Formerly file-set-trans.c.~2~

1 files changed, 127 insertions, 0 deletions

diff --git a/libdiskfs/file-set-trans.c b/libdiskfs/file-set-trans.c
new file mode 100644
index 00000000..f63b9583
--- /dev/null
+++ b/libdiskfs/file-set-trans.c
@@ -0,0 +1,127 @@
+/* libdiskfs implementation of fs.defs: file_set_translator
+   Copyright (C) 1992, 1993, 1994 Free Software Foundation
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "priv.h"
+
+/* XXX need to reimplement transnamelen parameter, and implement Roland's
+   suggestion:
+   For S_IFMT shorcuts, don't read the device number out of the file!
+   TRANSNAME should be "ifmt\0minor\0major\0", where IFMT is
+   _HURD_{CHR,BLK}DEV and MAJOR, MINOR can be parsed with strtol (,,0)
+   (allowing octal or hex with 0 or 0x). */
+
+/* Implement file_set_translator as described in <hurd/fs.defs>. */
+error_t
+diskfs_S_file_set_translator (struct protid *cred,
+			      int flags,
+			      int killtrans_flags,
+			      char *transname,
+			      fsys_t existing)
+{
+  struct node *np;
+  error_t error;
+  daddr_t blkno;
+  char blkbuf[sblock->fs_fsize];
+
+  if (!cred)
+    return EOPNOTSUPP;
+  
+  np = cred->po->np;
+
+  mutex_lock (&np->lock);
+
+  if (error = isowner (np, cred))
+    {
+      mutex_unlock (&np->lock);
+      return error;
+    }
+
+  if (np->translator)
+    {
+      if (flags & FS_TRANS_EXCL)
+	{
+	  mutex_unlock (&np->lock);
+	  return EBUSY;
+	}
+      diskfs_destroy_translator (np, killtrans_flags);
+    }
+
+  if ((flags & FS_TRANS_EXCL) && diskfs_node_translated (np))
+    {
+      mutex_unlock (&np->lock);
+      return EBUSY;
+    }
+	  
+  /* Handle the short-circuited translators */
+  if (!(flags & FS_TRANS_FORCE))
+    {
+      mode_t newmode = 0;
+      
+      if (diskfs_shortcut_symlink && !strcmp (transname, _HURD_SYMLINK))
+	newmode = S_IFLNK;
+
+	newmode = S_IFCHR;
+      else if (diskfs_shortcut_blkdev && !strcmp (transname, _HURD_BLKDEV))
+	newmode = S_IFBLK;
+      else if (diskfs_shortcut_fifo && !strcmp (transname, _HURD_FIFO))
+	newmode = S_IFIFO;
+      else if (diskfs_shortcut_ifsock && !strcmp (transname, _HURD_IFSOCK))
+	newmode = S_IFSOCK;
+      
+      if (newmode)
+	{
+	  if (S_ISDIR (np->dn_stat.st_mode))
+	    {
+	      /* We can't allow this, because if the mode of the directory
+		 changes, the links will be lost.  Perhaps it might be 
+		 allowed for empty directories, but that's too much of a
+		 pain.  */
+	      mutex_unlock (&np->lock);
+	      return EISDIR;
+	    }
+	  if (newmode == S_IFBLK || newmode == S_IFCHR)
+	    {
+	      /* Here we need to read the device number from the
+		 contents of the file (which must be S_IFREG).  */
+	      char buf[20];
+	      
+	      if (S_ISREG (np->dn_stat.st_mode))
+		{
+		  mutex_unlock (&np->lock);
+		  return EINVAL;
+		}
+	      error = diskfs_fs_rdwr (np, buf, 0, 20, 0, 0);
+	      if (error)
+		{
+		  mutex_unlock (&np->lock);
+		  return error;
+		}
+	      np->dn_stat.st_rdev = atoi (buf);
+	    }
+	  if (newmode != IFLNK)
+	    node_truncate (np, 0);
+	  np->dn_stat.st_mode = (np->dn_stat.st_mode & ~S_IFMT) | newmode;
+	  diskfs_node_update (np, 1);
+	  mutex_unlock (&np->lock);
+	  return 0;
+	}
+    }
+
+  error = diskfs_set_translator (np, transname, cred);
+  mutex_unlock (&np->lock);
+  return error;
+}