xref: /spdk/lib/log/log_deprecated.c (revision f7b31b2b9679b48e9e13514a6b668058bb45fd56)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
3  */
4 
5 #include "spdk/stdinc.h"
6 #include "spdk/string.h"
7 #include "spdk/thread.h"
8 #include "spdk/util.h"
9 #include "spdk/log.h"
10 
11 struct spdk_deprecation {
12 	const char tag[64];
13 	const char desc[64];
14 	const char remove[16];
15 	TAILQ_ENTRY(spdk_deprecation) link;
16 	uint64_t hits;
17 	/* How often (nanoseconds) to log. */
18 	uint64_t interval;
19 	/* How many messages were not logged due to rate limiting */
20 	uint32_t deferred;
21 	/* CLOCK_MONOTONIC microseconds since g_deprecation_epoch when last warning was logged */
22 	uint64_t last_log;
23 };
24 
25 static TAILQ_HEAD(, spdk_deprecation) g_deprecations = TAILQ_HEAD_INITIALIZER(g_deprecations);
26 static struct timespec g_deprecation_epoch;
27 
28 static void
29 __attribute__((constructor))
30 deprecation_init(void)
31 {
32 	clock_gettime(CLOCK_MONOTONIC, &g_deprecation_epoch);
33 }
34 
35 static inline uint64_t
36 get_ns_since_epoch(void)
37 {
38 	struct timespec now;
39 
40 	clock_gettime(CLOCK_MONOTONIC, &now);
41 	return (now.tv_sec - g_deprecation_epoch.tv_sec) * SPDK_SEC_TO_NSEC +
42 	       now.tv_nsec - g_deprecation_epoch.tv_nsec;
43 }
44 
45 int
46 spdk_log_deprecation_register(const char *tag, const char *description, const char *remove_release,
47 			      uint32_t rate_limit_seconds, struct spdk_deprecation **depp)
48 {
49 	struct spdk_deprecation *dep;
50 
51 	assert(strnlen(tag, sizeof(dep->tag)) < sizeof(dep->tag));
52 	assert(strnlen(description, sizeof(dep->desc)) < sizeof(dep->desc));
53 	assert(strnlen(remove_release, sizeof(dep->remove)) < sizeof(dep->remove));
54 
55 	dep = calloc(1, sizeof(*dep));
56 	if (dep == NULL) {
57 		return -ENOMEM;
58 	}
59 
60 	snprintf((char *)dep->tag, sizeof(dep->tag), "%s", tag);
61 	snprintf((char *)dep->desc, sizeof(dep->desc), "%s", description);
62 	snprintf((char *)dep->remove, sizeof(dep->remove), "%s", remove_release);
63 	dep->interval = rate_limit_seconds * SPDK_SEC_TO_NSEC;
64 
65 	TAILQ_INSERT_TAIL(&g_deprecations, dep, link);
66 	*depp = dep;
67 	return 0;
68 }
69 
70 /*
71  * There is potential for races between pthreads leading to over or under reporting of times that
72  * deprecated code was hit. If this function is called in a hot path where that is likely, we care
73  * more about performance than accuracy of the error counts. The important thing is that at least
74  * one of the racing updates the hits counter to non-zero and the warning is logged at least once.
75  */
76 void
77 spdk_log_deprecated(struct spdk_deprecation *dep, const char *file, uint32_t line, const char *func)
78 {
79 	uint64_t now = get_ns_since_epoch();
80 
81 	if (dep == NULL) {
82 		SPDK_ERRLOG("NULL deprecation passed from %s:%u:%s\n", file, line, func);
83 		assert(false);
84 		return;
85 	}
86 
87 	dep->hits++;
88 
89 	if (dep->interval != 0) {
90 		if (dep->last_log != 0 && now < dep->last_log + dep->interval) {
91 			dep->deferred++;
92 			return;
93 		}
94 	}
95 
96 	dep->last_log = now;
97 
98 	spdk_log(SPDK_LOG_WARN, file, line, func, "%s: deprecated feature %s to be removed in %s\n",
99 		 dep->tag, dep->desc, dep->remove);
100 	if (dep->deferred != 0) {
101 		SPDK_WARNLOG("%s: %u messages suppressed\n", dep->tag, dep->deferred);
102 		dep->deferred = 0;
103 	}
104 }
105 
106 int
107 spdk_log_for_each_deprecation(void *ctx, spdk_log_for_each_deprecation_fn fn)
108 {
109 	struct spdk_deprecation *dep;
110 	int rc = 0;
111 
112 	TAILQ_FOREACH(dep, &g_deprecations, link) {
113 		rc = fn(ctx, dep);
114 		if (rc != 0) {
115 			break;
116 		}
117 	}
118 
119 	return rc;
120 }
121 
122 const char *
123 spdk_deprecation_get_tag(const struct spdk_deprecation *deprecation)
124 {
125 	return deprecation->tag;
126 }
127 
128 const char *
129 spdk_deprecation_get_description(const struct spdk_deprecation *deprecation)
130 {
131 	return deprecation->desc;
132 }
133 
134 const char *
135 spdk_deprecation_get_remove_release(const struct spdk_deprecation *deprecation)
136 {
137 	return deprecation->remove;
138 }
139 
140 uint64_t
141 spdk_deprecation_get_hits(const struct spdk_deprecation *deprecation)
142 {
143 	return deprecation->hits;
144 }
145