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freebsd/sys/kern/uipc_mqueue.c
Jeff Roberson 069c6953a0 - Use vget() to lock the vnode rather than refing without a lock and 
locking in separate steps.
2008-03-29 23:30:40 +00:00

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/*-
* Copyright (c) 2005 David Xu <davidxu@freebsd.org>
* 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.
*
*/
/*
* POSIX message queue implementation.
*
* 1) A mqueue filesystem can be mounted, each message queue appears
* in mounted directory, user can change queue's permission and
* ownership, or remove a queue. Manually creating a file in the
* directory causes a message queue to be created in the kernel with
* default message queue attributes applied and same name used, this
* method is not advocated since mq_open syscall allows user to specify
* different attributes. Also the file system can be mounted multiple
* times at different mount points but shows same contents.
*
* 2) Standard POSIX message queue API. The syscalls do not use vfs layer,
* but directly operate on internal data structure, this allows user to
* use the IPC facility without having to mount mqueue file system.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/limits.h>
#include <sys/buf.h>
#include <sys/dirent.h>
#include <sys/event.h>
#include <sys/eventhandler.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mount.h>
#include <sys/mqueue.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/posix4.h>
#include <sys/poll.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/sysproto.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <machine/atomic.h>
/*
* Limits and constants
*/
#define MQFS_NAMELEN NAME_MAX
#define MQFS_DELEN (8 + MQFS_NAMELEN)
/* node types */
typedef enum {
mqfstype_none = 0,
mqfstype_root,
mqfstype_dir,
mqfstype_this,
mqfstype_parent,
mqfstype_file,
mqfstype_symlink,
} mqfs_type_t;
struct mqfs_node;
/*
* mqfs_info: describes a mqfs instance
*/
struct mqfs_info {
struct sx mi_lock;
struct mqfs_node *mi_root;
struct unrhdr *mi_unrhdr;
};
struct mqfs_vdata {
LIST_ENTRY(mqfs_vdata) mv_link;
struct mqfs_node *mv_node;
struct vnode *mv_vnode;
struct task mv_task;
};
/*
* mqfs_node: describes a node (file or directory) within a mqfs
*/
struct mqfs_node {
char mn_name[MQFS_NAMELEN+1];
struct mqfs_info *mn_info;
struct mqfs_node *mn_parent;
LIST_HEAD(,mqfs_node) mn_children;
LIST_ENTRY(mqfs_node) mn_sibling;
LIST_HEAD(,mqfs_vdata) mn_vnodes;
int mn_refcount;
mqfs_type_t mn_type;
int mn_deleted;
u_int32_t mn_fileno;
void *mn_data;
struct timespec mn_birth;
struct timespec mn_ctime;
struct timespec mn_atime;
struct timespec mn_mtime;
uid_t mn_uid;
gid_t mn_gid;
int mn_mode;
};
#define VTON(vp) (((struct mqfs_vdata *)((vp)->v_data))->mv_node)
#define VTOMQ(vp) ((struct mqueue *)(VTON(vp)->mn_data))
#define VFSTOMQFS(m) ((struct mqfs_info *)((m)->mnt_data))
#define FPTOMQ(fp) ((struct mqueue *)(((struct mqfs_node *) \
(fp)->f_data)->mn_data))
TAILQ_HEAD(msgq, mqueue_msg);
struct mqueue;
struct mqueue_notifier {
LIST_ENTRY(mqueue_notifier) nt_link;
struct sigevent nt_sigev;
ksiginfo_t nt_ksi;
struct proc *nt_proc;
};
struct mqueue {
struct mtx mq_mutex;
int mq_flags;
long mq_maxmsg;
long mq_msgsize;
long mq_curmsgs;
long mq_totalbytes;
struct msgq mq_msgq;
int mq_receivers;
int mq_senders;
struct selinfo mq_rsel;
struct selinfo mq_wsel;
struct mqueue_notifier *mq_notifier;
};
#define MQ_RSEL 0x01
#define MQ_WSEL 0x02
struct mqueue_msg {
TAILQ_ENTRY(mqueue_msg) msg_link;
unsigned int msg_prio;
unsigned int msg_size;
/* following real data... */
};
SYSCTL_NODE(_kern, OID_AUTO, mqueue, CTLFLAG_RW, 0,
"POSIX real time message queue");
static int default_maxmsg = 10;
static int default_msgsize = 1024;
static int maxmsg = 100;
SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsg, CTLFLAG_RW,
&maxmsg, 0, "Default maximum messages in queue");
static int maxmsgsize = 16384;
SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsgsize, CTLFLAG_RW,
&maxmsgsize, 0, "Default maximum message size");
static int maxmq = 100;
SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmq, CTLFLAG_RW,
&maxmq, 0, "maximum message queues");
static int curmq = 0;
SYSCTL_INT(_kern_mqueue, OID_AUTO, curmq, CTLFLAG_RW,
&curmq, 0, "current message queue number");
static int unloadable = 0;
static MALLOC_DEFINE(M_MQUEUEDATA, "mqdata", "mqueue data");
static eventhandler_tag exit_tag;
/* Only one instance per-system */
static struct mqfs_info mqfs_data;
static uma_zone_t mqnode_zone;
static uma_zone_t mqueue_zone;
static uma_zone_t mvdata_zone;
static uma_zone_t mqnoti_zone;
static struct vop_vector mqfs_vnodeops;
static struct fileops mqueueops;
/*
* Directory structure construction and manipulation
*/
#ifdef notyet
static struct mqfs_node *mqfs_create_dir(struct mqfs_node *parent,
const char *name, int namelen, struct ucred *cred, int mode);
static struct mqfs_node *mqfs_create_link(struct mqfs_node *parent,
const char *name, int namelen, struct ucred *cred, int mode);
#endif
static struct mqfs_node *mqfs_create_file(struct mqfs_node *parent,
const char *name, int namelen, struct ucred *cred, int mode);
static int mqfs_destroy(struct mqfs_node *mn);
static void mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn);
static void mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn);
static int mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn);
/*
* Message queue construction and maniplation
*/
static struct mqueue *mqueue_alloc(const struct mq_attr *attr);
static void mqueue_free(struct mqueue *mq);
static int mqueue_send(struct mqueue *mq, const char *msg_ptr,
size_t msg_len, unsigned msg_prio, int waitok,
const struct timespec *abs_timeout);
static int mqueue_receive(struct mqueue *mq, char *msg_ptr,
size_t msg_len, unsigned *msg_prio, int waitok,
const struct timespec *abs_timeout);
static int _mqueue_send(struct mqueue *mq, struct mqueue_msg *msg,
int timo);
static int _mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg,
int timo);
static void mqueue_send_notification(struct mqueue *mq);
static void mqueue_fdclose(struct thread *td, int fd, struct file *fp);
static void mq_proc_exit(void *arg, struct proc *p);
/*
* kqueue filters
*/
static void filt_mqdetach(struct knote *kn);
static int filt_mqread(struct knote *kn, long hint);
static int filt_mqwrite(struct knote *kn, long hint);
struct filterops mq_rfiltops =
{ 1, NULL, filt_mqdetach, filt_mqread };
struct filterops mq_wfiltops =
{ 1, NULL, filt_mqdetach, filt_mqwrite };
/*
* Initialize fileno bitmap
*/
static void
mqfs_fileno_init(struct mqfs_info *mi)
{
struct unrhdr *up;
up = new_unrhdr(1, INT_MAX, NULL);
mi->mi_unrhdr = up;
