[net-next-2.6.git] / fs / nfs / delegation.c

/*
 * linux/fs/nfs/delegation.c
 *
 * Copyright (C) 2004 Trond Myklebust
 *
 * NFS file delegation management
 *
 */
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/spinlock.h>

#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_xdr.h>

#include "nfs4_fs.h"
#include "delegation.h"

static struct nfs_delegation *nfs_alloc_delegation(void)
{
	return (struct nfs_delegation *)kmalloc(sizeof(struct nfs_delegation), GFP_KERNEL);
}

static void nfs_free_delegation(struct nfs_delegation *delegation)
{
	if (delegation->cred)
		put_rpccred(delegation->cred);
	kfree(delegation);
}

static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
{
	struct inode *inode = state->inode;
	struct file_lock *fl;
	int status;

	for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
		if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
			continue;
		if ((struct nfs_open_context *)fl->fl_file->private_data != ctx)
			continue;
		status = nfs4_lock_delegation_recall(state, fl);
		if (status >= 0)
			continue;
		switch (status) {
			default:
				printk(KERN_ERR "%s: unhandled error %d.\n",
						__FUNCTION__, status);
			case -NFS4ERR_EXPIRED:
				/* kill_proc(fl->fl_pid, SIGLOST, 1); */
			case -NFS4ERR_STALE_CLIENTID:
				nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs4_state);
				goto out_err;
		}
	}
	return 0;
out_err:
	return status;
}

static void nfs_delegation_claim_opens(struct inode *inode)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_open_context *ctx;
	struct nfs4_state *state;
	int err;

again:
	spin_lock(&inode->i_lock);
	list_for_each_entry(ctx, &nfsi->open_files, list) {
		state = ctx->state;
		if (state == NULL)
			continue;
		if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
			continue;
		get_nfs_open_context(ctx);
		spin_unlock(&inode->i_lock);
		err = nfs4_open_delegation_recall(ctx->dentry, state);
		if (err >= 0)
			err = nfs_delegation_claim_locks(ctx, state);
		put_nfs_open_context(ctx);
		if (err != 0)
			return;
		goto again;
	}
	spin_unlock(&inode->i_lock);
}

/*
 * Set up a delegation on an inode
 */
void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
{
	struct nfs_delegation *delegation = NFS_I(inode)->delegation;

	if (delegation == NULL)
		return;
	memcpy(delegation->stateid.data, res->delegation.data,
			sizeof(delegation->stateid.data));
	delegation->type = res->delegation_type;
	delegation->maxsize = res->maxsize;
	put_rpccred(cred);
	delegation->cred = get_rpccred(cred);
	delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
	NFS_I(inode)->delegation_state = delegation->type;
	smp_wmb();
}

/*
 * Set up a delegation on an inode
 */
int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
{
	struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_delegation *delegation;
	int status = 0;

	/* Ensure we first revalidate the attributes and page cache! */
	if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
		__nfs_revalidate_inode(NFS_SERVER(inode), inode);

	delegation = nfs_alloc_delegation();
	if (delegation == NULL)
		return -ENOMEM;
	memcpy(delegation->stateid.data, res->delegation.data,
			sizeof(delegation->stateid.data));
	delegation->type = res->delegation_type;
	delegation->maxsize = res->maxsize;
	delegation->change_attr = nfsi->change_attr;
	delegation->cred = get_rpccred(cred);
	delegation->inode = inode;

	spin_lock(&clp->cl_lock);
	if (nfsi->delegation == NULL) {
		list_add(&delegation->super_list, &clp->cl_delegations);
		nfsi->delegation = delegation;
		nfsi->delegation_state = delegation->type;
		delegation = NULL;
	} else {
		if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
					sizeof(delegation->stateid)) != 0 ||
				delegation->type != nfsi->delegation->type) {
			printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
					__FUNCTION__, NIPQUAD(clp->cl_addr));
			status = -EIO;
		}
	}
	spin_unlock(&clp->cl_lock);
	kfree(delegation);
	return status;
}

static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
{
	int res = 0;

	res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
	nfs_free_delegation(delegation);
	return res;
}

