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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Christoph Hellwigd2852032014-01-17 12:06:53 +01002 * Copyright (C) 1999 Eric Youngdale
3 * Copyright (C) 2014 Christoph Hellwig
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * SCSI queueing library.
6 * Initial versions: Eric Youngdale (eric@andante.org).
7 * Based upon conversations with large numbers
8 * of people at Linux Expo.
9 */
10
11#include <linux/bio.h>
James Bottomleyd3f46f32008-01-15 11:11:46 -060012#include <linux/bitops.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/blkdev.h>
14#include <linux/completion.h>
15#include <linux/kernel.h>
Paul Gortmaker09703662011-05-27 09:37:25 -040016#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/init.h>
18#include <linux/pci.h>
19#include <linux/delay.h>
James Bottomleyfaead262006-02-14 10:42:07 -060020#include <linux/hardirq.h>
Jens Axboec6132da2007-10-16 11:08:49 +020021#include <linux/scatterlist.h>
Christoph Hellwigd2852032014-01-17 12:06:53 +010022#include <linux/blk-mq.h>
Hannes Reineckef1569ff2014-10-24 14:27:07 +020023#include <linux/ratelimit.h>
Hannes Reineckea8aa3972015-12-01 10:16:57 +010024#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26#include <scsi/scsi.h>
Christoph Hellwigbeb40482006-06-10 18:01:03 +020027#include <scsi/scsi_cmnd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <scsi/scsi_dbg.h>
29#include <scsi/scsi_device.h>
30#include <scsi/scsi_driver.h>
31#include <scsi/scsi_eh.h>
32#include <scsi/scsi_host.h>
Christoph Hellwigee14c672015-08-27 14:16:59 +020033#include <scsi/scsi_dh.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Christoph Hellwig3b5382c2014-05-06 12:25:40 +020035#include <trace/events/scsi.h>
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include "scsi_priv.h"
38#include "scsi_logging.h"
39
40
Martin K. Petersen7027ad72008-07-17 17:08:48 -040041struct kmem_cache *scsi_sdb_cache;
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +020042
Jens Axboea488e742010-04-16 21:13:15 +020043/*
44 * When to reinvoke queueing after a resource shortage. It's 3 msecs to
45 * not change behaviour from the previous unplug mechanism, experimentation
46 * may prove this needs changing.
47 */
48#define SCSI_QUEUE_DELAY 3
49
Christoph Hellwigde3e8bf2014-01-23 13:55:38 +010050static void
51scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
53 struct Scsi_Host *host = cmd->device->host;
54 struct scsi_device *device = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -050055 struct scsi_target *starget = scsi_target(device);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
57 /*
Tejun Heo d8c37e72005-05-14 00:46:08 +090058 * Set the appropriate busy bit for the device/host.
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 *
60 * If the host/device isn't busy, assume that something actually
61 * completed, and that we should be able to queue a command now.
62 *
63 * Note that the prior mid-layer assumption that any host could
64 * always queue at least one command is now broken. The mid-layer
65 * will implement a user specifiable stall (see
66 * scsi_host.max_host_blocked and scsi_device.max_device_blocked)
67 * if a command is requeued with no other commands outstanding
68 * either for the device or for the host.
69 */
Mike Christief0c0a372008-08-17 15:24:38 -050070 switch (reason) {
71 case SCSI_MLQUEUE_HOST_BUSY:
Christoph Hellwigcd9070c2014-01-23 12:07:41 +010072 atomic_set(&host->host_blocked, host->max_host_blocked);
Mike Christief0c0a372008-08-17 15:24:38 -050073 break;
74 case SCSI_MLQUEUE_DEVICE_BUSY:
James Smart573e5912011-07-06 12:45:17 -040075 case SCSI_MLQUEUE_EH_RETRY:
Christoph Hellwigcd9070c2014-01-23 12:07:41 +010076 atomic_set(&device->device_blocked,
77 device->max_device_blocked);
Mike Christief0c0a372008-08-17 15:24:38 -050078 break;
79 case SCSI_MLQUEUE_TARGET_BUSY:
Christoph Hellwigcd9070c2014-01-23 12:07:41 +010080 atomic_set(&starget->target_blocked,
81 starget->max_target_blocked);
Mike Christief0c0a372008-08-17 15:24:38 -050082 break;
83 }
Christoph Hellwigde3e8bf2014-01-23 13:55:38 +010084}
85
Christoph Hellwigd2852032014-01-17 12:06:53 +010086static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
87{
88 struct scsi_device *sdev = cmd->device;
Christoph Hellwigd2852032014-01-17 12:06:53 +010089
Bart Van Assche2b053ac2016-10-28 17:21:41 -070090 blk_mq_requeue_request(cmd->request, true);
Christoph Hellwigd2852032014-01-17 12:06:53 +010091 put_device(&sdev->sdev_gendev);
92}
93
Christoph Hellwigde3e8bf2014-01-23 13:55:38 +010094/**
95 * __scsi_queue_insert - private queue insertion
96 * @cmd: The SCSI command being requeued
97 * @reason: The reason for the requeue
98 * @unbusy: Whether the queue should be unbusied
99 *
100 * This is a private queue insertion. The public interface
101 * scsi_queue_insert() always assumes the queue should be unbusied
102 * because it's always called before the completion. This function is
103 * for a requeue after completion, which should only occur in this
104 * file.
105 */
106static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
107{
108 struct scsi_device *device = cmd->device;
109 struct request_queue *q = device->request_queue;
110 unsigned long flags;
111
112 SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd,
113 "Inserting command %p into mlqueue\n", cmd));
114
115 scsi_set_blocked(cmd, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
117 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 * Decrement the counters, since these commands are no longer
119 * active on the host/device.
120 */
James Bottomley4f5299a2009-01-02 10:42:21 -0600121 if (unbusy)
122 scsi_device_unbusy(device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124 /*
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500125 * Requeue this command. It will go before all other commands
Bart Van Asscheb4854622012-06-29 15:36:07 +0000126 * that are already in the queue. Schedule requeue work under
127 * lock such that the kblockd_schedule_work() call happens
128 * before blk_cleanup_queue() finishes.
Jens Axboea488e742010-04-16 21:13:15 +0200129 */
Alan Stern644373a2014-03-28 10:51:15 -0700130 cmd->result = 0;
Christoph Hellwigd2852032014-01-17 12:06:53 +0100131 if (q->mq_ops) {
132 scsi_mq_requeue_cmd(cmd);
133 return;
134 }
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500135 spin_lock_irqsave(q->queue_lock, flags);
James Bottomley59897da2005-09-14 12:57:42 -0400136 blk_requeue_request(q, cmd->request);
Jens Axboe59c3d452014-04-08 09:15:35 -0600137 kblockd_schedule_work(&device->requeue_work);
Bart Van Asscheb4854622012-06-29 15:36:07 +0000138 spin_unlock_irqrestore(q->queue_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139}
140
James Bottomley4f5299a2009-01-02 10:42:21 -0600141/*
142 * Function: scsi_queue_insert()
143 *
144 * Purpose: Insert a command in the midlevel queue.
145 *
146 * Arguments: cmd - command that we are adding to queue.
147 * reason - why we are inserting command to queue.
148 *
149 * Lock status: Assumed that lock is not held upon entry.
150 *
151 * Returns: Nothing.
152 *
153 * Notes: We do this for one of two cases. Either the host is busy
154 * and it cannot accept any more commands for the time being,
155 * or the device returned QUEUE_FULL and can accept no more
156 * commands.
157 * Notes: This could be called either from an interrupt context or a
158 * normal process context.
159 */
Bart Van Assche84feb162012-06-29 15:35:05 +0000160void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
James Bottomley4f5299a2009-01-02 10:42:21 -0600161{
Bart Van Assche84feb162012-06-29 15:35:05 +0000162 __scsi_queue_insert(cmd, reason, 1);
James Bottomley4f5299a2009-01-02 10:42:21 -0600163}
Christoph Hellwige8064022016-10-20 15:12:13 +0200164
165static int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
James Bottomley33aa6872005-08-28 11:31:14 -0500166 int data_direction, void *buffer, unsigned bufflen,
Martin K. Petersen2bfad212014-04-09 22:20:48 -0400167 unsigned char *sense, int timeout, int retries, u64 flags,
Christoph Hellwige8064022016-10-20 15:12:13 +0200168 req_flags_t rq_flags, int *resid)
James Bottomley39216032005-06-15 18:48:29 -0500169{
170 struct request *req;
171 int write = (data_direction == DMA_TO_DEVICE);
172 int ret = DRIVER_ERROR << 24;
173
Mel Gorman71baba42015-11-06 16:28:28 -0800174 req = blk_get_request(sdev->request_queue, write, __GFP_RECLAIM);
Joe Lawrencea492f072014-08-28 08:15:21 -0600175 if (IS_ERR(req))
James Bottomleybfe159a2011-07-07 15:45:40 -0500176 return ret;
Jens Axboef27b0872014-06-06 07:57:37 -0600177 blk_rq_set_block_pc(req);
James Bottomley39216032005-06-15 18:48:29 -0500178
179 if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
Mel Gorman71baba42015-11-06 16:28:28 -0800180 buffer, bufflen, __GFP_RECLAIM))
James Bottomley39216032005-06-15 18:48:29 -0500181 goto out;
182
183 req->cmd_len = COMMAND_SIZE(cmd[0]);
184 memcpy(req->cmd, cmd, req->cmd_len);
185 req->sense = sense;
186 req->sense_len = 0;
Mike Christie17e01f22005-11-11 05:31:37 -0600187 req->retries = retries;
James Bottomley39216032005-06-15 18:48:29 -0500188 req->timeout = timeout;
Christoph Hellwige8064022016-10-20 15:12:13 +0200189 req->cmd_flags |= flags;
190 req->rq_flags |= rq_flags | RQF_QUIET | RQF_PREEMPT;
James Bottomley39216032005-06-15 18:48:29 -0500191
192 /*
193 * head injection *required* here otherwise quiesce won't work
194 */
195 blk_execute_rq(req->q, NULL, req, 1);
196
Alan Sternbdb2b8c2008-06-24 14:03:14 -0400197 /*
198 * Some devices (USB mass-storage in particular) may transfer
199 * garbage data together with a residue indicating that the data
200 * is invalid. Prevent the garbage from being misinterpreted
201 * and prevent security leaks by zeroing out the excess data.
202 */
Tejun Heoc3a4d782009-05-07 22:24:37 +0900203 if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen))
204 memset(buffer + (bufflen - req->resid_len), 0, req->resid_len);
Alan Sternbdb2b8c2008-06-24 14:03:14 -0400205
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900206 if (resid)
Tejun Heoc3a4d782009-05-07 22:24:37 +0900207 *resid = req->resid_len;
James Bottomley39216032005-06-15 18:48:29 -0500208 ret = req->errors;
209 out:
210 blk_put_request(req);
211
212 return ret;
213}
Christoph Hellwige8064022016-10-20 15:12:13 +0200214
215/**
216 * scsi_execute - insert request and wait for the result
217 * @sdev: scsi device
218 * @cmd: scsi command
219 * @data_direction: data direction
220 * @buffer: data buffer
221 * @bufflen: len of buffer
222 * @sense: optional sense buffer
223 * @timeout: request timeout in seconds
224 * @retries: number of times to retry request
225 * @flags: or into request flags;
226 * @resid: optional residual length
227 *
228 * returns the req->errors value which is the scsi_cmnd result
229 * field.
230 */
231int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
232 int data_direction, void *buffer, unsigned bufflen,
233 unsigned char *sense, int timeout, int retries, u64 flags,
234 int *resid)
235{
236 return __scsi_execute(sdev, cmd, data_direction, buffer, bufflen, sense,
237 timeout, retries, flags, 0, resid);
238}
James Bottomley33aa6872005-08-28 11:31:14 -0500239EXPORT_SYMBOL(scsi_execute);
James Bottomley39216032005-06-15 18:48:29 -0500240
Lin Ming9b214932013-03-23 11:42:25 +0800241int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd,
James Bottomleyea73a9f2005-08-28 11:33:52 -0500242 int data_direction, void *buffer, unsigned bufflen,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900243 struct scsi_sense_hdr *sshdr, int timeout, int retries,
Christoph Hellwige8064022016-10-20 15:12:13 +0200244 int *resid, u64 flags, req_flags_t rq_flags)
James Bottomleyea73a9f2005-08-28 11:33:52 -0500245{
246 char *sense = NULL;
akpm@osdl.org1ccb48b2005-06-26 00:12:51 -0700247 int result;
248
James Bottomleyea73a9f2005-08-28 11:33:52 -0500249 if (sshdr) {
Jes Sorensen24669f752006-01-16 10:31:18 -0500250 sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500251 if (!sense)
252 return DRIVER_ERROR << 24;
James Bottomleyea73a9f2005-08-28 11:33:52 -0500253 }
Christoph Hellwige8064022016-10-20 15:12:13 +0200254 result = __scsi_execute(sdev, cmd, data_direction, buffer, bufflen,
255 sense, timeout, retries, flags, rq_flags, resid);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500256 if (sshdr)
James Bottomleye5143852005-08-09 11:55:36 -0500257 scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500258
259 kfree(sense);
260 return result;
261}
Lin Ming9b214932013-03-23 11:42:25 +0800262EXPORT_SYMBOL(scsi_execute_req_flags);
James Bottomleyea73a9f2005-08-28 11:33:52 -0500263
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264/*
265 * Function: scsi_init_cmd_errh()
266 *
267 * Purpose: Initialize cmd fields related to error handling.
268 *
269 * Arguments: cmd - command that is ready to be queued.
270 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 * Notes: This function has the job of initializing a number of
272 * fields related to error handling. Typically this will
273 * be called once for each command, as required.
274 */
Christoph Hellwig631c2282006-07-08 20:42:15 +0200275static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 cmd->serial_number = 0;
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200278 scsi_set_resid(cmd, 0);
FUJITA Tomonorib80ca4f2008-01-13 15:46:13 +0900279 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 if (cmd->cmd_len == 0)
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300281 cmd->cmd_len = scsi_command_size(cmd->cmnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282}
283
284void scsi_device_unbusy(struct scsi_device *sdev)
285{
286 struct Scsi_Host *shost = sdev->host;
Mike Christief0c0a372008-08-17 15:24:38 -0500287 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 unsigned long flags;
289
Christoph Hellwig74665012014-01-22 15:29:29 +0100290 atomic_dec(&shost->host_busy);
Christoph Hellwig2ccbb002014-03-26 10:35:00 +0100291 if (starget->can_queue > 0)
292 atomic_dec(&starget->target_busy);
Christoph Hellwig74665012014-01-22 15:29:29 +0100293
James Bottomley939647e2005-09-18 15:05:20 -0500294 if (unlikely(scsi_host_in_recovery(shost) &&
Christoph Hellwig74665012014-01-22 15:29:29 +0100295 (shost->host_failed || shost->host_eh_scheduled))) {
296 spin_lock_irqsave(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 scsi_eh_wakeup(shost);
Christoph Hellwig74665012014-01-22 15:29:29 +0100298 spin_unlock_irqrestore(shost->host_lock, flags);
299 }
300
Christoph Hellwig71e75c92014-04-11 19:07:01 +0200301 atomic_dec(&sdev->device_busy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302}
303
Christoph Hellwigd2852032014-01-17 12:06:53 +0100304static void scsi_kick_queue(struct request_queue *q)
305{
306 if (q->mq_ops)
307 blk_mq_start_hw_queues(q);
308 else
309 blk_run_queue(q);
310}
311
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312/*
313 * Called for single_lun devices on IO completion. Clear starget_sdev_user,
314 * and call blk_run_queue for all the scsi_devices on the target -
315 * including current_sdev first.
316 *
317 * Called with *no* scsi locks held.
318 */
319static void scsi_single_lun_run(struct scsi_device *current_sdev)
320{
321 struct Scsi_Host *shost = current_sdev->host;
322 struct scsi_device *sdev, *tmp;
323 struct scsi_target *starget = scsi_target(current_sdev);
324 unsigned long flags;
325
326 spin_lock_irqsave(shost->host_lock, flags);
327 starget->starget_sdev_user = NULL;
328 spin_unlock_irqrestore(shost->host_lock, flags);
329
330 /*
331 * Call blk_run_queue for all LUNs on the target, starting with
332 * current_sdev. We race with others (to set starget_sdev_user),
333 * but in most cases, we will be first. Ideally, each LU on the
334 * target would get some limited time or requests on the target.
