Change namei cache to record vnode->(parent,name) entries (for directories).
Add kernel implementation of getcwd() which uses this cache, falling back to reading the filesystem on a cache miss. Along for the ride: add new VOP_FSYNC flag FSYNC_RECLAIM indicating that a reclaim is being done, so only a "shallow" fsync is needed.
This commit is contained in:
sommerfe
parent
75fb6d661f
commit
095cd96cd5
@ -1,4 +1,4 @@
|
||||
$NetBSD: syscalls.master,v 1.88 1999/02/10 18:02:28 kleink Exp $
|
||||
$NetBSD: syscalls.master,v 1.89 1999/03/22 17:01:55 sommerfe Exp $
|
||||
|
||||
; @(#)syscalls.master 8.2 (Berkeley) 1/13/94
|
||||
|
||||
@ -564,3 +564,5 @@
|
||||
sigset_t *oset); }
|
||||
294 STD { int sys___sigsuspend14(const sigset_t *set); }
|
||||
295 STD { int sys___sigreturn14(struct sigcontext *sigcntxp); }
|
||||
296 STD { int sys___getcwd(char *bufp, size_t length); }
|
||||
297 STD { int sys_fchroot(int fd); }
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
/* $NetBSD: vfs_cache.c,v 1.18 1998/09/01 04:33:56 thorpej Exp $ */
|
||||
/* $NetBSD: vfs_cache.c,v 1.19 1999/03/22 17:01:55 sommerfe Exp $ */
|
||||
|
||||
/*
|
||||
* Copyright (c) 1989, 1993
|
||||
@ -69,6 +69,10 @@
|
||||
LIST_HEAD(nchashhead, namecache) *nchashtbl;
|
||||
u_long nchash; /* size of hash table - 1 */
|
||||
long numcache; /* number of cache entries allocated */
|
||||
|
||||
LIST_HEAD(ncvhashhead, namecache) *ncvhashtbl;
|
||||
u_long ncvhash; /* size of hash table - 1 */
|
||||
|
||||
TAILQ_HEAD(, namecache) nclruhead; /* LRU chain */
|
||||
struct nchstats nchstats; /* cache effectiveness statistics */
|
||||
|
||||
@ -163,10 +167,84 @@ cache_lookup(dvp, vpp, cnp)
|
||||
TAILQ_REMOVE(&nclruhead, ncp, nc_lru);
|
||||
LIST_REMOVE(ncp, nc_hash);
|
||||
ncp->nc_hash.le_prev = 0;
|
||||
if (ncp->nc_vhash.le_prev != NULL) {
|
||||
LIST_REMOVE(ncp, nc_vhash);
|
||||
ncp->nc_vhash.le_prev = 0;
|
||||
}
|
||||
TAILQ_INSERT_HEAD(&nclruhead, ncp, nc_lru);
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Scan cache looking for name of directory entry pointing at vp.
|
||||
*
|
||||
* Fill in dvpp.
|
||||
*
|
||||
* If bufp is non-NULL, also place the name in the buffer which starts
|
||||
* at bufp, immediately before *bpp, and move bpp backwards to point
|
||||
* at the start of it. (Yes, this is a little baroque, but it's done
|
||||
* this way to cater to the whims of getcwd).
|
||||
*
|
||||
* Returns 0 on success, -1 on cache miss, positive errno on failure.
|
||||
*/
|
||||
int
|
||||
cache_revlookup (vp, dvpp, bpp, bufp)
|
||||
struct vnode *vp, **dvpp;
|
||||
char **bpp;
|
||||
char *bufp;
|
||||
{
|
||||
struct namecache *ncp;
|
||||
struct vnode *dvp;
|
||||
struct ncvhashhead *nvcpp;
|
||||
|
||||
if (!doingcache)
|
||||
goto out;
|
||||
|
||||
nvcpp = &ncvhashtbl[(vp->v_id & ncvhash)];
|
||||
|
||||
for (ncp = nvcpp->lh_first; ncp != 0; ncp = ncp->nc_vhash.le_next) {
|
||||
if ((ncp->nc_vp == vp) &&
|
||||
(ncp->nc_vpid == vp->v_id) &&
|
||||
((dvp = ncp->nc_dvp) != 0) &&
|
||||
(dvp != vp) && /* avoid pesky . entries.. */
|
||||
(dvp->v_id == ncp->nc_dvpid))
|
||||
{
|
||||
char *bp;
|
||||
|
||||
#ifdef DIAGNOSTIC
|
||||
if ((ncp->nc_nlen == 1) &&
|
||||
(ncp->nc_name[0] == '.'))
