nfs4state.c

Linux Kernel 2.6.9 for OMAP1710

			goto out;
		}
	}
out:
	return status;
}


static inline void
nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny)
{
	struct nfs4_stateowner *sop = (struct nfs4_stateowner *) fl->fl_owner;
	unsigned int hval = lockownerid_hashval(sop->so_id);

	deny->ld_sop = NULL;
	if (nfs4_verify_lock_stateowner(sop, hval))
		deny->ld_sop = sop;
	deny->ld_start = fl->fl_start;
	deny->ld_length = ~(u64)0;
	if (fl->fl_end != ~(u64)0)
		deny->ld_length = fl->fl_end - fl->fl_start + 1;        
	deny->ld_type = NFS4_READ_LT;
	if (fl->fl_type != F_RDLCK)
		deny->ld_type = NFS4_WRITE_LT;
}

static struct nfs4_stateowner *
find_lockstateowner(struct xdr_netobj *owner, clientid_t *clid)
{
	struct nfs4_stateowner *local = NULL;
	int i;

	for (i = 0; i < LOCK_HASH_SIZE; i++) {
		list_for_each_entry(local, &lock_ownerid_hashtbl[i], so_idhash) {
			if (!cmp_owner_str(local, owner, clid))
				continue;
			return local;
		}
	}
	return NULL;
}

static int
find_lockstateowner_str(unsigned int hashval, struct xdr_netobj *owner, clientid_t *clid, struct nfs4_stateowner **op) {
	struct nfs4_stateowner *local = NULL;

	list_for_each_entry(local, &lock_ownerstr_hashtbl[hashval], so_strhash) {
		if (!cmp_owner_str(local, owner, clid))
			continue;
		*op = local;
		return(1);
	}
	*op = NULL;
	return 0;
}

/*
 * Alloc a lock owner structure.
 * Called in nfsd4_lock - therefore, OPEN and OPEN_CONFIRM (if needed) has 
 * occured. 
 *
 * strhashval = lock_ownerstr_hashval 
 * so_seqid = lock->lk_new_lock_seqid - 1: it gets bumped in encode 
 */

static struct nfs4_stateowner *
alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, struct nfs4_stateid *open_stp, struct nfsd4_lock *lock) {
	struct nfs4_stateowner *sop;
	struct nfs4_replay *rp;
	unsigned int idhashval;

	if (!(sop = alloc_stateowner(&lock->lk_new_owner)))
		return NULL;
	idhashval = lockownerid_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_perfilestate);
	INIT_LIST_HEAD(&sop->so_perlockowner);
	INIT_LIST_HEAD(&sop->so_close_lru); /* not used */
	sop->so_time = 0;
	list_add(&sop->so_idhash, &lock_ownerid_hashtbl[idhashval]);
	list_add(&sop->so_strhash, &lock_ownerstr_hashtbl[strhashval]);
	list_add(&sop->so_perclient, &clp->cl_perclient);
	list_add(&sop->so_perlockowner, &open_stp->st_perlockowner);
	add_perclient++;
	sop->so_is_open_owner = 0;
	sop->so_id = current_ownerid++;
	sop->so_client = clp;
	sop->so_seqid = lock->lk_new_lock_seqid - 1;
	sop->so_confirmed = 1;
	rp = &sop->so_replay;
	rp->rp_status = NFSERR_SERVERFAULT;
	rp->rp_buflen = 0;
	rp->rp_buf = rp->rp_ibuf;
	alloc_lsowner++;
	return sop;
}

struct nfs4_stateid *
alloc_init_lock_stateid(struct nfs4_stateowner *sop, struct nfs4_file *fp, struct nfs4_stateid *open_stp)
{
	struct nfs4_stateid *stp;
	unsigned int hashval = stateid_hashval(sop->so_id, fp->fi_id);

