From owner-svn-src-stable@freebsd.org Tue Aug 11 05:10:02 2020 Return-Path: Delivered-To: svn-src-stable@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 58BF437AADC; Tue, 11 Aug 2020 05:10:02 +0000 (UTC) (envelope-from rmacklem@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4BQgrB0TD8z426y; Tue, 11 Aug 2020 05:10:02 +0000 (UTC) (envelope-from rmacklem@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id E7CED16103; Tue, 11 Aug 2020 05:10:01 +0000 (UTC) (envelope-from rmacklem@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 07B5A19g082473; Tue, 11 Aug 2020 05:10:01 GMT (envelope-from rmacklem@FreeBSD.org) Received: (from rmacklem@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 07B5A1HV082472; Tue, 11 Aug 2020 05:10:01 GMT (envelope-from rmacklem@FreeBSD.org) Message-Id: <202008110510.07B5A1HV082472@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: rmacklem set sender to rmacklem@FreeBSD.org using -f From: Rick Macklem Date: Tue, 11 Aug 2020 05:10:01 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r364097 - stable/12/sys/fs/nfsclient X-SVN-Group: stable-12 X-SVN-Commit-Author: rmacklem X-SVN-Commit-Paths: stable/12/sys/fs/nfsclient X-SVN-Commit-Revision: 364097 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Aug 2020 05:10:02 -0000 Author: rmacklem Date: Tue Aug 11 05:10:01 2020 New Revision: 364097 URL: https://svnweb.freebsd.org/changeset/base/364097 Log: MFC: r363210 Fix the pNFS flexible file layout client for servers with small write size. The code in nfscl_dofflayout() loops when a flexible file layout server provides a small write data limit (no extant server is known to do this). If/when it looped, it erroneously reused the "drpc" argument for the mirror worker thread, corrupting it. This patch fixes the problem by only using the calling thread after the first loop iteration. Found during testing by simulating a server with a small write size. Since no extant pNFS server is known to provide a small write size, this fix it not needed in practice at this time. Modified: stable/12/sys/fs/nfsclient/nfs_clrpcops.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/fs/nfsclient/nfs_clrpcops.c ============================================================================== --- stable/12/sys/fs/nfsclient/nfs_clrpcops.c Tue Aug 11 02:05:09 2020 (r364096) +++ stable/12/sys/fs/nfsclient/nfs_clrpcops.c Tue Aug 11 05:10:01 2020 (r364097) @@ -6103,10 +6103,17 @@ nfscl_dofflayoutio(vnode_t vp, struct uio *uiop, int * NFSCL_DEBUG(4, "mcopy reloff=%d xfer=%jd\n", rel_off, (uintmax_t)xfer); /* - * Do last write to a mirrored DS with this + * Do the writes after the first loop iteration + * and the write for the last mirror via this * thread. + * This loop only iterates for small values + * of nfsdi_wsize, which may never occur in + * practice. However, the drpc is completely + * used by the first iteration and, as such, + * cannot be used after that. */ - if (mirror < flp->nfsfl_mirrorcnt - 1) + if (mirror < flp->nfsfl_mirrorcnt - 1 && + rel_off == 0) error = nfsio_writedsmir(vp, iomode, must_commit, stateidp, *dspp, off, xfer, fhp, m, dp->nfsdi_vers,