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Thomas Gleixner457c8992019-05-19 13:08:55 +01001// SPDX-License-Identifier: GPL-2.0-only
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
Christoph Hellwigd2852032014-01-17 12:06:53 +01003 * Copyright (C) 1999 Eric Youngdale
4 * Copyright (C) 2014 Christoph Hellwig
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * SCSI queueing library.
7 * Initial versions: Eric Youngdale (eric@andante.org).
8 * Based upon conversations with large numbers
9 * of people at Linux Expo.
10 */
11
12#include <linux/bio.h>
James Bottomleyd3f46f32008-01-15 11:11:46 -060013#include <linux/bitops.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/blkdev.h>
15#include <linux/completion.h>
16#include <linux/kernel.h>
Paul Gortmaker09703662011-05-27 09:37:25 -040017#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/init.h>
19#include <linux/pci.h>
20#include <linux/delay.h>
James Bottomleyfaead262006-02-14 10:42:07 -060021#include <linux/hardirq.h>
Jens Axboec6132da2007-10-16 11:08:49 +020022#include <linux/scatterlist.h>
Christoph Hellwigd2852032014-01-17 12:06:53 +010023#include <linux/blk-mq.h>
Hannes Reineckef1569ff2014-10-24 14:27:07 +020024#include <linux/ratelimit.h>
Hannes Reineckea8aa3972015-12-01 10:16:57 +010025#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27#include <scsi/scsi.h>
Christoph Hellwigbeb40482006-06-10 18:01:03 +020028#include <scsi/scsi_cmnd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <scsi/scsi_dbg.h>
30#include <scsi/scsi_device.h>
31#include <scsi/scsi_driver.h>
32#include <scsi/scsi_eh.h>
33#include <scsi/scsi_host.h>
Bart Van Assche7aa686d2017-05-02 10:45:03 -070034#include <scsi/scsi_transport.h> /* __scsi_init_queue() */
Christoph Hellwigee14c672015-08-27 14:16:59 +020035#include <scsi/scsi_dh.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Christoph Hellwig3b5382c2014-05-06 12:25:40 +020037#include <trace/events/scsi.h>
38
Bart Van Assche0eebd002017-04-26 13:47:57 -070039#include "scsi_debugfs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#include "scsi_priv.h"
41#include "scsi_logging.h"
42
Ming Lei92524fa2019-04-28 15:39:31 +080043/*
44 * Size of integrity metadata is usually small, 1 inline sg should
45 * cover normal cases.
46 */
Ming Lei3e99b3b2019-06-06 16:34:09 +080047#ifdef CONFIG_ARCH_NO_SG_CHAIN
48#define SCSI_INLINE_PROT_SG_CNT 0
49#define SCSI_INLINE_SG_CNT 0
50#else
Ming Lei92524fa2019-04-28 15:39:31 +080051#define SCSI_INLINE_PROT_SG_CNT 1
Ming Lei3dccdf52019-04-28 15:39:32 +080052#define SCSI_INLINE_SG_CNT 2
Ming Lei3e99b3b2019-06-06 16:34:09 +080053#endif
Ming Lei3dccdf52019-04-28 15:39:32 +080054
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030055static struct kmem_cache *scsi_sense_cache;
56static struct kmem_cache *scsi_sense_isadma_cache;
57static DEFINE_MUTEX(scsi_sense_cache_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Bart Van Asschea45a1f362017-08-30 16:58:42 -070059static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd);
60
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030061static inline struct kmem_cache *
Bart Van Assche8e688252017-06-02 14:21:52 -070062scsi_select_sense_cache(bool unchecked_isa_dma)
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030063{
Bart Van Assche8e688252017-06-02 14:21:52 -070064 return unchecked_isa_dma ? scsi_sense_isadma_cache : scsi_sense_cache;
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030065}
66
Bart Van Assche8e688252017-06-02 14:21:52 -070067static void scsi_free_sense_buffer(bool unchecked_isa_dma,
68 unsigned char *sense_buffer)
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030069{
Bart Van Assche8e688252017-06-02 14:21:52 -070070 kmem_cache_free(scsi_select_sense_cache(unchecked_isa_dma),
71 sense_buffer);
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030072}
73
Bart Van Assche8e688252017-06-02 14:21:52 -070074static unsigned char *scsi_alloc_sense_buffer(bool unchecked_isa_dma,
Christoph Hellwige9c787e2017-01-02 21:55:26 +030075 gfp_t gfp_mask, int numa_node)
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030076{
Bart Van Assche8e688252017-06-02 14:21:52 -070077 return kmem_cache_alloc_node(scsi_select_sense_cache(unchecked_isa_dma),
78 gfp_mask, numa_node);
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030079}
80
81int scsi_init_sense_cache(struct Scsi_Host *shost)
82{
83 struct kmem_cache *cache;
84 int ret = 0;
85
Ming Leif9b05302019-07-12 10:08:19 +080086 mutex_lock(&scsi_sense_cache_mutex);
Bart Van Assche8e688252017-06-02 14:21:52 -070087 cache = scsi_select_sense_cache(shost->unchecked_isa_dma);
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030088 if (cache)
Ming Leif9b05302019-07-12 10:08:19 +080089 goto exit;
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030090
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030091 if (shost->unchecked_isa_dma) {
92 scsi_sense_isadma_cache =
93 kmem_cache_create("scsi_sense_cache(DMA)",
David Windsor0afe76e2017-06-10 22:50:45 -040094 SCSI_SENSE_BUFFERSIZE, 0,
95 SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL);
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +030096 if (!scsi_sense_isadma_cache)
97 ret = -ENOMEM;
98 } else {
99 scsi_sense_cache =
David Windsor0afe76e2017-06-10 22:50:45 -0400100 kmem_cache_create_usercopy("scsi_sense_cache",
101 SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN,
102 0, SCSI_SENSE_BUFFERSIZE, NULL);
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +0300103 if (!scsi_sense_cache)
104 ret = -ENOMEM;
105 }
Ming Leif9b05302019-07-12 10:08:19 +0800106 exit:
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +0300107 mutex_unlock(&scsi_sense_cache_mutex);
108 return ret;
109}
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200110
Jens Axboea488e742010-04-16 21:13:15 +0200111/*
112 * When to reinvoke queueing after a resource shortage. It's 3 msecs to
113 * not change behaviour from the previous unplug mechanism, experimentation
114 * may prove this needs changing.
115 */
116#define SCSI_QUEUE_DELAY 3
117
Christoph Hellwigde3e8bf2014-01-23 13:55:38 +0100118static void
119scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120{
121 struct Scsi_Host *host = cmd->device->host;
122 struct scsi_device *device = cmd->device;
Mike Christief0c0a372008-08-17 15:24:38 -0500123 struct scsi_target *starget = scsi_target(device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125 /*
Tejun Heo d8c37e72005-05-14 00:46:08 +0900126 * Set the appropriate busy bit for the device/host.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 *
128 * If the host/device isn't busy, assume that something actually
129 * completed, and that we should be able to queue a command now.
130 *
131 * Note that the prior mid-layer assumption that any host could
132 * always queue at least one command is now broken. The mid-layer
133 * will implement a user specifiable stall (see
134 * scsi_host.max_host_blocked and scsi_device.max_device_blocked)
135 * if a command is requeued with no other commands outstanding
136 * either for the device or for the host.
137 */
Mike Christief0c0a372008-08-17 15:24:38 -0500138 switch (reason) {
139 case SCSI_MLQUEUE_HOST_BUSY:
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100140 atomic_set(&host->host_blocked, host->max_host_blocked);
Mike Christief0c0a372008-08-17 15:24:38 -0500141 break;
142 case SCSI_MLQUEUE_DEVICE_BUSY:
James Smart573e5912011-07-06 12:45:17 -0400143 case SCSI_MLQUEUE_EH_RETRY:
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100144 atomic_set(&device->device_blocked,
145 device->max_device_blocked);
Mike Christief0c0a372008-08-17 15:24:38 -0500146 break;
147 case SCSI_MLQUEUE_TARGET_BUSY:
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100148 atomic_set(&starget->target_blocked,
149 starget->max_target_blocked);
Mike Christief0c0a372008-08-17 15:24:38 -0500150 break;
151 }
Christoph Hellwigde3e8bf2014-01-23 13:55:38 +0100152}
153
Christoph Hellwigd2852032014-01-17 12:06:53 +0100154static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
155{
Bart Van Asschea45a1f362017-08-30 16:58:42 -0700156 if (cmd->request->rq_flags & RQF_DONTPREP) {
157 cmd->request->rq_flags &= ~RQF_DONTPREP;
158 scsi_mq_uninit_cmd(cmd);
159 } else {
160 WARN_ON_ONCE(true);
161 }
Bart Van Assche2b053ac2016-10-28 17:21:41 -0700162 blk_mq_requeue_request(cmd->request, true);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100163}
164
Christoph Hellwigde3e8bf2014-01-23 13:55:38 +0100165/**
166 * __scsi_queue_insert - private queue insertion
167 * @cmd: The SCSI command being requeued
168 * @reason: The reason for the requeue
169 * @unbusy: Whether the queue should be unbusied
170 *
171 * This is a private queue insertion. The public interface
172 * scsi_queue_insert() always assumes the queue should be unbusied
173 * because it's always called before the completion. This function is
174 * for a requeue after completion, which should only occur in this
175 * file.
176 */
Bart Van Assche08640e82018-01-10 14:41:45 -0800177static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
Christoph Hellwigde3e8bf2014-01-23 13:55:38 +0100178{
179 struct scsi_device *device = cmd->device;
Christoph Hellwigde3e8bf2014-01-23 13:55:38 +0100180
181 SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd,
182 "Inserting command %p into mlqueue\n", cmd));
183
184 scsi_set_blocked(cmd, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
186 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 * Decrement the counters, since these commands are no longer
188 * active on the host/device.
