Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 1 | /* |
| 2 | * SCSI device handler infrastruture. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License as published by the |
| 6 | * Free Software Foundation; either version 2 of the License, or (at your |
| 7 | * option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, but |
| 10 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | * |
| 18 | * Copyright IBM Corporation, 2007 |
| 19 | * Authors: |
| 20 | * Chandra Seetharaman <sekharan@us.ibm.com> |
| 21 | * Mike Anderson <andmike@linux.vnet.ibm.com> |
| 22 | */ |
| 23 | |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 24 | #include <linux/slab.h> |
Paul Gortmaker | acf3368f | 2011-05-27 09:47:43 -0400 | [diff] [blame] | 25 | #include <linux/module.h> |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 26 | #include <scsi/scsi_dh.h> |
| 27 | #include "../scsi_priv.h" |
| 28 | |
| 29 | static DEFINE_SPINLOCK(list_lock); |
| 30 | static LIST_HEAD(scsi_dh_list); |
| 31 | |
| 32 | static struct scsi_device_handler *get_device_handler(const char *name) |
| 33 | { |
| 34 | struct scsi_device_handler *tmp, *found = NULL; |
| 35 | |
| 36 | spin_lock(&list_lock); |
| 37 | list_for_each_entry(tmp, &scsi_dh_list, list) { |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 38 | if (!strncmp(tmp->name, name, strlen(tmp->name))) { |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 39 | found = tmp; |
| 40 | break; |
| 41 | } |
| 42 | } |
| 43 | spin_unlock(&list_lock); |
| 44 | return found; |
| 45 | } |
| 46 | |
Hannes Reinecke | 7c32c7a | 2008-07-17 16:53:33 -0700 | [diff] [blame] | 47 | /* |
Hannes Reinecke | 6c3633d | 2011-08-24 10:51:15 +0200 | [diff] [blame] | 48 | * device_handler_match_function - Match a device handler to a device |
| 49 | * @sdev - SCSI device to be tested |
| 50 | * |
| 51 | * Tests @sdev against the match function of all registered device_handler. |
| 52 | * Returns the found device handler or NULL if not found. |
| 53 | */ |
| 54 | static struct scsi_device_handler * |
| 55 | device_handler_match_function(struct scsi_device *sdev) |
| 56 | { |
| 57 | struct scsi_device_handler *tmp_dh, *found_dh = NULL; |
| 58 | |
| 59 | spin_lock(&list_lock); |
| 60 | list_for_each_entry(tmp_dh, &scsi_dh_list, list) { |
| 61 | if (tmp_dh->match && tmp_dh->match(sdev)) { |
| 62 | found_dh = tmp_dh; |
| 63 | break; |
| 64 | } |
| 65 | } |
| 66 | spin_unlock(&list_lock); |
| 67 | return found_dh; |
| 68 | } |
| 69 | |
| 70 | /* |
Hannes Reinecke | 7c32c7a | 2008-07-17 16:53:33 -0700 | [diff] [blame] | 71 | * device_handler_match - Attach a device handler to a device |
| 72 | * @scsi_dh - The device handler to match against or NULL |
| 73 | * @sdev - SCSI device to be tested against @scsi_dh |
| 74 | * |
| 75 | * Tests @sdev against the device handler @scsi_dh or against |
| 76 | * all registered device_handler if @scsi_dh == NULL. |
| 77 | * Returns the found device handler or NULL if not found. |
| 78 | */ |
| 79 | static struct scsi_device_handler * |
| 80 | device_handler_match(struct scsi_device_handler *scsi_dh, |
| 81 | struct scsi_device *sdev) |
| 82 | { |
Hannes Reinecke | 6c3633d | 2011-08-24 10:51:15 +0200 | [diff] [blame] | 83 | struct scsi_device_handler *found_dh; |
Hannes Reinecke | 7c32c7a | 2008-07-17 16:53:33 -0700 | [diff] [blame] | 84 | |
Hannes Reinecke | 6c3633d | 2011-08-24 10:51:15 +0200 | [diff] [blame] | 85 | found_dh = device_handler_match_function(sdev); |
Hannes Reinecke | 7c32c7a | 2008-07-17 16:53:33 -0700 | [diff] [blame] | 86 | |
