[DLM] The core of the DLM for GFS2/CLVM
This is the core of the distributed lock manager which is required
to use GFS2 as a cluster filesystem. It is also used by CLVM and
can be used as a standalone lock manager independantly of either
of these two projects.
It implements VAX-style locking modes.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
new file mode 100644
index 0000000..0020cd0
--- /dev/null
+++ b/fs/dlm/dlm_internal.h
@@ -0,0 +1,518 @@
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+** Copyright (C) 2004-2005 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 <asm/semaphore.h>
+#include <asm/uaccess.h>
+
+#include <linux/dlm.h>
+
+#define DLM_LOCKSPACE_LEN 64
+
+#ifndef TRUE
+#define TRUE 1
+#endif
+
+#ifndef FALSE
+#define FALSE 0
+#endif
+
+#if (BITS_PER_LONG == 64)
+#define PRIx64 "lx"
+#else
+#define PRIx64 "Lx"
+#endif
+
+/* 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)
+
+#ifdef DLM_LOG_DEBUG
+#define log_debug(ls, fmt, args...) log_error(ls, fmt, ##args)
+#else
+#define log_debug(ls, fmt, args...)
+#endif
+
+#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"); \
+ } \
+}
+
+
+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;
+ struct dlm_range *range;
+};
+
+
+/*
+ * 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_range[] */
+
+#define GR_RANGE_START 0
+#define GR_RANGE_END 1
+#define RQ_RANGE_START 2
+#define RQ_RANGE_END 3
+
+/* 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_RANGE 0x00000001
+
+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_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 */
+
+ uint64_t *lkb_range; /* array of gr/rq ranges */
+ 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 semaphore res_sem;
+ 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,
+};
+
+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 0x00020000
+#define DLM_HEADER_MINOR 0x00000001
+
+#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
+
+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 */
+ uint64_t m_range[2];
+ 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 */
+ 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;
+ uint64_t rl_range[4];
+ char rl_name[DLM_RESNAME_MAXLEN];
+ char rl_lvb[0];
+};
+
+struct dlm_ls {
+ struct list_head ls_list; /* list of lockspaces */
+ 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 semaphore ls_waiters_sem;
+ struct list_head ls_waiters; /* lkbs needing a reply */
+
+ 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;
+
+ 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_dentry; /* debugfs */
+
+ wait_queue_head_t ls_uevent_wait; /* user part of join/leave */
+ int ls_uevent_result;
+
+ /* recovery related */
+
+ struct timer_list ls_timer;
+ struct task_struct *ls_recoverd_task;
+ struct semaphore ls_recoverd_active;
+ spinlock_t ls_recover_lock;
+ 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 list_head ls_requestqueue;/* queue remote requests */
+ struct semaphore ls_requestqueue_lock;
+ char *ls_recover_buf;
+ 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 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_UEVENT_WAIT 4
+
+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__ */
+