/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* stackglue.c
*
* Code which implements an OCFS2 specific interface to underlying
* cluster stacks.
*
* 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.
*/
#include <linux/slab.h>
#include <linux/crc32.h>
/* Needed for AOP_TRUNCATED_PAGE in mlog_errno() */
#include <linux/fs.h>
#include "cluster/masklog.h"
#include "cluster/nodemanager.h"
#include "stackglue.h"
static struct ocfs2_locking_protocol *lproto;
struct o2dlm_private {
struct dlm_eviction_cb op_eviction_cb;
};
/* These should be identical */
#if (DLM_LOCK_IV != LKM_IVMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_NL != LKM_NLMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_CR != LKM_CRMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_CW != LKM_CWMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_PR != LKM_PRMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_PW != LKM_PWMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_EX != LKM_EXMODE)
# error Lock modes do not match
#endif
static inline int mode_to_o2dlm(int mode)
{
BUG_ON(mode > LKM_MAXMODE);
return mode;
}
#define map_flag(_generic, _o2dlm) \
if (flags & (_generic)) { \
flags &= ~(_generic); \
o2dlm_flags |= (_o2dlm); \
}
static int flags_to_o2dlm(u32 flags)
{
int o2dlm_flags = 0;
map_flag(DLM_LKF_NOQUEUE, LKM_NOQUEUE);
map_flag(DLM_LKF_CANCEL, LKM_CANCEL);
map_flag(DLM_LKF_CONVERT, LKM_CONVERT);
map_flag(DLM_LKF_VALBLK, LKM_VALBLK);
map_flag(DLM_LKF_IVVALBLK, LKM_INVVALBLK);
map_flag(DLM_LKF_ORPHAN, LKM_ORPHAN);
map_flag(DLM_LKF_FORCEUNLOCK, LKM_FORCE);
map_flag(DLM_LKF_TIMEOUT, LKM_TIMEOUT);
map_flag(DLM_LKF_LOCAL, LKM_LOCAL);
/* map_flag() should have cleared every flag passed in */
BUG_ON(flags != 0);
return o2dlm_flags;
}
#undef map_flag
/*
* Map an o2dlm status to standard errno values.
*
* o2dlm only uses a handful of these, and returns even fewer to the
* caller. Still, we try to assign sane values to each error.
*
* The following value pairs have special meanings to dlmglue, thus
* the right hand side needs to stay unique - never duplicate the
* mapping elsewhere in the table!
*
* DLM_NORMAL: 0
* DLM_NOTQUEUED: -EAGAIN
* DLM_CANCELGRANT: -DLM_ECANCEL
* DLM_CANCEL: -DLM_EUNLOCK
*/
/* Keep in sync with dlmapi.h */
static int status_map[] = {
[DLM_NORMAL] = 0, /* Success */
[DLM_GRANTED] = -EINVAL,
[DLM_DENIED] = -EACCES,
[DLM_DENIED_NOLOCKS] = -EACCES,
[DLM_WORKING] = -EBUSY,
[DLM_BLOCKED] = -EINVAL,
[DLM_BLOCKED_ORPHAN] = -EINVAL,
[DLM_DENIED_GRACE_PERIOD] = -EACCES,
[DLM_SYSERR] = -ENOMEM, /* It is what it is */
[DLM_NOSUPPORT] = -EPROTO,
[DLM_CANCELGRANT] = -DLM_ECANCEL, /* Cancel after grant */
[DLM_IVLOCKID] = -EINVAL,
[DLM_SYNC] = -EINVAL,
[DLM_BADTYPE] = -EINVAL,
[DLM_BADRESOURCE] = -EINVAL,
[DLM_MAXHANDLES] = -ENOMEM,
[DLM_NOCLINFO] = -EINVAL,
[DLM_NOLOCKMGR] = -EINVAL,
[DLM_NOPURGED] = -EINVAL,
[DLM_BADARGS] = -EINVAL,
[DLM_VOID] = -EINVAL,
[DLM_NOTQUEUED] = -EAGAIN, /* Trylock failed */
[DLM_IVBUFLEN] = -EINVAL,
[DLM_CVTUNGRANT] = -EPERM,
[DLM_BADPARAM] = -EINVAL,
[DLM_VALNOTVALID] = -EINVAL,
[DLM_REJECTED] = -EPERM,
[DLM_ABORT] = -EINVAL,
[DLM_CANCEL] = -DLM_EUNLOCK, /* Successful cancel */
