freebsd-dev/sys/coda/coda_vfsops.c
David Schultz 0e2b18143f Replace the workaround for a deadlock bug in Coda with a different
workaround that does not rely on vfs_start().
2005-02-20 23:01:57 +00:00

530 lines
14 KiB
C

/*-
* 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/cfs/coda_vfsops.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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <coda/coda.h>
#include <coda/cnode.h>
#include <coda/coda_vfsops.h>
#include <coda/coda_venus.h>
#include <coda/coda_subr.h>
#include <coda/coda_opstats.h>
MALLOC_DEFINE(M_CODA, "CODA storage", "Various Coda Structures");
int codadebug = 0;
int coda_vfsop_print_entry = 0;
#define ENTRY if(coda_vfsop_print_entry) myprintf(("Entered %s\n",__func__))
struct vnode *coda_ctlvp;
/* structure to keep statistics of internally generated/satisfied calls */
struct coda_op_stats coda_vfsopstats[CODA_VFSOPS_SIZE];
#define MARK_ENTRY(op) (coda_vfsopstats[op].entries++)
#define MARK_INT_SAT(op) (coda_vfsopstats[op].sat_intrn++)
#define MARK_INT_FAIL(op) (coda_vfsopstats[op].unsat_intrn++)
#define MRAK_INT_GEN(op) (coda_vfsopstats[op].gen_intrn++)
extern int coda_nc_initialized; /* Set if cache has been initialized */
extern int vc_nb_open(struct cdev *, int, int, struct thread *);
int
coda_vfsopstats_init(void)
{
register int i;
for (i=0;i<CODA_VFSOPS_SIZE;i++) {
coda_vfsopstats[i].opcode = i;
coda_vfsopstats[i].entries = 0;
coda_vfsopstats[i].sat_intrn = 0;
coda_vfsopstats[i].unsat_intrn = 0;
coda_vfsopstats[i].gen_intrn = 0;
}
return 0;
}
static const char *coda_opts[] = { "from", NULL };
/*
* cfs mount vfsop
* Set up mount info record and attach it to vfs struct.
*/
/*ARGSUSED*/
int
coda_mount(struct mount *vfsp, struct thread *td)
{
struct vnode *dvp;
struct cnode *cp;
struct cdev *dev;
struct coda_mntinfo *mi;
struct vnode *rootvp;
CodaFid rootfid = INVAL_FID;
CodaFid ctlfid = CTL_FID;
int error;
struct nameidata ndp;
ENTRY;
char *from;
if (vfs_filteropt(vfsp->mnt_optnew, coda_opts))
return (EINVAL);
from = vfs_getopts(vfsp->mnt_optnew, "from", &error);
if (error)
return (error);
coda_vfsopstats_init();
coda_vnodeopstats_init();
MARK_ENTRY(CODA_MOUNT_STATS);
if (CODA_MOUNTED(vfsp)) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
return(EBUSY);
}
/* Validate mount device. Similar to getmdev(). */
NDINIT(&ndp, LOOKUP, FOLLOW, UIO_SYSSPACE, from, td);
error = namei(&ndp);
dvp = ndp.ni_vp;
if (error) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
return (error);
}
if (dvp->v_type != VCHR) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
vrele(dvp);
NDFREE(&ndp, NDF_ONLY_PNBUF);
return(ENXIO);
}
dev = dvp->v_rdev;
vrele(dvp);
NDFREE(&ndp, NDF_ONLY_PNBUF);
/*
* See if the device table matches our expectations.
*/
if (dev->si_devsw->d_open != vc_nb_open)
{
MARK_INT_FAIL(CODA_MOUNT_STATS);
return(ENXIO);
}
/*
* Initialize the mount record and link it to the vfs struct
*/
mi = dev2coda_mntinfo(dev);
if (!VC_OPEN(&mi->mi_vcomm)) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
return(ENODEV);
}
/* No initialization (here) of mi_vcomm! */
vfsp->mnt_data = (qaddr_t)mi;
vfs_getnewfsid (vfsp);
mi->mi_vfsp = vfsp;
mi->mi_started = 0; /* XXX See coda_root() */
/*
* Make a root vnode to placate the Vnode interface, but don't
* actually make the CODA_ROOT call to venus until the first call
* to coda_root in case a server is down while venus is starting.
