2 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
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28 * from BSDI nfs_lock.c,v 2.4 1998/12/14 23:49:56 jch Exp
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
35 #include <sys/systm.h>
37 #include <sys/fcntl.h>
38 #include <sys/kernel.h> /* for hz */
39 #include <sys/limits.h>
41 #include <sys/malloc.h>
42 #include <sys/lockf.h> /* for hz */ /* Must come after sys/malloc.h */
44 #include <sys/mount.h>
45 #include <sys/namei.h>
48 #include <sys/resourcevar.h>
49 #include <sys/socket.h>
50 #include <sys/socket.h>
51 #include <sys/unistd.h>
52 #include <sys/vnode.h>
56 #include <nfs/nfsproto.h>
57 #include <nfs/nfs_lock.h>
58 #include <nfsclient/nfs.h>
59 #include <nfsclient/nfsmount.h>
60 #include <nfsclient/nfsnode.h>
61 #include <nfsclient/nlminfo.h>
63 extern void (*nlminfo_release_p)(struct proc *p);
65 vop_advlock_t *nfs_advlock_p = nfs_dolock;
66 vop_reclaim_t *nfs_reclaim_p = NULL;
68 MALLOC_DEFINE(M_NFSLOCK, "nfsclient_lock", "NFS lock request");
69 MALLOC_DEFINE(M_NLMINFO, "nfsclient_nlminfo", "NFS lock process structure");
71 static int nfslockdans(struct thread *td, struct lockd_ans *ansp);
72 static void nlminfo_release(struct proc *p);
74 * --------------------------------------------------------------------
75 * A miniature device driver which the userland uses to talk to us.
79 static struct cdev *nfslock_dev;
80 static struct mtx nfslock_mtx;
81 static int nfslock_isopen;
82 static TAILQ_HEAD(,__lock_msg) nfslock_list;
85 nfslock_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
89 error = priv_check(td, PRIV_NFS_LOCKD);
93 mtx_lock(&nfslock_mtx);
94 if (!nfslock_isopen) {
100 mtx_unlock(&nfslock_mtx);
106 nfslock_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
108 struct __lock_msg *lm;
110 mtx_lock(&nfslock_mtx);
112 while (!TAILQ_EMPTY(&nfslock_list)) {
113 lm = TAILQ_FIRST(&nfslock_list);
114 /* XXX: answer request */
115 TAILQ_REMOVE(&nfslock_list, lm, lm_link);
118 mtx_unlock(&nfslock_mtx);
123 nfslock_read(struct cdev *dev, struct uio *uio, int ioflag)
126 struct __lock_msg *lm;
128 if (uio->uio_resid != sizeof *lm)
132 mtx_lock(&nfslock_mtx);
133 while (TAILQ_EMPTY(&nfslock_list)) {
134 error = msleep(&nfslock_list, &nfslock_mtx, PSOCK | PCATCH,
140 lm = TAILQ_FIRST(&nfslock_list);
141 TAILQ_REMOVE(&nfslock_list, lm, lm_link);
143 mtx_unlock(&nfslock_mtx);
145 error = uiomove(lm, sizeof *lm, uio);
152 nfslock_write(struct cdev *dev, struct uio *uio, int ioflag)
157 if (uio->uio_resid != sizeof la)
159 error = uiomove(&la, sizeof la, uio);
161 error = nfslockdans(curthread, &la);
166 nfslock_send(struct __lock_msg *lm)
168 struct __lock_msg *lm2;
172 lm2 = malloc(sizeof *lm2, M_NFSLOCK, M_WAITOK);
173 mtx_lock(&nfslock_mtx);
174 if (nfslock_isopen) {
175 memcpy(lm2, lm, sizeof *lm2);
176 TAILQ_INSERT_TAIL(&nfslock_list, lm2, lm_link);
177 wakeup(&nfslock_list);
181 mtx_unlock(&nfslock_mtx);
183 free(lm2, M_NFSLOCK);
187 static struct cdevsw nfslock_cdevsw = {
188 .d_version = D_VERSION,
189 .d_open = nfslock_open,
190 .d_close = nfslock_close,
191 .d_read = nfslock_read,
192 .d_write = nfslock_write,
197 nfslock_modevent(module_t mod __unused, int type, void *data __unused)
203 printf("nfslock: pseudo-device\n");
204 mtx_init(&nfslock_mtx, "nfslock", NULL, MTX_DEF);
205 TAILQ_INIT(&nfslock_list);
206 nlminfo_release_p = nlminfo_release;
207 nfslock_dev = make_dev(&nfslock_cdevsw, 0,
208 UID_ROOT, GID_KMEM, 0600, _PATH_NFSLCKDEV);
215 DEV_MODULE(nfslock, nfslock_modevent, NULL);
216 MODULE_VERSION(nfslock, 1);
221 * We have to let the process know if the call succeeded. I'm using an extra
222 * field in the p_nlminfo field in the proc structure, as it is already for
228 * NFS advisory byte-level locks.
