The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/nlm/nlm_advlock.c

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    1 /*-
    2  * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
    3  * Authors: Doug Rabson <dfr@rabson.org>
    4  * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions
    8  * are met:
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  *
   15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   25  * SUCH DAMAGE.
   26  */
   27 
   28 #include <sys/cdefs.h>
   29 __FBSDID("$FreeBSD: releng/7.4/sys/nlm/nlm_advlock.c 181328 2008-08-05 10:35:51Z dfr $");
   30 
   31 #include <sys/param.h>
   32 #include <sys/fcntl.h>
   33 #include <sys/kernel.h>
   34 #include <sys/limits.h>
   35 #include <sys/lock.h>
   36 #include <sys/lockf.h>
   37 #include <sys/malloc.h>
   38 #include <sys/mount.h>
   39 #include <sys/mutex.h>
   40 #include <sys/proc.h>
   41 #include <sys/syslog.h>
   42 #include <sys/systm.h>
   43 #include <sys/unistd.h>
   44 #include <sys/vnode.h>
   45 
   46 #include <rpc/rpcclnt.h>
   47 #include <nfs/nfsproto.h>
   48 #include <nfsclient/nfs.h>
   49 #include <nfsclient/nfsnode.h>
   50 #include <nfsclient/nfsmount.h>
   51 
   52 #include <nlm/nlm_prot.h>
   53 #include <nlm/nlm.h>
   54 
   55 /*
   56  * We need to keep track of the svid values used for F_FLOCK locks.
   57  */
   58 struct nlm_file_svid {
   59         int             ns_refs;        /* thread count + 1 if active */
   60         int             ns_svid;        /* on-the-wire SVID for this file */
   61         struct ucred    *ns_ucred;      /* creds to use for lock recovery */
   62         void            *ns_id;         /* local struct file pointer */
   63         bool_t          ns_active;      /* TRUE if we own a lock */
   64         LIST_ENTRY(nlm_file_svid) ns_link;
   65 };
   66 LIST_HEAD(nlm_file_svid_list, nlm_file_svid);
   67 
   68 #define NLM_SVID_HASH_SIZE      256
   69 struct nlm_file_svid_list nlm_file_svids[NLM_SVID_HASH_SIZE];
   70 
   71 struct mtx nlm_svid_lock;
   72 static struct unrhdr *nlm_svid_allocator;
   73 static volatile u_int nlm_xid = 1;
   74 
   75 static int nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext,
   76     rpcvers_t vers, struct timeval *timo, int retries,
   77     struct vnode *vp, int op, struct flock *fl, int flags,
   78     int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim);
   79 static int nlm_clearlock(struct nlm_host *host,  struct rpc_callextra *ext,
   80     rpcvers_t vers, struct timeval *timo, int retries,
   81     struct vnode *vp, int op, struct flock *fl, int flags,
   82     int svid, size_t fhlen, void *fh, off_t size);
   83 static int nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext,
   84     rpcvers_t vers, struct timeval *timo, int retries,
   85     struct vnode *vp, int op, struct flock *fl, int flags,
   86     int svid, size_t fhlen, void *fh, off_t size);
   87 static int nlm_map_status(nlm4_stats stat);
   88 static struct nlm_file_svid *nlm_find_svid(void *id);
   89 static void nlm_free_svid(struct nlm_file_svid *nf);
   90 static int nlm_init_lock(struct flock *fl, int flags, int svid,
   91     rpcvers_t vers, size_t fhlen, void *fh, off_t size,
   92     struct nlm4_lock *lock, char oh_space[32]);
   93 
   94 static void
   95 nlm_client_init(void *dummy)
   96 {
   97         int i;
   98 
   99         mtx_init(&nlm_svid_lock, "NLM svid lock", NULL, MTX_DEF);
  100         nlm_svid_allocator = new_unrhdr(PID_MAX + 2, INT_MAX, &nlm_svid_lock);
  101         for (i = 0; i < NLM_SVID_HASH_SIZE; i++)
  102                 LIST_INIT(&nlm_file_svids[i]);
  103 }
  104 SYSINIT(nlm_client_init, SI_SUB_LOCK, SI_ORDER_FIRST, nlm_client_init, NULL);
  105 
  106 static int
  107 nlm_msg(struct thread *td, const char *server, const char *msg, int error)
  108 {
  109         struct proc *p;
  110 
  111         p = td ? td->td_proc : NULL;
  112         if (error) {
  113                 tprintf(p, LOG_INFO, "nfs server %s: %s, error %d\n", server,
  114                     msg, error);
  115         } else {
  116                 tprintf(p, LOG_INFO, "nfs server %s: %s\n", server, msg);
  117         }
  118         return (0);
  119 }
  120 
  121 struct nlm_feedback_arg {
  122         bool_t  nf_printed;
  123         struct nfsmount *nf_nmp;
  124 };
  125 
  126 static void
  127 nlm_down(struct nlm_feedback_arg *nf, struct thread *td,
  128     const char *msg, int error)
  129 {
  130         struct nfsmount *nmp = nf->nf_nmp;
  131 
  132         if (nmp == NULL)
  133                 return;
  134         mtx_lock(&nmp->nm_mtx);
  135         if (!(nmp->nm_state & NFSSTA_LOCKTIMEO)) {
  136                 nmp->nm_state |= NFSSTA_LOCKTIMEO;
  137                 mtx_unlock(&nmp->nm_mtx);
  138                 vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid,
  139                     VQ_NOTRESPLOCK, 0);
  140         } else {
  141                 mtx_unlock(&nmp->nm_mtx);
  142         }
  143 
  144         nf->nf_printed = TRUE;
  145         nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, error);
  146 }
  147 
  148 static void
  149 nlm_up(struct nlm_feedback_arg *nf, struct thread *td,
  150     const char *msg)
  151 {
  152         struct nfsmount *nmp = nf->nf_nmp;
  153 
  154         if (!nf->nf_printed)
  155                 return;
  156 
  157         nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, 0);
  158 
  159         mtx_lock(&nmp->nm_mtx);
  160         if (nmp->nm_state & NFSSTA_LOCKTIMEO) {
  161                 nmp->nm_state &= ~NFSSTA_LOCKTIMEO;
  162                 mtx_unlock(&nmp->nm_mtx);
  163                 vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid,
  164                     VQ_NOTRESPLOCK, 1);
  165         } else {
  166                 mtx_unlock(&nmp->nm_mtx);
  167         }
  168 }
  169 
  170 static void
  171 nlm_feedback(int type, int proc, void *arg)
  172 {
  173         struct thread *td = curthread;
  174         struct nlm_feedback_arg *nf = (struct nlm_feedback_arg *) arg;
  175 
  176         switch (type) {
  177         case FEEDBACK_REXMIT2:
  178         case FEEDBACK_RECONNECT:
  179                 nlm_down(nf, td, "lockd not responding", 0);
  180                 break;
  181 
  182         case FEEDBACK_OK:
  183                 nlm_up(nf, td, "lockd is alive again");
  184                 break;
  185         }
  186 }
  187 
  188 /*
  189  * nlm_advlock --
  190  *      NFS advisory byte-level locks.
