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FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/fs/devfs/devfs_rule.c |
/*-
* Copyright (c) 2002 Dima Dorfman.
* All rights reserved.
*
* 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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR 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.
*
* $FreeBSD: release/9.1.0/sys/fs/devfs/devfs_rule.c 232728 2012-03-09 16:17:46Z mm $
*/
/*
* DEVFS ruleset implementation.
*
* A note on terminology: To "run" a rule on a dirent is to take the
* prescribed action; to "apply" a rule is to check whether it matches
* a dirent and run if if it does.
*
* A note on locking: Only foreign entry points (non-static functions)
* should deal with locking. Everything else assumes we already hold
* the required kind of lock.
*
* A note on namespace: devfs_rules_* are the non-static functions for
* the entire "ruleset" subsystem, devfs_rule_* are the static
* functions that operate on rules, and devfs_ruleset_* are the static
* functions that operate on rulesets. The line between the last two
* isn't always clear, but the guideline is still useful.
*
* A note on "special" identifiers: Ruleset 0 is the NULL, or empty,
* ruleset; it cannot be deleted or changed in any way. This may be
* assumed inside the code; e.g., a ruleset of 0 may be interpeted to
* mean "no ruleset". The interpretation of rule 0 is
* command-dependent, but in no case is there a real rule with number
* 0.
*
* A note on errno codes: To make it easier for the userland to tell
* what went wrong, we sometimes use errno codes that are not entirely
* appropriate for the error but that would be less ambiguous than the
* appropriate "generic" code. For example, when we can't find a
* ruleset, we return ESRCH instead of ENOENT (except in
* DEVFSIO_{R,S}GETNEXT, where a nonexistent ruleset means "end of
* list", and the userland expects ENOENT to be this indicator); this
* way, when an operation fails, it's clear that what couldn't be
* found is a ruleset and not a rule (well, it's clear to those who
* know the convention).
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/priv.h>
#include <sys/dirent.h>
#include <sys/ioccom.h>
#include <sys/lock.h>
#include <sys/sx.h>
#include <fs/devfs/devfs.h>
#include <fs/devfs/devfs_int.h>
/*
* Kernel version of devfs_rule.
*/
struct devfs_krule {
TAILQ_ENTRY(devfs_krule) dk_list;
struct devfs_ruleset *dk_ruleset;
struct devfs_rule dk_rule;
};
TAILQ_HEAD(rulehead, devfs_krule);
static MALLOC_DEFINE(M_DEVFSRULE, "DEVFS_RULE", "DEVFS rule storage");
/*
* Structure to describe a ruleset.
*/
struct devfs_ruleset {
TAILQ_ENTRY(devfs_ruleset) ds_list;
struct rulehead ds_rules;
devfs_rsnum ds_number;
int ds_refcount;
};
static devfs_rid devfs_rid_input(devfs_rid rid, struct devfs_mount *dm);
static void devfs_rule_applyde_recursive(struct devfs_krule *dk,
struct devfs_dirent *de);
static void devfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm);
static int devfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnp);
static struct devfs_krule *devfs_rule_byid(devfs_rid rid);
static int devfs_rule_delete(struct devfs_krule *dkp);
static struct cdev *devfs_rule_getdev(struct devfs_dirent *de);
static int devfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm);
static int devfs_rule_insert(struct devfs_rule *dr);
static int devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de);
static int devfs_rule_matchpath(struct devfs_krule *dk,
struct devfs_dirent *de);
static void devfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de, unsigned depth);
static void devfs_ruleset_applyde(struct devfs_ruleset *ds,
struct devfs_dirent *de, unsigned depth);
static void devfs_ruleset_applydm(struct devfs_ruleset *ds,
struct devfs_mount *dm);
static struct devfs_ruleset *devfs_ruleset_bynum(devfs_rsnum rsnum);
static struct devfs_ruleset *devfs_ruleset_create(devfs_rsnum rsnum);
static void devfs_ruleset_reap(struct devfs_ruleset *dsp);
static int devfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm);
static struct sx sx_rules;
SX_SYSINIT(sx_rules, &sx_rules, "DEVFS ruleset lock");
static TAILQ_HEAD(, devfs_ruleset) devfs_rulesets =
TAILQ_HEAD_INITIALIZER(devfs_rulesets);
/*
* Called to apply the proper rules for 'de' before it can be
* exposed to the userland. This should be called with an exclusive
* lock on dm in case we need to run anything.
