path: root/fs/dlm/dlm_internal.h

/* SPDX-License-Identifier: GPL-2.0-only */
/******************************************************************************
*******************************************************************************
**
**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
**  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
**
**
*******************************************************************************
******************************************************************************/

#ifndef __DLM_INTERNAL_DOT_H__
#define __DLM_INTERNAL_DOT_H__

/*
 * This is the main header file to be included in each DLM source file.
 */

#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <linux/delay.h>
#include <linux/socket.h>
#include <linux/kthread.h>
#include <linux/kobject.h>
#include <linux/kref.h>
#include <linux/kernel.h>
#include <linux/jhash.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
#include <linux/idr.h>
#include <linux/ratelimit.h>
#include <linux/uaccess.h>

#include <linux/dlm.h>
#include "config.h"

/* Size of the temp buffer midcomms allocates on the stack.
   We try to make this large enough so most messages fit.
   FIXME: should sctp make this unnecessary? */

#define DLM_INBUF_LEN		148

struct dlm_ls;
struct dlm_lkb;
struct dlm_rsb;
struct dlm_member;
struct dlm_rsbtable;
struct dlm_recover;
struct dlm_header;
struct dlm_message;
struct dlm_rcom;
struct dlm_mhandle;

#define log_print(fmt, args...) \
	printk(KERN_ERR "dlm: "fmt"\n" , ##args)
#define log_error(ls, fmt, args...) \
	printk(KERN_ERR "dlm: %s: " fmt "\n", (ls)->ls_name , ##args)

#define log_rinfo(ls, fmt, args...) \
do { \
	if (dlm_config.ci_log_info) \
		printk(KERN_INFO "dlm: %s: " fmt "\n", \
			(ls)->ls_name, ##args); \
	else if (dlm_config.ci_log_debug) \
		printk(KERN_DEBUG "dlm: %s: " fmt "\n", \
		       (ls)->ls_name , ##args); \
} while (0)

#define log_debug(ls, fmt, args...) \
do { \
	if (dlm_config.ci_log_debug) \
		printk(KERN_DEBUG "dlm: %s: " fmt "\n", \
		       (ls)->ls_name , ##args); \
} while (0)

#define log_limit(ls, fmt, args...) \
do { \
	if (dlm_config.ci_log_debug) \
		printk_ratelimited(KERN_DEBUG "dlm: %s: " fmt "\n", \
			(ls)->ls_name , ##args); \
} while (0)

#define DLM_ASSERT(x, do) \
{ \
  if (!(x)) \
  { \
    printk(KERN_ERR "\nDLM:  Assertion failed on line %d of file %s\n" \
               "DLM:  assertion:  \"%s\"\n" \
               "DLM:  time = %lu\n", \
               __LINE__, __FILE__, #x, jiffies); \
    {do} \
    printk("\n"); \
    panic("DLM:  Record message above and reboot.\n"); \
  } \
}


#define DLM_RTF_SHRINK		0x00000001

struct dlm_rsbtable {
	struct rb_root		keep;
	struct rb_root		toss;
	spinlock_t		lock;
	uint32_t		flags;
};


/*
 * Lockspace member (per node in a ls)
 */

struct dlm_member {
	struct list_head	list;
	int			nodeid;
	int			weight;
	int			slot;
	int			slot_prev;
	int			comm_seq;
	uint32_t		generation;
};

/*
 * Save and manage recovery state for a lockspace.
 */

struct dlm_recover {
	struct list_head	list;
	struct dlm_config_node	*nodes;
	int			nodes_count;
	uint64_t		seq;
};

/*
 * Pass input args to second stage locking function.
 */

struct dlm_args {
	uint32_t		flags;
	void			(*astfn) (void *astparam);
	void			*astparam;
	void			(*bastfn) (void *astparam, int mode);
	int			mode;
	struct dlm_lksb		*lksb;
	unsigned long		timeout;
};


/*
 * Lock block
 *
 * A lock can be one of three types:
 *
 * local copy      lock is mastered locally
 *                 (lkb_nodeid is zero and DLM_LKF_MSTCPY is not set)
 * process copy    lock is mastered on a remote node
 *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is not set)
 * master copy     master node's copy of a lock owned by remote node
 *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is set)
 *
 * lkb_exflags: a copy of the most recent flags arg provided to dlm_lock or
 * dlm_unlock.  The dlm does not modify these or use any private flags in
 * this field; it only contains DLM_LKF_ flags from dlm.h.  These flags
 * are sent as-is to the remote master when the lock is remote.
 *
 * lkb_flags: internal dlm flags (DLM_IFL_ prefix) from dlm_internal.h.
 * Some internal flags are shared between the master and process nodes;
 * these shared flags are kept in the lower two bytes.  One of these
 * flags set on the master copy will be propagated to the process copy
 * and v.v.  Other internal flags are private to the master or process
 * node (e.g. DLM_IFL_MSTCPY).  These are kept in the high two bytes.
 *
 * lkb_sbflags: status block flags.  These flags are copied directly into
 * the caller's lksb.sb_flags prior to the dlm_lock/dlm_unlock completion
 * ast.  All defined in dlm.h with DLM_SBF_ prefix.
 *
 * lkb_status: the lock status indicates which rsb queue the lock is
 * on, grant, convert, or wait.  DLM_LKSTS_ WAITING/GRANTED/CONVERT
 *
 * lkb_wait_type: the dlm message type (DLM_MSG_ prefix) for which a
 * reply is needed.  Only set when the lkb is on the lockspace waiters
 * list awaiting a reply from a remote node.
 *
 * lkb_nodeid: when the lkb is a local copy, nodeid is 0; when the lkb
 * is a master copy, nodeid specifies the remote lock holder, when the
 * lkb is a process copy, the nodeid specifies the lock master.
 */

