C++ write_lock_irq函数代码示例

/**
 * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 * @port: pointer to port where unit is added
 * @fcp_lun: FCP LUN of unit to be enqueued
 * Returns: pointer to enqueued unit on success, ERR_PTR on error
 *
 * Sets up some unit internal structures and creates sysfs entry.
 */
struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
{
	struct zfcp_unit *unit;
	int retval = -ENOMEM;

	get_device(&port->dev);

	unit = zfcp_get_unit_by_lun(port, fcp_lun);
	if (unit) {
		put_device(&unit->dev);
		retval = -EEXIST;
		goto err_out;
	}

	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
	if (!unit)
		goto err_out;

	unit->port = port;
	unit->fcp_lun = fcp_lun;
	unit->dev.parent = &port->dev;
	unit->dev.release = zfcp_unit_release;

	if (dev_set_name(&unit->dev, "0x%016llx",
			 (unsigned long long) fcp_lun)) {
		kfree(unit);
		goto err_out;
	}
	retval = -EINVAL;

	INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);

	spin_lock_init(&unit->latencies.lock);
	unit->latencies.write.channel.min = 0xFFFFFFFF;
	unit->latencies.write.fabric.min = 0xFFFFFFFF;
	unit->latencies.read.channel.min = 0xFFFFFFFF;
	unit->latencies.read.fabric.min = 0xFFFFFFFF;
	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;

	if (device_register(&unit->dev)) {
		put_device(&unit->dev);
		goto err_out;
	}

	if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs))
		goto err_out_put;

	write_lock_irq(&port->unit_list_lock);
	list_add_tail(&unit->list, &port->unit_list);
	write_unlock_irq(&port->unit_list_lock);

	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);

	return unit;

err_out_put:
	device_unregister(&unit->dev);
err_out:
	put_device(&port->dev);
	return ERR_PTR(retval);
}

static int ptrace_attach(struct task_struct *task)
{
	bool wait_trap = false;
	int retval;

	audit_ptrace(task);

	retval = -EPERM;
	if (unlikely(task->flags & PF_KTHREAD))
		goto out;
	if (same_thread_group(task, current))
		goto out;

	/*
	 * Protect exec's credential calculations against our interference;
	 * interference; SUID, SGID and LSM creds get determined differently
	 * under ptrace.
	 */
	retval = -ERESTARTNOINTR;
	if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
		goto out;

	task_lock(task);
	retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
	task_unlock(task);
	if (retval)
		goto unlock_creds;

	write_lock_irq(&tasklist_lock);
	retval = -EPERM;
	if (unlikely(task->exit_state))
		goto unlock_tasklist;
	if (task->ptrace)
		goto unlock_tasklist;

	task->ptrace = PT_PTRACED;
	if (task_ns_capable(task, CAP_SYS_PTRACE))
		task->ptrace |= PT_PTRACE_CAP;

	__ptrace_link(task, current);
	send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);

	spin_lock(&task->sighand->siglock);

	/*
	 * If the task is already STOPPED, set GROUP_STOP_PENDING and
	 * TRAPPING, and kick it so that it transits to TRACED.  TRAPPING
	 * will be cleared if the child completes the transition or any
	 * event which clears the group stop states happens.  We'll wait
	 * for the transition to complete before returning from this
	 * function.
	 *
	 * This hides STOPPED -> RUNNING -> TRACED transition from the
	 * attaching thread but a different thread in the same group can
	 * still observe the transient RUNNING state.  IOW, if another
	 * thread's WNOHANG wait(2) on the stopped tracee races against
	 * ATTACH, the wait(2) may fail due to the transient RUNNING.
	 *
	 * The following task_is_stopped() test is safe as both transitions
	 * in and out of STOPPED are protected by siglock.
	 */
	if (task_is_stopped(task)) {
		task->group_stop |= GROUP_STOP_PENDING | GROUP_STOP_TRAPPING;
		signal_wake_up(task, 1);
		wait_trap = true;
	}

	spin_unlock(&task->sighand->siglock);

	retval = 0;
unlock_tasklist:
	write_unlock_irq(&tasklist_lock);
unlock_creds:
	mutex_unlock(&task->signal->cred_guard_mutex);
out:
	if (wait_trap)
		wait_event(current->signal->wait_chldexit,
			   !(task->group_stop & GROUP_STOP_TRAPPING));
	return retval;
}

