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c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1733446137; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3UXgSEi5wlQMWnDXdlDTHWAqc2sRjQcLevVVifVJ6Po=; b=avJoho5mqrCn8R53avPSlp+pBE5jMGSEVPab9oadxWxX1fWM/HewszmfIVejKwOsK+Nfrc xv3GOycn9ddFD9Bw== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 535BB132EB; Fri, 6 Dec 2024 00:48:55 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Qh9cAvdJUmfZDQAAD6G6ig (envelope-from ); Fri, 06 Dec 2024 00:48:55 +0000 From: NeilBrown To: Chuck Lever , Jeff Layton Cc: linux-nfs@vger.kernel.org, Olga Kornievskaia , Dai Ngo , Tom Talpey Subject: [PATCH 1/6] nfsd: use an xarray to store v4.1 session slots Date: Fri, 6 Dec 2024 11:43:15 +1100 Message-ID: <20241206004829.3497925-2-neilb@suse.de> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241206004829.3497925-1-neilb@suse.de> References: <20241206004829.3497925-1-neilb@suse.de> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Level: X-Spamd-Result: default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; TO_DN_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo]; RCVD_TLS_ALL(0.00)[] X-Spam-Score: -2.80 X-Spam-Flag: NO Using an xarray to store session slots will make it easier to change the number of active slots based on demand, and removes an unnecessary limit. To achieve good throughput with a high-latency server it can be helpful to have hundreds of concurrent writes, which means hundreds of slots. So increase the limit to 2048 (twice what the Linux client will currently use). This limit is only a sanity check, not a hard limit. Signed-off-by: NeilBrown --- fs/nfsd/nfs4state.c | 28 ++++++++++++++++++---------- fs/nfsd/state.h | 9 ++++++--- 2 files changed, 24 insertions(+), 13 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 741b9449f727..aa4f1293d4d3 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1915,8 +1915,11 @@ free_session_slots(struct nfsd4_session *ses) int i; for (i = 0; i < ses->se_fchannel.maxreqs; i++) { - free_svc_cred(&ses->se_slots[i]->sl_cred); - kfree(ses->se_slots[i]); + struct nfsd4_slot *slot = xa_load(&ses->se_slots, i); + + xa_erase(&ses->se_slots, i); + free_svc_cred(&slot->sl_cred); + kfree(slot); } } @@ -1996,17 +1999,20 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs, struct nfsd4_session *new; int i; - BUILD_BUG_ON(struct_size(new, se_slots, NFSD_MAX_SLOTS_PER_SESSION) - > PAGE_SIZE); - - new = kzalloc(struct_size(new, se_slots, numslots), GFP_KERNEL); + new = kzalloc(sizeof(*new), GFP_KERNEL); if (!new) return NULL; + xa_init(&new->se_slots); /* allocate each struct nfsd4_slot and data cache in one piece */ for (i = 0; i < numslots; i++) { - new->se_slots[i] = kzalloc(slotsize, GFP_KERNEL); - if (!new->se_slots[i]) + struct nfsd4_slot *slot; + slot = kzalloc(slotsize, GFP_KERNEL); + if (!slot) goto out_free; + if (xa_is_err(xa_store(&new->se_slots, i, slot, GFP_KERNEL))) { + kfree(slot); + goto out_free; + } } memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs)); @@ -2017,7 +2023,8 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs, return new; out_free: while (i--) - kfree(new->se_slots[i]); + kfree(xa_load(&new->se_slots, i)); + xa_destroy(&new->se_slots); kfree(new); return NULL; } @@ -2124,6 +2131,7 @@ static void nfsd4_del_conns(struct nfsd4_session *s) static void __free_session(struct nfsd4_session *ses) { free_session_slots(ses); + xa_destroy(&ses->se_slots); kfree(ses); } @@ -4278,7 +4286,7 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, if (seq->slotid >= session->se_fchannel.maxreqs) goto out_put_session; - slot = session->se_slots[seq->slotid]; + slot = xa_load(&session->se_slots, seq->slotid); dprintk("%s: slotid %d\n", __func__, seq->slotid); /* We do not negotiate the number of slots yet, so set the diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index e16bb3717fb9..aad547d3ad8b 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -227,8 +227,11 @@ static inline struct nfs4_delegation *delegstateid(struct nfs4_stid *s) return container_of(s, struct nfs4_delegation, dl_stid); } -/* Maximum number of slots per session. 