blob: 65a123d9c67649822e2ab0333bf534f820b8b212 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
James Bottomleyd3f46f32008-01-15 11:11:46 -060011#include <linux/bitops.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/blkdev.h>
13#include <linux/completion.h>
14#include <linux/kernel.h>
Paul Gortmaker09703662011-05-27 09:37:25 -040015#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/mempool.h>
17#include <linux/slab.h>
18#include <linux/init.h>
19#include <linux/pci.h>
20#include <linux/delay.h>
James Bottomleyfaead262006-02-14 10:42:07 -060021#include <linux/hardirq.h>
Jens Axboec6132da2007-10-16 11:08:49 +020022#include <linux/scatterlist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
24#include <scsi/scsi.h>
Christoph Hellwigbeb40482006-06-10 18:01:03 +020025#include <scsi/scsi_cmnd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <scsi/scsi_dbg.h>
27#include <scsi/scsi_device.h>
28#include <scsi/scsi_driver.h>
29#include <scsi/scsi_eh.h>
30#include <scsi/scsi_host.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32#include "scsi_priv.h"
33#include "scsi_logging.h"
34
35
Tobias Klauser6391a112006-06-08 22:23:48 -070036#define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools)
Jens Axboe59725112007-04-02 10:06:42 +020037#define SG_MEMPOOL_SIZE 2
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39struct scsi_host_sg_pool {
40 size_t size;
Jens Axboea8474ce2007-08-07 09:02:51 +020041 char *name;
Christoph Lametere18b8902006-12-06 20:33:20 -080042 struct kmem_cache *slab;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 mempool_t *pool;
44};
45
James Bottomleyd3f46f32008-01-15 11:11:46 -060046#define SP(x) { x, "sgpool-" __stringify(x) }
47#if (SCSI_MAX_SG_SEGMENTS < 32)
48#error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater)
49#endif
Adrian Bunk52c1da32005-06-23 22:05:33 -070050static struct scsi_host_sg_pool scsi_sg_pools[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 SP(8),
52 SP(16),
FUJITA Tomonorifd820f42007-09-18 12:14:37 +020053#if (SCSI_MAX_SG_SEGMENTS > 32)
James Bottomleyd3f46f32008-01-15 11:11:46 -060054 SP(32),
FUJITA Tomonorifd820f42007-09-18 12:14:37 +020055#if (SCSI_MAX_SG_SEGMENTS > 64)
James Bottomleyd3f46f32008-01-15 11:11:46 -060056 SP(64),
57#if (SCSI_MAX_SG_SEGMENTS > 128)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 SP(128),
James Bottomleyd3f46f32008-01-15 11:11:46 -060059#if (SCSI_MAX_SG_SEGMENTS > 256)
60#error SCSI_MAX_SG_SEGMENTS is too large (256 MAX)
FUJITA Tomonorifd820f42007-09-18 12:14:37 +020061#endif
62#endif
63#endif
James Bottomleyd3f46f32008-01-15 11:11:46 -060064#endif
65 SP(SCSI_MAX_SG_SEGMENTS)
Jens Axboea8474ce2007-08-07 09:02:51 +020066};
Linus Torvalds1da177e2005-04-16 15:20:36 -070067#undef SP
68
Martin K. Petersen7027ad72008-07-17 17:08:48 -040069struct kmem_cache *scsi_sdb_cache;
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +020070
Jens Axboea488e742010-04-16 21:13:15 +020071/*
72 * When to reinvoke queueing after a resource shortage. It's 3 msecs to
73 * not change behaviour from the previous unplug mechanism, experimentation
74 * may prove this needs changing.
75 */
76#define SCSI_QUEUE_DELAY 3
77
James Bottomley4f5299a2009-01-02 10:42:21 -060078/**
79 * __scsi_queue_insert - private queue insertion
80 * @cmd: The SCSI command being requeued
81 * @reason: The reason for the requeue
82 * @unbusy: Whether the queue should be unbusied
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 *
James Bottomley4f5299a2009-01-02 10:42:21 -060084 * This is a private queue insertion. The public interface
85 * scsi_queue_insert() always assumes the queue should be unbusied
86 * because it's always called before the completion. This function is
87 * for a requeue after completion, which should only occur in this
88 * file.
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 */
Bart Van Assche84feb162012-06-29 15:35:05 +000090static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
92 struct Scsi_Host *host = cmd->device->host;
93 struct scsi_device *device = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -050094 struct scsi_target *starget = scsi_target(device);
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -050095 struct request_queue *q = device->request_queue;
96 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98 SCSI_LOG_MLQUEUE(1,
99 printk("Inserting command %p into mlqueue\n", cmd));
100
101 /*
Tejun Heo d8c37e72005-05-14 00:46:08 +0900102 * Set the appropriate busy bit for the device/host.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 *
104 * If the host/device isn't busy, assume that something actually
105 * completed, and that we should be able to queue a command now.
106 *
107 * Note that the prior mid-layer assumption that any host could
108 * always queue at least one command is now broken. The mid-layer
109 * will implement a user specifiable stall (see
110 * scsi_host.max_host_blocked and scsi_device.max_device_blocked)
111 * if a command is requeued with no other commands outstanding
112 * either for the device or for the host.
113 */
Mike Christief0c0a372008-08-17 15:24:38 -0500114 switch (reason) {
115 case SCSI_MLQUEUE_HOST_BUSY:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 host->host_blocked = host->max_host_blocked;
Mike Christief0c0a372008-08-17 15:24:38 -0500117 break;
118 case SCSI_MLQUEUE_DEVICE_BUSY:
James Smart573e5912011-07-06 12:45:17 -0400119 case SCSI_MLQUEUE_EH_RETRY:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 device->device_blocked = device->max_device_blocked;
Mike Christief0c0a372008-08-17 15:24:38 -0500121 break;
122 case SCSI_MLQUEUE_TARGET_BUSY:
123 starget->target_blocked = starget->max_target_blocked;
124 break;
125 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 * Decrement the counters, since these commands are no longer
129 * active on the host/device.
130 */
James Bottomley4f5299a2009-01-02 10:42:21 -0600131 if (unbusy)
132 scsi_device_unbusy(device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
134 /*
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500135 * Requeue this command. It will go before all other commands
Bart Van Asscheb4854622012-06-29 15:36:07 +0000136 * that are already in the queue. Schedule requeue work under
137 * lock such that the kblockd_schedule_work() call happens
138 * before blk_cleanup_queue() finishes.
Jens Axboea488e742010-04-16 21:13:15 +0200139 */
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500140 spin_lock_irqsave(q->queue_lock, flags);
James Bottomley59897da2005-09-14 12:57:42 -0400141 blk_requeue_request(q, cmd->request);
Jens Axboe9937a5e2011-05-17 11:04:44 +0200142 kblockd_schedule_work(q, &device->requeue_work);
Bart Van Asscheb4854622012-06-29 15:36:07 +0000143 spin_unlock_irqrestore(q->queue_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144}
145
James Bottomley4f5299a2009-01-02 10:42:21 -0600146/*
147 * Function: scsi_queue_insert()
148 *
149 * Purpose: Insert a command in the midlevel queue.
150 *
151 * Arguments: cmd - command that we are adding to queue.
152 * reason - why we are inserting command to queue.
153 *
154 * Lock status: Assumed that lock is not held upon entry.
155 *
156 * Returns: Nothing.
157 *
158 * Notes: We do this for one of two cases. Either the host is busy
159 * and it cannot accept any more commands for the time being,
160 * or the device returned QUEUE_FULL and can accept no more
161 * commands.
162 * Notes: This could be called either from an interrupt context or a
163 * normal process context.
164 */
Bart Van Assche84feb162012-06-29 15:35:05 +0000165void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
James Bottomley4f5299a2009-01-02 10:42:21 -0600166{
Bart Van Assche84feb162012-06-29 15:35:05 +0000167 __scsi_queue_insert(cmd, reason, 1);
James Bottomley4f5299a2009-01-02 10:42:21 -0600168}
James Bottomley39216032005-06-15 18:48:29 -0500169/**
James Bottomley33aa6872005-08-28 11:31:14 -0500170 * scsi_execute - insert request and wait for the result
James Bottomley39216032005-06-15 18:48:29 -0500171 * @sdev: scsi device
172 * @cmd: scsi command
173 * @data_direction: data direction
174 * @buffer: data buffer
175 * @bufflen: len of buffer
176 * @sense: optional sense buffer
177 * @timeout: request timeout in seconds
178 * @retries: number of times to retry request
James Bottomley33aa6872005-08-28 11:31:14 -0500179 * @flags: or into request flags;
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900180 * @resid: optional residual length
James Bottomley39216032005-06-15 18:48:29 -0500181 *
Michael Opdenacker59c51592007-05-09 08:57:56 +0200182 * returns the req->errors value which is the scsi_cmnd result
James Bottomleyea73a9f2005-08-28 11:33:52 -0500183 * field.
Rob Landleyeb448202007-11-03 13:30:39 -0500184 */
James Bottomley33aa6872005-08-28 11:31:14 -0500185int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
186 int data_direction, void *buffer, unsigned bufflen,
Martin K. Petersen2bfad212014-04-09 22:20:48 -0400187 unsigned char *sense, int timeout, int retries, u64 flags,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900188 int *resid)
James Bottomley39216032005-06-15 18:48:29 -0500189{
190 struct request *req;
191 int write = (data_direction == DMA_TO_DEVICE);
192 int ret = DRIVER_ERROR << 24;
193
194 req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);
James Bottomleybfe159a2011-07-07 15:45:40 -0500195 if (!req)
196 return ret;
James Bottomley39216032005-06-15 18:48:29 -0500197
198 if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
199 buffer, bufflen, __GFP_WAIT))
200 goto out;
201
202 req->cmd_len = COMMAND_SIZE(cmd[0]);
203 memcpy(req->cmd, cmd, req->cmd_len);
204 req->sense = sense;
205 req->sense_len = 0;
Mike Christie17e01f22005-11-11 05:31:37 -0600206 req->retries = retries;
James Bottomley39216032005-06-15 18:48:29 -0500207 req->timeout = timeout;
Jens Axboe4aff5e22006-08-10 08:44:47 +0200208 req->cmd_type = REQ_TYPE_BLOCK_PC;
209 req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT;
James Bottomley39216032005-06-15 18:48:29 -0500210
211 /*
212 * head injection *required* here otherwise quiesce won't work
213 */
214 blk_execute_rq(req->q, NULL, req, 1);
215
Alan Sternbdb2b8c2008-06-24 14:03:14 -0400216 /*
217 * Some devices (USB mass-storage in particular) may transfer
218 * garbage data together with a residue indicating that the data
219 * is invalid. Prevent the garbage from being misinterpreted
220 * and prevent security leaks by zeroing out the excess data.
221 */
Tejun Heoc3a4d782009-05-07 22:24:37 +0900222 if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen))
223 memset(buffer + (bufflen - req->resid_len), 0, req->resid_len);
Alan Sternbdb2b8c2008-06-24 14:03:14 -0400224
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900225 if (resid)
Tejun Heoc3a4d782009-05-07 22:24:37 +0900226 *resid = req->resid_len;
James Bottomley39216032005-06-15 18:48:29 -0500227 ret = req->errors;
228 out:
229 blk_put_request(req);
230
231 return ret;
232}
James Bottomley33aa6872005-08-28 11:31:14 -0500233EXPORT_SYMBOL(scsi_execute);
James Bottomley39216032005-06-15 18:48:29 -0500234
Lin Ming9b214932013-03-23 11:42:25 +0800235int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd,
James Bottomleyea73a9f2005-08-28 11:33:52 -0500236 int data_direction, void *buffer, unsigned bufflen,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900237 struct scsi_sense_hdr *sshdr, int timeout, int retries,
Martin K. Petersen2bfad212014-04-09 22:20:48 -0400238 int *resid, u64 flags)
James Bottomleyea73a9f2005-08-28 11:33:52 -0500239{
240 char *sense = NULL;
akpm@osdl.org1ccb48b2005-06-26 00:12:51 -0700241 int result;
242
James Bottomleyea73a9f2005-08-28 11:33:52 -0500243 if (sshdr) {
Jes Sorensen24669f752006-01-16 10:31:18 -0500244 sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500245 if (!sense)
246 return DRIVER_ERROR << 24;
James Bottomleyea73a9f2005-08-28 11:33:52 -0500247 }
akpm@osdl.org1ccb48b2005-06-26 00:12:51 -0700248 result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen,
Lin Ming9b214932013-03-23 11:42:25 +0800249 sense, timeout, retries, flags, resid);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500250 if (sshdr)
James Bottomleye5143852005-08-09 11:55:36 -0500251 scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500252
253 kfree(sense);
254 return result;
255}
Lin Ming9b214932013-03-23 11:42:25 +0800256EXPORT_SYMBOL(scsi_execute_req_flags);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500257
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258/*
259 * Function: scsi_init_cmd_errh()
260 *
261 * Purpose: Initialize cmd fields related to error handling.
262 *
263 * Arguments: cmd - command that is ready to be queued.
264 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 * Notes: This function has the job of initializing a number of
266 * fields related to error handling. Typically this will
267 * be called once for each command, as required.
