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darling-xnu/bsd/miscfs/devfs/devfs_tree.c
Thomas A cdbc10b677 Upload xnu-7195.141.2 Source
2023-05-16 21:41:14 -07:00

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/*
* Copyright (c) 2000-2014 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* Copyright 1997,1998 Julian Elischer. All rights reserved.
* julian@freebsd.org
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* devfs_tree.c
*/
/*
* NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
* support for mandatory and extensible security protections. This notice
* is included in support of clause 2.2 (b) of the Apple Public License,
* Version 2.0.
*/
/*
* HISTORY
* Dieter Siegmund (dieter@apple.com) Thu Apr 8 14:08:19 PDT 1999
* - removed mounting of "hidden" mountpoint
* - fixed problem in which devnode->dn_vn pointer was not
* updated with the vnode returned from checkalias()
* - replaced devfs_vntodn() with a macro VTODN()
* - rewrote dev_finddir() to not use recursion
* - added locking to avoid data structure corruption (DEVFS_(UN)LOCK())
* Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
* - fixed problem with devfs_dntovn() checking the v_id against the
* value cached in the device node; a union mount on top of us causes
* the v_id to get incremented thus, we would end up returning a new
* vnode instead of the existing one that has the mounted_here
* field filled in; the net effect was that the filesystem mounted
* on top of us would never show up
* - added devfs_stats to store how many data structures are actually
* allocated
*/
/* SPLIT_DEVS means each devfs uses a different devnode for the same device */
/* Otherwise the same device always ends up at the same vnode even if */
/* reached througgh a different devfs instance. The practical difference */
/* is that with the same vnode, chmods and chowns show up on all instances of */
/* a device. (etc) */
#define SPLIT_DEVS 1 /* maybe make this an option */
/*#define SPLIT_DEVS 1*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/malloc.h>
#include <sys/mount_internal.h>
#include <sys/proc.h>
#include <sys/vnode_internal.h>
#include <stdarg.h>
#include <libkern/OSAtomic.h>
#include <os/refcnt.h>
#define BSD_KERNEL_PRIVATE 1 /* devfs_make_link() prototype */
#include "devfs.h"
#include "devfsdefs.h"
#if CONFIG_MACF
#include <security/mac_framework.h>
#endif
#if FDESC
#include "fdesc.h"
#endif
typedef struct devfs_vnode_event {
vnode_t dve_vp;
uint32_t dve_vid;
uint32_t dve_events;
} *devfs_vnode_event_t;
/*
* Size of stack buffer (fast path) for notifications. If
* the number of mounts is small, no need to malloc a buffer.
*/
#define NUM_STACK_ENTRIES 5
typedef struct devfs_event_log {
size_t del_max;
size_t del_used;
devfs_vnode_event_t del_entries;
} *devfs_event_log_t;
static void dev_free_hier(devdirent_t *);
static int devfs_propogate(devdirent_t *, devdirent_t *, devfs_event_log_t);
static int dev_finddir(const char *, devnode_t *, int, devnode_t **, devfs_event_log_t);
static int dev_dup_entry(devnode_t *, devdirent_t *, devdirent_t **, struct devfsmount *);
void devfs_ref_node(devnode_t *);
void devfs_rele_node(devnode_t *);
static void devfs_record_event(devfs_event_log_t, devnode_t*, uint32_t);
static int devfs_init_event_log(devfs_event_log_t, uint32_t, devfs_vnode_event_t);
static void devfs_release_event_log(devfs_event_log_t, int);
static void devfs_bulk_notify(devfs_event_log_t);
static devdirent_t *devfs_make_node_internal(dev_t, devfstype_t type, uid_t, gid_t, int,
int (*clone)(dev_t dev, int action), const char *fmt, va_list ap);
static LCK_GRP_DECLARE(devfs_lck_grp, "devfs_lock");
LCK_MTX_DECLARE(devfs_mutex, &devfs_lck_grp);
LCK_MTX_DECLARE(devfs_attr_mutex, &devfs_lck_grp);
os_refgrp_decl(static, devfs_refgrp, "devfs", NULL);
devdirent_t * dev_root = NULL; /* root of backing tree */
struct devfs_stats devfs_stats; /* hold stats */
static ino_t devfs_unique_fileno = 0;
#ifdef HIDDEN_MOUNTPOINT
static struct mount *devfs_hidden_mount;
#endif /* HIDDEN_MOINTPOINT */
static int devfs_ready = 0;
static uint32_t devfs_nmountplanes = 0; /* The first plane is not used for a mount */
#define DEVFS_NOCREATE FALSE
#define DEVFS_CREATE TRUE
/*
* Set up the root directory node in the backing plane
* This is happenning before the vfs system has been
* set up yet, so be careful about what we reference..
* Notice that the ops are by indirection.. as they haven't
* been set up yet!
* DEVFS has a hidden mountpoint that is used as the anchor point
* for the internal 'blueprint' version of the dev filesystem tree.
*/
/*proto*/
int
devfs_sinit(void)
{
int error;
DEVFS_LOCK();
error = dev_add_entry("root", NULL, DEV_DIR, NULL, NULL, NULL, &dev_root);
DEVFS_UNLOCK();
if (error) {
printf("devfs_sinit: dev_add_entry failed ");
return ENOTSUP;
}
#ifdef HIDDEN_MOUNTPOINT
devfs_hidden_mount = zalloc_flags(mount_zone, Z_WAITOK | Z_ZERO);
mount_lock_init(devfs_hidden_mount);
TAILQ_INIT(&devfs_hidden_mount->mnt_vnodelist);
TAILQ_INIT(&devfs_hidden_mount->mnt_workerqueue);
TAILQ_INIT(&devfs_hidden_mount->mnt_newvnodes);
#if CONFIG_MACF
mac_mount_label_init(devfs_hidden_mount);
mac_mount_label_associate(vfs_context_kernel(), devfs_hidden_mount);
#endif
/* Initialize the default IO constraints */
mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
mp->mnt_ioflags = 0;
mp->mnt_realrootvp = NULLVP;
mp->mnt_authcache_ttl = CACHED_LOOKUP_RIGHT_TTL;
devfs_mount(devfs_hidden_mount, "dummy", NULL, NULL, NULL);
dev_root->de_dnp->dn_dvm
= (struct devfsmount *)devfs_hidden_mount->mnt_data;
#endif /* HIDDEN_MOUNTPOINT */
#if CONFIG_MACF
mac_devfs_label_associate_directory("/", (int) strlen("/"),
dev_root->de_dnp, "/");
#endif
devfs_ready = 1;
return 0;
}
/***********************************************************************\
*************************************************************************
* Routines used to find our way to a point in the tree *
*************************************************************************
\***********************************************************************/
/***************************************************************
* Search down the linked list off a dir to find "name"
* return the devnode_t * for that node.