*/
cp = make_coda_node(&rootfid, vfsp, VDIR);
rootvp = CTOV(cp);
rootvp->v_vflag |= VV_ROOT;
/* cp = make_coda_node(&ctlfid, vfsp, VCHR);
The above code seems to cause a loop in the cnode links.
I don't totally understand when it happens, it is caught
when closing down the system.
*/
cp = make_coda_node(&ctlfid, 0, VCHR);
coda_ctlvp = CTOV(cp);
/* Add vfs and rootvp to chain of vfs hanging off mntinfo */
mi->mi_vfsp = vfsp;
mi->mi_rootvp = rootvp;
vfs_mountedfrom(vfsp, from);
/* error is currently guaranteed to be zero, but in case some
code changes... */
CODADEBUG(1,
myprintf(("coda_omount returned %d\n",error)););
if (error)
MARK_INT_FAIL(CODA_MOUNT_STATS);
else
MARK_INT_SAT(CODA_MOUNT_STATS);
return(error);
}
int
coda_unmount(vfsp, mntflags, td)
struct mount *vfsp;
int mntflags;
struct thread *td;
{
struct coda_mntinfo *mi = vftomi(vfsp);
int active, error = 0;
ENTRY;
MARK_ENTRY(CODA_UMOUNT_STATS);
if (!CODA_MOUNTED(vfsp)) {
MARK_INT_FAIL(CODA_UMOUNT_STATS);
return(EINVAL);
}
if (mi->mi_vfsp == vfsp) { /* We found the victim */
if (!IS_UNMOUNTING(VTOC(mi->mi_rootvp)))
return (EBUSY); /* Venus is still running */
#ifdef DEBUG
printf("coda_unmount: ROOT: vp %p, cp %p\n", mi->mi_rootvp, VTOC(mi->mi_rootvp));
#endif
vrele(mi->mi_rootvp);
active = coda_kill(vfsp, NOT_DOWNCALL);
ASSERT_VOP_LOCKED(mi->mi_rootvp, "coda_unmount");
mi->mi_rootvp->v_vflag &= ~VV_ROOT;
error = vflush(mi->mi_vfsp, 0, FORCECLOSE, td);
#ifdef CODA_VERBOSE
printf("coda_unmount: active = %d, vflush active %d\n", active, error);
#endif
error = 0;
/* I'm going to take this out to allow lookups to go through. I'm
* not sure it's important anyway. -- DCS 2/2/94
*/
/* vfsp->VFS_DATA = NULL; */
/* No more vfsp's to hold onto */
mi->mi_vfsp = NULL;
mi->mi_rootvp = NULL;
if (error)
MARK_INT_FAIL(CODA_UMOUNT_STATS);
else
MARK_INT_SAT(CODA_UMOUNT_STATS);
return(error);
}
return (EINVAL);
}
/*
* find root of cfs
*/
int
coda_root(vfsp, vpp, td)
struct mount *vfsp;
struct vnode **vpp;
struct thread *td;
{
struct coda_mntinfo *mi = vftomi(vfsp);
struct vnode **result;
int error;
struct proc *p = td->td_proc;
CodaFid VFid;
static const CodaFid invalfid = INVAL_FID;
ENTRY;
MARK_ENTRY(CODA_ROOT_STATS);
result = NULL;
if (vfsp == mi->mi_vfsp) {
/*
* Cache the root across calls. We only need to pass the request
* on to Venus if the root vnode is the dummy we installed in
* coda_omount() with all c_fid members zeroed.
