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> |
Christoph Hellwig | beb4048 | 2006-06-10 18:01:03 +0200 | [diff] [blame] | 22 | #include <scsi/scsi_cmnd.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <scsi/scsi_dbg.h> |
| 24 | #include <scsi/scsi_device.h> |
| 25 | #include <scsi/scsi_driver.h> |
| 26 | #include <scsi/scsi_eh.h> |
| 27 | #include <scsi/scsi_host.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
| 29 | #include "scsi_priv.h" |
| 30 | #include "scsi_logging.h" |
| 31 | |
| 32 | |
Tobias Klauser | 6391a11 | 2006-06-08 22:23:48 -0700 | [diff] [blame] | 33 | #define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Christoph Hellwig | beb4048 | 2006-06-10 18:01:03 +0200 | [diff] [blame] | 86 | req->special = NULL; |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 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 | |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 164 | /** |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 165 | * scsi_execute - insert request and wait for the result |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 166 | * @sdev: scsi device |
| 167 | * @cmd: scsi command |
| 168 | * @data_direction: data direction |
| 169 | * @buffer: data buffer |
| 170 | * @bufflen: len of buffer |
| 171 | * @sense: optional sense buffer |
| 172 | * @timeout: request timeout in seconds |
| 173 | * @retries: number of times to retry request |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 174 | * @flags: or into request flags; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 175 | * |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 176 | * returns the req->errors value which is the the scsi_cmnd result |
| 177 | * field. |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 178 | **/ |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 179 | int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, |
| 180 | int data_direction, void *buffer, unsigned bufflen, |
| 181 | unsigned char *sense, int timeout, int retries, int flags) |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 182 | { |
| 183 | struct request *req; |
| 184 | int write = (data_direction == DMA_TO_DEVICE); |
| 185 | int ret = DRIVER_ERROR << 24; |
| 186 | |
| 187 | req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); |
| 188 | |
| 189 | if (bufflen && blk_rq_map_kern(sdev->request_queue, req, |
| 190 | buffer, bufflen, __GFP_WAIT)) |
| 191 | goto out; |
| 192 | |
| 193 | req->cmd_len = COMMAND_SIZE(cmd[0]); |
| 194 | memcpy(req->cmd, cmd, req->cmd_len); |
| 195 | req->sense = sense; |
| 196 | req->sense_len = 0; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 197 | req->retries = retries; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 198 | req->timeout = timeout; |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 199 | req->flags |= flags | REQ_BLOCK_PC | REQ_SPECIAL | REQ_QUIET; |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 200 | |
| 201 | /* |
| 202 | * head injection *required* here otherwise quiesce won't work |
| 203 | */ |
| 204 | blk_execute_rq(req->q, NULL, req, 1); |
| 205 | |
| 206 | ret = req->errors; |
| 207 | out: |
| 208 | blk_put_request(req); |
| 209 | |
| 210 | return ret; |
| 211 | } |
James Bottomley | 33aa687 | 2005-08-28 11:31:14 -0500 | [diff] [blame] | 212 | EXPORT_SYMBOL(scsi_execute); |
James Bottomley | 3921603 | 2005-06-15 18:48:29 -0500 | [diff] [blame] | 213 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 214 | |
| 215 | int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, |
| 216 | int data_direction, void *buffer, unsigned bufflen, |
| 217 | struct scsi_sense_hdr *sshdr, int timeout, int retries) |
| 218 | { |
| 219 | char *sense = NULL; |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 220 | int result; |
| 221 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 222 | if (sshdr) { |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 223 | sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 224 | if (!sense) |
| 225 | return DRIVER_ERROR << 24; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 226 | } |
akpm@osdl.org | 1ccb48b | 2005-06-26 00:12:51 -0700 | [diff] [blame] | 227 | result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, |
Jes Sorensen | 24669f75 | 2006-01-16 10:31:18 -0500 | [diff] [blame] | 228 | sense, timeout, retries, 0); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 229 | if (sshdr) |
James Bottomley | e514385 | 2005-08-09 11:55:36 -0500 | [diff] [blame] | 230 | scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 231 | |
| 232 | kfree(sense); |
| 233 | return result; |
| 234 | } |
| 235 | EXPORT_SYMBOL(scsi_execute_req); |
| 236 | |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 237 | struct scsi_io_context { |
| 238 | void *data; |
| 239 | void (*done)(void *data, char *sense, int result, int resid); |
| 240 | char sense[SCSI_SENSE_BUFFERSIZE]; |
| 241 | }; |
| 242 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 243 | static kmem_cache_t *scsi_io_context_cache; |
| 244 | |
Jens Axboe | e650c30 | 2006-01-06 12:38:30 +0100 | [diff] [blame] | 245 | static void scsi_end_async(struct request *req, int uptodate) |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 246 | { |
| 247 | struct scsi_io_context *sioc = req->end_io_data; |
| 248 | |
| 249 | if (sioc->done) |
| 250 | sioc->done(sioc->data, sioc->sense, req->errors, req->data_len); |
| 251 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 252 | kmem_cache_free(scsi_io_context_cache, sioc); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 253 | __blk_put_request(req->q, req); |
| 254 | } |
| 255 | |
| 256 | static int scsi_merge_bio(struct request *rq, struct bio *bio) |
| 257 | { |
| 258 | struct request_queue *q = rq->q; |
| 259 | |
| 260 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
| 261 | if (rq_data_dir(rq) == WRITE) |
| 262 | bio->bi_rw |= (1 << BIO_RW); |
| 263 | blk_queue_bounce(q, &bio); |
| 264 | |
| 265 | if (!rq->bio) |
| 266 | blk_rq_bio_prep(q, rq, bio); |
| 267 | else if (!q->back_merge_fn(q, rq, bio)) |
| 268 | return -EINVAL; |
| 269 | else { |
| 270 | rq->biotail->bi_next = bio; |
| 271 | rq->biotail = bio; |
| 272 | rq->hard_nr_sectors += bio_sectors(bio); |
| 273 | rq->nr_sectors = rq->hard_nr_sectors; |
| 274 | } |
| 275 | |
| 276 | return 0; |
| 277 | } |
| 278 | |
| 279 | static int scsi_bi_endio(struct bio *bio, unsigned int bytes_done, int error) |
| 280 | { |
| 281 | if (bio->bi_size) |
| 282 | return 1; |
| 283 | |
| 284 | bio_put(bio); |
| 285 | return 0; |
| 286 | } |
| 287 | |
| 288 | /** |
| 289 | * scsi_req_map_sg - map a scatterlist into a request |
| 290 | * @rq: request to fill |
| 291 | * @sg: scatterlist |
| 292 | * @nsegs: number of elements |
| 293 | * @bufflen: len of buffer |
| 294 | * @gfp: memory allocation flags |
| 295 | * |
| 296 | * scsi_req_map_sg maps a scatterlist into a request so that the |
| 297 | * request can be sent to the block layer. We do not trust the scatterlist |
| 298 | * sent to use, as some ULDs use that struct to only organize the pages. |
| 299 | */ |
| 300 | static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, |
| 301 | int nsegs, unsigned bufflen, gfp_t gfp) |
| 302 | { |
| 303 | struct request_queue *q = rq->q; |
Bryan Holty | f523596 | 2006-03-22 06:35:39 -0600 | [diff] [blame] | 304 | int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 305 | unsigned int data_len = 0, len, bytes, off; |
| 306 | struct page *page; |
| 307 | struct bio *bio = NULL; |
| 308 | int i, err, nr_vecs = 0; |
| 309 | |
| 310 | for (i = 0; i < nsegs; i++) { |
| 311 | page = sgl[i].page; |
| 312 | off = sgl[i].offset; |
| 313 | len = sgl[i].length; |
| 314 | data_len += len; |
| 315 | |
| 316 | while (len > 0) { |
| 317 | bytes = min_t(unsigned int, len, PAGE_SIZE - off); |
| 318 | |
| 319 | if (!bio) { |
| 320 | nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); |
| 321 | nr_pages -= nr_vecs; |
| 322 | |
| 323 | bio = bio_alloc(gfp, nr_vecs); |
| 324 | if (!bio) { |
| 325 | err = -ENOMEM; |
| 326 | goto free_bios; |
| 327 | } |
| 328 | bio->bi_end_io = scsi_bi_endio; |
| 329 | } |
| 330 | |
| 331 | if (bio_add_pc_page(q, bio, page, bytes, off) != |
| 332 | bytes) { |
| 333 | bio_put(bio); |
| 334 | err = -EINVAL; |
| 335 | goto free_bios; |
| 336 | } |
| 337 | |
| 338 | if (bio->bi_vcnt >= nr_vecs) { |
| 339 | err = scsi_merge_bio(rq, bio); |
| 340 | if (err) { |
| 341 | bio_endio(bio, bio->bi_size, 0); |
| 342 | goto free_bios; |
| 343 | } |
| 344 | bio = NULL; |
| 345 | } |
| 346 | |
| 347 | page++; |
| 348 | len -= bytes; |
| 349 | off = 0; |
| 350 | } |
| 351 | } |
| 352 | |
| 353 | rq->buffer = rq->data = NULL; |
| 354 | rq->data_len = data_len; |
| 355 | return 0; |
| 356 | |
| 357 | free_bios: |
| 358 | while ((bio = rq->bio) != NULL) { |
| 359 | rq->bio = bio->bi_next; |
| 360 | /* |
| 361 | * call endio instead of bio_put incase it was bounced |
| 362 | */ |
| 363 | bio_endio(bio, bio->bi_size, 0); |
| 364 | } |
| 365 | |
| 366 | return err; |
| 367 | } |
| 368 | |
| 369 | /** |
| 370 | * scsi_execute_async - insert request |
| 371 | * @sdev: scsi device |
| 372 | * @cmd: scsi command |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 373 | * @cmd_len: length of scsi cdb |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 374 | * @data_direction: data direction |
| 375 | * @buffer: data buffer (this can be a kernel buffer or scatterlist) |
| 376 | * @bufflen: len of buffer |
| 377 | * @use_sg: if buffer is a scatterlist this is the number of elements |
| 378 | * @timeout: request timeout in seconds |
| 379 | * @retries: number of times to retry request |
| 380 | * @flags: or into request flags |
| 381 | **/ |
| 382 | 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] | 383 | int cmd_len, int data_direction, void *buffer, unsigned bufflen, |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 384 | int use_sg, int timeout, int retries, void *privdata, |
| 385 | void (*done)(void *, char *, int, int), gfp_t gfp) |
| 386 | { |
| 387 | struct request *req; |
| 388 | struct scsi_io_context *sioc; |
| 389 | int err = 0; |
| 390 | int write = (data_direction == DMA_TO_DEVICE); |
| 391 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 392 | sioc = kmem_cache_alloc(scsi_io_context_cache, gfp); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 393 | if (!sioc) |
| 394 | return DRIVER_ERROR << 24; |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 395 | memset(sioc, 0, sizeof(*sioc)); |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 396 | |
| 397 | req = blk_get_request(sdev->request_queue, write, gfp); |
| 398 | if (!req) |
| 399 | goto free_sense; |
Mike Christie | defd94b | 2005-12-05 02:37:06 -0600 | [diff] [blame] | 400 | req->flags |= REQ_BLOCK_PC | REQ_QUIET; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 401 | |
| 402 | if (use_sg) |
| 403 | err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp); |
| 404 | else if (bufflen) |
| 405 | err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp); |
| 406 | |
| 407 | if (err) |
| 408 | goto free_req; |
| 409 | |