*
* called with DEVFS_LOCK held
***************************************************************/
devdirent_t *
dev_findname(devnode_t * dir, const char *name)
{
devdirent_t * newfp;
if (dir->dn_type != DEV_DIR) {
return 0; /*XXX*/ /* printf?*/
}
if (name[0] == '.') {
if (name[1] == 0) {
return dir->dn_typeinfo.Dir.myname;
}
if ((name[1] == '.') && (name[2] == 0)) {
/* for root, .. == . */
return dir->dn_typeinfo.Dir.parent->dn_typeinfo.Dir.myname;
}
}
newfp = dir->dn_typeinfo.Dir.dirlist;
while (newfp) {
if (!(strncmp(name, newfp->de_name, sizeof(newfp->de_name)))) {
return newfp;
}
newfp = newfp->de_next;
}
return NULL;
}
/***********************************************************************
* Given a starting node (0 for root) and a pathname, return the node
* for the end item on the path. It MUST BE A DIRECTORY. If the 'DEVFS_CREATE'
* option is true, then create any missing nodes in the path and create
* and return the final node as well.
* This is used to set up a directory, before making nodes in it..
*
* called with DEVFS_LOCK held
***********************************************************************/
static int
dev_finddir(const char * path,
devnode_t * dirnode,
int create,
devnode_t * * dn_pp,
devfs_event_log_t delp)
{
devnode_t * dnp = NULL;
int error = 0;
const char * scan;
#if CONFIG_MACF
char fullpath[DEVMAXPATHSIZE];
#endif
if (!dirnode) { /* dirnode == NULL means start at root */
dirnode = dev_root->de_dnp;
}
if (dirnode->dn_type != DEV_DIR) {
return ENOTDIR;
}
if (strlen(path) > (DEVMAXPATHSIZE - 1)) {
return ENAMETOOLONG;
}
#if CONFIG_MACF
strlcpy(fullpath, path, DEVMAXPATHSIZE);
#endif
scan = path;
while (*scan == '/') {
scan++;
}
*dn_pp = NULL;
while (1) {
char component[DEVMAXPATHSIZE];
devdirent_t * dirent_p;
const char * start;
if (*scan == 0) {
/* we hit the end of the string, we're done */
*dn_pp = dirnode;
break;
}
start = scan;
while (*scan != '/' && *scan) {
scan++;
}
strlcpy(component, start, (scan - start) + 1);
if (*scan == '/') {
scan++;
}
dirent_p = dev_findname(dirnode, component);
if (dirent_p) {
dnp = dirent_p->de_dnp;
if (dnp->dn_type != DEV_DIR) {
error = ENOTDIR;
break;
}
} else {
if (!create) {
error = ENOENT;
break;
}
error = dev_add_entry(component, dirnode,
DEV_DIR, NULL, NULL, NULL, &dirent_p);
if (error) {
break;
}
dnp = dirent_p->de_dnp;
#if CONFIG_MACF
mac_devfs_label_associate_directory(
dirnode->dn_typeinfo.Dir.myname->de_name,
(int) strlen(dirnode->dn_typeinfo.Dir.myname->de_name),
dnp, fullpath);
#endif
devfs_propogate(dirnode->dn_typeinfo.Dir.myname, dirent_p, delp);
}
dirnode = dnp; /* continue relative to this directory */
}
return error;
}
/***********************************************************************
* Add a new NAME element to the devfs
* If we're creating a root node, then dirname is NULL
* Basically this creates a new namespace entry for the device node
*
* Creates a name node, and links it to the supplied node
*
* called with DEVFS_LOCK held
***********************************************************************/
int
dev_add_name(const char * name, devnode_t * dirnode, __unused devdirent_t * back,
devnode_t * dnp, devdirent_t * *dirent_pp)
{
devdirent_t * dirent_p = NULL;
if (dirnode != NULL) {
if (dirnode->dn_type != DEV_DIR) {
return ENOTDIR;
}
if (dev_findname(dirnode, name)) {
return EEXIST;
}
}
/*
* make sure the name is legal
* slightly misleading in the case of NULL
*/
if (!name || (strlen(name) > (DEVMAXNAMESIZE - 1))) {
return ENAMETOOLONG;
}
/*
* Allocate and fill out a new directory entry
*/
MALLOC(dirent_p, devdirent_t *, sizeof(devdirent_t),
M_DEVFSNAME, M_WAITOK);
if (!dirent_p) {
return ENOMEM;
}
bzero(dirent_p, sizeof(devdirent_t));
/* inherrit our parent's mount info */ /*XXX*/
/* a kludge but.... */
if (dirnode && (dnp->dn_dvm == NULL)) {
dnp->dn_dvm = dirnode->dn_dvm;
/* if(!dnp->dn_dvm) printf("parent had null dvm "); */
}
/*
* Link the two together
* include the implicit link in the count of links to the devnode..
* this stops it from being accidentally freed later.
*/
dirent_p->de_dnp = dnp;
dnp->dn_links++; /* implicit from our own name-node */
/*
* Make sure that we can find all the links that reference a node
* so that we can get them all if we need to zap the node.
*/
if (dnp->dn_linklist) {
dirent_p->de_nextlink = dnp->dn_linklist;
dirent_p->de_prevlinkp = dirent_p->de_nextlink->de_prevlinkp;
dirent_p->de_nextlink->de_prevlinkp = &(dirent_p->de_nextlink);
*dirent_p->de_prevlinkp = dirent_p;
} else {
dirent_p->de_nextlink = dirent_p;
dirent_p->de_prevlinkp = &(dirent_p->de_nextlink);
}
dnp->dn_linklist = dirent_p;
/*
* If the node is a directory, then we need to handle the
* creation of the .. link.
* A NULL dirnode indicates a root node, so point to ourself.
*/
if (dnp->dn_type == DEV_DIR) {
dnp->dn_typeinfo.Dir.myname = dirent_p;
/*
* If we are unlinking from an old dir, decrement its links
* as we point our '..' elsewhere
* Note: it's up to the calling code to remove the
* us from the original directory's list
*/
if (dnp->dn_typeinfo.Dir.parent) {
dnp->dn_typeinfo.Dir.parent->dn_links--;
}
if (dirnode) {
dnp->dn_typeinfo.Dir.parent = dirnode;
} else {
dnp->dn_typeinfo.Dir.parent = dnp;
}
dnp->dn_typeinfo.Dir.parent->dn_links++; /* account for the new '..' */
}
/*
* put the name into the directory entry.