268 */
Christoph Hellwig631c2282006-07-08 20:42:15 +0200269static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 cmd->serial_number = 0;
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200272 scsi_set_resid(cmd, 0);
FUJITA Tomonorib80ca4f2008-01-13 15:46:13 +0900273 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 if (cmd->cmd_len == 0)
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300275 cmd->cmd_len = scsi_command_size(cmd->cmnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276}
277
278void scsi_device_unbusy(struct scsi_device *sdev)
279{
280 struct Scsi_Host *shost = sdev->host;
Mike Christief0c0a372008-08-17 15:24:38 -0500281 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 unsigned long flags;
283
284 spin_lock_irqsave(shost->host_lock, flags);
285 shost->host_busy--;
Mike Christief0c0a372008-08-17 15:24:38 -0500286 starget->target_busy--;
James Bottomley939647e2005-09-18 15:05:20 -0500287 if (unlikely(scsi_host_in_recovery(shost) &&
Tejun Heoee7863b2006-05-15 20:57:20 +0900288 (shost->host_failed || shost->host_eh_scheduled)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 scsi_eh_wakeup(shost);
290 spin_unlock(shost->host_lock);
152587d2005-04-12 16:22:06 -0500291 spin_lock(sdev->request_queue->queue_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 sdev->device_busy--;
152587d2005-04-12 16:22:06 -0500293 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294}
295
296/*
297 * Called for single_lun devices on IO completion. Clear starget_sdev_user,
298 * and call blk_run_queue for all the scsi_devices on the target -
299 * including current_sdev first.
300 *
301 * Called with *no* scsi locks held.
302 */
303static void scsi_single_lun_run(struct scsi_device *current_sdev)
304{
305 struct Scsi_Host *shost = current_sdev->host;
306 struct scsi_device *sdev, *tmp;
307 struct scsi_target *starget = scsi_target(current_sdev);
308 unsigned long flags;
309
310 spin_lock_irqsave(shost->host_lock, flags);
311 starget->starget_sdev_user = NULL;
312 spin_unlock_irqrestore(shost->host_lock, flags);
313
314 /*
315 * Call blk_run_queue for all LUNs on the target, starting with
316 * current_sdev. We race with others (to set starget_sdev_user),
317 * but in most cases, we will be first. Ideally, each LU on the
318 * target would get some limited time or requests on the target.
319 */
320 blk_run_queue(current_sdev->request_queue);
321
322 spin_lock_irqsave(shost->host_lock, flags);
323 if (starget->starget_sdev_user)
324 goto out;
325 list_for_each_entry_safe(sdev, tmp, &starget->devices,
326 same_target_siblings) {
327 if (sdev == current_sdev)
328 continue;
329 if (scsi_device_get(sdev))
330 continue;
331
332 spin_unlock_irqrestore(shost->host_lock, flags);
333 blk_run_queue(sdev->request_queue);
334 spin_lock_irqsave(shost->host_lock, flags);
335
336 scsi_device_put(sdev);
337 }
338 out:
339 spin_unlock_irqrestore(shost->host_lock, flags);
340}
341
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400342static inline int scsi_device_is_busy(struct scsi_device *sdev)
343{
344 if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked)
345 return 1;
346
347 return 0;
348}
349
Mike Christief0c0a372008-08-17 15:24:38 -0500350static inline int scsi_target_is_busy(struct scsi_target *starget)
351{
352 return ((starget->can_queue > 0 &&
353 starget->target_busy >= starget->can_queue) ||
354 starget->target_blocked);
355}
356
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400357static inline int scsi_host_is_busy(struct Scsi_Host *shost)
358{
359 if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) ||
360 shost->host_blocked || shost->host_self_blocked)
361 return 1;
362
363 return 0;
364}
365
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800366static void scsi_starved_list_run(struct Scsi_Host *shost)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367{
Mike Christie2a3a59e2008-11-11 13:42:35 -0600368 LIST_HEAD(starved_list);
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800369 struct scsi_device *sdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 unsigned long flags;
371
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 spin_lock_irqsave(shost->host_lock, flags);
Mike Christie2a3a59e2008-11-11 13:42:35 -0600373 list_splice_init(&shost->starved_list, &starved_list);
374
375 while (!list_empty(&starved_list)) {
James Bottomleye2eb7242013-07-02 15:05:26 +0200376 struct request_queue *slq;
377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 /*
379 * As long as shost is accepting commands and we have
380 * starved queues, call blk_run_queue. scsi_request_fn
381 * drops the queue_lock and can add us back to the
382 * starved_list.
383 *
384 * host_lock protects the starved_list and starved_entry.
385 * scsi_request_fn must get the host_lock before checking
386 * or modifying starved_list or starved_entry.
387 */
Mike Christie2a3a59e2008-11-11 13:42:35 -0600388 if (scsi_host_is_busy(shost))
Mike Christief0c0a372008-08-17 15:24:38 -0500389 break;
Mike Christief0c0a372008-08-17 15:24:38 -0500390
Mike Christie2a3a59e2008-11-11 13:42:35 -0600391 sdev = list_entry(starved_list.next,
392 struct scsi_device, starved_entry);
393 list_del_init(&sdev->starved_entry);
Mike Christief0c0a372008-08-17 15:24:38 -0500394 if (scsi_target_is_busy(scsi_target(sdev))) {
395 list_move_tail(&sdev->starved_entry,
396 &shost->starved_list);
397 continue;
398 }
399
James Bottomleye2eb7242013-07-02 15:05:26 +0200400 /*
401 * Once we drop the host lock, a racing scsi_remove_device()
402 * call may remove the sdev from the starved list and destroy
403 * it and the queue. Mitigate by taking a reference to the
404 * queue and never touching the sdev again after we drop the
405 * host lock. Note: if __scsi_remove_device() invokes
406 * blk_cleanup_queue() before the queue is run from this
407 * function then blk_run_queue() will return immediately since
408 * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING.
409 */
410 slq = sdev->request_queue;
411 if (!blk_get_queue(slq))
412 continue;
413 spin_unlock_irqrestore(shost->host_lock, flags);
414
415 blk_run_queue(slq);
416 blk_put_queue(slq);
417
418 spin_lock_irqsave(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 }
Mike Christie2a3a59e2008-11-11 13:42:35 -0600420 /* put any unprocessed entries back */
421 list_splice(&starved_list, &shost->starved_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 spin_unlock_irqrestore(shost->host_lock, flags);
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800423}
424
425/*
426 * Function: scsi_run_queue()
427 *
428 * Purpose: Select a proper request queue to serve next
429 *
430 * Arguments: q - last request's queue
431 *
432 * Returns: Nothing
433 *
434 * Notes: The previous command was completely finished, start
435 * a new one if possible.
436 */
437static void scsi_run_queue(struct request_queue *q)
438{
439 struct scsi_device *sdev = q->queuedata;
440
441 if (scsi_target(sdev)->single_lun)
442 scsi_single_lun_run(sdev);
443 if (!list_empty(&sdev->host->starved_list))
444 scsi_starved_list_run(sdev->host);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
446 blk_run_queue(q);
447}
448
Jens Axboe9937a5e2011-05-17 11:04:44 +0200449void scsi_requeue_run_queue(struct work_struct *work)
450{
451 struct scsi_device *sdev;
452 struct request_queue *q;
453
454 sdev = container_of(work, struct scsi_device, requeue_work);
455 q = sdev->request_queue;
456 scsi_run_queue(q);
457}
458
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459/*
460 * Function: scsi_requeue_command()
461 *
462 * Purpose: Handle post-processing of completed commands.
463 *
464 * Arguments: q - queue to operate on
465 * cmd - command that may need to be requeued.
466 *
467 * Returns: Nothing
468 *
469 * Notes: After command completion, there may be blocks left
470 * over which weren't finished by the previous command
471 * this can be for a number of reasons - the main one is
472 * I/O errors in the middle of the request, in which case
473 * we need to request the blocks that come after the bad
474 * sector.
James Bottomleye91442b2005-09-09 10:44:16 -0500475 * Notes: Upon return, cmd is a stale pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 */
477static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
478{
Bart Van Assche940f5d42012-06-29 15:34:26 +0000479 struct scsi_device *sdev = cmd->device;
James Bottomleye91442b2005-09-09 10:44:16 -0500480 struct request *req = cmd->request;
Tejun Heo 283369c2005-04-24 02:06:36 -0500481 unsigned long flags;
482
Tejun Heo 283369c2005-04-24 02:06:36 -0500483 spin_lock_irqsave(q->queue_lock, flags);
Christoph Hellwig134997a2014-02-20 14:20:58 -0800484 blk_unprep_request(req);
485 req->special = NULL;
486 scsi_put_command(cmd);
James Bottomleye91442b2005-09-09 10:44:16 -0500487 blk_requeue_request(q, req);
Tejun Heo 283369c2005-04-24 02:06:36 -0500488 spin_unlock_irqrestore(q->queue_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
490 scsi_run_queue(q);
Bart Van Assche940f5d42012-06-29 15:34:26 +0000491
492 put_device(&sdev->sdev_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493}
494
495void scsi_next_command(struct scsi_cmnd *cmd)
496{
Linus Torvalds49d7bc62005-12-12 11:25:04 -0800497 struct scsi_device *sdev = cmd->device;
498 struct request_queue *q = sdev->request_queue;
499
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 scsi_put_command(cmd);
501 scsi_run_queue(q);
Linus Torvalds49d7bc62005-12-12 11:25:04 -0800502
Linus Torvalds49d7bc62005-12-12 11:25:04 -0800503 put_device(&sdev->sdev_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504}
505
506void scsi_run_host_queues(struct Scsi_Host *shost)
507{
508 struct scsi_device *sdev;
509
510 shost_for_each_device(sdev, shost)
511 scsi_run_queue(sdev->request_queue);
512}
513
James Bottomley79ed2422009-01-06 13:15:20 -0600514static void __scsi_release_buffers(struct scsi_cmnd *, int);
515
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516/*
517 * Function: scsi_end_request()
518 *
519 * Purpose: Post-processing of completed commands (usually invoked at end
520 * of upper level post-processing and scsi_io_completion).
521 *
522 * Arguments: cmd - command that is complete.
Kiyoshi Ueda610d8b02007-12-11 17:52:09 -0500523 * error - 0 if I/O indicates success, < 0 for I/O error.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 * bytes - number of bytes of completed I/O
525 * requeue - indicates whether we should requeue leftovers.
526 *
527 * Lock status: Assumed that lock is not held upon entry.
528 *
James Bottomleye91442b2005-09-09 10:44:16 -0500529 * Returns: cmd if requeue required, NULL otherwise.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 *
531 * Notes: This is called for block device requests in order to
532 * mark some number of sectors as complete.
533 *
534 * We are guaranteeing that the request queue will be goosed
535 * at some point during this call.
James Bottomleye91442b2005-09-09 10:44:16 -0500536 * Notes: If cmd was requeued, upon return it will be a stale pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 */
Kiyoshi Ueda610d8b02007-12-11 17:52:09 -0500538static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 int bytes, int requeue)
540{
Jens Axboe165125e2007-07-24 09:28:11 +0200541 struct request_queue *q = cmd->device->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 struct request *req = cmd->request;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543
544 /*
545 * If there are blocks left over at the end, set up the command
546 * to queue the remainder of them.
547 */
Kiyoshi Ueda610d8b02007-12-11 17:52:09 -0500548 if (blk_end_request(req, error, bytes)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 /* kill remainder if no retrys */
Mike Christie4a274462008-08-19 18:45:31 -0500550 if (error && scsi_noretry_cmd(cmd))
Tejun Heoe4588242009-05-12 08:49:32 +0200551 blk_end_request_all(req, error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 else {
James Bottomleye91442b2005-09-09 10:44:16 -0500553 if (requeue) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 /*
555 * Bleah. Leftovers again. Stick the
556 * leftovers in the front of the
557 * queue, and goose the queue again.
558 */
James Bottomley79ed2422009-01-06 13:15:20 -0600559 scsi_release_buffers(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 scsi_requeue_command(q, cmd);
James Bottomleye91442b2005-09-09 10:44:16 -0500561 cmd = NULL;
562 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 return cmd;
564 }
565 }
566
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 /*
568 * This will goose the queue request function at the end, so we don't
569 * need to worry about launching another command.
570 */
James Bottomley79ed2422009-01-06 13:15:20 -0600571 __scsi_release_buffers(cmd, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 scsi_next_command(cmd);
573 return NULL;
574}
575
Jens Axboea8474ce2007-08-07 09:02:51 +0200576static inline unsigned int scsi_sgtable_index(unsigned short nents)
577{
578 unsigned int index;
579
James Bottomleyd3f46f32008-01-15 11:11:46 -0600580 BUG_ON(nents > SCSI_MAX_SG_SEGMENTS);
581
582 if (nents <= 8)
Jens Axboea8474ce2007-08-07 09:02:51 +0200583 index = 0;
James Bottomleyd3f46f32008-01-15 11:11:46 -0600584 else
585 index = get_count_order(nents) - 3;
Jens Axboea8474ce2007-08-07 09:02:51 +0200586
587 return index;
588}
589
Jens Axboe5ed79592007-11-15 09:13:11 +0100590static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591{
592 struct scsi_host_sg_pool *sgp;
Jens Axboe5ed79592007-11-15 09:13:11 +0100593
594 sgp = scsi_sg_pools + scsi_sgtable_index(nents);
595 mempool_free(sgl, sgp->pool);
596}
597
598static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
599{
600 struct scsi_host_sg_pool *sgp;
601
602 sgp = scsi_sg_pools + scsi_sgtable_index(nents);
603 return mempool_alloc(sgp->pool, gfp_mask);
604}
605
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200606static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents,
607 gfp_t gfp_mask)
Jens Axboe5ed79592007-11-15 09:13:11 +0100608{
609 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200611 BUG_ON(!nents);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200613 ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS,
614 gfp_mask, scsi_sg_alloc);
Jens Axboe5ed79592007-11-15 09:13:11 +0100615 if (unlikely(ret))
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200616 __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS,
James Bottomley7cedb1f2008-01-13 14:15:28 -0600617 scsi_sg_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
Jens Axboea8474ce2007-08-07 09:02:51 +0200619 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620}
621
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200622static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623{
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200624 __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625}
626
James Bottomley79ed2422009-01-06 13:15:20 -0600627static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check)
628{
629
630 if (cmd->sdb.table.nents)
631 scsi_free_sgtable(&cmd->sdb);
632
633 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
634
635 if (do_bidi_check && scsi_bidi_cmnd(cmd)) {
636 struct scsi_data_buffer *bidi_sdb =
637 cmd->request->next_rq->special;
638 scsi_free_sgtable(bidi_sdb);
639 kmem_cache_free(scsi_sdb_cache, bidi_sdb);
640 cmd->request->next_rq->special = NULL;
641 }
642
643 if (scsi_prot_sg_count(cmd))
644 scsi_free_sgtable(cmd->prot_sdb);
645}
646
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647/*
648 * Function: scsi_release_buffers()
649 *
650 * Purpose: Completion processing for block device I/O requests.
