linux/fs/ocfs2/locks.c
Thomas Gleixner 328970de0e treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 145
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 84 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190524100844.756442981@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:25:18 -07:00

131 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- 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.
*/
#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;
struct file_lock request;
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.
*/
locks_init_lock(&request);
request.fl_type = F_UNLCK;
request.fl_flags = FL_FLOCK;
locks_lock_file_wait(file, &request);
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 = locks_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 = locks_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 locks_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);
}