|
||||
panic("cache_revlookup: found entry for .");
|
||||
|
||||
if ((ncp->nc_nlen == 2) &&
|
||||
(ncp->nc_name[0] == '.') &&
|
||||
(ncp->nc_name[1] == '.'))
|
||||
panic("cache_revlookup: found entry for ..");
|
||||
#endif
|
||||
nchstats.ncs_revhits++;
|
||||
|
||||
if (bufp) {
|
||||
bp = *bpp;
|
||||
bp -= ncp->nc_nlen;
|
||||
if (bp <= bufp) {
|
||||
*dvpp = 0;
|
||||
return ERANGE;
|
||||
}
|
||||
memcpy(bp, ncp->nc_name, ncp->nc_nlen);
|
||||
*bpp = bp;
|
||||
}
|
||||
|
||||
/* XXX MP: how do we know dvp won't evaporate? */
|
||||
*dvpp = dvp;
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
nchstats.ncs_revmiss++;
|
||||
out:
|
||||
*dvpp = 0;
|
||||
return -1;
|
||||
}
|
||||
|
||||
/*
|
||||
* Add an entry to the cache
|
||||
*/
|
||||
@ -178,6 +256,7 @@ cache_enter(dvp, vp, cnp)
|
||||
{
|
||||
register struct namecache *ncp;
|
||||
register struct nchashhead *ncpp;
|
||||
register struct ncvhashhead *nvcpp;
|
||||
|
||||
#ifdef DIAGNOSTIC
|
||||
if (cnp->cn_namelen > NCHNAMLEN)
|
||||
@ -198,6 +277,10 @@ cache_enter(dvp, vp, cnp)
|
||||
LIST_REMOVE(ncp, nc_hash);
|
||||
ncp->nc_hash.le_prev = 0;
|
||||
}
|
||||
if (ncp->nc_vhash.le_prev != 0) {
|
||||
LIST_REMOVE(ncp, nc_vhash);
|
||||
ncp->nc_vhash.le_prev = 0;
|
||||
}
|
||||
} else
|
||||
return;
|
||||
/* grab the vnode we just found */
|
||||
@ -219,6 +302,24 @@ cache_enter(dvp, vp, cnp)
|
||||
TAILQ_INSERT_TAIL(&nclruhead, ncp, nc_lru);
|
||||
ncpp = &nchashtbl[(cnp->cn_hash ^ dvp->v_id) & nchash];
|
||||
LIST_INSERT_HEAD(ncpp, ncp, nc_hash);
|
||||
|
||||
ncp->nc_vhash.le_prev = 0;
|
||||
ncp->nc_vhash.le_next = 0;
|
||||
|
||||
/*
|
||||
* Create reverse-cache entries (used in getcwd) for directories.
|
||||
*/
|
||||
if (vp &&
|
||||
(vp != dvp) &&
|
||||
(vp->v_type == VDIR) &&
|
||||
((ncp->nc_nlen > 2) ||
|
||||
((ncp->nc_nlen == 2) && (ncp->nc_name[0] != '.') && (ncp->nc_name[1] != '.')) ||
|
||||
((ncp->nc_nlen == 1) && (ncp->nc_name[0] != '.'))))
|
||||
{
|
||||
nvcpp = &ncvhashtbl[(vp->v_id & ncvhash)];
|
||||
LIST_INSERT_HEAD(nvcpp, ncp, nc_vhash);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/*
|
||||
@ -230,6 +331,7 @@ nchinit()
|
||||
|
||||
TAILQ_INIT(&nclruhead);
|
||||
nchashtbl = hashinit(desiredvnodes, M_CACHE, M_WAITOK, &nchash);
|
||||
ncvhashtbl = hashinit(desiredvnodes/8, M_CACHE, M_WAITOK, &ncvhash);
|
||||
pool_init(&namecache_pool, sizeof(struct namecache), 0, 0, 0,
|
||||
"ncachepl", 0, pool_page_alloc_nointr, pool_page_free_nointr,
|
||||
M_CACHE);
|
||||
@ -285,8 +387,13 @@ cache_purgevfs(mp)
|
||||
LIST_REMOVE(ncp, nc_hash);
|
||||
ncp->nc_hash.le_prev = 0;
|
||||
}
|
||||
if (ncp->nc_vhash.le_prev != 0) {
|
||||
LIST_REMOVE(ncp, nc_vhash);
|
||||
ncp->nc_vhash.le_prev = 0;
|
||||
}
|
||||
/* cause rescan of list, it may have altered */
|
||||
nxtcp = nclruhead.tqh_first;
|
||||
TAILQ_INSERT_HEAD(&nclruhead, ncp, nc_lru);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
643
sys/kern/vfs_getcwd.c
Normal file
643
sys/kern/vfs_getcwd.c
Normal file
@ -0,0 +1,643 @@
|
||||
/* $NetBSD: vfs_getcwd.c,v 1.1 1999/03/22 17:01:55 sommerfe Exp $ */
|
||||
|
||||
/*-
|
||||
* Copyright (c) 1999 The NetBSD Foundation, Inc.
