Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * scsi_lib.c Copyright (C) 1999 Eric Youngdale |
| 3 | * |
| 4 | * SCSI queueing library. |
| 5 | * Initial versions: Eric Youngdale (eric@andante.org). |
| 6 | * Based upon conversations with large numbers |
| 7 | * of people at Linux Expo. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/bio.h> |
| 11 | #include <linux/blkdev.h> |
| 12 | #include <linux/completion.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/mempool.h> |
| 15 | #include <linux/slab.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/pci.h> |
| 18 | #include <linux/delay.h> |
James Bottomley | faead26 | 2006-02-14 10:42:07 -0600 | [diff] [blame] | 19 | #include <linux/hardirq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
| 21 | #include <scsi/scsi.h> |
| 22 | #include <scsi/scsi_dbg.h> |
| 23 | #include <scsi/scsi_device.h> |
| 24 | #include <scsi/scsi_driver.h> |
| 25 | #include <scsi/scsi_eh.h> |
| 26 | #include <scsi/scsi_host.h> |
| 27 | #include <scsi/scsi_request.h> |
| 28 | |
| 29 | #include "scsi_priv.h" |
| 30 | #include "scsi_logging.h" |
| 31 | |
| 32 | |
| 33 | #define SG_MEMPOOL_NR (sizeof(scsi_sg_pools)/sizeof(struct scsi_host_sg_pool)) |
| 34 | #define SG_MEMPOOL_SIZE 32 |
| 35 | |
| 36 | struct scsi_host_sg_pool { |
| 37 | size_t size; |
| 38 | char *name; |
| 39 | kmem_cache_t *slab; |
| 40 | mempool_t *pool; |
| 41 | }; |
| 42 | |
| 43 | #if (SCSI_MAX_PHYS_SEGMENTS < 32) |
| 44 | #error SCSI_MAX_PHYS_SEGMENTS is too small |
| 45 | #endif |
| 46 | |
| 47 | #define SP(x) { x, "sgpool-" #x } |
Adrian Bunk | 52c1da3 | 2005-06-23 22:05:33 -0700 | [diff] [blame] | 48 | static struct scsi_host_sg_pool scsi_sg_pools[] = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | SP(8), |
| 50 | SP(16), |
| 51 | SP(32), |
| 52 | #if (SCSI_MAX_PHYS_SEGMENTS > 32) |
| 53 | SP(64), |
| 54 | #if (SCSI_MAX_PHYS_SEGMENTS > 64) |
| 55 | SP(128), |
| 56 | #if (SCSI_MAX_PHYS_SEGMENTS > 128) |
| 57 | SP(256), |
| 58 | #if (SCSI_MAX_PHYS_SEGMENTS > 256) |
| 59 | #error SCSI_MAX_PHYS_SEGMENTS is too large |
| 60 | #endif |
| 61 | #endif |
| 62 | #endif |
| 63 | #endif |
| 64 | }; |
| 65 | #undef SP |
| 66 | |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 67 | static void scsi_run_queue(struct request_queue *q); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 68 | |
| 69 | /* |
| 70 | * Function: scsi_unprep_request() |
| 71 | * |
| 72 | * Purpose: Remove all preparation done for a request, including its |
| 73 | * associated scsi_cmnd, so that it can be requeued. |
| 74 | * |
| 75 | * Arguments: req - request to unprepare |
| 76 | * |
| 77 | * Lock status: Assumed that no locks are held upon entry. |
| 78 | * |
| 79 | * Returns: Nothing. |
| 80 | */ |
| 81 | static void scsi_unprep_request(struct request *req) |
| 82 | { |
| 83 | struct scsi_cmnd *cmd = req->special; |
| 84 | |
| 85 | req->flags &= ~REQ_DONTPREP; |
| 86 | req->special = (req->flags & REQ_SPECIAL) ? cmd->sc_request : NULL; |
| 87 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 88 | scsi_put_command(cmd); |
| 89 | } |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 90 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | /* |
| 92 | * Function: scsi_queue_insert() |
| 93 | * |
| 94 | * Purpose: Insert a command in the midlevel queue. |
| 95 | * |
| 96 | * Arguments: cmd - command that we are adding to queue. |
| 97 | * reason - why we are inserting command to queue. |
| 98 | * |
| 99 | * Lock status: Assumed that lock is not held upon entry. |
| 100 | * |
| 101 | * Returns: Nothing. |
| 102 | * |
| 103 | * Notes: We do this for one of two cases. Either the host is busy |
| 104 | * and it cannot accept any more commands for the time being, |
| 105 | * or the device returned QUEUE_FULL and can accept no more |
| 106 | * commands. |
| 107 | * Notes: This could be called either from an interrupt context or a |
| 108 | * normal process context. |
| 109 | */ |
| 110 | int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) |
| 111 | { |
| 112 | struct Scsi_Host *host = cmd->device->host; |
| 113 | struct scsi_device *device = cmd->device; |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 114 | struct request_queue *q = device->request_queue; |
| 115 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | |
| 117 | SCSI_LOG_MLQUEUE(1, |
| 118 | printk("Inserting command %p into mlqueue\n", cmd)); |
| 119 | |
| 120 | /* |
Tejun Heo | d8c37e7 | 2005-05-14 00:46:08 +0900 | [diff] [blame] | 121 | * Set the appropriate busy bit for the device/host. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | * |
| 123 | * If the host/device isn't busy, assume that something actually |
| 124 | * completed, and that we should be able to queue a command now. |
| 125 | * |
| 126 | * Note that the prior mid-layer assumption that any host could |
| 127 | * always queue at least one command is now broken. The mid-layer |
| 128 | * will implement a user specifiable stall (see |
| 129 | * scsi_host.max_host_blocked and scsi_device.max_device_blocked) |
| 130 | * if a command is requeued with no other commands outstanding |
| 131 | * either for the device or for the host. |
| 132 | */ |
| 133 | if (reason == SCSI_MLQUEUE_HOST_BUSY) |
| 134 | host->host_blocked = host->max_host_blocked; |
| 135 | else if (reason == SCSI_MLQUEUE_DEVICE_BUSY) |
| 136 | device->device_blocked = device->max_device_blocked; |
| 137 | |
| 138 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | * Decrement the counters, since these commands are no longer |
| 140 | * active on the host/device. |
| 141 | */ |
| 142 | scsi_device_unbusy(device); |
| 143 | |
| 144 | /* |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 145 | * Requeue this command. It will go before all other commands |
| 146 | * that are already in the queue. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | * |
| 148 | * NOTE: there is magic here about the way the queue is plugged if |
| 149 | * we have no outstanding commands. |
| 150 | * |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 151 | * Although we *don't* plug the queue, we call the request |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | * function. The SCSI request function detects the blocked condition |
| 153 | * and plugs the queue appropriately. |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 154 | */ |
| 155 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | 59897da | 2005-09-14 12:57:42 -0400 | [diff] [blame] | 156 | blk_requeue_request(q, cmd->request); |
Tejun Heo | a1bf9d1d | 2005-04-24 02:08:52 -0500 | [diff] [blame] | 157 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 158 | |
| 159 | scsi_run_queue(q); |
| 160 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * Function: scsi_do_req |
| 166 | * |
| 167 | * Purpose: Queue a SCSI request |
| 168 | * |
| 169 | * Arguments: sreq - command descriptor. |
| 170 | * cmnd - actual SCSI command to be performed. |
| 171 | * buffer - data buffer. |
| 172 | * bufflen - size of data buffer. |
| 173 | * done - completion function to be run. |
| 174 | * timeout - how long to let it run before timeout. |
| 175 | * retries - number of retries we allow. |
| 176 | * |
| 177 | * Lock status: No locks held upon entry. |
| 178 | * |
| 179 | * Returns: Nothing. |
| 180 | * |
| 181 | * Notes: This function is only used for queueing requests for things |
| 182 | * like ioctls and character device requests - this is because |
| 183 | * we essentially just inject a request into the queue for the |
| 184 | * device. |
| 185 | * |
| 186 | * In order to support the scsi_device_quiesce function, we |
| 187 | * now inject requests on the *head* of the device queue |
| 188 | * rather than the tail. |
| 189 | */ |
| 190 | void scsi_do_req(struct scsi_request *sreq, const void *cmnd, |
| 191 | void *buffer, unsigned bufflen, |
| 192 | void (*done)(struct scsi_cmnd *), |
| 193 | int timeout, int retries) |
| 194 | { |
| 195 | /* |
| 196 | * If the upper level driver is reusing these things, then |
| 197 | * we should release the low-level block now. Another one will |
| 198 | * be allocated later when this request is getting queued. |
| 199 | */ |
| 200 | __scsi_release_request(sreq); |
| 201 | |
| 202 | /* |
| 203 | * Our own function scsi_done (which marks the host as not busy, |
| 204 | * disables the timeout counter, etc) will be called by us or by the |
| 205 | * scsi_hosts[host].queuecommand() function needs to also call |
| 206 | * the completion function for the high level driver. |
| 207 | */ |
| 208 | memcpy(sreq->sr_cmnd, cmnd, sizeof(sreq->sr_cmnd)); |
| 209 | sreq->sr_bufflen = bufflen; |
| 210 | sreq->sr_buffer = buffer; |
| 211 | sreq->sr_allowed = retries; |
| 212 | sreq->sr_done = done; |
| 213 | sreq->sr_timeout_per_command = timeout; |
| 214 | |
| 215 | if (sreq->sr_cmd_len == 0) |
| 216 | sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]); |
| 217 | |
| 218 | /* |
| 219 | * head injection *required* here otherwise quiesce won't work |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 220 | * |
| 221 | * Because users of this function are apt to reuse requests with no |
| 222 | * modification, we have to sanitise the request flags here |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | */ |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 224 | sreq->sr_request->flags &= ~REQ_DONTPREP; |
| 225 | blk_insert_request(sreq->sr_device->request_queue, sreq->sr_request, |
| 226 | 1, sreq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | } |
| 228 | EXPORT_SYMBOL(scsi_do_req); |
| 229 | |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 230 | /** |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 231 | * scsi_execute - insert request and wait for the result |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 232 | * @sdev: scsi device |
| 233 | * @cmd: scsi command |
| 234 | * @data_direction: data direction |
| 235 | * @buffer: data buffer |
| 236 | * @bufflen: len of buffer |
| 237 | * @sense: optional sense buffer |
| 238 | * @timeout: request timeout in seconds |
| 239 | * @retries: number of times to retry request |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 240 | * @flags: or into request flags; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 241 | * |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 242 | * returns the req->errors value which is the the scsi_cmnd result |
| 243 | * field. |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 244 | **/ |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 245 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
| 246 | int data_direction, void *buffer, unsigned bufflen, |
| 247 | unsigned char *sense, int timeout, int retries, int flags) |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 248 | { |
| 249 | struct request *req; |
| 250 | int write = (data_direction == DMA_TO_DEVICE); |
| 251 | int ret = DRIVER_ERROR << 24; |
| 252 | |
| 253 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); |
| 254 | |
| 255 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, |
| 256 | buffer, bufflen, __GFP_WAIT)) |
| 257 | goto out; |
| 258 | |
| 259 | req->cmd_len = COMMAND_SIZE(cmd[0]); |
| 260 | memcpy(req->cmd, cmd, req->cmd_len); |
| 261 | req->sense = sense; |
| 262 | req->sense_len = 0; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 263 | req->retries = retries; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 264 | req->timeout = timeout; |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 265 | req->flags |= flags | REQ_BLOCK_PC | REQ_SPECIAL | REQ_QUIET; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 266 | |
| 267 | /* |
| 268 | * head injection *required* here otherwise quiesce won't work |
| 269 | */ |
| 270 | blk_execute_rq(req->q, NULL, req, 1); |
| 271 | |
| 272 | ret = req->errors; |
| 273 | out: |
