Re: [9fans] p9p vac/vacfs compatibility: uid/gid, ctime, 9P2000.L, 9pserve

[David du Colombier <0intro@gmail.com>]

> Would you care to share?

Sure. But beware it's just a quick hack.

diff -r 92a579c6549c src/cmd/9pfuse/main.c
--- a/src/cmd/9pfuse/main.c     Mon Dec 12 16:44:50 2011 -0500
+++ b/src/cmd/9pfuse/main.c     Mon Jan 02 19:00:00 2012 +0100
@@ -837,6 +837,8 @@
 void
 fusereadlink(FuseMsg *m)
 {
+       int n;
+       uchar *buf;
        Dir *d;
        CFid *fid;

@@ -852,9 +854,19 @@
                replyfuseerrno(m, EINVAL);
                return;
        }
-       replyfuse(m, d->ext, strlen(d->ext));
+       n = d->length;
        free(d);
-       return;
+       if(n > fusemaxwrite)
+               n = fusemaxwrite;
+       buf = emalloc(n);
+       n = fsread(fid, buf, n);
+       if(n < 0){
+               free(buf);
+               replyfuseerrstr(m);
+               return;
+       }
+       replyfuse(m, buf, n);
+       free(buf);
 }

 /*
diff -r 92a579c6549c src/cmd/vac/vacfs.c
--- a/src/cmd/vac/vacfs.c       Mon Dec 12 16:44:50 2011 -0500
+++ b/src/cmd/vac/vacfs.c       Mon Jan 02 19:00:00 2012 +0100
@@ -548,8 +548,6 @@
                n = vacdirread(f, buf, off, cnt);
        else if(vacfilegetmode(f->file)&ModeDevice)
                return vtstrdup("device");
-       else if(vacfilegetmode(f->file)&ModeLink)
-               return vtstrdup("symbolic link");
        else if(vacfilegetmode(f->file)&ModeNamedPipe)
                return vtstrdup("named pipe");
        else

Then symlinks are working. Now you need to fix the uid/gid
problem and handle devices, named pipes and sockets in 9pserve.

Also, you should apply this patch:

http://codereview.appspot.com/download/issue5500097_1.diff

It fixes two problems:

 - fix segfault when the first file is DMSYMLINK or DMDEVICE,
 - set the buffer to zero before calling readlink.

Symlinks will not work without this patch.

--
David du Colombier