  191  */
  192 static int
  193 nlm_advlock_internal(struct vnode *vp, void *id, int op, struct flock *fl,
  194     int flags, bool_t reclaim, bool_t unlock_vp)
  195 {
  196         struct thread *td = curthread;
  197         struct nfsmount *nmp;
  198         struct nfsnode *np;
  199         off_t size;
  200         size_t fhlen;
  201         union nfsfh fh;
  202         struct sockaddr *sa;
  203         struct sockaddr_storage ss;
  204         char servername[MNAMELEN];
  205         struct timeval timo;
  206         int retries;
  207         rpcvers_t vers;
  208         struct nlm_host *host;
  209         struct rpc_callextra ext;
  210         struct nlm_feedback_arg nf;
  211         AUTH *auth;
  212         struct ucred *cred;
  213         struct nlm_file_svid *ns;
  214         int svid;
  215         int error;
  216 
  217         ASSERT_VOP_LOCKED(vp, "nlm_advlock_1");
  218 
  219         /*
  220          * Push any pending writes to the server and flush our cache
  221          * so that if we are contending with another machine for a
  222          * file, we get whatever they wrote and vice-versa.
  223          */
  224         if (op == F_SETLK || op == F_UNLCK)
  225                 nfs_vinvalbuf(vp, V_SAVE, td, 1);
  226 
  227         np = VTONFS(vp);
  228         nmp = VFSTONFS(vp->v_mount);
  229         size = np->n_size;
  230         sa = nmp->nm_nam;
  231         memcpy(&ss, sa, sa->sa_len);
  232         sa = (struct sockaddr *) &ss;
  233         strcpy(servername, nmp->nm_hostname);
  234         fhlen = np->n_fhsize;
  235         memcpy(&fh.fh_bytes, np->n_fhp, fhlen);
  236         timo.tv_sec = nmp->nm_timeo / NFS_HZ;
  237         timo.tv_usec = (nmp->nm_timeo % NFS_HZ) * (1000000 / NFS_HZ);
  238         if (NFS_ISV3(vp))
  239                 vers = NLM_VERS4;
  240         else
  241                 vers = NLM_VERS;
  242 
  243         if (nmp->nm_flag & NFSMNT_SOFT)
  244                 retries = nmp->nm_retry;
  245         else
  246                 retries = INT_MAX;
  247 
  248         if (unlock_vp)
  249                 VOP_UNLOCK(vp, 0, td);
  250 
  251         /*
  252          * We need to switch to mount-point creds so that we can send
  253          * packets from a privileged port.
  254          */
  255         cred = td->td_ucred;
  256         td->td_ucred = vp->v_mount->mnt_cred;
  257 
  258         host = nlm_find_host_by_name(servername, sa, vers);
  259         auth = authunix_create(cred);
  260         memset(&ext, 0, sizeof(ext));
  261 
  262         nf.nf_printed = FALSE;
  263         nf.nf_nmp = nmp;
  264         ext.rc_auth = auth;
  265 
  266         ext.rc_feedback = nlm_feedback;
  267         ext.rc_feedback_arg = &nf;
  268 
  269         ns = NULL;
  270         if (flags & F_FLOCK) {
  271                 ns = nlm_find_svid(id);
  272                 KASSERT(fl->l_start == 0 && fl->l_len == 0,
  273                     ("F_FLOCK lock requests must be whole-file locks"));
  274                 if (!ns->ns_ucred) {
  275                         /*
  276                          * Remember the creds used for locking in case
  277                          * we need to recover the lock later.
  278                          */
  279                         ns->ns_ucred = crdup(cred);
  280                 }
  281                 svid = ns->ns_svid;
  282         } else if (flags & F_REMOTE) {
  283                 /*
  284                  * If we are recovering after a server restart or
  285                  * trashing locks on a force unmount, use the same
  286                  * svid as last time.
  287                  */
  288                 svid = fl->l_pid;
  289         } else {
  290                 svid = ((struct proc *) id)->p_pid;
  291         }
  292 
  293         switch(op) {
  294         case F_SETLK:
  295                 if ((flags & (F_FLOCK|F_WAIT)) == (F_FLOCK|F_WAIT)
  296                     && fl->l_type == F_WRLCK) {
  297                         /*
  298                          * The semantics for flock(2) require that any
  299                          * shared lock on the file must be released
  300                          * before an exclusive lock is granted. The
  301                          * local locking code interprets this by
  302                          * unlocking the file before sleeping on a
  303                          * blocked exclusive lock request. We
  304                          * approximate this by first attempting
  305                          * non-blocking and if that fails, we unlock
  306                          * the file and block.