/* lkb_status */

#define DLM_LKSTS_WAITING	1
#define DLM_LKSTS_GRANTED	2
#define DLM_LKSTS_CONVERT	3

/* lkb_flags */

#define DLM_IFL_MSTCPY		0x00010000
#define DLM_IFL_RESEND		0x00020000
#define DLM_IFL_DEAD		0x00040000
#define DLM_IFL_OVERLAP_UNLOCK  0x00080000
#define DLM_IFL_OVERLAP_CANCEL  0x00100000
#define DLM_IFL_ENDOFLIFE	0x00200000
#define DLM_IFL_WATCH_TIMEWARN	0x00400000
#define DLM_IFL_TIMEOUT_CANCEL	0x00800000
#define DLM_IFL_DEADLOCK_CANCEL	0x01000000
#define DLM_IFL_STUB_MS		0x02000000 /* magic number for m_flags */
#define DLM_IFL_USER		0x00000001
#define DLM_IFL_ORPHAN		0x00000002

#define DLM_CALLBACKS_SIZE	6

#define DLM_CB_CAST		0x00000001
#define DLM_CB_BAST		0x00000002
#define DLM_CB_SKIP		0x00000004

struct dlm_callback {
	uint64_t		seq;
	uint32_t		flags;		/* DLM_CBF_ */
	int			sb_status;	/* copy to lksb status */
	uint8_t			sb_flags;	/* copy to lksb flags */
	int8_t			mode; /* rq mode of bast, gr mode of cast */
};

struct dlm_lkb {
	struct dlm_rsb		*lkb_resource;	/* the rsb */
	struct kref		lkb_ref;
	int			lkb_nodeid;	/* copied from rsb */
	int			lkb_ownpid;	/* pid of lock owner */
	uint32_t		lkb_id;		/* our lock ID */
	uint32_t		lkb_remid;	/* lock ID on remote partner */
	uint32_t		lkb_exflags;	/* external flags from caller */
	uint32_t		lkb_sbflags;	/* lksb flags */
	uint32_t		lkb_flags;	/* internal flags */
	uint32_t		lkb_lvbseq;	/* lvb sequence number */

	int8_t			lkb_status;     /* granted, waiting, convert */
	int8_t			lkb_rqmode;	/* requested lock mode */
	int8_t			lkb_grmode;	/* granted lock mode */
	int8_t			lkb_highbast;	/* highest mode bast sent for */

	int8_t			lkb_wait_type;	/* type of reply waiting for */
	int8_t			lkb_wait_count;
	int			lkb_wait_nodeid; /* for debugging */

	struct list_head	lkb_statequeue;	/* rsb g/c/w list */
	struct list_head	lkb_rsb_lookup;	/* waiting for rsb lookup */
	struct list_head	lkb_wait_reply;	/* waiting for remote reply */
	struct list_head	lkb_ownqueue;	/* list of locks for a process */
	struct list_head	lkb_time_list;
	ktime_t			lkb_timestamp;
	ktime_t			lkb_wait_time;
	unsigned long		lkb_timeout_cs;

	struct mutex		lkb_cb_mutex;
	struct work_struct	lkb_cb_work;
	struct list_head	lkb_cb_list; /* for ls_cb_delay or proc->asts */
	struct dlm_callback	lkb_callbacks[DLM_CALLBACKS_SIZE];
	struct dlm_callback	lkb_last_cast;
	struct dlm_callback	lkb_last_bast;
	ktime_t			lkb_last_cast_time;	/* for debugging */
	ktime_t			lkb_last_bast_time;	/* for debugging */

	uint64_t		lkb_recover_seq; /* from ls_recover_seq */

	char			*lkb_lvbptr;
	struct dlm_lksb		*lkb_lksb;      /* caller's status block */
	void			(*lkb_astfn) (void *astparam);
	void			(*lkb_bastfn) (void *astparam, int mode);
	union {
		void			*lkb_astparam;	/* caller's ast arg */
		struct dlm_user_args	*lkb_ua;
	};
};

/*
 * res_master_nodeid is "normal": 0 is unset/invalid, non-zero is the real
 * nodeid, even when nodeid is our_nodeid.
 *
 * res_nodeid is "odd": -1 is unset/invalid, zero means our_nodeid,
 * greater than zero when another nodeid.
 *
 * (TODO: remove res_nodeid and only use res_master_nodeid)
 */

struct dlm_rsb {
	struct dlm_ls		*res_ls;	/* the lockspace */
	struct kref		res_ref;
	struct mutex		res_mutex;
	unsigned long		res_flags;
	int			res_length;	/* length of rsb name */
	int			res_nodeid;
	int			res_master_nodeid;
	int			res_dir_nodeid;
	int			res_id;		/* for ls_recover_idr */
	uint32_t                res_lvbseq;
	uint32_t		res_hash;
	uint32_t		res_bucket;	/* rsbtbl */
	unsigned long		res_toss_time;
	uint32_t		res_first_lkid;
	struct list_head	res_lookup;	/* lkbs waiting on first */
	union {
		struct list_head	res_hashchain;
		struct rb_node		res_hashnode;	/* rsbtbl */
	};
	struct list_head	res_grantqueue;
	struct list_head	res_convertqueue;
	struct list_head	res_waitqueue;

	struct list_head	res_root_list;	    /* used for recovery */
	struct list_head	res_recover_list;   /* used for recovery */
	int			res_recover_locks_count;

	char			*res_lvbptr