160 is useful for long haul TCP */ -#define NFSD_MAX_SLOTS_PER_SESSION 160 +/* Maximum number of slots per session. This is for sanity-check only. + * It could be increased if we had a mechanism to shutdown misbehaving clients. + * A large number can be needed to get good throughput on high-latency servers. + */ +#define NFSD_MAX_SLOTS_PER_SESSION 2048 /* Maximum session per slot cache size */ #define NFSD_SLOT_CACHE_SIZE 2048 /* Maximum number of NFSD_SLOT_CACHE_SIZE slots per session */ @@ -327,7 +330,7 @@ struct nfsd4_session { struct nfsd4_cb_sec se_cb_sec; struct list_head se_conns; u32 se_cb_seq_nr[NFSD_BC_SLOT_TABLE_SIZE]; - struct nfsd4_slot *se_slots[]; /* forward channel slots */ + struct xarray se_slots; /* forward channel slots */ }; /* formatted contents of nfs4_sessionid */ From patchwork Fri Dec 6 00:43:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 13896169 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 30A1C1EEF9 for ; 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Fri, 6 Dec 2024 00:49:04 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id N5zBKQBKUmfhDQAAD6G6ig (envelope-from ); Fri, 06 Dec 2024 00:49:04 +0000 From: NeilBrown To: Chuck Lever , Jeff Layton Cc: linux-nfs@vger.kernel.org, Olga Kornievskaia , Dai Ngo , Tom Talpey Subject: [PATCH 2/6] nfsd: remove artificial limits on the session-based DRC Date: Fri, 6 Dec 2024 11:43:16 +1100 Message-ID: <20241206004829.3497925-3-neilb@suse.de> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241206004829.3497925-1-neilb@suse.de> References: <20241206004829.3497925-1-neilb@suse.de> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: 23B062118A X-Spam-Level: X-Spamd-Result: default: False [-3.01 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns]; FROM_HAS_DN(0.00)[]; ASN(0.00)[asn:25478, ipnet:::/0, country:RU]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; R_RATELIMIT(0.00)[from(RLewrxuus8mos16izbn)]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; DKIM_TRACE(0.00)[suse.de:+] X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Action: no action X-Spam-Score: -3.01 X-Spam-Flag: NO Rather than guessing how much space it might be safe to use for the DRC, simply try allocating slots and be prepared to accept failure. The first slot for each session is allocated with GFP_KERNEL which is unlikely to fail. Subsequent slots are allocated with the addition of __GFP_NORETRY which is expected to fail if there isn't much free memory. This is probably too aggressive but clears the way for adding a shrinker interface to free extra slots when memory is tight. Signed-off-by: NeilBrown --- fs/nfsd/nfs4state.c | 94 ++++++++------------------------------------- fs/nfsd/nfsd.h | 3 -- fs/nfsd/nfssvc.c | 32 --------------- 3 files changed, 16 insertions(+), 113 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index aa4f1293d4d3..808cb0d897d5 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1938,65 +1938,13 @@ static inline u32 slot_bytes(struct nfsd4_channel_attrs *ca) return size + sizeof(struct nfsd4_slot); } -/* - * XXX: If we run out of reserved DRC memory we could (up to a point) - * re-negotiate active sessions and reduce their slot usage to make - * room for new connections. For now we just fail the create session. - */ -static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca, struct nfsd_net *nn) -{ - u32 slotsize = slot_bytes(ca); - u32 num = ca->maxreqs; - unsigned long avail, total_avail; - unsigned int scale_factor; - - spin_lock(&nfsd_drc_lock); - if (nfsd_drc_max_mem > nfsd_drc_mem_used) - total_avail = nfsd_drc_max_mem - nfsd_drc_mem_used; - else - /* We have handed out more space than we chose in - * set_max_drc() to allow. That isn't really a - * problem as long as that doesn't make us think we - * have lots more due to integer overflow. - */ - total_avail = 0; - avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION, total_avail); - /* - * Never use more than a fraction of the remaining memory, - * unless it's the only way to give this client a slot. - * The chosen fraction is either 1/8 or 1/number of threads, - * whichever is smaller. This ensures there are adequate - * slots to support multiple clients per thread. - * Give the client one slot even if that would require - * over-allocation--it is better than failure. - */ - scale_factor = max_t(unsigned int, 8, nn->nfsd_serv->sv_nrthreads); - - avail = clamp_t(unsigned long, avail, slotsize, - total_avail/scale_factor); - num = min_t(int, num, avail / slotsize); - num = max_t(int, num, 1); - nfsd_drc_mem_used += num * slotsize; - spin_unlock(&nfsd_drc_lock); - - return num; -} - -static void nfsd4_put_drc_mem(struct nfsd4_channel_attrs *ca) -{ - int slotsize = slot_bytes(ca); - - spin_lock(&nfsd_drc_lock); - nfsd_drc_mem_used -= slotsize * ca->maxreqs; - spin_unlock(&nfsd_drc_lock); -} - static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs, struct nfsd4_channel_attrs *battrs) { int numslots = fattrs->maxreqs; int slotsize = slot_bytes(fattrs); struct nfsd4_session *new; + struct