NetBSD/sys/coda/coda_vfsops.c
christos 020a6ad2d4 - move debugging functions to vcoda so modules with -DDEBUG link
- fix writing to coda files. this is probably not the right way to do
  this, but it satisfies the locking protocol:
	1. Sometimes coda_open() is called with an unlocked vnode which
	   does not satisfy the locking protocol. Lock it for now. We
	   need to find out why this happens
	2. VFS_VGET sometimes returns the container vnode unlocked. What
	   is the locking protocol for VFS_VGET? We also lock it here.
2012-08-02 16:06:58 +00:00

629 lines
16 KiB
C

/* $NetBSD: coda_vfsops.c,v 1.74 2012/08/02 16:06:58 christos 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.
*
* @(#) cfs/coda_vfsops.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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: coda_vfsops.c,v 1.74 2012/08/02 16:06:58 christos Exp $");
#ifndef _KERNEL_OPT
#define NVCODA 4
#else
#include <vcoda.h>
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/conf.h>
#include <sys/namei.h>
#include <sys/dirent.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/select.h>
#include <sys/kauth.h>
#include <sys/module.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>
/* for VN_RDEV */
#include <miscfs/specfs/specdev.h>
#include <miscfs/genfs/genfs.h>
MODULE(MODULE_CLASS_VFS, coda, "vcoda");
#define ENTRY if(coda_vfsop_print_entry) myprintf(("Entered %s\n",__func__))
extern struct vnode *coda_ctlvp;
extern struct coda_mntinfo coda_mnttbl[NVCODA]; /* indexed by minor device number */
/* 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 const struct cdevsw vcoda_cdevsw;
extern const struct vnodeopv_desc coda_vnodeop_opv_desc;
const struct vnodeopv_desc * const coda_vnodeopv_descs[] = {
&coda_vnodeop_opv_desc,
NULL,
};
struct vfsops coda_vfsops = {
MOUNT_CODA,
256, /* This is the pathname, unlike every other fs */
coda_mount,
coda_start,
coda_unmount,
coda_root,
(void *)eopnotsupp, /* vfs_quotactl */
coda_nb_statvfs,
coda_sync,
coda_vget,
(void *)eopnotsupp, /* vfs_fhtovp */
(void *)eopnotsupp, /* vfs_vptofh */
coda_init,
NULL, /* vfs_reinit */
coda_done,
(int (*)(void)) eopnotsupp,
(int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
vfs_stdextattrctl,
(void *)eopnotsupp, /* vfs_suspendctl */
genfs_renamelock_enter,
genfs_renamelock_exit,
(void *)eopnotsupp,
coda_vnodeopv_descs,
0, /* vfs_refcount */
{ NULL, NULL }, /* vfs_list */
};
static int
coda_modcmd(modcmd_t cmd, void *arg)
{
switch (cmd) {
case MODULE_CMD_INIT:
return vfs_attach(&coda_vfsops);
case MODULE_CMD_FINI:
return vfs_detach(&coda_vfsops);
default:
return ENOTTY;
}
}
int
coda_vfsopstats_init(void)
{
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;
}
/*
* cfs mount vfsop
* Set up mount info record and attach it to vfs struct.
*/
/*ARGSUSED*/
int
coda_mount(struct mount *vfsp, /* Allocated and initialized by mount(2) */
const char *path, /* path covered: ignored by the fs-layer */
void *data, /* Need to define a data type for this in netbsd? */
size_t *data_len)
{
struct lwp *l = curlwp;
struct vnode *dvp;
struct cnode *cp;
dev_t dev;
struct coda_mntinfo *mi;
struct vnode *rtvp;
const struct cdevsw *cdev;
CodaFid rootfid = INVAL_FID;
CodaFid ctlfid = CTL_FID;
int error;
if (vfsp->mnt_flag & MNT_GETARGS)
return EINVAL;
ENTRY;
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(). */
/*
* XXX: coda passes the mount device as the entire mount args,
* All other fs pass a structure contining a pointer.