*/
void
devfs_rules_apply(struct devfs_mount *dm, struct devfs_dirent *de)
{
struct devfs_ruleset *ds;
sx_assert(&dm->dm_lock, SX_XLOCKED);
if (dm->dm_ruleset == 0)
return;
sx_slock(&sx_rules);
ds = devfs_ruleset_bynum(dm->dm_ruleset);
KASSERT(ds != NULL, ("mount-point has NULL ruleset"));
devfs_ruleset_applyde(ds, de, devfs_rule_depth);
sx_sunlock(&sx_rules);
}
/*
* Rule subsystem ioctl hook.
*/
int
devfs_rules_ioctl(struct devfs_mount *dm, u_long cmd, caddr_t data, struct thread *td)
{
struct devfs_ruleset *ds;
struct devfs_krule *dk;
struct devfs_rule *dr;
devfs_rsnum rsnum;
devfs_rnum rnum;
devfs_rid rid;
int error;
sx_assert(&dm->dm_lock, SX_XLOCKED);
/*
* XXX: This returns an error regardless of whether we actually
* support the cmd or not.
*
* We could make this privileges finer grained if desired.
*/
error = priv_check(td, PRIV_DEVFS_RULE);
if (error)
return (error);
sx_xlock(&sx_rules);
switch (cmd) {
case DEVFSIO_RADD:
dr = (struct devfs_rule *)data;
error = devfs_rule_input(dr, dm);
if (error != 0)
break;
dk = devfs_rule_byid(dr->dr_id);
if (dk != NULL) {
error = EEXIST;
break;
}
if (rid2rsn(dr->dr_id) == 0) {
error = EIO;
break;
}
error = devfs_rule_insert(dr);
break;
case DEVFSIO_RAPPLY:
dr = (struct devfs_rule *)data;
error = devfs_rule_input(dr, dm);
if (error != 0)
break;
/*
* This is one of many possible hackish
* implementations. The primary contender is an
* implementation where the rule we read in is
* temporarily inserted into some ruleset, perhaps
* with a hypothetical DRO_NOAUTO flag so that it
* doesn't get used where it isn't intended, and
* applied in the normal way. This can be done in the
* userland (DEVFSIO_ADD, DEVFSIO_APPLYID,
* DEVFSIO_DEL) or in the kernel; either way it breaks
* some corner case assumptions in other parts of the
* code (not that this implementation doesn't do
* that).
*/
if (dr->dr_iacts & DRA_INCSET &&
devfs_ruleset_bynum(dr->dr_incset) == NULL) {
error = ESRCH;
break;
}
dk = malloc(sizeof(*dk), M_TEMP, M_WAITOK | M_ZERO);
memcpy(&dk->dk_rule, dr, sizeof(*dr));
devfs_rule_applydm(dk, dm);
free(dk, M_TEMP);
break;
case DEVFSIO_RAPPLYID:
rid = *(devfs_rid *)data;
rid = devfs_rid_input(rid, dm);
dk = devfs_rule_byid(rid);
if (dk == NULL) {
error = ENOENT;
break;
}
devfs_rule_applydm(dk, dm);
break;
case DEVFSIO_RDEL:
rid = *(devfs_rid *)data;
rid = devfs_rid_input(rid, dm);
dk = devfs_rule_byid(rid);
if (dk == NULL) {
error = ENOENT;
break;
}
ds = dk->dk_ruleset;
error = devfs_rule_delete(dk);
break;
case DEVFSIO_RGETNEXT:
dr = (struct devfs_rule *)data;
error = devfs_rule_input(dr, dm);
if (error != 0)
break;
/*
* We can't use devfs_rule_byid() here since that
* requires the rule specified to exist, but we want
* getnext(N) to work whether there is a rule N or not
* (specifically, getnext(0) must work, but we should
* never have a rule 0 since the add command
* interprets 0 to mean "auto-number").