brking@us.ibm.com | bb1d107 | 2006-01-23 15:03:22 -0600 | [diff] [blame] | 410 | req->cmd_len = cmd_len; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 411 | memcpy(req->cmd, cmd, req->cmd_len); |
| 412 | req->sense = sioc->sense; |
| 413 | req->sense_len = 0; |
| 414 | req->timeout = timeout; |
Mike Christie | 17e01f2 | 2005-11-11 05:31:37 -0600 | [diff] [blame] | 415 | req->retries = retries; |
Mike Christie | 6e68af6 | 2005-11-11 05:30:27 -0600 | [diff] [blame] | 416 | req->end_io_data = sioc; |
| 417 | |
| 418 | sioc->data = privdata; |
| 419 | sioc->done = done; |
| 420 | |
| 421 | blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async); |
| 422 | return 0; |
| 423 | |
| 424 | free_req: |
| 425 | blk_put_request(req); |
| 426 | free_sense: |
| 427 | kfree(sioc); |
| 428 | return DRIVER_ERROR << 24; |
| 429 | } |
| 430 | EXPORT_SYMBOL_GPL(scsi_execute_async); |
| 431 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | /* |
| 433 | * Function: scsi_init_cmd_errh() |
| 434 | * |
| 435 | * Purpose: Initialize cmd fields related to error handling. |
| 436 | * |
| 437 | * Arguments: cmd - command that is ready to be queued. |
| 438 | * |
| 439 | * Returns: Nothing |
| 440 | * |
| 441 | * Notes: This function has the job of initializing a number of |
| 442 | * fields related to error handling. Typically this will |
| 443 | * be called once for each command, as required. |
| 444 | */ |
| 445 | static int scsi_init_cmd_errh(struct scsi_cmnd *cmd) |
| 446 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | cmd->serial_number = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | |
| 449 | memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer); |
| 450 | |
| 451 | if (cmd->cmd_len == 0) |
| 452 | cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]); |
| 453 | |
| 454 | /* |
| 455 | * We need saved copies of a number of fields - this is because |
| 456 | * error handling may need to overwrite these with different values |
| 457 | * to run different commands, and once error handling is complete, |
| 458 | * we will need to restore these values prior to running the actual |
| 459 | * command. |
| 460 | */ |
| 461 | cmd->old_use_sg = cmd->use_sg; |
| 462 | cmd->old_cmd_len = cmd->cmd_len; |
| 463 | cmd->sc_old_data_direction = cmd->sc_data_direction; |
| 464 | cmd->old_underflow = cmd->underflow; |
| 465 | memcpy(cmd->data_cmnd, cmd->cmnd, sizeof(cmd->cmnd)); |
| 466 | cmd->buffer = cmd->request_buffer; |
| 467 | cmd->bufflen = cmd->request_bufflen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | |
| 469 | return 1; |
| 470 | } |
| 471 | |
| 472 | /* |
| 473 | * Function: scsi_setup_cmd_retry() |
| 474 | * |
| 475 | * Purpose: Restore the command state for a retry |
| 476 | * |
| 477 | * Arguments: cmd - command to be restored |
| 478 | * |
| 479 | * Returns: Nothing |
| 480 | * |
| 481 | * Notes: Immediately prior to retrying a command, we need |
| 482 | * to restore certain fields that we saved above. |
| 483 | */ |
| 484 | void scsi_setup_cmd_retry(struct scsi_cmnd *cmd) |
| 485 | { |
| 486 | memcpy(cmd->cmnd, cmd->data_cmnd, sizeof(cmd->data_cmnd)); |
| 487 | cmd->request_buffer = cmd->buffer; |
| 488 | cmd->request_bufflen = cmd->bufflen; |
| 489 | cmd->use_sg = cmd->old_use_sg; |
| 490 | cmd->cmd_len = cmd->old_cmd_len; |
| 491 | cmd->sc_data_direction = cmd->sc_old_data_direction; |
| 492 | cmd->underflow = cmd->old_underflow; |
| 493 | } |
| 494 | |
| 495 | void scsi_device_unbusy(struct scsi_device *sdev) |
| 496 | { |
| 497 | struct Scsi_Host *shost = sdev->host; |
| 498 | unsigned long flags; |
| 499 | |
| 500 | spin_lock_irqsave(shost->host_lock, flags); |
| 501 | shost->host_busy--; |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 502 | if (unlikely(scsi_host_in_recovery(shost) && |
Tejun Heo | ee7863b | 2006-05-15 20:57:20 +0900 | [diff] [blame] | 503 | (shost->host_failed || shost->host_eh_scheduled))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | scsi_eh_wakeup(shost); |
| 505 | spin_unlock(shost->host_lock); |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 506 | spin_lock(sdev->request_queue->queue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | sdev->device_busy--; |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 508 | spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | } |
| 510 | |
| 511 | /* |
| 512 | * Called for single_lun devices on IO completion. Clear starget_sdev_user, |
| 513 | * and call blk_run_queue for all the scsi_devices on the target - |
| 514 | * including current_sdev first. |
| 515 | * |
| 516 | * Called with *no* scsi locks held. |
| 517 | */ |
| 518 | static void scsi_single_lun_run(struct scsi_device *current_sdev) |
| 519 | { |
| 520 | struct Scsi_Host *shost = current_sdev->host; |
| 521 | struct scsi_device *sdev, *tmp; |
| 522 | struct scsi_target *starget = scsi_target(current_sdev); |
| 523 | unsigned long flags; |
| 524 | |
| 525 | spin_lock_irqsave(shost->host_lock, flags); |
| 526 | starget->starget_sdev_user = NULL; |
| 527 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 528 | |
| 529 | /* |
| 530 | * Call blk_run_queue for all LUNs on the target, starting with |
| 531 | * current_sdev. We race with others (to set starget_sdev_user), |
| 532 | * but in most cases, we will be first. Ideally, each LU on the |
| 533 | * target would get some limited time or requests on the target. |
| 534 | */ |
| 535 | blk_run_queue(current_sdev->request_queue); |
| 536 | |
| 537 | spin_lock_irqsave(shost->host_lock, flags); |
| 538 | if (starget->starget_sdev_user) |
| 539 | goto out; |
| 540 | list_for_each_entry_safe(sdev, tmp, &starget->devices, |
| 541 | same_target_siblings) { |
| 542 | if (sdev == current_sdev) |
| 543 | continue; |
| 544 | if (scsi_device_get(sdev)) |
| 545 | continue; |
| 546 | |
| 547 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 548 | blk_run_queue(sdev->request_queue); |
| 549 | spin_lock_irqsave(shost->host_lock, flags); |
| 550 | |
| 551 | scsi_device_put(sdev); |
| 552 | } |
| 553 | out: |
| 554 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 555 | } |
| 556 | |
| 557 | /* |
| 558 | * Function: scsi_run_queue() |
| 559 | * |
| 560 | * Purpose: Select a proper request queue to serve next |
| 561 | * |
| 562 | * Arguments: q - last request's queue |
| 563 | * |
| 564 | * Returns: Nothing |
| 565 | * |
| 566 | * Notes: The previous command was completely finished, start |
| 567 | * a new one if possible. |
| 568 | */ |
| 569 | static void scsi_run_queue(struct request_queue *q) |
| 570 | { |
| 571 | struct scsi_device *sdev = q->queuedata; |
| 572 | struct Scsi_Host *shost = sdev->host; |
| 573 | unsigned long flags; |
| 574 | |
| 575 | if (sdev->single_lun) |
| 576 | scsi_single_lun_run(sdev); |
| 577 | |
| 578 | spin_lock_irqsave(shost->host_lock, flags); |
| 579 | while (!list_empty(&shost->starved_list) && |
| 580 | !shost->host_blocked && !shost->host_self_blocked && |
| 581 | !((shost->can_queue > 0) && |
| 582 | (shost->host_busy >= shost->can_queue))) { |
| 583 | /* |
| 584 | * As long as shost is accepting commands and we have |
| 585 | * starved queues, call blk_run_queue. scsi_request_fn |
| 586 | * drops the queue_lock and can add us back to the |
| 587 | * starved_list. |
| 588 | * |
| 589 | * host_lock protects the starved_list and starved_entry. |
| 590 | * scsi_request_fn must get the host_lock before checking |
| 591 | * or modifying starved_list or starved_entry. |
| 592 | */ |
| 593 | sdev = list_entry(shost->starved_list.next, |
| 594 | struct scsi_device, starved_entry); |
| 595 | list_del_init(&sdev->starved_entry); |
| 596 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 597 | |
| 598 | blk_run_queue(sdev->request_queue); |
| 599 | |
| 600 | spin_lock_irqsave(shost->host_lock, flags); |
| 601 | if (unlikely(!list_empty(&sdev->starved_entry))) |
| 602 | /* |
| 603 | * sdev lost a race, and was put back on the |
| 604 | * starved list. This is unlikely but without this |
| 605 | * in theory we could loop forever. |
| 606 | */ |
| 607 | break; |
| 608 | } |
| 609 | spin_unlock_irqrestore(shost->host_lock, flags); |
| 610 | |
| 611 | blk_run_queue(q); |
| 612 | } |
| 613 | |
| 614 | /* |
| 615 | * Function: scsi_requeue_command() |
| 616 | * |
| 617 | * Purpose: Handle post-processing of completed commands. |
| 618 | * |
| 619 | * Arguments: q - queue to operate on |
| 620 | * cmd - command that may need to be requeued. |
| 621 | * |
| 622 | * Returns: Nothing |
| 623 | * |
| 624 | * Notes: After command completion, there may be blocks left |
| 625 | * over which weren't finished by the previous command |
| 626 | * this can be for a number of reasons - the main one is |
| 627 | * I/O errors in the middle of the request, in which case |
| 628 | * we need to request the blocks that come after the bad |
| 629 | * sector. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 630 | * Notes: Upon return, cmd is a stale pointer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | */ |
| 632 | static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) |
| 633 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 634 | struct request *req = cmd->request; |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 635 | unsigned long flags; |
| 636 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 637 | scsi_unprep_request(req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 638 | spin_lock_irqsave(q->queue_lock, flags); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 639 | blk_requeue_request(q, req); |
Tejun Heo | 283369c | 2005-04-24 02:06:36 -0500 | [diff] [blame] | 640 | spin_unlock_irqrestore(q->queue_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | |
| 642 | scsi_run_queue(q); |
| 643 | } |
| 644 | |
| 645 | void scsi_next_command(struct scsi_cmnd *cmd) |
| 646 | { |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 647 | struct scsi_device *sdev = cmd->device; |
| 648 | struct request_queue *q = sdev->request_queue; |
| 649 | |
| 650 | /* need to hold a reference on the device before we let go of the cmd */ |
| 651 | get_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | |
| 653 | scsi_put_command(cmd); |
| 654 | scsi_run_queue(q); |
Linus Torvalds | 49d7bc6 | 2005-12-12 11:25:04 -0800 | [diff] [blame] | 655 | |
| 656 | /* ok to remove device now */ |
| 657 | put_device(&sdev->sdev_gendev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | } |
| 659 | |
| 660 | void scsi_run_host_queues(struct Scsi_Host *shost) |
| 661 | { |
| 662 | struct scsi_device *sdev; |
| 663 | |
| 664 | shost_for_each_device(sdev, shost) |
| 665 | scsi_run_queue(sdev->request_queue); |
| 666 | } |
| 667 | |
| 668 | /* |
| 669 | * Function: scsi_end_request() |
| 670 | * |
| 671 | * Purpose: Post-processing of completed commands (usually invoked at end |
| 672 | * of upper level post-processing and scsi_io_completion). |
| 673 | * |
| 674 | * Arguments: cmd - command that is complete. |
| 675 | * uptodate - 1 if I/O indicates success, <= 0 for I/O error. |
| 676 | * bytes - number of bytes of completed I/O |
| 677 | * requeue - indicates whether we should requeue leftovers. |
| 678 | * |