651 *
652 * Arguments: cmd - command that we are bailing.
653 *
654 * Lock status: Assumed that no lock is held upon entry.
655 *
656 * Returns: Nothing
657 *
658 * Notes: In the event that an upper level driver rejects a
659 * command, we must release resources allocated during
660 * the __init_io() function. Primarily this would involve
661 * the scatter-gather table, and potentially any bounce
662 * buffers.
663 */
Boaz Harroshbb52d822007-12-13 16:14:27 -0800664void scsi_release_buffers(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665{
James Bottomley79ed2422009-01-06 13:15:20 -0600666 __scsi_release_buffers(cmd, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667}
Boaz Harroshbb52d822007-12-13 16:14:27 -0800668EXPORT_SYMBOL(scsi_release_buffers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
Hannes Reinecke0f7f6232013-07-01 15:16:23 +0200670/**
671 * __scsi_error_from_host_byte - translate SCSI error code into errno
672 * @cmd: SCSI command (unused)
673 * @result: scsi error code
674 *
675 * Translate SCSI error code into standard UNIX errno.
676 * Return values:
677 * -ENOLINK temporary transport failure
678 * -EREMOTEIO permanent target failure, do not retry
679 * -EBADE permanent nexus failure, retry on other path
Hannes Reineckea9d6ceb82013-07-01 15:16:25 +0200680 * -ENOSPC No write space available
Hannes Reinecke7e782af2013-07-01 15:16:26 +0200681 * -ENODATA Medium error
Hannes Reinecke0f7f6232013-07-01 15:16:23 +0200682 * -EIO unspecified I/O error
683 */
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100684static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
685{
686 int error = 0;
687
688 switch(host_byte(result)) {
689 case DID_TRANSPORT_FAILFAST:
690 error = -ENOLINK;
691 break;
692 case DID_TARGET_FAILURE:
Moger, Babu2082ebc2012-01-24 20:38:46 +0000693 set_host_byte(cmd, DID_OK);
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100694 error = -EREMOTEIO;
695 break;
696 case DID_NEXUS_FAILURE:
Moger, Babu2082ebc2012-01-24 20:38:46 +0000697 set_host_byte(cmd, DID_OK);
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100698 error = -EBADE;
699 break;
Hannes Reineckea9d6ceb82013-07-01 15:16:25 +0200700 case DID_ALLOC_FAILURE:
701 set_host_byte(cmd, DID_OK);
702 error = -ENOSPC;
703 break;
Hannes Reinecke7e782af2013-07-01 15:16:26 +0200704 case DID_MEDIUM_ERROR:
705 set_host_byte(cmd, DID_OK);
706 error = -ENODATA;
707 break;
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100708 default:
709 error = -EIO;
710 break;
711 }
712
713 return error;
714}
715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716/*
717 * Function: scsi_io_completion()
718 *
719 * Purpose: Completion processing for block device I/O requests.
720 *
721 * Arguments: cmd - command that is finished.
722 *
723 * Lock status: Assumed that no lock is held upon entry.
724 *
725 * Returns: Nothing
726 *
727 * Notes: This function is matched in terms of capabilities to
728 * the function that created the scatter-gather list.
729 * In other words, if there are no bounce buffers
730 * (the normal case for most drivers), we don't need
731 * the logic to deal with cleaning up afterwards.
732 *
Alan Sternb60af5b2008-11-03 15:56:47 -0500733 * We must call scsi_end_request(). This will finish off
734 * the specified number of sectors. If we are done, the
735 * command block will be released and the queue function
736 * will be goosed. If we are not done then we have to
737 * figure out what to do next:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 *
Alan Sternb60af5b2008-11-03 15:56:47 -0500739 * a) We can call scsi_requeue_command(). The request
740 * will be unprepared and put back on the queue. Then
741 * a new command will be created for it. This should
742 * be used if we made forward progress, or if we want
743 * to switch from READ(10) to READ(6) for example.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 *
Alan Sternb60af5b2008-11-03 15:56:47 -0500745 * b) We can call scsi_queue_insert(). The request will
746 * be put back on the queue and retried using the same
747 * command as before, possibly after a delay.
748 *
749 * c) We can call blk_end_request() with -EIO to fail
750 * the remainder of the request.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 */
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700752void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753{
754 int result = cmd->result;
Jens Axboe165125e2007-07-24 09:28:11 +0200755 struct request_queue *q = cmd->device->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 struct request *req = cmd->request;
James Bottomleyfa8e36c2008-04-02 18:11:52 -0500757 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 struct scsi_sense_hdr sshdr;
759 int sense_valid = 0;
760 int sense_deferred = 0;
Alan Sternb60af5b2008-11-03 15:56:47 -0500761 enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
762 ACTION_DELAYED_RETRY} action;
763 char *description = NULL;
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900764 unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 if (result) {
767 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
768 if (sense_valid)
769 sense_deferred = scsi_sense_is_deferred(&sshdr);
770 }
Christoph Hellwig631c2282006-07-08 20:42:15 +0200771
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200772 if (req->cmd_type == REQ_TYPE_BLOCK_PC) { /* SG_IO ioctl from block level */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 if (result) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 if (sense_valid && req->sense) {
775 /*
776 * SG_IO wants current and deferred errors
777 */
778 int len = 8 + cmd->sense_buffer[7];
779
780 if (len > SCSI_SENSE_BUFFERSIZE)
781 len = SCSI_SENSE_BUFFERSIZE;
782 memcpy(req->sense, cmd->sense_buffer, len);
783 req->sense_len = len;
784 }
James Bottomleyfa8e36c2008-04-02 18:11:52 -0500785 if (!sense_deferred)
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100786 error = __scsi_error_from_host_byte(cmd, result);
Pete Wyckoffb22f6872007-03-13 16:53:28 -0400787 }
Mike Snitzer27c41972012-05-31 15:05:33 -0400788 /*
789 * __scsi_error_from_host_byte may have reset the host_byte
790 */
791 req->errors = cmd->result;
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900792
793 req->resid_len = scsi_get_resid(cmd);
794
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200795 if (scsi_bidi_cmnd(cmd)) {
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900796 /*
797 * Bidi commands Must be complete as a whole,
798 * both sides at once.
799 */
800 req->next_rq->resid_len = scsi_in(cmd)->resid;
801
Boaz Harrosh63c43b02009-12-15 17:25:43 +0200802 scsi_release_buffers(cmd);
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900803 blk_end_request_all(req, 0);
804
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900805 scsi_next_command(cmd);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200806 return;
807 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 }
809
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200810 /* no bidi support for !REQ_TYPE_BLOCK_PC yet */
811 BUG_ON(blk_bidi_rq(req));
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200812
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 * Next deal with any sectors which we were able to correctly
815 * handle.
816 */
Tejun Heo83096eb2009-05-07 22:24:39 +0900817 SCSI_LOG_HLCOMPLETE(1, printk("%u sectors total, "
James Bottomleyd6b0c532006-07-02 10:06:28 -0500818 "%d bytes done.\n",
Tejun Heo83096eb2009-05-07 22:24:39 +0900819 blk_rq_sectors(req), good_bytes));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820
James Bottomleya9bddd72009-03-30 16:55:51 +0000821 /*
822 * Recovered errors need reporting, but they're always treated
823 * as success, so fiddle the result code here. For BLOCK_PC
824 * we already took a copy of the original into rq->errors which
825 * is what gets returned to the user
826 */
Douglas Gilberte7efe592010-01-03 13:51:15 -0500827 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
828 /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip
829 * print since caller wants ATA registers. Only occurs on
830 * SCSI ATA PASS_THROUGH commands when CK_COND=1
831 */
832 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
833 ;
834 else if (!(req->cmd_flags & REQ_QUIET))
James Bottomleya9bddd72009-03-30 16:55:51 +0000835 scsi_print_sense("", cmd);
836 result = 0;
837 /* BLOCK_PC may have set error */
838 error = 0;
839 }
840
841 /*
842 * A number of bytes were successfully read. If there
James Bottomleyd6b0c532006-07-02 10:06:28 -0500843 * are leftovers and there is some kind of error
844 * (result != 0), retry the rest.
845 */
James Bottomleyfa8e36c2008-04-02 18:11:52 -0500846 if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL)
James Bottomleyd6b0c532006-07-02 10:06:28 -0500847 return;
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700848
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100849 error = __scsi_error_from_host_byte(cmd, result);
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500850
Alan Sternb60af5b2008-11-03 15:56:47 -0500851 if (host_byte(result) == DID_RESET) {
852 /* Third party bus reset or reset for error recovery
853 * reasons. Just retry the command and see what
854 * happens.
855 */
856 action = ACTION_RETRY;
857 } else if (sense_valid && !sense_deferred) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 switch (sshdr.sense_key) {
859 case UNIT_ATTENTION:
860 if (cmd->device->removable) {
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700861 /* Detected disc change. Set a bit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 * and quietly refuse further access.
863 */
864 cmd->device->changed = 1;
Alan Sternb60af5b2008-11-03 15:56:47 -0500865 description = "Media Changed";
866 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 } else {
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700868 /* Must have been a power glitch, or a
869 * bus reset. Could not have been a
870 * media change, so we just retry the
Alan Sternb60af5b2008-11-03 15:56:47 -0500871 * command and see what happens.
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700872 */
Alan Sternb60af5b2008-11-03 15:56:47 -0500873 action = ACTION_RETRY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 }
875 break;
876 case ILLEGAL_REQUEST:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700877 /* If we had an ILLEGAL REQUEST returned, then
878 * we may have performed an unsupported
879 * command. The only thing this should be
880 * would be a ten byte read where only a six
881 * byte read was supported. Also, on a system
882 * where READ CAPACITY failed, we may have
883 * read past the end of the disk.
884 */
Jens Axboe26a68012005-11-29 21:03:34 +0100885 if ((cmd->device->use_10_for_rw &&
886 sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 (cmd->cmnd[0] == READ_10 ||
888 cmd->cmnd[0] == WRITE_10)) {
Alan Sternb60af5b2008-11-03 15:56:47 -0500889 /* This will issue a new 6-byte command. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 cmd->device->use_10_for_rw = 0;
Alan Sternb60af5b2008-11-03 15:56:47 -0500891 action = ACTION_REPREP;
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500892 } else if (sshdr.asc == 0x10) /* DIX */ {
893 description = "Host Data Integrity Failure";
894 action = ACTION_FAIL;
895 error = -EILSEQ;
Martin K. Petersenc98a0eb2011-03-08 02:07:15 -0500896 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
Martin K. Petersen5db44862012-09-18 12:19:32 -0400897 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
898 switch (cmd->cmnd[0]) {
899 case UNMAP:
900 description = "Discard failure";
901 break;
902 case WRITE_SAME:
903 case WRITE_SAME_16:
904 if (cmd->cmnd[1] & 0x8)
905 description = "Discard failure";
906 else
907 description =
908 "Write same failure";
909 break;
910 default:
911 description = "Invalid command failure";
912 break;
913 }
Martin K. Petersenc98a0eb2011-03-08 02:07:15 -0500914 action = ACTION_FAIL;
Martin K. Petersen66a651a2012-02-13 15:38:22 -0500915 error = -EREMOTEIO;
Alan Sternb60af5b2008-11-03 15:56:47 -0500916 } else
917 action = ACTION_FAIL;
918 break;
Martin K. Petersen511e44f2008-07-17 04:28:33 -0400919 case ABORTED_COMMAND:
James Bottomley126c09822009-02-19 21:48:54 +0000920 action = ACTION_FAIL;
Martin K. Petersen511e44f2008-07-17 04:28:33 -0400921 if (sshdr.asc == 0x10) { /* DIF */
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500922 description = "Target Data Integrity Failure";
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500923 error = -EILSEQ;
James Bottomley126c09822009-02-19 21:48:54 +0000924 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 break;
926 case NOT_READY:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700927 /* If the device is in the process of becoming
James Bottomleyf3e93f72006-04-25 16:48:30 -0500928 * ready, or has a temporary blockage, retry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 */
James Bottomleyf3e93f72006-04-25 16:48:30 -0500930 if (sshdr.asc == 0x04) {
931 switch (sshdr.ascq) {
932 case 0x01: /* becoming ready */
933 case 0x04: /* format in progress */
934 case 0x05: /* rebuild in progress */
935 case 0x06: /* recalculation in progress */
936 case 0x07: /* operation in progress */
937 case 0x08: /* Long write in progress */
938 case 0x09: /* self test in progress */
Martin K. Petersend8705f12009-11-26 12:00:41 -0500939 case 0x14: /* space allocation in progress */
Alan Sternb60af5b2008-11-03 15:56:47 -0500940 action = ACTION_DELAYED_RETRY;
James Bottomleyf3e93f72006-04-25 16:48:30 -0500941 break;
Alan Stern3dbf6a52008-12-15 10:31:28 -0500942 default:
943 description = "Device not ready";
944 action = ACTION_FAIL;
945 break;
James Bottomleyf3e93f72006-04-25 16:48:30 -0500946 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500947 } else {
948 description = "Device not ready";
949 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500951 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 case VOLUME_OVERFLOW:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700953 /* See SSC3rXX or current. */
Alan Sternb60af5b2008-11-03 15:56:47 -0500954 action = ACTION_FAIL;
955 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 default:
Alan Sternb60af5b2008-11-03 15:56:47 -0500957 description = "Unhandled sense code";
958 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 break;
960 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500961 } else {
962 description = "Unhandled error code";
963 action = ACTION_FAIL;
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700964 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500965
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900966 if (action != ACTION_FAIL &&
967 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
968 action = ACTION_FAIL;
969 description = "Command timed out";
970 }
971
Alan Sternb60af5b2008-11-03 15:56:47 -0500972 switch (action) {
973 case ACTION_FAIL:
974 /* Give up and fail the remainder of the request */
James Bottomley79ed2422009-01-06 13:15:20 -0600975 scsi_release_buffers(cmd);
Jens Axboe4aff5e22006-08-10 08:44:47 +0200976 if (!(req->cmd_flags & REQ_QUIET)) {
Alan Sternb60af5b2008-11-03 15:56:47 -0500977 if (description)
Alan Stern3dbf6a52008-12-15 10:31:28 -0500978 scmd_printk(KERN_INFO, cmd, "%s\n",
Alan Sternb60af5b2008-11-03 15:56:47 -0500979 description);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500980 scsi_print_result(cmd);
James Bottomley3173d8c2005-09-04 11:32:05 -0500981 if (driver_byte(result) & DRIVER_SENSE)
982 scsi_print_sense("", cmd);
Martin K. Petersen002b1eb2009-05-23 11:45:07 -0400983 scsi_print_command(cmd);
James Bottomley3173d8c2005-09-04 11:32:05 -0500984 }
Mike Christiead630822009-09-28 15:50:52 -0500985 if (blk_end_request_err(req, error))
Tejun Heoda6c5c72009-09-11 14:26:40 +0200986 scsi_requeue_command(q, cmd);
987 else
988 scsi_next_command(cmd);
Alan Sternb60af5b2008-11-03 15:56:47 -0500989 break;
990 case ACTION_REPREP:
991 /* Unprep the request and put it back at the head of the queue.
