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([129.226.128.251]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-73242581ad2sm1962989b3a.77.2025.02.13.17.43.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Feb 2025 17:43:47 -0800 (PST) From: Jinliang Zheng X-Google-Original-From: Jinliang Zheng To: viro@zeniv.linux.org.uk Cc: alexjlzheng@gmail.com, alexjlzheng@tencent.com, brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fs: remove useless d_unhashed() retry in d_alloc_parallel() Date: Fri, 14 Feb 2025 09:43:44 +0800 Message-ID: <20250214014344.329213-1-alexjlzheng@tencent.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250213132006.GV1977892@ZenIV> References: <20250213132006.GV1977892@ZenIV> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 13 Feb 2025 13:20:06 +0000, Al Viro wrote: > On Thu, Feb 14, 2025 at 08:21:37PM +0800, Jinliang Zheng wrote: > > After commit 45f78b0a2743 ("fs/dcache: Move the wakeup from > > __d_lookup_done() to the caller."), we will only wake up > > d_wait_lookup() after adding dentry to dentry_hashtable. > > Not true. d_lookup_done() might be called without having > *ever* hashed the sucker. > > Just think for a moment - what, for example, should happen > if ->lookup() fails? Would you have d_alloc_parallel() > coming during that ->lookup() (while dentry is in in-lookup > hash) hang forever? Haha, yes, my bad. Thanks for pointing out my mistake. Thank you, :) Jinliang Zheng > > NAK.