189 */
James Bottomley4f5299a2009-01-02 10:42:21 -0600190 if (unbusy)
Ming Lei6eb045e2019-10-25 14:58:55 +0800191 scsi_device_unbusy(device, cmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
193 /*
Tejun Heo a1bf9d1d2005-04-24 02:08:52 -0500194 * Requeue this command. It will go before all other commands
Bart Van Asscheb4854622012-06-29 15:36:07 +0000195 * that are already in the queue. Schedule requeue work under
196 * lock such that the kblockd_schedule_work() call happens
197 * before blk_cleanup_queue() finishes.
Jens Axboea488e742010-04-16 21:13:15 +0200198 */
Alan Stern644373a2014-03-28 10:51:15 -0700199 cmd->result = 0;
Jens Axboef664a3c2018-11-01 16:36:27 -0600200
Jens Axboef664a3c2018-11-01 16:36:27 -0600201 blk_mq_requeue_request(cmd->request, true);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202}
203
André Almeidaea941012020-04-19 02:01:48 -0300204/**
205 * scsi_queue_insert - Reinsert a command in the queue.
206 * @cmd: command that we are adding to queue.
207 * @reason: why we are inserting command to queue.
James Bottomley4f5299a2009-01-02 10:42:21 -0600208 *
André Almeidaea941012020-04-19 02:01:48 -0300209 * We do this for one of two cases. Either the host is busy and it cannot accept
210 * any more commands for the time being, or the device returned QUEUE_FULL and
211 * can accept no more commands.
James Bottomley4f5299a2009-01-02 10:42:21 -0600212 *
André Almeidaea941012020-04-19 02:01:48 -0300213 * Context: This could be called either from an interrupt context or a normal
214 * process context.
James Bottomley4f5299a2009-01-02 10:42:21 -0600215 */
Bart Van Assche84feb162012-06-29 15:35:05 +0000216void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
James Bottomley4f5299a2009-01-02 10:42:21 -0600217{
Bart Van Assche08640e82018-01-10 14:41:45 -0800218 __scsi_queue_insert(cmd, reason, true);
James Bottomley4f5299a2009-01-02 10:42:21 -0600219}
Christoph Hellwige8064022016-10-20 15:12:13 +0200220
Christoph Hellwig76aaf872017-02-23 16:02:36 +0100221
222/**
Kees Cook704f8392018-07-31 12:51:54 -0700223 * __scsi_execute - insert request and wait for the result
Christoph Hellwig76aaf872017-02-23 16:02:36 +0100224 * @sdev: scsi device
225 * @cmd: scsi command
226 * @data_direction: data direction
227 * @buffer: data buffer
228 * @bufflen: len of buffer
229 * @sense: optional sense buffer
230 * @sshdr: optional decoded sense header
231 * @timeout: request timeout in seconds
232 * @retries: number of times to retry request
233 * @flags: flags for ->cmd_flags
234 * @rq_flags: flags for ->rq_flags
235 * @resid: optional residual length
236 *
Christoph Hellwig17d53632017-04-20 16:03:01 +0200237 * Returns the scsi_cmnd result field if a command was executed, or a negative
238 * Linux error code if we didn't get that far.
Christoph Hellwig76aaf872017-02-23 16:02:36 +0100239 */
Kees Cook704f8392018-07-31 12:51:54 -0700240int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
James Bottomley33aa6872005-08-28 11:31:14 -0500241 int data_direction, void *buffer, unsigned bufflen,
Christoph Hellwig3949e2f2017-02-14 20:15:58 +0100242 unsigned char *sense, struct scsi_sense_hdr *sshdr,
243 int timeout, int retries, u64 flags, req_flags_t rq_flags,
244 int *resid)
James Bottomley39216032005-06-15 18:48:29 -0500245{
246 struct request *req;
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100247 struct scsi_request *rq;
James Bottomley39216032005-06-15 18:48:29 -0500248 int ret = DRIVER_ERROR << 24;
249
Christoph Hellwigff005a02018-05-09 09:54:05 +0200250 req = blk_get_request(sdev->request_queue,
Christoph Hellwigaebf5262017-01-31 16:57:31 +0100251 data_direction == DMA_TO_DEVICE ?
Bart Van Assche039c6352017-11-09 10:49:56 -0800252 REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT);
Joe Lawrencea492f072014-08-28 08:15:21 -0600253 if (IS_ERR(req))
James Bottomleybfe159a2011-07-07 15:45:40 -0500254 return ret;
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100255 rq = scsi_req(req);
James Bottomley39216032005-06-15 18:48:29 -0500256
257 if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
Christoph Hellwig0eb0b632018-05-09 09:54:08 +0200258 buffer, bufflen, GFP_NOIO))
James Bottomley39216032005-06-15 18:48:29 -0500259 goto out;
260
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100261 rq->cmd_len = COMMAND_SIZE(cmd[0]);
262 memcpy(rq->cmd, cmd, rq->cmd_len);
Christoph Hellwig64c7f1d2017-04-05 19:18:12 +0200263 rq->retries = retries;
James Bottomley39216032005-06-15 18:48:29 -0500264 req->timeout = timeout;
Christoph Hellwige8064022016-10-20 15:12:13 +0200265 req->cmd_flags |= flags;
Bart Van Assche039c6352017-11-09 10:49:56 -0800266 req->rq_flags |= rq_flags | RQF_QUIET;
James Bottomley39216032005-06-15 18:48:29 -0500267
268 /*
269 * head injection *required* here otherwise quiesce won't work
270 */
271 blk_execute_rq(req->q, NULL, req, 1);
272
Alan Sternbdb2b8c2008-06-24 14:03:14 -0400273 /*
274 * Some devices (USB mass-storage in particular) may transfer
275 * garbage data together with a residue indicating that the data
276 * is invalid. Prevent the garbage from being misinterpreted
277 * and prevent security leaks by zeroing out the excess data.
278 */
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100279 if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen))
280 memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len);
Alan Sternbdb2b8c2008-06-24 14:03:14 -0400281
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +0900282 if (resid)
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100283 *resid = rq->resid_len;
284 if (sense && rq->sense_len)
285 memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
Christoph Hellwig3949e2f2017-02-14 20:15:58 +0100286 if (sshdr)
287 scsi_normalize_sense(rq->sense, rq->sense_len, sshdr);
Christoph Hellwig17d53632017-04-20 16:03:01 +0200288 ret = rq->result;
James Bottomley39216032005-06-15 18:48:29 -0500289 out:
290 blk_put_request(req);
291
292 return ret;
293}
Kees Cook704f8392018-07-31 12:51:54 -0700294EXPORT_SYMBOL(__scsi_execute);
James Bottomley39216032005-06-15 18:48:29 -0500295
André Almeidaea941012020-04-19 02:01:48 -0300296/**
297 * scsi_init_cmd_errh - Initialize cmd fields related to error handling.
298 * @cmd: command that is ready to be queued.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 *
André Almeidaea941012020-04-19 02:01:48 -0300300 * This function has the job of initializing a number of fields related to error
301 * handling. Typically this will be called once for each command, as required.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 */
Christoph Hellwig631c2282006-07-08 20:42:15 +0200303static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304{
Boaz Harrosh30b0c372007-12-13 13:47:40 +0200305 scsi_set_resid(cmd, 0);
FUJITA Tomonorib80ca4f2008-01-13 15:46:13 +0900306 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 if (cmd->cmd_len == 0)
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300308 cmd->cmd_len = scsi_command_size(cmd->cmnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309}
310
Bart Van Assche3bd6f432017-12-04 10:06:23 -0800311/*
Ming Lei6eb045e2019-10-25 14:58:55 +0800312 * Wake up the error handler if necessary. Avoid as follows that the error
313 * handler is not woken up if host in-flight requests number ==
314 * shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination
315 * with an RCU read lock in this function to ensure that this function in
316 * its entirety either finishes before scsi_eh_scmd_add() increases the
Bart Van Assche3bd6f432017-12-04 10:06:23 -0800317 * host_failed counter or that it notices the shost state change made by
318 * scsi_eh_scmd_add().
319 */
Ming Lei6eb045e2019-10-25 14:58:55 +0800320static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
Bart Van Assche3bd6f432017-12-04 10:06:23 -0800321{
322 unsigned long flags;
323
324 rcu_read_lock();
Ming Lei6eb045e2019-10-25 14:58:55 +0800325 __clear_bit(SCMD_STATE_INFLIGHT, &cmd->state);
Bart Van Assche3bd6f432017-12-04 10:06:23 -0800326 if (unlikely(scsi_host_in_recovery(shost))) {
327 spin_lock_irqsave(shost->host_lock, flags);
328 if (shost->host_failed || shost->host_eh_scheduled)
329 scsi_eh_wakeup(shost);
330 spin_unlock_irqrestore(shost->host_lock, flags);
331 }
332 rcu_read_unlock();
333}
334
Ming Lei6eb045e2019-10-25 14:58:55 +0800335void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336{
337 struct Scsi_Host *shost = sdev->host;
Mike Christief0c0a372008-08-17 15:24:38 -0500338 struct scsi_target *starget = scsi_target(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339
Ming Lei6eb045e2019-10-25 14:58:55 +0800340 scsi_dec_host_busy(shost, cmd);
Bart Van Assche3bd6f432017-12-04 10:06:23 -0800341
Christoph Hellwig2ccbb002014-03-26 10:35:00 +0100342 if (starget->can_queue > 0)
343 atomic_dec(&starget->target_busy);
Christoph Hellwig74665012014-01-22 15:29:29 +0100344
Christoph Hellwig71e75c92014-04-11 19:07:01 +0200345 atomic_dec(&sdev->device_busy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346}
347
Christoph Hellwigd2852032014-01-17 12:06:53 +0100348static void scsi_kick_queue(struct request_queue *q)
349{
Jens Axboef664a3c2018-11-01 16:36:27 -0600350 blk_mq_run_hw_queues(q, false);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100351}
352
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353/*
354 * Called for single_lun devices on IO completion. Clear starget_sdev_user,
355 * and call blk_run_queue for all the scsi_devices on the target -
356 * including current_sdev first.
357 *
358 * Called with *no* scsi locks held.