|
||||
* All rights reserved.
|
||||
*
|
||||
* This code is derived from software contributed to The NetBSD Foundation
|
||||
* by Bill Sommerfeld.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
* 3. All advertising materials mentioning features or use of this software
|
||||
* must display the following acknowledgement:
|
||||
* This product includes software developed by the NetBSD
|
||||
* Foundation, Inc. and its contributors.
|
||||
* 4. Neither the name of The NetBSD Foundation nor the names of its
|
||||
* contributors may be used to endorse or promote products derived
|
||||
* from this software without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
||||
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
||||
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||||
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
||||
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
||||
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
||||
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
||||
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
||||
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
||||
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
#include <sys/param.h>
|
||||
#include <sys/systm.h>
|
||||
#include <sys/namei.h>
|
||||
#include <sys/filedesc.h>
|
||||
#include <sys/kernel.h>
|
||||
#include <sys/file.h>
|
||||
#include <sys/stat.h>
|
||||
#include <sys/vnode.h>
|
||||
#include <sys/mount.h>
|
||||
#include <sys/proc.h>
|
||||
#include <sys/uio.h>
|
||||
#include <sys/malloc.h>
|
||||
#include <sys/dirent.h>
|
||||
#include <ufs/ufs/dir.h> /* XXX only for DIRBLKSIZ */
|
||||
|
||||
#include <sys/syscallargs.h>
|
||||
|
||||
static int
|
||||
getcwd_scandir __P((struct vnode *, struct vnode **,
|
||||
char **, char *, struct proc *));
|
||||
static int
|
||||
getcwd_getcache __P((struct vnode **, struct vnode **,
|
||||
char **, char *));
|
||||
static int
|
||||
getcwd_common __P((struct vnode *, struct vnode *,
|
||||
char **, char *, int, int, struct proc *));
|
||||
|
||||
int vn_isunder __P((struct vnode *, struct vnode *, struct proc *));
|
||||
|
||||
#define DIRENT_MINSIZE (sizeof(struct dirent) - (MAXNAMLEN+1) + 4)
|
||||
|
||||
/*
|
||||
* XXX Will infinite loop in certain cases if a directory read reliably
|
||||
* returns EINVAL on last block.
|
||||
* XXX is EINVAL the right thing to return if a directory is malformed?
|
||||
*/
|
||||
|
||||
/*
|
||||
* Find parent vnode of cvp, return in *pvpp
|
||||
* Scan it looking for name of directory entry pointing at cvp.
|
||||
*
|
||||
* Place the name in the buffer which starts at bufp, immediately
|
||||
* before *bpp, and move bpp backwards to point at the start of it.
|
||||
*/
|
||||
static int
|
||||
getcwd_scandir(cvp, pvpp, bpp, bufp, p)
|
||||
struct vnode *cvp;
|
||||
struct vnode **pvpp;
|
||||
char **bpp;
|
||||
char *bufp;
|
||||
struct proc *p;
|
||||
{
|
||||
char *entry;
|
||||
int error = 0;
|
||||
int eofflag;
|
||||
off_t off;
|
||||
int tries;
|
||||
struct uio uio;
|
||||
struct iovec iov;
|
||||
char *dirbuf = NULL;
|
||||
int dirbuflen;
|
||||
ino_t fileno;
|
||||
struct vattr va;
|
||||
struct vnode *pvp = NULL;
|
||||
struct componentname cn;
|
||||
int len, reclen;
|
||||
tries = 0;
|
||||
|
||||
/*
|
||||
* Ok, we have to do it the hard way..
|
||||
* First, get parent vnode using lookup of ..