/*-------------------------------------------------------------------------
 *  bproc_masq_wait
 */
int masq_wait(pid_t pid, int options, struct siginfo *infop,
	      unsigned int * stat_addr, struct rusage * ru) {
    int result, lpid, status;
    struct bproc_krequest_t *req;
    struct bproc_rsyscall_msg_t *msg;
    struct bproc_wait_resp_t *resp_msg;
    struct task_struct *child;

    /* XXX to be 100% semantically correct, we need to verify_area
     * here on stat_addr and ru here... */
    req = bpr_rsyscall1(BPROC_SYS_WAIT);
    if (!req){
	printk("bproc: masq: sys_wait: out of memory.\n");
	return -ENOMEM;
    }
    msg = (struct bproc_rsyscall_msg_t *) bproc_msg(req);
    msg->arg[0] = pid;
    msg->arg[1] = options;

    if (bpr_rsyscall2(BPROC_MASQ_MASTER(current), req, 1) != 0) {
	bproc_put_req(req);
	return -EIO;
    }

    resp_msg = bproc_msg(req->response);

    result = resp_msg->hdr.result;
    status = resp_msg->status;
    if (stat_addr) put_user(status, stat_addr);
    if (ru) {
	/* Only a few elements of the rusage structure are provided by
	 * Linux.  Also, convert the times back to the HZ
	 * representation. */
	struct rusage ru_tmp;
	memset(&ru_tmp, 0, sizeof(ru_tmp));
	ru_tmp.ru_utime.tv_sec  =  resp_msg->utime/HZ;
	ru_tmp.ru_utime.tv_usec = (resp_msg->utime*(1000000/HZ))%1000000;
	ru_tmp.ru_stime.tv_sec  =  resp_msg->stime/HZ;
	ru_tmp.ru_stime.tv_usec = (resp_msg->stime*(1000000/HZ))%1000000;
	ru_tmp.ru_minflt        =  resp_msg->minflt;
	ru_tmp.ru_majflt        =  resp_msg->majflt;
	ru_tmp.ru_nswap         =  resp_msg->nswap;
	copy_to_user(ru, &ru_tmp, sizeof(ru_tmp));
    }
    bproc_put_req(req);

    if (result > 0 && (status & 0xff) != 0x7f) {
	/* It's possible that the process we waited on was actually
	 * local.  We need to make sure and get it out of this process
	 * tree too.  If it's not, we need to down the non local child
	 * count by one... */
	write_lock_irq(&tasklist_lock);
	child = masq_find_task_by_pid(BPROC_MASQ_MASTER(current), result);
	if (child)
	    lpid = child->pid;
	else {
	    lpid = 0;
	    current->bproc.nlchild--;
	}
	write_unlock_irq(&tasklist_lock);
	if (lpid) {
	    /* Do all of this as a kernel call to avoid re-entering
	     * this whole mess... */
	    set_bit(BPROC_FLAG_KCALL, &current->bproc.flag);
	    if (k_wait4(lpid, options & ~WNOHANG, NULL, NULL, NULL) == -1) {
		printk(KERN_ERR "bproc: masq: local wait failed on %d (%d)\n",
		       lpid, result);
#if 0
		/* This probably isn't correct.  If we fail to wait,
		 * that probably means that somebody else picked it
		 * up. */
		write_lock_irq(&tasklist_lock);
		current->bproc.nlchild--;
		write_unlock_irq(&tasklist_lock);
#endif
	    }
	}
    }
    return result;
}

/*
 * Send signals to all our closest relatives so that they know
 * to properly mourn us..
 */
static void exit_notify(void)
{
	struct task_struct * p, *t;

	forget_original_parent(current);
	/*
	 * Check to see if any process groups have become orphaned
	 * as a result of our exiting, and if they have any stopped
	 * jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
	 *
	 * Case i: Our father is in a different pgrp than we are
	 * and we were the only connection outside, so our pgrp
	 * is about to become orphaned.
	 */
	 
	t = current->p_pptr;
	
	if ((t->pgrp != current->pgrp) &&
	    (t->session == current->session) &&
	    will_become_orphaned_pgrp(current->pgrp, current) &&
	    has_stopped_jobs(current->pgrp)) {
		kill_pg(current->pgrp,SIGHUP,1);
		kill_pg(current->pgrp,SIGCONT,1);
	}

	/* Let father know we died 
	 *
	 * Thread signals are configurable, but you aren't going to use
	 * that to send signals to arbitary processes. 
	 * That stops right now.
	 *
	 * If the parent exec id doesn't match the exec id we saved
	 * when we started then we know the parent has changed security
	 * domain.
	 *
	 * If our self_exec id doesn't match our parent_exec_id then
	 * we have changed execution domain as these two values started
	 * the same after a fork.
	 *	
	 */
	
	if(current->exit_signal != SIGCHLD &&
	    ( current->parent_exec_id != t->self_exec_id  ||
	      current->self_exec_id != current->parent_exec_id) 
	    && !capable(CAP_KILL))
		current->exit_signal = SIGCHLD;

	notify_parent(current, current->exit_signal);

