Add dev_t freeing code. Controlled by sysctl debug.free_devt, default
is off.
This commit is contained in:
Poul-Henning Kamp
parent
3de9d6fbe4
commit
d137accc89
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=50549
@ -35,6 +35,7 @@
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/sysctl.h>
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#include <sys/systm.h>
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#include <sys/module.h>
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#include <sys/malloc.h>
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@ -63,9 +64,15 @@ MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage");
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static struct specinfo devt_stash[DEVT_STASH];
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static SLIST_HEAD(devt_hash_head, specinfo) dev_hash[DEVT_HASH];
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static LIST_HEAD(, specinfo) dev_hash[DEVT_HASH];
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static LIST_HEAD(, specinfo) dev_free;
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devfs_create_t *devfs_create_hook;
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devfs_remove_t *devfs_remove_hook;
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static int free_devt;
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SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, "");
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/*
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* Routine to convert from character to block device number.
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@ -230,26 +237,47 @@ makedev(int x, int y)
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udev = (x << 8) | y;
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hash = udev % DEVT_HASH;
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SLIST_FOREACH(si, &dev_hash[hash], si_hash) {
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LIST_FOREACH(si, &dev_hash[hash], si_hash) {
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if (si->si_udev == udev)
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return (si);
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}
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if (stashed >= DEVT_STASH) {
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MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT,
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M_USE_RESERVE);
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bzero(si, sizeof(*si));
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} else if (LIST_FIRST(&dev_free)) {
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si = LIST_FIRST(&dev_free);
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LIST_REMOVE(si, si_hash);
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} else {
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si = devt_stash + stashed++;
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si->si_flags |= SI_STASHED;
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}
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bzero(si, sizeof(*si));
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si->si_udev = udev;
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if (y > 256)
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sprintf(si->si_name, "#%d/0x%x", x, y);
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else
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sprintf(si->si_name, "#%d/%d", x, y);
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SLIST_INSERT_HEAD(&dev_hash[hash], si, si_hash);
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LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash);
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return (si);
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}
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void
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freedev(dev_t dev)
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{
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int hash;
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if (!free_devt)
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return;
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if (SLIST_FIRST(&dev->si_hlist))
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return;
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if (dev->si_devsw || dev->si_drv1 || dev->si_drv2)
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return;
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hash = dev->si_udev % DEVT_HASH;
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LIST_REMOVE(dev, si_hash);
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if (dev->si_flags & SI_STASHED) {
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bzero(dev, sizeof(*dev));
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LIST_INSERT_HEAD(&dev_free, dev, si_hash);
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} else {
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FREE(dev, M_DEVT);
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}
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}
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udev_t
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dev2udev(dev_t x)
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{
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@ -318,10 +346,31 @@ make_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, char
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return (dev);
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}
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void
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remove_dev(dev_t dev)
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{
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if (devfs_remove_hook)
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devfs_remove_hook(dev);
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dev->si_drv1 = 0;
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dev->si_drv2 = 0;
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dev->si_devsw = 0;
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freedev(dev);
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}
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char *
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devtoname(dev_t dev)
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{
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char *p;
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if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') {
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p = dev->si_name;
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if (devsw(dev))
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sprintf(p, "#%s/", devsw(dev)->d_name);
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else
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sprintf(p, "#%d/", major(dev));
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p += strlen(p);
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sprintf(p, minor(dev) > 255 ? "0x%x" : "%d", minor(dev));
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}
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return (dev->si_name);
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}
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@ -1692,7 +1692,7 @@ vclean(vp, flags, p)
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if (VSHOULDFREE(vp))
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vfree(vp);
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/*
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* Done with purge, notify sleepers of the grim news.