Peter Jones | 940d7fa | 2011-01-06 15:38:24 -0500 | [diff] [blame] | 87 | if (scsi_dh && found_dh != scsi_dh) |
| 88 | found_dh = NULL; |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 89 | |
Hannes Reinecke | 7c32c7a | 2008-07-17 16:53:33 -0700 | [diff] [blame] | 90 | return found_dh; |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 91 | } |
| 92 | |
| 93 | /* |
| 94 | * scsi_dh_handler_attach - Attach a device handler to a device |
| 95 | * @sdev - SCSI device the device handler should attach to |
| 96 | * @scsi_dh - The device handler to attach |
| 97 | */ |
| 98 | static int scsi_dh_handler_attach(struct scsi_device *sdev, |
| 99 | struct scsi_device_handler *scsi_dh) |
| 100 | { |
Christoph Hellwig | 1d52032 | 2014-09-14 11:08:21 -0700 | [diff] [blame] | 101 | struct scsi_dh_data *d; |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 102 | |
| 103 | if (sdev->scsi_dh_data) { |
| 104 | if (sdev->scsi_dh_data->scsi_dh != scsi_dh) |
Christoph Hellwig | 27c888f | 2014-09-13 19:41:16 -0700 | [diff] [blame] | 105 | return -EBUSY; |
| 106 | |
| 107 | kref_get(&sdev->scsi_dh_data->kref); |
| 108 | return 0; |
| 109 | } |
| 110 | |
Christoph Hellwig | 1f12ffa | 2014-09-13 20:08:44 -0700 | [diff] [blame] | 111 | if (!try_module_get(scsi_dh->module)) |
| 112 | return -EINVAL; |
Christoph Hellwig | 27c888f | 2014-09-13 19:41:16 -0700 | [diff] [blame] | 113 | |
Christoph Hellwig | 1d52032 | 2014-09-14 11:08:21 -0700 | [diff] [blame] | 114 | d = scsi_dh->attach(sdev); |
| 115 | if (IS_ERR(d)) { |
| 116 | sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%ld)\n", |
| 117 | scsi_dh->name, PTR_ERR(d)); |
Christoph Hellwig | 1f12ffa | 2014-09-13 20:08:44 -0700 | [diff] [blame] | 118 | module_put(scsi_dh->module); |
Christoph Hellwig | 1d52032 | 2014-09-14 11:08:21 -0700 | [diff] [blame] | 119 | return PTR_ERR(d); |
Chandra Seetharaman | 6c10db7 | 2009-06-26 19:30:06 -0700 | [diff] [blame] | 120 | } |
Christoph Hellwig | 1f12ffa | 2014-09-13 20:08:44 -0700 | [diff] [blame] | 121 | |
Christoph Hellwig | 1d52032 | 2014-09-14 11:08:21 -0700 | [diff] [blame] | 122 | d->scsi_dh = scsi_dh; |
| 123 | kref_init(&d->kref); |
| 124 | d->sdev = sdev; |
| 125 | |
| 126 | spin_lock_irq(sdev->request_queue->queue_lock); |
| 127 | sdev->scsi_dh_data = d; |
| 128 | spin_unlock_irq(sdev->request_queue->queue_lock); |
| 129 | return 0; |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 130 | } |
| 131 | |
Chandra Seetharaman | 6c10db7 | 2009-06-26 19:30:06 -0700 | [diff] [blame] | 132 | static void __detach_handler (struct kref *kref) |
| 133 | { |
Christoph Hellwig | 27c888f | 2014-09-13 19:41:16 -0700 | [diff] [blame] | 134 | struct scsi_dh_data *scsi_dh_data = |
| 135 | container_of(kref, struct scsi_dh_data, kref); |
| 136 | struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; |
Christoph Hellwig | 1d52032 | 2014-09-14 11:08:21 -0700 | [diff] [blame] | 137 | struct scsi_device *sdev = scsi_dh_data->sdev; |
Christoph Hellwig | 27c888f | 2014-09-13 19:41:16 -0700 | [diff] [blame] | 138 | |
Christoph Hellwig | 1d52032 | 2014-09-14 11:08:21 -0700 | [diff] [blame] | 139 | spin_lock_irq(sdev->request_queue->queue_lock); |
| 140 | sdev->scsi_dh_data = NULL; |
| 141 | spin_unlock_irq(sdev->request_queue->queue_lock); |
| 142 | |
| 143 | scsi_dh->detach(sdev); |
| 144 | sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", scsi_dh->name); |
Christoph Hellwig | 27c888f | 2014-09-13 19:41:16 -0700 | [diff] [blame] | 145 | module_put(scsi_dh->module); |