	/*
	 * This loop does two things:
	 *
  	 * A.  Make init inherit all the child processes
	 * B.  Check to see if any process groups have become orphaned
	 *	as a result of our exiting, and if they have any stopped
	 *	jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
	 */

	write_lock_irq(&tasklist_lock);
	while (current->p_cptr != NULL) {
		p = current->p_cptr;
		current->p_cptr = p->p_osptr;
		p->p_ysptr = NULL;
		p->flags &= ~(PF_PTRACED|PF_TRACESYS);

		p->p_pptr = p->p_opptr;
		p->p_osptr = p->p_pptr->p_cptr;
		if (p->p_osptr)
			p->p_osptr->p_ysptr = p;
		p->p_pptr->p_cptr = p;
		if (p->state == TASK_ZOMBIE)
			notify_parent(p, p->exit_signal);
		/*
		 * process group orphan check
		 * Case ii: Our child is in a different pgrp
		 * than we are, and it was the only connection
		 * outside, so the child pgrp is now orphaned.
		 */
		if ((p->pgrp != current->pgrp) &&
		    (p->session == current->session)) {
			int pgrp = p->pgrp;

			write_unlock_irq(&tasklist_lock);
			if (is_orphaned_pgrp(pgrp) && has_stopped_jobs(pgrp)) {
				kill_pg(pgrp,SIGHUP,1);
				kill_pg(pgrp,SIGCONT,1);
			}
			write_lock_irq(&tasklist_lock);
		}
	}
	write_unlock_irq(&tasklist_lock);

	if (current->leader)
		disassociate_ctty(1);
}

//.........这里部分代码省略.........
			while (i < 4 && w7[i] == hp_sdc.r7[i])
				i++;

			if (i < 4) {
				hp_sdc_status_out8(HP_SDC_CMD_SET_D0 + i);
				hp_sdc.wi = 0x70 + i;
				goto finish;
			}

			idx++;
			if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAREG)
				goto actdone;

			curr->idx = idx;
			act &= ~HP_SDC_ACT_DATAREG;
			break;
		}

		hp_sdc_data_out8(w7[hp_sdc.wi - 0x70]);
		hp_sdc.r7[hp_sdc.wi - 0x70] = w7[hp_sdc.wi - 0x70];
		hp_sdc.wi++; /* write index register autoincrements */
		{
			int i = 0;

			while ((i < 4) && w7[i] == hp_sdc.r7[i])
				i++;
			if (i >= 4) {
				curr->idx = idx + 1;
				if ((act & HP_SDC_ACT_DURING) ==
				    HP_SDC_ACT_DATAREG)
					goto actdone;
			}
		}
		goto finish;
	}
	/* We don't go any further in the command if there is a pending read,
	   because we don't want interleaved results. */
	read_lock_irq(&hp_sdc.rtq_lock);
	if (hp_sdc.rcurr >= 0) {
		read_unlock_irq(&hp_sdc.rtq_lock);
		goto finish;
	}
	read_unlock_irq(&hp_sdc.rtq_lock);


	if (act & HP_SDC_ACT_POSTCMD) {
		uint8_t postcmd;

		/* curr->idx should == idx at this point. */
		postcmd = curr->seq[idx];
		curr->idx++;
		if (act & HP_SDC_ACT_DATAIN) {

			/* Start a new read */
			hp_sdc.rqty = curr->seq[curr->idx];
			do_gettimeofday(&hp_sdc.rtv);
			curr->idx++;
			/* Still need to lock here in case of spurious irq. */
			write_lock_irq(&hp_sdc.rtq_lock);
			hp_sdc.rcurr = curridx;
			write_unlock_irq(&hp_sdc.rtq_lock);
			hp_sdc_status_out8(postcmd);
			goto finish;
		}
		hp_sdc_status_out8(postcmd);
		goto actdone;
	}

 actdone:
	if (act & HP_SDC_ACT_SEMAPHORE)
		up(curr->act.semaphore);
	else if (act & HP_SDC_ACT_CALLBACK)
		curr->act.irqhook(0,NULL,0,0);

