| Current Path : /sys/fs/coda/ |
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| Current File : //sys/fs/coda/coda_subr.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/coda/coda_subr.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.
*/
/*-
* NOTES: rvb
* 1. Added coda_unmounting to mark all cnodes as being UNMOUNTING. This
* has to be done before dounmount is called. Because some of the
* routines that dounmount calls before coda_unmounted might try to
* force flushes to venus. The vnode pager does this.
* 2. coda_unmounting marks all cnodes scanning coda_cache.
* 3. cfs_checkunmounting (under DEBUG) checks all cnodes by chasing the
* vnodes under the /coda mount point.
* 4. coda_cacheprint (under DEBUG) prints names with vnode/cnode address.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/fs/coda/coda_subr.c 235626 2012-05-18 19:48:38Z mckusick $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mount.h>
#include <fs/coda/coda.h>
#include <fs/coda/cnode.h>
#include <fs/coda/coda_subr.h>
static int coda_active = 0;
static int coda_reuse = 0;
static int coda_new = 0;
static struct cnode *coda_freelist = NULL;
static struct cnode *coda_cache[CODA_CACHESIZE];
#define CNODE_NEXT(cp) ((cp)->c_next)
#ifdef CODA_COMPAT_5
#define coda_hash(fid) (((fid)->Volume + (fid)->Vnode) & (CODA_CACHESIZE-1))
#define IS_DIR(cnode) (cnode.Vnode & 0x1)
#else
#define coda_hash(fid) (coda_f2i(fid) & (CODA_CACHESIZE-1))
#define IS_DIR(cnode) (cnode.opaque[2] & 0x1)
#endif
/*
* Allocate a cnode.
*/
struct cnode *
coda_alloc(void)
{
struct cnode *cp;
if (coda_freelist != NULL) {
cp = coda_freelist;
coda_freelist = CNODE_NEXT(cp);
coda_reuse++;
} else {
CODA_ALLOC(cp, struct cnode *, sizeof(struct cnode));
/*
* FreeBSD vnodes don't have any Pager info in them ('cause
* there are no external pagers, duh!).
*/
#define VNODE_VM_INFO_INIT(vp) /* MT */
VNODE_VM_INFO_INIT(CTOV(cp));
coda_new++;
}
bzero(cp, sizeof (struct cnode));
return (cp);
}
/*
* Deallocate a cnode.
*/
void
coda_free(struct cnode *cp)
{
CNODE_NEXT(cp) = coda_freelist;
coda_freelist = cp;
}
/*
* Put a cnode in the hash table.
*/
void
coda_save(struct cnode *cp)
{
CNODE_NEXT(cp) = coda_cache[coda_hash(&cp->c_fid)];
coda_cache[coda_hash(&cp->c_fid)] = cp;
}
/*
* Remove a cnode from the hash table.
*/
void
coda_unsave(struct cnode *cp)
{
struct cnode *ptr;
struct cnode *ptrprev = NULL;
ptr = coda_cache[coda_hash(&cp->c_fid)];
while (ptr != NULL) {
if (ptr == cp) {
if (ptrprev == NULL)
coda_cache[coda_hash(&cp->c_fid)] =
CNODE_NEXT(ptr);
else
CNODE_NEXT(ptrprev) = CNODE_NEXT(ptr);
CNODE_NEXT(cp) = (struct cnode *)NULL;
return;
}
ptrprev = ptr;
ptr = CNODE_NEXT(ptr);
}
}
/*
* Lookup a cnode by fid. If the cnode is dying, it is bogus so skip it.
*
* NOTE: this allows multiple cnodes with same fid -- dcs 1/25/95
*/
struct cnode *
coda_find(struct CodaFid *fid)
{
struct cnode *cp;
cp = coda_cache[coda_hash(fid)];
while (cp) {
if (coda_fid_eq(&(cp->c_fid), fid) && (!IS_UNMOUNTING(cp))) {
coda_active++;
return (cp);
}
cp = CNODE_NEXT(cp);
}
return (NULL);
}
/*
* Clear all cached access control decisions from Coda.