}
/*
* Tear down fileno bitmap
*/
static void
mqfs_fileno_uninit(struct mqfs_info *mi)
{
struct unrhdr *up;
up = mi->mi_unrhdr;
mi->mi_unrhdr = NULL;
delete_unrhdr(up);
}
/*
* Allocate a file number
*/
static void
mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn)
{
/* make sure our parent has a file number */
if (mn->mn_parent && !mn->mn_parent->mn_fileno)
mqfs_fileno_alloc(mi, mn->mn_parent);
switch (mn->mn_type) {
case mqfstype_root:
case mqfstype_dir:
case mqfstype_file:
case mqfstype_symlink:
mn->mn_fileno = alloc_unr(mi->mi_unrhdr);
break;
case mqfstype_this:
KASSERT(mn->mn_parent != NULL,
("mqfstype_this node has no parent"));
mn->mn_fileno = mn->mn_parent->mn_fileno;
break;
case mqfstype_parent:
KASSERT(mn->mn_parent != NULL,
("mqfstype_parent node has no parent"));
if (mn->mn_parent == mi->mi_root) {
mn->mn_fileno = mn->mn_parent->mn_fileno;
break;
}
KASSERT(mn->mn_parent->mn_parent != NULL,
("mqfstype_parent node has no grandparent"));
mn->mn_fileno = mn->mn_parent->mn_parent->mn_fileno;
break;
default:
KASSERT(0,
("mqfs_fileno_alloc() called for unknown type node: %d",
mn->mn_type));
break;
}
}
/*
* Release a file number
*/
static void
mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn)
{
switch (mn->mn_type) {
case mqfstype_root:
case mqfstype_dir:
case mqfstype_file:
case mqfstype_symlink:
free_unr(mi->mi_unrhdr, mn->mn_fileno);
break;
case mqfstype_this:
case mqfstype_parent:
/* ignore these, as they don't "own" their file number */
break;
default:
KASSERT(0,
("mqfs_fileno_free() called for unknown type node: %d",
mn->mn_type));
break;
}
}
static __inline struct mqfs_node *
mqnode_alloc(void)
{
return uma_zalloc(mqnode_zone, M_WAITOK | M_ZERO);
}
static __inline void
mqnode_free(struct mqfs_node *node)
{
uma_zfree(mqnode_zone, node);
}
static __inline void
mqnode_addref(struct mqfs_node *node)
{
atomic_fetchadd_int(&node->mn_refcount, 1);
}
static __inline void
mqnode_release(struct mqfs_node *node)
{
int old, exp;
old = atomic_fetchadd_int(&node->mn_refcount, -1);
if (node->mn_type == mqfstype_dir ||
node->mn_type == mqfstype_root)
exp = 3; /* include . and .. */
else
exp = 1;
if (old == exp)
mqfs_destroy(node);
}
/*
* Add a node to a directory
*/
static int
mqfs_add_node(struct mqfs_node *parent, struct mqfs_node *node)
{
KASSERT(parent != NULL, ("%s(): parent is NULL", __func__));
KASSERT(parent->mn_info != NULL,
("%s(): parent has no mn_info", __func__));
KASSERT(parent->mn_type == mqfstype_dir ||
parent->mn_type == mqfstype_root,
("%s(): parent is not a directory", __func__));
node->mn_info = parent->mn_info;
node->mn_parent = parent;
LIST_INIT(&node->mn_children);
LIST_INIT(&node->mn_vnodes);
LIST_INSERT_HEAD(&parent->mn_children, node, mn_sibling);
mqnode_addref(parent);
return (0);
}
static struct mqfs_node *
mqfs_create_node(const char *name, int namelen, struct ucred *cred, int mode,
int nodetype)
{
struct mqfs_node *node;
node = mqnode_alloc();
strncpy(node->mn_name, name, namelen);
node->mn_type = nodetype;
node->mn_refcount = 1;
getnanotime(&node->mn_birth);
node->mn_ctime = node->mn_atime = node->mn_mtime
= node->mn_birth;
node->mn_uid = cred->cr_uid;
node->mn_gid = cred->cr_gid;
node->mn_mode = mode;
return (node);
}
/*
* Create a file
*/
static struct mqfs_node *
mqfs_create_file(struct mqfs_node *parent, const char *name, int namelen,
struct ucred *cred, int mode)
{
struct mqfs_node *node;
node = mqfs_create_node(name, namelen, cred, mode, mqfstype_file);
if (mqfs_add_node(parent, node) != 0) {
mqnode_free(node);
return (NULL);
}
return (node);
}
/*
* Add . and .. to a directory
*/
static int
mqfs_fixup_dir(struct mqfs_node *parent)
{
struct mqfs_node *dir;
dir = mqnode_alloc();
dir->mn_name[0] = '.';
dir->mn_type = mqfstype_this;
dir->mn_refcount = 1;
if (mqfs_add_node(parent, dir) != 0) {
mqnode_free(dir);
return (-1);
}
dir = mqnode_alloc();
dir->mn_name[0] = dir->mn_name[1] = '.';
dir->mn_type = mqfstype_parent;
dir->mn_refcount = 1;
if (mqfs_add_node(parent, dir) != 0) {
mqnode_free(dir);
return (-1);
}
return (0);
}
#ifdef notyet
/*
* Create a directory
*/
static struct mqfs_node *
mqfs_create_dir(struct mqfs_node *parent, const char *name, int namelen,
struct ucred *cred, int mode)
{
struct mqfs_node *node;
node = mqfs_create_node(name, namelen, cred, mode, mqfstype_dir);
if (mqfs_add_node(parent, node) != 0) {
mqnode_free(node);
return (NULL);
}
if (mqfs_fixup_dir(node) != 0) {
mqfs_destroy(node);
return (NULL);
}
return (node);
}
/*
* Create a symlink
*/
static struct mqfs_node *
mqfs_create_link(struct mqfs_node *parent, const char *name, int namelen,
struct ucred *cred, int mode)
{
struct mqfs_node *node;
node = mqfs_create_node(name, namelen, cred, mode, mqfstype_symlink);
if (mqfs_add_node(parent, node) != 0) {
mqnode_free(node);
return (NULL);
}
return (node);
}
#endif
/*
* Destroy a node or a tree of nodes
*/
static int
mqfs_destroy(struct mqfs_node *node)
{
struct mqfs_node *parent;
KASSERT(node != NULL,
("%s(): node is NULL", __func__));
KASSERT(node->mn_info != NULL,
("%s(): node has no mn_info", __func__));
/* destroy children */
if (node->mn_type == mqfstype_dir || node->mn_type == mqfstype_root)
while (! LIST_EMPTY(&node->mn_children))
mqfs_destroy(LIST_FIRST(&node->mn_children));
/* unlink from parent */
if ((parent = node->mn_parent) != NULL) {
KASSERT(parent->mn_info == node->mn_info,
("%s(): parent has different mn_info", __func__));
LIST_REMOVE(node, mn_sibling);
}
if (node->mn_fileno != 0)
mqfs_fileno_free(node->mn_info, node);
if (node->mn_data != NULL)
mqueue_free(node->mn_data);
mqnode_free(node);
return (0);
}
/*
* Mount a mqfs instance
*/
static int
mqfs_mount(struct mount *mp, struct thread *td)
{
struct statfs *sbp;
if (mp->mnt_flag & MNT_UPDATE)
return (EOPNOTSUPP);
mp->mnt_data = &mqfs_data;
MNT_ILOCK(mp);
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_kern_flag |= MNTK_MPSAFE;
MNT_IUNLOCK(mp);
vfs_getnewfsid(mp);
sbp = &mp->mnt_stat;
vfs_mountedfrom(mp, "mqueue");
sbp->f_bsize = PAGE_SIZE;
sbp->f_iosize = PAGE_SIZE;
sbp->f_blocks = 1;
sbp->f_bfree = 0;
sbp->f_bavail = 0;
sbp->f_files = 1;
sbp->f_ffree = 0;
return (0);
}
/*
* Unmount a mqfs instance
*/
static int
mqfs_unmount(struct mount *mp, int mntflags, struct thread *td)
{
int error;
error = vflush(mp, 0, (mntflags & MNT_FORCE) ? FORCECLOSE : 0, td);
return (error);
}
/*
* Return a root vnode
*/
static int
mqfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
{
struct mqfs_info *mqfs;
int ret;
mqfs = VFSTOMQFS(mp);
sx_xlock(&mqfs->mi_lock);
ret = mqfs_allocv(mp, vpp, mqfs->mi_root);
sx_xunlock(&mqfs->mi_lock);
return (ret);
}
/*
* Return filesystem stats
*/
static int
mqfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
