nfs4state.c

Linux Kernel 2.6.9 for OMAP1710

			if (close_val > u)
				close_val = u;
			break;
		}
		dprintk("NFSD: purging unused open stateowner (so_id %d)\n",
			sop->so_id);
		list_del(&sop->so_close_lru);
		free_stateowner(sop);
	}
	if (clientid_val < NFSD_LAUNDROMAT_MINTIMEOUT)
		clientid_val = NFSD_LAUNDROMAT_MINTIMEOUT;
	nfs4_unlock_state();
	return clientid_val;
}

void
laundromat_main(void *not_used)
{
	time_t t;

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

/* search ownerid_hashtbl[] and close_lru for stateid owner
 * (stateid->si_stateownerid)
 */
struct nfs4_stateowner *
find_openstateowner_id(u32 st_id, int flags) {
	struct nfs4_stateowner *local = NULL;

	dprintk("NFSD: find_openstateowner_id %d\n", st_id);
	if (flags & CLOSE_STATE) {
		list_for_each_entry(local, &close_lru, so_close_lru) {
			if (local->so_id == st_id)
				return local;
		}
	}
	return NULL;
}

static inline int
nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stateid *stp)
{
	return (stp->st_vfs_set == 0 ||
		fhp->fh_dentry->d_inode != stp->st_vfs_file->f_dentry->d_inode);
}

static int
STALE_STATEID(stateid_t *stateid)
{
	if (stateid->si_boot == boot_time)
		return 0;
	printk("NFSD: stale stateid (%08x/%08x/%08x/%08x)!\n",
		stateid->si_boot, stateid->si_stateownerid, stateid->si_fileid,
		stateid->si_generation);
	return 1;
}


/*
* Checks for stateid operations
*/
int
nfs4_preprocess_stateid_op(struct svc_fh *current_fh, stateid_t *stateid, int flags, struct nfs4_stateid **stpp)
{
	struct nfs4_stateid *stp;
	int status;

	dprintk("NFSD: preprocess_stateid_op: stateid = (%08x/%08x/%08x/%08x)\n",
		stateid->si_boot, stateid->si_stateownerid, 
		stateid->si_fileid, stateid->si_generation); 

	*stpp = NULL;

	/* STALE STATEID */
	status = nfserr_stale_stateid;
	if (STALE_STATEID(stateid)) 
		goto out;

	/* BAD STATEID */
	status = nfserr_bad_stateid;
	if (!(stp = find_stateid(stateid, flags))) {
		dprintk("NFSD: preprocess_stateid_op: no open stateid!\n");
		goto out;
	}
	if ((flags & CHECK_FH) && nfs4_check_fh(current_fh, stp)) {
		dprintk("NFSD: preprocess_stateid_op: fh-stateid mismatch!\n");
		stp->st_vfs_set = 0;
		goto out;
	}
	if (!stp->st_stateowner->so_confirmed) {
		dprintk("preprocess_stateid_op: lockowner not confirmed yet!\n");
		goto out;
	}
	if (stateid->si_generation > stp->st_stateid.si_generation) {
		dprintk("preprocess_stateid_op: future stateid?!\n");
		goto out;
	}

	/* OLD STATEID */
	status = nfserr_old_stateid;
	if (stateid->si_generation < stp->st_stateid.si_generation) {
		dprintk("preprocess_stateid_op: old stateid!\n");
		goto out;
	}
	*stpp = stp;
	status = nfs_ok;
	renew_client(stp->st_stateowner->so_client);
out:
	return status;
}


/* 
 * Checks for sequence id mutating operations. 
 */
int
nfs4_preprocess_seqid_op(struct svc_fh *current_fh, u32 seqid, stateid_t *stateid, int flags, struct nfs4_stateowner **sopp, struct nfs4_stateid **stpp, clientid_t *lockclid)
{
	int status;
	struct nfs4_stateid *stp;
	struct nfs4_stateowner *sop;

	dprintk("NFSD: preprocess_seqid_op: seqid=%d " 
			"stateid = (%08x/%08x/%08x/%08x)\n", seqid,
		stateid->si_boot, stateid->si_stateownerid, stateid->si_fileid,
		stateid->si_generation);
			        