[DLM_IVRESHANDLE] = -EINVAL,
[DLM_DEADLOCK] = -EDEADLK,
[DLM_DENIED_NOASTS] = -EINVAL,
[DLM_FORWARD] = -EINVAL,
[DLM_TIMEOUT] = -ETIMEDOUT,
[DLM_IVGROUPID] = -EINVAL,
[DLM_VERS_CONFLICT] = -EOPNOTSUPP,
[DLM_BAD_DEVICE_PATH] = -ENOENT,
[DLM_NO_DEVICE_PERMISSION] = -EPERM,
[DLM_NO_CONTROL_DEVICE] = -ENOENT,
[DLM_RECOVERING] = -ENOTCONN,
[DLM_MIGRATING] = -ERESTART,
[DLM_MAXSTATS] = -EINVAL,
};
static int dlm_status_to_errno(enum dlm_status status)
{
BUG_ON(status > (sizeof(status_map) / sizeof(status_map[0])));
return status_map[status];
}
static void o2dlm_lock_ast_wrapper(void *astarg)
{
BUG_ON(lproto == NULL);
lproto->lp_lock_ast(astarg);
}
static void o2dlm_blocking_ast_wrapper(void *astarg, int level)
{
BUG_ON(lproto == NULL);
lproto->lp_blocking_ast(astarg, level);
}
static void o2dlm_unlock_ast_wrapper(void *astarg, enum dlm_status status)
{
int error;
BUG_ON(lproto == NULL);
/*
* XXX: CANCEL values are sketchy.
*
* Currently we have preserved the o2dlm paradigm. You can get
* unlock_ast() whether the cancel succeded or not.
*
* First, we're going to pass DLM_EUNLOCK just like fs/dlm does for
* successful unlocks. That is a clean behavior.
*
* In o2dlm, you can get both the lock_ast() for the lock being
* granted and the unlock_ast() for the CANCEL failing. A
* successful cancel sends DLM_NORMAL here. If the
* lock grant happened before the cancel arrived, you get
* DLM_CANCELGRANT. For now, we'll use DLM_ECANCEL to signify
* CANCELGRANT - the CANCEL was supposed to happen but didn't. We
* can then use DLM_EUNLOCK to signify a successful CANCEL -
* effectively, the CANCEL caused the lock to roll back.
*
* In the future, we will likely move the o2dlm to send only one
* ast - either unlock_ast() for a successful CANCEL or lock_ast()
* when the grant succeeds. At that point, we'll send DLM_ECANCEL
* for all cancel results (CANCELGRANT will no longer exist).
*/
error = dlm_status_to_errno(status);
/* Successful unlock is DLM_EUNLOCK */
if (!error)
error = -DLM_EUNLOCK;
lproto->lp_unlock_ast(astarg, error);
}
int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
int mode,
union ocfs2_dlm_lksb *lksb,
u32 flags,
void *name,
unsigned int namelen,
void *astarg)
{
enum dlm_status status;
int o2dlm_mode = mode_to_o2dlm(mode);
int o2dlm_flags = flags_to_o2dlm(flags);
int ret;
BUG_ON(lproto == NULL);
status = dlmlock(conn->cc_lockspace, o2dlm_mode, &lksb->lksb_o2dlm,
o2dlm_flags, name, namelen,
o2dlm_lock_ast_wrapper, astarg,
o2dlm_blocking_ast_wrapper);
ret = dlm_status_to_errno(status);
return ret;
}
int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
union ocfs2_dlm_lksb *lksb,
u32 flags,
void *astarg)
{
enum dlm_status status;
int o2dlm_flags = flags_to_o2dlm(flags);
int ret;
BUG_ON(lproto == NULL);
status = dlmunlock(conn->cc_lockspace, &lksb->lksb_o2dlm,
o2dlm_flags, o2dlm_unlock_ast_wrapper, astarg);
ret = dlm_status_to_errno(status);
return ret;
}
int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
{
return dlm_status_to_errno(lksb->lksb_o2dlm.status);
}
/*
* Why don't we cast to ocfs2_meta_lvb? The "clean" answer is that we
* don't cast at the glue level. The real answer is that the header
* ordering is nigh impossible.
