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Diffstat (limited to 'include/linux/sunrpc/svc.h')
| -rw-r--r-- | include/linux/sunrpc/svc.h | 567 |
1 files changed, 567 insertions, 0 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h new file mode 100644 index 000000000..dbf5b21fe --- /dev/null +++ b/include/linux/sunrpc/svc.h @@ -0,0 +1,567 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * linux/include/linux/sunrpc/svc.h + * + * RPC server declarations. + * + * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> + */ + + +#ifndef SUNRPC_SVC_H +#define SUNRPC_SVC_H + +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/sunrpc/types.h> +#include <linux/sunrpc/xdr.h> +#include <linux/sunrpc/auth.h> +#include <linux/sunrpc/svcauth.h> +#include <linux/wait.h> +#include <linux/mm.h> +#include <linux/pagevec.h> + +/* + * + * RPC service thread pool. + * + * Pool of threads and temporary sockets. Generally there is only + * a single one of these per RPC service, but on NUMA machines those + * services that can benefit from it (i.e. nfs but not lockd) will + * have one pool per NUMA node. This optimisation reduces cross- + * node traffic on multi-node NUMA NFS servers. + */ +struct svc_pool { + unsigned int sp_id; /* pool id; also node id on NUMA */ + spinlock_t sp_lock; /* protects all fields */ + struct list_head sp_sockets; /* pending sockets */ + unsigned int sp_nrthreads; /* # of threads in pool */ + struct list_head sp_all_threads; /* all server threads */ + + /* statistics on pool operation */ + struct percpu_counter sp_messages_arrived; + struct percpu_counter sp_sockets_queued; + struct percpu_counter sp_threads_woken; + + unsigned long sp_flags; +} ____cacheline_aligned_in_smp; + +/* bits for sp_flags */ +enum { + SP_TASK_PENDING, /* still work to do even if no xprt is queued */ + SP_CONGESTED, /* all threads are busy, none idle */ +}; + + +/* + * RPC service. + * + * An RPC service is a ``daemon,'' possibly multithreaded, which + * receives and processes incoming RPC messages. + * It has one or more transport sockets associated with it, and maintains + * a list of idle threads waiting for input. + * + * We currently do not support more than one RPC program per daemon. + */ +struct svc_serv { + struct svc_program * sv_program; /* RPC program */ + struct svc_stat * sv_stats; /* RPC statistics */ + spinlock_t sv_lock; + struct kref sv_refcnt; + unsigned int sv_nrthreads; /* # of server threads */ + unsigned int sv_maxconn; /* max connections allowed or + * '0' causing max to be based + * on number of threads. */ + + unsigned int sv_max_payload; /* datagram payload size */ + unsigned int sv_max_mesg; /* max_payload + 1 page for overheads */ + unsigned int sv_xdrsize; /* XDR buffer size */ + struct list_head sv_permsocks; /* all permanent sockets */ + struct list_head sv_tempsocks; /* all temporary sockets */ + int sv_tmpcnt; /* count of temporary sockets */ + struct timer_list sv_temptimer; /* timer for aging temporary sockets */ + + char * sv_name; /* service name */ + + unsigned int sv_nrpools; /* number of thread pools */ + struct svc_pool * sv_pools; /* array of thread pools */ + int (*sv_threadfn)(void *data); + +#if defined(CONFIG_SUNRPC_BACKCHANNEL) + struct list_head sv_cb_list; /* queue for callback requests + * that arrive over the same + * connection */ + spinlock_t sv_cb_lock; /* protects the svc_cb_list */ + wait_queue_head_t sv_cb_waitq; /* sleep here if there are no + * entries in the svc_cb_list */ + bool sv_bc_enabled; /* service uses backchannel */ +#endif /* CONFIG_SUNRPC_BACKCHANNEL */ +}; + +/** + * svc_get() - increment reference count on a SUNRPC serv + * @serv: the svc_serv to have count incremented + * + * Returns: the svc_serv that was passed in. + */ +static inline struct svc_serv *svc_get(struct