|
||||
*/
|
||||
cn.cn_nameiop = LOOKUP;
|
||||
cn.cn_flags = ISLASTCN | ISDOTDOT | RDONLY | LOCKPARENT;
|
||||
cn.cn_proc = p;
|
||||
cn.cn_cred = p->p_ucred;
|
||||
cn.cn_pnbuf = NULL;
|
||||
cn.cn_nameptr = "..";
|
||||
cn.cn_namelen = 2;
|
||||
cn.cn_hash = 0;
|
||||
cn.cn_consume = 0;
|
||||
|
||||
/*
|
||||
* At this point, cvp is locked, and will be locked
|
||||
* on return in all cases.
|
||||
* On successful return, *pvpp will also be locked
|
||||
*/
|
||||
error = VOP_LOOKUP(cvp, pvpp, &cn);
|
||||
if (error) {
|
||||
*pvpp = NULL;
|
||||
return error;
|
||||
}
|
||||
pvp = *pvpp;
|
||||
|
||||
/* If we don't care about the pathname, we're done */
|
||||
if (bufp == NULL)
|
||||
return 0;
|
||||
|
||||
error = VOP_GETATTR(cvp, &va, p->p_ucred, p);
|
||||
if (error)
|
||||
return error;
|
||||
fileno = va.va_fileid;
|
||||
|
||||
|
||||
dirbuflen = DIRBLKSIZ;
|
||||
if (dirbuflen < va.va_blocksize)
|
||||
dirbuflen = va.va_blocksize;
|
||||
dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
|
||||
|
||||
#if 0
|
||||
unionread:
|
||||
#endif
|
||||
off = 0;
|
||||
do {
|
||||
/* call VOP_READDIR of parent */
|
||||
iov.iov_base = dirbuf;
|
||||
iov.iov_len = dirbuflen;
|
||||
|
||||
uio.uio_iov = &iov;
|
||||
uio.uio_iovcnt = 1;
|
||||
uio.uio_offset = off;
|
||||
uio.uio_resid = dirbuflen;
|
||||
uio.uio_segflg = UIO_SYSSPACE;
|
||||
uio.uio_rw = UIO_READ;
|
||||
uio.uio_procp = p;
|
||||
|
||||
eofflag = 0;
|
||||
|
||||
error = VOP_READDIR(pvp, &uio, p->p_ucred, &eofflag, 0, 0);
|
||||
|
||||
off = uio.uio_offset;
|
||||
|
||||
/*
|
||||
* Try again if NFS tosses its cookies.
|
||||
* XXX this can still loop forever if the directory is busted
|
||||
* such that the second or subsequent page of it always
|
||||
* returns EINVAL
|
||||
*/
|
||||
if ((error == EINVAL) && (tries < 3)) {
|
||||
off = 0;
|
||||
tries++;
|
||||
continue; /* once more, with feeling */
|
||||
}
|
||||
entry = NULL;
|
||||
if (!error) {
|
||||
char *cpos;
|
||||
struct dirent *dp;
|
||||
|
||||
cpos = dirbuf;
|
||||
tries = 0;
|
||||
|
||||
/* scan directory page looking for matching vnode */
|
||||
for (len = (dirbuflen - uio.uio_resid); len > 0; len -= reclen) {
|
||||
dp = (struct dirent *) cpos;
|
||||
reclen = dp->d_reclen;
|
||||
|
||||
/* check for malformed directory.. */
|
||||
if (reclen < DIRENT_MINSIZE) {
|
||||
error = EINVAL;
|
||||
goto out;
|
||||
}
|
||||
/*
|
||||
* XXX should perhaps do VOP_LOOKUP to
|
||||
* check that we got back to the right place,
|
||||
* but getting the locking games for that
|
||||
* right would be heinous.
|
||||
*/
|
||||
if ((dp->d_type != DT_WHT) &&
|
||||
(dp->d_fileno == fileno)) {
|
||||
char *bp = *bpp;
|
||||
bp -= dp->d_namlen;
|
||||
|
||||
if (bp <= bufp) {
|
||||
error = ERANGE;
|
||||
goto out;
|
||||
}
|
||||
memcpy(bp, dp->d_name, dp->d_namlen);
|
||||
error = 0;
|
||||
*bpp = bp;
|
||||
goto out;
|
||||
}
|
||||
cpos += reclen;
|
||||
}
|
||||
}
|
||||
} while (!eofflag && !entry);
|
||||
#if 0
|
||||
/*
|
||||
* Deal with mount -o union, which unions only the
|
||||
* root directory of the mount.