| 274 | blk_put_request(req); |
| 275 | |
| 276 | return ret; |
| 277 | } |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 278 | EXPORT_SYMBOL(scsi_execute); |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 279 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 280 | |
| 281 | int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, |
| 282 | int data_direction, void *buffer, unsigned bufflen, |
| 283 | struct scsi_sense_hdr *sshdr, int timeout, int retries) |
| 284 | { |
| 285 | char *sense = NULL; |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 286 | int result; |
| 287 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 288 | if (sshdr) { |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 289 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 290 | if (!sense) |
| 291 | return DRIVER_ERROR << 24; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 292 | } |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 293 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 294 | sense, timeout, retries, 0); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 295 | if (sshdr) |
James Bottomley | e514385 | 2005-08-09 11:55:36 -0500 | [diff] [blame] | 296 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 297 | |
| 298 | kfree(sense); |
| 299 | return result; |
| 300 | } |
| 301 | EXPORT_SYMBOL(scsi_execute_req); |
| 302 | |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 303 | struct scsi_io_context { |
| 304 | void *data; |
| 305 | void (*done)(void *data, char *sense, int result, int resid); |
| 306 | char sense[SCSI_SENSE_BUFFERSIZE]; |
| 307 | }; |
| 308 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 309 | static kmem_cache_t *scsi_io_context_cache; |
| 310 | |
Jens Axboe | e650c30 | 2006-01-06 12:38:30 +0100 | [diff] [blame] | 311 | static void scsi_end_async(struct request *req, int uptodate) |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 312 | { |
| 313 | struct scsi_io_context *sioc = req->end_io_data; |
| 314 | |
| 315 | if (sioc->done) |
| 316 | sioc->done(sioc->data, sioc->sense, req->errors, req->data_len); |
| 317 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 318 | kmem_cache_free(scsi_io_context_cache, sioc); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 319 | __blk_put_request(req->q, req); |
| 320 | } |
| 321 | |
| 322 | static int scsi_merge_bio(struct request *rq, struct bio *bio) |
| 323 | { |
| 324 | struct request_queue *q = rq->q; |
| 325 | |
| 326 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
| 327 | if (rq_data_dir(rq) == WRITE) |
| 328 | bio->bi_rw |= (1 << BIO_RW); |
| 329 | blk_queue_bounce(q, &bio); |
| 330 | |
| 331 | if (!rq->bio) |
| 332 | blk_rq_bio_prep(q, rq, bio); |
| 333 | else if (!q->back_merge_fn(q, rq, bio)) |
| 334 | return -EINVAL; |
| 335 | else { |
| 336 | rq->biotail->bi_next = bio; |
| 337 | rq->biotail = bio; |
| 338 | rq->hard_nr_sectors += bio_sectors(bio); |
| 339 | rq->nr_sectors = rq->hard_nr_sectors; |
| 340 | } |
| 341 | |
| 342 | return 0; |
| 343 | } |
| 344 | |
| 345 | static int scsi_bi_endio(struct bio *bio, unsigned int bytes_done, int error) |
| 346 | { |
| 347 | if (bio->bi_size) |
| 348 | return 1; |
| 349 | |
| 350 | bio_put(bio); |
| 351 | return 0; |
| 352 | } |
| 353 | |
| 354 | /** |
| 355 | * scsi_req_map_sg - map a scatterlist into a request |
| 356 | * @rq: request to fill |
| 357 | * @sg: scatterlist |
| 358 | * @nsegs: number of elements |
| 359 | * @bufflen: len of buffer |
| 360 | * @gfp: memory allocation flags |
| 361 | * |
| 362 | * scsi_req_map_sg maps a scatterlist into a request so that the |
| 363 | * request can be sent to the block layer. We do not trust the scatterlist |
| 364 | * sent to use, as some ULDs use that struct to only organize the pages. |
| 365 | */ |
| 366 | static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, |
| 367 | int nsegs, unsigned bufflen, gfp_t gfp) |
| 368 | { |
| 369 | struct request_queue *q = rq->q; |
Bryan Holty | f523596 | 2006-03-22 06:35:39 -0600 | [diff] [blame] | 370 | int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 371 | unsigned int data_len = 0, len, bytes, off; |
| 372 | struct page *page; |
| 373 | struct bio *bio = NULL; |
| 374 | int i, err, nr_vecs = 0; |
| 375 | |
| 376 | for (i = 0; i < nsegs; i++) { |
| 377 | page = sgl[i].page; |
| 378 | off = sgl[i].offset; |
| 379 | len = sgl[i].length; |
| 380 | data_len += len; |
| 381 | |
| 382 | while (len > 0) { |
| 383 | bytes = min_t(unsigned int, len, PAGE_SIZE - off); |
| 384 | |
| 385 | if (!bio) { |
| 386 | nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); |
| 387 | nr_pages -= nr_vecs; |
| 388 | |
| 389 | bio = bio_alloc(gfp, nr_vecs); |
| 390 | if (!bio) { |
| 391 | err = -ENOMEM; |
| 392 | goto free_bios; |
| 393 | } |
| 394 | bio->bi_end_io = scsi_bi_endio; |
| 395 | } |
| 396 | |
| 397 | if (bio_add_pc_page(q, bio, page, bytes, off) != |
| 398 | bytes) { |
| 399 | bio_put(bio); |
| 400 | err = -EINVAL; |
| 401 | goto free_bios; |
| 402 | } |
| 403 | |
| 404 | if (bio->bi_vcnt >= nr_vecs) { |
| 405 | err = scsi_merge_bio(rq, bio); |
| 406 | if (err) { |
| 407 | bio_endio(bio, bio->bi_size, 0); |
| 408 | goto free_bios; |
| 409 | } |
| 410 | bio = NULL; |
| 411 | } |
| 412 | |
| 413 | page++; |
| 414 | len -= bytes; |
| 415 | off = 0; |
| 416 | } |
| 417 | } |
| 418 | |
| 419 | rq->buffer = rq->data = NULL; |
| 420 | rq->data_len = data_len; |
| 421 | return 0; |
| 422 | |
| 423 | free_bios: |
| 424 | while ((bio = rq->bio) != NULL) { |
| 425 | rq->bio = bio->bi_next; |
| 426 | /* |
| 427 | * call endio instead of bio_put incase it was bounced |
| 428 | */ |
| 429 | bio_endio(bio, bio->bi_size, 0); |
| 430 | } |
| 431 | |
| 432 | return err; |
| 433 | } |
| 434 | |
| 435 | /** |
| 436 | * scsi_execute_async - insert request |
| 437 | * @sdev: scsi device |
| 438 | * @cmd: scsi command |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 439 | * @cmd_len: length of scsi cdb |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 440 | * @data_direction: data direction |
| 441 | * @buffer: data buffer (this can be a kernel buffer or scatterlist) |
| 442 | * @bufflen: len of buffer |
| 443 | * @use_sg: if buffer is a scatterlist this is the number of elements |
| 444 | * @timeout: request timeout in seconds |
| 445 | * @retries: number of times to retry request |
| 446 | * @flags: or into request flags |
| 447 | **/ |
| 448 | int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd, |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 449 | int cmd_len, int data_direction, void *buffer, unsigned bufflen, |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 450 | int use_sg, int timeout, int retries, void *privdata, |
| 451 | void (*done)(void *, char *, int, int), gfp_t gfp) |
| 452 | { |
| 453 | struct request *req; |
| 454 | struct scsi_io_context *sioc; |
| 455 | int err = 0; |
| 456 | int write = (data_direction == DMA_TO_DEVICE); |
| 457 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 458 | sioc = kmem_cache_alloc(scsi_io_context_cache, gfp); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 459 | if (!sioc) |
| 460 | return DRIVER_ERROR << 24; |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 461 | memset(sioc, 0, sizeof(*sioc)); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 462 | |
| 463 | req = blk_get_request(sdev->request_queue, write, gfp); |
| 464 | if (!req) |
| 465 | goto free_sense; |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 466 | req->flags |= REQ_BLOCK_PC | REQ_QUIET; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 467 | |
| 468 | if (use_sg) |
| 469 | err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp); |
| 470 | else if (bufflen) |
| 471 | err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp); |
| 472 | |
| 473 | if (err) |
| 474 | goto free_req; |
| 475 | |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 476 | req->cmd_len = cmd_len; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 477 | memcpy(req->cmd, cmd, req->cmd_len); |
| 478 | req->sense = sioc->sense; |
| 479 | req->sense_len = 0; |
| 480 | req->timeout = timeout; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 481 | req->retries = retries; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 482 | req->end_io_data = sioc; |
| 483 | |
| 484 | sioc->data = privdata; |
| 485 | sioc->done = done; |
| 486 | |
| 487 | blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async); |
| 488 | return 0; |
| 489 | |
| 490 | free_req: |
| 491 | blk_put_request(req); |
| 492 | free_sense: |
| 493 | kfree(sioc); |
| 494 | return DRIVER_ERROR << 24; |
| 495 | } |
| 496 | EXPORT_SYMBOL_GPL(scsi_execute_async); |
| 497 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | /* |
| 499 | * Function: scsi_init_cmd_errh() |
| 500 | * |
| 501 | * Purpose: Initialize cmd fields related to error handling. |
| 502 | * |
| 503 | * Arguments: cmd - command that is ready to be queued. |
| 504 | * |
| 505 | * Returns: Nothing |
| 506 | * |
| 507 | * Notes: This function has the job of initializing a number of |
| 508 | * fields related to error handling. Typically this will |
| 509 | * be called once for each command, as required. |
| 510 | */ |
| 511 | static int scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
| 512 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | cmd->serial_number = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | |
| 515 | memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer); |
| 516 | |
| 517 | if (cmd->cmd_len == 0) |
| 518 | cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]); |
| 519 | |
| 520 | /* |
| 521 | * We need saved copies of a number of fields - this is because |
| 522 | * error handling may need to overwrite these with different values |
| 523 | * to run different commands, and once error handling is complete, |
| 524 | * we will need to restore these values prior to running the actual |
| 525 | * command. |
| 526 | */ |
| 527 | cmd->old_use_sg = cmd->use_sg; |
| 528 | cmd->old_cmd_len = cmd->cmd_len; |
| 529 | cmd->sc_old_data_direction = cmd->sc_data_direction; |
| 530 | cmd->old_underflow = cmd->underflow; |
| 531 | memcpy(cmd->data_cmnd, cmd->cmnd, sizeof(cmd->cmnd)); |
| 532 | cmd->buffer = cmd->request_buffer; |
| 533 | cmd->bufflen = cmd->request_bufflen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | |
| 535 | return 1; |
| 536 | } |
| 537 | |
| 538 | /* |
| 539 | * Function: scsi_setup_cmd_retry() |
| 540 | * |
| 541 | * Purpose: Restore the command state for a retry |
| 542 | * |
| 543 | * Arguments: cmd - command to be restored |
| 544 | * |
| 545 | * Returns: Nothing |
| 546 | * |
| 547 | * Notes: Immediately prior to retrying a command, we need |
| 548 | * to restore certain fields that we saved above. |
| 549 | */ |
| 550 | void scsi_setup_cmd_retry(struct scsi_cmnd *cmd) |
| 551 | { |
| 552 | memcpy(cmd->cmnd, cmd->data_cmnd, sizeof(cmd->data_cmnd)); |
| 553 | cmd->request_buffer = cmd->buffer; |
| 554 | cmd->request_bufflen = cmd->bufflen; |
| 555 | cmd->use_sg = cmd->old_use_sg; |
| 556 | cmd->cmd_len = cmd->old_cmd_len; |
| 557 | cmd->sc_data_direction = cmd->sc_old_data_direction; |
| 558 | cmd->underflow = cmd->old_underflow; |
| 559 | } |
| 560 | |
| 561 | void scsi_device_unbusy(struct scsi_device *sdev) |
| 562 | { |
| 563 | struct Scsi_Host *shost = sdev->host; |
| 564 | unsigned long flags; |
| 565 | |
| 566 | spin_lock_irqsave(shost->host_lock, flags); |
| 567 | shost->host_busy--; |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 568 | if (unlikely(scsi_host_in_recovery(shost) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | shost->host_failed)) |
| 570 | scsi_eh_wakeup(shost); |
| 571 | spin_unlock(shost->host_lock); |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 572 | spin_lock(sdev->request_queue->queue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | sdev->device_busy--; |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 574 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | } |
| 576 | |
| 577 | /* |
| 578 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, |
| 579 | * and call blk_run_queue for all the scsi_devices on the target - |
| 580 | * including current_sdev first. |
| 581 | * |
| 582 | * Called with *no* scsi locks held. |
| 583 | */ |
| 584 | static void scsi_single_lun_run(struct scsi_device *current_sdev) |
| 585 | { |
| 586 | struct Scsi_Host *shost = current_sdev->host; |
| 587 | struct scsi_device *sdev, *tmp; |
| 588 | struct scsi_target *starget = scsi_target(current_sdev); |
| 589 | unsigned long flags; |
| 590 | |
| 591 | spin_lock_irqsave(shost->host_lock, flags); |
| 592 | starget->starget_sdev_user = NULL; |
| 593 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 594 | |
| 595 | /* |
| 596 | * Call blk_run_queue for all LUNs on the target, starting with |
| 597 | * current_sdev. We race with others (to set starget_sdev_user), |
| 598 | * but in most cases, we will be first. Ideally, each LU on the |
| 599 | * target would get some limited time or requests on the target. |
| 600 | */ |
| 601 | blk_run_queue(current_sdev->request_queue); |
| 602 | |
| 603 | spin_lock_irqsave(shost->host_lock, flags); |
| 604 | if (starget->starget_sdev_user) |
| 605 | goto out; |
| 606 | list_for_each_entry_safe(sdev, tmp, &starget->devices, |
| 607 | same_target_siblings) { |
| 608 | if (sdev == current_sdev) |
| 609 | continue; |
| 610 | if (scsi_device_get(sdev)) |
| 611 | continue; |
| 612 | |
| 613 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 614 | blk_run_queue(sdev->request_queue); |
| 615 | spin_lock_irqsave(shost->host_lock, flags); |
| 616 | |
| 617 | scsi_device_put(sdev); |
| 618 | } |
| 619 | out: |
| 620 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 621 | } |
| 622 | |
| 623 | /* |
| 624 | * Function: scsi_run_queue() |
| 625 | * |
| 626 | * Purpose: Select a proper request queue to serve next |
| 627 | * |
| 628 | * Arguments: q - last request's queue |
| 629 | * |
| 630 | * Returns: Nothing |
| 631 | * |
| 632 | * Notes: The previous command was completely finished, start |
| 633 | * a new one if possible. |
| 634 | */ |
| 635 | static void scsi_run_queue(struct request_queue *q) |
| 636 | { |
| 637 | struct scsi_device *sdev = q->queuedata; |
| 638 | struct Scsi_Host *shost = sdev->host; |
| 639 | unsigned long flags; |
| 640 | |
| 641 | if (sdev->single_lun) |
| 642 | scsi_single_lun_run(sdev); |
| 643 | |
| 644 | spin_lock_irqsave(shost->host_lock, flags); |
| 645 | while (!list_empty(&shost->starved_list) && |
| 646 | !shost->host_blocked && !shost->host_self_blocked && |
| 647 | !((shost->can_queue > 0) && |
| 648 | (shost->host_busy >= shost->can_queue))) { |
| 649 | /* |
| 650 | * As long as shost is accepting commands and we have |
| 651 | * starved queues, call blk_run_queue. scsi_request_fn |
| 652 | * drops the queue_lock and can add us back to the |
| 653 | * starved_list. |
| 654 | * |
| 655 | * host_lock protects the starved_list and starved_entry. |
| 656 | * scsi_request_fn must get the host_lock before checking |
| 657 | * or modifying starved_list or starved_entry. |
| 658 | */ |
| 659 | sdev = list_entry(shost->starved_list.next, |
| 660 | struct scsi_device, starved_entry); |
| 661 | list_del_init(&sdev->starved_entry); |
| 662 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 663 | |
| 664 | blk_run_queue(sdev->request_queue); |
| 665 | |
| 666 | spin_lock_irqsave(shost->host_lock, flags); |
| 667 | if (unlikely(!list_empty(&sdev->starved_entry))) |
| 668 | /* |
| 669 | * sdev lost a race, and was put back on the |
| 670 | * starved list. This is unlikely but without this |
| 671 | * in theory we could loop forever. |
| 672 | */ |
| 673 | break; |
| 674 | } |
| 675 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 676 | |
| 677 | blk_run_queue(q); |
| 678 | } |
| 679 | |
| 680 | /* |
| 681 | * Function: scsi_requeue_command() |
| 682 | * |
| 683 | * Purpose: Handle post-processing of completed commands. |
| 684 | * |
| 685 | * Arguments: q - queue to operate on |
| 686 | * cmd - command that may need to be requeued. |
| 687 | * |
| 688 | * Returns: Nothing |
| 689 | * |
| 690 | * Notes: After command completion, there may be blocks left |
| 691 | * over which weren't finished by the previous command |
| 692 | * this can be for a number of reasons - the main one is |
| 693 | * I/O errors in the middle of the request, in which case |
| 694 | * we need to request the blocks that come after the bad |
| 695 | * sector. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 696 | * Notes: Upon return, cmd is a stale pointer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | */ |
| 698 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) |
| 699 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 700 | struct request *req = cmd->request; |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 701 | unsigned long flags; |
| 702 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 703 | scsi_unprep_request(req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 704 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 705 | blk_requeue_request(q, req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 706 | spin_unlock_irqrestore(q->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 707 | |
| 708 | scsi_run_queue(q); |
| 709 | } |
| 710 | |
| 711 | void scsi_next_command(struct scsi_cmnd *cmd) |
| 712 | { |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 713 | struct scsi_device *sdev = cmd->device; |
| 714 | struct request_queue *q = sdev->request_queue; |
| 715 | |
| 716 | /* need to hold a reference on the device before we let go of the cmd */ |
| 717 | get_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | |
| 719 | scsi_put_command(cmd); |
| 720 | scsi_run_queue(q); |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 721 | |
| 722 | /* ok to remove device now */ |
| 723 | put_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | } |
| 725 | |
| 726 | void scsi_run_host_queues(struct Scsi_Host *shost) |
| 727 | { |
| 728 | struct scsi_device *sdev; |
| 729 | |
| 730 | shost_for_each_device(sdev, shost) |
| 731 | scsi_run_queue(sdev->request_queue); |
| 732 | } |
| 733 | |
| 734 | /* |
| 735 | * Function: scsi_end_request() |
| 736 | * |
| 737 | * Purpose: Post-processing of completed commands (usually invoked at end |
| 738 | * of upper level post-processing and scsi_io_completion). |
| 739 | * |
| 740 | * Arguments: cmd - command that is complete. |
| 741 | * uptodate - 1 if I/O indicates success, <= 0 for I/O error. |
| 742 | * bytes - number of bytes of completed I/O |
| 743 | * requeue - indicates whether we should requeue leftovers. |
| 744 | * |
| 745 | * Lock status: Assumed that lock is not held upon entry. |
| 746 | * |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 747 | * Returns: cmd if requeue required, NULL otherwise. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | * |
| 749 | * Notes: This is called for block device requests in order to |
| 750 | * mark some number of sectors as complete. |
| 751 | * |
| 752 | * We are guaranteeing that the request queue will be goosed |
| 753 | * at some point during this call. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 754 | * Notes: If cmd was requeued, upon return it will be a stale pointer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | */ |
| 756 | static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate, |
| 757 | int bytes, int requeue) |
| 758 | { |
| 759 | request_queue_t *q = cmd->device->request_queue; |
| 760 | struct request *req = cmd->request; |
| 761 | unsigned long flags; |
| 762 | |
| 763 | /* |
| 764 | * If there are blocks left over at the end, set up the command |
| 765 | * to queue the remainder of them. |
| 766 | */ |
| 767 | if (end_that_request_chunk(req, uptodate, bytes)) { |
| 768 | int leftover = (req->hard_nr_sectors << 9); |
| 769 | |
| 770 | if (blk_pc_request(req)) |
| 771 | leftover = req->data_len; |
| 772 | |
| 773 | /* kill remainder if no retrys */ |
| 774 | if (!uptodate && blk_noretry_request(req)) |
| 775 | end_that_request_chunk(req, 0, leftover); |
| 776 | else { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 777 | if (requeue) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | /* |
| 779 | * Bleah. Leftovers again. Stick the |
| 780 | * leftovers in the front of the |
| 781 | * queue, and goose the queue again. |
| 782 | */ |
| 783 | scsi_requeue_command(q, cmd); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 784 | cmd = NULL; |
| 785 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | return cmd; |
| 787 | } |
| 788 | } |
| 789 | |
| 790 | add_disk_randomness(req->rq_disk); |
| 791 | |
| 792 | spin_lock_irqsave(q->queue_lock, flags); |
| 793 | if (blk_rq_tagged(req)) |
| 794 | blk_queue_end_tag(q, req); |
Tejun Heo | 8ffdc65 | 2006-01-06 09:49:03 +0100 | [diff] [blame] | 795 | end_that_request_last(req, uptodate); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 797 | |
| 798 | /* |
| 799 | * This will goose the queue request function at the end, so we don't |
| 800 | * need to worry about launching another command. |
| 801 | */ |
| 802 | scsi_next_command(cmd); |
| 803 | return NULL; |
| 804 | } |
| 805 | |
Al Viro | c53033f | 2005-10-21 03:22:08 -0400 | [diff] [blame] | 806 | static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | { |
| 808 | struct scsi_host_sg_pool *sgp; |
| 809 | struct scatterlist *sgl; |
| 810 | |
| 811 | BUG_ON(!cmd->use_sg); |
| 812 | |
| 813 | switch (cmd->use_sg) { |
| 814 | case 1 ... 8: |
| 815 | cmd->sglist_len = 0; |
| 816 | break; |
| 817 | case 9 ... 16: |
| 818 | cmd->sglist_len = 1; |
| 819 | break; |
| 820 | case 17 ... 32: |
| 821 | cmd->sglist_len = 2; |
| 822 | break; |
| 823 | #if (SCSI_MAX_PHYS_SEGMENTS > 32) |
| 824 | case 33 ... 64: |
| 825 | cmd->sglist_len = 3; |
| 826 | break; |
| 827 | #if (SCSI_MAX_PHYS_SEGMENTS > 64) |
| 828 | case 65 ... 128: |
| 829 | cmd->sglist_len = 4; |
| 830 | break; |
| 831 | #if (SCSI_MAX_PHYS_SEGMENTS > 128) |
| 832 | case 129 ... 256: |
| 833 | cmd->sglist_len = 5; |
| 834 | break; |
| 835 | #endif |
| 836 | #endif |
| 837 | #endif |
| 838 | default: |
| 839 | return NULL; |
| 840 | } |
| 841 | |
| 842 | sgp = scsi_sg_pools + cmd->sglist_len; |
| 843 | sgl = mempool_alloc(sgp->pool, gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | return sgl; |
| 845 | } |
| 846 | |
| 847 | static void scsi_free_sgtable(struct scatterlist *sgl, int index) |
| 848 | { |
| 849 | struct scsi_host_sg_pool *sgp; |
| 850 | |
KAMBAROV, ZAUR | a77e336 | 2005-06-28 20:45:06 -0700 | [diff] [blame] | 851 | BUG_ON(index >= SG_MEMPOOL_NR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | |
| 853 | sgp = scsi_sg_pools + index; |
| 854 | mempool_free(sgl, sgp->pool); |
| 855 | } |
| 856 | |
| 857 | /* |
| 858 | * Function: scsi_release_buffers() |
| 859 | * |
| 860 | * Purpose: Completion processing for block device I/O requests. |
| 861 | * |
| 862 | * Arguments: cmd - command that we are bailing. |
| 863 | * |
| 864 | * Lock status: Assumed that no lock is held upon entry. |
| 865 | * |
| 866 | * Returns: Nothing |
| 867 | * |
| 868 | * Notes: In the event that an upper level driver rejects a |
| 869 | * command, we must release resources allocated during |
| 870 | * the __init_io() function. Primarily this would involve |
| 871 | * the scatter-gather table, and potentially any bounce |
| 872 | * buffers. |
| 873 | */ |
| 874 | static void scsi_release_buffers(struct scsi_cmnd *cmd) |
| 875 | { |
| 876 | struct request *req = cmd->request; |
| 877 | |
| 878 | /* |
| 879 | * Free up any indirection buffers we allocated for DMA purposes. |
| 880 | */ |
