From patchwork Thu Jul 14 20:04:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 12918475 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 7E875CCA47C for ; Thu, 14 Jul 2022 20:04:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239664AbiGNUEm (ORCPT ); Thu, 14 Jul 2022 16:04:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232113AbiGNUEl (ORCPT ); Thu, 14 Jul 2022 16:04:41 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89D7B46D87 for ; Thu, 14 Jul 2022 13:04:39 -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 ams.source.kernel.org (Postfix) with ESMTPS id 3F4F9B828C9 for ; Thu, 14 Jul 2022 20:04:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 673DAC341C6; Thu, 14 Jul 2022 20:04:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657829076; bh=FUSHl8KE9FYVdXFl7kKK+SZlM7W/c3K8uLnqJ9Sfngk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CX8Lt2262WAZZJOyCQCOvxFBQhdWgaMa06tUf0VCUMZ7KPWZC/nxaJg0XJupHR8EV iM+9p7W3enyP16pfK25oiGm7MR7j+XK5+KSFXVk+SiSgNv9YCZd1FUFURLIyamKYw8 akMNT5QYwqRZg+2LN4YTS01iPdYpdLwld+AwVM6OBwGYp69CWCbkPECXtj1uKk3+0w hNbtyyoGRSJpKoznUwhZ6e8MmdtuN0/SL9z9ykzUdYUYk8EsNqnS6mMFt9ITbLC5xs zwmSbDx+aajcDVdhC+qEkWlcO29tLLbJyg3Sn9/oFcNiogLDs17To4sZgH2taX0EWj 2Ye3fTx8X4n7w== From: Jeff Layton To: chuck.lever@oracle.com Cc: neilb@suse.de, linux-nfs@vger.kernel.org Subject: [PATCH 1/2] nfsd: drop fh argument from alloc_init_deleg Date: Thu, 14 Jul 2022 16:04:33 -0400 Message-Id: <20220714200434.161818-2-jlayton@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220714200434.161818-1-jlayton@kernel.org> References: <20220714200434.161818-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Currently, we pass the fh of the opened file down through several functions so that alloc_init_deleg can pass it to delegation_blocked. The filehandle of the open file is available in the nfs4_file however, so there's no need to pass it in a separate argument. Drop the argument from alloc_init_deleg, nfs4_open_delegation and nfs4_set_delegation. Signed-off-by: Jeff Layton --- fs/nfsd/nfs4state.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 8201d716a557..d2d21fdf5c41 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1131,7 +1131,6 @@ static void block_delegations(struct knfsd_fh *fh) static struct nfs4_delegation * alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp, - struct svc_fh *current_fh, struct nfs4_clnt_odstate *odstate) { struct nfs4_delegation *dp; @@ -1141,7 +1140,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp, n = atomic_long_inc_return(&num_delegations); if (n < 0 || n > max_delegations) goto out_dec; - if (delegation_blocked(¤t_fh->fh_handle)) + if (delegation_blocked(&fp->fi_fhandle)) goto out_dec; dp = delegstateid(nfs4_alloc_stid(clp, deleg_slab, nfs4_free_deleg)); if (dp == NULL) @@ -5269,7 +5268,7 @@ static int nfsd4_check_conflicting_opens(struct nfs4_client *clp, } static struct nfs4_delegation * -nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh, +nfs4_set_delegation(struct nfs4_client *clp, struct nfs4_file *fp, struct nfs4_clnt_odstate *odstate) { int status = 0; @@ -5314,7 +5313,7 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh, return ERR_PTR(status); status = -ENOMEM; - dp = alloc_init_deleg(clp, fp, fh, odstate); + dp = alloc_init_deleg(clp, fp, odstate); if (!dp) goto out_delegees; @@ -5382,8 +5381,7 @@ static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status) * proper support for them. */ static void -nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, - struct nfs4_ol_stateid *stp) +nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp) { struct nfs4_delegation *dp; struct nfs4_openowner *oo = openowner(stp->st_stateowner); @@ -5415,7 +5413,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, default: goto out_no_deleg; } - dp = nfs4_set_delegation(clp, fh, stp->st_stid.sc_file, stp->st_clnt_odstate); + dp = nfs4_set_delegation(clp, stp->st_stid.sc_file, stp->st_clnt_odstate); if (IS_ERR(dp)) goto out_no_deleg; @@ -5547,7 +5545,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf * Attempt to hand out a delegation. No error return, because the * OPEN succeeds even if we fail. */ - nfs4_open_delegation(current_fh, open, stp); + nfs4_open_delegation(open, stp); nodeleg: status = nfs_ok; trace_nfsd_open(&stp->st_stid.sc_stateid); From patchwork Thu Jul 14 20:04:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 12918476 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 0C8AAC433EF for ; Thu, 14 Jul 2022 20:04:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239940AbiGNUEl (ORCPT ); Thu, 14 Jul 2022 16:04:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239664AbiGNUEj (ORCPT ); Thu, 14 Jul 2022 