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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
Holger Machtde50ada52012-06-25 16:13:02 +080071#ifdef CONFIG_ACPI
72#include <acpi/acpi_bus.h>
73
74int scsi_register_acpi_bus_type(struct acpi_bus_type *bus)
75{
76 bus->bus = &scsi_bus_type;
77 return register_acpi_bus_type(bus);
78}
79EXPORT_SYMBOL_GPL(scsi_register_acpi_bus_type);
80
81void scsi_unregister_acpi_bus_type(struct acpi_bus_type *bus)
82{
83 unregister_acpi_bus_type(bus);
84}
85EXPORT_SYMBOL_GPL(scsi_unregister_acpi_bus_type);
86#endif
87
Jens Axboea488e742010-04-16 21:13:15 +020088/*
89 * When to reinvoke queueing after a resource shortage. It's 3 msecs to
90 * not change behaviour from the previous unplug mechanism, experimentation
91 * may prove this needs changing.
92 */
93#define SCSI_QUEUE_DELAY 3
94
James Bottomleye91442b2005-09-09 10:44:16 -050095/*
96 * Function: scsi_unprep_request()
97 *
98 * Purpose: Remove all preparation done for a request, including its
99 * associated scsi_cmnd, so that it can be requeued.
100 *
101 * Arguments: req - request to unprepare
102 *
103 * Lock status: Assumed that no locks are held upon entry.
104 *
105 * Returns: Nothing.
106 */
107static void scsi_unprep_request(struct request *req)
108{
109 struct scsi_cmnd *cmd = req->special;
110
James Bottomley28018c22010-07-01 19:49:17 +0900111 blk_unprep_request(req);
Christoph Hellwigbeb40482006-06-10 18:01:03 +0200112 req->special = NULL;
James Bottomleye91442b2005-09-09 10:44:16 -0500113
James Bottomleye91442b2005-09-09 10:44:16 -0500114 scsi_put_command(cmd);
115}
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500116
James Bottomley4f5299a2009-01-02 10:42:21 -0600117/**
118 * __scsi_queue_insert - private queue insertion
119 * @cmd: The SCSI command being requeued
120 * @reason: The reason for the requeue
121 * @unbusy: Whether the queue should be unbusied
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 *
James Bottomley4f5299a2009-01-02 10:42:21 -0600123 * This is a private queue insertion. The public interface
124 * scsi_queue_insert() always assumes the queue should be unbusied
125 * because it's always called before the completion. This function is
126 * for a requeue after completion, which should only occur in this
127 * file.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 */
Bart Van Assche84feb162012-06-29 15:35:05 +0000129static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130{
131 struct Scsi_Host *host = cmd->device->host;
132 struct scsi_device *device = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -0500133 struct scsi_target *starget = scsi_target(device);
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500134 struct request_queue *q = device->request_queue;
135 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137 SCSI_LOG_MLQUEUE(1,
138 printk("Inserting command %p into mlqueue\n", cmd));
139
140 /*
Tejun Heo d8c37e72005-05-14 00:46:08 +0900141 * Set the appropriate busy bit for the device/host.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 *
143 * If the host/device isn't busy, assume that something actually
144 * completed, and that we should be able to queue a command now.
145 *
146 * Note that the prior mid-layer assumption that any host could
147 * always queue at least one command is now broken. The mid-layer
148 * will implement a user specifiable stall (see
149 * scsi_host.max_host_blocked and scsi_device.max_device_blocked)
150 * if a command is requeued with no other commands outstanding
151 * either for the device or for the host.
152 */
Mike Christief0c0a372008-08-17 15:24:38 -0500153 switch (reason) {
154 case SCSI_MLQUEUE_HOST_BUSY:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 host->host_blocked = host->max_host_blocked;
Mike Christief0c0a372008-08-17 15:24:38 -0500156 break;
157 case SCSI_MLQUEUE_DEVICE_BUSY:
James Smart573e5912011-07-06 12:45:17 -0400158 case SCSI_MLQUEUE_EH_RETRY:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 device->device_blocked = device->max_device_blocked;
Mike Christief0c0a372008-08-17 15:24:38 -0500160 break;
161 case SCSI_MLQUEUE_TARGET_BUSY:
162 starget->target_blocked = starget->max_target_blocked;
163 break;
164 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 * Decrement the counters, since these commands are no longer
168 * active on the host/device.
169 */
James Bottomley4f5299a2009-01-02 10:42:21 -0600170 if (unbusy)
171 scsi_device_unbusy(device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
173 /*
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500174 * Requeue this command. It will go before all other commands
Bart Van Asscheb4854622012-06-29 15:36:07 +0000175 * that are already in the queue. Schedule requeue work under
176 * lock such that the kblockd_schedule_work() call happens
177 * before blk_cleanup_queue() finishes.
Jens Axboea488e742010-04-16 21:13:15 +0200178 */
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500179 spin_lock_irqsave(q->queue_lock, flags);
James Bottomley59897da2005-09-14 12:57:42 -0400180 blk_requeue_request(q, cmd->request);
Jens Axboe9937a5e2011-05-17 11:04:44 +0200181 kblockd_schedule_work(q, &device->requeue_work);
Bart Van Asscheb4854622012-06-29 15:36:07 +0000182 spin_unlock_irqrestore(q->queue_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183}
184
James Bottomley4f5299a2009-01-02 10:42:21 -0600185/*
186 * Function: scsi_queue_insert()
187 *
188 * Purpose: Insert a command in the midlevel queue.
189 *
190 * Arguments: cmd - command that we are adding to queue.
191 * reason - why we are inserting command to queue.
192 *
193 * Lock status: Assumed that lock is not held upon entry.
194 *
195 * Returns: Nothing.
196 *
197 * Notes: We do this for one of two cases. Either the host is busy
198 * and it cannot accept any more commands for the time being,
199 * or the device returned QUEUE_FULL and can accept no more
200 * commands.
201 * Notes: This could be called either from an interrupt context or a
202 * normal process context.
203 */
Bart Van Assche84feb162012-06-29 15:35:05 +0000204void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
James Bottomley4f5299a2009-01-02 10:42:21 -0600205{
Bart Van Assche84feb162012-06-29 15:35:05 +0000206 __scsi_queue_insert(cmd, reason, 1);
James Bottomley4f5299a2009-01-02 10:42:21 -0600207}
James Bottomley39216032005-06-15 18:48:29 -0500208/**
James Bottomley33aa6872005-08-28 11:31:14 -0500209 * scsi_execute - insert request and wait for the result
James Bottomley39216032005-06-15 18:48:29 -0500210 * @sdev: scsi device
211 * @cmd: scsi command
212 * @data_direction: data direction
213 * @buffer: data buffer
214 * @bufflen: len of buffer
215 * @sense: optional sense buffer
216 * @timeout: request timeout in seconds
217 * @retries: number of times to retry request
James Bottomley33aa6872005-08-28 11:31:14 -0500218 * @flags: or into request flags;
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900219 * @resid: optional residual length
James Bottomley39216032005-06-15 18:48:29 -0500220 *
Michael Opdenacker59c51592007-05-09 08:57:56 +0200221 * returns the req->errors value which is the scsi_cmnd result
James Bottomleyea73a9f2005-08-28 11:33:52 -0500222 * field.
Rob Landleyeb44820c2007-11-03 13:30:39 -0500223 */
James Bottomley33aa6872005-08-28 11:31:14 -0500224int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
225 int data_direction, void *buffer, unsigned bufflen,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900226 unsigned char *sense, int timeout, int retries, int flags,
227 int *resid)
James Bottomley39216032005-06-15 18:48:29 -0500228{
229 struct request *req;
230 int write = (data_direction == DMA_TO_DEVICE);
231 int ret = DRIVER_ERROR << 24;
232
233 req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);
James Bottomleybfe159a2011-07-07 15:45:40 -0500234 if (!req)
235 return ret;
James Bottomley39216032005-06-15 18:48:29 -0500236
237 if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
238 buffer, bufflen, __GFP_WAIT))
239 goto out;
240
241 req->cmd_len = COMMAND_SIZE(cmd[0]);
242 memcpy(req->cmd, cmd, req->cmd_len);
243 req->sense = sense;
244 req->sense_len = 0;
Mike Christie17e01f22005-11-11 05:31:37 -0600245 req->retries = retries;
James Bottomley39216032005-06-15 18:48:29 -0500246 req->timeout = timeout;
Jens Axboe4aff5e22006-08-10 08:44:47 +0200247 req->cmd_type = REQ_TYPE_BLOCK_PC;
248 req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT;
James Bottomley39216032005-06-15 18:48:29 -0500249
250 /*
251 * head injection *required* here otherwise quiesce won't work
252 */
253 blk_execute_rq(req->q, NULL, req, 1);
254
Alan Sternbdb2b8c2008-06-24 14:03:14 -0400255 /*
256 * Some devices (USB mass-storage in particular) may transfer
257 * garbage data together with a residue indicating that the data
258 * is invalid. Prevent the garbage from being misinterpreted
259 * and prevent security leaks by zeroing out the excess data.
260 */
Tejun Heoc3a4d782009-05-07 22:24:37 +0900261 if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen))
262 memset(buffer + (bufflen - req->resid_len), 0, req->resid_len);
Alan Sternbdb2b8c2008-06-24 14:03:14 -0400263
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900264 if (resid)
Tejun Heoc3a4d782009-05-07 22:24:37 +0900265 *resid = req->resid_len;
James Bottomley39216032005-06-15 18:48:29 -0500266 ret = req->errors;
267 out:
268 blk_put_request(req);
269
270 return ret;
271}
James Bottomley33aa6872005-08-28 11:31:14 -0500272EXPORT_SYMBOL(scsi_execute);
James Bottomley39216032005-06-15 18:48:29 -0500273
James Bottomleyea73a9f2005-08-28 11:33:52 -0500274
275int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
276 int data_direction, void *buffer, unsigned bufflen,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900277 struct scsi_sense_hdr *sshdr, int timeout, int retries,
278 int *resid)
James Bottomleyea73a9f2005-08-28 11:33:52 -0500279{
280 char *sense = NULL;
akpm@osdl.org1ccb48b2005-06-26 00:12:51 -0700281 int result;
282
James Bottomleyea73a9f2005-08-28 11:33:52 -0500283 if (sshdr) {
Jes Sorensen24669f752006-01-16 10:31:18 -0500284 sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500285 if (!sense)
286 return DRIVER_ERROR << 24;
James Bottomleyea73a9f2005-08-28 11:33:52 -0500287 }
akpm@osdl.org1ccb48b2005-06-26 00:12:51 -0700288 result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900289 sense, timeout, retries, 0, resid);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500290 if (sshdr)
James Bottomleye5143852005-08-09 11:55:36 -0500291 scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500292
293 kfree(sense);
294 return result;
295}
296EXPORT_SYMBOL(scsi_execute_req);
297
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298/*
299 * Function: scsi_init_cmd_errh()
300 *
301 * Purpose: Initialize cmd fields related to error handling.
302 *
303 * Arguments: cmd - command that is ready to be queued.
304 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 * Notes: This function has the job of initializing a number of
306 * fields related to error handling. Typically this will
307 * be called once for each command, as required.
308 */
Christoph Hellwig631c2282006-07-08 20:42:15 +0200309static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 cmd->serial_number = 0;
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200312 scsi_set_resid(cmd, 0);
FUJITA Tomonorib80ca4f2008-01-13 15:46:13 +0900313 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 if (cmd->cmd_len == 0)
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300315 cmd->cmd_len = scsi_command_size(cmd->cmnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316}
317
318void scsi_device_unbusy(struct scsi_device *sdev)
319{
320 struct Scsi_Host *shost = sdev->host;
Mike Christief0c0a372008-08-17 15:24:38 -0500321 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 unsigned long flags;
323
324 spin_lock_irqsave(shost->host_lock, flags);
325 shost->host_busy--;
Mike Christief0c0a372008-08-17 15:24:38 -0500326 starget->target_busy--;
James Bottomley939647e2005-09-18 15:05:20 -0500327 if (unlikely(scsi_host_in_recovery(shost) &&
Tejun Heoee7863b2006-05-15 20:57:20 +0900328 (shost->host_failed || shost->host_eh_scheduled)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 scsi_eh_wakeup(shost);
330 spin_unlock(shost->host_lock);
152587d2005-04-12 16:22:06 -0500331 spin_lock(sdev->request_queue->queue_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 sdev->device_busy--;
152587d2005-04-12 16:22:06 -0500333 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334}
335
336/*
337 * Called for single_lun devices on IO completion. Clear starget_sdev_user,
338 * and call blk_run_queue for all the scsi_devices on the target -
339 * including current_sdev first.
340 *
341 * Called with *no* scsi locks held.
