Commit 87dda67e authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4.1: Allow SEQUENCE to resize the slot table on the fly 



Instead of an array of slots, use a singly linked list of slots that
can be dynamically appended to or shrunk.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 97e548a9

fs/nfs/nfs4_fs.h

+2 −2
Original line number Diff line number Diff line
@@ -258,10 +258,10 @@ extern int nfs4_proc_get_lease_time(struct nfs_client *clp, 
extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,

				  bool sync);



extern struct nfs4_slot *nfs4_alloc_slots(struct nfs4_slot_table *table,

		u32 max_slots, gfp_t gfp_flags);

extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,

		u32 target_highest_slotid);

extern int nfs4_resize_slot_table(struct nfs4_slot_table *tbl,

		u32 max_reqs, u32 ivalue);



static inline bool

is_ds_only_client(struct nfs_client *clp)

fs/nfs/nfs4proc.c

+114 −60
Original line number Diff line number Diff line
@@ -396,6 +396,27 @@ static void renew_lease(const struct nfs_server *server, unsigned long timestamp 


#if defined(CONFIG_NFS_V4_1)



/*

 * nfs4_shrink_slot_table - free retired slots from the slot table

 */

static void nfs4_shrink_slot_table(struct nfs4_slot_table  *tbl, u32 newsize)

{

	struct nfs4_slot **p;

	if (newsize >= tbl->max_slots)

		return;



	p = &tbl->slots;

	while (newsize--)

		p = &(*p)->next;

	while (*p) {

		struct nfs4_slot *slot = *p;



		*p = slot->next;

		kfree(slot);

		tbl->max_slots--;

	}

}



/*

 * nfs4_free_slot - free a slot and efficiently update slot table.

 *
@@ -499,7 +520,7 @@ static void nfs41_set_target_slotid_locked(struct nfs4_slot_table *tbl, 
	tbl->target_highest_slotid = target_highest_slotid;

	tbl->generation++;



	max_slotid = min(tbl->max_slots - 1, tbl->target_highest_slotid);

	max_slotid = min(NFS4_MAX_SLOT_TABLE - 1, tbl->target_highest_slotid);

	for (i = tbl->max_slotid + 1; i <= max_slotid; i++)

		rpc_wake_up_next(&tbl->slot_tbl_waitq);

	tbl->max_slotid = max_slotid;
@@ -516,16 +537,12 @@ void nfs41_set_target_slotid(struct nfs4_slot_table *tbl, 
static void nfs41_set_server_slotid_locked(struct nfs4_slot_table *tbl,

		u32 highest_slotid)

{

	unsigned int max_slotid, i;



	if (tbl->server_highest_slotid == highest_slotid)

		return;

	if (tbl->highest_used_slotid > highest_slotid)

		return;

	max_slotid = min(tbl->max_slots - 1, highest_slotid);

	/* Reset the seq_nr for deallocated slots */

	for (i = tbl->server_highest_slotid + 1; i <= max_slotid; i++)

		tbl->slots[i].seq_nr = 1;

	/* Deallocate slots */

	nfs4_shrink_slot_table(tbl, highest_slotid + 1);

	tbl->server_highest_slotid = highest_slotid;

}
@@ -612,6 +629,42 @@ static int nfs4_sequence_done(struct rpc_task *task, 
	return nfs41_sequence_done(task, res);

}



static struct nfs4_slot *nfs4_new_slot(struct nfs4_slot_table  *tbl,

		u32 slotid, u32 seq_init, gfp_t gfp_mask)

{

	struct nfs4_slot *slot;



	slot = kzalloc(sizeof(*slot), gfp_mask);

	if (slot) {

		slot->table = tbl;

		slot->slot_nr = slotid;

		slot->seq_nr = seq_init;

	}

	return slot;

}



static struct nfs4_slot *nfs4_find_or_create_slot(struct nfs4_slot_table  *tbl,

		u32 slotid, u32 seq_init, gfp_t gfp_mask)

