NetBSD-5.0.2/sys/coda/coda_psdev.c
/* $NetBSD: coda_psdev.c,v 1.45 2008/05/06 18:43:44 ad Exp $ */
/*
*
* Coda: an Experimental Distributed File System
* Release 3.1
*
* Copyright (c) 1987-1998 Carnegie Mellon University
* All Rights Reserved
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation, and
* that credit is given to Carnegie Mellon University in all documents
* and publicity pertaining to direct or indirect use of this code or its
* derivatives.
*
* CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS KNOWN TO HAVE BUGS,
* SOME OF WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON ALLOWS
* FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. CARNEGIE MELLON
* DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER
* RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE OR OF
* ANY DERIVATIVE WORK.
*
* Carnegie Mellon encourages users of this software to return any
* improvements or extensions that they make, and to grant Carnegie
* Mellon the rights to redistribute these changes without encumbrance.
*
* @(#) coda/coda_psdev.c,v 1.1.1.1 1998/08/29 21:26:45 rvb Exp $
*/
/*
* Mach Operating System
* Copyright (c) 1989 Carnegie-Mellon University
* All rights reserved. The CMU software License Agreement specifies
* the terms and conditions for use and redistribution.
*/
/*
* This code was written for the Coda file system at Carnegie Mellon
* University. Contributers include David Steere, James Kistler, and
* M. Satyanarayanan. */
/* These routines define the pseudo device for communication between
* Coda's Venus and Minicache in Mach 2.6. They used to be in cfs_subr.c,
* but I moved them to make it easier to port the Minicache without
* porting coda. -- DCS 10/12/94
*
* Following code depends on file-system CODA.
*/
/* These routines are the device entry points for Venus. */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: coda_psdev.c,v 1.45 2008/05/06 18:43:44 ad Exp $");
extern int coda_nc_initialized; /* Set if cache has been initialized */
#ifdef _LKM
#define NVCODA 4
#else
#include <vcoda.h>
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/select.h>
#include <sys/conf.h>
#include <sys/atomic.h>
#include <miscfs/syncfs/syncfs.h>
#include <coda/coda.h>
#include <coda/cnode.h>
#include <coda/coda_namecache.h>
#include <coda/coda_io.h>
#define CTL_C
int coda_psdev_print_entry = 0;
static
int outstanding_upcalls = 0;
int coda_call_sleep = PZERO - 1;
#ifdef CTL_C
int coda_pcatch = PCATCH;
#else
#endif
#define ENTRY if(coda_psdev_print_entry) myprintf(("Entered %s\n",__func__))
void vcodaattach(int n);
dev_type_open(vc_nb_open);
dev_type_close(vc_nb_close);
dev_type_read(vc_nb_read);
dev_type_write(vc_nb_write);
dev_type_ioctl(vc_nb_ioctl);
dev_type_poll(vc_nb_poll);
dev_type_kqfilter(vc_nb_kqfilter);
const struct cdevsw vcoda_cdevsw = {
vc_nb_open, vc_nb_close, vc_nb_read, vc_nb_write, vc_nb_ioctl,
nostop, notty, vc_nb_poll, nommap, vc_nb_kqfilter, D_OTHER,
};
struct vmsg {
TAILQ_ENTRY(vmsg) vm_chain;
void * vm_data;
u_short vm_flags;
u_short vm_inSize; /* Size is at most 5000 bytes */
u_short vm_outSize;
u_short vm_opcode; /* copied from data to save ptr lookup */
int vm_unique;
void * vm_sleep; /* Not used by Mach. */
};
#define VM_READ 1
#define VM_WRITE 2
#define VM_INTR 4
/* vcodaattach: do nothing */
void
vcodaattach(int n)
{
}
/*
* These functions are written for NetBSD.
*/
int
vc_nb_open(dev_t dev, int flag, int mode,
struct lwp *l)
{
struct vcomm *vcp;
ENTRY;
if (minor(dev) >= NVCODA || minor(dev) < 0)
return(ENXIO);
if (!coda_nc_initialized)
coda_nc_init();
vcp = &coda_mnttbl[minor(dev)].mi_vcomm;
if (VC_OPEN(vcp))
return(EBUSY);
selinit(&vcp->vc_selproc);
TAILQ_INIT(&vcp->vc_requests);
TAILQ_INIT(&vcp->vc_replies);
MARK_VC_OPEN(vcp);
coda_mnttbl[minor(dev)].mi_vfsp = NULL;
coda_mnttbl[minor(dev)].mi_rootvp = NULL;
return(0);
}
int
vc_nb_close(dev_t dev, int flag, int mode, struct lwp *l)
{
struct vcomm *vcp;
struct vmsg *vmp;
struct coda_mntinfo *mi;
int err;
ENTRY;
if (minor(dev) >= NVCODA || minor(dev) < 0)
return(ENXIO);
mi = &coda_mnttbl[minor(dev)];
vcp = &(mi->mi_vcomm);
if (!VC_OPEN(vcp))
panic("vcclose: not open");
/* prevent future operations on this vfs from succeeding by auto-
* unmounting any vfs mounted via this device. This frees user or
* sysadm from having to remember where all mount points are located.