335 */
Christoph Hellwigd2852032014-01-17 12:06:53 +0100336 scsi_kick_queue(current_sdev->request_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
338 spin_lock_irqsave(shost->host_lock, flags);
339 if (starget->starget_sdev_user)
340 goto out;
341 list_for_each_entry_safe(sdev, tmp, &starget->devices,
342 same_target_siblings) {
343 if (sdev == current_sdev)
344 continue;
345 if (scsi_device_get(sdev))
346 continue;
347
348 spin_unlock_irqrestore(shost->host_lock, flags);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100349 scsi_kick_queue(sdev->request_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 spin_lock_irqsave(shost->host_lock, flags);
351
352 scsi_device_put(sdev);
353 }
354 out:
355 spin_unlock_irqrestore(shost->host_lock, flags);
356}
357
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100358static inline bool scsi_device_is_busy(struct scsi_device *sdev)
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400359{
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100360 if (atomic_read(&sdev->device_busy) >= sdev->queue_depth)
361 return true;
362 if (atomic_read(&sdev->device_blocked) > 0)
363 return true;
364 return false;
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400365}
366
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100367static inline bool scsi_target_is_busy(struct scsi_target *starget)
Mike Christief0c0a372008-08-17 15:24:38 -0500368{
Christoph Hellwig2ccbb002014-03-26 10:35:00 +0100369 if (starget->can_queue > 0) {
370 if (atomic_read(&starget->target_busy) >= starget->can_queue)
371 return true;
372 if (atomic_read(&starget->target_blocked) > 0)
373 return true;
374 }
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100375 return false;
Mike Christief0c0a372008-08-17 15:24:38 -0500376}
377
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100378static inline bool scsi_host_is_busy(struct Scsi_Host *shost)
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400379{
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100380 if (shost->can_queue > 0 &&
381 atomic_read(&shost->host_busy) >= shost->can_queue)
382 return true;
383 if (atomic_read(&shost->host_blocked) > 0)
384 return true;
385 if (shost->host_self_blocked)
386 return true;
387 return false;
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400388}
389
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800390static void scsi_starved_list_run(struct Scsi_Host *shost)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391{
Mike Christie2a3a59e2008-11-11 13:42:35 -0600392 LIST_HEAD(starved_list);
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800393 struct scsi_device *sdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 unsigned long flags;
395
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 spin_lock_irqsave(shost->host_lock, flags);
Mike Christie2a3a59e2008-11-11 13:42:35 -0600397 list_splice_init(&shost->starved_list, &starved_list);
398
399 while (!list_empty(&starved_list)) {
James Bottomleye2eb7242013-07-02 15:05:26 +0200400 struct request_queue *slq;
401
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 /*
403 * As long as shost is accepting commands and we have
404 * starved queues, call blk_run_queue. scsi_request_fn
405 * drops the queue_lock and can add us back to the
406 * starved_list.
407 *
408 * host_lock protects the starved_list and starved_entry.
409 * scsi_request_fn must get the host_lock before checking
410 * or modifying starved_list or starved_entry.
411 */
Mike Christie2a3a59e2008-11-11 13:42:35 -0600412 if (scsi_host_is_busy(shost))
Mike Christief0c0a372008-08-17 15:24:38 -0500413 break;
Mike Christief0c0a372008-08-17 15:24:38 -0500414
Mike Christie2a3a59e2008-11-11 13:42:35 -0600415 sdev = list_entry(starved_list.next,
416 struct scsi_device, starved_entry);
417 list_del_init(&sdev->starved_entry);
Mike Christief0c0a372008-08-17 15:24:38 -0500418 if (scsi_target_is_busy(scsi_target(sdev))) {
419 list_move_tail(&sdev->starved_entry,
420 &shost->starved_list);
421 continue;
422 }
423
James Bottomleye2eb7242013-07-02 15:05:26 +0200424 /*
425 * Once we drop the host lock, a racing scsi_remove_device()
426 * call may remove the sdev from the starved list and destroy
427 * it and the queue. Mitigate by taking a reference to the
428 * queue and never touching the sdev again after we drop the
429 * host lock. Note: if __scsi_remove_device() invokes
430 * blk_cleanup_queue() before the queue is run from this
431 * function then blk_run_queue() will return immediately since
432 * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING.
433 */
434 slq = sdev->request_queue;
435 if (!blk_get_queue(slq))
436 continue;
437 spin_unlock_irqrestore(shost->host_lock, flags);
438
Christoph Hellwigd2852032014-01-17 12:06:53 +0100439 scsi_kick_queue(slq);
James Bottomleye2eb7242013-07-02 15:05:26 +0200440 blk_put_queue(slq);
441
442 spin_lock_irqsave(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 }
Mike Christie2a3a59e2008-11-11 13:42:35 -0600444 /* put any unprocessed entries back */
445 list_splice(&starved_list, &shost->starved_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 spin_unlock_irqrestore(shost->host_lock, flags);
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800447}
448
449/*
450 * Function: scsi_run_queue()
451 *
452 * Purpose: Select a proper request queue to serve next
453 *
454 * Arguments: q - last request's queue
455 *
456 * Returns: Nothing
457 *
458 * Notes: The previous command was completely finished, start
459 * a new one if possible.
460 */
461static void scsi_run_queue(struct request_queue *q)
462{
463 struct scsi_device *sdev = q->queuedata;
464
465 if (scsi_target(sdev)->single_lun)
466 scsi_single_lun_run(sdev);
467 if (!list_empty(&sdev->host->starved_list))
468 scsi_starved_list_run(sdev->host);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
Christoph Hellwigd2852032014-01-17 12:06:53 +0100470 if (q->mq_ops)
471 blk_mq_start_stopped_hw_queues(q, false);
472 else
473 blk_run_queue(q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474}
475
Jens Axboe9937a5e2011-05-17 11:04:44 +0200476void scsi_requeue_run_queue(struct work_struct *work)
477{
478 struct scsi_device *sdev;
479 struct request_queue *q;
480
481 sdev = container_of(work, struct scsi_device, requeue_work);
482 q = sdev->request_queue;
483 scsi_run_queue(q);
484}
485
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486/*
487 * Function: scsi_requeue_command()
488 *
489 * Purpose: Handle post-processing of completed commands.
490 *
491 * Arguments: q - queue to operate on
492 * cmd - command that may need to be requeued.
493 *
494 * Returns: Nothing
495 *
496 * Notes: After command completion, there may be blocks left
497 * over which weren't finished by the previous command
498 * this can be for a number of reasons - the main one is
499 * I/O errors in the middle of the request, in which case
500 * we need to request the blocks that come after the bad
501 * sector.
James Bottomleye91442b2005-09-09 10:44:16 -0500502 * Notes: Upon return, cmd is a stale pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 */
504static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
505{
Bart Van Assche940f5d42012-06-29 15:34:26 +0000506 struct scsi_device *sdev = cmd->device;
James Bottomleye91442b2005-09-09 10:44:16 -0500507 struct request *req = cmd->request;
Tejun Heo 283369c2005-04-24 02:06:36 -0500508 unsigned long flags;
509
Tejun Heo 283369c2005-04-24 02:06:36 -0500510 spin_lock_irqsave(q->queue_lock, flags);
Christoph Hellwig134997a2014-02-20 14:20:58 -0800511 blk_unprep_request(req);
512 req->special = NULL;
513 scsi_put_command(cmd);
James Bottomleye91442b2005-09-09 10:44:16 -0500514 blk_requeue_request(q, req);
Tejun Heo 283369c2005-04-24 02:06:36 -0500515 spin_unlock_irqrestore(q->queue_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517 scsi_run_queue(q);
Bart Van Assche940f5d42012-06-29 15:34:26 +0000518
519 put_device(&sdev->sdev_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520}
521
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522void scsi_run_host_queues(struct Scsi_Host *shost)
523{
524 struct scsi_device *sdev;
525
526 shost_for_each_device(sdev, shost)
527 scsi_run_queue(sdev->request_queue);
528}
529
Christoph Hellwigd2852032014-01-17 12:06:53 +0100530static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
531{
532 if (cmd->request->cmd_type == REQ_TYPE_FS) {
533 struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
534
535 if (drv->uninit_command)
536 drv->uninit_command(cmd);
537 }
538}
539
540static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
541{
Ming Lin91dbc082016-04-04 14:48:07 -0700542 struct scsi_data_buffer *sdb;
543
Christoph Hellwigd2852032014-01-17 12:06:53 +0100544 if (cmd->sdb.table.nents)
Ming Lin001d63b2016-04-04 14:48:09 -0700545 sg_free_table_chained(&cmd->sdb.table, true);
Ming Lin91dbc082016-04-04 14:48:07 -0700546 if (cmd->request->next_rq) {
547 sdb = cmd->request->next_rq->special;
548 if (sdb)
Ming Lin001d63b2016-04-04 14:48:09 -0700549 sg_free_table_chained(&sdb->table, true);
Ming Lin91dbc082016-04-04 14:48:07 -0700550 }
Christoph Hellwigd2852032014-01-17 12:06:53 +0100551 if (scsi_prot_sg_count(cmd))
Ming Lin001d63b2016-04-04 14:48:09 -0700552 sg_free_table_chained(&cmd->prot_sdb->table, true);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100553}
554
555static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
556{
557 struct scsi_device *sdev = cmd->device;
Kashyap.Desai@avagotech.com64bdcbc2014-08-20 19:24:33 +0530558 struct Scsi_Host *shost = sdev->host;
Christoph Hellwigd2852032014-01-17 12:06:53 +0100559 unsigned long flags;
560
Christoph Hellwigd2852032014-01-17 12:06:53 +0100561 scsi_mq_free_sgtables(cmd);
562 scsi_uninit_cmd(cmd);
563
Kashyap.Desai@avagotech.com64bdcbc2014-08-20 19:24:33 +0530564 if (shost->use_cmd_list) {
565 BUG_ON(list_empty(&cmd->list));
566 spin_lock_irqsave(&sdev->list_lock, flags);
567 list_del_init(&cmd->list);
568 spin_unlock_irqrestore(&sdev->list_lock, flags);
569 }
Christoph Hellwigd2852032014-01-17 12:06:53 +0100570}
571
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572/*
573 * Function: scsi_release_buffers()
574 *
Christoph Hellwigc682adf2014-05-01 16:51:02 +0200575 * Purpose: Free resources allocate for a scsi_command.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 *
577 * Arguments: cmd - command that we are bailing.
578 *
579 * Lock status: Assumed that no lock is held upon entry.
580 *
581 * Returns: Nothing
582 *
583 * Notes: In the event that an upper level driver rejects a
584 * command, we must release resources allocated during
585 * the __init_io() function. Primarily this would involve
Christoph Hellwigc682adf2014-05-01 16:51:02 +0200586 * the scatter-gather table.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 */
Christoph Hellwigf1bea552014-04-15 12:26:54 +0200588static void scsi_release_buffers(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589{
Christoph Hellwigc682adf2014-05-01 16:51:02 +0200590 if (cmd->sdb.table.nents)
Ming Lin001d63b2016-04-04 14:48:09 -0700591 sg_free_table_chained(&cmd->sdb.table, false);
Christoph Hellwigc682adf2014-05-01 16:51:02 +0200592
593 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
594
595 if (scsi_prot_sg_count(cmd))
Ming Lin001d63b2016-04-04 14:48:09 -0700596 sg_free_table_chained(&cmd->prot_sdb->table, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597}
598
Christoph Hellwigc682adf2014-05-01 16:51:02 +0200599static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd)
600{
601 struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special;
602
Ming Lin001d63b2016-04-04 14:48:09 -0700603 sg_free_table_chained(&bidi_sdb->table, false);
Christoph Hellwigc682adf2014-05-01 16:51:02 +0200604 kmem_cache_free(scsi_sdb_cache, bidi_sdb);
605 cmd->request->next_rq->special = NULL;
606}
607
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800608static bool scsi_end_request(struct request *req, int error,
609 unsigned int bytes, unsigned int bidi_bytes)
610{
611 struct scsi_cmnd *cmd = req->special;
612 struct scsi_device *sdev = cmd->device;
613 struct request_queue *q = sdev->request_queue;
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800614
615 if (blk_update_request(req, error, bytes))
616 return true;
617
618 /* Bidi request must be completed as a whole */
619 if (unlikely(bidi_bytes) &&
620 blk_update_request(req->next_rq, error, bidi_bytes))
621 return true;
622
623 if (blk_queue_add_random(q))
624 add_disk_randomness(req->rq_disk);
625
Christoph Hellwigd2852032014-01-17 12:06:53 +0100626 if (req->mq_ctx) {
627 /*
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700628 * In the MQ case the command gets freed by __blk_mq_end_request,
Christoph Hellwigd2852032014-01-17 12:06:53 +0100629 * so we have to do all cleanup that depends on it earlier.
630 *
631 * We also can't kick the queues from irq context, so we
632 * will have to defer it to a workqueue.
633 */
634 scsi_mq_uninit_cmd(cmd);
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800635
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700636 __blk_mq_end_request(req, error);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100637
638 if (scsi_target(sdev)->single_lun ||
639 !list_empty(&sdev->host->starved_list))
640 kblockd_schedule_work(&sdev->requeue_work);
641 else
642 blk_mq_start_stopped_hw_queues(q, true);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100643 } else {
644 unsigned long flags;
645
Daniel Gryniewiczf81426a2014-09-16 10:41:13 -0400646 if (bidi_bytes)
647 scsi_release_bidi_buffers(cmd);
648
Christoph Hellwigd2852032014-01-17 12:06:53 +0100649 spin_lock_irqsave(q->queue_lock, flags);
650 blk_finish_request(req, error);
651 spin_unlock_irqrestore(q->queue_lock, flags);
652
Christoph Hellwigd2852032014-01-17 12:06:53 +0100653 scsi_release_buffers(cmd);
Christoph Hellwigbb3ec622014-09-05 18:02:09 -0700654
655 scsi_put_command(cmd);
656 scsi_run_queue(q);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100657 }
658
Christoph Hellwigbb3ec622014-09-05 18:02:09 -0700659 put_device(&sdev->sdev_gendev);
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800660 return false;
661}
662
Hannes Reinecke0f7f6232013-07-01 15:16:23 +0200663/**
664 * __scsi_error_from_host_byte - translate SCSI error code into errno
665 * @cmd: SCSI command (unused)
666 * @result: scsi error code
667 *
668 * Translate SCSI error code into standard UNIX errno.
669 * Return values:
670 * -ENOLINK temporary transport failure
671 * -EREMOTEIO permanent target failure, do not retry
672 * -EBADE permanent nexus failure, retry on other path
Hannes Reineckea9d6ceb82013-07-01 15:16:25 +0200673 * -ENOSPC No write space available
Hannes Reinecke7e782af2013-07-01 15:16:26 +0200674 * -ENODATA Medium error
Hannes Reinecke0f7f6232013-07-01 15:16:23 +0200675 * -EIO unspecified I/O error
676 */
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100677static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
678{
679 int error = 0;
680
681 switch(host_byte(result)) {
682 case DID_TRANSPORT_FAILFAST:
683 error = -ENOLINK;
684 break;
685 case DID_TARGET_FAILURE:
Moger, Babu2082ebc2012-01-24 20:38:46 +0000686 set_host_byte(cmd, DID_OK);
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100687 error = -EREMOTEIO;
688 break;
689 case DID_NEXUS_FAILURE:
Moger, Babu2082ebc2012-01-24 20:38:46 +0000690 set_host_byte(cmd, DID_OK);
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100691 error = -EBADE;
692 break;
Hannes Reineckea9d6ceb82013-07-01 15:16:25 +0200693 case DID_ALLOC_FAILURE:
694 set_host_byte(cmd, DID_OK);
695 error = -ENOSPC;
696 break;
Hannes Reinecke7e782af2013-07-01 15:16:26 +0200697 case DID_MEDIUM_ERROR:
698 set_host_byte(cmd, DID_OK);
699 error = -ENODATA;
700 break;
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100701 default:
702 error = -EIO;
703 break;
704 }
705
706 return error;
707}
708
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709/*
710 * Function: scsi_io_completion()
711 *
712 * Purpose: Completion processing for block device I/O requests.
713 *
714 * Arguments: cmd - command that is finished.
715 *
716 * Lock status: Assumed that no lock is held upon entry.
717 *
718 * Returns: Nothing
719 *
Christoph Hellwigbc85dc52014-05-01 16:51:03 +0200720 * Notes: We will finish off the specified number of sectors. If we
721 * are done, the command block will be released and the queue
722 * function will be goosed. If we are not done then we have to
Alan Sternb60af5b2008-11-03 15:56:47 -0500723 * figure out what to do next:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 *
Alan Sternb60af5b2008-11-03 15:56:47 -0500725 * a) We can call scsi_requeue_command(). The request
726 * will be unprepared and put back on the queue. Then
727 * a new command will be created for it. This should
728 * be used if we made forward progress, or if we want
729 * to switch from READ(10) to READ(6) for example.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 *
Christoph Hellwigbc85dc52014-05-01 16:51:03 +0200731 * b) We can call __scsi_queue_insert(). The request will
Alan Sternb60af5b2008-11-03 15:56:47 -0500732 * be put back on the queue and retried using the same
733 * command as before, possibly after a delay.
734 *
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800735 * c) We can call scsi_end_request() with -EIO to fail
Alan Sternb60af5b2008-11-03 15:56:47 -0500736 * the remainder of the request.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 */
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700738void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739{
740 int result = cmd->result;
Jens Axboe165125e2007-07-24 09:28:11 +0200741 struct request_queue *q = cmd->device->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 struct request *req = cmd->request;
James Bottomleyfa8e36c2008-04-02 18:11:52 -0500743 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 struct scsi_sense_hdr sshdr;
Hannes Reinecke4753cbc2014-10-24 14:26:52 +0200745 bool sense_valid = false;
Hannes Reineckec11c0042014-10-24 14:27:01 +0200746 int sense_deferred = 0, level = 0;
Alan Sternb60af5b2008-11-03 15:56:47 -0500747 enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
748 ACTION_DELAYED_RETRY} action;
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900749 unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 if (result) {
752 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
753 if (sense_valid)
754 sense_deferred = scsi_sense_is_deferred(&sshdr);
755 }
Christoph Hellwig631c2282006-07-08 20:42:15 +0200756
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200757 if (req->cmd_type == REQ_TYPE_BLOCK_PC) { /* SG_IO ioctl from block level */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 if (result) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 if (sense_valid && req->sense) {
760 /*
761 * SG_IO wants current and deferred errors
762 */
763 int len = 8 + cmd->sense_buffer[7];
764
765 if (len > SCSI_SENSE_BUFFERSIZE)
766 len = SCSI_SENSE_BUFFERSIZE;
767 memcpy(req->sense, cmd->sense_buffer, len);
768 req->sense_len = len;
769 }
James Bottomleyfa8e36c2008-04-02 18:11:52 -0500770 if (!sense_deferred)
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100771 error = __scsi_error_from_host_byte(cmd, result);
Pete Wyckoffb22f6872007-03-13 16:53:28 -0400772 }
Mike Snitzer27c41972012-05-31 15:05:33 -0400773 /*
774 * __scsi_error_from_host_byte may have reset the host_byte
775 */
776 req->errors = cmd->result;
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900777
778 req->resid_len = scsi_get_resid(cmd);
779
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200780 if (scsi_bidi_cmnd(cmd)) {
FUJITA Tomonorie6bb7a962009-05-11 17:56:08 +0900781 /*
782 * Bidi commands Must be complete as a whole,
783 * both sides at once.
