1 files changed, 108 insertions, 0 deletions
diff --git a/liblogfs/walk.c b/liblogfs/walk.c
new file mode 100644
index 00000000..05ae3f9c
--- /dev/null
+++ b/liblogfs/walk.c
@@ -0,0 +1,108 @@
+#include "lib9.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;
+}
+