The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/nfsclient/nfs_lock.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
    3  *
    4  * Redistribution and use in source and binary forms, with or without
    5  * modification, are permitted provided that the following conditions
    6  * are met:
    7  * 1. Redistributions of source code must retain the above copyright
    8  *    notice, this list of conditions and the following disclaimer.
    9  * 2. Redistributions in binary form must reproduce the above copyright
   10  *    notice, this list of conditions and the following disclaimer in the
   11  *    documentation and/or other materials provided with the distribution.
   12  * 3. Berkeley Software Design Inc's name may not be used to endorse or
   13  *    promote products derived from this software without specific prior
   14  *    written permission.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
   20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  *
   28  *      from BSDI nfs_lock.c,v 2.4 1998/12/14 23:49:56 jch Exp
   29  */
   30 
   31 #include <sys/cdefs.h>
   32 __FBSDID("$FreeBSD: releng/6.4/sys/nfsclient/nfs_lock.c 178459 2008-04-24 10:46:25Z dfr $");
   33 
   34 #include <sys/param.h>
   35 #include <sys/systm.h>
   36 #include <sys/conf.h>
   37 #include <sys/fcntl.h>
   38 #include <sys/kernel.h>         /* for hz */
   39 #include <sys/limits.h>
   40 #include <sys/lock.h>
   41 #include <sys/malloc.h>
   42 #include <sys/lockf.h>          /* for hz */ /* Must come after sys/malloc.h */
   43 #include <sys/mbuf.h>
   44 #include <sys/mount.h>
   45 #include <sys/namei.h>
   46 #include <sys/proc.h>
   47 #include <sys/resourcevar.h>
   48 #include <sys/socket.h>
   49 #include <sys/socket.h>
   50 #include <sys/unistd.h>
   51 #include <sys/vnode.h>
   52 
   53 #include <net/if.h>
   54 
   55 #include <rpc/rpcclnt.h>
   56 
   57 #include <nfs/rpcv2.h>
   58 #include <nfs/nfsproto.h>
   59 #include <nfsclient/nfs.h>
   60 #include <nfsclient/nfsmount.h>
   61 #include <nfsclient/nfsnode.h>
   62 #include <nfsclient/nfs_lock.h>
   63 #include <nfsclient/nlminfo.h>
   64 
   65 extern void (*nlminfo_release_p)(struct proc *p);
   66 
   67 MALLOC_DEFINE(M_NFSLOCK, "NFS lock", "NFS lock request");
   68 MALLOC_DEFINE(M_NLMINFO, "nlminfo", "NFS lock process structure");
   69 
   70 static int nfslockdans(struct thread *td, struct lockd_ans *ansp);
   71 static void nlminfo_release(struct proc *p);
   72 /*
   73  * --------------------------------------------------------------------
   74  * A miniature device driver which the userland uses to talk to us.
   75  *
   76  */
   77 
   78 static struct cdev *nfslock_dev;
   79 static struct mtx nfslock_mtx;
   80 static int nfslock_isopen;
   81 static TAILQ_HEAD(,__lock_msg)  nfslock_list;
   82 
   83 static int
   84 nfslock_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
   85 {
   86         int error;
   87 
   88         mtx_lock(&nfslock_mtx);
   89         if (!nfslock_isopen) {
   90                 error = 0;
   91                 nfslock_isopen = 1;
   92         } else {
   93                 error = EOPNOTSUPP;
   94         }
   95         mtx_unlock(&nfslock_mtx);
   96                 
   97         return (error);
   98 }
   99 
  100 static int
  101 nfslock_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
  102 {
  103         struct __lock_msg *lm;
  104 
  105         mtx_lock(&nfslock_mtx);
  106         nfslock_isopen = 0;
  107         while (!TAILQ_EMPTY(&nfslock_list)) {
  108                 lm = TAILQ_FIRST(&nfslock_list);
  109                 /* XXX: answer request */
  110                 TAILQ_REMOVE(&nfslock_list, lm, lm_link);
  111                 free(lm, M_NFSLOCK);
  112         }
  113         mtx_unlock(&nfslock_mtx);
  114         return (0);
  115 }
  116 
  117 static int
  118 nfslock_read(struct cdev *dev, struct uio *uio, int ioflag)
  119 {
  120         int error;
  121         struct __lock_msg *lm;
  122 
  123         if (uio->uio_resid != sizeof *lm)
  124                 return (EOPNOTSUPP);
  125         lm = NULL;
  126         error = 0;
  127         mtx_lock(&nfslock_mtx);
  128         while (TAILQ_EMPTY(&nfslock_list)) {
  129                 error = msleep(&nfslock_list, &nfslock_mtx, PSOCK | PCATCH,
  130                     "nfslockd", 0);