	if ((stp = kmalloc(sizeof(struct nfs4_stateid), 
					GFP_KERNEL)) == NULL)
		goto out;
	INIT_LIST_HEAD(&stp->st_hash);
	INIT_LIST_HEAD(&stp->st_perfile);
	INIT_LIST_HEAD(&stp->st_perfilestate);
	INIT_LIST_HEAD(&stp->st_perlockowner); /* not used */
	list_add(&stp->st_hash, &lockstateid_hashtbl[hashval]);
	list_add(&stp->st_perfile, &fp->fi_perfile);
	list_add_perfile++;
	list_add(&stp->st_perfilestate, &sop->so_perfilestate);
	stp->st_stateowner = sop;
	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_vfs_file = open_stp->st_vfs_file; /* FIXME refcount?? */
	stp->st_vfs_set = open_stp->st_vfs_set;
	stp->st_access_bmap = open_stp->st_access_bmap;
	stp->st_deny_bmap = open_stp->st_deny_bmap;

out:
	return stp;
}

int
check_lock_length(u64 offset, u64 length)
{
	return ((length == 0)  || ((length != ~(u64)0) &&
	     LOFF_OVERFLOW(offset, length)));
}

/*
 *  LOCK operation 
 *
 * nfs4_unlock_state(); called in encode
 */
int
nfsd4_lock(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_lock *lock)
{
	struct nfs4_stateowner *lock_sop = NULL, *open_sop = NULL;
	struct nfs4_stateid *lock_stp;
	struct file *filp;
	struct file_lock file_lock;
	struct file_lock *conflock;
	int status = 0;
	unsigned int strhashval;

	dprintk("NFSD: nfsd4_lock: start=%Ld length=%Ld\n",
		(long long) lock->lk_offset,
		(long long) lock->lk_length);

	if (nfs4_in_grace() && !lock->lk_reclaim)
		return nfserr_grace;
	if (!nfs4_in_grace() && lock->lk_reclaim)
		return nfserr_no_grace;

	if (check_lock_length(lock->lk_offset, lock->lk_length))
		 return nfserr_inval;

	lock->lk_stateowner = NULL;
	nfs4_lock_state();

	if (lock->lk_is_new) {
	/*
	 * Client indicates that this is a new lockowner.
	 * Use open owner and open stateid to create lock owner and lock 
	 * stateid.
	 */
		struct nfs4_stateid *open_stp = NULL;
		struct nfs4_file *fp;
		
		status = nfserr_stale_clientid;
		if (STALE_CLIENTID(&lock->lk_new_clientid)) {
			printk("NFSD: nfsd4_lock: clientid is stale!\n");
			goto out;
		}

		/* is the new lock seqid presented by the client zero? */
		status = nfserr_bad_seqid;
		if (lock->v.new.lock_seqid != 0)
			goto out;

		/* validate and update open stateid and open seqid */
		status = nfs4_preprocess_seqid_op(current_fh, 
				        lock->lk_new_open_seqid,
		                        &lock->lk_new_open_stateid,
		                        CHECK_FH | OPEN_STATE,
		                        &open_sop, &open_stp,
					&lock->v.new.clientid);
		if (status) {
			if (lock->lk_reclaim)
				status = nfserr_reclaim_bad;
			goto out;
		}
		/* create lockowner and lock stateid */
		fp = open_stp->st_file;
		strhashval = lock_ownerstr_hashval(fp->fi_inode, 
				open_sop->so_client->cl_clientid.cl_id, 
				lock->v.new.owner);
		/* 
		 * If we already have this lock owner, the client is in 
		 * error (or our bookeeping is wrong!) 
		 * for asking for a 'new lock'.
		 */
		status = nfserr_bad_stateid;
		lock_sop = find_lockstateowner(&lock->v.new.owner,
						&lock->v.new.clientid);
		if (lock_sop)
			goto out;
		status = nfserr_resource;
		if (!(lock->lk_stateowner = alloc_init_lock_stateowner(strhashval, open_sop->so_client, open_stp, lock)))
			goto out;
		if ((lock_stp = alloc_init_lock_stateid(lock->lk_stateowner, 
						fp, open_stp)) == NULL) {
			release_stateowner(lock->lk_stateowner);
			goto out;
		}
		/* bump the open seqid used to create the lock */
		open_sop->so_seqid++;
	} else {
		/* lock (lock owner + lock stateid) already exists */
		status = nfs4_preprocess_seqid_op(current_fh,
				       lock->lk_old_lock_seqid, 
				       &lock->lk_old_lock_stateid, 
				       CHECK_FH | LOCK_STATE, 
				       &lock->lk_stateowner, &lock_stp, NULL);
		if (status)
			goto out;
	}
	/* lock->lk_stateowner and lock_stp have been created or found */
	filp = lock_stp->st_vfs_file;

