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freebsd-dev/sys/coda/coda_psdev.c

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/*-
* 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.
*
* @(#) src/sys/coda/coda_psdev.c,v 1.1.1.1 1998/08/29 21:14:52 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 filesystem at Carnegie Mellon
* University. Contributers include David Steere, James Kistler, and
* M. Satyanarayanan. */
/*
* These routines define the psuedo 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
*/
/* These routines are the device entry points for Venus. */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
extern int coda_nc_initialized; /* Set if cache has been initialized */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioccom.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/file.h> /* must come after sys/malloc.h */
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <coda/coda.h>
#include <coda/cnode.h>
#include <coda/coda_namecache.h>
#include <coda/coda_io.h>
#include <coda/coda_psdev.h>
#define CTL_C
#ifdef CTL_C
#include <sys/signalvar.h>
#endif
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);
struct vmsg {
struct queue vm_chain;
caddr_t 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;
caddr_t vm_sleep; /* Not used by Mach. */
};
#define VM_READ 1
#define VM_WRITE 2
#define VM_INTR 4
/* vcodaattach: do nothing */
void
vcodaattach(n)
int n;
{
}
int
vc_nb_open(dev, flag, mode, td)
struct cdev *dev;
int flag;
int mode;
struct thread *td; /* NetBSD only */
{
struct vcomm *vcp;
struct coda_mntinfo *mnt;
ENTRY;
if (!coda_nc_initialized)
coda_nc_init();
mnt = dev2coda_mntinfo(dev);
vcp = &mnt->mi_vcomm;
if (VC_OPEN(vcp))
return(EBUSY);
bzero(&(vcp->vc_selproc), sizeof (struct selinfo));
INIT_QUEUE(vcp->vc_requests);
INIT_QUEUE(vcp->vc_replys);
MARK_VC_OPEN(vcp);
mnt->mi_vfsp = NULL;
mnt->mi_rootvp = NULL;
return(0);
}
int
vc_nb_close (dev, flag, mode, td)
struct cdev *dev;
int flag;
int mode;
struct thread *td;
{
register struct vcomm *vcp;
register struct vmsg *vmp, *nvmp = NULL;
struct coda_mntinfo *mi;
int err;
ENTRY;
mi = dev2coda_mntinfo(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 */
VTOC(mi->mi_rootvp)->c_flags |= C_UNMOUNTING;
coda_unmounting(mi->mi_vfsp);
outstanding_upcalls = 0;
/* Wakeup clients so they can return. */
for (vmp = (struct vmsg *)GETNEXT(vcp->vc_requests);
!EOQ(vmp, vcp->vc_requests);
vmp = nvmp)
{
nvmp = (struct vmsg *)GETNEXT(vmp->vm_chain);
/* Free signal request messages and don't wakeup cause
no one is waiting. */
if (vmp->vm_opcode == CODA_SIGNAL) {
CODA_FREE((caddr_t)vmp->vm_data, (u_int)VC_IN_NO_DATA);
CODA_FREE((caddr_t)vmp, (u_int)sizeof(struct vmsg));
continue;
}
outstanding_upcalls++;
wakeup(&vmp->vm_sleep);
}
for (vmp = (struct vmsg *)GETNEXT(vcp->vc_replys);
!EOQ(vmp, vcp->vc_replys);
vmp = (struct vmsg *)GETNEXT(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, td);
if (err)
myprintf(("Error %d unmounting vfs in vcclose(%d)\n",
err, minor(dev)));
return 0;
}
int
vc_nb_read(dev, uiop, flag)
struct cdev *dev;
struct uio *uiop;
int flag;
{
register struct vcomm * vcp;
register struct vmsg *vmp;
int error = 0;
ENTRY;
vcp = &dev2coda_mntinfo(dev)->mi_vcomm;
/* Get message at head of request queue. */
if (EMPTY(vcp->vc_requests))
return(0); /* Nothing to read */
vmp = (struct vmsg *)GETNEXT(vcp->vc_requests);
/* 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;
}
#ifdef OLD_DIAGNOSTIC
if (vmp->vm_chain.forw == 0 || vmp->vm_chain.back == 0)
panic("vc_nb_read: bad chain");
#endif
REMQUE(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((caddr_t)vmp->vm_data, (u_int)VC_IN_NO_DATA);
CODA_FREE((caddr_t)vmp, (u_int)sizeof(struct vmsg));
return(error);
}
vmp->vm_flags |= VM_READ;
INSQUE(vmp->vm_chain, vcp->vc_replys);
return(error);
}
int
vc_nb_write(dev, uiop, flag)
struct cdev *dev;
struct uio *uiop;
int flag;
{
register struct vcomm * vcp;
register struct vmsg *vmp;
struct coda_out_hdr *out;
u_long seq;
u_long opcode;
int buf[2];
int error = 0;
ENTRY;
vcp = &dev2coda_mntinfo(dev)->mi_vcomm;
