linux/fs/smbfs/smbiod.c

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/*
* smbiod.c
*
* Copyright (C) 2000, Charles Loep / Corel Corp.
* Copyright (C) 2001, Urban Widmark
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/file.h>
#include <linux/dcache.h>
#include <linux/smp_lock.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/kthread.h>
#include <net/ip.h>
#include <linux/smb_fs.h>
#include <linux/smbno.h>
#include <linux/smb_mount.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "smb_debug.h"
#include "request.h"
#include "proto.h"
enum smbiod_state {
SMBIOD_DEAD,
SMBIOD_STARTING,
SMBIOD_RUNNING,
};
static enum smbiod_state smbiod_state = SMBIOD_DEAD;
static struct task_struct *smbiod_thread;
static DECLARE_WAIT_QUEUE_HEAD(smbiod_wait);
static LIST_HEAD(smb_servers);
static DEFINE_SPINLOCK(servers_lock);
#define SMBIOD_DATA_READY (1<<0)
static long smbiod_flags;
static int smbiod(void *);
static int smbiod_start(void);
/*
* called when there's work for us to do
*/
void smbiod_wake_up(void)
{
if (smbiod_state == SMBIOD_DEAD)
return;
set_bit(SMBIOD_DATA_READY, &smbiod_flags);
wake_up_interruptible(&smbiod_wait);
}
/*
* start smbiod if none is running
*/
static int smbiod_start(void)
{
struct task_struct *tsk;
int err = 0;
if (smbiod_state != SMBIOD_DEAD)
return 0;
smbiod_state = SMBIOD_STARTING;
__module_get(THIS_MODULE);
spin_unlock(&servers_lock);
tsk = kthread_run(smbiod, NULL, "smbiod");
if (IS_ERR(tsk)) {
err = PTR_ERR(tsk);
module_put(THIS_MODULE);
}
spin_lock(&servers_lock);
if (err < 0) {
smbiod_state = SMBIOD_DEAD;
smbiod_thread = NULL;
} else {
smbiod_state = SMBIOD_RUNNING;
smbiod_thread = tsk;
}
return err;
}
/*
* register a server & start smbiod if necessary
*/
int smbiod_register_server(struct smb_sb_info *server)
{
int ret;
spin_lock(&servers_lock);
list_add(&server->entry, &smb_servers);
VERBOSE("%p\n", server);
ret = smbiod_start();
spin_unlock(&servers_lock);
return ret;
}
/*
* Unregister a server
* Must be called with the server lock held.
*/
void smbiod_unregister_server(struct smb_sb_info *server)
{
spin_lock(&servers_lock);
list_del_init(&server->entry);
VERBOSE("%p\n", server);
spin_unlock(&servers_lock);
smbiod_wake_up();
smbiod_flush(server);
}
void smbiod_flush(struct smb_sb_info *server)
{
struct list_head *tmp, *n;
struct smb_request *req;
list_for_each_safe(tmp, n, &server->xmitq) {
req = list_entry(tmp, struct smb_request, rq_queue);
req->rq_errno = -EIO;
list_del_init(&req->rq_queue);
smb_rput(req);
wake_up_interruptible(&req->rq_wait);
}
list_for_each_safe(tmp, n, &server->recvq) {
req = list_entry(tmp, struct smb_request, rq_queue);
req->rq_errno = -EIO;
list_del_init(&req->rq_queue);
smb_rput(req);
wake_up_interruptible(&req->rq_wait);
}
}
/*
* Wake up smbmount and make it reconnect to the server.
* This must be called with the server locked.
*
* FIXME: add smbconnect version to this
*/
int smbiod_retry(struct smb_sb_info *server)
{
struct list_head *head;
struct smb_request *req;
pid_t pid = server->conn_pid;
int result = 0;
VERBOSE("state: %d\n", server->state);
if (server->state == CONN_VALID || server->state == CONN_RETRYING)
goto out;
smb_invalidate_inodes(server);
/*
* Some requests are meaningless after a retry, so we abort them.
* One example are all requests using 'fileid' since the files are
* closed on retry.
