diff options
| -rw-r--r-- | blockdev.c | 71 |
1 files changed, 48 insertions, 23 deletions
diff --git a/blockdev.c b/blockdev.c index 3c8d994ced..3b598f8f0e 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1606,7 +1606,6 @@ typedef struct ExternalSnapshotState { BlkActionState common; BlockDriverState *old_bs; BlockDriverState *new_bs; - AioContext *aio_context; bool overlay_appended; } ExternalSnapshotState; @@ -1626,6 +1625,7 @@ static void external_snapshot_prepare(BlkActionState *common, ExternalSnapshotState *state = DO_UPCAST(ExternalSnapshotState, common, common); TransactionAction *action = common->action; + AioContext *aio_context; /* 'blockdev-snapshot' and 'blockdev-snapshot-sync' have similar * purpose but a different set of parameters */ @@ -1662,31 +1662,32 @@ static void external_snapshot_prepare(BlkActionState *common, return; } - /* Acquire AioContext now so any threads operating on old_bs stop */ - state->aio_context = bdrv_get_aio_context(state->old_bs); - aio_context_acquire(state->aio_context); + aio_context = bdrv_get_aio_context(state->old_bs); + aio_context_acquire(aio_context); + + /* Paired with .clean() */ bdrv_drained_begin(state->old_bs); if (!bdrv_is_inserted(state->old_bs)) { error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); - return; + goto out; } if (bdrv_op_is_blocked(state->old_bs, BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) { - return; + goto out; } if (!bdrv_is_read_only(state->old_bs)) { if (bdrv_flush(state->old_bs)) { error_setg(errp, QERR_IO_ERROR); - return; + goto out; } } if (!bdrv_is_first_non_filter(state->old_bs)) { error_setg(errp, QERR_FEATURE_DISABLED, "snapshot"); - return; + goto out; } if (action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC) { @@ -1698,13 +1699,13 @@ static void external_snapshot_prepare(BlkActionState *common, if (node_name && !snapshot_node_name) { error_setg(errp, "New snapshot node name missing"); - return; + goto out; } if (snapshot_node_name && bdrv_lookup_bs(snapshot_node_name, snapshot_node_name, NULL)) { error_setg(errp, "New snapshot node name already in use"); - return; + goto out; } flags = state->old_bs->open_flags; @@ -1717,7 +1718,7 @@ static void external_snapshot_prepare(BlkActionState *common, int64_t size = bdrv_getlength(state->old_bs); if (size < 0) { error_setg_errno(errp, -size, "bdrv_getlength failed"); - return; + goto out; } bdrv_img_create(new_image_file, format, state->old_bs->filename, @@ -1725,7 +1726,7 @@ static void external_snapshot_prepare(BlkActionState *common, NULL, size, flags, false, &local_err); if (local_err) { error_propagate(errp, local_err); - return; + goto out; } } @@ -1740,30 +1741,30 @@ static void external_snapshot_prepare(BlkActionState *common, errp); /* We will manually add the backing_hd field to the bs later */ if (!state->new_bs) { - return; + goto out; } if (bdrv_has_blk(state->new_bs)) { error_setg(errp, "The snapshot is already in use"); - return; + goto out; } if (bdrv_op_is_blocked(state->new_bs, BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, errp)) { - return; + goto out; } if (state->new_bs->backing != NULL) { error_setg(errp, "The snapshot already has a backing image"); - return; + goto out; } if (!state->new_bs->drv->supports_backing) { error_setg(errp, "The snapshot does not support backing images"); - return; + goto out; } - bdrv_set_aio_context(state->new_bs, state->aio_context); + bdrv_set_aio_context(state->new_bs, aio_context); /* This removes our old bs and adds the new bs. This is an operation that * can fail, so we need to do it in .prepare; undoing it for abort is @@ -1772,15 +1773,22 @@ static void external_snapshot_prepare(BlkActionState *common, bdrv_append(state->new_bs, state->old_bs, &local_err); if (local_err) { error_propagate(errp, local_err); - return; + goto out; } state->overlay_appended = true; + +out: + aio_context_release(aio_context); } static void external_snapshot_commit(BlkActionState *common) { ExternalSnapshotState *state = DO_UPCAST(ExternalSnapshotState, common, common); + AioContext *aio_context; + + aio_context = bdrv_get_aio_context(state->old_bs); + aio_context_acquire(aio_context); /* We don't need (or want) to use the transactional * bdrv_reopen_multiple() across all the entries at once, because we @@ -1789,6 +1797,8 @@ static void external_snapshot_commit(BlkActionState *common) bdrv_reopen(state->old_bs, state->old_bs->open_flags & ~BDRV_O_RDWR, NULL); } + + aio_context_release(aio_context); } static void external_snapshot_abort(BlkActionState *common) @@ -1797,11 +1807,18 @@ static void external_snapshot_abort(BlkActionState *common) DO_UPCAST(ExternalSnapshotState, common, common); if (state->new_bs) { if (state->overlay_appended) { + AioContext *aio_context; + + aio_context = bdrv_get_aio_context(state->old_bs); + aio_context_acquire(aio_context); + bdrv_ref(state->old_bs); /* we can't let bdrv_set_backind_hd() close state->old_bs; we need it */ bdrv_set_backing_hd(state->new_bs, NULL, &error_abort); bdrv_replace_node(state->new_bs, state->old_bs, &error_abort); bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */ + + aio_context_release(aio_context); } } } @@ -1810,11 +1827,19 @@ static void external_snapshot_clean(BlkActionState *common) { ExternalSnapshotState *state = DO_UPCAST(ExternalSnapshotState, common, common); - if (state->aio_context) { - bdrv_drained_end(state->old_bs); - bdrv_unref(state->new_bs); - aio_context_release(state->aio_context); + AioContext *aio_context; + + if (!state->old_bs) { + return; } + + aio_context = bdrv_get_aio_context(state->old_bs); + aio_context_acquire(aio_context); + + bdrv_drained_end(state->old_bs); + bdrv_unref(state->new_bs); + + aio_context_release(aio_context); } typedef struct DriveBackupState { |