From ece855a71d9234c58497f37cb5498f507742167d Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Thu, 27 Jul 2023 18:10:18 +0200 Subject: [PATCH 04/14] block/blkio: retry blkio_connect() if it fails using `fd` RH-Author: Stefano Garzarella RH-MergeRequest: 194: block/blkio: backport latest fixes for virtio-blk-* drivers RH-Bugzilla: 2225354 2225439 RH-Acked-by: Hanna Czenczek RH-Acked-by: Alberto Faria RH-Commit: [4/6] 14ebc1f333617ce22c68693dec1c9a186d4f8a08 (sgarzarella/qemu-kvm-c-9-s) libblkio 1.3.0 added support of "fd" property for virtio-blk-vhost-vdpa driver. In QEMU, starting from commit cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk") we are using `blkio_get_int(..., "fd")` to check if the "fd" property is supported for all the virtio-blk-* driver. Unfortunately that property is also available for those driver that do not support it, such as virtio-blk-vhost-user. So, `blkio_get_int()` is not enough to check whether the driver supports the `fd` property or not. This is because the virito-blk common libblkio driver only checks whether or not `fd` is set during `blkio_connect()` and fails with -EINVAL for those transports that do not support it (all except vhost-vdpa for now). So let's handle the `blkio_connect()` failure, retrying it using `path` directly. Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk") Suggested-by: Stefan Hajnoczi Signed-off-by: Stefano Garzarella Message-id: 20230727161020.84213-3-sgarzare@redhat.com Signed-off-by: Stefan Hajnoczi (cherry picked from commit 809c319f8a089fbc49223dc29e1cc2b978beeada) Signed-off-by: Stefano Garzarella --- block/blkio.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/block/blkio.c b/block/blkio.c index 85d1eed5fb..93a8f8fc5c 100644 --- a/block/blkio.c +++ b/block/blkio.c @@ -732,6 +732,35 @@ static int blkio_virtio_blk_connect(BlockDriverState *bs, QDict *options, } ret = blkio_connect(s->blkio); + /* + * If the libblkio driver doesn't support the `fd` property, blkio_connect() + * will fail with -EINVAL. So let's try calling blkio_connect() again by + * directly setting `path`. + */ + if (fd_supported && ret == -EINVAL) { + qemu_close(fd); + + /* + * We need to clear the `fd` property we set previously by setting + * it to -1. + */ + ret = blkio_set_int(s->blkio, "fd", -1); + if (ret < 0) { + error_setg_errno(errp, -ret, "failed to set fd: %s", + blkio_get_error_msg()); + return ret; + } + + ret = blkio_set_str(s->blkio, "path", path); + if (ret < 0) { + error_setg_errno(errp, -ret, "failed to set path: %s", + blkio_get_error_msg()); + return ret; + } + + ret = blkio_connect(s->blkio); + } + if (ret < 0) { error_setg_errno(errp, -ret, "blkio_connect failed: %s", blkio_get_error_msg()); -- 2.39.3