{
/* XXX update statistics */
return (0);
}
/*
* Initialize a mqfs instance
*/
static int
mqfs_init(struct vfsconf *vfc)
{
struct mqfs_node *root;
struct mqfs_info *mi;
mqnode_zone = uma_zcreate("mqnode", sizeof(struct mqfs_node),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
mqueue_zone = uma_zcreate("mqueue", sizeof(struct mqueue),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
mvdata_zone = uma_zcreate("mvdata",
sizeof(struct mqfs_vdata), NULL, NULL, NULL,
NULL, UMA_ALIGN_PTR, 0);
mqnoti_zone = uma_zcreate("mqnotifier", sizeof(struct mqueue_notifier),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
mi = &mqfs_data;
sx_init(&mi->mi_lock, "mqfs lock");
/* set up the root diretory */
root = mqfs_create_node("/", 1, curthread->td_ucred, 01777,
mqfstype_root);
root->mn_info = mi;
LIST_INIT(&root->mn_children);
LIST_INIT(&root->mn_vnodes);
mi->mi_root = root;
mqfs_fileno_init(mi);
mqfs_fileno_alloc(mi, root);
mqfs_fixup_dir(root);
exit_tag = EVENTHANDLER_REGISTER(process_exit, mq_proc_exit, NULL,
EVENTHANDLER_PRI_ANY);
mq_fdclose = mqueue_fdclose;
p31b_setcfg(CTL_P1003_1B_MESSAGE_PASSING, _POSIX_MESSAGE_PASSING);
return (0);
}
/*
* Destroy a mqfs instance
*/
static int
mqfs_uninit(struct vfsconf *vfc)
{
struct mqfs_info *mi;
if (!unloadable)
return (EOPNOTSUPP);
EVENTHANDLER_DEREGISTER(process_exit, exit_tag);
mi = &mqfs_data;
mqfs_destroy(mi->mi_root);
mi->mi_root = NULL;
mqfs_fileno_uninit(mi);
sx_destroy(&mi->mi_lock);
uma_zdestroy(mqnode_zone);
uma_zdestroy(mqueue_zone);
uma_zdestroy(mvdata_zone);
uma_zdestroy(mqnoti_zone);
return (0);
}
/*
* task routine
*/
static void
do_recycle(void *context, int pending __unused)
{
struct vnode *vp = (struct vnode *)context;
vrecycle(vp, curthread);
vdrop(vp);
}
/*
* Allocate a vnode
*/
static int
mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn)
{
struct mqfs_vdata *vd;
int error;
LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
if (vd->mv_vnode->v_mount == mp)
break;
}
if (vd != NULL) {
*vpp = vd->mv_vnode;
vget(*vpp, LK_RETRY | LK_EXCLUSIVE, curthread);
return (0);
}
error = getnewvnode("mqueue", mp, &mqfs_vnodeops, vpp);
if (error)
return (error);
vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY);
error = insmntque(*vpp, mp);
if (error != 0) {
*vpp = NULLVP;
return (error);
}
vd = uma_zalloc(mvdata_zone, M_WAITOK);
(*vpp)->v_data = vd;
vd->mv_vnode = *vpp;
vd->mv_node = pn;
TASK_INIT(&vd->mv_task, 0, do_recycle, *vpp);
LIST_INSERT_HEAD(&pn->mn_vnodes, vd, mv_link);
mqnode_addref(pn);
switch (pn->mn_type) {
case mqfstype_root:
(*vpp)->v_vflag = VV_ROOT;
/* fall through */
case mqfstype_dir:
case mqfstype_this:
case mqfstype_parent:
(*vpp)->v_type = VDIR;
break;
case mqfstype_file:
(*vpp)->v_type = VREG;
break;
case mqfstype_symlink:
(*vpp)->v_type = VLNK;
break;
case mqfstype_none:
KASSERT(0, ("mqfs_allocf called for null node\n"));
default:
panic("%s has unexpected type: %d", pn->mn_name, pn->mn_type);
}
return (0);
}
/*
* Search a directory entry
*/
static struct mqfs_node *
mqfs_search(struct mqfs_node *pd, const char *name, int len)
{
struct mqfs_node *pn;
LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
if (strncmp(pn->mn_name, name, len) == 0)
return (pn);
}
return (NULL);
}
/*
* Look up a file or directory.
*/
static int
mqfs_lookupx(struct vop_cachedlookup_args *ap)
{
struct componentname *cnp;
struct vnode *dvp, **vpp;
struct mqfs_node *pd;
struct mqfs_node *pn;
int nameiop, flags, error, namelen;
char *pname;
struct thread *td;
cnp = ap->a_cnp;
vpp = ap->a_vpp;
dvp = ap->a_dvp;
pname = cnp->cn_nameptr;
namelen = cnp->cn_namelen;
td = cnp->cn_thread;
flags = cnp->cn_flags;
nameiop = cnp->cn_nameiop;
pd = VTON(dvp);
pn = NULL;
*vpp = NULLVP;
if (dvp->v_type != VDIR)
return (ENOTDIR);
error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
if (error)
return (error);
/* shortcut: check if the name is too long */
if (cnp->cn_namelen >= MQFS_NAMELEN)
return (ENOENT);
/* self */
if (namelen == 1 && pname[0] == '.') {
if ((flags & ISLASTCN) && nameiop != LOOKUP)
return (EINVAL);
pn = pd;
*vpp = dvp;
VREF(dvp);
return (0);
}
/* parent */
if (cnp->cn_flags & ISDOTDOT) {
if (dvp->v_vflag & VV_ROOT)
return (EIO);
if ((flags & ISLASTCN) && nameiop != LOOKUP)
return (EINVAL);
VOP_UNLOCK(dvp, 0);
KASSERT(pd->mn_parent, ("non-root directory has no parent"));
pn = pd->mn_parent;
error = mqfs_allocv(dvp->v_mount, vpp, pn);
vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
return (error);
}
/* named node */
pn = mqfs_search(pd, pname, namelen);
/* found */
if (pn != NULL) {
/* DELETE */
if (nameiop == DELETE && (flags & ISLASTCN)) {
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
if (error)
return (error);
if (*vpp == dvp) {
VREF(dvp);
*vpp = dvp;
return (0);
}
}
/* allocate vnode */
error = mqfs_allocv(dvp->v_mount, vpp, pn);
if (error == 0 && cnp->cn_flags & MAKEENTRY)
cache_enter(dvp, *vpp, cnp);
return (error);
}
/* not found */
/* will create a new entry in the directory ? */
if ((nameiop == CREATE || nameiop == RENAME) && (flags & LOCKPARENT)
&& (flags & ISLASTCN)) {
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
if (error)
return (error);
cnp->cn_flags |= SAVENAME;
return (EJUSTRETURN);
}
return (ENOENT);
}
#if 0
struct vop_lookup_args {
struct vop_generic_args a_gen;
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
};
#endif
/*
* vnode lookup operation
*/
static int
mqfs_lookup(struct vop_cachedlookup_args *ap)
{
struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
int rc;
sx_xlock(&mqfs->mi_lock);
rc = mqfs_lookupx(ap);
sx_xunlock(&mqfs->mi_lock);
return (rc);
}
#if 0
struct vop_create_args {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
};
#endif
/*
* vnode creation operation
*/
static int
mqfs_create(struct vop_create_args *ap)
{
struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
struct componentname *cnp = ap->a_cnp;
struct mqfs_node *pd;
struct mqfs_node *pn;
struct mqueue *mq;
int error;
pd = VTON(ap->a_dvp);
if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
return (ENOTDIR);
mq = mqueue_alloc(NULL);
if (mq == NULL)
return (EAGAIN);
sx_xlock(&mqfs->mi_lock);
#if 0
/* named node */
pn = mqfs_search(pd, cnp->cn_nameptr, cnp->cn_namelen);
if (pn != NULL) {
mqueue_free(mq);
sx_xunlock(&mqfs->mi_lock);
return (EEXIST);
}
#else
if ((cnp->cn_flags & HASBUF) == 0)
panic("%s: no name", __func__);
#endif
pn = mqfs_create_file(pd, cnp->cn_nameptr, cnp->cn_namelen,
cnp->cn_cred, ap->a_vap->va_mode);
if (pn == NULL)
error = ENOSPC;
else {
error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
if (error)
mqfs_destroy(pn);
else
pn->mn_data = mq;
}
sx_xunlock(&mqfs->mi_lock);
if (error)
mqueue_free(mq);
