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: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2012-11-20 19:49:20 -05:00
parent 97e548a93d
commit 87dda67e73
4 changed files with 121 additions and 80 deletions

View File

@ -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)

View File

@ -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)
goto out;
}
ret = 0;
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;
spin_lock(&tbl->slot_tbl_lock);
nfs4_reset_slot_table(tbl, max_reqs - 1, ivalue);
spin_unlock(&tbl->slot_tbl_lock);
nfs4_add_and_init_slots(tbl, new, max_reqs, ivalue);
dprintk("%s: tbl=%p slots=%p max_slots=%d\n", __func__,
tbl, tbl->slots, tbl->max_slots);
out:
@ -5786,18 +5830,28 @@ out:
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);
}
/*

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@ -2025,29 +2025,15 @@ out:
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;
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)

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@ -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;