From mboxrd@z Thu Jan 1 00:00:00 1970 From: hooanon05@yahoo.co.jp Subject: Re: [PATCH v2] Fix i_mutex handling in nfsd readdir Date: Thu, 23 Apr 2009 15:40:23 +0900 Message-ID: <9180.1240468823@jrobl> References: <1237475837.16359.106.camel@macbook.infradead.org> <8913.1237476890@jrobl> <1239960739.3428.33.camel@macbook.infradead.org> <20090417193233.GM26366@ZenIV.linux.org.uk> <1240006620.19059.41.camel@macbook.infradead.org> <20090417224350.GN26366@ZenIV.linux.org.uk> <20090417225306.GO26366@ZenIV.linux.org.uk> <1240013753.21423.86.camel@macbook.infradead.org> <1240144069.3589.156.camel@macbook.infradead.org> <7321.1240375306@jrobl> <20090422191244.GD9541@fieldses.org> Cc: David Woodhouse , Al Viro , hch@infradead.org, "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" To: "J. Bruce Fields" Return-path: Received: from mtoichi11.ns.itscom.net ([219.110.2.181]:36103 "EHLO mtoichi11.ns.itscom.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751454AbZDWGkw (ORCPT ); Thu, 23 Apr 2009 02:40:52 -0400 In-Reply-To: <20090422191244.GD9541@fieldses.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: "J. Bruce Fields": > > Isn't it better to test it BEFORE fh_compose()? ::: > Yes, I think you're right. Then here you are. J. R. Okajima ---------------------------------------------------------------------- commit c98c6c4a207d602bd9498ea5f1d2993a00e98445 Author: J. R. Okajima Date: Thu Apr 23 15:38:43 2009 +0900 NFSD: test d_inode before fh_compose() After 2f9092e1020246168b1309b35e085ecd7ff9ff72 "Fix i_mutex vs. readdir handling in nfsd" (and 14f7dd63 "Copy XFS readdir hack into nfsd code"), an entry may be removed between the first mutex_unlock and the second mutex_lock. In this case, lookup_one_len() in compose_entry_fh() will return a negative dentry. It is better to test inode (positive/negative) BEFORE fh_compose(). Signed-off-by: J. R. Okajima diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 17d0dd9..1b5543b 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -851,8 +851,8 @@ compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp, if (IS_ERR(dchild)) return 1; if (d_mountpoint(dchild) || - fh_compose(fhp, exp, dchild, &cd->fh) != 0 || - !dchild->d_inode) + !dchild->d_inode || + fh_compose(fhp, exp, dchild, &cd->fh) != 0) rv = 1; dput(dchild); return rv;