992 * A new command will be prepared and issued.
993 */
James Bottomley79ed2422009-01-06 13:15:20 -0600994 scsi_release_buffers(cmd);
Alan Sternb60af5b2008-11-03 15:56:47 -0500995 scsi_requeue_command(q, cmd);
996 break;
997 case ACTION_RETRY:
998 /* Retry the same command immediately */
James Bottomley4f5299a2009-01-02 10:42:21 -0600999 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
Alan Sternb60af5b2008-11-03 15:56:47 -05001000 break;
1001 case ACTION_DELAYED_RETRY:
1002 /* Retry the same command after a delay */
James Bottomley4f5299a2009-01-02 10:42:21 -06001003 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
Alan Sternb60af5b2008-11-03 15:56:47 -05001004 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 }
1006}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001008static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
1009 gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010{
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001011 int count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012
1013 /*
Christoph Hellwig3b003152006-11-04 20:10:55 +01001014 * If sg table allocation fails, requeue request later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 */
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001016 if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments,
1017 gfp_mask))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 return BLKPREP_DEFER;
Alan Stern7c72ce82005-10-14 11:23:27 -04001019 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020
Christoph Hellwig3b003152006-11-04 20:10:55 +01001021 req->buffer = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022
1023 /*
1024 * Next, walk the list, and fill in the addresses and sizes of
1025 * each segment.
1026 */
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001027 count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
1028 BUG_ON(count > sdb->table.nents);
1029 sdb->table.nents = count;
Tejun Heo1011c1b2009-05-07 22:24:45 +09001030 sdb->length = blk_rq_bytes(req);
Rusty Russell4a03d902007-11-19 11:28:48 +11001031 return BLKPREP_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032}
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001033
1034/*
1035 * Function: scsi_init_io()
1036 *
1037 * Purpose: SCSI I/O initialize function.
1038 *
1039 * Arguments: cmd - Command descriptor we wish to initialize
1040 *
1041 * Returns: 0 on success
1042 * BLKPREP_DEFER if the failure is retryable
1043 * BLKPREP_KILL if the failure is fatal
1044 */
1045int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
1046{
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001047 struct request *rq = cmd->request;
1048
1049 int error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001050 if (error)
1051 goto err_exit;
1052
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001053 if (blk_bidi_rq(rq)) {
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001054 struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc(
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001055 scsi_sdb_cache, GFP_ATOMIC);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001056 if (!bidi_sdb) {
1057 error = BLKPREP_DEFER;
1058 goto err_exit;
1059 }
1060
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001061 rq->next_rq->special = bidi_sdb;
1062 error = scsi_init_sgtable(rq->next_rq, bidi_sdb, GFP_ATOMIC);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001063 if (error)
1064 goto err_exit;
1065 }
1066
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001067 if (blk_integrity_rq(rq)) {
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001068 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
1069 int ivecs, count;
1070
1071 BUG_ON(prot_sdb == NULL);
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001072 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001073
1074 if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) {
1075 error = BLKPREP_DEFER;
1076 goto err_exit;
1077 }
1078
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001079 count = blk_rq_map_integrity_sg(rq->q, rq->bio,
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001080 prot_sdb->table.sgl);
1081 BUG_ON(unlikely(count > ivecs));
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001082 BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q)));
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001083
1084 cmd->prot_sdb = prot_sdb;
1085 cmd->prot_sdb->table.nents = count;
1086 }
1087
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001088 return BLKPREP_OK ;
1089
1090err_exit:
1091 scsi_release_buffers(cmd);
FUJITA Tomonori610a6342010-07-08 10:16:17 +02001092 cmd->request->special = NULL;
James Bottomley3a5c19c2010-08-16 10:06:26 -05001093 scsi_put_command(cmd);
Christoph Hellwig04796332014-02-20 14:20:55 -08001094 put_device(&cmd->device->sdev_gendev);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001095 return error;
1096}
Boaz Harroshbb52d822007-12-13 16:14:27 -08001097EXPORT_SYMBOL(scsi_init_io);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098
Christoph Hellwig3b003152006-11-04 20:10:55 +01001099static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
1100 struct request *req)
1101{
1102 struct scsi_cmnd *cmd;
1103
1104 if (!req->special) {
Christoph Hellwig04796332014-02-20 14:20:55 -08001105 /* Bail if we can't get a reference to the device */
1106 if (!get_device(&sdev->sdev_gendev))
Christoph Hellwig3b003152006-11-04 20:10:55 +01001107 return NULL;
Christoph Hellwig04796332014-02-20 14:20:55 -08001108
1109 cmd = scsi_get_command(sdev, GFP_ATOMIC);
1110 if (unlikely(!cmd)) {
1111 put_device(&sdev->sdev_gendev);
1112 return NULL;
1113 }
Christoph Hellwig3b003152006-11-04 20:10:55 +01001114 req->special = cmd;
1115 } else {
1116 cmd = req->special;
1117 }
1118
1119 /* pull a tag out of the request if we have one */
1120 cmd->tag = req->tag;
1121 cmd->request = req;
1122
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001123 cmd->cmnd = req->cmd;
Martin K. Petersen72f7d322011-03-08 02:03:59 -05001124 cmd->prot_op = SCSI_PROT_NORMAL;
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001125
Christoph Hellwig3b003152006-11-04 20:10:55 +01001126 return cmd;
1127}
1128
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001129int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
James Bottomley7b163182005-12-15 20:17:02 -06001130{
Christoph Hellwig3b003152006-11-04 20:10:55 +01001131 struct scsi_cmnd *cmd;
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001132 int ret = scsi_prep_state_check(sdev, req);
1133
1134 if (ret != BLKPREP_OK)
1135 return ret;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001136
1137 cmd = scsi_get_cmd_from_req(sdev, req);
1138 if (unlikely(!cmd))
1139 return BLKPREP_DEFER;
1140
1141 /*
1142 * BLOCK_PC requests may transfer data, in which case they must
1143 * a bio attached to them. Or they might contain a SCSI command
1144 * that does not transfer data, in which case they may optionally
1145 * submit a request without an attached bio.
1146 */
1147 if (req->bio) {
1148 int ret;
1149
1150 BUG_ON(!req->nr_phys_segments);
1151
Boaz Harroshbb52d822007-12-13 16:14:27 -08001152 ret = scsi_init_io(cmd, GFP_ATOMIC);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001153 if (unlikely(ret))
1154 return ret;
1155 } else {
Tejun Heob0790412009-05-07 22:24:42 +09001156 BUG_ON(blk_rq_bytes(req));
Christoph Hellwig3b003152006-11-04 20:10:55 +01001157
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001158 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
Christoph Hellwig3b003152006-11-04 20:10:55 +01001159 req->buffer = NULL;
1160 }
James Bottomley7b163182005-12-15 20:17:02 -06001161
James Bottomley7b163182005-12-15 20:17:02 -06001162 cmd->cmd_len = req->cmd_len;
Tejun Heob0790412009-05-07 22:24:42 +09001163 if (!blk_rq_bytes(req))
James Bottomley7b163182005-12-15 20:17:02 -06001164 cmd->sc_data_direction = DMA_NONE;
1165 else if (rq_data_dir(req) == WRITE)
1166 cmd->sc_data_direction = DMA_TO_DEVICE;
1167 else
1168 cmd->sc_data_direction = DMA_FROM_DEVICE;
1169
Tejun Heob0790412009-05-07 22:24:42 +09001170 cmd->transfersize = blk_rq_bytes(req);
James Bottomley7b163182005-12-15 20:17:02 -06001171 cmd->allowed = req->retries;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001172 return BLKPREP_OK;
1173}
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001174EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001175
1176/*
1177 * Setup a REQ_TYPE_FS command. These are simple read/write request
1178 * from filesystems that still need to be translated to SCSI CDBs from
1179 * the ULD.
1180 */
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001181int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
Christoph Hellwig3b003152006-11-04 20:10:55 +01001182{
1183 struct scsi_cmnd *cmd;
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001184 int ret = scsi_prep_state_check(sdev, req);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001185
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001186 if (ret != BLKPREP_OK)
1187 return ret;
Chandra Seetharamana6a8d9f2008-05-01 14:49:46 -07001188
1189 if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh
1190 && sdev->scsi_dh_data->scsi_dh->prep_fn)) {
1191 ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req);
1192 if (ret != BLKPREP_OK)
1193 return ret;
1194 }
1195
Christoph Hellwig3b003152006-11-04 20:10:55 +01001196 /*
1197 * Filesystem requests must transfer data.
1198 */
1199 BUG_ON(!req->nr_phys_segments);
1200
1201 cmd = scsi_get_cmd_from_req(sdev, req);
1202 if (unlikely(!cmd))
1203 return BLKPREP_DEFER;
1204
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001205 memset(cmd->cmnd, 0, BLK_MAX_CDB);
Boaz Harroshbb52d822007-12-13 16:14:27 -08001206 return scsi_init_io(cmd, GFP_ATOMIC);
James Bottomley7b163182005-12-15 20:17:02 -06001207}
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001208EXPORT_SYMBOL(scsi_setup_fs_cmnd);
James Bottomley7b163182005-12-15 20:17:02 -06001209
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001210int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211{
Christoph Hellwig3b003152006-11-04 20:10:55 +01001212 int ret = BLKPREP_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213
1214 /*
Christoph Hellwig3b003152006-11-04 20:10:55 +01001215 * If the device is not in running state we will reject some
1216 * or all commands.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
Christoph Hellwig3b003152006-11-04 20:10:55 +01001219 switch (sdev->sdev_state) {
1220 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05001221 case SDEV_TRANSPORT_OFFLINE:
Christoph Hellwig3b003152006-11-04 20:10:55 +01001222 /*
1223 * If the device is offline we refuse to process any
1224 * commands. The device must be brought online
1225 * before trying any recovery commands.
1226 */
1227 sdev_printk(KERN_ERR, sdev,
1228 "rejecting I/O to offline device\n");
1229 ret = BLKPREP_KILL;
1230 break;
1231 case SDEV_DEL:
1232 /*
1233 * If the device is fully deleted, we refuse to
1234 * process any commands as well.
1235 */
James Bottomley9ccfc752005-10-02 11:45:08 -05001236 sdev_printk(KERN_ERR, sdev,
1237 "rejecting I/O to dead device\n");
Christoph Hellwig3b003152006-11-04 20:10:55 +01001238 ret = BLKPREP_KILL;
1239 break;
1240 case SDEV_QUIESCE:
1241 case SDEV_BLOCK:
James Bottomley6f4267e2008-08-22 16:53:31 -05001242 case SDEV_CREATED_BLOCK:
Christoph Hellwig3b003152006-11-04 20:10:55 +01001243 /*
1244 * If the devices is blocked we defer normal commands.
1245 */
1246 if (!(req->cmd_flags & REQ_PREEMPT))
1247 ret = BLKPREP_DEFER;
1248 break;
1249 default:
1250 /*
1251 * For any other not fully online state we only allow
1252 * special commands. In particular any user initiated
1253 * command is not allowed.