| 679 | * Lock status: Assumed that lock is not held upon entry. |
| 680 | * |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 681 | * Returns: cmd if requeue required, NULL otherwise. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | * |
| 683 | * Notes: This is called for block device requests in order to |
| 684 | * mark some number of sectors as complete. |
| 685 | * |
| 686 | * We are guaranteeing that the request queue will be goosed |
| 687 | * at some point during this call. |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 688 | * 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] | 689 | */ |
| 690 | static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate, |
| 691 | int bytes, int requeue) |
| 692 | { |
| 693 | request_queue_t *q = cmd->device->request_queue; |
| 694 | struct request *req = cmd->request; |
| 695 | unsigned long flags; |
| 696 | |
| 697 | /* |
| 698 | * If there are blocks left over at the end, set up the command |
| 699 | * to queue the remainder of them. |
| 700 | */ |
| 701 | if (end_that_request_chunk(req, uptodate, bytes)) { |
| 702 | int leftover = (req->hard_nr_sectors << 9); |
| 703 | |
| 704 | if (blk_pc_request(req)) |
| 705 | leftover = req->data_len; |
| 706 | |
| 707 | /* kill remainder if no retrys */ |
| 708 | if (!uptodate && blk_noretry_request(req)) |
| 709 | end_that_request_chunk(req, 0, leftover); |
| 710 | else { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 711 | if (requeue) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | /* |
| 713 | * Bleah. Leftovers again. Stick the |
| 714 | * leftovers in the front of the |
| 715 | * queue, and goose the queue again. |
| 716 | */ |
| 717 | scsi_requeue_command(q, cmd); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 718 | cmd = NULL; |
| 719 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | return cmd; |
| 721 | } |
| 722 | } |
| 723 | |
| 724 | add_disk_randomness(req->rq_disk); |
| 725 | |
| 726 | spin_lock_irqsave(q->queue_lock, flags); |
| 727 | if (blk_rq_tagged(req)) |
| 728 | blk_queue_end_tag(q, req); |
Tejun Heo | 8ffdc65 | 2006-01-06 09:49:03 +0100 | [diff] [blame] | 729 | end_that_request_last(req, uptodate); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 730 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 731 | |
| 732 | /* |
| 733 | * This will goose the queue request function at the end, so we don't |
| 734 | * need to worry about launching another command. |
| 735 | */ |
| 736 | scsi_next_command(cmd); |
| 737 | return NULL; |
| 738 | } |
| 739 | |
Al Viro | c53033f | 2005-10-21 03:22:08 -0400 | [diff] [blame] | 740 | 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] | 741 | { |
| 742 | struct scsi_host_sg_pool *sgp; |
| 743 | struct scatterlist *sgl; |
| 744 | |
| 745 | BUG_ON(!cmd->use_sg); |
| 746 | |
| 747 | switch (cmd->use_sg) { |
| 748 | case 1 ... 8: |
| 749 | cmd->sglist_len = 0; |
| 750 | break; |
| 751 | case 9 ... 16: |
| 752 | cmd->sglist_len = 1; |
| 753 | break; |
| 754 | case 17 ... 32: |
| 755 | cmd->sglist_len = 2; |
| 756 | break; |
| 757 | #if (SCSI_MAX_PHYS_SEGMENTS > 32) |
| 758 | case 33 ... 64: |
| 759 | cmd->sglist_len = 3; |
| 760 | break; |
| 761 | #if (SCSI_MAX_PHYS_SEGMENTS > 64) |
| 762 | case 65 ... 128: |
| 763 | cmd->sglist_len = 4; |
| 764 | break; |
| 765 | #if (SCSI_MAX_PHYS_SEGMENTS > 128) |
| 766 | case 129 ... 256: |
| 767 | cmd->sglist_len = 5; |
| 768 | break; |
| 769 | #endif |
| 770 | #endif |
| 771 | #endif |
| 772 | default: |
| 773 | return NULL; |
| 774 | } |
| 775 | |
| 776 | sgp = scsi_sg_pools + cmd->sglist_len; |
| 777 | sgl = mempool_alloc(sgp->pool, gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | return sgl; |
| 779 | } |
| 780 | |
| 781 | static void scsi_free_sgtable(struct scatterlist *sgl, int index) |
| 782 | { |
| 783 | struct scsi_host_sg_pool *sgp; |
| 784 | |
KAMBAROV, ZAUR | a77e336 | 2005-06-28 20:45:06 -0700 | [diff] [blame] | 785 | BUG_ON(index >= SG_MEMPOOL_NR); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | |
| 787 | sgp = scsi_sg_pools + index; |
| 788 | mempool_free(sgl, sgp->pool); |
| 789 | } |
| 790 | |
| 791 | /* |
| 792 | * Function: scsi_release_buffers() |
| 793 | * |
| 794 | * Purpose: Completion processing for block device I/O requests. |
| 795 | * |
| 796 | * Arguments: cmd - command that we are bailing. |
| 797 | * |
| 798 | * Lock status: Assumed that no lock is held upon entry. |
| 799 | * |
| 800 | * Returns: Nothing |
| 801 | * |
| 802 | * Notes: In the event that an upper level driver rejects a |
| 803 | * command, we must release resources allocated during |
| 804 | * the __init_io() function. Primarily this would involve |
| 805 | * the scatter-gather table, and potentially any bounce |
| 806 | * buffers. |
| 807 | */ |
| 808 | static void scsi_release_buffers(struct scsi_cmnd *cmd) |
| 809 | { |
| 810 | struct request *req = cmd->request; |
| 811 | |
| 812 | /* |
| 813 | * Free up any indirection buffers we allocated for DMA purposes. |
| 814 | */ |
| 815 | if (cmd->use_sg) |
| 816 | scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len); |
| 817 | else if (cmd->request_buffer != req->buffer) |
| 818 | kfree(cmd->request_buffer); |
| 819 | |
| 820 | /* |
| 821 | * Zero these out. They now point to freed memory, and it is |
| 822 | * dangerous to hang onto the pointers. |
| 823 | */ |
| 824 | cmd->buffer = NULL; |
| 825 | cmd->bufflen = 0; |
| 826 | cmd->request_buffer = NULL; |
| 827 | cmd->request_bufflen = 0; |
| 828 | } |
| 829 | |
| 830 | /* |
| 831 | * Function: scsi_io_completion() |
| 832 | * |
| 833 | * Purpose: Completion processing for block device I/O requests. |
| 834 | * |
| 835 | * Arguments: cmd - command that is finished. |
| 836 | * |
| 837 | * Lock status: Assumed that no lock is held upon entry. |
| 838 | * |
| 839 | * Returns: Nothing |
| 840 | * |
| 841 | * Notes: This function is matched in terms of capabilities to |
| 842 | * the function that created the scatter-gather list. |
| 843 | * In other words, if there are no bounce buffers |
| 844 | * (the normal case for most drivers), we don't need |
| 845 | * the logic to deal with cleaning up afterwards. |
| 846 | * |
| 847 | * We must do one of several things here: |
| 848 | * |
| 849 | * a) Call scsi_end_request. This will finish off the |
| 850 | * specified number of sectors. If we are done, the |
| 851 | * command block will be released, and the queue |
| 852 | * function will be goosed. If we are not done, then |
| 853 | * scsi_end_request will directly goose the queue. |
| 854 | * |
| 855 | * b) We can just use scsi_requeue_command() here. This would |
| 856 | * be used if we just wanted to retry, for example. |
| 857 | */ |
| 858 | void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes, |
| 859 | unsigned int block_bytes) |
| 860 | { |
| 861 | int result = cmd->result; |
| 862 | int this_count = cmd->bufflen; |
| 863 | request_queue_t *q = cmd->device->request_queue; |
| 864 | struct request *req = cmd->request; |
| 865 | int clear_errors = 1; |
| 866 | struct scsi_sense_hdr sshdr; |
| 867 | int sense_valid = 0; |
| 868 | int sense_deferred = 0; |
| 869 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 870 | /* |
| 871 | * Free up any indirection buffers we allocated for DMA purposes. |
| 872 | * For the case of a READ, we need to copy the data out of the |
| 873 | * bounce buffer and into the real buffer. |
| 874 | */ |
| 875 | if (cmd->use_sg) |
| 876 | scsi_free_sgtable(cmd->buffer, cmd->sglist_len); |
| 877 | else if (cmd->buffer != req->buffer) { |
| 878 | if (rq_data_dir(req) == READ) { |
| 879 | unsigned long flags; |
| 880 | char *to = bio_kmap_irq(req->bio, &flags); |
| 881 | memcpy(to, cmd->buffer, cmd->bufflen); |
| 882 | bio_kunmap_irq(to, &flags); |
| 883 | } |
| 884 | kfree(cmd->buffer); |
| 885 | } |
| 886 | |
| 887 | if (result) { |
| 888 | sense_valid = scsi_command_normalize_sense(cmd, &sshdr); |
| 889 | if (sense_valid) |
| 890 | sense_deferred = scsi_sense_is_deferred(&sshdr); |
| 891 | } |
| 892 | if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ |
| 893 | req->errors = result; |
| 894 | if (result) { |
| 895 | clear_errors = 0; |
| 896 | if (sense_valid && req->sense) { |
| 897 | /* |
| 898 | * SG_IO wants current and deferred errors |
| 899 | */ |
| 900 | int len = 8 + cmd->sense_buffer[7]; |
| 901 | |
| 902 | if (len > SCSI_SENSE_BUFFERSIZE) |
| 903 | len = SCSI_SENSE_BUFFERSIZE; |
| 904 | memcpy(req->sense, cmd->sense_buffer, len); |
| 905 | req->sense_len = len; |
| 906 | } |
| 907 | } else |
| 908 | req->data_len = cmd->resid; |
| 909 | } |
| 910 | |
| 911 | /* |
| 912 | * Zero these out. They now point to freed memory, and it is |
| 913 | * dangerous to hang onto the pointers. |
| 914 | */ |
| 915 | cmd->buffer = NULL; |
| 916 | cmd->bufflen = 0; |
| 917 | cmd->request_buffer = NULL; |
| 918 | cmd->request_bufflen = 0; |
| 919 | |
| 920 | /* |
| 921 | * Next deal with any sectors which we were able to correctly |
| 922 | * handle. |
| 923 | */ |
| 924 | if (good_bytes >= 0) { |
| 925 | SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, %d bytes done.\n", |
| 926 | req->nr_sectors, good_bytes)); |
| 927 | SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg)); |
| 928 | |
| 929 | if (clear_errors) |
| 930 | req->errors = 0; |
| 931 | /* |
| 932 | * If multiple sectors are requested in one buffer, then |
| 933 | * they will have been finished off by the first command. |
| 934 | * If not, then we have a multi-buffer command. |
| 935 | * |
| 936 | * If block_bytes != 0, it means we had a medium error |
| 937 | * of some sort, and that we want to mark some number of |
| 938 | * sectors as not uptodate. Thus we want to inhibit |
| 939 | * requeueing right here - we will requeue down below |
| 940 | * when we handle the bad sectors. |
| 941 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 942 | |
| 943 | /* |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 944 | * If the command completed without error, then either |
| 945 | * finish off the rest of the command, or start a new one. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | */ |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 947 | if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | } |
| 950 | /* |
| 951 | * Now, if we were good little boys and girls, Santa left us a request |
| 952 | * sense buffer. We can extract information from this, so we |
| 953 | * can choose a block to remap, etc. |
| 954 | */ |
| 955 | if (sense_valid && !sense_deferred) { |
| 956 | switch (sshdr.sense_key) { |
| 957 | case UNIT_ATTENTION: |
| 958 | if (cmd->device->removable) { |
| 959 | /* detected disc change. set a bit |
| 960 | * and quietly refuse further access. |
| 961 | */ |
| 962 | cmd->device->changed = 1; |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 963 | scsi_end_request(cmd, 0, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 964 | this_count, 1); |
| 965 | return; |
| 966 | } else { |
| 967 | /* |
| 968 | * Must have been a power glitch, or a |
| 969 | * bus reset. Could not have been a |
| 970 | * media change, so we just retry the |
| 971 | * request and see what happens. |
