From nobody Mon Nov 25 04:52:16 2024 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 648C11F8932; Wed, 30 Oct 2024 14:48:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730299736; cv=none; b=nxYTgxiwJ7HorjYqwvc37ruD+xt3w5wuLmNd8ItQKKkdDMbhAUf2aig9hBuj8ZVL9L0qUFXimQ0Svx4jJ0uOrNMvvCJaZyHJBS1VdB95B10LCs7pDHoMLtnkeDZv76VKVGisuGfalXi9RnHfm8y75DPhAke3PjldnjtQgJZvjAw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730299736; c=relaxed/simple; bh=nckgiPLG+atCu4LICe7r7yxWKsI+u0PyRhMLEBHtspc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=DGh718Mnk0kmK7fYeLhToBpnsKD3I5BkG5HEPecp0FNXTBTJOtebXgpX5Yic8byHLY3TvIAP8YaksixTSifHTAV3xeKFCTvbTc4AjmiYjGsM74eI9IrZaVbJVlKi8oZH92WPqtQuta/AQcJUnXIlpzjC3s93f1EwSAwnnWlX0Lo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TkjR/tl6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TkjR/tl6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CA33C4CED0; Wed, 30 Oct 2024 14:48:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730299736; bh=nckgiPLG+atCu4LICe7r7yxWKsI+u0PyRhMLEBHtspc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=TkjR/tl6x5m8+d8rk902Knv3sgxaCI205tj4oOzF/hffBere2oZvRV0jP5VLC6mhE aIlW6IYnpiqYnqilZiCL8hV/FY+GlkaDRPHlwIKPLaOAFetV6JulzCd0X8UavyUnaV 7OL8kYnO1O7a4P3/8UvWaOMX0QLIxWUtAHtmOTdJcpbfIlq3720MYId4bBg3G9Endi aNB659SQQPi8KNVM3UkQC9rvxzGRR0mOJVGIFOOK1icUx9g7lecFk1XPfxRDRNv1z5 5mpY8k0RpzqSddO6k01Lh+EanFCoybnN9m4Q4AHJuVoCAa8GKUHrOzpovQrMN6OMb2 Q55ef7JoJr4/Q== From: Jeff Layton Date: Wed, 30 Oct 2024 10:48:47 -0400 Subject: [PATCH v3 2/2] nfsd: allow for up to 32 callback session slots Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20241030-bcwide-v3-2-c2df49a26c45@kernel.org> References: <20241030-bcwide-v3-0-c2df49a26c45@kernel.org> In-Reply-To: <20241030-bcwide-v3-0-c2df49a26c45@kernel.org> To: Chuck Lever , Neil Brown , Dai Ngo , Tom Talpey Cc: Olga Kornievskaia , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Jeff Layton X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=11933; i=jlayton@kernel.org; h=from:subject:message-id; bh=nckgiPLG+atCu4LICe7r7yxWKsI+u0PyRhMLEBHtspc=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBnIkdV/l0NC6Cnn7zI+SdECwaA02BcMOcWmwmjr tc7f50kTKOJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZyJHVQAKCRAADmhBGVaC Fav9D/9eZk4dKz/6A5l0PD8sUXdXYSksKEhlSNaI033ZAVxdSUlRmJLZI6mG5ggrUQZGuaRrmjI vEW897Eq7O1zomVrHQmny7O6+n9pD3ggTWd9SFiYbUEaJLl5Z9bMQMXuLcWwIXFAPg5HxUyJpYH txnN/I0sXwBD0z5jdEn54LIP+GEHICb/j8Yaq78hRYGOArzhZAQ+r68E5XlZIS+O78BFS1xzZY9 ltqWyPf0C4Zumh1mO9qOBgQlebQ8EONbHoMYGz28zeJ7TnZkMJFJq+H1HveCyLzZFi1edpQMKkk HRGHRzZVHHShjXsnhoHi85xkEQvfSkkr2CFoAdnRHciUOMe1zNtvgbGV/4/zdetccPsOUOy7Kdt TXkhQPLWpcP+PbMZ0uUx6vJupqVOCX1uRUT42IPailjPLaj1J6XVeUxCOAWqEUlSg5TiLPS0RkM /ziFn8j5bqDVM1EWVyU+nqNBW686sDyWp/iTgbqDNz4jlTDgyP8mThb2Xmt7VBj7/GDc04asHPG gekSsfoZntI57GtwAevT3aUTWvouikCjlJxdB0ur4DmnXJP1EsJuRFHAFSXLQ/VOY+6qIM3rCrF FT8aqSLteGiSY5fO8UhwjVBt42Cvwb2DvM+n6iO7Gp39rFRqFXjCFzbK2UunuecvfpHdyI5kvBV FhHtdLLRykiy4RQ== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 nfsd currently only uses a single slot in the callback channel, which is proving to be a bottleneck in some cases. Widen the callback channel to a max of 32 slots (subject to the client's target_maxreqs value). Change the cb_holds_slot boolean to an integer that tracks the current slot number (with -1 meaning "unassigned"). Move the callback slot tracking info into the session. Add a new u32 that acts as a bitmap to track which slots are in use, and a u32 to track the latest callback target_slotid that the client reports. To protect the new fields, add a new per-session spinlock (the