*/
ds = devfs_ruleset_bynum(rid2rsn(dr->dr_id));
if (ds == NULL) {
error = ENOENT;
break;
}
rnum = rid2rn(dr->dr_id);
TAILQ_FOREACH(dk, &ds->ds_rules, dk_list) {
if (rid2rn(dk->dk_rule.dr_id) > rnum)
break;
}
if (dk == NULL) {
error = ENOENT;
break;
}
memcpy(dr, &dk->dk_rule, sizeof(*dr));
break;
case DEVFSIO_SUSE:
rsnum = *(devfs_rsnum *)data;
error = devfs_ruleset_use(rsnum, dm);
break;
case DEVFSIO_SAPPLY:
rsnum = *(devfs_rsnum *)data;
rsnum = rid2rsn(devfs_rid_input(mkrid(rsnum, 0), dm));
ds = devfs_ruleset_bynum(rsnum);
if (ds == NULL) {
error = ESRCH;
break;
}
devfs_ruleset_applydm(ds, dm);
break;
case DEVFSIO_SGETNEXT:
rsnum = *(devfs_rsnum *)data;
TAILQ_FOREACH(ds, &devfs_rulesets, ds_list) {
if (ds->ds_number > rsnum)
break;
}
if (ds == NULL) {
error = ENOENT;
break;
}
*(devfs_rsnum *)data = ds->ds_number;
break;
default:
error = ENOIOCTL;
break;
}
sx_xunlock(&sx_rules);
return (error);
}
/*
* Adjust the rule identifier to use the ruleset of dm if one isn't
* explicitly specified.
*
* Note that after this operation, rid2rsn(rid) might still be 0, and
* that's okay; ruleset 0 is a valid ruleset, but when it's read in
* from the userland, it means "current ruleset for this mount-point".
*/
static devfs_rid
devfs_rid_input(devfs_rid rid, struct devfs_mount *dm)
{
if (rid2rsn(rid) == 0)
return (mkrid(dm->dm_ruleset, rid2rn(rid)));
else
return (rid);
}
/*
* Apply dk to de and everything under de.
*
* XXX: This method needs a function call for every nested
* subdirectory in a devfs mount. If we plan to have many of these,
* we might eventually run out of kernel stack space.
* XXX: a linear search could be done through the cdev list instead.
*/
static void
devfs_rule_applyde_recursive(struct devfs_krule *dk, struct devfs_dirent *de)
{
struct devfs_dirent *de2;
TAILQ_FOREACH(de2, &de->de_dlist, de_list)
devfs_rule_applyde_recursive(dk, de2);
devfs_rule_run(dk, de, devfs_rule_depth);
}
/*
* Apply dk to all entires in dm.
*/
static void
devfs_rule_applydm(struct devfs_krule *dk, struct devfs_mount *dm)
{
devfs_rule_applyde_recursive(dk, dm->dm_rootdir);
}
/*
* Automatically select a number for a new rule in ds, and write the
* result into rnump.
*/
static int
devfs_rule_autonumber(struct devfs_ruleset *ds, devfs_rnum *rnump)
{
struct devfs_krule *dk;
/* Find the last rule. */
dk = TAILQ_LAST(&ds->ds_rules, rulehead);
if (dk == NULL)
*rnump = 100;
else {
*rnump = rid2rn(dk->dk_rule.dr_id) + 100;
/* Detect overflow. */
if (*rnump < rid2rn(dk->dk_rule.dr_id))
return (ERANGE);
}
KASSERT(devfs_rule_byid(mkrid(ds->ds_number, *rnump)) == NULL,
("autonumbering resulted in an already existing rule"));
return (0);
}
/*
* Find a krule by id.
*/
static struct devfs_krule *
devfs_rule_byid(devfs_rid rid)
{
struct devfs_ruleset *ds;
struct devfs_krule *dk;
devfs_rnum rn;
rn = rid2rn(rid);
ds = devfs_ruleset_bynum(rid2rsn(rid));
if (ds == NULL)
return (NULL);
TAILQ_FOREACH(dk, &ds->ds_rules, dk_list) {
if (rid2rn(dk->dk_rule.dr_id) == rn)
return (dk);
else if (rid2rn(dk->dk_rule.dr_id) > rn)
break;
}
return (NULL);
}
/*
* Remove dkp from any lists it may be on and remove memory associated
* with it.