| 972 | */ |
| 973 | scsi_requeue_command(q, cmd); |
| 974 | return; |
| 975 | } |
| 976 | break; |
| 977 | case ILLEGAL_REQUEST: |
| 978 | /* |
| 979 | * If we had an ILLEGAL REQUEST returned, then we may |
| 980 | * have performed an unsupported command. The only |
| 981 | * thing this should be would be a ten byte read where |
| 982 | * only a six byte read was supported. Also, on a |
| 983 | * system where READ CAPACITY failed, we may have read |
| 984 | * past the end of the disk. |
| 985 | */ |
Jens Axboe | 26a6801 | 2005-11-29 21:03:34 +0100 | [diff] [blame] | 986 | if ((cmd->device->use_10_for_rw && |
| 987 | sshdr.asc == 0x20 && sshdr.ascq == 0x00) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | (cmd->cmnd[0] == READ_10 || |
| 989 | cmd->cmnd[0] == WRITE_10)) { |
| 990 | cmd->device->use_10_for_rw = 0; |
| 991 | /* |
| 992 | * This will cause a retry with a 6-byte |
| 993 | * command. |
| 994 | */ |
| 995 | scsi_requeue_command(q, cmd); |
| 996 | result = 0; |
| 997 | } else { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 998 | scsi_end_request(cmd, 0, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 999 | return; |
| 1000 | } |
| 1001 | break; |
| 1002 | case NOT_READY: |
| 1003 | /* |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 1004 | * If the device is in the process of becoming |
| 1005 | * ready, or has a temporary blockage, retry. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1006 | */ |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 1007 | if (sshdr.asc == 0x04) { |
| 1008 | switch (sshdr.ascq) { |
| 1009 | case 0x01: /* becoming ready */ |
| 1010 | case 0x04: /* format in progress */ |
| 1011 | case 0x05: /* rebuild in progress */ |
| 1012 | case 0x06: /* recalculation in progress */ |
| 1013 | case 0x07: /* operation in progress */ |
| 1014 | case 0x08: /* Long write in progress */ |
| 1015 | case 0x09: /* self test in progress */ |
| 1016 | scsi_requeue_command(q, cmd); |
| 1017 | return; |
| 1018 | default: |
| 1019 | break; |
| 1020 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1021 | } |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 1022 | if (!(req->flags & REQ_QUIET)) { |
Jeff Garzik | 3bf743e | 2005-10-24 18:04:06 -0400 | [diff] [blame] | 1023 | scmd_printk(KERN_INFO, cmd, |
James Bottomley | f3e93f7 | 2006-04-25 16:48:30 -0500 | [diff] [blame] | 1024 | "Device not ready: "); |
| 1025 | scsi_print_sense_hdr("", &sshdr); |
| 1026 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1027 | scsi_end_request(cmd, 0, this_count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1028 | return; |
| 1029 | case VOLUME_OVERFLOW: |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 1030 | if (!(req->flags & REQ_QUIET)) { |
Jeff Garzik | 3bf743e | 2005-10-24 18:04:06 -0400 | [diff] [blame] | 1031 | scmd_printk(KERN_INFO, cmd, |
| 1032 | "Volume overflow, CDB: "); |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 1033 | __scsi_print_command(cmd->data_cmnd); |
| 1034 | scsi_print_sense("", cmd); |
| 1035 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1036 | scsi_end_request(cmd, 0, block_bytes, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1037 | return; |
| 1038 | default: |
| 1039 | break; |
| 1040 | } |
| 1041 | } /* driver byte != 0 */ |
| 1042 | if (host_byte(result) == DID_RESET) { |
| 1043 | /* |
| 1044 | * Third party bus reset or reset for error |
| 1045 | * recovery reasons. Just retry the request |
| 1046 | * and see what happens. |
| 1047 | */ |
| 1048 | scsi_requeue_command(q, cmd); |
| 1049 | return; |
| 1050 | } |
| 1051 | if (result) { |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 1052 | if (!(req->flags & REQ_QUIET)) { |
Jeff Garzik | 3bf743e | 2005-10-24 18:04:06 -0400 | [diff] [blame] | 1053 | scmd_printk(KERN_INFO, cmd, |
| 1054 | "SCSI error: return code = 0x%x\n", result); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1055 | |
James Bottomley | 3173d8c | 2005-09-04 11:32:05 -0500 | [diff] [blame] | 1056 | if (driver_byte(result) & DRIVER_SENSE) |
| 1057 | scsi_print_sense("", cmd); |
| 1058 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | /* |
| 1060 | * Mark a single buffer as not uptodate. Queue the remainder. |
| 1061 | * We sometimes get this cruft in the event that a medium error |
| 1062 | * isn't properly reported. |
| 1063 | */ |
| 1064 | block_bytes = req->hard_cur_sectors << 9; |
| 1065 | if (!block_bytes) |
| 1066 | block_bytes = req->data_len; |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1067 | scsi_end_request(cmd, 0, block_bytes, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1068 | } |
| 1069 | } |
| 1070 | EXPORT_SYMBOL(scsi_io_completion); |
| 1071 | |
| 1072 | /* |
| 1073 | * Function: scsi_init_io() |
| 1074 | * |
| 1075 | * Purpose: SCSI I/O initialize function. |
| 1076 | * |
| 1077 | * Arguments: cmd - Command descriptor we wish to initialize |
| 1078 | * |
| 1079 | * Returns: 0 on success |
| 1080 | * BLKPREP_DEFER if the failure is retryable |
| 1081 | * BLKPREP_KILL if the failure is fatal |
| 1082 | */ |
| 1083 | static int scsi_init_io(struct scsi_cmnd *cmd) |
| 1084 | { |
| 1085 | struct request *req = cmd->request; |
| 1086 | struct scatterlist *sgpnt; |
| 1087 | int count; |
| 1088 | |
| 1089 | /* |
| 1090 | * if this is a rq->data based REQ_BLOCK_PC, setup for a non-sg xfer |
| 1091 | */ |
| 1092 | if ((req->flags & REQ_BLOCK_PC) && !req->bio) { |
| 1093 | cmd->request_bufflen = req->data_len; |
| 1094 | cmd->request_buffer = req->data; |
| 1095 | req->buffer = req->data; |
| 1096 | cmd->use_sg = 0; |
| 1097 | return 0; |
| 1098 | } |
| 1099 | |
| 1100 | /* |
| 1101 | * we used to not use scatter-gather for single segment request, |
| 1102 | * but now we do (it makes highmem I/O easier to support without |
| 1103 | * kmapping pages) |
| 1104 | */ |
| 1105 | cmd->use_sg = req->nr_phys_segments; |
| 1106 | |
| 1107 | /* |
| 1108 | * if sg table allocation fails, requeue request later. |
| 1109 | */ |
| 1110 | sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC); |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1111 | if (unlikely(!sgpnt)) { |
| 1112 | scsi_unprep_request(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1113 | return BLKPREP_DEFER; |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1114 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1115 | |
| 1116 | cmd->request_buffer = (char *) sgpnt; |
| 1117 | cmd->request_bufflen = req->nr_sectors << 9; |
| 1118 | if (blk_pc_request(req)) |
| 1119 | cmd->request_bufflen = req->data_len; |
| 1120 | req->buffer = NULL; |
| 1121 | |
| 1122 | /* |
| 1123 | * Next, walk the list, and fill in the addresses and sizes of |
| 1124 | * each segment. |
| 1125 | */ |
| 1126 | count = blk_rq_map_sg(req->q, req, cmd->request_buffer); |
| 1127 | |
| 1128 | /* |
| 1129 | * mapped well, send it off |
| 1130 | */ |
| 1131 | if (likely(count <= cmd->use_sg)) { |
| 1132 | cmd->use_sg = count; |
| 1133 | return 0; |
| 1134 | } |
| 1135 | |
| 1136 | printk(KERN_ERR "Incorrect number of segments after building list\n"); |
| 1137 | printk(KERN_ERR "counted %d, received %d\n", count, cmd->use_sg); |
| 1138 | printk(KERN_ERR "req nr_sec %lu, cur_nr_sec %u\n", req->nr_sectors, |
| 1139 | req->current_nr_sectors); |
| 1140 | |
| 1141 | /* release the command and kill it */ |
| 1142 | scsi_release_buffers(cmd); |
| 1143 | scsi_put_command(cmd); |
| 1144 | return BLKPREP_KILL; |
| 1145 | } |
| 1146 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1147 | static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk, |
| 1148 | sector_t *error_sector) |
| 1149 | { |
| 1150 | struct scsi_device *sdev = q->queuedata; |
| 1151 | struct scsi_driver *drv; |
| 1152 | |
| 1153 | if (sdev->sdev_state != SDEV_RUNNING) |
| 1154 | return -ENXIO; |
| 1155 | |
| 1156 | drv = *(struct scsi_driver **) disk->private_data; |
| 1157 | if (drv->issue_flush) |
| 1158 | return drv->issue_flush(&sdev->sdev_gendev, error_sector); |
| 1159 | |
| 1160 | return -EOPNOTSUPP; |
| 1161 | } |
| 1162 | |
Christoph Hellwig | 776b23a | 2006-01-06 18:34:07 +0100 | [diff] [blame] | 1163 | static void scsi_blk_pc_done(struct scsi_cmnd *cmd) |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1164 | { |
| 1165 | BUG_ON(!blk_pc_request(cmd->request)); |
Mike Christie | 0d95716 | 2005-11-11 05:31:40 -0600 | [diff] [blame] | 1166 | /* |
| 1167 | * This will complete the whole command with uptodate=1 so |
| 1168 | * as far as the block layer is concerned the command completed |
| 1169 | * successfully. Since this is a REQ_BLOCK_PC command the |
| 1170 | * caller should check the request's errors value |
| 1171 | */ |
| 1172 | scsi_io_completion(cmd, cmd->bufflen, 0); |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1173 | } |
| 1174 | |
Christoph Hellwig | 776b23a | 2006-01-06 18:34:07 +0100 | [diff] [blame] | 1175 | static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd) |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1176 | { |
| 1177 | struct request *req = cmd->request; |
| 1178 | |
| 1179 | BUG_ON(sizeof(req->cmd) > sizeof(cmd->cmnd)); |
| 1180 | memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd)); |
| 1181 | cmd->cmd_len = req->cmd_len; |
| 1182 | if (!req->data_len) |
| 1183 | cmd->sc_data_direction = DMA_NONE; |
| 1184 | else if (rq_data_dir(req) == WRITE) |
| 1185 | cmd->sc_data_direction = DMA_TO_DEVICE; |
| 1186 | else |
| 1187 | cmd->sc_data_direction = DMA_FROM_DEVICE; |
| 1188 | |
| 1189 | cmd->transfersize = req->data_len; |
| 1190 | cmd->allowed = req->retries; |
| 1191 | cmd->timeout_per_command = req->timeout; |
Christoph Hellwig | 776b23a | 2006-01-06 18:34:07 +0100 | [diff] [blame] | 1192 | cmd->done = scsi_blk_pc_done; |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1193 | } |
James Bottomley | 7b16318 | 2005-12-15 20:17:02 -0600 | [diff] [blame] | 1194 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1195 | static int scsi_prep_fn(struct request_queue *q, struct request *req) |
| 1196 | { |
| 1197 | struct scsi_device *sdev = q->queuedata; |
| 1198 | struct scsi_cmnd *cmd; |
| 1199 | int specials_only = 0; |
| 1200 | |
| 1201 | /* |
| 1202 | * Just check to see if the device is online. If it isn't, we |
| 1203 | * refuse to process any commands. The device must be brought |
| 1204 | * online before trying any recovery commands |
| 1205 | */ |
| 1206 | if (unlikely(!scsi_device_online(sdev))) { |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1207 | sdev_printk(KERN_ERR, sdev, |
| 1208 | "rejecting I/O to offline device\n"); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1209 | goto kill; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1210 | } |
| 1211 | if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { |
| 1212 | /* OK, we're not in a running state don't prep |
| 1213 | * user commands */ |
| 1214 | if (sdev->sdev_state == SDEV_DEL) { |
| 1215 | /* Device is fully deleted, no commands |
| 1216 | * at all allowed down */ |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1217 | sdev_printk(KERN_ERR, sdev, |