784 */
785 req->next_rq->resid_len = scsi_in(cmd)->resid;
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800786 if (scsi_end_request(req, 0, blk_rq_bytes(req),
787 blk_rq_bytes(req->next_rq)))
788 BUG();
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200789 return;
790 }
James Bottomley89fb4cd2014-07-03 19:17:34 +0200791 } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) {
792 /*
793 * Certain non BLOCK_PC requests are commands that don't
794 * actually transfer anything (FLUSH), so cannot use
795 * good_bytes != blk_rq_bytes(req) as the signal for an error.
796 * This sets the error explicitly for the problem case.
797 */
798 error = __scsi_error_from_host_byte(cmd, result);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 }
800
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200801 /* no bidi support for !REQ_TYPE_BLOCK_PC yet */
802 BUG_ON(blk_bidi_rq(req));
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200803
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 * Next deal with any sectors which we were able to correctly
806 * handle.
807 */
Hannes Reinecke91921e02014-06-25 16:39:59 +0200808 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd,
809 "%u sectors total, %d bytes done.\n",
810 blk_rq_sectors(req), good_bytes));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811
James Bottomleya9bddd72009-03-30 16:55:51 +0000812 /*
813 * Recovered errors need reporting, but they're always treated
814 * as success, so fiddle the result code here. For BLOCK_PC
815 * we already took a copy of the original into rq->errors which
816 * is what gets returned to the user
817 */
Douglas Gilberte7efe592010-01-03 13:51:15 -0500818 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
819 /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip
820 * print since caller wants ATA registers. Only occurs on
821 * SCSI ATA PASS_THROUGH commands when CK_COND=1
822 */
823 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
824 ;
Christoph Hellwige8064022016-10-20 15:12:13 +0200825 else if (!(req->rq_flags & RQF_QUIET))
Hannes Reinecked811b842014-10-24 14:26:45 +0200826 scsi_print_sense(cmd);
James Bottomleya9bddd72009-03-30 16:55:51 +0000827 result = 0;
828 /* BLOCK_PC may have set error */
829 error = 0;
830 }
831
832 /*
James Bottomleya621bac2016-05-13 12:04:06 -0700833 * special case: failed zero length commands always need to
834 * drop down into the retry code. Otherwise, if we finished
835 * all bytes in the request we are done now.
James Bottomleyd6b0c532006-07-02 10:06:28 -0500836 */
James Bottomleya621bac2016-05-13 12:04:06 -0700837 if (!(blk_rq_bytes(req) == 0 && error) &&
838 !scsi_end_request(req, error, good_bytes, 0))
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800839 return;
Christoph Hellwigbc85dc52014-05-01 16:51:03 +0200840
841 /*
842 * Kill remainder if no retrys.
843 */
844 if (error && scsi_noretry_cmd(cmd)) {
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800845 if (scsi_end_request(req, error, blk_rq_bytes(req), 0))
846 BUG();
847 return;
Christoph Hellwigbc85dc52014-05-01 16:51:03 +0200848 }
849
850 /*
851 * If there had been no error, but we have leftover bytes in the
852 * requeues just queue the command up again.
853 */
854 if (result == 0)
855 goto requeue;
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700856
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100857 error = __scsi_error_from_host_byte(cmd, result);
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500858
Alan Sternb60af5b2008-11-03 15:56:47 -0500859 if (host_byte(result) == DID_RESET) {
860 /* Third party bus reset or reset for error recovery
861 * reasons. Just retry the command and see what
862 * happens.
863 */
864 action = ACTION_RETRY;
865 } else if (sense_valid && !sense_deferred) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 switch (sshdr.sense_key) {
867 case UNIT_ATTENTION:
868 if (cmd->device->removable) {
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700869 /* Detected disc change. Set a bit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 * and quietly refuse further access.
871 */
872 cmd->device->changed = 1;
Alan Sternb60af5b2008-11-03 15:56:47 -0500873 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 } else {
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700875 /* Must have been a power glitch, or a
876 * bus reset. Could not have been a
877 * media change, so we just retry the
Alan Sternb60af5b2008-11-03 15:56:47 -0500878 * command and see what happens.
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700879 */
Alan Sternb60af5b2008-11-03 15:56:47 -0500880 action = ACTION_RETRY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 }
882 break;
883 case ILLEGAL_REQUEST:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700884 /* If we had an ILLEGAL REQUEST returned, then
885 * we may have performed an unsupported
886 * command. The only thing this should be
887 * would be a ten byte read where only a six
888 * byte read was supported. Also, on a system
889 * where READ CAPACITY failed, we may have
890 * read past the end of the disk.
891 */
Jens Axboe26a68012005-11-29 21:03:34 +0100892 if ((cmd->device->use_10_for_rw &&
893 sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 (cmd->cmnd[0] == READ_10 ||
895 cmd->cmnd[0] == WRITE_10)) {
Alan Sternb60af5b2008-11-03 15:56:47 -0500896 /* This will issue a new 6-byte command. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 cmd->device->use_10_for_rw = 0;
Alan Sternb60af5b2008-11-03 15:56:47 -0500898 action = ACTION_REPREP;
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500899 } else if (sshdr.asc == 0x10) /* DIX */ {
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500900 action = ACTION_FAIL;
901 error = -EILSEQ;
Martin K. Petersenc98a0eb2011-03-08 02:07:15 -0500902 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
Martin K. Petersen5db44862012-09-18 12:19:32 -0400903 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
Martin K. Petersenc98a0eb2011-03-08 02:07:15 -0500904 action = ACTION_FAIL;
Martin K. Petersen66a651a2012-02-13 15:38:22 -0500905 error = -EREMOTEIO;
Alan Sternb60af5b2008-11-03 15:56:47 -0500906 } else
907 action = ACTION_FAIL;
908 break;
Martin K. Petersen511e44f2008-07-17 04:28:33 -0400909 case ABORTED_COMMAND:
James Bottomley126c09822009-02-19 21:48:54 +0000910 action = ACTION_FAIL;
Maurizio Lombardie6c11db2014-07-10 09:41:53 +0200911 if (sshdr.asc == 0x10) /* DIF */
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500912 error = -EILSEQ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 break;
914 case NOT_READY:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700915 /* If the device is in the process of becoming
James Bottomleyf3e93f72006-04-25 16:48:30 -0500916 * ready, or has a temporary blockage, retry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 */
James Bottomleyf3e93f72006-04-25 16:48:30 -0500918 if (sshdr.asc == 0x04) {
919 switch (sshdr.ascq) {
920 case 0x01: /* becoming ready */
921 case 0x04: /* format in progress */
922 case 0x05: /* rebuild in progress */
923 case 0x06: /* recalculation in progress */
924 case 0x07: /* operation in progress */
925 case 0x08: /* Long write in progress */
926 case 0x09: /* self test in progress */
Martin K. Petersend8705f12009-11-26 12:00:41 -0500927 case 0x14: /* space allocation in progress */
Alan Sternb60af5b2008-11-03 15:56:47 -0500928 action = ACTION_DELAYED_RETRY;
James Bottomleyf3e93f72006-04-25 16:48:30 -0500929 break;
Alan Stern3dbf6a52008-12-15 10:31:28 -0500930 default:
Alan Stern3dbf6a52008-12-15 10:31:28 -0500931 action = ACTION_FAIL;
932 break;
James Bottomleyf3e93f72006-04-25 16:48:30 -0500933 }
Maurizio Lombardie6c11db2014-07-10 09:41:53 +0200934 } else
Alan Sternb60af5b2008-11-03 15:56:47 -0500935 action = ACTION_FAIL;
Alan Sternb60af5b2008-11-03 15:56:47 -0500936 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 case VOLUME_OVERFLOW:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700938 /* See SSC3rXX or current. */
Alan Sternb60af5b2008-11-03 15:56:47 -0500939 action = ACTION_FAIL;
940 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 default:
Alan Sternb60af5b2008-11-03 15:56:47 -0500942 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 break;
944 }
Maurizio Lombardie6c11db2014-07-10 09:41:53 +0200945 } else
Alan Sternb60af5b2008-11-03 15:56:47 -0500946 action = ACTION_FAIL;
Alan Sternb60af5b2008-11-03 15:56:47 -0500947
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900948 if (action != ACTION_FAIL &&
Maurizio Lombardie6c11db2014-07-10 09:41:53 +0200949 time_before(cmd->jiffies_at_alloc + wait_for, jiffies))
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900950 action = ACTION_FAIL;
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900951
Alan Sternb60af5b2008-11-03 15:56:47 -0500952 switch (action) {
953 case ACTION_FAIL:
954 /* Give up and fail the remainder of the request */
Christoph Hellwige8064022016-10-20 15:12:13 +0200955 if (!(req->rq_flags & RQF_QUIET)) {
Hannes Reineckef1569ff2014-10-24 14:27:07 +0200956 static DEFINE_RATELIMIT_STATE(_rs,
957 DEFAULT_RATELIMIT_INTERVAL,
958 DEFAULT_RATELIMIT_BURST);
959
960 if (unlikely(scsi_logging_level))
961 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
962 SCSI_LOG_MLCOMPLETE_BITS);
963
964 /*
965 * if logging is enabled the failure will be printed
966 * in scsi_log_completion(), so avoid duplicate messages
967 */
968 if (!level && __ratelimit(&_rs)) {
969 scsi_print_result(cmd, NULL, FAILED);
970 if (driver_byte(result) & DRIVER_SENSE)
971 scsi_print_sense(cmd);
972 scsi_print_command(cmd);
973 }
James Bottomley3173d8c2005-09-04 11:32:05 -0500974 }
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800975 if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0))
976 return;
Christoph Hellwigbc85dc52014-05-01 16:51:03 +0200977 /*FALLTHRU*/
Alan Sternb60af5b2008-11-03 15:56:47 -0500978 case ACTION_REPREP:
Christoph Hellwigbc85dc52014-05-01 16:51:03 +0200979 requeue:
Alan Sternb60af5b2008-11-03 15:56:47 -0500980 /* Unprep the request and put it back at the head of the queue.
981 * A new command will be prepared and issued.
982 */
Christoph Hellwigd2852032014-01-17 12:06:53 +0100983 if (q->mq_ops) {
Christoph Hellwige8064022016-10-20 15:12:13 +0200984 cmd->request->rq_flags &= ~RQF_DONTPREP;
Christoph Hellwigd2852032014-01-17 12:06:53 +0100985 scsi_mq_uninit_cmd(cmd);
986 scsi_mq_requeue_cmd(cmd);
987 } else {
988 scsi_release_buffers(cmd);
989 scsi_requeue_command(q, cmd);
990 }
Alan Sternb60af5b2008-11-03 15:56:47 -0500991 break;
992 case ACTION_RETRY:
993 /* Retry the same command immediately */
James Bottomley4f5299a2009-01-02 10:42:21 -0600994 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
Alan Sternb60af5b2008-11-03 15:56:47 -0500995 break;
996 case ACTION_DELAYED_RETRY:
997 /* Retry the same command after a delay */
James Bottomley4f5299a2009-01-02 10:42:21 -0600998 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
Alan Sternb60af5b2008-11-03 15:56:47 -0500999 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 }
1001}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002
Christoph Hellwig3c356bd2014-09-05 18:20:23 -07001003static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004{
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001005 int count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006
1007 /*
Christoph Hellwig3b003152006-11-04 20:10:55 +01001008 * If sg table allocation fails, requeue request later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 */
Christoph Hellwigf9d03f92016-12-08 15:20:32 -07001010 if (unlikely(sg_alloc_table_chained(&sdb->table,
1011 blk_rq_nr_phys_segments(req), sdb->table.sgl)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 return BLKPREP_DEFER;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014 /*
1015 * Next, walk the list, and fill in the addresses and sizes of
1016 * each segment.
1017 */
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001018 count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
1019 BUG_ON(count > sdb->table.nents);
1020 sdb->table.nents = count;
Tejun Heo1011c1b2009-05-07 22:24:45 +09001021 sdb->length = blk_rq_bytes(req);
Rusty Russell4a03d902007-11-19 11:28:48 +11001022 return BLKPREP_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023}
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001024
1025/*
1026 * Function: scsi_init_io()
1027 *
1028 * Purpose: SCSI I/O initialize function.
1029 *
1030 * Arguments: cmd - Command descriptor we wish to initialize
1031 *
1032 * Returns: 0 on success
1033 * BLKPREP_DEFER if the failure is retryable
1034 * BLKPREP_KILL if the failure is fatal
1035 */
Christoph Hellwig3c356bd2014-09-05 18:20:23 -07001036int scsi_init_io(struct scsi_cmnd *cmd)
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001037{
Christoph Hellwig5e012aa2014-04-15 12:24:55 +02001038 struct scsi_device *sdev = cmd->device;
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001039 struct request *rq = cmd->request;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001040 bool is_mq = (rq->mq_ctx != NULL);
Christoph Hellwig635d98b2014-06-28 11:51:01 +02001041 int error;
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001042
Christoph Hellwigf9d03f92016-12-08 15:20:32 -07001043 BUG_ON(!blk_rq_nr_phys_segments(rq));
Christoph Hellwig635d98b2014-06-28 11:51:01 +02001044
Christoph Hellwig3c356bd2014-09-05 18:20:23 -07001045 error = scsi_init_sgtable(rq, &cmd->sdb);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001046 if (error)
1047 goto err_exit;
1048
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001049 if (blk_bidi_rq(rq)) {
Christoph Hellwigd2852032014-01-17 12:06:53 +01001050 if (!rq->q->mq_ops) {
1051 struct scsi_data_buffer *bidi_sdb =
1052 kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC);
1053 if (!bidi_sdb) {
1054 error = BLKPREP_DEFER;
1055 goto err_exit;
1056 }
1057
1058 rq->next_rq->special = bidi_sdb;
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001059 }
1060
Christoph Hellwig3c356bd2014-09-05 18:20:23 -07001061 error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001062 if (error)
1063 goto err_exit;
1064 }
1065
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001066 if (blk_integrity_rq(rq)) {
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001067 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
1068 int ivecs, count;
1069
Ewan D. Milne91724c22015-01-15 10:02:12 -05001070 if (prot_sdb == NULL) {
1071 /*
1072 * This can happen if someone (e.g. multipath)
1073 * queues a command to a device on an adapter
1074 * that does not support DIX.
1075 */
1076 WARN_ON_ONCE(1);
1077 error = BLKPREP_KILL;
1078 goto err_exit;
1079 }
1080
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001081 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001082
Ming Lin001d63b2016-04-04 14:48:09 -07001083 if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
Ming Lin22cc3d42016-04-04 14:48:08 -07001084 prot_sdb->table.sgl)) {
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001085 error = BLKPREP_DEFER;
1086 goto err_exit;
1087 }
1088
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001089 count = blk_rq_map_integrity_sg(rq->q, rq->bio,
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001090 prot_sdb->table.sgl);
1091 BUG_ON(unlikely(count > ivecs));
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001092 BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q)));
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001093
1094 cmd->prot_sdb = prot_sdb;
1095 cmd->prot_sdb->table.nents = count;
1096 }
1097
Christoph Hellwigd2852032014-01-17 12:06:53 +01001098 return BLKPREP_OK;
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001099err_exit:
Christoph Hellwigd2852032014-01-17 12:06:53 +01001100 if (is_mq) {
1101 scsi_mq_free_sgtables(cmd);
1102 } else {
1103 scsi_release_buffers(cmd);
1104 cmd->request->special = NULL;
1105 scsi_put_command(cmd);
1106 put_device(&sdev->sdev_gendev);
1107 }
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001108 return error;
1109}
Boaz Harroshbb52d822007-12-13 16:14:27 -08001110EXPORT_SYMBOL(scsi_init_io);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111
Christoph Hellwig3b003152006-11-04 20:10:55 +01001112static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
1113 struct request *req)
1114{
1115 struct scsi_cmnd *cmd;
1116
1117 if (!req->special) {
Christoph Hellwig04796332014-02-20 14:20:55 -08001118 /* Bail if we can't get a reference to the device */
1119 if (!get_device(&sdev->sdev_gendev))
Christoph Hellwig3b003152006-11-04 20:10:55 +01001120 return NULL;
Christoph Hellwig04796332014-02-20 14:20:55 -08001121
1122 cmd = scsi_get_command(sdev, GFP_ATOMIC);
1123 if (unlikely(!cmd)) {
1124 put_device(&sdev->sdev_gendev);
1125 return NULL;
1126 }
Christoph Hellwig3b003152006-11-04 20:10:55 +01001127 req->special = cmd;
1128 } else {
1129 cmd = req->special;
1130 }
1131
1132 /* pull a tag out of the request if we have one */
1133 cmd->tag = req->tag;
1134 cmd->request = req;
1135
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001136 cmd->cmnd = req->cmd;
Martin K. Petersen72f7d322011-03-08 02:03:59 -05001137 cmd->prot_op = SCSI_PROT_NORMAL;
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001138
Christoph Hellwig3b003152006-11-04 20:10:55 +01001139 return cmd;
1140}
1141
Christoph Hellwig4f1e5762014-06-28 12:36:28 +02001142static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
James Bottomley7b163182005-12-15 20:17:02 -06001143{
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001144 struct scsi_cmnd *cmd = req->special;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001145
1146 /*
1147 * BLOCK_PC requests may transfer data, in which case they must
1148 * a bio attached to them. Or they might contain a SCSI command
1149 * that does not transfer data, in which case they may optionally
1150 * submit a request without an attached bio.