*/
strlcpy(dirent_p->de_name, name, DEVMAXNAMESIZE);
/*
* Check if we are not making a root node..
* (i.e. have parent)
*/
if (dirnode) {
/*
* Put it on the END of the linked list of directory entries
*/
dirent_p->de_parent = dirnode; /* null for root */
dirent_p->de_prevp = dirnode->dn_typeinfo.Dir.dirlast;
dirent_p->de_next = *(dirent_p->de_prevp); /* should be NULL */
/*right?*/
*(dirent_p->de_prevp) = dirent_p;
dirnode->dn_typeinfo.Dir.dirlast = &(dirent_p->de_next);
dirnode->dn_typeinfo.Dir.entrycount++;
dirnode->dn_len += strlen(name) + 8;/*ok, ok?*/
}
*dirent_pp = dirent_p;
DEVFS_INCR_ENTRIES();
return 0;
}
/***********************************************************************
* Add a new element to the devfs plane.
*
* Creates a new dev_node to go with it if the prototype should not be
* reused. (Is a DIR, or we select SPLIT_DEVS at compile time)
* typeinfo gives us info to make our node if we don't have a prototype.
* If typeinfo is null and proto exists, then the typeinfo field of
* the proto is used intead in the DEVFS_CREATE case.
* note the 'links' count is 0 (except if a dir)
* but it is only cleared on a transition
* so this is ok till we link it to something
* Even in SPLIT_DEVS mode,
* if the node already exists on the wanted plane, just return it
*
* called with DEVFS_LOCK held
***********************************************************************/
int
dev_add_node(int entrytype, devnode_type_t * typeinfo, devnode_t * proto,
devnode_t * *dn_pp, struct devfsmount *dvm)
{
devnode_t * dnp = NULL;
int error = 0;
#if defined SPLIT_DEVS
/*
* If we have a prototype, then check if there is already a sibling
* on the mount plane we are looking at, if so, just return it.
*/
if (proto) {
dnp = proto->dn_nextsibling;
while (dnp != proto) {
if (dnp->dn_dvm == dvm) {
*dn_pp = dnp;
return 0;
}
dnp = dnp->dn_nextsibling;
}
if (typeinfo == NULL) {
typeinfo = &(proto->dn_typeinfo);
}
}
#else /* SPLIT_DEVS */
if (proto) {
switch (proto->type) {
case DEV_BDEV:
case DEV_CDEV:
*dn_pp = proto;
return 0;
}
}
#endif /* SPLIT_DEVS */
MALLOC(dnp, devnode_t *, sizeof(devnode_t), M_DEVFSNODE, M_WAITOK);
if (!dnp) {
return ENOMEM;
}
/*
* If we have a proto, that means that we are duplicating some
* other device, which can only happen if we are not at the back plane
*/
if (proto) {
bcopy(proto, dnp, sizeof(devnode_t));
dnp->dn_links = 0;
dnp->dn_linklist = NULL;
dnp->dn_vn = NULL;
dnp->dn_len = 0;
/* add to END of siblings list */
dnp->dn_prevsiblingp = proto->dn_prevsiblingp;
*(dnp->dn_prevsiblingp) = dnp;
dnp->dn_nextsibling = proto;
proto->dn_prevsiblingp = &(dnp->dn_nextsibling);
#if CONFIG_MACF
mac_devfs_label_init(dnp);
mac_devfs_label_copy(proto->dn_label, dnp->dn_label);
#endif
} else {
struct timeval tv;
/*
* We have no prototype, so start off with a clean slate
*/
microtime(&tv);
bzero(dnp, sizeof(devnode_t));
dnp->dn_type = entrytype;
dnp->dn_nextsibling = dnp;
dnp->dn_prevsiblingp = &(dnp->dn_nextsibling);
dnp->dn_atime.tv_sec = tv.tv_sec;
dnp->dn_mtime.tv_sec = tv.tv_sec;
dnp->dn_ctime.tv_sec = tv.tv_sec;
#if CONFIG_MACF
mac_devfs_label_init(dnp);
#endif
}
dnp->dn_dvm = dvm;
/* Note: this inits the reference count to 1, this is considered unreferenced */
os_ref_init_raw(&dnp->dn_refcount, &devfs_refgrp);
dnp->dn_ino = devfs_unique_fileno;
devfs_unique_fileno++;
/*
* fill out the dev node according to type
*/
switch (entrytype) {
case DEV_DIR:
/*
* As it's a directory, make sure
* it has a null entries list
*/
dnp->dn_typeinfo.Dir.dirlast = &(dnp->dn_typeinfo.Dir.dirlist);
dnp->dn_typeinfo.Dir.dirlist = (devdirent_t *)0;
dnp->dn_typeinfo.Dir.entrycount = 0;
/* until we know better, it has a null parent pointer*/
dnp->dn_typeinfo.Dir.parent = NULL;
dnp->dn_links++; /* for .*/
dnp->dn_typeinfo.Dir.myname = NULL;
/*
* make sure that the ops associated with it are the ops
* that we use (by default) for directories
*/
dnp->dn_ops = &devfs_vnodeop_p;
dnp->dn_mode |= 0555; /* default perms */
break;
case DEV_SLNK:
/*
* As it's a symlink allocate and store the link info
* Symlinks should only ever be created by the user,
* so they are not on the back plane and should not be
* propogated forward.. a bit like directories in that way..
* A symlink only exists on one plane and has its own
* node.. therefore we might be on any random plane.