| 1218 | "rejecting I/O to dead device\n"); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1219 | goto kill; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1220 | } |
| 1221 | /* OK, we only allow special commands (i.e. not |
| 1222 | * user initiated ones */ |
| 1223 | specials_only = sdev->sdev_state; |
| 1224 | } |
| 1225 | |
| 1226 | /* |
| 1227 | * Find the actual device driver associated with this command. |
| 1228 | * The SPECIAL requests are things like character device or |
| 1229 | * ioctls, which did not originate from ll_rw_blk. Note that |
| 1230 | * the special field is also used to indicate the cmd for |
| 1231 | * the remainder of a partially fulfilled request that can |
| 1232 | * come up when there is a medium error. We have to treat |
| 1233 | * these two cases differently. We differentiate by looking |
| 1234 | * at request->cmd, as this tells us the real story. |
| 1235 | */ |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1236 | if (req->flags & REQ_SPECIAL && req->special) { |
Christoph Hellwig | beb4048 | 2006-06-10 18:01:03 +0200 | [diff] [blame] | 1237 | cmd = req->special; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1238 | } else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) { |
| 1239 | |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1240 | if(unlikely(specials_only) && !(req->flags & REQ_SPECIAL)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1241 | if(specials_only == SDEV_QUIESCE || |
| 1242 | specials_only == SDEV_BLOCK) |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1243 | goto defer; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1245 | sdev_printk(KERN_ERR, sdev, |
| 1246 | "rejecting I/O to device being removed\n"); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1247 | goto kill; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1248 | } |
| 1249 | |
| 1250 | |
| 1251 | /* |
| 1252 | * Now try and find a command block that we can use. |
| 1253 | */ |
| 1254 | if (!req->special) { |
| 1255 | cmd = scsi_get_command(sdev, GFP_ATOMIC); |
| 1256 | if (unlikely(!cmd)) |
| 1257 | goto defer; |
| 1258 | } else |
| 1259 | cmd = req->special; |
| 1260 | |
| 1261 | /* pull a tag out of the request if we have one */ |
| 1262 | cmd->tag = req->tag; |
| 1263 | } else { |
| 1264 | blk_dump_rq_flags(req, "SCSI bad req"); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1265 | goto kill; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1266 | } |
| 1267 | |
| 1268 | /* note the overloading of req->special. When the tag |
| 1269 | * is active it always means cmd. If the tag goes |
| 1270 | * back for re-queueing, it may be reset */ |
| 1271 | req->special = cmd; |
| 1272 | cmd->request = req; |
| 1273 | |
| 1274 | /* |
| 1275 | * FIXME: drop the lock here because the functions below |
| 1276 | * expect to be called without the queue lock held. Also, |
| 1277 | * previously, we dequeued the request before dropping the |
| 1278 | * lock. We hope REQ_STARTED prevents anything untoward from |
| 1279 | * happening now. |
| 1280 | */ |
| 1281 | if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1282 | int ret; |
| 1283 | |
| 1284 | /* |
| 1285 | * This will do a couple of things: |
| 1286 | * 1) Fill in the actual SCSI command. |
| 1287 | * 2) Fill in any other upper-level specific fields |
| 1288 | * (timeout). |
| 1289 | * |
| 1290 | * If this returns 0, it means that the request failed |
| 1291 | * (reading past end of disk, reading offline device, |
| 1292 | * etc). This won't actually talk to the device, but |
| 1293 | * some kinds of consistency checking may cause the |
| 1294 | * request to be rejected immediately. |
| 1295 | */ |
| 1296 | |
| 1297 | /* |
| 1298 | * This sets up the scatter-gather table (allocating if |
| 1299 | * required). |
| 1300 | */ |
| 1301 | ret = scsi_init_io(cmd); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1302 | switch(ret) { |
Alan Stern | 7c72ce8 | 2005-10-14 11:23:27 -0400 | [diff] [blame] | 1303 | /* For BLKPREP_KILL/DEFER the cmd was released */ |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1304 | case BLKPREP_KILL: |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1305 | goto kill; |
| 1306 | case BLKPREP_DEFER: |
| 1307 | goto defer; |
| 1308 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1309 | |
| 1310 | /* |
| 1311 | * Initialize the actual SCSI command for this request. |
| 1312 | */ |
Christoph Hellwig | 776b23a | 2006-01-06 18:34:07 +0100 | [diff] [blame] | 1313 | if (req->flags & REQ_BLOCK_PC) { |
| 1314 | scsi_setup_blk_pc_cmnd(cmd); |
| 1315 | } else if (req->rq_disk) { |
| 1316 | struct scsi_driver *drv; |
| 1317 | |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1318 | drv = *(struct scsi_driver **)req->rq_disk->private_data; |
| 1319 | if (unlikely(!drv->init_command(cmd))) { |
| 1320 | scsi_release_buffers(cmd); |
| 1321 | scsi_put_command(cmd); |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1322 | goto kill; |
James Bottomley | e537a36 | 2005-06-05 02:07:14 -0500 | [diff] [blame] | 1323 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1324 | } |
| 1325 | } |
| 1326 | |
| 1327 | /* |
| 1328 | * The request is now prepped, no need to come back here |
| 1329 | */ |
| 1330 | req->flags |= REQ_DONTPREP; |
| 1331 | return BLKPREP_OK; |
| 1332 | |
| 1333 | defer: |
| 1334 | /* If we defer, the elv_next_request() returns NULL, but the |
| 1335 | * queue must be restarted, so we plug here if no returning |
| 1336 | * command will automatically do that. */ |
| 1337 | if (sdev->device_busy == 0) |
| 1338 | blk_plug_device(q); |
| 1339 | return BLKPREP_DEFER; |
Mike Christie | 6f16b53 | 2005-09-10 16:45:35 -0500 | [diff] [blame] | 1340 | kill: |
| 1341 | req->errors = DID_NO_CONNECT << 16; |
| 1342 | return BLKPREP_KILL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | } |
| 1344 | |
| 1345 | /* |
| 1346 | * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else |
| 1347 | * return 0. |
| 1348 | * |
| 1349 | * Called with the queue_lock held. |
| 1350 | */ |
| 1351 | static inline int scsi_dev_queue_ready(struct request_queue *q, |
| 1352 | struct scsi_device *sdev) |
| 1353 | { |
| 1354 | if (sdev->device_busy >= sdev->queue_depth) |
| 1355 | return 0; |
| 1356 | if (sdev->device_busy == 0 && sdev->device_blocked) { |
| 1357 | /* |
| 1358 | * unblock after device_blocked iterates to zero |
| 1359 | */ |
| 1360 | if (--sdev->device_blocked == 0) { |
| 1361 | SCSI_LOG_MLQUEUE(3, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1362 | sdev_printk(KERN_INFO, sdev, |
| 1363 | "unblocking device at zero depth\n")); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1364 | } else { |
| 1365 | blk_plug_device(q); |
| 1366 | return 0; |
| 1367 | } |
| 1368 | } |
| 1369 | if (sdev->device_blocked) |
| 1370 | return 0; |
| 1371 | |
| 1372 | return 1; |
| 1373 | } |
| 1374 | |
| 1375 | /* |
| 1376 | * scsi_host_queue_ready: if we can send requests to shost, return 1 else |
| 1377 | * return 0. We must end up running the queue again whenever 0 is |
| 1378 | * returned, else IO can hang. |
| 1379 | * |
| 1380 | * Called with host_lock held. |
| 1381 | */ |
| 1382 | static inline int scsi_host_queue_ready(struct request_queue *q, |
| 1383 | struct Scsi_Host *shost, |
| 1384 | struct scsi_device *sdev) |
| 1385 | { |
James Bottomley | 939647e | 2005-09-18 15:05:20 -0500 | [diff] [blame] | 1386 | if (scsi_host_in_recovery(shost)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1387 | return 0; |
| 1388 | if (shost->host_busy == 0 && shost->host_blocked) { |
| 1389 | /* |
| 1390 | * unblock after host_blocked iterates to zero |
| 1391 | */ |
| 1392 | if (--shost->host_blocked == 0) { |
| 1393 | SCSI_LOG_MLQUEUE(3, |
| 1394 | printk("scsi%d unblocking host at zero depth\n", |
| 1395 | shost->host_no)); |
| 1396 | } else { |
| 1397 | blk_plug_device(q); |
| 1398 | return 0; |
| 1399 | } |
| 1400 | } |
| 1401 | if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || |
| 1402 | shost->host_blocked || shost->host_self_blocked) { |
| 1403 | if (list_empty(&sdev->starved_entry)) |
| 1404 | list_add_tail(&sdev->starved_entry, &shost->starved_list); |
| 1405 | return 0; |
| 1406 | } |
| 1407 | |
| 1408 | /* We're OK to process the command, so we can't be starved */ |
| 1409 | if (!list_empty(&sdev->starved_entry)) |
| 1410 | list_del_init(&sdev->starved_entry); |
| 1411 | |
| 1412 | return 1; |
| 1413 | } |
| 1414 | |
| 1415 | /* |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1416 | * Kill a request for a dead device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | */ |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1418 | static void scsi_kill_request(struct request *req, request_queue_t *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1419 | { |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1420 | struct scsi_cmnd *cmd = req->special; |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1421 | struct scsi_device *sdev = cmd->device; |
| 1422 | struct Scsi_Host *shost = sdev->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | |
James Bottomley | 788ce43 | 2005-09-09 13:40:23 -0500 | [diff] [blame] | 1424 | blkdev_dequeue_request(req); |
| 1425 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1426 | if (unlikely(cmd == NULL)) { |
| 1427 | printk(KERN_CRIT "impossible request in %s.\n", |
| 1428 | __FUNCTION__); |
| 1429 | BUG(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | } |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1431 | |
| 1432 | scsi_init_cmd_errh(cmd); |
| 1433 | cmd->result = DID_NO_CONNECT << 16; |
| 1434 | atomic_inc(&cmd->device->iorequest_cnt); |
Tejun Heo | e36e0c8 | 2006-04-11 17:27:53 +0900 | [diff] [blame] | 1435 | |
| 1436 | /* |
| 1437 | * SCSI request completion path will do scsi_device_unbusy(), |
| 1438 | * bump busy counts. To bump the counters, we need to dance |
| 1439 | * with the locks as normal issue path does. |
| 1440 | */ |
| 1441 | sdev->device_busy++; |
| 1442 | spin_unlock(sdev->request_queue->queue_lock); |
| 1443 | spin_lock(shost->host_lock); |
| 1444 | shost->host_busy++; |
| 1445 | spin_unlock(shost->host_lock); |
| 1446 | spin_lock(sdev->request_queue->queue_lock); |
| 1447 | |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1448 | __scsi_done(cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | } |
| 1450 | |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1451 | static void scsi_softirq_done(struct request *rq) |
| 1452 | { |
| 1453 | struct scsi_cmnd *cmd = rq->completion_data; |
Brian King | 8884efa | 2006-02-24 17:10:04 -0600 | [diff] [blame] | 1454 | unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command; |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1455 | int disposition; |
| 1456 | |
| 1457 | INIT_LIST_HEAD(&cmd->eh_entry); |
| 1458 | |
| 1459 | disposition = scsi_decide_disposition(cmd); |
| 1460 | if (disposition != SUCCESS && |
| 1461 | time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { |
| 1462 | sdev_printk(KERN_ERR, cmd->device, |
| 1463 | "timing out command, waited %lus\n", |
| 1464 | wait_for/HZ); |
| 1465 | disposition = SUCCESS; |
| 1466 | } |
| 1467 | |
| 1468 | scsi_log_completion(cmd, disposition); |