|
||||
*/
|
||||
if ((pvp->v_flag & VROOT) &&
|
||||
(pvp->v_mount->mnt_flag & MNT_UNION)) {
|
||||
struct vnode *tvp = pvp;
|
||||
pvp = pvp->v_mount->mnt_vnodecovered;
|
||||
vput(tvp);
|
||||
VREF(pvp);
|
||||
*pvpp = pvp;
|
||||
error = vn_lock(pvp, LK_EXCLUSIVE | LK_RETRY);
|
||||
if (error != 0) {
|
||||
vrele(pvp);
|
||||
*pvpp = pvp = NULL;
|
||||
goto out;
|
||||
}
|
||||
goto unionread;
|
||||
}
|
||||
#endif
|
||||
error = ENOENT;
|
||||
|
||||
out:
|
||||
free(dirbuf, M_TEMP);
|
||||
return error;
|
||||
}
|
||||
|
||||
/*
|
||||
* Look in the vnode-to-name reverse cache to see if
|
||||
* we can find things the easy way.
|
||||
*
|
||||
* XXX vn_lock/vget failure paths are untested.
|
||||
*/
|
||||
|
||||
static int
|
||||
getcwd_getcache(vpp, dvpp, bpp, bufp)
|
||||
struct vnode **vpp, **dvpp;
|
||||
char **bpp;
|
||||
char *bufp;
|
||||
{
|
||||
struct vnode *cvp, *pvp = NULL;
|
||||
int error;
|
||||
|
||||
cvp = *vpp;
|
||||
|
||||
error = cache_revlookup(cvp, dvpp, bpp, bufp);
|
||||
if (error)
|
||||
return error;
|
||||
pvp = *dvpp;
|
||||
|
||||
/*
|
||||
* Do a little dance with the locks to avoid deadlocking
|
||||
* someone going the other way. Since we're going up, we have
|
||||
* to release the current lock before we take the parent lock,
|
||||
* and then re-take the current lock. Since either lock can
|
||||
* fail, causing us to abort, this is a little convoluted.
|
||||
*/
|
||||
|
||||
VOP_UNLOCK(cvp, 0);
|
||||
/* cur now unlocked... */
|
||||
error = vget(pvp, LK_EXCLUSIVE | LK_RETRY);
|
||||
if (error != 0) {
|
||||
vrele(cvp);
|
||||
*vpp = NULL;
|
||||
*dvpp = NULL;
|
||||
return error;
|
||||
}
|
||||
/* parent is now locked */
|
||||
error = vn_lock(cvp, LK_EXCLUSIVE | LK_RETRY);
|
||||
if (error != 0) {
|
||||
vrele(cvp);
|
||||
*vpp = NULL;
|
||||
return error;
|
||||
}
|
||||
/* ok, cur is now locked again.. */
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* common routine shared by sys___getcwd() and vn_isunder()
|
||||
*/
|
||||
|
||||
#define GETCWD_CHECK_ACCESS 0x0001
|
||||
|
||||
static int getcwd_common (dvp, rvp, bpp, bufp, limit, flags, p)
|
||||
struct vnode *dvp;
|
||||
struct vnode *rvp;
|
||||
char **bpp;
|
||||
char *bufp;
|
||||
int limit;
|
||||
int flags;
|
||||
struct proc *p;
|
||||
{
|
||||
struct filedesc *fdp = p->p_fd;
|
||||
struct vnode *pvp = NULL;
|
||||
char *bp;
|
||||
int error;
|
||||
|
||||
if (rvp == NULL) {
|
||||
rvp = fdp->fd_rdir;
|
||||
if (rvp == NULL)
|
||||
rvp = rootvnode;
|
||||
}
|
||||
|
||||
VREF(rvp);
|
||||
VREF(dvp);
|
||||
|
||||
/*
|
||||
* Error handling invariant:
|
||||
* Before a `goto out':
|
||||
* dvp is either NULL, or locked and held.
|
||||
* pvp is either NULL, or locked and held.
|
||||
*/
|
||||
|
||||
error = vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
|
||||
if (error) {
|
||||
vrele(dvp);
|
||||
dvp = NULL;
|
||||
goto out;
|
||||
}
|
||||
if (bufp)
|
||||
bp = *bpp;
|
||||
/*
|
||||
* this loop will terminate when one of the following happens:
|
||||
* - we hit the root
|
||||
* - getdirentries or lookup fails
|
||||
* - we run out of space in the buffer.