  307                          */
  308                         error = nlm_setlock(host, &ext, vers, &timo, retries,
  309                             vp, F_SETLK, fl, flags & ~F_WAIT,
  310                             svid, fhlen, &fh.fh_bytes, size, reclaim);
  311                         if (error == EAGAIN) {
  312                                 fl->l_type = F_UNLCK;
  313                                 error = nlm_clearlock(host, &ext, vers, &timo,
  314                                     retries, vp, F_UNLCK, fl, flags,
  315                                     svid, fhlen, &fh.fh_bytes, size);
  316                                 fl->l_type = F_WRLCK;
  317                                 if (!error) {
  318                                         mtx_lock(&nlm_svid_lock);
  319                                         if (ns->ns_active) {
  320                                                 ns->ns_refs--;
  321                                                 ns->ns_active = FALSE;
  322                                         }
  323                                         mtx_unlock(&nlm_svid_lock);
  324                                         flags |= F_WAIT;
  325                                         error = nlm_setlock(host, &ext, vers,
  326                                             &timo, retries, vp, F_SETLK, fl,
  327                                             flags, svid, fhlen, &fh.fh_bytes,
  328                                             size, reclaim);
  329                                 }
  330                         }
  331                 } else {
  332                         error = nlm_setlock(host, &ext, vers, &timo, retries,
  333                             vp, op, fl, flags, svid, fhlen, &fh.fh_bytes,
  334                             size, reclaim);
  335                 }
  336                 if (!error && ns) {
  337                         mtx_lock(&nlm_svid_lock);
  338                         if (!ns->ns_active) {
  339                                 /*
  340                                  * Add one to the reference count to
  341                                  * hold onto the SVID for the lifetime
  342                                  * of the lock. Note that since
  343                                  * F_FLOCK only supports whole-file
  344                                  * locks, there can only be one active
  345                                  * lock for this SVID.
  346                                  */
  347                                 ns->ns_refs++;
  348                                 ns->ns_active = TRUE;
  349                         }
  350                         mtx_unlock(&nlm_svid_lock);
  351                 }
  352                 break;
  353 
  354         case F_UNLCK:
  355                 error = nlm_clearlock(host, &ext, vers, &timo, retries,
  356                     vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, size);
  357                 if (!error && ns) {
  358                         mtx_lock(&nlm_svid_lock);
  359                         if (ns->ns_active) {
  360                                 ns->ns_refs--;
  361                                 ns->ns_active = FALSE;
  362                         }
  363                         mtx_unlock(&nlm_svid_lock);
  364                 }
  365                 break;
  366 
  367         case F_GETLK:
  368                 error = nlm_getlock(host, &ext, vers, &timo, retries,
  369                     vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, size);
  370                 break;
  371 
  372         default:
  373                 error = EINVAL;
  374                 break;
  375         }
  376 
  377         if (ns)
  378                 nlm_free_svid(ns);
  379 
  380         td->td_ucred = cred;
  381         AUTH_DESTROY(auth);
  382 
  383         nlm_host_release(host);
  384 
  385         return (error);
  386 }
  387 
  388 int
  389 nlm_advlock(struct vop_advlock_args *ap)
  390 {
  391 
  392         return (nlm_advlock_internal(ap->a_vp, ap->a_id, ap->a_op, ap->a_fl,
  393                 ap->a_flags, FALSE, TRUE));
  394 }
  395 
  396 /*
  397  * Set the creds of td to the creds of the given lock's owner. The new
  398  * creds reference count will be incremented via crhold. The caller is
  399  * responsible for calling crfree and restoring td's original creds.
  400  */
  401 static void
  402 nlm_set_creds_for_lock(struct thread *td, struct flock *fl)
  403 {
  404         int i;
  405         struct nlm_file_svid *ns;
  406         struct proc *p;
  407         struct ucred *cred;
  408 
  409         cred = NULL;
  410         if (fl->l_pid > PID_MAX) {
  411                 /*
  412                  * If this was originally a F_FLOCK-style lock, we
  413                  * recorded the creds used when it was originally
  414                  * locked in the nlm_file_svid structure.
  415                  */
  416                 mtx_lock(&nlm_svid_lock);
  417                 for (i = 0; i < NLM_SVID_HASH_SIZE; i++) {
  418                         for (ns = LIST_FIRST(&nlm_file_svids[i]); ns;
  419                              ns = LIST_NEXT(ns, ns_link)) {
  420                                 if (ns->ns_svid == fl->l_pid) {
  421                                         cred = crhold(ns->ns_ucred);
  422                                         break;
  423                                 }
  424                         }
  425                 }
  426                 mtx_unlock(&nlm_svid_lock);
  427         } else {
  428                 /*
  429                  * This lock is owned by a process. Get a reference to
  430                  * the process creds.
  431                  */
  432                 p = pfind(fl->l_pid);
  433                 if (p) {
  434                         cred = crhold(p->p_ucred);
  435                         PROC_UNLOCK(p);
  436                 }
  437         }
  438 
  439         /*
  440          * If we can't find a cred, fall back on the recovery
  441          * thread's cred.
