diff options
Diffstat (limited to 'net/sunrpc/xprtmultipath.c')
| -rw-r--r-- | net/sunrpc/xprtmultipath.c | 284 |
1 files changed, 230 insertions, 54 deletions
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c index 8394124126f8..4c5e08b0aa64 100644 --- a/net/sunrpc/xprtmultipath.c +++ b/net/sunrpc/xprtmultipath.c @@ -7,24 +7,27 @@ * Trond Myklebust <trond.myklebust@primarydata.com> * */ +#include <linux/atomic.h> #include <linux/types.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/rcupdate.h> #include <linux/rculist.h> #include <linux/slab.h> -#include <asm/cmpxchg.h> #include <linux/spinlock.h> #include <linux/sunrpc/xprt.h> #include <linux/sunrpc/addr.h> #include <linux/sunrpc/xprtmultipath.h> -typedef struct rpc_xprt *(*xprt_switch_find_xprt_t)(struct list_head *head, +#include "sysfs.h" + +typedef struct rpc_xprt *(*xprt_switch_find_xprt_t)(struct rpc_xprt_switch *xps, const struct rpc_xprt *cur); static const struct rpc_xprt_iter_ops rpc_xprt_iter_singular; static const struct rpc_xprt_iter_ops rpc_xprt_iter_roundrobin; static const struct rpc_xprt_iter_ops rpc_xprt_iter_listall; +static const struct rpc_xprt_iter_ops rpc_xprt_iter_listoffline; static void xprt_switch_add_xprt_locked(struct rpc_xprt_switch *xps, struct rpc_xprt *xprt) @@ -36,6 +39,7 @@ static void xprt_switch_add_xprt_locked(struct rpc_xprt_switch *xps, if (xps->xps_nxprts == 0) xps->xps_net = xprt->xprt_net; xps->xps_nxprts++; + xps->xps_nactive++; } /** @@ -51,17 +55,19 @@ void rpc_xprt_switch_add_xprt(struct rpc_xprt_switch *xps, if (xprt == NULL) return; spin_lock(&xps->xps_lock); - if ((xps->xps_net == xprt->xprt_net || xps->xps_net == NULL) && - !rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr)) + if (xps->xps_net == xprt->xprt_net || xps->xps_net == NULL) xprt_switch_add_xprt_locked(xps, xprt); spin_unlock(&xps->xps_lock); + rpc_sysfs_xprt_setup(xps, xprt, GFP_KERNEL); } static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps, - struct rpc_xprt *xprt) + struct rpc_xprt *xprt, bool offline) { if (unlikely(xprt == NULL)) return; + if (!test_bit(XPRT_OFFLINE, &xprt->state) && offline) + xps->xps_nactive--; xps->xps_nxprts--; if (xps->xps_nxprts == 0) xps->xps_net = NULL; @@ -73,19 +79,65 @@ static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps, * rpc_xprt_switch_remove_xprt - Removes an rpc_xprt from a rpc_xprt_switch * @xps: pointer to struct rpc_xprt_switch * @xprt: pointer to struct rpc_xprt + * @offline: indicates if the xprt that's being removed is in an offline state * * Removes xprt from the list of struct rpc_xprt in xps. */ void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps, - struct rpc_xprt *xprt) + struct rpc_xprt *xprt, bool offline) { spin_lock(&xps->xps_lock); - xprt_switch_remove_xprt_locked(xps, xprt); + xprt_switch_remove_xprt_locked(xps, xprt, offline); spin_unlock(&xps->xps_lock); xprt_put(xprt); } /** + * rpc_xprt_switch_get_main_xprt - Get the 'main' xprt for an xprt switch. + * @xps: pointer to struct rpc_xprt_switch. + */ +struct rpc_xprt *rpc_xprt_switch_get_main_xprt(struct rpc_xprt_switch *xps) +{ + struct rpc_xprt_iter xpi; + struct rpc_xprt *xprt; + + xprt_iter_init_listall(&xpi, xps); + + xprt = xprt_iter_get_next(&xpi); + while (xprt && !xprt->main) { + xprt_put(xprt); + xprt = xprt_iter_get_next(&xpi); + } + + xprt_iter_destroy(&xpi); + return xprt; +} + +static DEFINE_IDA(rpc_xprtswitch_ids); + +void xprt_multipath_cleanup_ids(void) +{ + ida_destroy(&rpc_xprtswitch_ids); +} + +static int xprt_switch_alloc_id(struct rpc_xprt_switch *xps, gfp_t gfp_flags) +{ + int id; + + id = ida_alloc(&rpc_xprtswitch_ids, gfp_flags); + if (id < 0) + return id; + + xps->xps_id = id; + return 0; +} + +static void xprt_switch_free_id(struct rpc_xprt_switch *xps) +{ + ida_free(&rpc_xprtswitch_ids, xps->xps_id); +} + +/** * xprt_switch_alloc - Allocate a new struct rpc_xprt_switch * @xprt: pointer to struct rpc_xprt * @gfp_flags: allocation flags @@ -102,10 +154,16 @@ struct rpc_xprt_switch *xprt_switch_alloc(struct rpc_xprt *xprt, if (xps != NULL) { spin_lock_init(&xps->xps_lock); kref_init(&xps->xps_kref); - xps->xps_nxprts = 0; + xprt_switch_alloc_id(xps, gfp_flags); + xps->xps_nxprts = xps->xps_nactive = 0; + atomic_long_set(&xps->xps_queuelen, 0); + xps->xps_net = NULL; INIT_LIST_HEAD(&xps->xps_xprt_list); xps->xps_iter_ops = &rpc_xprt_iter_singular; + rpc_sysfs_xprt_switch_setup(xps, xprt, gfp_flags); xprt_switch_add_xprt_locked(xps, xprt); + xps->xps_nunique_destaddr_xprts = 1; + rpc_sysfs_xprt_setup(xps, xprt, gfp_flags); } return xps; @@ -119,7 +177,7 @@ static void xprt_switch_free_entries(struct rpc_xprt_switch *xps) xprt = list_first_entry(&xps->xps_xprt_list, struct rpc_xprt, xprt_switch); - xprt_switch_remove_xprt_locked(xps, xprt); + xprt_switch_remove_xprt_locked(xps, xprt, true); spin_unlock(&xps->xps_lock); xprt_put(xprt); spin_lock(&xps->xps_lock); @@ -133,6 +191,8 @@ static void xprt_switch_free(struct kref *kref) struct rpc_xprt_switch, xps_kref); xprt_switch_free_entries(xps); + rpc_sysfs_xprt_switch_destroy(xps); + xprt_switch_free_id(xps); kfree_rcu(xps, xps_rcu); } @@ -193,9 +253,34 @@ void xprt_iter_default_rewind(struct rpc_xprt_iter *xpi) } static +bool xprt_is_active(const struct rpc_xprt *xprt) +{ + return (kref_read(&xprt->kref) != 0 && + !test_bit(XPRT_OFFLINE, &xprt->state)); +} + +static struct rpc_xprt *xprt_switch_find_first_entry(struct list_head *head) { - return list_first_or_null_rcu(head, struct rpc_xprt, xprt_switch); + struct rpc_xprt *pos; + + list_for_each_entry_rcu(pos, head, xprt_switch) { + if (xprt_is_active(pos)) + return pos; + } + return NULL; +} + +static +struct rpc_xprt *xprt_switch_find_first_entry_offline(struct list_head *head) +{ + struct rpc_xprt *pos; + + list_for_each_entry_rcu(pos, head, xprt_switch) { + if (!xprt_is_active(pos)) + return pos; + } + return NULL; } static @@ -209,20 +294,35 @@ struct rpc_xprt *xprt_iter_first_entry(struct rpc_xprt_iter *xpi) } static -struct rpc_xprt *xprt_switch_find_current_entry(struct list_head *head, - const struct rpc_xprt *cur) +struct rpc_xprt *_xprt_switch_find_current_entry(struct list_head *head, + const struct rpc_xprt *cur, + bool find_active) { struct rpc_xprt *pos; + bool found = false; list_for_each_entry_rcu(pos, head, xprt_switch) { if (cur == pos) + found = true; + if (found && ((find_active && xprt_is_active(pos)) || + (!find_active && !xprt_is_active(pos)))) return pos; } return NULL; } static -struct rpc_xprt *xprt_iter_current_entry(struct rpc_xprt_iter *xpi) +struct rpc_xprt *xprt_switch_find_current_entry(struct list_head *head, + const struct rpc_xprt *cur) +{ + return _xprt_switch_find_current_entry(head, cur, true); +} + +static +struct rpc_xprt * _xprt_iter_current_entry(struct rpc_xprt_iter *xpi, + struct rpc_xprt *first_entry(struct list_head *head), + struct rpc_xprt *current_entry(struct list_head *head, + const