Chandra Seetharaman | 6c10db7 | 2009-06-26 19:30:06 -0700 | [diff] [blame] | 146 | } |
| 147 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 148 | /* |
| 149 | * scsi_dh_handler_detach - Detach a device handler from a device |
| 150 | * @sdev - SCSI device the device handler should be detached from |
| 151 | * @scsi_dh - Device handler to be detached |
| 152 | * |
| 153 | * Detach from a device handler. If a device handler is specified, |
Hannes Reinecke | 4c05ae5 | 2008-07-17 16:52:57 -0700 | [diff] [blame] | 154 | * only detach if the currently attached handler matches @scsi_dh. |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 155 | */ |
| 156 | static void scsi_dh_handler_detach(struct scsi_device *sdev, |
| 157 | struct scsi_device_handler *scsi_dh) |
| 158 | { |
| 159 | if (!sdev->scsi_dh_data) |
| 160 | return; |
| 161 | |
| 162 | if (scsi_dh && scsi_dh != sdev->scsi_dh_data->scsi_dh) |
| 163 | return; |
| 164 | |
| 165 | if (!scsi_dh) |
| 166 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
| 167 | |
Christoph Hellwig | 1f12ffa | 2014-09-13 20:08:44 -0700 | [diff] [blame] | 168 | if (scsi_dh) |
Chandra Seetharaman | 6c10db7 | 2009-06-26 19:30:06 -0700 | [diff] [blame] | 169 | kref_put(&sdev->scsi_dh_data->kref, __detach_handler); |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 170 | } |
| 171 | |
| 172 | /* |
Hannes Reinecke | 4c05ae5 | 2008-07-17 16:52:57 -0700 | [diff] [blame] | 173 | * Functions for sysfs attribute 'dh_state' |
| 174 | */ |
| 175 | static ssize_t |
| 176 | store_dh_state(struct device *dev, struct device_attribute *attr, |
| 177 | const char *buf, size_t count) |
| 178 | { |
| 179 | struct scsi_device *sdev = to_scsi_device(dev); |
| 180 | struct scsi_device_handler *scsi_dh; |
| 181 | int err = -EINVAL; |
| 182 | |
Hannes Reinecke | 6bc8d2a | 2011-08-24 10:51:17 +0200 | [diff] [blame] | 183 | if (sdev->sdev_state == SDEV_CANCEL || |
| 184 | sdev->sdev_state == SDEV_DEL) |
| 185 | return -ENODEV; |
| 186 | |
Hannes Reinecke | 4c05ae5 | 2008-07-17 16:52:57 -0700 | [diff] [blame] | 187 | if (!sdev->scsi_dh_data) { |
| 188 | /* |
| 189 | * Attach to a device handler |
| 190 | */ |
| 191 | if (!(scsi_dh = get_device_handler(buf))) |
| 192 | return err; |
| 193 | err = scsi_dh_handler_attach(sdev, scsi_dh); |
| 194 | } else { |
| 195 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
| 196 | if (!strncmp(buf, "detach", 6)) { |
| 197 | /* |
| 198 | * Detach from a device handler |
| 199 | */ |
| 200 | scsi_dh_handler_detach(sdev, scsi_dh); |
| 201 | err = 0; |
| 202 | } else if (!strncmp(buf, "activate", 8)) { |
| 203 | /* |
| 204 | * Activate a device handler |
| 205 | */ |
| 206 | if (scsi_dh->activate) |
Chandra Seetharaman | 3ae31f6 | 2009-10-21 09:22:46 -0700 | [diff] [blame] | 207 | err = scsi_dh->activate(sdev, NULL, NULL); |
Hannes Reinecke | 4c05ae5 | 2008-07-17 16:52:57 -0700 | [diff] [blame] | 208 | else |
| 209 | err = 0; |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | return err<0?err:count; |
| 214 | } |
| 215 | |
| 216 | static ssize_t |
| 217 | show_dh_state(struct device *dev, struct device_attribute *attr, char *buf) |
| 218 | { |
| 219 | struct scsi_device *sdev = to_scsi_device(dev); |
| 220 | |
| 221 | if (!sdev->scsi_dh_data) |
| 222 | return snprintf(buf, 20, "detached\n"); |
| 223 | |
| 224 | return snprintf(buf, 20, "%s\n", sdev->scsi_dh_data->scsi_dh->name); |
| 225 | } |
| 226 | |
| 227 | static struct device_attribute scsi_dh_state_attr = |