| 1469 | |
| 1470 | switch (disposition) { |
| 1471 | case SUCCESS: |
| 1472 | scsi_finish_command(cmd); |
| 1473 | break; |
| 1474 | case NEEDS_RETRY: |
| 1475 | scsi_retry_command(cmd); |
| 1476 | break; |
| 1477 | case ADD_TO_MLQUEUE: |
| 1478 | scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); |
| 1479 | break; |
| 1480 | default: |
| 1481 | if (!scsi_eh_scmd_add(cmd, 0)) |
| 1482 | scsi_finish_command(cmd); |
| 1483 | } |
| 1484 | } |
| 1485 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1486 | /* |
| 1487 | * Function: scsi_request_fn() |
| 1488 | * |
| 1489 | * Purpose: Main strategy routine for SCSI. |
| 1490 | * |
| 1491 | * Arguments: q - Pointer to actual queue. |
| 1492 | * |
| 1493 | * Returns: Nothing |
| 1494 | * |
| 1495 | * Lock status: IO request lock assumed to be held when called. |
| 1496 | */ |
| 1497 | static void scsi_request_fn(struct request_queue *q) |
| 1498 | { |
| 1499 | struct scsi_device *sdev = q->queuedata; |
| 1500 | struct Scsi_Host *shost; |
| 1501 | struct scsi_cmnd *cmd; |
| 1502 | struct request *req; |
| 1503 | |
| 1504 | if (!sdev) { |
| 1505 | printk("scsi: killing requests for dead queue\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1506 | while ((req = elv_next_request(q)) != NULL) |
| 1507 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1508 | return; |
| 1509 | } |
| 1510 | |
| 1511 | if(!get_device(&sdev->sdev_gendev)) |
| 1512 | /* We must be tearing the block queue down already */ |
| 1513 | return; |
| 1514 | |
| 1515 | /* |
| 1516 | * To start with, we keep looping until the queue is empty, or until |
| 1517 | * the host is no longer able to accept any more requests. |
| 1518 | */ |
| 1519 | shost = sdev->host; |
| 1520 | while (!blk_queue_plugged(q)) { |
| 1521 | int rtn; |
| 1522 | /* |
| 1523 | * get next queueable request. We do this early to make sure |
| 1524 | * that the request is fully prepared even if we cannot |
| 1525 | * accept it. |
| 1526 | */ |
| 1527 | req = elv_next_request(q); |
| 1528 | if (!req || !scsi_dev_queue_ready(q, sdev)) |
| 1529 | break; |
| 1530 | |
| 1531 | if (unlikely(!scsi_device_online(sdev))) { |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 1532 | sdev_printk(KERN_ERR, sdev, |
| 1533 | "rejecting I/O to offline device\n"); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1534 | scsi_kill_request(req, q); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1535 | continue; |
| 1536 | } |
| 1537 | |
| 1538 | |
| 1539 | /* |
| 1540 | * Remove the request from the request list. |
| 1541 | */ |
| 1542 | if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) |
| 1543 | blkdev_dequeue_request(req); |
| 1544 | sdev->device_busy++; |
| 1545 | |
| 1546 | spin_unlock(q->queue_lock); |
James Bottomley | e91442b | 2005-09-09 10:44:16 -0500 | [diff] [blame] | 1547 | cmd = req->special; |
| 1548 | if (unlikely(cmd == NULL)) { |
| 1549 | printk(KERN_CRIT "impossible request in %s.\n" |
| 1550 | "please mail a stack trace to " |
| 1551 | "linux-scsi@vger.kernel.org", |
| 1552 | __FUNCTION__); |
| 1553 | BUG(); |
| 1554 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1555 | spin_lock(shost->host_lock); |
| 1556 | |
| 1557 | if (!scsi_host_queue_ready(q, shost, sdev)) |
| 1558 | goto not_ready; |
| 1559 | if (sdev->single_lun) { |
| 1560 | if (scsi_target(sdev)->starget_sdev_user && |
| 1561 | scsi_target(sdev)->starget_sdev_user != sdev) |
| 1562 | goto not_ready; |
| 1563 | scsi_target(sdev)->starget_sdev_user = sdev; |
| 1564 | } |
| 1565 | shost->host_busy++; |
| 1566 | |
| 1567 | /* |
| 1568 | * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will |
| 1569 | * take the lock again. |
| 1570 | */ |
| 1571 | spin_unlock_irq(shost->host_lock); |
| 1572 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1573 | /* |
| 1574 | * Finally, initialize any error handling parameters, and set up |
| 1575 | * the timers for timeouts. |
| 1576 | */ |
| 1577 | scsi_init_cmd_errh(cmd); |
| 1578 | |
| 1579 | /* |
| 1580 | * Dispatch the command to the low-level driver. |
| 1581 | */ |
| 1582 | rtn = scsi_dispatch_cmd(cmd); |
| 1583 | spin_lock_irq(q->queue_lock); |
| 1584 | if(rtn) { |
| 1585 | /* we're refusing the command; because of |
| 1586 | * the way locks get dropped, we need to |
| 1587 | * check here if plugging is required */ |
| 1588 | if(sdev->device_busy == 0) |
| 1589 | blk_plug_device(q); |
| 1590 | |
| 1591 | break; |
| 1592 | } |
| 1593 | } |
| 1594 | |
| 1595 | goto out; |
| 1596 | |
| 1597 | not_ready: |
| 1598 | spin_unlock_irq(shost->host_lock); |
| 1599 | |
| 1600 | /* |
| 1601 | * lock q, handle tag, requeue req, and decrement device_busy. We |
| 1602 | * must return with queue_lock held. |
| 1603 | * |
| 1604 | * Decrementing device_busy without checking it is OK, as all such |
| 1605 | * cases (host limits or settings) should run the queue at some |
| 1606 | * later time. |
| 1607 | */ |
| 1608 | spin_lock_irq(q->queue_lock); |
| 1609 | blk_requeue_request(q, req); |
| 1610 | sdev->device_busy--; |
| 1611 | if(sdev->device_busy == 0) |
| 1612 | blk_plug_device(q); |
| 1613 | out: |
| 1614 | /* must be careful here...if we trigger the ->remove() function |
| 1615 | * we cannot be holding the q lock */ |
| 1616 | spin_unlock_irq(q->queue_lock); |
| 1617 | put_device(&sdev->sdev_gendev); |
| 1618 | spin_lock_irq(q->queue_lock); |
| 1619 | } |
| 1620 | |
| 1621 | u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |
| 1622 | { |
| 1623 | struct device *host_dev; |
| 1624 | u64 bounce_limit = 0xffffffff; |
| 1625 | |
| 1626 | if (shost->unchecked_isa_dma) |
| 1627 | return BLK_BOUNCE_ISA; |
| 1628 | /* |
| 1629 | * Platforms with virtual-DMA translation |
| 1630 | * hardware have no practical limit. |
| 1631 | */ |
| 1632 | if (!PCI_DMA_BUS_IS_PHYS) |
| 1633 | return BLK_BOUNCE_ANY; |
| 1634 | |
| 1635 | host_dev = scsi_get_device(shost); |
| 1636 | if (host_dev && host_dev->dma_mask) |
| 1637 | bounce_limit = *host_dev->dma_mask; |
| 1638 | |
| 1639 | return bounce_limit; |
| 1640 | } |
| 1641 | EXPORT_SYMBOL(scsi_calculate_bounce_limit); |
| 1642 | |
| 1643 | struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) |
| 1644 | { |
| 1645 | struct Scsi_Host *shost = sdev->host; |
| 1646 | struct request_queue *q; |
| 1647 | |
| 152587d | 2005-04-12 16:22:06 -0500 | [diff] [blame] | 1648 | q = blk_init_queue(scsi_request_fn, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1649 | if (!q) |
| 1650 | return NULL; |
| 1651 | |
| 1652 | blk_queue_prep_rq(q, scsi_prep_fn); |
| 1653 | |
| 1654 | blk_queue_max_hw_segments(q, shost->sg_tablesize); |
| 1655 | blk_queue_max_phys_segments(q, SCSI_MAX_PHYS_SEGMENTS); |
| 1656 | blk_queue_max_sectors(q, shost->max_sectors); |
| 1657 | blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); |
| 1658 | blk_queue_segment_boundary(q, shost->dma_boundary); |
| 1659 | blk_queue_issue_flush_fn(q, scsi_issue_flush_fn); |
Jens Axboe | 1aea643 | 2006-01-09 16:03:03 +0100 | [diff] [blame] | 1660 | blk_queue_softirq_done(q, scsi_softirq_done); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1661 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1662 | if (!shost->use_clustering) |
| 1663 | clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); |
| 1664 | return q; |
| 1665 | } |
| 1666 | |
| 1667 | void scsi_free_queue(struct request_queue *q) |
| 1668 | { |
| 1669 | blk_cleanup_queue(q); |
| 1670 | } |
| 1671 | |
| 1672 | /* |
| 1673 | * Function: scsi_block_requests() |
| 1674 | * |
| 1675 | * Purpose: Utility function used by low-level drivers to prevent further |
| 1676 | * commands from being queued to the device. |
| 1677 | * |
| 1678 | * Arguments: shost - Host in question |
| 1679 | * |
| 1680 | * Returns: Nothing |
| 1681 | * |
| 1682 | * Lock status: No locks are assumed held. |
| 1683 | * |
| 1684 | * Notes: There is no timer nor any other means by which the requests |
| 1685 | * get unblocked other than the low-level driver calling |
| 1686 | * scsi_unblock_requests(). |
| 1687 | */ |
| 1688 | void scsi_block_requests(struct Scsi_Host *shost) |
| 1689 | { |
| 1690 | shost->host_self_blocked = 1; |
| 1691 | } |
| 1692 | EXPORT_SYMBOL(scsi_block_requests); |
| 1693 | |
| 1694 | /* |
| 1695 | * Function: scsi_unblock_requests() |
| 1696 | * |
| 1697 | * Purpose: Utility function used by low-level drivers to allow further |
| 1698 | * commands from being queued to the device. |
| 1699 | * |
| 1700 | * Arguments: shost - Host in question |
| 1701 | * |
| 1702 | * Returns: Nothing |
| 1703 | * |
| 1704 | * Lock status: No locks are assumed held. |
| 1705 | * |
| 1706 | * Notes: There is no timer nor any other means by which the requests |
| 1707 | * get unblocked other than the low-level driver calling |
| 1708 | * scsi_unblock_requests(). |
| 1709 | * |
| 1710 | * This is done as an API function so that changes to the |
| 1711 | * internals of the scsi mid-layer won't require wholesale |
| 1712 | * changes to drivers that use this feature. |
| 1713 | */ |
| 1714 | void scsi_unblock_requests(struct Scsi_Host *shost) |
| 1715 | { |
| 1716 | shost->host_self_blocked = 0; |
| 1717 | scsi_run_host_queues(shost); |
| 1718 | } |
| 1719 | EXPORT_SYMBOL(scsi_unblock_requests); |
| 1720 | |
| 1721 | int __init scsi_init_queue(void) |
| 1722 | { |
| 1723 | int i; |
| 1724 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1725 | scsi_io_context_cache = kmem_cache_create("scsi_io_context", |
| 1726 | sizeof(struct scsi_io_context), |
| 1727 | 0, 0, NULL, NULL); |
| 1728 | if (!scsi_io_context_cache) { |
| 1729 | printk(KERN_ERR "SCSI: can't init scsi io context cache\n"); |
| 1730 | return -ENOMEM; |
| 1731 | } |
| 1732 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1733 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1734 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1735 | int size = sgp->size * sizeof(struct scatterlist); |
| 1736 | |
| 1737 | sgp->slab = kmem_cache_create(sgp->name, size, 0, |
| 1738 | SLAB_HWCACHE_ALIGN, NULL, NULL); |
| 1739 | if (!sgp->slab) { |
| 1740 | printk(KERN_ERR "SCSI: can't init sg slab %s\n", |
| 1741 | sgp->name); |
| 1742 | } |
| 1743 | |
Matthew Dobson | 93d2341 | 2006-03-26 01:37:50 -0800 | [diff] [blame] | 1744 | sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, |
| 1745 | sgp->slab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1746 | if (!sgp->pool) { |
| 1747 | printk(KERN_ERR "SCSI: can't init sg mempool %s\n", |
| 1748 | sgp->name); |
| 1749 | } |
| 1750 | } |
| 1751 | |
| 1752 | return 0; |
| 1753 | } |
| 1754 | |
| 1755 | void scsi_exit_queue(void) |
| 1756 | { |
| 1757 | int i; |
| 1758 | |
Mike Christie | aa7b5cd | 2005-11-11 05:31:41 -0600 | [diff] [blame] | 1759 | kmem_cache_destroy(scsi_io_context_cache); |
| 1760 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1761 | for (i = 0; i < SG_MEMPOOL_NR; i++) { |
| 1762 | struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; |
| 1763 | mempool_destroy(sgp->pool); |
| 1764 | kmem_cache_destroy(sgp->slab); |
| 1765 | } |
| 1766 | } |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1767 | |
| 1768 | /** |