	if ((status = fh_verify(rqstp, current_fh, S_IFREG, MAY_LOCK))) {
		printk("NFSD: nfsd4_lock: permission denied!\n");
		goto out;
	}

	locks_init_lock(&file_lock);
	switch (lock->lk_type) {
		case NFS4_READ_LT:
		case NFS4_READW_LT:
			file_lock.fl_type = F_RDLCK;
		break;
		case NFS4_WRITE_LT:
		case NFS4_WRITEW_LT:
			file_lock.fl_type = F_WRLCK;
		break;
		default:
			status = nfserr_inval;
		goto out;
	}
	file_lock.fl_owner = (fl_owner_t) lock->lk_stateowner;
	file_lock.fl_pid = current->tgid;
	file_lock.fl_file = filp;
	file_lock.fl_flags = FL_POSIX;

	file_lock.fl_start = lock->lk_offset;
	if ((lock->lk_length == ~(u64)0) || 
			LOFF_OVERFLOW(lock->lk_offset, lock->lk_length))
		file_lock.fl_end = ~(u64)0;
	else
		file_lock.fl_end = lock->lk_offset + lock->lk_length - 1;
	nfs4_transform_lock_offset(&file_lock);

	/*
	* Try to lock the file in the VFS.
	* Note: locks.c uses the BKL to protect the inode's lock list.
	*/

	status = posix_lock_file(filp, &file_lock);
	if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private)
		file_lock.fl_ops->fl_release_private(&file_lock);
	dprintk("NFSD: nfsd4_lock: posix_lock_file status %d\n",status);
	switch (-status) {
	case 0: /* success! */
		update_stateid(&lock_stp->st_stateid);
		memcpy(&lock->lk_resp_stateid, &lock_stp->st_stateid, 
				sizeof(stateid_t));
		goto out;
	case (EAGAIN):
		goto conflicting_lock;
	case (EDEADLK):
		status = nfserr_deadlock;
	default:        
		dprintk("NFSD: nfsd4_lock: posix_lock_file() failed! status %d\n",status);
		goto out_destroy_new_stateid;
	}

conflicting_lock:
	dprintk("NFSD: nfsd4_lock: conflicting lock found!\n");
	status = nfserr_denied;
	/* XXX There is a race here. Future patch needed to provide 
	 * an atomic posix_lock_and_test_file
	 */
	if (!(conflock = posix_test_lock(filp, &file_lock))) {
		status = nfserr_serverfault;
		goto out;
	}
	nfs4_set_lock_denied(conflock, &lock->lk_denied);

out_destroy_new_stateid:
	if (lock->lk_is_new) {
		dprintk("NFSD: nfsd4_lock: destroy new stateid!\n");
	/*
	* An error encountered after instantiation of the new
	* stateid has forced us to destroy it.
	*/
		if (!seqid_mutating_err(status))
			open_sop->so_seqid--;

		release_state_owner(lock_stp, &lock->lk_stateowner, LOCK_STATE);
	}
out:
	return status;
}

/*
 * LOCKT operation
 */
int
nfsd4_lockt(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_lockt *lockt)
{
	struct inode *inode;
	struct file file;
	struct file_lock file_lock;
	struct file_lock *conflicting_lock;
	unsigned int strhashval;
	int status;

	if (nfs4_in_grace())
		return nfserr_grace;

	if (check_lock_length(lockt->lt_offset, lockt->lt_length))
		 return nfserr_inval;

	lockt->lt_stateowner = NULL;
	nfs4_lock_state();

	status = nfserr_stale_clientid;
	if (STALE_CLIENTID(&lockt->lt_clientid)) {
		printk("NFSD: nfsd4_lockt: clientid is stale!\n");
		goto out;
	}

	if ((status = fh_verify(rqstp, current_fh, S_IFREG, 0))) {
		printk("NFSD: nfsd4_lockt: fh_verify() failed!\n");
		if (status == nfserr_symlink)
			status = nfserr_inval;
		goto out;
	}