return (error);
}
/*
* Remove an entry
*/
static
int do_unlink(struct mqfs_node *pn, struct ucred *ucred)
{
struct mqfs_node *parent;
struct mqfs_vdata *vd;
int error = 0;
sx_assert(&pn->mn_info->mi_lock, SX_LOCKED);
if (ucred->cr_uid != pn->mn_uid &&
(error = priv_check_cred(ucred, PRIV_MQ_ADMIN, 0)) != 0)
error = EACCES;
else if (!pn->mn_deleted) {
parent = pn->mn_parent;
pn->mn_parent = NULL;
pn->mn_deleted = 1;
LIST_REMOVE(pn, mn_sibling);
LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
cache_purge(vd->mv_vnode);
vhold(vd->mv_vnode);
taskqueue_enqueue(taskqueue_thread, &vd->mv_task);
}
mqnode_release(pn);
mqnode_release(parent);
} else
error = ENOENT;
return (error);
}
#if 0
struct vop_remove_args {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
};
#endif
/*
* vnode removal operation
*/
static int
mqfs_remove(struct vop_remove_args *ap)
{
struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
struct mqfs_node *pn;
int error;
if (ap->a_vp->v_type == VDIR)
return (EPERM);
pn = VTON(ap->a_vp);
sx_xlock(&mqfs->mi_lock);
error = do_unlink(pn, ap->a_cnp->cn_cred);
sx_xunlock(&mqfs->mi_lock);
return (error);
}
#if 0
struct vop_inactive_args {
struct vnode *a_vp;
struct thread *a_td;
};
#endif
static int
mqfs_inactive(struct vop_inactive_args *ap)
{
struct mqfs_node *pn = VTON(ap->a_vp);
if (pn->mn_deleted)
vrecycle(ap->a_vp, ap->a_td);
return (0);
}
#if 0
struct vop_reclaim_args {
struct vop_generic_args a_gen;
struct vnode *a_vp;
struct thread *a_td;
};
#endif
static int
mqfs_reclaim(struct vop_reclaim_args *ap)
{
struct mqfs_info *mqfs = VFSTOMQFS(ap->a_vp->v_mount);
struct vnode *vp = ap->a_vp;
struct mqfs_node *pn;
struct mqfs_vdata *vd;
vd = vp->v_data;
pn = vd->mv_node;
sx_xlock(&mqfs->mi_lock);
vp->v_data = NULL;
LIST_REMOVE(vd, mv_link);
uma_zfree(mvdata_zone, vd);
mqnode_release(pn);
sx_xunlock(&mqfs->mi_lock);
return (0);
}
#if 0
struct vop_open_args {
struct vop_generic_args a_gen;
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct thread *a_td;
int a_fdidx;
};
#endif
static int
mqfs_open(struct vop_open_args *ap)
{
return (0);
}
#if 0
struct vop_close_args {
struct vop_generic_args a_gen;
struct vnode *a_vp;
int a_fflag;
struct ucred *a_cred;
struct thread *a_td;
};
#endif
static int
mqfs_close(struct vop_close_args *ap)
{
return (0);
}
#if 0
struct vop_access_args {
struct vop_generic_args a_gen;
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct thread *a_td;
};
#endif
/*
* Verify permissions
*/
static int
mqfs_access(struct vop_access_args *ap)
{
struct vnode *vp = ap->a_vp;
struct vattr vattr;
int error;
error = VOP_GETATTR(vp, &vattr, ap->a_cred, ap->a_td);
if (error)
return (error);
error = vaccess(vp->v_type, vattr.va_mode, vattr.va_uid,
vattr.va_gid, ap->a_mode, ap->a_cred, NULL);
return (error);
}
#if 0
struct vop_getattr_args {
struct vop_generic_args a_gen;
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct thread *a_td;
};
#endif
/*
* Get file attributes
*/
static int
mqfs_getattr(struct vop_getattr_args *ap)
{
struct vnode *vp = ap->a_vp;
struct mqfs_node *pn = VTON(vp);
struct vattr *vap = ap->a_vap;
int error = 0;
VATTR_NULL(vap);
vap->va_type = vp->v_type;
vap->va_mode = pn->mn_mode;
vap->va_nlink = 1;
vap->va_uid = pn->mn_uid;
vap->va_gid = pn->mn_gid;
vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
vap->va_fileid = pn->mn_fileno;
vap->va_size = 0;
vap->va_blocksize = PAGE_SIZE;
vap->va_bytes = vap->va_size = 0;
vap->va_atime = pn->mn_atime;
vap->va_mtime = pn->mn_mtime;
vap->va_ctime = pn->mn_ctime;
vap->va_birthtime = pn->mn_birth;
vap->va_gen = 0;
vap->va_flags = 0;
vap->va_rdev = 0;
vap->va_bytes = 0;
vap->va_filerev = 0;
vap->va_vaflags = 0;
return (error);
}
#if 0
struct vop_setattr_args {
struct vop_generic_args a_gen;
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct thread *a_td;
};
#endif
/*
* Set attributes
*/
static int
mqfs_setattr(struct vop_setattr_args *ap)
{
struct mqfs_node *pn;
struct vattr *vap;
struct vnode *vp;
int c, error;
uid_t uid;
gid_t gid;
vap = ap->a_vap;
vp = ap->a_vp;
if ((vap->va_type != VNON) ||
(vap->va_nlink != VNOVAL) ||
(vap->va_fsid != VNOVAL) ||
(vap->va_fileid != VNOVAL) ||
(vap->va_blocksize != VNOVAL) ||
(vap->va_flags != VNOVAL && vap->va_flags != 0) ||
(vap->va_rdev != VNOVAL) ||
((int)vap->va_bytes != VNOVAL) ||
(vap->va_gen != VNOVAL)) {
return (EINVAL);
}
pn = VTON(vp);
error = c = 0;
if (vap->va_uid == (uid_t)VNOVAL)
uid = pn->mn_uid;
else
uid = vap->va_uid;
if (vap->va_gid == (gid_t)VNOVAL)
gid = pn->mn_gid;
else
gid = vap->va_gid;
if (uid != pn->mn_uid || gid != pn->mn_gid) {
/*
* To modify the ownership of a file, must possess VADMIN
* for that file.
*/
if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, ap->a_td)))
return (error);
/*
* XXXRW: Why is there a privilege check here: shouldn't the
* check in VOP_ACCESS() be enough? Also, are the group bits
* below definitely right?
*/
if (((ap->a_cred->cr_uid != pn->mn_uid) || uid != pn->mn_uid ||
(gid != pn->mn_gid && !groupmember(gid, ap->a_cred))) &&
(error = priv_check(ap->a_td, PRIV_MQ_ADMIN)) != 0)
return (error);
pn->mn_uid = uid;
pn->mn_gid = gid;
c = 1;
}
if (vap->va_mode != (mode_t)VNOVAL) {
if ((ap->a_cred->cr_uid != pn->mn_uid) &&
(error = priv_check(ap->a_td, PRIV_MQ_ADMIN)))
return (error);
pn->mn_mode = vap->va_mode;
c = 1;
}
if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
/* See the comment in ufs_vnops::ufs_setattr(). */
if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, ap->a_td)) &&
((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
(error = VOP_ACCESS(vp, VWRITE, ap->a_cred, ap->a_td))))
return (error);
if (vap->va_atime.tv_sec != VNOVAL) {
pn->mn_atime = vap->va_atime;
}
if (vap->va_mtime.tv_sec != VNOVAL) {
pn->mn_mtime = vap->va_mtime;
}
c = 1;
}
if (c) {
vfs_timestamp(&pn->mn_ctime);
}
return (0);
}
#if 0
struct vop_read_args {
struct vop_generic_args a_gen;
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
};
#endif
/*
* Read from a file
*/
static int
mqfs_read(struct vop_read_args *ap)
{
char buf[80];
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct mqfs_node *pn;
struct mqueue *mq;
int len, error;
if (vp->v_type != VREG)
return (EINVAL);
pn = VTON(vp);
mq = VTOMQ(vp);
snprintf(buf, sizeof(buf),
"QSIZE:%-10ld MAXMSG:%-10ld CURMSG:%-10ld MSGSIZE:%-10ld\n",
mq->mq_totalbytes,
mq->mq_maxmsg,
mq->mq_curmsgs,
mq->mq_msgsize);
buf[sizeof(buf)-1] = '\0';
len = strlen(buf);
error = uiomove_frombuf(buf, len, uio);
return (error);
}
#if 0
struct vop_readdir_args {
struct vop_generic_args a_gen;
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *a_eofflag;
int *a_ncookies;
u_long **a_cookies;
};
#endif
/*
* Return directory entries.