se_lock). Fix nfsd41_cb_get_slot to always search for the lowest slotid (using ffs()), and change it to retry until there is a slot available or the rpc_task is signalled. Finally, convert the session->se_cb_seq_nr field into an array of counters and add the necessary handling to ensure that the seqids get reset at the appropriate times. Signed-off-by: Jeff Layton --- fs/nfsd/nfs4callback.c | 108 ++++++++++++++++++++++++++++++++++-----------= ---- fs/nfsd/nfs4state.c | 11 +++-- fs/nfsd/state.h | 15 ++++--- fs/nfsd/trace.h | 2 +- 4 files changed, 94 insertions(+), 42 deletions(-) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index e38fa834b3d91333acf1425eb14c644e5d5f2601..04b52ae182fc55659662232712a= 2439fb9a3b95a 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -406,6 +406,19 @@ encode_cb_getattr4args(struct xdr_stream *xdr, struct = nfs4_cb_compound_hdr *hdr, hdr->nops++; } =20 +static u32 highest_slotid(struct nfsd4_session *ses) +{ + u32 idx; + + spin_lock(&ses->se_lock); + idx =3D fls(~ses->se_cb_slot_avail); + if (idx > 0) + --idx; + idx =3D max(idx, ses->se_cb_highest_slot); + spin_unlock(&ses->se_lock); + return idx; +} + /* * CB_SEQUENCE4args * @@ -432,15 +445,35 @@ static void encode_cb_sequence4args(struct xdr_stream= *xdr, encode_sessionid4(xdr, session); =20 p =3D xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4); - *p++ =3D cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */ - *p++ =3D xdr_zero; /* csa_slotid */ - *p++ =3D xdr_zero; /* csa_highest_slotid */ + *p++ =3D cpu_to_be32(session->se_cb_seq_nr[cb->cb_held_slot]); /* csa_seq= uenceid */ + *p++ =3D cpu_to_be32(cb->cb_held_slot); /* csa_slotid */ + *p++ =3D cpu_to_be32(highest_slotid(session)); /* csa_highest_slotid */ *p++ =3D xdr_zero; /* csa_cachethis */ xdr_encode_empty_array(p); /* csa_referring_call_lists */ =20 hdr->nops++; } =20 +static void update_cb_slot_table(struct nfsd4_session *ses, u32 target) +{ + /* No need to do anything if nothing changed */ + if (likely(target =3D=3D READ_ONCE(ses->se_cb_highest_slot))) + return; + + spin_lock(&ses->se_lock); + if (target > ses->se_cb_highest_slot) { + int i; + + target =3D min(target, NFSD_BC_SLOT_TABLE_MAX); + + /* Growing the slot table. Reset any new sequences to 1 */ + for (i =3D ses->se_cb_highest_slot + 1; i <=3D target; ++i) + ses->se_cb_seq_nr[i] =3D 1; + } + ses->se_cb_highest_slot =3D target; + spin_unlock(&ses->se_lock); +} + /* * CB_SEQUENCE4resok * @@ -468,7 +501,7 @@ static int decode_cb_sequence4resok(struct xdr_stream *= xdr, struct nfsd4_session *session =3D cb->cb_clp->cl_cb_session; int status =3D -ESERVERFAULT; __be32 *p; - u32 dummy; + u32 seqid, slotid, target; =20 /* * If the server returns different values for sessionID, slotID or @@ -484,21 +517,22 @@ static int decode_cb_sequence4resok(struct xdr_stream= *xdr, } p +=3D XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN); =20 - dummy =3D be32_to_cpup(p++); - if (dummy !=3D session->se_cb_seq_nr) { + seqid =3D be32_to_cpup(p++); + if (seqid !=3D session->se_cb_seq_nr[cb->cb_held_slot]) { dprintk("NFS: %s Invalid sequence number\n", __func__); goto out; } =20 - dummy =3D be32_to_cpup(p++); - if (dummy !=3D 0) { + slotid =3D be32_to_cpup(p++); + if (slotid !=3D cb->cb_held_slot) { dprintk("NFS: %s Invalid slotid\n", __func__); goto out; } =20 - /* - * FIXME: process highest slotid and target highest slotid - */ + p++; // ignore current highest slot value + + target =3D be32_to_cpup(p++); + update_cb_slot_table(session, target); status =3D 0; out: cb->cb_seq_status =3D status; @@ -1211,28 +1245,39 @@ void nfsd4_change_callback(struct nfs4_client *clp,= struct nfs4_cb_conn *conn) static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task = *task) { struct nfs4_client *clp =3D cb->cb_clp; + struct nfsd4_session *ses =3D clp->cl_cb_session; + int idx; =20 - if (!cb->cb_holds_slot && - test_and_set_bit(0, &clp->cl_cb_slot_busy) !