kernel-ark/fs/ocfs2/stack_user.c
Joel Becker 1c520dfbf3 ocfs2: Provide the ocfs2_dlm_lvb_valid() stack API.
The Lock Value Block (LVB) of a DLM lock can be lost when nodes die and
the DLM cannot reconstruct its state.  Clients of the DLM need to know
this.

ocfs2's internal DLM, o2dlm, explicitly zeroes out the LVB when it loses
track of the state.  This is not a standard behavior, but ocfs2 has
always relied on it.  Thus, an o2dlm LVB is always "valid".

ocfs2 now supports both o2dlm and fs/dlm via the stack glue.  When
fs/dlm loses track of an LVBs state, it sets a flag
(DLM_SBF_VALNOTVALID) on the Lock Status Block (LKSB).  The contents of
the LVB may be garbage or merely stale.

ocfs2 doesn't want to try to guess at the validity of the stale LVB.
Instead, it should be checking the VALNOTVALID flag.  As this is the
'standard' way of treating LVBs, we will promote this behavior.

We add a stack glue API ocfs2_dlm_lvb_valid().  It returns non-zero when
the LVB is valid.  o2dlm will always return valid, while fs/dlm will
check VALNOTVALID.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
2009-06-22 14:24:30 -07:00

921 lines
24 KiB
C

/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* stack_user.c
*
* Code which interfaces ocfs2 with fs/dlm and a userspace 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.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
#include <linux/smp_lock.h>
#include <linux/reboot.h>
#include <asm/uaccess.h>
#include "ocfs2.h" /* For struct ocfs2_lock_res */
#include "stackglue.h"
#include <linux/dlm_plock.h>
/*
* The control protocol starts with a handshake. Until the handshake
* is complete, the control device will fail all write(2)s.
*
* The handshake is simple. First, the client reads until EOF. Each line
* of output is a supported protocol tag. All protocol tags are a single
* character followed by a two hex digit version number. Currently the
* only things supported is T01, for "Text-base version 0x01". Next, the
* client writes the version they would like to use, including the newline.
* Thus, the protocol tag is 'T01\n'. If the version tag written is
* unknown, -EINVAL is returned. Once the negotiation is complete, the
* client can start sending messages.
*
* The T01 protocol has three messages. First is the "SETN" message.
* It has the following syntax:
*
* SETN<space><8-char-hex-nodenum><newline>
*
* This is 14 characters.
*
* The "SETN" message must be the first message following the protocol.
* It tells ocfs2_control the local node number.
*
* Next comes the "SETV" message. It has the following syntax:
*
* SETV<space><2-char-hex-major><space><2-char-hex-minor><newline>
*
* This is 11 characters.
*
* The "SETV" message sets the filesystem locking protocol version as
* negotiated by the client. The client negotiates based on the maximum
* version advertised in /sys/fs/ocfs2/max_locking_protocol. The major
* number from the "SETV" message must match
* ocfs2_user_plugin.sp_proto->lp_max_version.pv_major, and the minor number
* must be less than or equal to ...->lp_max_version.pv_minor.
*
* Once this information has been set, mounts will be allowed. From this
* point on, the "DOWN" message can be sent for node down notification.
* It has the following syntax:
*
* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline>
*
* eg:
*
* DOWN 632A924FDD844190BDA93C0DF6B94899 00000001\n
*
* This is 47 characters.
*/
/*
* Whether or not the client has done the handshake.
* For now, we have just one protocol version.
*/
#define OCFS2_CONTROL_PROTO "T01\n"
#define OCFS2_CONTROL_PROTO_LEN 4
/* Handshake states */
#define OCFS2_CONTROL_HANDSHAKE_INVALID (0)
#define OCFS2_CONTROL_HANDSHAKE_READ (1)
#define OCFS2_CONTROL_HANDSHAKE_PROTOCOL (2)
#define OCFS2_CONTROL_HANDSHAKE_VALID (3)
/* Messages */
#define OCFS2_CONTROL_MESSAGE_OP_LEN 4
#define OCFS2_CONTROL_MESSAGE_SETNODE_OP "SETN"
#define OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN 14
#define OCFS2_CONTROL_MESSAGE_SETVERSION_OP "SETV"
#define OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN 11
#define OCFS2_CONTROL_MESSAGE_DOWN_OP "DOWN"
#define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47
#define OCFS2_TEXT_UUID_LEN 32
#define OCFS2_CONTROL_MESSAGE_VERNUM_LEN 2
#define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8
/*
* ocfs2_live_connection is refcounted because the filesystem and
* miscdevice sides can detach in different order. Let's just be safe.
