15bd415478
closes the race where the cdev was reclaimed before it ever made it back to devfs lookup.
140 lines
3.7 KiB
C
140 lines
3.7 KiB
C
/*-
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* Coda: an Experimental Distributed File System
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* Release 3.1
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*
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* Copyright (c) 1987-1998 Carnegie Mellon University
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* All Rights Reserved
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*
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* Permission to use, copy, modify and distribute this software and its
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* documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation, and
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* that credit is given to Carnegie Mellon University in all documents
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* and publicity pertaining to direct or indirect use of this code or its
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* derivatives.
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*
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* CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS KNOWN TO HAVE BUGS,
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* SOME OF WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON ALLOWS
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* FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. CARNEGIE MELLON
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* DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER
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* RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE OR OF
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* ANY DERIVATIVE WORK.
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*
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* Carnegie Mellon encourages users of this software to return any
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* improvements or extensions that they make, and to grant Carnegie
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* Mellon the rights to redistribute these changes without encumbrance.
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*
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* @(#) src/sys/coda/coda_fbsd.cr,v 1.1.1.1 1998/08/29 21:14:52 rvb Exp $
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include <sys/fcntl.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/ucred.h>
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#include <sys/vnode.h>
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#include <vm/vm.h>
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#include <vm/vnode_pager.h>
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#include <coda/coda.h>
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#include <coda/cnode.h>
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#include <coda/coda_vnops.h>
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#include <coda/coda_psdev.h>
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static struct cdevsw codadevsw = {
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.d_version = D_VERSION,
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.d_flags = D_NEEDGIANT,
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.d_open = vc_nb_open,
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.d_close = vc_nb_close,
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.d_read = vc_nb_read,
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.d_write = vc_nb_write,
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.d_ioctl = vc_nb_ioctl,
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.d_poll = vc_nb_poll,
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.d_name = "Coda",
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};
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static eventhandler_tag clonetag;
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static LIST_HEAD(, coda_mntinfo) coda_mnttbl;
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int vcdebug = 1;
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#define VCDEBUG if (vcdebug) printf
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/* for DEVFS, using bpf & tun drivers as examples*/
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static void coda_fbsd_clone(void *arg, char *name, int namelen,
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struct cdev **dev);
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static int
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codadev_modevent(module_t mod, int type, void *data)
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{
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struct coda_mntinfo *mnt;
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switch (type) {
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case MOD_LOAD:
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LIST_INIT(&coda_mnttbl);
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clonetag = EVENTHANDLER_REGISTER(dev_clone, coda_fbsd_clone,
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0, 1000);
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break;
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case MOD_UNLOAD:
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EVENTHANDLER_DEREGISTER(dev_clone, clonetag);
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while ((mnt = LIST_FIRST(&coda_mnttbl)) != NULL) {
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LIST_REMOVE(mnt, mi_list);
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destroy_dev(mnt->dev);
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free(mnt, M_CODA);
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}
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break;
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default:
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return (EOPNOTSUPP);
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}
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return 0;
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}
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static moduledata_t codadev_mod = {
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"codadev",
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codadev_modevent,
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NULL
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};
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DECLARE_MODULE(codadev, codadev_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
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static void coda_fbsd_clone(arg, name, namelen, dev)
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void *arg;
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char *name;
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int namelen;
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struct cdev **dev;
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{
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int u;
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struct coda_mntinfo *mnt;
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if (*dev != NULL)
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return;
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if (dev_stdclone(name,NULL,"cfs",&u) != 1)
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return;
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*dev = make_dev(&codadevsw,unit2minor(u),UID_ROOT,GID_WHEEL,0600,"cfs%d",u);
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dev_ref(*dev);
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mnt = malloc(sizeof(struct coda_mntinfo), M_CODA, M_WAITOK|M_ZERO);
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LIST_INSERT_HEAD(&coda_mnttbl, mnt, mi_list);
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}
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struct coda_mntinfo *
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dev2coda_mntinfo(struct cdev *dev)
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{
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struct coda_mntinfo *mnt;
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LIST_FOREACH(mnt, &coda_mnttbl, mi_list) {
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if (mnt->dev == dev)
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break;
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}
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return mnt;
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}
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