nfs4state.c

linux 内核源代码

	fp = kmem_cache_alloc(file_slab, GFP_KERNEL);
	if (fp) {
		kref_init(&fp->fi_ref);
		INIT_LIST_HEAD(&fp->fi_hash);
		INIT_LIST_HEAD(&fp->fi_stateids);
		INIT_LIST_HEAD(&fp->fi_delegations);
		list_add(&fp->fi_hash, &file_hashtbl[hashval]);
		fp->fi_inode = igrab(ino);
		fp->fi_id = current_fileid++;
		fp->fi_had_conflict = false;
		return fp;
	}
	return NULL;
}

static void
nfsd4_free_slab(struct kmem_cache **slab)
{
	if (*slab == NULL)
		return;
	kmem_cache_destroy(*slab);
	*slab = NULL;
}

void
nfsd4_free_slabs(void)
{
	nfsd4_free_slab(&stateowner_slab);
	nfsd4_free_slab(&file_slab);
	nfsd4_free_slab(&stateid_slab);
	nfsd4_free_slab(&deleg_slab);
}

static int
nfsd4_init_slabs(void)
{
	stateowner_slab = kmem_cache_create("nfsd4_stateowners",
			sizeof(struct nfs4_stateowner), 0, 0, NULL);
	if (stateowner_slab == NULL)
		goto out_nomem;
	file_slab = kmem_cache_create("nfsd4_files",
			sizeof(struct nfs4_file), 0, 0, NULL);
	if (file_slab == NULL)
		goto out_nomem;
	stateid_slab = kmem_cache_create("nfsd4_stateids",
			sizeof(struct nfs4_stateid), 0, 0, NULL);
	if (stateid_slab == NULL)
		goto out_nomem;
	deleg_slab = kmem_cache_create("nfsd4_delegations",
			sizeof(struct nfs4_delegation), 0, 0, NULL);
	if (deleg_slab == NULL)
		goto out_nomem;
	return 0;
out_nomem:
	nfsd4_free_slabs();
	dprintk("nfsd4: out of memory while initializing nfsv4\n");
	return -ENOMEM;
}

void
nfs4_free_stateowner(struct kref *kref)
{
	struct nfs4_stateowner *sop =
		container_of(kref, struct nfs4_stateowner, so_ref);
	kfree(sop->so_owner.data);
	kmem_cache_free(stateowner_slab, sop);
}

static inline struct nfs4_stateowner *
alloc_stateowner(struct xdr_netobj *owner)
{
	struct nfs4_stateowner *sop;

	if ((sop = kmem_cache_alloc(stateowner_slab, GFP_KERNEL))) {
		if ((sop->so_owner.data = kmalloc(owner->len, GFP_KERNEL))) {
			memcpy(sop->so_owner.data, owner->data, owner->len);
			sop->so_owner.len = owner->len;
			kref_init(&sop->so_ref);
			return sop;
		} 
		kmem_cache_free(stateowner_slab, sop);
	}
	return NULL;
}

static struct nfs4_stateowner *
alloc_init_open_stateowner(unsigned int strhashval, struct nfs4_client *clp, struct nfsd4_open *open) {
	struct nfs4_stateowner *sop;
	struct nfs4_replay *rp;
	unsigned int idhashval;

	if (!(sop = alloc_stateowner(&open->op_owner)))
		return NULL;
	idhashval = ownerid_hashval(current_ownerid);
	INIT_LIST_HEAD(&sop->so_idhash);
	INIT_LIST_HEAD(&sop->so_strhash);
	INIT_LIST_HEAD(&sop->so_perclient);
	INIT_LIST_HEAD(&sop->so_stateids);
	INIT_LIST_HEAD(&sop->so_perstateid);  /* not used */
	INIT_LIST_HEAD(&sop->so_close_lru);
	sop->so_time = 0;
	list_add(&sop->so_idhash, &ownerid_hashtbl[idhashval]);
	list_add(&sop->so_strhash, &ownerstr_hashtbl[strhashval]);
	list_add(&sop->so_perclient, &clp->cl_openowners);
	sop->so_is_open_owner = 1;
	sop->so_id = current_ownerid++;
	sop->so_client = clp;
	sop->so_seqid = open->op_seqid;
	sop->so_confirmed = 0;
	rp = &sop->so_replay;
	rp->rp_status = nfserr_serverfault;
	rp->rp_buflen = 0;
	rp->rp_buf = rp->rp_ibuf;
	return sop;
}