1254 */
1255 if (!(req->cmd_flags & REQ_PREEMPT))
1256 ret = BLKPREP_KILL;
1257 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 }
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001260 return ret;
1261}
1262EXPORT_SYMBOL(scsi_prep_state_check);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001264int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
1265{
1266 struct scsi_device *sdev = q->queuedata;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267
Christoph Hellwig3b003152006-11-04 20:10:55 +01001268 switch (ret) {
1269 case BLKPREP_KILL:
1270 req->errors = DID_NO_CONNECT << 16;
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001271 /* release the command and kill it */
1272 if (req->special) {
1273 struct scsi_cmnd *cmd = req->special;
1274 scsi_release_buffers(cmd);
1275 scsi_put_command(cmd);
Christoph Hellwig04796332014-02-20 14:20:55 -08001276 put_device(&cmd->device->sdev_gendev);
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001277 req->special = NULL;
1278 }
Christoph Hellwig3b003152006-11-04 20:10:55 +01001279 break;
1280 case BLKPREP_DEFER:
1281 /*
Tejun Heo9934c8c2009-05-08 11:54:16 +09001282 * If we defer, the blk_peek_request() returns NULL, but the
Jens Axboea488e742010-04-16 21:13:15 +02001283 * queue must be restarted, so we schedule a callback to happen
1284 * shortly.
Christoph Hellwig3b003152006-11-04 20:10:55 +01001285 */
1286 if (sdev->device_busy == 0)
Jens Axboea488e742010-04-16 21:13:15 +02001287 blk_delay_queue(q, SCSI_QUEUE_DELAY);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001288 break;
1289 default:
1290 req->cmd_flags |= REQ_DONTPREP;
1291 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292
Christoph Hellwig3b003152006-11-04 20:10:55 +01001293 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294}
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001295EXPORT_SYMBOL(scsi_prep_return);
1296
James Bottomley751bf4d2008-01-02 11:14:30 -06001297int scsi_prep_fn(struct request_queue *q, struct request *req)
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001298{
1299 struct scsi_device *sdev = q->queuedata;
1300 int ret = BLKPREP_KILL;
1301
1302 if (req->cmd_type == REQ_TYPE_BLOCK_PC)
1303 ret = scsi_setup_blk_pc_cmnd(sdev, req);
1304 return scsi_prep_return(q, req, ret);
1305}
Hannes Reineckeb3912772009-06-18 09:57:18 +02001306EXPORT_SYMBOL(scsi_prep_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307
1308/*
1309 * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
1310 * return 0.
1311 *
1312 * Called with the queue_lock held.
1313 */
1314static inline int scsi_dev_queue_ready(struct request_queue *q,
1315 struct scsi_device *sdev)
1316{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 if (sdev->device_busy == 0 && sdev->device_blocked) {
1318 /*
1319 * unblock after device_blocked iterates to zero
1320 */
1321 if (--sdev->device_blocked == 0) {
1322 SCSI_LOG_MLQUEUE(3,
James Bottomley9ccfc752005-10-02 11:45:08 -05001323 sdev_printk(KERN_INFO, sdev,
1324 "unblocking device at zero depth\n"));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 } else {
Jens Axboea488e742010-04-16 21:13:15 +02001326 blk_delay_queue(q, SCSI_QUEUE_DELAY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 return 0;
1328 }
1329 }
Kiyoshi Ueda9d112512008-10-04 14:11:06 -04001330 if (scsi_device_is_busy(sdev))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 return 0;
1332
1333 return 1;
1334}
1335
Mike Christief0c0a372008-08-17 15:24:38 -05001336
1337/*
1338 * scsi_target_queue_ready: checks if there we can send commands to target
1339 * @sdev: scsi device on starget to check.
1340 *
1341 * Called with the host lock held.
1342 */
1343static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
1344 struct scsi_device *sdev)
1345{
1346 struct scsi_target *starget = scsi_target(sdev);
1347
1348 if (starget->single_lun) {
1349 if (starget->starget_sdev_user &&
1350 starget->starget_sdev_user != sdev)
1351 return 0;
1352 starget->starget_sdev_user = sdev;
1353 }
1354
1355 if (starget->target_busy == 0 && starget->target_blocked) {
1356 /*
1357 * unblock after target_blocked iterates to zero
1358 */
1359 if (--starget->target_blocked == 0) {
1360 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
1361 "unblocking target at zero depth\n"));
Mike Christieb4efdd52009-04-09 15:57:10 -05001362 } else
Mike Christief0c0a372008-08-17 15:24:38 -05001363 return 0;
Mike Christief0c0a372008-08-17 15:24:38 -05001364 }
1365
1366 if (scsi_target_is_busy(starget)) {
Shaohua Li466c08c2012-01-10 11:27:01 +08001367 list_move_tail(&sdev->starved_entry, &shost->starved_list);
Hillf Dantonfd01a662010-12-16 14:26:37 -06001368 return 0;
Mike Christief0c0a372008-08-17 15:24:38 -05001369 }
1370
Mike Christief0c0a372008-08-17 15:24:38 -05001371 return 1;
1372}
1373
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374/*
1375 * scsi_host_queue_ready: if we can send requests to shost, return 1 else
1376 * return 0. We must end up running the queue again whenever 0 is
1377 * returned, else IO can hang.
1378 *
1379 * Called with host_lock held.
1380 */
1381static inline int scsi_host_queue_ready(struct request_queue *q,
1382 struct Scsi_Host *shost,
1383 struct scsi_device *sdev)
1384{
James Bottomley939647e2005-09-18 15:05:20 -05001385 if (scsi_host_in_recovery(shost))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 return 0;
1387 if (shost->host_busy == 0 && shost->host_blocked) {
1388 /*
1389 * unblock after host_blocked iterates to zero
1390 */
1391 if (--shost->host_blocked == 0) {
1392 SCSI_LOG_MLQUEUE(3,
1393 printk("scsi%d unblocking host at zero depth\n",
1394 shost->host_no));
1395 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001396 return 0;
1397 }
1398 }
Kiyoshi Ueda9d112512008-10-04 14:11:06 -04001399 if (scsi_host_is_busy(shost)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 if (list_empty(&sdev->starved_entry))
1401 list_add_tail(&sdev->starved_entry, &shost->starved_list);
1402 return 0;
1403 }
1404
1405 /* We're OK to process the command, so we can't be starved */
1406 if (!list_empty(&sdev->starved_entry))
1407 list_del_init(&sdev->starved_entry);
1408
1409 return 1;
1410}
1411
1412/*
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001413 * Busy state exporting function for request stacking drivers.
1414 *
1415 * For efficiency, no lock is taken to check the busy state of
1416 * shost/starget/sdev, since the returned value is not guaranteed and
1417 * may be changed after request stacking drivers call the function,
1418 * regardless of taking lock or not.
1419 *
Bart Van Assche67bd9412012-06-29 15:33:22 +00001420 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
1421 * needs to return 'not busy'. Otherwise, request stacking drivers
1422 * may hold requests forever.
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001423 */
1424static int scsi_lld_busy(struct request_queue *q)
1425{
1426 struct scsi_device *sdev = q->queuedata;
1427 struct Scsi_Host *shost;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001428
Bart Van Assche3f3299d2012-11-28 13:42:38 +01001429 if (blk_queue_dying(q))
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001430 return 0;
1431
1432 shost = sdev->host;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001433
Jun'ichi Nomurab7e94a12012-05-22 18:57:17 +09001434 /*
1435 * Ignore host/starget busy state.
1436 * Since block layer does not have a concept of fairness across
1437 * multiple queues, congestion of host/starget needs to be handled
1438 * in SCSI layer.
1439 */
1440 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001441 return 1;
1442
1443 return 0;
1444}
1445
1446/*
James Bottomleye91442b2005-09-09 10:44:16 -05001447 * Kill a request for a dead device
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 */
Jens Axboe165125e2007-07-24 09:28:11 +02001449static void scsi_kill_request(struct request *req, struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450{
James Bottomleye91442b2005-09-09 10:44:16 -05001451 struct scsi_cmnd *cmd = req->special;
Jiri Slaby03b14702009-09-23 16:15:35 +02001452 struct scsi_device *sdev;
1453 struct scsi_target *starget;
1454 struct Scsi_Host *shost;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001455
Tejun Heo9934c8c2009-05-08 11:54:16 +09001456 blk_start_request(req);
James Bottomley788ce432005-09-09 13:40:23 -05001457
Hannes Reinecke74571812011-11-09 08:39:24 +01001458 scmd_printk(KERN_INFO, cmd, "killing request\n");
1459
Jiri Slaby03b14702009-09-23 16:15:35 +02001460 sdev = cmd->device;
1461 starget = scsi_target(sdev);
1462 shost = sdev->host;
James Bottomleye91442b2005-09-09 10:44:16 -05001463 scsi_init_cmd_errh(cmd);
1464 cmd->result = DID_NO_CONNECT << 16;
1465 atomic_inc(&cmd->device->iorequest_cnt);
Tejun Heoe36e0c82006-04-11 17:27:53 +09001466
1467 /*
1468 * SCSI request completion path will do scsi_device_unbusy(),
1469 * bump busy counts. To bump the counters, we need to dance
1470 * with the locks as normal issue path does.
1471 */
1472 sdev->device_busy++;
1473 spin_unlock(sdev->request_queue->queue_lock);
1474 spin_lock(shost->host_lock);
1475 shost->host_busy++;
Mike Christief0c0a372008-08-17 15:24:38 -05001476 starget->target_busy++;
Tejun Heoe36e0c82006-04-11 17:27:53 +09001477 spin_unlock(shost->host_lock);
1478 spin_lock(sdev->request_queue->queue_lock);
1479
Jens Axboe242f9dc2008-09-14 05:55:09 -07001480 blk_complete_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001481}
1482
Jens Axboe1aea6432006-01-09 16:03:03 +01001483static void scsi_softirq_done(struct request *rq)
1484{
Jens Axboe242f9dc2008-09-14 05:55:09 -07001485 struct scsi_cmnd *cmd = rq->special;
1486 unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
Jens Axboe1aea6432006-01-09 16:03:03 +01001487 int disposition;
1488
1489 INIT_LIST_HEAD(&cmd->eh_entry);
1490
Jens Axboe242f9dc2008-09-14 05:55:09 -07001491 atomic_inc(&cmd->device->iodone_cnt);
1492 if (cmd->result)
1493 atomic_inc(&cmd->device->ioerr_cnt);
1494
Jens Axboe1aea6432006-01-09 16:03:03 +01001495 disposition = scsi_decide_disposition(cmd);
1496 if (disposition != SUCCESS &&
1497 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
1498 sdev_printk(KERN_ERR, cmd->device,
1499 "timing out command, waited %lus\n",
1500 wait_for/HZ);
1501 disposition = SUCCESS;
1502 }
1503
1504 scsi_log_completion(cmd, disposition);
1505
1506 switch (disposition) {
1507 case SUCCESS:
1508 scsi_finish_command(cmd);
1509 break;
1510 case NEEDS_RETRY:
Christoph Hellwig596f4822007-01-02 12:56:00 +01001511 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
Jens Axboe1aea6432006-01-09 16:03:03 +01001512 break;
1513 case ADD_TO_MLQUEUE:
1514 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
1515 break;
1516 default:
1517 if (!scsi_eh_scmd_add(cmd, 0))
1518 scsi_finish_command(cmd);
1519 }
1520}
1521
Linus Torvalds1da177e2005-04-16 15:20:36 -07001522/*
1523 * Function: scsi_request_fn()
1524 *
1525 * Purpose: Main strategy routine for SCSI.
1526 *
1527 * Arguments: q - Pointer to actual queue.
1528 *
1529 * Returns: Nothing
1530 *
1531 * Lock status: IO request lock assumed to be held when called.
1532 */
1533static void scsi_request_fn(struct request_queue *q)
Bart Van Assche613be1f2014-02-20 14:20:56 -08001534 __releases(q->queue_lock)
1535 __acquires(q->queue_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536{
1537 struct scsi_device *sdev = q->queuedata;
1538 struct Scsi_Host *shost;
1539 struct scsi_cmnd *cmd;
1540 struct request *req;
1541
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 /*
1543 * To start with, we keep looping until the queue is empty, or until
1544 * the host is no longer able to accept any more requests.
1545 */
1546 shost = sdev->host;
Jens Axboea488e742010-04-16 21:13:15 +02001547 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548 int rtn;
1549 /*
1550 * get next queueable request. We do this early to make sure
1551 * that the request is fully prepared even if we cannot
1552 * accept it.
1553 */
Tejun Heo9934c8c2009-05-08 11:54:16 +09001554 req = blk_peek_request(q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555 if (!req || !scsi_dev_queue_ready(q, sdev))
1556 break;
1557
1558 if (unlikely(!scsi_device_online(sdev))) {
James Bottomley9ccfc752005-10-02 11:45:08 -05001559 sdev_printk(KERN_ERR, sdev,
1560 "rejecting I/O to offline device\n");
James Bottomleye91442b2005-09-09 10:44:16 -05001561 scsi_kill_request(req, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562 continue;
1563 }
1564
1565
1566 /*
1567 * Remove the request from the request list.