{

	struct nfs4_slot **p, *slot;



	p = &tbl->slots;

	for (;;) {

		if (*p == NULL) {

			*p = nfs4_new_slot(tbl, tbl->max_slots,

					seq_init, gfp_mask);

			if (*p == NULL)

				break;

			tbl->max_slots++;

		}

		slot = *p;

		if (slot->slot_nr == slotid)

			return slot;

		p = &slot->next;

	}

	return NULL;

}



/*

 * nfs4_alloc_slot - efficiently look for a free slot

 *
@@ -628,15 +681,17 @@ static struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl) 


	dprintk("--> %s used_slots=%04lx highest_used=%u max_slots=%u\n",

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

		tbl->max_slots);

		tbl->max_slotid + 1);

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

	if (slotid > tbl->max_slotid)

		goto out;

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

	if (ret == NULL)

		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 = &tbl->slots[slotid];

	ret->renewal_time = jiffies;

	ret->generation = tbl->generation;
@@ -5718,67 +5773,56 @@ int nfs4_proc_get_lease_time(struct nfs_client *clp, struct nfs_fsinfo *fsinfo) 
	return status;

}



struct nfs4_slot *nfs4_alloc_slots(struct nfs4_slot_table *table,

		u32 max_slots, gfp_t gfp_flags)

static int nfs4_grow_slot_table(struct nfs4_slot_table *tbl,

		 u32 max_reqs, u32 ivalue)

{

	struct nfs4_slot *tbl;

	u32 i;



	tbl = kmalloc_array(max_slots, sizeof(*tbl), gfp_flags);

	if (tbl != NULL) {

		for (i = 0; i < max_slots; i++) {

			tbl[i].table = table;

			tbl[i].slot_nr = i;

		}

	}

	return tbl;

	if (max_reqs <= tbl->max_slots)

		return 0;

	if (nfs4_find_or_create_slot(tbl, max_reqs - 1, ivalue, GFP_NOFS))

		return 0;

	return -ENOMEM;

}



static void nfs4_add_and_init_slots(struct nfs4_slot_table *tbl,

		struct nfs4_slot *new,

		u32 max_slots,

static void nfs4_reset_slot_table(struct nfs4_slot_table *tbl,

		u32 server_highest_slotid,

		u32 ivalue)

{

	struct nfs4_slot *old = NULL;

	u32 i;

	struct nfs4_slot **p;



	spin_lock(&tbl->slot_tbl_lock);

	if (new) {

		old = tbl->slots;

		tbl->slots = new;

		tbl->max_slots = max_slots;

	nfs4_shrink_slot_table(tbl, server_highest_slotid + 1);

	p = &tbl->slots;

	while (*p) {

		(*p)->seq_nr = ivalue;

		p = &(*p)->next;

	}

	tbl->highest_used_slotid = NFS4_NO_SLOT;

	tbl->target_highest_slotid = max_slots - 1;

	tbl->server_highest_slotid = max_slots - 1;

	tbl->max_slotid = max_slots - 1;

	for (i = 0; i < tbl->max_slots; i++)

		tbl->slots[i].seq_nr = ivalue;

	spin_unlock(&tbl->slot_tbl_lock);

	kfree(old);

	tbl->target_highest_slotid = server_highest_slotid;

	tbl->server_highest_slotid = server_highest_slotid;

	tbl->max_slotid = server_highest_slotid;

}



/*

 * (re)Initialise a slot table

 */

static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl, u32 max_reqs,

				 u32 ivalue)

static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl,

		u32 max_reqs, u32 ivalue)

{

	struct nfs4_slot *new = NULL;

	int ret = -ENOMEM;

	int ret;



	dprintk("--> %s: max_reqs=%u, tbl->max_slots %d\n", __func__,

		max_reqs, tbl->max_slots);



	/* Does the newly negotiated max_reqs match the existing slot table? */

	if (max_reqs != tbl->max_slots) {

		new = nfs4_alloc_slots(tbl, max_reqs, GFP_NOFS);

		if (!new)

	if (max_reqs > NFS4_MAX_SLOT_TABLE)

		max_reqs = NFS4_MAX_SLOT_TABLE;



	ret = nfs4_grow_slot_table(tbl, max_reqs, ivalue);

	if (ret)

		goto out;