*/
static int
mqfs_readdir(struct vop_readdir_args *ap)
{
struct vnode *vp;
struct mqfs_info *mi;
struct mqfs_node *pd;
struct mqfs_node *pn;
struct dirent entry;
struct uio *uio;
int *tmp_ncookies = NULL;
off_t offset;
int error, i;
vp = ap->a_vp;
mi = VFSTOMQFS(vp->v_mount);
pd = VTON(vp);
uio = ap->a_uio;
if (vp->v_type != VDIR)
return (ENOTDIR);
if (uio->uio_offset < 0)
return (EINVAL);
if (ap->a_ncookies != NULL) {
tmp_ncookies = ap->a_ncookies;
*ap->a_ncookies = 0;
ap->a_ncookies = NULL;
}
error = 0;
offset = 0;
sx_xlock(&mi->mi_lock);
LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
entry.d_reclen = sizeof(entry);
if (!pn->mn_fileno)
mqfs_fileno_alloc(mi, pn);
entry.d_fileno = pn->mn_fileno;
for (i = 0; i < MQFS_NAMELEN - 1 && pn->mn_name[i] != '\0'; ++i)
entry.d_name[i] = pn->mn_name[i];
entry.d_name[i] = 0;
entry.d_namlen = i;
switch (pn->mn_type) {
case mqfstype_root:
case mqfstype_dir:
case mqfstype_this:
case mqfstype_parent:
entry.d_type = DT_DIR;
break;
case mqfstype_file:
entry.d_type = DT_REG;
break;
case mqfstype_symlink:
entry.d_type = DT_LNK;
break;
default:
panic("%s has unexpected node type: %d", pn->mn_name,
pn->mn_type);
}
if (entry.d_reclen > uio->uio_resid)
break;
if (offset >= uio->uio_offset) {
error = vfs_read_dirent(ap, &entry, offset);
if (error)
break;
}
offset += entry.d_reclen;
}
sx_xunlock(&mi->mi_lock);
uio->uio_offset = offset;
if (tmp_ncookies != NULL)
ap->a_ncookies = tmp_ncookies;
return (error);
}
#ifdef notyet
#if 0
struct vop_mkdir_args {
struct vnode *a_dvp;
struvt vnode **a_vpp;
struvt componentname *a_cnp;
struct vattr *a_vap;
};
#endif
/*
* Create a directory.
*/
static int
mqfs_mkdir(struct vop_mkdir_args *ap)
{
struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
struct componentname *cnp = ap->a_cnp;
struct mqfs_node *pd = VTON(ap->a_dvp);
struct mqfs_node *pn;
int error;
if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
return (ENOTDIR);
sx_xlock(&mqfs->mi_lock);
#if 0
/* named node */
pn = mqfs_search(pd, cnp->cn_nameptr, cnp->cn_namelen);
if (pn != NULL) {
sx_xunlock(&mqfs->mi_lock);
return (EEXIST);
}
#else
if ((cnp->cn_flags & HASBUF) == 0)
panic("%s: no name", __func__);
#endif
pn = mqfs_create_dir(pd, cnp->cn_nameptr, cnp->cn_namelen,
ap->a_vap->cn_cred, ap->a_vap->va_mode);
if (pn == NULL)
error = ENOSPC;
else
error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
sx_xunlock(&mqfs->mi_lock);
return (error);
}
#if 0
struct vop_rmdir_args {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
};
#endif
/*
* Remove a directory.
*/
static int
mqfs_rmdir(struct vop_rmdir_args *ap)
{
struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
struct mqfs_node *pn = VTON(ap->a_vp);
struct mqfs_node *pt;
if (pn->mn_type != mqfstype_dir)
return (ENOTDIR);
sx_xlock(&mqfs->mi_lock);
if (pn->mn_deleted) {
sx_xunlock(&mqfs->mi_lock);
return (ENOENT);
}
pt = LIST_FIRST(&pn->mn_children);
pt = LIST_NEXT(pt, mn_sibling);
pt = LIST_NEXT(pt, mn_sibling);
if (pt != NULL) {
sx_xunlock(&mqfs->mi_lock);
return (ENOTEMPTY);
}
pt = pn->mn_parent;
pn->mn_parent = NULL;
pn->mn_deleted = 1;
LIST_REMOVE(pn, mn_sibling);
mqnode_release(pn);
mqnode_release(pt);
sx_xunlock(&mqfs->mi_lock);
cache_purge(ap->a_vp);
return (0);
}
#endif /* notyet */
/*
* Allocate a message queue
*/
static struct mqueue *
mqueue_alloc(const struct mq_attr *attr)
{
struct mqueue *mq;
if (curmq >= maxmq)
return (NULL);
mq = uma_zalloc(mqueue_zone, M_WAITOK | M_ZERO);
TAILQ_INIT(&mq->mq_msgq);
if (attr != NULL) {
mq->mq_maxmsg = attr->mq_maxmsg;
mq->mq_msgsize = attr->mq_msgsize;
} else {
mq->mq_maxmsg = default_maxmsg;
mq->mq_msgsize = default_msgsize;
}
mtx_init(&mq->mq_mutex, "mqueue", NULL, MTX_DEF);
knlist_init(&mq->mq_rsel.si_note, &mq->mq_mutex, NULL, NULL, NULL);
knlist_init(&mq->mq_wsel.si_note, &mq->mq_mutex, NULL, NULL, NULL);
atomic_add_int(&curmq, 1);
return (mq);
}
/*
* Destroy a message queue
*/
static void
mqueue_free(struct mqueue *mq)
{
struct mqueue_msg *msg;
while ((msg = TAILQ_FIRST(&mq->mq_msgq)) != NULL) {
TAILQ_REMOVE(&mq->mq_msgq, msg, msg_link);
FREE(msg, M_MQUEUEDATA);
}
mtx_destroy(&mq->mq_mutex);
knlist_destroy(&mq->mq_rsel.si_note);
knlist_destroy(&mq->mq_wsel.si_note);
uma_zfree(mqueue_zone, mq);
atomic_add_int(&curmq, -1);
}
/*
* Load a message from user space
*/
static struct mqueue_msg *
mqueue_loadmsg(const char *msg_ptr, size_t msg_size, int msg_prio)
{
struct mqueue_msg *msg;
size_t len;
int error;
len = sizeof(struct mqueue_msg) + msg_size;
MALLOC(msg, struct mqueue_msg *, len, M_MQUEUEDATA, M_WAITOK);
error = copyin(msg_ptr, ((char *)msg) + sizeof(struct mqueue_msg),
msg_size);
if (error) {
FREE(msg, M_MQUEUEDATA);
msg = NULL;
} else {
msg->msg_size = msg_size;
msg->msg_prio = msg_prio;
}
return (msg);
}
/*
* Save a message to user space
*/
static int
mqueue_savemsg(struct mqueue_msg *msg, char *msg_ptr, int *msg_prio)
{
int error;
error = copyout(((char *)msg) + sizeof(*msg), msg_ptr,
msg->msg_size);
if (error == 0 && msg_prio != NULL)
error = copyout(&msg->msg_prio, msg_prio, sizeof(int));
return (error);
}
/*
* Free a message's memory
*/
static __inline void
mqueue_freemsg(struct mqueue_msg *msg)
{
FREE(msg, M_MQUEUEDATA);
}
/*
* Send a message. if waitok is false, thread will not be
* blocked if there is no data in queue, otherwise, absolute
* time will be checked.