| 1769 | * scsi_mode_select - issue a mode select |
| 1770 | * @sdev: SCSI device to be queried |
| 1771 | * @pf: Page format bit (1 == standard, 0 == vendor specific) |
| 1772 | * @sp: Save page bit (0 == don't save, 1 == save) |
| 1773 | * @modepage: mode page being requested |
| 1774 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1775 | * @len: length of request buffer. |
| 1776 | * @timeout: command timeout |
| 1777 | * @retries: number of retries before failing |
| 1778 | * @data: returns a structure abstracting the mode header data |
| 1779 | * @sense: place to put sense data (or NULL if no sense to be collected). |
| 1780 | * must be SCSI_SENSE_BUFFERSIZE big. |
| 1781 | * |
| 1782 | * Returns zero if successful; negative error number or scsi |
| 1783 | * status on error |
| 1784 | * |
| 1785 | */ |
| 1786 | int |
| 1787 | scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, |
| 1788 | unsigned char *buffer, int len, int timeout, int retries, |
| 1789 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1790 | { |
| 1791 | unsigned char cmd[10]; |
| 1792 | unsigned char *real_buffer; |
| 1793 | int ret; |
| 1794 | |
| 1795 | memset(cmd, 0, sizeof(cmd)); |
| 1796 | cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); |
| 1797 | |
| 1798 | if (sdev->use_10_for_ms) { |
| 1799 | if (len > 65535) |
| 1800 | return -EINVAL; |
| 1801 | real_buffer = kmalloc(8 + len, GFP_KERNEL); |
| 1802 | if (!real_buffer) |
| 1803 | return -ENOMEM; |
| 1804 | memcpy(real_buffer + 8, buffer, len); |
| 1805 | len += 8; |
| 1806 | real_buffer[0] = 0; |
| 1807 | real_buffer[1] = 0; |
| 1808 | real_buffer[2] = data->medium_type; |
| 1809 | real_buffer[3] = data->device_specific; |
| 1810 | real_buffer[4] = data->longlba ? 0x01 : 0; |
| 1811 | real_buffer[5] = 0; |
| 1812 | real_buffer[6] = data->block_descriptor_length >> 8; |
| 1813 | real_buffer[7] = data->block_descriptor_length; |
| 1814 | |
| 1815 | cmd[0] = MODE_SELECT_10; |
| 1816 | cmd[7] = len >> 8; |
| 1817 | cmd[8] = len; |
| 1818 | } else { |
| 1819 | if (len > 255 || data->block_descriptor_length > 255 || |
| 1820 | data->longlba) |
| 1821 | return -EINVAL; |
| 1822 | |
| 1823 | real_buffer = kmalloc(4 + len, GFP_KERNEL); |
| 1824 | if (!real_buffer) |
| 1825 | return -ENOMEM; |
| 1826 | memcpy(real_buffer + 4, buffer, len); |
| 1827 | len += 4; |
| 1828 | real_buffer[0] = 0; |
| 1829 | real_buffer[1] = data->medium_type; |
| 1830 | real_buffer[2] = data->device_specific; |
| 1831 | real_buffer[3] = data->block_descriptor_length; |
| 1832 | |
| 1833 | |
| 1834 | cmd[0] = MODE_SELECT; |
| 1835 | cmd[4] = len; |
| 1836 | } |
| 1837 | |
| 1838 | ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, |
| 1839 | sshdr, timeout, retries); |
| 1840 | kfree(real_buffer); |
| 1841 | return ret; |
| 1842 | } |
| 1843 | EXPORT_SYMBOL_GPL(scsi_mode_select); |
| 1844 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1845 | /** |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1846 | * scsi_mode_sense - issue a mode sense, falling back from 10 to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1847 | * six bytes if necessary. |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1848 | * @sdev: SCSI device to be queried |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1849 | * @dbd: set if mode sense will allow block descriptors to be returned |
| 1850 | * @modepage: mode page being requested |
| 1851 | * @buffer: request buffer (may not be smaller than eight bytes) |
| 1852 | * @len: length of request buffer. |
| 1853 | * @timeout: command timeout |
| 1854 | * @retries: number of retries before failing |
| 1855 | * @data: returns a structure abstracting the mode header data |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1856 | * @sense: place to put sense data (or NULL if no sense to be collected). |
| 1857 | * must be SCSI_SENSE_BUFFERSIZE big. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1858 | * |
| 1859 | * Returns zero if unsuccessful, or the header offset (either 4 |
| 1860 | * or 8 depending on whether a six or ten byte command was |
| 1861 | * issued) if successful. |
| 1862 | **/ |
| 1863 | int |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1864 | scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1865 | unsigned char *buffer, int len, int timeout, int retries, |
James Bottomley | 5baba83 | 2006-03-18 14:10:35 -0600 | [diff] [blame] | 1866 | struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) |
| 1867 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1868 | unsigned char cmd[12]; |
| 1869 | int use_10_for_ms; |
| 1870 | int header_length; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1871 | int result; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1872 | struct scsi_sense_hdr my_sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1873 | |
| 1874 | memset(data, 0, sizeof(*data)); |
| 1875 | memset(&cmd[0], 0, 12); |
| 1876 | cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ |
| 1877 | cmd[2] = modepage; |
| 1878 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1879 | /* caller might not be interested in sense, but we need it */ |
| 1880 | if (!sshdr) |
| 1881 | sshdr = &my_sshdr; |
| 1882 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1883 | retry: |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1884 | use_10_for_ms = sdev->use_10_for_ms; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1885 | |
| 1886 | if (use_10_for_ms) { |
| 1887 | if (len < 8) |
| 1888 | len = 8; |
| 1889 | |
| 1890 | cmd[0] = MODE_SENSE_10; |
| 1891 | cmd[8] = len; |
| 1892 | header_length = 8; |
| 1893 | } else { |
| 1894 | if (len < 4) |
| 1895 | len = 4; |
| 1896 | |
| 1897 | cmd[0] = MODE_SENSE; |
| 1898 | cmd[4] = len; |
| 1899 | header_length = 4; |
| 1900 | } |
| 1901 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1902 | memset(buffer, 0, len); |
| 1903 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1904 | result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1905 | sshdr, timeout, retries); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1906 | |
| 1907 | /* This code looks awful: what it's doing is making sure an |
| 1908 | * ILLEGAL REQUEST sense return identifies the actual command |
| 1909 | * byte as the problem. MODE_SENSE commands can return |
| 1910 | * ILLEGAL REQUEST if the code page isn't supported */ |
| 1911 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1912 | if (use_10_for_ms && !scsi_status_is_good(result) && |
| 1913 | (driver_byte(result) & DRIVER_SENSE)) { |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1914 | if (scsi_sense_valid(sshdr)) { |
| 1915 | if ((sshdr->sense_key == ILLEGAL_REQUEST) && |
| 1916 | (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1917 | /* |
| 1918 | * Invalid command operation code |
| 1919 | */ |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1920 | sdev->use_10_for_ms = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1921 | goto retry; |
| 1922 | } |
| 1923 | } |
| 1924 | } |
| 1925 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1926 | if(scsi_status_is_good(result)) { |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 1927 | if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && |
| 1928 | (modepage == 6 || modepage == 8))) { |
| 1929 | /* Initio breakage? */ |
| 1930 | header_length = 0; |
| 1931 | data->length = 13; |
| 1932 | data->medium_type = 0; |
| 1933 | data->device_specific = 0; |
| 1934 | data->longlba = 0; |
| 1935 | data->block_descriptor_length = 0; |
| 1936 | } else if(use_10_for_ms) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1937 | data->length = buffer[0]*256 + buffer[1] + 2; |
| 1938 | data->medium_type = buffer[2]; |
| 1939 | data->device_specific = buffer[3]; |
| 1940 | data->longlba = buffer[4] & 0x01; |
| 1941 | data->block_descriptor_length = buffer[6]*256 |
| 1942 | + buffer[7]; |
| 1943 | } else { |
| 1944 | data->length = buffer[0] + 1; |
| 1945 | data->medium_type = buffer[1]; |
| 1946 | data->device_specific = buffer[2]; |
| 1947 | data->block_descriptor_length = buffer[3]; |
| 1948 | } |
Al Viro | 6d73c85 | 2006-02-23 02:03:16 +0100 | [diff] [blame] | 1949 | data->header_length = header_length; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1950 | } |
| 1951 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1952 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1953 | } |
| 1954 | EXPORT_SYMBOL(scsi_mode_sense); |
| 1955 | |
| 1956 | int |
| 1957 | scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries) |
| 1958 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1959 | char cmd[] = { |
| 1960 | TEST_UNIT_READY, 0, 0, 0, 0, 0, |
| 1961 | }; |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1962 | struct scsi_sense_hdr sshdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1963 | int result; |
| 1964 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1965 | result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, &sshdr, |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1966 | timeout, retries); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1967 | |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1968 | if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1969 | |
James Bottomley | ea73a9f | 2005-08-28 11:33:52 -0500 | [diff] [blame] | 1970 | if ((scsi_sense_valid(&sshdr)) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1971 | ((sshdr.sense_key == UNIT_ATTENTION) || |
| 1972 | (sshdr.sense_key == NOT_READY))) { |
| 1973 | sdev->changed = 1; |
James Bottomley | 1cf7269 | 2005-08-28 11:27:01 -0500 | [diff] [blame] | 1974 | result = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1975 | } |
| 1976 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1977 | return result; |
| 1978 | } |
| 1979 | EXPORT_SYMBOL(scsi_test_unit_ready); |
| 1980 | |
| 1981 | /** |
| 1982 | * scsi_device_set_state - Take the given device through the device |
| 1983 | * state model. |
| 1984 | * @sdev: scsi device to change the state of. |
| 1985 | * @state: state to change to. |
| 1986 | * |
| 1987 | * Returns zero if unsuccessful or an error if the requested |
| 1988 | * transition is illegal. |
| 1989 | **/ |
| 1990 | int |
| 1991 | scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) |
| 1992 | { |
| 1993 | enum scsi_device_state oldstate = sdev->sdev_state; |
| 1994 | |
| 1995 | if (state == oldstate) |
| 1996 | return 0; |
| 1997 | |
| 1998 | switch (state) { |
| 1999 | case SDEV_CREATED: |
| 2000 | /* There are no legal states that come back to |
| 2001 | * created. This is the manually initialised start |
| 2002 | * state */ |
| 2003 | goto illegal; |
| 2004 | |
| 2005 | case SDEV_RUNNING: |
| 2006 | switch (oldstate) { |
| 2007 | case SDEV_CREATED: |
| 2008 | case SDEV_OFFLINE: |
| 2009 | case SDEV_QUIESCE: |
| 2010 | case SDEV_BLOCK: |
| 2011 | break; |
| 2012 | default: |
| 2013 | goto illegal; |
| 2014 | } |
| 2015 | break; |
| 2016 | |
| 2017 | case SDEV_QUIESCE: |
| 2018 | switch (oldstate) { |
| 2019 | case SDEV_RUNNING: |
| 2020 | case SDEV_OFFLINE: |
| 2021 | break; |
| 2022 | default: |
| 2023 | goto illegal; |
| 2024 | } |
| 2025 | break; |
