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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * Config dependent data structures for the Streams Administrative Driver 30 * (or "Ballad of the SAD Cafe"). 31 */ 32 #include <sys/types.h> 33 #include <sys/conf.h> 34 #include <sys/stream.h> 35 #include <sys/strsubr.h> 36 #include <sys/sad.h> 37 #include <sys/kmem.h> 38 #include <sys/sysmacros.h> 39 40 /* 41 * Currently we store all the sad data in a hash table keyed by major 42 * number. This is far from ideal. It means that if a single device 43 * starts using lots of SAP_ONE entries all its entries will hash 44 * to the same bucket and we'll get very long chains for that bucket. 45 * 46 * Unfortunately, it's not possible to hash by a different key or to easily 47 * break up our one hash into seperate hashs. The reason is because 48 * the hash contains mixed data types. Ie, it has three different 49 * types of autopush nodes in it: SAP_ALL, SAP_RANGE, SAP_ONE. Not 50 * only does the hash table contain nodes of different types, but we 51 * have to be able to search the table with a node of one type that 52 * might match another node with a different type. (ie, we might search 53 * for a SAP_ONE node with a value that matches a SAP_ALL node in the 54 * hash, or vice versa.) 55 * 56 * An ideal solution would probably be an AVL tree sorted by major 57 * numbers. Each node in the AVL tree would have the following optional 58 * data associated with it: 59 * - a single SAP_ALL autopush node 60 * - an or avl tree or hash table of SAP_RANGE and SAP_ONE autopush 61 * nodes indexed by minor numbers. perhaps two separate tables, 62 * one for each type of autopush nodes. 63 * 64 * Note that regardless of how the data is stored there can't be any overlap 65 * stored between autopush nodes. For example, if there is a SAP_ALL node 66 * for a given major number then there can't be any SAP_RANGE or SAP_ONE 67 * nodes for that same major number. 68 */ 69 70 /* 71 * Private Internal Interfaces 72 */ 73 /*ARGSUSED*/ 74 static uint_t 75 sad_hash_alg(void *hash_data, mod_hash_key_t key) 76 { 77 struct apcommon *apc = (struct apcommon *)key; 78 79 ASSERT(sad_apc_verify(apc) == 0); 80 return (apc->apc_major); 81 } 82 83 /* 84 * Compare hash keys based off of major, minor, lastminor, and type. 85 */ 86 static int 87 sad_hash_keycmp(mod_hash_key_t key1, mod_hash_key_t key2) 88 { 89 struct apcommon *apc1 = (struct apcommon *)key1; 90 struct apcommon *apc2 = (struct apcommon *)key2; 91 92 ASSERT(sad_apc_verify(apc1) == 0); 93 ASSERT(sad_apc_verify(apc2) == 0); 94 95 /* Filter out cases where the major number doesn't match. */ 96 if (apc1->apc_major != apc2->apc_major) 97 return (1); 98 99 /* If either type is SAP_ALL then we're done. */ 100 if ((apc1->apc_cmd == SAP_ALL) || (apc2->apc_cmd == SAP_ALL)) 101 return (0); 102 103 /* Deal with the case where both types are SAP_ONE. */ 104 if ((apc1->apc_cmd == SAP_ONE) && (apc2->apc_cmd == SAP_ONE)) { 105 /* Check if the minor numbers match. */ 106 return (apc1->apc_minor != apc2->apc_minor); 107 } 108 109 /* Deal with the case where both types are SAP_RANGE. */ 110 if ((apc1->apc_cmd == SAP_RANGE) && (apc2->apc_cmd == SAP_RANGE)) { 111 /* Check for overlapping ranges. */ 112 if ((apc1->apc_lastminor < apc2->apc_minor) || 113 (apc1->apc_minor > apc2->apc_lastminor)) 114 return (1); 115 return (0); 116 } 117 118 /* 119 * We know that one type is SAP_ONE and the other is SAP_RANGE. 120 * So now let's do range matching. 121 */ 122 if (apc1->apc_cmd == SAP_RANGE) { 123 ASSERT(apc2->apc_cmd == SAP_ONE); 124 if ((apc1->apc_lastminor < apc2->apc_minor) || 125 (apc1->apc_minor > apc2->apc_minor)) 126 return (1); 127 } else { 128 ASSERT(apc1->apc_cmd == SAP_ONE); 129 ASSERT(apc2->apc_cmd == SAP_RANGE); 130 if ((apc1->apc_minor < apc2->apc_minor) || 131 (apc1->apc_minor > apc2->apc_lastminor)) 132 return (1); 133 } 134 return (0); 135 } 136 137 /* 138 * External Interfaces 139 */ 140 int 141 sad_apc_verify(struct apcommon *apc) 142 { 143 /* sanity check the number of modules to push */ 144 if ((apc->apc_npush == 0) || (apc->apc_npush > MAXAPUSH) || 145 (apc->apc_npush > nstrpush)) 146 return (EINVAL); 147 148 /* Check for NODEV major vaule */ 149 if (apc->apc_major == -1) 150 return (EINVAL); 151 152 switch (apc->apc_cmd) { 153 case SAP_ALL: 154 case SAP_ONE: 155 /* 156 * Really, we'd like to be strict here and make sure that 157 * apc_lastminor is 0 (since setting apc_lastminor for 158 * SAP_ALL and SAP_ONE commands doesn't make any sense), 159 * but we can't since historically apc_lastminor has been 160 * silently ignored for non-SAP_RANGE commands. 