1151 */
1152 if (req->bio) {
Christoph Hellwig3c356bd2014-09-05 18:20:23 -07001153 int ret = scsi_init_io(cmd);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001154 if (unlikely(ret))
1155 return ret;
1156 } else {
Tejun Heob0790412009-05-07 22:24:42 +09001157 BUG_ON(blk_rq_bytes(req));
Christoph Hellwig3b003152006-11-04 20:10:55 +01001158
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001159 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
Christoph Hellwig3b003152006-11-04 20:10:55 +01001160 }
James Bottomley7b163182005-12-15 20:17:02 -06001161
James Bottomley7b163182005-12-15 20:17:02 -06001162 cmd->cmd_len = req->cmd_len;
Tejun Heob0790412009-05-07 22:24:42 +09001163 cmd->transfersize = blk_rq_bytes(req);
James Bottomley7b163182005-12-15 20:17:02 -06001164 cmd->allowed = req->retries;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001165 return BLKPREP_OK;
1166}
1167
1168/*
Christoph Hellwig3868cf82014-06-28 11:58:42 +02001169 * Setup a REQ_TYPE_FS command. These are simple request from filesystems
1170 * that still need to be translated to SCSI CDBs from the ULD.
Christoph Hellwig3b003152006-11-04 20:10:55 +01001171 */
Christoph Hellwig3868cf82014-06-28 11:58:42 +02001172static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
Christoph Hellwig3b003152006-11-04 20:10:55 +01001173{
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001174 struct scsi_cmnd *cmd = req->special;
Chandra Seetharamana6a8d9f2008-05-01 14:49:46 -07001175
Christoph Hellwigee14c672015-08-27 14:16:59 +02001176 if (unlikely(sdev->handler && sdev->handler->prep_fn)) {
1177 int ret = sdev->handler->prep_fn(sdev, req);
Chandra Seetharamana6a8d9f2008-05-01 14:49:46 -07001178 if (ret != BLKPREP_OK)
1179 return ret;
1180 }
1181
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001182 memset(cmd->cmnd, 0, BLK_MAX_CDB);
Christoph Hellwig3868cf82014-06-28 11:58:42 +02001183 return scsi_cmd_to_driver(cmd)->init_command(cmd);
James Bottomley7b163182005-12-15 20:17:02 -06001184}
James Bottomley7b163182005-12-15 20:17:02 -06001185
Christoph Hellwig6af7a4f2014-07-08 13:16:17 +02001186static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req)
1187{
1188 struct scsi_cmnd *cmd = req->special;
1189
1190 if (!blk_rq_bytes(req))
1191 cmd->sc_data_direction = DMA_NONE;
1192 else if (rq_data_dir(req) == WRITE)
1193 cmd->sc_data_direction = DMA_TO_DEVICE;
1194 else
1195 cmd->sc_data_direction = DMA_FROM_DEVICE;
1196
1197 switch (req->cmd_type) {
1198 case REQ_TYPE_FS:
1199 return scsi_setup_fs_cmnd(sdev, req);
1200 case REQ_TYPE_BLOCK_PC:
1201 return scsi_setup_blk_pc_cmnd(sdev, req);
1202 default:
1203 return BLKPREP_KILL;
1204 }
1205}
1206
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001207static int
1208scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209{
Christoph Hellwig3b003152006-11-04 20:10:55 +01001210 int ret = BLKPREP_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211
1212 /*
Christoph Hellwig3b003152006-11-04 20:10:55 +01001213 * If the device is not in running state we will reject some
1214 * or all commands.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
Christoph Hellwig3b003152006-11-04 20:10:55 +01001217 switch (sdev->sdev_state) {
1218 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05001219 case SDEV_TRANSPORT_OFFLINE:
Christoph Hellwig3b003152006-11-04 20:10:55 +01001220 /*
1221 * If the device is offline we refuse to process any
1222 * commands. The device must be brought online
1223 * before trying any recovery commands.
1224 */
1225 sdev_printk(KERN_ERR, sdev,
1226 "rejecting I/O to offline device\n");
1227 ret = BLKPREP_KILL;
1228 break;
1229 case SDEV_DEL:
1230 /*
1231 * If the device is fully deleted, we refuse to
1232 * process any commands as well.
1233 */
James Bottomley9ccfc752005-10-02 11:45:08 -05001234 sdev_printk(KERN_ERR, sdev,
1235 "rejecting I/O to dead device\n");
Christoph Hellwig3b003152006-11-04 20:10:55 +01001236 ret = BLKPREP_KILL;
1237 break;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001238 case SDEV_BLOCK:
James Bottomley6f4267e2008-08-22 16:53:31 -05001239 case SDEV_CREATED_BLOCK:
Bart Van Asschebba0bdd2015-03-04 10:31:47 +01001240 ret = BLKPREP_DEFER;
1241 break;
1242 case SDEV_QUIESCE:
Christoph Hellwig3b003152006-11-04 20:10:55 +01001243 /*
1244 * If the devices is blocked we defer normal commands.
1245 */
Christoph Hellwige8064022016-10-20 15:12:13 +02001246 if (!(req->rq_flags & RQF_PREEMPT))
Christoph Hellwig3b003152006-11-04 20:10:55 +01001247 ret = BLKPREP_DEFER;
1248 break;
1249 default:
1250 /*
1251 * For any other not fully online state we only allow
1252 * special commands. In particular any user initiated
1253 * command is not allowed.
1254 */
Christoph Hellwige8064022016-10-20 15:12:13 +02001255 if (!(req->rq_flags & RQF_PREEMPT))
Christoph Hellwig3b003152006-11-04 20:10:55 +01001256 ret = BLKPREP_KILL;
1257 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 }
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001260 return ret;
1261}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001263static int
1264scsi_prep_return(struct request_queue *q, struct request *req, int ret)
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001265{
1266 struct scsi_device *sdev = q->queuedata;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267
Christoph Hellwig3b003152006-11-04 20:10:55 +01001268 switch (ret) {
1269 case BLKPREP_KILL:
jiangyiwene1cd3912016-02-16 20:14:13 +08001270 case BLKPREP_INVALID:
Christoph Hellwig3b003152006-11-04 20:10:55 +01001271 req->errors = DID_NO_CONNECT << 16;
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001272 /* release the command and kill it */
1273 if (req->special) {
1274 struct scsi_cmnd *cmd = req->special;
1275 scsi_release_buffers(cmd);
1276 scsi_put_command(cmd);
Christoph Hellwig68c03d92014-04-15 12:24:56 +02001277 put_device(&sdev->sdev_gendev);
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001278 req->special = NULL;
1279 }
Christoph Hellwig3b003152006-11-04 20:10:55 +01001280 break;
1281 case BLKPREP_DEFER:
1282 /*
Tejun Heo9934c8c2009-05-08 11:54:16 +09001283 * If we defer, the blk_peek_request() returns NULL, but the
Jens Axboea488e742010-04-16 21:13:15 +02001284 * queue must be restarted, so we schedule a callback to happen
1285 * shortly.
Christoph Hellwig3b003152006-11-04 20:10:55 +01001286 */
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001287 if (atomic_read(&sdev->device_busy) == 0)
Jens Axboea488e742010-04-16 21:13:15 +02001288 blk_delay_queue(q, SCSI_QUEUE_DELAY);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001289 break;
1290 default:
Christoph Hellwige8064022016-10-20 15:12:13 +02001291 req->rq_flags |= RQF_DONTPREP;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001292 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001293
Christoph Hellwig3b003152006-11-04 20:10:55 +01001294 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295}
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001296
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001297static int scsi_prep_fn(struct request_queue *q, struct request *req)
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001298{
1299 struct scsi_device *sdev = q->queuedata;
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001300 struct scsi_cmnd *cmd;
1301 int ret;
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001302
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001303 ret = scsi_prep_state_check(sdev, req);
1304 if (ret != BLKPREP_OK)
1305 goto out;
1306
1307 cmd = scsi_get_cmd_from_req(sdev, req);
1308 if (unlikely(!cmd)) {
1309 ret = BLKPREP_DEFER;
1310 goto out;
1311 }
1312
Christoph Hellwig6af7a4f2014-07-08 13:16:17 +02001313 ret = scsi_setup_cmnd(sdev, req);
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001314out:
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001315 return scsi_prep_return(q, req, ret);
1316}
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001317
1318static void scsi_unprep_fn(struct request_queue *q, struct request *req)
1319{
Christoph Hellwigd2852032014-01-17 12:06:53 +01001320 scsi_uninit_cmd(req->special);
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001321}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322
1323/*
1324 * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
1325 * return 0.
1326 *
1327 * Called with the queue_lock held.
1328 */
1329static inline int scsi_dev_queue_ready(struct request_queue *q,
1330 struct scsi_device *sdev)
1331{
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001332 unsigned int busy;
1333
1334 busy = atomic_inc_return(&sdev->device_busy) - 1;
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001335 if (atomic_read(&sdev->device_blocked)) {
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001336 if (busy)
1337 goto out_dec;
1338
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339 /*
1340 * unblock after device_blocked iterates to zero
1341 */
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001342 if (atomic_dec_return(&sdev->device_blocked) > 0) {
Christoph Hellwigd2852032014-01-17 12:06:53 +01001343 /*
1344 * For the MQ case we take care of this in the caller.
1345 */
1346 if (!q->mq_ops)
1347 blk_delay_queue(q, SCSI_QUEUE_DELAY);
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001348 goto out_dec;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 }
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001350 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
1351 "unblocking device at zero depth\n"));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 }
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001353
1354 if (busy >= sdev->queue_depth)
1355 goto out_dec;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001356
1357 return 1;
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001358out_dec:
1359 atomic_dec(&sdev->device_busy);
1360 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361}
1362
Mike Christief0c0a372008-08-17 15:24:38 -05001363/*
1364 * scsi_target_queue_ready: checks if there we can send commands to target
1365 * @sdev: scsi device on starget to check.
Mike Christief0c0a372008-08-17 15:24:38 -05001366 */
1367static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
1368 struct scsi_device *sdev)
1369{
1370 struct scsi_target *starget = scsi_target(sdev);
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001371 unsigned int busy;
Mike Christief0c0a372008-08-17 15:24:38 -05001372
1373 if (starget->single_lun) {
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001374 spin_lock_irq(shost->host_lock);
Mike Christief0c0a372008-08-17 15:24:38 -05001375 if (starget->starget_sdev_user &&
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001376 starget->starget_sdev_user != sdev) {
1377 spin_unlock_irq(shost->host_lock);
1378 return 0;
1379 }
Mike Christief0c0a372008-08-17 15:24:38 -05001380 starget->starget_sdev_user = sdev;
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001381 spin_unlock_irq(shost->host_lock);
Mike Christief0c0a372008-08-17 15:24:38 -05001382 }
1383
Christoph Hellwig2ccbb002014-03-26 10:35:00 +01001384 if (starget->can_queue <= 0)
1385 return 1;
1386
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001387 busy = atomic_inc_return(&starget->target_busy) - 1;
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001388 if (atomic_read(&starget->target_blocked) > 0) {
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001389 if (busy)
1390 goto starved;
1391
Mike Christief0c0a372008-08-17 15:24:38 -05001392 /*
1393 * unblock after target_blocked iterates to zero
1394 */
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001395 if (atomic_dec_return(&starget->target_blocked) > 0)
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001396 goto out_dec;
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001397
1398 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
1399 "unblocking target at zero depth\n"));
Mike Christief0c0a372008-08-17 15:24:38 -05001400 }
1401
Christoph Hellwig2ccbb002014-03-26 10:35:00 +01001402 if (busy >= starget->can_queue)
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001403 goto starved;
Mike Christief0c0a372008-08-17 15:24:38 -05001404
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001405 return 1;
1406
1407starved:
1408 spin_lock_irq(shost->host_lock);
1409 list_move_tail(&sdev->starved_entry, &shost->starved_list);
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001410 spin_unlock_irq(shost->host_lock);
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001411out_dec:
Christoph Hellwig2ccbb002014-03-26 10:35:00 +01001412 if (starget->can_queue > 0)
1413 atomic_dec(&starget->target_busy);
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001414 return 0;
Mike Christief0c0a372008-08-17 15:24:38 -05001415}
1416
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417/*
1418 * scsi_host_queue_ready: if we can send requests to shost, return 1 else
1419 * return 0. We must end up running the queue again whenever 0 is
1420 * returned, else IO can hang.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 */
1422static inline int scsi_host_queue_ready(struct request_queue *q,
1423 struct Scsi_Host *shost,
1424 struct scsi_device *sdev)
1425{
Christoph Hellwig74665012014-01-22 15:29:29 +01001426 unsigned int busy;
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001427
James Bottomley939647e2005-09-18 15:05:20 -05001428 if (scsi_host_in_recovery(shost))
Christoph Hellwig74665012014-01-22 15:29:29 +01001429 return 0;
1430
1431 busy = atomic_inc_return(&shost->host_busy) - 1;
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001432 if (atomic_read(&shost->host_blocked) > 0) {
Christoph Hellwig74665012014-01-22 15:29:29 +01001433 if (busy)
1434 goto starved;
1435
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 /*
1437 * unblock after host_blocked iterates to zero
1438 */
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001439 if (atomic_dec_return(&shost->host_blocked) > 0)
Christoph Hellwig74665012014-01-22 15:29:29 +01001440 goto out_dec;
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001441
1442 SCSI_LOG_MLQUEUE(3,
1443 shost_printk(KERN_INFO, shost,
1444 "unblocking host at zero depth\n"));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445 }
Christoph Hellwig74665012014-01-22 15:29:29 +01001446
1447 if (shost->can_queue > 0 && busy >= shost->can_queue)
1448 goto starved;
1449 if (shost->host_self_blocked)
1450 goto starved;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451
1452 /* We're OK to process the command, so we can't be starved */
Christoph Hellwig74665012014-01-22 15:29:29 +01001453 if (!list_empty(&sdev->starved_entry)) {
1454 spin_lock_irq(shost->host_lock);
1455 if (!list_empty(&sdev->starved_entry))
1456 list_del_init(&sdev->starved_entry);
1457 spin_unlock_irq(shost->host_lock);
1458 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459
Christoph Hellwig74665012014-01-22 15:29:29 +01001460 return 1;
1461
1462starved:
1463 spin_lock_irq(shost->host_lock);
1464 if (list_empty(&sdev->starved_entry))
1465 list_add_tail(&sdev->starved_entry, &shost->starved_list);
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001466 spin_unlock_irq(shost->host_lock);
Christoph Hellwig74665012014-01-22 15:29:29 +01001467out_dec:
1468 atomic_dec(&shost->host_busy);
1469 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001470}
1471
1472/*
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001473 * Busy state exporting function for request stacking drivers.
1474 *
1475 * For efficiency, no lock is taken to check the busy state of
1476 * shost/starget/sdev, since the returned value is not guaranteed and
1477 * may be changed after request stacking drivers call the function,
1478 * regardless of taking lock or not.
1479 *
Bart Van Assche67bd9412012-06-29 15:33:22 +00001480 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
1481 * needs to return 'not busy'. Otherwise, request stacking drivers
1482 * may hold requests forever.
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001483 */
1484static int scsi_lld_busy(struct request_queue *q)
1485{
1486 struct scsi_device *sdev = q->queuedata;
1487 struct Scsi_Host *shost;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001488
Bart Van Assche3f3299d2012-11-28 13:42:38 +01001489 if (blk_queue_dying(q))
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001490 return 0;
1491
1492 shost = sdev->host;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001493
Jun'ichi Nomurab7e94a12012-05-22 18:57:17 +09001494 /*
1495 * Ignore host/starget busy state.
1496 * Since block layer does not have a concept of fairness across
1497 * multiple queues, congestion of host/starget needs to be handled
1498 * in SCSI layer.
1499 */
1500 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001501 return 1;
1502
1503 return 0;
1504}
1505
1506/*
James Bottomleye91442b2005-09-09 10:44:16 -05001507 * Kill a request for a dead device
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508 */
Jens Axboe165125e2007-07-24 09:28:11 +02001509static void scsi_kill_request(struct request *req, struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510{
James Bottomleye91442b2005-09-09 10:44:16 -05001511 struct scsi_cmnd *cmd = req->special;
Jiri Slaby03b14702009-09-23 16:15:35 +02001512 struct scsi_device *sdev;
1513 struct scsi_target *starget;
1514 struct Scsi_Host *shost;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515
Tejun Heo9934c8c2009-05-08 11:54:16 +09001516 blk_start_request(req);
James Bottomley788ce432005-09-09 13:40:23 -05001517
Hannes Reinecke74571812011-11-09 08:39:24 +01001518 scmd_printk(KERN_INFO, cmd, "killing request\n");
1519
Jiri Slaby03b14702009-09-23 16:15:35 +02001520 sdev = cmd->device;
1521 starget = scsi_target(sdev);
1522 shost = sdev->host;
James Bottomleye91442b2005-09-09 10:44:16 -05001523 scsi_init_cmd_errh(cmd);
1524 cmd->result = DID_NO_CONNECT << 16;
1525 atomic_inc(&cmd->device->iorequest_cnt);
Tejun Heoe36e0c82006-04-11 17:27:53 +09001526
1527 /*
1528 * SCSI request completion path will do scsi_device_unbusy(),
1529 * bump busy counts. To bump the counters, we need to dance
1530 * with the locks as normal issue path does.