/* Sync all data to disk upon delegation return */
static void nfs_msync_inode(struct inode *inode)
{
	filemap_fdatawrite(inode->i_mapping);
	nfs_wb_all(inode);
	filemap_fdatawait(inode->i_mapping);
}

/*
 * Basic procedure for returning a delegation to the server
 */
int __nfs_inode_return_delegation(struct inode *inode)
{
	struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_delegation *delegation;
	int res = 0;

	nfs_msync_inode(inode);
	down_read(&clp->cl_sem);
	/* Guard against new delegated open calls */
	down_write(&nfsi->rwsem);
	spin_lock(&clp->cl_lock);
	delegation = nfsi->delegation;
	if (delegation != NULL) {
		list_del_init(&delegation->super_list);
		nfsi->delegation = NULL;
		nfsi->delegation_state = 0;
	}
	spin_unlock(&clp->cl_lock);
	nfs_delegation_claim_opens(inode);
	up_write(&nfsi->rwsem);
	up_read(&clp->cl_sem);
	nfs_msync_inode(inode);

	if (delegation != NULL)
		res = nfs_do_return_delegation(inode, delegation);
	return res;
}

/*
 * Return all delegations associated to a super block
 */
void nfs_return_all_delegations(struct super_block *sb)
{
	struct nfs4_client *clp = NFS_SB(sb)->nfs4_state;
	struct nfs_delegation *delegation;
	struct inode *inode;

	if (clp == NULL)
		return;
restart:
	spin_lock(&clp->cl_lock);
	list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
		if (delegation->inode->i_sb != sb)
			continue;
		inode = igrab(delegation->inode);
		if (inode == NULL)
			continue;
		spin_unlock(&clp->cl_lock);
		nfs_inode_return_delegation(inode);
		iput(inode);
		goto restart;
	}
	spin_unlock(&clp->cl_lock);
}

int nfs_do_expire_all_delegations(void *ptr)
{
	struct nfs4_client *clp = ptr;
	struct nfs_delegation *delegation;
	struct inode *inode;

	allow_signal(SIGKILL);
restart:
	spin_lock(&clp->cl_lock);
	if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
		goto out;
	if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
		goto out;
	list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
		inode = igrab(delegation->inode);
		if (inode == NULL)
			continue;
		spin_unlock(&clp->cl_lock);
		nfs_inode_return_delegation(inode);
		iput(inode);
		goto restart;
	}
out:
	spin_unlock(&clp->cl_lock);
	nfs4_put_client(clp);
	module_put_and_exit(0);
}

void nfs_expire_all_delegations(struct nfs4_client *clp)
{
	struct task_struct *task;

	__module_get(THIS_MODULE);
	atomic_inc(&clp->cl_count);
	task = kthread_run(nfs_do_expire_all_delegations, clp,
			"%u.%u.%u.%u-delegreturn",
			NIPQUAD(clp->cl_addr));
	if (!IS_ERR(task))
		return;
	nfs4_put_client(clp);
	module_put(THIS_MODULE);
}

/*
 * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
 */
void nfs_handle_cb_pathdown(struct nfs4_client *clp)
{
	struct nfs_delegation *delegation;
	struct inode *inode;

	if (clp == NULL)
		return;
restart:
	spin_lock(&clp->cl_lock);
	list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
		inode = igrab(delegation->inode);
		if (inode == NULL)
			continue;
		spin_unlock(&clp->cl_lock);
		nfs_inode_return_delegation(inode);
		iput(inode);
		goto restart;
	}
	spin_unlock(&clp->cl_lock);
}

struct recall_threadargs {
	struct inode *inode;
	struct nfs4_client *clp;
	const nfs4_stateid *stateid;

