJobType_lookup[driver->job_type]); > + bdrv_op_block_all(bs, job->blocker); > + > job->driver =3D driver; > job->bs =3D bs; > job->cb =3D cb; > @@ -63,8 +65,9 @@ void *block_job_create(const BlockJobDriver *driver, = BlockDriverState *bs, > block_job_set_speed(job, speed, &local_err); > if (error_is_set(&local_err)) { > bs->job =3D NULL; > + bdrv_op_unblock_all(bs, job->blocker); > + error_free(job->blocker); > g_free(job); > - bdrv_set_in_use(bs, 0); > error_propagate(errp, local_err); > return NULL; > } > @@ -79,8 +82,9 @@ void block_job_completed(BlockJob *job, int ret) > assert(bs->job =3D=3D job); > job->cb(job->opaque, ret); > bs->job =3D NULL; > + bdrv_op_unblock_all(bs, job->blocker); > + error_free(job->blocker); > g_free(job); > - bdrv_set_in_use(bs, 0); > } > =20 > void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) > diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virti= o-blk.c > index 2237edb..cee0aa5 100644 > --- a/hw/block/dataplane/virtio-blk.c > +++ b/hw/block/dataplane/virtio-blk.c > @@ -69,6 +69,9 @@ struct VirtIOBlockDataPlane { > queue */ > =20 > unsigned int num_reqs; > + > + /* Operation blocker on BDS */ > + Error *blocker; > }; > =20 > /* Raise an interrupt to signal guest, if necessary */ > @@ -368,6 +371,7 @@ void virtio_blk_data_plane_create(VirtIODevice *vde= v, VirtIOBlkConf *blk, > { > VirtIOBlockDataPlane *s; > int fd; > + Error *local_err =3D NULL; > =20 > *dataplane =3D NULL; > =20 > @@ -390,9 +394,10 @@ void virtio_blk_data_plane_create(VirtIODevice *vd= ev, VirtIOBlkConf *blk, > /* If dataplane is (re-)enabled while the guest is running there c= ould be > * block jobs that can conflict. > */ > - if (bdrv_in_use(blk->conf.bs)) { > - error_setg(errp, > - "cannot start dataplane thread while device is in u= se"); > + if (bdrv_op_is_blocked(blk->conf.bs, BLOCK_OP_TYPE_DATAPLANE, &loc= al_err)) { > + error_report("cannot start dataplane thread: %s", > + error_get_pretty(local_err)); > + error_free(local_err); > return; > } > =20 > @@ -407,9 +412,8 @@ void virtio_blk_data_plane_create(VirtIODevice *vde= v, VirtIOBlkConf *blk, > s->vdev =3D vdev; > s->fd =3D fd; > s->blk =3D blk; > - > - /* Prevent block operations that conflict with data plane thread *= / > - bdrv_set_in_use(blk->conf.bs, 1); > + error_setg(&s->blocker, "block device is in use by data plane"); > + bdrv_op_block_all(blk->conf.bs, s->blocker); > =20 > *dataplane =3D s; > } > @@ -421,7 +425,8 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataP= lane *s) > } > =20 > virtio_blk_data_plane_stop(s); > - bdrv_set_in_use(s->blk->conf.bs, 0); > + bdrv_op_unblock_all(s->blk->conf.bs, s->blocker); > + error_free(s->blocker); > g_free(s); > } > =20 > diff --git a/include/block/block.h b/include/block/block.h > index 4874e2a..a46f70a 100644 > --- a/include/block/block.h > +++ b/include/block/block.h > @@ -471,8 +471,6 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs= ); > =20 > void bdrv_ref(BlockDriverState *bs); > void bdrv_unref(BlockDriverState *bs); > -void bdrv_set_in_use(BlockDriverState *bs, int in_use); > -int bdrv_in_use(BlockDriverState *bs); > =20 > bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **= errp); > void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason= ); > diff --git a/include/block/block_int.h b/include/block/block_int.h > index 4e558d0..1d3f76f 100644 > --- a/include/block/block_int.h > +++ b/include/block/block_int.h > @@ -359,7 +359,6 @@ struct BlockDriverState { > QTAILQ_ENTRY(BlockDriverState) device_list; > QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps; > int refcnt; > - int in_use; /* users other than guest access, eg. block migration = */ > =20 > QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; > =20 > diff --git a/include/block/blockjob.h b/include/block/blockjob.h > index d76de62..c0a7875 100644 > --- a/include/block/blockjob.h > +++ b/include/block/blockjob.h > @@ -106,6 +106,9 @@ struct BlockJob { > /** The completion function that will be called when the job compl= etes. */ > BlockDriverCompletionFunc *cb; > =20 > + /** Block other operations when block job is running */ > + Error *blocker; > + > /** The opaque value that is passed to the completion function. *= / > void *opaque; > }; > --=20 > 1.8.5.4 >=20 Reviewed-by: Benoit Canet