nfs4state.c

linux 内核源代码

		clp = sop->so_client;
		release_stateowner(sop);
		open->op_stateowner = NULL;
		goto renew;
	}
	if (open->op_seqid == sop->so_seqid - 1) {
		if (sop->so_replay.rp_buflen)
			return nfserr_replay_me;
		/* The original OPEN failed so spectacularly
		 * that we don't even have replay data saved!
		 * Therefore, we have no choice but to continue
		 * processing this OPEN; presumably, we'll
		 * fail again for the same reason.
		 */
		dprintk("nfsd4_process_open1: replay with no replay cache\n");
		goto renew;
	}
	if (open->op_seqid != sop->so_seqid)
		return nfserr_bad_seqid;
renew:
	if (open->op_stateowner == NULL) {
		sop = alloc_init_open_stateowner(strhashval, clp, open);
		if (sop == NULL)
			return nfserr_resource;
		open->op_stateowner = sop;
	}
	list_del_init(&sop->so_close_lru);
	renew_client(sop->so_client);
	return nfs_ok;
}

static inline __be32
nfs4_check_delegmode(struct nfs4_delegation *dp, int flags)
{
	if ((flags & WR_STATE) && (dp->dl_type == NFS4_OPEN_DELEGATE_READ))
		return nfserr_openmode;
	else
		return nfs_ok;
}

static struct nfs4_delegation *
find_delegation_file(struct nfs4_file *fp, stateid_t *stid)
{
	struct nfs4_delegation *dp;

	list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) {
		if (dp->dl_stateid.si_stateownerid == stid->si_stateownerid)
			return dp;
	}
	return NULL;
}

static __be32
nfs4_check_deleg(struct nfs4_file *fp, struct nfsd4_open *open,
		struct nfs4_delegation **dp)
{
	int flags;
	__be32 status = nfserr_bad_stateid;

	*dp = find_delegation_file(fp, &open->op_delegate_stateid);
	if (*dp == NULL)
		goto out;
	flags = open->op_share_access == NFS4_SHARE_ACCESS_READ ?
						RD_STATE : WR_STATE;
	status = nfs4_check_delegmode(*dp, flags);
	if (status)
		*dp = NULL;
out:
	if (open->op_claim_type != NFS4_OPEN_CLAIM_DELEGATE_CUR)
		return nfs_ok;
	if (status)
		return status;
	open->op_stateowner->so_confirmed = 1;
	return nfs_ok;
}

static __be32
nfs4_check_open(struct nfs4_file *fp, struct nfsd4_open *open, struct nfs4_stateid **stpp)
{
	struct nfs4_stateid *local;
	__be32 status = nfserr_share_denied;
	struct nfs4_stateowner *sop = open->op_stateowner;

	list_for_each_entry(local, &fp->fi_stateids, st_perfile) {
		/* ignore lock owners */
		if (local->st_stateowner->so_is_open_owner == 0)
			continue;
		/* remember if we have seen this open owner */
		if (local->st_stateowner == sop)
			*stpp = local;
		/* check for conflicting share reservations */
		if (!test_share(local, open))
			goto out;
	}
	status = 0;
out:
	return status;
}

static inline struct nfs4_stateid *
nfs4_alloc_stateid(void)
{
	return kmem_cache_alloc(stateid_slab, GFP_KERNEL);
}

static __be32
nfs4_new_open(struct svc_rqst *rqstp, struct nfs4_stateid **stpp,
		struct nfs4_delegation *dp,
		struct svc_fh *cur_fh, int flags)
{
	struct nfs4_stateid *stp;

	stp = nfs4_alloc_stateid();
	if (stp == NULL)
		return nfserr_resource;

	if (dp) {
		get_file(dp->dl_vfs_file);
		stp->st_vfs_file = dp->dl_vfs_file;
	} else {
		__be32 status;
		status = nfsd_open(rqstp, cur_fh, S_IFREG, flags,
				&stp->st_vfs_file);
		if (status) {
			if (status == nfserr_dropit)
				status = nfserr_jukebox;
			kmem_cache_free(stateid_slab, stp);
			return status;
		}
	}
	*stpp = stp;
	return 0;
}

