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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
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+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)
+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);
}

/*
+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)
+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;