nfs4proc.c

Linux Kernel 2.6.9 for OMAP1710

int
nfs4_proc_async_renew(struct nfs4_client *clp)
{
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_RENEW],
		.rpc_argp	= clp,
		.rpc_cred	= clp->cl_cred,
	};

	return rpc_call_async(clp->cl_rpcclient, &msg, RPC_TASK_SOFT,
			renew_done, (void *)jiffies);
}

int
nfs4_proc_renew(struct nfs4_client *clp)
{
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_RENEW],
		.rpc_argp	= clp,
		.rpc_cred	= clp->cl_cred,
	};
	unsigned long now = jiffies;
	int status;

	status = rpc_call_sync(clp->cl_rpcclient, &msg, 0);
	if (status < 0)
		return status;
	spin_lock(&clp->cl_lock);
	if (time_before(clp->cl_last_renewal,now))
		clp->cl_last_renewal = now;
	spin_unlock(&clp->cl_lock);
	return 0;
}

/*
 * We will need to arrange for the VFS layer to provide an atomic open.
 * Until then, this open method is prone to inefficiency and race conditions
 * due to the lookup, potential create, and open VFS calls from sys_open()
 * placed on the wire.
 */
static int
nfs4_proc_file_open(struct inode *inode, struct file *filp)
{
	struct dentry *dentry = filp->f_dentry;
	struct nfs_open_context *ctx;
	struct nfs4_state *state = NULL;
	struct rpc_cred *cred;
	int status = -ENOMEM;

	dprintk("nfs4_proc_file_open: starting on (%.*s/%.*s)\n",
	                       (int)dentry->d_parent->d_name.len,
	                       dentry->d_parent->d_name.name,
	                       (int)dentry->d_name.len, dentry->d_name.name);


	/* Find our open stateid */
	cred = rpcauth_lookupcred(NFS_SERVER(inode)->client->cl_auth, 0);
	if (unlikely(cred == NULL))
		return -ENOMEM;
	ctx = alloc_nfs_open_context(dentry, cred);
	put_rpccred(cred);
	if (unlikely(ctx == NULL))
		return -ENOMEM;
	status = -EIO; /* ERACE actually */
	state = nfs4_find_state(inode, cred, filp->f_mode);
	if (unlikely(state == NULL))
		goto no_state;
	ctx->state = state;
	nfs4_close_state(state, filp->f_mode);
	ctx->mode = filp->f_mode;
	nfs_file_set_open_context(filp, ctx);
	put_nfs_open_context(ctx);
	if (filp->f_mode & FMODE_WRITE)
		nfs_begin_data_update(inode);
	return 0;
no_state:
	printk(KERN_WARNING "NFS: v4 raced in function %s\n", __FUNCTION__);
	put_nfs_open_context(ctx);
	return status;
}

/*
 * Release our state
 */
static int
nfs4_proc_file_release(struct inode *inode, struct file *filp)
{
	if (filp->f_mode & FMODE_WRITE)
		nfs_end_data_update(inode);
	nfs_file_clear_open_context(filp);
	return 0;
}

static int
nfs4_async_handle_error(struct rpc_task *task, struct nfs_server *server)
{
	struct nfs4_client *clp = server->nfs4_state;

	if (!clp || task->tk_status >= 0)
		return 0;
	switch(task->tk_status) {
		case -NFS4ERR_STALE_CLIENTID:
		case -NFS4ERR_STALE_STATEID:
		case -NFS4ERR_EXPIRED:
			rpc_sleep_on(&clp->cl_rpcwaitq, task, NULL, NULL);
			nfs4_schedule_state_recovery(clp);
			if (test_bit(NFS4CLNT_OK, &clp->cl_state))
				rpc_wake_up_task(task);
			task->tk_status = 0;
			return -EAGAIN;
		case -NFS4ERR_GRACE:
		case -NFS4ERR_DELAY:
			rpc_delay(task, NFS4_POLL_RETRY_MAX);
			task->tk_status = 0;
			return -EAGAIN;
		case -NFS4ERR_OLD_STATEID:
			task->tk_status = 0;
			return -EAGAIN;
	}
	task->tk_status = nfs4_map_errors(task->tk_status);
	return 0;
}

int nfs4_wait_clnt_recover(struct rpc_clnt *clnt, struct nfs4_client *clp)
{
	DEFINE_WAIT(wait);
	sigset_t oldset;
	int interruptible, res = 0;

	might_sleep();

	rpc_clnt_sigmask(clnt, &oldset);
	interruptible = TASK_UNINTERRUPTIBLE;
	if (clnt->cl_intr)
		interruptible = TASK_INTERRUPTIBLE;
	prepare_to_wait(&clp->cl_waitq, &wait, interruptible);
	nfs4_schedule_state_recovery(clp);
	if (clnt->cl_intr && signalled())
		res = -ERESTARTSYS;
	else if (!test_bit(NFS4CLNT_OK, &clp->cl_state))
		schedule();
	finish_wait(&clp->cl_waitq, &wait);
	rpc_clnt_sigunmask(clnt, &oldset);
	return res;
}