*/
MALLOC(dnp->dn_typeinfo.Slnk.name, char *,
typeinfo->Slnk.namelen + 1,
M_DEVFSNODE, M_WAITOK);
if (!dnp->dn_typeinfo.Slnk.name) {
error = ENOMEM;
break;
}
strlcpy(dnp->dn_typeinfo.Slnk.name, typeinfo->Slnk.name,
typeinfo->Slnk.namelen + 1);
dnp->dn_typeinfo.Slnk.namelen = typeinfo->Slnk.namelen;
DEVFS_INCR_STRINGSPACE(dnp->dn_typeinfo.Slnk.namelen + 1);
dnp->dn_ops = &devfs_vnodeop_p;
dnp->dn_mode |= 0555; /* default perms */
break;
case DEV_CDEV:
case DEV_BDEV:
/*
* Make sure it has DEVICE type ops
* and device specific fields are correct
*/
dnp->dn_ops = &devfs_spec_vnodeop_p;
dnp->dn_typeinfo.dev = typeinfo->dev;
break;
#if FDESC
/* /dev/fd is special */
case DEV_DEVFD:
dnp->dn_ops = &devfs_devfd_vnodeop_p;
dnp->dn_mode |= 0555; /* default perms */
break;
#endif /* FDESC */
default:
error = EINVAL;
}
if (error) {
FREE(dnp, M_DEVFSNODE);
} else {
*dn_pp = dnp;
DEVFS_INCR_NODES();
}
return error;
}
/***********************************************************************
* called with DEVFS_LOCK held
**********************************************************************/
void
devnode_free(devnode_t * dnp)
{
#if CONFIG_MACF
mac_devfs_label_destroy(dnp);
#endif
if (dnp->dn_type == DEV_SLNK) {
DEVFS_DECR_STRINGSPACE(dnp->dn_typeinfo.Slnk.namelen + 1);
FREE(dnp->dn_typeinfo.Slnk.name, M_DEVFSNODE);
}
DEVFS_DECR_NODES();
FREE(dnp, M_DEVFSNODE);
}
/***********************************************************************
* called with DEVFS_LOCK held
**********************************************************************/
static void
devfs_dn_free(devnode_t * dnp)
{
if (--dnp->dn_links <= 0) { /* can be -1 for initial free, on error */
/*probably need to do other cleanups XXX */
if (dnp->dn_nextsibling != dnp) {
devnode_t * * prevp = dnp->dn_prevsiblingp;
*prevp = dnp->dn_nextsibling;
dnp->dn_nextsibling->dn_prevsiblingp = prevp;
}
/* Can only free if there are no references; otherwise, wait for last vnode to be reclaimed */
os_ref_count_t rc = os_ref_get_count_raw(&dnp->dn_refcount);
if (rc == 1) {
/* release final reference from dev_add_node */
(void) os_ref_release_locked_raw(&dnp->dn_refcount, &devfs_refgrp);
devnode_free(dnp);
} else {
dnp->dn_lflags |= DN_DELETE;
}
}
}
/***********************************************************************\
* Front Node Operations *
* Add or delete a chain of front nodes *
\***********************************************************************/
/***********************************************************************
* Given a directory backing node, and a child backing node, add the
* appropriate front nodes to the front nodes of the directory to
* represent the child node to the user
*
* on failure, front nodes will either be correct or not exist for each
* front dir, however dirs completed will not be stripped of completed
* frontnodes on failure of a later frontnode
*
* This allows a new node to be propogated through all mounted planes
*
* called with DEVFS_LOCK held
***********************************************************************/
static int
devfs_propogate(devdirent_t * parent, devdirent_t * child, devfs_event_log_t delp)
{
int error;
devdirent_t * newnmp;
devnode_t * dnp = child->de_dnp;
devnode_t * pdnp = parent->de_dnp;
devnode_t * adnp = parent->de_dnp;
int type = child->de_dnp->dn_type;
uint32_t events;
events = (dnp->dn_type == DEV_DIR ? VNODE_EVENT_DIR_CREATED : VNODE_EVENT_FILE_CREATED);
if (delp != NULL) {
devfs_record_event(delp, pdnp, events);
}
/***********************************************
* Find the other instances of the parent node
***********************************************/
for (adnp = pdnp->dn_nextsibling;
adnp != pdnp;
adnp = adnp->dn_nextsibling) {
/*
* Make the node, using the original as a prototype)
* if the node already exists on that plane it won't be
* re-made..
*/
if ((error = dev_add_entry(child->de_name, adnp, type,
NULL, dnp, adnp->dn_dvm,
&newnmp)) != 0) {
printf("duplicating %s failed\n", child->de_name);
} else {
if (delp != NULL) {
devfs_record_event(delp, adnp, events);
/*
* Slightly subtle. We're guaranteed that there will
* only be a vnode hooked into this devnode if we're creating
* a new link to an existing node; otherwise, the devnode is new
* and no one can have looked it up yet. If we're making a link,
* then the buffer is large enough for two nodes in each
* plane; otherwise, there's no vnode and this call will
* do nothing.
*/
devfs_record_event(delp, newnmp->de_dnp, VNODE_EVENT_LINK);
}
}
}
return 0; /* for now always succeed */
}
static uint32_t
remove_notify_count(devnode_t *dnp)
{
uint32_t notify_count = 0;
devnode_t *dnp2;
/*
* Could need to notify for one removed node on each mount and
* one parent for each such node.
*/
notify_count = devfs_nmountplanes;
notify_count += dnp->dn_links;
for (dnp2 = dnp->dn_nextsibling; dnp2 != dnp; dnp2 = dnp2->dn_nextsibling) {
notify_count += dnp2->dn_links;
}
return notify_count;
}
/***********************************************************************
* remove all instances of this devicename [for backing nodes..]