1568 */
1569 if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
Tejun Heo9934c8c2009-05-08 11:54:16 +09001570 blk_start_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571 sdev->device_busy++;
1572
1573 spin_unlock(q->queue_lock);
James Bottomleye91442b2005-09-09 10:44:16 -05001574 cmd = req->special;
1575 if (unlikely(cmd == NULL)) {
1576 printk(KERN_CRIT "impossible request in %s.\n"
1577 "please mail a stack trace to "
Jens Axboe4aff5e22006-08-10 08:44:47 +02001578 "linux-scsi@vger.kernel.org\n",
Harvey Harrisoncadbd4a2008-07-03 23:47:27 -07001579 __func__);
Jens Axboe4aff5e22006-08-10 08:44:47 +02001580 blk_dump_rq_flags(req, "foo");
James Bottomleye91442b2005-09-09 10:44:16 -05001581 BUG();
1582 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 spin_lock(shost->host_lock);
1584
Mike Christieecefe8a2008-07-11 19:50:35 -05001585 /*
1586 * We hit this when the driver is using a host wide
1587 * tag map. For device level tag maps the queue_depth check
1588 * in the device ready fn would prevent us from trying
1589 * to allocate a tag. Since the map is a shared host resource
1590 * we add the dev to the starved list so it eventually gets
1591 * a run when a tag is freed.
1592 */
Mike Christie6bd522f2008-07-22 15:34:38 -05001593 if (blk_queue_tagged(q) && !blk_rq_tagged(req)) {
Mike Christieecefe8a2008-07-11 19:50:35 -05001594 if (list_empty(&sdev->starved_entry))
1595 list_add_tail(&sdev->starved_entry,
1596 &shost->starved_list);
1597 goto not_ready;
1598 }
1599
Mike Christief0c0a372008-08-17 15:24:38 -05001600 if (!scsi_target_queue_ready(shost, sdev))
1601 goto not_ready;
1602
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603 if (!scsi_host_queue_ready(q, shost, sdev))
1604 goto not_ready;
Mike Christief0c0a372008-08-17 15:24:38 -05001605
1606 scsi_target(sdev)->target_busy++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607 shost->host_busy++;
1608
1609 /*
1610 * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will
1611 * take the lock again.
1612 */
1613 spin_unlock_irq(shost->host_lock);
1614
Linus Torvalds1da177e2005-04-16 15:20:36 -07001615 /*
1616 * Finally, initialize any error handling parameters, and set up
1617 * the timers for timeouts.
1618 */
1619 scsi_init_cmd_errh(cmd);
1620
1621 /*
1622 * Dispatch the command to the low-level driver.
1623 */
1624 rtn = scsi_dispatch_cmd(cmd);
1625 spin_lock_irq(q->queue_lock);
Jens Axboea488e742010-04-16 21:13:15 +02001626 if (rtn)
1627 goto out_delay;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628 }
1629
Bart Van Assche613be1f2014-02-20 14:20:56 -08001630 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631
1632 not_ready:
1633 spin_unlock_irq(shost->host_lock);
1634
1635 /*
1636 * lock q, handle tag, requeue req, and decrement device_busy. We
1637 * must return with queue_lock held.
1638 *
1639 * Decrementing device_busy without checking it is OK, as all such
1640 * cases (host limits or settings) should run the queue at some
1641 * later time.
1642 */
1643 spin_lock_irq(q->queue_lock);
1644 blk_requeue_request(q, req);
1645 sdev->device_busy--;
Jens Axboea488e742010-04-16 21:13:15 +02001646out_delay:
1647 if (sdev->device_busy == 0)
1648 blk_delay_queue(q, SCSI_QUEUE_DELAY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649}
1650
1651u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)
1652{
1653 struct device *host_dev;
1654 u64 bounce_limit = 0xffffffff;
1655
1656 if (shost->unchecked_isa_dma)
1657 return BLK_BOUNCE_ISA;
1658 /*
1659 * Platforms with virtual-DMA translation
1660 * hardware have no practical limit.
1661 */
1662 if (!PCI_DMA_BUS_IS_PHYS)
1663 return BLK_BOUNCE_ANY;
1664
1665 host_dev = scsi_get_device(shost);
1666 if (host_dev && host_dev->dma_mask)
Russell Kinge83b3662014-02-11 17:11:04 +00001667 bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001668
1669 return bounce_limit;
1670}
1671EXPORT_SYMBOL(scsi_calculate_bounce_limit);
1672
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001673struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
1674 request_fn_proc *request_fn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 struct request_queue *q;
Lin Ming6f381fa2012-04-12 13:50:38 +08001677 struct device *dev = shost->dma_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001678
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001679 q = blk_init_queue(request_fn, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001680 if (!q)
1681 return NULL;
1682
Jens Axboea8474ce2007-08-07 09:02:51 +02001683 /*
1684 * this limit is imposed by hardware restrictions
1685 */
Martin K. Petersen8a783622010-02-26 00:20:39 -05001686 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize,
1687 SCSI_MAX_SG_CHAIN_SEGMENTS));
Jens Axboea8474ce2007-08-07 09:02:51 +02001688
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001689 if (scsi_host_prot_dma(shost)) {
1690 shost->sg_prot_tablesize =
1691 min_not_zero(shost->sg_prot_tablesize,
1692 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS);
1693 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize);
1694 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
1695 }
1696
Martin K. Petersen086fa5f2010-02-26 00:20:38 -05001697 blk_queue_max_hw_sectors(q, shost->max_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
1699 blk_queue_segment_boundary(q, shost->dma_boundary);
FUJITA Tomonori99c84db2008-02-04 22:28:17 -08001700 dma_set_seg_boundary(dev, shost->dma_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701
FUJITA Tomonori860ac562008-02-04 22:28:05 -08001702 blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
1703
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704 if (!shost->use_clustering)
Martin K. Petersene692cb62010-12-01 19:41:49 +01001705 q->limits.cluster = 0;
James Bottomley465ff312008-01-01 10:00:10 -06001706
1707 /*
1708 * set a reasonable default alignment on word boundaries: the
1709 * host and device may alter it using
1710 * blk_queue_update_dma_alignment() later.
1711 */
1712 blk_queue_dma_alignment(q, 0x03);
1713
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 return q;
1715}
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001716EXPORT_SYMBOL(__scsi_alloc_queue);
1717
1718struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
1719{
1720 struct request_queue *q;
1721
1722 q = __scsi_alloc_queue(sdev->host, scsi_request_fn);
1723 if (!q)
1724 return NULL;
1725
1726 blk_queue_prep_rq(q, scsi_prep_fn);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001727 blk_queue_softirq_done(q, scsi_softirq_done);
Jens Axboe242f9dc2008-09-14 05:55:09 -07001728 blk_queue_rq_timed_out(q, scsi_times_out);
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001729 blk_queue_lld_busy(q, scsi_lld_busy);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001730 return q;
1731}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733/*
1734 * Function: scsi_block_requests()
1735 *
1736 * Purpose: Utility function used by low-level drivers to prevent further
1737 * commands from being queued to the device.
1738 *
1739 * Arguments: shost - Host in question
1740 *
1741 * Returns: Nothing
1742 *
1743 * Lock status: No locks are assumed held.
1744 *
1745 * Notes: There is no timer nor any other means by which the requests
1746 * get unblocked other than the low-level driver calling
1747 * scsi_unblock_requests().
1748 */
1749void scsi_block_requests(struct Scsi_Host *shost)
1750{
1751 shost->host_self_blocked = 1;
1752}
1753EXPORT_SYMBOL(scsi_block_requests);
1754
1755/*
1756 * Function: scsi_unblock_requests()
1757 *
1758 * Purpose: Utility function used by low-level drivers to allow further
1759 * commands from being queued to the device.
1760 *
1761 * Arguments: shost - Host in question
1762 *
1763 * Returns: Nothing
1764 *
1765 * Lock status: No locks are assumed held.
1766 *
1767 * Notes: There is no timer nor any other means by which the requests
1768 * get unblocked other than the low-level driver calling
1769 * scsi_unblock_requests().
1770 *
1771 * This is done as an API function so that changes to the
1772 * internals of the scsi mid-layer won't require wholesale
1773 * changes to drivers that use this feature.
1774 */
1775void scsi_unblock_requests(struct Scsi_Host *shost)
1776{
1777 shost->host_self_blocked = 0;
1778 scsi_run_host_queues(shost);
1779}
1780EXPORT_SYMBOL(scsi_unblock_requests);
1781
1782int __init scsi_init_queue(void)
1783{
1784 int i;
1785
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001786 scsi_sdb_cache = kmem_cache_create("scsi_data_buffer",
1787 sizeof(struct scsi_data_buffer),
1788 0, 0, NULL);
1789 if (!scsi_sdb_cache) {
1790 printk(KERN_ERR "SCSI: can't init scsi sdb cache\n");
FUJITA Tomonorif0787272008-12-14 01:23:45 +09001791 return -ENOMEM;
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001792 }
1793
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794 for (i = 0; i < SG_MEMPOOL_NR; i++) {
1795 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
1796 int size = sgp->size * sizeof(struct scatterlist);
1797
1798 sgp->slab = kmem_cache_create(sgp->name, size, 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001799 SLAB_HWCACHE_ALIGN, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 if (!sgp->slab) {
1801 printk(KERN_ERR "SCSI: can't init sg slab %s\n",
1802 sgp->name);
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001803 goto cleanup_sdb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804 }
1805
Matthew Dobson93d23412006-03-26 01:37:50 -08001806 sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE,
1807 sgp->slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001808 if (!sgp->pool) {
1809 printk(KERN_ERR "SCSI: can't init sg mempool %s\n",
1810 sgp->name);
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001811 goto cleanup_sdb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 }
1813 }
1814
1815 return 0;
FUJITA Tomonori3d9dd6e2008-01-25 23:25:14 +09001816
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001817cleanup_sdb:
FUJITA Tomonori3d9dd6e2008-01-25 23:25:14 +09001818 for (i = 0; i < SG_MEMPOOL_NR; i++) {
1819 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
1820 if (sgp->pool)
1821 mempool_destroy(sgp->pool);
1822 if (sgp->slab)
1823 kmem_cache_destroy(sgp->slab);
1824 }
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001825 kmem_cache_destroy(scsi_sdb_cache);
FUJITA Tomonori3d9dd6e2008-01-25 23:25:14 +09001826
1827 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828}
1829
1830void scsi_exit_queue(void)
1831{
1832 int i;
1833
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001834 kmem_cache_destroy(scsi_sdb_cache);
Mike Christieaa7b5cd2005-11-11 05:31:41 -06001835
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836 for (i = 0; i < SG_MEMPOOL_NR; i++) {
1837 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
1838 mempool_destroy(sgp->pool);
1839 kmem_cache_destroy(sgp->slab);
1840 }
1841}
James Bottomley5baba832006-03-18 14:10:35 -06001842
1843/**
1844 * scsi_mode_select - issue a mode select
1845 * @sdev: SCSI device to be queried
1846 * @pf: Page format bit (1 == standard, 0 == vendor specific)
1847 * @sp: Save page bit (0 == don't save, 1 == save)
1848 * @modepage: mode page being requested
1849 * @buffer: request buffer (may not be smaller than eight bytes)
1850 * @len: length of request buffer.
1851 * @timeout: command timeout
1852 * @retries: number of retries before failing
1853 * @data: returns a structure abstracting the mode header data
Rob Landleyeb448202007-11-03 13:30:39 -05001854 * @sshdr: place to put sense data (or NULL if no sense to be collected).
James Bottomley5baba832006-03-18 14:10:35 -06001855 * must be SCSI_SENSE_BUFFERSIZE big.
1856 *
1857 * Returns zero if successful; negative error number or scsi
1858 * status on error
1859 *
1860 */
1861int
1862scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
1863 unsigned char *buffer, int len, int timeout, int retries,
1864 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
1865{
1866 unsigned char cmd[10];
1867 unsigned char *real_buffer;
1868 int ret;
1869
1870 memset(cmd, 0, sizeof(cmd));
1871 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
1872
1873 if (sdev->use_10_for_ms) {
1874 if (len > 65535)
1875 return -EINVAL;
1876 real_buffer = kmalloc(8 + len, GFP_KERNEL);
1877 if (!real_buffer)
1878 return -ENOMEM;
1879 memcpy(real_buffer + 8, buffer, len);
1880 len += 8;
1881 real_buffer[0] = 0;
1882 real_buffer[1] = 0;
1883 real_buffer[2] = data->medium_type;
1884 real_buffer[3] = data->device_specific;
1885 real_buffer[4] = data->longlba ? 0x01 : 0;
1886 real_buffer[5] = 0;
1887 real_buffer[6] = data->block_descriptor_length >> 8;
1888 real_buffer[7] = data->block_descriptor_length;
1889
1890 cmd[0] = MODE_SELECT_10;
1891 cmd[7] = len >> 8;
1892 cmd[8] = len;
1893 } else {
1894 if (len > 255 || data->block_descriptor_length > 255 ||
1895 data->longlba)
1896 return -EINVAL;
1897
1898 real_buffer = kmalloc(4 + len, GFP_KERNEL);
1899 if (!real_buffer)
1900 return -ENOMEM;
1901 memcpy(real_buffer + 4, buffer, len);
1902 len += 4;
1903 real_buffer[0] = 0;
1904 real_buffer[1] = data->medium_type;
1905 real_buffer[2] = data->device_specific;
1906 real_buffer[3] = data->block_descriptor_length;
1907
1908
1909 cmd[0] = MODE_SELECT;
1910 cmd[4] = len;
1911 }
1912
1913 ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09001914 sshdr, timeout, retries, NULL);
James Bottomley5baba832006-03-18 14:10:35 -06001915 kfree(real_buffer);
1916 return ret;
1917}
1918EXPORT_SYMBOL_GPL(scsi_mode_select);
1919
Linus Torvalds1da177e2005-04-16 15:20:36 -07001920/**
Rob Landleyeb448202007-11-03 13:30:39 -05001921 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
James Bottomley1cf72692005-08-28 11:27:01 -05001922 * @sdev: SCSI device to be queried
Linus Torvalds1da177e2005-04-16 15:20:36 -07001923 * @dbd: set if mode sense will allow block descriptors to be returned
1924 * @modepage: mode page being requested
1925 * @buffer: request buffer (may not be smaller than eight bytes)
1926 * @len: length of request buffer.