  442          */
  443         if (!cred) {
  444                 cred = crhold(td->td_ucred);
  445         }
  446 
  447         td->td_ucred = cred;
  448 }
  449 
  450 static int
  451 nlm_reclaim_free_lock(struct vnode *vp, struct flock *fl, void *arg)
  452 {
  453         struct flock newfl;
  454         struct thread *td = curthread;
  455         struct ucred *oldcred;
  456         int error;
  457 
  458         newfl = *fl;
  459         newfl.l_type = F_UNLCK;
  460 
  461         oldcred = td->td_ucred;
  462         nlm_set_creds_for_lock(td, &newfl);
  463 
  464         error = nlm_advlock_internal(vp, NULL, F_UNLCK, &newfl, F_REMOTE,
  465             FALSE, FALSE);
  466 
  467         crfree(td->td_ucred);
  468         td->td_ucred = oldcred;
  469 
  470         return (error);
  471 }
  472 
  473 int
  474 nlm_reclaim(struct vop_reclaim_args *ap)
  475 {
  476 
  477         nlm_cancel_wait(ap->a_vp);
  478         lf_iteratelocks_vnode(ap->a_vp, nlm_reclaim_free_lock, NULL);
  479         return (0);
  480 }
  481 
  482 struct nlm_recovery_context {
  483         struct nlm_host *nr_host;       /* host we are recovering */
  484         int             nr_state;       /* remote NSM state for recovery */
  485 };
  486 
  487 static int
  488 nlm_client_recover_lock(struct vnode *vp, struct flock *fl, void *arg)
  489 {
  490         struct nlm_recovery_context *nr = (struct nlm_recovery_context *) arg;
  491         struct thread *td = curthread;
  492         struct ucred *oldcred;
  493         int state, error;
  494 
  495         /*
  496          * If the remote NSM state changes during recovery, the host
  497          * must have rebooted a second time. In that case, we must
  498          * restart the recovery.
  499          */
  500         state = nlm_host_get_state(nr->nr_host);
  501         if (nr->nr_state != state)
  502                 return (ERESTART);
  503 
  504         error = vn_lock(vp, LK_SHARED, td);
  505         if (error)
  506                 return (error);
  507 
  508         oldcred = td->td_ucred;
  509         nlm_set_creds_for_lock(td, fl);
  510 
  511         error = nlm_advlock_internal(vp, NULL, F_SETLK, fl, F_REMOTE,
  512             TRUE, TRUE);
  513 
  514         crfree(td->td_ucred);
  515         td->td_ucred = oldcred;
  516 
  517         return (error);
  518 }
  519 
  520 void
  521 nlm_client_recovery(struct nlm_host *host)
  522 {
  523         struct nlm_recovery_context nr;
  524         int sysid, error;
  525 
  526         sysid = NLM_SYSID_CLIENT | nlm_host_get_sysid(host);
  527         do {
  528                 nr.nr_host = host;
  529                 nr.nr_state = nlm_host_get_state(host);
  530                 error = lf_iteratelocks_sysid(sysid,
  531                     nlm_client_recover_lock, &nr);
  532         } while (error == ERESTART);
  533 }
  534 
  535 static void
  536 nlm_convert_to_nlm_lock(struct nlm_lock *dst, struct nlm4_lock *src)
  537 {
  538 
  539         dst->caller_name = src->caller_name;
  540         dst->fh = src->fh;
  541         dst->oh = src->oh;
  542         dst->svid = src->svid;
  543         dst->l_offset = src->l_offset;
  544         dst->l_len = src->l_len;
  545 }
  546 
  547 static void
  548 nlm_convert_to_nlm4_holder(struct nlm4_holder *dst, struct nlm_holder *src)
  549 {
  550 
  551         dst->exclusive = src->exclusive;
  552         dst->svid = src->svid;
  553         dst->oh = src->oh;
  554         dst->l_offset = src->l_offset;
  555         dst->l_len = src->l_len;
  556 }
  557 
  558 static void
  559 nlm_convert_to_nlm4_res(struct nlm4_res *dst, struct nlm_res *src)
  560 {
  561         dst->cookie = src->cookie;
  562         dst->stat.stat = (enum nlm4_stats) src->stat.stat;
  563 }
  564 
  565 static enum clnt_stat
  566 nlm_test_rpc(rpcvers_t vers, nlm4_testargs *args, nlm4_testres *res, CLIENT *client,
  567     struct rpc_callextra *ext, struct timeval timo)
  568 {
  569         if (vers == NLM_VERS4) {
  570                 return nlm4_test_4(args, res, client, ext, timo);
  571         } else {
  572                 nlm_testargs args1;
  573                 nlm_testres res1;
  574                 enum clnt_stat stat;
  575 
  576                 args1.cookie = args->cookie;
  577                 args1.exclusive = args->exclusive;
  578                 nlm_convert_to_nlm_lock(&args1.alock, &args->alock);
  579                 memset(&res1, 0, sizeof(res1));
  580 
  581                 stat = nlm_test_1(&args1, &res1, client, ext, timo);
  582 
  583                 if (stat == RPC_SUCCESS) {
  584                         res->cookie = res1.cookie;
  585                         res->stat.stat = (enum nlm4_stats) res1.stat.stat;
  586                         if (res1.stat.stat == nlm_denied)
  587                                 nlm_convert_to_nlm4_holder(
  588                                         &res->stat.nlm4_testrply_u.holder,
  589                                         &res1.stat.nlm_testrply_u.holder);
  590                 }
  591 
  592                 return (stat);
  593         }
  594 }
  595 
  596 static enum clnt_stat
  597 nlm_lock_rpc(rpcvers_t vers, nlm4_lockargs *args, nlm4_res *res, CLIENT *client,
  598     struct rpc_callextra *ext, struct timeval timo)
  599 {
  600         if (vers == NLM_VERS4) {
  601                 return nlm4_lock_4(args, res, client, ext, timo);
  602         } else {
  603                 nlm_lockargs args1;
  604                 nlm_res res1;
  605                 enum clnt_stat stat;
  606 
  607                 args1.cookie = args->cookie;
  608                 args1.block = args->block;
  609                 args1.exclusive = args->exclusive;
  610                 nlm_convert_to_nlm_lock(&args1.alock, &args->alock);
  611                 args1.reclaim = args->reclaim;
  612                 args1.state = args->state;
  613                 memset(&res1, 0, sizeof(res1));
  614 
  615                 stat = nlm_lock_1(&args1, &res1, client, ext, timo);
  616 
  617                 if (stat == RPC_SUCCESS) {
  618                         nlm_convert_to_nlm4_res(res, &res1);