static inline __be32
nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
		struct nfsd4_open *open)
{
	struct iattr iattr = {
		.ia_valid = ATTR_SIZE,
		.ia_size = 0,
	};
	if (!open->op_truncate)
		return 0;
	if (!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
		return nfserr_inval;
	return nfsd_setattr(rqstp, fh, &iattr, 0, (time_t)0);
}

static __be32
nfs4_upgrade_open(struct svc_rqst *rqstp, struct svc_fh *cur_fh, struct nfs4_stateid *stp, struct nfsd4_open *open)
{
	struct file *filp = stp->st_vfs_file;
	struct inode *inode = filp->f_path.dentry->d_inode;
	unsigned int share_access, new_writer;
	__be32 status;

	set_access(&share_access, stp->st_access_bmap);
	new_writer = (~share_access) & open->op_share_access
			& NFS4_SHARE_ACCESS_WRITE;

	if (new_writer) {
		int err = get_write_access(inode);
		if (err)
			return nfserrno(err);
	}
	status = nfsd4_truncate(rqstp, cur_fh, open);
	if (status) {
		if (new_writer)
			put_write_access(inode);
		return status;
	}
	/* remember the open */
	filp->f_mode |= open->op_share_access;
	set_bit(open->op_share_access, &stp->st_access_bmap);
	set_bit(open->op_share_deny, &stp->st_deny_bmap);

	return nfs_ok;
}


static void
nfs4_set_claim_prev(struct nfsd4_open *open)
{
	open->op_stateowner->so_confirmed = 1;
	open->op_stateowner->so_client->cl_firststate = 1;
}

/*
 * Attempt to hand out a delegation.
 */
static void
nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_stateid *stp)
{
	struct nfs4_delegation *dp;
	struct nfs4_stateowner *sop = stp->st_stateowner;
	struct nfs4_callback *cb = &sop->so_client->cl_callback;
	struct file_lock fl, *flp = &fl;
	int status, flag = 0;

	flag = NFS4_OPEN_DELEGATE_NONE;
	open->op_recall = 0;
	switch (open->op_claim_type) {
		case NFS4_OPEN_CLAIM_PREVIOUS:
			if (!atomic_read(&cb->cb_set))
				open->op_recall = 1;
			flag = open->op_delegate_type;
			if (flag == NFS4_OPEN_DELEGATE_NONE)
				goto out;
			break;
		case NFS4_OPEN_CLAIM_NULL:
			/* Let's not give out any delegations till everyone's
			 * had the chance to reclaim theirs.... */
			if (nfs4_in_grace())
				goto out;
			if (!atomic_read(&cb->cb_set) || !sop->so_confirmed)
				goto out;
			if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
				flag = NFS4_OPEN_DELEGATE_WRITE;
			else
				flag = NFS4_OPEN_DELEGATE_READ;
			break;
		default:
			goto out;
	}

	dp = alloc_init_deleg(sop->so_client, stp, fh, flag);
	if (dp == NULL) {
		flag = NFS4_OPEN_DELEGATE_NONE;
		goto out;
	}
	locks_init_lock(&fl);
	fl.fl_lmops = &nfsd_lease_mng_ops;
	fl.fl_flags = FL_LEASE;
	fl.fl_end = OFFSET_MAX;
	fl.fl_owner =  (fl_owner_t)dp;
	fl.fl_file = stp->st_vfs_file;
	fl.fl_pid = current->tgid;