*/
struct ocfs2_live_connection {
struct list_head oc_list;
struct ocfs2_cluster_connection *oc_conn;
};
struct ocfs2_control_private {
struct list_head op_list;
int op_state;
int op_this_node;
struct ocfs2_protocol_version op_proto;
};
/* SETN<space><8-char-hex-nodenum><newline> */
struct ocfs2_control_message_setn {
char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
char space;
char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
char newline;
};
/* SETV<space><2-char-hex-major><space><2-char-hex-minor><newline> */
struct ocfs2_control_message_setv {
char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
char space1;
char major[OCFS2_CONTROL_MESSAGE_VERNUM_LEN];
char space2;
char minor[OCFS2_CONTROL_MESSAGE_VERNUM_LEN];
char newline;
};
/* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */
struct ocfs2_control_message_down {
char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
char space1;
char uuid[OCFS2_TEXT_UUID_LEN];
char space2;
char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
char newline;
};
union ocfs2_control_message {
char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
struct ocfs2_control_message_setn u_setn;
struct ocfs2_control_message_setv u_setv;
struct ocfs2_control_message_down u_down;
};
static struct ocfs2_stack_plugin ocfs2_user_plugin;
static atomic_t ocfs2_control_opened;
static int ocfs2_control_this_node = -1;
static struct ocfs2_protocol_version running_proto;
static LIST_HEAD(ocfs2_live_connection_list);
static LIST_HEAD(ocfs2_control_private_list);
static DEFINE_MUTEX(ocfs2_control_lock);
static inline void ocfs2_control_set_handshake_state(struct file *file,
int state)
{
struct ocfs2_control_private *p = file->private_data;
p->op_state = state;
}
static inline int ocfs2_control_get_handshake_state(struct file *file)
{
struct ocfs2_control_private *p = file->private_data;
return p->op_state;
}
static struct ocfs2_live_connection *ocfs2_connection_find(const char *name)
{
size_t len = strlen(name);
struct ocfs2_live_connection *c;
BUG_ON(!mutex_is_locked(&ocfs2_control_lock));
list_for_each_entry(c, &ocfs2_live_connection_list, oc_list) {
if ((c->oc_conn->cc_namelen == len) &&
!strncmp(c->oc_conn->cc_name, name, len))
return c;
}
return c;
}
/*
* ocfs2_live_connection structures are created underneath the ocfs2
* mount path. Since the VFS prevents multiple calls to
* fill_super(), we can't get dupes here.
*/
static int ocfs2_live_connection_new(struct ocfs2_cluster_connection *conn,
struct ocfs2_live_connection **c_ret)
{
int rc = 0;
struct ocfs2_live_connection *c;
c = kzalloc(sizeof(struct ocfs2_live_connection), GFP_KERNEL);
if (!c)
return -ENOMEM;
mutex_lock(&ocfs2_control_lock);
c->oc_conn = conn;
if (atomic_read(&ocfs2_control_opened))
list_add(&c->oc_list, &ocfs2_live_connection_list);
else {
printk(KERN_ERR
"ocfs2: Userspace control daemon is not present\n");
rc = -ESRCH;
}
mutex_unlock(&ocfs2_control_lock);
if (!rc)
*c_ret = c;
else
kfree(c);
return rc;
}
/*
* This function disconnects the cluster connection from ocfs2_control.
* Afterwards, userspace can't affect the cluster connection.
*/
static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c)
{
mutex_lock(&ocfs2_control_lock);
list_del_init(&c->oc_list);
c->oc_conn = NULL;
mutex_unlock(&ocfs2_control_lock);
kfree(c);
}
static int ocfs2_control_cfu(void *target, size_t target_len,
const char __user *buf, size_t count)
{
/* The T01 expects write(2) calls to have exactly one command */
if ((count != target_len) ||
(count > sizeof(union ocfs2_control_message)))
return -EINVAL;
if (copy_from_user(target, buf, target_len))
return -EFAULT;
return 0;
}
static ssize_t ocfs2_control_validate_protocol(struct file *file,
const char __user *buf,
size_t count)
{
ssize_t ret;
char kbuf[OCFS2_CONTROL_PROTO_LEN];
ret = ocfs2_control_cfu(kbuf, OCFS2_CONTROL_PROTO_LEN,
buf, count);
if (ret)
return ret;
if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN))
return -EINVAL;
ocfs2_control_set_handshake_state(file,
OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
return count;
}
static void ocfs2_control_send_down(const char *uuid,
int nodenum)
{
struct ocfs2_live_connection *c;
mutex_lock(&ocfs2_control_lock);
c = ocfs2_connection_find(uuid);
if (c) {
BUG_ON(c->oc_conn == NULL);
c->oc_conn->cc_recovery_handler(nodenum,
c->oc_conn->cc_recovery_data);
}
mutex_unlock(&ocfs2_control_lock);
}
/*
* Called whenever configuration elements are sent to /dev/ocfs2_control.