  619                 }
  620 
  621                 return (stat);
  622         }
  623 }
  624 
  625 static enum clnt_stat
  626 nlm_cancel_rpc(rpcvers_t vers, nlm4_cancargs *args, nlm4_res *res, CLIENT *client,
  627     struct rpc_callextra *ext, struct timeval timo)
  628 {
  629         if (vers == NLM_VERS4) {
  630                 return nlm4_cancel_4(args, res, client, ext, timo);
  631         } else {
  632                 nlm_cancargs args1;
  633                 nlm_res res1;
  634                 enum clnt_stat stat;
  635 
  636                 args1.cookie = args->cookie;
  637                 args1.block = args->block;
  638                 args1.exclusive = args->exclusive;
  639                 nlm_convert_to_nlm_lock(&args1.alock, &args->alock);
  640                 memset(&res1, 0, sizeof(res1));
  641 
  642                 stat = nlm_cancel_1(&args1, &res1, client, ext, timo);
  643 
  644                 if (stat == RPC_SUCCESS) {
  645                         nlm_convert_to_nlm4_res(res, &res1);
  646                 }
  647 
  648                 return (stat);
  649         }
  650 }
  651 
  652 static enum clnt_stat
  653 nlm_unlock_rpc(rpcvers_t vers, nlm4_unlockargs *args, nlm4_res *res, CLIENT *client,
  654     struct rpc_callextra *ext, struct timeval timo)
  655 {
  656         if (vers == NLM_VERS4) {
  657                 return nlm4_unlock_4(args, res, client, ext, timo);
  658         } else {
  659                 nlm_unlockargs args1;
  660                 nlm_res res1;
  661                 enum clnt_stat stat;
  662 
  663                 args1.cookie = args->cookie;
  664                 nlm_convert_to_nlm_lock(&args1.alock, &args->alock);
  665                 memset(&res1, 0, sizeof(res1));
  666 
  667                 stat = nlm_unlock_1(&args1, &res1, client, ext, timo);
  668 
  669                 if (stat == RPC_SUCCESS) {
  670                         nlm_convert_to_nlm4_res(res, &res1);
  671                 }
  672 
  673                 return (stat);
  674         }
  675 }
  676 
  677 /*
  678  * Called after a lock request (set or clear) succeeded. We record the
  679  * details in the local lock manager. Note that since the remote
  680  * server has granted the lock, we can be sure that it doesn't
  681  * conflict with any other locks we have in the local lock manager.
  682  *
  683  * Since it is possible that host may also make NLM client requests to
  684  * our NLM server, we use a different sysid value to record our own
  685  * client locks.
  686  *
  687  * Note that since it is possible for us to receive replies from the
  688  * server in a different order than the locks were granted (e.g. if
  689  * many local threads are contending for the same lock), we must use a
  690  * blocking operation when registering with the local lock manager.
  691  * We expect that any actual wait will be rare and short hence we
  692  * ignore signals for this.
  693  */
  694 static void
  695 nlm_record_lock(struct vnode *vp, int op, struct flock *fl,
  696     int svid, int sysid, off_t size)
  697 {
  698         struct vop_advlockasync_args a;
  699         struct flock newfl;
  700         int error;
  701 
  702         a.a_vp = vp;
  703         a.a_id = NULL;
  704         a.a_op = op;
  705         a.a_fl = &newfl;
  706         a.a_flags = F_REMOTE|F_WAIT|F_NOINTR;
  707         a.a_task = NULL;
  708         a.a_cookiep = NULL;
  709         newfl.l_start = fl->l_start;
  710         newfl.l_len = fl->l_len;
  711         newfl.l_type = fl->l_type;
  712         newfl.l_whence = fl->l_whence;
  713         newfl.l_pid = svid;
  714         newfl.l_sysid = NLM_SYSID_CLIENT | sysid;
  715 
  716         error = lf_advlockasync(&a, &vp->v_lockf, size);
  717         KASSERT(error == 0, ("Failed to register NFS lock locally - error=%d",
  718                 error));
  719 }
  720 
  721 static int
  722 nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext,
  723     rpcvers_t vers, struct timeval *timo, int retries,
  724     struct vnode *vp, int op, struct flock *fl, int flags,
  725     int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim)
  726 {
  727         struct nlm4_lockargs args;
  728         char oh_space[32];
  729         struct nlm4_res res;
  730         u_int xid;
  731         CLIENT *client;
  732         enum clnt_stat stat;
  733         int retry, block, exclusive;
  734         void *wait_handle = NULL;
  735         int error;
  736 
  737         memset(&args, 0, sizeof(args));
  738         memset(&res, 0, sizeof(res));
  739 
  740         block = (flags & F_WAIT) ? TRUE : FALSE;
  741         exclusive = (fl->l_type == F_WRLCK);
  742 
  743         error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
  744             &args.alock, oh_space);
  745         if (error)
  746                 return (error);
  747         args.block = block;
  748         args.exclusive = exclusive;
  749         args.reclaim = reclaim;
  750         args.state = nlm_nsm_state;
  751 
  752         retry = 5*hz;
  753         for (;;) {
  754                 client = nlm_host_get_rpc(host);
  755                 if (!client)
  756                         return (ENOLCK); /* XXX retry? */
  757 
  758                 if (block)
  759                         wait_handle = nlm_register_wait_lock(&args.alock, vp);
  760 
  761                 xid = atomic_fetchadd_int(&nlm_xid, 1);
  762                 args.cookie.n_len = sizeof(xid);
  763                 args.cookie.n_bytes = (char*) &xid;
  764 
  765                 stat = nlm_lock_rpc(vers, &args, &res, client, ext, *timo);
  766 
  767                 CLNT_RELEASE(client);
  768 
  769                 if (stat != RPC_SUCCESS) {
  770                         if (block)
  771                                 nlm_deregister_wait_lock(wait_handle);
  772                         if (retries) {
  773                                 retries--;
  774                                 continue;
  775                         }
  776                         return (EINVAL);
  777                 }
  778 
  779                 /*
  780                  * Free res.cookie.