* In order to get sys_mount() to do the copyin() we've set a
* fixed default size for the filename buffer.
*/
/* Ensure that namei() doesn't run off the filename buffer */
((char *)data)[*data_len - 1] = 0;
error = namei_simple_kernel((char *)data, NSM_FOLLOW_NOEMULROOT,
&dvp);
if (error) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
return (error);
}
if (dvp->v_type != VCHR) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
vrele(dvp);
return(ENXIO);
}
dev = dvp->v_rdev;
vrele(dvp);
cdev = cdevsw_lookup(dev);
if (cdev == NULL) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
return(ENXIO);
}
/*
* See if the device table matches our expectations.
*/
if (cdev != &vcoda_cdevsw)
{
MARK_INT_FAIL(CODA_MOUNT_STATS);
return(ENXIO);
}
if (minor(dev) >= NVCODA) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
return(ENXIO);
}
/*
* Initialize the mount record and link it to the vfs struct
*/
mi = &coda_mnttbl[minor(dev)];
if (!VC_OPEN(&mi->mi_vcomm)) {
MARK_INT_FAIL(CODA_MOUNT_STATS);
return(ENODEV);
}
/* No initialization (here) of mi_vcomm! */
vfsp->mnt_data = mi;
vfsp->mnt_stat.f_fsidx.__fsid_val[0] = 0;
vfsp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_CODA);
vfsp->mnt_stat.f_fsid = vfsp->mnt_stat.f_fsidx.__fsid_val[0];
vfsp->mnt_stat.f_namemax = CODA_MAXNAMLEN;
mi->mi_vfsp = vfsp;
/*
* 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);
rtvp = CTOV(cp);
rtvp->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 = rtvp;
/* set filesystem block size */
vfsp->mnt_stat.f_bsize = 8192; /* XXX -JJK */
vfsp->mnt_stat.f_frsize = 8192; /* XXX -JJK */
/* error is currently guaranteed to be zero, but in case some
code changes... */
CODADEBUG(1,
myprintf(("coda_mount returned %d\n",error)););
if (error)
MARK_INT_FAIL(CODA_MOUNT_STATS);
else
MARK_INT_SAT(CODA_MOUNT_STATS);
return set_statvfs_info("/coda", UIO_SYSSPACE, "CODA", UIO_SYSSPACE,
vfsp->mnt_op->vfs_name, vfsp, l);
}
int
coda_start(struct mount *vfsp, int flags)
{
ENTRY;
vftomi(vfsp)->mi_started = 1;
return (0);
}
int
coda_unmount(struct mount *vfsp, int mntflags)
{
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
mi->mi_started = 0;
vrele(mi->mi_rootvp);
active = coda_kill(vfsp, NOT_DOWNCALL);
mi->mi_rootvp->v_vflag &= ~VV_ROOT;
error = vflush(mi->mi_vfsp, NULLVP, FORCECLOSE);
printf("coda_unmount: active = %d, vflush active %d\n", active, error);
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(struct mount *vfsp, struct vnode **vpp)
{
struct coda_mntinfo *mi = vftomi(vfsp);
int error;
struct lwp *l = curlwp; /* XXX - bnoble */
CodaFid VFid;
static const CodaFid invalfid = INVAL_FID;
ENTRY;
MARK_ENTRY(CODA_ROOT_STATS);
if (vfsp == mi->mi_vfsp) {
if (memcmp(&VTOC(mi->mi_rootvp)->c_fid, &invalfid, sizeof(CodaFid)))
{ /* Found valid root. */
*vpp = mi->mi_rootvp;
/* On Mach, this is vref. On NetBSD, VOP_LOCK */
vref(*vpp);
vn_lock(*vpp, LK_EXCLUSIVE);
MARK_INT_SAT(CODA_ROOT_STATS);
return(0);
}
}
error = venus_root(vftomi(vfsp), l->l_cred, l->l_proc, &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;
vref(*vpp);
vn_lock(*vpp, LK_EXCLUSIVE);
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;
vref(*vpp);
vn_lock(*vpp, LK_EXCLUSIVE);
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 file system statistics.