342 */
343static void scsi_single_lun_run(struct scsi_device *current_sdev)
344{
345 struct Scsi_Host *shost = current_sdev->host;
346 struct scsi_device *sdev, *tmp;
347 struct scsi_target *starget = scsi_target(current_sdev);
348 unsigned long flags;
349
350 spin_lock_irqsave(shost->host_lock, flags);
351 starget->starget_sdev_user = NULL;
352 spin_unlock_irqrestore(shost->host_lock, flags);
353
354 /*
355 * Call blk_run_queue for all LUNs on the target, starting with
356 * current_sdev. We race with others (to set starget_sdev_user),
357 * but in most cases, we will be first. Ideally, each LU on the
358 * target would get some limited time or requests on the target.
359 */
360 blk_run_queue(current_sdev->request_queue);
361
362 spin_lock_irqsave(shost->host_lock, flags);
363 if (starget->starget_sdev_user)
364 goto out;
365 list_for_each_entry_safe(sdev, tmp, &starget->devices,
366 same_target_siblings) {
367 if (sdev == current_sdev)
368 continue;
369 if (scsi_device_get(sdev))
370 continue;
371
372 spin_unlock_irqrestore(shost->host_lock, flags);
373 blk_run_queue(sdev->request_queue);
374 spin_lock_irqsave(shost->host_lock, flags);
375
376 scsi_device_put(sdev);
377 }
378 out:
379 spin_unlock_irqrestore(shost->host_lock, flags);
380}
381
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400382static inline int scsi_device_is_busy(struct scsi_device *sdev)
383{
384 if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked)
385 return 1;
386
387 return 0;
388}
389
Mike Christief0c0a372008-08-17 15:24:38 -0500390static inline int scsi_target_is_busy(struct scsi_target *starget)
391{
392 return ((starget->can_queue > 0 &&
393 starget->target_busy >= starget->can_queue) ||
394 starget->target_blocked);
395}
396
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400397static inline int scsi_host_is_busy(struct Scsi_Host *shost)
398{
399 if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) ||
400 shost->host_blocked || shost->host_self_blocked)
401 return 1;
402
403 return 0;
404}
405
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406/*
407 * Function: scsi_run_queue()
408 *
409 * Purpose: Select a proper request queue to serve next
410 *
411 * Arguments: q - last request's queue
412 *
413 * Returns: Nothing
414 *
415 * Notes: The previous command was completely finished, start
416 * a new one if possible.
417 */
418static void scsi_run_queue(struct request_queue *q)
419{
Mike Christie2a3a59e2008-11-11 13:42:35 -0600420 struct scsi_device *sdev = q->queuedata;
James Bottomleyc055f5b2011-05-01 09:42:07 -0500421 struct Scsi_Host *shost;
Mike Christie2a3a59e2008-11-11 13:42:35 -0600422 LIST_HEAD(starved_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 unsigned long flags;
424
James Bottomleyc055f5b2011-05-01 09:42:07 -0500425 shost = sdev->host;
Tony Battersby25d7c362007-11-12 10:00:44 -0500426 if (scsi_target(sdev)->single_lun)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 scsi_single_lun_run(sdev);
428
429 spin_lock_irqsave(shost->host_lock, flags);
Mike Christie2a3a59e2008-11-11 13:42:35 -0600430 list_splice_init(&shost->starved_list, &starved_list);
431
432 while (!list_empty(&starved_list)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 /*
434 * As long as shost is accepting commands and we have
435 * starved queues, call blk_run_queue. scsi_request_fn
436 * drops the queue_lock and can add us back to the
437 * starved_list.
438 *
439 * host_lock protects the starved_list and starved_entry.
440 * scsi_request_fn must get the host_lock before checking
441 * or modifying starved_list or starved_entry.
442 */
Mike Christie2a3a59e2008-11-11 13:42:35 -0600443 if (scsi_host_is_busy(shost))
Mike Christief0c0a372008-08-17 15:24:38 -0500444 break;
Mike Christief0c0a372008-08-17 15:24:38 -0500445
Mike Christie2a3a59e2008-11-11 13:42:35 -0600446 sdev = list_entry(starved_list.next,
447 struct scsi_device, starved_entry);
448 list_del_init(&sdev->starved_entry);
Mike Christief0c0a372008-08-17 15:24:38 -0500449 if (scsi_target_is_busy(scsi_target(sdev))) {
450 list_move_tail(&sdev->starved_entry,
451 &shost->starved_list);
452 continue;
453 }
454
Jens Axboe9937a5e2011-05-17 11:04:44 +0200455 spin_unlock(shost->host_lock);
456 spin_lock(sdev->request_queue->queue_lock);
457 __blk_run_queue(sdev->request_queue);
458 spin_unlock(sdev->request_queue->queue_lock);
459 spin_lock(shost->host_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 }
Mike Christie2a3a59e2008-11-11 13:42:35 -0600461 /* put any unprocessed entries back */
462 list_splice(&starved_list, &shost->starved_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 spin_unlock_irqrestore(shost->host_lock, flags);
464
465 blk_run_queue(q);
466}
467
Jens Axboe9937a5e2011-05-17 11:04:44 +0200468void scsi_requeue_run_queue(struct work_struct *work)
469{
470 struct scsi_device *sdev;
471 struct request_queue *q;
472
473 sdev = container_of(work, struct scsi_device, requeue_work);
474 q = sdev->request_queue;
475 scsi_run_queue(q);
476}
477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478/*
479 * Function: scsi_requeue_command()
480 *
481 * Purpose: Handle post-processing of completed commands.
482 *
483 * Arguments: q - queue to operate on
484 * cmd - command that may need to be requeued.
485 *
486 * Returns: Nothing
487 *
488 * Notes: After command completion, there may be blocks left
489 * over which weren't finished by the previous command
490 * this can be for a number of reasons - the main one is
491 * I/O errors in the middle of the request, in which case
492 * we need to request the blocks that come after the bad
493 * sector.
James Bottomleye91442b2005-09-09 10:44:16 -0500494 * Notes: Upon return, cmd is a stale pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 */
496static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
497{
Bart Van Assche940f5d42012-06-29 15:34:26 +0000498 struct scsi_device *sdev = cmd->device;
James Bottomleye91442b2005-09-09 10:44:16 -0500499 struct request *req = cmd->request;
Tejun Heo 283369c2005-04-24 02:06:36 -0500500 unsigned long flags;
501
Bart Van Assche940f5d42012-06-29 15:34:26 +0000502 /*
503 * We need to hold a reference on the device to avoid the queue being
504 * killed after the unlock and before scsi_run_queue is invoked which
505 * may happen because scsi_unprep_request() puts the command which
506 * releases its reference on the device.
507 */
508 get_device(&sdev->sdev_gendev);
509
Tejun Heo 283369c2005-04-24 02:06:36 -0500510 spin_lock_irqsave(q->queue_lock, flags);
James Bottomley02bd3492008-12-12 13:28:29 -0600511 scsi_unprep_request(req);
James Bottomleye91442b2005-09-09 10:44:16 -0500512 blk_requeue_request(q, req);
Tejun Heo 283369c2005-04-24 02:06:36 -0500513 spin_unlock_irqrestore(q->queue_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
515 scsi_run_queue(q);
Bart Van Assche940f5d42012-06-29 15:34:26 +0000516
517 put_device(&sdev->sdev_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518}
519
520void scsi_next_command(struct scsi_cmnd *cmd)
521{
Linus Torvalds49d7bc62005-12-12 11:25:04 -0800522 struct scsi_device *sdev = cmd->device;
523 struct request_queue *q = sdev->request_queue;
524
525 /* need to hold a reference on the device before we let go of the cmd */
526 get_device(&sdev->sdev_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
528 scsi_put_command(cmd);
529 scsi_run_queue(q);
Linus Torvalds49d7bc62005-12-12 11:25:04 -0800530
531 /* ok to remove device now */
532 put_device(&sdev->sdev_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533}
534
535void scsi_run_host_queues(struct Scsi_Host *shost)
536{
537 struct scsi_device *sdev;
538
539 shost_for_each_device(sdev, shost)
540 scsi_run_queue(sdev->request_queue);
541}
542
James Bottomley79ed2422009-01-06 13:15:20 -0600543static void __scsi_release_buffers(struct scsi_cmnd *, int);
544
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545/*
546 * Function: scsi_end_request()
547 *
548 * Purpose: Post-processing of completed commands (usually invoked at end
549 * of upper level post-processing and scsi_io_completion).
550 *
551 * Arguments: cmd - command that is complete.
Kiyoshi Ueda610d8b02007-12-11 17:52:09 -0500552 * error - 0 if I/O indicates success, < 0 for I/O error.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 * bytes - number of bytes of completed I/O
554 * requeue - indicates whether we should requeue leftovers.
555 *
556 * Lock status: Assumed that lock is not held upon entry.
557 *
James Bottomleye91442b2005-09-09 10:44:16 -0500558 * Returns: cmd if requeue required, NULL otherwise.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 *
560 * Notes: This is called for block device requests in order to
561 * mark some number of sectors as complete.
562 *
563 * We are guaranteeing that the request queue will be goosed
564 * at some point during this call.
James Bottomleye91442b2005-09-09 10:44:16 -0500565 * Notes: If cmd was requeued, upon return it will be a stale pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 */
Kiyoshi Ueda610d8b02007-12-11 17:52:09 -0500567static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 int bytes, int requeue)
569{
Jens Axboe165125e2007-07-24 09:28:11 +0200570 struct request_queue *q = cmd->device->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 struct request *req = cmd->request;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572
573 /*
574 * If there are blocks left over at the end, set up the command
575 * to queue the remainder of them.
576 */
Kiyoshi Ueda610d8b02007-12-11 17:52:09 -0500577 if (blk_end_request(req, error, bytes)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 /* kill remainder if no retrys */
Mike Christie4a274462008-08-19 18:45:31 -0500579 if (error && scsi_noretry_cmd(cmd))
Tejun Heoe4588242009-05-12 08:49:32 +0200580 blk_end_request_all(req, error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 else {
James Bottomleye91442b2005-09-09 10:44:16 -0500582 if (requeue) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 /*
584 * Bleah. Leftovers again. Stick the
585 * leftovers in the front of the
586 * queue, and goose the queue again.
587 */
James Bottomley79ed2422009-01-06 13:15:20 -0600588 scsi_release_buffers(cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 scsi_requeue_command(q, cmd);
James Bottomleye91442b2005-09-09 10:44:16 -0500590 cmd = NULL;
591 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 return cmd;
593 }
594 }
595
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 /*
597 * This will goose the queue request function at the end, so we don't
598 * need to worry about launching another command.
599 */
James Bottomley79ed2422009-01-06 13:15:20 -0600600 __scsi_release_buffers(cmd, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 scsi_next_command(cmd);
602 return NULL;
603}
604
Jens Axboea8474ce2007-08-07 09:02:51 +0200605static inline unsigned int scsi_sgtable_index(unsigned short nents)
606{
607 unsigned int index;
608
James Bottomleyd3f46f32008-01-15 11:11:46 -0600609 BUG_ON(nents > SCSI_MAX_SG_SEGMENTS);
610
611 if (nents <= 8)
Jens Axboea8474ce2007-08-07 09:02:51 +0200612 index = 0;
James Bottomleyd3f46f32008-01-15 11:11:46 -0600613 else
614 index = get_count_order(nents) - 3;
Jens Axboea8474ce2007-08-07 09:02:51 +0200615
616 return index;
617}
618
Jens Axboe5ed79592007-11-15 09:13:11 +0100619static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620{
621 struct scsi_host_sg_pool *sgp;
Jens Axboe5ed79592007-11-15 09:13:11 +0100622
623 sgp = scsi_sg_pools + scsi_sgtable_index(nents);
624 mempool_free(sgl, sgp->pool);
625}
626
627static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
628{
629 struct scsi_host_sg_pool *sgp;
630
631 sgp = scsi_sg_pools + scsi_sgtable_index(nents);
632 return mempool_alloc(sgp->pool, gfp_mask);
633}
634
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200635static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents,
636 gfp_t gfp_mask)
Jens Axboe5ed79592007-11-15 09:13:11 +0100637{
638 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200640 BUG_ON(!nents);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200642 ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS,
643 gfp_mask, scsi_sg_alloc);
Jens Axboe5ed79592007-11-15 09:13:11 +0100644 if (unlikely(ret))
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200645 __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS,
James Bottomley7cedb1f2008-01-13 14:15:28 -0600646 scsi_sg_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
Jens Axboea8474ce2007-08-07 09:02:51 +0200648 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649}
650
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200651static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652{
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200653 __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654}
655
James Bottomley79ed2422009-01-06 13:15:20 -0600656static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check)
657{
658
659 if (cmd->sdb.table.nents)
660 scsi_free_sgtable(&cmd->sdb);
661
662 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
663
664 if (do_bidi_check && scsi_bidi_cmnd(cmd)) {
665 struct scsi_data_buffer *bidi_sdb =
666 cmd->request->next_rq->special;
667 scsi_free_sgtable(bidi_sdb);
668 kmem_cache_free(scsi_sdb_cache, bidi_sdb);
669 cmd->request->next_rq->special = NULL;
670 }
671
672 if (scsi_prot_sg_count(cmd))
673 scsi_free_sgtable(cmd->prot_sdb);
674}
675
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676/*
677 * Function: scsi_release_buffers()
678 *
679 * Purpose: Completion processing for block device I/O requests.
