Return-Path: Received: from mail-gx0-f174.google.com ([209.85.161.174]:34664 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756551Ab1H3TSt (ORCPT ); Tue, 30 Aug 2011 15:18:49 -0400 Received: by gxk21 with SMTP id 21so5915942gxk.19 for ; Tue, 30 Aug 2011 12:18:48 -0700 (PDT) Date: Tue, 30 Aug 2011 15:18:45 -0400 From: Jeff Layton To: Chuck Lever Cc: bfields@redhat.com, linux-nfs@vger.kernel.org Subject: Re: [PATCH] NFSD: Add a cache for fs_locations information Message-ID: <20110830151845.4dec5b40@tlielax.poochiereds.net> In-Reply-To: <20110829185115.3413.92459.stgit@matisse.1015granger.net> References: <20110829185115.3413.92459.stgit@matisse.1015granger.net> Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Mon, 29 Aug 2011 14:51:15 -0400 Chuck Lever wrote: > From: Trond Myklebust > > Signed-off-by: Trond Myklebust > [ cel: since this is server-side, use nfsd4_ prefix instead of nfs4_ prefix. ] > Signed-off-by: Chuck Lever > --- > > fs/nfsd/nfsd.h | 7 +++++++ > fs/nfsd/vfs.c | 15 +++++++++++++++ > 2 files changed, 22 insertions(+), 0 deletions(-) > > diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h > index 7ecfa24..d314812 100644 > --- a/fs/nfsd/nfsd.h > +++ b/fs/nfsd/nfsd.h > @@ -335,6 +335,13 @@ static inline u32 nfsd_suppattrs2(u32 minorversion) > #define NFSD_SUPPATTR_EXCLCREAT_WORD2 \ > NFSD_WRITEABLE_ATTRS_WORD2 > > +extern int nfsd4_is_junction(struct dentry *dentry); > +#else > +static inline int nfsd4_is_junction(struct dentry *dentry) > +{ > + return 0; > +} > + > #endif /* CONFIG_NFSD_V4 */ > > #endif /* LINUX_NFSD_NFSD_H */ > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c > index fd0acca..5dac667 100644 > --- a/fs/nfsd/vfs.c > +++ b/fs/nfsd/vfs.c > @@ -168,6 +168,8 @@ int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) > { > if (d_mountpoint(dentry)) > return 1; > + if (nfsd4_is_junction(dentry)) > + return 1; > if (!(exp->ex_flags & NFSEXP_V4ROOT)) > return 0; > return dentry->d_inode != NULL; > @@ -592,6 +594,19 @@ nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_ac > return error; > } > > +#define NFSD_XATTR_JUNCTION_PREFIX XATTR_TRUSTED_PREFIX "junction." > +#define NFSD_XATTR_JUNCTION_TYPE NFSD_XATTR_JUNCTION_PREFIX "type" > +int nfsd4_is_junction(struct dentry *dentry) > +{ > + ssize_t ret; > + > + if (dentry->d_inode != NULL) { > + ret = vfs_getxattr(dentry, NFSD_XATTR_JUNCTION_TYPE, NULL, 0); > + if (ret > 0) > + return 1; > + } > + return 0; > +} Won't the above check be rather expensive? You'll need to do a getxattr call on almost every path component of every lookup, right? I may be misremembering your talk from connectathon, but I thought you were planning to use a well-known mode for junctions that would cut down on the number of unnecessary getxattrs... > #endif /* defined(CONFIG_NFSD_V4) */ > > #ifdef CONFIG_NFSD_V3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jeff Layton