^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Multipath support for RPC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2015, 2016, Primary Data, Inc. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Trond Myklebust <trond.myklebust@primarydata.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/kref.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/rcupdate.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/rculist.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <asm/cmpxchg.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/sunrpc/xprt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/sunrpc/addr.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/sunrpc/xprtmultipath.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) typedef struct rpc_xprt *(*xprt_switch_find_xprt_t)(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) const struct rpc_xprt *cur);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static const struct rpc_xprt_iter_ops rpc_xprt_iter_singular;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) static const struct rpc_xprt_iter_ops rpc_xprt_iter_roundrobin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) static const struct rpc_xprt_iter_ops rpc_xprt_iter_listall;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) static void xprt_switch_add_xprt_locked(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) struct rpc_xprt *xprt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) if (unlikely(xprt_get(xprt) == NULL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) list_add_tail_rcu(&xprt->xprt_switch, &xps->xps_xprt_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) if (xps->xps_nxprts == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) xps->xps_net = xprt->xprt_net;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) xps->xps_nxprts++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) xps->xps_nactive++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * rpc_xprt_switch_add_xprt - Add a new rpc_xprt to an rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * @xps: pointer to struct rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * @xprt: pointer to struct rpc_xprt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * Adds xprt to the end of the list of struct rpc_xprt in xps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) void rpc_xprt_switch_add_xprt(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) struct rpc_xprt *xprt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) if (xprt == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) spin_lock(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) if (xps->xps_net == xprt->xprt_net || xps->xps_net == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) xprt_switch_add_xprt_locked(xps, xprt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) spin_unlock(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) struct rpc_xprt *xprt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) if (unlikely(xprt == NULL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) xps->xps_nactive--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) xps->xps_nxprts--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) if (xps->xps_nxprts == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) xps->xps_net = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) list_del_rcu(&xprt->xprt_switch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * rpc_xprt_switch_remove_xprt - Removes an rpc_xprt from a rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * @xps: pointer to struct rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) * @xprt: pointer to struct rpc_xprt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * Removes xprt from the list of struct rpc_xprt in xps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) struct rpc_xprt *xprt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) spin_lock(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) xprt_switch_remove_xprt_locked(xps, xprt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) spin_unlock(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) xprt_put(xprt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) * xprt_switch_alloc - Allocate a new struct rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * @xprt: pointer to struct rpc_xprt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) * @gfp_flags: allocation flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * On success, returns an initialised struct rpc_xprt_switch, containing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * the entry xprt. Returns NULL on failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) struct rpc_xprt_switch *xprt_switch_alloc(struct rpc_xprt *xprt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) gfp_t gfp_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) struct rpc_xprt_switch *xps;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) xps = kmalloc(sizeof(*xps), gfp_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) if (xps != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) spin_lock_init(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) kref_init(&xps->xps_kref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) xps->xps_nxprts = xps->xps_nactive = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) atomic_long_set(&xps->xps_queuelen, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) xps->xps_net = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) INIT_LIST_HEAD(&xps->xps_xprt_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) xps->xps_iter_ops = &rpc_xprt_iter_singular;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) xprt_switch_add_xprt_locked(xps, xprt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) return xps;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) static void xprt_switch_free_entries(struct rpc_xprt_switch *xps)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) spin_lock(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) while (!list_empty(&xps->xps_xprt_list)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) struct rpc_xprt *xprt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) xprt = list_first_entry(&xps->xps_xprt_list,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) struct rpc_xprt, xprt_switch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) xprt_switch_remove_xprt_locked(xps, xprt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) spin_unlock(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) xprt_put(xprt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) spin_lock(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) spin_unlock(&xps->xps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) static void xprt_switch_free(struct kref *kref)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) struct rpc_xprt_switch *xps = container_of(kref,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) struct rpc_xprt_switch, xps_kref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) xprt_switch_free_entries(xps);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) kfree_rcu(xps, xps_rcu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) * xprt_switch_get - Return a reference to a rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * @xps: pointer to struct rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * Returns a reference to xps unless the refcount is already zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) struct rpc_xprt_switch *xprt_switch_get(struct rpc_xprt_switch *xps)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) if (xps != NULL && kref_get_unless_zero(&xps->xps_kref))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) return xps;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) * xprt_switch_put - Release a reference to a rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) * @xps: pointer to struct rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * Release the reference to xps, and free it once the refcount is zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) void xprt_switch_put(struct rpc_xprt_switch *xps)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) if (xps != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) kref_put(&xps->xps_kref, xprt_switch_free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * rpc_xprt_switch_set_roundrobin - Set a round-robin policy on rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) * @xps: pointer to struct rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) * Sets a round-robin default policy for iterators acting on xps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) void rpc_xprt_switch_set_roundrobin(struct rpc_xprt_switch *xps)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) if (READ_ONCE(xps->xps_iter_ops) != &rpc_xprt_iter_roundrobin)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) WRITE_ONCE(xps->xps_iter_ops, &rpc_xprt_iter_roundrobin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) const struct rpc_xprt_iter_ops *xprt_iter_ops(const struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) if (xpi->xpi_ops != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) return xpi->xpi_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) return rcu_dereference(xpi->xpi_xpswitch)->xps_iter_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) void xprt_iter_no_rewind(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) void xprt_iter_default_rewind(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) WRITE_ONCE(xpi->xpi_cursor, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) bool xprt_is_active(const struct rpc_xprt *xprt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) return kref_read(&xprt->kref) != 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) struct rpc_xprt *xprt_switch_find_first_entry(struct list_head *head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) struct rpc_xprt *pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) list_for_each_entry_rcu(pos, head, xprt_switch) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) if (xprt_is_active(pos))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) return pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) struct rpc_xprt *xprt_iter_first_entry(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) if (xps == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) return xprt_switch_find_first_entry(&xps->xps_xprt_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) struct rpc_xprt *xprt_switch_find_current_entry(struct list_head *head,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) const struct rpc_xprt *cur)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) struct rpc_xprt *pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) bool found = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) list_for_each_entry_rcu(pos, head, xprt_switch) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) if (cur == pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) found = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) if (found && xprt_is_active(pos))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) return pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) struct rpc_xprt *xprt_iter_current_entry(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) struct list_head *head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) if (xps == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) head = &xps->xps_xprt_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) if (xpi->xpi_cursor == NULL || xps->xps_nxprts < 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) return xprt_switch_find_first_entry(head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) return xprt_switch_find_current_entry(head, xpi->xpi_cursor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) const struct sockaddr *sap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) struct list_head *head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) struct rpc_xprt *pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) if (xps == NULL || sap == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) head = &xps->xps_xprt_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) list_for_each_entry_rcu(pos, head, xprt_switch) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) if (rpc_cmp_addr_port(sap, (struct sockaddr *)&pos->addr)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) pr_info("RPC: addr %s already in xprt switch\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) pos->address_strings[RPC_DISPLAY_ADDR]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) struct rpc_xprt *xprt_switch_find_next_entry(struct list_head *head,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) const struct rpc_xprt *cur)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) struct rpc_xprt *pos, *prev = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) bool found = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) list_for_each_entry_rcu(pos, head, xprt_switch) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) if (cur == prev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) found = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) if (found && xprt_is_active(pos))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) return pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) prev = pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) struct rpc_xprt *xprt_switch_set_next_cursor(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) struct rpc_xprt **cursor,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) xprt_switch_find_xprt_t find_next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) struct rpc_xprt *pos, *old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) old = smp_load_acquire(cursor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) pos = find_next(xps, old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) smp_store_release(cursor, pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) return pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) struct rpc_xprt *xprt_iter_next_entry_multiple(struct rpc_xprt_iter *xpi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) xprt_switch_find_xprt_t find_next)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) if (xps == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) return xprt_switch_set_next_cursor(xps, &xpi->xpi_cursor, find_next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) struct rpc_xprt *__xprt_switch_find_next_entry_roundrobin(struct list_head *head,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) const struct rpc_xprt *cur)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) struct rpc_xprt *ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) ret = xprt_switch_find_next_entry(head, cur);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) if (ret != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) return xprt_switch_find_first_entry(head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) struct rpc_xprt *xprt_switch_find_next_entry_roundrobin(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) const struct rpc_xprt *cur)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) struct list_head *head = &xps->xps_xprt_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) struct rpc_xprt *xprt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) unsigned int nactive;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) unsigned long xprt_queuelen, xps_queuelen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) xprt = __xprt_switch_find_next_entry_roundrobin(head, cur);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) if (!xprt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) xprt_queuelen = atomic_long_read(&xprt->queuelen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) xps_queuelen = atomic_long_read(&xps->xps_queuelen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) nactive = READ_ONCE(xps->xps_nactive);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) /* Exit loop if xprt_queuelen <= average queue length */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) if (xprt_queuelen * nactive <= xps_queuelen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) cur = xprt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) return xprt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) struct rpc_xprt *xprt_iter_next_entry_roundrobin(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) return xprt_iter_next_entry_multiple(xpi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) xprt_switch_find_next_entry_roundrobin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) struct rpc_xprt *xprt_switch_find_next_entry_all(struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) const struct rpc_xprt *cur)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) return xprt_switch_find_next_entry(&xps->xps_xprt_list, cur);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) struct rpc_xprt *xprt_iter_next_entry_all(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) return xprt_iter_next_entry_multiple(xpi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) xprt_switch_find_next_entry_all);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) * xprt_iter_rewind - Resets the xprt iterator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) * @xpi: pointer to rpc_xprt_iter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) * Resets xpi to ensure that it points to the first entry in the list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) * of transports.