1927 * @timeout: command timeout
1928 * @retries: number of retries before failing
1929 * @data: returns a structure abstracting the mode header data
Rob Landleyeb448202007-11-03 13:30:39 -05001930 * @sshdr: place to put sense data (or NULL if no sense to be collected).
James Bottomley1cf72692005-08-28 11:27:01 -05001931 * must be SCSI_SENSE_BUFFERSIZE big.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001932 *
1933 * Returns zero if unsuccessful, or the header offset (either 4
1934 * or 8 depending on whether a six or ten byte command was
1935 * issued) if successful.
Rob Landleyeb448202007-11-03 13:30:39 -05001936 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001937int
James Bottomley1cf72692005-08-28 11:27:01 -05001938scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001939 unsigned char *buffer, int len, int timeout, int retries,
James Bottomley5baba832006-03-18 14:10:35 -06001940 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
1941{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001942 unsigned char cmd[12];
1943 int use_10_for_ms;
1944 int header_length;
James Bottomley1cf72692005-08-28 11:27:01 -05001945 int result;
James Bottomleyea73a9f2005-08-28 11:33:52 -05001946 struct scsi_sense_hdr my_sshdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001947
1948 memset(data, 0, sizeof(*data));
1949 memset(&cmd[0], 0, 12);
1950 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */
1951 cmd[2] = modepage;
1952
James Bottomleyea73a9f2005-08-28 11:33:52 -05001953 /* caller might not be interested in sense, but we need it */
1954 if (!sshdr)
1955 sshdr = &my_sshdr;
1956
Linus Torvalds1da177e2005-04-16 15:20:36 -07001957 retry:
James Bottomley1cf72692005-08-28 11:27:01 -05001958 use_10_for_ms = sdev->use_10_for_ms;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001959
1960 if (use_10_for_ms) {
1961 if (len < 8)
1962 len = 8;
1963
1964 cmd[0] = MODE_SENSE_10;
1965 cmd[8] = len;
1966 header_length = 8;
1967 } else {
1968 if (len < 4)
1969 len = 4;
1970
1971 cmd[0] = MODE_SENSE;
1972 cmd[4] = len;
1973 header_length = 4;
1974 }
1975
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976 memset(buffer, 0, len);
1977
James Bottomley1cf72692005-08-28 11:27:01 -05001978 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09001979 sshdr, timeout, retries, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001980
1981 /* This code looks awful: what it's doing is making sure an
1982 * ILLEGAL REQUEST sense return identifies the actual command
1983 * byte as the problem. MODE_SENSE commands can return
1984 * ILLEGAL REQUEST if the code page isn't supported */
1985
James Bottomley1cf72692005-08-28 11:27:01 -05001986 if (use_10_for_ms && !scsi_status_is_good(result) &&
1987 (driver_byte(result) & DRIVER_SENSE)) {
James Bottomleyea73a9f2005-08-28 11:33:52 -05001988 if (scsi_sense_valid(sshdr)) {
1989 if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
1990 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001991 /*
1992 * Invalid command operation code
1993 */
James Bottomley1cf72692005-08-28 11:27:01 -05001994 sdev->use_10_for_ms = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001995 goto retry;
1996 }
1997 }
1998 }
1999
James Bottomley1cf72692005-08-28 11:27:01 -05002000 if(scsi_status_is_good(result)) {
Al Viro6d73c852006-02-23 02:03:16 +01002001 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
2002 (modepage == 6 || modepage == 8))) {
2003 /* Initio breakage? */
2004 header_length = 0;
2005 data->length = 13;
2006 data->medium_type = 0;
2007 data->device_specific = 0;
2008 data->longlba = 0;
2009 data->block_descriptor_length = 0;
2010 } else if(use_10_for_ms) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002011 data->length = buffer[0]*256 + buffer[1] + 2;
2012 data->medium_type = buffer[2];
2013 data->device_specific = buffer[3];
2014 data->longlba = buffer[4] & 0x01;
2015 data->block_descriptor_length = buffer[6]*256
2016 + buffer[7];
2017 } else {
2018 data->length = buffer[0] + 1;
2019 data->medium_type = buffer[1];
2020 data->device_specific = buffer[2];
2021 data->block_descriptor_length = buffer[3];
2022 }
Al Viro6d73c852006-02-23 02:03:16 +01002023 data->header_length = header_length;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002024 }
2025
James Bottomley1cf72692005-08-28 11:27:01 -05002026 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002027}
2028EXPORT_SYMBOL(scsi_mode_sense);
2029
James Bottomley001aac22007-12-02 19:10:40 +02002030/**
2031 * scsi_test_unit_ready - test if unit is ready
2032 * @sdev: scsi device to change the state of.
2033 * @timeout: command timeout
2034 * @retries: number of retries before failing
2035 * @sshdr_external: Optional pointer to struct scsi_sense_hdr for
2036 * returning sense. Make sure that this is cleared before passing
2037 * in.
2038 *
2039 * Returns zero if unsuccessful or an error if TUR failed. For
Tejun Heo9f8a2c22010-12-08 20:57:40 +01002040 * removable media, UNIT_ATTENTION sets ->changed flag.
James Bottomley001aac22007-12-02 19:10:40 +02002041 **/
Linus Torvalds1da177e2005-04-16 15:20:36 -07002042int
James Bottomley001aac22007-12-02 19:10:40 +02002043scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
2044 struct scsi_sense_hdr *sshdr_external)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002045{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046 char cmd[] = {
2047 TEST_UNIT_READY, 0, 0, 0, 0, 0,
2048 };
James Bottomley001aac22007-12-02 19:10:40 +02002049 struct scsi_sense_hdr *sshdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002050 int result;
James Bottomley001aac22007-12-02 19:10:40 +02002051
2052 if (!sshdr_external)
2053 sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
2054 else
2055 sshdr = sshdr_external;
2056
2057 /* try to eat the UNIT_ATTENTION if there are enough retries */
2058 do {
2059 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09002060 timeout, retries, NULL);
James Bottomley32c356d2008-08-20 00:58:13 +02002061 if (sdev->removable && scsi_sense_valid(sshdr) &&
2062 sshdr->sense_key == UNIT_ATTENTION)
2063 sdev->changed = 1;
2064 } while (scsi_sense_valid(sshdr) &&
2065 sshdr->sense_key == UNIT_ATTENTION && --retries);
James Bottomley001aac22007-12-02 19:10:40 +02002066
James Bottomley001aac22007-12-02 19:10:40 +02002067 if (!sshdr_external)
2068 kfree(sshdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002069 return result;
2070}
2071EXPORT_SYMBOL(scsi_test_unit_ready);
2072
2073/**
Rob Landleyeb448202007-11-03 13:30:39 -05002074 * scsi_device_set_state - Take the given device through the device state model.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002075 * @sdev: scsi device to change the state of.
2076 * @state: state to change to.
2077 *
2078 * Returns zero if unsuccessful or an error if the requested
2079 * transition is illegal.
Rob Landleyeb448202007-11-03 13:30:39 -05002080 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002081int
2082scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
2083{
2084 enum scsi_device_state oldstate = sdev->sdev_state;
2085
2086 if (state == oldstate)
2087 return 0;
2088
2089 switch (state) {
2090 case SDEV_CREATED:
James Bottomley6f4267e2008-08-22 16:53:31 -05002091 switch (oldstate) {
2092 case SDEV_CREATED_BLOCK:
2093 break;
2094 default:
2095 goto illegal;
2096 }
2097 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002098
2099 case SDEV_RUNNING:
2100 switch (oldstate) {
2101 case SDEV_CREATED:
2102 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002103 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002104 case SDEV_QUIESCE:
2105 case SDEV_BLOCK:
2106 break;
2107 default:
2108 goto illegal;
2109 }
2110 break;
2111
2112 case SDEV_QUIESCE:
2113 switch (oldstate) {
2114 case SDEV_RUNNING:
2115 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002116 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002117 break;
2118 default:
2119 goto illegal;
2120 }
2121 break;
2122
2123 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002124 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002125 switch (oldstate) {
2126 case SDEV_CREATED:
2127 case SDEV_RUNNING:
2128 case SDEV_QUIESCE:
2129 case SDEV_BLOCK:
2130 break;
2131 default:
2132 goto illegal;
2133 }
2134 break;
2135
2136 case SDEV_BLOCK:
2137 switch (oldstate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002138 case SDEV_RUNNING:
James Bottomley6f4267e2008-08-22 16:53:31 -05002139 case SDEV_CREATED_BLOCK:
2140 break;
2141 default:
2142 goto illegal;
2143 }
2144 break;
2145
2146 case SDEV_CREATED_BLOCK:
2147 switch (oldstate) {
2148 case SDEV_CREATED:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002149 break;
2150 default:
2151 goto illegal;
2152 }
2153 break;
2154
2155 case SDEV_CANCEL:
2156 switch (oldstate) {
2157 case SDEV_CREATED:
2158 case SDEV_RUNNING:
Alan Stern9ea72902006-06-23 14:25:34 -04002159 case SDEV_QUIESCE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002160 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002161 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162 case SDEV_BLOCK:
2163 break;
2164 default:
2165 goto illegal;
2166 }
2167 break;
2168
2169 case SDEV_DEL:
2170 switch (oldstate) {
Brian King309bd272006-06-27 11:10:43 -05002171 case SDEV_CREATED:
2172 case SDEV_RUNNING:
2173 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002174 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002175 case SDEV_CANCEL:
Bart Van Assche0516c082013-07-02 15:06:33 +02002176 case SDEV_CREATED_BLOCK:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002177 break;
2178 default:
2179 goto illegal;
2180 }
2181 break;
2182
2183 }
2184 sdev->sdev_state = state;
2185 return 0;
2186
2187 illegal:
2188 SCSI_LOG_ERROR_RECOVERY(1,
James Bottomley9ccfc752005-10-02 11:45:08 -05002189 sdev_printk(KERN_ERR, sdev,
2190 "Illegal state transition %s->%s\n",
2191 scsi_device_state_name(oldstate),
2192 scsi_device_state_name(state))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002193 );
2194 return -EINVAL;
2195}
2196EXPORT_SYMBOL(scsi_device_set_state);
2197
2198/**
Jeff Garzika341cd02007-10-29 17:15:22 -04002199 * sdev_evt_emit - emit a single SCSI device uevent
2200 * @sdev: associated SCSI device
2201 * @evt: event to emit
2202 *
2203 * Send a single uevent (scsi_event) to the associated scsi_device.
2204 */
2205static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
2206{
2207 int idx = 0;
2208 char *envp[3];
2209
2210 switch (evt->evt_type) {
2211 case SDEV_EVT_MEDIA_CHANGE:
2212 envp[idx++] = "SDEV_MEDIA_CHANGE=1";
2213 break;
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002214 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2215 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
2216 break;
2217 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2218 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
2219 break;
2220 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2221 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED";
2222 break;
2223 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2224 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED";
2225 break;
2226 case SDEV_EVT_LUN_CHANGE_REPORTED:
2227 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
2228 break;
Jeff Garzika341cd02007-10-29 17:15:22 -04002229 default:
2230 /* do nothing */
2231 break;
2232 }
2233
2234 envp[idx++] = NULL;
2235
2236 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
2237}
2238
2239/**
2240 * sdev_evt_thread - send a uevent for each scsi event
2241 * @work: work struct for scsi_device
2242 *
2243 * Dispatch queued events to their associated scsi_device kobjects
2244 * as uevents.
2245 */
2246void scsi_evt_thread(struct work_struct *work)
2247{
2248 struct scsi_device *sdev;
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002249 enum scsi_device_event evt_type;
Jeff Garzika341cd02007-10-29 17:15:22 -04002250 LIST_HEAD(event_list);
2251
2252 sdev = container_of(work, struct scsi_device, event_work);
2253
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002254 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++)
2255 if (test_and_clear_bit(evt_type, sdev->pending_events))
2256 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL);
2257
Jeff Garzika341cd02007-10-29 17:15:22 -04002258 while (1) {
2259 struct scsi_event *evt;
2260 struct list_head *this, *tmp;
2261 unsigned long flags;
2262
2263 spin_lock_irqsave(&sdev->list_lock, flags);
2264 list_splice_init(&sdev->event_list, &event_list);
2265 spin_unlock_irqrestore(&sdev->list_lock, flags);
2266
2267 if (list_empty(&event_list))
2268 break;
2269
2270 list_for_each_safe(this, tmp, &event_list) {
2271 evt = list_entry(this, struct scsi_event, node);
2272 list_del(&evt->node);
2273 scsi_evt_emit(sdev, evt);
2274 kfree(evt);
2275 }
2276 }
2277}
2278
2279/**
2280 * sdev_evt_send - send asserted event to uevent thread
2281 * @sdev: scsi_device event occurred on
2282 * @evt: event to send
2283 *
2284 * Assert scsi device event asynchronously.