359 */
360static void scsi_single_lun_run(struct scsi_device *current_sdev)
361{
362 struct Scsi_Host *shost = current_sdev->host;
363 struct scsi_device *sdev, *tmp;
364 struct scsi_target *starget = scsi_target(current_sdev);
365 unsigned long flags;
366
367 spin_lock_irqsave(shost->host_lock, flags);
368 starget->starget_sdev_user = NULL;
369 spin_unlock_irqrestore(shost->host_lock, flags);
370
371 /*
372 * Call blk_run_queue for all LUNs on the target, starting with
373 * current_sdev. We race with others (to set starget_sdev_user),
374 * but in most cases, we will be first. Ideally, each LU on the
375 * target would get some limited time or requests on the target.
376 */
Christoph Hellwigd2852032014-01-17 12:06:53 +0100377 scsi_kick_queue(current_sdev->request_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379 spin_lock_irqsave(shost->host_lock, flags);
380 if (starget->starget_sdev_user)
381 goto out;
382 list_for_each_entry_safe(sdev, tmp, &starget->devices,
383 same_target_siblings) {
384 if (sdev == current_sdev)
385 continue;
386 if (scsi_device_get(sdev))
387 continue;
388
389 spin_unlock_irqrestore(shost->host_lock, flags);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100390 scsi_kick_queue(sdev->request_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 spin_lock_irqsave(shost->host_lock, flags);
Bean Huo4c7b4d62020-06-19 17:41:17 +0200392
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 scsi_device_put(sdev);
394 }
395 out:
396 spin_unlock_irqrestore(shost->host_lock, flags);
397}
398
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100399static inline bool scsi_device_is_busy(struct scsi_device *sdev)
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400400{
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100401 if (atomic_read(&sdev->device_busy) >= sdev->queue_depth)
402 return true;
403 if (atomic_read(&sdev->device_blocked) > 0)
404 return true;
405 return false;
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400406}
407
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100408static inline bool scsi_target_is_busy(struct scsi_target *starget)
Mike Christief0c0a372008-08-17 15:24:38 -0500409{
Christoph Hellwig2ccbb002014-03-26 10:35:00 +0100410 if (starget->can_queue > 0) {
411 if (atomic_read(&starget->target_busy) >= starget->can_queue)
412 return true;
413 if (atomic_read(&starget->target_blocked) > 0)
414 return true;
415 }
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100416 return false;
Mike Christief0c0a372008-08-17 15:24:38 -0500417}
418
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100419static inline bool scsi_host_is_busy(struct Scsi_Host *shost)
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400420{
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100421 if (atomic_read(&shost->host_blocked) > 0)
422 return true;
423 if (shost->host_self_blocked)
424 return true;
425 return false;
Kiyoshi Ueda9d112512008-10-04 14:11:06 -0400426}
427
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800428static void scsi_starved_list_run(struct Scsi_Host *shost)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429{
Mike Christie2a3a59e2008-11-11 13:42:35 -0600430 LIST_HEAD(starved_list);
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800431 struct scsi_device *sdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 unsigned long flags;
433
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 spin_lock_irqsave(shost->host_lock, flags);
Mike Christie2a3a59e2008-11-11 13:42:35 -0600435 list_splice_init(&shost->starved_list, &starved_list);
436
437 while (!list_empty(&starved_list)) {
James Bottomleye2eb7242013-07-02 15:05:26 +0200438 struct request_queue *slq;
439
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 /*
441 * As long as shost is accepting commands and we have
442 * starved queues, call blk_run_queue. scsi_request_fn
443 * drops the queue_lock and can add us back to the
444 * starved_list.
445 *
446 * host_lock protects the starved_list and starved_entry.
447 * scsi_request_fn must get the host_lock before checking
448 * or modifying starved_list or starved_entry.
449 */
Mike Christie2a3a59e2008-11-11 13:42:35 -0600450 if (scsi_host_is_busy(shost))
Mike Christief0c0a372008-08-17 15:24:38 -0500451 break;
Mike Christief0c0a372008-08-17 15:24:38 -0500452
Mike Christie2a3a59e2008-11-11 13:42:35 -0600453 sdev = list_entry(starved_list.next,
454 struct scsi_device, starved_entry);
455 list_del_init(&sdev->starved_entry);
Mike Christief0c0a372008-08-17 15:24:38 -0500456 if (scsi_target_is_busy(scsi_target(sdev))) {
457 list_move_tail(&sdev->starved_entry,
458 &shost->starved_list);
459 continue;
460 }
461
James Bottomleye2eb7242013-07-02 15:05:26 +0200462 /*
463 * Once we drop the host lock, a racing scsi_remove_device()
464 * call may remove the sdev from the starved list and destroy
465 * it and the queue. Mitigate by taking a reference to the
466 * queue and never touching the sdev again after we drop the
467 * host lock. Note: if __scsi_remove_device() invokes
468 * blk_cleanup_queue() before the queue is run from this
469 * function then blk_run_queue() will return immediately since
470 * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING.
471 */
472 slq = sdev->request_queue;
473 if (!blk_get_queue(slq))
474 continue;
475 spin_unlock_irqrestore(shost->host_lock, flags);
476
Christoph Hellwigd2852032014-01-17 12:06:53 +0100477 scsi_kick_queue(slq);
James Bottomleye2eb7242013-07-02 15:05:26 +0200478 blk_put_queue(slq);
479
480 spin_lock_irqsave(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 }
Mike Christie2a3a59e2008-11-11 13:42:35 -0600482 /* put any unprocessed entries back */
483 list_splice(&starved_list, &shost->starved_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 spin_unlock_irqrestore(shost->host_lock, flags);
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800485}
486
André Almeidaea941012020-04-19 02:01:48 -0300487/**
488 * scsi_run_queue - Select a proper request queue to serve next.
489 * @q: last request's queue
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800490 *
André Almeidaea941012020-04-19 02:01:48 -0300491 * The previous command was completely finished, start a new one if possible.
Christoph Hellwig21a05df2014-02-20 14:20:54 -0800492 */
493static void scsi_run_queue(struct request_queue *q)
494{
495 struct scsi_device *sdev = q->queuedata;
496
497 if (scsi_target(sdev)->single_lun)
498 scsi_single_lun_run(sdev);
499 if (!list_empty(&sdev->host->starved_list))
500 scsi_starved_list_run(sdev->host);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501
Jens Axboef664a3c2018-11-01 16:36:27 -0600502 blk_mq_run_hw_queues(q, false);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503}
504
Jens Axboe9937a5e2011-05-17 11:04:44 +0200505void scsi_requeue_run_queue(struct work_struct *work)
506{
507 struct scsi_device *sdev;
508 struct request_queue *q;
509
510 sdev = container_of(work, struct scsi_device, requeue_work);
511 q = sdev->request_queue;
512 scsi_run_queue(q);
513}
514
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515void scsi_run_host_queues(struct Scsi_Host *shost)
516{
517 struct scsi_device *sdev;
518
519 shost_for_each_device(sdev, shost)
520 scsi_run_queue(sdev->request_queue);
521}
522
Christoph Hellwigd2852032014-01-17 12:06:53 +0100523static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
524{
Christoph Hellwig57292b52017-01-31 16:57:29 +0100525 if (!blk_rq_is_passthrough(cmd->request)) {
Christoph Hellwigd2852032014-01-17 12:06:53 +0100526 struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
527
528 if (drv->uninit_command)
529 drv->uninit_command(cmd);
530 }
531}
532
Johannes Thumshirn20a66f22020-04-28 19:45:55 +0900533static void scsi_free_sgtables(struct scsi_cmnd *cmd)
Christoph Hellwigd2852032014-01-17 12:06:53 +0100534{
535 if (cmd->sdb.table.nents)
Ming Lei3dccdf52019-04-28 15:39:32 +0800536 sg_free_table_chained(&cmd->sdb.table,
537 SCSI_INLINE_SG_CNT);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100538 if (scsi_prot_sg_count(cmd))
Ming Lei92524fa2019-04-28 15:39:31 +0800539 sg_free_table_chained(&cmd->prot_sdb->table,
540 SCSI_INLINE_PROT_SG_CNT);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100541}
542
543static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
544{
Johannes Thumshirn20a66f22020-04-28 19:45:55 +0900545 scsi_free_sgtables(cmd);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100546 scsi_uninit_cmd(cmd);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100547}
548
Ming Lei3f0dcfb2020-07-20 10:54:35 +0800549static void scsi_run_queue_async(struct scsi_device *sdev)
550{
551 if (scsi_target(sdev)->single_lun ||
Ming Leied5dd6a2020-09-10 15:50:56 +0800552 !list_empty(&sdev->host->starved_list)) {
Ming Lei3f0dcfb2020-07-20 10:54:35 +0800553 kblockd_schedule_work(&sdev->requeue_work);
Ming Leied5dd6a2020-09-10 15:50:56 +0800554 } else {
555 /*
556 * smp_mb() present in sbitmap_queue_clear() or implied in
557 * .end_io is for ordering writing .device_busy in
558 * scsi_device_unbusy() and reading sdev->restarts.
559 */
560 int old = atomic_read(&sdev->restarts);
561
562 /*
563 * ->restarts has to be kept as non-zero if new budget
564 * contention occurs.
565 *
566 * No need to run queue when either another re-run
567 * queue wins in updating ->restarts or a new budget
568 * contention occurs.
569 */
570 if (old && atomic_cmpxchg(&sdev->restarts, old, 0) == old)
571 blk_mq_run_hw_queues(sdev->request_queue, true);
572 }
Ming Lei3f0dcfb2020-07-20 10:54:35 +0800573}
574
Douglas Gilbert7e63b5a2018-06-23 12:22:14 +0200575/* Returns false when no more bytes to process, true if there are more */
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200576static bool scsi_end_request(struct request *req, blk_status_t error,
Christoph Hellwigae3d56d2019-01-29 09:33:07 +0100577 unsigned int bytes)
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800578{
Bart Van Asschebed22132017-08-25 13:46:32 -0700579 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800580 struct scsi_device *sdev = cmd->device;
581 struct request_queue *q = sdev->request_queue;
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800582
583 if (blk_update_request(req, error, bytes))
584 return true;
585
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800586 if (blk_queue_add_random(q))
587 add_disk_randomness(req->rq_disk);
588
Bart Van Assche64104f72017-08-30 16:58:39 -0700589 if (!blk_rq_is_scsi(req)) {
590 WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED));
591 cmd->flags &= ~SCMD_INITIALIZED;
592 }
593
Jens Axboef664a3c2018-11-01 16:36:27 -0600594 /*
Bart Van Asschedb983f62019-03-18 09:29:26 -0700595 * Calling rcu_barrier() is not necessary here because the
596 * SCSI error handler guarantees that the function called by
597 * call_rcu() has been called before scsi_end_request() is
598 * called.
