From 3718d8ab65f68de2acccbe6a315907805f54e3cc Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Fri, 23 May 2014 21:29:43 +0800 Subject: [PATCH] block: Replace in_use with operation blocker This drops BlockDriverState.in_use with op_blockers: - 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, ...). There is one exception in block_job_create, where bdrv_op_blocker_is_empty() is used, because we don't know the operation type here. This doesn't matter because in a few commits away we will drop the check and move it to callers that _do_ know the type. - Check bdrv_op_blocker_is_empty() in place of assert(!bs->in_use). Note: there is only bdrv_op_block_all and bdrv_op_unblock_all callers at 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. Signed-off-by: Fam Zheng Reviewed-by: Jeff Cody Reviewed-by: Stefan Hajnoczi Signed-off-by: Stefan Hajnoczi --- block-migration.c | 7 +++++-- block.c | 24 +++++++----------------- blockdev.c | 19 +++++++++---------- blockjob.c | 14 +++++++++----- hw/block/dataplane/virtio-blk.c | 18 ++++++++++++------ include/block/block.h | 2 -- include/block/block_int.h | 1 - include/block/blockjob.h | 3 +++ 8 files changed, 45 insertions(+), 43 deletions(-) diff --git a/block-migration.c b/block-migration.c index 56951e09ae..16562709c8 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; typedef struct BlkMigBlock { @@ -361,7 +362,8 @@ static void init_blk_migration_it(void *opaque, BlockDriverState *bs) bmds->completed_sectors = 0; bmds->shared_base = 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 migration"); + bdrv_op_block_all(bs, bmds->blocker); bdrv_ref(bs); block_mig_state.total_sector_sum += sectors; @@ -599,7 +601,8 @@ static void blk_mig_cleanup(void) blk_mig_lock(); while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != 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 589c6e3376..64c48a54a1 100644 --- a/block.c +++ b/block.c @@ -1949,7 +1949,6 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest, bs_dest->refcnt = bs_src->refcnt; /* job */ - bs_dest->in_use = bs_src->in_use; bs_dest->job = bs_src->job; /* keep the same entry in bdrv_states */ @@ -1992,7 +1991,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); assert(bs_new->job == NULL); assert(bs_new->dev == NULL); - assert(bs_new->in_use == 0); + assert(bdrv_op_blocker_is_empty(bs_new)); assert(bs_new->io_limits_enabled == false); assert(!throttle_have_timer(&bs_new->throttle_state)); @@ -2011,7 +2010,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) /* Check a few fields that should remain attached to the device */ assert(bs_new->dev == NULL); assert(bs_new->job == NULL); - assert(bs_new->in_use == 0); + assert(bdrv_op_blocker_is_empty(bs_new)); assert(bs_new->io_limits_enabled == false); assert(!throttle_have_timer(&bs_new->throttle_state)); @@ -2056,7 +2055,7 @@ 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)); @@ -2238,7 +2237,8 @@ int bdrv_commit(BlockDriverState *bs) return -ENOTSUP; } - 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; } @@ -3500,8 +3500,9 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset) 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 = drv->bdrv_truncate(bs, offset); if (ret == 0) { ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); @@ -5401,17 +5402,6 @@ bool bdrv_op_blocker_is_empty(BlockDriverState *bs) return true; } -void bdrv_set_in_use(BlockDriverState *bs, int in_use) -{ - assert(bs->in_use != in_use); - bs->in_use = in_use; -} - -int bdrv_in_use(BlockDriverState *bs) -{ - return bs->in_use; -} - void bdrv_iostatus_enable(BlockDriverState *bs) { bs->iostatus_enabled = true; diff --git a/blockdev.c b/blockdev.c index 1cbcc1c785..0a519029b8 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1334,8 +1334,8 @@ static void external_snapshot_prepare(BlkTransactionState *common, return; } - 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; } @@ -1557,8 +1557,7 @@ exit: 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)) { @@ -1760,14 +1759,16 @@ int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data) { const char *id = qdict_get_str(qdict, "id"); BlockDriverState *bs; + Error *local_err = NULL; bs = bdrv_find(id); if (!bs) { qerror_report(QERR_DEVICE_NOT_FOUND, id); return -1; } - if (bdrv_in_use(bs)) { - qerror_report(QERR_DEVICE_IN_USE, id); + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_DRIVE_DEL, &local_err)) { + error_report("%s", error_get_pretty(local_err)); + error_free(local_err); return -1; } @@ -2023,8 +2024,7 @@ void qmp_drive_backup(const char *device, const char *target, } } - 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; } @@ -2157,8 +2157,7 @@ void qmp_drive_mirror(const char *device, const char *target, } } - 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; } diff --git a/blockjob.c b/blockjob.c index cd4784f053..60e72f5d90 100644 --- a/blockjob.c +++ b/blockjob.c @@ -41,14 +41,16 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, { BlockJob *job; - 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 = 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 = driver; job->bs = bs; job->cb = cb; @@ -63,8 +65,9 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, block_job_set_speed(job, speed, &local_err); if (local_err) { bs->job = 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 == job); job->cb(job->opaque, ret); bs->job = NULL; + bdrv_op_unblock_all(bs, job->blocker); + error_free(job->blocker); g_free(job); - bdrv_set_in_use(bs, 0); } 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/virtio-blk.c index 70b8a5ab75..e49c2536b1 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -70,6 +70,9 @@ struct VirtIOBlockDataPlane { queue */ unsigned int num_reqs; + + /* Operation blocker on BDS */ + Error *blocker; }; /* Raise an interrupt to signal guest, if necessary */ @@ -350,6 +353,7 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, { VirtIOBlockDataPlane *s; int fd; + Error *local_err = NULL; *dataplane = NULL; @@ -372,9 +376,10 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, /* If dataplane is (re-)enabled while the guest is running there could be * block jobs that can conflict. */ - if (bdrv_in_use(blk->conf.bs)) { - error_setg(errp, - "cannot start dataplane thread while device is in use"); + if (bdrv_op_is_blocked(blk->conf.bs, BLOCK_OP_TYPE_DATAPLANE, &local_err)) { + error_report("cannot start dataplane thread: %s", + error_get_pretty(local_err)); + error_free(local_err); return; } @@ -406,8 +411,8 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, } s->ctx = iothread_get_aio_context(s->iothread); - /* 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); *dataplane = s; } @@ -420,7 +425,8 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s) } 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); object_unref(OBJECT(s->iothread)); g_free(s); } diff --git a/include/block/block.h b/include/block/block.h index 7f0448c19f..22935f1cbd 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -472,8 +472,6 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs); 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); 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 fdf2a7da8f..7b1c013c30 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -358,7 +358,6 @@ 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 */ QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; diff --git a/include/block/blockjob.h b/include/block/blockjob.h index d76de62a46..c0a787530b 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 completes. */ BlockDriverCompletionFunc *cb; + /** Block other operations when block job is running */ + Error *blocker; + /** The opaque value that is passed to the completion function. */ void *opaque; }; -- GitLab