=3D 0) { - rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); - /* Race breaker */ - if (test_and_set_bit(0, &clp->cl_cb_slot_busy) !=3D 0) { - dprintk("%s slot is busy\n", __func__); + if (cb->cb_held_slot >=3D 0) + return true; +retry: + spin_lock(&ses->se_lock); + idx =3D ffs(ses->se_cb_slot_avail) - 1; + if (idx < 0 || idx > ses->se_cb_highest_slot) { + spin_unlock(&ses->se_lock); + if (RPC_SIGNALLED(task)) return false; - } + rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); rpc_wake_up_queued_task(&clp->cl_cb_waitq, task); + goto retry; } - cb->cb_holds_slot =3D true; + /* clear the bit for the slot */ + ses->se_cb_slot_avail &=3D ~BIT(idx); + spin_unlock(&ses->se_lock); + cb->cb_held_slot =3D idx; return true; } =20 static void nfsd41_cb_release_slot(struct nfsd4_callback *cb) { struct nfs4_client *clp =3D cb->cb_clp; + struct nfsd4_session *ses =3D clp->cl_cb_session; =20 - if (cb->cb_holds_slot) { - cb->cb_holds_slot =3D false; - clear_bit(0, &clp->cl_cb_slot_busy); + if (cb->cb_held_slot >=3D 0) { + spin_lock(&ses->se_lock); + ses->se_cb_slot_avail |=3D BIT(cb->cb_held_slot); + spin_unlock(&ses->se_lock); + cb->cb_held_slot =3D -1; rpc_wake_up_next(&clp->cl_cb_waitq); } } @@ -1249,8 +1294,8 @@ static void nfsd41_destroy_cb(struct nfsd4_callback *= cb) } =20 /* - * TODO: cb_sequence should support referring call lists, cachethis, multi= ple - * slots, and mark callback channel down on communication errors. + * TODO: cb_sequence should support referring call lists, cachethis, + * and mark callback channel down on communication errors. */ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) { @@ -1292,7 +1337,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *t= ask, struct nfsd4_callback return true; } =20 - if (!cb->cb_holds_slot) + if (cb->cb_held_slot < 0) goto need_restart; =20 /* This is the operation status code for CB_SEQUENCE */ @@ -1306,10 +1351,10 @@ static bool nfsd4_cb_sequence_done(struct rpc_task = *task, struct nfsd4_callback * If CB_SEQUENCE returns an error, then the state of the slot * (sequence ID, cached reply) MUST NOT change. */ - ++session->se_cb_seq_nr; + ++session->se_cb_seq_nr[cb->cb_held_slot]; break; case -ESERVERFAULT: - ++session->se_cb_seq_nr; + ++session->se_cb_seq_nr[cb->cb_held_slot]; nfsd4_mark_cb_fault(cb->cb_clp); ret =3D false; break; @@ -1335,17 +1380,16 @@ static bool nfsd4_cb_sequence_done(struct rpc_task = *task, struct nfsd4_callback case -NFS4ERR_BADSLOT: goto retry_nowait; case -NFS4ERR_SEQ_MISORDERED: - if (session->se_cb_seq_nr !=3D 1) { - session->se_cb_seq_nr =3D 1; + if (session->se_cb_seq_nr[cb->cb_held_slot] !=3D 1) { + session->se_cb_seq_nr[cb->cb_held_slot] =3D 1; goto retry_nowait; } break; default: nfsd4_mark_cb_fault(cb->cb_clp); } - nfsd41_cb_release_slot(cb); - trace_nfsd_cb_free_slot(task, cb); + nfsd41_cb_release_slot(cb); =20 if (RPC_SIGNALLED(task)) goto need_restart; @@ -1565,7 +1609,7 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struct = nfs4_client *clp, INIT_WORK(&cb->cb_work, nfsd4_run_cb_work); cb->cb_status =3D 0; cb->cb_need_restart =3D false; - cb->cb_holds_slot =3D false; + cb->cb_held_slot =3D -1; } =20 /** diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index baf7994131fe1b0a4715174ba943fd2a9882aa12..75557e7cc9265517f51952563be= aa4cfe8adcc3f 