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authorrmacklem <rmacklem@FreeBSD.org>2010-07-24 22:11:11 +0000
committerrmacklem <rmacklem@FreeBSD.org>2010-07-24 22:11:11 +0000
commitc7c4e3ebae85ae531fe298149a6ce0b2a0643a04 (patch)
tree4eec6454349918ebb035552eba42b0ef1fd7eaa6 /sys/nfs
parent0dd9a760b4e6c729904b4821a46073d2840a105c (diff)
downloadFreeBSD-src-c7c4e3ebae85ae531fe298149a6ce0b2a0643a04.zip
FreeBSD-src-c7c4e3ebae85ae531fe298149a6ce0b2a0643a04.tar.gz
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
Diffstat (limited to 'sys/nfs')
-rw-r--r--sys/nfs/nfs_lock.c396
-rw-r--r--sys/nfs/nfs_lock.h90
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
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