599 */
600 destroy_rcu_head(&cmd->rcu);
601
602 /*
Jens Axboef664a3c2018-11-01 16:36:27 -0600603 * In the MQ case the command gets freed by __blk_mq_end_request,
604 * so we have to do all cleanup that depends on it earlier.
605 *
606 * We also can't kick the queues from irq context, so we
607 * will have to defer it to a workqueue.
608 */
609 scsi_mq_uninit_cmd(cmd);
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800610
Jens Axboea78b03b2018-11-18 15:46:03 -0700611 /*
612 * queue is still alive, so grab the ref for preventing it
613 * from being cleaned up during running queue.
614 */
615 percpu_ref_get(&q->q_usage_counter);
Ming Lei8dc765d2018-11-14 16:25:51 +0800616
Jens Axboef664a3c2018-11-01 16:36:27 -0600617 __blk_mq_end_request(req, error);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100618
Ming Lei3f0dcfb2020-07-20 10:54:35 +0800619 scsi_run_queue_async(sdev);
Christoph Hellwigd2852032014-01-17 12:06:53 +0100620
Jens Axboea78b03b2018-11-18 15:46:03 -0700621 percpu_ref_put(&q->q_usage_counter);
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800622 return false;
623}
624
Hannes Reinecke0f7f6232013-07-01 15:16:23 +0200625/**
Bart Van Asschea77b32d82018-04-05 10:33:00 -0700626 * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t
627 * @cmd: SCSI command
Hannes Reinecke0f7f6232013-07-01 15:16:23 +0200628 * @result: scsi error code
629 *
Bart Van Asschea77b32d82018-04-05 10:33:00 -0700630 * Translate a SCSI result code into a blk_status_t value. May reset the host
631 * byte of @cmd->result.
Hannes Reinecke0f7f6232013-07-01 15:16:23 +0200632 */
Bart Van Asschea77b32d82018-04-05 10:33:00 -0700633static blk_status_t scsi_result_to_blk_status(struct scsi_cmnd *cmd, int result)
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100634{
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200635 switch (host_byte(result)) {
Bart Van Asschef4abab32018-04-05 10:33:01 -0700636 case DID_OK:
637 /*
638 * Also check the other bytes than the status byte in result
639 * to handle the case when a SCSI LLD sets result to
640 * DRIVER_SENSE << 24 without setting SAM_STAT_CHECK_CONDITION.
641 */
642 if (scsi_status_is_good(result) && (result & ~0xff) == 0)
643 return BLK_STS_OK;
644 return BLK_STS_IOERR;
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100645 case DID_TRANSPORT_FAILFAST:
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200646 return BLK_STS_TRANSPORT;
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100647 case DID_TARGET_FAILURE:
Moger, Babu2082ebc2012-01-24 20:38:46 +0000648 set_host_byte(cmd, DID_OK);
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200649 return BLK_STS_TARGET;
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100650 case DID_NEXUS_FAILURE:
Martin Wilck4a067cf2019-02-14 22:57:41 +0100651 set_host_byte(cmd, DID_OK);
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200652 return BLK_STS_NEXUS;
Hannes Reineckea9d6ceb82013-07-01 15:16:25 +0200653 case DID_ALLOC_FAILURE:
654 set_host_byte(cmd, DID_OK);
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200655 return BLK_STS_NOSPC;
Hannes Reinecke7e782af2013-07-01 15:16:26 +0200656 case DID_MEDIUM_ERROR:
657 set_host_byte(cmd, DID_OK);
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200658 return BLK_STS_MEDIUM;
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100659 default:
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200660 return BLK_STS_IOERR;
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100661 }
Hannes Reinecke63583cc2011-01-18 10:13:11 +0100662}
663
Douglas Gilbert4ae61c62018-06-23 12:22:18 +0200664/* Helper for scsi_io_completion() when "reprep" action required. */
665static void scsi_io_completion_reprep(struct scsi_cmnd *cmd,
666 struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667{
Douglas Gilbert4ae61c62018-06-23 12:22:18 +0200668 /* A new command will be prepared and issued. */
Jens Axboef664a3c2018-11-01 16:36:27 -0600669 scsi_mq_requeue_cmd(cmd);
Douglas Gilbert4ae61c62018-06-23 12:22:18 +0200670}
671
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200672/* Helper for scsi_io_completion() when special action required. */
673static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
Douglas Gilbertab831082018-06-23 12:22:16 +0200674{
Jens Axboe165125e2007-07-24 09:28:11 +0200675 struct request_queue *q = cmd->device->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 struct request *req = cmd->request;
Douglas Gilbert1f7cbb82018-06-23 12:22:15 +0200677 int level = 0;
Alan Sternb60af5b2008-11-03 15:56:47 -0500678 enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
679 ACTION_DELAYED_RETRY} action;
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900680 unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200681 struct scsi_sense_hdr sshdr;
682 bool sense_valid;
683 bool sense_current = true; /* false implies "deferred sense" */
684 blk_status_t blk_stat;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200686 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
687 if (sense_valid)
688 sense_current = !scsi_sense_is_deferred(&sshdr);
Christoph Hellwig631c2282006-07-08 20:42:15 +0200689
Douglas Gilbert1f7cbb82018-06-23 12:22:15 +0200690 blk_stat = scsi_result_to_blk_status(cmd, result);
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500691
Alan Sternb60af5b2008-11-03 15:56:47 -0500692 if (host_byte(result) == DID_RESET) {
693 /* Third party bus reset or reset for error recovery
694 * reasons. Just retry the command and see what
695 * happens.
696 */
697 action = ACTION_RETRY;
Douglas Gilbert1f7cbb82018-06-23 12:22:15 +0200698 } else if (sense_valid && sense_current) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 switch (sshdr.sense_key) {
700 case UNIT_ATTENTION:
701 if (cmd->device->removable) {
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700702 /* Detected disc change. Set a bit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 * and quietly refuse further access.
704 */
705 cmd->device->changed = 1;
Alan Sternb60af5b2008-11-03 15:56:47 -0500706 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 } else {
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700708 /* Must have been a power glitch, or a
709 * bus reset. Could not have been a
710 * media change, so we just retry the
Alan Sternb60af5b2008-11-03 15:56:47 -0500711 * command and see what happens.
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700712 */
Alan Sternb60af5b2008-11-03 15:56:47 -0500713 action = ACTION_RETRY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 }
715 break;
716 case ILLEGAL_REQUEST:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700717 /* If we had an ILLEGAL REQUEST returned, then
718 * we may have performed an unsupported
719 * command. The only thing this should be
720 * would be a ten byte read where only a six
721 * byte read was supported. Also, on a system
722 * where READ CAPACITY failed, we may have
723 * read past the end of the disk.
