From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hao Xu Subject: [PATCH 10/11] vfs: trylock inode->i_rwsem in iterate_dir() to support nowait Date: Sun, 27 Aug 2023 21:28:34 +0800 Message-ID: <20230827132835.1373581-11-hao.xu@linux.dev> References: <20230827132835.1373581-1-hao.xu@linux.dev> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=CL8wzJoAbQ75iZcN0EHSqoGXIWt+IFMvEgcKIhs6zqE=; b=DXhsO6G87tZhi1H0fY3PZSs8iG fdB8DWd21C0cxcuJK9ttaDi/2wGOuar4CCEvvuFOygxPjIiQqYyhiF7eJ80KhrH3RTmnFFDFyCidk yXb8mvOAtp3kWxFswtj/gABlcP8E06KsxctI/alnMyAHfq5HLE7JP8AGKIXe5IX/Bz/Y=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=CL8wzJoAbQ75iZcN0EHSqoGXIWt+IFMvEgcKIhs6zqE=; b=ijwK5cvRthSRpRvhU8KiRYJVw3 e/d6REnar5TDn8jqgb9PbrwAgIvLdeYAZEAj+S2ieC28ggxt5z8maJPLP1iFQBWMmsKJYsTlkCt5A P8xHaPpxPQJPljLz94xA0eu3LOJEM1lhrG0sIRUx8Vm2kyqzUV2HGig7dZQQgAJ9GFJE=; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1693143333; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CL8wzJoAbQ75iZcN0EHSqoGXIWt+IFMvEgcKIhs6zqE=; b=BRJIOv0sJCNWH9arCNNuOEeHNgvBAsJDXsD/9ROslY/E3EvWdOi7NTa+04JucH099rNnul 4aa7v7DjXCaaQfzVNr38jK1tfhfTVUIcRN9rZkXC1mcdwty8x7yMXlzmlXd+zl6Ur2HPps a6OaK6jfFgLdJwLH2JKSlhPncqJxHqY= In-Reply-To: <20230827132835.1373581-1-hao.xu@linux.dev> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: io-uring@vger.kernel.org, Jens Axboe Cc: Wanpeng Li , "Darrick J . Wong" , Dominique Martinet , Dave Chinner , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Stefan Roesch , Clay Harris , linux-s390@vger.kernel.org, linux-nilfs@vger.kernel.org, codalist@coda.cs.cmu.edu, cluster-devel@redhat.com, linux-cachefs@redhat.com, linux-ext4@vger.kernel.org, devel@lists.orangefs.org, linux-cifs@vger.kernel.org, ecryptfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-block@vger.kernel.org, Alexander Viro , Christian Brauner , netdev@vger.kernel.org, samba-technical@lists.samba.org, linux-unionfs@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mtd@lists.infradead.org, bpf@vger.kernel.o From: Hao Xu Trylock inode->i_rwsem in iterate_dir() to support nowait semantics and error out -EAGAIN when there is contention. Signed-off-by: Hao Xu --- fs/readdir.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/fs/readdir.c b/fs/readdir.c index 6469f076ba6e..664ecd9665a1 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -43,6 +43,8 @@ int iterate_dir(struct file *file, struct dir_context *ctx) struct inode *inode = file_inode(file); bool shared = false; int res = -ENOTDIR; + bool nowait; + if (file->f_op->iterate_shared) shared = true; else if (!file->f_op->iterate) @@ -52,16 +54,22 @@ int iterate_dir(struct file *file, struct dir_context *ctx) if (res) goto out; - if (shared) - res = down_read_killable(&inode->i_rwsem); - else - res = down_write_killable(&inode->i_rwsem); - if (res) + nowait = ctx->flags & DIR_CONTEXT_F_NOWAIT; + if (nowait) { + res = shared ? down_read_trylock(&inode->i_rwsem) : + down_write_trylock(&inode->i_rwsem); + if (!res) + res = -EAGAIN; + } else { + res = shared ? down_read_killable(&inode->i_rwsem) : + down_write_killable(&inode->i_rwsem); + } + if (res < 0) goto out; res = -ENOENT; if (!IS_DEADDIR(inode)) { - res = file_accessed(file, ctx->flags & DIR_CONTEXT_F_NOWAIT); + res = file_accessed(file, nowait); if (res == -EAGAIN) goto out_unlock; -- 2.25.1