Mark McLoughlin <mar...@redhat.com> writes:
> On Thu, 2009-10-01 at 09:42 -0500, Justin M. Forbes wrote:
>> Author: Justin M. Forbes <jfor...@redhat.com>
>> Date: Thu Oct 1 09:34:56 2009 -0500
>>
>> Improve error reporting on file access
>>
>> By making the error reporting include strerror(errno), it gives the user
>> a bit more indication as to why qemu failed. This is particularly
>> important for people running qemu as a non root user.
>>
>> Signed-off-by: Justin M. Forbes <jfor...@redhat.com>
>
> Certainly looks sensible to me
>
> Not having this is hurting us in Fedora 12 because we've started running
> qemu as an unprivileged user and people are having a hard time figuring
> out the various errors they're seeing caused by the change. This should
> help them.
>
> Only concern is that errno might not be getting propagated correctly by
> some of these functions, but we can fix that later if so.
Here's one:
diff --git a/vl.c b/vl.c
index 7bfd415..70fd2ca 100644
--- a/vl.c
+++ b/vl.c
@@ -2232,8 +2232,8 @@ DriveInfo *drive_init(QemuOpts *opts, void *opaque,
}
if (bdrv_open2(dinfo->bdrv, file, bdrv_flags, drv) < 0) {
- fprintf(stderr, "qemu: could not open disk image %s\n",
- file);
+ fprintf(stderr, "qemu: could not open disk image %s: %s\n",
+ file, strerror(errno));
return NULL;
}
bdrv_open2() returns the error code. Usually, it also leaves it in
errno, but not always. Try:
$ >mt.img
$ ~/work/qemu/bld/qemu-img create -f qcow2 -b mt.img mt.qcow2
Formatting 'mt.qcow2', fmt=qcow2 size=0 backing_file='mt.img'
encryption=off cluster_size=0
$ qemu [...] -drive file=mt.qcow2
qemu: could not open disk image mt.qcow2: Success
