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auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-trivial@nongnu.org, qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 16.12.2020 um 14:06 hat David Edmondson geschrieben: > On Wednesday, 2020-12-16 at 12:57:46 +01, Kevin Wolf wrote: > > > Am 16.12.2020 um 12:38 hat David Edmondson geschrieben: > >> On Wednesday, 2020-12-16 at 12:29:40 +01, Kevin Wolf wrote: > >> > >> > Am 15.12.2020 um 20:01 hat David Edmondson geschrieben: > >> >> 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 > >> > > >> > Is appending "Resource temporarily unavailable" in the common case (a > >> > file locked by another process) actually an improvement for the message > >> > or more confusing? It would be good to mention the motivation for the > >> > change in the commit message. > >> > >> Distinguishing between the common case and others is at least a start > >> when trying to figure out why it failed. We have potentially useful > >> information to assist in diagnosis, why throw it away? > > > > I agree in principle, just when I saw the result, it felt more confusing > > than helpful. Maybe the best option would be to include the errno only > > if it's different from EAGAIN? Then the qemu-iotests reference output > > would probably stay unchanged, too. > > This is a pretty low-level error report even today - unless you > understand the implementation then it doesn't shout "the file is being > shared". Hm, certainly true for raw_apply_lock_bytes(), which shouldn't normally fail, so I agree that we don't need to simplify messages there. >From raw_check_lock_bytes(), you get messages like 'Failed to get "write" lock', which I think is fairly obvious? I'm not saying that it's perfect and couldn't be improved, of course, but it doesn't feel horrible. > Given that, I don't see any value in eliding the EAGAIN message, as I > have to know that the lack of the errno string means that it was EAGAIN, > meaning that another process holds a lock. When you debug an error, you'll look at the code anyway. And a normal user won't know what EAGAIN or "Resource temporarily unavailable" means even if it's displayed. Temporarily sounds more like it will go away by itself, not that I have to shut down a different process first. I wonder if anyone else has an opinion on this? If people think that displaying it is preferable or it doesn't matter much, we can add it despite my concerns. Kevin