ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
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; }