	struct completion started;
	int result;
};

static int recall_thread(void *data)
{
	struct recall_threadargs *args = (struct recall_threadargs *)data;
	struct inode *inode = igrab(args->inode);
	struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_delegation *delegation;

	daemonize("nfsv4-delegreturn");

	nfs_msync_inode(inode);
	down_read(&clp->cl_sem);
	down_write(&nfsi->rwsem);
	spin_lock(&clp->cl_lock);
	delegation = nfsi->delegation;
	if (delegation != NULL && memcmp(delegation->stateid.data,
				args->stateid->data,
				sizeof(delegation->stateid.data)) == 0) {
		list_del_init(&delegation->super_list);
		nfsi->delegation = NULL;
		nfsi->delegation_state = 0;
		args->result = 0;
	} else {
		delegation = NULL;
		args->result = -ENOENT;
	}
	spin_unlock(&clp->cl_lock);
	complete(&args->started);
	nfs_delegation_claim_opens(inode);
	up_write(&nfsi->rwsem);
	up_read(&clp->cl_sem);
	nfs_msync_inode(inode);

	if (delegation != NULL)
		nfs_do_return_delegation(inode, delegation);
	iput(inode);
	module_put_and_exit(0);
}

/*
 * Asynchronous delegation recall!
 */
int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
{
	struct recall_threadargs data = {
		.inode = inode,
		.stateid = stateid,
	};
	int status;

	init_completion(&data.started);
	__module_get(THIS_MODULE);
	status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
	if (status < 0)
		goto out_module_put;
	wait_for_completion(&data.started);
	return data.result;
out_module_put:
	module_put(THIS_MODULE);
	return status;
}

/*
 * Retrieve the inode associated with a delegation
 */
struct inode *nfs_delegation_find_inode(struct nfs4_client *clp, const struct nfs_fh *fhandle)
{
	struct nfs_delegation *delegation;
	struct inode *res = NULL;
	spin_lock(&clp->cl_lock);
	list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
		if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
			res = igrab(delegation->inode);
			break;
		}
	}
	spin_unlock(&clp->cl_lock);
	return res;
}

/*
 * Mark all delegations as needing to be reclaimed
 */
void nfs_delegation_mark_reclaim(struct nfs4_client *clp)
{
	struct nfs_delegation *delegation;
	spin_lock(&clp->cl_lock);
	list_for_each_entry(delegation, &clp->cl_delegations, super_list)
		delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
	spin_unlock(&clp->cl_lock);
}

/*
 * Reap all unclaimed delegations after reboot recovery is done
 */
void nfs_delegation_reap_unclaimed(struct nfs4_client *clp)
{
	struct nfs_delegation *delegation, *n;
	LIST_HEAD(head);
	spin_lock(&clp->cl_lock);
	list_for_each_entry_safe(delegation, n, &clp->cl_delegations, super_list) {
		if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
			continue;
		list_move(&delegation->super_list, &head);
		NFS_I(delegation->inode)->delegation = NULL;
		NFS_I(delegation->inode)->delegation_state = 0;
	}
	spin_unlock(&clp->cl_lock);
	while(!list_empty(&head)) {
		delegation = list_entry(head.next, struct nfs_delegation, super_list);
		list_del(&delegation->super_list);
		nfs_free_delegation(delegation);
	}
}

int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
{
	struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_delegation *delegation;
	int res = 0;

