2003-08-03 Marco Gerards <metgerards@student.han.nl>

	* fatfs.h (struct disknode): New member DIRNODE.
	* inode.c (read_node): Added assertion to be sure the directory
	can always be found.  Add directory dependancy to node by
	initializing DIRNODE and holding a reference.
	(diskfs_node_norefs): Release reference to DIRNODE.
	(write_node): Don't use diskfs_cached_lookup to lookup the
	directory, use DIRNODE instead and lock DP.  Don't use diskfs_nput,
	use mutex_unlock instead.
	(diskfs_alloc_node): Add directory dependancy to node by
	initializing DIRNODE and holding a reference.

3 files changed, 73 insertions, 32 deletions

diff --git a/fatfs/ChangeLog b/fatfs/ChangeLog
index 63c9fcb4..3c5acce8 100644
--- a/fatfs/ChangeLog
+++ b/fatfs/ChangeLog
@@ -1,3 +1,16 @@
+2003-08-03  Marco Gerards  <metgerards@student.han.nl>
+
+	* fatfs.h (struct disknode): New member DIRNODE.
+	* inode.c (read_node): Added assertion to be sure the directory
+	can always be found.  Add directory dependancy to node by
+	initializing DIRNODE and holding a reference.
+	(diskfs_node_norefs): Release reference to DIRNODE.
+	(write_node): Don't use diskfs_cached_lookup to lookup the
+	directory, use DIRNODE instead and lock DP.  Don't use diskfs_nput,
+	use mutex_unlock instead.
+	(diskfs_alloc_node): Add directory dependancy to node by
+	initializing DIRNODE and holding a reference.
+
 2003-08-05  Marcus Brinkmann  <marcus@gnu.org>
 
 	* fat.c (fat_read_sblock): Catch error from store_read.
diff --git a/fatfs/fatfs.h b/fatfs/fatfs.h
index 943ccad3..16b058a8 100644
--- a/fatfs/fatfs.h
+++ b/fatfs/fatfs.h
@@ -42,6 +42,9 @@ struct disknode
   /* The inode as returned by virtual inode management routines.  */
   inode_t inode;
 
+  /* The directory that hold this file, always hold a reference.  */
+  struct node *dirnode;
+
   struct rwlock dirent_lock;
     
   char *link_target;            /* For S_ISLNK.  */
diff --git a/fatfs/inode.c b/fatfs/inode.c
index f8780eb5..9122fee4 100644
--- a/fatfs/inode.c
+++ b/fatfs/inode.c
@@ -223,6 +223,15 @@ diskfs_node_norefs (struct node *np)
   if (np->dn->translator)
     free (np->dn->translator);
 
+  /* It is safe to unlock diskfs_node_refcnt_lock here for a while because
+     all references to the node have been deleted.  */
+  if (np->dn->dirnode)
+    {
+      spin_unlock (&diskfs_node_refcnt_lock);
+      diskfs_nrele (np->dn->dirnode);
+      spin_lock (&diskfs_node_refcnt_lock);
+    }
+
   assert (!np->dn->pager);
 
   free (np->dn);
@@ -255,7 +264,7 @@ diskfs_new_hardrefs (struct node *np)
 static error_t
 read_node (struct node *np, vm_address_t buf)
 {
-  /* XXX This needs careful investigation */
+  /* XXX This needs careful investigation.  */
   error_t err;
   struct stat *st = &np->dn_stat;
   struct disknode *dn = np->dn;
@@ -267,6 +276,30 @@ read_node (struct node *np, vm_address_t buf)
   vm_size_t buflen = 0;
   int our_buf = 0;
 