724 */
Jens Axboe26a68012005-11-29 21:03:34 +0100725 if ((cmd->device->use_10_for_rw &&
726 sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 (cmd->cmnd[0] == READ_10 ||
728 cmd->cmnd[0] == WRITE_10)) {
Alan Sternb60af5b2008-11-03 15:56:47 -0500729 /* This will issue a new 6-byte command. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 cmd->device->use_10_for_rw = 0;
Alan Sternb60af5b2008-11-03 15:56:47 -0500731 action = ACTION_REPREP;
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500732 } else if (sshdr.asc == 0x10) /* DIX */ {
Martin K. Petersen3e695f82009-01-04 03:04:31 -0500733 action = ACTION_FAIL;
Douglas Gilbert1f7cbb82018-06-23 12:22:15 +0200734 blk_stat = BLK_STS_PROTECTION;
Martin K. Petersenc98a0eb2011-03-08 02:07:15 -0500735 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
Martin K. Petersen5db44862012-09-18 12:19:32 -0400736 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
Martin K. Petersenc98a0eb2011-03-08 02:07:15 -0500737 action = ACTION_FAIL;
Douglas Gilbert1f7cbb82018-06-23 12:22:15 +0200738 blk_stat = BLK_STS_TARGET;
Alan Sternb60af5b2008-11-03 15:56:47 -0500739 } else
740 action = ACTION_FAIL;
741 break;
Martin K. Petersen511e44f2008-07-17 04:28:33 -0400742 case ABORTED_COMMAND:
James Bottomley126c09822009-02-19 21:48:54 +0000743 action = ACTION_FAIL;
Maurizio Lombardie6c11db2014-07-10 09:41:53 +0200744 if (sshdr.asc == 0x10) /* DIF */
Douglas Gilbert1f7cbb82018-06-23 12:22:15 +0200745 blk_stat = BLK_STS_PROTECTION;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 break;
747 case NOT_READY:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700748 /* If the device is in the process of becoming
James Bottomleyf3e93f72006-04-25 16:48:30 -0500749 * ready, or has a temporary blockage, retry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 */
James Bottomleyf3e93f72006-04-25 16:48:30 -0500751 if (sshdr.asc == 0x04) {
752 switch (sshdr.ascq) {
753 case 0x01: /* becoming ready */
754 case 0x04: /* format in progress */
755 case 0x05: /* rebuild in progress */
756 case 0x06: /* recalculation in progress */
757 case 0x07: /* operation in progress */
758 case 0x08: /* Long write in progress */
759 case 0x09: /* self test in progress */
Martin K. Petersend8705f12009-11-26 12:00:41 -0500760 case 0x14: /* space allocation in progress */
Douglas Gilberte37c7d92018-05-18 19:25:47 -0400761 case 0x1a: /* start stop unit in progress */
762 case 0x1b: /* sanitize in progress */
763 case 0x1d: /* configuration in progress */
764 case 0x24: /* depopulation in progress */
Alan Sternb60af5b2008-11-03 15:56:47 -0500765 action = ACTION_DELAYED_RETRY;
James Bottomleyf3e93f72006-04-25 16:48:30 -0500766 break;
Alan Stern3dbf6a52008-12-15 10:31:28 -0500767 default:
Alan Stern3dbf6a52008-12-15 10:31:28 -0500768 action = ACTION_FAIL;
769 break;
James Bottomleyf3e93f72006-04-25 16:48:30 -0500770 }
Maurizio Lombardie6c11db2014-07-10 09:41:53 +0200771 } else
Alan Sternb60af5b2008-11-03 15:56:47 -0500772 action = ACTION_FAIL;
Alan Sternb60af5b2008-11-03 15:56:47 -0500773 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 case VOLUME_OVERFLOW:
Luben Tuikov03aba2f2006-06-23 09:39:09 -0700775 /* See SSC3rXX or current. */
Alan Sternb60af5b2008-11-03 15:56:47 -0500776 action = ACTION_FAIL;
777 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 default:
Alan Sternb60af5b2008-11-03 15:56:47 -0500779 action = ACTION_FAIL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 break;
781 }
Maurizio Lombardie6c11db2014-07-10 09:41:53 +0200782 } else
Alan Sternb60af5b2008-11-03 15:56:47 -0500783 action = ACTION_FAIL;
Alan Sternb60af5b2008-11-03 15:56:47 -0500784
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900785 if (action != ACTION_FAIL &&
Maurizio Lombardie6c11db2014-07-10 09:41:53 +0200786 time_before(cmd->jiffies_at_alloc + wait_for, jiffies))
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900787 action = ACTION_FAIL;
Eiichi Tsukataee60b2c2014-02-11 14:29:52 +0900788
Alan Sternb60af5b2008-11-03 15:56:47 -0500789 switch (action) {
790 case ACTION_FAIL:
791 /* Give up and fail the remainder of the request */
Christoph Hellwige8064022016-10-20 15:12:13 +0200792 if (!(req->rq_flags & RQF_QUIET)) {
Hannes Reineckef1569ff2014-10-24 14:27:07 +0200793 static DEFINE_RATELIMIT_STATE(_rs,
794 DEFAULT_RATELIMIT_INTERVAL,
795 DEFAULT_RATELIMIT_BURST);
796
797 if (unlikely(scsi_logging_level))
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200798 level =
799 SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
800 SCSI_LOG_MLCOMPLETE_BITS);
Hannes Reineckef1569ff2014-10-24 14:27:07 +0200801
802 /*
803 * if logging is enabled the failure will be printed
804 * in scsi_log_completion(), so avoid duplicate messages
805 */
806 if (!level && __ratelimit(&_rs)) {
807 scsi_print_result(cmd, NULL, FAILED);
Johannes Thumshirnc65be1a2018-06-25 13:20:58 +0200808 if (driver_byte(result) == DRIVER_SENSE)
Hannes Reineckef1569ff2014-10-24 14:27:07 +0200809 scsi_print_sense(cmd);
810 scsi_print_command(cmd);
811 }
James Bottomley3173d8c2005-09-04 11:32:05 -0500812 }
Christoph Hellwigae3d56d2019-01-29 09:33:07 +0100813 if (!scsi_end_request(req, blk_stat, blk_rq_err_bytes(req)))
Christoph Hellwigf6d47e72014-02-16 06:16:13 -0800814 return;
Christoph Hellwigbc85dc52014-05-01 16:51:03 +0200815 /*FALLTHRU*/
Alan Sternb60af5b2008-11-03 15:56:47 -0500816 case ACTION_REPREP:
Douglas Gilbert4ae61c62018-06-23 12:22:18 +0200817 scsi_io_completion_reprep(cmd, q);
Alan Sternb60af5b2008-11-03 15:56:47 -0500818 break;
819 case ACTION_RETRY:
820 /* Retry the same command immediately */
Bart Van Assche08640e82018-01-10 14:41:45 -0800821 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false);
Alan Sternb60af5b2008-11-03 15:56:47 -0500822 break;
823 case ACTION_DELAYED_RETRY:
824 /* Retry the same command after a delay */
Bart Van Assche08640e82018-01-10 14:41:45 -0800825 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false);
Alan Sternb60af5b2008-11-03 15:56:47 -0500826 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 }
828}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200830/*
831 * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a
832 * new result that may suppress further error checking. Also modifies
833 * *blk_statp in some cases.
834 */
835static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result,
836 blk_status_t *blk_statp)
837{
838 bool sense_valid;
839 bool sense_current = true; /* false implies "deferred sense" */
840 struct request *req = cmd->request;
841 struct scsi_sense_hdr sshdr;
842
843 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
844 if (sense_valid)
845 sense_current = !scsi_sense_is_deferred(&sshdr);
846
847 if (blk_rq_is_passthrough(req)) {
848 if (sense_valid) {
849 /*
850 * SG_IO wants current and deferred errors
851 */
852 scsi_req(req)->sense_len =
853 min(8 + cmd->sense_buffer[7],
854 SCSI_SENSE_BUFFERSIZE);
855 }
856 if (sense_current)
857 *blk_statp = scsi_result_to_blk_status(cmd, result);
858 } else if (blk_rq_bytes(req) == 0 && sense_current) {
859 /*
860 * Flush commands do not transfers any data, and thus cannot use
861 * good_bytes != blk_rq_bytes(req) as the signal for an error.
862 * This sets *blk_statp explicitly for the problem case.
863 */
864 *blk_statp = scsi_result_to_blk_status(cmd, result);
865 }
866 /*
867 * Recovered errors need reporting, but they're always treated as
868 * success, so fiddle the result code here. For passthrough requests
869 * we already took a copy of the original into sreq->result which
870 * is what gets returned to the user
871 */
872 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
873 bool do_print = true;
874 /*
875 * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d]
876 * skip print since caller wants ATA registers. Only occurs
877 * on SCSI ATA PASS_THROUGH commands when CK_COND=1
878 */
879 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
880 do_print = false;
881 else if (req->rq_flags & RQF_QUIET)
882 do_print = false;
883 if (do_print)
884 scsi_print_sense(cmd);
885 result = 0;
886 /* for passthrough, *blk_statp may be set */
887 *blk_statp = BLK_STS_OK;
888 }
889 /*
890 * Another corner case: the SCSI status byte is non-zero but 'good'.
891 * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when
892 * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD
893 * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related
894 * intermediate statuses (both obsolete in SAM-4) as good.
895 */
896 if (status_byte(result) && scsi_status_is_good(result)) {
897 result = 0;
898 *blk_statp = BLK_STS_OK;
899 }
900 return result;
901}
902
André Almeidaea941012020-04-19 02:01:48 -0300903/**
904 * scsi_io_completion - Completion processing for SCSI commands.
905 * @cmd: command that is finished.
906 * @good_bytes: number of processed bytes.
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200907 *
André Almeidaea941012020-04-19 02:01:48 -0300908 * We will finish off the specified number of sectors. If we are done, the
909 * command block will be released and the queue function will be goosed. If we
910 * are not done then we have to figure out what to do next:
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200911 *
André Almeidaea941012020-04-19 02:01:48 -0300912 * a) We can call scsi_io_completion_reprep(). The request will be
913 * unprepared and put back on the queue. Then a new command will
914 * be created for it. This should be used if we made forward
915 * progress, or if we want to switch from READ(10) to READ(6) for
916 * example.
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200917 *
André Almeidaea941012020-04-19 02:01:48 -0300918 * b) We can call scsi_io_completion_action(). The request will be
919 * put back on the queue and retried using the same command as
920 * before, possibly after a delay.
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200921 *
André Almeidaea941012020-04-19 02:01:48 -0300922 * c) We can call scsi_end_request() with blk_stat other than
923 * BLK_STS_OK, to fail the remainder of the request.
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200924 */
925void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
926{
927 int result = cmd->result;
928 struct request_queue *q = cmd->device->request_queue;
929 struct request *req = cmd->request;
930 blk_status_t blk_stat = BLK_STS_OK;
931
Douglas Gilbert0d437902018-06-23 12:22:19 +0200932 if (unlikely(result)) /* a nz result may or may not be an error */
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200933 result = scsi_io_completion_nz_result(cmd, result, &blk_stat);
934
Douglas Gilbert0d437902018-06-23 12:22:19 +0200935 if (unlikely(blk_rq_is_passthrough(req))) {
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200936 /*
937 * scsi_result_to_blk_status may have reset the host_byte
938 */
939 scsi_req(req)->result = cmd->result;
Douglas Gilbert8e1695a02018-06-23 12:22:20 +0200940 }
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200941
942 /*
943 * Next deal with any sectors which we were able to correctly
944 * handle.
945 */
946 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd,
947 "%u sectors total, %d bytes done.\n",
948 blk_rq_sectors(req), good_bytes));
949
950 /*
André Almeidaea941012020-04-19 02:01:48 -0300951 * Failed, zero length commands always need to drop down
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200952 * to retry code. Fast path should return in this block.
953 */
Douglas Gilbert0d437902018-06-23 12:22:19 +0200954 if (likely(blk_rq_bytes(req) > 0 || blk_stat == BLK_STS_OK)) {
Christoph Hellwigae3d56d2019-01-29 09:33:07 +0100955 if (likely(!scsi_end_request(req, blk_stat, good_bytes)))
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200956 return; /* no bytes remaining */
957 }
958
Douglas Gilbert0d437902018-06-23 12:22:19 +0200959 /* Kill remainder if no retries. */
960 if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) {
Christoph Hellwigae3d56d2019-01-29 09:33:07 +0100961 if (scsi_end_request(req, blk_stat, blk_rq_bytes(req)))
Douglas Gilbert8e1695a02018-06-23 12:22:20 +0200962 WARN_ONCE(true,
963 "Bytes remaining after failed, no-retry command");
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200964 return;
965 }
966
967 /*
968 * If there had been no error, but we have leftover bytes in the
969 * requeues just queue the command up again.