svc_serv *serv) +{ + kref_get(&serv->sv_refcnt); + return serv; +} + +void svc_destroy(struct kref *); + +/** + * svc_put - decrement reference count on a SUNRPC serv + * @serv: the svc_serv to have count decremented + * + * When the reference count reaches zero, svc_destroy() + * is called to clean up and free the serv. + */ +static inline void svc_put(struct svc_serv *serv) +{ + kref_put(&serv->sv_refcnt, svc_destroy); +} + +/* + * Maximum payload size supported by a kernel RPC server. + * This is use to determine the max number of pages nfsd is + * willing to return in a single READ operation. + * + * These happen to all be powers of 2, which is not strictly + * necessary but helps enforce the real limitation, which is + * that they should be multiples of PAGE_SIZE. + * + * For UDP transports, a block plus NFS,RPC, and UDP headers + * has to fit into the IP datagram limit of 64K. The largest + * feasible number for all known page sizes is probably 48K, + * but we choose 32K here. This is the same as the historical + * Linux limit; someone who cares more about NFS/UDP performance + * can test a larger number. + * + * For TCP transports we have more freedom. A size of 1MB is + * chosen to match the client limit. Other OSes are known to + * have larger limits, but those numbers are probably beyond + * the point of diminishing returns. + */ +#define RPCSVC_MAXPAYLOAD (1*1024*1024u) +#define RPCSVC_MAXPAYLOAD_TCP RPCSVC_MAXPAYLOAD +#define RPCSVC_MAXPAYLOAD_UDP (32*1024u) + +extern u32 svc_max_payload(const struct svc_rqst *rqstp); + +/* + * RPC Requests and replies are stored in one or more pages. + * We maintain an array of pages for each server thread. + * Requests are copied into these pages as they arrive. Remaining + * pages are available to write the reply into. + * + * Pages are sent using ->sendmsg with MSG_SPLICE_PAGES so each server thread + * needs to allocate more to replace those used in sending. To help keep track + * of these pages we have a receive list where all pages initialy live, and a + * send list where pages are moved to when there are to be part of a reply. + * + * We use xdr_buf for holding responses as it fits well with NFS + * read responses (that have a header, and some data pages, and possibly + * a tail) and means we can share some client side routines. + * + * The xdr_buf.head kvec always points to the first page in the rq_*pages + * list. The xdr_buf.pages pointer points to the second page on that + * list. xdr_buf.tail points to the end of the first page. + * This assumes that the non-page part of an rpc reply will fit + * in a page - NFSd ensures this. lockd also has no trouble. + * + * Each request/reply pair can have at most one "payload", plus two pages, + * one for the request, and one for the reply. + * We using ->sendfile to return read data, we might need one extra page + * if the request is not page-aligned. So add another '1'. + */ +#define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \ + + 2 + 1) + +/* + * The context of a single thread, including the request currently being + * processed. + */ +struct svc_rqst { + struct list_head rq_all; /* all threads list */ + struct rcu_head rq_rcu_head; /* for RCU deferred kfree */ + struct svc_xprt * rq_xprt; /* transport ptr */ + + struct sockaddr_storage rq_addr; /* peer address */ + size_t rq_addrlen; + struct sockaddr_storage rq_daddr; /* dest addr of request + * - reply from here */ + size_t rq_daddrlen; + + struct svc_serv * rq_server; /* RPC service definition */ + struct svc_pool * rq_pool; /* thread pool */ + const struct svc_procedure *rq_procinfo;/* procedure info */ + struct auth_ops * rq_authop; /* authentication flavour */ + struct svc_cred rq_cred; /* auth info */ + void * rq_xprt_ctxt; /* transport specific context ptr */ + struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */ + + struct xdr_buf rq_arg; + struct xdr_stream rq_arg_stream; + struct xdr_stream rq_res_stream; + struct page *rq_scratch_page; + struct xdr_buf rq_res; + struct page *rq_pages[RPCSVC_MAXPAGES + 1]; + struct page * *rq_respages; /* points into rq_pages */ + struct page * *rq_next_page; /* next reply page to use */ + struct page * *rq_page_end; /* one past the last page */ + + struct folio_batch rq_fbatch; + struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */ + struct bio_vec rq_bvec[RPCSVC_MAXPAGES]; + + __be32 rq_xid; /* transmission id */ + u32 rq_prog; /* program number */ + u32 rq_vers; /* program version */ + u32 rq_proc; /* procedure number */ + u32 rq_prot; /* IP protocol */ + int rq_cachetype; /* catering to nfsd */ + unsigned long rq_flags; /* flags field */ + ktime_t rq_qtime; /* enqueue time */ + + void * rq_argp; /* decoded arguments */ + void * rq_resp; /* xdr'd results */ + __be32 *rq_accept_statp; + void * rq_auth_data; /* flavor-specific data */ + __be32 rq_auth_stat; /* authentication status */ + int rq_auth_slack; /* extra space xdr code + * should leave in head + * for krb5i, krb5p. + */ + int rq_reserved; /* space on socket outq + * reserved for this request + */ + ktime_t rq_stime; /* start time */ + + struct cache_req rq_chandle; /* handle passed to caches for + * request delaying + */ + /* Catering to nfsd */ + struct auth_domain * rq_client; /* RPC peer info */ + struct auth_domain * rq_gssclient; /* "gss/"-style peer info */ + struct task_struct *rq_task; /* service thread */ + struct net *rq_bc_net; /* pointer to backchannel's + * net namespace + */ + void ** rq_lease_breaker; /* The v4 client breaking a lease */ +}; + +/* bits for rq_flags */ +enum { + RQ_SECURE, /* secure port */ + RQ_LOCAL, /* local request */ + RQ_USEDEFERRAL, /* use deferral */ + RQ_DROPME, /* drop current reply */ + RQ_SPLICE_OK, /* turned off in gss privacy to prevent + * encrypting page cache pages */ + RQ_VICTIM, /* about to be shut down */ + RQ_BUSY, /* request is busy */ + RQ_DATA, /* request has data */ +}; + +#define SVC_NET(rqst) (rqst->rq_xprt ? rqst->rq_xprt->xpt_net : rqst->rq_bc_net) + +/* + * Rigorous type checking on sockaddr type conversions + */ +static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst) +{ + return (struct sockaddr_in *) &rqst->rq_addr; +} + +static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst) +{ + return (struct sockaddr_in6 *) &rqst->rq_addr; +} + +static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst) +{ + return (struct sockaddr *) &rqst->rq_addr; +} + +static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst) +{ + return (struct sockaddr_in *) &rqst->rq_daddr; +} + +static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst) +{ + return (struct sockaddr_in6 *) &rqst->rq_daddr; +} + +static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst) +{ + return (struct sockaddr *) &rqst->rq_daddr; +} + +struct svc_deferred_req { + u32 prot; /* protocol (UDP or TCP) */ + struct svc_xprt *xprt; + struct sockaddr_storage addr; /* where reply must go */ + size_t addrlen; + struct sockaddr_storage daddr; /* where reply must come from */ + size_t daddrlen; + void *xprt_ctxt; + struct cache_deferred_req handle; + int argslen; + __be32 args[]; +}; + +struct svc_process_info { + union { + int (*dispatch)(struct svc_rqst *rqstp); + struct { + unsigned int lovers; + unsigned int hivers; + } mismatch; + }; +}; + +/* + * List of RPC programs on the same transport endpoint + */ +struct svc_program { + struct svc_program * pg_next; /* other programs (same xprt) */ + u32 pg_prog; /* program number */ + unsigned int pg_lovers; /* lowest version */ + unsigned int pg_hivers; /* highest version */ + unsigned int pg_nvers; /* number of