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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 | // SPDX-License-Identifier: GPL-2.0-or-later /* * SCSI device handler infrastructure. * * Copyright IBM Corporation, 2007 * Authors: * Chandra Seetharaman <sekharan@us.ibm.com> * Mike Anderson <andmike@linux.vnet.ibm.com> */ #include <linux/slab.h> #include <linux/module.h> #include <scsi/scsi_dh.h> #include "scsi_priv.h" static DEFINE_SPINLOCK(list_lock); static LIST_HEAD(scsi_dh_list); struct scsi_dh_blist { const char *vendor; const char *model; const char *driver; }; static const struct scsi_dh_blist scsi_dh_blist[] = { {"DGC", "RAID", "emc" }, {"DGC", "DISK", "emc" }, {"DGC", "VRAID", "emc" }, {"COMPAQ", "MSA1000 VOLUME", "hp_sw" }, {"COMPAQ", "HSV110", "hp_sw" }, {"HP", "HSV100", "hp_sw"}, {"DEC", "HSG80", "hp_sw"}, {"IBM", "1722", "rdac", }, {"IBM", "1724", "rdac", }, {"IBM", "1726", "rdac", }, {"IBM", "1742", "rdac", }, {"IBM", "1745", "rdac", }, {"IBM", "1746", "rdac", }, {"IBM", "1813", "rdac", }, {"IBM", "1814", "rdac", }, {"IBM", "1815", "rdac", }, {"IBM", "1818", "rdac", }, {"IBM", "3526", "rdac", }, {"IBM", "3542", "rdac", }, {"IBM", "3552", "rdac", }, {"SGI", "TP9300", "rdac", }, {"SGI", "TP9400", "rdac", }, {"SGI", "TP9500", "rdac", }, {"SGI", "TP9700", "rdac", }, {"SGI", "IS", "rdac", }, {"STK", "OPENstorage", "rdac", }, {"STK", "FLEXLINE 380", "rdac", }, {"STK", "BladeCtlr", "rdac", }, {"SUN", "CSM", "rdac", }, {"SUN", "LCSM100", "rdac", }, {"SUN", "STK6580_6780", "rdac", }, {"SUN", "SUN_6180", "rdac", }, {"SUN", "ArrayStorage", "rdac", }, {"DELL", "MD3", "rdac", }, {"NETAPP", "INF-01-00", "rdac", }, {"LSI", "INF-01-00", "rdac", }, {"ENGENIO", "INF-01-00", "rdac", }, {"LENOVO", "DE_Series", "rdac", }, {"FUJITSU", "ETERNUS_AHB", "rdac", }, {NULL, NULL, NULL }, }; static const char * scsi_dh_find_driver(struct scsi_device *sdev) { const struct scsi_dh_blist *b; if (scsi_device_tpgs(sdev)) return "alua"; for (b = scsi_dh_blist; b->vendor; b++) { if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) && !strncmp(sdev->model, b->model, strlen(b->model))) { return b->driver; } } return NULL; } static struct scsi_device_handler *__scsi_dh_lookup(const char *name) { struct scsi_device_handler *tmp, *found = NULL; spin_lock(&list_lock); list_for_each_entry(tmp, &scsi_dh_list, list) { if (!strncmp(tmp->name, name, strlen(tmp->name))) { found = tmp; break; } } spin_unlock(&list_lock); return found; } static struct scsi_device_handler *scsi_dh_lookup(const char *name) { struct scsi_device_handler *dh; if (!name || strlen(name) == 0) return NULL; dh = __scsi_dh_lookup(name); if (!dh) { request_module("scsi_dh_%s", name); dh = __scsi_dh_lookup(name); } return dh; } /* * scsi_dh_handler_attach - Attach a device handler to a device * @sdev - SCSI device the device handler should attach to * @scsi_dh - The device handler to attach */ static int scsi_dh_handler_attach(struct scsi_device *sdev, struct scsi_device_handler *scsi_dh) { int error, ret = 0; if (!try_module_get(scsi_dh->module)) return -EINVAL; error = scsi_dh->attach(sdev); if (error != SCSI_DH_OK) { switch (error) { case SCSI_DH_NOMEM: ret = -ENOMEM; break; case SCSI_DH_RES_TEMP_UNAVAIL: ret = -EAGAIN; break; case SCSI_DH_DEV_UNSUPP: case SCSI_DH_NOSYS: ret = -ENODEV; break; default: ret = -EINVAL; break; } if (ret != -ENODEV) sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n", scsi_dh->name, error); module_put(scsi_dh->module); } else sdev->handler = scsi_dh; return ret; } /* * scsi_dh_handler_detach - Detach a device handler from a device * @sdev - SCSI device the device handler should be detached from */ static void scsi_dh_handler_detach(struct scsi_device *sdev) { sdev->handler->detach(sdev); sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name); module_put(sdev->handler->module); } void scsi_dh_add_device(struct scsi_device *sdev) { struct scsi_device_handler *devinfo = NULL; const char *drv; drv = scsi_dh_find_driver(sdev); if (drv) devinfo = __scsi_dh_lookup(drv); /* * device_handler is optional, so ignore errors * from scsi_dh_handler_attach() */ if (devinfo) (void)scsi_dh_handler_attach(sdev, devinfo); } void scsi_dh_release_device(struct scsi_device *sdev) { if (sdev->handler) scsi_dh_handler_detach(sdev); } /* * scsi_register_device_handler - register a device handler personality * module. * @scsi_dh - device handler to be registered. * * Returns 