| /* -*- mode: c; c-basic-offset: 8; -*- |
| * vim: noexpandtab sw=8 ts=8 sts=0: |
| * |
| * stackglue.h |
| * |
| * Glue to the underlying cluster stack. |
| * |
| * Copyright (C) 2007 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License as published by the Free Software Foundation, version 2. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| */ |
| |
| |
| #ifndef STACKGLUE_H |
| #define STACKGLUE_H |
| |
| #include <linux/types.h> |
| #include <linux/list.h> |
| #include <linux/dlmconstants.h> |
| |
| #include "dlm/dlmapi.h" |
| #include <linux/dlm.h> |
| |
| /* Needed for plock-related prototypes */ |
| struct file; |
| struct file_lock; |
| |
| /* |
| * dlmconstants.h does not have a LOCAL flag. We hope to remove it |
| * some day, but right now we need it. Let's fake it. This value is larger |
| * than any flag in dlmconstants.h. |
| */ |
| #define DLM_LKF_LOCAL 0x00100000 |
| |
| /* |
| * This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h. That probably |
| * wants to be in a public header. |
| */ |
| #define GROUP_NAME_MAX 64 |
| |
| |
| /* |
| * ocfs2_protocol_version changes when ocfs2 does something different in |
| * its inter-node behavior. See dlmglue.c for more information. |
| */ |
| struct ocfs2_protocol_version { |
| u8 pv_major; |
| u8 pv_minor; |
| }; |
| |
| /* |
| * The dlm_lockstatus struct includes lvb space, but the dlm_lksb struct only |
| * has a pointer to separately allocated lvb space. This struct exists only to |
| * include in the lksb union to make space for a combined dlm_lksb and lvb. |
| */ |
| struct fsdlm_lksb_plus_lvb { |
| struct dlm_lksb lksb; |
| char lvb[DLM_LVB_LEN]; |
| }; |
| |
| /* |
| * A union of all lock status structures. We define it here so that the |
| * size of the union is known. Lock status structures are embedded in |
| * ocfs2 inodes. |
| */ |
| struct ocfs2_cluster_connection; |
| struct ocfs2_dlm_lksb { |
| union { |
| struct dlm_lockstatus lksb_o2dlm; |
| struct dlm_lksb lksb_fsdlm; |
| struct fsdlm_lksb_plus_lvb padding; |
| }; |
| struct ocfs2_cluster_connection *lksb_conn; |
| }; |
| |
| /* |
| * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf. |
| */ |
| struct ocfs2_locking_protocol { |
| struct ocfs2_protocol_version lp_max_version; |
| void (*lp_lock_ast)(struct ocfs2_dlm_lksb *lksb); |
| void (*lp_blocking_ast)(struct ocfs2_dlm_lksb *lksb, int level); |
| void (*lp_unlock_ast)(struct ocfs2_dlm_lksb *lksb, int error); |
| }; |
| |
| |
| /* |
| * A cluster connection. Mostly opaque to ocfs2, the connection holds |
| * state for the underlying stack. ocfs2 does use cc_version to determine |
| * locking compatibility. |
| */ |
| struct ocfs2_cluster_connection { |
| char cc_name[GROUP_NAME_MAX]; |
| int cc_namelen; |
| struct ocfs2_protocol_version cc_version; |
| void (*cc_recovery_handler)(int node_num, void *recovery_data); |
| void *cc_recovery_data; |
| void *cc_lockspace; |
| void *cc_private; |
| }; |
| |
| /* |
| * Each cluster stack implements the stack operations structure. Not used |
| * in the ocfs2 code, the stackglue code translates generic cluster calls |
| * into stack operations. |
| */ |
| struct ocfs2_stack_operations { |
| /* |
| * The fs code calls ocfs2_cluster_connect() to attach a new |
| * filesystem to the cluster stack. The ->connect() op is passed |
| * an ocfs2_cluster_connection with the name and recovery field |
| * filled in. |
| * |
| * The stack must set up any notification mechanisms and create |
| * the filesystem lockspace in the DLM. The lockspace should be |
| * stored on cc_lockspace. Any other information can be stored on |
| * cc_private. |
| * |
| * ->connect() must not return until it is guaranteed that |
| * |
| * - Node down notifications for the filesystem will be recieved |
| * and passed to conn->cc_recovery_handler(). |
| * - Locking requests for the filesystem will be processed. |
| */ |
| int (*connect)(struct ocfs2_cluster_connection *conn); |
| |
| /* |
| * The fs code calls ocfs2_cluster_disconnect() when a filesystem |
| * no longer needs cluster services. All DLM locks have been |
| * dropped, and recovery notification is being ignored by the |
| * fs code. The stack must disengage from the DLM and discontinue |
| * recovery notification. |
| * |
| * Once ->disconnect() has returned, the connection structure will |
| * be freed. Thus, a stack must not return from ->disconnect() |
| * until it will no longer reference the conn pointer. |