| 881 | if (cmd->use_sg) |
| 882 | scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len); |
| 883 | else if (cmd->request_buffer != req->buffer) |
| 884 | kfree(cmd->request_buffer); |
| 885 | |
| 886 | /* |
| 887 | * Zero these out. They now point to freed memory, and it is |
| 888 | * dangerous to hang onto the pointers. |
| 889 | */ |
| 890 | cmd->buffer = NULL; |
| 891 | cmd->bufflen = 0; |
| 892 | cmd->request_buffer = NULL; |
| 893 | cmd->request_bufflen = 0; |
| 894 | } |
| 895 | |
| 896 | /* |
| 897 | * Function: scsi_io_completion() |
| 898 | * |
| 899 | * Purpose: Completion processing for block device I/O requests. |
| 900 | * |
| 901 | * Arguments: cmd - command that is finished. |
| 902 | * |
| 903 | * Lock status: Assumed that no lock is held upon entry. |
| 904 | * |
| 905 | * Returns: Nothing |
| 906 | * |
| 907 | * Notes: This function is matched in terms of capabilities to |
| 908 | * the function that created the scatter-gather list. |
| 909 | * In other words, if there are no bounce buffers |
| 910 | * (the normal case for most drivers), we don't need |
| 911 | * the logic to deal with cleaning up afterwards. |
| 912 | * |
| 913 | * We must do one of several things here: |
| 914 | * |
| 915 | * a) Call scsi_end_request. This will finish off the |
| 916 | * specified number of sectors. If we are done, the |
| 917 | * command block will be released, and the queue |
| 918 | * function will be goosed. If we are not done, then |
| 919 | * scsi_end_request will directly goose the queue. |
| 920 | * |
| 921 | * b) We can just use scsi_requeue_command() here. This would |
| 922 | * be used if we just wanted to retry, for example. |
| 923 | */ |
| 924 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes, |
| 925 | unsigned int block_bytes) |
| 926 | { |
| 927 | int result = cmd->result; |
| 928 | int this_count = cmd->bufflen; |
| 929 | request_queue_t *q = cmd->device->request_queue; |
| 930 | struct request *req = cmd->request; |
| 931 | int clear_errors = 1; |
| 932 | struct scsi_sense_hdr sshdr; |
| 933 | int sense_valid = 0; |
| 934 | int sense_deferred = 0; |
| 935 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 936 | /* |
| 937 | * Free up any indirection buffers we allocated for DMA purposes. |
| 938 | * For the case of a READ, we need to copy the data out of the |
| 939 | * bounce buffer and into the real buffer. |
| 940 | */ |
| 941 | if (cmd->use_sg) |
| 942 | scsi_free_sgtable(cmd->buffer, cmd->sglist_len); |
| 943 | else if (cmd->buffer != req->buffer) { |
| 944 | if (rq_data_dir(req) == READ) { |
| 945 | unsigned long flags; |
| 946 | char *to = bio_kmap_irq(req->bio, &flags); |
| 947 | memcpy(to, cmd->buffer, cmd->bufflen); |
| 948 | bio_kunmap_irq(to, &flags); |
| 949 | } |
| 950 | kfree(cmd->buffer); |
| 951 | } |
| 952 | |
| 953 | if (result) { |
| 954 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); |
| 955 | if (sense_valid) |
| 956 | sense_deferred = scsi_sense_is_deferred(&sshdr); |
| 957 | } |
| 958 | if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ |
| 959 | req->errors = result; |
| 960 | if (result) { |
| 961 | clear_errors = 0; |
| 962 | if (sense_valid && req->sense) { |
| 963 | /* |
| 964 | * SG_IO wants current and deferred errors |
| 965 | */ |
| 966 | int len = 8 + cmd->sense_buffer[7]; |
| 967 | |
| 968 | if (len > SCSI_SENSE_BUFFERSIZE) |
| 969 | len = SCSI_SENSE_BUFFERSIZE; |
| 970 | memcpy(req->sense, cmd->sense_buffer, len); |
| 971 | req->sense_len = len; |
| 972 | } |
| 973 | } else |
| 974 | req->data_len = cmd->resid; |
| 975 | } |
| 976 | |
| 977 | /* |
| 978 | * Zero these out. They now point to freed memory, and it is |
| 979 | * dangerous to hang onto the pointers. |
| 980 | */ |
| 981 | cmd->buffer = NULL; |
| 982 | cmd->bufflen = 0; |
| 983 | cmd->request_buffer = NULL; |
| 984 | cmd->request_bufflen = 0; |
| 985 | |
| 986 | /* |
| 987 | * Next deal with any sectors which we were able to correctly |
| 988 | * handle. |
| 989 | */ |
| 990 | if (good_bytes >= 0) { |
| 991 | SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, %d bytes done.\n", |
| 992 | req->nr_sectors, good_bytes)); |
| 993 | SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg)); |
| 994 | |
| 995 | if (clear_errors) |
| 996 | req->errors = 0; |
| 997 | /* |
| 998 | * If multiple sectors are requested in one buffer, then |
| 999 | * they will have been finished off by the first command. |
| 1000 | * If not, then we have a multi-buffer command. |
| 1001 | * |
| 1002 | * If block_bytes != 0, it means we had a medium error |
| 1003 | * of some sort, and that we want to mark some number of |
| 1004 | * sectors as not uptodate. Thus we want to inhibit |
| 1005 | * requeueing right here - we will requeue down below |
| 1006 | * when we handle the bad sectors. |
| 1007 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | |
| 1009 | /* |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1010 | * If the command completed without error, then either |
| 1011 | * finish off the rest of the command, or start a new one. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | */ |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1013 | if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1015 | } |
| 1016 | /* |
| 1017 | * Now, if we were good little boys and girls, Santa left us a request |
| 1018 | * sense buffer. We can extract information from this, so we |
| 1019 | * can choose a block to remap, etc. |
| 1020 | */ |
| 1021 | if (sense_valid && !sense_deferred) { |
| 1022 | switch (sshdr.sense_key) { |
| 1023 | case UNIT_ATTENTION: |
| 1024 | if (cmd->device->removable) { |
| 1025 | /* detected disc change. set a bit |
| 1026 | * and quietly refuse further access. |
| 1027 | */ |
| 1028 | cmd->device->changed = 1; |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1029 | scsi_end_request(cmd, 0, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | this_count, 1); |
| 1031 | return; |
| 1032 | } else { |
| 1033 | /* |
| 1034 | * Must have been a power glitch, or a |
| 1035 | * bus reset. Could not have been a |
| 1036 | * media change, so we just retry the |
| 1037 | * request and see what happens. |
| 1038 | */ |
| 1039 | scsi_requeue_command(q, cmd); |
| 1040 | return; |
| 1041 | } |
| 1042 | break; |
| 1043 | case ILLEGAL_REQUEST: |
| 1044 | /* |
| 1045 | * If we had an ILLEGAL REQUEST returned, then we may |
| 1046 | * have performed an unsupported command. The only |
| 1047 | * thing this should be would be a ten byte read where |
| 1048 | * only a six byte read was supported. Also, on a |
| 1049 | * system where READ CAPACITY failed, we may have read |
| 1050 | * past the end of the disk. |
| 1051 | */ |
Jens Axboe | 26a6801 | 2005-11-29 21:03:34 +0100 | [diff] [blame] | 1052 | if ((cmd->device->use_10_for_rw && |
| 1053 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1054 | (cmd->cmnd[0] == READ_10 || |
| 1055 | cmd->cmnd[0] == WRITE_10)) { |
| 1056 | cmd->device->use_10_for_rw = 0; |
| 1057 | /* |
| 1058 | * This will cause a retry with a 6-byte |
| 1059 | * command. |
| 1060 | */ |
| 1061 | scsi_requeue_command(q, cmd); |
| 1062 | result = 0; |
| 1063 | } else { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1064 | scsi_end_request(cmd, 0, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | return; |
| 1066 | } |
| 1067 | break; |
| 1068 | case NOT_READY: |
| 1069 | /* |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 1070 | * If the device is in the process of becoming |
| 1071 | * ready, or has a temporary blockage, retry. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1072 | */ |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 1073 | if (sshdr.asc == 0x04) { |
| 1074 | switch (sshdr.ascq) { |
| 1075 | case 0x01: /* becoming ready */ |
| 1076 | case 0x04: /* format in progress */ |
| 1077 | case 0x05: /* rebuild in progress */ |
| 1078 | case 0x06: /* recalculation in progress */ |
| 1079 | case 0x07: /* operation in progress */ |
| 1080 | case 0x08: /* Long write in progress */ |
| 1081 | case 0x09: /* self test in progress */ |
| 1082 | scsi_requeue_command(q, cmd); |
| 1083 | return; |
| 1084 | default: |
| 1085 | break; |
| 1086 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1087 | } |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 1088 | if (!(req->flags & REQ_QUIET)) { |
Jeff Garzik | 3bf743e | 2005-10-24 18:04:06 -0400 | [diff] [blame] | 1089 | scmd_printk(KERN_INFO, cmd, |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 1090 | "Device not ready: "); |
| 1091 | scsi_print_sense_hdr("", &sshdr); |
| 1092 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1093 | scsi_end_request(cmd, 0, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1094 | return; |
| 1095 | case VOLUME_OVERFLOW: |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 1096 | if (!(req->flags & REQ_QUIET)) { |
Jeff Garzik | 3bf743e | 2005-10-24 18:04:06 -0400 | [diff] [blame] | 1097 | scmd_printk(KERN_INFO, cmd, |
| 1098 | "Volume overflow, CDB: "); |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 1099 | __scsi_print_command(cmd->data_cmnd); |
| 1100 | scsi_print_sense("", cmd); |
| 1101 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1102 | scsi_end_request(cmd, 0, block_bytes, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1103 | return; |
| 1104 | default: |
| 1105 | break; |
| 1106 | } |
| 1107 | } /* driver byte != 0 */ |
| 1108 | if (host_byte(result) == DID_RESET) { |
| 1109 | /* |
| 1110 | * Third party bus reset or reset for error |
| 1111 | * recovery reasons. Just retry the request |
| 1112 | * and see what happens. |
| 1113 | */ |
| 1114 | scsi_requeue_command(q, cmd); |
| 1115 | return; |
| 1116 | } |
| 1117 | if (result) { |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 1118 | if (!(req->flags & REQ_QUIET)) { |
Jeff Garzik | 3bf743e | 2005-10-24 18:04:06 -0400 | [diff] [blame] | 1119 | scmd_printk(KERN_INFO, cmd, |
| 1120 | "SCSI error: return code = 0x%x\n", result); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1121 | |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 1122 | if (driver_byte(result) & DRIVER_SENSE) |
| 1123 | scsi_print_sense("", cmd); |
| 1124 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1125 | /* |
| 1126 | * Mark a single buffer as not uptodate. Queue the remainder. |
| 1127 | * We sometimes get this cruft in the event that a medium error |
| 1128 | * isn't properly reported. |
| 1129 | */ |
| 1130 | block_bytes = req->hard_cur_sectors << 9; |
| 1131 | if (!block_bytes) |
| 1132 | block_bytes = req->data_len; |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1133 | scsi_end_request(cmd, 0, block_bytes, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | } |
| 1135 | } |
| 1136 | EXPORT_SYMBOL(scsi_io_completion); |
| 1137 | |
| 1138 | /* |
| 1139 | * Function: scsi_init_io() |
| 1140 | * |
| 1141 | * Purpose: SCSI I/O initialize function. |
| 1142 | * |
| 1143 | * Arguments: cmd - Command descriptor we wish to initialize |
| 1144 | * |
| 1145 | * Returns: 0 on success |
| 1146 | * BLKPREP_DEFER if the failure is retryable |
| 1147 | * BLKPREP_KILL if the failure is fatal |
| 1148 | */ |
| 1149 | static int scsi_init_io(struct scsi_cmnd *cmd) |
| 1150 | { |
| 1151 | struct request *req = cmd->request; |
| 1152 | struct scatterlist *sgpnt; |
| 1153 | int count; |
| 1154 | |
| 1155 | /* |
| 1156 | * if this is a rq->data based REQ_BLOCK_PC, setup for a non-sg xfer |
| 1157 | */ |
| 1158 | if ((req->flags & REQ_BLOCK_PC) && !req->bio) { |
| 1159 | cmd->request_bufflen = req->data_len; |
| 1160 | cmd->request_buffer = req->data; |
| 1161 | req->buffer = req->data; |
| 1162 | cmd->use_sg = 0; |
| 1163 | return 0; |
| 1164 | } |
| 1165 | |
| 1166 | /* |
| 1167 | * we used to not use scatter-gather for single segment request, |
| 1168 | * but now we do (it makes highmem I/O easier to support without |