|
||||
*/
|
||||
if (dvp == rvp) {
|
||||
if (bufp)
|
||||
*(--(*bpp)) = '/';
|
||||
goto out;
|
||||
}
|
||||
do {
|
||||
if (dvp->v_type != VDIR) {
|
||||
error = ENOTDIR;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/*
|
||||
* access check here is optional, depending on
|
||||
* whether or not caller cares.
|
||||
*/
|
||||
if (flags & GETCWD_CHECK_ACCESS) {
|
||||
error = VOP_ACCESS(dvp, VEXEC|VREAD, p->p_ucred, p);
|
||||
if (error)
|
||||
goto out;
|
||||
}
|
||||
|
||||
/*
|
||||
* step up if we're a covered vnode..
|
||||
*/
|
||||
while (dvp->v_flag & VROOT) {
|
||||
struct vnode *tvp;
|
||||
|
||||
if (dvp == rvp)
|
||||
goto out;
|
||||
|
||||
tvp = dvp;
|
||||
dvp = dvp->v_mount->mnt_vnodecovered;
|
||||
vput(tvp);
|
||||
/*
|
||||
* hodie natus est radici frater
|
||||
*/
|
||||
if (dvp == NULL) {
|
||||
error = ENOENT;
|
||||
goto out;
|
||||
}
|
||||
VREF(dvp);
|
||||
error = vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
|
||||
if (error != 0) {
|
||||
vrele(dvp);
|
||||
dvp = NULL;
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
/*
|
||||
* Look in the name cache; if that fails, look in the
|
||||
* directory..
|
||||
*/
|
||||
error = getcwd_getcache(&dvp, &pvp, bpp, bufp);
|
||||
if (error == -1)
|
||||
error = getcwd_scandir(dvp, &pvp, bpp, bufp, p);
|
||||
if (error)
|
||||
goto out;
|
||||
#if DIAGNOSTIC
|
||||
if (dvp == pvp) {
|
||||
panic("getcwd: oops, dvp == pvp");
|
||||
}
|
||||
if (bufp && (bp <= bufp)) {
|
||||
panic("getcwd: oops, went back too far");
|
||||
}
|
||||
#endif
|
||||
if (bufp) *(--(*bpp)) = '/';
|
||||
|
||||
vput(dvp);
|
||||
dvp = pvp;
|
||||
pvp = NULL;
|
||||
limit--;
|
||||
} while ((dvp != rvp) && (limit > 0));
|
||||
|
||||
out:
|
||||
if (pvp)
|
||||
vput(pvp);
|
||||
if (dvp)
|
||||
vput(dvp);
|
||||
vrele(rvp);
|
||||
return error;
|
||||
}
|
||||
|
||||
/*
|
||||
* Check if one directory can be found inside another in the directory
|
||||
* hierarchy.
|
||||
*
|
||||
* Intended to be used in chroot, chdir, fchdir, etc., to ensure that
|
||||
* chroot() actually means something.
|
||||
*/
|
||||
int vn_isunder(dvp, rvp, p)
|
||||
struct vnode *dvp;
|
||||
struct vnode *rvp;
|
||||
struct proc *p;
|
||||
{
|
||||
int error;
|
||||
|
||||
error = getcwd_common (dvp, rvp, NULL, NULL, MAXPATHLEN/2, 0, p);
|
||||
|
||||
if (!error)
|
||||
return 1;
|
||||
else
|
||||
return 0;
|
||||
}
|
||||
|
||||
int sys___getcwd(p, v, retval)
|
||||
struct proc *p;
|
||||
void *v;
|
||||
register_t *retval;
|
||||
{
|
||||
register struct sys___getcwd_args /* {
|
||||
syscallarg(char *) bufp;
|
||||
syscallarg(size_t) length;
|
||||
} */ *uap = v;
|
||||
|
||||
int error;
|
||||
char *path;
|
||||
char *bp, *bend;
|
||||
int len = SCARG(uap, length);
|
||||
int lenused;
|
||||
|
||||
if ((len < 2) || (len > MAXPATHLEN*4))
|
||||
return ERANGE;
|
||||
|
||||
path = (char *)malloc(len, M_TEMP, M_WAITOK);
|
||||
if (!path)
|
||||
return ENOMEM;
|
||||
|
||||
bp = &path[len];
|
||||
bend = bp;
|
||||
*(--bp) = '\0';
|
||||
|
||||
error = getcwd_common (p->p_fd->fd_cdir, NULL, &bp, path, len/2,
|
||||
GETCWD_CHECK_ACCESS, p);
|
||||
|
||||
if (error)
|
||||
goto out;
|
||||
lenused = bend - bp;
|
||||
*retval = lenused;
|
||||
/* put the result into user buffer */
|
||||
error = copyout(bp, SCARG(uap, bufp), lenused);
|
||||
|
||||
out:
|
||||
free(path, M_TEMP);
|
||||
return error;
|
||||
}
|
||||
|
||||
|
||||
|
||||
/*
|
||||
* Find pathname of process's current directory.
