304 lines
8.9 KiB
C
304 lines
8.9 KiB
C
/*
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* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License version 2.
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*/
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#ifndef __GLOCK_DOT_H__
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#define __GLOCK_DOT_H__
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#include <linux/sched.h>
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#include <linux/parser.h>
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#include "incore.h"
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#include "util.h"
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/* Options for hostdata parser */
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enum {
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Opt_jid,
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Opt_id,
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Opt_first,
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Opt_nodir,
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Opt_err,
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};
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/*
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* lm_lockname types
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*/
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#define LM_TYPE_RESERVED 0x00
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#define LM_TYPE_NONDISK 0x01
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#define LM_TYPE_INODE 0x02
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#define LM_TYPE_RGRP 0x03
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#define LM_TYPE_META 0x04
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#define LM_TYPE_IOPEN 0x05
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#define LM_TYPE_FLOCK 0x06
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#define LM_TYPE_PLOCK 0x07
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#define LM_TYPE_QUOTA 0x08
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#define LM_TYPE_JOURNAL 0x09
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/*
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* lm_lock() states
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*
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* SHARED is compatible with SHARED, not with DEFERRED or EX.
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* DEFERRED is compatible with DEFERRED, not with SHARED or EX.
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*/
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#define LM_ST_UNLOCKED 0
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#define LM_ST_EXCLUSIVE 1
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#define LM_ST_DEFERRED 2
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#define LM_ST_SHARED 3
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/*
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* lm_lock() flags
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*
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* LM_FLAG_TRY
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* Don't wait to acquire the lock if it can't be granted immediately.
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*
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* LM_FLAG_TRY_1CB
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* Send one blocking callback if TRY is set and the lock is not granted.
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*
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* LM_FLAG_NOEXP
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* GFS sets this flag on lock requests it makes while doing journal recovery.
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* These special requests should not be blocked due to the recovery like
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* ordinary locks would be.
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*
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* LM_FLAG_ANY
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* A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
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* also be granted in SHARED. The preferred state is whichever is compatible
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* with other granted locks, or the specified state if no other locks exist.
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*
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* LM_FLAG_PRIORITY
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* Override fairness considerations. Suppose a lock is held in a shared state
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* and there is a pending request for the deferred state. A shared lock
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* request with the priority flag would be allowed to bypass the deferred
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* request and directly join the other shared lock. A shared lock request
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* without the priority flag might be forced to wait until the deferred
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* requested had acquired and released the lock.
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*/
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#define LM_FLAG_TRY 0x0001
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#define LM_FLAG_TRY_1CB 0x0002
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#define LM_FLAG_NOEXP 0x0004
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#define LM_FLAG_ANY 0x0008
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#define LM_FLAG_PRIORITY 0x0010
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#define GL_ASYNC 0x0040
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#define GL_EXACT 0x0080
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#define GL_SKIP 0x0100
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#define GL_NOCACHE 0x0400
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/*
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* lm_async_cb return flags
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*
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* LM_OUT_ST_MASK
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* Masks the lower two bits of lock state in the returned value.
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*
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* LM_OUT_CANCELED
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* The lock request was canceled.
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*
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*/
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#define LM_OUT_ST_MASK 0x00000003
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#define LM_OUT_CANCELED 0x00000008
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#define LM_OUT_ERROR 0x00000004
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/*
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* lm_recovery_done() messages
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*/
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#define LM_RD_GAVEUP 308
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#define LM_RD_SUCCESS 309
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#define GLR_TRYFAILED 13
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#define GL_GLOCK_MAX_HOLD (long)(HZ / 5)
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#define GL_GLOCK_DFT_HOLD (long)(HZ / 5)
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#define GL_GLOCK_MIN_HOLD (long)(10)
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#define GL_GLOCK_HOLD_INCR (long)(HZ / 20)
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#define GL_GLOCK_HOLD_DECR (long)(HZ / 40)
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struct lm_lockops {
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const char *lm_proto_name;
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int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
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void (*lm_first_done) (struct gfs2_sbd *sdp);
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void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
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unsigned int result);
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void (*lm_unmount) (struct gfs2_sbd *sdp);
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void (*lm_withdraw) (struct gfs2_sbd *sdp);
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void (*lm_put_lock) (struct gfs2_glock *gl);
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int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
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unsigned int flags);
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void (*lm_cancel) (struct gfs2_glock *gl);
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const match_table_t *lm_tokens;
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};
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extern struct workqueue_struct *gfs2_delete_workqueue;
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static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
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{
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struct gfs2_holder *gh;
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struct pid *pid;
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/* Look in glock's list of holders for one with current task as owner */
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spin_lock(&gl->gl_lockref.lock);
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pid = task_pid(current);
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list_for_each_entry(gh, &gl->gl_holders, gh_list) {
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if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
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break;
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if (gh->gh_owner_pid == pid)
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goto out;
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}
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gh = NULL;
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out:
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spin_unlock(&gl->gl_lockref.lock);
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return gh;
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}