* note.. if there is another link to the node (non dir nodes only)
* then the devfs_node will still exist as the ref count will be non-0
* removing a directory node will remove all sup-nodes on all planes (ZAP)
*
* Used by device drivers to remove nodes that are no longer relevant
* The argument is the 'cookie' they were given when they created the node
* this function is exported.. see devfs.h
***********************************************************************/
void
devfs_remove(void *dirent_p)
{
devnode_t * dnp = ((devdirent_t *)dirent_p)->de_dnp;
devnode_t * dnp2;
boolean_t lastlink;
struct devfs_event_log event_log;
uint32_t log_count = 0;
int do_notify = 0;
int need_free = 0;
struct devfs_vnode_event stackbuf[NUM_STACK_ENTRIES];
DEVFS_LOCK();
if (!devfs_ready) {
printf("devfs_remove: not ready for devices!\n");
goto out;
}
log_count = remove_notify_count(dnp);
if (log_count > NUM_STACK_ENTRIES) {
uint32_t new_count;
wrongsize:
DEVFS_UNLOCK();
if (devfs_init_event_log(&event_log, log_count, NULL) == 0) {
do_notify = 1;
need_free = 1;
}
DEVFS_LOCK();
new_count = remove_notify_count(dnp);
if (need_free && (new_count > log_count)) {
devfs_release_event_log(&event_log, 1);
need_free = 0;
do_notify = 0;
log_count = log_count * 2;
goto wrongsize;
}
} else {
if (devfs_init_event_log(&event_log, NUM_STACK_ENTRIES, &stackbuf[0]) == 0) {
do_notify = 1;
}
}
/* This file has been deleted */
if (do_notify != 0) {
devfs_record_event(&event_log, dnp, VNODE_EVENT_DELETE);
}
/* keep removing the next sibling till only we exist. */
while ((dnp2 = dnp->dn_nextsibling) != dnp) {
/*
* Keep removing the next front node till no more exist
*/
dnp->dn_nextsibling = dnp2->dn_nextsibling;
dnp->dn_nextsibling->dn_prevsiblingp = &(dnp->dn_nextsibling);
dnp2->dn_nextsibling = dnp2;
dnp2->dn_prevsiblingp = &(dnp2->dn_nextsibling);
/* This file has been deleted in this plane */
if (do_notify != 0) {
devfs_record_event(&event_log, dnp2, VNODE_EVENT_DELETE);
}
if (dnp2->dn_linklist) {
do {
lastlink = (1 == dnp2->dn_links);
/* Each parent of a link to this file has lost a child in this plane */
if (do_notify != 0) {
devfs_record_event(&event_log, dnp2->dn_linklist->de_parent, VNODE_EVENT_FILE_REMOVED);
}
dev_free_name(dnp2->dn_linklist);
} while (!lastlink);
}
}
/*
* then free the main node
* If we are not running in SPLIT_DEVS mode, then
* THIS is what gets rid of the propogated nodes.
*/
if (dnp->dn_linklist) {
do {
lastlink = (1 == dnp->dn_links);
/* Each parent of a link to this file has lost a child */
if (do_notify != 0) {
devfs_record_event(&event_log, dnp->dn_linklist->de_parent, VNODE_EVENT_FILE_REMOVED);
}
dev_free_name(dnp->dn_linklist);
} while (!lastlink);
}
out:
DEVFS_UNLOCK();
if (do_notify != 0) {
devfs_bulk_notify(&event_log);
devfs_release_event_log(&event_log, need_free);
}
return;
}
/***************************************************************
* duplicate the backing tree into a tree of nodes hung off the
* mount point given as the argument. Do this by
* calling dev_dup_entry which recurses all the way
* up the tree..
*
* called with DEVFS_LOCK held
**************************************************************/
int
dev_dup_plane(struct devfsmount *devfs_mp_p)
{
devdirent_t * new;
int error = 0;
if ((error = dev_dup_entry(NULL, dev_root, &new, devfs_mp_p))) {
return error;
}
devfs_mp_p->plane_root = new;
devfs_nmountplanes++;
return error;
}
/***************************************************************
* Free a whole plane
*
* called with DEVFS_LOCK held
***************************************************************/
void
devfs_free_plane(struct devfsmount *devfs_mp_p)
{
devdirent_t * dirent_p;
dirent_p = devfs_mp_p->plane_root;
if (dirent_p) {
dev_free_hier(dirent_p);
dev_free_name(dirent_p);
}
devfs_mp_p->plane_root = NULL;
devfs_nmountplanes--;
if (devfs_nmountplanes > (devfs_nmountplanes + 1)) {
panic("plane count wrapped around.\n");
}
}
/***************************************************************
* Create and link in a new front element..
* Parent can be 0 for a root node
* Not presently usable to make a symlink XXX
* (Ok, symlinks don't propogate)
* recursively will create subnodes corresponding to equivalent
* child nodes in the base level
*
* called with DEVFS_LOCK held
***************************************************************/
static int
dev_dup_entry(devnode_t * parent, devdirent_t * back, devdirent_t * *dnm_pp,
struct devfsmount *dvm)
{
devdirent_t * entry_p = NULL;
devdirent_t * newback;
devdirent_t * newfront;
int error;
devnode_t * dnp = back->de_dnp;
int type = dnp->dn_type;
/*
* go get the node made (if we need to)
* use the back one as a prototype
*/
error = dev_add_entry(back->de_name, parent, type, NULL, dnp,
parent?parent->dn_dvm:dvm, &entry_p);
if (!error && (entry_p == NULL)) {
error = ENOMEM; /* Really can't happen, but make static analyzer happy */
}
if (error != 0) {
printf("duplicating %s failed\n", back->de_name);
goto out;
}
/*
* If we have just made the root, then insert the pointer to the
* mount information
*/
if (dvm) {
entry_p->de_dnp->dn_dvm = dvm;
}
/*
* If it is a directory, then recurse down all the other
* subnodes in it....
* note that this time we don't pass on the mount info..
*/
if (type == DEV_DIR) {
for (newback = back->de_dnp->dn_typeinfo.Dir.dirlist;
newback; newback = newback->de_next) {
if ((error = dev_dup_entry(entry_p->de_dnp,
newback, &newfront, NULL)) != 0) {
break; /* back out with an error */
}
}
}
out:
*dnm_pp = entry_p;
return error;
}
/***************************************************************
* Free a name node
* remember that if there are other names pointing to the
* dev_node then it may not get freed yet
* can handle if there is no dnp
*
* called with DEVFS_LOCK held
***************************************************************/
int
dev_free_name(devdirent_t * dirent_p)
{
devnode_t * parent = dirent_p->de_parent;
devnode_t * dnp = dirent_p->de_dnp;
if (dnp) {
if (dnp->dn_type == DEV_DIR) {
devnode_t * p;
if (dnp->dn_typeinfo.Dir.dirlist) {
return ENOTEMPTY;
}
p = dnp->dn_typeinfo.Dir.parent;
devfs_dn_free(dnp); /* account for '.' */
devfs_dn_free(p); /* '..' */
}
/*
* unlink us from the list of links for this node
* If we are the only link, it's easy!
* if we are a DIR of course there should not be any
* other links.
*/
if (dirent_p->de_nextlink == dirent_p) {
dnp->dn_linklist = NULL;
} else {
if (dnp->dn_linklist == dirent_p) {
dnp->dn_linklist = dirent_p->de_nextlink;
}
}
devfs_dn_free(dnp);
}
dirent_p->de_nextlink->de_prevlinkp = dirent_p->de_prevlinkp;
*(dirent_p->de_prevlinkp) = dirent_p->de_nextlink;
/*
* unlink ourselves from the directory on this plane
*/
if (parent) { /* if not fs root */
if ((*dirent_p->de_prevp = dirent_p->de_next)) {/* yes, assign */
dirent_p->de_next->de_prevp = dirent_p->de_prevp;
} else {
parent->dn_typeinfo.Dir.dirlast
= dirent_p->de_prevp;
}
parent->dn_typeinfo.Dir.entrycount--;
parent->dn_len -= strlen(dirent_p->de_name) + 8;
}
DEVFS_DECR_ENTRIES();
FREE(dirent_p, M_DEVFSNAME);
return 0;
}
/***************************************************************
* Free a hierarchy starting at a directory node name
* remember that if there are other names pointing to the
* dev_node then it may not get freed yet
* can handle if there is no dnp
* leave the node itself allocated.
