^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Copyright (C) 2003 Sistina Software.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Module Author: Heinz Mauelshagen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * This file is released under the GPL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Path selector registration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/device-mapper.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include "dm-path-selector.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) struct ps_internal {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) struct path_selector_type pst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) struct list_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #define pst_to_psi(__pst) container_of((__pst), struct ps_internal, pst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) static LIST_HEAD(_path_selectors);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) static DECLARE_RWSEM(_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) static struct ps_internal *__find_path_selector_type(const char *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct ps_internal *psi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) list_for_each_entry(psi, &_path_selectors, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) if (!strcmp(name, psi->pst.name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) return psi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static struct ps_internal *get_path_selector(const char *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) struct ps_internal *psi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) down_read(&_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) psi = __find_path_selector_type(name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) if (psi && !try_module_get(psi->pst.module))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) psi = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) up_read(&_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) return psi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) struct path_selector_type *dm_get_path_selector(const char *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) struct ps_internal *psi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) if (!name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) psi = get_path_selector(name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) if (!psi) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) request_module("dm-%s", name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) psi = get_path_selector(name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) return psi ? &psi->pst : NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) void dm_put_path_selector(struct path_selector_type *pst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) struct ps_internal *psi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (!pst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) down_read(&_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) psi = __find_path_selector_type(pst->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) if (!psi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) module_put(psi->pst.module);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) up_read(&_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) static struct ps_internal *_alloc_path_selector(struct path_selector_type *pst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) struct ps_internal *psi = kzalloc(sizeof(*psi), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) if (psi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) psi->pst = *pst;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) return psi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) int dm_register_path_selector(struct path_selector_type *pst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) int r = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) struct ps_internal *psi = _alloc_path_selector(pst);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (!psi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) down_write(&_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (__find_path_selector_type(pst->name)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) kfree(psi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) r = -EEXIST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) list_add(&psi->list, &_path_selectors);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) up_write(&_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) int dm_unregister_path_selector(struct path_selector_type *pst)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) struct ps_internal *psi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) down_write(&_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) psi = __find_path_selector_type(pst->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) if (!psi) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) up_write(&_ps_lock);
^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) list_del(&psi->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) up_write(&_ps_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) kfree(psi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) EXPORT_SYMBOL_GPL(dm_register_path_selector);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) EXPORT_SYMBOL_GPL(dm_unregister_path_selector);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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