1531 */
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001532 atomic_inc(&sdev->device_busy);
Christoph Hellwig74665012014-01-22 15:29:29 +01001533 atomic_inc(&shost->host_busy);
Christoph Hellwig2ccbb002014-03-26 10:35:00 +01001534 if (starget->can_queue > 0)
1535 atomic_inc(&starget->target_busy);
Tejun Heoe36e0c82006-04-11 17:27:53 +09001536
Jens Axboe242f9dc2008-09-14 05:55:09 -07001537 blk_complete_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001538}
1539
Jens Axboe1aea6432006-01-09 16:03:03 +01001540static void scsi_softirq_done(struct request *rq)
1541{
Jens Axboe242f9dc2008-09-14 05:55:09 -07001542 struct scsi_cmnd *cmd = rq->special;
1543 unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
Jens Axboe1aea6432006-01-09 16:03:03 +01001544 int disposition;
1545
1546 INIT_LIST_HEAD(&cmd->eh_entry);
1547
Jens Axboe242f9dc2008-09-14 05:55:09 -07001548 atomic_inc(&cmd->device->iodone_cnt);
1549 if (cmd->result)
1550 atomic_inc(&cmd->device->ioerr_cnt);
1551
Jens Axboe1aea6432006-01-09 16:03:03 +01001552 disposition = scsi_decide_disposition(cmd);
1553 if (disposition != SUCCESS &&
1554 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
1555 sdev_printk(KERN_ERR, cmd->device,
1556 "timing out command, waited %lus\n",
1557 wait_for/HZ);
1558 disposition = SUCCESS;
1559 }
Hannes Reinecke91921e02014-06-25 16:39:59 +02001560
Jens Axboe1aea6432006-01-09 16:03:03 +01001561 scsi_log_completion(cmd, disposition);
1562
1563 switch (disposition) {
1564 case SUCCESS:
1565 scsi_finish_command(cmd);
1566 break;
1567 case NEEDS_RETRY:
Christoph Hellwig596f4822007-01-02 12:56:00 +01001568 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
Jens Axboe1aea6432006-01-09 16:03:03 +01001569 break;
1570 case ADD_TO_MLQUEUE:
1571 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
1572 break;
1573 default:
1574 if (!scsi_eh_scmd_add(cmd, 0))
1575 scsi_finish_command(cmd);
1576 }
1577}
1578
Christoph Hellwig3b5382c2014-05-06 12:25:40 +02001579/**
Christoph Hellwig82042a22014-09-05 18:23:07 -07001580 * scsi_dispatch_command - Dispatch a command to the low-level driver.
1581 * @cmd: command block we are dispatching.
1582 *
1583 * Return: nonzero return request was rejected and device's queue needs to be
1584 * plugged.
1585 */
1586static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
1587{
1588 struct Scsi_Host *host = cmd->device->host;
1589 int rtn = 0;
1590
1591 atomic_inc(&cmd->device->iorequest_cnt);
1592
1593 /* check if the device is still usable */
1594 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
1595 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
1596 * returns an immediate error upwards, and signals
1597 * that the device is no longer present */
1598 cmd->result = DID_NO_CONNECT << 16;
1599 goto done;
1600 }
1601
1602 /* Check to see if the scsi lld made this device blocked. */
1603 if (unlikely(scsi_device_blocked(cmd->device))) {
1604 /*
1605 * in blocked state, the command is just put back on
1606 * the device queue. The suspend state has already
1607 * blocked the queue so future requests should not
1608 * occur until the device transitions out of the
1609 * suspend state.
1610 */
1611 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1612 "queuecommand : device blocked\n"));
1613 return SCSI_MLQUEUE_DEVICE_BUSY;
1614 }
1615
1616 /* Store the LUN value in cmnd, if needed. */
1617 if (cmd->device->lun_in_cdb)
1618 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
1619 (cmd->device->lun << 5 & 0xe0);
1620
1621 scsi_log_send(cmd);
1622
1623 /*
1624 * Before we queue this command, check if the command
1625 * length exceeds what the host adapter can handle.
1626 */
1627 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
1628 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1629 "queuecommand : command too long. "
1630 "cdb_size=%d host->max_cmd_len=%d\n",
1631 cmd->cmd_len, cmd->device->host->max_cmd_len));
1632 cmd->result = (DID_ABORT << 16);
1633 goto done;
1634 }
1635
1636 if (unlikely(host->shost_state == SHOST_DEL)) {
1637 cmd->result = (DID_NO_CONNECT << 16);
1638 goto done;
1639
1640 }
1641
1642 trace_scsi_dispatch_cmd_start(cmd);
1643 rtn = host->hostt->queuecommand(host, cmd);
1644 if (rtn) {
1645 trace_scsi_dispatch_cmd_error(cmd, rtn);
1646 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
1647 rtn != SCSI_MLQUEUE_TARGET_BUSY)
1648 rtn = SCSI_MLQUEUE_HOST_BUSY;
1649
1650 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1651 "queuecommand : request rejected\n"));
1652 }
1653
1654 return rtn;
1655 done:
1656 cmd->scsi_done(cmd);
1657 return 0;
1658}
1659
1660/**
Christoph Hellwig3b5382c2014-05-06 12:25:40 +02001661 * scsi_done - Invoke completion on finished SCSI command.
1662 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
1663 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
1664 *
1665 * Description: This function is the mid-level's (SCSI Core) interrupt routine,
1666 * which regains ownership of the SCSI command (de facto) from a LLDD, and
1667 * calls blk_complete_request() for further processing.
1668 *
1669 * This function is interrupt context safe.
1670 */
1671static void scsi_done(struct scsi_cmnd *cmd)
1672{
1673 trace_scsi_dispatch_cmd_done(cmd);
1674 blk_complete_request(cmd->request);
1675}
1676
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677/*
1678 * Function: scsi_request_fn()
1679 *
1680 * Purpose: Main strategy routine for SCSI.
1681 *
1682 * Arguments: q - Pointer to actual queue.
1683 *
1684 * Returns: Nothing
1685 *
1686 * Lock status: IO request lock assumed to be held when called.
1687 */
1688static void scsi_request_fn(struct request_queue *q)
Bart Van Assche613be1f2014-02-20 14:20:56 -08001689 __releases(q->queue_lock)
1690 __acquires(q->queue_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691{
1692 struct scsi_device *sdev = q->queuedata;
1693 struct Scsi_Host *shost;
1694 struct scsi_cmnd *cmd;
1695 struct request *req;
1696
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697 /*
1698 * To start with, we keep looping until the queue is empty, or until
1699 * the host is no longer able to accept any more requests.
1700 */
1701 shost = sdev->host;
Jens Axboea488e742010-04-16 21:13:15 +02001702 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703 int rtn;
1704 /*
1705 * get next queueable request. We do this early to make sure
Hannes Reinecke91921e02014-06-25 16:39:59 +02001706 * that the request is fully prepared even if we cannot
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707 * accept it.
1708 */
Tejun Heo9934c8c2009-05-08 11:54:16 +09001709 req = blk_peek_request(q);
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001710 if (!req)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711 break;
1712
1713 if (unlikely(!scsi_device_online(sdev))) {
James Bottomley9ccfc752005-10-02 11:45:08 -05001714 sdev_printk(KERN_ERR, sdev,
1715 "rejecting I/O to offline device\n");
James Bottomleye91442b2005-09-09 10:44:16 -05001716 scsi_kill_request(req, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717 continue;
1718 }
1719
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001720 if (!scsi_dev_queue_ready(q, sdev))
1721 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001722
1723 /*
1724 * Remove the request from the request list.
1725 */
1726 if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
Tejun Heo9934c8c2009-05-08 11:54:16 +09001727 blk_start_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001728
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001729 spin_unlock_irq(q->queue_lock);
James Bottomleye91442b2005-09-09 10:44:16 -05001730 cmd = req->special;
1731 if (unlikely(cmd == NULL)) {
1732 printk(KERN_CRIT "impossible request in %s.\n"
1733 "please mail a stack trace to "
Jens Axboe4aff5e22006-08-10 08:44:47 +02001734 "linux-scsi@vger.kernel.org\n",
Harvey Harrisoncadbd4a2008-07-03 23:47:27 -07001735 __func__);
Jens Axboe4aff5e22006-08-10 08:44:47 +02001736 blk_dump_rq_flags(req, "foo");
James Bottomleye91442b2005-09-09 10:44:16 -05001737 BUG();
1738 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001739
Mike Christieecefe8a2008-07-11 19:50:35 -05001740 /*
1741 * We hit this when the driver is using a host wide
1742 * tag map. For device level tag maps the queue_depth check
1743 * in the device ready fn would prevent us from trying
1744 * to allocate a tag. Since the map is a shared host resource
1745 * we add the dev to the starved list so it eventually gets
1746 * a run when a tag is freed.
1747 */
Christoph Hellwige8064022016-10-20 15:12:13 +02001748 if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) {
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001749 spin_lock_irq(shost->host_lock);
Mike Christieecefe8a2008-07-11 19:50:35 -05001750 if (list_empty(&sdev->starved_entry))
1751 list_add_tail(&sdev->starved_entry,
1752 &shost->starved_list);
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001753 spin_unlock_irq(shost->host_lock);
Mike Christieecefe8a2008-07-11 19:50:35 -05001754 goto not_ready;
1755 }
1756
Mike Christief0c0a372008-08-17 15:24:38 -05001757 if (!scsi_target_queue_ready(shost, sdev))
1758 goto not_ready;
1759
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760 if (!scsi_host_queue_ready(q, shost, sdev))
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001761 goto host_not_ready;
Christoph Hellwig125c99b2014-11-03 12:47:47 +01001762
1763 if (sdev->simple_tags)
1764 cmd->flags |= SCMD_TAGGED;
1765 else
1766 cmd->flags &= ~SCMD_TAGGED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001767
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768 /*
1769 * Finally, initialize any error handling parameters, and set up
1770 * the timers for timeouts.
1771 */
1772 scsi_init_cmd_errh(cmd);
1773
1774 /*
1775 * Dispatch the command to the low-level driver.
1776 */
Christoph Hellwig3b5382c2014-05-06 12:25:40 +02001777 cmd->scsi_done = scsi_done;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778 rtn = scsi_dispatch_cmd(cmd);
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +01001779 if (rtn) {
1780 scsi_queue_insert(cmd, rtn);
1781 spin_lock_irq(q->queue_lock);
Jens Axboea488e742010-04-16 21:13:15 +02001782 goto out_delay;
Christoph Hellwigd0d3bbf2014-01-22 18:39:04 +01001783 }
1784 spin_lock_irq(q->queue_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001785 }
1786
Bart Van Assche613be1f2014-02-20 14:20:56 -08001787 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001788
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001789 host_not_ready:
Christoph Hellwig2ccbb002014-03-26 10:35:00 +01001790 if (scsi_target(sdev)->can_queue > 0)
1791 atomic_dec(&scsi_target(sdev)->target_busy);
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001792 not_ready:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793 /*
1794 * lock q, handle tag, requeue req, and decrement device_busy. We
1795 * must return with queue_lock held.
1796 *
1797 * Decrementing device_busy without checking it is OK, as all such
1798 * cases (host limits or settings) should run the queue at some
1799 * later time.
1800 */
1801 spin_lock_irq(q->queue_lock);
1802 blk_requeue_request(q, req);
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001803 atomic_dec(&sdev->device_busy);
Jens Axboea488e742010-04-16 21:13:15 +02001804out_delay:
Guenter Roeck480cadc2014-08-10 05:54:25 -07001805 if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev))
Jens Axboea488e742010-04-16 21:13:15 +02001806 blk_delay_queue(q, SCSI_QUEUE_DELAY);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807}
1808
Christoph Hellwigd2852032014-01-17 12:06:53 +01001809static inline int prep_to_mq(int ret)
1810{
1811 switch (ret) {
1812 case BLKPREP_OK:
Omar Sandoval2868f132016-11-15 11:11:59 -08001813 return BLK_MQ_RQ_QUEUE_OK;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001814 case BLKPREP_DEFER:
1815 return BLK_MQ_RQ_QUEUE_BUSY;
1816 default:
1817 return BLK_MQ_RQ_QUEUE_ERROR;
1818 }
1819}
1820
1821static int scsi_mq_prep_fn(struct request *req)
1822{
1823 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1824 struct scsi_device *sdev = req->q->queuedata;
1825 struct Scsi_Host *shost = sdev->host;
1826 unsigned char *sense_buf = cmd->sense_buffer;
1827 struct scatterlist *sg;
1828
1829 memset(cmd, 0, sizeof(struct scsi_cmnd));
1830
1831 req->special = cmd;
1832
1833 cmd->request = req;
1834 cmd->device = sdev;
1835 cmd->sense_buffer = sense_buf;
1836
1837 cmd->tag = req->tag;
1838
Christoph Hellwigd2852032014-01-17 12:06:53 +01001839 cmd->cmnd = req->cmd;
1840 cmd->prot_op = SCSI_PROT_NORMAL;
1841
1842 INIT_LIST_HEAD(&cmd->list);
1843 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
1844 cmd->jiffies_at_alloc = jiffies;
1845
Kashyap.Desai@avagotech.com64bdcbc2014-08-20 19:24:33 +05301846 if (shost->use_cmd_list) {
1847 spin_lock_irq(&sdev->list_lock);
1848 list_add_tail(&cmd->list, &sdev->cmd_list);
1849 spin_unlock_irq(&sdev->list_lock);
1850 }
Christoph Hellwigd2852032014-01-17 12:06:53 +01001851
1852 sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
1853 cmd->sdb.table.sgl = sg;
1854
1855 if (scsi_host_get_prot(shost)) {
1856 cmd->prot_sdb = (void *)sg +
Tony Battersby120bb3e2014-12-08 17:20:52 -05001857 min_t(unsigned int,
Ming Lin65e86172016-04-04 14:48:10 -07001858 shost->sg_tablesize, SG_CHUNK_SIZE) *
Tony Battersby120bb3e2014-12-08 17:20:52 -05001859 sizeof(struct scatterlist);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001860 memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
1861
1862 cmd->prot_sdb->table.sgl =
1863 (struct scatterlist *)(cmd->prot_sdb + 1);
1864 }
1865
1866 if (blk_bidi_rq(req)) {
1867 struct request *next_rq = req->next_rq;
1868 struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq);
1869
1870 memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer));
1871 bidi_sdb->table.sgl =
1872 (struct scatterlist *)(bidi_sdb + 1);
1873
1874 next_rq->special = bidi_sdb;
1875 }
1876
Christoph Hellwigfe052522014-09-22 15:59:31 +02001877 blk_mq_start_request(req);
1878
Christoph Hellwigd2852032014-01-17 12:06:53 +01001879 return scsi_setup_cmnd(sdev, req);
1880}
1881
1882static void scsi_mq_done(struct scsi_cmnd *cmd)
1883{
1884 trace_scsi_dispatch_cmd_done(cmd);
Christoph Hellwigf4829a92015-09-27 21:01:50 +02001885 blk_mq_complete_request(cmd->request, cmd->request->errors);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001886}
1887
Jens Axboe74c45052014-10-29 11:14:52 -06001888static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
1889 const struct blk_mq_queue_data *bd)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001890{
Jens Axboe74c45052014-10-29 11:14:52 -06001891 struct request *req = bd->rq;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001892 struct request_queue *q = req->q;
1893 struct scsi_device *sdev = q->queuedata;
1894 struct Scsi_Host *shost = sdev->host;
1895 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1896 int ret;
1897 int reason;
1898
1899 ret = prep_to_mq(scsi_prep_state_check(sdev, req));
Omar Sandoval2868f132016-11-15 11:11:59 -08001900 if (ret != BLK_MQ_RQ_QUEUE_OK)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001901 goto out;
1902
1903 ret = BLK_MQ_RQ_QUEUE_BUSY;
1904 if (!get_device(&sdev->sdev_gendev))
1905 goto out;
1906
1907 if (!scsi_dev_queue_ready(q, sdev))
1908 goto out_put_device;
1909 if (!scsi_target_queue_ready(shost, sdev))
1910 goto out_dec_device_busy;
1911 if (!scsi_host_queue_ready(q, shost, sdev))
1912 goto out_dec_target_busy;
1913
Christoph Hellwigfe052522014-09-22 15:59:31 +02001914
Christoph Hellwige8064022016-10-20 15:12:13 +02001915 if (!(req->rq_flags & RQF_DONTPREP)) {
Christoph Hellwigd2852032014-01-17 12:06:53 +01001916 ret = prep_to_mq(scsi_mq_prep_fn(req));
Omar Sandoval2868f132016-11-15 11:11:59 -08001917 if (ret != BLK_MQ_RQ_QUEUE_OK)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001918 goto out_dec_host_busy;
Christoph Hellwige8064022016-10-20 15:12:13 +02001919 req->rq_flags |= RQF_DONTPREP;
Christoph Hellwigfe052522014-09-22 15:59:31 +02001920 } else {
1921 blk_mq_start_request(req);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001922 }
1923
Christoph Hellwig125c99b2014-11-03 12:47:47 +01001924 if (sdev->simple_tags)
1925 cmd->flags |= SCMD_TAGGED;
Christoph Hellwigb1dd2aa2014-10-19 17:13:58 +02001926 else
Christoph Hellwig125c99b2014-11-03 12:47:47 +01001927 cmd->flags &= ~SCMD_TAGGED;
Christoph Hellwigb1dd2aa2014-10-19 17:13:58 +02001928
Christoph Hellwigd2852032014-01-17 12:06:53 +01001929 scsi_init_cmd_errh(cmd);
1930 cmd->scsi_done = scsi_mq_done;
1931
1932 reason = scsi_dispatch_cmd(cmd);
1933 if (reason) {
1934 scsi_set_blocked(cmd, reason);
1935 ret = BLK_MQ_RQ_QUEUE_BUSY;
1936 goto out_dec_host_busy;
1937 }
1938
1939 return BLK_MQ_RQ_QUEUE_OK;
1940
1941out_dec_host_busy:
1942 atomic_dec(&shost->host_busy);
1943out_dec_target_busy:
1944 if (scsi_target(sdev)->can_queue > 0)
1945 atomic_dec(&scsi_target(sdev)->target_busy);
1946out_dec_device_busy:
1947 atomic_dec(&sdev->device_busy);
1948out_put_device:
1949 put_device(&sdev->sdev_gendev);
1950out:
1951 switch (ret) {
1952 case BLK_MQ_RQ_QUEUE_BUSY:
Christoph Hellwigd2852032014-01-17 12:06:53 +01001953 if (atomic_read(&sdev->device_busy) == 0 &&
1954 !scsi_device_blocked(sdev))
1955 blk_mq_delay_queue(hctx, SCSI_QUEUE_DELAY);
1956 break;
1957 case BLK_MQ_RQ_QUEUE_ERROR:
1958 /*
1959 * Make sure to release all allocated ressources when
1960 * we hit an error, as we will never see this command
1961 * again.