* Put this before WAKEUPs to avoid queuing new messages between
* the WAKEUP and the unmount (which can happen if we're unlucky)
*/
if (!mi->mi_rootvp) {
/* just a simple open/close w no mount */
MARK_VC_CLOSED(vcp);
return 0;
}
/* Let unmount know this is for real */
atomic_inc_uint(&mi->mi_vfsp->mnt_refcnt);
VTOC(mi->mi_rootvp)->c_flags |= C_UNMOUNTING;
coda_unmounting(mi->mi_vfsp);
/* Wakeup clients so they can return. */
while ((vmp = TAILQ_FIRST(&vcp->vc_requests)) != NULL) {
TAILQ_REMOVE(&vcp->vc_requests, vmp, vm_chain);
/* Free signal request messages and don't wakeup cause
no one is waiting. */
if (vmp->vm_opcode == CODA_SIGNAL) {
CODA_FREE(vmp->vm_data, VC_IN_NO_DATA);
CODA_FREE(vmp, sizeof(struct vmsg));
continue;
}
outstanding_upcalls++;
wakeup(&vmp->vm_sleep);
}
while ((vmp = TAILQ_FIRST(&vcp->vc_replies)) != NULL) {
TAILQ_REMOVE(&vcp->vc_replies, vmp, vm_chain);
outstanding_upcalls++;
wakeup(&vmp->vm_sleep);
}
MARK_VC_CLOSED(vcp);
if (outstanding_upcalls) {
#ifdef CODA_VERBOSE
printf("presleep: outstanding_upcalls = %d\n", outstanding_upcalls);
(void) tsleep(&outstanding_upcalls, coda_call_sleep, "coda_umount", 0);
printf("postsleep: outstanding_upcalls = %d\n", outstanding_upcalls);
#else
(void) tsleep(&outstanding_upcalls, coda_call_sleep, "coda_umount", 0);
#endif
}
err = dounmount(mi->mi_vfsp, flag, l);
if (err)
myprintf(("Error %d unmounting vfs in vcclose(%d)\n",
err, minor(dev)));
seldestroy(&vcp->vc_selproc);
return 0;
}
int
vc_nb_read(dev_t dev, struct uio *uiop, int flag)
{
struct vcomm * vcp;
struct vmsg *vmp;
int error = 0;
ENTRY;
if (minor(dev) >= NVCODA || minor(dev) < 0)
return(ENXIO);
vcp = &coda_mnttbl[minor(dev)].mi_vcomm;
/* Get message at head of request queue. */
vmp = TAILQ_FIRST(&vcp->vc_requests);
if (vmp == NULL)
return(0); /* Nothing to read */
/* Move the input args into userspace */
uiop->uio_rw = UIO_READ;
error = uiomove(vmp->vm_data, vmp->vm_inSize, uiop);
if (error) {
myprintf(("vcread: error (%d) on uiomove\n", error));
error = EINVAL;
}
TAILQ_REMOVE(&vcp->vc_requests, vmp, vm_chain);
/* If request was a signal, free up the message and don't
enqueue it in the reply queue. */
if (vmp->vm_opcode == CODA_SIGNAL) {
if (codadebug)
myprintf(("vcread: signal msg (%d, %d)\n",
vmp->vm_opcode, vmp->vm_unique));
CODA_FREE(vmp->vm_data, VC_IN_NO_DATA);
CODA_FREE(vmp, sizeof(struct vmsg));
return(error);
}
vmp->vm_flags |= VM_READ;
TAILQ_INSERT_TAIL(&vcp->vc_replies, vmp, vm_chain);
return(error);
}
int
vc_nb_write(dev_t dev, struct uio *uiop, int flag)
{
struct vcomm * vcp;
struct vmsg *vmp;
struct coda_out_hdr *out;
u_long seq;
u_long opcode;
int tbuf[2];
int error = 0;
ENTRY;
if (minor(dev) >= NVCODA || minor(dev) < 0)
return(ENXIO);
vcp = &coda_mnttbl[minor(dev)].mi_vcomm;
/* Peek at the opcode, unique without transfering the data. */
uiop->uio_rw = UIO_WRITE;
error = uiomove(tbuf, sizeof(int) * 2, uiop);
if (error) {
myprintf(("vcwrite: error (%d) on uiomove\n", error));
return(EINVAL);
}
opcode = tbuf[0];
seq = tbuf[1];
if (codadebug)
myprintf(("vcwrite got a call for %ld.%ld\n", opcode, seq));
if (DOWNCALL(opcode)) {
union outputArgs pbuf;
/* get the rest of the data. */
uiop->uio_rw = UIO_WRITE;
error = uiomove(&pbuf.coda_purgeuser.oh.result, sizeof(pbuf) - (sizeof(int)*2), uiop);
if (error) {
myprintf(("vcwrite: error (%d) on uiomove (Op %ld seq %ld)\n",
error, opcode, seq));
return(EINVAL);
}
return handleDownCall(opcode, &pbuf);
}
/* Look for the message on the (waiting for) reply queue. */
TAILQ_FOREACH(vmp, &vcp->vc_replies, vm_chain) {