| 2026 | |
| 2027 | case SDEV_OFFLINE: |
| 2028 | switch (oldstate) { |
| 2029 | case SDEV_CREATED: |
| 2030 | case SDEV_RUNNING: |
| 2031 | case SDEV_QUIESCE: |
| 2032 | case SDEV_BLOCK: |
| 2033 | break; |
| 2034 | default: |
| 2035 | goto illegal; |
| 2036 | } |
| 2037 | break; |
| 2038 | |
| 2039 | case SDEV_BLOCK: |
| 2040 | switch (oldstate) { |
| 2041 | case SDEV_CREATED: |
| 2042 | case SDEV_RUNNING: |
| 2043 | break; |
| 2044 | default: |
| 2045 | goto illegal; |
| 2046 | } |
| 2047 | break; |
| 2048 | |
| 2049 | case SDEV_CANCEL: |
| 2050 | switch (oldstate) { |
| 2051 | case SDEV_CREATED: |
| 2052 | case SDEV_RUNNING: |
| 2053 | case SDEV_OFFLINE: |
| 2054 | case SDEV_BLOCK: |
| 2055 | break; |
| 2056 | default: |
| 2057 | goto illegal; |
| 2058 | } |
| 2059 | break; |
| 2060 | |
| 2061 | case SDEV_DEL: |
| 2062 | switch (oldstate) { |
| 2063 | case SDEV_CANCEL: |
| 2064 | break; |
| 2065 | default: |
| 2066 | goto illegal; |
| 2067 | } |
| 2068 | break; |
| 2069 | |
| 2070 | } |
| 2071 | sdev->sdev_state = state; |
| 2072 | return 0; |
| 2073 | |
| 2074 | illegal: |
| 2075 | SCSI_LOG_ERROR_RECOVERY(1, |
James Bottomley | 9ccfc75 | 2005-10-02 11:45:08 -0500 | [diff] [blame] | 2076 | sdev_printk(KERN_ERR, sdev, |
| 2077 | "Illegal state transition %s->%s\n", |
| 2078 | scsi_device_state_name(oldstate), |
| 2079 | scsi_device_state_name(state)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2080 | ); |
| 2081 | return -EINVAL; |
| 2082 | } |
| 2083 | EXPORT_SYMBOL(scsi_device_set_state); |
| 2084 | |
| 2085 | /** |
| 2086 | * scsi_device_quiesce - Block user issued commands. |
| 2087 | * @sdev: scsi device to quiesce. |
| 2088 | * |
| 2089 | * This works by trying to transition to the SDEV_QUIESCE state |
| 2090 | * (which must be a legal transition). When the device is in this |
| 2091 | * state, only special requests will be accepted, all others will |
| 2092 | * be deferred. Since special requests may also be requeued requests, |
| 2093 | * a successful return doesn't guarantee the device will be |
| 2094 | * totally quiescent. |
| 2095 | * |
| 2096 | * Must be called with user context, may sleep. |
| 2097 | * |
| 2098 | * Returns zero if unsuccessful or an error if not. |
| 2099 | **/ |
| 2100 | int |
| 2101 | scsi_device_quiesce(struct scsi_device *sdev) |
| 2102 | { |
| 2103 | int err = scsi_device_set_state(sdev, SDEV_QUIESCE); |
| 2104 | if (err) |
| 2105 | return err; |
| 2106 | |
| 2107 | scsi_run_queue(sdev->request_queue); |
| 2108 | while (sdev->device_busy) { |
| 2109 | msleep_interruptible(200); |
| 2110 | scsi_run_queue(sdev->request_queue); |
| 2111 | } |
| 2112 | return 0; |
| 2113 | } |
| 2114 | EXPORT_SYMBOL(scsi_device_quiesce); |
| 2115 | |
| 2116 | /** |
| 2117 | * scsi_device_resume - Restart user issued commands to a quiesced device. |
| 2118 | * @sdev: scsi device to resume. |
| 2119 | * |
| 2120 | * Moves the device from quiesced back to running and restarts the |
| 2121 | * queues. |
| 2122 | * |
| 2123 | * Must be called with user context, may sleep. |
| 2124 | **/ |
| 2125 | void |
| 2126 | scsi_device_resume(struct scsi_device *sdev) |
| 2127 | { |
| 2128 | if(scsi_device_set_state(sdev, SDEV_RUNNING)) |
| 2129 | return; |
| 2130 | scsi_run_queue(sdev->request_queue); |
| 2131 | } |
| 2132 | EXPORT_SYMBOL(scsi_device_resume); |
| 2133 | |
| 2134 | static void |
| 2135 | device_quiesce_fn(struct scsi_device *sdev, void *data) |
| 2136 | { |
| 2137 | scsi_device_quiesce(sdev); |
| 2138 | } |
| 2139 | |
| 2140 | void |
| 2141 | scsi_target_quiesce(struct scsi_target *starget) |
| 2142 | { |
| 2143 | starget_for_each_device(starget, NULL, device_quiesce_fn); |
| 2144 | } |
| 2145 | EXPORT_SYMBOL(scsi_target_quiesce); |
| 2146 | |
| 2147 | static void |
| 2148 | device_resume_fn(struct scsi_device *sdev, void *data) |
| 2149 | { |
| 2150 | scsi_device_resume(sdev); |
| 2151 | } |
| 2152 | |
| 2153 | void |
| 2154 | scsi_target_resume(struct scsi_target *starget) |
| 2155 | { |
| 2156 | starget_for_each_device(starget, NULL, device_resume_fn); |
| 2157 | } |
| 2158 | EXPORT_SYMBOL(scsi_target_resume); |
| 2159 | |
| 2160 | /** |
| 2161 | * scsi_internal_device_block - internal function to put a device |
| 2162 | * temporarily into the SDEV_BLOCK state |
| 2163 | * @sdev: device to block |
| 2164 | * |
| 2165 | * Block request made by scsi lld's to temporarily stop all |
| 2166 | * scsi commands on the specified device. Called from interrupt |
| 2167 | * or normal process context. |
| 2168 | * |
| 2169 | * Returns zero if successful or error if not |
| 2170 | * |
| 2171 | * Notes: |
| 2172 | * This routine transitions the device to the SDEV_BLOCK state |
| 2173 | * (which must be a legal transition). When the device is in this |
| 2174 | * state, all commands are deferred until the scsi lld reenables |
| 2175 | * the device with scsi_device_unblock or device_block_tmo fires. |
| 2176 | * This routine assumes the host_lock is held on entry. |
| 2177 | **/ |
| 2178 | int |
| 2179 | scsi_internal_device_block(struct scsi_device *sdev) |
| 2180 | { |
| 2181 | request_queue_t *q = sdev->request_queue; |
| 2182 | unsigned long flags; |
| 2183 | int err = 0; |
| 2184 | |
| 2185 | err = scsi_device_set_state(sdev, SDEV_BLOCK); |
| 2186 | if (err) |
| 2187 | return err; |
| 2188 | |
| 2189 | /* |
| 2190 | * The device has transitioned to SDEV_BLOCK. Stop the |
| 2191 | * block layer from calling the midlayer with this device's |
| 2192 | * request queue. |
| 2193 | */ |
| 2194 | spin_lock_irqsave(q->queue_lock, flags); |
| 2195 | blk_stop_queue(q); |
| 2196 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2197 | |
| 2198 | return 0; |
| 2199 | } |
| 2200 | EXPORT_SYMBOL_GPL(scsi_internal_device_block); |
| 2201 | |
| 2202 | /** |
| 2203 | * scsi_internal_device_unblock - resume a device after a block request |
| 2204 | * @sdev: device to resume |
| 2205 | * |
| 2206 | * Called by scsi lld's or the midlayer to restart the device queue |
| 2207 | * for the previously suspended scsi device. Called from interrupt or |
| 2208 | * normal process context. |
| 2209 | * |
| 2210 | * Returns zero if successful or error if not. |
| 2211 | * |
| 2212 | * Notes: |
| 2213 | * This routine transitions the device to the SDEV_RUNNING state |
| 2214 | * (which must be a legal transition) allowing the midlayer to |
| 2215 | * goose the queue for this device. This routine assumes the |
| 2216 | * host_lock is held upon entry. |
| 2217 | **/ |
| 2218 | int |
| 2219 | scsi_internal_device_unblock(struct scsi_device *sdev) |
| 2220 | { |
| 2221 | request_queue_t *q = sdev->request_queue; |
| 2222 | int err; |
| 2223 | unsigned long flags; |
| 2224 | |
| 2225 | /* |
| 2226 | * Try to transition the scsi device to SDEV_RUNNING |
| 2227 | * and goose the device queue if successful. |
| 2228 | */ |
| 2229 | err = scsi_device_set_state(sdev, SDEV_RUNNING); |
| 2230 | if (err) |
| 2231 | return err; |
| 2232 | |
| 2233 | spin_lock_irqsave(q->queue_lock, flags); |
| 2234 | blk_start_queue(q); |
| 2235 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2236 | |
| 2237 | return 0; |
| 2238 | } |
| 2239 | EXPORT_SYMBOL_GPL(scsi_internal_device_unblock); |
| 2240 | |
| 2241 | static void |
| 2242 | device_block(struct scsi_device *sdev, void *data) |
| 2243 | { |
| 2244 | scsi_internal_device_block(sdev); |
| 2245 | } |
| 2246 | |
| 2247 | static int |
| 2248 | target_block(struct device *dev, void *data) |
| 2249 | { |
| 2250 | if (scsi_is_target_device(dev)) |
| 2251 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2252 | device_block); |
| 2253 | return 0; |
| 2254 | } |
| 2255 | |
| 2256 | void |
| 2257 | scsi_target_block(struct device *dev) |
| 2258 | { |
| 2259 | if (scsi_is_target_device(dev)) |
| 2260 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2261 | device_block); |
| 2262 | else |
| 2263 | device_for_each_child(dev, NULL, target_block); |
| 2264 | } |
| 2265 | EXPORT_SYMBOL_GPL(scsi_target_block); |
| 2266 | |
| 2267 | static void |
| 2268 | device_unblock(struct scsi_device *sdev, void *data) |
| 2269 | { |
| 2270 | scsi_internal_device_unblock(sdev); |
| 2271 | } |
| 2272 | |
| 2273 | static int |
| 2274 | target_unblock(struct device *dev, void *data) |
| 2275 | { |
| 2276 | if (scsi_is_target_device(dev)) |
| 2277 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2278 | device_unblock); |
| 2279 | return 0; |
| 2280 | } |
| 2281 | |
| 2282 | void |
| 2283 | scsi_target_unblock(struct device *dev) |
| 2284 | { |
| 2285 | if (scsi_is_target_device(dev)) |
| 2286 | starget_for_each_device(to_scsi_target(dev), NULL, |
| 2287 | device_unblock); |
| 2288 | else |
| 2289 | device_for_each_child(dev, NULL, target_unblock); |
| 2290 | } |
| 2291 | EXPORT_SYMBOL_GPL(scsi_target_unblock); |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2292 | |
| 2293 | /** |
| 2294 | * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt |
| 2295 | * @sg: scatter-gather list |
| 2296 | * @sg_count: number of segments in sg |
| 2297 | * @offset: offset in bytes into sg, on return offset into the mapped area |
| 2298 | * @len: bytes to map, on return number of bytes mapped |
| 2299 | * |
| 2300 | * Returns virtual address of the start of the mapped page |
| 2301 | */ |
| 2302 | void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count, |
| 2303 | size_t *offset, size_t *len) |
| 2304 | { |
| 2305 | int i; |
| 2306 | size_t sg_len = 0, len_complete = 0; |
| 2307 | struct page *page; |
| 2308 | |
| 2309 | for (i = 0; i < sg_count; i++) { |
| 2310 | len_complete = sg_len; /* Complete sg-entries */ |
| 2311 | sg_len += sg[i].length; |
| 2312 | if (sg_len > *offset) |
| 2313 | break; |
| 2314 | } |
| 2315 | |
| 2316 | if (unlikely(i == sg_count)) { |
Andrew Morton | 169e1a2 | 2006-04-18 21:09:08 -0700 | [diff] [blame] | 2317 | printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " |
| 2318 | "elements %d\n", |
Guennadi Liakhovetski | cdb8c2a | 2006-04-02 21:57:43 +0200 | [diff] [blame] | 2319 | __FUNCTION__, sg_len, *offset, sg_count); |
| 2320 | WARN_ON(1); |
| 2321 | return NULL; |
| 2322 | } |
| 2323 | |
| 2324 | /* Offset starting from the beginning of first page in this sg-entry */ |
| 2325 | *offset = *offset - len_complete + sg[i].offset; |
| 2326 | |
| 2327 | /* Assumption: contiguous pages can be accessed as "page + i" */ |
| 2328 | page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT)); |
| 2329 | *offset &= ~PAGE_MASK; |
| 2330 | |
| 2331 | /* Bytes in this sg-entry from *offset to the end of the page */ |
| 2332 | sg_len = PAGE_SIZE - *offset; |
| 2333 | if (*len > sg_len) |
| 2334 | *len = sg_len; |
| 2335 | |
| 2336 | return kmap_atomic(page, KM_BIO_SRC_IRQ); |
| 2337 | } |
| 2338 | EXPORT_SYMBOL(scsi_kmap_atomic_sg); |
| 2339 | |
| 2340 | /** |
| 2341 | * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously |
| 2342 | * mapped with scsi_kmap_atomic_sg |
| 2343 | * @virt: virtual address to be unmapped |
| 2344 | */ |
| 2345 | void scsi_kunmap_atomic_sg(void *virt) |
| 2346 | { |
| 2347 | kunmap_atomic(virt, KM_BIO_SRC_IRQ); |
| 2348 | } |
| 2349 | EXPORT_SYMBOL(scsi_kunmap_atomic_sg); |