| 228 | __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state, |
| 229 | store_dh_state); |
| 230 | |
| 231 | /* |
| 232 | * scsi_dh_sysfs_attr_add - Callback for scsi_init_dh |
| 233 | */ |
| 234 | static int scsi_dh_sysfs_attr_add(struct device *dev, void *data) |
| 235 | { |
| 236 | struct scsi_device *sdev; |
| 237 | int err; |
| 238 | |
| 239 | if (!scsi_is_sdev_device(dev)) |
| 240 | return 0; |
| 241 | |
| 242 | sdev = to_scsi_device(dev); |
| 243 | |
| 244 | err = device_create_file(&sdev->sdev_gendev, |
| 245 | &scsi_dh_state_attr); |
| 246 | |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | /* |
| 251 | * scsi_dh_sysfs_attr_remove - Callback for scsi_exit_dh |
| 252 | */ |
| 253 | static int scsi_dh_sysfs_attr_remove(struct device *dev, void *data) |
| 254 | { |
| 255 | struct scsi_device *sdev; |
| 256 | |
| 257 | if (!scsi_is_sdev_device(dev)) |
| 258 | return 0; |
| 259 | |
| 260 | sdev = to_scsi_device(dev); |
| 261 | |
| 262 | device_remove_file(&sdev->sdev_gendev, |
| 263 | &scsi_dh_state_attr); |
| 264 | |
| 265 | return 0; |
| 266 | } |
| 267 | |
| 268 | /* |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 269 | * scsi_dh_notifier - notifier chain callback |
| 270 | */ |
| 271 | static int scsi_dh_notifier(struct notifier_block *nb, |
| 272 | unsigned long action, void *data) |
| 273 | { |
| 274 | struct device *dev = data; |
| 275 | struct scsi_device *sdev; |
| 276 | int err = 0; |
Hannes Reinecke | 7c32c7a | 2008-07-17 16:53:33 -0700 | [diff] [blame] | 277 | struct scsi_device_handler *devinfo = NULL; |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 278 | |
| 279 | if (!scsi_is_sdev_device(dev)) |
| 280 | return 0; |
| 281 | |
| 282 | sdev = to_scsi_device(dev); |
| 283 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 284 | if (action == BUS_NOTIFY_ADD_DEVICE) { |
Chandra Seetharaman | 5917290 | 2009-09-11 10:20:35 -0700 | [diff] [blame] | 285 | err = device_create_file(dev, &scsi_dh_state_attr); |
| 286 | /* don't care about err */ |
Hannes Reinecke | 7c32c7a | 2008-07-17 16:53:33 -0700 | [diff] [blame] | 287 | devinfo = device_handler_match(NULL, sdev); |
Chandra Seetharaman | 5917290 | 2009-09-11 10:20:35 -0700 | [diff] [blame] | 288 | if (devinfo) |
| 289 | err = scsi_dh_handler_attach(sdev, devinfo); |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 290 | } else if (action == BUS_NOTIFY_DEL_DEVICE) { |
Hannes Reinecke | 4c05ae5 | 2008-07-17 16:52:57 -0700 | [diff] [blame] | 291 | device_remove_file(dev, &scsi_dh_state_attr); |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 292 | scsi_dh_handler_detach(sdev, NULL); |
| 293 | } |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 294 | return err; |
| 295 | } |
| 296 | |
| 297 | /* |
| 298 | * scsi_dh_notifier_add - Callback for scsi_register_device_handler |
| 299 | */ |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 300 | static int scsi_dh_notifier_add(struct device *dev, void *data) |
| 301 | { |
| 302 | struct scsi_device_handler *scsi_dh = data; |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 303 | struct scsi_device *sdev; |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 304 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 305 | if (!scsi_is_sdev_device(dev)) |
| 306 | return 0; |
| 307 | |
| 308 | if (!get_device(dev)) |
| 309 | return 0; |
| 310 | |
| 311 | sdev = to_scsi_device(dev); |
| 312 | |
| 313 | if (device_handler_match(scsi_dh, sdev)) |
| 314 | scsi_dh_handler_attach(sdev, scsi_dh); |
| 315 | |
