linux-stable/fs/ocfs2/ocfs2_lockid.h
Mark Fasheh cf8e06f1a8 [PATCH 1/2] ocfs2: add flock lock type
This adds a new dlmglue lock type which is intended to back flock()
requests.

Since these locks are driven from userspace, usage rules are much more
liberal than the typical Ocfs2 internal cluster lock. As a result, we can't
make use of most dlmglue features - lock caching and lock level
optimizations in particular. Additionally, userspace is free to deadlock
itself, so we have to deal with that in the same way as the rest of the
kernel - by allowing a signal to abort a lock request.

In order to keep ocfs2_cluster_lock() complexity down, ocfs2_file_lock()
does it's own dlm coordination. We still use the same helper functions
though, so duplicated code is kept to a minimum.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2008-01-25 15:05:43 -08:00

108 lines
2.7 KiB
C

/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* ocfs2_lockid.h
*
* Defines OCFS2 lockid bits.
*
* Copyright (C) 2002, 2005 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.
*/
#ifndef OCFS2_LOCKID_H
#define OCFS2_LOCKID_H
/* lock ids are made up in the following manner:
* name[0] --> type
* name[1-6] --> 6 pad characters, reserved for now
* name[7-22] --> block number, expressed in hex as 16 chars
* name[23-30] --> i_generation, expressed in hex 8 chars
* name[31] --> '\0' */
#define OCFS2_LOCK_ID_MAX_LEN 32
#define OCFS2_LOCK_ID_PAD "000000"
#define OCFS2_DENTRY_LOCK_INO_START 18
enum ocfs2_lock_type {
OCFS2_LOCK_TYPE_META = 0,
OCFS2_LOCK_TYPE_DATA,
OCFS2_LOCK_TYPE_SUPER,
OCFS2_LOCK_TYPE_RENAME,
OCFS2_LOCK_TYPE_RW,
OCFS2_LOCK_TYPE_DENTRY,
OCFS2_LOCK_TYPE_OPEN,
OCFS2_LOCK_TYPE_FLOCK,
OCFS2_NUM_LOCK_TYPES
};
static inline char ocfs2_lock_type_char(enum ocfs2_lock_type type)
{
char c;
switch (type) {
case OCFS2_LOCK_TYPE_META:
c = 'M';
break;
case OCFS2_LOCK_TYPE_DATA:
c = 'D';
break;
case OCFS2_LOCK_TYPE_SUPER:
c = 'S';
break;
case OCFS2_LOCK_TYPE_RENAME:
c = 'R';
break;
case OCFS2_LOCK_TYPE_RW:
c = 'W';
break;
case OCFS2_LOCK_TYPE_DENTRY:
c = 'N';
break;
case OCFS2_LOCK_TYPE_OPEN:
c = 'O';
break;
case OCFS2_LOCK_TYPE_FLOCK:
c = 'F';
break;
default:
c = '\0';
}
return c;
}
static char *ocfs2_lock_type_strings[] = {
[OCFS2_LOCK_TYPE_META] = "Meta",
[OCFS2_LOCK_TYPE_DATA] = "Data",
[OCFS2_LOCK_TYPE_SUPER] = "Super",
[OCFS2_LOCK_TYPE_RENAME] = "Rename",
/* Need to differntiate from [R]ename.. serializing writes is the
* important job it does, anyway. */
[OCFS2_LOCK_TYPE_RW] = "Write/Read",
[OCFS2_LOCK_TYPE_DENTRY] = "Dentry",
[OCFS2_LOCK_TYPE_OPEN] = "Open",
[OCFS2_LOCK_TYPE_FLOCK] = "Flock",
};
static inline const char *ocfs2_lock_type_string(enum ocfs2_lock_type type)
{
#ifdef __KERNEL__
mlog_bug_on_msg(type >= OCFS2_NUM_LOCK_TYPES, "%d\n", type);
#endif
return ocfs2_lock_type_strings[type];
}
#endif /* OCFS2_LOCKID_H */