From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52255) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YfrDi-0005eU-HQ for qemu-devel@nongnu.org; Wed, 08 Apr 2015 10:44:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YfrDc-0002uV-FZ for qemu-devel@nongnu.org; Wed, 08 Apr 2015 10:44:46 -0400 From: Alberto Garcia Date: Wed, 8 Apr 2015 17:43:38 +0300 Message-Id: In-Reply-To: References: In-Reply-To: References: Subject: [Qemu-devel] [PATCH 4/6] block: Support streaming to an intermediate layer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Alberto Garcia , qemu-block@nongnu.org, Stefan Hajnoczi This makes sure that the image we are steaming into is open in read-write mode during the operation. Operation blockers are also set in all intermediate nodes, since they will be removed from the chain afterwards. Finally, this also unblocks the stream operation in backing files. Signed-off-by: Alberto Garcia --- block.c | 4 +++- block/stream.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/block.c b/block.c index 25289ef..e892cb4 100644 --- a/block.c +++ b/block.c @@ -1240,9 +1240,11 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) backing_hd->drv ? backing_hd->drv->format_name : ""); bdrv_op_block_all(bs->backing_hd, bs->backing_blocker); - /* Otherwise we won't be able to commit due to check in bdrv_commit */ + /* Otherwise we won't be able to commit or stream */ bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, bs->backing_blocker); + bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_STREAM, + bs->backing_blocker); out: bdrv_refresh_limits(bs, NULL); } diff --git a/block/stream.c b/block/stream.c index 37bfd8b..327d964 100644 --- a/block/stream.c +++ b/block/stream.c @@ -33,6 +33,8 @@ typedef struct StreamBlockJob { BlockDriverState *base; BlockdevOnError on_error; char *backing_file_str; + int bs_flags; + Error *blocker; } StreamBlockJob; static int coroutine_fn stream_populate(BlockDriverState *bs, @@ -88,8 +90,15 @@ static void stream_complete(BlockJob *job, void *opaque) { StreamBlockJob *s = container_of(job, StreamBlockJob, common); StreamCompleteData *data = opaque; + BlockDriverState *i; BlockDriverState *base = s->base; + /* Remove all blockers set in stream_start() */ + for (i = job->bs->backing_hd; i && i != s->base; i = i->backing_hd) { + bdrv_op_unblock_all(i, s->blocker); + } + error_free(s->blocker); + if (!block_job_is_cancelled(&s->common) && data->reached_end && data->ret == 0) { const char *base_id = NULL, *base_fmt = NULL; @@ -103,6 +112,11 @@ static void stream_complete(BlockJob *job, void *opaque) close_unused_images(job->bs, base, base_id); } + /* Reopen the image back in read-only mode if necessary */ + if (s->bs_flags != bdrv_get_flags(job->bs)) { + bdrv_reopen(job->bs, s->bs_flags, NULL); + } + g_free(s->backing_file_str); block_job_completed(&s->common, data->ret); g_free(data); @@ -246,7 +260,9 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base, BlockCompletionFunc *cb, void *opaque, Error **errp) { + BlockDriverState *i; StreamBlockJob *s; + int orig_bs_flags; if ((on_error == BLOCKDEV_ON_ERROR_STOP || on_error == BLOCKDEV_ON_ERROR_ENOSPC) && @@ -255,13 +271,33 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base, return; } + /* Make sure that the image in opened in read-write mode */ + orig_bs_flags = bdrv_get_flags(bs); + if (!(orig_bs_flags & BDRV_O_RDWR)) { + Error *local_err = NULL; + bdrv_reopen(bs, orig_bs_flags | BDRV_O_RDWR, &local_err); + if (local_err != NULL) { + error_propagate(errp, local_err); + return; + } + } + s = block_job_create(&stream_job_driver, bs, speed, cb, opaque, errp); if (!s) { return; } + /* Block all intermediate nodes between bs and base, because they + * will disappear from the chain after this operation */ + error_setg(&s->blocker, "blocked by the block-stream operation in '%s'", + bdrv_get_node_name(bs)); + for (i = bs->backing_hd; i != base && i != NULL; i = i->backing_hd) { + bdrv_op_block_all(i, s->blocker); + } + s->base = base; s->backing_file_str = g_strdup(backing_file_str); + s->bs_flags = orig_bs_flags; s->on_error = on_error; s->common.co = qemu_coroutine_create(stream_run); -- 2.1.4