| 316 | put_device(dev); |
| 317 | |
| 318 | return 0; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | * scsi_dh_notifier_remove - Callback for scsi_unregister_device_handler |
| 323 | */ |
| 324 | static int scsi_dh_notifier_remove(struct device *dev, void *data) |
| 325 | { |
| 326 | struct scsi_device_handler *scsi_dh = data; |
| 327 | struct scsi_device *sdev; |
| 328 | |
| 329 | if (!scsi_is_sdev_device(dev)) |
| 330 | return 0; |
| 331 | |
| 332 | if (!get_device(dev)) |
| 333 | return 0; |
| 334 | |
| 335 | sdev = to_scsi_device(dev); |
| 336 | |
| 337 | scsi_dh_handler_detach(sdev, scsi_dh); |
| 338 | |
| 339 | put_device(dev); |
| 340 | |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 341 | return 0; |
| 342 | } |
| 343 | |
| 344 | /* |
| 345 | * scsi_register_device_handler - register a device handler personality |
| 346 | * module. |
| 347 | * @scsi_dh - device handler to be registered. |
| 348 | * |
| 349 | * Returns 0 on success, -EBUSY if handler already registered. |
| 350 | */ |
| 351 | int scsi_register_device_handler(struct scsi_device_handler *scsi_dh) |
| 352 | { |
Peter Jones | 940d7fa | 2011-01-06 15:38:24 -0500 | [diff] [blame] | 353 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 354 | if (get_device_handler(scsi_dh->name)) |
| 355 | return -EBUSY; |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 356 | |
Christoph Hellwig | 1f12ffa | 2014-09-13 20:08:44 -0700 | [diff] [blame] | 357 | if (!scsi_dh->attach || !scsi_dh->detach) |
| 358 | return -EINVAL; |
| 359 | |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 360 | spin_lock(&list_lock); |
| 361 | list_add(&scsi_dh->list, &scsi_dh_list); |
| 362 | spin_unlock(&list_lock); |
Peter Jones | 940d7fa | 2011-01-06 15:38:24 -0500 | [diff] [blame] | 363 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 364 | bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add); |
| 365 | printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name); |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 366 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 367 | return SCSI_DH_OK; |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 368 | } |
| 369 | EXPORT_SYMBOL_GPL(scsi_register_device_handler); |
| 370 | |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 371 | /* |
| 372 | * scsi_unregister_device_handler - register a device handler personality |
| 373 | * module. |
| 374 | * @scsi_dh - device handler to be unregistered. |
| 375 | * |
| 376 | * Returns 0 on success, -ENODEV if handler not registered. |
| 377 | */ |
| 378 | int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) |
| 379 | { |
Hannes Reinecke | 7c32c7a | 2008-07-17 16:53:33 -0700 | [diff] [blame] | 380 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 381 | if (!get_device_handler(scsi_dh->name)) |
| 382 | return -ENODEV; |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 383 | |
| 384 | bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 385 | scsi_dh_notifier_remove); |
| 386 | |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 387 | spin_lock(&list_lock); |
| 388 | list_del(&scsi_dh->list); |
| 389 | spin_unlock(&list_lock); |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 390 | printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name); |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 391 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 392 | return SCSI_DH_OK; |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 393 | } |