	if (curr->idx >= curr->endidx) { /* This transaction is over. */
		if (act & HP_SDC_ACT_DEALLOC)
			kfree(curr);
		hp_sdc.tq[curridx] = NULL;
	} else {
		curr->actidx = idx + 1;
		curr->idx = idx + 2;
	}
	/* Interleave outbound data between the transactions. */
	hp_sdc.wcurr++;
	if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
		hp_sdc.wcurr = 0;

 finish:
	/* If by some quirk IBF has cleared and our ISR has run to
	   see that that has happened, do it all again. */
	if (!hp_sdc.ibf && limit++ < 20)
		goto anew;

 done:
	if (hp_sdc.wcurr >= 0)
		tasklet_schedule(&hp_sdc.task);
	write_unlock(&hp_sdc.lock);

	return 0;
}

//.........这里部分代码省略.........
	/*
	 * Clear TID on mm_release()?
	 */
	p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;

	/*
	 * Syscall tracing should be turned off in the child regardless
	 * of CLONE_PTRACE.
	 */
	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);

	/* Our parent execution domain becomes current domain
	   These must match for thread signalling to apply */
	   
	p->parent_exec_id = p->self_exec_id;

	/* ok, now we should be set up.. */
	p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
	p->pdeath_signal = 0;

	/* Perform scheduler related setup */
	sched_fork(p);

	/*
	 * Ok, make it visible to the rest of the system.
	 * We dont wake it up yet.
	 */
	p->tgid = p->pid;
	p->group_leader = p;
	INIT_LIST_HEAD(&p->ptrace_children);
	INIT_LIST_HEAD(&p->ptrace_list);

	/* Need tasklist lock for parent etc handling! */
	write_lock_irq(&tasklist_lock);
	/*
	 * Check for pending SIGKILL! The new thread should not be allowed
	 * to slip out of an OOM kill. (or normal SIGKILL.)
	 */
	if (sigismember(&current->pending.signal, SIGKILL)) {
		write_unlock_irq(&tasklist_lock);
		retval = -EINTR;
		goto bad_fork_cleanup_namespace;
	}

	/* CLONE_PARENT re-uses the old parent */
	if (clone_flags & CLONE_PARENT)
		p->real_parent = current->real_parent;
	else
		p->real_parent = current;
	p->parent = p->real_parent;

	if (clone_flags & CLONE_THREAD) {
		spin_lock(&current->sighand->siglock);
		/*
		 * Important: if an exit-all has been started then
		 * do not create this new thread - the whole thread
		 * group is supposed to exit anyway.
		 */
		if (current->signal->group_exit) {
			spin_unlock(&current->sighand->siglock);
			write_unlock_irq(&tasklist_lock);
			retval = -EAGAIN;
			goto bad_fork_cleanup_namespace;
		}
		p->tgid = current->tgid;
		p->group_leader = current->group_leader;

static void vcc_remove_socket(struct sock *sk)
{
	write_lock_irq(&vcc_sklist_lock);
	sk_del_node_init(sk);
	write_unlock_irq(&vcc_sklist_lock);
}

//.........这里部分代码省略.........
#endif
	if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM)
		p->sas_ss_sp = p->sas_ss_size = 0;

	user_disable_single_step(p);
	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
#ifdef TIF_SYSCALL_EMU
	clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
#endif
	clear_all_latency_tracing(p);

	
	if (clone_flags & CLONE_THREAD)
		p->exit_signal = -1;
	else if (clone_flags & CLONE_PARENT)
		p->exit_signal = current->group_leader->exit_signal;
	else
		p->exit_signal = (clone_flags & CSIGNAL);

	p->pdeath_signal = 0;
	p->exit_state = 0;

	p->nr_dirtied = 0;
	p->nr_dirtied_pause = 128 >> (PAGE_SHIFT - 10);
	p->dirty_paused_when = 0;

	p->group_leader = p;
	INIT_LIST_HEAD(&p->thread_group);

	cgroup_fork_callbacks(p);
	cgroup_callbacks_done = 1;

	
	write_lock_irq(&tasklist_lock);

	
	if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
		p->real_parent = current->real_parent;
		p->parent_exec_id = current->parent_exec_id;
	} else {
		p->real_parent = current;
		p->parent_exec_id = current->self_exec_id;
	}

	spin_lock(&current->sighand->siglock);

	recalc_sigpending();
	if (signal_pending(current)) {
		spin_unlock(&current->sighand->siglock);
		write_unlock_irq(&tasklist_lock);
		retval = -ERESTARTNOINTR;
		goto bad_fork_free_pid;
	}

	if (clone_flags & CLONE_THREAD) {
		current->signal->nr_threads++;
		atomic_inc(&current->signal->live);
		atomic_inc(&current->signal->sigcnt);
		p->group_leader = current->group_leader;
		list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
	}