*/
static int
devfs_rule_delete(struct devfs_krule *dk)
{
struct devfs_ruleset *ds;
if (dk->dk_rule.dr_iacts & DRA_INCSET) {
ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset);
KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset"));
--ds->ds_refcount;
devfs_ruleset_reap(ds);
}
ds = dk->dk_ruleset;
TAILQ_REMOVE(&ds->ds_rules, dk, dk_list);
devfs_ruleset_reap(ds);
free(dk, M_DEVFSRULE);
return (0);
}
/*
* Get a struct cdev *corresponding to de so we can try to match rules based
* on it. If this routine returns NULL, there is no struct cdev *associated
* with the dirent (symlinks and directories don't have dev_ts), and
* the caller should assume that any critera dependent on a dev_t
* don't match.
*/
static struct cdev *
devfs_rule_getdev(struct devfs_dirent *de)
{
if (de->de_cdp == NULL)
return (NULL);
if (de->de_cdp->cdp_flags & CDP_ACTIVE)
return (&de->de_cdp->cdp_c);
else
return (NULL);
}
/*
* Do what we need to do to a rule that we just loaded from the
* userland. In particular, we need to check the magic, and adjust
* the ruleset appropriate if desired.
*/
static int
devfs_rule_input(struct devfs_rule *dr, struct devfs_mount *dm)
{
if (dr->dr_magic != DEVFS_MAGIC)
return (ERPCMISMATCH);
dr->dr_id = devfs_rid_input(dr->dr_id, dm);
return (0);
}
/*
* Import dr into the appropriate place in the kernel (i.e., make a
* krule). The value of dr is copied, so the pointer may be destroyed
* after this call completes.
*/
static int
devfs_rule_insert(struct devfs_rule *dr)
{
struct devfs_ruleset *ds, *dsi;
struct devfs_krule *k1;
struct devfs_krule *dk;
devfs_rsnum rsnum;
devfs_rnum dkrn;
int error;
/*
* This stuff seems out of place here, but we want to do it as
* soon as possible so that if it fails, we don't have to roll
* back any changes we already made (e.g., ruleset creation).
*/
if (dr->dr_iacts & DRA_INCSET) {
dsi = devfs_ruleset_bynum(dr->dr_incset);
if (dsi == NULL)
return (ESRCH);
} else
dsi = NULL;
rsnum = rid2rsn(dr->dr_id);
KASSERT(rsnum != 0, ("Inserting into ruleset zero"));
ds = devfs_ruleset_bynum(rsnum);
if (ds == NULL)
ds = devfs_ruleset_create(rsnum);
dkrn = rid2rn(dr->dr_id);
if (dkrn == 0) {
error = devfs_rule_autonumber(ds, &dkrn);
if (error != 0) {
devfs_ruleset_reap(ds);
return (error);
}
}
dk = malloc(sizeof(*dk), M_DEVFSRULE, M_WAITOK | M_ZERO);
dk->dk_ruleset = ds;
if (dsi != NULL)
++dsi->ds_refcount;
/* XXX: Inspect dr? */
memcpy(&dk->dk_rule, dr, sizeof(*dr));
dk->dk_rule.dr_id = mkrid(rid2rsn(dk->dk_rule.dr_id), dkrn);
TAILQ_FOREACH(k1, &ds->ds_rules, dk_list) {
if (rid2rn(k1->dk_rule.dr_id) > dkrn) {
TAILQ_INSERT_BEFORE(k1, dk, dk_list);
break;
}
}
if (k1 == NULL)
TAILQ_INSERT_TAIL(&ds->ds_rules, dk, dk_list);
return (0);
}
/*
* Determine whether dk matches de. Returns 1 if dk should be run on
* de; 0, otherwise.