/* Peek at the opcode, unique without transfering the data. */
uiop->uio_rw = UIO_WRITE;
error = uiomove((caddr_t)buf, sizeof(int) * 2, uiop);
if (error) {
myprintf(("vcwrite: error (%d) on uiomove\n", error));
return(EINVAL);
}
opcode = buf[0];
seq = buf[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((caddr_t)&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. */
for (vmp = (struct vmsg *)GETNEXT(vcp->vc_replys);
!EOQ(vmp, vcp->vc_replys);
vmp = (struct vmsg *)GETNEXT(vmp->vm_chain))
{
if (vmp->vm_unique == seq) break;
}
if (EOQ(vmp, vcp->vc_replys)) {
if (codadebug)
myprintf(("vcwrite: msg (%ld, %ld) not found\n", opcode, seq));
return(ESRCH);
}
/* Remove the message from the reply queue */
REMQUE(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 < %d)\n",
vmp->vm_outSize, uiop->uio_resid));
wakeup(&vmp->vm_sleep); /* Notify caller of the error. */
return(EINVAL);
}
buf[0] = uiop->uio_resid; /* Save this value. */
uiop->uio_rw = UIO_WRITE;
error = uiomove((caddr_t) &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 = buf[0]; /* Amount of data transferred? */
vmp->vm_flags |= VM_WRITE;
wakeup(&vmp->vm_sleep);
return(0);
}
int
vc_nb_ioctl(dev, cmd, addr, flag, td)
struct cdev *dev;
u_long cmd;
caddr_t addr;
int flag;
struct thread *td;
{
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, events, td)
struct cdev *dev;
int events;
struct thread *td;
{
register struct vcomm *vcp;
int event_msk = 0;
ENTRY;
vcp = &dev2coda_mntinfo(dev)->mi_vcomm;
event_msk = events & (POLLIN|POLLRDNORM);
if (!event_msk)
return(0);
if (!EMPTY(vcp->vc_requests))
return(events & (POLLIN|POLLRDNORM));
selrecord(td, &(vcp->vc_selproc));
return(0);
}
/*
* Statistics
*/
struct coda_clstat coda_clstat;
/*
* Key question: whether to sleep interuptably or uninteruptably 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(mntinfo, inSize, outSize, buffer)
struct coda_mntinfo *mntinfo; int inSize; int *outSize; caddr_t buffer;
{
struct vcomm *vcp;
struct vmsg *vmp;
int error;
#ifdef CTL_C
struct thread *td = curthread;
struct proc *p = td->td_proc;
sigset_t psig_omask;
sigset_t tempset;
int i;
#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. */
INSQUE(vmp->vm_chain, vcp->vc_requests);
selwakeuppri(&(vcp->vc_selproc), coda_call_sleep);
/* 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;
PROC_LOCK(p);
psig_omask = td->td_sigmask;
do {
error = msleep(&vmp->vm_sleep, &p->p_mtx,
(coda_call_sleep|coda_pcatch), "coda_call",
hz*2);
if (error == 0)
break;
else if (error == EWOULDBLOCK) {
#ifdef CODA_VERBOSE
printf("coda_call: tsleep TIMEOUT %d sec\n", 2+2*i);
#endif
}
else {
SIGEMPTYSET(tempset);
SIGADDSET(tempset, SIGIO);
if (SIGSETEQ(td->td_siglist, tempset)) {
SIGADDSET(td->td_sigmask, SIGIO);
#ifdef CODA_VERBOSE
printf("coda_call: tsleep returns %d SIGIO, cnt %d\n",
error, i);
#endif
} else {
SIGDELSET(tempset, SIGIO);
SIGADDSET(tempset, SIGALRM);
if (SIGSETEQ(td->td_siglist, tempset)) {
SIGADDSET(td->td_sigmask, SIGALRM);
#ifdef CODA_VERBOSE
printf("coda_call: tsleep returns %d SIGALRM, cnt %d\n",
error, i);
#endif
}
else {
#ifdef CODA_VERBOSE
printf("coda_call: tsleep returns %d, cnt %d\n",
error, i);
#endif
#if notyet
tempset = td->td_siglist;
SIGSETNAND(tempset, td->td_sigmask);
printf("coda_call: siglist = %p, sigmask = %p, mask %p\n",
td->td_siglist, td->td_sigmask,
tempset);
break;
SIGSETOR(td->td_sigmask, td->td_siglist);
tempset = td->td_siglist;
SIGSETNAND(tempset, td->td_sigmask);
printf("coda_call: new mask, siglist = %p, sigmask = %p, mask %p\n",
td->td_siglist, td->td_sigmask,
tempset);
#endif
}
}
}
} while (error && i++ < 128 && VC_OPEN(vcp));
td->td_sigmask = psig_omask;
signotify(td);
PROC_UNLOCK(p);
#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));
REMQUE(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));
REMQUE(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! */
INSQUE(svmp->vm_chain, vcp->vc_requests);
selwakeuppri(&(vcp->vc_selproc), coda_call_sleep);
}
}
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);
}
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