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: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2016-01-23 15:18:18 -05:00
parent 5f83d86cf5
commit 810d82e683
5 changed files with 69 additions and 22 deletions

View File

@ -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;
};

View File

@ -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));

View File

@ -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;

View File

@ -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;
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 (slotid <= tbl->max_slotid) {
ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
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);

View File

@ -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);