static int nfs4_delay(struct rpc_clnt *clnt, long *timeout)
{
	sigset_t oldset;
	int res = 0;

	might_sleep();

	if (*timeout <= 0)
		*timeout = NFS4_POLL_RETRY_MIN;
	if (*timeout > NFS4_POLL_RETRY_MAX)
		*timeout = NFS4_POLL_RETRY_MAX;
	rpc_clnt_sigmask(clnt, &oldset);
	if (clnt->cl_intr) {
		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(*timeout);
		if (signalled())
			res = -ERESTARTSYS;
	} else {
		set_current_state(TASK_UNINTERRUPTIBLE);
		schedule_timeout(*timeout);
	}
	rpc_clnt_sigunmask(clnt, &oldset);
	*timeout <<= 1;
	return res;
}

/* This is the error handling routine for processes that are allowed
 * to sleep.
 */
int nfs4_handle_exception(struct nfs_server *server, int errorcode, struct nfs4_exception *exception)
{
	struct nfs4_client *clp = server->nfs4_state;
	int ret = errorcode;

	exception->retry = 0;
	switch(errorcode) {
		case 0:
			return 0;
		case -NFS4ERR_STALE_CLIENTID:
		case -NFS4ERR_STALE_STATEID:
		case -NFS4ERR_EXPIRED:
			ret = nfs4_wait_clnt_recover(server->client, clp);
			if (ret == 0)
				exception->retry = 1;
			break;
		case -NFS4ERR_GRACE:
		case -NFS4ERR_DELAY:
			ret = nfs4_delay(server->client, &exception->timeout);
			if (ret == 0)
				exception->retry = 1;
			break;
		case -NFS4ERR_OLD_STATEID:
			if (ret == 0)
				exception->retry = 1;
	}
	/* We failed to handle the error */
	return nfs4_map_errors(ret);
}

int nfs4_proc_setclientid(struct nfs4_client *clp, u32 program, unsigned short port)
{
	static nfs4_verifier sc_verifier;
	static int initialized;
	
	struct nfs4_setclientid setclientid = {
		.sc_verifier = &sc_verifier,
		.sc_prog = program,
	};
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETCLIENTID],
		.rpc_argp = &setclientid,
		.rpc_resp = clp,
		.rpc_cred = clp->cl_cred,
	};

	if (!initialized) {
		struct timespec boot_time;
		u32 *p;

		initialized = 1;
		boot_time = CURRENT_TIME;
		p = (u32*)sc_verifier.data;
		*p++ = htonl((u32)boot_time.tv_sec);
		*p = htonl((u32)boot_time.tv_nsec);
	}
	setclientid.sc_name_len = scnprintf(setclientid.sc_name,
			sizeof(setclientid.sc_name), "%s/%u.%u.%u.%u",
			clp->cl_ipaddr, NIPQUAD(clp->cl_addr.s_addr));
	setclientid.sc_netid_len = scnprintf(setclientid.sc_netid,
			sizeof(setclientid.sc_netid), "tcp");
	setclientid.sc_uaddr_len = scnprintf(setclientid.sc_uaddr,
			sizeof(setclientid.sc_uaddr), "%s.%d.%d",
			clp->cl_ipaddr, port >> 8, port & 255);

	return rpc_call_sync(clp->cl_rpcclient, &msg, 0);
}

int
nfs4_proc_setclientid_confirm(struct nfs4_client *clp)
{
	struct nfs_fsinfo fsinfo;
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETCLIENTID_CONFIRM],
		.rpc_argp = clp,
		.rpc_resp = &fsinfo,
		.rpc_cred = clp->cl_cred,
	};
	unsigned long now;
	int status;

	now = jiffies;
	status = rpc_call_sync(clp->cl_rpcclient, &msg, 0);
	if (status == 0) {
		spin_lock(&clp->cl_lock);
		clp->cl_lease_time = fsinfo.lease_time * HZ;
		clp->cl_last_renewal = now;
		spin_unlock(&clp->cl_lock);
	}
	return status;
}

static int _nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid)
{
	struct nfs4_delegreturnargs args = {
		.fhandle = NFS_FH(inode),
		.stateid = stateid,
	};
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DELEGRETURN],
		.rpc_argp = &args,
		.rpc_cred = cred,
	};

	return rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
}

int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid)
{
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs4_exception exception = { };
	int err;
	do {
		err = _nfs4_proc_delegreturn(inode, cred, stateid);
		switch (err) {
			case -NFS4ERR_STALE_STATEID:
			case -NFS4ERR_EXPIRED:
				nfs4_schedule_state_recovery(server->nfs4_state);
			case 0:
				return 0;
		}
		err = nfs4_handle_exception(server, err, &exception);
	} while (exception.retry);
	return err;
}

#define NFS4_LOCK_MINTIMEOUT (1 * HZ)
#define NFS4_LOCK_MAXTIMEOUT (30 * HZ)

