linux/fs/dlm/dlm_internal.h
David Teigland c36258b592 [DLM] block dlm_recv in recovery transition
Introduce a per-lockspace rwsem that's held in read mode by dlm_recv
threads while working in the dlm.  This allows dlm_recv activity to be
suspended when the lockspace transitions to, from and between recovery
cycles.

The specific bug prompting this change is one where an in-progress
recovery cycle is aborted by a new recovery cycle.  While dlm_recv was
processing a recovery message, the recovery cycle was aborted and
dlm_recoverd began cleaning up.  dlm_recv decremented recover_locks_count
on an rsb after dlm_recoverd had reset it to zero.  This is fixed by
suspending dlm_recv (taking write lock on the rwsem) before aborting the
current recovery.

The transitions to/from normal and recovery modes are simplified by using
this new ability to block dlm_recv.  The switch from normal to recovery
mode means dlm_recv goes from processing locking messages, to saving them
for later, and vice versa.  Races are avoided by blocking dlm_recv when
setting the flag that switches between modes.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-10-10 08:56:38 +01:00

575 lines
15 KiB
C

/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2007 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 __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/module.h>
#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 <asm/semaphore.h>
#include <asm/uaccess.h>
#include <linux/dlm.h>
#include "config.h"
#define DLM_LOCKSPACE_LEN 64
/* 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_lkbtable;
struct dlm_rsbtable;
struct dlm_dirtable;
struct dlm_direntry;
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_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 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"); \
BUG(); \
panic("DLM: Record message above and reboot.\n"); \
} \
}
#define DLM_FAKE_USER_AST ERR_PTR(-EINVAL)
struct dlm_direntry {
struct list_head list;
uint32_t master_nodeid;
uint16_t length;
char name[1];
};
struct dlm_dirtable {
struct list_head list;
rwlock_t lock;
};
struct dlm_rsbtable {
struct list_head list;
struct list_head toss;
rwlock_t lock;
};
struct dlm_lkbtable {
struct list_head list;
rwlock_t lock;
uint16_t counter;
};
/*
* Lockspace member (per node in a ls)
*/
struct dlm_member {
struct list_head list;
int nodeid;
int weight;
};
/*
* Save and manage recovery state for a lockspace.
*/
struct dlm_recover {
struct list_head list;
int *nodeids;
int node_count;
uint64_t seq;
};
/*
* Pass input args to second stage locking function.
*/
struct dlm_args {
uint32_t flags;
void *astaddr;
long astparam;
void *bastaddr;
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_ast_type */
#define AST_COMP 1
#define AST_BAST 2
/* 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_USER 0x00000001
#define DLM_IFL_ORPHAN 0x00000002
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_bastmode; /* requested 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;
int8_t lkb_ast_type; /* type of ast queued for */
struct list_head lkb_idtbl_list; /* lockspace lkbtbl */
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_astqueue; /* need ast to be sent */
struct list_head lkb_ownqueue; /* list of locks for a process */
struct list_head lkb_time_list;
unsigned long lkb_timestamp;
unsigned long lkb_timeout_cs;
char *lkb_lvbptr;
struct dlm_lksb *lkb_lksb; /* caller's status block */
void *lkb_astaddr; /* caller's ast function */
void *lkb_bastaddr; /* caller's bast function */
long lkb_astparam; /* caller's ast arg */