	if (likely(p->pid)) {
		ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);

		if (thread_group_leader(p)) {

asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
{
	int flag, retval;
	DECLARE_WAITQUEUE(wait, current);
	struct task_struct *tsk;

	if (options & ~(WNOHANG|WUNTRACED|__WNOTHREAD|__WCLONE|__WALL))
		return -EINVAL;

	add_wait_queue(&current->wait_chldexit,&wait);
repeat:
	flag = 0;
	current->state = TASK_INTERRUPTIBLE;
	read_lock(&tasklist_lock);
	tsk = current;
	do {
		struct task_struct *p;
	 	for (p = tsk->p_cptr ; p ; p = p->p_osptr) {
			if (pid>0) {
				if (p->pid != pid)
					continue;
			} else if (!pid) {
				if (p->pgrp != current->pgrp)
					continue;
			} else if (pid != -1) {
				if (p->pgrp != -pid)
					continue;
			}
			/* Wait for all children (clone and not) if __WALL is set;
			 * otherwise, wait for clone children *only* if __WCLONE is
			 * set; otherwise, wait for non-clone children *only*.  (Note:
			 * A "clone" child here is one that reports to its parent
			 * using a signal other than SIGCHLD.) */
			if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
			    && !(options & __WALL))
				continue;
			flag = 1;
			switch (p->state) {
			case TASK_STOPPED:
				if (!p->exit_code)
					continue;
				if (!(options & WUNTRACED) && !(p->ptrace & PT_PTRACED))
					continue;
				read_unlock(&tasklist_lock);
				retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0; 
				if (!retval && stat_addr) 
					retval = put_user((p->exit_code << 8) | 0x7f, stat_addr);
				if (!retval) {
					p->exit_code = 0;
					retval = p->pid;
				}
				goto end_wait4;
			case TASK_ZOMBIE:
				current->times.tms_cutime += p->times.tms_utime + p->times.tms_cutime;
				current->times.tms_cstime += p->times.tms_stime + p->times.tms_cstime;
				read_unlock(&tasklist_lock);
				retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
				if (!retval && stat_addr)
					retval = put_user(p->exit_code, stat_addr);
				if (retval)
					goto end_wait4; 
				retval = p->pid;
				if (p->p_opptr != p->p_pptr) {
					write_lock_irq(&tasklist_lock);
					REMOVE_LINKS(p);
					p->p_pptr = p->p_opptr;
					SET_LINKS(p);
					do_notify_parent(p, SIGCHLD);
					write_unlock_irq(&tasklist_lock);
				} else
					release_task(p);
				goto end_wait4;
			default:
				continue;
			}
		}
		if (options & __WNOTHREAD)
			break;
		tsk = next_thread(tsk);
	} while (tsk != current);
	read_unlock(&tasklist_lock);
	if (flag) {
		retval = 0;
		if (options & WNOHANG)
			goto end_wait4;
		retval = -ERESTARTSYS;
		if (signal_pending(current))
			goto end_wait4;
		schedule();
		goto repeat;
	}
	retval = -ECHILD;
end_wait4:
	current->state = TASK_RUNNING;
	remove_wait_queue(&current->wait_chldexit,&wait);
	return retval;
}

static void ib_cache_update(struct ib_device *device,
			    u8                port)
{
	struct ib_port_attr       *tprops = NULL;
	struct ib_pkey_cache      *pkey_cache = NULL, *old_pkey_cache;
	struct ib_gid_cache       *gid_cache = NULL, *old_gid_cache;
	int                        i, j;
	int                        ret;
	union ib_gid		   gid, empty_gid;
	u16			   pkey;

	tprops = kmalloc(sizeof *tprops, GFP_KERNEL);
	if (!tprops)
		return;

	ret = ib_query_port(device, port, tprops);
	if (ret) {
		printk(KERN_WARNING "ib_query_port failed (%d) for %s\n",
		       ret, device->name);
		goto err;
	}

	pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
			     sizeof *pkey_cache->entry, GFP_KERNEL);
	if (!pkey_cache)
		goto err;

	pkey_cache->table_len = 0;

	gid_cache = kmalloc(sizeof *gid_cache + tprops->gid_tbl_len *
			    sizeof *gid_cache->entry, GFP_KERNEL);
	if (!gid_cache)
		goto err;

	gid_cache->table_len = 0;

