Re: [PATCH v2 1/2] block: report errno when flock fcntl fails

[Max Reitz <mreitz@redhat.com>]

On 21.12.20 14:49, David Edmondson wrote:
> When a call to fcntl(2) for the purpose of manipulating file locks
> fails, report the error returned by fcntl.
> 
> Signed-off-by: David Edmondson <david.edmondson@oracle.com>
> ---
>   block/file-posix.c         | 20 +++++-----
>   tests/qemu-iotests/153.out | 76 +++++++++++++++++++-------------------
>   tests/qemu-iotests/182.out |  2 +-
>   3 files changed, 49 insertions(+), 49 deletions(-)

tests/qemu-iotests/296.out also needs to be adjusted (found by grepping 
for 'Failed to get').

And now I might as well add this idea: EAGAIN is the most common errno 
when flock fcntl fails, so would it make sense to generate a custom 
error message then?  I’d like to think we could do better than “Resource 
temporarily unavailable”, e.g. perhaps “Lock is already taken”.

OTOH, “Resource temporarily unavailable” isn’t *that* bad, so if you 
don’t want to, I won’t push for it.

Max