*
* called with DEVFS_LOCK held
***************************************************************/
static void
dev_free_hier(devdirent_t * dirent_p)
{
devnode_t * dnp = dirent_p->de_dnp;
if (dnp) {
if (dnp->dn_type == DEV_DIR) {
while (dnp->dn_typeinfo.Dir.dirlist) {
dev_free_hier(dnp->dn_typeinfo.Dir.dirlist);
dev_free_name(dnp->dn_typeinfo.Dir.dirlist);
}
}
}
}
/***************************************************************
* given a dev_node, find the appropriate vnode if one is already
* associated, or get a new one and associate it with the dev_node
*
* called with DEVFS_LOCK held
*
* If an error is returned, then the dnp may have been freed (we
* raced with a delete and lost). A devnode should not be accessed
* after devfs_dntovn() fails.
****************************************************************/
int
devfs_dntovn(devnode_t * dnp, struct vnode **vn_pp, __unused struct proc * p)
{
struct vnode *vn_p;
int error = 0;
struct vnode_fsparam vfsp;
enum vtype vtype = 0;
int markroot = 0;
int nretries = 0;
int n_minor = DEVFS_CLONE_ALLOC; /* new minor number for clone device */
/*
* We should never come in and find that our devnode has been marked for delete.
* The lookup should have held the lock from entry until now; it should not have
* been able to find a removed entry. Any other pathway would have just created
* the devnode and come here without dropping the devfs lock, so no one would
* have a chance to delete.
*/
if (dnp->dn_lflags & DN_DELETE) {
panic("devfs_dntovn: DN_DELETE set on a devnode upon entry.");
}
devfs_ref_node(dnp);
retry:
*vn_pp = NULL;
vn_p = dnp->dn_vn;
if (vn_p) { /* already has a vnode */
uint32_t vid;
vid = vnode_vid(vn_p);
DEVFS_UNLOCK();
/*
* We want to use the drainok variant of vnode_getwithvid
* because we _don't_ want to get an iocount if the vnode is
* is blocked in vnode_drain as it can cause infinite
* loops in vn_open_auth. While in use vnodes are typically
* only reclaimed on forced unmounts, In use devfs tty vnodes
* can be quite frequently reclaimed by revoke(2) or by the
* exit of a controlling process.
*/
error = vnode_getwithvid_drainok(vn_p, vid);
DEVFS_LOCK();
if (dnp->dn_lflags & DN_DELETE) {
/*
* our BUSY node got marked for
* deletion while the DEVFS lock
* was dropped...
*/
if (error == 0) {
/*
* vnode_getwithvid returned a valid ref
* which we need to drop
*/
vnode_put(vn_p);
}
/*
* This entry is no longer in the namespace. This is only
* possible for lookup: no other path would not find an existing
* vnode. Therefore, ENOENT is a valid result.
*/
error = ENOENT;
} else if (error == ENODEV) {
/*
* The Filesystem is getting unmounted.
*/
error = ENOENT;
} else if (error && (nretries < DEV_MAX_VNODE_RETRY)) {
/*
* If we got an error from vnode_getwithvid, it means
* we raced with a recycle and lost i.e. we asked for
* an iocount only after vnode_drain had been entered
* for the vnode and returned with an error only after
* devfs_reclaim was called on the vnode. devfs_reclaim
* sets dn_vn to NULL but while we were waiting to
* reacquire DEVFS_LOCK, another vnode might have gotten
* associated with the dnp. In either case, we need to
* retry otherwise we will end up returning an ENOENT
* for this lookup but the next lookup will succeed
* because it creates a new vnode (or a racing lookup
* created a new vnode already).
*/
error = 0;
nretries++;
goto retry;
}
if (!error) {
*vn_pp = vn_p;
}
goto out;
}
/*
* If we get here, then we've beaten any deletes;
* if someone sets DN_DELETE during a subsequent drop
* of the devfs lock, we'll still vend a vnode.
*/
if (dnp->dn_lflags & DN_CREATE) {
dnp->dn_lflags |= DN_CREATEWAIT;
msleep(&dnp->dn_lflags, &devfs_mutex, PRIBIO, 0, 0);
goto retry;
}
dnp->dn_lflags |= DN_CREATE;
switch (dnp->dn_type) {
case DEV_SLNK:
vtype = VLNK;
break;
case DEV_DIR:
if (dnp->dn_typeinfo.Dir.parent == dnp) {
markroot = 1;
}
vtype = VDIR;
break;
case DEV_BDEV:
case DEV_CDEV:
vtype = (dnp->dn_type == DEV_BDEV) ? VBLK : VCHR;
break;
#if FDESC
case DEV_DEVFD:
vtype = VDIR;
break;
#endif /* FDESC */
}
vfsp.vnfs_mp = dnp->dn_dvm->mount;
vfsp.vnfs_vtype = vtype;
vfsp.vnfs_str = "devfs";
vfsp.vnfs_dvp = 0;
vfsp.vnfs_fsnode = dnp;
vfsp.vnfs_cnp = 0;
vfsp.vnfs_vops = *(dnp->dn_ops);
if (vtype == VBLK || vtype == VCHR) {
/*
* Ask the clone minor number function for a new minor number
* to use for the next device instance. If an administative
* limit has been reached, this function will return -1.