1962 */
Christoph Hellwige8064022016-10-20 15:12:13 +02001963 if (req->rq_flags & RQF_DONTPREP)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001964 scsi_mq_uninit_cmd(cmd);
1965 break;
1966 default:
1967 break;
1968 }
1969 return ret;
1970}
1971
Christoph Hellwig0152fb62014-09-13 16:40:13 -07001972static enum blk_eh_timer_return scsi_timeout(struct request *req,
1973 bool reserved)
1974{
1975 if (reserved)
1976 return BLK_EH_RESET_TIMER;
1977 return scsi_times_out(req);
1978}
1979
Christoph Hellwigd2852032014-01-17 12:06:53 +01001980static int scsi_init_request(void *data, struct request *rq,
1981 unsigned int hctx_idx, unsigned int request_idx,
1982 unsigned int numa_node)
1983{
1984 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1985
1986 cmd->sense_buffer = kzalloc_node(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL,
1987 numa_node);
1988 if (!cmd->sense_buffer)
1989 return -ENOMEM;
1990 return 0;
1991}
1992
1993static void scsi_exit_request(void *data, struct request *rq,
1994 unsigned int hctx_idx, unsigned int request_idx)
1995{
1996 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1997
1998 kfree(cmd->sense_buffer);
1999}
2000
Christoph Hellwig2d9c5c22016-11-01 08:12:48 -06002001static int scsi_map_queues(struct blk_mq_tag_set *set)
2002{
2003 struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set);
2004
2005 if (shost->hostt->map_queues)
2006 return shost->hostt->map_queues(shost);
2007 return blk_mq_map_queues(set);
2008}
2009
Christoph Hellwigf1bea552014-04-15 12:26:54 +02002010static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002011{
2012 struct device *host_dev;
2013 u64 bounce_limit = 0xffffffff;
2014
2015 if (shost->unchecked_isa_dma)
2016 return BLK_BOUNCE_ISA;
2017 /*
2018 * Platforms with virtual-DMA translation
2019 * hardware have no practical limit.
2020 */
2021 if (!PCI_DMA_BUS_IS_PHYS)
2022 return BLK_BOUNCE_ANY;
2023
2024 host_dev = scsi_get_device(shost);
2025 if (host_dev && host_dev->dma_mask)
Russell Kinge83b3662014-02-11 17:11:04 +00002026 bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002027
2028 return bounce_limit;
2029}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002030
Christoph Hellwigd2852032014-01-17 12:06:53 +01002031static void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002032{
Lin Ming6f381fa2012-04-12 13:50:38 +08002033 struct device *dev = shost->dma_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002034
Jens Axboea8474ce2007-08-07 09:02:51 +02002035 /*
2036 * this limit is imposed by hardware restrictions
2037 */
Martin K. Petersen8a783622010-02-26 00:20:39 -05002038 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize,
Ming Lin65e86172016-04-04 14:48:10 -07002039 SG_MAX_SEGMENTS));
Jens Axboea8474ce2007-08-07 09:02:51 +02002040
Martin K. Petersen13f05c82010-09-10 20:50:10 +02002041 if (scsi_host_prot_dma(shost)) {
2042 shost->sg_prot_tablesize =
2043 min_not_zero(shost->sg_prot_tablesize,
2044 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS);
2045 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize);
2046 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
2047 }
2048
Martin K. Petersen086fa5f2010-02-26 00:20:38 -05002049 blk_queue_max_hw_sectors(q, shost->max_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002050 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
2051 blk_queue_segment_boundary(q, shost->dma_boundary);
FUJITA Tomonori99c84db2008-02-04 22:28:17 -08002052 dma_set_seg_boundary(dev, shost->dma_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002053
FUJITA Tomonori860ac562008-02-04 22:28:05 -08002054 blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
2055
Linus Torvalds1da177e2005-04-16 15:20:36 -07002056 if (!shost->use_clustering)
Martin K. Petersene692cb62010-12-01 19:41:49 +01002057 q->limits.cluster = 0;
James Bottomley465ff312008-01-01 10:00:10 -06002058
2059 /*
2060 * set a reasonable default alignment on word boundaries: the
2061 * host and device may alter it using
2062 * blk_queue_update_dma_alignment() later.
2063 */
2064 blk_queue_dma_alignment(q, 0x03);
Christoph Hellwigd2852032014-01-17 12:06:53 +01002065}
James Bottomley465ff312008-01-01 10:00:10 -06002066
Christoph Hellwigd2852032014-01-17 12:06:53 +01002067struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
2068 request_fn_proc *request_fn)
2069{
2070 struct request_queue *q;
2071
2072 q = blk_init_queue(request_fn, NULL);
2073 if (!q)
2074 return NULL;
2075 __scsi_init_queue(shost, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002076 return q;
2077}
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09002078EXPORT_SYMBOL(__scsi_alloc_queue);
2079
2080struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
2081{
2082 struct request_queue *q;
2083
2084 q = __scsi_alloc_queue(sdev->host, scsi_request_fn);
2085 if (!q)
2086 return NULL;
2087
2088 blk_queue_prep_rq(q, scsi_prep_fn);
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02002089 blk_queue_unprep_rq(q, scsi_unprep_fn);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09002090 blk_queue_softirq_done(q, scsi_softirq_done);
Jens Axboe242f9dc2008-09-14 05:55:09 -07002091 blk_queue_rq_timed_out(q, scsi_times_out);
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04002092 blk_queue_lld_busy(q, scsi_lld_busy);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +09002093 return q;
2094}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002095
Christoph Hellwigd2852032014-01-17 12:06:53 +01002096static struct blk_mq_ops scsi_mq_ops = {
Christoph Hellwigd2852032014-01-17 12:06:53 +01002097 .queue_rq = scsi_queue_rq,
2098 .complete = scsi_softirq_done,
Christoph Hellwig0152fb62014-09-13 16:40:13 -07002099 .timeout = scsi_timeout,
Christoph Hellwigd2852032014-01-17 12:06:53 +01002100 .init_request = scsi_init_request,
2101 .exit_request = scsi_exit_request,
Christoph Hellwig2d9c5c22016-11-01 08:12:48 -06002102 .map_queues = scsi_map_queues,
Christoph Hellwigd2852032014-01-17 12:06:53 +01002103};
2104
2105struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev)
2106{
2107 sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set);
2108 if (IS_ERR(sdev->request_queue))
2109 return NULL;
2110
2111 sdev->request_queue->queuedata = sdev;
2112 __scsi_init_queue(sdev->host, sdev->request_queue);
2113 return sdev->request_queue;
2114}
2115
2116int scsi_mq_setup_tags(struct Scsi_Host *shost)
2117{
2118 unsigned int cmd_size, sgl_size, tbl_size;
2119
2120 tbl_size = shost->sg_tablesize;
Ming Lin65e86172016-04-04 14:48:10 -07002121 if (tbl_size > SG_CHUNK_SIZE)
2122 tbl_size = SG_CHUNK_SIZE;
Christoph Hellwigd2852032014-01-17 12:06:53 +01002123 sgl_size = tbl_size * sizeof(struct scatterlist);
2124 cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size;
2125 if (scsi_host_get_prot(shost))
2126 cmd_size += sizeof(struct scsi_data_buffer) + sgl_size;
2127
2128 memset(&shost->tag_set, 0, sizeof(shost->tag_set));
2129 shost->tag_set.ops = &scsi_mq_ops;
Bart Van Asscheefec4b92014-10-30 14:45:36 +01002130 shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1;
Christoph Hellwigd2852032014-01-17 12:06:53 +01002131 shost->tag_set.queue_depth = shost->can_queue;
2132 shost->tag_set.cmd_size = cmd_size;
2133 shost->tag_set.numa_node = NUMA_NO_NODE;
2134 shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
Shaohua Li24391c02015-01-23 14:18:00 -07002135 shost->tag_set.flags |=
2136 BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
Christoph Hellwigd2852032014-01-17 12:06:53 +01002137 shost->tag_set.driver_data = shost;
2138
2139 return blk_mq_alloc_tag_set(&shost->tag_set);
2140}
2141
2142void scsi_mq_destroy_tags(struct Scsi_Host *shost)
2143{
2144 blk_mq_free_tag_set(&shost->tag_set);
2145}
2146
Linus Torvalds1da177e2005-04-16 15:20:36 -07002147/*
2148 * Function: scsi_block_requests()
2149 *
2150 * Purpose: Utility function used by low-level drivers to prevent further
2151 * commands from being queued to the device.
2152 *
2153 * Arguments: shost - Host in question
2154 *
2155 * Returns: Nothing
2156 *
2157 * Lock status: No locks are assumed held.
2158 *
2159 * Notes: There is no timer nor any other means by which the requests
2160 * get unblocked other than the low-level driver calling
2161 * scsi_unblock_requests().
2162 */
2163void scsi_block_requests(struct Scsi_Host *shost)
2164{
2165 shost->host_self_blocked = 1;
2166}
2167EXPORT_SYMBOL(scsi_block_requests);
2168
2169/*
2170 * Function: scsi_unblock_requests()
2171 *
2172 * Purpose: Utility function used by low-level drivers to allow further
2173 * commands from being queued to the device.
2174 *
2175 * Arguments: shost - Host in question
2176 *
2177 * Returns: Nothing
2178 *
2179 * Lock status: No locks are assumed held.
2180 *
2181 * Notes: There is no timer nor any other means by which the requests
2182 * get unblocked other than the low-level driver calling
2183 * scsi_unblock_requests().
2184 *
2185 * This is done as an API function so that changes to the
2186 * internals of the scsi mid-layer won't require wholesale
2187 * changes to drivers that use this feature.
2188 */
2189void scsi_unblock_requests(struct Scsi_Host *shost)
2190{
2191 shost->host_self_blocked = 0;
2192 scsi_run_host_queues(shost);
2193}
2194EXPORT_SYMBOL(scsi_unblock_requests);
2195
2196int __init scsi_init_queue(void)
2197{
Martin K. Petersen6362abd2008-06-05 23:30:03 -04002198 scsi_sdb_cache = kmem_cache_create("scsi_data_buffer",
2199 sizeof(struct scsi_data_buffer),
2200 0, 0, NULL);
2201 if (!scsi_sdb_cache) {
2202 printk(KERN_ERR "SCSI: can't init scsi sdb cache\n");
FUJITA Tomonorif0787272008-12-14 01:23:45 +09002203 return -ENOMEM;
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02002204 }
2205
Linus Torvalds1da177e2005-04-16 15:20:36 -07002206 return 0;
2207}
2208
2209void scsi_exit_queue(void)
2210{
Martin K. Petersen6362abd2008-06-05 23:30:03 -04002211 kmem_cache_destroy(scsi_sdb_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002212}
James Bottomley5baba832006-03-18 14:10:35 -06002213
2214/**
2215 * scsi_mode_select - issue a mode select
2216 * @sdev: SCSI device to be queried
2217 * @pf: Page format bit (1 == standard, 0 == vendor specific)
2218 * @sp: Save page bit (0 == don't save, 1 == save)
2219 * @modepage: mode page being requested
2220 * @buffer: request buffer (may not be smaller than eight bytes)
2221 * @len: length of request buffer.
2222 * @timeout: command timeout
2223 * @retries: number of retries before failing
2224 * @data: returns a structure abstracting the mode header data
Rob Landleyeb448202007-11-03 13:30:39 -05002225 * @sshdr: place to put sense data (or NULL if no sense to be collected).
James Bottomley5baba832006-03-18 14:10:35 -06002226 * must be SCSI_SENSE_BUFFERSIZE big.
2227 *
2228 * Returns zero if successful; negative error number or scsi
2229 * status on error
2230 *
2231 */
2232int
2233scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
2234 unsigned char *buffer, int len, int timeout, int retries,
2235 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2236{
2237 unsigned char cmd[10];
2238 unsigned char *real_buffer;
2239 int ret;
2240
2241 memset(cmd, 0, sizeof(cmd));
2242 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
2243
2244 if (sdev->use_10_for_ms) {
2245 if (len > 65535)
2246 return -EINVAL;
2247 real_buffer = kmalloc(8 + len, GFP_KERNEL);
2248 if (!real_buffer)
2249 return -ENOMEM;
2250 memcpy(real_buffer + 8, buffer, len);
2251 len += 8;
2252 real_buffer[0] = 0;
2253 real_buffer[1] = 0;
2254 real_buffer[2] = data->medium_type;
2255 real_buffer[3] = data->device_specific;
2256 real_buffer[4] = data->longlba ? 0x01 : 0;
2257 real_buffer[5] = 0;
2258 real_buffer[6] = data->block_descriptor_length >> 8;
2259 real_buffer[7] = data->block_descriptor_length;
2260
2261 cmd[0] = MODE_SELECT_10;
2262 cmd[7] = len >> 8;
2263 cmd[8] = len;
2264 } else {
2265 if (len > 255 || data->block_descriptor_length > 255 ||
2266 data->longlba)
2267 return -EINVAL;
2268
2269 real_buffer = kmalloc(4 + len, GFP_KERNEL);
2270 if (!real_buffer)
2271 return -ENOMEM;
2272 memcpy(real_buffer + 4, buffer, len);
2273 len += 4;
2274 real_buffer[0] = 0;
2275 real_buffer[1] = data->medium_type;
2276 real_buffer[2] = data->device_specific;
2277 real_buffer[3] = data->block_descriptor_length;
2278
2279
2280 cmd[0] = MODE_SELECT;
2281 cmd[4] = len;
2282 }
2283
2284 ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09002285 sshdr, timeout, retries, NULL);
James Bottomley5baba832006-03-18 14:10:35 -06002286 kfree(real_buffer);
2287 return ret;
2288}
2289EXPORT_SYMBOL_GPL(scsi_mode_select);
2290
Linus Torvalds1da177e2005-04-16 15:20:36 -07002291/**
Rob Landleyeb448202007-11-03 13:30:39 -05002292 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
James Bottomley1cf72692005-08-28 11:27:01 -05002293 * @sdev: SCSI device to be queried
Linus Torvalds1da177e2005-04-16 15:20:36 -07002294 * @dbd: set if mode sense will allow block descriptors to be returned
2295 * @modepage: mode page being requested
2296 * @buffer: request buffer (may not be smaller than eight bytes)
2297 * @len: length of request buffer.
2298 * @timeout: command timeout
2299 * @retries: number of retries before failing
2300 * @data: returns a structure abstracting the mode header data
Rob Landleyeb448202007-11-03 13:30:39 -05002301 * @sshdr: place to put sense data (or NULL if no sense to be collected).
James Bottomley1cf72692005-08-28 11:27:01 -05002302 * must be SCSI_SENSE_BUFFERSIZE big.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002303 *
2304 * Returns zero if unsuccessful, or the header offset (either 4
2305 * or 8 depending on whether a six or ten byte command was
2306 * issued) if successful.