/* 
 * sleep, with exponential backoff, and retry the LOCK operation. 
 */
static unsigned long
nfs4_set_lock_task_retry(unsigned long timeout)
{
	current->state = TASK_INTERRUPTIBLE;
	schedule_timeout(timeout);
	timeout <<= 1;
	if (timeout > NFS4_LOCK_MAXTIMEOUT)
		return NFS4_LOCK_MAXTIMEOUT;
	return timeout;
}

static inline int
nfs4_lck_type(int cmd, struct file_lock *request)
{
	/* set lock type */
	switch (request->fl_type) {
		case F_RDLCK:
			return IS_SETLKW(cmd) ? NFS4_READW_LT : NFS4_READ_LT;
		case F_WRLCK:
			return IS_SETLKW(cmd) ? NFS4_WRITEW_LT : NFS4_WRITE_LT;
		case F_UNLCK:
			return NFS4_WRITE_LT; 
	}
	BUG();
	return 0;
}

static inline uint64_t
nfs4_lck_length(struct file_lock *request)
{
	if (request->fl_end == OFFSET_MAX)
		return ~(uint64_t)0;
	return request->fl_end - request->fl_start + 1;
}

static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock *request)
{
	struct inode *inode = state->inode;
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs4_client *clp = server->nfs4_state;
	struct nfs_lockargs arg = {
		.fh = NFS_FH(inode),
		.type = nfs4_lck_type(cmd, request),
		.offset = request->fl_start,
		.length = nfs4_lck_length(request),
	};
	struct nfs_lockres res = {
		.server = server,
	};
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_LOCKT],
		.rpc_argp       = &arg,
		.rpc_resp       = &res,
		.rpc_cred	= state->owner->so_cred,
	};
	struct nfs_lowner nlo;
	struct nfs4_lock_state *lsp;
	int status;

	down_read(&clp->cl_sem);
	nlo.clientid = clp->cl_clientid;
	down(&state->lock_sema);
	lsp = nfs4_find_lock_state(state, request->fl_owner);
	if (lsp)
		nlo.id = lsp->ls_id; 
	else {
		spin_lock(&clp->cl_lock);
		nlo.id = nfs4_alloc_lockowner_id(clp);
		spin_unlock(&clp->cl_lock);
	}
	arg.u.lockt = &nlo;
	status = rpc_call_sync(server->client, &msg, 0);
	if (!status) {
		request->fl_type = F_UNLCK;
	} else if (status == -NFS4ERR_DENIED) {
		int64_t len, start, end;
		start = res.u.denied.offset;
		len = res.u.denied.length;
		end = start + len - 1;
		if (end < 0 || len == 0)
			request->fl_end = OFFSET_MAX;
		else
			request->fl_end = (loff_t)end;
		request->fl_start = (loff_t)start;
		request->fl_type = F_WRLCK;
		if (res.u.denied.type & 1)
			request->fl_type = F_RDLCK;
		request->fl_pid = 0;
		status = 0;
	}
	if (lsp)
		nfs4_put_lock_state(lsp);
	up(&state->lock_sema);
	up_read(&clp->cl_sem);
	return status;
}

static int nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock *request)
{
	struct nfs4_exception exception = { };
	int err;

	do {
		err = nfs4_handle_exception(NFS_SERVER(state->inode),
				_nfs4_proc_getlk(state, cmd, request),
				&exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request)
{
	struct inode *inode = state->inode;
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs4_client *clp = server->nfs4_state;
	struct nfs_lockargs arg = {
		.fh = NFS_FH(inode),
		.type = nfs4_lck_type(cmd, request),
		.offset = request->fl_start,
		.length = nfs4_lck_length(request),
	};
	struct nfs_lockres res = {
		.server = server,
	};
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_LOCKU],
		.rpc_argp       = &arg,
		.rpc_resp       = &res,
		.rpc_cred	= state->owner->so_cred,
	};
	struct nfs4_lock_state *lsp;
	struct nfs_locku_opargs luargs;
	int status = 0;
			
	down_read(&clp->cl_sem);
	down(&state->lock_sema);
	lsp = nfs4_find_lock_state(state, request->fl_owner);
	if (!lsp)
		goto out;
	/* We might have lost the locks! */
	if ((lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0) {
		luargs.seqid = lsp->ls_seqid;
		memcpy(&luargs.stateid, &lsp->ls_stateid, sizeof(luargs.stateid));
		arg.u.locku = &luargs;
		status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);
		nfs4_increment_lock_seqid(status, lsp);
	}

	if (status == 0) {
		memcpy(&lsp->ls_stateid,  &res.u.stateid, 
				sizeof(lsp->ls_stateid));
		nfs4_notify_unlck(state, request, lsp);
	}
	nfs4_put_lock_state(lsp);
out:
	up(&state->lock_sema);
	if (status == 0)
		posix_lock_file(request->fl_file, request);
	up_read(&clp->cl_sem);
	return status;
}

static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request)
{
	struct nfs4_exception exception = { };
	int err;

	do {
		err = nfs4_handle_exception(NFS_SERVER(state->inode),
				_nfs4_proc_unlck(state, cmd, request),
				&exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *request, int reclaim)
{
	struct inode *inode = state->inode;
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs4_lock_state *lsp;
	struct nfs_