diff options
Diffstat (limited to 'blockdev.c')
| -rw-r--r-- | blockdev.c | 101 |
1 files changed, 80 insertions, 21 deletions
diff --git a/blockdev.c b/blockdev.c index 3848a9c8ab..7f2561081e 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1562,7 +1562,12 @@ static void external_snapshot_prepare(BlkActionState *common, goto out; } - if (state->new_bs->backing != NULL) { + if (state->new_bs->drv->is_filter) { + error_setg(errp, "Filters cannot be used as overlays"); + goto out; + } + + if (bdrv_cow_child(state->new_bs)) { error_setg(errp, "The overlay already has a backing image"); goto out; } @@ -1736,7 +1741,13 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp) * on top of. */ if (backup->sync == MIRROR_SYNC_MODE_TOP) { - source = backing_bs(bs); + /* + * Backup will not replace the source by the target, so none + * of the filters skipped here will be removed (in contrast to + * mirror). Therefore, we can skip all of them when looking + * for the first COW relationship. + */ + source = bdrv_cow_bs(bdrv_skip_filters(bs)); if (!source) { backup->sync = MIRROR_SYNC_MODE_FULL; } @@ -1756,9 +1767,14 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp) if (backup->mode != NEW_IMAGE_MODE_EXISTING) { assert(backup->format); if (source) { - bdrv_refresh_filename(source); - bdrv_img_create(backup->target, backup->format, source->filename, - source->drv->format_name, NULL, + /* Implicit filters should not appear in the filename */ + BlockDriverState *explicit_backing = + bdrv_skip_implicit_filters(source); + + bdrv_refresh_filename(explicit_backing); + bdrv_img_create(backup->target, backup->format, + explicit_backing->filename, + explicit_backing->drv->format_name, NULL, size, flags, false, &local_err); } else { bdrv_img_create(backup->target, backup->format, NULL, NULL, NULL, @@ -2528,7 +2544,9 @@ void qmp_block_stream(bool has_job_id, const char *job_id, const char *device, } /* Check for op blockers in the whole chain between bs and base */ - for (iter = bs; iter && iter != base_bs; iter = backing_bs(iter)) { + for (iter = bs; iter && iter != base_bs; + iter = bdrv_filter_or_cow_bs(iter)) + { if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_STREAM, errp)) { goto out; } @@ -2584,6 +2602,7 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device, AioContext *aio_context; Error *local_err = NULL; int job_flags = JOB_DEFAULT; + uint64_t top_perm, top_shared; if (!has_speed) { speed = 0; @@ -2685,7 +2704,9 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device, assert(bdrv_get_aio_context(base_bs) == aio_context); - for (iter = top_bs; iter != backing_bs(base_bs); iter = backing_bs(iter)) { + for (iter = top_bs; iter != bdrv_filter_or_cow_bs(base_bs); + iter = bdrv_filter_or_cow_bs(iter)) + { if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) { goto out; } @@ -2697,14 +2718,38 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device, goto out; } - if (top_bs == bs) { + /* + * Active commit is required if and only if someone has taken a + * WRITE permission on the top node. Historically, we have always + * used active commit for top nodes, so continue that practice + * lest we possibly break clients that rely on this behavior, e.g. + * to later attach this node to a writing parent. + * (Active commit is never really wrong.) + */ + bdrv_get_cumulative_perm(top_bs, &top_perm, &top_shared); + if (top_perm & BLK_PERM_WRITE || + bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs)) + { if (has_backing_file) { - error_setg(errp, "'backing-file' specified," - " but 'top' is the active layer"); + if (bdrv_skip_filters(top_bs) == bdrv_skip_filters(bs)) { + error_setg(errp, "'backing-file' specified," + " but 'top' is the active layer"); + } else { + error_setg(errp, "'backing-file' specified, but 'top' has a " + "writer on it"); + } goto out; } - commit_active_start(has_job_id ? job_id : NULL, bs, base_bs, - job_flags, speed, on_error, + if (!has_job_id) { + /* + * Emulate here what block_job_create() does, because it + * is possible that @bs != @top_bs (the block job should + * be named after @bs, even if @top_bs is the actual + * source) + */ + job_id = bdrv_get_device_name(bs); + } + commit_active_start(job_id, top_bs, base_bs, job_flags, speed, on_error, filter_node_name, NULL, NULL, false, &local_err); } else { BlockDriverState *overlay_bs = bdrv_find_overlay(bs, top_bs); @@ -2892,6 +2937,7 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs, bool has_auto_dismiss, bool auto_dismiss, Error **errp) { + BlockDriverState *unfiltered_bs; int job_flags = JOB_DEFAULT; if (!has_speed) { @@ -2943,10 +2989,19 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs, return; } - if (!bs->backing && sync == MIRROR_SYNC_MODE_TOP) { + if (!bdrv_backing_chain_next(bs) && sync == MIRROR_SYNC_MODE_TOP) { sync = MIRROR_SYNC_MODE_FULL; } + if (!has_replaces) { + /* We want to mirror from @bs, but keep implicit filters on top */ + unfiltered_bs = bdrv_skip_implicit_filters(bs); + if (unfiltered_bs != bs) { + replaces = unfiltered_bs->node_name; + has_replaces = true; + } + } + if (has_replaces) { BlockDriverState *to_replace_bs; AioContext *replace_aio_context; @@ -2993,7 +3048,7 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs, void qmp_drive_mirror(DriveMirror *arg, Error **errp) { BlockDriverState *bs; - BlockDriverState *source, *target_bs; + BlockDriverState *target_backing_bs, *target_bs; AioContext *aio_context; AioContext *old_context; BlockMirrorBackingMode backing_mode; @@ -3028,12 +3083,12 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) } flags = bs->open_flags | BDRV_O_RDWR; - source = backing_bs(bs); - if (!source && arg->sync == MIRROR_SYNC_MODE_TOP) { + target_backing_bs = bdrv_cow_bs(bdrv_skip_filters(bs)); + if (!target_backing_bs && arg->sync == MIRROR_SYNC_MODE_TOP) { arg->sync = MIRROR_SYNC_MODE_FULL; } if (arg->sync == MIRROR_SYNC_MODE_NONE) { - source = bs; + target_backing_bs = bs; } size = bdrv_getlength(bs); @@ -3059,7 +3114,7 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) /* Don't open backing image in create() */ flags |= BDRV_O_NO_BACKING; - if ((arg->sync == MIRROR_SYNC_MODE_FULL || !source) + if ((arg->sync == MIRROR_SYNC_MODE_FULL || !target_backing_bs) && arg->mode != NEW_IMAGE_MODE_EXISTING) { /* create new image w/o backing file */ @@ -3067,15 +3122,19 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) bdrv_img_create(arg->target, format, NULL, NULL, NULL, size, flags, false, &local_err); } else { + /* Implicit filters should not appear in the filename */ + BlockDriverState *explicit_backing = + bdrv_skip_implicit_filters(target_backing_bs); + switch (arg->mode) { case NEW_IMAGE_MODE_EXISTING: break; case NEW_IMAGE_MODE_ABSOLUTE_PATHS: /* create new image with backing file */ - bdrv_refresh_filename(source); + bdrv_refresh_filename(explicit_backing); bdrv_img_create(arg->target, format, - source->filename, - source->drv->format_name, + explicit_backing->filename, + explicit_backing->drv->format_name, NULL, size, flags, false, &local_err); break; default: |