2285 */
2286void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
2287{
2288 unsigned long flags;
2289
Kay Sievers4d1566e2008-03-19 13:04:47 +01002290#if 0
2291 /* FIXME: currently this check eliminates all media change events
2292 * for polled devices. Need to update to discriminate between AN
2293 * and polled events */
Jeff Garzika341cd02007-10-29 17:15:22 -04002294 if (!test_bit(evt->evt_type, sdev->supported_events)) {
2295 kfree(evt);
2296 return;
2297 }
Kay Sievers4d1566e2008-03-19 13:04:47 +01002298#endif
Jeff Garzika341cd02007-10-29 17:15:22 -04002299
2300 spin_lock_irqsave(&sdev->list_lock, flags);
2301 list_add_tail(&evt->node, &sdev->event_list);
2302 schedule_work(&sdev->event_work);
2303 spin_unlock_irqrestore(&sdev->list_lock, flags);
2304}
2305EXPORT_SYMBOL_GPL(sdev_evt_send);
2306
2307/**
2308 * sdev_evt_alloc - allocate a new scsi event
2309 * @evt_type: type of event to allocate
2310 * @gfpflags: GFP flags for allocation
2311 *
2312 * Allocates and returns a new scsi_event.
2313 */
2314struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
2315 gfp_t gfpflags)
2316{
2317 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
2318 if (!evt)
2319 return NULL;
2320
2321 evt->evt_type = evt_type;
2322 INIT_LIST_HEAD(&evt->node);
2323
2324 /* evt_type-specific initialization, if any */
2325 switch (evt_type) {
2326 case SDEV_EVT_MEDIA_CHANGE:
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002327 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2328 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2329 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2330 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2331 case SDEV_EVT_LUN_CHANGE_REPORTED:
Jeff Garzika341cd02007-10-29 17:15:22 -04002332 default:
2333 /* do nothing */
2334 break;
2335 }
2336
2337 return evt;
2338}
2339EXPORT_SYMBOL_GPL(sdev_evt_alloc);
2340
2341/**
2342 * sdev_evt_send_simple - send asserted event to uevent thread
2343 * @sdev: scsi_device event occurred on
2344 * @evt_type: type of event to send
2345 * @gfpflags: GFP flags for allocation
2346 *
2347 * Assert scsi device event asynchronously, given an event type.
2348 */
2349void sdev_evt_send_simple(struct scsi_device *sdev,
2350 enum scsi_device_event evt_type, gfp_t gfpflags)
2351{
2352 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
2353 if (!evt) {
2354 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
2355 evt_type);
2356 return;
2357 }
2358
2359 sdev_evt_send(sdev, evt);
2360}
2361EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
2362
2363/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07002364 * scsi_device_quiesce - Block user issued commands.
2365 * @sdev: scsi device to quiesce.
2366 *
2367 * This works by trying to transition to the SDEV_QUIESCE state
2368 * (which must be a legal transition). When the device is in this
2369 * state, only special requests will be accepted, all others will
2370 * be deferred. Since special requests may also be requeued requests,
2371 * a successful return doesn't guarantee the device will be
2372 * totally quiescent.
2373 *
2374 * Must be called with user context, may sleep.
2375 *
2376 * Returns zero if unsuccessful or an error if not.
Rob Landleyeb448202007-11-03 13:30:39 -05002377 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002378int
2379scsi_device_quiesce(struct scsi_device *sdev)
2380{
2381 int err = scsi_device_set_state(sdev, SDEV_QUIESCE);
2382 if (err)
2383 return err;
2384
2385 scsi_run_queue(sdev->request_queue);
2386 while (sdev->device_busy) {
2387 msleep_interruptible(200);
2388 scsi_run_queue(sdev->request_queue);
2389 }
2390 return 0;
2391}
2392EXPORT_SYMBOL(scsi_device_quiesce);
2393
2394/**
2395 * scsi_device_resume - Restart user issued commands to a quiesced device.
2396 * @sdev: scsi device to resume.
2397 *
2398 * Moves the device from quiesced back to running and restarts the
2399 * queues.
2400 *
2401 * Must be called with user context, may sleep.
Rob Landleyeb448202007-11-03 13:30:39 -05002402 */
Dan Williamsa7a20d12012-03-22 17:05:11 -07002403void scsi_device_resume(struct scsi_device *sdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002404{
Dan Williamsa7a20d12012-03-22 17:05:11 -07002405 /* check if the device state was mutated prior to resume, and if
2406 * so assume the state is being managed elsewhere (for example
2407 * device deleted during suspend)
2408 */
2409 if (sdev->sdev_state != SDEV_QUIESCE ||
2410 scsi_device_set_state(sdev, SDEV_RUNNING))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002411 return;
2412 scsi_run_queue(sdev->request_queue);
2413}
2414EXPORT_SYMBOL(scsi_device_resume);
2415
2416static void
2417device_quiesce_fn(struct scsi_device *sdev, void *data)
2418{
2419 scsi_device_quiesce(sdev);
2420}
2421
2422void
2423scsi_target_quiesce(struct scsi_target *starget)
2424{
2425 starget_for_each_device(starget, NULL, device_quiesce_fn);
2426}
2427EXPORT_SYMBOL(scsi_target_quiesce);
2428
2429static void
2430device_resume_fn(struct scsi_device *sdev, void *data)
2431{
2432 scsi_device_resume(sdev);
2433}
2434
2435void
2436scsi_target_resume(struct scsi_target *starget)
2437{
2438 starget_for_each_device(starget, NULL, device_resume_fn);
2439}
2440EXPORT_SYMBOL(scsi_target_resume);
2441
2442/**
Rob Landleyeb448202007-11-03 13:30:39 -05002443 * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state
Linus Torvalds1da177e2005-04-16 15:20:36 -07002444 * @sdev: device to block
2445 *
2446 * Block request made by scsi lld's to temporarily stop all
2447 * scsi commands on the specified device. Called from interrupt
2448 * or normal process context.
2449 *
2450 * Returns zero if successful or error if not
2451 *
2452 * Notes:
2453 * This routine transitions the device to the SDEV_BLOCK state
2454 * (which must be a legal transition). When the device is in this
2455 * state, all commands are deferred until the scsi lld reenables
2456 * the device with scsi_device_unblock or device_block_tmo fires.
Rob Landleyeb448202007-11-03 13:30:39 -05002457 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002458int
2459scsi_internal_device_block(struct scsi_device *sdev)
2460{
Jens Axboe165125e2007-07-24 09:28:11 +02002461 struct request_queue *q = sdev->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002462 unsigned long flags;
2463 int err = 0;
2464
2465 err = scsi_device_set_state(sdev, SDEV_BLOCK);
James Bottomley6f4267e2008-08-22 16:53:31 -05002466 if (err) {
2467 err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
2468
2469 if (err)
2470 return err;
2471 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002472
2473 /*
2474 * The device has transitioned to SDEV_BLOCK. Stop the
2475 * block layer from calling the midlayer with this device's
2476 * request queue.
2477 */
2478 spin_lock_irqsave(q->queue_lock, flags);
2479 blk_stop_queue(q);
2480 spin_unlock_irqrestore(q->queue_lock, flags);
2481
2482 return 0;
2483}
2484EXPORT_SYMBOL_GPL(scsi_internal_device_block);
2485
2486/**
2487 * scsi_internal_device_unblock - resume a device after a block request
2488 * @sdev: device to resume
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002489 * @new_state: state to set devices to after unblocking
Linus Torvalds1da177e2005-04-16 15:20:36 -07002490 *
2491 * Called by scsi lld's or the midlayer to restart the device queue
2492 * for the previously suspended scsi device. Called from interrupt or
2493 * normal process context.
2494 *
2495 * Returns zero if successful or error if not.
2496 *
2497 * Notes:
2498 * This routine transitions the device to the SDEV_RUNNING state
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002499 * or to one of the offline states (which must be a legal transition)
Mike Christied0754982012-05-17 23:56:58 -05002500 * allowing the midlayer to goose the queue for this device.
Rob Landleyeb448202007-11-03 13:30:39 -05002501 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002502int
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002503scsi_internal_device_unblock(struct scsi_device *sdev,
2504 enum scsi_device_state new_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002505{
Jens Axboe165125e2007-07-24 09:28:11 +02002506 struct request_queue *q = sdev->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002507 unsigned long flags;
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002508
2509 /*
2510 * Try to transition the scsi device to SDEV_RUNNING or one of the
2511 * offlined states and goose the device queue if successful.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002512 */
Vikas Chaudhary0e580762012-08-09 04:51:30 -04002513 if ((sdev->sdev_state == SDEV_BLOCK) ||
2514 (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002515 sdev->sdev_state = new_state;
2516 else if (sdev->sdev_state == SDEV_CREATED_BLOCK) {
2517 if (new_state == SDEV_TRANSPORT_OFFLINE ||
2518 new_state == SDEV_OFFLINE)
2519 sdev->sdev_state = new_state;
2520 else
2521 sdev->sdev_state = SDEV_CREATED;
2522 } else if (sdev->sdev_state != SDEV_CANCEL &&
Mike Christie986fe6c2010-10-06 03:10:59 -05002523 sdev->sdev_state != SDEV_OFFLINE)
Takahiro Yasui5c10e632009-04-29 12:13:02 -04002524 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002525
2526 spin_lock_irqsave(q->queue_lock, flags);
2527 blk_start_queue(q);
2528 spin_unlock_irqrestore(q->queue_lock, flags);
2529
2530 return 0;
2531}
2532EXPORT_SYMBOL_GPL(scsi_internal_device_unblock);
2533
2534static void
2535device_block(struct scsi_device *sdev, void *data)
2536{
2537 scsi_internal_device_block(sdev);
2538}
2539
2540static int
2541target_block(struct device *dev, void *data)
2542{
2543 if (scsi_is_target_device(dev))
2544 starget_for_each_device(to_scsi_target(dev), NULL,
2545 device_block);
2546 return 0;
2547}
2548
2549void
2550scsi_target_block(struct device *dev)
2551{
2552 if (scsi_is_target_device(dev))
2553 starget_for_each_device(to_scsi_target(dev), NULL,
2554 device_block);
2555 else
2556 device_for_each_child(dev, NULL, target_block);
2557}
2558EXPORT_SYMBOL_GPL(scsi_target_block);
2559
2560static void
2561device_unblock(struct scsi_device *sdev, void *data)
2562{
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002563 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002564}
2565
2566static int
2567target_unblock(struct device *dev, void *data)
2568{
2569 if (scsi_is_target_device(dev))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002570 starget_for_each_device(to_scsi_target(dev), data,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002571 device_unblock);
2572 return 0;
2573}
2574
2575void
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002576scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002577{
2578 if (scsi_is_target_device(dev))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002579 starget_for_each_device(to_scsi_target(dev), &new_state,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002580 device_unblock);
2581 else
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002582 device_for_each_child(dev, &new_state, target_unblock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002583}
2584EXPORT_SYMBOL_GPL(scsi_target_unblock);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002585
2586/**
2587 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
Rob Landleyeb448202007-11-03 13:30:39 -05002588 * @sgl: scatter-gather list
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002589 * @sg_count: number of segments in sg
2590 * @offset: offset in bytes into sg, on return offset into the mapped area
2591 * @len: bytes to map, on return number of bytes mapped
2592 *
2593 * Returns virtual address of the start of the mapped page
2594 */
Jens Axboec6132da2007-10-16 11:08:49 +02002595void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002596 size_t *offset, size_t *len)
2597{
2598 int i;
2599 size_t sg_len = 0, len_complete = 0;
Jens Axboec6132da2007-10-16 11:08:49 +02002600 struct scatterlist *sg;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002601 struct page *page;
2602
Andrew Morton22cfefb2007-02-05 16:39:03 -08002603 WARN_ON(!irqs_disabled());
2604
Jens Axboec6132da2007-10-16 11:08:49 +02002605 for_each_sg(sgl, sg, sg_count, i) {
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002606 len_complete = sg_len; /* Complete sg-entries */
Jens Axboec6132da2007-10-16 11:08:49 +02002607 sg_len += sg->length;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002608 if (sg_len > *offset)
2609 break;
2610 }
2611
2612 if (unlikely(i == sg_count)) {
Andrew Morton169e1a22006-04-18 21:09:08 -07002613 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
2614 "elements %d\n",
Harvey Harrisoncadbd4a2008-07-03 23:47:27 -07002615 __func__, sg_len, *offset, sg_count);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002616 WARN_ON(1);
2617 return NULL;
2618 }
2619
2620 /* Offset starting from the beginning of first page in this sg-entry */
Jens Axboec6132da2007-10-16 11:08:49 +02002621 *offset = *offset - len_complete + sg->offset;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002622
2623 /* Assumption: contiguous pages can be accessed as "page + i" */
Jens Axboe45711f12007-10-22 21:19:53 +02002624 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002625 *offset &= ~PAGE_MASK;
2626
2627 /* Bytes in this sg-entry from *offset to the end of the page */
2628 sg_len = PAGE_SIZE - *offset;
2629 if (*len > sg_len)
2630 *len = sg_len;
2631
Cong Wang77dfce02011-11-25 23:14:23 +08002632 return kmap_atomic(page);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002633}
2634EXPORT_SYMBOL(scsi_kmap_atomic_sg);
2635
2636/**
Rob Landleyeb448202007-11-03 13:30:39 -05002637 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002638 * @virt: virtual address to be unmapped
2639 */
2640void scsi_kunmap_atomic_sg(void *virt)
2641{
Cong Wang77dfce02011-11-25 23:14:23 +08002642 kunmap_atomic(virt);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002643}
2644EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
Aaron Lu6f4c8272013-01-23 15:09:32 +08002645
2646void sdev_disable_disk_events(struct scsi_device *sdev)
2647{
2648 atomic_inc(&sdev->disk_events_disable_depth);
2649}
2650EXPORT_SYMBOL(sdev_disable_disk_events);
2651
2652void sdev_enable_disk_events(struct scsi_device *sdev)
2653{
2654 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0))
2655 return;
2656 atomic_dec(&sdev->disk_events_disable_depth);
2657}
2658EXPORT_SYMBOL(sdev_enable_disk_events);