	*stpp = NULL;
	*sopp = NULL;

	status = nfserr_bad_stateid;
	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid)) {
		printk("NFSD: preprocess_seqid_op: magic stateid!\n");
		goto out;
	}

	status = nfserr_stale_stateid;
	if (STALE_STATEID(stateid))
		goto out;
	/*
	* We return BAD_STATEID if filehandle doesn't match stateid, 
	* the confirmed flag is incorrecly set, or the generation 
	* number is incorrect.  
	* If there is no entry in the openfile table for this id, 
	* we can't always return BAD_STATEID;
	* this might be a retransmitted CLOSE which has arrived after 
	* the openfile has been released.
	*/
	if (!(stp = find_stateid(stateid, flags)))
		goto no_nfs4_stateid;

	status = nfserr_bad_stateid;

	/* for new lock stateowners:
	 * check that the lock->v.new.open_stateid
	 * refers to an open stateowner
	 *
	 * check that the lockclid (nfs4_lock->v.new.clientid) is the same
	 * as the open_stateid->st_stateowner->so_client->clientid
	 */
	if (lockclid) {
		struct nfs4_stateowner *sop = stp->st_stateowner;
		struct nfs4_client *clp = sop->so_client;

		if (!sop->so_is_open_owner)
			goto out;
		if (!cmp_clid(&clp->cl_clientid, lockclid))
			goto out;
	}

	if ((flags & CHECK_FH) && nfs4_check_fh(current_fh, stp)) {
		printk("NFSD: preprocess_seqid_op: fh-stateid mismatch!\n");
		stp->st_vfs_set = 0;
		goto out;
	}

	*stpp = stp;
	*sopp = sop = stp->st_stateowner;

	/*
	*  We now validate the seqid and stateid generation numbers.
	*  For the moment, we ignore the possibility of 
	*  generation number wraparound.
	*/
	if (seqid != sop->so_seqid + 1)
		goto check_replay;

	if (sop->so_confirmed) {
		if (flags & CONFIRM) {
			printk("NFSD: preprocess_seqid_op: expected unconfirmed stateowner!\n");
			goto out;
		}
	}
	else {
		if (!(flags & CONFIRM)) {
			printk("NFSD: preprocess_seqid_op: stateowner not confirmed yet!\n");
			goto out;
		}
	}
	if (stateid->si_generation > stp->st_stateid.si_generation) {
		printk("NFSD: preprocess_seqid_op: future stateid?!\n");
		goto out;
	}

	status = nfserr_old_stateid;
	if (stateid->si_generation < stp->st_stateid.si_generation) {
		printk("NFSD: preprocess_seqid_op: old stateid!\n");
		goto out;
	}
	/* XXX renew the client lease here */
	status = nfs_ok;

out:
	return status;

no_nfs4_stateid:

	/*
	* We determine whether this is a bad stateid or a replay, 
	* starting by trying to look up the stateowner.
	* If stateowner is not found - stateid is bad.
	*/
	if (!(sop = find_openstateowner_id(stateid->si_stateownerid, flags))) {
		printk("NFSD: preprocess_seqid_op: no stateowner or nfs4_stateid!\n");
		status = nfserr_bad_stateid;
		goto out;
	}
	*sopp = sop;

check_replay:
	if (seqid == sop->so_seqid) {
		printk("NFSD: preprocess_seqid_op: retransmission?\n");
		/* indicate replay to calling function */
		status = NFSERR_REPLAY_ME;
	} else  {
		printk("NFSD: preprocess_seqid_op: bad seqid (expected %d, got %d\n", sop->so_seqid +1, seqid);

		*sopp = NULL;
		status = nfserr_bad_seqid;
	}
	goto out;
}

/*
 * eventually, this will perform an upcall to the 'state daemon' as well as
 * set the cl_first_state field.
 */
void
first_state(struct nfs4_client *clp)
{
	if (!clp->cl_first_state)
		clp->cl_first_state = get_seconds();
}