680 *
681 * Arguments: cmd - command that we are bailing.
682 *
683 * Lock status: Assumed that no lock is held upon entry.
684 *
685 * Returns: Nothing
686 *
687 * Notes: In the event that an upper level driver rejects a
688 * command, we must release resources allocated during
689 * the __init_io() function. Primarily this would involve
690 * the scatter-gather table, and potentially any bounce
691 * buffers.
692 */
Boaz Harroshbb52d822007-12-13 16:14:27 -0800693void scsi_release_buffers(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694{
James Bottomley79ed2422009-01-06 13:15:20 -0600695 __scsi_release_buffers(cmd, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696}
Boaz Harroshbb52d822007-12-13 16:14:27 -0800697EXPORT_SYMBOL(scsi_release_buffers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100699static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
700{
701 int error = 0;
702
703 switch(host_byte(result)) {
704 case DID_TRANSPORT_FAILFAST:
705 error = -ENOLINK;
706 break;
707 case DID_TARGET_FAILURE:
Moger, Babu2082ebc2012-01-24 20:38:46 +0000708 set_host_byte(cmd, DID_OK);
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100709 error = -EREMOTEIO;
710 break;
711 case DID_NEXUS_FAILURE:
Moger, Babu2082ebc2012-01-24 20:38:46 +0000712 set_host_byte(cmd, DID_OK);
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100713 error = -EBADE;
714 break;
715 default:
716 error = -EIO;
717 break;
718 }
719
720 return error;
721}
722
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723/*
724 * Function: scsi_io_completion()
725 *
726 * Purpose: Completion processing for block device I/O requests.
727 *
728 * Arguments: cmd - command that is finished.
729 *
730 * Lock status: Assumed that no lock is held upon entry.
731 *
732 * Returns: Nothing
733 *
734 * Notes: This function is matched in terms of capabilities to
735 * the function that created the scatter-gather list.
736 * In other words, if there are no bounce buffers
737 * (the normal case for most drivers), we don't need
738 * the logic to deal with cleaning up afterwards.
739 *
Alan Sternb60af5b2008-11-03 15:56:47 -0500740 * We must call scsi_end_request(). This will finish off
741 * the specified number of sectors. If we are done, the
742 * command block will be released and the queue function
743 * will be goosed. If we are not done then we have to
744 * figure out what to do next:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 *
Alan Sternb60af5b2008-11-03 15:56:47 -0500746 * a) We can call scsi_requeue_command(). The request
747 * will be unprepared and put back on the queue. Then
748 * a new command will be created for it. This should
749 * be used if we made forward progress, or if we want
750 * to switch from READ(10) to READ(6) for example.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 *
Alan Sternb60af5b2008-11-03 15:56:47 -0500752 * b) We can call scsi_queue_insert(). The request will
753 * be put back on the queue and retried using the same
754 * command as before, possibly after a delay.
755 *
756 * c) We can call blk_end_request() with -EIO to fail
757 * the remainder of the request.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 */
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700759void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760{
761 int result = cmd->result;
Jens Axboe165125e2007-07-24 09:28:11 +0200762 struct request_queue *q = cmd->device->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 struct request *req = cmd->request;
James Bottomleyfa8e36c2008-04-02 18:11:52 -0500764 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 struct scsi_sense_hdr sshdr;
766 int sense_valid = 0;
767 int sense_deferred = 0;
Alan Sternb60af5b2008-11-03 15:56:47 -0500768 enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
769 ACTION_DELAYED_RETRY} action;
770 char *description = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 if (result) {
773 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
774 if (sense_valid)
775 sense_deferred = scsi_sense_is_deferred(&sshdr);
776 }
Christoph Hellwig631c2282006-07-08 20:42:15 +0200777
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200778 if (req->cmd_type == REQ_TYPE_BLOCK_PC) { /* SG_IO ioctl from block level */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 if (result) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 if (sense_valid && req->sense) {
781 /*
782 * SG_IO wants current and deferred errors
783 */
784 int len = 8 + cmd->sense_buffer[7];
785
786 if (len > SCSI_SENSE_BUFFERSIZE)
787 len = SCSI_SENSE_BUFFERSIZE;
788 memcpy(req->sense, cmd->sense_buffer, len);
789 req->sense_len = len;
790 }
James Bottomleyfa8e36c2008-04-02 18:11:52 -0500791 if (!sense_deferred)
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100792 error = __scsi_error_from_host_byte(cmd, result);
Pete Wyckoffb22f6872007-03-13 16:53:28 -0400793 }
Mike Snitzer27c41972012-05-31 15:05:33 -0400794 /*
795 * __scsi_error_from_host_byte may have reset the host_byte
796 */
797 req->errors = cmd->result;
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900798
799 req->resid_len = scsi_get_resid(cmd);
800
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200801 if (scsi_bidi_cmnd(cmd)) {
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900802 /*
803 * Bidi commands Must be complete as a whole,
804 * both sides at once.
805 */
806 req->next_rq->resid_len = scsi_in(cmd)->resid;
807
Boaz Harrosh63c43b02009-12-15 17:25:43 +0200808 scsi_release_buffers(cmd);
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900809 blk_end_request_all(req, 0);
810
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900811 scsi_next_command(cmd);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200812 return;
813 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 }
815
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200816 /* no bidi support for !REQ_TYPE_BLOCK_PC yet */
817 BUG_ON(blk_bidi_rq(req));
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200818
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 * Next deal with any sectors which we were able to correctly
821 * handle.
822 */
Tejun Heo83096eb2009-05-07 22:24:39 +0900823 SCSI_LOG_HLCOMPLETE(1, printk("%u sectors total, "
James Bottomleyd6b0c532006-07-02 10:06:28 -0500824 "%d bytes done.\n",
Tejun Heo83096eb2009-05-07 22:24:39 +0900825 blk_rq_sectors(req), good_bytes));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826
James Bottomleya9bddd72009-03-30 16:55:51 +0000827 /*
828 * Recovered errors need reporting, but they're always treated
829 * as success, so fiddle the result code here. For BLOCK_PC
830 * we already took a copy of the original into rq->errors which
831 * is what gets returned to the user
832 */
Douglas Gilberte7efe592010-01-03 13:51:15 -0500833 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
834 /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip
835 * print since caller wants ATA registers. Only occurs on
836 * SCSI ATA PASS_THROUGH commands when CK_COND=1
837 */
838 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
839 ;
840 else if (!(req->cmd_flags & REQ_QUIET))
James Bottomleya9bddd72009-03-30 16:55:51 +0000841 scsi_print_sense("", cmd);
842 result = 0;
843 /* BLOCK_PC may have set error */
844 error = 0;
845 }
846
847 /*
848 * A number of bytes were successfully read. If there
James Bottomleyd6b0c532006-07-02 10:06:28 -0500849 * are leftovers and there is some kind of error
850 * (result != 0), retry the rest.
851 */
James Bottomleyfa8e36c2008-04-02 18:11:52 -0500852 if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL)
James Bottomleyd6b0c532006-07-02 10:06:28 -0500853 return;
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700854
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100855 error = __scsi_error_from_host_byte(cmd, result);
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500856
Alan Sternb60af5b2008-11-03 15:56:47 -0500857 if (host_byte(result) == DID_RESET) {
858 /* Third party bus reset or reset for error recovery
859 * reasons. Just retry the command and see what
860 * happens.
861 */
862 action = ACTION_RETRY;
863 } else if (sense_valid && !sense_deferred) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 switch (sshdr.sense_key) {
865 case UNIT_ATTENTION:
866 if (cmd->device->removable) {
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700867 /* Detected disc change. Set a bit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 * and quietly refuse further access.
869 */
870 cmd->device->changed = 1;
Alan Sternb60af5b2008-11-03 15:56:47 -0500871 description = "Media Changed";
872 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 } else {
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700874 /* Must have been a power glitch, or a
875 * bus reset. Could not have been a
876 * media change, so we just retry the
Alan Sternb60af5b2008-11-03 15:56:47 -0500877 * command and see what happens.
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700878 */
Alan Sternb60af5b2008-11-03 15:56:47 -0500879 action = ACTION_RETRY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 }
881 break;
882 case ILLEGAL_REQUEST:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700883 /* If we had an ILLEGAL REQUEST returned, then
884 * we may have performed an unsupported
885 * command. The only thing this should be
886 * would be a ten byte read where only a six
887 * byte read was supported. Also, on a system
888 * where READ CAPACITY failed, we may have
889 * read past the end of the disk.
890 */
Jens Axboe26a68012005-11-29 21:03:34 +0100891 if ((cmd->device->use_10_for_rw &&
892 sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 (cmd->cmnd[0] == READ_10 ||
894 cmd->cmnd[0] == WRITE_10)) {
Alan Sternb60af5b2008-11-03 15:56:47 -0500895 /* This will issue a new 6-byte command. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 cmd->device->use_10_for_rw = 0;
Alan Sternb60af5b2008-11-03 15:56:47 -0500897 action = ACTION_REPREP;
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500898 } else if (sshdr.asc == 0x10) /* DIX */ {
899 description = "Host Data Integrity Failure";
900 action = ACTION_FAIL;
901 error = -EILSEQ;
Martin K. Petersenc98a0eb2011-03-08 02:07:15 -0500902 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
903 } else if ((sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
904 (cmd->cmnd[0] == UNMAP ||
905 cmd->cmnd[0] == WRITE_SAME_16 ||
906 cmd->cmnd[0] == WRITE_SAME)) {
907 description = "Discard failure";
908 action = ACTION_FAIL;
Martin K. Petersen66a651a2012-02-13 15:38:22 -0500909 error = -EREMOTEIO;
Alan Sternb60af5b2008-11-03 15:56:47 -0500910 } else
911 action = ACTION_FAIL;
912 break;
Martin K. Petersen511e44f2008-07-17 04:28:33 -0400913 case ABORTED_COMMAND:
James Bottomley126c09822009-02-19 21:48:54 +0000914 action = ACTION_FAIL;
Martin K. Petersen511e44f2008-07-17 04:28:33 -0400915 if (sshdr.asc == 0x10) { /* DIF */
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500916 description = "Target Data Integrity Failure";
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500917 error = -EILSEQ;
James Bottomley126c09822009-02-19 21:48:54 +0000918 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 break;
920 case NOT_READY:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700921 /* If the device is in the process of becoming
James Bottomleyf3e93f72006-04-25 16:48:30 -0500922 * ready, or has a temporary blockage, retry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 */
James Bottomleyf3e93f72006-04-25 16:48:30 -0500924 if (sshdr.asc == 0x04) {
925 switch (sshdr.ascq) {
926 case 0x01: /* becoming ready */
927 case 0x04: /* format in progress */
928 case 0x05: /* rebuild in progress */
929 case 0x06: /* recalculation in progress */
930 case 0x07: /* operation in progress */
931 case 0x08: /* Long write in progress */
932 case 0x09: /* self test in progress */
Martin K. Petersend8705f12009-11-26 12:00:41 -0500933 case 0x14: /* space allocation in progress */
Alan Sternb60af5b2008-11-03 15:56:47 -0500934 action = ACTION_DELAYED_RETRY;
James Bottomleyf3e93f72006-04-25 16:48:30 -0500935 break;
Alan Stern3dbf6a52008-12-15 10:31:28 -0500936 default:
937 description = "Device not ready";
938 action = ACTION_FAIL;
939 break;
James Bottomleyf3e93f72006-04-25 16:48:30 -0500940 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500941 } else {
942 description = "Device not ready";
943 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500945 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 case VOLUME_OVERFLOW:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700947 /* See SSC3rXX or current. */
Alan Sternb60af5b2008-11-03 15:56:47 -0500948 action = ACTION_FAIL;
949 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 default:
Alan Sternb60af5b2008-11-03 15:56:47 -0500951 description = "Unhandled sense code";
952 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 break;
954 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500955 } else {
956 description = "Unhandled error code";
957 action = ACTION_FAIL;
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700958 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500959
960 switch (action) {
961 case ACTION_FAIL:
962 /* Give up and fail the remainder of the request */
James Bottomley79ed2422009-01-06 13:15:20 -0600963 scsi_release_buffers(cmd);
Jens Axboe4aff5e22006-08-10 08:44:47 +0200964 if (!(req->cmd_flags & REQ_QUIET)) {
Alan Sternb60af5b2008-11-03 15:56:47 -0500965 if (description)
Alan Stern3dbf6a52008-12-15 10:31:28 -0500966 scmd_printk(KERN_INFO, cmd, "%s\n",
Alan Sternb60af5b2008-11-03 15:56:47 -0500967 description);
Martin K. Petersena4d04a42007-02-27 22:40:27 -0500968 scsi_print_result(cmd);
James Bottomley3173d8c2005-09-04 11:32:05 -0500969 if (driver_byte(result) & DRIVER_SENSE)
970 scsi_print_sense("", cmd);
Martin K. Petersen002b1eb2009-05-23 11:45:07 -0400971 scsi_print_command(cmd);
James Bottomley3173d8c2005-09-04 11:32:05 -0500972 }
Mike Christiead630822009-09-28 15:50:52 -0500973 if (blk_end_request_err(req, error))
Tejun Heoda6c5c72009-09-11 14:26:40 +0200974 scsi_requeue_command(q, cmd);
975 else
976 scsi_next_command(cmd);
Alan Sternb60af5b2008-11-03 15:56:47 -0500977 break;
978 case ACTION_REPREP:
979 /* Unprep the request and put it back at the head of the queue.