	if (nfsi->delegation_state == 0)
		return 0;
	spin_lock(&clp->cl_lock);
	delegation = nfsi->delegation;
	if (delegation != NULL) {
		memcpy(dst->data, delegation->stateid.data, sizeof(dst->data));
		res = 1;
	}
	spin_unlock(&clp->cl_lock);
	return res;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfs/delegation.c
	3	*
	4	* Copyright (C) 2004 Trond Myklebust
	5	*
	6	* NFS file delegation management
	7	*
	8	*/
1da177e4	9	#include <linux/completion.h>
58d9714a	10	#include <linux/kthread.h>
1da177e4 LT	11	#include <linux/module.h>
	12	#include <linux/sched.h>
	13	#include <linux/spinlock.h>
	14
	15	#include <linux/nfs4.h>
	16	#include <linux/nfs_fs.h>
	17	#include <linux/nfs_xdr.h>
	18
4ce79717	19	#include "nfs4_fs.h"
1da177e4 LT	20	#include "delegation.h"
	21
	22	static struct nfs_delegation *nfs_alloc_delegation(void)
	23	{
	24	return (struct nfs_delegation *)kmalloc(sizeof(struct nfs_delegation), GFP_KERNEL);
	25	}
	26
	27	static void nfs_free_delegation(struct nfs_delegation *delegation)
	28	{
	29	if (delegation->cred)
	30	put_rpccred(delegation->cred);
	31	kfree(delegation);
	32	}
	33
888e694c TM	34	static int nfs_delegation_claim_locks(struct nfs_open_context ctx, struct nfs4_state state)
	35	{
	36	struct inode *inode = state->inode;
	37	struct file_lock *fl;
	38	int status;
	39
	40	for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
	41	if (!(fl->fl_flags & (FL_POSIX\|FL_FLOCK)))
	42	continue;
	43	if ((struct nfs_open_context *)fl->fl_file->private_data != ctx)
	44	continue;
	45	status = nfs4_lock_delegation_recall(state, fl);
	46	if (status >= 0)
	47	continue;
	48	switch (status) {
	49	default:
	50	printk(KERN_ERR "%s: unhandled error %d.\n",
	51	__FUNCTION__, status);
	52	case -NFS4ERR_EXPIRED:
	53	/* kill_proc(fl->fl_pid, SIGLOST, 1); */
	54	case -NFS4ERR_STALE_CLIENTID:
	55	nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs4_state);
	56	goto out_err;
	57	}
	58	}
	59	return 0;
	60	out_err:
	61	return status;
	62	}
	63
1da177e4 LT	64	static void nfs_delegation_claim_opens(struct inode *inode)
	65	{
	66	struct nfs_inode *nfsi = NFS_I(inode);
	67	struct nfs_open_context *ctx;
	68	struct nfs4_state *state;
888e694c	69	int err;
1da177e4 LT	70
	71	again:
	72	spin_lock(&inode->i_lock);
	73	list_for_each_entry(ctx, &nfsi->open_files, list) {
	74	state = ctx->state;
	75	if (state == NULL)
	76	continue;
	77	if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
	78	continue;
	79	get_nfs_open_context(ctx);
	80	spin_unlock(&inode->i_lock);
888e694c TM	81	err = nfs4_open_delegation_recall(ctx->dentry, state);
	82	if (err >= 0)
	83	err = nfs_delegation_claim_locks(ctx, state);
1da177e4	84	put_nfs_open_context(ctx);
888e694c TM	85	if (err != 0)
888e694c TM	86	return;
1da177e4 LT	87	goto again;
	88	}
	89	spin_unlock(&inode->i_lock);
	90	}
	91
	92	/*
	93	* Set up a delegation on an inode
	94	*/
	95	void nfs_inode_reclaim_delegation(struct inode inode, struct rpc_cred cred, struct nfs_openres *res)
	96	{
	97	struct nfs_delegation *delegation = NFS_I(inode)->delegation;
	98
	99	if (delegation == NULL)
	100	return;
	101	memcpy(delegation->stateid.data, res->delegation.data,
	102	sizeof(delegation->stateid.data));
	103	delegation->type = res->delegation_type;
	104	delegation->maxsize = res->maxsize;
	105	put_rpccred(cred);
	106	delegation->cred = get_rpccred(cred);