*
* XXX In addition, we assume that the first call to coda_root()
* is from vfs_omount()
* (before the call to checkdirs()) and return the dummy root
* node to avoid a deadlock. This bug is fixed in the Coda CVS
* repository but not in any released versions as of 6 Mar 2003.
*/
if (memcmp(&VTOC(mi->mi_rootvp)->c_fid, &invalfid,
sizeof(CodaFid)) != 0 || mi->mi_started == 0)
{ /* Found valid root. */
*vpp = mi->mi_rootvp;
mi->mi_started = 1;
/* On Mach, this is vref. On NetBSD, VOP_LOCK */
#if 1
vref(*vpp);
vn_lock(*vpp, LK_EXCLUSIVE, td);
#else
vget(*vpp, LK_EXCLUSIVE, td);
#endif
MARK_INT_SAT(CODA_ROOT_STATS);
return(0);
}
}
error = venus_root(vftomi(vfsp), td->td_ucred, p, &VFid);
if (!error) {
/*
* Save the new rootfid in the cnode, and rehash the cnode into the
* cnode hash with the new fid key.
*/
coda_unsave(VTOC(mi->mi_rootvp));
VTOC(mi->mi_rootvp)->c_fid = VFid;
coda_save(VTOC(mi->mi_rootvp));
*vpp = mi->mi_rootvp;
#if 1
vref(*vpp);
vn_lock(*vpp, LK_EXCLUSIVE, td);
#else
vget(*vpp, LK_EXCLUSIVE, td);
#endif
MARK_INT_SAT(CODA_ROOT_STATS);
goto exit;
} else if (error == ENODEV || error == EINTR) {
/* Gross hack here! */
/*
* If Venus fails to respond to the CODA_ROOT call, coda_call returns
* ENODEV. Return the uninitialized root vnode to allow vfs
* operations such as unmount to continue. Without this hack,
* there is no way to do an unmount if Venus dies before a
* successful CODA_ROOT call is done. All vnode operations
* will fail.
*/
*vpp = mi->mi_rootvp;
#if 1
vref(*vpp);
vn_lock(*vpp, LK_EXCLUSIVE, td);
#else
vget(*vpp, LK_EXCLUSIVE, td);
#endif
MARK_INT_FAIL(CODA_ROOT_STATS);
error = 0;
goto exit;
} else {
CODADEBUG( CODA_ROOT, myprintf(("error %d in CODA_ROOT\n", error)); );
MARK_INT_FAIL(CODA_ROOT_STATS);
goto exit;
}
exit:
return(error);
}
/*
* Get filesystem statistics.
*/
int
coda_nb_statfs(vfsp, sbp, td)
register struct mount *vfsp;
struct statfs *sbp;
struct thread *td;
{
ENTRY;
/* MARK_ENTRY(CODA_STATFS_STATS); */
if (!CODA_MOUNTED(vfsp)) {
/* MARK_INT_FAIL(CODA_STATFS_STATS);*/
return(EINVAL);
}
bzero(sbp, sizeof(struct statfs));
/* XXX - what to do about f_flags, others? --bnoble */
/* Below This is what AFS does
#define NB_SFS_SIZ 0x895440
*/
/* Note: Normal fs's have a bsize of 0x400 == 1024 */
sbp->f_type = vfsp->mnt_vfc->vfc_typenum;
sbp->f_bsize = 8192; /* XXX */
sbp->f_iosize = 8192; /* XXX */
#define NB_SFS_SIZ 0x8AB75D
sbp->f_blocks = NB_SFS_SIZ;
sbp->f_bfree = NB_SFS_SIZ;
sbp->f_bavail = NB_SFS_SIZ;
sbp->f_files = NB_SFS_SIZ;
sbp->f_ffree = NB_SFS_SIZ;
bcopy((caddr_t)&(vfsp->mnt_stat.f_fsid), (caddr_t)&(sbp->f_fsid), sizeof (fsid_t));
snprintf(sbp->f_mntonname, sizeof(sbp->f_mntonname), "/coda");
snprintf(sbp->f_fstypename, sizeof(sbp->f_fstypename), "coda");
/* MARK_INT_SAT(CODA_STATFS_STATS); */
return(0);
}
/*
* Flush any pending I/O.