static void
release_stateid_lockowners(struct nfs4_stateid *open_stp)
{
	struct nfs4_stateowner *lock_sop;

	while (!list_empty(&open_stp->st_lockowners)) {
		lock_sop = list_entry(open_stp->st_lockowners.next,
				struct nfs4_stateowner, so_perstateid);
		/* list_del(&open_stp->st_lockowners);  */
		BUG_ON(lock_sop->so_is_open_owner);
		release_stateowner(lock_sop);
	}
}

static void
unhash_stateowner(struct nfs4_stateowner *sop)
{
	struct nfs4_stateid *stp;

	list_del(&sop->so_idhash);
	list_del(&sop->so_strhash);
	if (sop->so_is_open_owner)
		list_del(&sop->so_perclient);
	list_del(&sop->so_perstateid);
	while (!list_empty(&sop->so_stateids)) {
		stp = list_entry(sop->so_stateids.next,
			struct nfs4_stateid, st_perstateowner);
		if (sop->so_is_open_owner)
			release_stateid(stp, OPEN_STATE);
		else
			release_stateid(stp, LOCK_STATE);
	}
}

static void
release_stateowner(struct nfs4_stateowner *sop)
{
	unhash_stateowner(sop);
	list_del(&sop->so_close_lru);
	nfs4_put_stateowner(sop);
}

static inline void
init_stateid(struct nfs4_stateid *stp, struct nfs4_file *fp, struct nfsd4_open *open) {
	struct nfs4_stateowner *sop = open->op_stateowner;
	unsigned int hashval = stateid_hashval(sop->so_id, fp->fi_id);

	INIT_LIST_HEAD(&stp->st_hash);
	INIT_LIST_HEAD(&stp->st_perstateowner);
	INIT_LIST_HEAD(&stp->st_lockowners);
	INIT_LIST_HEAD(&stp->st_perfile);
	list_add(&stp->st_hash, &stateid_hashtbl[hashval]);
	list_add(&stp->st_perstateowner, &sop->so_stateids);
	list_add(&stp->st_perfile, &fp->fi_stateids);
	stp->st_stateowner = sop;
	get_nfs4_file(fp);
	stp->st_file = fp;
	stp->st_stateid.si_boot = boot_time;
	stp->st_stateid.si_stateownerid = sop->so_id;
	stp->st_stateid.si_fileid = fp->fi_id;
	stp->st_stateid.si_generation = 0;
	stp->st_access_bmap = 0;
	stp->st_deny_bmap = 0;
	__set_bit(open->op_share_access, &stp->st_access_bmap);
	__set_bit(open->op_share_deny, &stp->st_deny_bmap);
	stp->st_openstp = NULL;
}

static void
release_stateid(struct nfs4_stateid *stp, int flags)
{
	struct file *filp = stp->st_vfs_file;

	list_del(&stp->st_hash);
	list_del(&stp->st_perfile);
	list_del(&stp->st_perstateowner);
	if (flags & OPEN_STATE) {
		release_stateid_lockowners(stp);
		stp->st_vfs_file = NULL;
		nfsd_close(filp);
	} else if (flags & LOCK_STATE)
		locks_remove_posix(filp, (fl_owner_t) stp->st_stateowner);
	put_nfs4_file(stp->st_file);
	kmem_cache_free(stateid_slab, stp);
}

static void
move_to_close_lru(struct nfs4_stateowner *sop)
{
	dprintk("NFSD: move_to_close_lru nfs4_stateowner %p\n", sop);

	list_move_tail(&sop->so_close_lru, &close_lru);
	sop->so_time = get_seconds();
}

static int
same_owner_str(struct nfs4_stateowner *sop, struct xdr_netobj *owner,
							clientid_t *clid)
{
	return (sop->so_owner.len == owner->len) &&
		0 == memcmp(sop->so_owner.data, owner->data, owner->len) &&
		(sop->so_client->cl_clientid.cl_id == clid->cl_id);
}

static struct nfs4_stateowner *
find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open)
{
	struct nfs4_stateowner *so = NULL;

	list_for_each_entry(so, &ownerstr_hashtbl[hashval], so_strhash) {
		if (same_owner_str(so, &open->op_owner, &open->op_clientid))
			return so;
	}
	return NULL;
}

