mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 16:24:13 +08:00
5970e15dbc
The file locking definitions have lived in fs.h since the dawn of time, but they are only used by a small subset of the source files that include it. Move the file locking definitions to a new header file, and add the appropriate #include directives to the source files that need them. By doing this we trim down fs.h a bit and limit the amount of rebuilding that has to be done when we make changes to the file locking APIs. Reviewed-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Chuck Lever <chuck.lever@oracle.com> Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com> Acked-by: Steve French <stfrench@microsoft.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Jeff Layton <jlayton@kernel.org>
126 lines
2.6 KiB
C
126 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* locks.c
|
|
*
|
|
* Userspace file locking support
|
|
*
|
|
* Copyright (C) 2007 Oracle. All rights reserved.
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/filelock.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 ((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;
|
|
|
|
return ocfs2_plock(osb->cconn, OCFS2_I(inode)->ip_blkno, file, cmd, fl);
|
|
}
|