forked from luck/tmp_suning_uos_patched
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
205 lines
7.5 KiB
C
205 lines
7.5 KiB
C
/*
|
|
* Copyright (c) 2000-2003 Silicon Graphics, Inc. All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of version 2 of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it would be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
|
*
|
|
* Further, this software is distributed without any warranty that it is
|
|
* free of the rightful claim of any third person regarding infringement
|
|
* or the like. Any license provided herein, whether implied or
|
|
* otherwise, applies only to this software file. Patent licenses, if
|
|
* any, provided herein do not apply to combinations of this program with
|
|
* other software, or any other product whatsoever.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write the Free Software Foundation, Inc., 59
|
|
* Temple Place - Suite 330, Boston MA 02111-1307, USA.
|
|
*
|
|
* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
|
|
* Mountain View, CA 94043, or:
|
|
*
|
|
* http://www.sgi.com
|
|
*
|
|
* For further information regarding this notice, see:
|
|
*
|
|
* http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
|
|
*/
|
|
#ifndef __XFS_BEHAVIOR_H__
|
|
#define __XFS_BEHAVIOR_H__
|
|
|
|
/*
|
|
* Header file used to associate behaviors with virtualized objects.
|
|
*
|
|
* A virtualized object is an internal, virtualized representation of
|
|
* OS entities such as persistent files, processes, or sockets. Examples
|
|
* of virtualized objects include vnodes, vprocs, and vsockets. Often
|
|
* a virtualized object is referred to simply as an "object."
|
|
*
|
|
* A behavior is essentially an implementation layer associated with
|
|
* an object. Multiple behaviors for an object are chained together,
|
|
* the order of chaining determining the order of invocation. Each
|
|
* behavior of a given object implements the same set of interfaces
|
|
* (e.g., the VOP interfaces).
|
|
*
|
|
* Behaviors may be dynamically inserted into an object's behavior chain,
|
|
* such that the addition is transparent to consumers that already have
|
|
* references to the object. Typically, a given behavior will be inserted
|
|
* at a particular location in the behavior chain. Insertion of new
|
|
* behaviors is synchronized with operations-in-progress (oip's) so that
|
|
* the oip's always see a consistent view of the chain.
|
|
*
|
|
* The term "interpostion" is used to refer to the act of inserting
|
|
* a behavior such that it interposes on (i.e., is inserted in front
|
|
* of) a particular other behavior. A key example of this is when a
|
|
* system implementing distributed single system image wishes to
|
|
* interpose a distribution layer (providing distributed coherency)
|
|
* in front of an object that is otherwise only accessed locally.
|
|
*
|
|
* Note that the traditional vnode/inode combination is simply a virtualized
|
|
* object that has exactly one associated behavior.
|
|
*
|
|
* Behavior synchronization is logic which is necessary under certain
|
|
* circumstances that there is no conflict between ongoing operations
|
|
* traversing the behavior chain and those dunamically modifying the
|
|
* behavior chain. Because behavior synchronization adds extra overhead
|
|
* to virtual operation invocation, we want to restrict, as much as
|
|
* we can, the requirement for this extra code, to those situations
|
|
* in which it is truly necessary.
|
|
*
|
|
* Behavior synchronization is needed whenever there's at least one class
|
|
* of object in the system for which:
|
|
* 1) multiple behaviors for a given object are supported,
|
|
* -- AND --
|
|
* 2a) insertion of a new behavior can happen dynamically at any time during
|
|
* the life of an active object,
|
|
* -- AND --
|
|
* 3a) insertion of a new behavior needs to synchronize with existing
|
|
* ops-in-progress.
|
|
* -- OR --
|
|
* 3b) multiple different behaviors can be dynamically inserted at
|
|
* any time during the life of an active object
|
|
* -- OR --
|
|
* 3c) removal of a behavior can occur at any time during the life of
|
|
* an active object.
|
|
* -- OR --
|
|
* 2b) removal of a behavior can occur at any time during the life of an
|
|
* active object
|
|
*
|
|
*/
|
|
|
|
struct bhv_head_lock;
|
|
|
|
/*
|
|
* Behavior head. Head of the chain of behaviors.
|
|
* Contained within each virtualized object data structure.
|
|
*/
|
|
typedef struct bhv_head {
|
|
struct bhv_desc *bh_first; /* first behavior in chain */
|
|
struct bhv_head_lock *bh_lockp; /* pointer to lock info struct */
|
|
} bhv_head_t;
|
|
|
|
/*
|
|
* Behavior descriptor. Descriptor associated with each behavior.
|
|
* Contained within the behavior's private data structure.