*/
static void
coda_acccache_purge(struct mount *mnt)
{
struct cnode *cp;
int hash;
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL;
cp = CNODE_NEXT(cp)) {
if (CTOV(cp)->v_mount == mnt && VALID_ACCCACHE(cp)) {
CODADEBUG(CODA_FLUSH, myprintf(("acccache "
"purge fid %s uid %d mode 0x%x\n",
coda_f2s(&cp->c_fid), cp->c_cached_uid,
(int)cp->c_cached_mode)););
cp->c_flags &= ~C_ACCCACHE;
}
}
}
}
/*
* When a user loses their tokens (or other related events), we invalidate
* any cached access rights in the access cache. In the Linux version of
* Coda, we maintain a global epoch and simply bump it to invalidate all
* cached results generated in the epoch. For now, we walk all cnodes and
* manually invalidate just that uid in FreeBSD.
*/
static void
coda_acccache_purgeuser(struct mount *mnt, uid_t uid)
{
struct cnode *cp;
int hash;
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL;
cp = CNODE_NEXT(cp)) {
if (CTOV(cp)->v_mount == mnt &&
VALID_ACCCACHE(cp) && (cp->c_cached_uid == uid)) {
CODADEBUG(CODA_PURGEUSER, myprintf((
"acccache purgeuser fid %s uid %d mode "
"0x%x\n", coda_f2s(&cp->c_fid),
cp->c_cached_uid, (int)cp->c_cached_mode)););
cp->c_flags &= ~C_ACCCACHE;
}
}
}
}
/*
* coda_kill is called as a side effect to vcopen. To prevent any cnodes
* left around from an earlier run of a venus or warden from causing problems
* with the new instance, mark any outstanding cnodes as dying. Future
* operations on these cnodes should fail (excepting coda_inactive of
* course!). Since multiple venii/wardens can be running, only kill the
* cnodes for a particular entry in the coda_mnttbl. -- DCS 12/1/94
*
* XXX: I don't believe any special behavior is required with respect to the
* global namecache here, as /coda will have unmounted and hence cache_flush
* will have run...?
*/
int
coda_kill(struct mount *whoIam, enum dc_status dcstat)
{
int hash, count = 0;
struct cnode *cp;
/*-
* Algorithm is as follows:
* Second, flush whatever vnodes we can from the name cache.
*
* Finally, step through whatever is left and mark them dying.
* This prevents any operation at all.
*
* This is slightly overkill, but should work. Eventually it'd be
* nice to only flush those entries from the namecache that reference
* a vnode in this vfs.
*
* XXXRW: Perhaps we no longer need to purge the name cache when
* using the VFS name cache, as unmount will do that.
*/
cache_purgevfs(whoIam);
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash];cp != NULL;
cp = CNODE_NEXT(cp)) {
if (CTOV(cp)->v_mount == whoIam) {
#ifdef DEBUG
printf("coda_kill: vp %p, cp %p\n", CTOV(cp),
cp);
#endif
count++;
CODADEBUG(CODA_FLUSH, myprintf(("Live cnode "
"fid %s flags %d count %d\n",
coda_f2s(&cp->c_fid), cp->c_flags,
vrefcnt(CTOV(cp)))););
}
}
}
return (count);
}
/*
* There are two reasons why a cnode may be in use, it may be in the name
* cache or it may be executing.
*/
void
coda_flush(struct coda_mntinfo *mnt, enum dc_status dcstat)
{
int hash;
struct cnode *cp;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_FLUSH]++;
coda_acccache_purge(mnt->mi_vfsp);
cache_purgevfs(mnt->mi_vfsp);
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL;
cp = CNODE_NEXT(cp)) {
/*
* Only files that can be executed need to be flushed
* from the VM.
*
* NOTE: Currently this doesn't do anything, but
* perhaps it should?
*/
if (!IS_DIR(cp->c_fid))
coda_vmflush(cp);
}
}
}
/*
* As a debugging measure, print out any cnodes that lived through a name
* cache flush.
*/
void
coda_testflush(void)
{
int hash;
struct cnode *cp;
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL;
cp = CNODE_NEXT(cp))
myprintf(("Live cnode fid %s count %d\n",
coda_f2s(&cp->c_fid), CTOV(cp)->v_usecount));
}
}
/*
* First, step through all cnodes and mark them unmounting. FreeBSD kernels
* may try to fsync them now that venus is dead, which would be a bad thing.
