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([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id g11sm6375121edt.85.2021.05.11.01.37.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 11 May 2021 01:37:15 -0700 (PDT) Subject: Re: [PATCH v2 5/5] blkdebug: protect rules and suspended_reqs with a lock To: Eric Blake , Emanuele Giuseppe Esposito , qemu-block@nongnu.org References: <20210507151203.39643-1-eesposit@redhat.com> <20210507151203.39643-6-eesposit@redhat.com> <55310f7a-583c-3001-141c-4eac4afd185c@redhat.com> From: Paolo Bonzini Message-ID: Date: Tue, 11 May 2021 10:37:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <55310f7a-583c-3001-141c-4eac4afd185c@redhat.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.698, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: Kevin Wolf , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 07/05/21 17:29, Eric Blake wrote: >> + qemu_mutex_lock(&s->lock); >> QLIST_FOREACH(r, &s->suspended_reqs, next) { >> if (!strcmp(r->tag, tag)) { >> + qemu_mutex_unlock(&s->lock); >> return true; >> } >> } >> + qemu_mutex_unlock(&s->lock); >> return false; > Would code like this be easier to write by using QEMU_LOCK_GUARD from > lockable.h? Yes, this one would. In other cases (rule_check) it's not so clear cut. It depends whether you prefer to have the simplest code, or rather to have homogeneous use of either guards or lock/unlock. Paolo