nfsd4_slot *slot; int i; new = kzalloc(sizeof(*new), GFP_KERNEL); @@ -2004,17 +1952,21 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs, return NULL; xa_init(&new->se_slots); /* allocate each struct nfsd4_slot and data cache in one piece */ - for (i = 0; i < numslots; i++) { - struct nfsd4_slot *slot; - slot = kzalloc(slotsize, GFP_KERNEL); + slot = kzalloc(slotsize, GFP_KERNEL); + if (!slot || xa_is_err(xa_store(&new->se_slots, 0, slot, GFP_KERNEL))) + goto out_free; + + for (i = 1; i < numslots; i++) { + const gfp_t gfp = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN; + slot = kzalloc(slotsize, gfp); if (!slot) - goto out_free; - if (xa_is_err(xa_store(&new->se_slots, i, slot, GFP_KERNEL))) { + break; + if (xa_is_err(xa_store(&new->se_slots, i, slot, gfp))) { kfree(slot); - goto out_free; + break; } } - + fattrs->maxreqs = i; memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs)); new->se_cb_slot_avail = ~0U; new->se_cb_highest_slot = min(battrs->maxreqs - 1, @@ -2022,8 +1974,7 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs, spin_lock_init(&new->se_lock); return new; out_free: - while (i--) - kfree(xa_load(&new->se_slots, i)); + kfree(slot); xa_destroy(&new->se_slots); kfree(new); return NULL; @@ -2138,7 +2089,6 @@ static void __free_session(struct nfsd4_session *ses) static void free_session(struct nfsd4_session *ses) { nfsd4_del_conns(ses); - nfsd4_put_drc_mem(&ses->se_fchannel); __free_session(ses); } @@ -3786,17 +3736,6 @@ static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca, struct nfs ca->maxresp_cached = min_t(u32, ca->maxresp_cached, NFSD_SLOT_CACHE_SIZE + NFSD_MIN_HDR_SEQ_SZ); ca->maxreqs = min_t(u32, ca->maxreqs, NFSD_MAX_SLOTS_PER_SESSION); - /* - * Note decreasing slot size below client's request may make it - * difficult for client to function correctly, whereas - * decreasing the number of slots will (just?) affect - * performance. When short on memory we therefore prefer to - * decrease number of slots instead of their size. Clients that - * request larger slots than they need will get poor results: - * Note that we always allow at least one slot, because our - * accounting is soft and provides no guarantees either way. - */ - ca->maxreqs = nfsd4_get_drc_mem(ca, nn); return nfs_ok; } @@ -3874,11 +3813,11 @@ nfsd4_create_session(struct svc_rqst *rqstp, return status; status = check_backchannel_attrs(&cr_ses->back_channel); if (status) - goto out_release_drc_mem; + goto out_err; status = nfserr_jukebox; new = alloc_session(&cr_ses->fore_channel, &cr_ses->back_channel); if (!new) - goto out_release_drc_mem; + goto out_err; conn = alloc_conn_from_crses(rqstp, cr_ses); if (!conn) goto out_free_session; @@ -3987,8 +3926,7 @@ nfsd4_create_session(struct svc_rqst *rqstp, free_conn(conn); out_free_session: __free_session(new); -out_release_drc_mem: - nfsd4_put_drc_mem(&cr_ses->fore_channel); +out_err: return status; } diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 4b56ba1e8e48..3eb21e63b921 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -88,9 +88,6 @@ struct nfsd_genl_rqstp { extern struct svc_program nfsd_programs[]; extern const struct svc_version nfsd_version2, nfsd_version3, nfsd_version4; extern struct mutex nfsd_mutex; -extern spinlock_t nfsd_drc_lock; -extern unsigned long nfsd_drc_max_mem; -extern unsigned long nfsd_drc_mem_used; extern atomic_t nfsd_th_cnt; /* number of available threads */ extern const struct seq_operations nfs_exports_op; diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 49e2f32102ab..3dbaefc96608 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -70,16 +70,6 @@ static __be32 nfsd_init_request(struct svc_rqst *, */ DEFINE_MUTEX(nfsd_mutex); -/* - * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used. - * nfsd_drc_max_pages limits the total amount of memory available for - * version 4.1 DRC caches. - * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage. - */ -DEFINE_SPINLOCK(nfsd_drc_lock); -unsigned long nfsd_drc_max_mem; -unsigned long nfsd_drc_mem_used; - #if IS_ENABLED(CONFIG_NFS_LOCALIO) static const struct svc_version *localio_versions[] = { [1] = &localio_version1, @@ -575,27 +565,6 @@ void nfsd_reset_versions(struct nfsd_net *nn) } } -/* - * Each session guarantees a negotiated per slot memory cache for replies - * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated - * NFSv4.1 server might want to use more memory for a DRC than a machine - * with mutiple services. - * - * Impose a hard limit on the number of pages for the DRC which varies - * according to the machines free pages. This is of course only