Re: [PATCH 2/7] block/blkio: fix error return value on getlength()

[Akihiko Odaki]

On 2026/07/25 23:00, Marc-André Lureau wrote:
Negative values should be return for errors.

Nit: s/return/returned/


It also helps with GCC false-positives:
../block/blkio.c: In function ‘blkio_co_getlength’:
../block/blkio.c:943:8: error: ‘ret’ may be used uninitialized 
[-Werror=maybe-uninitialized]
   943 |     if (ret < 0) {
       |        ^

Fixes: fd66dbd424 ("blkio: add libblkio block driver")
Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
---
  block/blkio.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blkio.c b/block/blkio.c
index fb8bec27d71a..d2ba2a4d58dc 100644
--- a/block/blkio.c
+++ b/block/blkio.c
@@ -935,13 +935,13 @@ static int64_t coroutine_fn 
blkio_co_getlength(BlockDriverState *bs)
  {
      BDRVBlkioState *s = bs->opaque;
      uint64_t capacity;
-    int ret;
+    int ret = -1;

Initializing a variable with a dummy value can suppress a useful 
warning. Replacing WITH_QEMU_LOCK_GUARD() with QEMU_LOCK_GUARD() will 
fix it without introducing a dummy value and also result in a bit 
simpler code.

Regards,
Akihiko Odaki

  
      WITH_QEMU_LOCK_GUARD(&s->blkio_lock) {
          ret = blkio_get_uint64(s->blkio, "capacity", &capacity);
      }
      if (ret < 0) {
-        return -ret;
+        return ret;
      }
  
      return capacity;