Commit 810d82e6 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4.x: Allow multiple callbacks in flight 



Hook the callback channel into the same session management machinery
as we use for the forward channel.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 5f83d86c

fs/nfs/callback.h

+2 −1
Original line number Diff line number Diff line
@@ -37,10 +37,11 @@ enum nfs4_callback_opnum { 
	OP_CB_ILLEGAL = 10044,

};



struct nfs4_slot;

struct cb_process_state {

	__be32			drc_status;

	struct nfs_client	*clp;

	u32			slotid;

	struct nfs4_slot	*slot;

	u32			minorversion;

	struct net		*net;

};

fs/nfs/callback_proc.c

+10 −4
Original line number Diff line number Diff line
@@ -367,7 +367,7 @@ validate_seqid(const struct nfs4_slot_table *tbl, const struct nfs4_slot *slot, 
	if (args->csa_sequenceid == slot->seq_nr) {

		dprintk("%s seqid %u is a replay\n",

			__func__, args->csa_sequenceid);

		if (tbl->highest_used_slotid != NFS4_NO_SLOT)

		if (nfs4_test_locked_slot(tbl, slot->slot_nr))

			return htonl(NFS4ERR_DELAY);

		/* Signal process_op to set this error on next op */

		if (args->csa_cachethis == 0)
@@ -476,12 +476,18 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args, 
		goto out_unlock;

	}



	status = htonl(NFS4ERR_BADSLOT);

	slot = nfs4_lookup_slot(tbl, args->csa_slotid);

	if (IS_ERR(slot))

		goto out_unlock;

	status = validate_seqid(tbl, slot, args);

	if (status)

		goto out_unlock;



	cps->slotid = args->csa_slotid;

	tbl->highest_used_slotid = args->csa_slotid;

	if (!nfs4_try_to_lock_slot(tbl, slot)) {

		status = htonl(NFS4ERR_DELAY);

		goto out_unlock;

	}

	cps->slot = slot;



	memcpy(&res->csr_sessionid, &args->csa_sessionid,

	       sizeof(res->csr_sessionid));

fs/nfs/callback_xdr.c

+7 −5
Original line number Diff line number Diff line
@@ -752,7 +752,8 @@ preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op) 
	return htonl(NFS_OK);

}



static void nfs4_callback_free_slot(struct nfs4_session *session)

static void nfs4_callback_free_slot(struct nfs4_session *session,

		struct nfs4_slot *slot)

{

	struct nfs4_slot_table *tbl = &session->bc_slot_table;
@@ -761,15 +762,17 @@ static void nfs4_callback_free_slot(struct nfs4_session *session) 
	 * Let the state manager know callback processing done.

	 * A single slot, so highest used slotid is either 0 or -1

	 */

	tbl->highest_used_slotid = NFS4_NO_SLOT;

	nfs4_free_slot(tbl, slot);

	nfs4_slot_tbl_drain_complete(tbl);

	spin_unlock(&tbl->slot_tbl_lock);

}



static void nfs4_cb_free_slot(struct cb_process_state *cps)

{

	if (cps->slotid != NFS4_NO_SLOT)

		nfs4_callback_free_slot(cps->clp->cl_session);

	if (cps->slot) {

		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);

		cps->slot = NULL;

	}

}



#else /* CONFIG_NFS_V4_1 */
@@ -893,7 +896,6 @@ static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *r 
	struct cb_process_state cps = {

		.drc_status = 0,

		.clp = NULL,

		.slotid = NFS4_NO_SLOT,

		.net = SVC_NET(rqstp),

	};

	unsigned int nops = 0;

fs/nfs/nfs4session.c

+42 −12
Original line number Diff line number Diff line
@@ -135,6 +135,43 @@ static struct nfs4_slot *nfs4_find_or_create_slot(struct nfs4_slot_table *tbl, 
	return ERR_PTR(-ENOMEM);

}



static void nfs4_lock_slot(struct nfs4_slot_table *tbl,

		struct nfs4_slot *slot)

{

	u32 slotid = slot->slot_nr;



	__set_bit(slotid, tbl->used_slots);

	if (slotid > tbl->highest_used_slotid ||

	    tbl->highest_used_slotid == NFS4_NO_SLOT)

		tbl->highest_used_slotid = slotid;

	slot->generation = tbl->generation;

}



/*

 * nfs4_try_to_lock_slot - Given a slot try to allocate it

 *

 * Note: must be called with the slot_tbl_lock held.

 */

bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot)

{

	if (nfs4_test_locked_slot(tbl, slot->slot_nr))

		return false;

	nfs4_lock_slot(tbl, slot);

	return true;

}



/*

 * nfs4_lookup_slot - Find a slot but don't allocate it

 *

 * Note: must be called with the slot_tbl_lock held.

 */

struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid)

{

	if (slotid <= tbl->max_slotid)

		return nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);

	return ERR_PTR(-E2BIG);

}



/*

 * nfs4_alloc_slot - efficiently look for a free slot

 *
@@ -153,18 +190,11 @@ struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl) 
		__func__, tbl->used_slots[0], tbl->highest_used_slotid,

		tbl->max_slotid + 1);

	slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1);

	if (slotid > tbl->max_slotid)

		goto out;

	if (slotid <= tbl->max_slotid) {

		ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);

	if (IS_ERR(ret))

		goto out;

	__set_bit(slotid, tbl->used_slots);

	if (slotid > tbl->highest_used_slotid ||

			tbl->highest_used_slotid == NFS4_NO_SLOT)

		tbl->highest_used_slotid = slotid;

	ret->generation = tbl->generation;



out:

		if (!IS_ERR(ret))

			nfs4_lock_slot(tbl, ret);

	}

	dprintk("<-- %s used_slots=%04lx highest_used=%u slotid=%u\n",

		__func__, tbl->used_slots[0], tbl->highest_used_slotid,

		!IS_ERR(ret) ? ret->slot_nr : NFS4_NO_SLOT);

fs/nfs/nfs4session.h

+8 −0
Original line number Diff line number Diff line
@@ -77,6 +77,8 @@ extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl, 
		unsigned int max_reqs, const char *queue);

extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);

extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);

extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);

extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);

extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);

extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);

bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
@@ -88,6 +90,12 @@ static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl) 
	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);

}



static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,

		u32 slotid)

{

	return !!test_bit(slotid, tbl->used_slots);

}



#if defined(CONFIG_NFS_V4_1)

extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,

		u32 target_highest_slotid);