From patchwork Fri May 13 19:39:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12849314 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B202C433FE for ; Fri, 13 May 2022 19:39:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383893AbiEMTjw (ORCPT ); Fri, 13 May 2022 15:39:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47216 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350745AbiEMTjv (ORCPT ); Fri, 13 May 2022 15:39:51 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EB234C41C; Fri, 13 May 2022 12:39:50 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1AB1F61759; Fri, 13 May 2022 19:39:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 552DEC34100; Fri, 13 May 2022 19:39:49 +0000 (UTC) Subject: [PATCH 4/8] NFSD: Refactor NFSv3 CREATE From: Chuck Lever To: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk Date: Fri, 13 May 2022 15:39:48 -0400 Message-ID: <165247078834.6691.636687374106210345.stgit@bazille.1015granger.net> In-Reply-To: <165247056822.6691.9087206893184705325.stgit@bazille.1015granger.net> References: <165247056822.6691.9087206893184705325.stgit@bazille.1015granger.net> User-Agent: StGit/1.5 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The NFSv3 CREATE and NFSv4 OPEN(CREATE) use cases are about to diverge such that it makes sense to split do_nfsd_create() into one version for NFSv3 and one for NFSv4. As a first step, copy do_nfsd_create() to nfs3proc.c and remove NFSv4-specific logic. One immediate legibility benefit is that the logic for handling NFSv3 createhow is now quite straightforward. NFSv4 createhow has some subtleties that IMO do not belong in generic code. Signed-off-by: Chuck Lever --- fs/nfsd/nfs3proc.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 121 insertions(+), 6 deletions(-) diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 981a2a71c5af..981a3a7a6e16 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -8,6 +8,7 @@ #include #include #include +#include #include "cache.h" #include "xdr3.h" @@ -220,10 +221,126 @@ nfsd3_proc_write(struct svc_rqst *rqstp) } /* - * With NFSv3, CREATE processing is a lot easier than with NFSv2. - * At least in theory; we'll see how it fares in practice when the - * first reports about SunOS compatibility problems start to pour in... + * Implement NFSv3's unchecked, guarded, and exclusive CREATE + * semantics for regular files. Except for the created file, + * this operation is stateless on the server. + * + * Upon return, caller must release @fhp and @resfhp. */ +static __be32 +nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp, + struct svc_fh *resfhp, struct nfsd3_createargs *argp) +{ + struct iattr *iap = &argp->attrs; + struct dentry *parent, *child; + __u32 v_mtime, v_atime; + struct inode *inode; + __be32 status; + int host_err; + + if (isdotent(argp->name, argp->len)) + return nfserr_exist; + if (!(iap->ia_valid & ATTR_MODE)) + iap->ia_mode = 0; + + status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); + if (status != nfs_ok) + return status; + + parent = fhp->fh_dentry; + inode = d_inode(parent); + + host_err = fh_want_write(fhp); + if (host_err) + return nfserrno(host_err); + + fh_lock_nested(fhp, I_MUTEX_PARENT); + + child = lookup_one_len(argp->name, parent, argp->len); + if (IS_ERR(child)) { + status = nfserrno(PTR_ERR(child)); + goto out; + } + + if (d_really_is_negative(child)) { + status = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); + if (status != nfs_ok) + goto out; + } + + status = fh_compose(resfhp, fhp->fh_export, child, fhp); + if (status != nfs_ok) + goto out; + + v_mtime = 0; + v_atime = 0; + if (argp->createmode == NFS3_CREATE_EXCLUSIVE) { + u32 *verifier = (u32 *)argp->verf; + + /* + * Solaris 7 gets confused (bugid 4218508) if these have + * the high bit set, as do xfs filesystems without the + * "bigtime" feature. So just clear the high bits. + */ + v_mtime = verifier[0] & 0x7fffffff; + v_atime = verifier[1] & 0x7fffffff; + } + + if (d_really_is_positive(child)) { + status = nfs_ok; + + switch (argp->createmode) { + case NFS3_CREATE_UNCHECKED: + if (!d_is_reg(child)) + break; + iap->ia_valid &= ATTR_SIZE; + goto set_attr; + case NFS3_CREATE_GUARDED: + status = nfserr_exist; + break; + case NFS3_CREATE_EXCLUSIVE: + if (d_inode(child)->i_mtime.tv_sec == v_mtime && + d_inode(child)->i_atime.tv_sec == v_atime && + d_inode(child)->i_size == 0) { + break; + } + status = nfserr_exist; + } + goto out; + } + + if (!IS_POSIXACL(inode)) + iap->ia_mode &= ~current_umask(); + + host_err = vfs_create(&init_user_ns, inode, child, iap->ia_mode, true); + if (host_err < 0) { + status = nfserrno(host_err); + goto out; + } + + /* A newly created file already has a file size of zero. */ + if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) + iap->ia_valid &= ~ATTR_SIZE; + if (argp->createmode == NFS3_CREATE_EXCLUSIVE) { + iap->ia_valid = ATTR_MTIME | ATTR_ATIME | + ATTR_MTIME_SET | ATTR_ATIME_SET; + iap->ia_mtime.tv_sec = v_mtime; + iap->ia_atime.tv_sec = v_atime; + iap->ia_mtime.tv_nsec = 0; + iap->ia_atime.tv_nsec = 0; + } + +set_attr: + status = nfsd_create_setattr(rqstp, fhp, resfhp, iap); + +out: + fh_unlock(fhp); + if (child && !IS_ERR(child)) + dput(child); + fh_drop_write(fhp); + return status; +} + static __be32 nfsd3_proc_create(struct svc_rqst *rqstp) { @@ -239,9 +356,7 @@ nfsd3_proc_create(struct svc_rqst *rqstp) dirfhp = fh_copy(&resp->dirfh, &argp->fh); newfhp = fh_init(&resp->fh, NFS3_FHSIZE); - resp->status = do_nfsd_create(rqstp, dirfhp, argp->name, argp->len, - &argp->attrs, newfhp, argp->createmode, - (u32 *)argp->verf, NULL, NULL); + resp->status = nfsd3_create_file(rqstp, dirfhp, newfhp, argp); return rpc_success; }