linux/fs/gfs2/glock.h
Steven Whitehouse feaa7bba02 [GFS2] Fix unlinked file handling
This patch fixes the way we have been dealing with unlinked,
but still open files. It removes all limits (other than memory
for inodes, as per every other filesystem) on numbers of these
which we can support on GFS2. It also means that (like other
fs) its the responsibility of the last process to close the file
to deallocate the storage, rather than the person who did the
unlinking. Note that with GFS2, those two events might take place
on different nodes.

Also there are a number of other changes:

 o We use the Linux inode subsystem as it was intended to be
used, wrt allocating GFS2 inodes
 o The Linux inode cache is now the point which we use for
local enforcement of only holding one copy of the inode in
core at once (previous to this we used the glock layer).
 o We no longer use the unlinked "special" file. We just ignore it
completely. This makes unlinking more efficient.
 o We now use the 4th block allocation state. The previously unused
state is used to track unlinked but still open inodes.
 o gfs2_inoded is no longer needed
 o Several fields are now no longer needed (and removed) from the in
core struct gfs2_inode
 o Several fields are no longer needed (and removed) from the in core
superblock

There are a number of future possible optimisations and clean ups
which have been made possible by this patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-06-14 15:32:57 -04:00

153 lines
4.3 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*/
#ifndef __GLOCK_DOT_H__
#define __GLOCK_DOT_H__
/* Flags for lock requests; used in gfs2_holder gh_flag field.
From lm_interface.h:
#define LM_FLAG_TRY 0x00000001
#define LM_FLAG_TRY_1CB 0x00000002
#define LM_FLAG_NOEXP 0x00000004
#define LM_FLAG_ANY 0x00000008
#define LM_FLAG_PRIORITY 0x00000010 */
#define GL_LOCAL_EXCL 0x00000020
#define GL_ASYNC 0x00000040
#define GL_EXACT 0x00000080
#define GL_SKIP 0x00000100
#define GL_ATIME 0x00000200
#define GL_NOCACHE 0x00000400
#define GL_SYNC 0x00000800
#define GL_NOCANCEL 0x00001000
#define GL_AOP 0x00004000
#define GL_DUMP 0x00008000
#define GLR_TRYFAILED 13
#define GLR_CANCELED 14
static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
{
struct gfs2_holder *gh;
int locked = 0;
/* Look in glock's list of holders for one with current task as owner */
spin_lock(&gl->gl_spin);
list_for_each_entry(gh, &gl->gl_holders, gh_list) {
if (gh->gh_owner == current) {
locked = 1;
break;
}
}
spin_unlock(&gl->gl_spin);
return locked;
}
static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
{
return (gl->gl_state == LM_ST_EXCLUSIVE);
}
static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
{
return (gl->gl_state == LM_ST_DEFERRED);
}
static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
{
return (gl->gl_state == LM_ST_SHARED);
}
static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
{
int ret;
spin_lock(&gl->gl_spin);
ret = !list_empty(&gl->gl_waiters2) || !list_empty(&gl->gl_waiters3);
spin_unlock(&gl->gl_spin);
return ret;
}
int gfs2_glock_get(struct gfs2_sbd *sdp,
uint64_t number, struct gfs2_glock_operations *glops,
int create, struct gfs2_glock **glp);
void gfs2_glock_hold(struct gfs2_glock *gl);
int gfs2_glock_put(struct gfs2_glock *gl);
void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
struct gfs2_holder *gh);
void gfs2_holder_reinit(unsigned int state, unsigned flags,
struct gfs2_holder *gh);
void gfs2_holder_uninit(struct gfs2_holder *gh);
void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags);
void gfs2_glock_drop_th(struct gfs2_glock *gl);
int gfs2_glock_nq(struct gfs2_holder *gh);
int gfs2_glock_poll(struct gfs2_holder *gh);
int gfs2_glock_wait(struct gfs2_holder *gh);
void gfs2_glock_dq(struct gfs2_holder *gh);
int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time);
void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
uint64_t number, struct gfs2_glock_operations *glops,
unsigned int state, int flags, struct gfs2_holder *gh);
int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
void gfs2_glock_prefetch_num(struct gfs2_sbd *sdp, uint64_t number,
struct gfs2_glock_operations *glops,
unsigned int state, int flags);
void gfs2_glock_inode_squish(struct inode *inode);
/**
* gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
* @gl: the glock
* @state: the state we're requesting
* @flags: the modifier flags
* @gh: the holder structure
*
* Returns: 0, GLR_*, or errno
*/
static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
unsigned int state, int flags,
struct gfs2_holder *gh)
{
int error;
gfs2_holder_init(gl, state, flags, gh);
error = gfs2_glock_nq(gh);
if (error)
gfs2_holder_uninit(gh);
return error;
}
/* Lock Value Block functions */
int gfs2_lvb_hold(struct gfs2_glock *gl);
void gfs2_lvb_unhold(struct gfs2_glock *gl);
void gfs2_glock_cb(lm_fsdata_t *fsdata, unsigned int type, void *data);
void gfs2_iopen_go_callback(struct gfs2_glock *gl, unsigned int state);
void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
void gfs2_scand_internal(struct gfs2_sbd *sdp);
void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
#endif /* __GLOCK_DOT_H__ */