Move sys/nfsclient/nfs_lock.c into sys/nfs and build it as a separate

module that can be used by both the regular and experimental nfs
clients. This fixes the problem reported by jh@ where /dev/nfslock
would be registered twice when both nfs clients were used.
I also defined the size of the lm_fh field to be the correct value,
as it should be the maximum size of an NFSv3 file handle.

Reviewed by:	jh
MFC after:	2 weeks

2 files changed, 486 insertions, 0 deletions

diff --git a/sys/nfs/nfs_lock.c b/sys/nfs/nfs_lock.c
new file mode 100644
index 0000000..89ad654
--- /dev/null
+++ b/sys/nfs/nfs_lock.c
@@ -0,0 +1,396 @@
+/*-
+ * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Berkeley Software Design Inc's name may not be used to endorse or
+ *    promote products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *      from BSDI nfs_lock.c,v 2.4 1998/12/14 23:49:56 jch Exp
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/conf.h>
+#include <sys/fcntl.h>
+#include <sys/kernel.h>		/* for hz */
+#include <sys/limits.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/lockf.h>		/* for hz */ /* Must come after sys/malloc.h */
+#include <sys/mbuf.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/priv.h>
+#include <sys/proc.h>
+#include <sys/resourcevar.h>
+#include <sys/socket.h>
+#include <sys/socket.h>
+#include <sys/unistd.h>
+#include <sys/vnode.h>
+
+#include <net/if.h>
+
+#include <nfs/nfsproto.h>
+#include <nfs/nfs_lock.h>
+#include <nfsclient/nfs.h>
+#include <nfsclient/nfsmount.h>
+#include <nfsclient/nfsnode.h>
+#include <nfsclient/nlminfo.h>
+
+extern void (*nlminfo_release_p)(struct proc *p);
+
+MALLOC_DEFINE(M_NFSLOCK, "nfsclient_lock", "NFS lock request");
+MALLOC_DEFINE(M_NLMINFO, "nfsclient_nlminfo", "NFS lock process structure");
+
+static int nfslockdans(struct thread *td, struct lockd_ans *ansp);
+static void nlminfo_release(struct proc *p);
+/*
+ * --------------------------------------------------------------------
+ * A miniature device driver which the userland uses to talk to us.
+ *
+ */
+
+static struct cdev *nfslock_dev;
+static struct mtx nfslock_mtx;
+static int nfslock_isopen;
+static TAILQ_HEAD(,__lock_msg)	nfslock_list;
+
+static int
+nfslock_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
+{
+	int error;
+
+	error = priv_check(td, PRIV_NFS_LOCKD);
+	if (error)
+		return (error);
+
+	mtx_lock(&nfslock_mtx);
+	if (!nfslock_isopen) {
+		error = 0;
+		nfslock_isopen = 1;
+	} else {
+		error = EOPNOTSUPP;
+	}
+	mtx_unlock(&nfslock_mtx);
+		
+	return (error);
+}
+
+static int
+nfslock_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
+{
+	struct __lock_msg *lm;
+
+	mtx_lock(&nfslock_mtx);
+	nfslock_isopen = 0;
+	while (!TAILQ_EMPTY(&nfslock_list)) {
+		lm = TAILQ_FIRST(&nfslock_list);
+		/* XXX: answer request */
+		TAILQ_REMOVE(&nfslock_list, lm, lm_link);
+		free(lm, M_NFSLOCK);
+	}
+	mtx_unlock(&nfslock_mtx);
+	return (0);
+}
+
+static int
+nfslock_read(struct cdev *dev, struct uio *uio, int ioflag)
+{
+	int error;