*/
static int
devfs_rule_match(struct devfs_krule *dk, struct devfs_dirent *de)
{
struct devfs_rule *dr = &dk->dk_rule;
struct cdev *dev;
struct cdevsw *dsw;
int ref;
dev = devfs_rule_getdev(de);
/*
* At this point, if dev is NULL, we should assume that any
* criteria that depend on it don't match. We should *not*
* just ignore them (i.e., act like they weren't specified),
* since that makes a rule that only has criteria dependent on
* the struct cdev *match all symlinks and directories.
*
* Note also that the following tests are somewhat reversed:
* They're actually testing to see whether the condition does
* *not* match, since the default is to assume the rule should
* be run (such as if there are no conditions).
*/
if (dr->dr_icond & DRC_DSWFLAGS) {
if (dev == NULL)
return (0);
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (0);
if ((dsw->d_flags & dr->dr_dswflags) == 0) {
dev_relthread(dev, ref);
return (0);
}
dev_relthread(dev, ref);
}
if (dr->dr_icond & DRC_PATHPTRN)
if (!devfs_rule_matchpath(dk, de))
return (0);
return (1);
}
/*
* Determine whether dk matches de on account of dr_pathptrn.
*/
static int
devfs_rule_matchpath(struct devfs_krule *dk, struct devfs_dirent *de)
{
struct devfs_rule *dr = &dk->dk_rule;
char *pname;
struct cdev *dev;
dev = devfs_rule_getdev(de);
if (dev != NULL)
pname = dev->si_name;
else if (de->de_dirent->d_type == DT_LNK ||
de->de_dirent->d_type == DT_DIR)
pname = de->de_dirent->d_name;
else
return (0);
KASSERT(pname != NULL, ("devfs_rule_matchpath: NULL pname"));
return (fnmatch(dr->dr_pathptrn, pname, 0) == 0);
}
/*
* Run dk on de.
*/
static void
devfs_rule_run(struct devfs_krule *dk, struct devfs_dirent *de, unsigned depth)
{
struct devfs_rule *dr = &dk->dk_rule;
struct devfs_ruleset *ds;
if (!devfs_rule_match(dk, de))
return;
if (dr->dr_iacts & DRA_BACTS) {
if (dr->dr_bacts & DRB_HIDE)
de->de_flags |= DE_WHITEOUT;
if (dr->dr_bacts & DRB_UNHIDE)
de->de_flags &= ~DE_WHITEOUT;
}
if (dr->dr_iacts & DRA_UID)
de->de_uid = dr->dr_uid;
if (dr->dr_iacts & DRA_GID)
de->de_gid = dr->dr_gid;
if (dr->dr_iacts & DRA_MODE)
de->de_mode = dr->dr_mode;
if (dr->dr_iacts & DRA_INCSET) {
/*
* XXX: we should tell the user if the depth is exceeded here
* XXX: but it is not obvious how to. A return value will
* XXX: not work as this is called when devices are created
* XXX: long time after the rules were instantiated.
* XXX: a printf() would probably give too much noise, or
* XXX: DoS the machine. I guess a rate-limited message
* XXX: might work.
*/
if (depth > 0) {
ds = devfs_ruleset_bynum(dk->dk_rule.dr_incset);
KASSERT(ds != NULL, ("DRA_INCSET but bad dr_incset"));
devfs_ruleset_applyde(ds, de, depth - 1);
}
}
}
/*
* Apply all the rules in ds to de.
*/
static void
devfs_ruleset_applyde(struct devfs_ruleset *ds, struct devfs_dirent *de, unsigned depth)
{
struct devfs_krule *dk;
TAILQ_FOREACH(dk, &ds->ds_rules, dk_list)
devfs_rule_run(dk, de, depth);
}
/*
* Apply all the rules in ds to all the entires in dm.
*/
static void
devfs_ruleset_applydm(struct devfs_ruleset *ds, struct devfs_mount *dm)
{
struct devfs_krule *dk;
/*
* XXX: Does it matter whether we do
*
* foreach(dk in ds)
* foreach(de in dm)
* apply(dk to de)
*
* as opposed to
*
* foreach(de in dm)
* foreach(dk in ds)
* apply(dk to de)
*
* The end result is obviously the same, but does the order
* matter?