0 on success, -EBUSY if handler already registered. */ int scsi_register_device_handler(struct scsi_device_handler *scsi_dh) { if (__scsi_dh_lookup(scsi_dh->name)) return -EBUSY; if (!scsi_dh->attach || !scsi_dh->detach) return -EINVAL; spin_lock(&list_lock); list_add(&scsi_dh->list, &scsi_dh_list); spin_unlock(&list_lock); printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name); return SCSI_DH_OK; } EXPORT_SYMBOL_GPL(scsi_register_device_handler); /* * scsi_unregister_device_handler - register a device handler personality * module. * @scsi_dh - device handler to be unregistered. * * Returns 0 on success, -ENODEV if handler not registered. */ int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) { if (!__scsi_dh_lookup(scsi_dh->name)) return -ENODEV; spin_lock(&list_lock); list_del(&scsi_dh->list); spin_unlock(&list_lock); printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name); return SCSI_DH_OK; } EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); /* * scsi_dh_activate - activate the path associated with the scsi_device * corresponding to the given request queue. * Returns immediately without waiting for activation to be completed. * @q - Request queue that is associated with the scsi_device to be * activated. * @fn - Function to be called upon completion of the activation. * Function fn is called with data (below) and the error code. * Function fn may be called from the same calling context. So, * do not hold the lock in the caller which may be needed in fn. * @data - data passed to the function fn upon completion. * */ int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) { struct scsi_device *sdev; int err = SCSI_DH_NOSYS; sdev = scsi_device_from_queue(q); if (!sdev) { if (fn) fn(data, err); return err; } if (!sdev->handler) goto out_fn; err = SCSI_DH_NOTCONN; if (sdev->sdev_state == SDEV_CANCEL || sdev->sdev_state == SDEV_DEL) goto out_fn; err = SCSI_DH_DEV_OFFLINED; if (sdev->sdev_state == SDEV_OFFLINE) goto out_fn; if (sdev->handler->activate) err = sdev->handler->activate(sdev, fn, data); out_put_device: put_device(&sdev->sdev_gendev); return err; out_fn: if (fn) fn(data, err); goto out_put_device; } EXPORT_SYMBOL_GPL(scsi_dh_activate); /* * scsi_dh_set_params - set the parameters for the device as per the * string specified in params. * @q - Request queue that is associated with the scsi_device for * which the parameters to be set. * @params - parameters in the following format * "no_of_params\0param1\0param2\0param3\0...\0" * for example, string for 2 parameters with value 10 and 21 * is specified as "2\010\021\0". */ int scsi_dh_set_params(struct request_queue *q, const char *params) { struct scsi_device *sdev; int err = -SCSI_DH_NOSYS; sdev = scsi_device_from_queue(q); if (!sdev) return err; if (sdev->handler && sdev->handler->set_params) err = sdev->handler->set_params(sdev, params); put_device(&sdev->sdev_gendev); return err; } EXPORT_SYMBOL_GPL(scsi_dh_set_params); /* * scsi_dh_attach - Attach device handler * @q - Request queue that is associated with the scsi_device * the handler should be attached to * @name - name of the handler to attach */ int scsi_dh_attach(struct request_queue *q, const char *name) { struct scsi_device *sdev; struct scsi_device_handler *scsi_dh; int err = 0; sdev = scsi_device_from_queue(q); if (!sdev) return -ENODEV; scsi_dh = scsi_dh_lookup(name); if (!scsi_dh) { err = -EINVAL; goto out_put_device; } if (sdev->handler) { if (sdev->handler != scsi_dh) err = -EBUSY; goto out_put_device; } err = scsi_dh_handler_attach(sdev, scsi_dh); out_put_device: put_device(&sdev->sdev_gendev); return err; } EXPORT_SYMBOL_GPL(scsi_dh_attach); /* * scsi_dh_attached_handler_name - Get attached device handler's name * @q - Request queue that is associated with the scsi_device * that may have a device handler attached * @gfp - the GFP mask used in the kmalloc() call when allocating memory * * Returns name of attached handler, NULL if no handler is attached. * Caller must take care to free the returned string. */ const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) { struct scsi_device *sdev; const char *handler_name = NULL; sdev = scsi_device_from_queue(q); if (!sdev) return NULL; if (sdev->handler) handler_name = kstrdup(sdev->handler->name, gfp); put_device(&sdev->sdev_gendev); return handler_name; } EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name); |