*/
void
coda_unmounting(struct mount *whoIam)
{
int hash;
struct cnode *cp;
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL;
cp = CNODE_NEXT(cp)) {
if (CTOV(cp)->v_mount == whoIam) {
if (cp->c_flags & (C_LOCKED|C_WANTED)) {
printf("coda_unmounting: Unlocking "
"%p\n", cp);
cp->c_flags &= ~(C_LOCKED|C_WANTED);
wakeup((caddr_t) cp);
}
cp->c_flags |= C_UNMOUNTING;
}
}
}
}
#ifdef DEBUG
void
coda_checkunmounting(struct mount *mp)
{
struct vnode *vp, *nvp;
struct cnode *cp;
int count = 0, bad = 0;
MNT_VNODE_FOREACH_ALL(vp, mp, nvp) {
cp = VTOC(vp);
count++;
if (!(cp->c_flags & C_UNMOUNTING)) {
bad++;
printf("vp %p, cp %p missed\n", vp, cp);
cp->c_flags |= C_UNMOUNTING;
}
VI_UNLOCK(vp);
}
}
void
coda_cacheprint(struct mount *whoIam)
{
int hash;
struct cnode *cp;
int count = 0;
printf("coda_cacheprint: coda_ctlvp %p, cp %p", coda_ctlvp,
VTOC(coda_ctlvp));
#if 0
coda_nc_name(VTOC(coda_ctlvp));
#endif
printf("\n");
for (hash = 0; hash < CODA_CACHESIZE; hash++) {
for (cp = coda_cache[hash]; cp != NULL;
cp = CNODE_NEXT(cp)) {
if (CTOV(cp)->v_mount == whoIam) {
printf("coda_cacheprint: vp %p, cp %p",
CTOV(cp), cp);
#if 0
coda_nc_name(cp);
#endif
printf("\n");
count++;
}
}
}
printf("coda_cacheprint: count %d\n", count);
}
#endif
/*-
* There are 6 cases where invalidations occur. The semantics of each is
* listed here:
*
* CODA_FLUSH -- Flush all entries from the name cache and the cnode
* cache.
*
* CODA_PURGEUSER -- Flush all entries from the name cache for a specific
* user. This call is a result of token expiration.
*
* The next two are the result of callbacks on a file or directory:
*
* CODA_ZAPDIR -- Flush the attributes for the dir from its cnode. Zap
* all children of this directory from the namecache.
*
* CODA_ZAPFILE -- Flush the attributes for a file.
*
* The fifth is a result of Venus detecting an inconsistent file:
*
* CODA_PURGEFID -- Flush the attribute for the file; if it is a dir (odd
* vnode), purge its children from the namecache; remove
* the file from the namecache.
*
* The sixth allows Venus to replace local fids with global ones during
* reintegration.
*
* CODA_REPLACE -- Replace one CodaFid with another throughout the name
* cache.
*/
int
handleDownCall(struct coda_mntinfo *mnt, int opcode, union outputArgs *out)
{
int error;
/*
* Handle invalidate requests.
*/
switch (opcode) {
case CODA_FLUSH: {
coda_flush(mnt, IS_DOWNCALL);
/* Print any remaining cnodes. */
CODADEBUG(CODA_FLUSH, coda_testflush(););
return (0);
}
case CODA_PURGEUSER: {
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_PURGEUSER]++;
/* XXX - need to prevent fsync's. */
/*
* Purge any access cache entries for the uid.