Rob Landleyeb448202007-11-03 13:30:39 -05002307 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002308int
James Bottomley1cf72692005-08-28 11:27:01 -05002309scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002310 unsigned char *buffer, int len, int timeout, int retries,
James Bottomley5baba832006-03-18 14:10:35 -06002311 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2312{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002313 unsigned char cmd[12];
2314 int use_10_for_ms;
2315 int header_length;
Hannes Reinecke0ae80ba2015-06-12 16:12:48 +02002316 int result, retry_count = retries;
James Bottomleyea73a9f2005-08-28 11:33:52 -05002317 struct scsi_sense_hdr my_sshdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002318
2319 memset(data, 0, sizeof(*data));
2320 memset(&cmd[0], 0, 12);
2321 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */
2322 cmd[2] = modepage;
2323
James Bottomleyea73a9f2005-08-28 11:33:52 -05002324 /* caller might not be interested in sense, but we need it */
2325 if (!sshdr)
2326 sshdr = &my_sshdr;
2327
Linus Torvalds1da177e2005-04-16 15:20:36 -07002328 retry:
James Bottomley1cf72692005-08-28 11:27:01 -05002329 use_10_for_ms = sdev->use_10_for_ms;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002330
2331 if (use_10_for_ms) {
2332 if (len < 8)
2333 len = 8;
2334
2335 cmd[0] = MODE_SENSE_10;
2336 cmd[8] = len;
2337 header_length = 8;
2338 } else {
2339 if (len < 4)
2340 len = 4;
2341
2342 cmd[0] = MODE_SENSE;
2343 cmd[4] = len;
2344 header_length = 4;
2345 }
2346
Linus Torvalds1da177e2005-04-16 15:20:36 -07002347 memset(buffer, 0, len);
2348
James Bottomley1cf72692005-08-28 11:27:01 -05002349 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09002350 sshdr, timeout, retries, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002351
2352 /* This code looks awful: what it's doing is making sure an
2353 * ILLEGAL REQUEST sense return identifies the actual command
2354 * byte as the problem. MODE_SENSE commands can return
2355 * ILLEGAL REQUEST if the code page isn't supported */
2356
James Bottomley1cf72692005-08-28 11:27:01 -05002357 if (use_10_for_ms && !scsi_status_is_good(result) &&
2358 (driver_byte(result) & DRIVER_SENSE)) {
James Bottomleyea73a9f2005-08-28 11:33:52 -05002359 if (scsi_sense_valid(sshdr)) {
2360 if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
2361 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002362 /*
2363 * Invalid command operation code
2364 */
James Bottomley1cf72692005-08-28 11:27:01 -05002365 sdev->use_10_for_ms = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002366 goto retry;
2367 }
2368 }
2369 }
2370
James Bottomley1cf72692005-08-28 11:27:01 -05002371 if(scsi_status_is_good(result)) {
Al Viro6d73c852006-02-23 02:03:16 +01002372 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
2373 (modepage == 6 || modepage == 8))) {
2374 /* Initio breakage? */
2375 header_length = 0;
2376 data->length = 13;
2377 data->medium_type = 0;
2378 data->device_specific = 0;
2379 data->longlba = 0;
2380 data->block_descriptor_length = 0;
2381 } else if(use_10_for_ms) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002382 data->length = buffer[0]*256 + buffer[1] + 2;
2383 data->medium_type = buffer[2];
2384 data->device_specific = buffer[3];
2385 data->longlba = buffer[4] & 0x01;
2386 data->block_descriptor_length = buffer[6]*256
2387 + buffer[7];
2388 } else {
2389 data->length = buffer[0] + 1;
2390 data->medium_type = buffer[1];
2391 data->device_specific = buffer[2];
2392 data->block_descriptor_length = buffer[3];
2393 }
Al Viro6d73c852006-02-23 02:03:16 +01002394 data->header_length = header_length;
Hannes Reinecke0ae80ba2015-06-12 16:12:48 +02002395 } else if ((status_byte(result) == CHECK_CONDITION) &&
2396 scsi_sense_valid(sshdr) &&
2397 sshdr->sense_key == UNIT_ATTENTION && retry_count) {
2398 retry_count--;
2399 goto retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002400 }
2401
James Bottomley1cf72692005-08-28 11:27:01 -05002402 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002403}
2404EXPORT_SYMBOL(scsi_mode_sense);
2405
James Bottomley001aac22007-12-02 19:10:40 +02002406/**
2407 * scsi_test_unit_ready - test if unit is ready
2408 * @sdev: scsi device to change the state of.
2409 * @timeout: command timeout
2410 * @retries: number of retries before failing
2411 * @sshdr_external: Optional pointer to struct scsi_sense_hdr for
2412 * returning sense. Make sure that this is cleared before passing
2413 * in.
2414 *
2415 * Returns zero if unsuccessful or an error if TUR failed. For
Tejun Heo9f8a2c22010-12-08 20:57:40 +01002416 * removable media, UNIT_ATTENTION sets ->changed flag.
James Bottomley001aac22007-12-02 19:10:40 +02002417 **/
Linus Torvalds1da177e2005-04-16 15:20:36 -07002418int
James Bottomley001aac22007-12-02 19:10:40 +02002419scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
2420 struct scsi_sense_hdr *sshdr_external)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002421{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002422 char cmd[] = {
2423 TEST_UNIT_READY, 0, 0, 0, 0, 0,
2424 };
James Bottomley001aac22007-12-02 19:10:40 +02002425 struct scsi_sense_hdr *sshdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002426 int result;
James Bottomley001aac22007-12-02 19:10:40 +02002427
2428 if (!sshdr_external)
2429 sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
2430 else
2431 sshdr = sshdr_external;
2432
2433 /* try to eat the UNIT_ATTENTION if there are enough retries */
2434 do {
2435 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09002436 timeout, retries, NULL);
James Bottomley32c356d2008-08-20 00:58:13 +02002437 if (sdev->removable && scsi_sense_valid(sshdr) &&
2438 sshdr->sense_key == UNIT_ATTENTION)
2439 sdev->changed = 1;
2440 } while (scsi_sense_valid(sshdr) &&
2441 sshdr->sense_key == UNIT_ATTENTION && --retries);
James Bottomley001aac22007-12-02 19:10:40 +02002442
James Bottomley001aac22007-12-02 19:10:40 +02002443 if (!sshdr_external)
2444 kfree(sshdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002445 return result;
2446}
2447EXPORT_SYMBOL(scsi_test_unit_ready);
2448
2449/**
Rob Landleyeb448202007-11-03 13:30:39 -05002450 * scsi_device_set_state - Take the given device through the device state model.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002451 * @sdev: scsi device to change the state of.
2452 * @state: state to change to.
2453 *
2454 * Returns zero if unsuccessful or an error if the requested
2455 * transition is illegal.
Rob Landleyeb448202007-11-03 13:30:39 -05002456 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002457int
2458scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
2459{
2460 enum scsi_device_state oldstate = sdev->sdev_state;
2461
2462 if (state == oldstate)
2463 return 0;
2464
2465 switch (state) {
2466 case SDEV_CREATED:
James Bottomley6f4267e2008-08-22 16:53:31 -05002467 switch (oldstate) {
2468 case SDEV_CREATED_BLOCK:
2469 break;
2470 default:
2471 goto illegal;
2472 }
2473 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002474
2475 case SDEV_RUNNING:
2476 switch (oldstate) {
2477 case SDEV_CREATED:
2478 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002479 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002480 case SDEV_QUIESCE:
2481 case SDEV_BLOCK:
2482 break;
2483 default:
2484 goto illegal;
2485 }
2486 break;
2487
2488 case SDEV_QUIESCE:
2489 switch (oldstate) {
2490 case SDEV_RUNNING:
2491 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002492 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002493 break;
2494 default:
2495 goto illegal;
2496 }
2497 break;
2498
2499 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002500 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002501 switch (oldstate) {
2502 case SDEV_CREATED:
2503 case SDEV_RUNNING:
2504 case SDEV_QUIESCE:
2505 case SDEV_BLOCK:
2506 break;
2507 default:
2508 goto illegal;
2509 }
2510 break;
2511
2512 case SDEV_BLOCK:
2513 switch (oldstate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002514 case SDEV_RUNNING:
James Bottomley6f4267e2008-08-22 16:53:31 -05002515 case SDEV_CREATED_BLOCK:
2516 break;
2517 default:
2518 goto illegal;
2519 }
2520 break;
2521
2522 case SDEV_CREATED_BLOCK:
2523 switch (oldstate) {
2524 case SDEV_CREATED:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002525 break;
2526 default:
2527 goto illegal;
2528 }
2529 break;
2530
2531 case SDEV_CANCEL:
2532 switch (oldstate) {
2533 case SDEV_CREATED:
2534 case SDEV_RUNNING:
Alan Stern9ea72902006-06-23 14:25:34 -04002535 case SDEV_QUIESCE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002536 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002537 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538 case SDEV_BLOCK:
2539 break;
2540 default:
2541 goto illegal;
2542 }
2543 break;
2544
2545 case SDEV_DEL:
2546 switch (oldstate) {
Brian King309bd272006-06-27 11:10:43 -05002547 case SDEV_CREATED:
2548 case SDEV_RUNNING:
2549 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002550 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002551 case SDEV_CANCEL:
Bart Van Assche0516c082013-07-02 15:06:33 +02002552 case SDEV_CREATED_BLOCK:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002553 break;
2554 default:
2555 goto illegal;
2556 }
2557 break;
2558
2559 }
2560 sdev->sdev_state = state;
2561 return 0;
2562
2563 illegal:
Hannes Reinecke91921e02014-06-25 16:39:59 +02002564 SCSI_LOG_ERROR_RECOVERY(1,
James Bottomley9ccfc752005-10-02 11:45:08 -05002565 sdev_printk(KERN_ERR, sdev,
Hannes Reinecke91921e02014-06-25 16:39:59 +02002566 "Illegal state transition %s->%s",
James Bottomley9ccfc752005-10-02 11:45:08 -05002567 scsi_device_state_name(oldstate),
2568 scsi_device_state_name(state))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002569 );
2570 return -EINVAL;
2571}
2572EXPORT_SYMBOL(scsi_device_set_state);
2573
2574/**
Jeff Garzika341cd02007-10-29 17:15:22 -04002575 * sdev_evt_emit - emit a single SCSI device uevent
2576 * @sdev: associated SCSI device
2577 * @evt: event to emit
2578 *
2579 * Send a single uevent (scsi_event) to the associated scsi_device.
2580 */
2581static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
2582{
2583 int idx = 0;
2584 char *envp[3];
2585
2586 switch (evt->evt_type) {
2587 case SDEV_EVT_MEDIA_CHANGE:
2588 envp[idx++] = "SDEV_MEDIA_CHANGE=1";
2589 break;
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002590 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
Hannes Reinecked3d32892016-02-19 09:17:16 +01002591 scsi_rescan_device(&sdev->sdev_gendev);
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002592 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
2593 break;
2594 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2595 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
2596 break;
2597 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2598 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED";
2599 break;
2600 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2601 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED";
2602 break;
2603 case SDEV_EVT_LUN_CHANGE_REPORTED:
2604 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
2605 break;
Hannes Reinecke14c3e672015-07-06 13:41:53 +02002606 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
2607 envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
2608 break;
Jeff Garzika341cd02007-10-29 17:15:22 -04002609 default:
2610 /* do nothing */
2611 break;
2612 }
2613
2614 envp[idx++] = NULL;
2615
2616 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
2617}
2618
2619/**
2620 * sdev_evt_thread - send a uevent for each scsi event
2621 * @work: work struct for scsi_device
2622 *
2623 * Dispatch queued events to their associated scsi_device kobjects
2624 * as uevents.
2625 */
2626void scsi_evt_thread(struct work_struct *work)
2627{
2628 struct scsi_device *sdev;
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002629 enum scsi_device_event evt_type;
Jeff Garzika341cd02007-10-29 17:15:22 -04002630 LIST_HEAD(event_list);
2631
2632 sdev = container_of(work, struct scsi_device, event_work);
2633
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002634 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++)
2635 if (test_and_clear_bit(evt_type, sdev->pending_events))
2636 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL);
2637
Jeff Garzika341cd02007-10-29 17:15:22 -04002638 while (1) {
2639 struct scsi_event *evt;
2640 struct list_head *this, *tmp;
2641 unsigned long flags;
2642
2643 spin_lock_irqsave(&sdev->list_lock, flags);
2644 list_splice_init(&sdev->event_list, &event_list);
2645 spin_unlock_irqrestore(&sdev->list_lock, flags);
2646
2647 if (list_empty(&event_list))
2648 break;
2649
2650 list_for_each_safe(this, tmp, &event_list) {
2651 evt = list_entry(this, struct scsi_event, node);
2652 list_del(&evt->node);
2653 scsi_evt_emit(sdev, evt);
2654 kfree(evt);
2655 }
2656 }
2657}
2658
2659/**
2660 * sdev_evt_send - send asserted event to uevent thread
2661 * @sdev: scsi_device event occurred on
2662 * @evt: event to send
2663 *
2664 * Assert scsi device event asynchronously.
2665 */
2666void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
2667{
2668 unsigned long flags;
2669
Kay Sievers4d1566e2008-03-19 13:04:47 +01002670#if 0
2671 /* FIXME: currently this check eliminates all media change events
2672 * for polled devices. Need to update to discriminate between AN
2673 * and polled events */
Jeff Garzika341cd02007-10-29 17:15:22 -04002674 if (!test_bit(evt->evt_type, sdev->supported_events)) {
2675 kfree(evt);
2676 return;
2677 }
Kay Sievers4d1566e2008-03-19 13:04:47 +01002678#endif
Jeff Garzika341cd02007-10-29 17:15:22 -04002679
2680 spin_lock_irqsave(&sdev->list_lock, flags);
2681 list_add_tail(&evt->node, &sdev->event_list);
2682 schedule_work(&sdev->event_work);
2683 spin_unlock_irqrestore(&sdev->list_lock, flags);
2684}
2685EXPORT_SYMBOL_GPL(sdev_evt_send);
2686
2687/**
2688 * sdev_evt_alloc - allocate a new scsi event
2689 * @evt_type: type of event to allocate
2690 * @gfpflags: GFP flags for allocation
2691 *
2692 * Allocates and returns a new scsi_event.
2693 */
2694struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
2695 gfp_t gfpflags)
2696{
2697 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
2698 if (!evt)
2699 return NULL;
2700
2701 evt->evt_type = evt_type;
2702 INIT_LIST_HEAD(&evt->node);
2703
2704 /* evt_type-specific initialization, if any */
2705 switch (evt_type) {
2706 case SDEV_EVT_MEDIA_CHANGE:
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002707 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2708 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2709 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2710 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2711 case SDEV_EVT_LUN_CHANGE_REPORTED:
Hannes Reinecke14c3e672015-07-06 13:41:53 +02002712 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
Jeff Garzika341cd02007-10-29 17:15:22 -04002713 default:
2714 /* do nothing */
2715 break;
2716 }
2717
2718 return evt;
2719}
2720EXPORT_SYMBOL_GPL(sdev_evt_alloc);
2721
2722/**
2723 * sdev_evt_send_simple - send asserted event to uevent thread
2724 * @sdev: scsi_device event occurred on
2725 * @evt_type: type of event to send
2726 * @gfpflags: GFP flags for allocation
2727 *
2728 * Assert scsi device event asynchronously, given an event type.
2729 */
2730void sdev_evt_send_simple(struct scsi_device *sdev,
2731 enum scsi_device_event evt_type, gfp_t gfpflags)
2732{
2733 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
2734 if (!evt) {
2735 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
2736 evt_type);
2737 return;
2738 }
2739
2740 sdev_evt_send(sdev, evt);
2741}
2742EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
2743
2744/**
Bart Van Assche669f0442016-11-22 16:17:13 -08002745 * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
2746 * @sdev: SCSI device to count the number of scsi_request_fn() callers for.
2747 */
2748static int scsi_request_fn_active(struct scsi_device *sdev)
2749{
2750 struct request_queue *q = sdev->request_queue;
2751 int request_fn_active;
2752
2753 WARN_ON_ONCE(sdev->host->use_blk_mq);
2754
2755 spin_lock_irq(q->queue_lock);
2756 request_fn_active = q->request_fn_active;
2757 spin_unlock_irq(q->queue_lock);
2758
2759 return request_fn_active;
2760}
2761
2762/**
2763 * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls
2764 * @sdev: SCSI device pointer.
2765 *
2766 * Wait until the ongoing shost->hostt->queuecommand() calls that are
2767 * invoked from scsi_request_fn() have finished.
2768 */
2769static void scsi_wait_for_queuecommand(struct scsi_device *sdev)
2770{
2771 WARN_ON_ONCE(sdev->host->use_blk_mq);
2772
2773 while (scsi_request_fn_active(sdev))
2774 msleep(20);
2775}
2776
2777/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07002778 * scsi_device_quiesce - Block user issued commands.
2779 * @sdev: scsi device to quiesce.
2780 *
2781 * This works by trying to transition to the SDEV_QUIESCE state
2782 * (which must be a legal transition). When the device is in this
2783 * state, only special requests will be accepted, all others will
2784 * be deferred. Since special requests may also be requeued requests,
2785 * a successful return doesn't guarantee the device will be
2786 * totally quiescent.
2787 *
2788 * Must be called with user context, may sleep.
2789 *
2790 * Returns zero if unsuccessful or an error if not.
Rob Landleyeb448202007-11-03 13:30:39 -05002791 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002792int
2793scsi_device_quiesce(struct scsi_device *sdev)
2794{
2795 int err = scsi_device_set_state(sdev, SDEV_QUIESCE);
2796 if (err)
2797 return err;
2798
2799 scsi_run_queue(sdev->request_queue);
Christoph Hellwig71e75c92014-04-11 19:07:01 +02002800 while (atomic_read(&sdev->device_busy)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002801 msleep_interruptible(200);
2802 scsi_run_queue(sdev->request_queue);
2803 }
2804 return 0;
2805}
2806EXPORT_SYMBOL(scsi_device_quiesce);
2807
2808/**
2809 * scsi_device_resume - Restart user issued commands to a quiesced device.
2810 * @sdev: scsi device to resume.
2811 *
2812 * Moves the device from quiesced back to running and restarts the
2813 * queues.
2814 *
2815 * Must be called with user context, may sleep.