versions */ + const struct svc_version **pg_vers; /* version array */ + char * pg_name; /* service name */ + char * pg_class; /* class name: services sharing authentication */ + struct svc_stat * pg_stats; /* rpc statistics */ + enum svc_auth_status (*pg_authenticate)(struct svc_rqst *rqstp); + __be32 (*pg_init_request)(struct svc_rqst *, + const struct svc_program *, + struct svc_process_info *); + int (*pg_rpcbind_set)(struct net *net, + const struct svc_program *, + u32 version, int family, + unsigned short proto, + unsigned short port); +}; + +/* + * RPC program version + */ +struct svc_version { + u32 vs_vers; /* version number */ + u32 vs_nproc; /* number of procedures */ + const struct svc_procedure *vs_proc; /* per-procedure info */ + unsigned long __percpu *vs_count; /* call counts */ + u32 vs_xdrsize; /* xdrsize needed for this version */ + + /* Don't register with rpcbind */ + bool vs_hidden; + + /* Don't care if the rpcbind registration fails */ + bool vs_rpcb_optnl; + + /* Need xprt with congestion control */ + bool vs_need_cong_ctrl; + + /* Dispatch function */ + int (*vs_dispatch)(struct svc_rqst *rqstp); +}; + +/* + * RPC procedure info + */ +struct svc_procedure { + /* process the request: */ + __be32 (*pc_func)(struct svc_rqst *); + /* XDR decode args: */ + bool (*pc_decode)(struct svc_rqst *rqstp, + struct xdr_stream *xdr); + /* XDR encode result: */ + bool (*pc_encode)(struct svc_rqst *rqstp, + struct xdr_stream *xdr); + /* XDR free result: */ + void (*pc_release)(struct svc_rqst *); + unsigned int pc_argsize; /* argument struct size */ + unsigned int pc_argzero; /* how much of argument to clear */ + unsigned int pc_ressize; /* result struct size */ + unsigned int pc_cachetype; /* cache info (NFS) */ + unsigned int pc_xdrressize; /* maximum size of XDR reply */ + const char * pc_name; /* for display */ +}; + +/* + * Function prototypes. + */ +int svc_rpcb_setup(struct svc_serv *serv, struct net *net); +void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net); +int svc_bind(struct svc_serv *serv, struct net *net); +struct svc_serv *svc_create(struct svc_program *, unsigned int, + int (*threadfn)(void *data)); +struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv, + struct svc_pool *pool, int node); +bool svc_rqst_replace_page(struct svc_rqst *rqstp, + struct page *page); +void svc_rqst_release_pages(struct svc_rqst *rqstp); +void svc_rqst_free(struct svc_rqst *); +void svc_exit_thread(struct svc_rqst *); +struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int, + int (*threadfn)(void *data)); +int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int); +int svc_pool_stats_open(struct svc_serv *serv, struct file *file); +void svc_process(struct svc_rqst *rqstp); +int bc_svc_process(struct svc_serv *, struct rpc_rqst *, + struct svc_rqst *); +int svc_register(const struct svc_serv *, struct net *, const int, + const unsigned short, const unsigned short); + +void svc_wake_up(struct svc_serv *); +void svc_reserve(struct svc_rqst *rqstp, int space); +void svc_pool_wake_idle_thread(struct svc_pool *pool); +struct svc_pool *svc_pool_for_cpu(struct svc_serv *serv); +char * svc_print_addr(struct svc_rqst *, char *, size_t); +const char * svc_proc_name(const struct svc_rqst *rqstp); +int svc_encode_result_payload(struct svc_rqst *rqstp, + unsigned int offset, + unsigned int length); +unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, + struct xdr_buf *payload); +char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, + struct kvec *first, void *p, + size_t total); +__be32 svc_generic_init_request(struct svc_rqst *rqstp, + const struct svc_program *progp, + struct svc_process_info *procinfo); +int svc_generic_rpcbind_set(struct net *net, + const struct svc_program *progp, + u32 version, int family, + unsigned