NFSv4.1: Support dynamic resizing of the session slot table

Allow the server to control the size of the session slot table
by adjusting the value of sr_target_max_slots in the reply to the
SEQUENCE operation.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2012-11-20 14:45:48 -05:00
parent 1b285ff16a
commit 97e548a93d
3 changed files with 14 additions and 5 deletions

View File

@ -492,10 +492,17 @@ static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
static void nfs41_set_target_slotid_locked(struct nfs4_slot_table *tbl,
u32 target_highest_slotid)
{
unsigned int max_slotid, i;
if (tbl->target_highest_slotid == target_highest_slotid)
return;
tbl->target_highest_slotid = target_highest_slotid;
tbl->generation++;
max_slotid = min(tbl->max_slots - 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;
}
void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
@ -622,8 +629,8 @@ 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);
slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slots);
if (slotid >= tbl->max_slots)
slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1);
if (slotid > tbl->max_slotid)
goto out;
__set_bit(slotid, tbl->used_slots);
if (slotid > tbl->highest_used_slotid ||
@ -5744,6 +5751,7 @@ static void nfs4_add_and_init_slots(struct nfs4_slot_table *tbl,
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);

View File

@ -254,15 +254,14 @@ static void nfs4_end_drain_session(struct nfs_client *clp)
{
struct nfs4_session *ses = clp->cl_session;
struct nfs4_slot_table *tbl;
int max_slots;
unsigned int i;
if (ses == NULL)
return;
tbl = &ses->fc_slot_table;
if (test_and_clear_bit(NFS4_SESSION_DRAINING, &ses->session_state)) {
spin_lock(&tbl->slot_tbl_lock);
max_slots = tbl->max_slots;
while (max_slots--) {
for (i = 0; i <= tbl->max_slotid; i++) {
if (rpc_wake_up_first(&tbl->slot_tbl_waitq,
nfs4_set_task_privileged,
NULL) == NULL)
@ -2043,6 +2042,7 @@ static int nfs4_recall_slot(struct nfs_client *clp)
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);

View File

@ -215,6 +215,7 @@ struct nfs4_slot_table {
spinlock_t slot_tbl_lock;
struct rpc_wait_queue slot_tbl_waitq; /* allocators may wait here */
u32 max_slots; /* # slots in table */
u32 max_slotid; /* Max allowed slotid value */
u32 highest_used_slotid; /* sent to server on each SEQ.
* op for dynamic resizing */
u32 target_highest_slotid; /* Server max_slot target */