*/
int
mqueue_send(struct mqueue *mq, const char *msg_ptr,
size_t msg_len, unsigned msg_prio, int waitok,
const struct timespec *abs_timeout)
{
struct mqueue_msg *msg;
struct timespec ets, ts, ts2;
struct timeval tv;
int error;
if (msg_prio >= MQ_PRIO_MAX)
return (EINVAL);
if (msg_len > mq->mq_msgsize)
return (EMSGSIZE);
msg = mqueue_loadmsg(msg_ptr, msg_len, msg_prio);
if (msg == NULL)
return (EFAULT);
/* O_NONBLOCK case */
if (!waitok) {
error = _mqueue_send(mq, msg, -1);
if (error)
goto bad;
return (0);
}
/* we allow a null timeout (wait forever) */
if (abs_timeout == NULL) {
error = _mqueue_send(mq, msg, 0);
if (error)
goto bad;
return (0);
}
/* send it before checking time */
error = _mqueue_send(mq, msg, -1);
if (error == 0)
return (0);
if (error != EAGAIN)
goto bad;
error = copyin(abs_timeout, &ets, sizeof(ets));
if (error != 0)
goto bad;
if (ets.tv_nsec >= 1000000000 || ets.tv_nsec < 0) {
error = EINVAL;
goto bad;
}
for (;;) {
ts2 = ets;
getnanotime(&ts);
timespecsub(&ts2, &ts);
if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
error = ETIMEDOUT;
break;
}
TIMESPEC_TO_TIMEVAL(&tv, &ts2);
error = _mqueue_send(mq, msg, tvtohz(&tv));
if (error != ETIMEDOUT)
break;
}
if (error == 0)
return (0);
bad:
mqueue_freemsg(msg);
return (error);
}
/*
* Common routine to send a message
*/
static int
_mqueue_send(struct mqueue *mq, struct mqueue_msg *msg, int timo)
{
struct mqueue_msg *msg2;
int error = 0;
mtx_lock(&mq->mq_mutex);
while (mq->mq_curmsgs >= mq->mq_maxmsg && error == 0) {
if (timo < 0) {
mtx_unlock(&mq->mq_mutex);
return (EAGAIN);
}
mq->mq_senders++;
error = msleep(&mq->mq_senders, &mq->mq_mutex,
PCATCH, "mqsend", timo);
mq->mq_senders--;
if (error == EAGAIN)
error = ETIMEDOUT;
}
if (mq->mq_curmsgs >= mq->mq_maxmsg) {
mtx_unlock(&mq->mq_mutex);
return (error);
}
error = 0;
if (TAILQ_EMPTY(&mq->mq_msgq)) {
TAILQ_INSERT_HEAD(&mq->mq_msgq, msg, msg_link);
} else {
if (msg->msg_prio <= TAILQ_LAST(&mq->mq_msgq, msgq)->msg_prio) {
TAILQ_INSERT_TAIL(&mq->mq_msgq, msg, msg_link);
} else {
TAILQ_FOREACH(msg2, &mq->mq_msgq, msg_link) {
if (msg2->msg_prio < msg->msg_prio)
break;
}
TAILQ_INSERT_BEFORE(msg2, msg, msg_link);
}
}
mq->mq_curmsgs++;
mq->mq_totalbytes += msg->msg_size;
if (mq->mq_receivers)
wakeup_one(&mq->mq_receivers);
else if (mq->mq_notifier != NULL)
mqueue_send_notification(mq);
if (mq->mq_flags & MQ_RSEL) {
mq->mq_flags &= ~MQ_RSEL;
selwakeup(&mq->mq_rsel);
}
KNOTE_LOCKED(&mq->mq_rsel.si_note, 0);
mtx_unlock(&mq->mq_mutex);
return (0);
}
/*
* Send realtime a signal to process which registered itself
* successfully by mq_notify.
*/
static void
mqueue_send_notification(struct mqueue *mq)
{
struct mqueue_notifier *nt;
struct proc *p;
mtx_assert(&mq->mq_mutex, MA_OWNED);
nt = mq->mq_notifier;
if (nt->nt_sigev.sigev_notify != SIGEV_NONE) {
p = nt->nt_proc;
PROC_LOCK(p);
if (!KSI_ONQ(&nt->nt_ksi))
psignal_event(p, &nt->nt_sigev, &nt->nt_ksi);
PROC_UNLOCK(p);
}
mq->mq_notifier = NULL;
}
/*
* Get a message. if waitok is false, thread will not be
* blocked if there is no data in queue, otherwise, absolute
* time will be checked.
*/
int
mqueue_receive(struct mqueue *mq, char *msg_ptr,
size_t msg_len, unsigned *msg_prio, int waitok,
const struct timespec *abs_timeout)
{
struct mqueue_msg *msg;
struct timespec ets, ts, ts2;
struct timeval tv;
int error;
if (msg_len < mq->mq_msgsize)
return (EMSGSIZE);
/* O_NONBLOCK case */
if (!waitok) {
error = _mqueue_recv(mq, &msg, -1);
if (error)
return (error);
goto received;
}
/* we allow a null timeout (wait forever). */
if (abs_timeout == NULL) {
error = _mqueue_recv(mq, &msg, 0);
if (error)
return (error);
goto received;
}
/* try to get a message before checking time */
error = _mqueue_recv(mq, &msg, -1);
if (error == 0)
goto received;
if (error != EAGAIN)
return (error);
error = copyin(abs_timeout, &ets, sizeof(ets));
if (error != 0)
return (error);
if (ets.tv_nsec >= 1000000000 || ets.tv_nsec < 0) {
error = EINVAL;
return (error);
}
for (;;) {
ts2 = ets;
getnanotime(&ts);
timespecsub(&ts2, &ts);
if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
error = ETIMEDOUT;
return (error);
}
TIMESPEC_TO_TIMEVAL(&tv, &ts2);
error = _mqueue_recv(mq, &msg, tvtohz(&tv));
if (error == 0)
break;
if (error != ETIMEDOUT)
return (error);
}
received:
error = mqueue_savemsg(msg, msg_ptr, msg_prio);
if (error == 0) {
curthread->td_retval[0] = msg->msg_size;
curthread->td_retval[1] = 0;
}
mqueue_freemsg(msg);
return (error);
}
/*
* Common routine to receive a message
*/
static int
_mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg, int timo)
{
int error = 0;
mtx_lock(&mq->mq_mutex);
while ((*msg = TAILQ_FIRST(&mq->mq_msgq)) == NULL && error == 0) {
if (timo < 0) {
mtx_unlock(&mq->mq_mutex);
return (EAGAIN);
}
mq->mq_receivers++;
error = msleep(&mq->mq_receivers, &mq->mq_mutex,
PCATCH, "mqrecv", timo);
mq->mq_receivers--;
if (error == EAGAIN)
error = ETIMEDOUT;
}
if (*msg != NULL) {
error = 0;
TAILQ_REMOVE(&mq->mq_msgq, *msg, msg_link);
mq->mq_curmsgs--;
mq->mq_totalbytes -= (*msg)->msg_size;
if (mq->mq_senders)
wakeup_one(&mq->mq_senders);
if (mq->mq_flags & MQ_WSEL) {
mq->mq_flags &= ~MQ_WSEL;
selwakeup(&mq->mq_wsel);
}
KNOTE_LOCKED(&mq->mq_wsel.si_note, 0);
}
if (mq->mq_notifier != NULL && mq->mq_receivers == 0 &&
!TAILQ_EMPTY(&mq->mq_msgq)) {
mqueue_send_notification(mq);
}
mtx_unlock(&mq->mq_mutex);
return (error);
}
static __inline struct mqueue_notifier *
notifier_alloc(void)
{
return (uma_zalloc(mqnoti_zone, M_WAITOK | M_ZERO));
}
static __inline void
notifier_free(struct mqueue_notifier *p)
{
uma_zfree(mqnoti_zone, p);
}
static struct mqueue_notifier *
notifier_search(struct proc *p, int fd)
{
struct mqueue_notifier *nt;
LIST_FOREACH(nt, &p->p_mqnotifier, nt_link) {
if (nt->nt_ksi.ksi_mqd == fd)
break;
}
return (nt);
}
static __inline void
notifier_insert(struct proc *p, struct mqueue_notifier *nt)
{
LIST_INSERT_HEAD(&p->p_mqnotifier, nt, nt_link);
}
static __inline void
notifier_delete(struct proc *p, struct mqueue_notifier *nt)
{
LIST_REMOVE(nt, nt_link);
notifier_free(nt);
}
static void
notifier_remove(struct proc *p, struct mqueue *mq, int fd)
{
struct mqueue_notifier *nt;
mtx_assert(&mq->mq_mutex, MA_OWNED);
PROC_LOCK(p);
nt = notifier_search(p, fd);
if (nt != NULL) {
if (mq->mq_notifier == nt)
mq->mq_notifier = NULL;
sigqueue_take(&nt->nt_ksi);
notifier_delete(p, nt);
}
PROC_UNLOCK(p);
}
/*
* Syscall to open a message queue.