struct rpc_xprt *cur)) { struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch); struct list_head *head; @@ -231,12 +331,35 @@ struct rpc_xprt *xprt_iter_current_entry(struct rpc_xprt_iter *xpi) return NULL; head = &xps->xps_xprt_list; if (xpi->xpi_cursor == NULL || xps->xps_nxprts < 2) - return xprt_switch_find_first_entry(head); - return xprt_switch_find_current_entry(head, xpi->xpi_cursor); + return first_entry(head); + return current_entry(head, xpi->xpi_cursor); } -bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps, - const struct sockaddr *sap) +static +struct rpc_xprt *xprt_iter_current_entry(struct rpc_xprt_iter *xpi) +{ + return _xprt_iter_current_entry(xpi, xprt_switch_find_first_entry, + xprt_switch_find_current_entry); +} + +static +struct rpc_xprt *xprt_switch_find_current_entry_offline(struct list_head *head, + const struct rpc_xprt *cur) +{ + return _xprt_switch_find_current_entry(head, cur, false); +} + +static +struct rpc_xprt *xprt_iter_current_entry_offline(struct rpc_xprt_iter *xpi) +{ + return _xprt_iter_current_entry(xpi, + xprt_switch_find_first_entry_offline, + xprt_switch_find_current_entry_offline); +} + +static +bool __rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps, + const struct sockaddr *sap) { struct list_head *head; struct rpc_xprt *pos; @@ -255,14 +378,34 @@ bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps, return false; } +bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps, + const struct sockaddr *sap) +{ + bool res; + + rcu_read_lock(); + res = __rpc_xprt_switch_has_addr(xps, sap); + rcu_read_unlock(); + + return res; +} + static struct rpc_xprt *xprt_switch_find_next_entry(struct list_head *head, - const struct rpc_xprt *cur) + const struct rpc_xprt *cur, bool check_active) { struct rpc_xprt *pos, *prev = NULL; + bool found = false; list_for_each_entry_rcu(pos, head, xprt_switch) { if (cur == prev) + found = true; + /* for request to return active transports return only + * active, for request to return offline transports + * return only offline + */ + if (found && ((check_active && xprt_is_active(pos)) || + (!check_active && !xprt_is_active(pos)))) return pos; prev = pos; } @@ -270,22 +413,15 @@ struct rpc_xprt *xprt_switch_find_next_entry(struct list_head *head, } static -struct rpc_xprt *xprt_switch_set_next_cursor(struct list_head *head, +struct rpc_xprt *xprt_switch_set_next_cursor(struct rpc_xprt_switch *xps, struct rpc_xprt **cursor, xprt_switch_find_xprt_t find_next) { - struct rpc_xprt *cur, *pos, *old; + struct rpc_xprt *pos, *old; - cur = READ_ONCE(*cursor); - for (;;) { - old = cur; - pos = find_next(head, old); - if (pos == NULL) - break; - cur = cmpxchg_relaxed(cursor, old, pos); - if (cur == old) - break; - } + old = smp_load_acquire(cursor); + pos = find_next(xps, old); + smp_store_release(cursor, pos); return pos; } @@ -297,24 +433,47 @@ struct rpc_xprt *xprt_iter_next_entry_multiple(struct rpc_xprt_iter *xpi, if (xps == NULL) return NULL; - return xprt_switch_set_next_cursor(&xps->xps_xprt_list, - &xpi->xpi_cursor, - find_next); + return xprt_switch_set_next_cursor(xps, &xpi->xpi_cursor, find_next); } static -struct rpc_xprt *xprt_switch_find_next_entry_roundrobin(struct list_head *head, +struct rpc_xprt *__xprt_switch_find_next_entry_roundrobin(struct list_head *head, const struct rpc_xprt *cur) { struct rpc_xprt *ret; - ret = xprt_switch_find_next_entry(head, cur); + ret = xprt_switch_find_next_entry(head, cur, true); if (ret != NULL) return ret; return xprt_switch_find_first_entry(head); } static +struct rpc_xprt *xprt_switch_find_next_entry_roundrobin(struct rpc_xprt_switch *xps, + const struct rpc_xprt *cur) +{ + struct list_head *head = &xps->xps_xprt_list; + struct rpc_xprt *xprt; + unsigned int nactive; + + for (;;) { + unsigned long xprt_queuelen, xps_queuelen; + + xprt = __xprt_switch_find_next_entry_roundrobin(head, cur); + if (!xprt) + break; + xprt_queuelen = atomic_long_read(&xprt->queuelen); + xps_queuelen = atomic_long_read(&xps->xps_queuelen); + nactive = READ_ONCE(xps->xps_nactive); + /* Exit loop if xprt_queuelen <= average queue length */ + if (xprt_queuelen * nactive <= xps_queuelen) + break; + cur = xprt; + } + return xprt; +} + +static struct rpc_xprt *xprt_iter_next_entry_roundrobin(struct rpc_xprt_iter *xpi) { return xprt_iter_next_entry_multiple(xpi, @@ -322,9 +481,31 @@ struct rpc_xprt *xprt_iter_next_entry_roundrobin(struct rpc_xprt_iter *xpi) } static +struct rpc_xprt *xprt_switch_find_next_entry_all(struct rpc_xprt_switch *xps, + const struct rpc_xprt *cur) +{ + return xprt_switch_find_next_entry(&xps->xps_xprt_list, cur, true); +} + +static +struct rpc_xprt *xprt_switch_find_next_entry_offline(struct rpc_xprt_switch *xps, + const struct rpc_xprt *cur) +{ + return xprt_switch_find_next_entry(&xps->xps_xprt_list, cur, false); +} + +static struct rpc_xprt *xprt_iter_next_entry_all(struct rpc_xprt_iter *xpi) { - return xprt_iter_next_entry_multiple(xpi, xprt_switch_find_next_entry); + return xprt_iter_next_entry_multiple(xpi, + xprt_switch_find_next_entry_all); +} + +static +struct rpc_xprt *xprt_iter_next_entry_offline(struct rpc_xprt_iter *xpi) +{ + return xprt_iter_next_entry_multiple(xpi, + xprt_switch_find_next_entry_offline); } /* @@ -334,7 +515,6 @@ struct rpc_xprt *xprt_iter_next_entry_all(struct rpc_xprt_iter *xpi) * Resets xpi to ensure that it points to the first entry in the list * of transports. */ -static void xprt_iter_rewind(struct rpc_xprt_iter *xpi) { rcu_read_lock(); @@ -380,6 +560,12 @@ void xprt_iter_init_listall(struct rpc_xprt_iter *xpi, __xprt_iter_init(xpi, xps, &rpc_xprt_iter_listall); } +void xprt_iter_init_listoffline(struct rpc_xprt_iter *xpi, + struct rpc_xprt_switch *xps) +{ + __xprt_iter_init(xpi, xps, &rpc_xprt_iter_listoffline); +} + /** * xprt_iter_xchg_switch - Atomically swap out the rpc_xprt_switch * @xpi: pointer to rpc_xprt_iter @@ -438,23 +624,6 @@ struct rpc_xprt *xprt_iter_get_helper(struct rpc_xprt_iter *xpi, } /** - * xprt_iter_get_xprt - Returns the rpc_xprt pointed to by the cursor - * @xpi: pointer to rpc_xprt_iter - * - * Returns a reference to the struct rpc_xprt that is currently - * pointed to by the cursor. - */ -struct rpc_xprt *xprt_iter_get_xprt(struct rpc_xprt_iter *xpi) -{ - struct rpc_xprt *xprt; - - rcu_read_lock(); - xprt = xprt_iter_get_helper(xpi, xprt_iter_ops(xpi)->xpi_xprt); - rcu_read_unlock(); - return xprt; -} - -/** * xprt_iter_get_next - Returns the next rpc_xprt following the cursor * @xpi: pointer to rpc_xprt_iter * @@ -494,3 +663,10 @@ const struct rpc_xprt_iter_ops rpc_xprt_iter_listall = { .xpi_xprt = xprt_iter_current_entry, .xpi_next = xprt_iter_next_entry_all, }; + +static +const struct rpc_xprt_iter_ops rpc_xprt_iter_listoffline = { + .xpi_rewind = xprt_iter_default_rewind, + .xpi_xprt = xprt_iter_current_entry_offline, + .xpi_next = xprt_iter_next_entry_offline, +}; |