*/
TAILQ_FOREACH(dk, &ds->ds_rules, dk_list)
devfs_rule_applydm(dk, dm);
}
/*
* Find a ruleset by number.
*/
static struct devfs_ruleset *
devfs_ruleset_bynum(devfs_rsnum rsnum)
{
struct devfs_ruleset *ds;
TAILQ_FOREACH(ds, &devfs_rulesets, ds_list) {
if (ds->ds_number == rsnum)
return (ds);
}
return (NULL);
}
/*
* Create a new ruleset.
*/
static struct devfs_ruleset *
devfs_ruleset_create(devfs_rsnum rsnum)
{
struct devfs_ruleset *s1;
struct devfs_ruleset *ds;
KASSERT(rsnum != 0, ("creating ruleset zero"));
KASSERT(devfs_ruleset_bynum(rsnum) == NULL,
("creating already existent ruleset %d", rsnum));
ds = malloc(sizeof(*ds), M_DEVFSRULE, M_WAITOK | M_ZERO);
ds->ds_number = rsnum;
TAILQ_INIT(&ds->ds_rules);
TAILQ_FOREACH(s1, &devfs_rulesets, ds_list) {
if (s1->ds_number > rsnum) {
TAILQ_INSERT_BEFORE(s1, ds, ds_list);
break;
}
}
if (s1 == NULL)
TAILQ_INSERT_TAIL(&devfs_rulesets, ds, ds_list);
return (ds);
}
/*
* Remove a ruleset from the system if it's empty and not used
* anywhere. This should be called after every time a rule is deleted
* from this ruleset or the reference count is decremented.
*/
static void
devfs_ruleset_reap(struct devfs_ruleset *ds)
{
KASSERT(ds->ds_number != 0, ("reaping ruleset zero "));
if (!TAILQ_EMPTY(&ds->ds_rules) || ds->ds_refcount != 0)
return;
TAILQ_REMOVE(&devfs_rulesets, ds, ds_list);
free(ds, M_DEVFSRULE);
}
/*
* Make rsnum the active ruleset for dm.
*/
static int
devfs_ruleset_use(devfs_rsnum rsnum, struct devfs_mount *dm)
{
struct devfs_ruleset *cds, *ds;
if (dm->dm_ruleset != 0) {
cds = devfs_ruleset_bynum(dm->dm_ruleset);
--cds->ds_refcount;
devfs_ruleset_reap(cds);
}
if (rsnum == 0) {
dm->dm_ruleset = 0;
return (0);
}
ds = devfs_ruleset_bynum(rsnum);
if (ds == NULL)
ds = devfs_ruleset_create(rsnum);
/* These should probably be made atomic somehow. */
++ds->ds_refcount;
dm->dm_ruleset = rsnum;
return (0);
}
void
devfs_rules_cleanup(struct devfs_mount *dm)
{
struct devfs_ruleset *ds;
sx_assert(&dm->dm_lock, SX_XLOCKED);
if (dm->dm_ruleset != 0) {
ds = devfs_ruleset_bynum(dm->dm_ruleset);
--ds->ds_refcount;
devfs_ruleset_reap(ds);
}
}
/*
* Make rsnum the active ruleset for dm (locked)
*/
void
devfs_ruleset_set(devfs_rsnum rsnum, struct devfs_mount *dm)
{
sx_assert(&dm->dm_lock, SX_XLOCKED);
sx_xlock(&sx_rules);
devfs_ruleset_use(rsnum, dm);
sx_xunlock(&sx_rules);
}
/*
* Apply the current active ruleset on a mount
*/
void
devfs_ruleset_apply(struct devfs_mount *dm)
{
struct devfs_ruleset *ds;
sx_assert(&dm->dm_lock, SX_XLOCKED);
sx_xlock(&sx_rules);
if (dm->dm_ruleset == 0) {
sx_xunlock(&sx_rules);
return;
}
ds = devfs_ruleset_bynum(dm->dm_ruleset);
if (ds != NULL)
devfs_ruleset_applydm(ds, dm);
sx_xunlock(&sx_rules);
}