*/
if (dnp->dn_clone != NULL) {
int n_major = major(dnp->dn_typeinfo.dev);
n_minor = (*dnp->dn_clone)(dnp->dn_typeinfo.dev, DEVFS_CLONE_ALLOC);
if (n_minor == -1) {
error = ENOMEM;
goto out;
}
vfsp.vnfs_rdev = makedev(n_major, n_minor);;
} else {
vfsp.vnfs_rdev = dnp->dn_typeinfo.dev;
}
} else {
vfsp.vnfs_rdev = 0;
}
vfsp.vnfs_filesize = 0;
vfsp.vnfs_flags = VNFS_NOCACHE | VNFS_CANTCACHE;
/* Tag system files */
vfsp.vnfs_marksystem = 0;
vfsp.vnfs_markroot = markroot;
DEVFS_UNLOCK();
error = vnode_create(VNCREATE_FLAVOR, VCREATESIZE, &vfsp, &vn_p);
/* Do this before grabbing the lock */
if (error == 0) {
vnode_setneedinactive(vn_p);
}
DEVFS_LOCK();
if (error == 0) {
vnode_settag(vn_p, VT_DEVFS);
if ((dnp->dn_clone != NULL) && (dnp->dn_vn != NULLVP)) {
panic("devfs_dntovn: cloning device with a vnode?\n");
}
*vn_pp = vn_p;
/*
* Another vnode that has this devnode as its v_data.
* This reference, unlike the one taken at the start
* of the function, persists until a VNOP_RECLAIM
* comes through for this vnode.
*/
devfs_ref_node(dnp);
/*
* A cloned vnode is not hooked into the devnode; every lookup
* gets a new vnode.
*/
if (dnp->dn_clone == NULL) {
dnp->dn_vn = vn_p;
}
} else if (n_minor != DEVFS_CLONE_ALLOC) {
/*
* If we failed the create, we need to release the cloned minor
* back to the free list. In general, this is only useful if
* the clone function results in a state change in the cloned
* device for which the minor number was obtained. If we get
* past this point withouth falling into this case, it's
* assumed that any state to be released will be released when
* the vnode is dropped, instead.
*/
(void)(*dnp->dn_clone)(dnp->dn_typeinfo.dev, DEVFS_CLONE_FREE);
}
dnp->dn_lflags &= ~DN_CREATE;
if (dnp->dn_lflags & DN_CREATEWAIT) {
dnp->dn_lflags &= ~DN_CREATEWAIT;
wakeup(&dnp->dn_lflags);
}
out:
/*
* Release the reference we took to prevent deletion while we weren't holding the lock.
* If not returning success, then dropping this reference could delete the devnode;
* no one should access a devnode after a call to devfs_dntovn fails.
*/
devfs_rele_node(dnp);
return error;
}
/*
* Increment refcount on a devnode; prevents free of the node
* while the devfs lock is not held.
*/
void
devfs_ref_node(devnode_t *dnp)
{
os_ref_retain_locked_raw(&dnp->dn_refcount, &devfs_refgrp);
}
/*
* Release a reference on a devnode. If the devnode is marked for
* free and the refcount is dropped to one, do the free.
*/
void
devfs_rele_node(devnode_t *dnp)
{
os_ref_count_t rc = os_ref_release_locked_raw(&dnp->dn_refcount, &devfs_refgrp);
if (rc < 1) {
panic("devfs_rele_node: devnode without a refcount!\n");
} else if ((rc == 1) && (dnp->dn_lflags & DN_DELETE)) {
/* release final reference from dev_add_node */
(void) os_ref_release_locked_raw(&dnp->dn_refcount, &devfs_refgrp);
devnode_free(dnp);
}
}
/***********************************************************************
* add a whole device, with no prototype.. make name element and node
* Used for adding the original device entries
*
* called with DEVFS_LOCK held
***********************************************************************/
int
dev_add_entry(const char *name, devnode_t * parent, int type, devnode_type_t * typeinfo,
devnode_t * proto, struct devfsmount *dvm, devdirent_t * *nm_pp)
{
devnode_t * dnp;
int error = 0;
if ((error = dev_add_node(type, typeinfo, proto, &dnp,
(parent?parent->dn_dvm:dvm))) != 0) {
printf("devfs: %s: base node allocation failed (Errno=%d)\n",
name, error);
return error;
}
if ((error = dev_add_name(name, parent, NULL, dnp, nm_pp)) != 0) {
devfs_dn_free(dnp); /* 1->0 for dir, 0->(-1) for other */
printf("devfs: %s: name slot allocation failed (Errno=%d)\n",
name, error);
}
return error;
}
static void
devfs_bulk_notify(devfs_event_log_t delp)
{
uint32_t i;
for (i = 0; i < delp->del_used; i++) {
devfs_vnode_event_t dvep = &delp->del_entries[i];
if (vnode_getwithvid(dvep->dve_vp, dvep->dve_vid) == 0) {
vnode_notify(dvep->dve_vp, dvep->dve_events, NULL);
vnode_put(dvep->dve_vp);
}
}
}
static void
devfs_record_event(devfs_event_log_t delp, devnode_t *dnp, uint32_t events)
{
if (delp->del_used >= delp->del_max) {
panic("devfs event log overflowed.\n");
}
/* Can only notify for nodes that have an associated vnode */
if (dnp->dn_vn != NULLVP && vnode_ismonitored(dnp->dn_vn)) {
devfs_vnode_event_t dvep = &delp->del_entries[delp->del_used];
dvep->dve_vp = dnp->dn_vn;
dvep->dve_vid = vnode_vid(dnp->dn_vn);
dvep->dve_events = events;
delp->del_used++;
}
}
static int
devfs_init_event_log(devfs_event_log_t delp, uint32_t count, devfs_vnode_event_t buf)
{
devfs_vnode_event_t dvearr;
if (buf == NULL) {
MALLOC(dvearr, devfs_vnode_event_t, count * sizeof(struct devfs_vnode_event), M_TEMP, M_WAITOK | M_ZERO);
if (dvearr == NULL) {
return ENOMEM;
}
} else {
dvearr = buf;
}
delp->del_max = count;
delp->del_used = 0;
delp->del_entries = dvearr;
return 0;
}
static void
devfs_release_event_log(devfs_event_log_t delp, int need_free)
{
if (delp->del_entries == NULL) {
panic("Free of devfs notify info that has not been intialized.\n");
}
if (need_free) {
FREE(delp->del_entries, M_TEMP);
}
delp->del_entries = NULL;
}
/*
* Function: devfs_make_node
*
* Purpose
* Create a device node with the given pathname in the devfs namespace.
*
* Parameters:
* dev - the dev_t value to associate
* chrblk - block or character device (DEVFS_CHAR or DEVFS_BLOCK)
* uid, gid - ownership
* perms - permissions
* clone - minor number cloning function
* fmt, ... - path format string with printf args to format the path name
* Returns:
* A handle to a device node if successful, NULL otherwise.
*/
void *
devfs_make_node_clone(dev_t dev, int chrblk, uid_t uid,
gid_t gid, int perms, int (*clone)(dev_t dev, int action),
const char *fmt, ...)
