From owner-freebsd-fs@freebsd.org Fri Oct 11 08:28:52 2019 Return-Path: Delivered-To: freebsd-fs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id C33F61429A0; Fri, 11 Oct 2019 08:28:52 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 46qLhM6mkqz4BB2; Fri, 11 Oct 2019 08:28:51 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id x9B8SdJi050252 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Fri, 11 Oct 2019 11:28:42 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua x9B8SdJi050252 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id x9B8ScYm050251; Fri, 11 Oct 2019 11:28:38 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Fri, 11 Oct 2019 11:28:38 +0300 From: Konstantin Belousov To: Zhichao1.Li@dell.com Cc: freebsd-fs@freebsd.org, freebsd-drivers@freebsd.org, Shunchao.Hu@dell.com Subject: Re: a issue about getting a devfs node's fullpath Message-ID: <20191011082838.GR44691@kib.kiev.ua> References: <20191010153932.GO44691@kib.kiev.ua> <54b7173c96df43689de04f848ca86de6@KULX13MDC103.APAC.DELL.COM> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54b7173c96df43689de04f848ca86de6@KULX13MDC103.APAC.DELL.COM> User-Agent: Mutt/1.12.2 (2019-09-21) X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on tom.home X-Rspamd-Queue-Id: 46qLhM6mkqz4BB2 X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=gmail.com (policy=none); spf=softfail (mx1.freebsd.org: 2001:470:d5e7:1::1 is neither permitted nor denied by domain of kostikbel@gmail.com) smtp.mailfrom=kostikbel@gmail.com X-Spamd-Result: default: False [-2.00 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; FREEMAIL_FROM(0.00)[gmail.com]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all:c]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; IP_SCORE(0.00)[ip: (-2.65), ipnet: 2001:470::/32(-4.57), asn: 6939(-3.40), country: US(-0.05)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Oct 2019 08:28:52 -0000 On Fri, Oct 11, 2019 at 02:23:14AM +0000, Zhichao1.Li@dell.com wrote: > Hello > Thank you for your time > Unfortunately it does not work, how about this way? It does not work in which way ? I tried it and it worked as expected. Your patch is wrong, VOP_VPTOCNP() must return parent vnode, if any. > > --- a/src/sys/fs/devfs/devfs_vnops.c > +++ b/src/sys/fs/devfs/devfs_vnops.c > @@ -293,7 +293,14 @@ devfs_vptocnp(struct vop_vptocnp_args *ap) > } > bcopy(dd->de_cdp->cdp_c.si_name, buf + i, > strlen(dd->de_cdp->cdp_c.si_name)); > - de = dd->de_dir; > + /* > + * when dealing with VCHR > + * the element 'si_name' already > + * holds the full path string > + * except rootdir, so just go > + * to the rootdir > + */ > + de = dmp->dm_rootdir; > } else if (vp->v_type == VDIR) { > if (dd == dmp->dm_rootdir) { > *dvp = vp; > @@ -307,13 +314,17 @@ devfs_vptocnp(struct vop_vptocnp_args *ap) > } > bcopy(dd->de_dirent->d_name, buf + i, > dd->de_dirent->d_namlen); > - de = dd; > + /* > + * when dealing with VDIR > + * get its parent > + */ > + de = devfs_parent_dirent(dd); > } else { > error = ENOENT; > goto finished; > } > *buflen = i; > - de = devfs_parent_dirent(de); > + /*no need to get another parent*/ > if (de == NULL) { > error = ENOENT; > goto finished; > > another thing is this func is called by many modules, I want to ensure modifying the func this way will not impact other modules and not bring some bugs, would you be so kind to help me out? > > thank you > > -----Original Message----- > From: Konstantin Belousov > Sent: Thursday, October 10, 2019 11:40 PM > To: Li, Zhichao1 > Cc: freebsd-fs@freebsd.org; freebsd-drivers@freebsd.org; Hu, Shunchao > Subject: Re: a issue about getting a devfs node's fullpath > > > [EXTERNAL EMAIL] > > On Thu, Oct 10, 2019 at 05:49:55AM +0000, Zhichao1.Li@dell.com wrote: > > Dear freebsd developers > > I know you're swamped, so I'll be brief. > > I am trying to get a node's full under /dev by calling the function 'vn_fullpath', when dealing with things like '/dev/null' or '/dev/usb/1.0.1', it works well. > > However when dealing a node under more than 2 sub directories (e.g. /dev/bus/usb/001/002) which I made by calling 'make_dev_s' , it goes a little bit different, I got a string "/dev/bus/usb/bus/usb/001/002" > > And I found the function 'devfs_vptocnp' gets the string wrongly when > > dealing multi slashes path string, I have remark the code as followed and put some comments would you please take a look, and tell me what the purpose this func pass the string that way? > > Try this. Not tested. > > diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c index 3b80c68e309..f20b466d88b 100644 > --- a/sys/fs/devfs/devfs_vnops.c > +++ b/sys/fs/devfs/devfs_vnops.c > @@ -284,38 +284,27 @@ devfs_vptocnp(struct vop_vptocnp_args *ap) > if (error != 0) > return (error); > > - i = *buflen; > + if (vp->v_type != VCHR && vp->v_type != VDIR) { > + error = ENOENT; > + goto finished; > + } > + > dd = vp->v_data; > + if (vp->v_type == VDIR && dd == dmp->dm_rootdir) { > + *dvp = vp; > + vref(*dvp); > + goto finished; > + } > > - if (vp->v_type == VCHR) { > - i -= strlen(dd->de_cdp->cdp_c.si_name); > - if (i < 0) { > - error = ENOMEM; > - goto finished; > - } > - bcopy(dd->de_cdp->cdp_c.si_name, buf + i, > - strlen(dd->de_cdp->cdp_c.si_name)); > - de = dd->de_dir; > - } else if (vp->v_type == VDIR) { > - if (dd == dmp->dm_rootdir) { > - *dvp = vp; > - vref(*dvp); > - goto finished; > - } > - i -= dd->de_dirent->d_namlen; > - if (i < 0) { > - error = ENOMEM; > - goto finished; > - } > - bcopy(dd->de_dirent->d_name, buf + i, > - dd->de_dirent->d_namlen); > - de = dd; > - } else { > - error = ENOENT; > + i = *buflen; > + i -= dd->de_dirent->d_namlen; > + if (i < 0) { > + error = ENOMEM; > goto finished; > } > + bcopy(dd->de_dirent->d_name, buf + i, dd->de_dirent->d_namlen); > *buflen = i; > - de = devfs_parent_dirent(de); > + de = devfs_parent_dirent(dd); > if (de == NULL) { > error = ENOENT; > goto finished;