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*/
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@ -1821,6 +1821,7 @@ vgonel(vp, p)
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if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_rdev != NULL) {
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simple_lock(&spechash_slock);
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SLIST_REMOVE(&vp->v_hashchain, vp, vnode, v_specnext);
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freedev(vp->v_rdev);
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simple_unlock(&spechash_slock);
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vp->v_rdev = NULL;
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}
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@ -1692,7 +1692,7 @@ vclean(vp, flags, p)
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if (VSHOULDFREE(vp))
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vfree(vp);
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/*
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* Done with purge, notify sleepers of the grim news.
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*/
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@ -1821,6 +1821,7 @@ vgonel(vp, p)
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if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_rdev != NULL) {
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simple_lock(&spechash_slock);
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SLIST_REMOVE(&vp->v_hashchain, vp, vnode, v_specnext);
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freedev(vp->v_rdev);
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simple_unlock(&spechash_slock);
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vp->v_rdev = NULL;
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}
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@ -50,9 +50,10 @@ struct tty;
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struct vnode;
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struct specinfo {
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u_int si_flags;
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#define SI_STASHED 0x0001 /* created in stashed storage */
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udev_t si_udev;
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SLIST_ENTRY(specinfo) si_hash;
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LIST_ENTRY(specinfo) si_hash;
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SLIST_HEAD(, vnode) si_hlist;
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char si_name[SPECNAMELEN + 1];
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void *si_drv1, *si_drv2;
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@ -127,6 +128,7 @@ typedef int l_modem_t __P((struct tty *tp, int flag));
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/* This is type of the function DEVFS uses to hook into the kernel with */
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typedef void devfs_create_t __P((dev_t dev, uid_t uid, gid_t gid, int perms));
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typedef void devfs_remove_t __P((dev_t dev));
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/*
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* XXX: The dummy argument can be used to do what strategy1() never
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@ -275,11 +277,13 @@ dev_t chrtoblk __P((dev_t dev));
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struct cdevsw *devsw __P((dev_t dev));
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int devsw_module_handler __P((struct module *mod, int what, void *arg));
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char *devtoname __P((dev_t dev));
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void freedev __P((dev_t dev));
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int iskmemdev __P((dev_t dev));
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int iszerodev __P((dev_t dev));
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dev_t makebdev __P((int maj, int min));
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dev_t make_dev __P((struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, char *fmt, ...)) __printflike(6, 7);
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int lminor __P((dev_t dev));
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void remove_dev __P((dev_t dev));
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void setconf __P((void));
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extern devfs_create_t *devfs_create_hook;
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@ -50,9 +50,10 @@ struct tty;
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struct vnode;
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struct specinfo {
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u_int si_flags;
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#define SI_STASHED 0x0001 /* created in stashed storage */
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udev_t si_udev;
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SLIST_ENTRY(specinfo) si_hash;
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LIST_ENTRY(specinfo) si_hash;
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SLIST_HEAD(, vnode) si_hlist;
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char si_name[SPECNAMELEN + 1];
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void *si_drv1, *si_drv2;
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@ -127,6 +128,7 @@ typedef int l_modem_t __P((struct tty *tp, int flag));
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/* This is type of the function DEVFS uses to hook into the kernel with */
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typedef void devfs_create_t __P((dev_t dev, uid_t uid, gid_t gid, int perms));
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typedef void devfs_remove_t __P((dev_t dev));
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/*
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* XXX: The dummy argument can be used to do what strategy1() never
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@ -275,11 +277,13 @@ dev_t chrtoblk __P((dev_t dev));
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struct cdevsw *devsw __P((dev_t dev));
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int devsw_module_handler __P((struct module *mod, int what, void *arg));
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char *devtoname __P((dev_t dev));
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void freedev __P((dev_t dev));
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int iskmemdev __P((dev_t dev));
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int iszerodev __P((dev_t dev));
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dev_t makebdev __P((int maj, int min));
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dev_t make_dev __P((struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, char *fmt, ...)) __printflike(6, 7);
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int lminor __P((dev_t dev));
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void remove_dev __P((dev_t dev));
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void setconf __P((void));
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extern devfs_create_t *devfs_create_hook;
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