	for (i = 0, j = 0; i < tprops->pkey_tbl_len; ++i) {
		ret = ib_query_pkey(device, port, i, &pkey);
		if (ret) {
			printk(KERN_WARNING "ib_query_pkey failed (%d) for %s (index %d)\n",
			       ret, device->name, i);
			goto err;
		}
		/* pkey 0xffff must be the default pkeyand 0x0000 must be the invalid
		 * pkey per IBTA spec */
		if (pkey) {
			pkey_cache->entry[j].index = i;
			pkey_cache->entry[j++].pkey = pkey;
		}
	}
	pkey_cache->table_len = j;

	memset(&empty_gid, 0, sizeof empty_gid);
	for (i = 0, j = 0; i < tprops->gid_tbl_len; ++i) {
		ret = ib_query_gid(device, port, i, &gid);
		if (ret) {
			printk(KERN_WARNING "ib_query_gid failed (%d) for %s (index %d)\n",
			       ret, device->name, i);
			goto err;
		}
		/* if the lower 8 bytes the device GID entry is all 0,
		 * our entry is a blank, invalid entry...
		 * depending on device, the upper 8 bytes might or might
		 * not be prefilled with a valid subnet prefix, so
		 * don't rely on them for determining a valid gid
		 * entry
		 */
		if (memcmp(&gid + 8, &empty_gid + 8, sizeof gid - 8)) {
			gid_cache->entry[j].index = i;
			gid_cache->entry[j++].gid = gid;
		}
	}
	gid_cache->table_len = j;

	old_pkey_cache = pkey_cache;
	pkey_cache = kmalloc(sizeof *pkey_cache + old_pkey_cache->table_len *
			     sizeof *pkey_cache->entry, GFP_KERNEL);
	if (!pkey_cache)
		pkey_cache = old_pkey_cache;
	else {
		pkey_cache->table_len = old_pkey_cache->table_len;
		memcpy(&pkey_cache->entry[0], &old_pkey_cache->entry[0],
		       pkey_cache->table_len * sizeof *pkey_cache->entry);
		kfree(old_pkey_cache);
	}

	old_gid_cache = gid_cache;
	gid_cache = kmalloc(sizeof *gid_cache + old_gid_cache->table_len *
			    sizeof *gid_cache->entry, GFP_KERNEL);
	if (!gid_cache)
		gid_cache = old_gid_cache;
	else {
		gid_cache->table_len = old_gid_cache->table_len;
		memcpy(&gid_cache->entry[0], &old_gid_cache->entry[0],
		       gid_cache->table_len * sizeof *gid_cache->entry);
		kfree(old_gid_cache);
	}

	write_lock_irq(&device->cache.lock);

//.........这里部分代码省略.........

/*
 * Adjust the time obtained from the CMOS to be UTC time instead of
 * local time.
 * 
 * This is ugly, but preferable to the alternatives.  Otherwise we
 * would either need to write a program to do it in /etc/rc (and risk
 * confusion if the program gets run more than once; it would also be 
 * hard to make the program warp the clock precisely n hours)  or
 * compile in the timezone information into the kernel.  Bad, bad....
 *
 *              				- TYT, 1992-01-01
 *
 * The best thing to do is to keep the CMOS clock in universal time (UTC)
 * as real UNIX machines always do it. This avoids all headaches about
 * daylight saving times and warping kernel clocks.
 */
inline static void warp_clock(void)
{
	write_lock_irq(&xtime_lock);
	xtime.tv_sec += sys_tz.tz_minuteswest * 60;
	write_unlock_irq(&xtime_lock);
}

//.........这里部分代码省略.........
	/*
	 * Clear TID on mm_release()?
	 */
	p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;

	/*
	 * Syscall tracing should be turned off in the child regardless
	 * of CLONE_PTRACE.
	 */
	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);

	/* Our parent execution domain becomes current domain
	   These must match for thread signalling to apply */
	   
	p->parent_exec_id = p->self_exec_id;

	/* ok, now we should be set up.. */
	p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
	p->pdeath_signal = 0;
	p->exit_state = 0;

	/* Perform scheduler related setup */
	sched_fork(p);

	/*
	 * Ok, make it visible to the rest of the system.
	 * We dont wake it up yet.
	 */
	p->group_leader = p;
	INIT_LIST_HEAD(&p->ptrace_children);
	INIT_LIST_HEAD(&p->ptrace_list);

	/* Need tasklist lock for parent etc handling! */
	write_lock_irq(&tasklist_lock);

	/*
	 * The task hasn't been attached yet, so cpus_allowed mask cannot
	 * have changed. The cpus_allowed mask of the parent may have
	 * changed after it was copied first time, and it may then move to
	 * another CPU - so we re-copy it here and set the child's CPU to
	 * the parent's CPU. This avoids alot of nasty races.
	 */
	p->cpus_allowed = current->cpus_allowed;
	set_task_cpu(p, smp_processor_id());