a default. - * - * For now this is a #defined shift which could be under admin control - * in the future. - */ -static void set_max_drc(void) -{ - #define NFSD_DRC_SIZE_SHIFT 7 - nfsd_drc_max_mem = (nr_free_buffer_pages() - >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE; - nfsd_drc_mem_used = 0; - dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem); -} - static int nfsd_get_default_max_blksize(void) { struct sysinfo i; @@ -678,7 +647,6 @@ int nfsd_create_serv(struct net *net) nn->nfsd_serv = serv; spin_unlock(&nfsd_notifier_lock); - set_max_drc(); /* check if the notifier is already set */ if (atomic_inc_return(&nfsd_notifier_refcount) == 1) { register_inetaddr_notifier(&nfsd_inetaddr_notifier); From patchwork Fri Dec 6 00:43:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 13896170 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A1A9BE46 for ; 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Fri, 6 Dec 2024 00:49:18 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id A38bEA5KUmfpDQAAD6G6ig (envelope-from ); Fri, 06 Dec 2024 00:49:18 +0000 From: NeilBrown To: Chuck Lever , Jeff Layton Cc: linux-nfs@vger.kernel.org, Olga Kornievskaia , Dai Ngo , Tom Talpey Subject: [PATCH 3/6] nfsd: add session slot count to /proc/fs/nfsd/clients/*/info Date: Fri, 6 Dec 2024 11:43:17 +1100 Message-ID: <20241206004829.3497925-4-neilb@suse.de> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241206004829.3497925-1-neilb@suse.de> References: <20241206004829.3497925-1-neilb@suse.de> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: A6C93210FB X-Spam-Level: X-Spamd-Result: default: False [-3.01 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; 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Signed-off-by: NeilBrown --- fs/nfsd/nfs4state.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 808cb0d897d5..67dfc699e411 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2643,6 +2643,7 @@ static const char *cb_state2str(int state) static int client_info_show(struct seq_file *m, void *v) { struct inode *inode = file_inode(m->file); + struct nfsd4_session *ses; struct nfs4_client *clp; u64 clid; @@ -2679,6 +2680,13 @@ static int client_info_show(struct seq_file *m, void *v) seq_printf(m, "callback address: \"%pISpc\"\n", &clp->cl_cb_conn.cb_addr); seq_printf(m, "admin-revoked states: %d\n", atomic_read(&clp->cl_admin_revoked)); + spin_lock(&clp->cl_lock); + seq_printf(m, "session slots:"); + list_for_each_entry(ses, &clp->cl_sessions, se_perclnt) + seq_printf(m, " %u", ses->se_fchannel.maxreqs); + spin_unlock(&clp->cl_lock); + seq_puts(m, "\n"); + drop_client(clp); return 0; From patchwork Fri Dec 6 00:43:18 2024 Content-Type: text/plain; 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Date: Fri, 6 Dec 2024 11:43:18 +1100 Message-ID: <20241206004829.3497925-5-neilb@suse.de> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241206004829.3497925-1-neilb@suse.de> References: <20241206004829.3497925-1-neilb@suse.de> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: 43FAD1F37C X-Spam-Level: X-Spamd-Result: default: False [-3.01 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns]; ASN(0.00)[asn:25478, ipnet:::/0, country:RU]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; MIME_TRACE(0.00)[0:+]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; DKIM_TRACE(0.00)[suse.de:+] X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Action: no action X-Spam-Score: -3.01 X-Spam-Flag: NO If a client ever uses the highest available slot for a given session, attempt to allocate more slots so there is room for the client to use them if wanted. GFP_NOWAIT is used so if there is not plenty of free memory, failure is expected - which is what we want. It also allows the allocation while holding a spinlock. Each time we increase the number of slots by 20% (rounded up). This allows fairly quick growth while avoiding excessive over-shoot. We would expect to stablise with around 10% more slots available than the client actually uses. Signed-off-by: NeilBrown --- fs/nfsd/nfs4state.c | 40 +++++++++++++++++++++++++++++++++++----- 1 file changed, 35 insertions(+), 5 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 67dfc699e411..ec4468ebbd40 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4235,11 +4235,6 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, slot = xa_load(&session->se_slots, seq->slotid); dprintk("%s: slotid %d\n", __func__, seq->slotid); - /* We do not negotiate the number of slots yet, so set the - * maxslots to the session maxreqs which is used to encode - * sr_highest_slotid