* If all configuration elements are present, try to set the global
* values. If there is a problem, return an error. Skip any missing
* elements, and only bump ocfs2_control_opened when we have all elements
* and are successful.
*/
static int ocfs2_control_install_private(struct file *file)
{
int rc = 0;
int set_p = 1;
struct ocfs2_control_private *p = file->private_data;
BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
mutex_lock(&ocfs2_control_lock);
if (p->op_this_node < 0) {
set_p = 0;
} else if ((ocfs2_control_this_node >= 0) &&
(ocfs2_control_this_node != p->op_this_node)) {
rc = -EINVAL;
goto out_unlock;
}
if (!p->op_proto.pv_major) {
set_p = 0;
} else if (!list_empty(&ocfs2_live_connection_list) &&
((running_proto.pv_major != p->op_proto.pv_major) ||
(running_proto.pv_minor != p->op_proto.pv_minor))) {
rc = -EINVAL;
goto out_unlock;
}
if (set_p) {
ocfs2_control_this_node = p->op_this_node;
running_proto.pv_major = p->op_proto.pv_major;
running_proto.pv_minor = p->op_proto.pv_minor;
}
out_unlock:
mutex_unlock(&ocfs2_control_lock);
if (!rc && set_p) {
/* We set the global values successfully */
atomic_inc(&ocfs2_control_opened);
ocfs2_control_set_handshake_state(file,
OCFS2_CONTROL_HANDSHAKE_VALID);
}
return rc;
}
static int ocfs2_control_get_this_node(void)
{
int rc;
mutex_lock(&ocfs2_control_lock);
if (ocfs2_control_this_node < 0)
rc = -EINVAL;
else
rc = ocfs2_control_this_node;
mutex_unlock(&ocfs2_control_lock);
return rc;
}
static int ocfs2_control_do_setnode_msg(struct file *file,
struct ocfs2_control_message_setn *msg)
{
long nodenum;
char *ptr = NULL;
struct ocfs2_control_private *p = file->private_data;
if (ocfs2_control_get_handshake_state(file) !=
OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
return -EINVAL;
if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
OCFS2_CONTROL_MESSAGE_OP_LEN))
return -EINVAL;
if ((msg->space != ' ') || (msg->newline != '\n'))
return -EINVAL;
msg->space = msg->newline = '\0';
nodenum = simple_strtol(msg->nodestr, &ptr, 16);
if (!ptr || *ptr)
return -EINVAL;
if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
(nodenum > INT_MAX) || (nodenum < 0))
return -ERANGE;
p->op_this_node = nodenum;
return ocfs2_control_install_private(file);
}
static int ocfs2_control_do_setversion_msg(struct file *file,
struct ocfs2_control_message_setv *msg)
{
long major, minor;
char *ptr = NULL;
struct ocfs2_control_private *p = file->private_data;
struct ocfs2_protocol_version *max =
&ocfs2_user_plugin.sp_proto->lp_max_version;
if (ocfs2_control_get_handshake_state(file) !=
OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
return -EINVAL;
if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP,
OCFS2_CONTROL_MESSAGE_OP_LEN))
return -EINVAL;
if ((msg->space1 != ' ') || (msg->space2 != ' ') ||
(msg->newline != '\n'))
return -EINVAL;
msg->space1 = msg->space2 = msg->newline = '\0';
major = simple_strtol(msg->major, &ptr, 16);
if (!ptr || *ptr)
return -EINVAL;
minor = simple_strtol(msg->minor, &ptr, 16);
if (!ptr || *ptr)
return -EINVAL;
/*
* The major must be between 1 and 255, inclusive. The minor
* must be between 0 and 255, inclusive. The version passed in
* must be within the maximum version supported by the filesystem.
