^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Copyright (C) 2004-2005 IBM Corp. All Rights Reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2006-2009 NEC Corporation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * dm-queue-length.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Module Author: Stefan Bader, IBM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Modified by: Kiyoshi Ueda, NEC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * This file is released under the GPL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * queue-length path selector - choose a path with the least number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * in-flight I/Os.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include "dm.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include "dm-path-selector.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/ctype.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/atomic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #define DM_MSG_PREFIX "multipath queue-length"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #define QL_MIN_IO 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #define QL_VERSION "0.2.0"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) struct selector {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) struct list_head valid_paths;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct list_head failed_paths;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) spinlock_t lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) struct path_info {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) struct list_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) struct dm_path *path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) unsigned repeat_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) atomic_t qlen; /* the number of in-flight I/Os */
^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) static struct selector *alloc_selector(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) struct selector *s = kmalloc(sizeof(*s), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) if (s) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) INIT_LIST_HEAD(&s->valid_paths);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) INIT_LIST_HEAD(&s->failed_paths);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) spin_lock_init(&s->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) return s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) static int ql_create(struct path_selector *ps, unsigned argc, char **argv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) struct selector *s = alloc_selector();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) if (!s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) ps->context = s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) static void ql_free_paths(struct list_head *paths)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) struct path_info *pi, *next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) list_for_each_entry_safe(pi, next, paths, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) list_del(&pi->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) kfree(pi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) static void ql_destroy(struct path_selector *ps)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) struct selector *s = ps->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) ql_free_paths(&s->valid_paths);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) ql_free_paths(&s->failed_paths);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) kfree(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) ps->context = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) static int ql_status(struct path_selector *ps, struct dm_path *path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) status_type_t type, char *result, unsigned maxlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) unsigned sz = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) struct path_info *pi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) /* When called with NULL path, return selector status/args. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) if (!path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) DMEMIT("0 ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) pi = path->pscontext;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) switch (type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) case STATUSTYPE_INFO:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) DMEMIT("%d ", atomic_read(&pi->qlen));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) case STATUSTYPE_TABLE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) DMEMIT("%u ", pi->repeat_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) return sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) static int ql_add_path(struct path_selector *ps, struct dm_path *path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) int argc, char **argv, char **error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) struct selector *s = ps->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) struct path_info *pi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) unsigned repeat_count = QL_MIN_IO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) char dummy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * Arguments: [<repeat_count>]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * <repeat_count>: The number of I/Os before switching path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * If not given, default (QL_MIN_IO) is used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) if (argc > 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) *error = "queue-length ps: incorrect number of arguments";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) if ((argc == 1) && (sscanf(argv[0], "%u%c", &repeat_count, &dummy) != 1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) *error = "queue-length ps: invalid repeat count";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (repeat_count > 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) DMWARN_LIMIT("repeat_count > 1 is deprecated, using 1 instead");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) repeat_count = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) /* Allocate the path information structure */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) pi = kmalloc(sizeof(*pi), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) if (!pi) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) *error = "queue-length ps: Error allocating path information";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) pi->path = path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) pi->repeat_count = repeat_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) atomic_set(&pi->qlen, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) path->pscontext = pi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) spin_lock_irqsave(&s->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) list_add_tail(&pi->list, &s->valid_paths);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) spin_unlock_irqrestore(&s->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) static void ql_fail_path(struct path_selector *ps, struct dm_path *path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) struct selector *s = ps->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) struct path_info *pi = path->pscontext;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) spin_lock_irqsave(&s->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) list_move(&pi->list, &s->failed_paths);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) spin_unlock_irqrestore(&s->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) static int ql_reinstate_path(struct path_selector *ps, struct dm_path *path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) struct selector *s = ps->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) struct path_info *pi = path->pscontext;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) spin_lock_irqsave(&s->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) list_move_tail(&pi->list, &s->valid_paths);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) spin_unlock_irqrestore(&s->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) * Select a path having the minimum number of in-flight I/Os
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) static struct dm_path *ql_select_path(struct path_selector *ps, size_t nr_bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) struct selector *s = ps->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) struct path_info *pi = NULL, *best = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) struct dm_path *ret = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) spin_lock_irqsave(&s->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) if (list_empty(&s->valid_paths))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) list_for_each_entry(pi, &s->valid_paths, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) if (!best ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) (atomic_read(&pi->qlen) < atomic_read(&best->qlen)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) best = pi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) if (!atomic_read(&best->qlen))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if (!best)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) /* Move most recently used to least preferred to evenly balance. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) list_move_tail(&best->list, &s->valid_paths);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) ret = best->path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) spin_unlock_irqrestore(&s->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) static int ql_start_io(struct path_selector *ps, struct dm_path *path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) size_t nr_bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) struct path_info *pi = path->pscontext;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) atomic_inc(&pi->qlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) static int ql_end_io(struct path_selector *ps, struct dm_path *path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) size_t nr_bytes, u64 start_time)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) struct path_info *pi = path->pscontext;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) atomic_dec(&pi->qlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) static struct path_selector_type ql_ps = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) .name = "queue-length",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) .module = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) .table_args = 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) .info_args = 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) .create = ql_create,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) .destroy = ql_destroy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) .status = ql_status,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) .add_path = ql_add_path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) .fail_path = ql_fail_path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) .reinstate_path = ql_reinstate_path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) .select_path = ql_select_path,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) .start_io = ql_start_io,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) .end_io = ql_end_io,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) static int __init dm_ql_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) int r = dm_register_path_selector(&ql_ps);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) if (r < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) DMERR("register failed %d", r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) DMINFO("version " QL_VERSION " loaded");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) static void __exit dm_ql_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) int r = dm_unregister_path_selector(&ql_ps);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) if (r < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) DMERR("unregister failed %d", r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) module_init(dm_ql_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) module_exit(dm_ql_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) MODULE_AUTHOR("Stefan Bader <Stefan.Bader at de.ibm.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) MODULE_DESCRIPTION(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) "(C) Copyright IBM Corp. 2004,2005 All Rights Reserved.\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) DM_NAME " path selector to balance the number of in-flight I/Os"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) MODULE_LICENSE("GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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