980 * A new command will be prepared and issued.
981 */
James Bottomley79ed2422009-01-06 13:15:20 -0600982 scsi_release_buffers(cmd);
Alan Sternb60af5b2008-11-03 15:56:47 -0500983 scsi_requeue_command(q, cmd);
984 break;
985 case ACTION_RETRY:
986 /* Retry the same command immediately */
James Bottomley4f5299a2009-01-02 10:42:21 -0600987 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
Alan Sternb60af5b2008-11-03 15:56:47 -0500988 break;
989 case ACTION_DELAYED_RETRY:
990 /* Retry the same command after a delay */
James Bottomley4f5299a2009-01-02 10:42:21 -0600991 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
Alan Sternb60af5b2008-11-03 15:56:47 -0500992 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 }
994}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200996static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
997 gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998{
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200999 int count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000
1001 /*
Christoph Hellwig3b003152006-11-04 20:10:55 +01001002 * If sg table allocation fails, requeue request later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 */
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001004 if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments,
1005 gfp_mask))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 return BLKPREP_DEFER;
Alan Stern7c72ce82005-10-14 11:23:27 -04001007 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008
Christoph Hellwig3b003152006-11-04 20:10:55 +01001009 req->buffer = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010
1011 /*
1012 * Next, walk the list, and fill in the addresses and sizes of
1013 * each segment.
1014 */
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001015 count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
1016 BUG_ON(count > sdb->table.nents);
1017 sdb->table.nents = count;
Tejun Heo1011c1b2009-05-07 22:24:45 +09001018 sdb->length = blk_rq_bytes(req);
Rusty Russell4a03d902007-11-19 11:28:48 +11001019 return BLKPREP_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020}
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001021
1022/*
1023 * Function: scsi_init_io()
1024 *
1025 * Purpose: SCSI I/O initialize function.
1026 *
1027 * Arguments: cmd - Command descriptor we wish to initialize
1028 *
1029 * Returns: 0 on success
1030 * BLKPREP_DEFER if the failure is retryable
1031 * BLKPREP_KILL if the failure is fatal
1032 */
1033int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
1034{
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001035 struct request *rq = cmd->request;
1036
1037 int error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001038 if (error)
1039 goto err_exit;
1040
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001041 if (blk_bidi_rq(rq)) {
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001042 struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc(
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001043 scsi_sdb_cache, GFP_ATOMIC);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001044 if (!bidi_sdb) {
1045 error = BLKPREP_DEFER;
1046 goto err_exit;
1047 }
1048
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001049 rq->next_rq->special = bidi_sdb;
1050 error = scsi_init_sgtable(rq->next_rq, bidi_sdb, GFP_ATOMIC);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001051 if (error)
1052 goto err_exit;
1053 }
1054
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001055 if (blk_integrity_rq(rq)) {
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001056 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
1057 int ivecs, count;
1058
1059 BUG_ON(prot_sdb == NULL);
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001060 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001061
1062 if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) {
1063 error = BLKPREP_DEFER;
1064 goto err_exit;
1065 }
1066
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001067 count = blk_rq_map_integrity_sg(rq->q, rq->bio,
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001068 prot_sdb->table.sgl);
1069 BUG_ON(unlikely(count > ivecs));
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001070 BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q)));
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001071
1072 cmd->prot_sdb = prot_sdb;
1073 cmd->prot_sdb->table.nents = count;
1074 }
1075
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001076 return BLKPREP_OK ;
1077
1078err_exit:
1079 scsi_release_buffers(cmd);
FUJITA Tomonori610a6342010-07-08 10:16:17 +02001080 cmd->request->special = NULL;
James Bottomley3a5c19c2010-08-16 10:06:26 -05001081 scsi_put_command(cmd);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001082 return error;
1083}
Boaz Harroshbb52d822007-12-13 16:14:27 -08001084EXPORT_SYMBOL(scsi_init_io);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085
Christoph Hellwig3b003152006-11-04 20:10:55 +01001086static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
1087 struct request *req)
1088{
1089 struct scsi_cmnd *cmd;
1090
1091 if (!req->special) {
1092 cmd = scsi_get_command(sdev, GFP_ATOMIC);
1093 if (unlikely(!cmd))
1094 return NULL;
1095 req->special = cmd;
1096 } else {
1097 cmd = req->special;
1098 }
1099
1100 /* pull a tag out of the request if we have one */
1101 cmd->tag = req->tag;
1102 cmd->request = req;
1103
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001104 cmd->cmnd = req->cmd;
Martin K. Petersen72f7d322011-03-08 02:03:59 -05001105 cmd->prot_op = SCSI_PROT_NORMAL;
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001106
Christoph Hellwig3b003152006-11-04 20:10:55 +01001107 return cmd;
1108}
1109
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001110int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
James Bottomley7b163182005-12-15 20:17:02 -06001111{
Christoph Hellwig3b003152006-11-04 20:10:55 +01001112 struct scsi_cmnd *cmd;
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001113 int ret = scsi_prep_state_check(sdev, req);
1114
1115 if (ret != BLKPREP_OK)
1116 return ret;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001117
1118 cmd = scsi_get_cmd_from_req(sdev, req);
1119 if (unlikely(!cmd))
1120 return BLKPREP_DEFER;
1121
1122 /*
1123 * BLOCK_PC requests may transfer data, in which case they must
1124 * a bio attached to them. Or they might contain a SCSI command
1125 * that does not transfer data, in which case they may optionally
1126 * submit a request without an attached bio.
1127 */
1128 if (req->bio) {
1129 int ret;
1130
1131 BUG_ON(!req->nr_phys_segments);
1132
Boaz Harroshbb52d822007-12-13 16:14:27 -08001133 ret = scsi_init_io(cmd, GFP_ATOMIC);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001134 if (unlikely(ret))
1135 return ret;
1136 } else {
Tejun Heob07904102009-05-07 22:24:42 +09001137 BUG_ON(blk_rq_bytes(req));
Christoph Hellwig3b003152006-11-04 20:10:55 +01001138
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001139 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
Christoph Hellwig3b003152006-11-04 20:10:55 +01001140 req->buffer = NULL;
1141 }
James Bottomley7b163182005-12-15 20:17:02 -06001142
James Bottomley7b163182005-12-15 20:17:02 -06001143 cmd->cmd_len = req->cmd_len;
Tejun Heob07904102009-05-07 22:24:42 +09001144 if (!blk_rq_bytes(req))
James Bottomley7b163182005-12-15 20:17:02 -06001145 cmd->sc_data_direction = DMA_NONE;
1146 else if (rq_data_dir(req) == WRITE)
1147 cmd->sc_data_direction = DMA_TO_DEVICE;
1148 else
1149 cmd->sc_data_direction = DMA_FROM_DEVICE;
1150
Tejun Heob07904102009-05-07 22:24:42 +09001151 cmd->transfersize = blk_rq_bytes(req);
James Bottomley7b163182005-12-15 20:17:02 -06001152 cmd->allowed = req->retries;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001153 return BLKPREP_OK;
1154}
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001155EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001156
1157/*
1158 * Setup a REQ_TYPE_FS command. These are simple read/write request
1159 * from filesystems that still need to be translated to SCSI CDBs from
1160 * the ULD.
1161 */
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001162int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
Christoph Hellwig3b003152006-11-04 20:10:55 +01001163{
1164 struct scsi_cmnd *cmd;
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001165 int ret = scsi_prep_state_check(sdev, req);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001166
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001167 if (ret != BLKPREP_OK)
1168 return ret;
Chandra Seetharamana6a8d9f2008-05-01 14:49:46 -07001169
1170 if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh
1171 && sdev->scsi_dh_data->scsi_dh->prep_fn)) {
1172 ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req);
1173 if (ret != BLKPREP_OK)
1174 return ret;
1175 }
1176
Christoph Hellwig3b003152006-11-04 20:10:55 +01001177 /*
1178 * Filesystem requests must transfer data.
1179 */
1180 BUG_ON(!req->nr_phys_segments);
1181
1182 cmd = scsi_get_cmd_from_req(sdev, req);
1183 if (unlikely(!cmd))
1184 return BLKPREP_DEFER;
1185
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001186 memset(cmd->cmnd, 0, BLK_MAX_CDB);
Boaz Harroshbb52d822007-12-13 16:14:27 -08001187 return scsi_init_io(cmd, GFP_ATOMIC);
James Bottomley7b163182005-12-15 20:17:02 -06001188}
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001189EXPORT_SYMBOL(scsi_setup_fs_cmnd);
James Bottomley7b163182005-12-15 20:17:02 -06001190
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001191int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192{
Christoph Hellwig3b003152006-11-04 20:10:55 +01001193 int ret = BLKPREP_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194
1195 /*
Christoph Hellwig3b003152006-11-04 20:10:55 +01001196 * If the device is not in running state we will reject some
1197 * or all commands.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
Christoph Hellwig3b003152006-11-04 20:10:55 +01001200 switch (sdev->sdev_state) {
1201 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05001202 case SDEV_TRANSPORT_OFFLINE:
Christoph Hellwig3b003152006-11-04 20:10:55 +01001203 /*
1204 * If the device is offline we refuse to process any
1205 * commands. The device must be brought online
1206 * before trying any recovery commands.
1207 */
1208 sdev_printk(KERN_ERR, sdev,
1209 "rejecting I/O to offline device\n");
1210 ret = BLKPREP_KILL;
1211 break;
1212 case SDEV_DEL:
1213 /*
1214 * If the device is fully deleted, we refuse to
1215 * process any commands as well.
1216 */
James Bottomley9ccfc752005-10-02 11:45:08 -05001217 sdev_printk(KERN_ERR, sdev,
1218 "rejecting I/O to dead device\n");
Christoph Hellwig3b003152006-11-04 20:10:55 +01001219 ret = BLKPREP_KILL;
1220 break;
1221 case SDEV_QUIESCE:
1222 case SDEV_BLOCK:
James Bottomley6f4267e2008-08-22 16:53:31 -05001223 case SDEV_CREATED_BLOCK:
Christoph Hellwig3b003152006-11-04 20:10:55 +01001224 /*
1225 * If the devices is blocked we defer normal commands.
1226 */
1227 if (!(req->cmd_flags & REQ_PREEMPT))
1228 ret = BLKPREP_DEFER;
1229 break;
1230 default:
1231 /*
1232 * For any other not fully online state we only allow
1233 * special commands. In particular any user initiated
1234 * command is not allowed.
1235 */
1236 if (!(req->cmd_flags & REQ_PREEMPT))
1237 ret = BLKPREP_KILL;
1238 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 }
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001241 return ret;
1242}
1243EXPORT_SYMBOL(scsi_prep_state_check);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001245int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
1246{
1247 struct scsi_device *sdev = q->queuedata;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248
Christoph Hellwig3b003152006-11-04 20:10:55 +01001249 switch (ret) {
1250 case BLKPREP_KILL:
1251 req->errors = DID_NO_CONNECT << 16;
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001252 /* release the command and kill it */
1253 if (req->special) {
1254 struct scsi_cmnd *cmd = req->special;
1255 scsi_release_buffers(cmd);
1256 scsi_put_command(cmd);
1257 req->special = NULL;
1258 }
Christoph Hellwig3b003152006-11-04 20:10:55 +01001259 break;
1260 case BLKPREP_DEFER:
1261 /*
Tejun Heo9934c8c2009-05-08 11:54:16 +09001262 * If we defer, the blk_peek_request() returns NULL, but the
Jens Axboea488e742010-04-16 21:13:15 +02001263 * queue must be restarted, so we schedule a callback to happen
1264 * shortly.
Christoph Hellwig3b003152006-11-04 20:10:55 +01001265 */
1266 if (sdev->device_busy == 0)
Jens Axboea488e742010-04-16 21:13:15 +02001267 blk_delay_queue(q, SCSI_QUEUE_DELAY);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001268 break;
1269 default:
1270 req->cmd_flags |= REQ_DONTPREP;
1271 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272
Christoph Hellwig3b003152006-11-04 20:10:55 +01001273 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274}
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001275EXPORT_SYMBOL(scsi_prep_return);
1276
James Bottomley751bf4d2008-01-02 11:14:30 -06001277int scsi_prep_fn(struct request_queue *q, struct request *req)
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001278{
1279 struct scsi_device *sdev = q->queuedata;
1280 int ret = BLKPREP_KILL;
1281
1282 if (req->cmd_type == REQ_TYPE_BLOCK_PC)
1283 ret = scsi_setup_blk_pc_cmnd(sdev, req);
1284 return scsi_prep_return(q, req, ret);
1285}
Hannes Reineckeb3912772009-06-18 09:57:18 +02001286EXPORT_SYMBOL(scsi_prep_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287
1288/*
1289 * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
1290 * return 0.