| 394 | EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); |
| 395 | |
| 396 | /* |
| 397 | * scsi_dh_activate - activate the path associated with the scsi_device |
| 398 | * corresponding to the given request queue. |
Chandra Seetharaman | 3ae31f6 | 2009-10-21 09:22:46 -0700 | [diff] [blame] | 399 | * Returns immediately without waiting for activation to be completed. |
| 400 | * @q - Request queue that is associated with the scsi_device to be |
| 401 | * activated. |
| 402 | * @fn - Function to be called upon completion of the activation. |
| 403 | * Function fn is called with data (below) and the error code. |
| 404 | * Function fn may be called from the same calling context. So, |
| 405 | * do not hold the lock in the caller which may be needed in fn. |
| 406 | * @data - data passed to the function fn upon completion. |
| 407 | * |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 408 | */ |
Chandra Seetharaman | 3ae31f6 | 2009-10-21 09:22:46 -0700 | [diff] [blame] | 409 | int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 410 | { |
| 411 | int err = 0; |
| 412 | unsigned long flags; |
| 413 | struct scsi_device *sdev; |
| 414 | struct scsi_device_handler *scsi_dh = NULL; |
Mike Snitzer | 0b83935 | 2011-04-08 15:05:36 -0400 | [diff] [blame] | 415 | struct device *dev = NULL; |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 416 | |
| 417 | spin_lock_irqsave(q->queue_lock, flags); |
| 418 | sdev = q->queuedata; |
Moger, Babu | a18a920 | 2011-10-26 14:29:38 -0400 | [diff] [blame] | 419 | if (!sdev) { |
| 420 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 421 | err = SCSI_DH_NOSYS; |
| 422 | if (fn) |
| 423 | fn(data, err); |
| 424 | return err; |
| 425 | } |
| 426 | |
| 427 | if (sdev->scsi_dh_data) |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 428 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
Mike Snitzer | 0b83935 | 2011-04-08 15:05:36 -0400 | [diff] [blame] | 429 | dev = get_device(&sdev->sdev_gendev); |
| 430 | if (!scsi_dh || !dev || |
Menny Hamburger | db42231 | 2010-12-16 14:57:07 -0500 | [diff] [blame] | 431 | sdev->sdev_state == SDEV_CANCEL || |
| 432 | sdev->sdev_state == SDEV_DEL) |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 433 | err = SCSI_DH_NOSYS; |
Menny Hamburger | db42231 | 2010-12-16 14:57:07 -0500 | [diff] [blame] | 434 | if (sdev->sdev_state == SDEV_OFFLINE) |
| 435 | err = SCSI_DH_DEV_OFFLINED; |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 436 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 437 | |
Menny Hamburger | db42231 | 2010-12-16 14:57:07 -0500 | [diff] [blame] | 438 | if (err) { |
| 439 | if (fn) |
| 440 | fn(data, err); |
Mike Snitzer | 0b83935 | 2011-04-08 15:05:36 -0400 | [diff] [blame] | 441 | goto out; |
Menny Hamburger | db42231 | 2010-12-16 14:57:07 -0500 | [diff] [blame] | 442 | } |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 443 | |
| 444 | if (scsi_dh->activate) |
Chandra Seetharaman | 3ae31f6 | 2009-10-21 09:22:46 -0700 | [diff] [blame] | 445 | err = scsi_dh->activate(sdev, fn, data); |
Mike Snitzer | 0b83935 | 2011-04-08 15:05:36 -0400 | [diff] [blame] | 446 | out: |
| 447 | put_device(dev); |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 448 | return err; |
| 449 | } |
| 450 | EXPORT_SYMBOL_GPL(scsi_dh_activate); |
| 451 | |
| 452 | /* |
Chandra Seetharaman | 18ee70c | 2009-08-03 12:42:33 -0700 | [diff] [blame] | 453 | * scsi_dh_set_params - set the parameters for the device as per the |
| 454 | * string specified in params. |