970 */
Douglas Gilbert0d437902018-06-23 12:22:19 +0200971 if (likely(result == 0))
Douglas Gilbert4ae61c62018-06-23 12:22:18 +0200972 scsi_io_completion_reprep(cmd, q);
973 else
Douglas Gilbertda32bae2018-06-23 12:22:17 +0200974 scsi_io_completion_action(cmd, result);
975}
976
Christoph Hellwigcc979232020-04-14 09:42:24 +0200977static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev,
978 struct request *rq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979{
Christoph Hellwigcc979232020-04-14 09:42:24 +0200980 return sdev->dma_drain_len && blk_rq_is_passthrough(rq) &&
981 !op_is_write(req_op(rq)) &&
982 sdev->host->hostt->dma_need_drain(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983}
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200984
André Almeidaea941012020-04-19 02:01:48 -0300985/**
986 * scsi_init_io - SCSI I/O initialization function.
987 * @cmd: command descriptor we wish to initialize
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200988 *
André Almeidaea941012020-04-19 02:01:48 -0300989 * Returns:
990 * * BLK_STS_OK - on success
991 * * BLK_STS_RESOURCE - if the failure is retryable
992 * * BLK_STS_IOERR - if the failure is fatal
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200993 */
Christoph Hellwig159b2cb2018-11-09 14:42:39 +0100994blk_status_t scsi_init_io(struct scsi_cmnd *cmd)
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +0200995{
Christoph Hellwigcc979232020-04-14 09:42:24 +0200996 struct scsi_device *sdev = cmd->device;
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200997 struct request *rq = cmd->request;
Christoph Hellwigcc979232020-04-14 09:42:24 +0200998 unsigned short nr_segs = blk_rq_nr_phys_segments(rq);
999 struct scatterlist *last_sg = NULL;
Christoph Hellwig159b2cb2018-11-09 14:42:39 +01001000 blk_status_t ret;
Christoph Hellwigcc979232020-04-14 09:42:24 +02001001 bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq);
Christoph Hellwig0475bd62020-04-14 09:42:23 +02001002 int count;
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001003
Christoph Hellwigcc979232020-04-14 09:42:24 +02001004 if (WARN_ON_ONCE(!nr_segs))
Christoph Hellwig159b2cb2018-11-09 14:42:39 +01001005 return BLK_STS_IOERR;
Christoph Hellwig635d98b2014-06-28 11:51:01 +02001006
Christoph Hellwig0475bd62020-04-14 09:42:23 +02001007 /*
Christoph Hellwigcc979232020-04-14 09:42:24 +02001008 * Make sure there is space for the drain. The driver must adjust
1009 * max_hw_segments to be prepared for this.
1010 */
1011 if (need_drain)
1012 nr_segs++;
1013
1014 /*
Christoph Hellwig0475bd62020-04-14 09:42:23 +02001015 * If sg table allocation fails, requeue request later.
1016 */
Christoph Hellwigcc979232020-04-14 09:42:24 +02001017 if (unlikely(sg_alloc_table_chained(&cmd->sdb.table, nr_segs,
1018 cmd->sdb.table.sgl, SCSI_INLINE_SG_CNT)))
Christoph Hellwig0475bd62020-04-14 09:42:23 +02001019 return BLK_STS_RESOURCE;
1020
1021 /*
1022 * Next, walk the list, and fill in the addresses and sizes of
1023 * each segment.
1024 */
Christoph Hellwigcc979232020-04-14 09:42:24 +02001025 count = __blk_rq_map_sg(rq->q, rq, cmd->sdb.table.sgl, &last_sg);
1026
Christoph Hellwigbdf87102020-04-14 09:42:25 +02001027 if (blk_rq_bytes(rq) & rq->q->dma_pad_mask) {
1028 unsigned int pad_len =
1029 (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
1030
1031 last_sg->length += pad_len;
1032 cmd->extra_len += pad_len;
1033 }
1034
Christoph Hellwigcc979232020-04-14 09:42:24 +02001035 if (need_drain) {
1036 sg_unmark_end(last_sg);
1037 last_sg = sg_next(last_sg);
1038 sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len);
1039 sg_mark_end(last_sg);
1040
Christoph Hellwigbdf87102020-04-14 09:42:25 +02001041 cmd->extra_len += sdev->dma_drain_len;
Christoph Hellwigcc979232020-04-14 09:42:24 +02001042 count++;
1043 }
1044
Christoph Hellwig0475bd62020-04-14 09:42:23 +02001045 BUG_ON(count > cmd->sdb.table.nents);
1046 cmd->sdb.table.nents = count;
1047 cmd->sdb.length = blk_rq_payload_bytes(rq);
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001048
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001049 if (blk_integrity_rq(rq)) {
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001050 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
Christoph Hellwig0475bd62020-04-14 09:42:23 +02001051 int ivecs;
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001052
Christoph Hellwig14784562018-11-09 14:42:38 +01001053 if (WARN_ON_ONCE(!prot_sdb)) {
Ewan D. Milne91724c22015-01-15 10:02:12 -05001054 /*
1055 * This can happen if someone (e.g. multipath)
1056 * queues a command to a device on an adapter
1057 * that does not support DIX.
1058 */
Christoph Hellwig159b2cb2018-11-09 14:42:39 +01001059 ret = BLK_STS_IOERR;
Christoph Hellwig14784562018-11-09 14:42:38 +01001060 goto out_free_sgtables;
Ewan D. Milne91724c22015-01-15 10:02:12 -05001061 }
1062
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001063 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001064
Ming Lin001d63b2016-04-04 14:48:09 -07001065 if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
Ming Lei46358732019-04-28 15:39:30 +08001066 prot_sdb->table.sgl,
Ming Lei92524fa2019-04-28 15:39:31 +08001067 SCSI_INLINE_PROT_SG_CNT)) {
Christoph Hellwig159b2cb2018-11-09 14:42:39 +01001068 ret = BLK_STS_RESOURCE;
Christoph Hellwig14784562018-11-09 14:42:38 +01001069 goto out_free_sgtables;
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001070 }
1071
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001072 count = blk_rq_map_integrity_sg(rq->q, rq->bio,
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001073 prot_sdb->table.sgl);
Igor Stoppa6f1d8a52018-09-05 23:47:20 +03001074 BUG_ON(count > ivecs);
1075 BUG_ON(count > queue_max_integrity_segments(rq->q));
Martin K. Petersen7027ad72008-07-17 17:08:48 -04001076
1077 cmd->prot_sdb = prot_sdb;
1078 cmd->prot_sdb->table.nents = count;
1079 }
1080
Christoph Hellwig159b2cb2018-11-09 14:42:39 +01001081 return BLK_STS_OK;
Christoph Hellwig14784562018-11-09 14:42:38 +01001082out_free_sgtables:
Johannes Thumshirn20a66f22020-04-28 19:45:55 +09001083 scsi_free_sgtables(cmd);
Christoph Hellwig159b2cb2018-11-09 14:42:39 +01001084 return ret;
Boaz Harrosh6f9a35e2007-12-13 13:50:53 +02001085}
Boaz Harroshbb52d822007-12-13 16:14:27 -08001086EXPORT_SYMBOL(scsi_init_io);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087
Bart Van Asscheca18d6f2017-06-20 11:15:41 -07001088/**
Bart Van Assche832889f2017-08-30 16:58:40 -07001089 * scsi_initialize_rq - initialize struct scsi_cmnd partially
Jonathan Corbet35c05062017-08-24 16:11:09 -06001090 * @rq: Request associated with the SCSI command to be initialized.
Bart Van Asscheca18d6f2017-06-20 11:15:41 -07001091 *
Bart Van Assche832889f2017-08-30 16:58:40 -07001092 * This function initializes the members of struct scsi_cmnd that must be
1093 * initialized before request processing starts and that won't be
1094 * reinitialized if a SCSI command is requeued.
1095 *
Bart Van Assche64104f72017-08-30 16:58:39 -07001096 * Called from inside blk_get_request() for pass-through requests and from
1097 * inside scsi_init_command() for filesystem requests.
Bart Van Asscheca18d6f2017-06-20 11:15:41 -07001098 */
Bart Van Asschee4c94702017-12-07 15:59:31 -08001099static void scsi_initialize_rq(struct request *rq)
Bart Van Asscheca18d6f2017-06-20 11:15:41 -07001100{
Bart Van Asschec8d9cf22017-06-20 11:15:42 -07001101 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1102
1103 scsi_req_init(&cmd->req);
Bart Van Assche3be88282018-02-22 11:30:20 -08001104 init_rcu_head(&cmd->rcu);
Bart Van Assche832889f2017-08-30 16:58:40 -07001105 cmd->jiffies_at_alloc = jiffies;
1106 cmd->retries = 0;
Bart Van Asscheca18d6f2017-06-20 11:15:41 -07001107}
Bart Van Asscheca18d6f2017-06-20 11:15:41 -07001108
Ming Leib7e9e1f2019-07-25 10:05:00 +08001109/*
1110 * Only called when the request isn't completed by SCSI, and not freed by
1111 * SCSI
1112 */
1113static void scsi_cleanup_rq(struct request *rq)
1114{
1115 if (rq->rq_flags & RQF_DONTPREP) {
1116 scsi_mq_uninit_cmd(blk_mq_rq_to_pdu(rq));
1117 rq->rq_flags &= ~RQF_DONTPREP;
1118 }
1119}
1120
Bart Van Assche65ca8462020-01-22 19:56:34 -08001121/* Called before a request is prepared. See also scsi_mq_prep_fn(). */
Christoph Hellwige9c787e2017-01-02 21:55:26 +03001122void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
Christoph Hellwig3b003152006-11-04 20:10:55 +01001123{
Christoph Hellwige9c787e2017-01-02 21:55:26 +03001124 void *buf = cmd->sense_buffer;
1125 void *prot = cmd->prot_sdb;
Bart Van Assche64104f72017-08-30 16:58:39 -07001126 struct request *rq = blk_mq_rq_from_pdu(cmd);
1127 unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS;
Bart Van Assche832889f2017-08-30 16:58:40 -07001128 unsigned long jiffies_at_alloc;
Bart Van Assche65ca8462020-01-22 19:56:34 -08001129 int retries, to_clear;
Ming Lei6eb045e2019-10-25 14:58:55 +08001130 bool in_flight;
Bart Van Assche64104f72017-08-30 16:58:39 -07001131
1132 if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) {
1133 flags |= SCMD_INITIALIZED;
1134 scsi_initialize_rq(rq);
1135 }
Christoph Hellwig3b003152006-11-04 20:10:55 +01001136
Bart Van Assche832889f2017-08-30 16:58:40 -07001137 jiffies_at_alloc = cmd->jiffies_at_alloc;
1138 retries = cmd->retries;
Ming Lei6eb045e2019-10-25 14:58:55 +08001139 in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state);
Bart Van Assche65ca8462020-01-22 19:56:34 -08001140 /*
1141 * Zero out the cmd, except for the embedded scsi_request. Only clear
1142 * the driver-private command data if the LLD does not supply a
1143 * function to initialize that data.