if (vmp->vm_unique == seq) break;
}
if (vmp == NULL) {
if (codadebug)
myprintf(("vcwrite: msg (%ld, %ld) not found\n", opcode, seq));
return(ESRCH);
}
/* Remove the message from the reply queue */
TAILQ_REMOVE(&vcp->vc_replies, vmp, vm_chain);
/* move data into response buffer. */
out = (struct coda_out_hdr *)vmp->vm_data;
/* Don't need to copy opcode and uniquifier. */
/* get the rest of the data. */
if (vmp->vm_outSize < uiop->uio_resid) {
myprintf(("vcwrite: more data than asked for (%d < %lu)\n",
vmp->vm_outSize, (unsigned long) uiop->uio_resid));
wakeup(&vmp->vm_sleep); /* Notify caller of the error. */
return(EINVAL);
}
tbuf[0] = uiop->uio_resid; /* Save this value. */
uiop->uio_rw = UIO_WRITE;
error = uiomove(&out->result, vmp->vm_outSize - (sizeof(int) * 2), uiop);
if (error) {
myprintf(("vcwrite: error (%d) on uiomove (op %ld seq %ld)\n",
error, opcode, seq));
return(EINVAL);
}
/* I don't think these are used, but just in case. */
/* XXX - aren't these two already correct? -bnoble */
out->opcode = opcode;
out->unique = seq;
vmp->vm_outSize = tbuf[0]; /* Amount of data transferred? */
vmp->vm_flags |= VM_WRITE;
wakeup(&vmp->vm_sleep);
return(0);
}
int
vc_nb_ioctl(dev_t dev, u_long cmd, void *addr, int flag,
struct lwp *l)
{
ENTRY;
switch(cmd) {
case CODARESIZE: {
struct coda_resize *data = (struct coda_resize *)addr;
return(coda_nc_resize(data->hashsize, data->heapsize, IS_DOWNCALL));
break;
}
case CODASTATS:
if (coda_nc_use) {
coda_nc_gather_stats();
return(0);
} else {
return(ENODEV);
}
break;
case CODAPRINT:
if (coda_nc_use) {
print_coda_nc();
return(0);
} else {
return(ENODEV);
}
break;
case CIOC_KERNEL_VERSION:
switch (*(u_int *)addr) {
case 0:
*(u_int *)addr = coda_kernel_version;
return 0;
break;
case 1:
case 2:
if (coda_kernel_version != *(u_int *)addr)
return ENOENT;
else
return 0;
default:
return ENOENT;
}
break;
default :
return(EINVAL);
break;
}
}
int
vc_nb_poll(dev_t dev, int events, struct lwp *l)
{
struct vcomm *vcp;
int event_msk = 0;
ENTRY;
if (minor(dev) >= NVCODA || minor(dev) < 0)
return(ENXIO);
vcp = &coda_mnttbl[minor(dev)].mi_vcomm;
event_msk = events & (POLLIN|POLLRDNORM);
if (!event_msk)
return(0);
if (!TAILQ_EMPTY(&vcp->vc_requests))
return(events & (POLLIN|POLLRDNORM));
selrecord(l, &(vcp->vc_selproc));
return(0);
}
static void
filt_vc_nb_detach(struct knote *kn)
{
struct vcomm *vcp = kn->kn_hook;
SLIST_REMOVE(&vcp->vc_selproc.sel_klist, kn, knote, kn_selnext);
}
static int
filt_vc_nb_read(struct knote *kn, long hint)
{
struct vcomm *vcp = kn->kn_hook;
struct vmsg *vmp;
vmp = TAILQ_FIRST(&vcp->vc_requests);
if (vmp == NULL)
return (0);
kn->kn_data = vmp->vm_inSize;
return (1);
}
static const struct filterops vc_nb_read_filtops =
{ 1, NULL, filt_vc_nb_detach, filt_vc_nb_read };
int
vc_nb_kqfilter(dev_t dev, struct knote *kn)
{
struct vcomm *vcp;
struct klist *klist;
ENTRY;
if (minor(dev) >= NVCODA || minor(dev) < 0)
return(ENXIO);
vcp = &coda_mnttbl[minor(dev)].mi_vcomm;
switch (kn->kn_filter) {
case EVFILT_READ:
klist = &vcp->vc_selproc.sel_klist;
kn->kn_fop = &vc_nb_read_filtops;
break;
default:
return (EINVAL);
}
kn->kn_hook = vcp;
SLIST_INSERT_HEAD(klist, kn, kn_selnext);
return (0);
}
/*
* Statistics
*/
struct coda_clstat coda_clstat;
/*
* Key question: whether to sleep interruptably or uninterruptably when
* waiting for Venus. The former seems better (cause you can ^C a
* job), but then GNU-EMACS completion breaks. Use tsleep with no
* timeout, and no longjmp happens. But, when sleeping
* "uninterruptibly", we don't get told if it returns abnormally
* (e.g. kill -9).
