From owner-svn-src-head@freebsd.org Mon Sep 16 21:33:17 2019 Return-Path: Delivered-To: svn-src-head@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 21916ED40D; Mon, 16 Sep 2019 21:33:17 +0000 (UTC) (envelope-from mjg@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) server-signature RSA-PSS (4096 bits) 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 46XKH06tWRz4BLL; Mon, 16 Sep 2019 21:33:16 +0000 (UTC) (envelope-from mjg@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 CF42126556; Mon, 16 Sep 2019 21:33:16 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x8GLXGe8006438; Mon, 16 Sep 2019 21:33:16 GMT (envelope-from mjg@FreeBSD.org) Received: (from mjg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x8GLXGrG006436; Mon, 16 Sep 2019 21:33:16 GMT (envelope-from mjg@FreeBSD.org) Message-Id: <201909162133.x8GLXGrG006436@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org using -f From: Mateusz Guzik Date: Mon, 16 Sep 2019 21:33:16 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r352426 - in head/sys: kern ufs/ffs X-SVN-Group: head X-SVN-Commit-Author: mjg X-SVN-Commit-Paths: in head/sys: kern ufs/ffs X-SVN-Commit-Revision: 352426 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Sep 2019 21:33:17 -0000 Author: mjg Date: Mon Sep 16 21:33:16 2019 New Revision: 352426 URL: https://svnweb.freebsd.org/changeset/base/352426 Log: vfs: manage mnt_writeopcount with atomics See r352424. Reviewed by: kib, jeff Tested by: pho Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21575 Modified: head/sys/kern/vfs_vnops.c head/sys/ufs/ffs/ffs_softdep.c Modified: head/sys/kern/vfs_vnops.c ============================================================================== --- head/sys/kern/vfs_vnops.c Mon Sep 16 21:32:21 2019 (r352425) +++ head/sys/kern/vfs_vnops.c Mon Sep 16 21:33:16 2019 (r352426) @@ -1621,11 +1621,23 @@ vn_suspendable(struct mount *mp) * suspension is over, and then proceed. */ static int -vn_start_write_locked(struct mount *mp, int flags) +vn_start_write_refed(struct mount *mp, int flags, bool mplocked) { int error, mflags; - mtx_assert(MNT_MTX(mp), MA_OWNED); + if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 && + vfs_op_thread_enter(mp)) { + MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0); + atomic_add_int(&mp->mnt_writeopcount, 1); + vfs_op_thread_exit(mp); + return (0); + } + + if (mplocked) + mtx_assert(MNT_MTX(mp), MA_OWNED); + else + MNT_ILOCK(mp); + error = 0; /* @@ -1648,7 +1660,7 @@ vn_start_write_locked(struct mount *mp, int flags) } if (flags & V_XSLEEP) goto unlock; - mp->mnt_writeopcount++; + atomic_add_int(&mp->mnt_writeopcount, 1); unlock: if (error != 0 || (flags & V_XSLEEP) != 0) MNT_REL(mp); @@ -1694,11 +1706,10 @@ vn_start_write(struct vnode *vp, struct mount **mpp, i * refcount for the provided mountpoint too, in order to * emulate a vfs_ref(). */ - MNT_ILOCK(mp); if (vp == NULL && (flags & V_MNTREF) == 0) - MNT_REF(mp); + vfs_ref(mp); - return (vn_start_write_locked(mp, flags)); + return (vn_start_write_refed(mp, flags, false)); } /* @@ -1780,15 +1791,26 @@ vn_start_secondary_write(struct vnode *vp, struct moun void vn_finished_write(struct mount *mp) { + int c; + if (mp == NULL || !vn_suspendable(mp)) return; + + if (vfs_op_thread_enter(mp)) { + c = atomic_fetchadd_int(&mp->mnt_writeopcount, -1) - 1; + if (c < 0) + panic("vn_finished_write: invalid writeopcount %d", c); + MNT_REL_UNLOCKED(mp); + vfs_op_thread_exit(mp); + return; + } + MNT_ILOCK(mp); MNT_REL(mp); - mp->mnt_writeopcount--; - if (mp->mnt_writeopcount < 0) - panic("vn_finished_write: neg cnt"); - if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && - mp->mnt_writeopcount <= 0) + c = atomic_fetchadd_int(&mp->mnt_writeopcount, -1) - 1; + if (c < 0) + panic("vn_finished_write: invalid writeopcount %d", c); + if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0) wakeup(&mp->mnt_writeopcount); MNT_IUNLOCK(mp); } @@ -1827,8 +1849,11 @@ vfs_write_suspend(struct mount *mp, int flags) MPASS(vn_suspendable(mp)); + vfs_op_enter(mp); + MNT_ILOCK(mp); if (mp->mnt_susp_owner == curthread) { + vfs_op_exit_locked(mp); MNT_IUNLOCK(mp); return (EALREADY); } @@ -1845,6 +1870,7 @@ vfs_write_suspend(struct mount *mp, int flags) */ if ((flags & VS_SKIP_UNMOUNT) != 0 && (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { + vfs_op_exit_locked(mp); MNT_IUNLOCK(mp); return (EBUSY); } @@ -1856,8 +1882,10 @@ vfs_write_suspend(struct mount *mp, int flags) MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); else MNT_IUNLOCK(mp); - if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) + if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) { vfs_write_resume(mp, 0); + vfs_op_exit(mp); + } return (error); } @@ -1881,14 +1909,15 @@ vfs_write_resume(struct mount *mp, int flags) curthread->td_pflags &= ~TDP_IGNSUSP; if ((flags & VR_START_WRITE) != 0) { MNT_REF(mp); - mp->mnt_writeopcount++; + atomic_add_int(&mp->mnt_writeopcount, 1); } MNT_IUNLOCK(mp); if ((flags & VR_NO_SUSPCLR) == 0) VFS_SUSP_CLEAN(mp); + vfs_op_exit(mp); } else if ((flags & VR_START_WRITE) != 0) { MNT_REF(mp); - vn_start_write_locked(mp, 0); + vn_start_write_refed(mp, 0, true); } else { MNT_IUNLOCK(mp); } Modified: head/sys/ufs/ffs/ffs_softdep.c ============================================================================== --- head/sys/ufs/ffs/ffs_softdep.c Mon Sep 16 21:32:21 2019 (r352425) +++ head/sys/ufs/ffs/ffs_softdep.c Mon Sep 16 21:33:16 2019 (r352426) @@ -2954,17 +2954,26 @@ journal_suspend(ump) { struct jblocks *jblocks; struct mount *mp; + bool set; mp = UFSTOVFS(ump); + if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) + return; + jblocks = ump->softdep_jblocks; + vfs_op_enter(mp); + set = false; MNT_ILOCK(mp); if ((mp->mnt_kern_flag & MNTK_SUSPEND) == 0) { stat_journal_min++; mp->mnt_kern_flag |= MNTK_SUSPEND; mp->mnt_susp_owner = ump->softdep_flushtd; + set = true; } jblocks->jb_suspended = 1; MNT_IUNLOCK(mp); + if (!set) + vfs_op_exit(mp); } static int