On 18.07.2016 17:48, Halil Pasic wrote: > > > On 07/18/2016 04:41 PM, Max Reitz wrote: >> On 18.07.2016 14:30, Halil Pasic wrote: >>> Make raw_open for POSIX more consistent in handling errors by setting >>> the error object also when qemu_open fails. The error object was >>> generally set in case of errors, but I guess this case was overlooked. >>> Do the same for win32. >>> >>> Signed-off-by: Halil Pasic <[email protected]> >>> Reviewed-by: Cornelia Huck <[email protected]> >>> Reviewed-by: Sascha Silbe <[email protected]> >>> Tested-by: Marc Hartmayer <[email protected]> (POSIX only) >>> >>> --- >>> >>> Stumbled upon this (POSIX) while testing VMs with too many SCSI disks in >>> respect to my nofile limit. When open hits the nofile limit while trying >>> to hotplug yet another SCSI disk via libvirt we end up with no adequate >>> error message (one stating too many files). Sadly this patch in not >>> sufficient to fix this problem because drive_new (/qemu/blockdev.c) >>> handles errors using error_report_err which is documented as not to be >>> used in QMP context. Do not have a patch for that, because I'm unsure >>> whats the best way to deal with it. My guess right now is to make sure >>> we propagate errors at least until reaching code which is called only >>> QMP in context and handle communicating the error to the requester of >>> the operation there. Any suggestions or ideas? >>> >>> The win32 part was not tested, and the sole reason I touched it is >>> to not introduce unnecessary divergence. >>> --- >>> block/raw-posix.c | 1 + >>> block/raw-win32.c | 1 + >>> 2 files changed, 2 insertions(+) >>> >>> diff --git a/block/raw-posix.c b/block/raw-posix.c >>> index c979ac3..4a7056e 100644 >>> --- a/block/raw-posix.c >>> +++ b/block/raw-posix.c >>> @@ -489,6 +489,7 @@ static int raw_open_common(BlockDriverState *bs, QDict >>> *options, >>> if (ret == -EROFS) { >>> ret = -EACCES; >>> } >>> + error_setg_errno(errp, -ret, "Could not open file"); >> >> How about putting this above the "if (ret == -EROFS)" block? While other >> parts of qemu may want to treat EROFS and EACCES in the same way, I >> think it makes sense to distinguish both cases in messages meant for a >> human user. >> >> Max > > > Thanks for the comment! > > Have no strong opinion here. AFAIU the errno argument is only used to > generate a message so there should be no consistency issue, and it would > be more consistent with the win32. How about moving both (posix and > win32) before the conditional statements readjusting the return value > and use errno and err directly?
Regarding win32, the issue is that we don't get an errno value but a
Windows-specific error value from GetLastError(). I don't think
error_setg_errno() understands those values. Therefore, for win32 we
don't have much choice but to use the "preprocessed" errno value.
I don't really see a consistency issue. It's just a human-readable error
message and I think we should be as specific as we can be; it's just
that it depends on the OS how much that is.
Max
>
> Cheers,
> Halil
>
>>
>>> goto fail;
>>> }
>>> s->fd = fd;
>>> diff --git a/block/raw-win32.c b/block/raw-win32.c
>>> index 62edb1a..f324f4e 100644
>>> --- a/block/raw-win32.c
>>> +++ b/block/raw-win32.c
>>> @@ -342,6 +342,7 @@ static int raw_open(BlockDriverState *bs, QDict
>>> *options, int flags,
>>> } else {
>>> ret = -EINVAL;
>>> }
>>> + error_setg_errno(errp, err, "Could not open file");
>>> goto fail;
>>> }
>>>
>>>
>>
>>
>
signature.asc
Description: OpenPGP digital signature