230 * The vnode shall be (shared) locked on the entry, it is
231 * unconditionally unlocked after.
234 nfs_dolock(struct vop_advlock_args *ap)
242 struct nfsmount *nmp;
249 nmp = VFSTONFS(vp->v_mount);
251 ASSERT_VOP_LOCKED(vp, "nfs_dolock");
253 nmp->nm_getinfo(vp, msg.lm_fh, &msg.lm_fh_len, &msg.lm_addr,
254 &msg.lm_nfsv3, NULL, NULL);
258 * the NLM protocol doesn't allow the server to return an error
259 * on ranges, so we do it.
261 if (fl->l_whence != SEEK_END) {
262 if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) ||
265 (fl->l_start == 0 || fl->l_start + fl->l_len < 0)))
268 (fl->l_len - 1 > OFF_MAX - fl->l_start))
273 * Fill in the information structure.
275 msg.lm_version = LOCKD_MSG_VERSION;
276 msg.lm_msg_ident.pid = p->p_pid;
280 * if there is no nfsowner table yet, allocate one.
282 if (p->p_nlminfo == NULL) {
283 p->p_nlminfo = malloc(sizeof(struct nlminfo),
284 M_NLMINFO, M_WAITOK | M_ZERO);
285 p->p_nlminfo->pid_start = p->p_stats->p_start;
286 timevaladd(&p->p_nlminfo->pid_start, &boottime);
288 msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start;
289 msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq);
292 msg.lm_wait = ap->a_flags & F_WAIT;
293 msg.lm_getlk = ap->a_op == F_GETLK;
294 cru2x(td->td_ucred, &msg.lm_cred);
297 error = nfslock_send(&msg);
301 /* Unlocks succeed immediately. */
302 if (fl->l_type == F_UNLCK)
306 * Retry after 20 seconds if we haven't gotten a response yet.
307 * This number was picked out of thin air... but is longer
308 * then even a reasonably loaded system should take (at least
309 * on a local network). XXX Probably should use a back-off
312 * XXX: No PCATCH here since we currently have no useful
313 * way to signal to the userland rpc.lockd that the request
314 * has been aborted. Once the rpc.lockd implementation
315 * can handle aborts, and we report them properly,
316 * PCATCH can be put back. In the mean time, if we did
317 * permit aborting, the lock attempt would "get lost"
318 * and the lock would get stuck in the locked state.
320 error = tsleep(p->p_nlminfo, PUSER, "lockd", 20*hz);
322 if (error == EWOULDBLOCK) {
324 * We timed out, so we rewrite the request
333 if (msg.lm_getlk && p->p_nlminfo->retcode == 0) {
334 if (p->p_nlminfo->set_getlk_pid) {
335 fl->l_sysid = 0; /* XXX */
336 fl->l_pid = p->p_nlminfo->getlk_pid;
338 fl->l_type = F_UNLCK;
341 error = p->p_nlminfo->retcode;
351 * NFS advisory byte-level locks answer from the lock daemon.
354 nfslockdans(struct thread *td, struct lockd_ans *ansp)
356 struct proc *targetp;
358 /* the version should match, or we're out of sync */
359 if (ansp->la_vers != LOCKD_ANS_VERSION)
362 /* Find the process, set its return errno and wake it up. */
363 if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL)
366 /* verify the pid hasn't been reused (if we can), and it isn't waiting
367 * for an answer from a more recent request. We return an EPIPE if
368 * the match fails, because we've already used ESRCH above, and this
369 * is sort of like writing on a pipe after the reader has closed it.
371 if (targetp->p_nlminfo == NULL ||
372 ((ansp->la_msg_ident.msg_seq != -1) &&
373 (timevalcmp(&targetp->p_nlminfo->pid_start,
374 &ansp->la_msg_ident.pid_start, !=) ||
375 targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) {
376 PROC_UNLOCK(targetp);
380 targetp->p_nlminfo->retcode = ansp->la_errno;
381 targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid;
382 targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid;
384 wakeup(targetp->p_nlminfo);
386 PROC_UNLOCK(targetp);
391 * Free nlminfo attached to process.
394 nlminfo_release(struct proc *p)
396 free(p->p_nlminfo, M_NLMINFO);