+	struct __lock_msg *lm;
+
+	if (uio->uio_resid != sizeof *lm)
+		return (EOPNOTSUPP);
+	lm = NULL;
+	error = 0;
+	mtx_lock(&nfslock_mtx);
+	while (TAILQ_EMPTY(&nfslock_list)) {
+		error = msleep(&nfslock_list, &nfslock_mtx, PSOCK | PCATCH,
+		    "nfslockd", 0);
+		if (error)
+			break;
+	}
+	if (!error) {
+		lm = TAILQ_FIRST(&nfslock_list);
+		TAILQ_REMOVE(&nfslock_list, lm, lm_link);
+	}
+	mtx_unlock(&nfslock_mtx);
+	if (!error) {
+		error = uiomove(lm, sizeof *lm, uio);
+		free(lm, M_NFSLOCK);
+	}
+	return (error);
+}
+
+static int
+nfslock_write(struct cdev *dev, struct uio *uio, int ioflag)
+{
+	struct lockd_ans la;
+	int error;
+
+	if (uio->uio_resid != sizeof la)
+		return (EOPNOTSUPP);
+	error = uiomove(&la, sizeof la, uio);
+	if (!error)
+		error = nfslockdans(curthread, &la);
+	return (error);
+}
+
+static int
+nfslock_send(struct __lock_msg *lm)
+{
+	struct __lock_msg *lm2;
+	int error;
+
+	error = 0;
+	lm2 = malloc(sizeof *lm2, M_NFSLOCK, M_WAITOK);
+	mtx_lock(&nfslock_mtx);
+	if (nfslock_isopen) {
+		memcpy(lm2, lm, sizeof *lm2);
+		TAILQ_INSERT_TAIL(&nfslock_list, lm2, lm_link);
+		wakeup(&nfslock_list);
+	} else {
+		error = EOPNOTSUPP;
+	}
+	mtx_unlock(&nfslock_mtx);
+	if (error)
+		free(lm2, M_NFSLOCK);
+	return (error);
+}
+
+static struct cdevsw nfslock_cdevsw = {
+	.d_version =	D_VERSION,
+	.d_open =	nfslock_open,
+	.d_close =	nfslock_close,
+	.d_read =	nfslock_read,
+	.d_write =	nfslock_write,
+	.d_name =	"nfslock"
+};
+
+static int
+nfslock_modevent(module_t mod __unused, int type, void *data __unused)
+{
+
+	switch (type) {
+	case MOD_LOAD:
+		if (bootverbose)
+			printf("nfslock: pseudo-device\n");
+		mtx_init(&nfslock_mtx, "nfslock", NULL, MTX_DEF);
+		TAILQ_INIT(&nfslock_list);
+		nlminfo_release_p = nlminfo_release;
+		nfslock_dev = make_dev(&nfslock_cdevsw, 0,
+		    UID_ROOT, GID_KMEM, 0600, _PATH_NFSLCKDEV);
+		return (0);
+	default:
+		return (EOPNOTSUPP);
+	}
+}
+
+DEV_MODULE(nfslock, nfslock_modevent, NULL);
+MODULE_VERSION(nfslock, 1);
+
+
+/*
+ * XXX
+ * We have to let the process know if the call succeeded.  I'm using an extra
+ * field in the p_nlminfo field in the proc structure, as it is already for
+ * lockd stuff.
+ */
+
+/*
+ * nfs_advlock --
+ *      NFS advisory byte-level locks.
+ *
+ * The vnode shall be (shared) locked on the entry, it is
+ * unconditionally unlocked after.
+ */
+int
+nfs_dolock(struct vop_advlock_args *ap)
+{
+	LOCKD_MSG msg;
+	struct thread *td;
+	struct vnode *vp;
+	int error;
+	struct flock *fl;
+	struct proc *p;
+
+	td = curthread;
+	p = td->td_proc;
+
+	vp = ap->a_vp;
+	fl = ap->a_fl;
+
+	ASSERT_VOP_LOCKED(vp, "nfs_dolock");
+
+	bcopy(VFSTONFS(vp->v_mount)->nm_nam, &msg.lm_addr,
+		min(sizeof msg.lm_addr, VFSTONFS(vp->v_mount)->nm_nam->sa_len));
+	msg.lm_fh_len = NFS_ISV3(vp) ? VTONFS(vp)->n_fhsize : NFSX_V2FH;
+	bcopy(VTONFS(vp)->n_fhp, msg.lm_fh, msg.lm_fh_len);
+	msg.lm_nfsv3 = NFS_ISV3(vp);
+	VOP_UNLOCK(vp, 0);
+
+	/*
+	 * the NLM protocol doesn't allow the server to return an error
+	 * on ranges, so we do it.