  781                  */
  782                 xdr_free((xdrproc_t) xdr_nlm4_res, &res);
  783 
  784                 if (block && res.stat.stat != nlm4_blocked)
  785                         nlm_deregister_wait_lock(wait_handle);
  786 
  787                 if (res.stat.stat == nlm4_denied_grace_period) {
  788                         /*
  789                          * The server has recently rebooted and is
  790                          * giving old clients a change to reclaim
  791                          * their locks. Wait for a few seconds and try
  792                          * again.
  793                          */
  794                         error = tsleep(&args, PCATCH, "nlmgrace", retry);
  795                         if (error && error != EWOULDBLOCK)
  796                                 return (error);
  797                         retry = 2*retry;
  798                         if (retry > 30*hz)
  799                                 retry = 30*hz;
  800                         continue;
  801                 }
  802 
  803                 if (block && res.stat.stat == nlm4_blocked) {
  804                         /*
  805                          * The server should call us back with a
  806                          * granted message when the lock succeeds. In
  807                          * order to deal with broken servers, lost
  808                          * granted messages and server reboots, we
  809                          * will also re-try every few seconds.
  810                          */
  811                         error = nlm_wait_lock(wait_handle, retry);
  812                         if (error == EWOULDBLOCK) {
  813                                 retry = 2*retry;
  814                                 if (retry > 30*hz)
  815                                         retry = 30*hz;
  816                                 continue;
  817                         }
  818                         if (error) {
  819                                 /*
  820                                  * We need to call the server to
  821                                  * cancel our lock request.
  822                                  */
  823                                 nlm4_cancargs cancel;
  824 
  825                                 memset(&cancel, 0, sizeof(cancel));
  826 
  827                                 xid = atomic_fetchadd_int(&nlm_xid, 1);
  828                                 cancel.cookie.n_len = sizeof(xid);
  829                                 cancel.cookie.n_bytes = (char*) &xid;
  830                                 cancel.block = block;
  831                                 cancel.exclusive = exclusive;
  832                                 cancel.alock = args.alock;
  833 
  834                                 do {
  835                                         client = nlm_host_get_rpc(host);
  836                                         if (!client)
  837                                                 /* XXX retry? */
  838                                                 return (ENOLCK);
  839 
  840                                         stat = nlm_cancel_rpc(vers, &cancel,
  841                                             &res, client, ext, *timo);
  842 
  843                                         CLNT_RELEASE(client);
  844 
  845                                         if (stat != RPC_SUCCESS) {
  846                                                 /*
  847                                                  * We need to cope
  848                                                  * with temporary
  849                                                  * network partitions
  850                                                  * as well as server
  851                                                  * reboots. This means
  852                                                  * we have to keep
  853                                                  * trying to cancel
  854                                                  * until the server
  855                                                  * wakes up again.
  856                                                  */
  857                                                 pause("nlmcancel", 10*hz);
  858                                         }
  859                                 } while (stat != RPC_SUCCESS);
  860 
  861                                 /*
  862                                  * Free res.cookie.
  863                                  */
  864                                 xdr_free((xdrproc_t) xdr_nlm4_res, &res);
  865 
  866                                 switch (res.stat.stat) {
  867                                 case nlm_denied:
  868                                         /*
  869                                          * There was nothing
  870                                          * to cancel. We are
  871                                          * going to go ahead
  872                                          * and assume we got
  873                                          * the lock.
  874                                          */
  875                                         error = 0;
  876                                         break;
  877 
  878                                 case nlm4_denied_grace_period:
  879                                         /*
  880                                          * The server has
  881                                          * recently rebooted -
  882                                          * treat this as a
  883                                          * successful
  884                                          * cancellation.
  885                                          */
  886                                         break;
  887 
  888                                 case nlm4_granted:
  889                                         /*
  890                                          * We managed to
  891                                          * cancel.
  892                                          */
  893                                         break;
  894 
  895                                 default:
  896                                         /*
  897                                          * Broken server
  898                                          * implementation -
  899                                          * can't really do
  900                                          * anything here.