*/
int
coda_call(struct coda_mntinfo *mntinfo, int inSize, int *outSize,
void *buffer)
{
struct vcomm *vcp;
struct vmsg *vmp;
int error;
#ifdef CTL_C
struct lwp *l = curlwp;
struct proc *p = l->l_proc;
sigset_t psig_omask;
int i;
psig_omask = l->l_sigmask; /* XXXSA */
#endif
if (mntinfo == NULL) {
/* Unlikely, but could be a race condition with a dying warden */
return ENODEV;
}
vcp = &(mntinfo->mi_vcomm);
coda_clstat.ncalls++;
coda_clstat.reqs[((struct coda_in_hdr *)buffer)->opcode]++;
if (!VC_OPEN(vcp))
return(ENODEV);
CODA_ALLOC(vmp,struct vmsg *,sizeof(struct vmsg));
/* Format the request message. */
vmp->vm_data = buffer;
vmp->vm_flags = 0;
vmp->vm_inSize = inSize;
vmp->vm_outSize
= *outSize ? *outSize : inSize; /* |buffer| >= inSize */
vmp->vm_opcode = ((struct coda_in_hdr *)buffer)->opcode;
vmp->vm_unique = ++vcp->vc_seq;
if (codadebug)
myprintf(("Doing a call for %d.%d\n",
vmp->vm_opcode, vmp->vm_unique));
/* Fill in the common input args. */
((struct coda_in_hdr *)buffer)->unique = vmp->vm_unique;
/* Append msg to request queue and poke Venus. */
TAILQ_INSERT_TAIL(&vcp->vc_requests, vmp, vm_chain);
selnotify(&(vcp->vc_selproc), 0, 0);
/* We can be interrupted while we wait for Venus to process
* our request. If the interrupt occurs before Venus has read
* the request, we dequeue and return. If it occurs after the
* read but before the reply, we dequeue, send a signal
* message, and return. If it occurs after the reply we ignore
* it. In no case do we want to restart the syscall. If it
* was interrupted by a venus shutdown (vcclose), return
* ENODEV. */
/* Ignore return, We have to check anyway */
#ifdef CTL_C
/* This is work in progress. Setting coda_pcatch lets tsleep reawaken
on a ^c or ^z. The problem is that emacs sets certain interrupts
as SA_RESTART. This means that we should exit sleep handle the
"signal" and then go to sleep again. Mostly this is done by letting
the syscall complete and be restarted. We are not idempotent and
can not do this. A better solution is necessary.