	/*
	 * Check for pending SIGKILL! The new thread should not be allowed
	 * to slip out of an OOM kill. (or normal SIGKILL.)
	 */
	if (sigismember(&current->pending.signal, SIGKILL)) {
		write_unlock_irq(&tasklist_lock);
		retval = -EINTR;
		goto bad_fork_cleanup_namespace;
	}

	/* CLONE_PARENT re-uses the old parent */
	if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
		p->real_parent = current->real_parent;
	else
		p->real_parent = current;
	p->parent = p->real_parent;

	if (clone_flags & CLONE_THREAD) {
		spin_lock(&current->sighand->siglock);
		/*
		 * Important: if an exit-all has been started then

long sys_ptrace(long request, pid_t pid, long addr, long data)
{
	struct task_struct *child;
	long ret;

	lock_kernel();
	ret = -EPERM;
	if (request == PTRACE_TRACEME) {
		/* are we already being traced? */
		if (current->ptrace & PT_PTRACED)
			goto out;
		/* set the ptrace bit in the process flags. */
		current->ptrace |= PT_PTRACED;
		ret = 0;
		goto out;
	}

	ret = -ESRCH;
	read_lock(&tasklist_lock);
	child = find_task_by_pid(pid);
	if (child)
		get_task_struct(child);
	read_unlock(&tasklist_lock);
	if (!child)
		goto out;
	ret = -EPERM;
	if (pid == 1)		/* no messing around with init! */
		goto out_tsk;

	if (request == PTRACE_ATTACH) {
		if (child == current)
			goto out_tsk;
		if ((!child->dumpable ||
		    (current->uid != child->euid) ||
		    (current->uid != child->suid) ||
		    (current->uid != child->uid) ||
	 	    (current->gid != child->egid) ||
	 	    (current->gid != child->sgid) ||
	 	    (!cap_issubset(child->cap_permitted, current->cap_permitted)) ||
	 	    (current->gid != child->gid)) && !capable(CAP_SYS_PTRACE))
			goto out_tsk;
		/* the same process cannot be attached many times */
		if (child->ptrace & PT_PTRACED)
			goto out_tsk;
		child->ptrace |= PT_PTRACED;
		if (child->p_pptr != current) {
			unsigned long flags;

			write_lock_irqsave(&tasklist_lock, flags);
			REMOVE_LINKS(child);
			child->p_pptr = current;
			SET_LINKS(child);
			write_unlock_irqrestore(&tasklist_lock, flags);
		}
		send_sig(SIGSTOP, child, 1);
		ret = 0;
		goto out_tsk;
	}
	ret = -ESRCH;
	if (!(child->ptrace & PT_PTRACED))
		goto out_tsk;
	if (child->state != TASK_STOPPED) {
		if (request != PTRACE_KILL)
			goto out_tsk;
	}
	if (child->p_pptr != current)
		goto out_tsk;

	switch (request) {
	case PTRACE_PEEKTEXT: /* read word at location addr. */ 
	case PTRACE_PEEKDATA: {
		unsigned long tmp;
		int copied;

		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
		ret = -EIO;
		if (copied != sizeof(tmp))
			goto out_tsk;
		ret = put_user(tmp,(unsigned long *) data);
		goto out_tsk;
	}

	/* when I and D space are separate, this will have to be fixed. */
	case PTRACE_POKETEXT: /* write the word at location addr. */
	case PTRACE_POKEDATA:
		ret = 0;
		if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
			goto out_tsk;
		ret = -EIO;
		goto out_tsk;

	/* Read the word at location addr in the USER area.  This will need
	   to change when the kernel no longer saves all regs on a syscall. */
	case PTRACE_PEEKUSR: {
		unsigned long tmp;

		ret = -EIO;
		if ((addr & 3) || (unsigned long) addr >= sizeof(struct pt_regs))
			goto out_tsk;

//.........这里部分代码省略.........