	/* vfs_setlease checks to see if delegation should be handed out.
	 * the lock_manager callbacks fl_mylease and fl_change are used
	 */
	if ((status = vfs_setlease(stp->st_vfs_file,
		flag == NFS4_OPEN_DELEGATE_READ? F_RDLCK: F_WRLCK, &flp))) {
		dprintk("NFSD: setlease failed [%d], no delegation\n", status);
		unhash_delegation(dp);
		flag = NFS4_OPEN_DELEGATE_NONE;
		goto out;
	}

	memcpy(&open->op_delegate_stateid, &dp->dl_stateid, sizeof(dp->dl_stateid));

	dprintk("NFSD: delegation stateid=(%08x/%08x/%08x/%08x)\n\n",
	             dp->dl_stateid.si_boot,
	             dp->dl_stateid.si_stateownerid,
	             dp->dl_stateid.si_fileid,
	             dp->dl_stateid.si_generation);
out:
	if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS
			&& flag == NFS4_OPEN_DELEGATE_NONE
			&& open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
		dprintk("NFSD: WARNING: refusing delegation reclaim\n");
	open->op_delegate_type = flag;
}

/*
 * called with nfs4_lock_state() held.
 */
__be32
nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
{
	struct nfs4_file *fp = NULL;
	struct inode *ino = current_fh->fh_dentry->d_inode;
	struct nfs4_stateid *stp = NULL;
	struct nfs4_delegation *dp = NULL;
	__be32 status;

	status = nfserr_inval;
	if (!access_valid(open->op_share_access)
			|| !deny_valid(open->op_share_deny))
		goto out;
	/*
	 * Lookup file; if found, lookup stateid and check open request,
	 * and check for delegations in the process of being recalled.
	 * If not found, create the nfs4_file struct
	 */
	fp = find_file(ino);
	if (fp) {
		if ((status = nfs4_check_open(fp, open, &stp)))
			goto out;
		status = nfs4_check_deleg(fp, open, &dp);
		if (status)
			goto out;
	} else {
		status = nfserr_bad_stateid;
		if (open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR)
			goto out;
		status = nfserr_resource;
		fp = alloc_init_file(ino);
		if (fp == NULL)
			goto out;
	}

	/*
	 * OPEN the file, or upgrade an existing OPEN.
	 * If truncate fails, the OPEN fails.
	 */
	if (stp) {
		/* Stateid was found, this is an OPEN upgrade */
		status = nfs4_upgrade_open(rqstp, current_fh, stp, open);
		if (status)
			goto out;
		update_stateid(&stp->st_stateid);
	} else {
		/* Stateid was not found, this is a new OPEN */
		int flags = 0;
		if (open->op_share_access & NFS4_SHARE_ACCESS_READ)
			flags |= MAY_READ;
		if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
			flags |= MAY_WRITE;
		status = nfs4_new_open(rqstp, &stp, dp, current_fh, flags);
		if (status)
			goto out;
		init_stateid(stp, fp, open);
		status = nfsd4_truncate(rqstp, current_fh, open);
		if (status) {
			release_stateid(stp, OPEN_STATE);
			goto out;
		}
	}
	memcpy(&open->op_stateid, &stp->st_stateid, sizeof(stateid_t));

	/*
	* Attempt to hand out a delegation. No error return, because the
	* OPEN succeeds even if we fail.
	*/
	nfs4_open_delegation(current_fh, open, stp);

	status = nfs_ok;

	dprintk("nfs4_process_open2: stateid=(%08x/%08x/%08x/%08x)\n",
	            stp->st_stateid.si_boot, stp->st_stateid.si_stateownerid,
	            stp->st_stateid.si_fileid, stp->st_stateid.si_generation);
out:
	if (fp)
		put_nfs4_file(fp);
	if (status == 0 && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
		nfs4_set_claim_prev(open);
	/*
	* To finish the open response, we just need to set the rflags.
	*/
	open->op_rflags = NFS4_OPEN_RESULT_LOCKTYPE_POSIX;
	if (!open->op_stateowner->so_confirmed)
		open->op_rflags |= NFS4_OPEN_RESULT_CONFIRM;

	return status;
}

static struct workqueue_struct *laundry_wq;
static void laundromat_main(struct work_struct *);
static DECLARE_DELAYED_WORK(laundromat_work, laundromat_main);

