From f89d273c01e149c574f57e329fa4d58aba71812d Mon Sep 17 00:00:00 2001
From: David Crawshaw <david@zentus.com>
Date: Sat, 30 Jun 2007 03:34:40 -0700
Subject: [PATCH] support unlink before close (from Joe Wilson)

darcs-hash:20070630103440-0c629-4f1eec911ced256699d8278ef038e7f8fb073561.gz
---
 src/org/ibex/nestedvm/Runtime.java     |   18 +++++++++++++-----
 src/org/ibex/nestedvm/UnixRuntime.java |   30 +++++++++++++++++++++++++++---
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/src/org/ibex/nestedvm/Runtime.java b/src/org/ibex/nestedvm/Runtime.java
index 8e6b5f0..161e3a9 100644
--- a/src/org/ibex/nestedvm/Runtime.java
+++ b/src/org/ibex/nestedvm/Runtime.java
@@ -698,18 +698,18 @@ public abstract class Runtime implements UsermodeConstants,Registers,Cloneable {
         return i;
     }
 
-    /** Hook for subclasses to do something when the process closes an FD */
-    void _closedFD(FD fd) {  }
+    /** Hooks for subclasses before and after the process closes an FD */
+    void _preCloseFD(FD fd) {  }
+    void _postCloseFD(FD fd) {  }
 
     /** Closes file descriptor <i>fdn</i> and removes it from the file descriptor table */
     public final boolean closeFD(int fdn) {
         if(state == EXITED || state == EXECED) throw new IllegalStateException("closeFD called in inappropriate state");
         if(fdn < 0 || fdn >= OPEN_MAX) return false;
         if(fds[fdn] == null) return false;
-
-        _closedFD(fds[fdn]);
-
+        _preCloseFD(fds[fdn]);
         fds[fdn].close();
+        _postCloseFD(fds[fdn]);
         fds[fdn] = null;        
         return true;
     }
@@ -1209,6 +1209,14 @@ public abstract class Runtime implements UsermodeConstants,Registers,Cloneable {
     /** File Descriptor class */
     public static abstract class FD {
         private int refCount = 1;
+        private String normalizedPath = null;
+        private boolean deleteOnClose = false;
+
+        public void setNormalizedPath(String path) { normalizedPath = path; }
+        public String getNormalizedPath() { return normalizedPath; }
+
+        public void markDeleteOnClose() { deleteOnClose = true; }
+        public boolean isMarkedForDeleteOnClose() { return deleteOnClose; }
         
         /** Read some bytes. Should return the number of bytes read, 0 on EOF, or throw an IOException on error */
         public int read(byte[] a, int off, int length) throws ErrnoException { throw new ErrnoException(EBADFD); }
diff --git a/src/org/ibex/nestedvm/UnixRuntime.java b/src/org/ibex/nestedvm/UnixRuntime.java
index 0291ab8..fed82d0 100644
--- a/src/org/ibex/nestedvm/UnixRuntime.java
+++ b/src/org/ibex/nestedvm/UnixRuntime.java
@@ -164,7 +164,10 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
     }
     
     FD _open(String path, int flags, int mode) throws ErrnoException {
-        return gs.open(this,normalizePath(path),flags,mode);
+        path = normalizePath(path);
+        FD fd = gs.open(this,path,flags,mode);
+        if (fd != null && path != null) fd.setNormalizedPath(path);
+        return fd;
     }
     
     private int sys_getppid() {
@@ -703,7 +706,7 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
         return n;
     }
 
-    void _closedFD(FD fd) {
+    void _preCloseFD(FD fd) {
         // release all fcntl locks on this file
         Seekable s = fd.seekable();
         if (s == null) return;
@@ -720,6 +723,13 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
         } catch (IOException e) { throw new RuntimeException(e); }
     }
 
+    void _postCloseFD(FD fd) {
+        if (fd.isMarkedForDeleteOnClose()) {
+            try { gs.unlink(this, fd.getNormalizedPath()); }
+            catch (Throwable t) {}
+        }
+    }
+
     /** Implements the F_GETLK and F_SETLK cases of fcntl syscall.
      *  If l_start = 0 and l_len = 0 the lock refers to the entire file.
      *  Uses GlobalState to ensure locking across processes in the same JVM.
@@ -1617,7 +1627,21 @@ public abstract class UnixRuntime extends Runtime implements Cloneable {
             File f = hostFile(path);
             if(r.sm != null && !r.sm.allowUnlink(f)) throw new ErrnoException(EPERM);
             if(!f.exists()) throw new ErrnoException(ENOENT);
-            if(!f.delete()) throw new ErrnoException(EPERM);
+            if(!f.delete()) {
+                // Can't delete file immediately, so mark for
+                // delete on close all matching FDs
+                boolean marked = false;
+                for(int i=0;i<OPEN_MAX;i++) {
+                    if(r.fds[i] != null) {
+                        String fdpath = r.fds[i].getNormalizedPath();
+                        if(fdpath != null && fdpath.equals(path)) {
+                            r.fds[i].markDeleteOnClose();
+                            marked = true;
+                        }
+                    }
+                }
+                if(!marked) throw new ErrnoException(EPERM);
+            }
         }
         
         public FStat stat(UnixRuntime r, String path) throws ErrnoException {
-- 
1.7.10.4