| 1169 | * kmapping pages) |
| 1170 | */ |
| 1171 | cmd->use_sg = req->nr_phys_segments; |
| 1172 | |
| 1173 | /* |
| 1174 | * if sg table allocation fails, requeue request later. |
| 1175 | */ |
| 1176 | sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC); |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1177 | if (unlikely(!sgpnt)) { |
| 1178 | scsi_unprep_request(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1179 | return BLKPREP_DEFER; |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1180 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | |
| 1182 | cmd->request_buffer = (char *) sgpnt; |
| 1183 | cmd->request_bufflen = req->nr_sectors << 9; |
| 1184 | if (blk_pc_request(req)) |
| 1185 | cmd->request_bufflen = req->data_len; |
| 1186 | req->buffer = NULL; |
| 1187 | |
| 1188 | /* |
| 1189 | * Next, walk the list, and fill in the addresses and sizes of |
| 1190 | * each segment. |
| 1191 | */ |
| 1192 | count = blk_rq_map_sg(req->q, req, cmd->request_buffer); |
| 1193 | |
| 1194 | /* |
| 1195 | * mapped well, send it off |
| 1196 | */ |
| 1197 | if (likely(count <= cmd->use_sg)) { |
| 1198 | cmd->use_sg = count; |
| 1199 | return 0; |
| 1200 | } |
| 1201 | |
| 1202 | printk(KERN_ERR "Incorrect number of segments after building list\n"); |
| 1203 | printk(KERN_ERR "counted %d, received %d\n", count, cmd->use_sg); |
| 1204 | printk(KERN_ERR "req nr_sec %lu, cur_nr_sec %u\n", req->nr_sectors, |
| 1205 | req->current_nr_sectors); |
| 1206 | |
| 1207 | /* release the command and kill it */ |
| 1208 | scsi_release_buffers(cmd); |
| 1209 | scsi_put_command(cmd); |
| 1210 | return BLKPREP_KILL; |
| 1211 | } |
| 1212 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1213 | static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk, |
| 1214 | sector_t *error_sector) |
| 1215 | { |
| 1216 | struct scsi_device *sdev = q->queuedata; |
| 1217 | struct scsi_driver *drv; |
| 1218 | |
| 1219 | if (sdev->sdev_state != SDEV_RUNNING) |
| 1220 | return -ENXIO; |
| 1221 | |
| 1222 | drv = *(struct scsi_driver **) disk->private_data; |
| 1223 | if (drv->issue_flush) |
| 1224 | return drv->issue_flush(&sdev->sdev_gendev, error_sector); |
| 1225 | |
| 1226 | return -EOPNOTSUPP; |
| 1227 | } |
| 1228 | |
Christoph Hellwig | 776b23a | 2006-01-06 18:34:07 +0100 | [diff] [blame] | 1229 | static void scsi_blk_pc_done(struct scsi_cmnd *cmd) |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1230 | { |
| 1231 | BUG_ON(!blk_pc_request(cmd->request)); |
Mike Christie | 0d95716 | 2005-11-11 05:31:40 -0600 | [diff] [blame] | 1232 | /* |
| 1233 | * This will complete the whole command with uptodate=1 so |
| 1234 | * as far as the block layer is concerned the command completed |
| 1235 | * successfully. Since this is a REQ_BLOCK_PC command the |
| 1236 | * caller should check the request's errors value |
| 1237 | */ |
| 1238 | scsi_io_completion(cmd, cmd->bufflen, 0); |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1239 | } |
| 1240 | |
Christoph Hellwig | 776b23a | 2006-01-06 18:34:07 +0100 | [diff] [blame] | 1241 | static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd) |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1242 | { |
| 1243 | struct request *req = cmd->request; |
| 1244 | |
| 1245 | BUG_ON(sizeof(req->cmd) > sizeof(cmd->cmnd)); |
| 1246 | memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd)); |
| 1247 | cmd->cmd_len = req->cmd_len; |
| 1248 | if (!req->data_len) |
| 1249 | cmd->sc_data_direction = DMA_NONE; |
| 1250 | else if (rq_data_dir(req) == WRITE) |
| 1251 | cmd->sc_data_direction = DMA_TO_DEVICE; |
| 1252 | else |
| 1253 | cmd->sc_data_direction = DMA_FROM_DEVICE; |
| 1254 | |
| 1255 | cmd->transfersize = req->data_len; |
| 1256 | cmd->allowed = req->retries; |
| 1257 | cmd->timeout_per_command = req->timeout; |
Christoph Hellwig | 776b23a | 2006-01-06 18:34:07 +0100 | [diff] [blame] | 1258 | cmd->done = scsi_blk_pc_done; |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1259 | } |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1260 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1261 | static int scsi_prep_fn(struct request_queue *q, struct request *req) |
| 1262 | { |
| 1263 | struct scsi_device *sdev = q->queuedata; |
| 1264 | struct scsi_cmnd *cmd; |
| 1265 | int specials_only = 0; |
| 1266 | |
| 1267 | /* |
| 1268 | * Just check to see if the device is online. If it isn't, we |
| 1269 | * refuse to process any commands. The device must be brought |
| 1270 | * online before trying any recovery commands |
| 1271 | */ |
| 1272 | if (unlikely(!scsi_device_online(sdev))) { |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1273 | sdev_printk(KERN_ERR, sdev, |
| 1274 | "rejecting I/O to offline device\n"); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1275 | goto kill; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | } |
| 1277 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
| 1278 | /* OK, we're not in a running state don't prep |
| 1279 | * user commands */ |
| 1280 | if (sdev->sdev_state == SDEV_DEL) { |
| 1281 | /* Device is fully deleted, no commands |
| 1282 | * at all allowed down */ |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1283 | sdev_printk(KERN_ERR, sdev, |
| 1284 | "rejecting I/O to dead device\n"); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1285 | goto kill; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | } |
| 1287 | /* OK, we only allow special commands (i.e. not |
| 1288 | * user initiated ones */ |
| 1289 | specials_only = sdev->sdev_state; |
| 1290 | } |
| 1291 | |
| 1292 | /* |
| 1293 | * Find the actual device driver associated with this command. |
| 1294 | * The SPECIAL requests are things like character device or |
| 1295 | * ioctls, which did not originate from ll_rw_blk. Note that |
| 1296 | * the special field is also used to indicate the cmd for |
| 1297 | * the remainder of a partially fulfilled request that can |
| 1298 | * come up when there is a medium error. We have to treat |
| 1299 | * these two cases differently. We differentiate by looking |
| 1300 | * at request->cmd, as this tells us the real story. |
| 1301 | */ |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1302 | if (req->flags & REQ_SPECIAL && req->special) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | struct scsi_request *sreq = req->special; |
| 1304 | |
| 1305 | if (sreq->sr_magic == SCSI_REQ_MAGIC) { |
| 1306 | cmd = scsi_get_command(sreq->sr_device, GFP_ATOMIC); |
| 1307 | if (unlikely(!cmd)) |
| 1308 | goto defer; |
| 1309 | scsi_init_cmd_from_req(cmd, sreq); |
| 1310 | } else |
| 1311 | cmd = req->special; |
| 1312 | } else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) { |
| 1313 | |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1314 | if(unlikely(specials_only) && !(req->flags & REQ_SPECIAL)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1315 | if(specials_only == SDEV_QUIESCE || |
| 1316 | specials_only == SDEV_BLOCK) |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1317 | goto defer; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1318 | |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1319 | sdev_printk(KERN_ERR, sdev, |
| 1320 | "rejecting I/O to device being removed\n"); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1321 | goto kill; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1322 | } |
| 1323 | |
| 1324 | |
| 1325 | /* |
| 1326 | * Now try and find a command block that we can use. |
| 1327 | */ |
| 1328 | if (!req->special) { |
| 1329 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
| 1330 | if (unlikely(!cmd)) |
| 1331 | goto defer; |
| 1332 | } else |
| 1333 | cmd = req->special; |
| 1334 | |
| 1335 | /* pull a tag out of the request if we have one */ |
| 1336 | cmd->tag = req->tag; |
| 1337 | } else { |
| 1338 | blk_dump_rq_flags(req, "SCSI bad req"); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1339 | goto kill; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1340 | } |
| 1341 | |
| 1342 | /* note the overloading of req->special. When the tag |
| 1343 | * is active it always means cmd. If the tag goes |
| 1344 | * back for re-queueing, it may be reset */ |
| 1345 | req->special = cmd; |
| 1346 | cmd->request = req; |
| 1347 | |
| 1348 | /* |
| 1349 | * FIXME: drop the lock here because the functions below |
| 1350 | * expect to be called without the queue lock held. Also, |
| 1351 | * previously, we dequeued the request before dropping the |
| 1352 | * lock. We hope REQ_STARTED prevents anything untoward from |
| 1353 | * happening now. |
| 1354 | */ |
| 1355 | if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1356 | int ret; |
| 1357 | |
| 1358 | /* |
| 1359 | * This will do a couple of things: |
| 1360 | * 1) Fill in the actual SCSI command. |
| 1361 | * 2) Fill in any other upper-level specific fields |
| 1362 | * (timeout). |
| 1363 | * |
| 1364 | * If this returns 0, it means that the request failed |
| 1365 | * (reading past end of disk, reading offline device, |
| 1366 | * etc). This won't actually talk to the device, but |
| 1367 | * some kinds of consistency checking may cause the |
| 1368 | * request to be rejected immediately. |
| 1369 | */ |
| 1370 | |
| 1371 | /* |
| 1372 | * This sets up the scatter-gather table (allocating if |
| 1373 | * required). |
| 1374 | */ |
| 1375 | ret = scsi_init_io(cmd); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1376 | switch(ret) { |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1377 | /* For BLKPREP_KILL/DEFER the cmd was released */ |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1378 | case BLKPREP_KILL: |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1379 | goto kill; |
| 1380 | case BLKPREP_DEFER: |
| 1381 | goto defer; |
| 1382 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1383 | |
| 1384 | /* |
| 1385 | * Initialize the actual SCSI command for this request. |
| 1386 | */ |
Christoph Hellwig | 776b23a | 2006-01-06 18:34:07 +0100 | [diff] [blame] | 1387 | if (req->flags & REQ_BLOCK_PC) { |
| 1388 | scsi_setup_blk_pc_cmnd(cmd); |
| 1389 | } else if (req->rq_disk) { |
| 1390 | struct scsi_driver *drv; |
| 1391 | |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1392 | drv = *(struct scsi_driver **)req->rq_disk->private_data; |
| 1393 | if (unlikely(!drv->init_command(cmd))) { |
| 1394 | scsi_release_buffers(cmd); |
| 1395 | scsi_put_command(cmd); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1396 | goto kill; |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1397 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1398 | } |
| 1399 | } |
| 1400 | |
| 1401 | /* |
| 1402 | * The request is now prepped, no need to come back here |
| 1403 | */ |
| 1404 | req->flags |= REQ_DONTPREP; |
| 1405 | return BLKPREP_OK; |
| 1406 | |
| 1407 | defer: |
| 1408 | /* If we defer, the elv_next_request() returns NULL, but the |
| 1409 | * queue must be restarted, so we plug here if no returning |
| 1410 | * command will automatically do that. */ |
| 1411 | if (sdev->device_busy == 0) |
| 1412 | blk_plug_device(q); |
| 1413 | return BLKPREP_DEFER; |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1414 | kill: |
| 1415 | req->errors = DID_NO_CONNECT << 16; |
| 1416 | return BLKPREP_KILL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | } |
| 1418 | |
| 1419 | /* |
| 1420 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else |
| 1421 | * return 0. |
| 1422 | * |
| 1423 | * Called with the queue_lock held. |
| 1424 | */ |
| 1425 | static inline int scsi_dev_queue_ready(struct request_queue *q, |
| 1426 | struct scsi_device *sdev) |
| 1427 | { |
| 1428 | if (sdev->device_busy >= sdev->queue_depth) |
| 1429 | return 0; |
| 1430 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
| 1431 | /* |