*/
#ifdef CODA_COMPAT_5
coda_acccache_purgeuser(mnt->mi_vfsp,
out->coda_purgeuser.cred.cr_uid);
#else
coda_acccache_purgeuser(mnt->mi_vfsp,
out->coda_purgeuser.uid);
#endif
return (0);
}
case CODA_ZAPFILE: {
struct cnode *cp;
error = 0;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_ZAPFILE]++;
cp = coda_find(&out->coda_zapfile.Fid);
if (cp != NULL) {
vref(CTOV(cp));
cache_purge(CTOV(cp));
cp->c_flags &= ~(C_VATTR | C_ACCCACHE);
ASSERT_VOP_LOCKED(CTOV(cp), "coda HandleDownCall");
if (CTOV(cp)->v_vflag & VV_TEXT)
error = coda_vmflush(cp);
CODADEBUG(CODA_ZAPFILE,
myprintf(("zapfile: fid = %s, refcnt = %d, error = "
"%d\n", coda_f2s(&cp->c_fid),
CTOV(cp)->v_usecount - 1, error)););
if (vrefcnt(CTOV(cp)) == 1)
cp->c_flags |= C_PURGING;
vrele(CTOV(cp));
}
return (error);
}
case CODA_ZAPDIR: {
struct cnode *cp;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_ZAPDIR]++;
cp = coda_find(&out->coda_zapdir.Fid);
if (cp != NULL) {
vref(CTOV(cp));
cache_purge(CTOV(cp));
cp->c_flags &= ~(C_VATTR | C_ACCCACHE);
CODADEBUG(CODA_ZAPDIR, myprintf(("zapdir: fid = %s, "
"refcnt = %d\n", coda_f2s(&cp->c_fid),
CTOV(cp)->v_usecount - 1)););
if (vrefcnt(CTOV(cp)) == 1)
cp->c_flags |= C_PURGING;
vrele(CTOV(cp));
}
return (0);
}
case CODA_PURGEFID: {
struct cnode *cp;
error = 0;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_PURGEFID]++;
cp = coda_find(&out->coda_purgefid.Fid);
if (cp != NULL) {
vref(CTOV(cp));
cache_purge(CTOV(cp));
cp->c_flags &= ~(C_VATTR | C_ACCCACHE);
ASSERT_VOP_LOCKED(CTOV(cp), "coda HandleDownCall");
if (!(IS_DIR(out->coda_purgefid.Fid))
&& (CTOV(cp)->v_vflag & VV_TEXT))
error = coda_vmflush(cp);
CODADEBUG(CODA_PURGEFID, myprintf(("purgefid: fid "
"= %s, refcnt = %d, error = %d\n",
coda_f2s(&cp->c_fid),
CTOV(cp)->v_usecount - 1, error)););
if (vrefcnt(CTOV(cp)) == 1)
cp->c_flags |= C_PURGING;
vrele(CTOV(cp));
}
return (error);
}
case CODA_REPLACE: {
struct cnode *cp = NULL;
coda_clstat.ncalls++;
coda_clstat.reqs[CODA_REPLACE]++;
cp = coda_find(&out->coda_replace.OldFid);
if (cp != NULL) {
/*
* Remove the cnode from the hash table, replace the
* fid, and reinsert. Clear the attribute cache as
* the "inode number" may have changed (it's just a
* hash of the fid, and the fid is changing).
*/
vref(CTOV(cp));
coda_unsave(cp);
cp->c_fid = out->coda_replace.NewFid;
cp->c_flags &= ~C_VATTR;
coda_save(cp);
CODADEBUG(CODA_REPLACE, myprintf(("replace: oldfid "
"= %s, newfid = %s, cp = %p\n",
coda_f2s(&out->coda_replace.OldFid),
coda_f2s(&cp->c_fid), cp)););
vrele(CTOV(cp));
}
return (0);
}
default:
myprintf(("handleDownCall: unknown opcode %d\n", opcode));
return (EINVAL);
}
}
int
coda_vmflush(struct cnode *cp)
{
return (0);
}
/*
* Kernel-internal debugging switches.
*/
void
coda_debugon(void)
{
codadebug = -1;
coda_vnop_print_entry = 1;
coda_psdev_print_entry = 1;
coda_vfsop_print_entry = 1;
}
void
coda_debugoff(void)
{
codadebug = 0;
coda_vnop_print_entry = 0;
coda_psdev_print_entry = 0;
coda_vfsop_print_entry = 0;
}
/*-
* Utilities used by both client and server
* Standard levels:
* 0) no debugging
* 1) hard failures
* 2) soft failures
* 3) current test software
* 4) main procedure entry points
* 5) main procedure exit points
* 6) utility procedure entry points
* 7) utility procedure exit points
* 8) obscure procedure entry points
* 9) obscure procedure exit points
* 10) random stuff
* 11) all <= 1
* 12) all <= 2
* 13) all <= 3
* ...
*/