Rob Landleyeb448202007-11-03 13:30:39 -05002816 */
Dan Williamsa7a20d12012-03-22 17:05:11 -07002817void scsi_device_resume(struct scsi_device *sdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002818{
Dan Williamsa7a20d12012-03-22 17:05:11 -07002819 /* check if the device state was mutated prior to resume, and if
2820 * so assume the state is being managed elsewhere (for example
2821 * device deleted during suspend)
2822 */
2823 if (sdev->sdev_state != SDEV_QUIESCE ||
2824 scsi_device_set_state(sdev, SDEV_RUNNING))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002825 return;
2826 scsi_run_queue(sdev->request_queue);
2827}
2828EXPORT_SYMBOL(scsi_device_resume);
2829
2830static void
2831device_quiesce_fn(struct scsi_device *sdev, void *data)
2832{
2833 scsi_device_quiesce(sdev);
2834}
2835
2836void
2837scsi_target_quiesce(struct scsi_target *starget)
2838{
2839 starget_for_each_device(starget, NULL, device_quiesce_fn);
2840}
2841EXPORT_SYMBOL(scsi_target_quiesce);
2842
2843static void
2844device_resume_fn(struct scsi_device *sdev, void *data)
2845{
2846 scsi_device_resume(sdev);
2847}
2848
2849void
2850scsi_target_resume(struct scsi_target *starget)
2851{
2852 starget_for_each_device(starget, NULL, device_resume_fn);
2853}
2854EXPORT_SYMBOL(scsi_target_resume);
2855
2856/**
Rob Landleyeb448202007-11-03 13:30:39 -05002857 * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state
Linus Torvalds1da177e2005-04-16 15:20:36 -07002858 * @sdev: device to block
2859 *
2860 * Block request made by scsi lld's to temporarily stop all
Bart Van Assche669f0442016-11-22 16:17:13 -08002861 * scsi commands on the specified device. May sleep.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002862 *
2863 * Returns zero if successful or error if not
2864 *
2865 * Notes:
2866 * This routine transitions the device to the SDEV_BLOCK state
2867 * (which must be a legal transition). When the device is in this
2868 * state, all commands are deferred until the scsi lld reenables
2869 * the device with scsi_device_unblock or device_block_tmo fires.
Bart Van Assche669f0442016-11-22 16:17:13 -08002870 *
2871 * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after
2872 * scsi_internal_device_block() has blocked a SCSI device and also
2873 * remove the rport mutex lock and unlock calls from srp_queuecommand().
Rob Landleyeb448202007-11-03 13:30:39 -05002874 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002875int
2876scsi_internal_device_block(struct scsi_device *sdev)
2877{
Jens Axboe165125e2007-07-24 09:28:11 +02002878 struct request_queue *q = sdev->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002879 unsigned long flags;
2880 int err = 0;
2881
2882 err = scsi_device_set_state(sdev, SDEV_BLOCK);
James Bottomley6f4267e2008-08-22 16:53:31 -05002883 if (err) {
2884 err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
2885
2886 if (err)
2887 return err;
2888 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002889
2890 /*
2891 * The device has transitioned to SDEV_BLOCK. Stop the
2892 * block layer from calling the midlayer with this device's
2893 * request queue.
2894 */
Christoph Hellwigd2852032014-01-17 12:06:53 +01002895 if (q->mq_ops) {
Bart Van Assche7dbbf0f2016-11-22 16:17:50 -08002896 blk_mq_quiesce_queue(q);
Christoph Hellwigd2852032014-01-17 12:06:53 +01002897 } else {
2898 spin_lock_irqsave(q->queue_lock, flags);
2899 blk_stop_queue(q);
2900 spin_unlock_irqrestore(q->queue_lock, flags);
Bart Van Assche669f0442016-11-22 16:17:13 -08002901 scsi_wait_for_queuecommand(sdev);
Christoph Hellwigd2852032014-01-17 12:06:53 +01002902 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002903
2904 return 0;
2905}
2906EXPORT_SYMBOL_GPL(scsi_internal_device_block);
2907
2908/**
2909 * scsi_internal_device_unblock - resume a device after a block request
2910 * @sdev: device to resume
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002911 * @new_state: state to set devices to after unblocking
Linus Torvalds1da177e2005-04-16 15:20:36 -07002912 *
2913 * Called by scsi lld's or the midlayer to restart the device queue
2914 * for the previously suspended scsi device. Called from interrupt or
2915 * normal process context.
2916 *
2917 * Returns zero if successful or error if not.
2918 *
2919 * Notes:
2920 * This routine transitions the device to the SDEV_RUNNING state
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002921 * or to one of the offline states (which must be a legal transition)
Mike Christied0754982012-05-17 23:56:58 -05002922 * allowing the midlayer to goose the queue for this device.
Rob Landleyeb448202007-11-03 13:30:39 -05002923 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002924int
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002925scsi_internal_device_unblock(struct scsi_device *sdev,
2926 enum scsi_device_state new_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002927{
Jens Axboe165125e2007-07-24 09:28:11 +02002928 struct request_queue *q = sdev->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002929 unsigned long flags;
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002930
2931 /*
2932 * Try to transition the scsi device to SDEV_RUNNING or one of the
2933 * offlined states and goose the device queue if successful.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002934 */
Vikas Chaudhary0e580762012-08-09 04:51:30 -04002935 if ((sdev->sdev_state == SDEV_BLOCK) ||
2936 (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002937 sdev->sdev_state = new_state;
2938 else if (sdev->sdev_state == SDEV_CREATED_BLOCK) {
2939 if (new_state == SDEV_TRANSPORT_OFFLINE ||
2940 new_state == SDEV_OFFLINE)
2941 sdev->sdev_state = new_state;
2942 else
2943 sdev->sdev_state = SDEV_CREATED;
2944 } else if (sdev->sdev_state != SDEV_CANCEL &&
Mike Christie986fe6c2010-10-06 03:10:59 -05002945 sdev->sdev_state != SDEV_OFFLINE)
Takahiro Yasui5c10e632009-04-29 12:13:02 -04002946 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002947
Christoph Hellwigd2852032014-01-17 12:06:53 +01002948 if (q->mq_ops) {
2949 blk_mq_start_stopped_hw_queues(q, false);
2950 } else {
2951 spin_lock_irqsave(q->queue_lock, flags);
2952 blk_start_queue(q);
2953 spin_unlock_irqrestore(q->queue_lock, flags);
2954 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002955
2956 return 0;
2957}
2958EXPORT_SYMBOL_GPL(scsi_internal_device_unblock);
2959
2960static void
2961device_block(struct scsi_device *sdev, void *data)
2962{
2963 scsi_internal_device_block(sdev);
2964}
2965
2966static int
2967target_block(struct device *dev, void *data)
2968{
2969 if (scsi_is_target_device(dev))
2970 starget_for_each_device(to_scsi_target(dev), NULL,
2971 device_block);
2972 return 0;
2973}
2974
2975void
2976scsi_target_block(struct device *dev)
2977{
2978 if (scsi_is_target_device(dev))
2979 starget_for_each_device(to_scsi_target(dev), NULL,
2980 device_block);
2981 else
2982 device_for_each_child(dev, NULL, target_block);
2983}
2984EXPORT_SYMBOL_GPL(scsi_target_block);
2985
2986static void
2987device_unblock(struct scsi_device *sdev, void *data)
2988{
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002989 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002990}
2991
2992static int
2993target_unblock(struct device *dev, void *data)
2994{
2995 if (scsi_is_target_device(dev))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002996 starget_for_each_device(to_scsi_target(dev), data,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002997 device_unblock);
2998 return 0;
2999}
3000
3001void
Mike Christie5d9fb5c2012-05-17 23:56:57 -05003002scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003003{
3004 if (scsi_is_target_device(dev))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05003005 starget_for_each_device(to_scsi_target(dev), &new_state,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003006 device_unblock);
3007 else
Mike Christie5d9fb5c2012-05-17 23:56:57 -05003008 device_for_each_child(dev, &new_state, target_unblock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003009}
3010EXPORT_SYMBOL_GPL(scsi_target_unblock);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003011
3012/**
3013 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
Rob Landleyeb448202007-11-03 13:30:39 -05003014 * @sgl: scatter-gather list
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003015 * @sg_count: number of segments in sg
3016 * @offset: offset in bytes into sg, on return offset into the mapped area
3017 * @len: bytes to map, on return number of bytes mapped
3018 *
3019 * Returns virtual address of the start of the mapped page
3020 */
Jens Axboec6132da2007-10-16 11:08:49 +02003021void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003022 size_t *offset, size_t *len)
3023{
3024 int i;
3025 size_t sg_len = 0, len_complete = 0;
Jens Axboec6132da2007-10-16 11:08:49 +02003026 struct scatterlist *sg;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003027 struct page *page;
3028
Andrew Morton22cfefb2007-02-05 16:39:03 -08003029 WARN_ON(!irqs_disabled());
3030
Jens Axboec6132da2007-10-16 11:08:49 +02003031 for_each_sg(sgl, sg, sg_count, i) {
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003032 len_complete = sg_len; /* Complete sg-entries */
Jens Axboec6132da2007-10-16 11:08:49 +02003033 sg_len += sg->length;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003034 if (sg_len > *offset)
3035 break;
3036 }
3037
3038 if (unlikely(i == sg_count)) {
Andrew Morton169e1a22006-04-18 21:09:08 -07003039 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
3040 "elements %d\n",
Harvey Harrisoncadbd4a2008-07-03 23:47:27 -07003041 __func__, sg_len, *offset, sg_count);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003042 WARN_ON(1);
3043 return NULL;
3044 }
3045
3046 /* Offset starting from the beginning of first page in this sg-entry */
Jens Axboec6132da2007-10-16 11:08:49 +02003047 *offset = *offset - len_complete + sg->offset;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003048
3049 /* Assumption: contiguous pages can be accessed as "page + i" */
Jens Axboe45711f12007-10-22 21:19:53 +02003050 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003051 *offset &= ~PAGE_MASK;
3052
3053 /* Bytes in this sg-entry from *offset to the end of the page */
3054 sg_len = PAGE_SIZE - *offset;
3055 if (*len > sg_len)
3056 *len = sg_len;
3057
Cong Wang77dfce02011-11-25 23:14:23 +08003058 return kmap_atomic(page);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003059}
3060EXPORT_SYMBOL(scsi_kmap_atomic_sg);
3061
3062/**
Rob Landleyeb448202007-11-03 13:30:39 -05003063 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003064 * @virt: virtual address to be unmapped
3065 */
3066void scsi_kunmap_atomic_sg(void *virt)
3067{
Cong Wang77dfce02011-11-25 23:14:23 +08003068 kunmap_atomic(virt);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02003069}
3070EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
Aaron Lu6f4c8272013-01-23 15:09:32 +08003071
3072void sdev_disable_disk_events(struct scsi_device *sdev)
3073{
3074 atomic_inc(&sdev->disk_events_disable_depth);
3075}
3076EXPORT_SYMBOL(sdev_disable_disk_events);
3077
3078void sdev_enable_disk_events(struct scsi_device *sdev)
3079{
3080 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0))
3081 return;
3082 atomic_dec(&sdev->disk_events_disable_depth);
3083}
3084EXPORT_SYMBOL(sdev_enable_disk_events);
Hannes Reinecke9983bed2015-12-01 10:16:55 +01003085
3086/**
3087 * scsi_vpd_lun_id - return a unique device identification
3088 * @sdev: SCSI device
3089 * @id: buffer for the identification
3090 * @id_len: length of the buffer
3091 *
3092 * Copies a unique device identification into @id based
3093 * on the information in the VPD page 0x83 of the device.
3094 * The string will be formatted as a SCSI name string.
3095 *
3096 * Returns the length of the identification or error on failure.
3097 * If the identifier is longer than the supplied buffer the actual
3098 * identifier length is returned and the buffer is not zero-padded.
3099 */
3100int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
3101{
3102 u8 cur_id_type = 0xff;
3103 u8 cur_id_size = 0;
3104 unsigned char *d, *cur_id_str;
3105 unsigned char __rcu *vpd_pg83;
3106 int id_size = -EINVAL;
3107
3108 rcu_read_lock();
3109 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3110 if (!vpd_pg83) {
3111 rcu_read_unlock();
3112 return -ENXIO;
3113 }
3114
3115 /*
3116 * Look for the correct descriptor.
3117 * Order of preference for lun descriptor:
3118 * - SCSI name string
3119 * - NAA IEEE Registered Extended
3120 * - EUI-64 based 16-byte
3121 * - EUI-64 based 12-byte
3122 * - NAA IEEE Registered
3123 * - NAA IEEE Extended
Hannes Reinecked2308232016-05-09 09:14:29 +02003124 * - T10 Vendor ID
Hannes Reinecke9983bed2015-12-01 10:16:55 +01003125 * as longer descriptors reduce the likelyhood
3126 * of identification clashes.
3127 */
3128
3129 /* The id string must be at least 20 bytes + terminating NULL byte */
3130 if (id_len < 21) {
3131 rcu_read_unlock();
3132 return -EINVAL;
3133 }
3134
3135 memset(id, 0, id_len);
3136 d = vpd_pg83 + 4;
3137 while (d < vpd_pg83 + sdev->vpd_pg83_len) {
3138 /* Skip designators not referring to the LUN */
3139 if ((d[1] & 0x30) != 0x00)
3140 goto next_desig;
3141
3142 switch (d[1] & 0xf) {
Hannes Reinecked2308232016-05-09 09:14:29 +02003143 case 0x1:
3144 /* T10 Vendor ID */
3145 if (cur_id_size > d[3])
3146 break;
3147 /* Prefer anything */
3148 if (cur_id_type > 0x01 && cur_id_type != 0xff)
3149 break;
3150 cur_id_size = d[3];
3151 if (cur_id_size + 4 > id_len)
3152 cur_id_size = id_len - 4;
3153 cur_id_str = d + 4;
3154 cur_id_type = d[1] & 0xf;
3155 id_size = snprintf(id, id_len, "t10.%*pE",
3156 cur_id_size, cur_id_str);
3157 break;
Hannes Reinecke9983bed2015-12-01 10:16:55 +01003158 case 0x2:
3159 /* EUI-64 */
3160 if (cur_id_size > d[3])
3161 break;
3162 /* Prefer NAA IEEE Registered Extended */
3163 if (cur_id_type == 0x3 &&
3164 cur_id_size == d[3])
3165 break;
3166 cur_id_size = d[3];
3167 cur_id_str = d + 4;
3168 cur_id_type = d[1] & 0xf;
3169 switch (cur_id_size) {
3170 case 8:
3171 id_size = snprintf(id, id_len,
3172 "eui.%8phN",
3173 cur_id_str);
3174 break;
3175 case 12:
3176 id_size = snprintf(id, id_len,
3177 "eui.%12phN",
3178 cur_id_str);
3179 break;
3180 case 16:
3181 id_size = snprintf(id, id_len,
3182 "eui.%16phN",
3183 cur_id_str);
3184 break;
3185 default:
3186 cur_id_size = 0;
3187 break;
3188 }
3189 break;
3190 case 0x3:
3191 /* NAA */
3192 if (cur_id_size > d[3])
3193 break;
3194 cur_id_size = d[3];
3195 cur_id_str = d + 4;
3196 cur_id_type = d[1] & 0xf;
3197 switch (cur_id_size) {
3198 case 8:
3199 id_size = snprintf(id, id_len,
3200 "naa.%8phN",
3201 cur_id_str);
3202 break;
3203 case 16:
3204 id_size = snprintf(id, id_len,
3205 "naa.%16phN",
3206 cur_id_str);
3207 break;
3208 default:
3209 cur_id_size = 0;
3210 break;
3211 }
3212 break;
3213 case 0x8:
3214 /* SCSI name string */
3215 if (cur_id_size + 4 > d[3])
3216 break;
3217 /* Prefer others for truncated descriptor */
3218 if (cur_id_size && d[3] > id_len)
3219 break;
3220 cur_id_size = id_size = d[3];
3221 cur_id_str = d + 4;
3222 cur_id_type = d[1] & 0xf;
3223 if (cur_id_size >= id_len)
3224 cur_id_size = id_len - 1;
3225 memcpy(id, cur_id_str, cur_id_size);
3226 /* Decrease priority for truncated descriptor */
3227 if (cur_id_size != id_size)
3228 cur_id_size = 6;
3229 break;
3230 default:
3231 break;
3232 }
3233next_desig:
3234 d += d[3] + 4;
3235 }
3236 rcu_read_unlock();
3237
3238 return id_size;
3239}
3240EXPORT_SYMBOL(scsi_vpd_lun_id);
Hannes Reineckea8aa3972015-12-01 10:16:57 +01003241
3242/*
3243 * scsi_vpd_tpg_id - return a target port group identifier
3244 * @sdev: SCSI device
3245 *
3246 * Returns the Target Port Group identifier from the information
3247 * froom VPD page 0x83 of the device.
3248 *
3249 * Returns the identifier or error on failure.
3250 */
3251int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id)
3252{
3253 unsigned char *d;
3254 unsigned char __rcu *vpd_pg83;
3255 int group_id = -EAGAIN, rel_port = -1;
3256
3257 rcu_read_lock();
3258 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3259 if (!vpd_pg83) {
3260 rcu_read_unlock();
3261 return -ENXIO;
3262 }
3263
3264 d = sdev->vpd_pg83 + 4;
3265 while (d < sdev->vpd_pg83 + sdev->vpd_pg83_len) {
3266 switch (d[1] & 0xf) {
3267 case 0x4:
3268 /* Relative target port */
3269 rel_port = get_unaligned_be16(&d[6]);
3270 break;
3271 case 0x5:
3272 /* Target port group */
3273 group_id = get_unaligned_be16(&d[6]);
3274 break;
3275 default:
3276 break;
3277 }
3278 d += d[3] + 4;
3279 }
3280 rcu_read_unlock();
3281
3282 if (group_id >= 0 && rel_id && rel_port != -1)
3283 *rel_id = rel_port;
3284
3285 return group_id;
3286}
3287EXPORT_SYMBOL(scsi_vpd_tpg_id);