*/
int
kmq_open(struct thread *td, struct kmq_open_args *uap)
{
char path[MQFS_NAMELEN + 1];
struct mq_attr attr, *pattr;
struct mqfs_node *pn;
struct filedesc *fdp;
struct file *fp;
struct mqueue *mq;
int fd, error, len, flags, cmode;
if ((uap->flags & O_ACCMODE) == O_ACCMODE)
return (EINVAL);
fdp = td->td_proc->p_fd;
flags = FFLAGS(uap->flags);
cmode = (((uap->mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT);
mq = NULL;
if ((flags & O_CREAT) && (uap->attr != NULL)) {
error = copyin(uap->attr, &attr, sizeof(attr));
if (error)
return (error);
if (attr.mq_maxmsg <= 0 || attr.mq_maxmsg > maxmsg)
return (EINVAL);
if (attr.mq_msgsize <= 0 || attr.mq_msgsize > maxmsgsize)
return (EINVAL);
pattr = &attr;
} else
pattr = NULL;
error = copyinstr(uap->path, path, MQFS_NAMELEN + 1, NULL);
if (error)
return (error);
/*
* The first character of name must be a slash (/) character
* and the remaining characters of name cannot include any slash
* characters.
*/
len = strlen(path);
if (len < 2 || path[0] != '/' || index(path + 1, '/') != NULL)
return (EINVAL);
error = falloc(td, &fp, &fd);
if (error)
return (error);
sx_xlock(&mqfs_data.mi_lock);
pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
if (pn == NULL) {
if (!(flags & O_CREAT)) {
error = ENOENT;
} else {
mq = mqueue_alloc(pattr);
if (mq == NULL) {
error = ENFILE;
} else {
pn = mqfs_create_file(mqfs_data.mi_root,
path + 1, len - 1, td->td_ucred,
cmode);
if (pn == NULL) {
error = ENOSPC;
mqueue_free(mq);
}
}
}
if (error == 0) {
pn->mn_data = mq;
}
} else {
if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) {
error = EEXIST;
} else {
int acc_mode = 0;
if (flags & FREAD)
acc_mode |= VREAD;
if (flags & FWRITE)
acc_mode |= VWRITE;
error = vaccess(VREG, pn->mn_mode, pn->mn_uid,
pn->mn_gid, acc_mode, td->td_ucred, NULL);
}
}
if (error) {
sx_xunlock(&mqfs_data.mi_lock);
fdclose(fdp, fp, fd, td);
fdrop(fp, td);
return (error);
}
mqnode_addref(pn);
sx_xunlock(&mqfs_data.mi_lock);
finit(fp, flags & (FREAD | FWRITE | O_NONBLOCK), DTYPE_MQUEUE, pn,
&mqueueops);
FILEDESC_XLOCK(fdp);
if (fdp->fd_ofiles[fd] == fp)
fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
FILEDESC_XUNLOCK(fdp);
td->td_retval[0] = fd;
fdrop(fp, td);
return (0);
}
/*
* Syscall to unlink a message queue.
*/
int
kmq_unlink(struct thread *td, struct kmq_unlink_args *uap)
{
char path[MQFS_NAMELEN+1];
struct mqfs_node *pn;
int error, len;
error = copyinstr(uap->path, path, MQFS_NAMELEN + 1, NULL);
if (error)
return (error);
len = strlen(path);
if (len < 2 || path[0] != '/' || index(path + 1, '/') != NULL)
return (EINVAL);
sx_xlock(&mqfs_data.mi_lock);
pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
if (pn != NULL)
error = do_unlink(pn, td->td_ucred);
else
error = ENOENT;
sx_xunlock(&mqfs_data.mi_lock);
return (error);
}
typedef int (*_fgetf)(struct thread *, int, struct file **);
/*
* Get message queue by giving file slot
*/
static int
_getmq(struct thread *td, int fd, _fgetf func,
struct file **fpp, struct mqfs_node **ppn, struct mqueue **pmq)
{
struct mqfs_node *pn;
int error;
error = func(td, fd, fpp);
if (error)
return (error);
if (&mqueueops != (*fpp)->f_ops) {
fdrop(*fpp, td);
return (EBADF);
}
pn = (*fpp)->f_data;
if (ppn)
*ppn = pn;
if (pmq)
*pmq = pn->mn_data;
return (0);
}
static __inline int
getmq(struct thread *td, int fd, struct file **fpp, struct mqfs_node **ppn,
struct mqueue **pmq)
{
return _getmq(td, fd, fget, fpp, ppn, pmq);
}
static __inline int
getmq_read(struct thread *td, int fd, struct file **fpp,
struct mqfs_node **ppn, struct mqueue **pmq)
{
return _getmq(td, fd, fget_read, fpp, ppn, pmq);
}
static __inline int
getmq_write(struct thread *td, int fd, struct file **fpp,
struct mqfs_node **ppn, struct mqueue **pmq)
{
return _getmq(td, fd, fget_write, fpp, ppn, pmq);
}
int
kmq_setattr(struct thread *td, struct kmq_setattr_args *uap)
{
struct mqueue *mq;
struct file *fp;
struct mq_attr attr, oattr;
u_int oflag, flag;
int error;
if (uap->attr) {
error = copyin(uap->attr, &attr, sizeof(attr));
if (error)
return (error);
if (attr.mq_flags & ~O_NONBLOCK)
return (EINVAL);
}
error = getmq(td, uap->mqd, &fp, NULL, &mq);
if (error)
return (error);
oattr.mq_maxmsg = mq->mq_maxmsg;
oattr.mq_msgsize = mq->mq_msgsize;
oattr.mq_curmsgs = mq->mq_curmsgs;
if (uap->attr) {
do {
oflag = flag = fp->f_flag;
flag &= ~O_NONBLOCK;
flag |= (attr.mq_flags & O_NONBLOCK);
} while (atomic_cmpset_int(&fp->f_flag, oflag, flag) == 0);
} else
oflag = fp->f_flag;
oattr.mq_flags = (O_NONBLOCK & oflag);
fdrop(fp, td);
if (uap->oattr)
error = copyout(&oattr, uap->oattr, sizeof(oattr));
return (error);
}
int
kmq_timedreceive(struct thread *td, struct kmq_timedreceive_args *uap)
{
struct mqueue *mq;
struct file *fp;
int error;
int waitok;
error = getmq_read(td, uap->mqd, &fp, NULL, &mq);
if (error)
return (error);
waitok = !(fp->f_flag & O_NONBLOCK);
error = mqueue_receive(mq, uap->msg_ptr, uap->msg_len,
uap->msg_prio, waitok, uap->abs_timeout);
fdrop(fp, td);
return (error);
}
int
kmq_timedsend(struct thread *td, struct kmq_timedsend_args *uap)
{
struct mqueue *mq;
struct file *fp;
int error, waitok;
error = getmq_write(td, uap->mqd, &fp, NULL, &mq);
if (error)
return (error);
waitok = !(fp->f_flag & O_NONBLOCK);
error = mqueue_send(mq, uap->msg_ptr, uap->msg_len,
uap->msg_prio, waitok, uap->abs_timeout);
fdrop(fp, td);
return (error);
}
int
kmq_notify(struct thread *td, struct kmq_notify_args *uap)
{
struct sigevent ev;
struct filedesc *fdp;
struct proc *p;
struct mqueue *mq;
struct file *fp;
struct mqueue_notifier *nt, *newnt = NULL;
int error;
p = td->td_proc;
fdp = td->td_proc->p_fd;
if (uap->sigev) {
error = copyin(uap->sigev, &ev, sizeof(ev));
if (error)
return (error);
if (ev.sigev_notify != SIGEV_SIGNAL &&
ev.sigev_notify != SIGEV_THREAD_ID &&
ev.sigev_notify != SIGEV_NONE)
return (EINVAL);
if ((ev.sigev_notify == SIGEV_SIGNAL ||
ev.sigev_notify == SIGEV_THREAD_ID) &&
!_SIG_VALID(ev.sigev_signo))
return (EINVAL);
}
error = getmq(td, uap->mqd, &fp, NULL, &mq);
if (error)
return (error);
again:
FILEDESC_SLOCK(fdp);
if (fget_locked(fdp, uap->mqd) != fp) {
FILEDESC_SUNLOCK(fdp);
error = EBADF;
goto out;
}
mtx_lock(&mq->mq_mutex);
FILEDESC_SUNLOCK(fdp);
if (uap->sigev != NULL) {
if (mq->mq_notifier != NULL) {
error = EBUSY;
} else {
PROC_LOCK(p);
nt = notifier_search(p, uap->mqd);
if (nt == NULL) {
if (newnt == NULL) {
PROC_UNLOCK(p);
mtx_unlock(&mq->mq_mutex);
newnt = notifier_alloc();
goto again;
}
}
if (nt != NULL) {
sigqueue_take(&nt->nt_ksi);
if (newnt != NULL) {
notifier_free(newnt);
newnt = NULL;
}
} else {
nt = newnt;
newnt = NULL;
ksiginfo_init(&nt->nt_ksi);
nt->nt_ksi.ksi_flags |= KSI_INS | KSI_EXT;
nt->nt_ksi.ksi_code = SI_MESGQ;
nt->nt_proc = p;
nt->nt_ksi.ksi_mqd = uap->mqd;
notifier_insert(p, nt);
}
nt->nt_sigev = ev;
mq->mq_notifier = nt;
PROC_UNLOCK(p);
/*
* if there is no receivers and message queue
* is not empty, we should send notification
* as soon as possible.