	107	delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
	108	NFS_I(inode)->delegation_state = delegation->type;
	109	smp_wmb();
	110	}
	111
	112	/*
	113	* Set up a delegation on an inode
	114	*/
	115	int nfs_inode_set_delegation(struct inode inode, struct rpc_cred cred, struct nfs_openres *res)
	116	{
	117	struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
	118	struct nfs_inode *nfsi = NFS_I(inode);
	119	struct nfs_delegation *delegation;
	120	int status = 0;
	121
b3c52da3 TM	122	/* Ensure we first revalidate the attributes and page cache! */
	123	if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE\|NFS_INO_INVALID_ATTR)))
	124	__nfs_revalidate_inode(NFS_SERVER(inode), inode);
	125
1da177e4 LT	126	delegation = nfs_alloc_delegation();
	127	if (delegation == NULL)
	128	return -ENOMEM;
	129	memcpy(delegation->stateid.data, res->delegation.data,
	130	sizeof(delegation->stateid.data));
	131	delegation->type = res->delegation_type;
	132	delegation->maxsize = res->maxsize;
beb2a5ec	133	delegation->change_attr = nfsi->change_attr;
1da177e4 LT	134	delegation->cred = get_rpccred(cred);
	135	delegation->inode = inode;
	136
	137	spin_lock(&clp->cl_lock);
	138	if (nfsi->delegation == NULL) {
	139	list_add(&delegation->super_list, &clp->cl_delegations);
	140	nfsi->delegation = delegation;
	141	nfsi->delegation_state = delegation->type;
	142	delegation = NULL;
	143	} else {
	144	if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
	145	sizeof(delegation->stateid)) != 0 \|\|
	146	delegation->type != nfsi->delegation->type) {
	147	printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
	148	__FUNCTION__, NIPQUAD(clp->cl_addr));
	149	status = -EIO;
	150	}
	151	}
	152	spin_unlock(&clp->cl_lock);
f99d49ad	153	kfree(delegation);
1da177e4 LT	154	return status;
	155	}
	156
	157	static int nfs_do_return_delegation(struct inode inode, struct nfs_delegation delegation)
	158	{
	159	int res = 0;
	160
1da177e4 LT	161	res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
	162	nfs_free_delegation(delegation);
	163	return res;
	164	}
	165
	166	/* Sync all data to disk upon delegation return */
	167	static void nfs_msync_inode(struct inode *inode)
	168	{
	169	filemap_fdatawrite(inode->i_mapping);
	170	nfs_wb_all(inode);
	171	filemap_fdatawait(inode->i_mapping);
	172	}
	173
	174	/*
	175	* Basic procedure for returning a delegation to the server
	176	*/
cae7a073	177	int __nfs_inode_return_delegation(struct inode *inode)
1da177e4 LT	178	{
	179	struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
	180	struct nfs_inode *nfsi = NFS_I(inode);
	181	struct nfs_delegation *delegation;
	182	int res = 0;
	183
	184	nfs_msync_inode(inode);
	185	down_read(&clp->cl_sem);
	186	/* Guard against new delegated open calls */
	187	down_write(&nfsi->rwsem);
	188	spin_lock(&clp->cl_lock);
	189	delegation = nfsi->delegation;
	190	if (delegation != NULL) {
	191	list_del_init(&delegation->super_list);
	192	nfsi->delegation = NULL;
	193	nfsi->delegation_state = 0;
	194	}
	195	spin_unlock(&clp->cl_lock);
	196	nfs_delegation_claim_opens(inode);
	197	up_write(&nfsi->rwsem);
	198	up_read(&clp->cl_sem);
	199	nfs_msync_inode(inode);
	200
	201	if (delegation != NULL)
	202	res = nfs_do_return_delegation(inode, delegation);
	203	return res;
	204	}
	205
	206	/*
	207	* Return all delegations associated to a super block