+	 */
+	if (fl->l_whence != SEEK_END) {
+		if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) ||
+		    fl->l_start < 0 ||
+		    (fl->l_len < 0 &&
+		     (fl->l_start == 0 || fl->l_start + fl->l_len < 0)))
+			return (EINVAL);
+		if (fl->l_len > 0 &&
+			 (fl->l_len - 1 > OFF_MAX - fl->l_start))
+			return (EOVERFLOW);
+	}
+
+	/*
+	 * Fill in the information structure.
+	 */
+	msg.lm_version = LOCKD_MSG_VERSION;
+	msg.lm_msg_ident.pid = p->p_pid;
+
+	mtx_lock(&Giant);
+	/*
+	 * if there is no nfsowner table yet, allocate one.
+	 */
+	if (p->p_nlminfo == NULL) {
+		p->p_nlminfo = malloc(sizeof(struct nlminfo),
+		    M_NLMINFO, M_WAITOK | M_ZERO);
+		p->p_nlminfo->pid_start = p->p_stats->p_start;
+		timevaladd(&p->p_nlminfo->pid_start, &boottime);
+	}
+	msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start;
+	msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq);
+
+	msg.lm_fl = *fl;
+	msg.lm_wait = ap->a_flags & F_WAIT;
+	msg.lm_getlk = ap->a_op == F_GETLK;
+	cru2x(td->td_ucred, &msg.lm_cred);
+
+	for (;;) {
+		error = nfslock_send(&msg);
+		if (error)
+			goto out;
+
+		/* Unlocks succeed immediately.  */
+		if (fl->l_type == F_UNLCK)
+			goto out;
+
+		/*
+		 * Retry after 20 seconds if we haven't gotten a response yet.
+		 * This number was picked out of thin air... but is longer
+		 * then even a reasonably loaded system should take (at least
+		 * on a local network).  XXX Probably should use a back-off
+		 * scheme.
+		 *
+		 * XXX: No PCATCH here since we currently have no useful
+		 * way to signal to the userland rpc.lockd that the request
+		 * has been aborted.  Once the rpc.lockd implementation
+		 * can handle aborts, and we report them properly,
+		 * PCATCH can be put back.  In the mean time, if we did
+		 * permit aborting, the lock attempt would "get lost"
+		 * and the lock would get stuck in the locked state.
+		 */
+		error = tsleep(p->p_nlminfo, PUSER, "lockd", 20*hz);
+		if (error != 0) {
+			if (error == EWOULDBLOCK) {
+				/*
+				 * We timed out, so we rewrite the request
+				 * to the fifo.
+				 */
+				continue;
+			}
+
+			break;
+		}
+
+		if (msg.lm_getlk && p->p_nlminfo->retcode == 0) {
+			if (p->p_nlminfo->set_getlk_pid) {
+				fl->l_sysid = 0; /* XXX */
+				fl->l_pid = p->p_nlminfo->getlk_pid;
+			} else {
+				fl->l_type = F_UNLCK;
+			}
+		}
+		error = p->p_nlminfo->retcode;
+		break;
+	}
+ out:
+	mtx_unlock(&Giant);
+	return (error);
+}
+
+/*
+ * nfslockdans --
+ *      NFS advisory byte-level locks answer from the lock daemon.
+ */
+static int
+nfslockdans(struct thread *td, struct lockd_ans *ansp)
+{
+	struct proc *targetp;
+
+	/* the version should match, or we're out of sync */
+	if (ansp->la_vers != LOCKD_ANS_VERSION)
+		return (EINVAL);
+
+	/* Find the process, set its return errno and wake it up. */
+	if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL)
+		return (ESRCH);
+
+	/* verify the pid hasn't been reused (if we can), and it isn't waiting
+	 * for an answer from a more recent request.  We return an EPIPE if
+	 * the match fails, because we've already used ESRCH above, and this
+	 * is sort of like writing on a pipe after the reader has closed it.
