cmd/zed/agents/fmd_serd.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2016, Intel Corporation.
  27  */
  28
  29 #include <assert.h>
  30 #include <stddef.h>
  31 #include <stdlib.h>
  32 #include <strings.h>
  33 #include <sys/list.h>
  34 #include <sys/time.h>
  35
  36 #include "fmd_api.h"
  37 #include "fmd_serd.h"
  38 #include "../zed_log.h"
  39
  40
  41 #define FMD_STR_BUCKETS         211
  42
  43
  44 #ifdef SERD_ENG_DEBUG
  45 #define serd_log_msg(fmt, ...) \
  46         zed_log_msg(LOG_INFO, fmt, __VA_ARGS__)
  47 #else
  48 #define serd_log_msg(fmt, ...)
  49 #endif
  50
  51
  52 /*
  53  * SERD Engine Backend
  54  */
  55
  56 /*
  57  * Compute the delta between events in nanoseconds.  To account for very old
  58  * events which are replayed, we must handle the case where time is negative.
  59  * We convert the hrtime_t's to unsigned 64-bit integers and then handle the
  60  * case where 'old' is greater than 'new' (i.e. high-res time has wrapped).
  61  */
  62 static hrtime_t
  63 fmd_event_delta(hrtime_t t1, hrtime_t t2)
  64 {
  65         uint64_t old = t1;
  66         uint64_t new = t2;
  67
  68         return (new >= old ? new - old : (UINT64_MAX - old) + new + 1);
  69 }
  70
  71 static fmd_serd_eng_t *
  72 fmd_serd_eng_alloc(const char *name, uint64_t n, hrtime_t t)
  73 {
  74         fmd_serd_eng_t *sgp;
  75
  76         sgp = malloc(sizeof (fmd_serd_eng_t));
  77         bzero(sgp, sizeof (fmd_serd_eng_t));
  78
  79         sgp->sg_name = strdup(name);
  80         sgp->sg_flags = FMD_SERD_DIRTY;
  81         sgp->sg_n = n;
  82         sgp->sg_t = t;
  83
  84         list_create(&sgp->sg_list, sizeof (fmd_serd_elem_t),
  85             offsetof(fmd_serd_elem_t, se_list));
  86
  87         return (sgp);
  88 }
  89
  90 static void
  91 fmd_serd_eng_free(fmd_serd_eng_t *sgp)
  92 {
  93         fmd_serd_eng_reset(sgp);
  94         free(sgp->sg_name);
  95         list_destroy(&sgp->sg_list);
  96         free(sgp);
  97 }
  98
  99 /*
 100  * sourced from fmd_string.c
 101  */
 102 static ulong_t
 103 fmd_strhash(const char *key)
 104 {
 105         ulong_t g, h = 0;
 106         const char *p;
 107
 108         for (p = key; *p != '\0'; p++) {
 109                 h = (h << 4) + *p;
 110
 111                 if ((g = (h & 0xf0000000)) != 0) {
 112                         h ^= (g >> 24);
 113                         h ^= g;
 114                 }
 115         }
 116
 117         return (h);
 118 }
 119
 120 void
 121 fmd_serd_hash_create(fmd_serd_hash_t *shp)
 122 {
 123         shp->sh_hashlen = FMD_STR_BUCKETS;
 124         shp->sh_hash = calloc(shp->sh_hashlen, sizeof (void *));
 125         shp->sh_count = 0;
 126 }
 127
 128 void
 129 fmd_serd_hash_destroy(fmd_serd_hash_t *shp)
 130 {
 131         fmd_serd_eng_t *sgp, *ngp;
 132         uint_t i;
 133
 134         for (i = 0; i < shp->sh_hashlen; i++) {
 135                 for (sgp = shp->sh_hash[i]; sgp != NULL; sgp = ngp) {
 136                         ngp = sgp->sg_next;
 137                         fmd_serd_eng_free(sgp);
 138                 }
 139         }
 140
 141         free(shp->sh_hash);
 142         bzero(shp, sizeof (fmd_serd_hash_t));
 143 }
 144
 145 void
 146 fmd_serd_hash_apply(fmd_serd_hash_t *shp, fmd_serd_eng_f *func, void *arg)
 147 {
 148         fmd_serd_eng_t *sgp;
 149         uint_t i;
 150
 151         for (i = 0; i < shp->sh_hashlen; i++) {
 152                 for (sgp = shp->sh_hash[i]; sgp != NULL; sgp = sgp->sg_next)
 153                         func(sgp, arg);
 154         }
 155 }
 156
 157 fmd_serd_eng_t *
 158 fmd_serd_eng_insert(fmd_serd_hash_t *shp, const char *name,
 159     uint_t n, hrtime_t t)
 160 {
 161         uint_t h = fmd_strhash(name) % shp->sh_hashlen;
 162         fmd_serd_eng_t *sgp = fmd_serd_eng_alloc(name, n, t);
 163
 164         serd_log_msg("  SERD Engine: inserting  %s N %d T %llu",
 165             name, (int)n, (long long unsigned)t);
 166
 167         sgp->sg_next = shp->sh_hash[h];
 168         shp->sh_hash[h] = sgp;
 169         shp->sh_count++;
 170
 171         return (sgp);
 172 }
 173
 174 fmd_serd_eng_t *
 175 fmd_serd_eng_lookup(fmd_serd_hash_t *shp, const char *name)
 176 {
 177         uint_t h = fmd_strhash(name) % shp->sh_hashlen;
 178         fmd_serd_eng_t *sgp;
 179
 180         for (sgp = shp->sh_hash[h]; sgp != NULL; sgp = sgp->sg_next) {
 181                 if (strcmp(name, sgp->sg_name) == 0)