	208	*/
	209	void nfs_return_all_delegations(struct super_block *sb)
	210	{
	211	struct nfs4_client *clp = NFS_SB(sb)->nfs4_state;
	212	struct nfs_delegation *delegation;
	213	struct inode *inode;
	214
	215	if (clp == NULL)
	216	return;
	217	restart:
	218	spin_lock(&clp->cl_lock);
	219	list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
	220	if (delegation->inode->i_sb != sb)
	221	continue;
	222	inode = igrab(delegation->inode);
	223	if (inode == NULL)
	224	continue;
	225	spin_unlock(&clp->cl_lock);
	226	nfs_inode_return_delegation(inode);
	227	iput(inode);
	228	goto restart;
	229	}
	230	spin_unlock(&clp->cl_lock);
	231	}
	232
58d9714a TM	233	int nfs_do_expire_all_delegations(void *ptr)
	234	{
	235	struct nfs4_client *clp = ptr;
	236	struct nfs_delegation *delegation;
	237	struct inode *inode;
58d9714a TM	238
	239	allow_signal(SIGKILL);
	240	restart:
	241	spin_lock(&clp->cl_lock);
	242	if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
	243	goto out;
	244	if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
	245	goto out;
	246	list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
	247	inode = igrab(delegation->inode);
	248	if (inode == NULL)
	249	continue;
	250	spin_unlock(&clp->cl_lock);
26c78e15	251	nfs_inode_return_delegation(inode);
58d9714a	252	iput(inode);
26c78e15	253	goto restart;
58d9714a TM	254	}
	255	out:
	256	spin_unlock(&clp->cl_lock);
	257	nfs4_put_client(clp);
	258	module_put_and_exit(0);
	259	}
	260
	261	void nfs_expire_all_delegations(struct nfs4_client *clp)
	262	{
	263	struct task_struct *task;
	264
	265	__module_get(THIS_MODULE);
	266	atomic_inc(&clp->cl_count);
	267	task = kthread_run(nfs_do_expire_all_delegations, clp,
	268	"%u.%u.%u.%u-delegreturn",
	269	NIPQUAD(clp->cl_addr));
	270	if (!IS_ERR(task))
	271	return;
	272	nfs4_put_client(clp);
	273	module_put(THIS_MODULE);
	274	}
	275
1da177e4 LT	276	/*
	277	* Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
	278	*/
	279	void nfs_handle_cb_pathdown(struct nfs4_client *clp)
	280	{
	281	struct nfs_delegation *delegation;
	282	struct inode *inode;
	283
	284	if (clp == NULL)
	285	return;
	286	restart:
	287	spin_lock(&clp->cl_lock);
	288	list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
	289	inode = igrab(delegation->inode);
	290	if (inode == NULL)
	291	continue;
	292	spin_unlock(&clp->cl_lock);
	293	nfs_inode_return_delegation(inode);
	294	iput(inode);
	295	goto restart;
	296	}
	297	spin_unlock(&clp->cl_lock);
	298	}
	299
	300	struct recall_threadargs {
	301	struct inode *inode;
	302	struct nfs4_client *clp;
	303	const nfs4_stateid *stateid;
	304
	305	struct completion started;
	306	int result;
	307	};
	308
	309	static int recall_thread(void *data)
	310	{
	311	struct recall_threadargs args = (struct recall_threadargs )data;
	312	struct inode *inode = igrab(args->inode);
	313	struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
	314	struct nfs_inode *nfsi = NFS_I(inode);
	315	struct nfs_delegation *delegation;
	316
	317	daemonize("nfsv4-delegreturn");
	318
	319	nfs_msync_inode(inode);
	320	down_read(&clp->cl_sem);
	321	down_write(&nfsi->rwsem);
	322	spin_lock(&clp->cl_lock);
	323	delegation = nfsi->delegation;
	324	if (delegation != NULL && memcmp(delegation->stateid.data,
	325	args->stateid->data,
	326	sizeof(delegation->stateid.data)) == 0) {