|
|
*/
|
|
typedef struct bhv_desc {
|
|
void *bd_pdata; /* private data for this behavior */
|
|
void *bd_vobj; /* virtual object associated with */
|
|
void *bd_ops; /* ops for this behavior */
|
|
struct bhv_desc *bd_next; /* next behavior in chain */
|
|
} bhv_desc_t;
|
|
|
|
/*
|
|
* Behavior identity field. A behavior's identity determines the position
|
|
* where it lives within a behavior chain, and it's always the first field
|
|
* of the behavior's ops vector. The optional id field further identifies the
|
|
* subsystem responsible for the behavior.
|
|
*/
|
|
typedef struct bhv_identity {
|
|
__u16 bi_id; /* owning subsystem id */
|
|
__u16 bi_position; /* position in chain */
|
|
} bhv_identity_t;
|
|
|
|
typedef bhv_identity_t bhv_position_t;
|
|
|
|
#define BHV_IDENTITY_INIT(id,pos) {id, pos}
|
|
#define BHV_IDENTITY_INIT_POSITION(pos) BHV_IDENTITY_INIT(0, pos)
|
|
|
|
/*
|
|
* Define boundaries of position values.
|
|
*/
|
|
#define BHV_POSITION_INVALID 0 /* invalid position number */
|
|
#define BHV_POSITION_BASE 1 /* base (last) implementation layer */
|
|
#define BHV_POSITION_TOP 63 /* top (first) implementation layer */
|
|
|
|
/*
|
|
* Plumbing macros.
|
|
*/
|
|
#define BHV_HEAD_FIRST(bhp) (ASSERT((bhp)->bh_first), (bhp)->bh_first)
|
|
#define BHV_NEXT(bdp) (ASSERT((bdp)->bd_next), (bdp)->bd_next)
|
|
#define BHV_NEXTNULL(bdp) ((bdp)->bd_next)
|
|
#define BHV_VOBJ(bdp) (ASSERT((bdp)->bd_vobj), (bdp)->bd_vobj)
|
|
#define BHV_VOBJNULL(bdp) ((bdp)->bd_vobj)
|
|
#define BHV_PDATA(bdp) (bdp)->bd_pdata
|
|
#define BHV_OPS(bdp) (bdp)->bd_ops
|
|
#define BHV_IDENTITY(bdp) ((bhv_identity_t *)(bdp)->bd_ops)
|
|
#define BHV_POSITION(bdp) (BHV_IDENTITY(bdp)->bi_position)
|
|
|
|
extern void bhv_head_init(bhv_head_t *, char *);
|
|
extern void bhv_head_destroy(bhv_head_t *);
|
|
extern int bhv_insert(bhv_head_t *, bhv_desc_t *);
|
|
extern void bhv_insert_initial(bhv_head_t *, bhv_desc_t *);
|
|
|
|
/*
|
|
* Initialize a new behavior descriptor.
|
|
* Arguments:
|
|
* bdp - pointer to behavior descriptor
|
|
* pdata - pointer to behavior's private data
|
|
* vobj - pointer to associated virtual object
|
|
* ops - pointer to ops for this behavior
|
|
*/
|
|
#define bhv_desc_init(bdp, pdata, vobj, ops) \
|
|
{ \
|
|
(bdp)->bd_pdata = pdata; \
|
|
(bdp)->bd_vobj = vobj; \
|
|
(bdp)->bd_ops = ops; \
|
|
(bdp)->bd_next = NULL; \
|
|
}
|
|
|
|
/*
|
|
* Remove a behavior descriptor from a behavior chain.
|
|
*/
|
|
#define bhv_remove(bhp, bdp) \
|
|
{ \
|
|
if ((bhp)->bh_first == (bdp)) { \
|
|
/* \
|
|
* Remove from front of chain. \
|
|
* Atomic wrt oip's. \
|
|
*/ \
|
|
(bhp)->bh_first = (bdp)->bd_next; \
|
|
} else { \
|
|
/* remove from non-front of chain */ \
|
|
bhv_remove_not_first(bhp, bdp); \
|
|
} \
|
|
(bdp)->bd_vobj = NULL; \
|
|
}
|
|
|
|
/*
|
|
* Behavior module prototypes.
|
|
*/
|
|
extern void bhv_remove_not_first(bhv_head_t *bhp, bhv_desc_t *bdp);
|
|
extern bhv_desc_t * bhv_lookup(bhv_head_t *bhp, void *ops);
|
|
extern bhv_desc_t * bhv_lookup_range(bhv_head_t *bhp, int low, int high);
|
|
extern bhv_desc_t * bhv_base(bhv_head_t *bhp);
|
|
|
|
/* No bhv locking on Linux */
|
|
#define bhv_lookup_unlocked bhv_lookup
|
|
#define bhv_base_unlocked bhv_base
|
|
|
|
#endif /* __XFS_BEHAVIOR_H__ */
|