/* search file_hashtbl[] for file */
static struct nfs4_file *
find_file(struct inode *ino)
{
	unsigned int hashval = file_hashval(ino);
	struct nfs4_file *fp;

	list_for_each_entry(fp, &file_hashtbl[hashval], fi_hash) {
		if (fp->fi_inode == ino) {
			get_nfs4_file(fp);
			return fp;
		}
	}
	return NULL;
}

static int access_valid(u32 x)
{
	return (x > 0 && x < 4);
}

static int deny_valid(u32 x)
{
	return (x >= 0 && x < 5);
}

static void
set_access(unsigned int *access, unsigned long bmap) {
	int i;

	*access = 0;
	for (i = 1; i < 4; i++) {
		if (test_bit(i, &bmap))
			*access |= i;
	}
}

static void
set_deny(unsigned int *deny, unsigned long bmap) {
	int i;

	*deny = 0;
	for (i = 0; i < 4; i++) {
		if (test_bit(i, &bmap))
			*deny |= i ;
	}
}

static int
test_share(struct nfs4_stateid *stp, struct nfsd4_open *open) {
	unsigned int access, deny;

	set_access(&access, stp->st_access_bmap);
	set_deny(&deny, stp->st_deny_bmap);
	if ((access & open->op_share_deny) || (deny & open->op_share_access))
		return 0;
	return 1;
}

/*
 * Called to check deny when READ with all zero stateid or
 * WRITE with all zero or all one stateid
 */
static __be32
nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
{
	struct inode *ino = current_fh->fh_dentry->d_inode;
	struct nfs4_file *fp;
	struct nfs4_stateid *stp;
	__be32 ret;

	dprintk("NFSD: nfs4_share_conflict\n");

	fp = find_file(ino);
	if (!fp)
		return nfs_ok;
	ret = nfserr_locked;
	/* Search for conflicting share reservations */
	list_for_each_entry(stp, &fp->fi_stateids, st_perfile) {
		if (test_bit(deny_type, &stp->st_deny_bmap) ||
		    test_bit(NFS4_SHARE_DENY_BOTH, &stp->st_deny_bmap))
			goto out;
	}
	ret = nfs_ok;
out:
	put_nfs4_file(fp);
	return ret;
}

static inline void
nfs4_file_downgrade(struct file *filp, unsigned int share_access)
{
	if (share_access & NFS4_SHARE_ACCESS_WRITE) {
		put_write_access(filp->f_path.dentry->d_inode);
		filp->f_mode = (filp->f_mode | FMODE_READ) & ~FMODE_WRITE;
	}
}

/*
 * Recall a delegation
 */
static int
do_recall(void *__dp)
{
	struct nfs4_delegation *dp = __dp;

	dp->dl_file->fi_had_conflict = true;
	nfsd4_cb_recall(dp);
	return 0;
}

/*
 * Spawn a thread to perform a recall on the delegation represented
 * by the lease (file_lock)
 *
 * Called from break_lease() with lock_kernel() held.
 * Note: we assume break_lease will only call this *once* for any given
 * lease.
 */
static
void nfsd_break_deleg_cb(struct file_lock *fl)
{
	struct nfs4_delegation *dp=  (struct nfs4_delegation *)fl->fl_owner;
	struct task_struct *t;

	dprintk("NFSD nfsd_break_deleg_cb: dp %p fl %p\n",dp,fl);
	if (!dp)
		return;