__be32
nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
	    clientid_t *clid)
{
	struct nfs4_client *clp;
	__be32 status;

	nfs4_lock_state();
	dprintk("process_renew(%08x/%08x): starting\n", 
			clid->cl_boot, clid->cl_id);
	status = nfserr_stale_clientid;
	if (STALE_CLIENTID(clid))
		goto out;
	clp = find_confirmed_client(clid);
	status = nfserr_expired;
	if (clp == NULL) {
		/* We assume the client took too long to RENEW. */
		dprintk("nfsd4_renew: clientid not found!\n");
		goto out;
	}
	renew_client(clp);
	status = nfserr_cb_path_down;
	if (!list_empty(&clp->cl_delegations)
			&& !atomic_read(&clp->cl_callback.cb_set))
		goto out;
	status = nfs_ok;
out:
	nfs4_unlock_state();
	return status;
}

static void
end_grace(void)
{
	dprintk("NFSD: end of grace period\n");
	nfsd4_recdir_purge_old();
	in_grace = 0;
}

static time_t
nfs4_laundromat(void)
{
	struct nfs4_client *clp;
	struct nfs4_stateowner *sop;
	struct nfs4_delegation *dp;
	struct list_head *pos, *next, reaplist;
	time_t cutoff = get_seconds() - NFSD_LEASE_TIME;
	time_t t, clientid_val = NFSD_LEASE_TIME;
	time_t u, test_val = NFSD_LEASE_TIME;

	nfs4_lock_state();

	dprintk("NFSD: laundromat service - starting\n");
	if (in_grace)
		end_grace();
	list_for_each_safe(pos, next, &client_lru) {
		clp = list_entry(pos, struct nfs4_client, cl_lru);
		if (time_after((unsigned long)clp->cl_time, (unsigned long)cutoff)) {
			t = clp->cl_time - cutoff;
			if (clientid_val > t)
				clientid_val = t;
			break;
		}
		dprintk("NFSD: purging unused client (clientid %08x)\n",
			clp->cl_clientid.cl_id);
		nfsd4_remove_clid_dir(clp);
		expire_client(clp);
	}
	INIT_LIST_HEAD(&reaplist);
	spin_lock(&recall_lock);
	list_for_each_safe(pos, next, &del_recall_lru) {
		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
		if (time_after((unsigned long)dp->dl_time, (unsigned long)cutoff)) {
			u = dp->dl_time - cutoff;
			if (test_val > u)
				test_val = u;
			break;
		}
		dprintk("NFSD: purging unused delegation dp %p, fp %p\n",
			            dp, dp->dl_flock);
		list_move(&dp->dl_recall_lru, &reaplist);
	}
	spin_unlock(&recall_lock);
	list_for_each_safe(pos, next, &reaplist) {
		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
		list_del_init(&dp->dl_recall_lru);
		unhash_delegation(dp);
	}
	test_val = NFSD_LEASE_TIME;
	list_for_each_safe(pos, next, &close_lru) {
		sop = list_entry(pos, struct nfs4_stateowner, so_close_lru);
		if (time_after((unsigned long)sop->so_time, (unsigned long)cutoff)) {
			u = sop->so_time - cutoff;
			if (test_val > u)
				test_val = u;
			break;
		}
		dprintk("NFSD: purging unused open stateowner (so_id %d)\n",
			sop->so_id);
		release_stateowner(sop);
	}
	if (clientid_val < NFSD_LAUNDROMAT_MINTIMEOUT)
		clientid_val = NFSD_LAUNDROMAT_MINTIMEOUT;
	nfs4_unlock_state();
	return clientid_val;
}

void
laundromat_main(struct work_struct *not_used)
{
	time_t t;

	t = nfs4_laundromat();
	dprintk("NFSD: laundromat_main - sleeping for %ld seconds\n", t);
	queue_delayed_work(laundry_wq, &laundromat_work, t*HZ);
}

static struct nfs4_stateowner *
search_close_lru(u32 st_id, int flags)
{
	struct nfs4_stateowner *local = NULL;

	if (flags & CLOSE_STATE) {
		list_for_each_entry(local, &close_lru, so_close_lru) {
			if (local->so_id == st_id)
				return local;
		}
	}