16:04:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7726B46DB8 for ; Thu, 14 Jul 2022 13:04:38 -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 0361B6221B for ; Thu, 14 Jul 2022 20:04:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A964C34115; Thu, 14 Jul 2022 20:04:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657829077; bh=ZBokBBWVnSkst341i6kaq8Hiu+DHPq2Y0Y06wUBukvg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iSylfhlrAg/JeNZXQ+TEHVOr2MMYW+1fTBxbl186BAJUBxCqnhlfhNpHq+tHLOnhV PN85siOwE7DN5r6Hhe2QdaSizSTWfE85M/zMtFPr/hOAWWDEV5zFiYZ0H5cD/qDI8g 3wh9cPwLb2dfyfStkkm0loGY+sIciUj5YZCmQkEkEsny3Fw1snvM3uUW0rq7ljsQ/+ c54u36Jv1y10wLGmar8IReB42zXy5bpztd4yM0Eh8Z5ke5OjcWoMeQSNWtZqW0gYn4 QyroysijX5RmbKdg2ZcksQcUmoSTS/OvAKNv+mWwM/hq9Mgy8UkJyELny4ScXUZvZL 7Z+8MHqwtG/vA== From: Jeff Layton To: chuck.lever@oracle.com Cc: neilb@suse.de, linux-nfs@vger.kernel.org Subject: [PATCH 2/2] nfsd: vet the opened dentry after setting a delegation Date: Thu, 14 Jul 2022 16:04:34 -0400 Message-Id: <20220714200434.161818-3-jlayton@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220714200434.161818-1-jlayton@kernel.org> References: <20220714200434.161818-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Between opening a file and setting a delegation on it, someone could rename or unlink the dentry. If this happens, we do not want to grant a delegation on the open. On a CLAIM_NULL open, we're opening by filename, and we'll hold the i_rwsem while when attempting to set a delegation. After getting a lease, redo the lookup of the file being opened and validate that the resulting dentry matches the one in the open file description. Signed-off-by: Jeff Layton --- fs/nfsd/nfs4state.c | 48 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 5 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index d2d21fdf5c41..8a8d8c738950 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -5267,11 +5267,38 @@ static int nfsd4_check_conflicting_opens(struct nfs4_client *clp, return 0; } +/* + * It's possible that between opening the dentry and setting the delegation, + * that it has been renamed or unlinked. Redo the lookup to validate that this + * hasn't happened. + */ +static int +nfsd4_vet_deleg_dentry(struct nfsd4_open *open, struct nfs4_file *fp, + struct dentry *parent) +{ + struct dentry *child; + + lockdep_assert_held(&d_inode(parent)->i_rwsem); + + child = lookup_one_len(open->op_fname, parent, open->op_fnamelen); + if (IS_ERR(child)) + return PTR_ERR(child); + dput(child); + + if (child != file_dentry(fp->fi_deleg_file->nf_file)) + return -EAGAIN; + + return 0; +} + static struct nfs4_delegation * -nfs4_set_delegation(struct nfs4_client *clp, - struct nfs4_file *fp, struct nfs4_clnt_odstate *odstate) +nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, + struct dentry *parent) { int status = 0; + struct nfs4_client *clp = stp->st_stid.sc_client; + struct nfs4_file *fp = stp->st_stid.sc_file; + struct nfs4_clnt_odstate *odstate = stp->st_clnt_odstate; struct nfs4_delegation *dp; struct nfsd_file *nf; struct file_lock *fl; @@ -5326,6 +5353,13 @@ nfs4_set_delegation(struct nfs4_client *clp, locks_free_lock(fl); if (status) goto out_clnt_odstate; + + if (parent) { + status = nfsd4_vet_deleg_dentry(open, fp, parent); + if (status) + goto out_unlock; + } + status = nfsd4_check_conflicting_opens(clp, fp); if (status) goto out_unlock; @@ -5381,11 +5415,13 @@ static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status) * proper support for them. */ static void -nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp) +nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, + struct dentry *cdentry) { struct nfs4_delegation *dp; struct nfs4_openowner *oo = openowner(stp->st_stateowner); struct nfs4_client *clp = stp->st_stid.sc_client; + struct dentry *parent = NULL; int cb_up; int status = 0; @@ -5399,6 +5435,8 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp) goto out_no_deleg; break; case NFS4_OPEN_CLAIM_NULL: + parent = cdentry; + fallthrough; case NFS4_OPEN_CLAIM_FH: /* * Let's not give out any delegations till everyone's @@ -5413,7 +5451,7 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp) default: goto out_no_deleg; } - dp = nfs4_set_delegation(clp, stp->st_stid.sc_file, stp->st_clnt_odstate); + dp = nfs4_set_delegation(open, stp, parent); if (IS_ERR(dp)) goto out_no_deleg; @@ -5545,7 +5583,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf * Attempt to hand out a delegation. No error return, because the * OPEN succeeds even if we fail. */ - nfs4_open_delegation(open, stp); + nfs4_open_delegation(open, stp, resp->cstate.current_fh.fh_dentry); nodeleg: status = nfs_ok; trace_nfsd_open(&stp->st_stid.sc_stateid);