161 */ 162 break; 163 case SAP_RANGE: 164 if (apc->apc_lastminor <= apc->apc_minor) 165 return (ERANGE); 166 break; 167 default: 168 return (EINVAL); 169 } 170 return (0); 171 } 172 173 int 174 sad_ap_verify(struct autopush *ap) 175 { 176 int ret, i; 177 178 if ((ret = sad_apc_verify(&ap->ap_common)) != 0) 179 return (ret); 180 181 /* 182 * Validate that the specified list of modules exist. Note that 183 * ap_npush has already been sanity checked by sad_apc_verify(). 184 */ 185 for (i = 0; i < ap->ap_npush; i++) { 186 ap->ap_list[i][FMNAMESZ] = '\0'; 187 if (fmodsw_find(ap->ap_list[i], FMODSW_LOAD) == NULL) 188 return (EINVAL); 189 } 190 return (0); 191 } 192 193 struct autopush * 194 sad_ap_alloc(void) 195 { 196 struct autopush *ap_new; 197 198 ap_new = kmem_zalloc(sizeof (struct autopush), KM_SLEEP); 199 ap_new->ap_cnt = 1; 200 return (ap_new); 201 } 202 203 void 204 sad_ap_rele(struct autopush *ap, str_stack_t *ss) 205 { 206 mutex_enter(&ss->ss_sad_lock); 207 ASSERT(ap->ap_cnt > 0); 208 if (--(ap->ap_cnt) == 0) { 209 mutex_exit(&ss->ss_sad_lock); 210 kmem_free(ap, sizeof (struct autopush)); 211 } else { 212 mutex_exit(&ss->ss_sad_lock); 213 } 214 } 215 216 void 217 sad_ap_insert(struct autopush *ap, str_stack_t *ss) 218 { 219 ASSERT(MUTEX_HELD(&ss->ss_sad_lock)); 220 ASSERT(sad_apc_verify(&ap->ap_common) == 0); 221 ASSERT(sad_ap_find(&ap->ap_common, ss) == NULL); 222 (void) mod_hash_insert(ss->ss_sad_hash, &ap->ap_common, ap); 223 } 224 225 void 226 sad_ap_remove(struct autopush *ap, str_stack_t *ss) 227 { 228 struct autopush *ap_removed = NULL; 229 230 ASSERT(MUTEX_HELD(&ss->ss_sad_lock)); 231 (void) mod_hash_remove(ss->ss_sad_hash, &ap->ap_common, 232 (mod_hash_val_t *)&ap_removed); 233 ASSERT(ap == ap_removed); 234 } 235 236 struct autopush * 237 sad_ap_find(struct apcommon *apc, str_stack_t *ss) 238 { 239 struct autopush *ap_result = NULL; 240 241 ASSERT(MUTEX_HELD(&ss->ss_sad_lock)); 242 ASSERT(sad_apc_verify(apc) == 0); 243 244 (void) mod_hash_find(ss->ss_sad_hash, apc, 245 (mod_hash_val_t *)&ap_result); 246 if (ap_result != NULL) 247 ap_result->ap_cnt++; 248 return (ap_result); 249 } 250 251 struct autopush * 252 sad_ap_find_by_dev(dev_t dev, str_stack_t *ss) 253 { 254 struct apcommon apc; 255 struct autopush *ap_result; 256 257 ASSERT(MUTEX_NOT_HELD(&ss->ss_sad_lock)); 258 259 /* prepare an apcommon structure to search with */ 260 apc.apc_cmd = SAP_ONE; 261 apc.apc_major = getmajor(dev); 262 apc.apc_minor = getminor(dev); 263 264 /* 265 * the following values must be set but initialized to have a 266 * valid apcommon struct, but since we're only using this 267 * structure to do a query the values are never actually used. 268 */ 269 apc.apc_npush = 1; 270 apc.apc_lastminor = 0; 271 272 mutex_enter(&ss->ss_sad_lock); 273 ap_result = sad_ap_find(&apc, ss); 274 mutex_exit(&ss->ss_sad_lock); 275 return (ap_result); 276 } 277 278 void 279 sad_initspace(str_stack_t *ss) 280 { 281 mutex_init(&ss->ss_sad_lock, NULL, MUTEX_DEFAULT, NULL); 282 ss->ss_sad_hash_nchains = 127; 283 ss->ss_sadcnt = 16; 284 285 ss->ss_saddev = kmem_zalloc(ss->ss_sadcnt * sizeof (struct saddev), 286 KM_SLEEP); 287 ss->ss_sad_hash = mod_hash_create_extended("sad_hash", 288 ss->ss_sad_hash_nchains, mod_hash_null_keydtor, 289 mod_hash_null_valdtor, 290 sad_hash_alg, NULL, sad_hash_keycmp, KM_SLEEP); 291 } 292 293 void 294 sad_freespace(str_stack_t *ss) 295 { 296 kmem_free(ss->ss_saddev, ss->ss_sadcnt * sizeof (struct saddev)); 297 ss->ss_saddev = NULL; 298 299 mod_hash_destroy_hash(ss->ss_sad_hash); 300 ss->ss_sad_hash = NULL; 301 302 mutex_destroy(&ss->ss_sad_lock); 303 } 304