272 lines
6.9 KiB
C
272 lines
6.9 KiB
C
/*
|
|
* Copyright (c) 1994 Christian E. Hopps
|
|
* All rights reserved.
|
|
*
|
|
* 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 Christian E. Hopps.
|
|
* 4. The name of the author may not be used to endorse or promote products
|
|
* derived from this software without specific prior written permission
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
|
|
*
|
|
* $Id: adlookup.c,v 1.3 1994/05/31 03:13:41 chopps Exp $
|
|
*/
|
|
#include <sys/param.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/namei.h>
|
|
#include <sys/time.h>
|
|
#include <sys/queue.h>
|
|
#include <adosfs/adosfs.h>
|
|
|
|
#define strmatch(s1, l1, s2, l2) \
|
|
((l1) == (l2) && bcmp((s1), (s2), (l1)) == 0)
|
|
|
|
/*
|
|
* adosfs lookup. enters with:
|
|
* pvp (parent vnode) referenced and locked.
|
|
* exit with:
|
|
* target vp refernced and locked.
|
|
* unlock pvp unless LOCKPARENT and at end of search.
|
|
* special cases:
|
|
* pvp == vp, just ref pvp, pvp already holds a ref and lock from
|
|
* caller, this will not occur with RENAME or CREATE.
|
|
* LOOKUP always unlocks parent if last element. (not now!?!?)
|
|
*/
|
|
int
|
|
adosfs_lookup(pvp, ndp, p)
|
|
struct vnode *pvp;
|
|
struct nameidata *ndp;
|
|
struct proc *p;
|
|
{
|
|
int lockp, wantp, flag, error, last, cvalid, nocache, i;
|
|
struct amount *amp;
|
|
struct anode *pap, *ap;
|
|
struct buf *bp;
|
|
char *pelt;
|
|
u_long bn, plen, hval;
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("(adlookup ");
|
|
#endif
|
|
ndp->ni_dvp = pvp;
|
|
ndp->ni_vp = NULL;
|
|
pap = VTOA(pvp);
|
|
amp = pap->amp;
|
|
lockp = ndp->ni_nameiop & LOCKPARENT;
|
|
wantp = ndp->ni_nameiop & (LOCKPARENT | WANTPARENT);
|
|
flag = ndp->ni_nameiop & OPMASK;
|
|
pelt = ndp->ni_ptr;
|
|
plen = ndp->ni_namelen;
|
|
last = (*ndp->ni_next == 0);
|
|
nocache = 0;
|
|
|
|
/*
|
|
* check that:
|
|
* pvp is a dir, and that the user has rights to access
|
|
*/
|
|
if (pvp->v_type != VDIR) {
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("ENOTDIR)");
|
|
#endif
|
|
return(ENOTDIR);
|
|
}
|
|
if (error = VOP_ACCESS(pvp, VEXEC, ndp->ni_cred, p)) {
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("[VOP_ACCESS] %d)", error);
|
|
#endif
|
|
return(error);
|
|
}
|
|
/*
|
|
* cache lookup algorithm borrowed from ufs_lookup()
|
|
* its not consistent with otherthings in this function..
|
|
*/
|
|
if (error = cache_lookup(ndp)) {
|
|
if (error == ENOENT) {
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("[cache_lookup] %d)", error);
|
|
#endif
|
|
return(error);
|
|
}
|
|
|
|
ap = VTOA(ndp->ni_vp);
|
|
cvalid = ndp->ni_vp->v_id;
|
|
|
|
if (ap == pap) {
|
|
VREF(pvp);
|
|
error = 0;
|
|
} else if (ndp->ni_isdotdot) {
|
|
AUNLOCK(pap); /* race */
|
|
error = vget(ATOV(ap), 1);
|
|
if (error == 0 && lockp && last)
|
|
ALOCK(pap);
|
|
} else {
|
|
error = vget(ATOV(ap), 1);
|
|
if (lockp == 0 || error || last)
|
|
AUNLOCK(pap);
|
|
}
|
|
if (error == 0) {
|
|
if (cvalid == ATOV(ap)->v_id) {
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("[cache_lookup] 0)\n");
|
|
#endif
|
|
return(0);
|
|
}
|
|
aput(ap);
|
|
if (lockp && pap != ap && last)
|
|
AUNLOCK(pap);
|
|
}
|
|
ALOCK(pap);
|
|
ndp->ni_vp = NULL;
|
|
}
|
|
|
|
/*
|
|
* fake a '.'