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) void xprt_iter_rewind(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) xprt_iter_ops(xpi)->xpi_rewind(xpi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) static void __xprt_iter_init(struct rpc_xprt_iter *xpi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) struct rpc_xprt_switch *xps,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) const struct rpc_xprt_iter_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) rcu_assign_pointer(xpi->xpi_xpswitch, xprt_switch_get(xps));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) xpi->xpi_cursor = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) xpi->xpi_ops = ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) * xprt_iter_init - Initialise an xprt iterator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) * @xpi: pointer to rpc_xprt_iter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) * @xps: pointer to rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) * Initialises the iterator to use the default iterator ops
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * as set in xps. This function is mainly intended for internal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * use in the rpc_client.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) void xprt_iter_init(struct rpc_xprt_iter *xpi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) struct rpc_xprt_switch *xps)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) __xprt_iter_init(xpi, xps, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) * xprt_iter_init_listall - Initialise an xprt iterator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * @xpi: pointer to rpc_xprt_iter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * @xps: pointer to rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) * Initialises the iterator to iterate once through the entire list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) * of entries in xps.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) void xprt_iter_init_listall(struct rpc_xprt_iter *xpi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) struct rpc_xprt_switch *xps)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) __xprt_iter_init(xpi, xps, &rpc_xprt_iter_listall);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) * xprt_iter_xchg_switch - Atomically swap out the rpc_xprt_switch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) * @xpi: pointer to rpc_xprt_iter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) * @newswitch: pointer to a new rpc_xprt_switch or NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) * Swaps out the existing xpi->xpi_xpswitch with a new value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) struct rpc_xprt_switch *xprt_iter_xchg_switch(struct rpc_xprt_iter *xpi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) struct rpc_xprt_switch *newswitch)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) struct rpc_xprt_switch __rcu *oldswitch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) /* Atomically swap out the old xpswitch */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) oldswitch = xchg(&xpi->xpi_xpswitch, RCU_INITIALIZER(newswitch));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) if (newswitch != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) xprt_iter_rewind(xpi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) return rcu_dereference_protected(oldswitch, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) * xprt_iter_destroy - Destroys the xprt iterator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) * @xpi: pointer to rpc_xprt_iter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) void xprt_iter_destroy(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) xprt_switch_put(xprt_iter_xchg_switch(xpi, NULL));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) * xprt_iter_xprt - Returns the rpc_xprt pointed to by the cursor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) * @xpi: pointer to rpc_xprt_iter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) * Returns a pointer to the struct rpc_xprt that is currently
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) * pointed to by the cursor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) * Caller must be holding rcu_read_lock().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) struct rpc_xprt *xprt_iter_xprt(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) WARN_ON_ONCE(!rcu_read_lock_held());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) return xprt_iter_ops(xpi)->xpi_xprt(xpi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) struct rpc_xprt *xprt_iter_get_helper(struct rpc_xprt_iter *xpi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) struct rpc_xprt *(*fn)(struct rpc_xprt_iter *))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) struct rpc_xprt *ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) ret = fn(xpi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) if (ret == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) ret = xprt_get(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) } while (ret == NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) * xprt_iter_get_xprt - Returns the rpc_xprt pointed to by the cursor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) * @xpi: pointer to rpc_xprt_iter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) * Returns a reference to the struct rpc_xprt that is currently
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) * pointed to by the cursor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) struct rpc_xprt *xprt_iter_get_xprt(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) struct rpc_xprt *xprt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) xprt = xprt_iter_get_helper(xpi, xprt_iter_ops(xpi)->xpi_xprt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) return xprt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) * xprt_iter_get_next - Returns the next rpc_xprt following the cursor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) * @xpi: pointer to rpc_xprt_iter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) * Returns a reference to the struct rpc_xprt that immediately follows the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) * entry pointed to by the cursor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) struct rpc_xprt *xprt_iter_get_next(struct rpc_xprt_iter *xpi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) struct rpc_xprt *xprt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) xprt = xprt_iter_get_helper(xpi, xprt_iter_ops(xpi)->xpi_next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) return xprt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) /* Policy for always returning the first entry in the rpc_xprt_switch */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) const struct rpc_xprt_iter_ops rpc_xprt_iter_singular = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) .xpi_rewind = xprt_iter_no_rewind,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) .xpi_xprt = xprt_iter_first_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) .xpi_next = xprt_iter_first_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) /* Policy for round-robin iteration of entries in the rpc_xprt_switch */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) const struct rpc_xprt_iter_ops rpc_xprt_iter_roundrobin = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) .xpi_rewind = xprt_iter_default_rewind,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) .xpi_xprt = xprt_iter_current_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) .xpi_next = xprt_iter_next_entry_roundrobin,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) /* Policy for once-through iteration of entries in the rpc_xprt_switch */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) const struct rpc_xprt_iter_ops rpc_xprt_iter_listall = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) .xpi_rewind = xprt_iter_default_rewind,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) .xpi_xprt = xprt_iter_current_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) .xpi_next = xprt_iter_next_entry_all,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) };
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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