| 455 | * @q - Request queue that is associated with the scsi_device for |
| 456 | * which the parameters to be set. |
| 457 | * @params - parameters in the following format |
| 458 | * "no_of_params\0param1\0param2\0param3\0...\0" |
| 459 | * for example, string for 2 parameters with value 10 and 21 |
| 460 | * is specified as "2\010\021\0". |
| 461 | */ |
| 462 | int scsi_dh_set_params(struct request_queue *q, const char *params) |
| 463 | { |
| 464 | int err = -SCSI_DH_NOSYS; |
| 465 | unsigned long flags; |
| 466 | struct scsi_device *sdev; |
| 467 | struct scsi_device_handler *scsi_dh = NULL; |
| 468 | |
| 469 | spin_lock_irqsave(q->queue_lock, flags); |
| 470 | sdev = q->queuedata; |
| 471 | if (sdev && sdev->scsi_dh_data) |
| 472 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
| 473 | if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev)) |
| 474 | err = 0; |
| 475 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 476 | |
| 477 | if (err) |
| 478 | return err; |
| 479 | err = scsi_dh->set_params(sdev, params); |
| 480 | put_device(&sdev->sdev_gendev); |
| 481 | return err; |
| 482 | } |
| 483 | EXPORT_SYMBOL_GPL(scsi_dh_set_params); |
| 484 | |
| 485 | /* |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 486 | * scsi_dh_handler_exist - Return TRUE(1) if a device handler exists for |
| 487 | * the given name. FALSE(0) otherwise. |
| 488 | * @name - name of the device handler. |
| 489 | */ |
| 490 | int scsi_dh_handler_exist(const char *name) |
| 491 | { |
| 492 | return (get_device_handler(name) != NULL); |
| 493 | } |
| 494 | EXPORT_SYMBOL_GPL(scsi_dh_handler_exist); |
| 495 | |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 496 | /* |
Hannes Reinecke | 2a9ab40 | 2011-08-24 10:51:14 +0200 | [diff] [blame] | 497 | * scsi_dh_attach - Attach device handler |
Mike Snitzer | 7e8a74b | 2012-06-26 14:32:03 -0400 | [diff] [blame] | 498 | * @q - Request queue that is associated with the scsi_device |
| 499 | * the handler should be attached to |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 500 | * @name - name of the handler to attach |
| 501 | */ |
| 502 | int scsi_dh_attach(struct request_queue *q, const char *name) |
| 503 | { |
| 504 | unsigned long flags; |
| 505 | struct scsi_device *sdev; |
| 506 | struct scsi_device_handler *scsi_dh; |
| 507 | int err = 0; |
| 508 | |
| 509 | scsi_dh = get_device_handler(name); |
| 510 | if (!scsi_dh) |
| 511 | return -EINVAL; |
| 512 | |
| 513 | spin_lock_irqsave(q->queue_lock, flags); |
| 514 | sdev = q->queuedata; |
| 515 | if (!sdev || !get_device(&sdev->sdev_gendev)) |
| 516 | err = -ENODEV; |
| 517 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 518 | |
| 519 | if (!err) { |
| 520 | err = scsi_dh_handler_attach(sdev, scsi_dh); |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 521 | put_device(&sdev->sdev_gendev); |
| 522 | } |
| 523 | return err; |
| 524 | } |
| 525 | EXPORT_SYMBOL_GPL(scsi_dh_attach); |
| 526 | |
| 527 | /* |
Hannes Reinecke | 2a9ab40 | 2011-08-24 10:51:14 +0200 | [diff] [blame] | 528 | * scsi_dh_detach - Detach device handler |
Mike Snitzer | 7e8a74b | 2012-06-26 14:32:03 -0400 | [diff] [blame] | 529 | * @q - Request queue that is associated with the scsi_device |
| 530 | * the handler should be detached from |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 531 | * |
| 532 | * This function will detach the device handler only |
| 533 | * if the sdev is not part of the internal list, ie |
| 534 | * if it has been attached manually. |
| 535 | */ |