+	 */
+	if (targetp->p_nlminfo == NULL ||
+	    ((ansp->la_msg_ident.msg_seq != -1) &&
+	      (timevalcmp(&targetp->p_nlminfo->pid_start,
+			&ansp->la_msg_ident.pid_start, !=) ||
+	       targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) {
+		PROC_UNLOCK(targetp);
+		return (EPIPE);
+	}
+
+	targetp->p_nlminfo->retcode = ansp->la_errno;
+	targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid;
+	targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid;
+
+	wakeup(targetp->p_nlminfo);
+
+	PROC_UNLOCK(targetp);
+	return (0);
+}
+
+/*
+ * Free nlminfo attached to process.
+ */
+void        
+nlminfo_release(struct proc *p)
+{  
+	free(p->p_nlminfo, M_NLMINFO);
+	p->p_nlminfo = NULL;
+}
diff --git a/sys/nfs/nfs_lock.h b/sys/nfs/nfs_lock.h
new file mode 100644
index 0000000..aa99996
--- /dev/null
+++ b/sys/nfs/nfs_lock.h
@@ -0,0 +1,90 @@
+/*-
+ * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Berkeley Software Design Inc's name may not be used to endorse or
+ *    promote products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *      from nfs_lock.h,v 2.2 1998/04/28 19:38:41 don Exp
+ * $FreeBSD$
+ */
+
+/*
+ * lockd uses the nfssvc system call to get the unique kernel services it needs.
+ * It passes in a request structure with a version number at the start.
+ * This prevents libc from needing to change if the information passed
+ * between lockd and the kernel needs to change.
+ *
+ * If a structure changes, you must bump the version number.
+ */
+
+/*
+ * The fifo where the kernel writes requests for locks on remote NFS files,
+ * and where lockd reads these requests.
+ *
+ */
+#define	_PATH_NFSLCKDEV	"nfslock"
+
+/*
+ * This structure is used to uniquely identify the process which originated
+ * a particular message to lockd.  A sequence number is used to differentiate
+ * multiple messages from the same process.  A process start time is used to
+ * detect the unlikely, but possible, event of the recycling of a pid.
+ */
+struct lockd_msg_ident {
+	pid_t		pid;            /* The process ID. */
+	struct timeval	pid_start;	/* Start time of process id */
+	int		msg_seq;	/* Sequence number of message */
+};
+
+#define LOCKD_MSG_VERSION	3
+
+/*
+ * The structure that the kernel hands us for each lock request.
+ */
+typedef struct __lock_msg {
+	TAILQ_ENTRY(__lock_msg)	lm_link;	/* internal linkage */
+	int			lm_version;	/* which version is this */
+	struct lockd_msg_ident	lm_msg_ident;	/* originator of the message */
+	struct flock		lm_fl;             /* The lock request. */
+	int			lm_wait;           /* The F_WAIT flag. */
+	int			lm_getlk;		/* is this a F_GETLK request */
+	struct sockaddr_storage lm_addr;		/* The address. */
+	int			lm_nfsv3;		/* If NFS version 3. */
+	size_t			lm_fh_len;		/* The file handle length. */
+	struct xucred		lm_cred;		/* user cred for lock req */
+	u_int8_t		lm_fh[NFSX_V3FHMAX];/* The file handle. */
+} LOCKD_MSG;
+
+#define LOCKD_ANS_VERSION	1
+
+struct lockd_ans {
+	int		la_vers;
+	struct lockd_msg_ident	la_msg_ident;	/* originator of the message */
+	int		la_errno;
+	int		la_set_getlk_pid;		/* use returned pid */
+	int		la_getlk_pid;		/* returned pid for F_GETLK */
+};
+
+#ifdef _KERNEL
+int	nfs_dolock(struct vop_advlock_args *ap);
+#endif