*/
if ((major == LONG_MIN) || (major == LONG_MAX) ||
(major > (u8)-1) || (major < 1))
return -ERANGE;
if ((minor == LONG_MIN) || (minor == LONG_MAX) ||
(minor > (u8)-1) || (minor < 0))
return -ERANGE;
if ((major != max->pv_major) ||
(minor > max->pv_minor))
return -EINVAL;
p->op_proto.pv_major = major;
p->op_proto.pv_minor = minor;
return ocfs2_control_install_private(file);
}
static int ocfs2_control_do_down_msg(struct file *file,
struct ocfs2_control_message_down *msg)
{
long nodenum;
char *p = NULL;
if (ocfs2_control_get_handshake_state(file) !=
OCFS2_CONTROL_HANDSHAKE_VALID)
return -EINVAL;
if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,
OCFS2_CONTROL_MESSAGE_OP_LEN))
return -EINVAL;
if ((msg->space1 != ' ') || (msg->space2 != ' ') ||
(msg->newline != '\n'))
return -EINVAL;
msg->space1 = msg->space2 = msg->newline = '\0';
nodenum = simple_strtol(msg->nodestr, &p, 16);
if (!p || *p)
return -EINVAL;
if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
(nodenum > INT_MAX) || (nodenum < 0))
return -ERANGE;
ocfs2_control_send_down(msg->uuid, nodenum);
return 0;
}
static ssize_t ocfs2_control_message(struct file *file,
const char __user *buf,
size_t count)
{
ssize_t ret;
union ocfs2_control_message msg;
/* Try to catch padding issues */
WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) !=
(sizeof(msg.u_down.tag) + sizeof(msg.u_down.space1)));
memset(&msg, 0, sizeof(union ocfs2_control_message));
ret = ocfs2_control_cfu(&msg, count, buf, count);
if (ret)
goto out;
if ((count == OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN) &&
!strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
OCFS2_CONTROL_MESSAGE_OP_LEN))
ret = ocfs2_control_do_setnode_msg(file, &msg.u_setn);
else if ((count == OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN) &&
!strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP,
OCFS2_CONTROL_MESSAGE_OP_LEN))
ret = ocfs2_control_do_setversion_msg(file, &msg.u_setv);
else if ((count == OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN) &&
!strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,
OCFS2_CONTROL_MESSAGE_OP_LEN))
ret = ocfs2_control_do_down_msg(file, &msg.u_down);
else
ret = -EINVAL;
out:
return ret ? ret : count;
}
static ssize_t ocfs2_control_write(struct file *file,
const char __user *buf,
size_t count,
loff_t *ppos)
{
ssize_t ret;
switch (ocfs2_control_get_handshake_state(file)) {
case OCFS2_CONTROL_HANDSHAKE_INVALID:
ret = -EINVAL;
break;
case OCFS2_CONTROL_HANDSHAKE_READ:
ret = ocfs2_control_validate_protocol(file, buf,
count);
break;
case OCFS2_CONTROL_HANDSHAKE_PROTOCOL:
case OCFS2_CONTROL_HANDSHAKE_VALID:
ret = ocfs2_control_message(file, buf, count);
break;
default:
BUG();
ret = -EIO;
break;
}
return ret;
}
/*
* This is a naive version. If we ever have a new protocol, we'll expand
* it. Probably using seq_file.