*/
head = server->xmitq.next;
while (head != &server->xmitq) {
req = list_entry(head, struct smb_request, rq_queue);
head = head->next;
req->rq_bytes_sent = 0;
if (req->rq_flags & SMB_REQ_NORETRY) {
VERBOSE("aborting request %p on xmitq\n", req);
req->rq_errno = -EIO;
list_del_init(&req->rq_queue);
smb_rput(req);
wake_up_interruptible(&req->rq_wait);
}
}
/*
* FIXME: test the code for retrying request we already sent
*/
head = server->recvq.next;
while (head != &server->recvq) {
req = list_entry(head, struct smb_request, rq_queue);
head = head->next;
#if 0
if (req->rq_flags & SMB_REQ_RETRY) {
/* must move the request to the xmitq */
VERBOSE("retrying request %p on recvq\n", req);
list_move(&req->rq_queue, &server->xmitq);
continue;
}
#endif
VERBOSE("aborting request %p on recvq\n", req);
/* req->rq_rcls = ???; */ /* FIXME: set smb error code too? */
req->rq_errno = -EIO;
list_del_init(&req->rq_queue);
smb_rput(req);
wake_up_interruptible(&req->rq_wait);
}
smb_close_socket(server);
if (pid == 0) {
/* FIXME: this is fatal, umount? */
printk(KERN_ERR "smb_retry: no connection process\n");
server->state = CONN_RETRIED;
goto out;
}
/*
* Change state so that only one retry per server will be started.
*/
server->state = CONN_RETRYING;
/*
* Note: use the "priv" flag, as a user process may need to reconnect.
*/
result = kill_proc(pid, SIGUSR1, 1);
if (result) {
/* FIXME: this is most likely fatal, umount? */
printk(KERN_ERR "smb_retry: signal failed [%d]\n", result);
goto out;
}
VERBOSE("signalled pid %d\n", pid);
/* FIXME: The retried requests should perhaps get a "time boost". */
out:
return result;
}
/*
* Currently handles lockingX packets.
*/
static void smbiod_handle_request(struct smb_sb_info *server)
{
PARANOIA("smbiod got a request ... and we don't implement oplocks!\n");
server->rstate = SMB_RECV_DROP;
}
/*
* Do some IO for one server.
*/
static void smbiod_doio(struct smb_sb_info *server)
{
int result;
int maxwork = 7;
if (server->state != CONN_VALID)
goto out;
do {
result = smb_request_recv(server);
if (result < 0) {
server->state = CONN_INVALID;
smbiod_retry(server);
goto out; /* reconnecting is slow */
} else if (server->rstate == SMB_RECV_REQUEST)
smbiod_handle_request(server);
} while (result > 0 && maxwork-- > 0);
/*
* If there is more to read then we want to be sure to wake up again.
*/
if (server->state != CONN_VALID)
goto out;
if (smb_recv_available(server) > 0)
set_bit(SMBIOD_DATA_READY, &smbiod_flags);
do {
result = smb_request_send_server(server);
if (result < 0) {
server->state = CONN_INVALID;
smbiod_retry(server);
goto out; /* reconnecting is slow */
}
} while (result > 0);
/*
* If the last request was not sent out we want to wake up again.
*/
if (!list_empty(&server->xmitq))
set_bit(SMBIOD_DATA_READY, &smbiod_flags);
out:
return;
}
/*
* smbiod kernel thread
*/
static int smbiod(void *unused)
{
allow_signal(SIGKILL);
VERBOSE("SMB Kernel thread starting (%d) ...\n", current->pid);
for (;;) {
struct smb_sb_info *server;
struct list_head *pos, *n;
/* FIXME: Use poll? */
wait_event_interruptible(smbiod_wait,
test_bit(SMBIOD_DATA_READY, &smbiod_flags));
if (signal_pending(current)) {
spin_lock(&servers_lock);
smbiod_state = SMBIOD_DEAD;
spin_unlock(&servers_lock);
break;
}
clear_bit(SMBIOD_DATA_READY, &smbiod_flags);
spin_lock(&servers_lock);
if (list_empty(&smb_servers)) {
smbiod_state = SMBIOD_DEAD;
spin_unlock(&servers_lock);
break;
}
list_for_each_safe(pos, n, &smb_servers) {
server = list_entry(pos, struct smb_sb_info, entry);
VERBOSE("checking server %p\n", server);
if (server->state == CONN_VALID) {
spin_unlock(&servers_lock);
smb_lock_server(server);
smbiod_doio(server);
smb_unlock_server(server);
spin_lock(&servers_lock);
}
}
spin_unlock(&servers_lock);
}
VERBOSE("SMB Kernel thread exiting (%d) ...\n", current->pid);
module_put_and_exit(0);
}