/**
 * zfcp_adapter_enqueue - enqueue a new adapter to the list
 * @ccw_device: pointer to the struct cc_device
 *
 * Returns:	0             if a new adapter was successfully enqueued
 *		-ENOMEM       if alloc failed
 * Enqueues an adapter at the end of the adapter list in the driver data.
 * All adapter internal structures are set up.
 * Proc-fs entries are also created.
 * locks:	config_sema must be held to serialise changes to the adapter list
 */
int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
{
	struct zfcp_adapter *adapter;

	/*
	 * Note: It is safe to release the list_lock, as any list changes
	 * are protected by the config_sema, which must be held to get here
	 */

	adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
	if (!adapter)
		return -ENOMEM;

	ccw_device->handler = NULL;
	adapter->ccw_device = ccw_device;
	atomic_set(&adapter->refcount, 0);

	if (zfcp_qdio_allocate(adapter))
		goto qdio_allocate_failed;

	if (zfcp_allocate_low_mem_buffers(adapter))
		goto failed_low_mem_buffers;

	if (zfcp_reqlist_alloc(adapter))
		goto failed_low_mem_buffers;

	if (zfcp_adapter_debug_register(adapter))
		goto debug_register_failed;

	init_waitqueue_head(&adapter->remove_wq);
	init_waitqueue_head(&adapter->erp_thread_wqh);
	init_waitqueue_head(&adapter->erp_done_wqh);

	INIT_LIST_HEAD(&adapter->port_list_head);
	INIT_LIST_HEAD(&adapter->erp_ready_head);
	INIT_LIST_HEAD(&adapter->erp_running_head);

	spin_lock_init(&adapter->req_list_lock);

	spin_lock_init(&adapter->hba_dbf_lock);
	spin_lock_init(&adapter->san_dbf_lock);
	spin_lock_init(&adapter->scsi_dbf_lock);
	spin_lock_init(&adapter->rec_dbf_lock);
	spin_lock_init(&adapter->req_q_lock);

	rwlock_init(&adapter->erp_lock);
	rwlock_init(&adapter->abort_lock);

	sema_init(&adapter->erp_ready_sem, 0);

	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
	INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);

	/* mark adapter unusable as long as sysfs registration is not complete */
	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);

	dev_set_drvdata(&ccw_device->dev, adapter);

	if (sysfs_create_group(&ccw_device->dev.kobj,
			       &zfcp_sysfs_adapter_attrs))
		goto sysfs_failed;

	write_lock_irq(&zfcp_data.config_lock);
	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
	list_add_tail(&adapter->list, &zfcp_data.adapter_list_head);
	write_unlock_irq(&zfcp_data.config_lock);

	zfcp_fc_nameserver_init(adapter);

	return 0;

sysfs_failed:
	zfcp_adapter_debug_unregister(adapter);
debug_register_failed:
	dev_set_drvdata(&ccw_device->dev, NULL);
	kfree(adapter->req_list);
failed_low_mem_buffers:
	zfcp_free_low_mem_buffers(adapter);
qdio_allocate_failed:
	zfcp_qdio_free(adapter);
	kfree(adapter);
	return -ENOMEM;
}

/**
 * zfcp_port_enqueue - enqueue port to port list of adapter
 * @adapter: adapter where remote port is added
 * @wwpn: WWPN of the remote port to be enqueued
 * @status: initial status for the port
 * @d_id: destination id of the remote port to be enqueued
 * Returns: pointer to enqueued port on success, ERR_PTR on error
 *
 * All port internal structures are set up and the sysfs entry is generated.
 * d_id is used to enqueue ports with a well known address like the Directory
 * Service for nameserver lookup.
 */
struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
				     u32 status, u32 d_id)
{
	struct zfcp_port *port;
	int retval = -ENOMEM;

	kref_get(&adapter->ref);

	port = zfcp_get_port_by_wwpn(adapter, wwpn);
	if (port) {
		put_device(&port->dev);
		retval = -EEXIST;
		goto err_out;
	}

	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
	if (!port)
		goto err_out;

	rwlock_init(&port->unit_list_lock);
	INIT_LIST_HEAD(&port->unit_list);

	INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
	INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
	INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);

	port->adapter = adapter;
	port->d_id = d_id;
	port->wwpn = wwpn;
	port->rport_task = RPORT_NONE;
	port->dev.parent = &adapter->ccw_device->dev;
	port->dev.release = zfcp_port_release;

	if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
		kfree(port);
		goto err_out;
	}
	retval = -EINVAL;

	if (device_register(&port->dev)) {
		put_device(&port->dev);
		goto err_out;
	}

	if (sysfs_create_group(&port->dev.kobj,
			       &zfcp_sysfs_port_attrs))
		goto err_out_put;

	write_lock_irq(&adapter->port_list_lock);
	list_add_tail(&port->list, &adapter->port_list);
	write_unlock_irq(&adapter->port_list_lock);

	atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);

	return port;

err_out_put:
	device_unregister(&port->dev);
err_out:
	zfcp_ccw_adapter_put(adapter);
	return ERR_PTR(retval);
}