*/
static ssize_t ocfs2_control_read(struct file *file,
char __user *buf,
size_t count,
loff_t *ppos)
{
ssize_t ret;
ret = simple_read_from_buffer(buf, count, ppos,
OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN);
/* Have we read the whole protocol list? */
if (ret > 0 && *ppos >= OCFS2_CONTROL_PROTO_LEN)
ocfs2_control_set_handshake_state(file,
OCFS2_CONTROL_HANDSHAKE_READ);
return ret;
}
static int ocfs2_control_release(struct inode *inode, struct file *file)
{
struct ocfs2_control_private *p = file->private_data;
mutex_lock(&ocfs2_control_lock);
if (ocfs2_control_get_handshake_state(file) !=
OCFS2_CONTROL_HANDSHAKE_VALID)
goto out;
if (atomic_dec_and_test(&ocfs2_control_opened)) {
if (!list_empty(&ocfs2_live_connection_list)) {
/* XXX: Do bad things! */
printk(KERN_ERR
"ocfs2: Unexpected release of ocfs2_control!\n"
" Loss of cluster connection requires "
"an emergency restart!\n");
emergency_restart();
}
/*
* Last valid close clears the node number and resets
* the locking protocol version
*/
ocfs2_control_this_node = -1;
running_proto.pv_major = 0;
running_proto.pv_major = 0;
}
out:
list_del_init(&p->op_list);
file->private_data = NULL;
mutex_unlock(&ocfs2_control_lock);
kfree(p);
return 0;
}
static int ocfs2_control_open(struct inode *inode, struct file *file)
{
struct ocfs2_control_private *p;
p = kzalloc(sizeof(struct ocfs2_control_private), GFP_KERNEL);
if (!p)
return -ENOMEM;
p->op_this_node = -1;
lock_kernel();
mutex_lock(&ocfs2_control_lock);
file->private_data = p;
list_add(&p->op_list, &ocfs2_control_private_list);
mutex_unlock(&ocfs2_control_lock);
unlock_kernel();
return 0;
}
static const struct file_operations ocfs2_control_fops = {
.open = ocfs2_control_open,
.release = ocfs2_control_release,
.read = ocfs2_control_read,
.write = ocfs2_control_write,
.owner = THIS_MODULE,
};
static struct miscdevice ocfs2_control_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "ocfs2_control",
.fops = &ocfs2_control_fops,
};
static int ocfs2_control_init(void)
{
int rc;
atomic_set(&ocfs2_control_opened, 0);
rc = misc_register(&ocfs2_control_device);
if (rc)
printk(KERN_ERR
"ocfs2: Unable to register ocfs2_control device "
"(errno %d)\n",
-rc);
return rc;
}
static void ocfs2_control_exit(void)
{
int rc;
rc = misc_deregister(&ocfs2_control_device);
if (rc)
printk(KERN_ERR
"ocfs2: Unable to deregister ocfs2_control device "
"(errno %d)\n",
-rc);
}
static struct dlm_lksb *fsdlm_astarg_to_lksb(void *astarg)
{
struct ocfs2_lock_res *res = astarg;
return &res->l_lksb.lksb_fsdlm;
}
static void fsdlm_lock_ast_wrapper(void *astarg)
{
struct dlm_lksb *lksb = fsdlm_astarg_to_lksb(astarg);
int status = lksb->sb_status;
BUG_ON(ocfs2_user_plugin.sp_proto == NULL);
/*
* For now we're punting on the issue of other non-standard errors
* where we can't tell if the unlock_ast or lock_ast should be called.
* The main "other error" that's possible is EINVAL which means the
* function was called with invalid args, which shouldn't be possible
* since the caller here is under our control. Other non-standard
* errors probably fall into the same category, or otherwise are fatal
* which means we can't carry on anyway.
*/
if (status == -DLM_EUNLOCK || status == -DLM_ECANCEL)
ocfs2_user_plugin.sp_proto->lp_unlock_ast(astarg, 0);
else
ocfs2_user_plugin.sp_proto->lp_lock_ast(astarg);
}
static void fsdlm_blocking_ast_wrapper(void *astarg, int level)
{
BUG_ON(ocfs2_user_plugin.sp_proto == NULL);
ocfs2_user_plugin.sp_proto->lp_blocking_ast(astarg, level);
}
static int user_dlm_lock(struct ocfs2_cluster_connection *conn,
int mode,
union ocfs2_dlm_lksb *lksb,
u32 flags,
void *name,
unsigned int namelen,
void *astarg)
{
int ret;
if (!lksb->lksb_fsdlm.sb_lvbptr)
lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
sizeof(struct dlm_lksb);
ret = dlm_lock(conn->cc_lockspace, mode, &lksb->lksb_fsdlm,
flags|DLM_LKF_NODLCKWT, name, namelen, 0,
fsdlm_lock_ast_wrapper, astarg,
fsdlm_blocking_ast_wrapper);
return ret;
}
static int user_dlm_unlock(struct ocfs2_cluster_connection *conn,
union ocfs2_dlm_lksb *lksb,
u32 flags,
void *astarg)
{
int ret;
ret = dlm_unlock(conn->cc_lockspace, lksb->lksb_fsdlm.sb_lkid,
flags, &lksb->lksb_fsdlm, astarg);
return ret;
}
static int user_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
{
return lksb->lksb_fsdlm.sb_status;
}
static int user_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb)
{
int invalid = lksb->lksb_fsdlm.sb_flags & DLM_SBF_VALNOTVALID;
return !invalid;
}
static void *user_dlm_lvb(union ocfs2_dlm_lksb *lksb)
{
if (!lksb->lksb_fsdlm.sb_lvbptr)
lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
sizeof(struct dlm_lksb);
return (void *)(lksb->lksb_fsdlm.sb_lvbptr);
}
static void user_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb)
{
}
static int user_plock(struct ocfs2_cluster_connection *conn,
u64 ino,
struct file *file,
int cmd,
struct file_lock *fl)
{
/*
* This more or less just demuxes the plock request into any
* one of three dlm calls.
