From 810d82e6830100615e7481813a862d26ffcff6bd Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sat, 23 Jan 2016 15:18:18 -0500 Subject: 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 --- fs/nfs/callback.h | 3 ++- fs/nfs/callback_proc.c | 14 +++++++++---- fs/nfs/callback_xdr.c | 12 ++++++----- fs/nfs/nfs4session.c | 54 +++++++++++++++++++++++++++++++++++++++----------- fs/nfs/nfs4session.h | 8 ++++++++ 5 files changed, 69 insertions(+), 22 deletions(-) diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h index ff8195bd75ea..5fe1cecbf9f0 100644 --- a/fs/nfs/callback.h +++ b/fs/nfs/callback.h @@ -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; }; diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index 79c93b3bbfec..efd079d28946 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -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)); diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c index 646cdac73488..976c90608e56 100644 --- a/fs/nfs/callback_xdr.c +++ b/fs/nfs/callback_xdr.c @@ -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; diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c index e23366effcfb..332d06e64fa9 100644 --- a/fs/nfs/nfs4session.c +++ b/fs/nfs/nfs4session.c @@ -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); diff --git a/fs/nfs/nfs4session.h b/fs/nfs/nfs4session.h index e3ea2c5324d6..5b51298d1d03 100644 --- a/fs/nfs/nfs4session.h +++ b/fs/nfs/nfs4session.h @@ -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); -- cgit 1.4.1