From owner-svn-src-all@freebsd.org Sun Jun 23 13:44:07 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 3495615D184E; Sun, 23 Jun 2019 13:44:07 +0000 (UTC) (envelope-from asomers@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 CBB388BDCC; Sun, 23 Jun 2019 13:44:06 +0000 (UTC) (envelope-from asomers@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 B91472286A; Sun, 23 Jun 2019 13:44:06 +0000 (UTC) (envelope-from asomers@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x5NDi6Ex084870; Sun, 23 Jun 2019 13:44:06 GMT (envelope-from asomers@FreeBSD.org) Received: (from asomers@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x5NDi68M084869; Sun, 23 Jun 2019 13:44:06 GMT (envelope-from asomers@FreeBSD.org) Message-Id: <201906231344.x5NDi68M084869@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: asomers set sender to asomers@FreeBSD.org using -f From: Alan Somers Date: Sun, 23 Jun 2019 13:44:06 +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: r349307 - stable/12/sys/kern X-SVN-Group: stable-12 X-SVN-Commit-Author: asomers X-SVN-Commit-Paths: stable/12/sys/kern X-SVN-Commit-Revision: 349307 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: CBB388BDCC X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.95 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.95)[-0.955,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 Jun 2019 13:44:07 -0000 Author: asomers Date: Sun Jun 23 13:44:06 2019 New Revision: 349307 URL: https://svnweb.freebsd.org/changeset/base/349307 Log: MFC r348737: Add a testing facility to manually reclaim a vnode Add the debug.try_reclaim_vnode sysctl. When a pathname is written to it, it will be reclaimed, as long as it isn't already or doomed. The purpose is to gain test coverage for vnode reclamation, which is otherwise hard to achieve. Add the debug.ftry_reclaim_vnode sysctl. It does the same thing, except that its argument is a file descriptor instead of a pathname. Reviewed by: kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20519 Modified: stable/12/sys/kern/vfs_subr.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/kern/vfs_subr.c ============================================================================== --- stable/12/sys/kern/vfs_subr.c Sun Jun 23 13:40:56 2019 (r349306) +++ stable/12/sys/kern/vfs_subr.c Sun Jun 23 13:44:06 2019 (r349307) @@ -50,6 +50,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include #include @@ -337,6 +338,93 @@ SYSCTL_ULONG(_kern, OID_AUTO, minvnodes, CTLFLAG_RW, static int vnlru_nowhere; SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0, "Number of times the vnlru process ran without success"); + +static int +sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS) +{ + struct vnode *vp; + struct nameidata nd; + char *buf; + unsigned long ndflags; + int error; + + if (req->newptr == NULL) + return (EINVAL); + if (req->newlen > PATH_MAX) + return (E2BIG); + + buf = malloc(PATH_MAX + 1, M_TEMP, M_WAITOK); + error = SYSCTL_IN(req, buf, req->newlen); + if (error != 0) + goto out; + + buf[req->newlen] = '\0'; + + ndflags = LOCKLEAF | NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME; + NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread); + if ((error = namei(&nd)) != 0) + goto out; + vp = nd.ni_vp; + + if ((vp->v_iflag & VI_DOOMED) != 0) { + /* + * This vnode is being recycled. Return != 0 to let the caller + * know that the sysctl had no effect. Return EAGAIN because a + * subsequent call will likely succeed (since namei will create + * a new vnode if necessary) + */ + error = EAGAIN; + goto putvnode; + } + + counter_u64_add(recycles_count, 1); + vgone(vp); +putvnode: + NDFREE(&nd, 0); +out: + free(buf, M_TEMP); + return (error); +} + +static int +sysctl_ftry_reclaim_vnode(SYSCTL_HANDLER_ARGS) +{ + struct thread *td = curthread; + struct vnode *vp; + struct file *fp; + int error; + int fd; + + if (req->newptr == NULL) + return (EBADF); + + error = sysctl_handle_int(oidp, &fd, 0, req); + if (error != 0) + return (error); + error = getvnode(curthread, fd, &cap_fcntl_rights, &fp); + if (error != 0) + return (error); + vp = fp->f_vnode; + + error = vn_lock(vp, LK_EXCLUSIVE); + if (error != 0) + goto drop; + + counter_u64_add(recycles_count, 1); + vgone(vp); + VOP_UNLOCK(vp, 0); +drop: + fdrop(fp, td); + return (error); +} + +SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode, + CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, + sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname"); +SYSCTL_PROC(_debug, OID_AUTO, ftry_reclaim_vnode, + CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0, + sysctl_ftry_reclaim_vnode, "I", + "Try to reclaim a vnode by its file descriptor"); /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */ static int vnsz2log;