*
* Internally, fs/dlm will pass these to a misc device, which
* a userspace daemon will read and write to.
*
* For now, cancel requests (which happen internally only),
* are turned into unlocks. Most of this function taken from
* gfs2_lock.
*/
if (cmd == F_CANCELLK) {
cmd = F_SETLK;
fl->fl_type = F_UNLCK;
}
if (IS_GETLK(cmd))
return dlm_posix_get(conn->cc_lockspace, ino, file, fl);
else if (fl->fl_type == F_UNLCK)
return dlm_posix_unlock(conn->cc_lockspace, ino, file, fl);
else
return dlm_posix_lock(conn->cc_lockspace, ino, file, cmd, fl);
}
/*
* Compare a requested locking protocol version against the current one.
*
* If the major numbers are different, they are incompatible.
* If the current minor is greater than the request, they are incompatible.
* If the current minor is less than or equal to the request, they are
* compatible, and the requester should run at the current minor version.
*/
static int fs_protocol_compare(struct ocfs2_protocol_version *existing,
struct ocfs2_protocol_version *request)
{
if (existing->pv_major != request->pv_major)
return 1;
if (existing->pv_minor > request->pv_minor)
return 1;
if (existing->pv_minor < request->pv_minor)
request->pv_minor = existing->pv_minor;
return 0;
}
static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
{
dlm_lockspace_t *fsdlm;
struct ocfs2_live_connection *control;
int rc = 0;
BUG_ON(conn == NULL);
rc = ocfs2_live_connection_new(conn, &control);
if (rc)
goto out;
/*
* running_proto must have been set before we allowed any mounts
* to proceed.
*/
if (fs_protocol_compare(&running_proto, &conn->cc_version)) {
printk(KERN_ERR
"Unable to mount with fs locking protocol version "
"%u.%u because the userspace control daemon has "
"negotiated %u.%u\n",
conn->cc_version.pv_major, conn->cc_version.pv_minor,
running_proto.pv_major, running_proto.pv_minor);
rc = -EPROTO;
ocfs2_live_connection_drop(control);
goto out;
}
rc = dlm_new_lockspace(conn->cc_name, strlen(conn->cc_name),
&fsdlm, DLM_LSFL_FS, DLM_LVB_LEN);
if (rc) {
ocfs2_live_connection_drop(control);
goto out;
}
conn->cc_private = control;
conn->cc_lockspace = fsdlm;
out:
return rc;
}
static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
{
dlm_release_lockspace(conn->cc_lockspace, 2);
conn->cc_lockspace = NULL;
ocfs2_live_connection_drop(conn->cc_private);
conn->cc_private = NULL;
return 0;
}
static int user_cluster_this_node(unsigned int *this_node)
{
int rc;
rc = ocfs2_control_get_this_node();
if (rc < 0)
return rc;
*this_node = rc;
return 0;
}
static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
.connect = user_cluster_connect,
.disconnect = user_cluster_disconnect,
.this_node = user_cluster_this_node,
.dlm_lock = user_dlm_lock,
.dlm_unlock = user_dlm_unlock,
.lock_status = user_dlm_lock_status,
.lvb_valid = user_dlm_lvb_valid,
.lock_lvb = user_dlm_lvb,
.plock = user_plock,
.dump_lksb = user_dlm_dump_lksb,
};
static struct ocfs2_stack_plugin ocfs2_user_plugin = {
.sp_name = "user",
.sp_ops = &ocfs2_user_plugin_ops,
.sp_owner = THIS_MODULE,
};
static int __init ocfs2_user_plugin_init(void)
{
int rc;
rc = ocfs2_control_init();
if (!rc) {
rc = ocfs2_stack_glue_register(&ocfs2_user_plugin);
if (rc)
ocfs2_control_exit();
}
return rc;
}
static void __exit ocfs2_user_plugin_exit(void)
{
ocfs2_stack_glue_unregister(&ocfs2_user_plugin);
ocfs2_control_exit();
}
MODULE_AUTHOR("Oracle");
MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks");
MODULE_LICENSE("GPL");
module_init(ocfs2_user_plugin_init);
module_exit(ocfs2_user_plugin_exit);