1144 */
1145 to_clear = sizeof(*cmd) - sizeof(cmd->req);
1146 if (!dev->host->hostt->init_cmd_priv)
1147 to_clear += dev->host->hostt->cmd_size;
1148 memset((char *)cmd + sizeof(cmd->req), 0, to_clear);
Christoph Hellwig04796332014-02-20 14:20:55 -08001149
Christoph Hellwige9c787e2017-01-02 21:55:26 +03001150 cmd->device = dev;
1151 cmd->sense_buffer = buf;
1152 cmd->prot_sdb = prot;
Bart Van Assche64104f72017-08-30 16:58:39 -07001153 cmd->flags = flags;
Christoph Hellwige9c787e2017-01-02 21:55:26 +03001154 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
Bart Van Assche832889f2017-08-30 16:58:40 -07001155 cmd->jiffies_at_alloc = jiffies_at_alloc;
1156 cmd->retries = retries;
Ming Lei6eb045e2019-10-25 14:58:55 +08001157 if (in_flight)
1158 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001159
Christoph Hellwig3b003152006-11-04 20:10:55 +01001160}
1161
Christoph Hellwig785ba832018-11-09 14:42:37 +01001162static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
1163 struct request *req)
James Bottomley7b163182005-12-15 20:17:02 -06001164{
Bart Van Asschebed22132017-08-25 13:46:32 -07001165 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
Christoph Hellwig3b003152006-11-04 20:10:55 +01001166
1167 /*
Christoph Hellwigaebf5262017-01-31 16:57:31 +01001168 * Passthrough requests may transfer data, in which case they must
Christoph Hellwig3b003152006-11-04 20:10:55 +01001169 * a bio attached to them. Or they might contain a SCSI command
1170 * that does not transfer data, in which case they may optionally
1171 * submit a request without an attached bio.
1172 */
1173 if (req->bio) {
Christoph Hellwig159b2cb2018-11-09 14:42:39 +01001174 blk_status_t ret = scsi_init_io(cmd);
1175 if (unlikely(ret != BLK_STS_OK))
1176 return ret;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001177 } else {
Tejun Heob0790412009-05-07 22:24:42 +09001178 BUG_ON(blk_rq_bytes(req));
Christoph Hellwig3b003152006-11-04 20:10:55 +01001179
Boaz Harrosh30b0c372007-12-13 13:47:40 +02001180 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
Christoph Hellwig3b003152006-11-04 20:10:55 +01001181 }
James Bottomley7b163182005-12-15 20:17:02 -06001182
Christoph Hellwig82ed4db2017-01-27 09:46:29 +01001183 cmd->cmd_len = scsi_req(req)->cmd_len;
1184 cmd->cmnd = scsi_req(req)->cmd;
Tejun Heob0790412009-05-07 22:24:42 +09001185 cmd->transfersize = blk_rq_bytes(req);
Christoph Hellwig64c7f1d2017-04-05 19:18:12 +02001186 cmd->allowed = scsi_req(req)->retries;
Christoph Hellwig785ba832018-11-09 14:42:37 +01001187 return BLK_STS_OK;
Christoph Hellwig3b003152006-11-04 20:10:55 +01001188}
1189
1190/*
Christoph Hellwigaebf5262017-01-31 16:57:31 +01001191 * Setup a normal block command. These are simple request from filesystems
Christoph Hellwig3868cf82014-06-28 11:58:42 +02001192 * that still need to be translated to SCSI CDBs from the ULD.
Christoph Hellwig3b003152006-11-04 20:10:55 +01001193 */
Christoph Hellwig785ba832018-11-09 14:42:37 +01001194static blk_status_t scsi_setup_fs_cmnd(struct scsi_device *sdev,
1195 struct request *req)
Christoph Hellwig3b003152006-11-04 20:10:55 +01001196{
Bart Van Asschebed22132017-08-25 13:46:32 -07001197 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
Chandra Seetharamana6a8d9f2008-05-01 14:49:46 -07001198
Christoph Hellwigee14c672015-08-27 14:16:59 +02001199 if (unlikely(sdev->handler && sdev->handler->prep_fn)) {
Christoph Hellwig4c1cb672018-11-09 14:42:40 +01001200 blk_status_t ret = sdev->handler->prep_fn(sdev, req);
1201 if (ret != BLK_STS_OK)
1202 return ret;
Chandra Seetharamana6a8d9f2008-05-01 14:49:46 -07001203 }
1204
Christoph Hellwig82ed4db2017-01-27 09:46:29 +01001205 cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd;
Boaz Harrosh64a87b22008-04-30 11:19:47 +03001206 memset(cmd->cmnd, 0, BLK_MAX_CDB);
Christoph Hellwig159b2cb2018-11-09 14:42:39 +01001207 return scsi_cmd_to_driver(cmd)->init_command(cmd);
James Bottomley7b163182005-12-15 20:17:02 -06001208}
James Bottomley7b163182005-12-15 20:17:02 -06001209
Christoph Hellwig785ba832018-11-09 14:42:37 +01001210static blk_status_t scsi_setup_cmnd(struct scsi_device *sdev,
1211 struct request *req)
Christoph Hellwig6af7a4f2014-07-08 13:16:17 +02001212{
Bart Van Asschebed22132017-08-25 13:46:32 -07001213 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
Johannes Thumshirn20a66f22020-04-28 19:45:55 +09001214 blk_status_t ret;
Christoph Hellwig6af7a4f2014-07-08 13:16:17 +02001215
1216 if (!blk_rq_bytes(req))
1217 cmd->sc_data_direction = DMA_NONE;
1218 else if (rq_data_dir(req) == WRITE)
1219 cmd->sc_data_direction = DMA_TO_DEVICE;
1220 else
1221 cmd->sc_data_direction = DMA_FROM_DEVICE;
1222
Christoph Hellwigaebf5262017-01-31 16:57:31 +01001223 if (blk_rq_is_scsi(req))
Johannes Thumshirn20a66f22020-04-28 19:45:55 +09001224 ret = scsi_setup_scsi_cmnd(sdev, req);
Christoph Hellwigaebf5262017-01-31 16:57:31 +01001225 else
Johannes Thumshirn20a66f22020-04-28 19:45:55 +09001226 ret = scsi_setup_fs_cmnd(sdev, req);
1227
1228 if (ret != BLK_STS_OK)
1229 scsi_free_sgtables(cmd);
1230
1231 return ret;
Christoph Hellwig6af7a4f2014-07-08 13:16:17 +02001232}
1233
Christoph Hellwigc092d4e2018-11-09 14:42:36 +01001234static blk_status_t
Christoph Hellwiga1b73fc2014-05-01 16:51:04 +02001235scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236{
Christoph Hellwigc092d4e2018-11-09 14:42:36 +01001237 switch (sdev->sdev_state) {
1238 case SDEV_OFFLINE:
1239 case SDEV_TRANSPORT_OFFLINE:
1240 /*
1241 * If the device is offline we refuse to process any
1242 * commands. The device must be brought online
1243 * before trying any recovery commands.
1244 */
Ewan D. Milneb0962c52020-03-11 10:39:30 -04001245 if (!sdev->offline_already) {
1246 sdev->offline_already = true;
1247 sdev_printk(KERN_ERR, sdev,
1248 "rejecting I/O to offline device\n");
1249 }
Christoph Hellwigc092d4e2018-11-09 14:42:36 +01001250 return BLK_STS_IOERR;
1251 case SDEV_DEL:
1252 /*
1253 * If the device is fully deleted, we refuse to
1254 * process any commands as well.
1255 */
1256 sdev_printk(KERN_ERR, sdev,
1257 "rejecting I/O to dead device\n");
1258 return BLK_STS_IOERR;
1259 case SDEV_BLOCK:
1260 case SDEV_CREATED_BLOCK:
1261 return BLK_STS_RESOURCE;
1262 case SDEV_QUIESCE:
1263 /*
1264 * If the devices is blocked we defer normal commands.
1265 */
1266 if (req && !(req->rq_flags & RQF_PREEMPT))
1267 return BLK_STS_RESOURCE;
1268 return BLK_STS_OK;
1269 default:
1270 /*
1271 * For any other not fully online state we only allow
1272 * special commands. In particular any user initiated
1273 * command is not allowed.
1274 */
1275 if (req && !(req->rq_flags & RQF_PREEMPT))
1276 return BLK_STS_IOERR;
1277 return BLK_STS_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 }
James Bottomley7f9a6bc2007-08-04 10:06:25 -05001279}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281/*
1282 * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
1283 * return 0.
1284 *
1285 * Called with the queue_lock held.
1286 */
1287static inline int scsi_dev_queue_ready(struct request_queue *q,
1288 struct scsi_device *sdev)
1289{
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001290 unsigned int busy;
1291
1292 busy = atomic_inc_return(&sdev->device_busy) - 1;
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001293 if (atomic_read(&sdev->device_blocked)) {
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001294 if (busy)
1295 goto out_dec;
1296
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297 /*
1298 * unblock after device_blocked iterates to zero
1299 */
Jens Axboef664a3c2018-11-01 16:36:27 -06001300 if (atomic_dec_return(&sdev->device_blocked) > 0)
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001301 goto out_dec;
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001302 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
1303 "unblocking device at zero depth\n"));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304 }
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001305
1306 if (busy >= sdev->queue_depth)
1307 goto out_dec;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308
1309 return 1;
Christoph Hellwig71e75c92014-04-11 19:07:01 +02001310out_dec:
1311 atomic_dec(&sdev->device_busy);
1312 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313}
1314
Mike Christief0c0a372008-08-17 15:24:38 -05001315/*
1316 * scsi_target_queue_ready: checks if there we can send commands to target
1317 * @sdev: scsi device on starget to check.