/*
 * nfs4_unlock_state(); called in encode
 */
int
nfsd4_open_confirm(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open_confirm *oc)
{
	int status;
	struct nfs4_stateowner *sop;
	struct nfs4_stateid *stp;

	dprintk("NFSD: nfsd4_open_confirm on file %.*s\n",
			(int)current_fh->fh_dentry->d_name.len,
			current_fh->fh_dentry->d_name.name);

	if ((status = fh_verify(rqstp, current_fh, S_IFREG, 0)))
		goto out;

	oc->oc_stateowner = NULL;
	nfs4_lock_state();

	if ((status = nfs4_preprocess_seqid_op(current_fh, oc->oc_seqid,
					&oc->oc_req_stateid,
					CHECK_FH | CONFIRM | OPEN_STATE,
					&oc->oc_stateowner, &stp, NULL)))
		goto out; 

	sop = oc->oc_stateowner;
	sop->so_confirmed = 1;
	update_stateid(&stp->st_stateid);
	memcpy(&oc->oc_resp_stateid, &stp->st_stateid, sizeof(stateid_t));
	dprintk("NFSD: nfsd4_open_confirm: success, seqid=%d " 
		"stateid=(%08x/%08x/%08x/%08x)\n", oc->oc_seqid,
		         stp->st_stateid.si_boot,
		         stp->st_stateid.si_stateownerid,
		         stp->st_stateid.si_fileid,
		         stp->st_stateid.si_generation);
	status = nfs_ok;
	first_state(sop->so_client);
out:
	return status;
}


/*
 * unset all bits in union bitmap (bmap) that
 * do not exist in share (from successful OPEN_DOWNGRADE)
 */
static void
reset_union_bmap_access(unsigned long access, unsigned long *bmap)
{
	int i;
	for (i = 1; i < 4; i++) {
		if ((i & access) != i)
			__clear_bit(i, bmap);
	}
}

static void
reset_union_bmap_deny(unsigned long deny, unsigned long *bmap)
{
	int i;
	for (i = 0; i < 4; i++) {
		if ((i & deny) != i)
			__clear_bit(i, bmap);
	}
}

/*
 * nfs4_unlock_state(); called in encode
 */

int
nfsd4_open_downgrade(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open_downgrade *od)
{
	int status;
	struct nfs4_stateid *stp;
	unsigned int share_access;

	dprintk("NFSD: nfsd4_open_downgrade on file %.*s\n", 
			(int)current_fh->fh_dentry->d_name.len,
			current_fh->fh_dentry->d_name.name);

	od->od_stateowner = NULL;
	status = nfserr_inval;
	if (!TEST_ACCESS(od->od_share_access) || !TEST_DENY(od->od_share_deny))
		goto out;

	nfs4_lock_state();
	if ((status = nfs4_preprocess_seqid_op(current_fh, od->od_seqid, 
					&od->od_stateid, 
					CHECK_FH | OPEN_STATE, 
					&od->od_stateowner, &stp, NULL)))
		goto out; 

	status = nfserr_inval;
	if (!test_bit(od->od_share_access, &stp->st_access_bmap)) {
		dprintk("NFSD:access not a subset current bitmap: 0x%lx, input access=%08x\n",
			stp->st_access_bmap, od->od_share_access);
		goto out;
	}
	if (!test_bit(od->od_share_deny, &stp->st_deny_bmap)) {
		dprintk("NFSD:deny not a subset current bitmap: 0x%lx, input deny=%08x\n",
			stp->st_deny_bmap, od->od_share_deny);
		goto out;
	}
	set_access(&share_access, stp->st_access_bmap);
	nfs4_file_downgrade(stp->st_vfs_file,
	                    share_access & ~od->od_share_access);

	reset_union_bmap_access(od->od_share_access, &stp->st_access_bmap);
	reset_union_bmap_deny(od->od_share_deny, &stp->st_deny_bmap);

	update_stateid(&stp->st_stateid);
	memcpy(&od->od_stateid, &stp->st_stateid, sizeof(stateid_t));
	status = nfs_ok;
out:
	return status;
}