1291 *
1292 * Called with the queue_lock held.
1293 */
1294static inline int scsi_dev_queue_ready(struct request_queue *q,
1295 struct scsi_device *sdev)
1296{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297 if (sdev->device_busy == 0 && sdev->device_blocked) {
1298 /*
1299 * unblock after device_blocked iterates to zero
1300 */
1301 if (--sdev->device_blocked == 0) {
1302 SCSI_LOG_MLQUEUE(3,
James Bottomley9ccfc752005-10-02 11:45:08 -05001303 sdev_printk(KERN_INFO, sdev,
1304 "unblocking device at zero depth\n"));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 } else {
Jens Axboea488e742010-04-16 21:13:15 +02001306 blk_delay_queue(q, SCSI_QUEUE_DELAY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 return 0;
1308 }
1309 }
Kiyoshi Ueda9d112512008-10-04 14:11:06 -04001310 if (scsi_device_is_busy(sdev))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 return 0;
1312
1313 return 1;
1314}
1315
Mike Christief0c0a372008-08-17 15:24:38 -05001316
1317/*
1318 * scsi_target_queue_ready: checks if there we can send commands to target
1319 * @sdev: scsi device on starget to check.
1320 *
1321 * Called with the host lock held.
1322 */
1323static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
1324 struct scsi_device *sdev)
1325{
1326 struct scsi_target *starget = scsi_target(sdev);
1327
1328 if (starget->single_lun) {
1329 if (starget->starget_sdev_user &&
1330 starget->starget_sdev_user != sdev)
1331 return 0;
1332 starget->starget_sdev_user = sdev;
1333 }
1334
1335 if (starget->target_busy == 0 && starget->target_blocked) {
1336 /*
1337 * unblock after target_blocked iterates to zero
1338 */
1339 if (--starget->target_blocked == 0) {
1340 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
1341 "unblocking target at zero depth\n"));
Mike Christieb4efdd52009-04-09 15:57:10 -05001342 } else
Mike Christief0c0a372008-08-17 15:24:38 -05001343 return 0;
Mike Christief0c0a372008-08-17 15:24:38 -05001344 }
1345
1346 if (scsi_target_is_busy(starget)) {
Shaohua Li466c08c2012-01-10 11:27:01 +08001347 list_move_tail(&sdev->starved_entry, &shost->starved_list);
Hillf Dantonfd01a662010-12-16 14:26:37 -06001348 return 0;
Mike Christief0c0a372008-08-17 15:24:38 -05001349 }
1350
Mike Christief0c0a372008-08-17 15:24:38 -05001351 return 1;
1352}
1353
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354/*
1355 * scsi_host_queue_ready: if we can send requests to shost, return 1 else
1356 * return 0. We must end up running the queue again whenever 0 is
1357 * returned, else IO can hang.
1358 *
1359 * Called with host_lock held.
1360 */
1361static inline int scsi_host_queue_ready(struct request_queue *q,
1362 struct Scsi_Host *shost,
1363 struct scsi_device *sdev)
1364{
James Bottomley939647e2005-09-18 15:05:20 -05001365 if (scsi_host_in_recovery(shost))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366 return 0;
1367 if (shost->host_busy == 0 && shost->host_blocked) {
1368 /*
1369 * unblock after host_blocked iterates to zero
1370 */
1371 if (--shost->host_blocked == 0) {
1372 SCSI_LOG_MLQUEUE(3,
1373 printk("scsi%d unblocking host at zero depth\n",
1374 shost->host_no));
1375 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376 return 0;
1377 }
1378 }
Kiyoshi Ueda9d112512008-10-04 14:11:06 -04001379 if (scsi_host_is_busy(shost)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380 if (list_empty(&sdev->starved_entry))
1381 list_add_tail(&sdev->starved_entry, &shost->starved_list);
1382 return 0;
1383 }
1384
1385 /* We're OK to process the command, so we can't be starved */
1386 if (!list_empty(&sdev->starved_entry))
1387 list_del_init(&sdev->starved_entry);
1388
1389 return 1;
1390}
1391
1392/*
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001393 * Busy state exporting function for request stacking drivers.
1394 *
1395 * For efficiency, no lock is taken to check the busy state of
1396 * shost/starget/sdev, since the returned value is not guaranteed and
1397 * may be changed after request stacking drivers call the function,
1398 * regardless of taking lock or not.
1399 *
Bart Van Assche67bd9412012-06-29 15:33:22 +00001400 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
1401 * needs to return 'not busy'. Otherwise, request stacking drivers
1402 * may hold requests forever.
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001403 */
1404static int scsi_lld_busy(struct request_queue *q)
1405{
1406 struct scsi_device *sdev = q->queuedata;
1407 struct Scsi_Host *shost;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001408
Bart Van Assche67bd9412012-06-29 15:33:22 +00001409 if (blk_queue_dead(q))
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001410 return 0;
1411
1412 shost = sdev->host;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001413
Jun'ichi Nomurab7e94a12012-05-22 18:57:17 +09001414 /*
1415 * Ignore host/starget busy state.
1416 * Since block layer does not have a concept of fairness across
1417 * multiple queues, congestion of host/starget needs to be handled
1418 * in SCSI layer.
1419 */
1420 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001421 return 1;
1422
1423 return 0;
1424}
1425
1426/*
James Bottomleye91442b2005-09-09 10:44:16 -05001427 * Kill a request for a dead device
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428 */
Jens Axboe165125e2007-07-24 09:28:11 +02001429static void scsi_kill_request(struct request *req, struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430{
James Bottomleye91442b2005-09-09 10:44:16 -05001431 struct scsi_cmnd *cmd = req->special;
Jiri Slaby03b14702009-09-23 16:15:35 +02001432 struct scsi_device *sdev;
1433 struct scsi_target *starget;
1434 struct Scsi_Host *shost;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435
Tejun Heo9934c8c2009-05-08 11:54:16 +09001436 blk_start_request(req);
James Bottomley788ce432005-09-09 13:40:23 -05001437
Hannes Reinecke74571812011-11-09 08:39:24 +01001438 scmd_printk(KERN_INFO, cmd, "killing request\n");
1439
Jiri Slaby03b14702009-09-23 16:15:35 +02001440 sdev = cmd->device;
1441 starget = scsi_target(sdev);
1442 shost = sdev->host;
James Bottomleye91442b2005-09-09 10:44:16 -05001443 scsi_init_cmd_errh(cmd);
1444 cmd->result = DID_NO_CONNECT << 16;
1445 atomic_inc(&cmd->device->iorequest_cnt);
Tejun Heoe36e0c82006-04-11 17:27:53 +09001446
1447 /*
1448 * SCSI request completion path will do scsi_device_unbusy(),
1449 * bump busy counts. To bump the counters, we need to dance
1450 * with the locks as normal issue path does.
1451 */
1452 sdev->device_busy++;
1453 spin_unlock(sdev->request_queue->queue_lock);
1454 spin_lock(shost->host_lock);
1455 shost->host_busy++;
Mike Christief0c0a372008-08-17 15:24:38 -05001456 starget->target_busy++;
Tejun Heoe36e0c82006-04-11 17:27:53 +09001457 spin_unlock(shost->host_lock);
1458 spin_lock(sdev->request_queue->queue_lock);
1459
Jens Axboe242f9dc2008-09-14 05:55:09 -07001460 blk_complete_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461}
1462
Jens Axboe1aea6432006-01-09 16:03:03 +01001463static void scsi_softirq_done(struct request *rq)
1464{
Jens Axboe242f9dc2008-09-14 05:55:09 -07001465 struct scsi_cmnd *cmd = rq->special;
1466 unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
Jens Axboe1aea6432006-01-09 16:03:03 +01001467 int disposition;
1468
1469 INIT_LIST_HEAD(&cmd->eh_entry);
1470
Jens Axboe242f9dc2008-09-14 05:55:09 -07001471 atomic_inc(&cmd->device->iodone_cnt);
1472 if (cmd->result)
1473 atomic_inc(&cmd->device->ioerr_cnt);
1474
Jens Axboe1aea6432006-01-09 16:03:03 +01001475 disposition = scsi_decide_disposition(cmd);
1476 if (disposition != SUCCESS &&
1477 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
1478 sdev_printk(KERN_ERR, cmd->device,
1479 "timing out command, waited %lus\n",
1480 wait_for/HZ);
1481 disposition = SUCCESS;
1482 }
1483
1484 scsi_log_completion(cmd, disposition);
1485
1486 switch (disposition) {
1487 case SUCCESS:
1488 scsi_finish_command(cmd);
1489 break;
1490 case NEEDS_RETRY:
Christoph Hellwig596f4822007-01-02 12:56:00 +01001491 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
Jens Axboe1aea6432006-01-09 16:03:03 +01001492 break;
1493 case ADD_TO_MLQUEUE:
1494 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
1495 break;
1496 default:
1497 if (!scsi_eh_scmd_add(cmd, 0))
1498 scsi_finish_command(cmd);
1499 }
1500}
1501
Linus Torvalds1da177e2005-04-16 15:20:36 -07001502/*
1503 * Function: scsi_request_fn()
1504 *
1505 * Purpose: Main strategy routine for SCSI.
1506 *
1507 * Arguments: q - Pointer to actual queue.
1508 *
1509 * Returns: Nothing
1510 *
1511 * Lock status: IO request lock assumed to be held when called.
1512 */
1513static void scsi_request_fn(struct request_queue *q)
1514{
1515 struct scsi_device *sdev = q->queuedata;
1516 struct Scsi_Host *shost;
1517 struct scsi_cmnd *cmd;
1518 struct request *req;
1519
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520 if(!get_device(&sdev->sdev_gendev))
1521 /* We must be tearing the block queue down already */
1522 return;
1523
1524 /*
1525 * To start with, we keep looping until the queue is empty, or until
1526 * the host is no longer able to accept any more requests.
1527 */
1528 shost = sdev->host;
Jens Axboea488e742010-04-16 21:13:15 +02001529 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530 int rtn;
1531 /*
1532 * get next queueable request. We do this early to make sure
1533 * that the request is fully prepared even if we cannot
1534 * accept it.
1535 */
Tejun Heo9934c8c2009-05-08 11:54:16 +09001536 req = blk_peek_request(q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001537 if (!req || !scsi_dev_queue_ready(q, sdev))
1538 break;
1539
1540 if (unlikely(!scsi_device_online(sdev))) {
James Bottomley9ccfc752005-10-02 11:45:08 -05001541 sdev_printk(KERN_ERR, sdev,
1542 "rejecting I/O to offline device\n");
James Bottomleye91442b2005-09-09 10:44:16 -05001543 scsi_kill_request(req, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001544 continue;
1545 }
1546
1547
1548 /*
1549 * Remove the request from the request list.
1550 */
1551 if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
Tejun Heo9934c8c2009-05-08 11:54:16 +09001552 blk_start_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553 sdev->device_busy++;
1554
1555 spin_unlock(q->queue_lock);
James Bottomleye91442b2005-09-09 10:44:16 -05001556 cmd = req->special;
1557 if (unlikely(cmd == NULL)) {
1558 printk(KERN_CRIT "impossible request in %s.\n"
1559 "please mail a stack trace to "
Jens Axboe4aff5e22006-08-10 08:44:47 +02001560 "linux-scsi@vger.kernel.org\n",
Harvey Harrisoncadbd4a2008-07-03 23:47:27 -07001561 __func__);
Jens Axboe4aff5e22006-08-10 08:44:47 +02001562 blk_dump_rq_flags(req, "foo");
James Bottomleye91442b2005-09-09 10:44:16 -05001563 BUG();
1564 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 spin_lock(shost->host_lock);
1566
Mike Christieecefe8a2008-07-11 19:50:35 -05001567 /*
1568 * We hit this when the driver is using a host wide
1569 * tag map. For device level tag maps the queue_depth check
1570 * in the device ready fn would prevent us from trying
1571 * to allocate a tag. Since the map is a shared host resource
1572 * we add the dev to the starved list so it eventually gets
1573 * a run when a tag is freed.