	327	list_del_init(&delegation->super_list);
	328	nfsi->delegation = NULL;
	329	nfsi->delegation_state = 0;
	330	args->result = 0;
	331	} else {
	332	delegation = NULL;
	333	args->result = -ENOENT;
	334	}
	335	spin_unlock(&clp->cl_lock);
	336	complete(&args->started);
	337	nfs_delegation_claim_opens(inode);
	338	up_write(&nfsi->rwsem);
	339	up_read(&clp->cl_sem);
340	nfs_msync_inode(inode);
341
342	if (delegation != NULL)
343	nfs_do_return_delegation(inode, delegation);
344	iput(inode);
345	module_put_and_exit(0);
346	}
347
348	/*
349	* Asynchronous delegation recall!
350	*/
351	int nfs_async_inode_return_delegation(struct inode inode, const nfs4_stateid stateid)
352	{
353	struct recall_threadargs data = {
354	.inode = inode,
355	.stateid = stateid,
356	};
357	int status;
358
359	init_completion(&data.started);
360	__module_get(THIS_MODULE);
361	status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
362	if (status < 0)
363	goto out_module_put;
364	wait_for_completion(&data.started);
365	return data.result;
366	out_module_put:
367	module_put(THIS_MODULE);
368	return status;
369	}
370
371	/*
372	* Retrieve the inode associated with a delegation
373	*/
374	struct inode nfs_delegation_find_inode(struct nfs4_client clp, const struct nfs_fh *fhandle)
375	{
376	struct nfs_delegation *delegation;
377	struct inode *res = NULL;
378	spin_lock(&clp->cl_lock);
379	list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
380	if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
381	res = igrab(delegation->inode);
382	break;
383	}
384	}
385	spin_unlock(&clp->cl_lock);
386	return res;
387	}
388
389	/*
390	* Mark all delegations as needing to be reclaimed
391	*/
392	void nfs_delegation_mark_reclaim(struct nfs4_client *clp)
393	{
394	struct nfs_delegation *delegation;
395	spin_lock(&clp->cl_lock);
396	list_for_each_entry(delegation, &clp->cl_delegations, super_list)
397	delegation->flags \|= NFS_DELEGATION_NEED_RECLAIM;
398	spin_unlock(&clp->cl_lock);
399	}
400
401	/*
402	* Reap all unclaimed delegations after reboot recovery is done
403	*/
404	void nfs_delegation_reap_unclaimed(struct nfs4_client *clp)
405	{
406	struct nfs_delegation delegation, n;
407	LIST_HEAD(head);
408	spin_lock(&clp->cl_lock);
409	list_for_each_entry_safe(delegation, n, &clp->cl_delegations, super_list) {
410	if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
411	continue;
412	list_move(&delegation->super_list, &head);
413	NFS_I(delegation->inode)->delegation = NULL;
414	NFS_I(delegation->inode)->delegation_state = 0;
415	}
416	spin_unlock(&clp->cl_lock);
417	while(!list_empty(&head)) {
418	delegation = list_entry(head.next, struct nfs_delegation, super_list);
419	list_del(&delegation->super_list);
420	nfs_free_delegation(delegation);
421	}
422	}
3e4f6290 TM	423
	424	int nfs4_copy_delegation_stateid(nfs4_stateid dst, struct inode inode)
	425	{
	426	struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
	427	struct nfs_inode *nfsi = NFS_I(inode);
	428	struct nfs_delegation *delegation;
	429	int res = 0;
	430
	431	if (nfsi->delegation_state == 0)
	432	return 0;
	433	spin_lock(&clp->cl_lock);
	434	delegation = nfsi->delegation;
	435	if (delegation != NULL) {
	436	memcpy(dst->data, delegation->stateid.data, sizeof(dst->data));
	437	res = 1;
	438	}
	439	spin_unlock(&clp->cl_lock);
	440	return res;
	441	}