|
||||
*
|
||||
* Use vfs vnode-to-name reverse cache; if that fails, fall back
|
||||
* to reading directory contents.
|
||||
*/
|
||||
|
||||
/*
|
||||
* XXX Untested vs. mount -o union; probably does the wrong thing.
|
||||
* XXX Untested vs chroot
|
||||
* XXX most error paths probably work, but many locking-related ones
|
||||
* aren't tested well.
|
||||
*/
|
||||
#if 0
|
||||
|
||||
int
|
||||
sys___getcwd(p, v, retval)
|
||||
struct proc *p;
|
||||
void *v;
|
||||
register_t *retval;
|
||||
{
|
||||
register struct sys___getcwd_args /* {
|
||||
syscallarg(char *) bufp;
|
||||
syscallarg(size_t) length;
|
||||
} */ *uap = v;
|
||||
|
||||
struct filedesc *fdp = p->p_fd;
|
||||
struct vnode *cvp = NULL, *pvp = NULL, *rootvp = NULL;
|
||||
int error;
|
||||
char *path;
|
||||
char *bp, *bend;
|
||||
int len = SCARG(uap, length);
|
||||
int lenused;
|
||||
|
||||
if ((len < 2) || (len > MAXPATHLEN*4))
|
||||
return ERANGE;
|
||||
|
||||
path = (char *)malloc(len, M_TEMP, M_WAITOK);
|
||||
if (!path)
|
||||
return ENOMEM;
|
||||
|
||||
bp = &path[len];
|
||||
bend = bp;
|
||||
*(--bp) = '\0';
|
||||
|
||||
rootvp = fdp->fd_rdir;
|
||||
if (rootvp == NULL)
|
||||
rootvp = rootvnode;
|
||||
|
||||
cvp = fdp->fd_cdir;
|
||||
|
||||
VREF(rootvp);
|
||||
VREF(cvp);
|
||||
|
||||
/*
|
||||
* Error handling invariant:
|
||||
* Before a `goto out':
|
||||
* cvp is either NULL, or locked and held.
|
||||
* pvp is either NULL, or locked and held.
|
||||
*/
|
||||
|
||||
error = vn_lock(cvp, LK_EXCLUSIVE | LK_RETRY);
|
||||
if (error) {
|
||||
vrele(cvp);
|
||||
cvp = NULL;
|
||||
goto out;
|
||||
}
|
||||
/*
|
||||
* this loop will terminate when one of the following happens:
|
||||
* - we hit the root
|
||||
* - getdirentries or lookup fails
|
||||
* - we run out of space in the buffer.
|
||||
*/
|
||||
if (cvp == rootvp) {
|
||||
*(--bp) = '/';
|
||||
goto hitroot;
|
||||
}
|
||||
do {
|
||||
/*
|
||||
* so, are we even allowed to look at this directory?
|
||||
*/
|
||||
|
||||
error = VOP_ACCESS(cvp, VEXEC|VREAD, p->p_ucred, p);
|
||||
if (error)
|
||||
goto out;
|
||||
|
||||
/*
|
||||
* step up if we're a covered vnode..
|
||||
*/
|
||||
while (cvp->v_flag & VROOT) {
|
||||
struct vnode *tvp;
|
||||
|
||||
if (cvp == rootvp)
|
||||
goto hitroot;
|
||||
|
||||
tvp = cvp;
|
||||
cvp = cvp->v_mount->mnt_vnodecovered;
|
||||
vput(tvp);
|
||||
VREF(cvp);
|
||||
error = vn_lock(cvp, LK_EXCLUSIVE | LK_RETRY);
|
||||
if (error != 0) {
|
||||
vrele(cvp);
|
||||
cvp = NULL;
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
/*
|
||||
* Look in the name cache; if that fails, look in the directory..