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2002,6 +2002,9 @@ static struct nfsd4_session *alloc_session(struct nfs= d4_channel_attrs *fattrs, } =20 memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs)); + new->se_cb_slot_avail =3D ~0U; + new->se_cb_highest_slot =3D battrs->maxreqs - 1; + spin_lock_init(&new->se_lock); return new; out_free: while (i--) @@ -2132,11 +2135,14 @@ static void init_session(struct svc_rqst *rqstp, st= ruct nfsd4_session *new, stru =20 INIT_LIST_HEAD(&new->se_conns); =20 - new->se_cb_seq_nr =3D 1; + atomic_set(&new->se_ref, 0); new->se_dead =3D false; new->se_cb_prog =3D cses->callback_prog; new->se_cb_sec =3D cses->cb_sec; - atomic_set(&new->se_ref, 0); + + for (idx =3D 0; idx < NFSD_BC_SLOT_TABLE_MAX; ++idx) + new->se_cb_seq_nr[idx] =3D 1; + idx =3D hash_sessionid(&new->se_sessionid); list_add(&new->se_hash, &nn->sessionid_hashtbl[idx]); spin_lock(&clp->cl_lock); @@ -3159,7 +3165,6 @@ static struct nfs4_client *create_client(struct xdr_n= etobj name, kref_init(&clp->cl_nfsdfs.cl_ref); nfsd4_init_cb(&clp->cl_cb_null, clp, NULL, NFSPROC4_CLNT_CB_NULL); clp->cl_time =3D ktime_get_boottime_seconds(); - clear_bit(0, &clp->cl_cb_slot_busy); copy_verf(clp, verf); memcpy(&clp->cl_addr, sa, sizeof(struct sockaddr_storage)); clp->cl_cb_session =3D NULL; diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index d22e4f2c9039324a0953a9e15a3c255fb8ee1a44..848d023cb308f0b69916c4ee34b= 09075708f0de3 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -71,8 +71,8 @@ struct nfsd4_callback { struct work_struct cb_work; int cb_seq_status; int cb_status; + int cb_held_slot; bool cb_need_restart; - bool cb_holds_slot; }; =20 struct nfsd4_callback_ops { @@ -307,6 +307,9 @@ struct nfsd4_conn { unsigned char cn_flags; }; =20 +/* Highest slot index that nfsd implements in NFSv4.1+ backchannel */ +#define NFSD_BC_SLOT_TABLE_MAX (sizeof(u32) * 8 - 1) + /* * Representation of a v4.1+ session. These are refcounted in a similar fa= shion * to the nfs4_client. References are only taken when the server is active= ly @@ -314,6 +317,10 @@ struct nfsd4_conn { */ struct nfsd4_session { atomic_t se_ref; + spinlock_t se_lock; + u32 se_cb_slot_avail; /* bitmap of available slots */ + u32 se_cb_highest_slot; /* highest slot client wants */ + u32 se_cb_prog; bool se_dead; struct list_head se_hash; /* hash by sessionid */ struct list_head se_perclnt; @@ -322,8 +329,7 @@ struct nfsd4_session { struct nfsd4_channel_attrs se_fchannel; struct nfsd4_cb_sec se_cb_sec; struct list_head se_conns; - u32 se_cb_prog; - u32 se_cb_seq_nr; + u32 se_cb_seq_nr[NFSD_BC_SLOT_TABLE_MAX + 1]; struct nfsd4_slot *se_slots[]; /* forward channel slots */ }; =20 @@ -457,9 +463,6 @@ struct nfs4_client { */ struct dentry *cl_nfsd_info_dentry; =20 - /* for nfs41 callbacks */ - /* We currently support a single back channel with a single slot */ - unsigned long cl_cb_slot_busy; struct rpc_wait_queue cl_cb_waitq; /* backchannel callers may */ /* wait here for slots */ struct net *net; diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h index f318898cfc31614b5a84a4867e18c2b3a07122c9..a9c17186b6892f1df8d7f7b90e2= 50c2913ab23fe 100644 --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -1697,7 +1697,7 @@ TRACE_EVENT(nfsd_cb_free_slot, __entry->cl_id =3D sid->clientid.cl_id; __entry->seqno =3D sid->sequence; __entry->reserved =3D sid->reserved; - __entry->slot_seqno =3D session->se_cb_seq_nr; + __entry->slot_seqno =3D session->se_cb_seq_nr[cb->cb_held_slot]; ), TP_printk(SUNRPC_TRACE_TASK_SPECIFIER " sessionid=3D%08x:%08x:%08x:%08x new slot seqno=3D%u", --=20 2.47.0