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static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_EXCLUSIVE;
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}
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static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_DEFERRED;
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}
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static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_SHARED;
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}
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static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
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{
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if (gl->gl_ops->go_flags & GLOF_ASPACE)
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return (struct address_space *)(gl + 1);
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return NULL;
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}
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extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
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const struct gfs2_glock_operations *glops,
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int create, struct gfs2_glock **glp);
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extern void gfs2_glock_hold(struct gfs2_glock *gl);
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extern void gfs2_glock_put(struct gfs2_glock *gl);
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extern void gfs2_glock_queue_put(struct gfs2_glock *gl);
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extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
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u16 flags, struct gfs2_holder *gh);
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extern void gfs2_holder_reinit(unsigned int state, u16 flags,
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struct gfs2_holder *gh);
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extern void gfs2_holder_uninit(struct gfs2_holder *gh);
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extern int gfs2_glock_nq(struct gfs2_holder *gh);
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extern int gfs2_glock_poll(struct gfs2_holder *gh);
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extern int gfs2_glock_wait(struct gfs2_holder *gh);
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extern void gfs2_glock_dq(struct gfs2_holder *gh);
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extern void gfs2_glock_dq_wait(struct gfs2_holder *gh);
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extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
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extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
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const struct gfs2_glock_operations *glops,
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unsigned int state, u16 flags,
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struct gfs2_holder *gh);
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extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
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extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
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extern void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
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#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { gfs2_dump_glock(NULL, gl); BUG(); } } while(0)
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extern __printf(2, 3)
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void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
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/**
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* gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
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* @gl: the glock
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* @state: the state we're requesting
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* @flags: the modifier flags
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* @gh: the holder structure
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*
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* Returns: 0, GLR_*, or errno
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*/
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static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
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unsigned int state, u16 flags,
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struct gfs2_holder *gh)
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{
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int error;
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gfs2_holder_init(gl, state, flags, gh);
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error = gfs2_glock_nq(gh);
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if (error)
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gfs2_holder_uninit(gh);
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return error;
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}
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extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
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extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
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extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
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extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
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extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
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extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
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extern void gfs2_glock_free(struct gfs2_glock *gl);
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extern int __init gfs2_glock_init(void);
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extern void gfs2_glock_exit(void);
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extern int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
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extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
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extern int gfs2_register_debugfs(void);
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extern void gfs2_unregister_debugfs(void);
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extern const struct lm_lockops gfs2_dlm_ops;
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static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
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{
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gh->gh_gl = NULL;
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}
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static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
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{
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return gh->gh_gl;
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}
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/**
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* glock_set_object - set the gl_object field of a glock
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* @gl: the glock
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* @object: the object
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*/
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static inline void glock_set_object(struct gfs2_glock *gl, void *object)
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{
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spin_lock(&gl->gl_lockref.lock);
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if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL))
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gfs2_dump_glock(NULL, gl);
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gl->gl_object = object;
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spin_unlock(&gl->gl_lockref.lock);
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}
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/**
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* glock_clear_object - clear the gl_object field of a glock
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* @gl: the glock
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* @object: the object
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*
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* I'd love to similarly add this:
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* else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object))
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* gfs2_dump_glock(NULL, gl);
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* Unfortunately, that's not possible because as soon as gfs2_delete_inode
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* frees the block in the rgrp, another process can reassign it for an I_NEW
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* inode in gfs2_create_inode because that calls new_inode, not gfs2_iget.
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* That means gfs2_delete_inode may subsequently try to call this function
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* for a glock that's already pointing to a brand new inode. If we clear the
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* new inode's gl_object, we'll introduce metadata corruption. Function
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* gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also
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* tries to clear gl_object, so it's more than just gfs2_delete_inode.
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*
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*/
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static inline void glock_clear_object(struct gfs2_glock *gl, void *object)
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{
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spin_lock(&gl->gl_lockref.lock);
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if (gl->gl_object == object)
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gl->gl_object = NULL;
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spin_unlock(&gl->gl_lockref.lock);
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}
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#endif /* __GLOCK_DOT_H__ */
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