{
devdirent_t * new_dev = NULL;
devfstype_t type;
va_list ap;
switch (chrblk) {
case DEVFS_CHAR:
type = DEV_CDEV;
break;
case DEVFS_BLOCK:
type = DEV_BDEV;
break;
default:
goto out;
}
va_start(ap, fmt);
new_dev = devfs_make_node_internal(dev, type, uid, gid, perms, clone, fmt, ap);
va_end(ap);
out:
return new_dev;
}
/*
* Function: devfs_make_node
*
* Purpose
* Create a device node with the given pathname in the devfs namespace.
*
* Parameters:
* dev - the dev_t value to associate
* chrblk - block or character device (DEVFS_CHAR or DEVFS_BLOCK)
* uid, gid - ownership
* perms - permissions
* fmt, ... - path format string with printf args to format the path name
* Returns:
* A handle to a device node if successful, NULL otherwise.
*/
void *
devfs_make_node(dev_t dev, int chrblk, uid_t uid,
gid_t gid, int perms, const char *fmt, ...)
{
devdirent_t * new_dev = NULL;
devfstype_t type;
va_list ap;
if (chrblk != DEVFS_CHAR && chrblk != DEVFS_BLOCK) {
goto out;
}
type = (chrblk == DEVFS_BLOCK ? DEV_BDEV : DEV_CDEV);
va_start(ap, fmt);
new_dev = devfs_make_node_internal(dev, type, uid, gid, perms, NULL, fmt, ap);
va_end(ap);
out:
return new_dev;
}
static devdirent_t *
devfs_make_node_internal(dev_t dev, devfstype_t type, uid_t uid,
gid_t gid, int perms, int (*clone)(dev_t dev, int action), const char *fmt, va_list ap)
{
devdirent_t * new_dev = NULL;
devnode_t * dnp;
devnode_type_t typeinfo;
char *name, buf[256]; /* XXX */
const char *path;
#if CONFIG_MACF
char buff[sizeof(buf)];
#endif
size_t i;
uint32_t log_count;
struct devfs_event_log event_log;
struct devfs_vnode_event stackbuf[NUM_STACK_ENTRIES];
int need_free = 0;
vsnprintf(buf, sizeof(buf), fmt, ap);
#if CONFIG_MACF
bcopy(buf, buff, sizeof(buff));
buff[sizeof(buff) - 1] = 0;
#endif
name = NULL;
for (i = strlen(buf); i > 0; i--) {
if (buf[i] == '/') {
name = &buf[i];
buf[i] = 0;
break;
}
}
if (name) {
*name++ = '\0';
path = buf;
} else {
name = buf;
path = "/";
}
log_count = devfs_nmountplanes;
if (log_count > NUM_STACK_ENTRIES) {
wrongsize:
need_free = 1;
if (devfs_init_event_log(&event_log, log_count, NULL) != 0) {
return NULL;
}
} else {
need_free = 0;
log_count = NUM_STACK_ENTRIES;
if (devfs_init_event_log(&event_log, log_count, &stackbuf[0]) != 0) {
return NULL;
}
}
DEVFS_LOCK();
if (log_count < devfs_nmountplanes) {
DEVFS_UNLOCK();
devfs_release_event_log(&event_log, need_free);
log_count = log_count * 2;
goto wrongsize;
}
if (!devfs_ready) {
printf("devfs_make_node: not ready for devices!\n");
goto out;
}
/* find/create directory path ie. mkdir -p */
if (dev_finddir(path, NULL, DEVFS_CREATE, &dnp, &event_log) == 0) {
typeinfo.dev = dev;
if (dev_add_entry(name, dnp, type, &typeinfo, NULL, NULL, &new_dev) == 0) {
new_dev->de_dnp->dn_gid = gid;
new_dev->de_dnp->dn_uid = uid;
new_dev->de_dnp->dn_mode |= perms;
new_dev->de_dnp->dn_clone = clone;
#if CONFIG_MACF
mac_devfs_label_associate_device(dev, new_dev->de_dnp, buff);
#endif
devfs_propogate(dnp->dn_typeinfo.Dir.myname, new_dev, &event_log);
}
}
out:
DEVFS_UNLOCK();
devfs_bulk_notify(&event_log);
devfs_release_event_log(&event_log, need_free);
return new_dev;
}
/*
* Function: devfs_make_link
*
* Purpose:
* Create a link to a previously created device node.
*
* Returns:
* 0 if successful, -1 if failed
*/
int
devfs_make_link(void *original, char *fmt, ...)
{
devdirent_t * new_dev = NULL;
devdirent_t * orig = (devdirent_t *) original;
devnode_t * dirnode; /* devnode for parent directory */
struct devfs_event_log event_log;
uint32_t log_count;
va_list ap;
char *p, buf[256]; /* XXX */
size_t i;
DEVFS_LOCK();
if (!devfs_ready) {
DEVFS_UNLOCK();
printf("devfs_make_link: not ready for devices!\n");
return -1;
}
DEVFS_UNLOCK();
va_start(ap, fmt);
vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
p = NULL;
for (i = strlen(buf); i > 0; i--) {
if (buf[i] == '/') {
p = &buf[i];
buf[i] = 0;
break;
}
}
/*
* One slot for each directory, one for each devnode
* whose link count changes
*/
log_count = devfs_nmountplanes * 2;
wrongsize:
if (devfs_init_event_log(&event_log, log_count, NULL) != 0) {
/* No lock held, no allocations done, can just return */
return -1;
}
DEVFS_LOCK();
if (log_count < devfs_nmountplanes) {
DEVFS_UNLOCK();
devfs_release_event_log(&event_log, 1);
log_count = log_count * 2;
goto wrongsize;
}
if (p) {
*p++ = '\0';
if (dev_finddir(buf, NULL, DEVFS_CREATE, &dirnode, &event_log)
|| dev_add_name(p, dirnode, NULL, orig->de_dnp, &new_dev)) {
goto fail;
}
} else {
if (dev_finddir("", NULL, DEVFS_CREATE, &dirnode, &event_log)
|| dev_add_name(buf, dirnode, NULL, orig->de_dnp, &new_dev)) {
goto fail;
}
}
devfs_propogate(dirnode->dn_typeinfo.Dir.myname, new_dev, &event_log);
fail:
DEVFS_UNLOCK();
devfs_bulk_notify(&event_log);
devfs_release_event_log(&event_log, 1);
return (new_dev != NULL) ? 0 : -1;
}
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