hjfs: defer parent directory permission check for wstat

check parent directory permission *after* we determined
that the new name does not exist in the parent, so that
when the new name is the same as old name then no write
permission is required in the parent directory.

diff --git a/sys/src/cmd/hjfs/fs2.c b/sys/src/cmd/hjfs/fs2.c
index 71658cfb3e110dda78853c490786ea1a6b8e5b63..4390404f1b3c46767bc204a2ebe4efbf5c943890 100644 (file)
--- a/sys/src/cmd/hjfs/fs2.c
+++ b/sys/src/cmd/hjfs/fs2.c
@@ -698,18 +698,17 @@ chanwstat(Chan *ch, Dir *di)
                d = getdent(ch->loc->next, pb);
                if(d == nil)
                        goto error;
-               if((ch->flags & CHFNOPERM) == 0)
-                       if(!permcheck(ch->fs, d, ch->uid, OWRITE))
-                               goto perm;
                rc = findentry(ch->fs, ch->loc->next, pb, di->name, &f, ch->flags & CHFDUMP);
-               if(rc > 0){
-                       if(f.blk == ch->loc->blk && f.deind == ch->loc->deind)
-                               rc = 0;
-                       else
-                               werrstr(Eexists);
-               }
-               if(rc != 0)
+               if(rc < 0)
+                       goto error;
+               else if(rc == 0){
+                       if((ch->flags & CHFNOPERM) == 0)
+                               if(!permcheck(ch->fs, d, ch->uid, OWRITE))
+                                       goto perm;
+               } else if(f.blk != ch->loc->blk || f.deind != ch->loc->deind){
+                       werrstr(Eexists);
                        goto error;
+               }
        }
        b = getbuf(ch->fs->d, ch->loc->blk, TDENTRY, 0);
        if(b == nil)