*/
int
coda_sync(vfsp, waitfor, td)
struct mount *vfsp;
int waitfor;
struct thread *td;
{
ENTRY;
MARK_ENTRY(CODA_SYNC_STATS);
MARK_INT_SAT(CODA_SYNC_STATS);
return(0);
}
/*
* fhtovp is now what vget used to be in 4.3-derived systems. For
* some silly reason, vget is now keyed by a 32 bit ino_t, rather than
* a type-specific fid.
*/
int
coda_fhtovp(vfsp, fhp, nam, vpp, exflagsp, creadanonp)
register struct mount *vfsp;
struct fid *fhp;
struct mbuf *nam;
struct vnode **vpp;
int *exflagsp;
struct ucred **creadanonp;
{
struct cfid *cfid = (struct cfid *)fhp;
struct cnode *cp = 0;
int error;
struct thread *td = curthread; /* XXX -mach */
struct proc *p = td->td_proc;
CodaFid VFid;
int vtype;
ENTRY;
MARK_ENTRY(CODA_VGET_STATS);
/* Check for vget of control object. */
if (IS_CTL_FID(&cfid->cfid_fid)) {
*vpp = coda_ctlvp;
vref(coda_ctlvp);
MARK_INT_SAT(CODA_VGET_STATS);
return(0);
}
error = venus_fhtovp(vftomi(vfsp), &cfid->cfid_fid, td->td_ucred, p, &VFid, &vtype);
if (error) {
CODADEBUG(CODA_VGET, myprintf(("vget error %d\n",error));)
*vpp = (struct vnode *)0;
} else {
CODADEBUG(CODA_VGET,
myprintf(("vget: %s type %d result %d\n",
coda_f2s(&VFid), vtype, error)); )
cp = make_coda_node(&VFid, vfsp, vtype);
*vpp = CTOV(cp);
}
return(error);
}
/*
* To allow for greater ease of use, some vnodes may be orphaned when
* Venus dies. Certain operations should still be allowed to go
* through, but without propagating ophan-ness. So this function will
* get a new vnode for the file from the current run of Venus. */
int
getNewVnode(vpp)
struct vnode **vpp;
{
struct cfid cfid;
struct coda_mntinfo *mi = vftomi((*vpp)->v_mount);
ENTRY;
cfid.cfid_len = (short)sizeof(CodaFid);
cfid.cfid_fid = VTOC(*vpp)->c_fid; /* Structure assignment. */
/* XXX ? */
/* We're guessing that if set, the 1st element on the list is a
* valid vnode to use. If not, return ENODEV as venus is dead.
*/
if (mi->mi_vfsp == NULL)
return ENODEV;
return coda_fhtovp(mi->mi_vfsp, (struct fid*)&cfid, NULL, vpp,
NULL, NULL);
}
#include <ufs/ufs/extattr.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufsmount.h>
/* get the mount structure corresponding to a given device. Assume
* device corresponds to a UFS. Return NULL if no device is found.
*/
struct mount *devtomp(dev)
struct cdev *dev;
{
struct mount *mp;
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
if (((VFSTOUFS(mp))->um_dev == dev)) {
/* mount corresponds to UFS and the device matches one we want */
return(mp);
}
}
/* mount structure wasn't found */
return(NULL);
}
struct vfsops coda_vfsops = {
.vfs_mount = coda_mount,
.vfs_root = coda_root,
.vfs_statfs = coda_nb_statfs,
.vfs_sync = coda_sync,
.vfs_unmount = coda_unmount,
};
VFS_SET(coda_vfsops, coda, VFCF_NETWORK);