1574 */
Mike Christie6bd522f2008-07-22 15:34:38 -05001575 if (blk_queue_tagged(q) && !blk_rq_tagged(req)) {
Mike Christieecefe8a2008-07-11 19:50:35 -05001576 if (list_empty(&sdev->starved_entry))
1577 list_add_tail(&sdev->starved_entry,
1578 &shost->starved_list);
1579 goto not_ready;
1580 }
1581
Mike Christief0c0a372008-08-17 15:24:38 -05001582 if (!scsi_target_queue_ready(shost, sdev))
1583 goto not_ready;
1584
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585 if (!scsi_host_queue_ready(q, shost, sdev))
1586 goto not_ready;
Mike Christief0c0a372008-08-17 15:24:38 -05001587
1588 scsi_target(sdev)->target_busy++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589 shost->host_busy++;
1590
1591 /*
1592 * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will
1593 * take the lock again.
1594 */
1595 spin_unlock_irq(shost->host_lock);
1596
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 /*
1598 * Finally, initialize any error handling parameters, and set up
1599 * the timers for timeouts.
1600 */
1601 scsi_init_cmd_errh(cmd);
1602
1603 /*
1604 * Dispatch the command to the low-level driver.
1605 */
1606 rtn = scsi_dispatch_cmd(cmd);
1607 spin_lock_irq(q->queue_lock);
Jens Axboea488e742010-04-16 21:13:15 +02001608 if (rtn)
1609 goto out_delay;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 }
1611
1612 goto out;
1613
1614 not_ready:
1615 spin_unlock_irq(shost->host_lock);
1616
1617 /*
1618 * lock q, handle tag, requeue req, and decrement device_busy. We
1619 * must return with queue_lock held.
1620 *
1621 * Decrementing device_busy without checking it is OK, as all such
1622 * cases (host limits or settings) should run the queue at some
1623 * later time.
1624 */
1625 spin_lock_irq(q->queue_lock);
1626 blk_requeue_request(q, req);
1627 sdev->device_busy--;
Jens Axboea488e742010-04-16 21:13:15 +02001628out_delay:
1629 if (sdev->device_busy == 0)
1630 blk_delay_queue(q, SCSI_QUEUE_DELAY);
1631out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632 /* must be careful here...if we trigger the ->remove() function
1633 * we cannot be holding the q lock */
1634 spin_unlock_irq(q->queue_lock);
1635 put_device(&sdev->sdev_gendev);
1636 spin_lock_irq(q->queue_lock);
1637}
1638
1639u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)
1640{
1641 struct device *host_dev;
1642 u64 bounce_limit = 0xffffffff;
1643
1644 if (shost->unchecked_isa_dma)
1645 return BLK_BOUNCE_ISA;
1646 /*
1647 * Platforms with virtual-DMA translation
1648 * hardware have no practical limit.
1649 */
1650 if (!PCI_DMA_BUS_IS_PHYS)
1651 return BLK_BOUNCE_ANY;
1652
1653 host_dev = scsi_get_device(shost);
1654 if (host_dev && host_dev->dma_mask)
1655 bounce_limit = *host_dev->dma_mask;
1656
1657 return bounce_limit;
1658}
1659EXPORT_SYMBOL(scsi_calculate_bounce_limit);
1660
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001661struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
1662 request_fn_proc *request_fn)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664 struct request_queue *q;
Lin Ming6f381fa2012-04-12 13:50:38 +08001665 struct device *dev = shost->dma_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001667 q = blk_init_queue(request_fn, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001668 if (!q)
1669 return NULL;
1670
Jens Axboea8474ce2007-08-07 09:02:51 +02001671 /*
1672 * this limit is imposed by hardware restrictions
1673 */
Martin K. Petersen8a783622010-02-26 00:20:39 -05001674 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize,
1675 SCSI_MAX_SG_CHAIN_SEGMENTS));
Jens Axboea8474ce2007-08-07 09:02:51 +02001676
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001677 if (scsi_host_prot_dma(shost)) {
1678 shost->sg_prot_tablesize =
1679 min_not_zero(shost->sg_prot_tablesize,
1680 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS);
1681 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize);
1682 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
1683 }
1684
Martin K. Petersen086fa5f2010-02-26 00:20:38 -05001685 blk_queue_max_hw_sectors(q, shost->max_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
1687 blk_queue_segment_boundary(q, shost->dma_boundary);
FUJITA Tomonori99c84db2008-02-04 22:28:17 -08001688 dma_set_seg_boundary(dev, shost->dma_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689
FUJITA Tomonori860ac562008-02-04 22:28:05 -08001690 blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
1691
Linus Torvalds1da177e2005-04-16 15:20:36 -07001692 if (!shost->use_clustering)
Martin K. Petersene692cb62010-12-01 19:41:49 +01001693 q->limits.cluster = 0;
James Bottomley465ff312008-01-01 10:00:10 -06001694
1695 /*
1696 * set a reasonable default alignment on word boundaries: the
1697 * host and device may alter it using
1698 * blk_queue_update_dma_alignment() later.
1699 */
1700 blk_queue_dma_alignment(q, 0x03);
1701
Linus Torvalds1da177e2005-04-16 15:20:36 -07001702 return q;
1703}
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001704EXPORT_SYMBOL(__scsi_alloc_queue);
1705
1706struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
1707{
1708 struct request_queue *q;
1709
1710 q = __scsi_alloc_queue(sdev->host, scsi_request_fn);
1711 if (!q)
1712 return NULL;
1713
1714 blk_queue_prep_rq(q, scsi_prep_fn);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001715 blk_queue_softirq_done(q, scsi_softirq_done);
Jens Axboe242f9dc2008-09-14 05:55:09 -07001716 blk_queue_rq_timed_out(q, scsi_times_out);
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001717 blk_queue_lld_busy(q, scsi_lld_busy);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09001718 return q;
1719}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721/*
1722 * Function: scsi_block_requests()
1723 *
1724 * Purpose: Utility function used by low-level drivers to prevent further
1725 * commands from being queued to the device.
1726 *
1727 * Arguments: shost - Host in question
1728 *
1729 * Returns: Nothing
1730 *
1731 * Lock status: No locks are assumed held.
1732 *
1733 * Notes: There is no timer nor any other means by which the requests
1734 * get unblocked other than the low-level driver calling
1735 * scsi_unblock_requests().
1736 */
1737void scsi_block_requests(struct Scsi_Host *shost)
1738{
1739 shost->host_self_blocked = 1;
1740}
1741EXPORT_SYMBOL(scsi_block_requests);
1742
1743/*
1744 * Function: scsi_unblock_requests()
1745 *
1746 * Purpose: Utility function used by low-level drivers to allow further
1747 * commands from being queued to the device.
1748 *
1749 * Arguments: shost - Host in question
1750 *
1751 * Returns: Nothing
1752 *
1753 * Lock status: No locks are assumed held.
1754 *
1755 * Notes: There is no timer nor any other means by which the requests
1756 * get unblocked other than the low-level driver calling
1757 * scsi_unblock_requests().
1758 *
1759 * This is done as an API function so that changes to the
1760 * internals of the scsi mid-layer won't require wholesale
1761 * changes to drivers that use this feature.
1762 */
1763void scsi_unblock_requests(struct Scsi_Host *shost)
1764{
1765 shost->host_self_blocked = 0;
1766 scsi_run_host_queues(shost);
1767}
1768EXPORT_SYMBOL(scsi_unblock_requests);
1769
1770int __init scsi_init_queue(void)
1771{
1772 int i;
1773
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001774 scsi_sdb_cache = kmem_cache_create("scsi_data_buffer",
1775 sizeof(struct scsi_data_buffer),
1776 0, 0, NULL);
1777 if (!scsi_sdb_cache) {
1778 printk(KERN_ERR "SCSI: can't init scsi sdb cache\n");
FUJITA Tomonorif0787272008-12-14 01:23:45 +09001779 return -ENOMEM;
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001780 }
1781
Linus Torvalds1da177e2005-04-16 15:20:36 -07001782 for (i = 0; i < SG_MEMPOOL_NR; i++) {
1783 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
1784 int size = sgp->size * sizeof(struct scatterlist);
1785
1786 sgp->slab = kmem_cache_create(sgp->name, size, 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001787 SLAB_HWCACHE_ALIGN, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001788 if (!sgp->slab) {
1789 printk(KERN_ERR "SCSI: can't init sg slab %s\n",
1790 sgp->name);
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001791 goto cleanup_sdb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001792 }
1793
Matthew Dobson93d23412006-03-26 01:37:50 -08001794 sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE,
1795 sgp->slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001796 if (!sgp->pool) {
1797 printk(KERN_ERR "SCSI: can't init sg mempool %s\n",
1798 sgp->name);
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001799 goto cleanup_sdb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 }
1801 }
1802
1803 return 0;
FUJITA Tomonori3d9dd6e2008-01-25 23:25:14 +09001804
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001805cleanup_sdb:
FUJITA Tomonori3d9dd6e2008-01-25 23:25:14 +09001806 for (i = 0; i < SG_MEMPOOL_NR; i++) {
1807 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
1808 if (sgp->pool)
1809 mempool_destroy(sgp->pool);
1810 if (sgp->slab)
1811 kmem_cache_destroy(sgp->slab);
1812 }
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001813 kmem_cache_destroy(scsi_sdb_cache);
FUJITA Tomonori3d9dd6e2008-01-25 23:25:14 +09001814
1815 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001816}
1817
1818void scsi_exit_queue(void)
1819{
1820 int i;
1821
Martin K. Petersen6362abd2008-06-05 23:30:03 -04001822 kmem_cache_destroy(scsi_sdb_cache);
Mike Christieaa7b5cd2005-11-11 05:31:41 -06001823
Linus Torvalds1da177e2005-04-16 15:20:36 -07001824 for (i = 0; i < SG_MEMPOOL_NR; i++) {
1825 struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
1826 mempool_destroy(sgp->pool);
1827 kmem_cache_destroy(sgp->slab);
1828 }
1829}
James Bottomley5baba832006-03-18 14:10:35 -06001830
1831/**
1832 * scsi_mode_select - issue a mode select
1833 * @sdev: SCSI device to be queried
1834 * @pf: Page format bit (1 == standard, 0 == vendor specific)
1835 * @sp: Save page bit (0 == don't save, 1 == save)
1836 * @modepage: mode page being requested
1837 * @buffer: request buffer (may not be smaller than eight bytes)
1838 * @len: length of request buffer.
1839 * @timeout: command timeout
1840 * @retries: number of retries before failing
1841 * @data: returns a structure abstracting the mode header data
Rob Landleyeb44820c2007-11-03 13:30:39 -05001842 * @sshdr: place to put sense data (or NULL if no sense to be collected).
James Bottomley5baba832006-03-18 14:10:35 -06001843 * must be SCSI_SENSE_BUFFERSIZE big.
1844 *
1845 * Returns zero if successful; negative error number or scsi
1846 * status on error
1847 *
1848 */
1849int
1850scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
1851 unsigned char *buffer, int len, int timeout, int retries,
1852 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
1853{
1854 unsigned char cmd[10];
1855 unsigned char *real_buffer;
1856 int ret;
1857
1858 memset(cmd, 0, sizeof(cmd));
1859 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
1860
1861 if (sdev->use_10_for_ms) {
1862 if (len > 65535)
1863 return -EINVAL;
1864 real_buffer = kmalloc(8 + len, GFP_KERNEL);
1865 if (!real_buffer)
1866 return -ENOMEM;
1867 memcpy(real_buffer + 8, buffer, len);
1868 len += 8;
1869 real_buffer[0] = 0;
1870 real_buffer[1] = 0;
1871 real_buffer[2] = data->medium_type;
1872 real_buffer[3] = data->device_specific;
1873 real_buffer[4] = data->longlba ? 0x01 : 0;
1874 real_buffer[5] = 0;
1875 real_buffer[6] = data->block_descriptor_length >> 8;
1876 real_buffer[7] = data->block_descriptor_length;
1877
1878 cmd[0] = MODE_SELECT_10;
1879 cmd[7] = len >> 8;
1880 cmd[8] = len;
1881 } else {
1882 if (len > 255 || data->block_descriptor_length > 255 ||
1883 data->longlba)
1884 return -EINVAL;
1885
1886 real_buffer = kmalloc(4 + len, GFP_KERNEL);
1887 if (!real_buffer)
1888 return -ENOMEM;
1889 memcpy(real_buffer + 4, buffer, len);
1890 len += 4;
1891 real_buffer[0] = 0;
1892 real_buffer[1] = data->medium_type;
1893 real_buffer[2] = data->device_specific;
1894 real_buffer[3] = data->block_descriptor_length;
1895
1896
1897 cmd[0] = MODE_SELECT;
1898 cmd[4] = len;
1899 }
1900
1901 ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09001902 sshdr, timeout, retries, NULL);
James Bottomley5baba832006-03-18 14:10:35 -06001903 kfree(real_buffer);
1904 return ret;
1905}
1906EXPORT_SYMBOL_GPL(scsi_mode_select);
1907
Linus Torvalds1da177e2005-04-16 15:20:36 -07001908/**
Rob Landleyeb44820c2007-11-03 13:30:39 -05001909 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
James Bottomley1cf72692005-08-28 11:27:01 -05001910 * @sdev: SCSI device to be queried
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911 * @dbd: set if mode sense will allow block descriptors to be returned
1912 * @modepage: mode page being requested
1913 * @buffer: request buffer (may not be smaller than eight bytes)
1914 * @len: length of request buffer.