*/
i = 0;
do {
error = tsleep(&vmp->vm_sleep, (coda_call_sleep|coda_pcatch), "coda_call", hz*2);
if (error == 0)
break;
mutex_enter(p->p_lock);
if (error == EWOULDBLOCK) {
#ifdef CODA_VERBOSE
printf("coda_call: tsleep TIMEOUT %d sec\n", 2+2*i);
#endif
} else if (sigispending(l, SIGIO)) {
sigaddset(&l->l_sigmask, SIGIO);
#ifdef CODA_VERBOSE
printf("coda_call: tsleep returns %d SIGIO, cnt %d\n", error, i);
#endif
} else if (sigispending(l, SIGALRM)) {
sigaddset(&l->l_sigmask, SIGALRM);
#ifdef CODA_VERBOSE
printf("coda_call: tsleep returns %d SIGALRM, cnt %d\n", error, i);
#endif
} else {
sigset_t tmp;
tmp = p->p_sigpend.sp_set; /* array assignment */
sigminusset(&l->l_sigmask, &tmp);
#ifdef CODA_VERBOSE
printf("coda_call: tsleep returns %d, cnt %d\n", error, i);
printf("coda_call: siglist = %x.%x.%x.%x, sigmask = %x.%x.%x.%x, mask %x.%x.%x.%x\n",
p->p_sigpend.sp_set.__bits[0], p->p_sigpend.sp_set.__bits[1],
p->p_sigpend.sp_set.__bits[2], p->p_sigpend.sp_set.__bits[3],
l->l_sigmask.__bits[0], l->l_sigmask.__bits[1],
l->l_sigmask.__bits[2], l->l_sigmask.__bits[3],
tmp.__bits[0], tmp.__bits[1], tmp.__bits[2], tmp.__bits[3]);
#endif
mutex_exit(p->p_lock);
break;
#ifdef notyet
sigminusset(&l->l_sigmask, &p->p_sigpend.sp_set);
printf("coda_call: siglist = %x.%x.%x.%x, sigmask = %x.%x.%x.%x\n",
p->p_sigpend.sp_set.__bits[0], p->p_sigpend.sp_set.__bits[1],
p->p_sigpend.sp_set.__bits[2], p->p_sigpend.sp_set.__bits[3],
l->l_sigmask.__bits[0], l->l_sigmask.__bits[1],
l->l_sigmask.__bits[2], l->l_sigmask.__bits[3]);
#endif
}
mutex_exit(p->p_lock);
} while (error && i++ < 128 && VC_OPEN(vcp));
l->l_sigmask = psig_omask; /* XXXSA */
#else
(void) tsleep(&vmp->vm_sleep, coda_call_sleep, "coda_call", 0);
#endif
if (VC_OPEN(vcp)) { /* Venus is still alive */
/* Op went through, interrupt or not... */
if (vmp->vm_flags & VM_WRITE) {
error = 0;
*outSize = vmp->vm_outSize;
}
else if (!(vmp->vm_flags & VM_READ)) {
/* Interrupted before venus read it. */
#ifdef CODA_VERBOSE
if (1)
#else
if (codadebug)
#endif
myprintf(("interrupted before read: op = %d.%d, flags = %x\n",
vmp->vm_opcode, vmp->vm_unique, vmp->vm_flags));
TAILQ_REMOVE(&vcp->vc_requests, vmp, vm_chain);
error = EINTR;
}
else {
/* (!(vmp->vm_flags & VM_WRITE)) means interrupted after
upcall started */
/* Interrupted after start of upcall, send venus a signal */
struct coda_in_hdr *dog;
struct vmsg *svmp;
#ifdef CODA_VERBOSE
if (1)
#else
if (codadebug)
#endif
myprintf(("Sending Venus a signal: op = %d.%d, flags = %x\n",
vmp->vm_opcode, vmp->vm_unique, vmp->vm_flags));
TAILQ_REMOVE(&vcp->vc_replies, vmp, vm_chain);
error = EINTR;
CODA_ALLOC(svmp, struct vmsg *, sizeof (struct vmsg));
CODA_ALLOC((svmp->vm_data), char *, sizeof (struct coda_in_hdr));
dog = (struct coda_in_hdr *)svmp->vm_data;
svmp->vm_flags = 0;
dog->opcode = svmp->vm_opcode = CODA_SIGNAL;
dog->unique = svmp->vm_unique = vmp->vm_unique;
svmp->vm_inSize = sizeof (struct coda_in_hdr);
/*??? rvb */ svmp->vm_outSize = sizeof (struct coda_in_hdr);
if (codadebug)
myprintf(("coda_call: enqueing signal msg (%d, %d)\n",
svmp->vm_opcode, svmp->vm_unique));
/* insert at head of queue */
TAILQ_INSERT_HEAD(&vcp->vc_requests, svmp, vm_chain);
selnotify(&(vcp->vc_selproc), 0, 0);
}
}
else { /* If venus died (!VC_OPEN(vcp)) */
if (codadebug)
myprintf(("vcclose woke op %d.%d flags %d\n",
vmp->vm_opcode, vmp->vm_unique, vmp->vm_flags));
error = ENODEV;
}
CODA_FREE(vmp, sizeof(struct vmsg));
if (outstanding_upcalls > 0 && (--outstanding_upcalls == 0))
wakeup(&outstanding_upcalls);
if (!error)
error = ((struct coda_out_hdr *)buffer)->result;
return(error);
}