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freebsd-dev/sys/kern/uipc_mqueue.c
Tor Egge 61b9d89ff0 Make insmntque() externally visibile and allow it to fail (e.g. during 
late stages of unmount).  On failure, the vnode is recycled.

Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.

Change getnewvnode() to no longer call insmntque().  Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.

Change vfs_hash_insert() to no longer lock the vnode.  The caller now
has that responsibility.

Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup.  Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.

Approved by:	re (kensmith)
Reviewed by:	kib
In collaboration with:	kib
2007-03-13 01:50:27 +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/limits.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) {
if (vget(vd->mv_vnode, 0, curthread) == 0) {
*vpp = vd->mv_vnode;
vn_lock(*vpp, LK_RETRY | LK_EXCLUSIVE,
curthread);
return (0);
}
/* XXX if this can happen, we're in trouble */
}
error = getnewvnode("mqueue", mp, &mqfs_vnodeops, vpp);
if (error)
return (error);
vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY, curthread);
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, cnp->cn_thread);
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, td);
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);
/*
* XXXRW: Other instances of the message queue primitive are
* allowed in jail?
*/
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_cred(ap->a_td->td_ucred,
PRIV_MQ_ADMIN, SUSER_ALLOWJAIL)) != 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_cred(ap->a_td->td_ucred,
PRIV_MQ_ADMIN, SUSER_ALLOWJAIL)))
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);
FILE_LOCK(fp);
fp->f_flag = (flags & (FREAD | FWRITE | O_NONBLOCK));
fp->f_type = DTYPE_MQUEUE;
fp->f_ops = &mqueueops;
fp->f_data = pn;
FILE_UNLOCK(fp);
FILEDESC_LOCK_FAST(fdp);
if (fdp->fd_ofiles[fd] == fp)
fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
FILEDESC_UNLOCK_FAST(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;
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;
FILE_LOCK(fp);
oattr.mq_flags = (O_NONBLOCK & fp->f_flag);
if (uap->attr) {
fp->f_flag &= ~O_NONBLOCK;
fp->f_flag |= (attr.mq_flags & O_NONBLOCK);
}
FILE_UNLOCK(fp);
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_LOCK_FAST(fdp);
if (fget_locked(fdp, uap->mqd) != fp) {
FILEDESC_UNLOCK_FAST(fdp);
error = EBADF;
goto out;
}
mtx_lock(&mq->mq_mutex);
FILEDESC_UNLOCK_FAST(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, MA_OWNED);
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_LOCK_FAST(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_UNLOCK_FAST(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_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;
FILE_LOCK(fp);
fp->f_ops = &badfileops;
FILE_UNLOCK(fp);
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_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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