  131                 if (error)
  132                         break;
  133         }
  134         if (!error) {
  135                 lm = TAILQ_FIRST(&nfslock_list);
  136                 TAILQ_REMOVE(&nfslock_list, lm, lm_link);
  137         }
  138         mtx_unlock(&nfslock_mtx);
  139         if (!error) {
  140                 error = uiomove(lm, sizeof *lm, uio);
  141                 free(lm, M_NFSLOCK);
  142         }
  143         return (error);
  144 }
  145 
  146 static int
  147 nfslock_write(struct cdev *dev, struct uio *uio, int ioflag)
  148 {
  149         struct lockd_ans la;
  150         int error;
  151 
  152         if (uio->uio_resid != sizeof la)
  153                 return (EOPNOTSUPP);
  154         error = uiomove(&la, sizeof la, uio);
  155         if (!error)
  156                 error = nfslockdans(curthread, &la);
  157         return (error);
  158 }
  159 
  160 static int
  161 nfslock_send(struct __lock_msg *lm)
  162 {
  163         struct __lock_msg *lm2;
  164         int error;
  165 
  166         error = 0;
  167         lm2 = malloc(sizeof *lm2, M_NFSLOCK, M_WAITOK);
  168         mtx_lock(&nfslock_mtx);
  169         if (nfslock_isopen) {
  170                 memcpy(lm2, lm, sizeof *lm2);
  171                 TAILQ_INSERT_TAIL(&nfslock_list, lm2, lm_link);
  172                 wakeup(&nfslock_list);
  173         } else {
  174                 error = EOPNOTSUPP;
  175         }
  176         mtx_unlock(&nfslock_mtx);
  177         if (error)
  178                 free(lm2, M_NFSLOCK);
  179         return (error);
  180 }
  181 
  182 static struct cdevsw nfslock_cdevsw = {
  183         .d_version =    D_VERSION,
  184         .d_open =       nfslock_open,
  185         .d_close =      nfslock_close,
  186         .d_read =       nfslock_read,
  187         .d_write =      nfslock_write,
  188         .d_name =       "nfslock"
  189 };
  190 
  191 static int
  192 nfslock_modevent(module_t mod __unused, int type, void *data __unused)
  193 {
  194 
  195         switch (type) {
  196         case MOD_LOAD:
  197                 if (bootverbose)
  198                         printf("nfslock: pseudo-device\n");
  199                 mtx_init(&nfslock_mtx, "nfslock", NULL, MTX_DEF);
  200                 TAILQ_INIT(&nfslock_list);
  201                 nlminfo_release_p = nlminfo_release;
  202                 nfslock_dev = make_dev(&nfslock_cdevsw, 0,
  203                     UID_ROOT, GID_KMEM, 0600, _PATH_NFSLCKDEV);
  204                 return (0);
  205         default:
  206                 return (EOPNOTSUPP);
  207         }
  208 }
  209 
  210 DEV_MODULE(nfslock, nfslock_modevent, NULL);
  211 MODULE_VERSION(nfslock, 1);
  212 
  213 
  214 /*
  215  * XXX
  216  * We have to let the process know if the call succeeded.  I'm using an extra
  217  * field in the p_nlminfo field in the proc structure, as it is already for
  218  * lockd stuff.
  219  */
  220 
  221 /*
  222  * nfs_advlock --
  223  *      NFS advisory byte-level locks.
  224  */
  225 int
  226 nfs_dolock(struct vop_advlock_args *ap)
  227 {
  228         LOCKD_MSG msg;
  229         struct thread *td;
  230         struct vnode *vp;
  231         int error;
  232         struct flock *fl;
  233         struct proc *p;
  234 
  235         td = curthread;
  236         p = td->td_proc;
  237 
  238         vp = ap->a_vp;
  239         fl = ap->a_fl;
  240 
  241         /*
  242          * the NLM protocol doesn't allow the server to return an error
  243          * on ranges, so we do it.
  244          */
  245         if (fl->l_whence != SEEK_END) {
  246                 if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) ||
  247                     fl->l_start < 0 ||
  248                     (fl->l_len < 0 &&
  249                      (fl->l_start == 0 || fl->l_start + fl->l_len < 0)))
  250                         return (EINVAL);
  251                 if (fl->l_len > 0 &&
  252                          (fl->l_len - 1 > OFF_MAX - fl->l_start))
  253                         return (EOVERFLOW);
  254         }
  255 
  256         /*
  257          * Fill in the information structure.
  258          */
  259         msg.lm_version = LOCKD_MSG_VERSION;
  260         msg.lm_msg_ident.pid = p->p_pid;
  261         /*
  262          * if there is no nfsowner table yet, allocate one.