and the sr_target_slot id to maxslots */ - seq->maxslots = session->se_fchannel.maxreqs; - trace_nfsd_slot_seqid_sequence(clp, seq, slot); status = check_slot_seqid(seq->seqid, slot->sl_seqid, slot->sl_flags & NFSD4_SLOT_INUSE); @@ -4289,6 +4284,41 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, cstate->session = session; cstate->clp = clp; + /* + * If the client ever uses the highest available slot, + * gently try to allocate another 20%. This allows + * fairly quick growth without grossly over-shooting what + * the client might use. + */ + if (seq->slotid == session->se_fchannel.maxreqs - 1 && + session->se_fchannel.maxreqs < NFSD_MAX_SLOTS_PER_SESSION) { + int s = session->se_fchannel.maxreqs; + int cnt = DIV_ROUND_UP(s, 5); + + do { + /* + * GFP_NOWAIT is a low-priority non-blocking + * allocation which can be used under + * client_lock and only succeeds if there is + * plenty of memory. + * Use GFP_ATOMIC which is higher priority for + * xa_store() so we are less likely to waste the + * effort of the first allocation. + */ + slot = kzalloc(slot_bytes(&session->se_fchannel), + GFP_NOWAIT); + if (slot && + !xa_is_err(xa_store(&session->se_slots, s, slot, + GFP_ATOMIC | __GFP_NOWARN))) { + s += 1; + session->se_fchannel.maxreqs = s; + } else { + kfree(slot); + } + } while (slot && --cnt > 0); + } + seq->maxslots = session->se_fchannel.maxreqs; + out: switch (clp->cl_cb_state) { case NFSD4_CB_DOWN: From patchwork Fri Dec 6 00:43:19 2024 Content-Type: text/plain; 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Fri, 6 Dec 2024 00:49:48 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id djSRHSxKUmcLDgAAD6G6ig (envelope-from ); Fri, 06 Dec 2024 00:49:48 +0000 From: NeilBrown To: Chuck Lever , Jeff Layton Cc: linux-nfs@vger.kernel.org, Olga Kornievskaia , Dai Ngo , Tom Talpey Subject: [PATCH 5/6] nfsd: add support for freeing unused session-DRC slots Date: Fri, 6 Dec 2024 11:43:19 +1100 Message-ID: <20241206004829.3497925-6-neilb@suse.de> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241206004829.3497925-1-neilb@suse.de> References: <20241206004829.3497925-1-neilb@suse.de> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: 392FD1F37C X-Spam-Level: X-Spamd-Result: default: False [-3.01 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; 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This patch adds reduce_session_slots() which starts the process of getting confirmation, but never calls it. That will come in a later patch. Before we can free a slot we need to confirm that the client won't try to use it again. This involves returning a lower cr_maxrequests in a SEQUENCE reply and then seeing a ca_maxrequests on the same slot which is not larger than we limit we are trying to impose. So for each slot we need to remember that we have sent a reduced cr_maxrequests. To achieve this we introduce a concept of request "generations". Each time we decide to reduce cr_maxrequests we increment the generation number, and record this when we return the lower cr_maxrequests to the client. When a slot with the current generation reports a low ca_maxrequests, we commit to that level and free extra slots. We use an 8 bit generation number (64 seems wasteful) and if it cycles we iterate all slots and reset the generation number to avoid false matches. When we free a slot we store the seqid in the slot pointer so that it can be restored when we reactivate the slot. The RFC can be read as suggesting that the slot number could restart from one after a slot is retired and reactivated, but also suggests that retiring slots is not required. So when we reactive a slot we accept with the next seqid in sequence, or 1. When decoding sa_highest_slotid into maxslots we need to add 1 - this matches how it is encoded for the reply. Signed-off-by: NeilBrown --- fs/nfsd/nfs4state.c | 80 +++++++++++++++++++++++++++++++++++++++------ fs/nfsd/nfs4xdr.c | 5 +-- fs/nfsd/state.h | 4 +++ fs/nfsd/xdr4.h | 2 -- 4 files changed, 77 insertions(+), 14 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index ec4468ebbd40..e73668462739 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1910,17 +1910,54 @@ gen_sessionid(struct nfsd4_session *ses) #define NFSD_MIN_HDR_SEQ_SZ (24 + 12 + 44) static void -free_session_slots(struct nfsd4_session *ses) +free_session_slots(struct nfsd4_session *ses, int from) { int i; - for (i = 0; i < ses->se_fchannel.maxreqs; i++) { + if (from >= ses->se_fchannel.maxreqs) + return; + + for (i = from; i < ses->se_fchannel.maxreqs; i++) { struct nfsd4_slot *slot = xa_load(&ses->se_slots, i); - xa_erase(&ses->se_slots, i); + /* + * Save