	/* We're assuming the state code never drops its reference
	 * without first removing the lease.  Since we're in this lease
	 * callback (and since the lease code is serialized by the kernel
	 * lock) we know the server hasn't removed the lease yet, we know
	 * it's safe to take a reference: */
	atomic_inc(&dp->dl_count);
	atomic_inc(&dp->dl_client->cl_count);

	spin_lock(&recall_lock);
	list_add_tail(&dp->dl_recall_lru, &del_recall_lru);
	spin_unlock(&recall_lock);

	/* only place dl_time is set. protected by lock_kernel*/
	dp->dl_time = get_seconds();

	/*
	 * We don't want the locks code to timeout the lease for us;
	 * we'll remove it ourself if the delegation isn't returned
	 * in time.
	 */
	fl->fl_break_time = 0;

	t = kthread_run(do_recall, dp, "%s", "nfs4_cb_recall");
	if (IS_ERR(t)) {
		struct nfs4_client *clp = dp->dl_client;

		printk(KERN_INFO "NFSD: Callback thread failed for "
			"for client (clientid %08x/%08x)\n",
			clp->cl_clientid.cl_boot, clp->cl_clientid.cl_id);
		put_nfs4_client(dp->dl_client);
		nfs4_put_delegation(dp);
	}
}

/*
 * The file_lock is being reapd.
 *
 * Called by locks_free_lock() with lock_kernel() held.
 */
static
void nfsd_release_deleg_cb(struct file_lock *fl)
{
	struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner;

	dprintk("NFSD nfsd_release_deleg_cb: fl %p dp %p dl_count %d\n", fl,dp, atomic_read(&dp->dl_count));

	if (!(fl->fl_flags & FL_LEASE) || !dp)
		return;
	dp->dl_flock = NULL;
}

/*
 * Set the delegation file_lock back pointer.
 *
 * Called from setlease() with lock_kernel() held.
 */
static
void nfsd_copy_lock_deleg_cb(struct file_lock *new, struct file_lock *fl)
{
	struct nfs4_delegation *dp = (struct nfs4_delegation *)new->fl_owner;

	dprintk("NFSD: nfsd_copy_lock_deleg_cb: new fl %p dp %p\n", new, dp);
	if (!dp)
		return;
	dp->dl_flock = new;
}

/*
 * Called from setlease() with lock_kernel() held
 */
static
int nfsd_same_client_deleg_cb(struct file_lock *onlist, struct file_lock *try)
{
	struct nfs4_delegation *onlistd =
		(struct nfs4_delegation *)onlist->fl_owner;
	struct nfs4_delegation *tryd =
		(struct nfs4_delegation *)try->fl_owner;

	if (onlist->fl_lmops != try->fl_lmops)
		return 0;

	return onlistd->dl_client == tryd->dl_client;
}


static
int nfsd_change_deleg_cb(struct file_lock **onlist, int arg)
{
	if (arg & F_UNLCK)
		return lease_modify(onlist, arg);
	else
		return -EAGAIN;
}

static struct lock_manager_operations nfsd_lease_mng_ops = {
	.fl_break = nfsd_break_deleg_cb,
	.fl_release_private = nfsd_release_deleg_cb,
	.fl_copy_lock = nfsd_copy_lock_deleg_cb,
	.fl_mylease = nfsd_same_client_deleg_cb,
	.fl_change = nfsd_change_deleg_cb,
};


__be32
nfsd4_process_open1(struct nfsd4_open *open)
{
	clientid_t *clientid = &open->op_clientid;
	struct nfs4_client *clp = NULL;
	unsigned int strhashval;
	struct nfs4_stateowner *sop = NULL;

	if (!check_name(open->op_owner))
		return nfserr_inval;

	if (STALE_CLIENTID(&open->op_clientid))
		return nfserr_stale_clientid;

	strhashval = ownerstr_hashval(clientid->cl_id, open->op_owner);
	sop = find_openstateowner_str(strhashval, open);
	open->op_stateowner = sop;
	if (!sop) {
		/* Make sure the client's lease hasn't expired. */
		clp = find_confirmed_client(clientid);
		if (clp == NULL)
			return nfserr_expired;
		goto renew;
	}
	if (!sop->so_confirmed) {
		/* Replace unconfirmed owners without checking for replay. */