|
||||
*/
|
||||
error = getcwd_getcache(&cvp, &pvp, &bp, path);
|
||||
if (error == -1)
|
||||
error = getcwd_scandir(cvp, &pvp, &bp, path, p);
|
||||
|
||||
if (error)
|
||||
goto out;
|
||||
if (bp <= path) {
|
||||
error = ERANGE;
|
||||
goto out;
|
||||
}
|
||||
*(--bp) = '/';
|
||||
|
||||
vput(cvp);
|
||||
cvp = pvp;
|
||||
pvp = NULL;
|
||||
|
||||
} while (cvp != rootvp);
|
||||
hitroot:
|
||||
|
||||
lenused = bend - bp;
|
||||
*retval = lenused;
|
||||
/* put the result into user buffer */
|
||||
error = copyout(bp, SCARG(uap, bufp), lenused);
|
||||
|
||||
out:
|
||||
if (pvp)
|
||||
vput(pvp);
|
||||
if (cvp)
|
||||
vput(cvp);
|
||||
vrele(rootvp);
|
||||
free(path, M_TEMP);
|
||||
return error;
|
||||
}
|
||||
#endif
|
||||
@ -1,4 +1,4 @@
|
||||
/* $NetBSD: namei.h,v 1.14 1998/03/01 02:24:13 fvdl Exp $ */
|
||||
/* $NetBSD: namei.h,v 1.15 1999/03/22 17:01:55 sommerfe Exp $ */
|
||||
|
||||
/*
|
||||
* Copyright (c) 1985, 1989, 1991, 1993
|
||||
@ -163,6 +163,7 @@ struct nameidata {
|
||||
struct namecache {
|
||||
LIST_ENTRY(namecache) nc_hash; /* hash chain */
|
||||
TAILQ_ENTRY(namecache) nc_lru; /* LRU chain */
|
||||
LIST_ENTRY(namecache) nc_vhash; /* directory hash chain */
|
||||
struct vnode *nc_dvp; /* vnode of parent of name */
|
||||
u_long nc_dvpid; /* capability number of nc_dvp */
|
||||
struct vnode *nc_vp; /* vnode the name refers to */
|
||||
@ -179,6 +180,7 @@ int relookup __P((struct vnode *dvp, struct vnode **vpp,
|
||||
struct componentname *cnp));
|
||||
void cache_purge __P((struct vnode *));
|
||||
int cache_lookup __P((struct vnode *, struct vnode **, struct componentname *));
|
||||
int cache_revlookup __P((struct vnode *, struct vnode **, char **, char *));
|
||||
void cache_enter __P((struct vnode *, struct vnode *, struct componentname *));
|
||||
void nchinit __P((void));
|
||||
struct mount;
|
||||
@ -198,5 +200,7 @@ struct nchstats {
|
||||
long ncs_long; /* long names that ignore cache */
|
||||
long ncs_pass2; /* names found with passes == 2 */
|
||||
long ncs_2passes; /* number of times we attempt it */
|
||||
long ncs_revhits; /* reverse-cache hits */
|
||||
long ncs_revmiss; /* reverse-cache misses */
|
||||
};
|
||||
#endif /* !_SYS_NAMEI_H_ */
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
/* $NetBSD: vnode.h,v 1.57 1998/11/18 20:24:59 thorpej Exp $ */
|
||||
/* $NetBSD: vnode.h,v 1.58 1999/03/22 17:01:55 sommerfe Exp $ */
|
||||
|
||||
/*
|
||||
* Copyright (c) 1989, 1993
|
||||
@ -229,6 +229,7 @@ extern int vttoif_tab[];
|
||||
|
||||
#define FSYNC_WAIT 0x0001 /* fsync: wait for completition */
|
||||
#define FSYNC_DATAONLY 0x0002 /* fsync: hint: sync file data only */
|
||||
#define FSYNC_RECLAIM 0x0004 /* fsync: hint: vnode is being reclaimed */
|
||||
|
||||
#define HOLDRELE(vp) holdrele(vp)
|
||||
#define VHOLD(vp) vhold(vp)
|
||||
@ -483,6 +484,7 @@ int vn_stat __P((struct vnode *vp, struct stat *sb, struct proc *p));
|
||||
int vn_write __P((struct file *fp, off_t *offset, struct uio *uio,
|
||||
struct ucred *cred, int flags));
|
||||
int vn_writechk __P((struct vnode *vp));
|
||||
int vn_isunder __P((struct vnode *dvp, struct vnode *rvp, struct proc *p));
|
||||
struct vnode *
|
||||
checkalias __P((struct vnode *vp, dev_t nvp_rdev, struct mount *mp));
|
||||
void vput __P((struct vnode *vp));
|
||||
|
||||
Loading…
Reference in New Issue
Block a user