the seqid in case we reactivate this slot. + * This will never require a memory allocation so GFP + * flag is irrelevant + */ + xa_store(&ses->se_slots, i, xa_mk_value(slot->sl_seqid), 0); free_svc_cred(&slot->sl_cred); kfree(slot); } + ses->se_fchannel.maxreqs = from; + if (ses->se_target_maxslots > from) + ses->se_target_maxslots = from; +} + +static int __maybe_unused +reduce_session_slots(struct nfsd4_session *ses, int dec) +{ + struct nfsd_net *nn = net_generic(ses->se_client->net, + nfsd_net_id); + int ret = 0; + + if (ses->se_target_maxslots <= 1) + return ret; + if (!spin_trylock(&nn->client_lock)) + return ret; + ret = min(dec, ses->se_target_maxslots-1); + ses->se_target_maxslots -= ret; + ses->se_slot_gen += 1; + if (ses->se_slot_gen == 0) { + int i; + ses->se_slot_gen = 1; + for (i = 0; i < ses->se_fchannel.maxreqs; i++) { + struct nfsd4_slot *slot = xa_load(&ses->se_slots, i); + slot->sl_generation = 0; + } + } + spin_unlock(&nn->client_lock); + return ret; } /* @@ -1968,6 +2005,7 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs, } fattrs->maxreqs = i; memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs)); + new->se_target_maxslots = i; new->se_cb_slot_avail = ~0U; new->se_cb_highest_slot = min(battrs->maxreqs - 1, NFSD_BC_SLOT_TABLE_SIZE - 1); @@ -2081,7 +2119,7 @@ static void nfsd4_del_conns(struct nfsd4_session *s) static void __free_session(struct nfsd4_session *ses) { - free_session_slots(ses); + free_session_slots(ses, 0); xa_destroy(&ses->se_slots); kfree(ses); } @@ -2684,6 +2722,9 @@ static int client_info_show(struct seq_file *m, void *v) seq_printf(m, "session slots:"); list_for_each_entry(ses, &clp->cl_sessions, se_perclnt) seq_printf(m, " %u", ses->se_fchannel.maxreqs); + seq_printf(m, "\nsession target slots:"); + list_for_each_entry(ses, &clp->cl_sessions, se_perclnt) + seq_printf(m, " %u", ses->se_target_maxslots); spin_unlock(&clp->cl_lock); seq_puts(m, "\n"); @@ -3674,10 +3715,10 @@ nfsd4_exchange_id_release(union nfsd4_op_u *u) kfree(exid->server_impl_name); } -static __be32 check_slot_seqid(u32 seqid, u32 slot_seqid, bool slot_inuse) +static __be32 check_slot_seqid(u32 seqid, u32 slot_seqid, u8 flags) { /* The slot is in use, and no response has been sent. */ - if (slot_inuse) { + if (flags & NFSD4_SLOT_INUSE) { if (seqid == slot_seqid) return nfserr_jukebox; else @@ -3686,6 +3727,8 @@ static __be32 check_slot_seqid(u32 seqid, u32 slot_seqid, bool slot_inuse) /* Note unsigned 32-bit arithmetic handles wraparound: */ if (likely(seqid == slot_seqid + 1)) return nfs_ok; + if ((flags & NFSD4_SLOT_REUSED) && seqid == 1) + return nfs_ok; if (seqid == slot_seqid) return nfserr_replay_cache; return nfserr_seq_misordered; @@ -4236,8 +4279,7 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, dprintk("%s: slotid %d\n", __func__, seq->slotid); trace_nfsd_slot_seqid_sequence(clp, seq, slot); - status = check_slot_seqid(seq->seqid, slot->sl_seqid, - slot->sl_flags & NFSD4_SLOT_INUSE); + status = check_slot_seqid(seq->seqid, slot->sl_seqid, slot->sl_flags); if (status == nfserr_replay_cache) { status = nfserr_seq_misordered; if (!(slot->sl_flags & NFSD4_SLOT_INITIALIZED)) @@ -4262,6 +4304,12 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, if (status) goto out_put_session; + if (session->se_target_maxslots < session->se_fchannel.maxreqs && + slot->sl_generation == session->se_slot_gen && + seq->maxslots <= session->se_target_maxslots) + /* Client acknowledged our reduce maxreqs */ + free_session_slots(session, session->se_target_maxslots); + buflen = (seq->cachethis) ? session->se_fchannel.maxresp_cached : session->se_fchannel.maxresp_sz; @@ -4272,9 +4320,11 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, svc_reserve(rqstp, buflen); status = nfs_ok; - /* Success! bump slot seqid */ + /* Success! accept new slot seqid */ slot->sl_seqid = seq->seqid; + slot->sl_flags &= ~NFSD4_SLOT_REUSED; slot->sl_flags |= NFSD4_SLOT_INUSE; + slot->sl_generation = session->se_slot_gen; if (seq->cachethis) slot->sl_flags |= NFSD4_SLOT_CACHETHIS; else @@ -4291,9 +4341,11 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, * the client might use. */ if (seq->slotid == session->se_fchannel.maxreqs - 1 && + session->se_target_maxslots >= session->se_fchannel.maxreqs && session->se_fchannel.maxreqs < NFSD_MAX_SLOTS_PER_SESSION) { int s = session->se_fchannel.maxreqs; int cnt = DIV_ROUND_UP(s, 5); + void *prev_slot; do { /* @@ -4307,17 +4359,25 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, */ slot = kzalloc(slot_bytes(&session->se_fchannel), GFP_NOWAIT); + prev_slot = xa_load(&session->se_slots, s); + if (xa_is_value(prev_slot) && slot) { + slot->sl_seqid = xa_to_value(prev_slot); + slot->sl_flags |= NFSD4_SLOT_REUSED; + } if (slot && !xa_is_err(xa_store(&session->se_slots, s, slot, GFP_ATOMIC | __GFP_NOWARN))) { s += 1; session->se_fchannel.maxreqs = s; + session->se_target_maxslots = s; } else { kfree(slot); + slot = NULL; } } while (slot && --cnt > 0); } - seq->maxslots = session->se_fchannel.maxreqs; + seq->maxslots = max(session->se_target_maxslots, seq->maxslots); + seq->target_maxslots = session->se_target_maxslots; out: switch (clp->cl_cb_state) { diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 53fac037611c..4dcb03cd9292 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1884,7 +1884,8 @@ nfsd4_decode_sequence(struct nfsd4_compoundargs *argp, return nfserr_bad_xdr; seq->seqid = be32_to_cpup(p++); seq->slotid = be32_to_cpup(p++); - seq->maxslots = be32_to_cpup(p++); + /* sa_highest_slotid counts from 0 but maxslots counts from 1 ... */ + seq->maxslots = be32_to_cpup(p++) + 1; seq->cachethis = be32_to_cpup(p); seq->status_flags = 0; @@ -4968,7 +4969,7 @@ nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr, if (nfserr != nfs_ok) return nfserr; /* sr_target_highest_slotid */ - nfserr = nfsd4_encode_slotid4(xdr, seq->maxslots - 1); + nfserr = nfsd4_encode_slotid4(xdr, seq->target_maxslots - 1); if (nfserr != nfs_ok) return nfserr; /* sr_status_flags */ diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index aad547d3ad8b..74f2ab3c95aa 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -249,7 +249,9 @@ struct nfsd4_slot { #define NFSD4_SLOT_CACHETHIS (1 << 1) #define NFSD4_SLOT_INITIALIZED (1 << 2) #define NFSD4_SLOT_CACHED (1 << 3) +#define NFSD4_SLOT_REUSED (1 << 4) u8 sl_flags; + u8 sl_generation; char sl_data[]; }; @@ -331,6 +333,8 @@ struct nfsd4_session { struct list_head se_conns; u32 se_cb_seq_nr[NFSD_BC_SLOT_TABLE_SIZE]; struct xarray se_slots; /* forward channel slots */ + u8 se_slot_gen; + u32 se_target_maxslots; }; /* formatted contents of nfs4_sessionid */ diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h index 382cc1389396..c26ba86dbdfd 100644 --- a/fs/nfsd/xdr4.h +++ b/fs/nfsd/xdr4.h @@ -576,9 +576,7 @@ struct nfsd4_sequence { u32 slotid; 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Fri, 06 Dec 2024 00:49:54 +0000 From: NeilBrown To: Chuck Lever , Jeff Layton Cc: linux-nfs@vger.kernel.org, Olga Kornievskaia , Dai Ngo , Tom Talpey Subject: [PATCH 6/6] nfsd: add shrinker to reduce number of slots allocated per session Date: Fri, 6 Dec 2024 11:43:20 +1100 Message-ID: <20241206004829.3497925-7-neilb@suse.de> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241206004829.3497925-1-neilb@suse.de> References: <20241206004829.3497925-1-neilb@suse.de> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Level: X-Spamd-Result: default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_VIA_SMTP_AUTH(0.00)[]; MIME_TRACE(0.00)[0:+]; R_RATELIMIT(0.00)[from(RLewrxuus8mos16izbn)]; ARC_NA(0.00)[]; TO_DN_SOME(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo]; RCVD_TLS_ALL(0.00)[] X-Spam-Score: -2.80 X-Spam-Flag: NO Add a shrinker which frees unused slots and may ask the clients to use fewer slots on each session. We keep a global count of the number of freeable slots, which is the sum of one less than the current "target" slots in all sessions in all clients in all net-namespaces. This number is reported by the shrinker. When the shrinker is asked to free some, we call xxx on each session in a round-robin asking each to reduce the slot count by 1. This will reduce the "target" so the number reported by the shrinker will reduce immediately. The memory will only be freed later when the client confirmed that it is no longer needed. We use a global list of sessions and move the "head" to after the last session that we asked to reduce, so the next callback from the shrinker will move on to the next session. This pressure should be applied "evenly" across all sessions over time. Signed-off-by: NeilBrown --- fs/nfsd/nfs4state.c | 71 ++++++++++++++++++++++++++++++++++++++++++--- fs/nfsd/state.h | 1 + 2 files changed, 68 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index e73668462739..d7bccc237027 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1909,6 +1909,16 @@ gen_sessionid(struct nfsd4_session *ses) */ #define NFSD_MIN_HDR_SEQ_SZ (24 + 12 + 44) +static struct shrinker *nfsd_slot_shrinker; +static DEFINE_SPINLOCK(nfsd_session_list_lock); +static LIST_HEAD(nfsd_session_list); +/* The sum of "target_slots-1" on every