short proto, + unsigned short port); +int svc_rpcbind_set_version(struct net *net, + const struct svc_program *progp, + u32 version, int family, + unsigned short proto, + unsigned short port); + +#define RPC_MAX_ADDRBUFLEN (63U) + +/* + * When we want to reduce the size of the reserved space in the response + * buffer, we need to take into account the size of any checksum data that + * may be at the end of the packet. This is difficult to determine exactly + * for all cases without actually generating the checksum, so we just use a + * static value. + */ +static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space) +{ + svc_reserve(rqstp, space + rqstp->rq_auth_slack); +} + +/** + * svcxdr_init_decode - Prepare an xdr_stream for Call decoding + * @rqstp: controlling server RPC transaction context + * + */ +static inline void svcxdr_init_decode(struct svc_rqst *rqstp) +{ + struct xdr_stream *xdr = &rqstp->rq_arg_stream; + struct xdr_buf *buf = &rqstp->rq_arg; + struct kvec *argv = buf->head; + + WARN_ON(buf->len != buf->head->iov_len + buf->page_len + buf->tail->iov_len); + buf->len = buf->head->iov_len + buf->page_len + buf->tail->iov_len; + + xdr_init_decode(xdr, buf, argv->iov_base, NULL); + xdr_set_scratch_page(xdr, rqstp->rq_scratch_page); +} + +/** + * svcxdr_init_encode - Prepare an xdr_stream for svc Reply encoding + * @rqstp: controlling server RPC transaction context + * + */ +static inline void svcxdr_init_encode(struct svc_rqst *rqstp) +{ + struct xdr_stream *xdr = &rqstp->rq_res_stream; + struct xdr_buf *buf = &rqstp->rq_res; + struct kvec *resv = buf->head; + + xdr_reset_scratch_buffer(xdr); + + xdr->buf = buf; + xdr->iov = resv; + xdr->p = resv->iov_base + resv->iov_len; + xdr->end = resv->iov_base + PAGE_SIZE; + buf->len = resv->iov_len; + xdr->page_ptr = buf->pages - 1; + buf->buflen = PAGE_SIZE * (rqstp->rq_page_end - buf->pages); + xdr->rqst = NULL; +} + +/** + * svcxdr_encode_opaque_pages - Insert pages into an xdr_stream + * @xdr: xdr_stream to be updated + * @pages: array of pages to insert + * @base: starting offset of first data byte in @pages + * @len: number of data bytes in @pages to insert + * + * After the @pages are added, the tail iovec is instantiated pointing + * to end of the head buffer, and the stream is set up to encode + * subsequent items into the tail. + */ +static inline void svcxdr_encode_opaque_pages(struct svc_rqst *rqstp, + struct xdr_stream *xdr, + struct page **pages, + unsigned int base, + unsigned int len) +{ + xdr_write_pages(xdr, pages, base, len); + xdr->page_ptr = rqstp->rq_next_page - 1; +} + +/** + * svcxdr_set_auth_slack - + * @rqstp: RPC transaction + * @slack: buffer space to reserve for the transaction's security flavor + * + * Set the request's slack space requirement, and set aside that much + * space in the rqstp's rq_res.head for use when the auth wraps the Reply. + */ +static inline void svcxdr_set_auth_slack(struct svc_rqst *rqstp, int slack) +{ + struct xdr_stream *xdr = &rqstp->rq_res_stream; + struct xdr_buf *buf = &rqstp->rq_res; + struct kvec *resv = buf->head; + + rqstp->rq_auth_slack = slack; + + xdr->end -= XDR_QUADLEN(slack); + buf->buflen -= rqstp->rq_auth_slack; + + WARN_ON(xdr->iov != resv); + WARN_ON(xdr->p > xdr->end); +} + +/** + * svcxdr_set_accept_stat - Reserve space for the accept_stat field + * @rqstp: RPC transaction context + * + * Return values: + * %true: Success + * %false: No response buffer space was available + */ +static inline bool svcxdr_set_accept_stat(struct svc_rqst *rqstp) +{ + struct xdr_stream *xdr = &rqstp->rq_res_stream; + + rqstp->rq_accept_statp = xdr_reserve_space(xdr, XDR_UNIT); + if (unlikely(!rqstp->rq_accept_statp)) + return false; + *rqstp->rq_accept_statp = rpc_success; + return true; +} + +#endif /* SUNRPC_SVC_H */ |