| 1432 | * unblock after device_blocked iterates to zero |
| 1433 | */ |
| 1434 | if (--sdev->device_blocked == 0) { |
| 1435 | SCSI_LOG_MLQUEUE(3, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1436 | sdev_printk(KERN_INFO, sdev, |
| 1437 | "unblocking device at zero depth\n")); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | } else { |
| 1439 | blk_plug_device(q); |
| 1440 | return 0; |
| 1441 | } |
| 1442 | } |
| 1443 | if (sdev->device_blocked) |
| 1444 | return 0; |
| 1445 | |
| 1446 | return 1; |
| 1447 | } |
| 1448 | |
| 1449 | /* |
| 1450 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else |
| 1451 | * return 0. We must end up running the queue again whenever 0 is |
| 1452 | * returned, else IO can hang. |
| 1453 | * |
| 1454 | * Called with host_lock held. |
| 1455 | */ |
| 1456 | static inline int scsi_host_queue_ready(struct request_queue *q, |
| 1457 | struct Scsi_Host *shost, |
| 1458 | struct scsi_device *sdev) |
| 1459 | { |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 1460 | if (scsi_host_in_recovery(shost)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | return 0; |
| 1462 | if (shost->host_busy == 0 && shost->host_blocked) { |
| 1463 | /* |
| 1464 | * unblock after host_blocked iterates to zero |
| 1465 | */ |
| 1466 | if (--shost->host_blocked == 0) { |
| 1467 | SCSI_LOG_MLQUEUE(3, |
| 1468 | printk("scsi%d unblocking host at zero depth\n", |
| 1469 | shost->host_no)); |
| 1470 | } else { |
| 1471 | blk_plug_device(q); |
| 1472 | return 0; |
| 1473 | } |
| 1474 | } |
| 1475 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || |
| 1476 | shost->host_blocked || shost->host_self_blocked) { |
| 1477 | if (list_empty(&sdev->starved_entry)) |
| 1478 | list_add_tail(&sdev->starved_entry, &shost->starved_list); |
| 1479 | return 0; |
| 1480 | } |
| 1481 | |
| 1482 | /* We're OK to process the command, so we can't be starved */ |
| 1483 | if (!list_empty(&sdev->starved_entry)) |
| 1484 | list_del_init(&sdev->starved_entry); |
| 1485 | |
| 1486 | return 1; |
| 1487 | } |
| 1488 | |
| 1489 | /* |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1490 | * Kill a request for a dead device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1491 | */ |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1492 | static void scsi_kill_request(struct request *req, request_queue_t *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1493 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1494 | struct scsi_cmnd *cmd = req->special; |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1495 | struct scsi_device *sdev = cmd->device; |
| 1496 | struct Scsi_Host *shost = sdev->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1497 | |
James Bottomley | 788ce43 | 2005-09-09 13:40:23 -0500 | [diff] [blame] | 1498 | blkdev_dequeue_request(req); |
| 1499 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1500 | if (unlikely(cmd == NULL)) { |
| 1501 | printk(KERN_CRIT "impossible request in %s.\n", |
| 1502 | __FUNCTION__); |
| 1503 | BUG(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1504 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1505 | |
| 1506 | scsi_init_cmd_errh(cmd); |
| 1507 | cmd->result = DID_NO_CONNECT << 16; |
| 1508 | atomic_inc(&cmd->device->iorequest_cnt); |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1509 | |
| 1510 | /* |
| 1511 | * SCSI request completion path will do scsi_device_unbusy(), |
| 1512 | * bump busy counts. To bump the counters, we need to dance |
| 1513 | * with the locks as normal issue path does. |
| 1514 | */ |
| 1515 | sdev->device_busy++; |
| 1516 | spin_unlock(sdev->request_queue->queue_lock); |
| 1517 | spin_lock(shost->host_lock); |
| 1518 | shost->host_busy++; |
| 1519 | spin_unlock(shost->host_lock); |
| 1520 | spin_lock(sdev->request_queue->queue_lock); |
| 1521 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1522 | __scsi_done(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1523 | } |
| 1524 | |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1525 | static void scsi_softirq_done(struct request *rq) |
| 1526 | { |
| 1527 | struct scsi_cmnd *cmd = rq->completion_data; |
Brian King | 8884efa | 2006-02-24 17:10:04 -0600 | [diff] [blame] | 1528 | unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command; |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1529 | int disposition; |
| 1530 | |
| 1531 | INIT_LIST_HEAD(&cmd->eh_entry); |
| 1532 | |
| 1533 | disposition = scsi_decide_disposition(cmd); |
| 1534 | if (disposition != SUCCESS && |
| 1535 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { |
| 1536 | sdev_printk(KERN_ERR, cmd->device, |
| 1537 | "timing out command, waited %lus\n", |
| 1538 | wait_for/HZ); |
| 1539 | disposition = SUCCESS; |
| 1540 | } |
| 1541 | |
| 1542 | scsi_log_completion(cmd, disposition); |
| 1543 | |
| 1544 | switch (disposition) { |
| 1545 | case SUCCESS: |
| 1546 | scsi_finish_command(cmd); |
| 1547 | break; |
| 1548 | case NEEDS_RETRY: |
| 1549 | scsi_retry_command(cmd); |
| 1550 | break; |
| 1551 | case ADD_TO_MLQUEUE: |
| 1552 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
| 1553 | break; |
| 1554 | default: |
| 1555 | if (!scsi_eh_scmd_add(cmd, 0)) |
| 1556 | scsi_finish_command(cmd); |
| 1557 | } |
| 1558 | } |
| 1559 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1560 | /* |
| 1561 | * Function: scsi_request_fn() |
| 1562 | * |
| 1563 | * Purpose: Main strategy routine for SCSI. |
| 1564 | * |
| 1565 | * Arguments: q - Pointer to actual queue. |
| 1566 | * |
| 1567 | * Returns: Nothing |
| 1568 | * |
| 1569 | * Lock status: IO request lock assumed to be held when called. |
| 1570 | */ |
| 1571 | static void scsi_request_fn(struct request_queue *q) |
| 1572 | { |
| 1573 | struct scsi_device *sdev = q->queuedata; |
| 1574 | struct Scsi_Host *shost; |
| 1575 | struct scsi_cmnd *cmd; |
| 1576 | struct request *req; |
| 1577 | |
| 1578 | if (!sdev) { |
| 1579 | printk("scsi: killing requests for dead queue\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1580 | while ((req = elv_next_request(q)) != NULL) |
| 1581 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1582 | return; |
| 1583 | } |
| 1584 | |
| 1585 | if(!get_device(&sdev->sdev_gendev)) |
| 1586 | /* We must be tearing the block queue down already */ |
| 1587 | return; |
| 1588 | |
| 1589 | /* |
| 1590 | * To start with, we keep looping until the queue is empty, or until |
| 1591 | * the host is no longer able to accept any more requests. |
| 1592 | */ |
| 1593 | shost = sdev->host; |
| 1594 | while (!blk_queue_plugged(q)) { |
| 1595 | int rtn; |
| 1596 | /* |
| 1597 | * get next queueable request. We do this early to make sure |
| 1598 | * that the request is fully prepared even if we cannot |
| 1599 | * accept it. |
| 1600 | */ |
| 1601 | req = elv_next_request(q); |
| 1602 | if (!req || !scsi_dev_queue_ready(q, sdev)) |
| 1603 | break; |
| 1604 | |
| 1605 | if (unlikely(!scsi_device_online(sdev))) { |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1606 | sdev_printk(KERN_ERR, sdev, |
| 1607 | "rejecting I/O to offline device\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1608 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1609 | continue; |
| 1610 | } |
| 1611 | |
| 1612 | |
| 1613 | /* |
| 1614 | * Remove the request from the request list. |
| 1615 | */ |
| 1616 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) |
| 1617 | blkdev_dequeue_request(req); |
| 1618 | sdev->device_busy++; |
| 1619 | |
| 1620 | spin_unlock(q->queue_lock); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1621 | cmd = req->special; |
| 1622 | if (unlikely(cmd == NULL)) { |
| 1623 | printk(KERN_CRIT "impossible request in %s.\n" |
| 1624 | "please mail a stack trace to " |
| 1625 | "linux-scsi@vger.kernel.org", |
| 1626 | __FUNCTION__); |
| 1627 | BUG(); |
| 1628 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1629 | spin_lock(shost->host_lock); |
| 1630 | |
| 1631 | if (!scsi_host_queue_ready(q, shost, sdev)) |
| 1632 | goto not_ready; |
| 1633 | if (sdev->single_lun) { |
| 1634 | if (scsi_target(sdev)->starget_sdev_user && |
| 1635 | scsi_target(sdev)->starget_sdev_user != sdev) |
| 1636 | goto not_ready; |
| 1637 | scsi_target(sdev)->starget_sdev_user = sdev; |
| 1638 | } |
| 1639 | shost->host_busy++; |
| 1640 | |
| 1641 | /* |
| 1642 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will |
| 1643 | * take the lock again. |
| 1644 | */ |
| 1645 | spin_unlock_irq(shost->host_lock); |
| 1646 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1647 | /* |
| 1648 | * Finally, initialize any error handling parameters, and set up |
| 1649 | * the timers for timeouts. |
| 1650 | */ |
| 1651 | scsi_init_cmd_errh(cmd); |
| 1652 | |
| 1653 | /* |
| 1654 | * Dispatch the command to the low-level driver. |
| 1655 | */ |
| 1656 | rtn = scsi_dispatch_cmd(cmd); |
| 1657 | spin_lock_irq(q->queue_lock); |
| 1658 | if(rtn) { |
| 1659 | /* we're refusing the command; because of |
| 1660 | * the way locks get dropped, we need to |
| 1661 | * check here if plugging is required */ |
| 1662 | if(sdev->device_busy == 0) |
| 1663 | blk_plug_device(q); |
| 1664 | |
| 1665 | break; |
| 1666 | } |
| 1667 | } |
| 1668 | |
| 1669 | goto out; |
| 1670 | |
| 1671 | not_ready: |
| 1672 | spin_unlock_irq(shost->host_lock); |
| 1673 | |
| 1674 | /* |
| 1675 | * lock q, handle tag, requeue req, and decrement device_busy. We |
| 1676 | * must return with queue_lock held. |
| 1677 | * |
| 1678 | * Decrementing device_busy without checking it is OK, as all such |
| 1679 | * cases (host limits or settings) should run the queue at some |
| 1680 | * later time. |
| 1681 | */ |
| 1682 | spin_lock_irq(q->queue_lock); |
| 1683 | blk_requeue_request(q, req); |
| 1684 | sdev->device_busy--; |
| 1685 | if(sdev->device_busy == 0) |
| 1686 | blk_plug_device(q); |
| 1687 | out: |
| 1688 | /* must be careful here...if we trigger the ->remove() function |
| 1689 | * we cannot be holding the q lock */ |
| 1690 | spin_unlock_irq(q->queue_lock); |
| 1691 | put_device(&sdev->sdev_gendev); |
| 1692 | spin_lock_irq(q->queue_lock); |
| 1693 | } |
| 1694 | |
| 1695 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
| 1696 | { |
| 1697 | struct device *host_dev; |
| 1698 | u64 bounce_limit = 0xffffffff; |
| 1699 | |
| 1700 | if (shost->unchecked_isa_dma) |
| 1701 | return BLK_BOUNCE_ISA; |
| 1702 | /* |
| 1703 | * Platforms with virtual-DMA translation |
| 1704 | * hardware have no practical limit. |
| 1705 | */ |
| 1706 | if (!PCI_DMA_BUS_IS_PHYS) |
| 1707 | return BLK_BOUNCE_ANY; |
| 1708 | |
| 1709 | host_dev = scsi_get_device(shost); |
| 1710 | if (host_dev && host_dev->dma_mask) |
| 1711 | bounce_limit = *host_dev->dma_mask; |
| 1712 | |
| 1713 | return bounce_limit; |
| 1714 | } |
| 1715 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); |
| 1716 | |
| 1717 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) |
| 1718 | { |
| 1719 | struct Scsi_Host *shost = sdev->host; |
| 1720 | struct request_queue *q; |
| 1721 | |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 1722 | q = blk_init_queue(scsi_request_fn, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1723 | if (!q) |
| 1724 | return NULL; |
| 1725 | |
| 1726 | blk_queue_prep_rq(q, scsi_prep_fn); |
| 1727 | |
| 1728 | blk_queue_max_hw_segments(q, shost->sg_tablesize); |
| 1729 | blk_queue_max_phys_segments(q, SCSI_MAX_PHYS_SEGMENTS); |
| 1730 | blk_queue_max_sectors(q, shost->max_sectors); |
| 1731 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
| 1732 | blk_queue_segment_boundary(q, shost->dma_boundary); |
| 1733 | blk_queue_issue_flush_fn(q, scsi_issue_flush_fn); |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1734 | blk_queue_softirq_done(q, scsi_softirq_done); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1735 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1736 | if (!shost->use_clustering) |