*/
int
coda_nb_statvfs(struct mount *vfsp, struct statvfs *sbp)
{
struct lwp *l = curlwp;
struct coda_statfs fsstat;
int error;
ENTRY;
MARK_ENTRY(CODA_STATFS_STATS);
if (!CODA_MOUNTED(vfsp)) {
/* MARK_INT_FAIL(CODA_STATFS_STATS); */
return(EINVAL);
}
/* 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 */
error = venus_statfs(vftomi(vfsp), l->l_cred, l, &fsstat);
if (!error) {
sbp->f_bsize = 8192; /* XXX */
sbp->f_frsize = 8192; /* XXX */
sbp->f_iosize = 8192; /* XXX */
sbp->f_blocks = fsstat.f_blocks;
sbp->f_bfree = fsstat.f_bfree;
sbp->f_bavail = fsstat.f_bavail;
sbp->f_bresvd = 0;
sbp->f_files = fsstat.f_files;
sbp->f_ffree = fsstat.f_ffree;
sbp->f_favail = fsstat.f_ffree;
sbp->f_fresvd = 0;
copy_statvfs_info(sbp, vfsp);
}
MARK_INT_SAT(CODA_STATFS_STATS);
return(error);
}
/*
* Flush any pending I/O.
*/
int
coda_sync(struct mount *vfsp, int waitfor,
kauth_cred_t cred)
{
ENTRY;
MARK_ENTRY(CODA_SYNC_STATS);
MARK_INT_SAT(CODA_SYNC_STATS);
return(0);
}
int
coda_vget(struct mount *vfsp, ino_t ino,
struct vnode **vpp)
{
ENTRY;
return (EOPNOTSUPP);
}
/*
* 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(struct mount *vfsp, struct fid *fhp, struct mbuf *nam,
struct vnode **vpp, int *exflagsp,
kauth_cred_t *creadanonp)
{
struct cfid *cfid = (struct cfid *)fhp;
struct cnode *cp = 0;
int error;
struct lwp *l = curlwp; /* XXX -mach */
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, l->l_cred, l->l_proc, &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);
}
int
coda_vptofh(struct vnode *vnp, struct fid *fidp)
{
ENTRY;
return (EOPNOTSUPP);
}
void
coda_init(void)
{
ENTRY;
}
void
coda_done(void)
{
ENTRY;
}
SYSCTL_SETUP(sysctl_vfs_coda_setup, "sysctl vfs.coda subtree setup")
{
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "vfs", NULL,
NULL, 0, NULL, 0,
CTL_VFS, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "coda",
SYSCTL_DESCR("code vfs options"),
NULL, 0, NULL, 0,
CTL_VFS, 18, CTL_EOL);
/*
* XXX the "18" above could be dynamic, thereby eliminating
* one more instance of the "number to vfs" mapping problem,
* but "18" is the order as taken from sys/mount.h
*/
/*
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_INT, "clusterread",
SYSCTL_DESCR( anyone? ),
NULL, 0, &doclusterread, 0,
CTL_VFS, 18, FFS_CLUSTERREAD, CTL_EOL);
*/
}
/*
* 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 orphan-ness. So this function will
* get a new vnode for the file from the current run of Venus.
*/
int
getNewVnode(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/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_t dev)
{
struct mount *mp, *nmp;
for (mp = mountlist.cqh_first; mp != (void*)&mountlist; mp = nmp) {
nmp = mp->mnt_list.cqe_next;
if ((!strcmp(mp->mnt_op->vfs_name, MOUNT_UFS)) &&
((VFSTOUFS(mp))->um_dev == (dev_t) dev)) {
/* mount corresponds to UFS and the device matches one we want */
return(mp);
}
}
/* mount structure wasn't found */
return(NULL);
}