|
|
*/
|
|
if (plen == 1 && pelt[0] == '.') {
|
|
/* see special cases in prologue. */
|
|
ap = pap;
|
|
goto found;
|
|
}
|
|
/*
|
|
* fake a ".."
|
|
*/
|
|
if (ndp->ni_isdotdot) {
|
|
if (pap->type == AROOT)
|
|
panic("adosfs .. attemped through root");
|
|
/*
|
|
* cannot get previous entry while later is locked
|
|
* eg procA holds lock on previous and wats for pap
|
|
* we wait for previous and hold lock on pap. deadlock.
|
|
* becuase pap may have been acheived through symlink
|
|
* fancy detection code that decreases the race
|
|
* window size is not reasonably possible.
|
|
*/
|
|
AUNLOCK(pap); /* race */
|
|
error = aget(amp->mp, pap->pblock, &ap);
|
|
if (error || (last && lockp))
|
|
ALOCK(pap);
|
|
if (error) {
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("[..] %d)", error);
|
|
#endif
|
|
return(error);
|
|
}
|
|
goto found_lockdone;
|
|
}
|
|
|
|
/*
|
|
* hash the name and grab the first block in chain
|
|
* then walk the chain. if chain has not been fully
|
|
* walked before, track the count in `tabi'
|
|
*/
|
|
hval = adoshash(pelt, plen, pap->ntabent);
|
|
bn = pap->tab[hval];
|
|
i = min(pap->tabi[hval], 0);
|
|
while (bn != 0) {
|
|
if (error = aget(amp->mp, bn, &ap)) {
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("[aget] %d)", error);
|
|
#endif
|
|
return(error);
|
|
}
|
|
if (i < 0) {
|
|
if (i < pap->tabi[hval])
|
|
pap->tabi[hval] = i;
|
|
i--;
|
|
if (ap->hashf == 0)
|
|
pap->tabi[hval] = -pap->tabi[hval];
|
|
}
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("%s =? %s", pelt, ap->name);
|
|
#endif
|
|
if (strmatch(pelt, plen, ap->name, strlen(ap->name)))
|
|
goto found;
|
|
bn = ap->hashf;
|
|
aput(ap);
|
|
}
|
|
/*
|
|
* not found
|
|
*/
|
|
if ((flag == CREATE || flag == RENAME) && last) {
|
|
if (error = VOP_ACCESS(pvp, VWRITE, ndp->ni_cred, p)) {
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("[VOP_ACCESS] %d)", error);
|
|
#endif
|
|
return(error);
|
|
}
|
|
if (lockp == 0)
|
|
AUNLOCK(pap);
|
|
ndp->ni_nameiop |= SAVENAME;
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("EJUSTRETURN)");
|
|
#endif
|
|
return(EJUSTRETURN);
|
|
}
|
|
if (ndp->ni_makeentry && flag != CREATE)
|
|
cache_enter(ndp);
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("ENOENT)");
|
|
#endif
|
|
return(ENOENT);
|
|
|
|
found:
|
|
if (last && flag == DELETE) {
|
|
if (error = VOP_ACCESS(pvp, VWRITE, ndp->ni_cred, p)) {
|
|
if (pap != ap)
|
|
aput(ap);
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("[VOP_ACCESS] %d)", error);
|
|
#endif
|
|
return(error);
|
|
}
|
|
nocache = 1;
|
|
}
|
|
if (last && flag == RENAME && wantp) {
|
|
if (pap == ap) {
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("EISDIR)");
|
|
#endif
|
|
return(EISDIR);
|
|
}
|
|
if (error = VOP_ACCESS(pvp, VWRITE, ndp->ni_cred, p)) {
|
|
aput(ap);
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("[VOP_ACCESS] %d)", error);
|
|
#endif
|
|
return(error);
|
|
}
|
|
ndp->ni_nameiop |= SAVENAME;
|
|
nocache = 1;
|
|
}
|
|
if (ap == pap)
|
|
VREF(pvp);
|
|
else if (lockp == 0 || last == 0)
|
|
AUNLOCK(pap);
|
|
found_lockdone:
|
|
ndp->ni_vp = ATOV(ap);
|
|
|
|
if (ndp->ni_makeentry && nocache == 0)
|
|
cache_enter(ndp);
|
|
#ifdef ADOSFS_DIAGNOSTIC
|
|
printf("0)\n");
|
|
#endif
|
|
return(0);
|
|
}
|