1915 * @timeout: command timeout
1916 * @retries: number of retries before failing
1917 * @data: returns a structure abstracting the mode header data
Rob Landleyeb44820c2007-11-03 13:30:39 -05001918 * @sshdr: place to put sense data (or NULL if no sense to be collected).
James Bottomley1cf72692005-08-28 11:27:01 -05001919 * must be SCSI_SENSE_BUFFERSIZE big.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001920 *
1921 * Returns zero if unsuccessful, or the header offset (either 4
1922 * or 8 depending on whether a six or ten byte command was
1923 * issued) if successful.
Rob Landleyeb44820c2007-11-03 13:30:39 -05001924 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925int
James Bottomley1cf72692005-08-28 11:27:01 -05001926scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001927 unsigned char *buffer, int len, int timeout, int retries,
James Bottomley5baba832006-03-18 14:10:35 -06001928 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
1929{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001930 unsigned char cmd[12];
1931 int use_10_for_ms;
1932 int header_length;
James Bottomley1cf72692005-08-28 11:27:01 -05001933 int result;
James Bottomleyea73a9f2005-08-28 11:33:52 -05001934 struct scsi_sense_hdr my_sshdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001935
1936 memset(data, 0, sizeof(*data));
1937 memset(&cmd[0], 0, 12);
1938 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */
1939 cmd[2] = modepage;
1940
James Bottomleyea73a9f2005-08-28 11:33:52 -05001941 /* caller might not be interested in sense, but we need it */
1942 if (!sshdr)
1943 sshdr = &my_sshdr;
1944
Linus Torvalds1da177e2005-04-16 15:20:36 -07001945 retry:
James Bottomley1cf72692005-08-28 11:27:01 -05001946 use_10_for_ms = sdev->use_10_for_ms;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001947
1948 if (use_10_for_ms) {
1949 if (len < 8)
1950 len = 8;
1951
1952 cmd[0] = MODE_SENSE_10;
1953 cmd[8] = len;
1954 header_length = 8;
1955 } else {
1956 if (len < 4)
1957 len = 4;
1958
1959 cmd[0] = MODE_SENSE;
1960 cmd[4] = len;
1961 header_length = 4;
1962 }
1963
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964 memset(buffer, 0, len);
1965
James Bottomley1cf72692005-08-28 11:27:01 -05001966 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09001967 sshdr, timeout, retries, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001968
1969 /* This code looks awful: what it's doing is making sure an
1970 * ILLEGAL REQUEST sense return identifies the actual command
1971 * byte as the problem. MODE_SENSE commands can return
1972 * ILLEGAL REQUEST if the code page isn't supported */
1973
James Bottomley1cf72692005-08-28 11:27:01 -05001974 if (use_10_for_ms && !scsi_status_is_good(result) &&
1975 (driver_byte(result) & DRIVER_SENSE)) {
James Bottomleyea73a9f2005-08-28 11:33:52 -05001976 if (scsi_sense_valid(sshdr)) {
1977 if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
1978 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979 /*
1980 * Invalid command operation code
1981 */
James Bottomley1cf72692005-08-28 11:27:01 -05001982 sdev->use_10_for_ms = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001983 goto retry;
1984 }
1985 }
1986 }
1987
James Bottomley1cf72692005-08-28 11:27:01 -05001988 if(scsi_status_is_good(result)) {
Al Viro6d73c852006-02-23 02:03:16 +01001989 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
1990 (modepage == 6 || modepage == 8))) {
1991 /* Initio breakage? */
1992 header_length = 0;
1993 data->length = 13;
1994 data->medium_type = 0;
1995 data->device_specific = 0;
1996 data->longlba = 0;
1997 data->block_descriptor_length = 0;
1998 } else if(use_10_for_ms) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999 data->length = buffer[0]*256 + buffer[1] + 2;
2000 data->medium_type = buffer[2];
2001 data->device_specific = buffer[3];
2002 data->longlba = buffer[4] & 0x01;
2003 data->block_descriptor_length = buffer[6]*256
2004 + buffer[7];
2005 } else {
2006 data->length = buffer[0] + 1;
2007 data->medium_type = buffer[1];
2008 data->device_specific = buffer[2];
2009 data->block_descriptor_length = buffer[3];
2010 }
Al Viro6d73c852006-02-23 02:03:16 +01002011 data->header_length = header_length;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002012 }
2013
James Bottomley1cf72692005-08-28 11:27:01 -05002014 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002015}
2016EXPORT_SYMBOL(scsi_mode_sense);
2017
James Bottomley001aac22007-12-02 19:10:40 +02002018/**
2019 * scsi_test_unit_ready - test if unit is ready
2020 * @sdev: scsi device to change the state of.
2021 * @timeout: command timeout
2022 * @retries: number of retries before failing
2023 * @sshdr_external: Optional pointer to struct scsi_sense_hdr for
2024 * returning sense. Make sure that this is cleared before passing
2025 * in.
2026 *
2027 * Returns zero if unsuccessful or an error if TUR failed. For
Tejun Heo9f8a2c22010-12-08 20:57:40 +01002028 * removable media, UNIT_ATTENTION sets ->changed flag.
James Bottomley001aac22007-12-02 19:10:40 +02002029 **/
Linus Torvalds1da177e2005-04-16 15:20:36 -07002030int
James Bottomley001aac22007-12-02 19:10:40 +02002031scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
2032 struct scsi_sense_hdr *sshdr_external)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002033{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002034 char cmd[] = {
2035 TEST_UNIT_READY, 0, 0, 0, 0, 0,
2036 };
James Bottomley001aac22007-12-02 19:10:40 +02002037 struct scsi_sense_hdr *sshdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002038 int result;
James Bottomley001aac22007-12-02 19:10:40 +02002039
2040 if (!sshdr_external)
2041 sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
2042 else
2043 sshdr = sshdr_external;
2044
2045 /* try to eat the UNIT_ATTENTION if there are enough retries */
2046 do {
2047 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09002048 timeout, retries, NULL);
James Bottomley32c356d2008-08-20 00:58:13 +02002049 if (sdev->removable && scsi_sense_valid(sshdr) &&
2050 sshdr->sense_key == UNIT_ATTENTION)
2051 sdev->changed = 1;
2052 } while (scsi_sense_valid(sshdr) &&
2053 sshdr->sense_key == UNIT_ATTENTION && --retries);
James Bottomley001aac22007-12-02 19:10:40 +02002054
James Bottomley001aac22007-12-02 19:10:40 +02002055 if (!sshdr_external)
2056 kfree(sshdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002057 return result;
2058}
2059EXPORT_SYMBOL(scsi_test_unit_ready);
2060
2061/**
Rob Landleyeb44820c2007-11-03 13:30:39 -05002062 * scsi_device_set_state - Take the given device through the device state model.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002063 * @sdev: scsi device to change the state of.
2064 * @state: state to change to.
2065 *
2066 * Returns zero if unsuccessful or an error if the requested
2067 * transition is illegal.
Rob Landleyeb44820c2007-11-03 13:30:39 -05002068 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002069int
2070scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
2071{
2072 enum scsi_device_state oldstate = sdev->sdev_state;
2073
2074 if (state == oldstate)
2075 return 0;
2076
2077 switch (state) {
2078 case SDEV_CREATED:
James Bottomley6f4267e2008-08-22 16:53:31 -05002079 switch (oldstate) {
2080 case SDEV_CREATED_BLOCK:
2081 break;
2082 default:
2083 goto illegal;
2084 }
2085 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002086
2087 case SDEV_RUNNING:
2088 switch (oldstate) {
2089 case SDEV_CREATED:
2090 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002091 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002092 case SDEV_QUIESCE:
2093 case SDEV_BLOCK:
2094 break;
2095 default:
2096 goto illegal;
2097 }
2098 break;
2099
2100 case SDEV_QUIESCE:
2101 switch (oldstate) {
2102 case SDEV_RUNNING:
2103 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002104 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002105 break;
2106 default:
2107 goto illegal;
2108 }
2109 break;
2110
2111 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002112 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002113 switch (oldstate) {
2114 case SDEV_CREATED:
2115 case SDEV_RUNNING:
2116 case SDEV_QUIESCE:
2117 case SDEV_BLOCK:
2118 break;
2119 default:
2120 goto illegal;
2121 }
2122 break;
2123
2124 case SDEV_BLOCK:
2125 switch (oldstate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002126 case SDEV_RUNNING:
James Bottomley6f4267e2008-08-22 16:53:31 -05002127 case SDEV_CREATED_BLOCK:
2128 break;
2129 default:
2130 goto illegal;
2131 }
2132 break;
2133
2134 case SDEV_CREATED_BLOCK:
2135 switch (oldstate) {
2136 case SDEV_CREATED:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002137 break;
2138 default:
2139 goto illegal;
2140 }
2141 break;
2142
2143 case SDEV_CANCEL:
2144 switch (oldstate) {
2145 case SDEV_CREATED:
2146 case SDEV_RUNNING:
Alan Stern9ea72902006-06-23 14:25:34 -04002147 case SDEV_QUIESCE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002148 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002149 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002150 case SDEV_BLOCK:
2151 break;
2152 default:
2153 goto illegal;
2154 }
2155 break;
2156
2157 case SDEV_DEL:
2158 switch (oldstate) {
Brian King309bd272006-06-27 11:10:43 -05002159 case SDEV_CREATED:
2160 case SDEV_RUNNING:
2161 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002162 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002163 case SDEV_CANCEL:
2164 break;
2165 default:
2166 goto illegal;
2167 }
2168 break;
2169
2170 }
2171 sdev->sdev_state = state;
2172 return 0;
2173
2174 illegal:
2175 SCSI_LOG_ERROR_RECOVERY(1,
James Bottomley9ccfc752005-10-02 11:45:08 -05002176 sdev_printk(KERN_ERR, sdev,
2177 "Illegal state transition %s->%s\n",
2178 scsi_device_state_name(oldstate),
2179 scsi_device_state_name(state))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002180 );
2181 return -EINVAL;
2182}
2183EXPORT_SYMBOL(scsi_device_set_state);
2184
2185/**
Jeff Garzika341cd0f2007-10-29 17:15:22 -04002186 * sdev_evt_emit - emit a single SCSI device uevent
2187 * @sdev: associated SCSI device
2188 * @evt: event to emit
2189 *
2190 * Send a single uevent (scsi_event) to the associated scsi_device.
2191 */
2192static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
2193{
2194 int idx = 0;
2195 char *envp[3];
2196
2197 switch (evt->evt_type) {
2198 case SDEV_EVT_MEDIA_CHANGE:
2199 envp[idx++] = "SDEV_MEDIA_CHANGE=1";
2200 break;
2201
2202 default:
2203 /* do nothing */
2204 break;
2205 }
2206
2207 envp[idx++] = NULL;
2208
2209 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
2210}
2211
2212/**
2213 * sdev_evt_thread - send a uevent for each scsi event
2214 * @work: work struct for scsi_device
2215 *
2216 * Dispatch queued events to their associated scsi_device kobjects
2217 * as uevents.
2218 */
2219void scsi_evt_thread(struct work_struct *work)
2220{
2221 struct scsi_device *sdev;
2222 LIST_HEAD(event_list);
2223
2224 sdev = container_of(work, struct scsi_device, event_work);
2225
2226 while (1) {
2227 struct scsi_event *evt;
2228 struct list_head *this, *tmp;
2229 unsigned long flags;
2230
2231 spin_lock_irqsave(&sdev->list_lock, flags);
2232 list_splice_init(&sdev->event_list, &event_list);
2233 spin_unlock_irqrestore(&sdev->list_lock, flags);
2234
2235 if (list_empty(&event_list))
2236 break;
2237
2238 list_for_each_safe(this, tmp, &event_list) {
2239 evt = list_entry(this, struct scsi_event, node);
2240 list_del(&evt->node);
2241 scsi_evt_emit(sdev, evt);
2242 kfree(evt);
2243 }
2244 }
2245}
2246
2247/**
2248 * sdev_evt_send - send asserted event to uevent thread
2249 * @sdev: scsi_device event occurred on
2250 * @evt: event to send
2251 *
2252 * Assert scsi device event asynchronously.