  901                                          */
  902                                         break;
  903                                 }
  904 
  905                         }
  906                 } else {
  907                         error = nlm_map_status(res.stat.stat);
  908                 }
  909 
  910                 if (!error && !reclaim) {
  911                         nlm_record_lock(vp, op, fl, args.alock.svid,
  912                             nlm_host_get_sysid(host), size);
  913                         nlm_host_monitor(host, 0);
  914                 }
  915 
  916                 return (error);
  917         }
  918 }
  919 
  920 static int
  921 nlm_clearlock(struct nlm_host *host, struct rpc_callextra *ext,
  922     rpcvers_t vers, struct timeval *timo, int retries,
  923     struct vnode *vp, int op, struct flock *fl, int flags,
  924     int svid, size_t fhlen, void *fh, off_t size)
  925 {
  926         struct nlm4_unlockargs args;
  927         char oh_space[32];
  928         struct nlm4_res res;
  929         u_int xid;
  930         CLIENT *client;
  931         enum clnt_stat stat;
  932         int error;
  933 
  934         memset(&args, 0, sizeof(args));
  935         memset(&res, 0, sizeof(res));
  936 
  937         error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
  938             &args.alock, oh_space);
  939         if (error)
  940                 return (error);
  941 
  942         for (;;) {
  943                 client = nlm_host_get_rpc(host);
  944                 if (!client)
  945                         return (ENOLCK); /* XXX retry? */
  946 
  947                 xid = atomic_fetchadd_int(&nlm_xid, 1);
  948                 args.cookie.n_len = sizeof(xid);
  949                 args.cookie.n_bytes = (char*) &xid;
  950 
  951                 stat = nlm_unlock_rpc(vers, &args, &res, client, ext, *timo);
  952 
  953                 CLNT_RELEASE(client);
  954 
  955                 if (stat != RPC_SUCCESS) {
  956                         if (retries) {
  957                                 retries--;
  958                                 continue;
  959                         }
  960                         return (EINVAL);
  961                 }
  962 
  963                 /*
  964                  * Free res.cookie.
  965                  */
  966                 xdr_free((xdrproc_t) xdr_nlm4_res, &res);
  967 
  968                 if (res.stat.stat == nlm4_denied_grace_period) {
  969                         /*
  970                          * The server has recently rebooted and is
  971                          * giving old clients a change to reclaim
  972                          * their locks. Wait for a few seconds and try
  973                          * again.
  974                          */
  975                         error = tsleep(&args, PCATCH, "nlmgrace", 5*hz);
  976                         if (error && error != EWOULDBLOCK)
  977                                 return (error);
  978                         continue;
  979                 }
  980 
  981                 /*
  982                  * If we are being called via nlm_reclaim (which will
  983                  * use the F_REMOTE flag), don't record the lock
  984                  * operation in the local lock manager since the vnode
  985                  * is going away.
  986                  */
  987                 if (!(flags & F_REMOTE))
  988                         nlm_record_lock(vp, op, fl, args.alock.svid,
  989                             nlm_host_get_sysid(host), size);
  990 
  991                 return (0);
  992         }
  993 }
  994 
  995 static int
  996 nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext,
  997     rpcvers_t vers, struct timeval *timo, int retries,
  998     struct vnode *vp, int op, struct flock *fl, int flags,
  999     int svid, size_t fhlen, void *fh, off_t size)
 1000 {
 1001         struct nlm4_testargs args;
 1002         char oh_space[32];
 1003         struct nlm4_testres res;
 1004         u_int xid;
 1005         CLIENT *client;
 1006         enum clnt_stat stat;
 1007         int exclusive;
 1008         int error;
 1009 
 1010         KASSERT(!(flags & F_FLOCK), ("unexpected F_FLOCK for F_GETLK"));
 1011 
 1012         memset(&args, 0, sizeof(args));
 1013         memset(&res, 0, sizeof(res));
 1014 
 1015         exclusive = (fl->l_type == F_WRLCK);
 1016 
 1017         error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
 1018             &args.alock, oh_space);
 1019         if (error)
 1020                 return (error);
 1021         args.exclusive = exclusive;
 1022 
 1023         for (;;) {
 1024                 client = nlm_host_get_rpc(host);
 1025                 if (!client)
 1026                         return (ENOLCK); /* XXX retry? */
 1027 
 1028                 xid = atomic_fetchadd_int(&nlm_xid, 1);
 1029                 args.cookie.n_len = sizeof(xid);
 1030                 args.cookie.n_bytes = (char*) &xid;
 1031 
 1032                 stat = nlm_test_rpc(vers, &args, &res, client, ext, *timo);
 1033 
 1034                 CLNT_RELEASE(client);
 1035 
 1036                 if (stat != RPC_SUCCESS) {
 1037                         if (retries) {
 1038                                 retries--;
 1039                                 continue;
 1040                         }
 1041                         return (EINVAL);
 1042                 }
 1043 
 1044                 if (res.stat.stat == nlm4_denied_grace_period) {
 1045                         /*
 1046                          * The server has recently rebooted and is
 1047                          * giving old clients a change to reclaim
 1048                          * their locks. Wait for a few seconds and try
 1049                          * again.
