From patchwork Wed May 11 21:52:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12846648 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 20B5FC433F5 for ; Wed, 11 May 2022 21:52:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241641AbiEKVw5 (ORCPT ); Wed, 11 May 2022 17:52:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230306AbiEKVwz (ORCPT ); Wed, 11 May 2022 17:52:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4FD83102774 for ; Wed, 11 May 2022 14:52:54 -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 DFD9161B9D for ; Wed, 11 May 2022 21:52:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F28E5C34114; Wed, 11 May 2022 21:52:52 +0000 (UTC) Subject: [PATCH RFC 1/2] NFSD: nfsd4_release_lockowner() should drop clp->cl_lock sooner From: Chuck Lever To: linux-nfs@vger.kernel.org Cc: trondmy@hammerspace.com, bfields@fieldses.org, jlayton@redhat.com, dai.ngo@oracle.com Date: Wed, 11 May 2022 17:52:51 -0400 Message-ID: <165230597191.5906.5961060184718742042.stgit@klimt.1015granger.net> In-Reply-To: <165230584037.5906.5496655737644872339.stgit@klimt.1015granger.net> References: <165230584037.5906.5496655737644872339.stgit@klimt.1015granger.net> User-Agent: StGit/1.5.dev1+g8516920 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org nfsd4_release_lockowner() mustn't hold clp->cl_lock when check_for_locks() invokes nfsd_file_put(), which can sleep. Reported-by: Dai Ngo Signed-off-by: Chuck Lever Cc: --- fs/nfsd/nfs4state.c | 56 +++++++++++++++++++++++---------------------------- 1 file changed, 25 insertions(+), 31 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 234e852fcdfa..e2eb6d031643 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6611,8 +6611,8 @@ nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny) deny->ld_type = NFS4_WRITE_LT; } -static struct nfs4_lockowner * -find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner) +static struct nfs4_stateowner * +find_stateowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner) { unsigned int strhashval = ownerstr_hashval(owner); struct nfs4_stateowner *so; @@ -6624,11 +6624,22 @@ find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner) if (so->so_is_open_owner) continue; if (same_owner_str(so, owner)) - return lockowner(nfs4_get_stateowner(so)); + return nfs4_get_stateowner(so); } return NULL; } +static struct nfs4_lockowner * +find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner) +{ + struct nfs4_stateowner *so; + + so = find_stateowner_str_locked(clp, owner); + if (!so) + return NULL; + return lockowner(so); +} + static struct nfs4_lockowner * find_lockowner_str(struct nfs4_client *clp, struct xdr_netobj *owner) { @@ -7305,10 +7316,8 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp, struct nfsd4_release_lockowner *rlockowner = &u->release_lockowner; clientid_t *clid = &rlockowner->rl_clientid; struct nfs4_stateowner *sop; - struct nfs4_lockowner *lo = NULL; + struct nfs4_lockowner *lo; struct nfs4_ol_stateid *stp; - struct xdr_netobj *owner = &rlockowner->rl_owner; - unsigned int hashval = ownerstr_hashval(owner); __be32 status; struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); struct nfs4_client *clp; @@ -7322,32 +7331,18 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp, return status; clp = cstate->clp; - /* Find the matching lock stateowner */ spin_lock(&clp->cl_lock); - list_for_each_entry(sop, &clp->cl_ownerstr_hashtbl[hashval], - so_strhash) { - - if (sop->so_is_open_owner || !same_owner_str(sop, owner)) - continue; - - /* see if there are still any locks associated with it */ - lo = lockowner(sop); - list_for_each_entry(stp, &sop->so_stateids, st_perstateowner) { - if (check_for_locks(stp->st_stid.sc_file, lo)) { - status = nfserr_locks_held; - spin_unlock(&clp->cl_lock); - return status; - } - } + sop = find_stateowner_str_locked(clp, &rlockowner->rl_owner); + spin_unlock(&clp->cl_lock); + if (!sop) + return nfs_ok; - nfs4_get_stateowner(sop); - break; - } - if (!lo) { - spin_unlock(&clp->cl_lock); - return status; - } + lo = lockowner(sop); + list_for_each_entry(stp, &sop->so_stateids, st_perstateowner) + if (check_for_locks(stp->st_stid.sc_file, lo)) + return nfserr_locks_held; + spin_lock(&clp->cl_lock); unhash_lockowner_locked(lo); while (!list_empty(&lo->lo_owner.so_stateids)) { stp = list_first_entry(&lo->lo_owner.so_stateids, @@ -7360,8 +7355,7 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp, free_ol_stateid_reaplist(&reaplist); remove_blocked_locks(lo); nfs4_put_stateowner(&lo->lo_owner); - - return status; + return nfs_ok; } static inline struct nfs4_client_reclaim *