*/
void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb)
{
return (void *)(lksb->lksb_o2dlm.lvb);
}
/*
* Called from the dlm when it's about to evict a node. This is how the
* classic stack signals node death.
*/
static void o2dlm_eviction_cb(int node_num, void *data)
{
struct ocfs2_cluster_connection *conn = data;
mlog(ML_NOTICE, "o2dlm has evicted node %d from group %.*s\n",
node_num, conn->cc_namelen, conn->cc_name);
conn->cc_recovery_handler(node_num, conn->cc_recovery_data);
}
int ocfs2_cluster_connect(const char *group,
int grouplen,
void (*recovery_handler)(int node_num,
void *recovery_data),
void *recovery_data,
struct ocfs2_cluster_connection **conn)
{
int rc = 0;
struct ocfs2_cluster_connection *new_conn;
u32 dlm_key;
struct dlm_ctxt *dlm;
struct o2dlm_private *priv;
struct dlm_protocol_version dlm_version;
BUG_ON(group == NULL);
BUG_ON(conn == NULL);
BUG_ON(recovery_handler == NULL);
if (grouplen > GROUP_NAME_MAX) {
rc = -EINVAL;
goto out;
}
new_conn = kzalloc(sizeof(struct ocfs2_cluster_connection),
GFP_KERNEL);
if (!new_conn) {
rc = -ENOMEM;
goto out;
}
memcpy(new_conn->cc_name, group, grouplen);
new_conn->cc_namelen = grouplen;
new_conn->cc_recovery_handler = recovery_handler;
new_conn->cc_recovery_data = recovery_data;
/* Start the new connection at our maximum compatibility level */
new_conn->cc_version = lproto->lp_max_version;
priv = kzalloc(sizeof(struct o2dlm_private), GFP_KERNEL);
if (!priv) {
rc = -ENOMEM;
goto out_free;
}
/* This just fills the structure in. It is safe to use new_conn. */
dlm_setup_eviction_cb(&priv->op_eviction_cb, o2dlm_eviction_cb,
new_conn);
new_conn->cc_private = priv;
/* used by the dlm code to make message headers unique, each
* node in this domain must agree on this. */
dlm_key = crc32_le(0, group, grouplen);
dlm_version.pv_major = new_conn->cc_version.pv_major;
dlm_version.pv_minor = new_conn->cc_version.pv_minor;
dlm = dlm_register_domain(group, dlm_key, &dlm_version);
if (IS_ERR(dlm)) {
rc = PTR_ERR(dlm);
mlog_errno(rc);
goto out_free;
}
new_conn->cc_version.pv_major = dlm_version.pv_major;
new_conn->cc_version.pv_minor = dlm_version.pv_minor;
new_conn->cc_lockspace = dlm;
dlm_register_eviction_cb(dlm, &priv->op_eviction_cb);
*conn = new_conn;
out_free:
if (rc) {
kfree(new_conn->cc_private);
kfree(new_conn);
}
out:
return rc;
}
int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn)
{
struct dlm_ctxt *dlm = conn->cc_lockspace;
struct o2dlm_private *priv = conn->cc_private;
dlm_unregister_eviction_cb(&priv->op_eviction_cb);
dlm_unregister_domain(dlm);
kfree(priv);
kfree(conn);
return 0;
}
int ocfs2_cluster_this_node(unsigned int *node)
{
int node_num;
node_num = o2nm_this_node();
if (node_num == O2NM_INVALID_NODE_NUM)
return -ENOENT;
if (node_num >= O2NM_MAX_NODES)
return -EOVERFLOW;
*node = node_num;
return 0;
}
void o2cb_get_stack(struct ocfs2_locking_protocol *proto)
{
BUG_ON(proto == NULL);
lproto = proto;
}
void o2cb_put_stack(void)
{
lproto = NULL;
}
