From 55c760cfc40d75b4d8a17d56580ec306db2ab14f Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Mon, 8 Apr 2013 16:44:14 -0400 Subject: [PATCH] nfsd4: fix forechannel attribute negotiation Negotiation of the 4.1 session forechannel attributes is a mess. Fix: - Move it all into check_forechannel_attrs instead of spreading it between that, alloc_session, and init_forechannel_attrs. - set a minimum "slotsize" so that our drc memory limits apply even for small maxresponsesize_cached. This also fixes some bugs when slotsize becomes <= 0. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 116 +++++++++++++++++++------------------------- 1 file changed, 49 insertions(+), 67 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index f1262f73f08b..036d5f16fd7f 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -776,17 +776,15 @@ free_session_slots(struct nfsd4_session *ses) * We don't actually need to cache the rpc and session headers, so we * can allocate a little less for each slot: */ -static inline int slot_bytes(struct nfsd4_channel_attrs *ca) +static inline u32 slot_bytes(struct nfsd4_channel_attrs *ca) { - return ca->maxresp_cached - NFSD_MIN_HDR_SEQ_SZ; -} - -static int nfsd4_sanitize_slot_size(u32 size) -{ - size -= NFSD_MIN_HDR_SEQ_SZ; /* We don't cache the rpc header */ - size = min_t(u32, size, NFSD_SLOT_CACHE_SIZE); + u32 size; - return size; + if (ca->maxresp_cached < NFSD_MIN_HDR_SEQ_SZ) + size = 0; + else + size = ca->maxresp_cached - NFSD_MIN_HDR_SEQ_SZ; + return size + sizeof(struct nfsd4_slot); } /* @@ -794,12 +792,12 @@ static int nfsd4_sanitize_slot_size(u32 size) * re-negotiate active sessions and reduce their slot usage to make * room for new connections. For now we just fail the create session. */ -static int nfsd4_get_drc_mem(int slotsize, u32 num) +static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca) { + u32 slotsize = slot_bytes(ca); + u32 num = ca->maxreqs; int avail; - num = min_t(u32, num, NFSD_MAX_SLOTS_PER_SESSION); - spin_lock(&nfsd_drc_lock); avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION, nfsd_drc_max_mem - nfsd_drc_mem_used); @@ -810,15 +808,19 @@ static int nfsd4_get_drc_mem(int slotsize, u32 num) return num; } -static void nfsd4_put_drc_mem(int slotsize, int 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 * num; + nfsd_drc_mem_used -= slotsize * ca->maxreqs; spin_unlock(&nfsd_drc_lock); } -static struct nfsd4_session *__alloc_session(int slotsize, int numslots) +static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *attrs) { + int numslots = attrs->maxreqs; + int slotsize = slot_bytes(attrs); struct nfsd4_session *new; int mem, i; @@ -831,8 +833,7 @@ static struct nfsd4_session *__alloc_session(int slotsize, int numslots) return NULL; /* allocate each struct nfsd4_slot and data cache in one piece */ for (i = 0; i < numslots; i++) { - mem = sizeof(struct nfsd4_slot) + slotsize; - new->se_slots[i] = kzalloc(mem, GFP_KERNEL); + new->se_slots[i] = kzalloc(slotsize, GFP_KERNEL); if (!new->se_slots[i]) goto out_free; } @@ -844,21 +845,6 @@ out_free: return NULL; } -static void init_forechannel_attrs(struct nfsd4_channel_attrs *new, - struct nfsd4_channel_attrs *req, - int numslots, int slotsize, - struct nfsd_net *nn) -{ - u32 maxrpc = nn->nfsd_serv->sv_max_mesg; - - new->maxreqs = numslots; - new->maxresp_cached = min_t(u32, req->maxresp_cached, - slotsize + NFSD_MIN_HDR_SEQ_SZ); - new->maxreq_sz = min_t(u32, req->maxreq_sz, maxrpc); - new->maxresp_sz = min_t(u32, req->maxresp_sz, maxrpc); - new->maxops = min_t(u32, req->maxops, NFSD_MAX_OPS_PER_COMPOUND); -} - static void free_conn(struct nfsd4_conn *c) { svc_xprt_put(c->cn_xprt); @@ -960,7 +946,6 @@ static void nfsd4_del_conns(struct nfsd4_session *s) static void __free_session(struct nfsd4_session *ses) { - nfsd4_put_drc_mem(slot_bytes(&ses->se_fchannel), ses->se_fchannel.maxreqs); free_session_slots(ses); kfree(ses); } @@ -971,35 +956,10 @@ static void free_session(struct nfsd4_session *ses) lockdep_assert_held(&nn->client_lock); nfsd4_del_conns(ses); + nfsd4_put_drc_mem(&ses->se_fchannel); __free_session(ses); } -static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fchan, - struct nfsd_net *nn) -{ - struct nfsd4_session *new; - int numslots, slotsize; - /* - * 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. - */ - slotsize = nfsd4_sanitize_slot_size(fchan->maxresp_cached); - numslots = nfsd4_get_drc_mem(slotsize, fchan->maxreqs); - if (numslots < 1) - return NULL; - - new = __alloc_session(slotsize, numslots); - if (!new) { - nfsd4_put_drc_mem(slotsize, numslots); - return NULL; - } - init_forechannel_attrs(&new->se_fchannel, fchan, numslots, slotsize, nn); - return new; -} - static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, struct nfs4_client *clp, struct nfsd4_create_session *cses) { int idx; @@ -1022,7 +982,8 @@ 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_unlock(&nn->client_lock); - + memcpy(&new->se_fchannel, &cses->fore_channel, + sizeof(struct nfsd4_channel_attrs)); if (cses->flags & SESSION4_BACK_CHAN) { struct sockaddr *sa = svc_addr(rqstp); /* @@ -1803,12 +1764,33 @@ nfsd4_replay_create_session(struct nfsd4_create_session *cr_ses, /* seqid, slotID, slotID, slotID, status */ \ 5 ) * sizeof(__be32)) -static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca) +static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca, struct nfsd_net *nn) { + u32 maxrpc = nn->nfsd_serv->sv_max_mesg; + if (ca->maxreq_sz < NFSD_MIN_REQ_HDR_SEQ_SZ) return nfserr_toosmall; if (ca->maxresp_sz < NFSD_MIN_RESP_HDR_SEQ_SZ) return nfserr_toosmall; + ca->headerpadsz = 0; + ca->maxreq_sz = min_t(u32, ca->maxreq_sz, maxrpc); + ca->maxresp_sz = min_t(u32, ca->maxresp_sz, maxrpc); + ca->maxops = min_t(u32, ca->maxops, NFSD_MAX_OPS_PER_COMPOUND); + 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: + */ + ca->maxreqs = nfsd4_get_drc_mem(ca); + if (!ca->maxreqs) + return nfserr_jukebox; + return nfs_ok; } @@ -1827,13 +1809,13 @@ nfsd4_create_session(struct svc_rqst *rqstp, if (cr_ses->flags & ~SESSION4_FLAG_MASK_A) return nfserr_inval; - status = check_forechannel_attrs(&cr_ses->fore_channel); + status = check_forechannel_attrs(&cr_ses->fore_channel, nn); if (status) return status; - new = alloc_session(&cr_ses->fore_channel, nn); - if (!new) - return nfserr_jukebox; status = nfserr_jukebox; + new = alloc_session(&cr_ses->fore_channel); + if (!new) + goto out_release_drc_mem; conn = alloc_conn_from_crses(rqstp, cr_ses); if (!conn) goto out_free_session; @@ -1892,8 +1874,6 @@ nfsd4_create_session(struct svc_rqst *rqstp, memcpy(cr_ses->sessionid.data, new->se_sessionid.data, NFS4_MAX_SESSIONID_LEN); - memcpy(&cr_ses->fore_channel, &new->se_fchannel, - sizeof(struct nfsd4_channel_attrs)); cs_slot->sl_seqid++; cr_ses->seqid = cs_slot->sl_seqid; @@ -1906,6 +1886,8 @@ out_free_conn: free_conn(conn); out_free_session: __free_session(new); +out_release_drc_mem: + nfsd4_put_drc_mem(&cr_ses->fore_channel); return status; } -- 2.20.1