1 files changed, 133 insertions, 0 deletions
diff --git a/libdiskfs/dir-link.c b/libdiskfs/dir-link.c
new file mode 100644
index 00000000..7cc88633
--- /dev/null
+++ b/libdiskfs/dir-link.c
@@ -0,0 +1,133 @@
+/* libdiskfs implementation of fs.defs: dir_link
+   Copyright (C) 1992,93,94,95,96,97,99 Free Software Foundation, Inc.
+
+   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"
+#include "fs_S.h"
+
+/* Implement dir_link as described in <hurd/fs.defs>. */
+kern_return_t
+diskfs_S_dir_link (struct protid *dircred,
+		   struct protid *filecred,
+		   char *name,
+		   int excl)
+{
+  struct node *np;		/* node being linked */
+  struct node *tnp;		/* node being deleted implicitly */
+  struct node *dnp;		/* directory of new entry */
+  struct dirstat *ds = alloca (diskfs_dirstat_size);
+  error_t error;
+
+  if (!dircred)
+    return EOPNOTSUPP;
+
+  if (diskfs_check_readonly ())
+    return EROFS;
+
+  if (!filecred)
+    return EXDEV;
+
+  np = filecred->po->np;
+  mutex_lock (&np->lock);
+  if (S_ISDIR (np->dn_stat.st_mode))
+    {
+      mutex_unlock (&np->lock);
+      return EISDIR;
+    }
+  mutex_unlock (&np->lock);
+
+  dnp = dircred->po->np;
+  mutex_lock (&dnp->lock);
+
+  /* Lookup new location */
+  error = diskfs_lookup (dnp, name, RENAME, &tnp, ds, dircred);
+  if (!error && excl)
+    {
+      error = EEXIST;
+      diskfs_nput (tnp);
+    }
+  if (error && error != ENOENT)
+    {
+      if (error == EAGAIN)
+	error = EINVAL;
+      diskfs_drop_dirstat (dnp, ds);
+      mutex_unlock (&dnp->lock);
+      return error;
+    }
+
+  if (np == tnp)
+    {
+      diskfs_drop_dirstat (dnp, ds);
+      mutex_unlock (&dnp->lock);
+      mutex_unlock (&tnp->lock);
+      mach_port_deallocate (mach_task_self (), filecred->pi.port_right);
+      return 0;
+    }
+
+  if (tnp && S_ISDIR (tnp->dn_stat.st_mode))
+    {
+      diskfs_drop_dirstat (dnp, ds);
+      mutex_unlock (&dnp->lock);
+      mutex_unlock (&tnp->lock);
+      return EISDIR;
+    }
+
+  /* Create new entry for NP */
+
+  /* This is safe because NP is not a directory (thus not DNP) and
+     not TNP and is a leaf. */
+  mutex_lock (&np->lock);
+
+  /* Increment link count */
+  if (np->dn_stat.st_nlink == diskfs_link_max - 1)
+    {
+      diskfs_drop_dirstat (dnp, ds);
+      mutex_unlock (&np->lock);
+      mutex_unlock (&dnp->lock);
+      return EMLINK;
+    }
+  np->dn_stat.st_nlink++;
+  np->dn_set_ctime = 1;
+  diskfs_node_update (np, 1);
+
+  /* Attach it */
+  if (tnp)
+    {
+      assert (!excl);
+      error = diskfs_dirrewrite (dnp, tnp, np, name, ds);
+      if (!error)
+	{
+	  /* Deallocate link on TNP */
+	  tnp->dn_stat.st_nlink--;
+	  tnp->dn_set_ctime = 1;
+	  if (diskfs_synchronous)
+	    diskfs_node_update (tnp, 1);
+	}
+      diskfs_nput (tnp);
+    }
+  else
+    error = diskfs_direnter (dnp, name, np, ds, dircred);
+
+  if (diskfs_synchronous)
+    diskfs_node_update (dnp, 1);
+
+  mutex_unlock (&dnp->lock);
+  mutex_unlock (&np->lock);
+  if (!error)
+    /* MiG won't do this for us, which it ought to. */
+    mach_port_deallocate (mach_task_self (), filecred->pi.port_right);
+  return error;
+}