  263          */
  264         if (p->p_nlminfo == NULL) {
  265                 MALLOC(p->p_nlminfo, struct nlminfo *,
  266                         sizeof(struct nlminfo), M_NLMINFO, M_WAITOK | M_ZERO);
  267                 p->p_nlminfo->pid_start = p->p_stats->p_start;
  268                 timevaladd(&p->p_nlminfo->pid_start, &boottime);
  269         }
  270         msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start;
  271         msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq);
  272 
  273         msg.lm_fl = *fl;
  274         msg.lm_wait = ap->a_flags & F_WAIT;
  275         msg.lm_getlk = ap->a_op == F_GETLK;
  276         bcopy(VFSTONFS(vp->v_mount)->nm_nam, &msg.lm_addr,
  277                 min(sizeof msg.lm_addr, VFSTONFS(vp->v_mount)->nm_nam->sa_len));
  278         msg.lm_fh_len = NFS_ISV3(vp) ? VTONFS(vp)->n_fhsize : NFSX_V2FH;
  279         bcopy(VTONFS(vp)->n_fhp, msg.lm_fh, msg.lm_fh_len);
  280         msg.lm_nfsv3 = NFS_ISV3(vp);
  281         cru2x(td->td_ucred, &msg.lm_cred);
  282 
  283         for (;;) {
  284                 error = nfslock_send(&msg);
  285                 if (error)
  286                         return (error);
  287 
  288                 /* Unlocks succeed immediately.  */
  289                 if (fl->l_type == F_UNLCK)
  290                         return (error);
  291 
  292                 /*
  293                  * retry after 20 seconds if we haven't gotten a responce yet.
  294                  * This number was picked out of thin air... but is longer
  295                  * then even a reasonably loaded system should take (at least
  296                  * on a local network).  XXX Probably should use a back-off
  297                  * scheme.
  298                  *
  299                  * XXX: No PCATCH here since we currently have no useful
  300                  * way to signal to the userland rpc.lockd that the request
  301                  * has been aborted.  Once the rpc.lockd implementation
  302                  * can handle aborts, and we report them properly,
  303                  * PCATCH can be put back.  In the mean time, if we did
  304                  * permit aborting, the lock attempt would "get lost"
  305                  * and the lock would get stuck in the locked state.
  306                  */
  307                 error = tsleep(p->p_nlminfo, PUSER, "lockd", 20*hz);
  308                 if (error != 0) {
  309                         if (error == EWOULDBLOCK) {
  310                                 /*
  311                                  * We timed out, so we rewrite the request
  312                                  * to the fifo.
  313                                  */
  314                                 continue;
  315                         }
  316 
  317                         break;
  318                 }
  319 
  320                 if (msg.lm_getlk && p->p_nlminfo->retcode == 0) {
  321                         if (p->p_nlminfo->set_getlk_pid) {
  322                                 fl->l_sysid = 0; /* XXX */
  323                                 fl->l_pid = p->p_nlminfo->getlk_pid;
  324                         } else {
  325                                 fl->l_type = F_UNLCK;
  326                         }
  327                 }
  328                 error = p->p_nlminfo->retcode;
  329                 break;
  330         }
  331 
  332         return (error);
  333 }
  334 
  335 /*
  336  * nfslockdans --
  337  *      NFS advisory byte-level locks answer from the lock daemon.
  338  */
  339 static int
  340 nfslockdans(struct thread *td, struct lockd_ans *ansp)
  341 {
  342         struct proc *targetp;
  343         int error;
  344 
  345         /* Let root, or someone who once was root (lockd generally
  346          * switches to the daemon uid once it is done setting up) make
  347          * this call.
  348          *
  349          * XXX This authorization check is probably not right.
  350          */
  351         if ((error = suser(td)) != 0 &&
  352             td->td_ucred->cr_svuid != 0)
  353                 return (error);
  354 
  355         /* the version should match, or we're out of sync */
  356         if (ansp->la_vers != LOCKD_ANS_VERSION)
  357                 return (EINVAL);
  358 
  359         /* Find the process, set its return errno and wake it up. */
  360         if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL)
  361                 return (ESRCH);
  362 
  363         /* verify the pid hasn't been reused (if we can), and it isn't waiting
  364          * for an answer from a more recent request.  We return an EPIPE if
  365          * the match fails, because we've already used ESRCH above, and this
  366          * is sort of like writing on a pipe after the reader has closed it.
  367          */
  368         if (targetp->p_nlminfo == NULL ||
  369             ((ansp->la_msg_ident.msg_seq != -1) &&
  370               (timevalcmp(&targetp->p_nlminfo->pid_start,
  371                         &ansp->la_msg_ident.pid_start, !=) ||
  372                targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) {
  373                 PROC_UNLOCK(targetp);
  374                 return (EPIPE);
  375         }
  376 
  377         targetp->p_nlminfo->retcode = ansp->la_errno;
  378         targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid;
  379         targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid;
  380 
  381         wakeup(targetp->p_nlminfo);
  382 
  383         PROC_UNLOCK(targetp);
  384         return (0);
  385 }
  386 
  387 /*
  388  * Free nlminfo attached to process.
  389  */
  390 void        
  391 nlminfo_release(struct proc *p)
  392 {  
  393         free(p->p_nlminfo, M_NLMINFO);
  394         p->p_nlminfo = NULL;
  395 }

Cache object: 15f052b65a2732b741cd97fa1e9316ca


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.