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Fri, 28 May 2021 14:23:08 +0000 From: Justin He To: Matthew Wilcox CC: Linus Torvalds , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , Jonathan Corbet , Alexander Viro , Luca Coelho , Kalle Valo , "David S. Miller" , Jakub Kicinski , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Johannes Berg , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-wireless@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-s390@vger.kernel.org" Subject: RE: [PATCH RFCv2 1/3] fs: introduce helper d_path_fast() Thread-Topic: [PATCH RFCv2 1/3] fs: introduce helper d_path_fast() Thread-Index: AQHXU7Zi1wKgbL37X06FgTdtF6ajcqr42Q+AgAAZQNA= Date: Fri, 28 May 2021 14:23:08 +0000 Message-ID: References: <20210528113951.6225-1-justin.he@arm.com> <20210528113951.6225-2-justin.he@arm.com> In-Reply-To: Accept-Language: en-US, zh-CN Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ts-tracking-id: DEB36E7F64792C4CA5D0900C1B209CE8.0 x-checkrecipientchecked: true Authentication-Results-Original: infradead.org; dkim=none (message not signed) header.d=none;infradead.org; dmarc=none action=none header.from=arm.com; x-originating-ip: [223.166.32.249] x-ms-publictraffictype: Email X-MS-Office365-Filtering-Correlation-Id: 2132ab73-f0d6-4142-001c-08d921e42490 x-ms-traffictypediagnostic: AM6PR08MB3062:|AM4PR0802MB2147: X-Microsoft-Antispam-PRVS: x-checkrecipientrouted: true nodisclaimer: true x-ms-oob-tlc-oobclassifiers: OLM:4714;OLM:8882; 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X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 May 2021 14:23:19.7933 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 2132ab73-f0d6-4142-001c-08d921e42490 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[63.35.35.123];Helo=[64aa7808-outbound-1.mta.getcheckrecipient.com] X-MS-Exchange-CrossTenant-AuthSource: AM5EUR03FT004.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM4PR0802MB2147 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Matthew Wilcox > Sent: Friday, May 28, 2021 8:52 PM > To: Justin He > Cc: Linus Torvalds ; Petr Mladek > ; Steven Rostedt ; Sergey > Senozhatsky ; Andy Shevchenko > ; Rasmus Villemoes > ; Jonathan Corbet ; Alexander > Viro ; Luca Coelho ; > Kalle Valo ; David S. Miller ; > Jakub Kicinski ; Heiko Carstens ; > Vasily Gorbik ; Christian Borntraeger > ; Johannes Berg ; linux- > doc@vger.kernel.org; linux-kernel@vger.kernel.org; linux- > wireless@vger.kernel.org; netdev@vger.kernel.org; linux- > s390@vger.kernel.org > Subject: Re: [PATCH RFCv2 1/3] fs: introduce helper d_path_fast() > > On Fri, May 28, 2021 at 07:39:49PM +0800, Jia He wrote: > > +/** > > + * d_path_fast - fast return the full path of a dentry without taking > > + * any seqlock/spinlock. This helper is typical for debugging purpose > > + */ > > +char *d_path_fast(const struct path *path, char *buf, int buflen) > > I'd suggest calling it d_path_unsafe(). Otherwise people will call it > instead of d_path because who doesn't like fast? > Okay, thanks > > +{ > > + struct path root; > > + struct mount *mnt =3D real_mount(path->mnt); > > + DECLARE_BUFFER(b, buf, buflen); > > + > > + rcu_read_lock(); > > + get_fs_root_rcu(current->fs, &root); > > + > > + prepend(&b, "", 1); > > + __prepend_path(path->dentry, mnt, &root, &b); > > + rcu_read_unlock(); > > + > > + return extract_string(&b); > > +} > > +EXPORT_SYMBOL(d_path_fast); > > Why export it? What module needs this? Okay, indeed -- Cheers, Justin (Jia He) IMPORTANT NOTICE: The contents of this email and any attachments are confid= ential and may also be privileged. If you are not the intended recipient, p= lease notify the sender immediately and do not disclose the contents to any= other person, use it for any purpose, or store or copy the information in = any medium. Thank you.