| 536 | void scsi_dh_detach(struct request_queue *q) |
| 537 | { |
| 538 | unsigned long flags; |
| 539 | struct scsi_device *sdev; |
| 540 | struct scsi_device_handler *scsi_dh = NULL; |
| 541 | |
| 542 | spin_lock_irqsave(q->queue_lock, flags); |
| 543 | sdev = q->queuedata; |
| 544 | if (!sdev || !get_device(&sdev->sdev_gendev)) |
| 545 | sdev = NULL; |
| 546 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 547 | |
| 548 | if (!sdev) |
| 549 | return; |
| 550 | |
| 551 | if (sdev->scsi_dh_data) { |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 552 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
Chandra Seetharaman | 6c10db7 | 2009-06-26 19:30:06 -0700 | [diff] [blame] | 553 | scsi_dh_handler_detach(sdev, scsi_dh); |
Hannes Reinecke | ae11b1b | 2008-07-17 17:49:02 -0700 | [diff] [blame] | 554 | } |
| 555 | put_device(&sdev->sdev_gendev); |
| 556 | } |
| 557 | EXPORT_SYMBOL_GPL(scsi_dh_detach); |
| 558 | |
Mike Snitzer | 7e8a74b | 2012-06-26 14:32:03 -0400 | [diff] [blame] | 559 | /* |
| 560 | * scsi_dh_attached_handler_name - Get attached device handler's name |
| 561 | * @q - Request queue that is associated with the scsi_device |
| 562 | * that may have a device handler attached |
| 563 | * @gfp - the GFP mask used in the kmalloc() call when allocating memory |
| 564 | * |
| 565 | * Returns name of attached handler, NULL if no handler is attached. |
| 566 | * Caller must take care to free the returned string. |
| 567 | */ |
| 568 | const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) |
| 569 | { |
| 570 | unsigned long flags; |
| 571 | struct scsi_device *sdev; |
| 572 | const char *handler_name = NULL; |
| 573 | |
| 574 | spin_lock_irqsave(q->queue_lock, flags); |
| 575 | sdev = q->queuedata; |
| 576 | if (!sdev || !get_device(&sdev->sdev_gendev)) |
| 577 | sdev = NULL; |
| 578 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 579 | |
| 580 | if (!sdev) |
| 581 | return NULL; |
| 582 | |
| 583 | if (sdev->scsi_dh_data) |
| 584 | handler_name = kstrdup(sdev->scsi_dh_data->scsi_dh->name, gfp); |
| 585 | |
| 586 | put_device(&sdev->sdev_gendev); |
| 587 | return handler_name; |
| 588 | } |
| 589 | EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name); |
| 590 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 591 | static struct notifier_block scsi_dh_nb = { |
| 592 | .notifier_call = scsi_dh_notifier |
| 593 | }; |
| 594 | |
| 595 | static int __init scsi_dh_init(void) |
| 596 | { |
| 597 | int r; |
| 598 | |
| 599 | r = bus_register_notifier(&scsi_bus_type, &scsi_dh_nb); |
| 600 | |
Hannes Reinecke | 4c05ae5 | 2008-07-17 16:52:57 -0700 | [diff] [blame] | 601 | if (!r) |
| 602 | bus_for_each_dev(&scsi_bus_type, NULL, NULL, |
| 603 | scsi_dh_sysfs_attr_add); |
| 604 | |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 605 | return r; |
| 606 | } |
| 607 | |
| 608 | static void __exit scsi_dh_exit(void) |
| 609 | { |
Hannes Reinecke | 4c05ae5 | 2008-07-17 16:52:57 -0700 | [diff] [blame] | 610 | bus_for_each_dev(&scsi_bus_type, NULL, NULL, |
| 611 | scsi_dh_sysfs_attr_remove); |
Hannes Reinecke | 765cbc6 | 2008-07-17 16:52:51 -0700 | [diff] [blame] | 612 | bus_unregister_notifier(&scsi_bus_type, &scsi_dh_nb); |
| 613 | } |
| 614 | |
| 615 | module_init(scsi_dh_init); |
| 616 | module_exit(scsi_dh_exit); |
| 617 | |
Chandra Seetharaman | a6a8d9f | 2008-05-01 14:49:46 -0700 | [diff] [blame] | 618 | MODULE_DESCRIPTION("SCSI device handler"); |
| 619 | MODULE_AUTHOR("Chandra Seetharaman <sekharan@us.ibm.com>"); |
| 620 | MODULE_LICENSE("GPL"); |