+  st->st_fstype = FSTYPE_MSLOSS;
+  st->st_fsid = getpid ();
+  st->st_ino = np->cache_id;
+  st->st_gen = 0;
+  st->st_rdev = 0;
+
+  st->st_nlink = 1;
+  st->st_uid = fs_uid;
+  st->st_gid = fs_gid;
+
+  st->st_rdev = 0;
+
+  np->dn->translator = 0;
+  np->dn->translen = 0;
+
+  st->st_flags = 0;
+
+  /* FIXME: If we are called through diskfs_alloc_node for a newly
+     allocated node that has no directory entry yet, only set a
+     minimal amount of data until the dirent is created (and we get
+     called a second time?).  */
+  if (vk.dir_inode == 0 && vk.dir_offset == (void *) 2)
+    return 0;
+
   if (vk.dir_inode == 0)
     dr = &dr_root_node;
   else
@@ -277,6 +310,7 @@ read_node (struct node *np, vm_address_t buf)
 	     by libdiskfs.  The only case it is not locked is for NFS
 	     (fsys_getfile) and we disabled that.  */
 	  dp = ifind (vk.dir_inode);
+	  assert (dp);
       
 	  /* Map in the directory contents. */
 	  memobj = diskfs_get_filemap (dp, prot);
@@ -294,30 +328,10 @@ read_node (struct node *np, vm_address_t buf)
       dr = (struct dirrect *) (buf + vk.dir_offset);
     }
 
-  st->st_fstype = FSTYPE_MSLOSS;
-  st->st_fsid = getpid ();
-  st->st_ino = np->cache_id;
-  st->st_gen = 0;
-  st->st_rdev = 0;
-
-  st->st_nlink = 1;
-  st->st_uid = fs_uid;
-  st->st_gid = fs_gid;
-
-  st->st_rdev = 0;
-
-  np->dn->translator = 0;
-  np->dn->translen = 0;
-
-  st->st_flags = 0;
-
-  /* If we are called for a newly allocated node that has no directory
-     entry yet, only set a minimal amount of data until the dirent is
-     created (and we get called a second time?).  */
-  /* We will avoid this by overriding the relevant functions.
-     if (dr == (void *)1)
-     return 0;
-  */
+  /* Files in fatfs depend on the directory that hold the file.  */
+  np->dn->dirnode = dp;
+  if (dp)
+    dp->references++;
 
   rwlock_reader_lock(&np->dn->dirent_lock);
 
@@ -464,15 +478,20 @@ write_node (struct node *np)
     {
       assert (!diskfs_readonly);
 
-      err = diskfs_cached_lookup (vk.dir_inode, &dp);
-      if (err)
-	return;
+      dp = np->dn->dirnode;
+      assert (dp);
+
+      mutex_lock (&dp->lock);
 
       /* Map in the directory contents. */
       memobj = diskfs_get_filemap (dp, prot);
 
       if (memobj == MACH_PORT_NULL)
-	return;
+	{
+	  mutex_unlock (&dp->lock);
+	  /* FIXME: We shouldn't ignore this error.  */
+	  return;
+	}
 
       buflen = round_page (dp->dn_stat.st_size);
       err = vm_map (mach_task_self (),
@@ -487,7 +506,7 @@ write_node (struct node *np)
 
       write_dword (dr->file_size, st->st_size);
 
-      /* Write time. */
+      /* Write time.  */
       fat_from_epoch ((unsigned char *) &dr->write_date,
 		      (unsigned char *) &dr->write_time, &st->st_mtime);
 
@@ -495,7 +514,7 @@ write_node (struct node *np)
       np->dn_stat_dirty = 0;
 
       munmap ((caddr_t) buf, buflen);
-      diskfs_nput (dp);
+      mutex_unlock (&dp->lock);
     }
 }
 
@@ -745,7 +764,9 @@ diskfs_alloc_node (struct node *dir, mode_t mode, struct node **node)
   
   assert (!diskfs_readonly);
 
-  err = vi_new((struct vi_key) {0,1} /* XXX not allocated yet */, &inum, &inode);
+  /* FIXME: We use a magic key here that signals read_node that we are
+     not entered in any directory yet.  */
+  err = vi_new((struct vi_key) {0,2}, &inum, &inode);
   if (err)
     return err;
 
@@ -753,6 +774,10 @@ diskfs_alloc_node (struct node *dir, mode_t mode, struct node **node)
   if (err)
     return err;
 
+  /* FIXME: We know that readnode couldn't put this in.  */
+  np->dn->dirnode = dir;
+  dir->references++;
+
   *node = np;
   return 0;
 }