};
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;
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 */
struct list_head res_hashchain; /* 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;
char res_name[1];
};
/* find_rsb() flags */
#define R_MASTER 1 /* only return rsb if it's a master */
#define R_CREATE 2 /* create/add rsb if not found */
/* rsb_flags */
enum rsb_flags {
RSB_MASTER_UNCERTAIN,
RSB_VALNOTVALID,
RSB_VALNOTVALID_PREV,
RSB_NEW_MASTER,
RSB_NEW_MASTER2,
RSB_RECOVER_CONVERT,
RSB_LOCKS_PURGED,
};
static inline void rsb_set_flag(struct dlm_rsb *r, enum rsb_flags flag)
{
__set_bit(flag, &r->res_flags);
}
static inline void rsb_clear_flag(struct dlm_rsb *r, enum rsb_flags flag)
{
__clear_bit(flag, &r->res_flags);
}
static inline int rsb_flag(struct dlm_rsb *r, enum rsb_flags flag)
{
return test_bit(flag, &r->res_flags);
}
/* dlm_header is first element of all structs sent between nodes */
#define DLM_HEADER_MAJOR 0x00030000
#define DLM_HEADER_MINOR 0x00000000
#define DLM_MSG 1
#define DLM_RCOM 2
struct dlm_header {
uint32_t h_version;
uint32_t h_lockspace;
uint32_t h_nodeid; /* nodeid of sender */
uint16_t h_length;
uint8_t h_cmd; /* DLM_MSG, DLM_RCOM */
uint8_t h_pad;
};
#define DLM_MSG_REQUEST 1
#define DLM_MSG_CONVERT 2
#define DLM_MSG_UNLOCK 3
#define DLM_MSG_CANCEL 4
#define DLM_MSG_REQUEST_REPLY 5
#define DLM_MSG_CONVERT_REPLY 6
#define DLM_MSG_UNLOCK_REPLY 7
#define DLM_MSG_CANCEL_REPLY 8
#define DLM_MSG_GRANT 9
#define DLM_MSG_BAST 10
#define DLM_MSG_LOOKUP 11
#define DLM_MSG_REMOVE 12
#define DLM_MSG_LOOKUP_REPLY 13
#define DLM_MSG_PURGE 14
struct dlm_message {
struct dlm_header m_header;
uint32_t m_type; /* DLM_MSG_ */
uint32_t m_nodeid;
uint32_t m_pid;
uint32_t m_lkid; /* lkid on sender */
uint32_t m_remid; /* lkid on receiver */
uint32_t m_parent_lkid;
uint32_t m_parent_remid;
uint32_t m_exflags;
uint32_t m_sbflags;
uint32_t m_flags;
uint32_t m_lvbseq;
uint32_t m_hash;
int m_status;
int m_grmode;
int m_rqmode;
int m_bastmode;
int m_asts;
int m_result; /* 0 or -EXXX */
char m_extra[0]; /* name or lvb */
};
#define DLM_RS_NODES 0x00000001
#define DLM_RS_NODES_ALL 0x00000002
#define DLM_RS_DIR 0x00000004
#define DLM_RS_DIR_ALL 0x00000008
#define DLM_RS_LOCKS 0x00000010
#define DLM_RS_LOCKS_ALL 0x00000020
#define DLM_RS_DONE 0x00000040
#define DLM_RS_DONE_ALL 0x00000080
#define DLM_RCOM_STATUS 1
#define DLM_RCOM_NAMES 2
#define DLM_RCOM_LOOKUP 3
#define DLM_RCOM_LOCK 4
#define DLM_RCOM_STATUS_REPLY 5
#define DLM_RCOM_NAMES_REPLY 6
#define DLM_RCOM_LOOKUP_REPLY 7
#define DLM_RCOM_LOCK_REPLY 8
struct dlm_rcom {
struct dlm_header rc_header;
uint32_t rc_type; /* DLM_RCOM_ */
int rc_result; /* multi-purpose */
uint64_t rc_id; /* match reply with request */
uint64_t rc_seq; /* sender's ls_recover_seq */
uint64_t rc_seq_reply; /* remote ls_recover_seq */
char rc_buf[0];
};
struct rcom_config {
uint32_t rf_lvblen;
uint32_t rf_lsflags;
uint64_t rf_unused;
};
struct rcom_lock {
uint32_t rl_ownpid;
uint32_t rl_lkid;
uint32_t rl_remid;
uint32_t rl_parent_lkid;
uint32_t rl_parent_remid;
uint32_t rl_exflags;
uint32_t rl_flags;
uint32_t rl_lvbseq;
int rl_result;
int8_t rl_rqmode;
int8_t rl_grmode;
int8_t rl_status;
int8_t rl_asts;
uint16_t rl_wait_type;
uint16_t rl_namelen;
char rl_name[DLM_RESNAME_MAXLEN];
char rl_lvb[0];
};
struct dlm_ls {
struct list_head ls_list; /* list of lockspaces */
dlm_lockspace_t *ls_local_handle;
uint32_t ls_global_id; /* global unique lockspace ID */
uint32_t ls_exflags;
int ls_lvblen;
int ls_count; /* reference count */
unsigned long ls_flags; /* LSFL_ */