session. The shrinker can push this + * down, though it can take a little while for the memory to actually + * be freed. The "-1" is because we can never free slot 0 while the + * session is active. + */ +static atomic_t nfsd_total_target_slots = ATOMIC_INIT(0); + static void free_session_slots(struct nfsd4_session *ses, int from) { @@ -1930,11 +1940,14 @@ free_session_slots(struct nfsd4_session *ses, int from) kfree(slot); } ses->se_fchannel.maxreqs = from; - if (ses->se_target_maxslots > from) - ses->se_target_maxslots = from; + if (ses->se_target_maxslots > from) { + int new_target = from ?: 1; + atomic_sub(ses->se_target_maxslots - new_target, &nfsd_total_target_slots); + ses->se_target_maxslots = new_target; + } } -static int __maybe_unused +static int reduce_session_slots(struct nfsd4_session *ses, int dec) { struct nfsd_net *nn = net_generic(ses->se_client->net, @@ -1947,6 +1960,7 @@ reduce_session_slots(struct nfsd4_session *ses, int dec) return ret; ret = min(dec, ses->se_target_maxslots-1); ses->se_target_maxslots -= ret; + atomic_sub(ret, &nfsd_total_target_slots); ses->se_slot_gen += 1; if (ses->se_slot_gen == 0) { int i; @@ -2006,6 +2020,7 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs, fattrs->maxreqs = i; memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs)); new->se_target_maxslots = i; + atomic_add(i - 1, &nfsd_total_target_slots); new->se_cb_slot_avail = ~0U; new->se_cb_highest_slot = min(battrs->maxreqs - 1, NFSD_BC_SLOT_TABLE_SIZE - 1); @@ -2130,6 +2145,36 @@ static void free_session(struct nfsd4_session *ses) __free_session(ses); } +static unsigned long +nfsd_slot_count(struct shrinker *s, struct shrink_control *sc) +{ + unsigned long cnt = atomic_read(&nfsd_total_target_slots); + + return cnt ? cnt : SHRINK_EMPTY; +} + +static unsigned long +nfsd_slot_scan(struct shrinker *s, struct shrink_control *sc) +{ + struct nfsd4_session *ses; + unsigned long scanned = 0; + unsigned long freed = 0; + + spin_lock(&nfsd_session_list_lock); + list_for_each_entry(ses, &nfsd_session_list, se_all_sessions) { + freed += reduce_session_slots(ses, 1); + scanned += 1; + if (scanned >= sc->nr_to_scan) { + /* Move starting point for next scan */ + list_move(&nfsd_session_list, &ses->se_all_sessions); + break; + } + } + spin_unlock(&nfsd_session_list_lock); + sc->nr_scanned = scanned; + return freed; +} + static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, struct nfs4_client *clp, struct nfsd4_create_session *cses) { int idx; @@ -2154,6 +2199,10 @@ static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, stru list_add(&new->se_perclnt, &clp->cl_sessions); spin_unlock(&clp->cl_lock); + spin_lock(&nfsd_session_list_lock); + list_add_tail(&new->se_all_sessions, &nfsd_session_list); + spin_unlock(&nfsd_session_list_lock); + { struct sockaddr *sa = svc_addr(rqstp); /* @@ -2223,6 +2272,9 @@ unhash_session(struct nfsd4_session *ses) spin_lock(&ses->se_client->cl_lock); list_del(&ses->se_perclnt); spin_unlock(&ses->se_client->cl_lock); + spin_lock(&nfsd_session_list_lock); + list_del(&ses->se_all_sessions); + spin_unlock(&nfsd_session_list_lock); } /* SETCLIENTID and SETCLIENTID_CONFIRM Helper functions */ @@ -4369,6 +4421,8 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, GFP_ATOMIC | __GFP_NOWARN))) { s += 1; session->se_fchannel.maxreqs = s; + atomic_add(s - session->se_target_maxslots, + &nfsd_total_target_slots); session->se_target_maxslots = s; } else { kfree(slot); @@ -8765,7 +8819,6 @@ nfs4_state_start_net(struct net *net) } /* initialization to perform when the nfsd service is started: */ - int nfs4_state_start(void) { @@ -8775,6 +8828,15 @@ nfs4_state_start(void) if (ret) return ret; + nfsd_slot_shrinker = shrinker_alloc(0, "nfsd-DRC-slot"); + if (!nfsd_slot_shrinker) { + rhltable_destroy(&nfs4_file_rhltable); + return -ENOMEM; + } + nfsd_slot_shrinker->count_objects = nfsd_slot_count; + nfsd_slot_shrinker->scan_objects = nfsd_slot_scan; + shrinker_register(nfsd_slot_shrinker); + set_max_delegations(); return 0; } @@ -8816,6 +8878,7 @@ void nfs4_state_shutdown(void) { rhltable_destroy(&nfs4_file_rhltable); + shrinker_free(nfsd_slot_shrinker); } static void diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 74f2ab3c95aa..a4ce2cf3d6a3 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -326,6 +326,7 @@ struct nfsd4_session { bool se_dead; struct list_head se_hash; /* hash by sessionid */ struct list_head se_perclnt; + struct list_head se_all_sessions;/* global list of sessions */ struct nfs4_client *se_client; struct nfs4_sessionid se_sessionid; struct nfsd4_channel_attrs se_fchannel;