	inode = current_fh->fh_dentry->d_inode;
	locks_init_lock(&file_lock);
	switch (lockt->lt_type) {
		case NFS4_READ_LT:
		case NFS4_READW_LT:
			file_lock.fl_type = F_RDLCK;
		break;
		case NFS4_WRITE_LT:
		case NFS4_WRITEW_LT:
			file_lock.fl_type = F_WRLCK;
		break;
		default:
			printk("NFSD: nfs4_lockt: bad lock type!\n");
			status = nfserr_inval;
		goto out;
	}

	strhashval = lock_ownerstr_hashval(inode, 
			lockt->lt_clientid.cl_id, lockt->lt_owner);

	find_lockstateowner_str(strhashval, &lockt->lt_owner,
					&lockt->lt_clientid, 
					&lockt->lt_stateowner);
	if (lockt->lt_stateowner)
		file_lock.fl_owner = (fl_owner_t)lockt->lt_stateowner;
	file_lock.fl_pid = current->tgid;
	file_lock.fl_flags = FL_POSIX;

	file_lock.fl_start = lockt->lt_offset;
	if ((lockt->lt_length == ~(u64)0) || LOFF_OVERFLOW(lockt->lt_offset, lockt->lt_length))
		file_lock.fl_end = ~(u64)0;
	else
		file_lock.fl_end = lockt->lt_offset + lockt->lt_length - 1;

	nfs4_transform_lock_offset(&file_lock);

	/* posix_test_lock uses the struct file _only_ to resolve the inode.
	 * since LOCKT doesn't require an OPEN, and therefore a struct
	 * file may not exist, pass posix_test_lock a struct file with
	 * only the dentry:inode set.
	 */
	memset(&file, 0, sizeof (struct file));
	file.f_dentry = current_fh->fh_dentry;

	status = nfs_ok;
	conflicting_lock = posix_test_lock(&file, &file_lock);
	if (conflicting_lock) {
		status = nfserr_denied;
		nfs4_set_lock_denied(conflicting_lock, &lockt->lt_denied);
	}
out:
	nfs4_unlock_state();
	return status;
}

int
nfsd4_locku(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_locku *locku)
{
	struct nfs4_stateid *stp;
	struct file *filp = NULL;
	struct file_lock file_lock;
	int status;
						        
	dprintk("NFSD: nfsd4_locku: start=%Ld length=%Ld\n",
		(long long) locku->lu_offset,
		(long long) locku->lu_length);

	if (check_lock_length(locku->lu_offset, locku->lu_length))
		 return nfserr_inval;

	locku->lu_stateowner = NULL;
	nfs4_lock_state();
									        
	if ((status = nfs4_preprocess_seqid_op(current_fh, 
					locku->lu_seqid, 
					&locku->lu_stateid, 
					CHECK_FH | LOCK_STATE, 
					&locku->lu_stateowner, &stp, NULL)))
		goto out;

	filp = stp->st_vfs_file;
	BUG_ON(!filp);
	locks_init_lock(&file_lock);
	file_lock.fl_type = F_UNLCK;
	file_lock.fl_owner = (fl_owner_t) locku->lu_stateowner;
	file_lock.fl_pid = current->tgid;
	file_lock.fl_file = filp;
	file_lock.fl_flags = FL_POSIX; 
	file_lock.fl_start = locku->lu_offset;

	if ((locku->lu_length == ~(u64)0) || LOFF_OVERFLOW(locku->lu_offset, locku->lu_length))
		file_lock.fl_end = ~(u64)0;
	else
		file_lock.fl_end = locku->lu_offset + locku->lu_length - 1;
	nfs4_transform_lock_offset(&file_lock);

	/*
	*  Try to unlock the file in the VFS.
	*/
	status = posix_lock_file(filp, &file_lock); 
	if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private)
		file_lock.fl_ops->fl_release_private(&file_lock);
	if (status) {
		printk("NFSD: nfs4_locku: posix_lock_file failed!\n");
		goto out_nfserr;
	}
	/*
	* OK, unlock succeeded; the only thing left to do is update the stateid.
	*/
	update_stateid(&stp->st_stateid);
	memcpy(&locku->lu_stateid, &stp->st_stateid, sizeof(stateid_t));

out:
	return status;

out_nfserr:
	status = nfserrno(status);
	goto out;
}

/*
 * returns
 * 	1: locks held by lockowner
 * 	0: no locks held by lockowner
 */
static int
check_for