	}

	ret = 0;



	nfs4_add_and_init_slots(tbl, new, max_reqs, ivalue);

	spin_lock(&tbl->slot_tbl_lock);

	nfs4_reset_slot_table(tbl, max_reqs - 1, ivalue);

	spin_unlock(&tbl->slot_tbl_lock);



	dprintk("%s: tbl=%p slots=%p max_slots=%d\n", __func__,

		tbl, tbl->slots, tbl->max_slots);

out:
@@ -5786,18 +5830,28 @@ static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl, u32 max_reqs, 
	return ret;

}



int nfs4_resize_slot_table(struct nfs4_slot_table *tbl,

		 u32 max_reqs, u32 ivalue)

{

	int ret;



	if (max_reqs > NFS4_MAX_SLOT_TABLE)

		max_reqs = NFS4_MAX_SLOT_TABLE;

	ret = nfs4_grow_slot_table(tbl, max_reqs, ivalue);

	if (ret)

		return ret;

	spin_lock(&tbl->slot_tbl_lock);

	nfs4_shrink_slot_table(tbl, max_reqs);

	tbl->max_slotid = max_reqs - 1;

	spin_unlock(&tbl->slot_tbl_lock);

	return 0;

}



/* Destroy the slot table */

static void nfs4_destroy_slot_tables(struct nfs4_session *session)

{

	if (session->fc_slot_table.slots != NULL) {

		kfree(session->fc_slot_table.slots);

		session->fc_slot_table.slots = NULL;

	}

	if (session->bc_slot_table.slots != NULL) {

		kfree(session->bc_slot_table.slots);

		session->bc_slot_table.slots = NULL;

	}

	return;

	nfs4_shrink_slot_table(&session->fc_slot_table, 0);

	nfs4_shrink_slot_table(&session->bc_slot_table, 0);

}



/*

fs/nfs/nfs4state.c

+4 −18
Original line number Diff line number Diff line
@@ -2025,29 +2025,15 @@ static int nfs4_reset_session(struct nfs_client *clp) 
static int nfs4_recall_slot(struct nfs_client *clp)

{

	struct nfs4_slot_table *fc_tbl;

	struct nfs4_slot *new, *old;

	int i;

	u32 new_size;



	if (!nfs4_has_session(clp))

		return 0;

	nfs4_begin_drain_session(clp);

	fc_tbl = &clp->cl_session->fc_slot_table;

	new = nfs4_alloc_slots(fc_tbl, fc_tbl->target_highest_slotid + 1, GFP_NOFS);

        if (!new)

		return -ENOMEM;



	spin_lock(&fc_tbl->slot_tbl_lock);

	for (i = 0; i <= fc_tbl->target_highest_slotid; i++)

		new[i].seq_nr = fc_tbl->slots[i].seq_nr;

	old = fc_tbl->slots;

	fc_tbl->slots = new;

	fc_tbl->max_slots = fc_tbl->target_highest_slotid + 1;

	fc_tbl->max_slotid = fc_tbl->target_highest_slotid;

	clp->cl_session->fc_attrs.max_reqs = fc_tbl->max_slots;

	spin_unlock(&fc_tbl->slot_tbl_lock);



	kfree(old);

	return 0;

	fc_tbl = &clp->cl_session->fc_slot_table;

	new_size = fc_tbl->server_highest_slotid + 1;

	return nfs4_resize_slot_table(fc_tbl, new_size, 1);

}



static int nfs4_bind_conn_to_session(struct nfs_client *clp)

include/linux/nfs_xdr.h

+1 −0
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ struct nfs4_channel_attrs { 
/* nfs41 sessions slot seqid */

struct nfs4_slot {

	struct nfs4_slot_table	*table;

	struct nfs4_slot	*next;

	unsigned long		generation;

	unsigned long		renewal_time;

	u32			slot_nr;