| 1737 | clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); |
| 1738 | return q; |
| 1739 | } |
| 1740 | |
| 1741 | void scsi_free_queue(struct request_queue *q) |
| 1742 | { |
| 1743 | blk_cleanup_queue(q); |
| 1744 | } |
| 1745 | |
| 1746 | /* |
| 1747 | * Function: scsi_block_requests() |
| 1748 | * |
| 1749 | * Purpose: Utility function used by low-level drivers to prevent further |
| 1750 | * commands from being queued to the device. |
| 1751 | * |
| 1752 | * Arguments: shost - Host in question |
| 1753 | * |
| 1754 | * Returns: Nothing |
| 1755 | * |
| 1756 | * Lock status: No locks are assumed held. |
| 1757 | * |
| 1758 | * Notes: There is no timer nor any other means by which the requests |
| 1759 | * get unblocked other than the low-level driver calling |
| 1760 | * scsi_unblock_requests(). |
| 1761 | */ |
| 1762 | void scsi_block_requests(struct Scsi_Host *shost) |
| 1763 | { |
| 1764 | shost->host_self_blocked = 1; |
| 1765 | } |
| 1766 | EXPORT_SYMBOL(scsi_block_requests); |
| 1767 | |
| 1768 | /* |
| 1769 | * Function: scsi_unblock_requests() |
| 1770 | * |
| 1771 | * Purpose: Utility function used by low-level drivers to allow further |
| 1772 | * commands from being queued to the device. |
| 1773 | * |
| 1774 | * Arguments: shost - Host in question |
| 1775 | * |
| 1776 | * Returns: Nothing |
| 1777 | * |
| 1778 | * Lock status: No locks are assumed held. |
| 1779 | * |
| 1780 | * Notes: There is no timer nor any other means by which the requests |
| 1781 | * get unblocked other than the low-level driver calling |
| 1782 | * scsi_unblock_requests(). |
| 1783 | * |
| 1784 | * This is done as an API function so that changes to the |
| 1785 | * internals of the scsi mid-layer won't require wholesale |
| 1786 | * changes to drivers that use this feature. |
| 1787 | */ |
| 1788 | void scsi_unblock_requests(struct Scsi_Host *shost) |
| 1789 | { |
| 1790 | shost->host_self_blocked = 0; |
| 1791 | scsi_run_host_queues(shost); |
| 1792 | } |
| 1793 | EXPORT_SYMBOL(scsi_unblock_requests); |
| 1794 | |
| 1795 | int __init scsi_init_queue(void) |
| 1796 | { |
| 1797 | int i; |
| 1798 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1799 | scsi_io_context_cache = kmem_cache_create("scsi_io_context", |
| 1800 | sizeof(struct scsi_io_context), |
| 1801 | 0, 0, NULL, NULL); |
| 1802 | if (!scsi_io_context_cache) { |
| 1803 | printk(KERN_ERR "SCSI: can't init scsi io context cache\n"); |
| 1804 | return -ENOMEM; |
| 1805 | } |
| 1806 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1807 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1808 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1809 | int size = sgp->size * sizeof(struct scatterlist); |
| 1810 | |
| 1811 | sgp->slab = kmem_cache_create(sgp->name, size, 0, |
| 1812 | SLAB_HWCACHE_ALIGN, NULL, NULL); |
| 1813 | if (!sgp->slab) { |
| 1814 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", |
| 1815 | sgp->name); |
| 1816 | } |
| 1817 | |
Matthew Dobson | 93d2341 | 2006-03-26 01:37:50 -0800 | [diff] [blame] | 1818 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
| 1819 | sgp->slab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1820 | if (!sgp->pool) { |
| 1821 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", |
| 1822 | sgp->name); |
| 1823 | } |
| 1824 | } |
| 1825 | |
| 1826 | return 0; |
| 1827 | } |
| 1828 | |
| 1829 | void scsi_exit_queue(void) |
| 1830 | { |
| 1831 | int i; |
| 1832 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1833 | kmem_cache_destroy(scsi_io_context_cache); |
| 1834 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1835 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1836 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1837 | mempool_destroy(sgp->pool); |
| 1838 | kmem_cache_destroy(sgp->slab); |
| 1839 | } |
| 1840 | } |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1841 | |
| 1842 | /** |
| 1843 | * scsi_mode_select - issue a mode select |
| 1844 | * @sdev: SCSI device to be queried |
| 1845 | * @pf: Page format bit (1 == standard, 0 == vendor specific) |
| 1846 | * @sp: Save page bit (0 == don't save, 1 == save) |
| 1847 | * @modepage: mode page being requested |
| 1848 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1849 | * @len: length of request buffer. |
| 1850 | * @timeout: command timeout |
| 1851 | * @retries: number of retries before failing |
| 1852 | * @data: returns a structure abstracting the mode header data |
| 1853 | * @sense: place to put sense data (or NULL if no sense to be collected). |
| 1854 | * must be SCSI_SENSE_BUFFERSIZE big. |
| 1855 | * |
| 1856 | * Returns zero if successful; negative error number or scsi |
| 1857 | * status on error |
| 1858 | * |
| 1859 | */ |
| 1860 | int |
| 1861 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, |
| 1862 | unsigned char *buffer, int len, int timeout, int retries, |
| 1863 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1864 | { |
| 1865 | unsigned char cmd[10]; |
| 1866 | unsigned char *real_buffer; |
| 1867 | int ret; |
| 1868 | |
| 1869 | memset(cmd, 0, sizeof(cmd)); |
| 1870 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); |
| 1871 | |
| 1872 | if (sdev->use_10_for_ms) { |
| 1873 | if (len > 65535) |
| 1874 | return -EINVAL; |
| 1875 | real_buffer = kmalloc(8 + len, GFP_KERNEL); |
| 1876 | if (!real_buffer) |
| 1877 | return -ENOMEM; |
| 1878 | memcpy(real_buffer + 8, buffer, len); |
| 1879 | len += 8; |
| 1880 | real_buffer[0] = 0; |
| 1881 | real_buffer[1] = 0; |
| 1882 | real_buffer[2] = data->medium_type; |
| 1883 | real_buffer[3] = data->device_specific; |
| 1884 | real_buffer[4] = data->longlba ? 0x01 : 0; |
| 1885 | real_buffer[5] = 0; |
| 1886 | real_buffer[6] = data->block_descriptor_length >> 8; |
| 1887 | real_buffer[7] = data->block_descriptor_length; |
| 1888 | |
| 1889 | cmd[0] = MODE_SELECT_10; |
| 1890 | cmd[7] = len >> 8; |
| 1891 | cmd[8] = len; |
| 1892 | } else { |
| 1893 | if (len > 255 || data->block_descriptor_length > 255 || |
| 1894 | data->longlba) |
| 1895 | return -EINVAL; |
| 1896 | |
| 1897 | real_buffer = kmalloc(4 + len, GFP_KERNEL); |
| 1898 | if (!real_buffer) |
| 1899 | return -ENOMEM; |
| 1900 | memcpy(real_buffer + 4, buffer, len); |
| 1901 | len += 4; |
| 1902 | real_buffer[0] = 0; |
| 1903 | real_buffer[1] = data->medium_type; |
| 1904 | real_buffer[2] = data->device_specific; |
| 1905 | real_buffer[3] = data->block_descriptor_length; |
| 1906 | |
| 1907 | |
| 1908 | cmd[0] = MODE_SELECT; |
| 1909 | cmd[4] = len; |
| 1910 | } |
| 1911 | |
| 1912 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, |
| 1913 | sshdr, timeout, retries); |
| 1914 | kfree(real_buffer); |
| 1915 | return ret; |
| 1916 | } |
| 1917 | EXPORT_SYMBOL_GPL(scsi_mode_select); |
| 1918 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1919 | /** |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1920 | * scsi_mode_sense - issue a mode sense, falling back from 10 to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1921 | * six bytes if necessary. |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1922 | * @sdev: SCSI device to be queried |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1923 | * @dbd: set if mode sense will allow block descriptors to be returned |
| 1924 | * @modepage: mode page being requested |
| 1925 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1926 | * @len: length of request buffer. |
| 1927 | * @timeout: command timeout |
| 1928 | * @retries: number of retries before failing |
| 1929 | * @data: returns a structure abstracting the mode header data |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1930 | * @sense: place to put sense data (or NULL if no sense to be collected). |
| 1931 | * must be SCSI_SENSE_BUFFERSIZE big. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1932 | * |
| 1933 | * Returns zero if unsuccessful, or the header offset (either 4 |
| 1934 | * or 8 depending on whether a six or ten byte command was |
| 1935 | * issued) if successful. |
| 1936 | **/ |
| 1937 | int |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1938 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1939 | unsigned char *buffer, int len, int timeout, int retries, |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1940 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1941 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1942 | unsigned char cmd[12]; |
| 1943 | int use_10_for_ms; |
| 1944 | int header_length; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1945 | int result; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1946 | struct scsi_sense_hdr my_sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1947 | |
| 1948 | memset(data, 0, sizeof(*data)); |
| 1949 | memset(&cmd[0], 0, 12); |
| 1950 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ |
| 1951 | cmd[2] = modepage; |
| 1952 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1953 | /* caller might not be interested in sense, but we need it */ |
| 1954 | if (!sshdr) |
| 1955 | sshdr = &my_sshdr; |
| 1956 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1957 | retry: |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1958 | use_10_for_ms = sdev->use_10_for_ms; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1959 | |
| 1960 | if (use_10_for_ms) { |
| 1961 | if (len < 8) |
| 1962 | len = 8; |
| 1963 | |
| 1964 | cmd[0] = MODE_SENSE_10; |
| 1965 | cmd[8] = len; |
| 1966 | header_length = 8; |
| 1967 | } else { |
| 1968 | if (len < 4) |
| 1969 | len = 4; |
| 1970 | |
| 1971 | cmd[0] = MODE_SENSE; |
| 1972 | cmd[4] = len; |
| 1973 | header_length = 4; |
| 1974 | } |
| 1975 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1976 | memset(buffer, 0, len); |
| 1977 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1978 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1979 | sshdr, timeout, retries); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1980 | |
| 1981 | /* This code looks awful: what it's doing is making sure an |
| 1982 | * ILLEGAL REQUEST sense return identifies the actual command |
| 1983 | * byte as the problem. MODE_SENSE commands can return |
| 1984 | * ILLEGAL REQUEST if the code page isn't supported */ |
| 1985 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1986 | if (use_10_for_ms && !scsi_status_is_good(result) && |
| 1987 | (driver_byte(result) & DRIVER_SENSE)) { |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1988 | if (scsi_sense_valid(sshdr)) { |
| 1989 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && |
| 1990 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1991 | /* |
| 1992 | * Invalid command operation code |
| 1993 | */ |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1994 | sdev->use_10_for_ms = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1995 | goto retry; |
| 1996 | } |
| 1997 | } |
| 1998 | } |
| 1999 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 2000 | if(scsi_status_is_good(result)) { |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 2001 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
| 2002 | (modepage == 6 || modepage == 8))) { |
| 2003 | /* Initio breakage? */ |
| 2004 | header_length = 0; |
| 2005 | data->length = 13; |
| 2006 | data->medium_type = 0; |
| 2007 | data->device_specific = 0; |
| 2008 | data->longlba = 0; |
| 2009 | data->block_descriptor_length = 0; |
| 2010 | } else if(use_10_for_ms) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2011 | data->length = buffer[0]*256 + buffer[1] + 2; |
| 2012 | data->medium_type = buffer[2]; |
| 2013 | data->device_specific = buffer[3]; |
| 2014 | data->longlba = buffer[4] & 0x01; |
| 2015 | data->block_descriptor_length = buffer[6]*256 |
| 2016 | + buffer[7]; |
| 2017 | } else { |
| 2018 | data->length = buffer[0] + 1; |
| 2019 | data->medium_type = buffer[1]; |