 1050                          */
 1051                         xdr_free((xdrproc_t) xdr_nlm4_testres, &res);
 1052                         error = tsleep(&args, PCATCH, "nlmgrace", 5*hz);
 1053                         if (error && error != EWOULDBLOCK)
 1054                                 return (error);
 1055                         continue;
 1056                 }
 1057 
 1058                 if (res.stat.stat == nlm4_denied) {
 1059                         struct nlm4_holder *h =
 1060                                 &res.stat.nlm4_testrply_u.holder;
 1061                         fl->l_start = h->l_offset;
 1062                         fl->l_len = h->l_len;
 1063                         fl->l_pid = h->svid;
 1064                         if (h->exclusive)
 1065                                 fl->l_type = F_WRLCK;
 1066                         else
 1067                                 fl->l_type = F_RDLCK;
 1068                         fl->l_whence = SEEK_SET;
 1069                         fl->l_sysid = 0;
 1070                 } else {
 1071                         fl->l_type = F_UNLCK;
 1072                 }
 1073 
 1074                 xdr_free((xdrproc_t) xdr_nlm4_testres, &res);
 1075 
 1076                 return (0);
 1077         }
 1078 }
 1079 
 1080 static int
 1081 nlm_map_status(nlm4_stats stat)
 1082 {
 1083         switch (stat) {
 1084         case nlm4_granted:
 1085                 return (0);
 1086 
 1087         case nlm4_denied:
 1088                 return (EAGAIN);
 1089 
 1090         case nlm4_denied_nolocks:
 1091                 return (ENOLCK);
 1092 
 1093         case nlm4_deadlck:
 1094                 return (EDEADLK);
 1095 
 1096         case nlm4_rofs:
 1097                 return (EROFS);
 1098 
 1099         case nlm4_stale_fh:
 1100                 return (ESTALE);
 1101 
 1102         case nlm4_fbig:
 1103                 return (EFBIG);
 1104 
 1105         case nlm4_failed:
 1106                 return (EACCES);
 1107 
 1108         default:
 1109                 return (EINVAL);
 1110         }
 1111 }
 1112 
 1113 static struct nlm_file_svid *
 1114 nlm_find_svid(void *id)
 1115 {
 1116         struct nlm_file_svid *ns, *newns;
 1117         int h;
 1118 
 1119         h = (((uintptr_t) id) >> 7) % NLM_SVID_HASH_SIZE;
 1120 
 1121         mtx_lock(&nlm_svid_lock);
 1122         LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) {
 1123                 if (ns->ns_id == id) {
 1124                         ns->ns_refs++;
 1125                         break;
 1126                 }
 1127         }
 1128         mtx_unlock(&nlm_svid_lock);
 1129         if (!ns) {
 1130                 int svid = alloc_unr(nlm_svid_allocator);
 1131                 newns = malloc(sizeof(struct nlm_file_svid), M_NLM,
 1132                     M_WAITOK);
 1133                 newns->ns_refs = 1;
 1134                 newns->ns_id = id;
 1135                 newns->ns_svid = svid;
 1136                 newns->ns_ucred = NULL;
 1137                 newns->ns_active = FALSE;
 1138 
 1139                 /*
 1140                  * We need to check for a race with some other
 1141                  * thread allocating a svid for this file.
 1142                  */
 1143                 mtx_lock(&nlm_svid_lock);
 1144                 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) {
 1145                         if (ns->ns_id == id) {
 1146                                 ns->ns_refs++;
 1147                                 break;
 1148                         }
 1149                 }
 1150                 if (ns) {
 1151                         mtx_unlock(&nlm_svid_lock);
 1152                         free_unr(nlm_svid_allocator, newns->ns_svid);
 1153                         free(newns, M_NLM);
 1154                 } else {
 1155                         LIST_INSERT_HEAD(&nlm_file_svids[h], newns,
 1156                             ns_link);
 1157                         ns = newns;
 1158                         mtx_unlock(&nlm_svid_lock);
 1159                 }
 1160         }
 1161 
 1162         return (ns);
 1163 }
 1164 
 1165 static void
 1166 nlm_free_svid(struct nlm_file_svid *ns)
 1167 {
 1168 
 1169         mtx_lock(&nlm_svid_lock);
 1170         ns->ns_refs--;
 1171         if (!ns->ns_refs) {
 1172                 KASSERT(!ns->ns_active, ("Freeing active SVID"));
 1173                 LIST_REMOVE(ns, ns_link);
 1174                 mtx_unlock(&nlm_svid_lock);
 1175                 free_unr(nlm_svid_allocator, ns->ns_svid);
 1176                 if (ns->ns_ucred)
 1177                         crfree(ns->ns_ucred);
 1178                 free(ns, M_NLM);
 1179         } else {
 1180                 mtx_unlock(&nlm_svid_lock);
 1181         }
 1182 }
 1183 
 1184 static int
 1185 nlm_init_lock(struct flock *fl, int flags, int svid,
 1186     rpcvers_t vers, size_t fhlen, void *fh, off_t size,
 1187     struct nlm4_lock *lock, char oh_space[32])
 1188 {
 1189         size_t oh_len;
 1190         off_t start, len;
 1191 
 1192         if (fl->l_whence == SEEK_END) {
 1193                 if (size > OFF_MAX
 1194                     || (fl->l_start > 0 && size > OFF_MAX - fl->l_start))
 1195                         return (EOVERFLOW);
 1196                 start = size + fl->l_start;
 1197         } else if (fl->l_whence == SEEK_SET || fl->l_whence == SEEK_CUR) {
 1198                 start = fl->l_start;
 1199         } else {
 1200                 return (EINVAL);
 1201         }
 1202         if (start < 0)
 1203                 return (EINVAL);
 1204         if (fl->l_len < 0) {
 1205                 len = -fl->l_len;
 1206                 start -= len;
 1207                 if (start < 0)
 1208                         return (EINVAL);
 1209         } else {
 1210                 len = fl->l_len;
 1211         }
 1212 
 1213         if (vers == NLM_VERS) {
 1214                 /*
 1215                  * Enforce range limits on V1 locks
 1216                  */
 1217                 if (start > 0xffffffffLL || len > 0xffffffffLL)
 1218                         return (EOVERFLOW);
 1219         }
 1220 
 1221         snprintf(oh_space, 32, "%d@%s", svid, hostname);
 1222         oh_len = strlen(oh_space);
 1223 
 1224         memset(lock, 0, sizeof(*lock));
 1225         lock->caller_name = hostname;
 1226         lock->fh.n_len = fhlen;
 1227         lock->fh.n_bytes = fh;
 1228         lock->oh.n_len = oh_len;
 1229         lock->oh.n_bytes = oh_space;
 1230         lock->svid = svid;
 1231         lock->l_offset = start;
 1232         lock->l_len = len;
 1233 
 1234         return (0);
 1235 }

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