| * |
| * Once this call returns, the stack glue will be dropping this |
| * connection's reference on the module. |
| */ |
| int (*disconnect)(struct ocfs2_cluster_connection *conn); |
| |
| /* |
| * ->this_node() returns the cluster's unique identifier for the |
| * local node. |
| */ |
| int (*this_node)(unsigned int *node); |
| |
| /* |
| * Call the underlying dlm lock function. The ->dlm_lock() |
| * callback should convert the flags and mode as appropriate. |
| * |
| * ast and bast functions are not part of the call because the |
| * stack will likely want to wrap ast and bast calls before passing |
| * them to stack->sp_proto. There is no astarg. The lksb will |
| * be passed back to the ast and bast functions. The caller can |
| * use this to find their object. |
| */ |
| int (*dlm_lock)(struct ocfs2_cluster_connection *conn, |
| int mode, |
| struct ocfs2_dlm_lksb *lksb, |
| u32 flags, |
| void *name, |
| unsigned int namelen); |
| |
| /* |
| * Call the underlying dlm unlock function. The ->dlm_unlock() |
| * function should convert the flags as appropriate. |
| * |
| * The unlock ast is not passed, as the stack will want to wrap |
| * it before calling stack->sp_proto->lp_unlock_ast(). There is |
| * no astarg. The lksb will be passed back to the unlock ast |
| * function. The caller can use this to find their object. |
| */ |
| int (*dlm_unlock)(struct ocfs2_cluster_connection *conn, |
| struct ocfs2_dlm_lksb *lksb, |
| u32 flags); |
| |
| /* |
| * Return the status of the current lock status block. The fs |
| * code should never dereference the union. The ->lock_status() |
| * callback pulls out the stack-specific lksb, converts the status |
| * to a proper errno, and returns it. |
| */ |
| int (*lock_status)(struct ocfs2_dlm_lksb *lksb); |
| |
| /* |
| * Return non-zero if the LVB is valid. |
| */ |
| int (*lvb_valid)(struct ocfs2_dlm_lksb *lksb); |
| |
| /* |
| * Pull the lvb pointer off of the stack-specific lksb. |
| */ |
| void *(*lock_lvb)(struct ocfs2_dlm_lksb *lksb); |
| |
| /* |
| * Cluster-aware posix locks |
| * |
| * This is NULL for stacks which do not support posix locks. |
| */ |
| int (*plock)(struct ocfs2_cluster_connection *conn, |
| u64 ino, |
| struct file *file, |
| int cmd, |
| struct file_lock *fl); |
| |
| /* |
| * This is an optoinal debugging hook. If provided, the |
| * stack can dump debugging information about this lock. |
| */ |
| void (*dump_lksb)(struct ocfs2_dlm_lksb *lksb); |
| }; |
| |
| /* |
| * Each stack plugin must describe itself by registering a |
| * ocfs2_stack_plugin structure. This is only seen by stackglue and the |
| * stack driver. |
| */ |
| struct ocfs2_stack_plugin { |
| char *sp_name; |
| struct ocfs2_stack_operations *sp_ops; |
| struct module *sp_owner; |
| |
| /* These are managed by the stackglue code. */ |
| struct list_head sp_list; |
| unsigned int sp_count; |
| struct ocfs2_locking_protocol *sp_proto; |
| }; |
| |
| |
| /* Used by the filesystem */ |
| int ocfs2_cluster_connect(const char *stack_name, |
| const char *group, |
| int grouplen, |
| void (*recovery_handler)(int node_num, |
| void *recovery_data), |
| void *recovery_data, |
| struct ocfs2_cluster_connection **conn); |
| int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn, |
| int hangup_pending); |
| void ocfs2_cluster_hangup(const char *group, int grouplen); |
| int ocfs2_cluster_this_node(unsigned int *node); |
| |
| struct ocfs2_lock_res; |
| int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn, |
| int mode, |
| struct ocfs2_dlm_lksb *lksb, |
| u32 flags, |
| void *name, |
| unsigned int namelen); |
| int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn, |
| struct ocfs2_dlm_lksb *lksb, |
| u32 flags); |
| |
| int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb); |
| int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb); |
| void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb); |
| void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb); |
| |
| int ocfs2_stack_supports_plocks(void); |
| int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino, |
| struct file *file, int cmd, struct file_lock *fl); |
| |
| void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto); |
| |
| |
| /* Used by stack plugins */ |
| int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin); |
| void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin); |
| |
| #endif /* STACKGLUE_H */ |