ref: a8083462e62459b2ae8a243dc4ba88416eba03b1
dir: /liblogfs/walk.c/
#include "logfsos.h"
#include "logfs.h"
#include "fcall.h"
#include "local.h"
char *
logfsserverwalk(LogfsServer *server, u32int fid, u32int newfid, ushort nwname, char **wname, ushort *nwqid, Qid *wqid)
{
ushort i;
Entry *e;
char *errmsg;
Fid *f;
if(server->trace > 1) {
print("logfsserverwalk(%ud, %ud, %ud, \"", fid, newfid, nwname);
for(i = 0; i < nwname; i++) {
if(i > 0)
print("/");
print("%s", wname[i]);
}
print("\")\n");
}
f = logfsfidmapfindentry(server->fidmap, fid);
if(f == nil)
return logfsebadfid;
if(f->openmode >= 0)
return logfsefidopen;
errmsg = nil;
e = f->entry;
if(e->deadandgone)
return Eio;
for(i = 0; i < nwname; i++) {
Entry *se;
/*
* deal with ..
*/
if(strcmp(wname[i], "..") == 0)
se = e->parent;
else if(strcmp(wname[i], ".") == 0)
se = e;
else {
/*
* is it a directory?
*/
if((e->qid.type & QTDIR) == 0) {
errmsg = Enotdir;
break;
}
/*
* can we walk the walk, or just talk the protocol?
*/
if(!logfsuserpermcheck(server, e, f, DMEXEC)) {
errmsg = Eperm;
break;
}
/*
* search current entry for nwname[i]
*/
for(se = e->u.dir.list; se; se = se->next)
if(strcmp(se->name, wname[i]) == 0)
break;
if(se == nil) {
errmsg = Enonexist;
break;
}
}
wqid[i] = se->qid;
e = se;
}
if(nwname > 0 && i == 0) {
/*
* fell at the first fence
*/
return errmsg;
}
*nwqid = i;
if(i < nwname)
return nil;
/*
* new fid required?
*/
if(fid != newfid) {
Fid *newf;
char *errmsg;
errmsg = logfsfidmapnewentry(server->fidmap, newfid, &newf);
if(errmsg)
return errmsg;
if(newf == nil)
return logfsefidinuse;
newf->entry = e;
newf->uname = f->uname;
e->inuse++;
}
else {
/*
* this may now be right
* 1. increment reference on new entry first in case e and f->entry are the same
* 2. clunk the old one in case this has the effect of removing an old entry
* 3. dump the directory read state if the entry has changed
*/
e->inuse++;
logfsentryclunk(f->entry);
if(e != f->entry)
logfsdrsfree(&f->drs);
f->entry = e;
}
return nil;
}