v4.19.13 snapshot.
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
new file mode 100644
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+++ b/fs/ocfs2/stackglue.h
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+/* -*- 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
+
+/* This shadows OCFS2_CLUSTER_NAME_LEN */
+#define CLUSTER_NAME_MAX 16
+
+
+/*
+ * 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 + 1];
+ int cc_namelen;
+ char cc_cluster_name[CLUSTER_NAME_MAX + 1];
+ int cc_cluster_name_len;
+ struct ocfs2_protocol_version cc_version;
+ struct ocfs2_locking_protocol *cc_proto;
+ 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 received
+ * 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)(struct ocfs2_cluster_connection *conn,
+ 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_protocol_version sp_max_proto;
+};
+
+
+/* Used by the filesystem */
+int ocfs2_cluster_connect(const char *stack_name,
+ const char *cluster_name,
+ int cluster_name_len,
+ const char *group,
+ int grouplen,
+ struct ocfs2_locking_protocol *lproto,
+ void (*recovery_handler)(int node_num,
+ void *recovery_data),
+ void *recovery_data,
+ struct ocfs2_cluster_connection **conn);
+/*
+ * Used by callers that don't store their stack name. They must ensure
+ * all nodes have the same stack.
+ */
+int ocfs2_cluster_connect_agnostic(const char *group,
+ int grouplen,
+ struct ocfs2_locking_protocol *lproto,
+ 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(struct ocfs2_cluster_connection *conn,
+ 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_max_proto_version(struct ocfs2_protocol_version *max_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);
+
+/* In ocfs2_downconvert_lock(), we need to know which stack we are using */
+int ocfs2_is_o2cb_active(void);
+
+extern struct kset *ocfs2_kset;
+
+#endif /* STACKGLUE_H */