void commit_start(const char *job_id, BlockDriverState *bs, BlockDriverState *base, BlockDriverState *top, int64_t speed, BlockdevOnError on_error, const char *backing_file_str, Error **errp) { CommitBlockJob *s; BlockReopenQueue *reopen_queue = NULL; int orig_overlay_flags; int orig_base_flags; BlockDriverState *iter; BlockDriverState *overlay_bs; Error *local_err = NULL; int ret; assert(top != bs); if (top == base) { error_setg(errp, "Invalid files for merge: top and base are the same"); return; } overlay_bs = bdrv_find_overlay(bs, top); if (overlay_bs == NULL) { error_setg(errp, "Could not find overlay image for %s:", top->filename); return; } /* FIXME Use real permissions */ s = block_job_create(job_id, &commit_job_driver, bs, 0, BLK_PERM_ALL, speed, BLOCK_JOB_DEFAULT, NULL, NULL, errp); if (!s) { return; } orig_base_flags = bdrv_get_flags(base); orig_overlay_flags = bdrv_get_flags(overlay_bs); /* convert base & overlay_bs to r/w, if necessary */ if (!(orig_base_flags & BDRV_O_RDWR)) { reopen_queue = bdrv_reopen_queue(reopen_queue, base, NULL, orig_base_flags | BDRV_O_RDWR); } if (!(orig_overlay_flags & BDRV_O_RDWR)) { reopen_queue = bdrv_reopen_queue(reopen_queue, overlay_bs, NULL, orig_overlay_flags | BDRV_O_RDWR); } if (reopen_queue) { bdrv_reopen_multiple(bdrv_get_aio_context(bs), reopen_queue, &local_err); if (local_err != NULL) { error_propagate(errp, local_err); goto fail; } } /* Block all nodes between top and base, because they will * disappear from the chain after this operation. */ assert(bdrv_chain_contains(top, base)); for (iter = top; iter != backing_bs(base); iter = backing_bs(iter)) { /* FIXME Use real permissions */ block_job_add_bdrv(&s->common, "intermediate node", iter, 0, BLK_PERM_ALL, &error_abort); } /* overlay_bs must be blocked because it needs to be modified to * update the backing image string, but if it's the root node then * don't block it again */ if (bs != overlay_bs) { /* FIXME Use real permissions */ block_job_add_bdrv(&s->common, "overlay of top", overlay_bs, 0, BLK_PERM_ALL, &error_abort); } /* FIXME Use real permissions */ s->base = blk_new(0, BLK_PERM_ALL); ret = blk_insert_bs(s->base, base, errp); if (ret < 0) { goto fail; } /* FIXME Use real permissions */ s->top = blk_new(0, BLK_PERM_ALL); ret = blk_insert_bs(s->top, top, errp); if (ret < 0) { goto fail; } s->active = bs; s->base_flags = orig_base_flags; s->orig_overlay_flags = orig_overlay_flags; s->backing_file_str = g_strdup(backing_file_str); s->on_error = on_error; trace_commit_start(bs, base, top, s); block_job_start(&s->common); return; fail: if (s->base) { blk_unref(s->base); } if (s->top) { blk_unref(s->top); } block_job_unref(&s->common); }