2253 */
2254void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
2255{
2256 unsigned long flags;
2257
Kay Sievers4d1566e2008-03-19 13:04:47 +01002258#if 0
2259 /* FIXME: currently this check eliminates all media change events
2260 * for polled devices. Need to update to discriminate between AN
2261 * and polled events */
Jeff Garzika341cd0f2007-10-29 17:15:22 -04002262 if (!test_bit(evt->evt_type, sdev->supported_events)) {
2263 kfree(evt);
2264 return;
2265 }
Kay Sievers4d1566e2008-03-19 13:04:47 +01002266#endif
Jeff Garzika341cd0f2007-10-29 17:15:22 -04002267
2268 spin_lock_irqsave(&sdev->list_lock, flags);
2269 list_add_tail(&evt->node, &sdev->event_list);
2270 schedule_work(&sdev->event_work);
2271 spin_unlock_irqrestore(&sdev->list_lock, flags);
2272}
2273EXPORT_SYMBOL_GPL(sdev_evt_send);
2274
2275/**
2276 * sdev_evt_alloc - allocate a new scsi event
2277 * @evt_type: type of event to allocate
2278 * @gfpflags: GFP flags for allocation
2279 *
2280 * Allocates and returns a new scsi_event.
2281 */
2282struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
2283 gfp_t gfpflags)
2284{
2285 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
2286 if (!evt)
2287 return NULL;
2288
2289 evt->evt_type = evt_type;
2290 INIT_LIST_HEAD(&evt->node);
2291
2292 /* evt_type-specific initialization, if any */
2293 switch (evt_type) {
2294 case SDEV_EVT_MEDIA_CHANGE:
2295 default:
2296 /* do nothing */
2297 break;
2298 }
2299
2300 return evt;
2301}
2302EXPORT_SYMBOL_GPL(sdev_evt_alloc);
2303
2304/**
2305 * sdev_evt_send_simple - send asserted event to uevent thread
2306 * @sdev: scsi_device event occurred on
2307 * @evt_type: type of event to send
2308 * @gfpflags: GFP flags for allocation
2309 *
2310 * Assert scsi device event asynchronously, given an event type.
2311 */
2312void sdev_evt_send_simple(struct scsi_device *sdev,
2313 enum scsi_device_event evt_type, gfp_t gfpflags)
2314{
2315 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
2316 if (!evt) {
2317 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
2318 evt_type);
2319 return;
2320 }
2321
2322 sdev_evt_send(sdev, evt);
2323}
2324EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
2325
2326/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07002327 * scsi_device_quiesce - Block user issued commands.
2328 * @sdev: scsi device to quiesce.
2329 *
2330 * This works by trying to transition to the SDEV_QUIESCE state
2331 * (which must be a legal transition). When the device is in this
2332 * state, only special requests will be accepted, all others will
2333 * be deferred. Since special requests may also be requeued requests,
2334 * a successful return doesn't guarantee the device will be
2335 * totally quiescent.
2336 *
2337 * Must be called with user context, may sleep.
2338 *
2339 * Returns zero if unsuccessful or an error if not.
Rob Landleyeb44820c2007-11-03 13:30:39 -05002340 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002341int
2342scsi_device_quiesce(struct scsi_device *sdev)
2343{
2344 int err = scsi_device_set_state(sdev, SDEV_QUIESCE);
2345 if (err)
2346 return err;
2347
2348 scsi_run_queue(sdev->request_queue);
2349 while (sdev->device_busy) {
2350 msleep_interruptible(200);
2351 scsi_run_queue(sdev->request_queue);
2352 }
2353 return 0;
2354}
2355EXPORT_SYMBOL(scsi_device_quiesce);
2356
2357/**
2358 * scsi_device_resume - Restart user issued commands to a quiesced device.
2359 * @sdev: scsi device to resume.
2360 *
2361 * Moves the device from quiesced back to running and restarts the
2362 * queues.
2363 *
2364 * Must be called with user context, may sleep.
Rob Landleyeb44820c2007-11-03 13:30:39 -05002365 */
Dan Williamsa7a20d12012-03-22 17:05:11 -07002366void scsi_device_resume(struct scsi_device *sdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002367{
Dan Williamsa7a20d12012-03-22 17:05:11 -07002368 /* check if the device state was mutated prior to resume, and if
2369 * so assume the state is being managed elsewhere (for example
2370 * device deleted during suspend)
2371 */
2372 if (sdev->sdev_state != SDEV_QUIESCE ||
2373 scsi_device_set_state(sdev, SDEV_RUNNING))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002374 return;
2375 scsi_run_queue(sdev->request_queue);
2376}
2377EXPORT_SYMBOL(scsi_device_resume);
2378
2379static void
2380device_quiesce_fn(struct scsi_device *sdev, void *data)
2381{
2382 scsi_device_quiesce(sdev);
2383}
2384
2385void
2386scsi_target_quiesce(struct scsi_target *starget)
2387{
2388 starget_for_each_device(starget, NULL, device_quiesce_fn);
2389}
2390EXPORT_SYMBOL(scsi_target_quiesce);
2391
2392static void
2393device_resume_fn(struct scsi_device *sdev, void *data)
2394{
2395 scsi_device_resume(sdev);
2396}
2397
2398void
2399scsi_target_resume(struct scsi_target *starget)
2400{
2401 starget_for_each_device(starget, NULL, device_resume_fn);
2402}
2403EXPORT_SYMBOL(scsi_target_resume);
2404
2405/**
Rob Landleyeb44820c2007-11-03 13:30:39 -05002406 * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state
Linus Torvalds1da177e2005-04-16 15:20:36 -07002407 * @sdev: device to block
2408 *
2409 * Block request made by scsi lld's to temporarily stop all
2410 * scsi commands on the specified device. Called from interrupt
2411 * or normal process context.
2412 *
2413 * Returns zero if successful or error if not
2414 *
2415 * Notes:
2416 * This routine transitions the device to the SDEV_BLOCK state
2417 * (which must be a legal transition). When the device is in this
2418 * state, all commands are deferred until the scsi lld reenables
2419 * the device with scsi_device_unblock or device_block_tmo fires.
Rob Landleyeb44820c2007-11-03 13:30:39 -05002420 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002421int
2422scsi_internal_device_block(struct scsi_device *sdev)
2423{
Jens Axboe165125e2007-07-24 09:28:11 +02002424 struct request_queue *q = sdev->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002425 unsigned long flags;
2426 int err = 0;
2427
2428 err = scsi_device_set_state(sdev, SDEV_BLOCK);
James Bottomley6f4267e2008-08-22 16:53:31 -05002429 if (err) {
2430 err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
2431
2432 if (err)
2433 return err;
2434 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002435
2436 /*
2437 * The device has transitioned to SDEV_BLOCK. Stop the
2438 * block layer from calling the midlayer with this device's
2439 * request queue.
2440 */
2441 spin_lock_irqsave(q->queue_lock, flags);
2442 blk_stop_queue(q);
2443 spin_unlock_irqrestore(q->queue_lock, flags);
2444
2445 return 0;
2446}
2447EXPORT_SYMBOL_GPL(scsi_internal_device_block);
2448
2449/**
2450 * scsi_internal_device_unblock - resume a device after a block request
2451 * @sdev: device to resume
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002452 * @new_state: state to set devices to after unblocking
Linus Torvalds1da177e2005-04-16 15:20:36 -07002453 *
2454 * Called by scsi lld's or the midlayer to restart the device queue
2455 * for the previously suspended scsi device. Called from interrupt or
2456 * normal process context.
2457 *
2458 * Returns zero if successful or error if not.
2459 *
2460 * Notes:
2461 * This routine transitions the device to the SDEV_RUNNING state
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002462 * or to one of the offline states (which must be a legal transition)
Mike Christied0754982012-05-17 23:56:58 -05002463 * allowing the midlayer to goose the queue for this device.
Rob Landleyeb44820c2007-11-03 13:30:39 -05002464 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002465int
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002466scsi_internal_device_unblock(struct scsi_device *sdev,
2467 enum scsi_device_state new_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002468{
Jens Axboe165125e2007-07-24 09:28:11 +02002469 struct request_queue *q = sdev->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002470 unsigned long flags;
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002471
2472 /*
2473 * Try to transition the scsi device to SDEV_RUNNING or one of the
2474 * offlined states and goose the device queue if successful.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002475 */
Takahiro Yasui5c10e632009-04-29 12:13:02 -04002476 if (sdev->sdev_state == SDEV_BLOCK)
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002477 sdev->sdev_state = new_state;
2478 else if (sdev->sdev_state == SDEV_CREATED_BLOCK) {
2479 if (new_state == SDEV_TRANSPORT_OFFLINE ||
2480 new_state == SDEV_OFFLINE)
2481 sdev->sdev_state = new_state;
2482 else
2483 sdev->sdev_state = SDEV_CREATED;
2484 } else if (sdev->sdev_state != SDEV_CANCEL &&
Mike Christie986fe6c2010-10-06 03:10:59 -05002485 sdev->sdev_state != SDEV_OFFLINE)
Takahiro Yasui5c10e632009-04-29 12:13:02 -04002486 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002487
2488 spin_lock_irqsave(q->queue_lock, flags);
2489 blk_start_queue(q);
2490 spin_unlock_irqrestore(q->queue_lock, flags);
2491
2492 return 0;
2493}
2494EXPORT_SYMBOL_GPL(scsi_internal_device_unblock);
2495
2496static void
2497device_block(struct scsi_device *sdev, void *data)
2498{
2499 scsi_internal_device_block(sdev);
2500}
2501
2502static int
2503target_block(struct device *dev, void *data)
2504{
2505 if (scsi_is_target_device(dev))
2506 starget_for_each_device(to_scsi_target(dev), NULL,
2507 device_block);
2508 return 0;
2509}
2510
2511void
2512scsi_target_block(struct device *dev)
2513{
2514 if (scsi_is_target_device(dev))
2515 starget_for_each_device(to_scsi_target(dev), NULL,
2516 device_block);
2517 else
2518 device_for_each_child(dev, NULL, target_block);
2519}
2520EXPORT_SYMBOL_GPL(scsi_target_block);
2521
2522static void
2523device_unblock(struct scsi_device *sdev, void *data)
2524{
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002525 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002526}
2527
2528static int
2529target_unblock(struct device *dev, void *data)
2530{
2531 if (scsi_is_target_device(dev))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002532 starget_for_each_device(to_scsi_target(dev), data,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002533 device_unblock);
2534 return 0;
2535}
2536
2537void
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002538scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002539{
2540 if (scsi_is_target_device(dev))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002541 starget_for_each_device(to_scsi_target(dev), &new_state,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002542 device_unblock);
2543 else
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002544 device_for_each_child(dev, &new_state, target_unblock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002545}
2546EXPORT_SYMBOL_GPL(scsi_target_unblock);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002547
2548/**
2549 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
Rob Landleyeb44820c2007-11-03 13:30:39 -05002550 * @sgl: scatter-gather list
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002551 * @sg_count: number of segments in sg
2552 * @offset: offset in bytes into sg, on return offset into the mapped area
2553 * @len: bytes to map, on return number of bytes mapped
2554 *
2555 * Returns virtual address of the start of the mapped page
2556 */
Jens Axboec6132da2007-10-16 11:08:49 +02002557void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002558 size_t *offset, size_t *len)
2559{
2560 int i;
2561 size_t sg_len = 0, len_complete = 0;
Jens Axboec6132da2007-10-16 11:08:49 +02002562 struct scatterlist *sg;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002563 struct page *page;
2564
Andrew Morton22cfefb2007-02-05 16:39:03 -08002565 WARN_ON(!irqs_disabled());
2566
Jens Axboec6132da2007-10-16 11:08:49 +02002567 for_each_sg(sgl, sg, sg_count, i) {
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002568 len_complete = sg_len; /* Complete sg-entries */
Jens Axboec6132da2007-10-16 11:08:49 +02002569 sg_len += sg->length;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002570 if (sg_len > *offset)
2571 break;
2572 }
2573
2574 if (unlikely(i == sg_count)) {
Andrew Morton169e1a22006-04-18 21:09:08 -07002575 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
2576 "elements %d\n",
Harvey Harrisoncadbd4a2008-07-03 23:47:27 -07002577 __func__, sg_len, *offset, sg_count);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002578 WARN_ON(1);
2579 return NULL;
2580 }
2581
2582 /* Offset starting from the beginning of first page in this sg-entry */
Jens Axboec6132da2007-10-16 11:08:49 +02002583 *offset = *offset - len_complete + sg->offset;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002584
2585 /* Assumption: contiguous pages can be accessed as "page + i" */
Jens Axboe45711f12007-10-22 21:19:53 +02002586 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002587 *offset &= ~PAGE_MASK;
2588
2589 /* Bytes in this sg-entry from *offset to the end of the page */
2590 sg_len = PAGE_SIZE - *offset;
2591 if (*len > sg_len)
2592 *len = sg_len;
2593
Cong Wang77dfce02011-11-25 23:14:23 +08002594 return kmap_atomic(page);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002595}
2596EXPORT_SYMBOL(scsi_kmap_atomic_sg);
2597
2598/**
Rob Landleyeb44820c2007-11-03 13:30:39 -05002599 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002600 * @virt: virtual address to be unmapped
2601 */
2602void scsi_kunmap_atomic_sg(void *virt)
2603{
Cong Wang77dfce02011-11-25 23:14:23 +08002604 kunmap_atomic(virt);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002605}
2606EXPORT_SYMBOL(scsi_kunmap_atomic_sg);