From owner-svn-src-all@freebsd.org Thu Jun 6 15:04:52 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 BBFD415B621E; Thu, 6 Jun 2019 15:04:51 +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 5C95F706DF; Thu, 6 Jun 2019 15:04:51 +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 319FD1E229; Thu, 6 Jun 2019 15:04:51 +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 x56F4oN7034765; Thu, 6 Jun 2019 15:04:50 GMT (envelope-from asomers@FreeBSD.org) Received: (from asomers@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x56F4odw034764; Thu, 6 Jun 2019 15:04:50 GMT (envelope-from asomers@FreeBSD.org) Message-Id: <201906061504.x56F4odw034764@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: asomers set sender to asomers@FreeBSD.org using -f From: Alan Somers Date: Thu, 6 Jun 2019 15:04:50 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r348737 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: asomers X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 348737 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 5C95F706DF X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.98 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.98)[-0.982,0]; 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: Thu, 06 Jun 2019 15:04:52 -0000 Author: asomers Date: Thu Jun 6 15:04:50 2019 New Revision: 348737 URL: https://svnweb.freebsd.org/changeset/base/348737 Log: 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 MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20519 Modified: head/sys/kern/vfs_subr.c Modified: head/sys/kern/vfs_subr.c ============================================================================== --- head/sys/kern/vfs_subr.c Thu Jun 6 12:44:43 2019 (r348736) +++ head/sys/kern/vfs_subr.c Thu Jun 6 15:04:50 2019 (r348737) @@ -50,6 +50,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include #include @@ -338,6 +339,93 @@ 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;