*/
if (mq->mq_receivers == 0 &&
!TAILQ_EMPTY(&mq->mq_msgq))
mqueue_send_notification(mq);
}
} else {
notifier_remove(p, mq, uap->mqd);
}
mtx_unlock(&mq->mq_mutex);
out:
fdrop(fp, td);
if (newnt != NULL)
notifier_free(newnt);
return (error);
}
static void
mqueue_fdclose(struct thread *td, int fd, struct file *fp)
{
struct filedesc *fdp;
struct mqueue *mq;
fdp = td->td_proc->p_fd;
FILEDESC_LOCK_ASSERT(fdp);
if (fp->f_ops == &mqueueops) {
mq = FPTOMQ(fp);
mtx_lock(&mq->mq_mutex);
notifier_remove(td->td_proc, mq, fd);
/* have to wakeup thread in same process */
if (mq->mq_flags & MQ_RSEL) {
mq->mq_flags &= ~MQ_RSEL;
selwakeup(&mq->mq_rsel);
}
if (mq->mq_flags & MQ_WSEL) {
mq->mq_flags &= ~MQ_WSEL;
selwakeup(&mq->mq_wsel);
}
mtx_unlock(&mq->mq_mutex);
}
}
static void
mq_proc_exit(void *arg __unused, struct proc *p)
{
struct filedesc *fdp;
struct file *fp;
struct mqueue *mq;
int i;
fdp = p->p_fd;
FILEDESC_SLOCK(fdp);
for (i = 0; i < fdp->fd_nfiles; ++i) {
fp = fget_locked(fdp, i);
if (fp != NULL && fp->f_ops == &mqueueops) {
mq = FPTOMQ(fp);
mtx_lock(&mq->mq_mutex);
notifier_remove(p, FPTOMQ(fp), i);
mtx_unlock(&mq->mq_mutex);
}
}
FILEDESC_SUNLOCK(fdp);
KASSERT(LIST_EMPTY(&p->p_mqnotifier), ("mq notifiers left"));
}
static int
mqf_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
int flags, struct thread *td)
{
return (EOPNOTSUPP);
}
static int
mqf_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
int flags, struct thread *td)
{
return (EOPNOTSUPP);
}
static int
mqf_truncate(struct file *fp, off_t length, struct ucred *active_cred,
struct thread *td)
{
return (EINVAL);
}
static int
mqf_ioctl(struct file *fp, u_long cmd, void *data,
struct ucred *active_cred, struct thread *td)
{
return (ENOTTY);
}
static int
mqf_poll(struct file *fp, int events, struct ucred *active_cred,
struct thread *td)
{
struct mqueue *mq = FPTOMQ(fp);
int revents = 0;
mtx_lock(&mq->mq_mutex);
if (events & (POLLIN | POLLRDNORM)) {
if (mq->mq_curmsgs) {
revents |= events & (POLLIN | POLLRDNORM);
} else {
mq->mq_flags |= MQ_RSEL;
selrecord(td, &mq->mq_rsel);
}
}
if (events & POLLOUT) {
if (mq->mq_curmsgs < mq->mq_maxmsg)
revents |= POLLOUT;
else {
mq->mq_flags |= MQ_WSEL;
selrecord(td, &mq->mq_wsel);
}
}
mtx_unlock(&mq->mq_mutex);
return (revents);
}
static int
mqf_close(struct file *fp, struct thread *td)
{
struct mqfs_node *pn;
fp->f_ops = &badfileops;
pn = fp->f_data;
fp->f_data = NULL;
sx_xlock(&mqfs_data.mi_lock);
mqnode_release(pn);
sx_xunlock(&mqfs_data.mi_lock);
return (0);
}
static int
mqf_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
struct thread *td)
{
struct mqfs_node *pn = fp->f_data;
bzero(st, sizeof *st);
st->st_atimespec = pn->mn_atime;
st->st_mtimespec = pn->mn_mtime;
st->st_ctimespec = pn->mn_ctime;
st->st_birthtimespec = pn->mn_birth;
st->st_uid = pn->mn_uid;
st->st_gid = pn->mn_gid;
st->st_mode = S_IFIFO | pn->mn_mode;
return (0);
}
static int
mqf_kqfilter(struct file *fp, struct knote *kn)
{
struct mqueue *mq = FPTOMQ(fp);
int error = 0;
if (kn->kn_filter == EVFILT_READ) {
kn->kn_fop = &mq_rfiltops;
knlist_add(&mq->mq_rsel.si_note, kn, 0);
} else if (kn->kn_filter == EVFILT_WRITE) {
kn->kn_fop = &mq_wfiltops;
knlist_add(&mq->mq_wsel.si_note, kn, 0);
} else
error = EINVAL;
return (error);
}
static void
filt_mqdetach(struct knote *kn)
{
struct mqueue *mq = FPTOMQ(kn->kn_fp);
if (kn->kn_filter == EVFILT_READ)
knlist_remove(&mq->mq_rsel.si_note, kn, 0);
else if (kn->kn_filter == EVFILT_WRITE)
knlist_remove(&mq->mq_wsel.si_note, kn, 0);
else
panic("filt_mqdetach");
}
static int
filt_mqread(struct knote *kn, long hint)
{
struct mqueue *mq = FPTOMQ(kn->kn_fp);
mtx_assert(&mq->mq_mutex, MA_OWNED);
return (mq->mq_curmsgs != 0);
}
static int
filt_mqwrite(struct knote *kn, long hint)
{
struct mqueue *mq = FPTOMQ(kn->kn_fp);
mtx_assert(&mq->mq_mutex, MA_OWNED);
return (mq->mq_curmsgs < mq->mq_maxmsg);
}
static struct fileops mqueueops = {
.fo_read = mqf_read,
.fo_write = mqf_write,
.fo_truncate = mqf_truncate,
.fo_ioctl = mqf_ioctl,
.fo_poll = mqf_poll,
.fo_kqfilter = mqf_kqfilter,
.fo_stat = mqf_stat,
.fo_close = mqf_close
};
static struct vop_vector mqfs_vnodeops = {
.vop_default = &default_vnodeops,
.vop_access = mqfs_access,
.vop_cachedlookup = mqfs_lookup,
.vop_lookup = vfs_cache_lookup,
.vop_reclaim = mqfs_reclaim,
.vop_create = mqfs_create,
.vop_remove = mqfs_remove,
.vop_inactive = mqfs_inactive,
.vop_open = mqfs_open,
.vop_close = mqfs_close,
.vop_getattr = mqfs_getattr,
.vop_setattr = mqfs_setattr,
.vop_read = mqfs_read,
.vop_write = VOP_EOPNOTSUPP,
.vop_readdir = mqfs_readdir,
.vop_mkdir = VOP_EOPNOTSUPP,
.vop_rmdir = VOP_EOPNOTSUPP
};
static struct vfsops mqfs_vfsops = {
.vfs_init = mqfs_init,
.vfs_uninit = mqfs_uninit,
.vfs_mount = mqfs_mount,
.vfs_unmount = mqfs_unmount,
.vfs_root = mqfs_root,
.vfs_statfs = mqfs_statfs,
};
SYSCALL_MODULE_HELPER(kmq_open);
SYSCALL_MODULE_HELPER(kmq_setattr);
SYSCALL_MODULE_HELPER(kmq_timedsend);
SYSCALL_MODULE_HELPER(kmq_timedreceive);
SYSCALL_MODULE_HELPER(kmq_notify);
SYSCALL_MODULE_HELPER(kmq_unlink);
VFS_SET(mqfs_vfsops, mqueuefs, VFCF_SYNTHETIC);
MODULE_VERSION(mqueuefs, 1);
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