| 2020 | data->device_specific = buffer[2]; |
| 2021 | data->block_descriptor_length = buffer[3]; |
| 2022 | } |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 2023 | data->header_length = header_length; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2024 | } |
| 2025 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 2026 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2027 | } |
| 2028 | EXPORT_SYMBOL(scsi_mode_sense); |
| 2029 | |
| 2030 | int |
| 2031 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries) |
| 2032 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2033 | char cmd[] = { |
| 2034 | TEST_UNIT_READY, 0, 0, 0, 0, 0, |
| 2035 | }; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 2036 | struct scsi_sense_hdr sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2037 | int result; |
| 2038 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 2039 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, &sshdr, |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 2040 | timeout, retries); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2041 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 2042 | if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2043 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 2044 | if ((scsi_sense_valid(&sshdr)) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2045 | ((sshdr.sense_key == UNIT_ATTENTION) || |
| 2046 | (sshdr.sense_key == NOT_READY))) { |
| 2047 | sdev->changed = 1; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 2048 | result = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2049 | } |
| 2050 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2051 | return result; |
| 2052 | } |
| 2053 | EXPORT_SYMBOL(scsi_test_unit_ready); |
| 2054 | |
| 2055 | /** |
| 2056 | * scsi_device_set_state - Take the given device through the device |
| 2057 | * state model. |
| 2058 | * @sdev: scsi device to change the state of. |
| 2059 | * @state: state to change to. |
| 2060 | * |
| 2061 | * Returns zero if unsuccessful or an error if the requested |
| 2062 | * transition is illegal. |
| 2063 | **/ |
| 2064 | int |
| 2065 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) |
| 2066 | { |
| 2067 | enum scsi_device_state oldstate = sdev->sdev_state; |
| 2068 | |
| 2069 | if (state == oldstate) |
| 2070 | return 0; |
| 2071 | |
| 2072 | switch (state) { |
| 2073 | case SDEV_CREATED: |
| 2074 | /* There are no legal states that come back to |
| 2075 | * created. This is the manually initialised start |
| 2076 | * state */ |
| 2077 | goto illegal; |
| 2078 | |
| 2079 | case SDEV_RUNNING: |
| 2080 | switch (oldstate) { |
| 2081 | case SDEV_CREATED: |
| 2082 | case SDEV_OFFLINE: |
| 2083 | case SDEV_QUIESCE: |
| 2084 | case SDEV_BLOCK: |
| 2085 | break; |
| 2086 | default: |
| 2087 | goto illegal; |
| 2088 | } |
| 2089 | break; |
| 2090 | |
| 2091 | case SDEV_QUIESCE: |
| 2092 | switch (oldstate) { |
| 2093 | case SDEV_RUNNING: |
| 2094 | case SDEV_OFFLINE: |
| 2095 | break; |
| 2096 | default: |
| 2097 | goto illegal; |
| 2098 | } |
| 2099 | break; |
| 2100 | |
| 2101 | case SDEV_OFFLINE: |
| 2102 | switch (oldstate) { |
| 2103 | case SDEV_CREATED: |
| 2104 | case SDEV_RUNNING: |
| 2105 | case SDEV_QUIESCE: |
| 2106 | case SDEV_BLOCK: |
| 2107 | break; |
| 2108 | default: |
| 2109 | goto illegal; |
| 2110 | } |
| 2111 | break; |
| 2112 | |
| 2113 | case SDEV_BLOCK: |
| 2114 | switch (oldstate) { |
| 2115 | case SDEV_CREATED: |
| 2116 | case SDEV_RUNNING: |
| 2117 | break; |
| 2118 | default: |
| 2119 | goto illegal; |
| 2120 | } |
| 2121 | break; |
| 2122 | |
| 2123 | case SDEV_CANCEL: |
| 2124 | switch (oldstate) { |
| 2125 | case SDEV_CREATED: |
| 2126 | case SDEV_RUNNING: |
| 2127 | case SDEV_OFFLINE: |
| 2128 | case SDEV_BLOCK: |
| 2129 | break; |
| 2130 | default: |
| 2131 | goto illegal; |
| 2132 | } |
| 2133 | break; |
| 2134 | |
| 2135 | case SDEV_DEL: |
| 2136 | switch (oldstate) { |
| 2137 | case SDEV_CANCEL: |
| 2138 | break; |
| 2139 | default: |
| 2140 | goto illegal; |
| 2141 | } |
| 2142 | break; |
| 2143 | |
| 2144 | } |
| 2145 | sdev->sdev_state = state; |
| 2146 | return 0; |
| 2147 | |
| 2148 | illegal: |
| 2149 | SCSI_LOG_ERROR_RECOVERY(1, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 2150 | sdev_printk(KERN_ERR, sdev, |
| 2151 | "Illegal state transition %s->%s\n", |
| 2152 | scsi_device_state_name(oldstate), |
| 2153 | scsi_device_state_name(state)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2154 | ); |
| 2155 | return -EINVAL; |
| 2156 | } |
| 2157 | EXPORT_SYMBOL(scsi_device_set_state); |
| 2158 | |
| 2159 | /** |
| 2160 | * scsi_device_quiesce - Block user issued commands. |
| 2161 | * @sdev: scsi device to quiesce. |
| 2162 | * |
| 2163 | * This works by trying to transition to the SDEV_QUIESCE state |
| 2164 | * (which must be a legal transition). When the device is in this |
| 2165 | * state, only special requests will be accepted, all others will |
| 2166 | * be deferred. Since special requests may also be requeued requests, |
| 2167 | * a successful return doesn't guarantee the device will be |
| 2168 | * totally quiescent. |
| 2169 | * |
| 2170 | * Must be called with user context, may sleep. |
| 2171 | * |
| 2172 | * Returns zero if unsuccessful or an error if not. |
| 2173 | **/ |
| 2174 | int |
| 2175 | scsi_device_quiesce(struct scsi_device *sdev) |
| 2176 | { |
| 2177 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); |
| 2178 | if (err) |
| 2179 | return err; |
| 2180 | |
| 2181 | scsi_run_queue(sdev->request_queue); |
| 2182 | while (sdev->device_busy) { |
| 2183 | msleep_interruptible(200); |
| 2184 | scsi_run_queue(sdev->request_queue); |
| 2185 | } |
| 2186 | return 0; |
| 2187 | } |
| 2188 | EXPORT_SYMBOL(scsi_device_quiesce); |
| 2189 | |
| 2190 | /** |
| 2191 | * scsi_device_resume - Restart user issued commands to a quiesced device. |
| 2192 | * @sdev: scsi device to resume. |
| 2193 | * |
| 2194 | * Moves the device from quiesced back to running and restarts the |
| 2195 | * queues. |
| 2196 | * |
| 2197 | * Must be called with user context, may sleep. |
| 2198 | **/ |
| 2199 | void |
| 2200 | scsi_device_resume(struct scsi_device *sdev) |
| 2201 | { |
| 2202 | if(scsi_device_set_state(sdev, SDEV_RUNNING)) |
| 2203 | return; |
| 2204 | scsi_run_queue(sdev->request_queue); |
| 2205 | } |
| 2206 | EXPORT_SYMBOL(scsi_device_resume); |
| 2207 | |
| 2208 | static void |
| 2209 | device_quiesce_fn(struct scsi_device *sdev, void *data) |
| 2210 | { |
| 2211 | scsi_device_quiesce(sdev); |
| 2212 | } |
| 2213 | |
| 2214 | void |
| 2215 | scsi_target_quiesce(struct scsi_target *starget) |
| 2216 | { |
| 2217 | starget_for_each_device(starget, NULL, device_quiesce_fn); |
| 2218 | } |
| 2219 | EXPORT_SYMBOL(scsi_target_quiesce); |
| 2220 | |
| 2221 | static void |
| 2222 | device_resume_fn(struct scsi_device *sdev, void *data) |
| 2223 | { |
| 2224 | scsi_device_resume(sdev); |
| 2225 | } |
| 2226 | |
| 2227 | void |
| 2228 | scsi_target_resume(struct scsi_target *starget) |
| 2229 | { |
| 2230 | starget_for_each_device(starget, NULL, device_resume_fn); |
| 2231 | } |
| 2232 | EXPORT_SYMBOL(scsi_target_resume); |
| 2233 | |
| 2234 | /** |
| 2235 | * scsi_internal_device_block - internal function to put a device |
| 2236 | * temporarily into the SDEV_BLOCK state |
| 2237 | * @sdev: device to block |
| 2238 | * |
| 2239 | * Block request made by scsi lld's to temporarily stop all |
| 2240 | * scsi commands on the specified device. Called from interrupt |
| 2241 | * or normal process context. |
| 2242 | * |
| 2243 | * Returns zero if successful or error if not |
| 2244 | * |
| 2245 | * Notes: |
| 2246 | * This routine transitions the device to the SDEV_BLOCK state |
| 2247 | * (which must be a legal transition). When the device is in this |
| 2248 | * state, all commands are deferred until the scsi lld reenables |
| 2249 | * the device with scsi_device_unblock or device_block_tmo fires. |
| 2250 | * This routine assumes the host_lock is held on entry. |
| 2251 | **/ |
| 2252 | int |
| 2253 | scsi_internal_device_block(struct scsi_device *sdev) |
| 2254 | { |
| 2255 | request_queue_t *q = sdev->request_queue; |
| 2256 | unsigned long flags; |
| 2257 | int err = 0; |
| 2258 | |
| 2259 | err = scsi_device_set_state(sdev, SDEV_BLOCK); |
| 2260 | if (err) |
| 2261 | return err; |
| 2262 | |
| 2263 | /* |
| 2264 | * The device has transitioned to SDEV_BLOCK. Stop the |
| 2265 | * block layer from calling the midlayer with this device's |
| 2266 | * request queue. |
| 2267 | */ |
| 2268 | spin_lock_irqsave(q->queue_lock, flags); |
| 2269 | blk_stop_queue(q); |
| 2270 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2271 | |
| 2272 | return 0; |
| 2273 | } |
| 2274 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); |
| 2275 | |
| 2276 | /** |
| 2277 | * scsi_internal_device_unblock - resume a device after a block request |
| 2278 | * @sdev: device to resume |
| 2279 | * |
| 2280 | * Called by scsi lld's or the midlayer to restart the device queue |
| 2281 | * for the previously suspended scsi device. Called from interrupt or |
| 2282 | * normal process context. |
| 2283 | * |
| 2284 | * Returns zero if successful or error if not. |
| 2285 | * |
| 2286 | * Notes: |
| 2287 | * This routine transitions the device to the SDEV_RUNNING state |
| 2288 | * (which must be a legal transition) allowing the midlayer to |
| 2289 | * goose the queue for this device. This routine assumes the |
| 2290 | * host_lock is held upon entry. |
| 2291 | **/ |
| 2292 | int |
| 2293 | scsi_internal_device_unblock(struct scsi_device *sdev) |
| 2294 | { |
| 2295 | request_queue_t *q = sdev->request_queue; |
| 2296 | int err; |
| 2297 | unsigned long flags; |
| 2298 | |
| 2299 | /* |
| 2300 | * Try to transition the scsi device to SDEV_RUNNING |
| 2301 | * and goose the device queue if successful. |
| 2302 | */ |
| 2303 | err = scsi_device_set_state(sdev, SDEV_RUNNING); |
| 2304 | if (err) |
| 2305 | return err; |
| 2306 | |
| 2307 | spin_lock_irqsave(q->queue_lock, flags); |
| 2308 | blk_start_queue(q); |
| 2309 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2310 | |
| 2311 | return 0; |
| 2312 | } |
| 2313 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); |
| 2314 | |
| 2315 | static void |
| 2316 | device_block(struct scsi_device *sdev, void *data) |
| 2317 | { |
| 2318 | scsi_internal_device_block(sdev); |
| 2319 | } |
| 2320 | |
| 2321 | static int |
| 2322 | target_block(struct device *dev, void *data) |
| 2323 | { |
| 2324 | if (scsi_is_target_device(dev)) |
| 2325 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2326 | device_block); |
| 2327 | return 0; |
| 2328 | } |
| 2329 | |
| 2330 | void |
| 2331 | scsi_target_block(struct device *dev) |
| 2332 | { |
| 2333 | if (scsi_is_target_device(dev)) |
| 2334 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2335 | device_block); |
| 2336 | else |
| 2337 | device_for_each_child(dev, NULL, target_block); |
| 2338 | } |
| 2339 | EXPORT_SYMBOL_GPL(scsi_target_block); |
| 2340 | |
| 2341 | static void |
| 2342 | device_unblock(struct scsi_device *sdev, void *data) |
| 2343 | { |
| 2344 | scsi_internal_device_unblock(sdev); |
| 2345 | } |
| 2346 | |
| 2347 | static int |
| 2348 | target_unblock(struct device *dev, void *data) |
| 2349 | { |
| 2350 | if (scsi_is_target_device(dev)) |
| 2351 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2352 | device_unblock); |
| 2353 | return 0; |
| 2354 | } |
| 2355 | |
| 2356 | void |
| 2357 | scsi_target_unblock(struct device *dev) |
| 2358 | { |
| 2359 | if (scsi_is_target_device(dev)) |
| 2360 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2361 | device_unblock); |
| 2362 | else |
| 2363 | device_for_each_child(dev, NULL, target_unblock); |
| 2364 | } |
| 2365 | EXPORT_SYMBOL_GPL(scsi_target_unblock); |