usr/src/sys/nfs/nqnfs.h

/*
 * Copyright (c) 1992 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)nqnfs.h     7.5 (Berkeley) %G%
 */

/*
 * Definitions for NQNFS (Not Quite NFS) cache consistency protocol.
 */

/* Tunable constants */
#define NQ_CLOCKSKEW    3       /* Clock skew factor (sec) */
#define NQ_WRITESLACK   5       /* Delay for write cache flushing */
#define NQ_MAXLEASE     60      /* Max lease duration (sec) */
#define NQ_MINLEASE     5       /* Min lease duration (sec) */
#define NQ_DEFLEASE     30      /* Default lease duration (sec) */
#define NQ_RENEWAL      3       /* Time before expiry (sec) to renew */
#define NQ_TRYLATERDEL  15      /* Initial try later delay (sec) */
#define NQ_MAXNUMLEASE  2048    /* Upper bound on number of server leases */
#define NQ_DEADTHRESH   5       /* Default nm_deadthresh */
#define NQ_NEVERDEAD    9       /* Greater than max. nm_timeouts */
#define NQLCHSZ         256     /* Server hash table size */

#define NQNFS_PROG      300105  /* As assigned by Sun */
#define NQNFS_VER1      1
#define NQNFS_EVICTSIZ  156     /* Size of eviction request in bytes */

/*
 * Definitions used for saving the "last lease expires" time in Non-volatile
 * RAM on the server. The default definitions below assume that NOVRAM is not
 * available.
 */
#define NQSTORENOVRAM(t)
#define NQLOADNOVRAM(t)

/*
 * Defn and structs used on the server to maintain state for current leases.
 * The list of host(s) that hold the lease are kept as nqhost structures.
 * The first one lives in nqlease and any others are held in a linked
 * list of nqm structures hanging off of nqlease.
 *
 * Each nqlease structure is chained into two lists. The first is a list
 * ordered by increasing expiry time for nqsrv_timer() and the second is a chain
 * hashed on lc_fh.
 */
#define LC_MOREHOSTSIZ  10

struct nqhost {
        union {
                struct {
                        u_short udp_flag;
                        u_short udp_port;
                        union nethostaddr udp_haddr;
                } un_udp;
                struct {
                        u_short connless_flag;
                        u_short connless_spare;
                        union nethostaddr connless_haddr;
                } un_connless;
                struct {
                        u_short conn_flag;
                        u_short conn_spare;
                        struct nfssvc_sock *conn_slp;
                } un_conn;
        } lph_un;
};
#define lph_flag        lph_un.un_udp.udp_flag
#define lph_port        lph_un.un_udp.udp_port
#define lph_haddr       lph_un.un_udp.udp_haddr
#define lph_inetaddr    lph_un.un_udp.udp_haddr.had_inetaddr
#define lph_claddr      lph_un.un_connless.connless_haddr
#define lph_nam         lph_un.un_connless.connless_haddr.had_nam
#define lph_slp         lph_un.un_conn.conn_slp

struct nqlease {
        struct nqlease *lc_chain1[2];   /* Timer queue list (must be first) */
        struct nqlease *lc_fhnext;      /* Fhandle hash list */
        struct nqlease **lc_fhprev;
        time_t          lc_expiry;      /* Expiry time (sec) */
        struct nqhost   lc_host;        /* Host that got lease */
        struct nqm      *lc_morehosts;  /* Other hosts that share read lease */
        fsid_t          lc_fsid;        /* Fhandle */
        char            lc_fiddata[MAXFIDSZ];
        struct vnode    *lc_vp;         /* Soft reference to associated vnode */
};
#define lc_flag         lc_host.lph_un.un_udp.udp_flag

/* lc_flag bits */
#define LC_VALID        0x0001  /* Host address valid */
#define LC_WRITE        0x0002  /* Write cache */
#define LC_NONCACHABLE  0x0004  /* Non-cachable lease */
#define LC_LOCKED       0x0008  /* Locked */
#define LC_WANTED       0x0010  /* Lock wanted */
#define LC_EXPIREDWANTED 0x0020 /* Want lease when expired */
#define LC_UDP          0x0040  /* Host address for udp socket */
#define LC_CLTP         0x0080  /* Host address for other connectionless */
#define LC_LOCAL        0x0100  /* Host is server */
#define LC_VACATED      0x0200  /* Host has vacated lease */
#define LC_WRITTEN      0x0400  /* Recently wrote to the leased file */
#define LC_SREF         0x0800  /* Holds a nfssvc_sock reference */

struct nqm {
        struct nqm      *lpm_next;
        struct nqhost   lpm_hosts[LC_MOREHOSTSIZ];
};

/*
 * Flag bits for flags argument to nqsrv_getlease.
 */
#define NQL_READ        LEASE_READ      /* Read Request */
#define NQL_WRITE       LEASE_WRITE     /* Write Request */
#define NQL_CHECK       0x4             /* Check for lease */
#define NQL_NOVAL       0xffffffff      /* Invalid */

/*
 * Special value for slp for local server calls.
 */
#define NQLOCALSLP      ((struct nfssvc_sock *) -1)

/*
 * Server side macros.
 */
#define nqsrv_getl(v, l) \
                (void) nqsrv_getlease((v), &nfsd->nd_duration, \
                 ((nfsd->nd_nqlflag != 0 && nfsd->nd_nqlflag != NQL_NOVAL) ? nfsd->nd_nqlflag : \
                 ((l) | NQL_CHECK)), \
                 nfsd, nam, &cache, &frev, cred)

/*
 * Client side macros that check for a valid lease.
 */
#define NQNFS_CKINVALID(v, n, f) \
 ((time.tv_sec > (n)->n_expiry && \
 VFSTONFS((v)->v_mount)->nm_timeouts < VFSTONFS((v)->v_mount)->nm_deadthresh) \
  || ((f) == NQL_WRITE && ((n)->n_flag & NQNFSWRITE) == 0))

#define NQNFS_CKCACHABLE(v, f) \
 ((time.tv_sec <= VTONFS(v)->n_expiry || \
  VFSTONFS((v)->v_mount)->nm_timeouts >= VFSTONFS((v)->v_mount)->nm_deadthresh) \
   && (VTONFS(v)->n_flag & NQNFSNONCACHE) == 0 && \
   ((f) == NQL_READ || (VTONFS(v)->n_flag & NQNFSWRITE)))

#define NQNFS_NEEDLEASE(v, p) \
                (time.tv_sec > VTONFS(v)->n_expiry ? \
                 ((VTONFS(v)->n_flag & NQNFSEVICTED) ? 0 : nqnfs_piggy[p]) : \
                 (((time.tv_sec + NQ_RENEWAL) > VTONFS(v)->n_expiry && \
                   nqnfs_piggy[p]) ? \
                   ((VTONFS(v)->n_flag & NQNFSWRITE) ? \
                    NQL_WRITE : nqnfs_piggy[p]) : 0))

/*
 * List head for timer queue.
 */
extern union nqsrvthead {
        union   nqsrvthead *th_head[2];
        struct  nqlease *th_chain[2];
} nqthead;
extern struct nqlease **nqfhead;
extern u_long nqfheadhash;

/*
 * Nqnfs return status numbers.
 */
#define NQNFS_EXPIRED   500
#define NQNFS_TRYLATER  501
#define NQNFS_AUTHERR   502