Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / ocfs2 / locks.c

diff --git a/kernel/fs/ocfs2/locks.c b/kernel/fs/ocfs2/locks.c
new file mode 100644 (file)
index 0000000..6b6d092
--- /dev/null
+++ b/kernel/fs/ocfs2/locks.c
@@ -0,0 +1,141 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * locks.c
+ *
+ * Userspace file locking support
+ *
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * 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 of the License, 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/fcntl.h>
+
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "dlmglue.h"
+#include "file.h"
+#include "inode.h"
+#include "locks.h"
+
+static int ocfs2_do_flock(struct file *file, struct inode *inode,
+                         int cmd, struct file_lock *fl)
+{
+       int ret = 0, level = 0, trylock = 0;
+       struct ocfs2_file_private *fp = file->private_data;
+       struct ocfs2_lock_res *lockres = &fp->fp_flock;
+
+       if (fl->fl_type == F_WRLCK)
+               level = 1;
+       if (!IS_SETLKW(cmd))
+               trylock = 1;
+
+       mutex_lock(&fp->fp_mutex);
+
+       if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
+           lockres->l_level > LKM_NLMODE) {
+               int old_level = 0;
+
+               if (lockres->l_level == LKM_EXMODE)
+                       old_level = 1;
+
+               if (level == old_level)
+                       goto out;
+
+               /*
+                * Converting an existing lock is not guaranteed to be
+                * atomic, so we can get away with simply unlocking
+                * here and allowing the lock code to try at the new
+                * level.
+                */
+
+               flock_lock_file_wait(file,
+                                    &(struct file_lock){.fl_type = F_UNLCK});
+
+               ocfs2_file_unlock(file);
+       }
+
+       ret = ocfs2_file_lock(file, level, trylock);
+       if (ret) {
+               if (ret == -EAGAIN && trylock)
+                       ret = -EWOULDBLOCK;
+               else
+                       mlog_errno(ret);
+               goto out;
+       }
+
+       ret = flock_lock_file_wait(file, fl);
+       if (ret)
+               ocfs2_file_unlock(file);
+
+out:
+       mutex_unlock(&fp->fp_mutex);
+
+       return ret;
+}
+
+static int ocfs2_do_funlock(struct file *file, int cmd, struct file_lock *fl)
+{
+       int ret;
+       struct ocfs2_file_private *fp = file->private_data;
+
+       mutex_lock(&fp->fp_mutex);
+       ocfs2_file_unlock(file);
+       ret = flock_lock_file_wait(file, fl);
+       mutex_unlock(&fp->fp_mutex);
+
+       return ret;
+}
+
+/*
+ * Overall flow of ocfs2_flock() was influenced by gfs2_flock().
+ */
+int ocfs2_flock(struct file *file, int cmd, struct file_lock *fl)
+{
+       struct inode *inode = file->f_mapping->host;
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+       if (!(fl->fl_flags & FL_FLOCK))
+               return -ENOLCK;
+       if (__mandatory_lock(inode))
+               return -ENOLCK;
+
+       if ((osb->s_mount_opt & OCFS2_MOUNT_LOCALFLOCKS) ||
+           ocfs2_mount_local(osb))
+               return flock_lock_file_wait(file, fl);
+
+       if (fl->fl_type == F_UNLCK)
+               return ocfs2_do_funlock(file, cmd, fl);
+       else
+               return ocfs2_do_flock(file, inode, cmd, fl);
+}
+
+int ocfs2_lock(struct file *file, int cmd, struct file_lock *fl)
+{
+       struct inode *inode = file->f_mapping->host;
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+       if (!(fl->fl_flags & FL_POSIX))
+               return -ENOLCK;
+       if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
+               return -ENOLCK;
+
+       return ocfs2_plock(osb->cconn, OCFS2_I(inode)->ip_blkno, file, cmd, fl);
+}