[v2,1/2] block/blkio: close the fd when blkio_connect() fails

Commit Message

Stefano Garzarella Aug. 3, 2023, 8:28 a.m. UTC

libblkio drivers take ownership of `fd` only after a successful
blkio_connect(), so if it fails, we are still the owners.

Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk")
Suggested-by: Hanna Czenczek <[e-mail]>
Signed-off-by: Stefano Garzarella <[e-mail]>
---

Notes:
    v2:
    - avoid to use `fd_supported` to track a valid fd [Hanna]

 block/blkio.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Comments

Hanna Czenczek Aug. 3, 2023, 1:50 p.m. UTC | #1

On 03.08.23 10:28, Stefano Garzarella wrote:
> libblkio drivers take ownership of `fd` only after a successful
> blkio_connect(), so if it fails, we are still the owners.
>
> Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk")
> Suggested-by: Hanna Czenczek <[e-mail]>
> Signed-off-by: Stefano Garzarella <[e-mail]>
> ---
>
> Notes:
>      v2:
>      - avoid to use `fd_supported` to track a valid fd [Hanna]
>
>   block/blkio.c | 11 ++++++++---
>   1 file changed, 8 insertions(+), 3 deletions(-)

Thanks!

Reviewed-by: Hanna Czenczek <[e-mail]>

Patch

diff --git a/block/blkio.c b/block/blkio.c
index 8e7ce42c79..baba2f0b67 100644
--- a/block/blkio.c
+++ b/block/blkio.c
@@ -678,7 +678,7 @@  static int blkio_virtio_blk_connect(BlockDriverState *bs, QDict *options,
     const char *path = qdict_get_try_str(options, "path");
     BDRVBlkioState *s = bs->opaque;
     bool fd_supported = false;
-    int fd, ret;
+    int fd = -1, ret;
 
     if (!path) {
         error_setg(errp, "missing 'path' option");
@@ -719,6 +719,7 @@  static int blkio_virtio_blk_connect(BlockDriverState *bs, QDict *options,
             if (ret < 0) {
                 fd_supported = false;
                 qemu_close(fd);
+                fd = -1;
             }
         }
     }
@@ -733,14 +734,18 @@  static int blkio_virtio_blk_connect(BlockDriverState *bs, QDict *options,
     }
 
     ret = blkio_connect(s->blkio);
+    if (ret < 0 && fd >= 0) {
+        /* Failed to give the FD to libblkio, close it */
+        qemu_close(fd);
+        fd = -1;
+    }
+
     /*
      * 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.