/*
 * nfs4_unlock_state() called after encode
 */
int
nfsd4_close(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_close *close)
{
	int status;
	struct nfs4_stateid *stp;

	dprintk("NFSD: nfsd4_close on file %.*s\n", 
			(int)current_fh->fh_dentry->d_name.len,
			current_fh->fh_dentry->d_name.name);

	close->cl_stateowner = NULL;
	nfs4_lock_state();
	/* check close_lru for replay */
	if ((status = nfs4_preprocess_seqid_op(current_fh, close->cl_seqid, 
					&close->cl_stateid, 
					CHECK_FH | OPEN_STATE | CLOSE_STATE,
					&close->cl_stateowner, &stp, NULL)))
		goto out; 
	/*
	*  Return success, but first update the stateid.
	*/
	status = nfs_ok;
	update_stateid(&stp->st_stateid);
	memcpy(&close->cl_stateid, &stp->st_stateid, sizeof(stateid_t));

	/* release_state_owner() calls nfsd_close() if needed */
	release_state_owner(stp, &close->cl_stateowner, OPEN_STATE);
out:
	return status;
}

/* 
 * Lock owner state (byte-range locks)
 */
#define LOFF_OVERFLOW(start, len)      ((u64)(len) > ~(u64)(start))
#define LOCK_HASH_BITS              8
#define LOCK_HASH_SIZE             (1 << LOCK_HASH_BITS)
#define LOCK_HASH_MASK             (LOCK_HASH_SIZE - 1)

#define lockownerid_hashval(id) \
        ((id) & LOCK_HASH_MASK)
#define lock_ownerstr_hashval(x, clientid, ownername) \
        ((file_hashval(x) + (clientid) + opaque_hashval((ownername.data), (ownername.len))) & LOCK_HASH_MASK)

static struct list_head lock_ownerid_hashtbl[LOCK_HASH_SIZE];
static struct list_head	lock_ownerstr_hashtbl[LOCK_HASH_SIZE];
static struct list_head lockstateid_hashtbl[STATEID_HASH_SIZE];

struct nfs4_stateid *
find_stateid(stateid_t *stid, int flags)
{
	struct nfs4_stateid *local = NULL;
	u32 st_id = stid->si_stateownerid;
	u32 f_id = stid->si_fileid;
	unsigned int hashval;

	dprintk("NFSD: find_stateid flags 0x%x\n",flags);
	if ((flags & LOCK_STATE) || (flags & RDWR_STATE)) {
		hashval = stateid_hashval(st_id, f_id);
		list_for_each_entry(local, &lockstateid_hashtbl[hashval], st_hash) {
			if ((local->st_stateid.si_stateownerid == st_id) &&
			    (local->st_stateid.si_fileid == f_id))
				return local;
		}
	} 
	if ((flags & OPEN_STATE) || (flags & RDWR_STATE)) {
		hashval = stateid_hashval(st_id, f_id);
		list_for_each_entry(local, &stateid_hashtbl[hashval], st_hash) {
			if ((local->st_stateid.si_stateownerid == st_id) &&
			    (local->st_stateid.si_fileid == f_id))
				return local;
		}
	} else
		printk("NFSD: find_stateid: ERROR: no state flag\n");
	return NULL;
}


/*
 * TODO: Linux file offsets are _signed_ 64-bit quantities, which means that
 * we can't properly handle lock requests that go beyond the (2^63 - 1)-th
 * byte, because of sign extension problems.  Since NFSv4 calls for 64-bit
 * locking, this prevents us from being completely protocol-compliant.  The
 * real solution to this problem is to start using unsigned file offsets in
 * the VFS, but this is a very deep change!
 */
static inline void
nfs4_transform_lock_offset(struct file_lock *lock)
{
	if (lock->fl_start < 0)
		lock->fl_start = OFFSET_MAX;
	if (lock->fl_end < 0)
		lock->fl_end = OFFSET_MAX;
}

int
nfs4_verify_lock_stateowner(struct nfs4_stateowner *sop, unsigned int hashval)
{
	struct nfs4_stateowner *local = NULL;
	int status = 0;
			        
	if (hashval >= LOCK_HASH_SIZE)
		goto out;
	list_for_each_entry(local, &lock_ownerid_hashtbl[hashval], so_idhash) {
		if (local == sop) {
			status = 1;