 182                         return (sgp);
 183         }
 184
 185         return (NULL);
 186 }
 187
 188 void
 189 fmd_serd_eng_delete(fmd_serd_hash_t *shp, const char *name)
 190 {
 191         uint_t h = fmd_strhash(name) % shp->sh_hashlen;
 192         fmd_serd_eng_t *sgp, **pp = &shp->sh_hash[h];
 193
 194         serd_log_msg("  SERD Engine: deleting %s", name);
 195
 196         for (sgp = *pp; sgp != NULL; sgp = sgp->sg_next) {
 197                 if (strcmp(sgp->sg_name, name) != 0)
 198                         pp = &sgp->sg_next;
 199                 else
 200                         break;
 201         }
 202
 203         if (sgp != NULL) {
 204                 *pp = sgp->sg_next;
 205                 fmd_serd_eng_free(sgp);
 206                 assert(shp->sh_count != 0);
 207                 shp->sh_count--;
 208         }
 209 }
 210
 211 static void
 212 fmd_serd_eng_discard(fmd_serd_eng_t *sgp, fmd_serd_elem_t *sep)
 213 {
 214         list_remove(&sgp->sg_list, sep);
 215         sgp->sg_count--;
 216
 217         serd_log_msg("  SERD Engine: discarding %s, %d remaining",
 218             sgp->sg_name, (int)sgp->sg_count);
 219
 220         free(sep);
 221 }
 222
 223 int
 224 fmd_serd_eng_record(fmd_serd_eng_t *sgp, hrtime_t hrt)
 225 {
 226         fmd_serd_elem_t *sep, *oep;
 227
 228         /*
 229          * If the fired flag is already set, return false and discard the
 230          * event.  This means that the caller will only see the engine "fire"
 231          * once until fmd_serd_eng_reset() is called.  The fmd_serd_eng_fired()
 232          * function can also be used in combination with fmd_serd_eng_record().
 233          */
 234         if (sgp->sg_flags & FMD_SERD_FIRED) {
 235                 serd_log_msg("  SERD Engine: record %s already fired!",
 236                     sgp->sg_name);
 237                 return (FMD_B_FALSE);
 238         }
 239
 240         while (sgp->sg_count >= sgp->sg_n)
 241                 fmd_serd_eng_discard(sgp, list_tail(&sgp->sg_list));
 242
 243         sep = malloc(sizeof (fmd_serd_elem_t));
 244         sep->se_hrt = hrt;
 245
 246         list_insert_head(&sgp->sg_list, sep);
 247         sgp->sg_count++;
 248
 249         serd_log_msg("  SERD Engine: recording %s of %d (%llu)",
 250             sgp->sg_name, (int)sgp->sg_count, (long long unsigned)hrt);
 251
 252         /*
 253          * Pick up the oldest element pointer for comparison to 'sep'.  We must
 254          * do this after adding 'sep' because 'oep' and 'sep' can be the same.
 255          */
 256         oep = list_tail(&sgp->sg_list);
 257
 258         if (sgp->sg_count >= sgp->sg_n &&
 259             fmd_event_delta(oep->se_hrt, sep->se_hrt) <= sgp->sg_t) {
 260                 sgp->sg_flags |= FMD_SERD_FIRED | FMD_SERD_DIRTY;
 261                 serd_log_msg("  SERD Engine: fired %s", sgp->sg_name);
 262                 return (FMD_B_TRUE);
 263         }
 264
 265         sgp->sg_flags |= FMD_SERD_DIRTY;
 266         return (FMD_B_FALSE);
 267 }
 268
 269 int
 270 fmd_serd_eng_fired(fmd_serd_eng_t *sgp)
 271 {
 272         return (sgp->sg_flags & FMD_SERD_FIRED);
 273 }
 274
 275 int
 276 fmd_serd_eng_empty(fmd_serd_eng_t *sgp)
 277 {
 278         return (sgp->sg_count == 0);
 279 }
 280
 281 void
 282 fmd_serd_eng_reset(fmd_serd_eng_t *sgp)
 283 {
 284         serd_log_msg("  SERD Engine: reseting %s", sgp->sg_name);
 285
 286         while (sgp->sg_count != 0)
 287                 fmd_serd_eng_discard(sgp, list_head(&sgp->sg_list));
 288
 289         sgp->sg_flags &= ~FMD_SERD_FIRED;
 290         sgp->sg_flags |= FMD_SERD_DIRTY;
 291 }
 292
 293 void
 294 fmd_serd_eng_gc(fmd_serd_eng_t *sgp)
 295 {
 296         fmd_serd_elem_t *sep, *nep;
 297         hrtime_t hrt;
 298
 299         if (sgp->sg_count == 0 || (sgp->sg_flags & FMD_SERD_FIRED))
 300                 return; /* no garbage collection needed if empty or fired */
 301
 302         sep = list_head(&sgp->sg_list);
 303         if (sep == NULL)
 304                 return;
 305
 306         hrt = sep->se_hrt - sgp->sg_t;
 307
 308         for (sep = list_head(&sgp->sg_list); sep != NULL; sep = nep) {
 309                 if (sep->se_hrt >= hrt)
 310                         break; /* sep and subsequent events are all within T */
 311
 312                 nep = list_next(&sgp->sg_list, sep);
 313                 fmd_serd_eng_discard(sgp, sep);
 314                 sgp->sg_flags |= FMD_SERD_DIRTY;
 315         }
 316 }