struct kobject ls_kobj;
struct dlm_rsbtable *ls_rsbtbl;
uint32_t ls_rsbtbl_size;
struct dlm_lkbtable *ls_lkbtbl;
uint32_t ls_lkbtbl_size;
struct dlm_dirtable *ls_dirtbl;
uint32_t ls_dirtbl_size;
struct mutex ls_waiters_mutex;
struct list_head ls_waiters; /* lkbs needing a reply */
struct mutex ls_orphans_mutex;
struct list_head ls_orphans;
struct mutex ls_timeout_mutex;
struct list_head ls_timeout;
struct list_head ls_nodes; /* current nodes in ls */
struct list_head ls_nodes_gone; /* dead node list, recovery */
int ls_num_nodes; /* number of nodes in ls */
int ls_low_nodeid;
int ls_total_weight;
int *ls_node_array;
gfp_t ls_allocation;
struct dlm_rsb ls_stub_rsb; /* for returning errors */
struct dlm_lkb ls_stub_lkb; /* for returning errors */
struct dlm_message ls_stub_ms; /* for faking a reply */
struct dentry *ls_debug_rsb_dentry; /* debugfs */
struct dentry *ls_debug_waiters_dentry; /* debugfs */
struct dentry *ls_debug_locks_dentry; /* debugfs */
wait_queue_head_t ls_uevent_wait; /* user part of join/leave */
int ls_uevent_result;
struct completion ls_members_done;
int ls_members_result;
struct miscdevice ls_device;
/* recovery related */
struct timer_list ls_timer;
struct task_struct *ls_recoverd_task;
struct mutex ls_recoverd_active;
spinlock_t ls_recover_lock;
unsigned long ls_recover_begin; /* jiffies timestamp */
uint32_t ls_recover_status; /* DLM_RS_ */
uint64_t ls_recover_seq;
struct dlm_recover *ls_recover_args;
struct rw_semaphore ls_in_recovery; /* block local requests */
struct rw_semaphore ls_recv_active; /* block dlm_recv */
struct list_head ls_requestqueue;/* queue remote requests */
struct mutex ls_requestqueue_mutex;
char *ls_recover_buf;
int ls_recover_nodeid; /* for debugging */
uint64_t ls_rcom_seq;
spinlock_t ls_rcom_spin;
struct list_head ls_recover_list;
spinlock_t ls_recover_list_lock;
int ls_recover_list_count;
wait_queue_head_t ls_wait_general;
struct mutex ls_clear_proc_locks;
struct list_head ls_root_list; /* root resources */
struct rw_semaphore ls_root_sem; /* protect root_list */
int ls_namelen;
char ls_name[1];
};
#define LSFL_WORK 0
#define LSFL_RUNNING 1
#define LSFL_RECOVERY_STOP 2
#define LSFL_RCOM_READY 3
#define LSFL_RCOM_WAIT 4
#define LSFL_UEVENT_WAIT 5
#define LSFL_TIMEWARN 6
/* much of this is just saving user space pointers associated with the
lock that we pass back to the user lib with an ast */
struct dlm_user_args {
struct dlm_user_proc *proc; /* each process that opens the lockspace
device has private data
(dlm_user_proc) on the struct file,
the process's locks point back to it*/
struct dlm_lksb lksb;
int old_mode;
int update_user_lvb;
struct dlm_lksb __user *user_lksb;
void __user *castparam;
void __user *castaddr;
void __user *bastparam;
void __user *bastaddr;
uint64_t xid;
};
#define DLM_PROC_FLAGS_CLOSING 1
#define DLM_PROC_FLAGS_COMPAT 2
/* locks list is kept so we can remove all a process's locks when it
exits (or orphan those that are persistent) */
struct dlm_user_proc {
dlm_lockspace_t *lockspace;
unsigned long flags; /* DLM_PROC_FLAGS */
struct list_head asts;
spinlock_t asts_spin;
struct list_head locks;
spinlock_t locks_spin;
struct list_head unlocking;
wait_queue_head_t wait;
};
static inline int dlm_locking_stopped(struct dlm_ls *ls)
{
return !test_bit(LSFL_RUNNING, &ls->ls_flags);
}
static inline int dlm_recovery_stopped(struct dlm_ls *ls)
{
return test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
}
static inline int dlm_no_directory(struct dlm_ls *ls)
{
return (ls->ls_exflags & DLM_LSFL_NODIR) ? 1 : 0;
}
#endif /* __DLM_INTERNAL_DOT_H__ */