Mike Christief0c0a372008-08-17 15:24:38 -05001318 */
1319static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
1320 struct scsi_device *sdev)
1321{
1322 struct scsi_target *starget = scsi_target(sdev);
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001323 unsigned int busy;
Mike Christief0c0a372008-08-17 15:24:38 -05001324
1325 if (starget->single_lun) {
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001326 spin_lock_irq(shost->host_lock);
Mike Christief0c0a372008-08-17 15:24:38 -05001327 if (starget->starget_sdev_user &&
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001328 starget->starget_sdev_user != sdev) {
1329 spin_unlock_irq(shost->host_lock);
1330 return 0;
1331 }
Mike Christief0c0a372008-08-17 15:24:38 -05001332 starget->starget_sdev_user = sdev;
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001333 spin_unlock_irq(shost->host_lock);
Mike Christief0c0a372008-08-17 15:24:38 -05001334 }
1335
Christoph Hellwig2ccbb002014-03-26 10:35:00 +01001336 if (starget->can_queue <= 0)
1337 return 1;
1338
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001339 busy = atomic_inc_return(&starget->target_busy) - 1;
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001340 if (atomic_read(&starget->target_blocked) > 0) {
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001341 if (busy)
1342 goto starved;
1343
Mike Christief0c0a372008-08-17 15:24:38 -05001344 /*
1345 * unblock after target_blocked iterates to zero
1346 */
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001347 if (atomic_dec_return(&starget->target_blocked) > 0)
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001348 goto out_dec;
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001349
1350 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
1351 "unblocking target at zero depth\n"));
Mike Christief0c0a372008-08-17 15:24:38 -05001352 }
1353
Christoph Hellwig2ccbb002014-03-26 10:35:00 +01001354 if (busy >= starget->can_queue)
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001355 goto starved;
Mike Christief0c0a372008-08-17 15:24:38 -05001356
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001357 return 1;
1358
1359starved:
1360 spin_lock_irq(shost->host_lock);
1361 list_move_tail(&sdev->starved_entry, &shost->starved_list);
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001362 spin_unlock_irq(shost->host_lock);
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001363out_dec:
Christoph Hellwig2ccbb002014-03-26 10:35:00 +01001364 if (starget->can_queue > 0)
1365 atomic_dec(&starget->target_busy);
Christoph Hellwig7ae65c02014-01-22 14:49:41 +01001366 return 0;
Mike Christief0c0a372008-08-17 15:24:38 -05001367}
1368
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369/*
1370 * scsi_host_queue_ready: if we can send requests to shost, return 1 else
1371 * return 0. We must end up running the queue again whenever 0 is
1372 * returned, else IO can hang.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 */
1374static inline int scsi_host_queue_ready(struct request_queue *q,
1375 struct Scsi_Host *shost,
Ming Lei6eb045e2019-10-25 14:58:55 +08001376 struct scsi_device *sdev,
1377 struct scsi_cmnd *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378{
James Bottomley939647e2005-09-18 15:05:20 -05001379 if (scsi_host_in_recovery(shost))
Christoph Hellwig74665012014-01-22 15:29:29 +01001380 return 0;
1381
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001382 if (atomic_read(&shost->host_blocked) > 0) {
Ming Lei6eb045e2019-10-25 14:58:55 +08001383 if (scsi_host_busy(shost) > 0)
Christoph Hellwig74665012014-01-22 15:29:29 +01001384 goto starved;
1385
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 /*
1387 * unblock after host_blocked iterates to zero
1388 */
Christoph Hellwigcd9070c2014-01-23 12:07:41 +01001389 if (atomic_dec_return(&shost->host_blocked) > 0)
Christoph Hellwig74665012014-01-22 15:29:29 +01001390 goto out_dec;
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001391
1392 SCSI_LOG_MLQUEUE(3,
1393 shost_printk(KERN_INFO, shost,
1394 "unblocking host at zero depth\n"));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395 }
Christoph Hellwig74665012014-01-22 15:29:29 +01001396
Christoph Hellwig74665012014-01-22 15:29:29 +01001397 if (shost->host_self_blocked)
1398 goto starved;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001399
1400 /* We're OK to process the command, so we can't be starved */
Christoph Hellwig74665012014-01-22 15:29:29 +01001401 if (!list_empty(&sdev->starved_entry)) {
1402 spin_lock_irq(shost->host_lock);
1403 if (!list_empty(&sdev->starved_entry))
1404 list_del_init(&sdev->starved_entry);
1405 spin_unlock_irq(shost->host_lock);
1406 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407
Ming Lei6eb045e2019-10-25 14:58:55 +08001408 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state);
1409
Christoph Hellwig74665012014-01-22 15:29:29 +01001410 return 1;
1411
1412starved:
1413 spin_lock_irq(shost->host_lock);
1414 if (list_empty(&sdev->starved_entry))
1415 list_add_tail(&sdev->starved_entry, &shost->starved_list);
Christoph Hellwigcf68d332014-01-22 14:36:32 +01001416 spin_unlock_irq(shost->host_lock);
Christoph Hellwig74665012014-01-22 15:29:29 +01001417out_dec:
Ming Lei6eb045e2019-10-25 14:58:55 +08001418 scsi_dec_host_busy(shost, cmd);
Christoph Hellwig74665012014-01-22 15:29:29 +01001419 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001420}
1421
1422/*
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001423 * Busy state exporting function for request stacking drivers.
1424 *
1425 * For efficiency, no lock is taken to check the busy state of
1426 * shost/starget/sdev, since the returned value is not guaranteed and
1427 * may be changed after request stacking drivers call the function,
1428 * regardless of taking lock or not.
1429 *
Bart Van Assche67bd9412012-06-29 15:33:22 +00001430 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
1431 * needs to return 'not busy'. Otherwise, request stacking drivers
1432 * may hold requests forever.
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001433 */
Jens Axboef664a3c2018-11-01 16:36:27 -06001434static bool scsi_mq_lld_busy(struct request_queue *q)
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001435{
1436 struct scsi_device *sdev = q->queuedata;
1437 struct Scsi_Host *shost;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001438
Bart Van Assche3f3299d2012-11-28 13:42:38 +01001439 if (blk_queue_dying(q))
Jens Axboef664a3c2018-11-01 16:36:27 -06001440 return false;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001441
1442 shost = sdev->host;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001443
Jun'ichi Nomurab7e94a12012-05-22 18:57:17 +09001444 /*
1445 * Ignore host/starget busy state.
1446 * Since block layer does not have a concept of fairness across
1447 * multiple queues, congestion of host/starget needs to be handled
1448 * in SCSI layer.
1449 */
1450 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
Jens Axboef664a3c2018-11-01 16:36:27 -06001451 return true;
Kiyoshi Ueda6c5121b2008-10-04 14:11:35 -04001452
Jens Axboef664a3c2018-11-01 16:36:27 -06001453 return false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454}
1455
Jens Axboe1aea6432006-01-09 16:03:03 +01001456static void scsi_softirq_done(struct request *rq)
1457{
Bart Van Asschebed22132017-08-25 13:46:32 -07001458 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
Jens Axboe242f9dc2008-09-14 05:55:09 -07001459 unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
Jens Axboe1aea6432006-01-09 16:03:03 +01001460 int disposition;
1461
1462 INIT_LIST_HEAD(&cmd->eh_entry);
1463
Jens Axboe242f9dc2008-09-14 05:55:09 -07001464 atomic_inc(&cmd->device->iodone_cnt);
1465 if (cmd->result)
1466 atomic_inc(&cmd->device->ioerr_cnt);
1467
Jens Axboe1aea6432006-01-09 16:03:03 +01001468 disposition = scsi_decide_disposition(cmd);
1469 if (disposition != SUCCESS &&
1470 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
Maurizio Lombardi463cdad82019-07-02 13:27:05 +02001471 scmd_printk(KERN_ERR, cmd,
Jens Axboe1aea6432006-01-09 16:03:03 +01001472 "timing out command, waited %lus\n",
1473 wait_for/HZ);
1474 disposition = SUCCESS;
1475 }
Hannes Reinecke91921e02014-06-25 16:39:59 +02001476
Jens Axboe1aea6432006-01-09 16:03:03 +01001477 scsi_log_completion(cmd, disposition);
1478
1479 switch (disposition) {
Bean Huo4c7b4d62020-06-19 17:41:17 +02001480 case SUCCESS:
1481 scsi_finish_command(cmd);
1482 break;
1483 case NEEDS_RETRY:
1484 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
1485 break;
1486 case ADD_TO_MLQUEUE:
1487 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
1488 break;
1489 default:
1490 scsi_eh_scmd_add(cmd);
1491 break;
Jens Axboe1aea6432006-01-09 16:03:03 +01001492 }
1493}
1494
Christoph Hellwig3b5382c2014-05-06 12:25:40 +02001495/**
Christoph Hellwig82042a22014-09-05 18:23:07 -07001496 * scsi_dispatch_command - Dispatch a command to the low-level driver.
1497 * @cmd: command block we are dispatching.
1498 *
1499 * Return: nonzero return request was rejected and device's queue needs to be
1500 * plugged.
1501 */
1502static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
1503{
1504 struct Scsi_Host *host = cmd->device->host;
1505 int rtn = 0;
1506
1507 atomic_inc(&cmd->device->iorequest_cnt);
1508
1509 /* check if the device is still usable */
1510 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
1511 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
1512 * returns an immediate error upwards, and signals
1513 * that the device is no longer present */
1514 cmd->result = DID_NO_CONNECT << 16;
1515 goto done;
1516 }
1517
1518 /* Check to see if the scsi lld made this device blocked. */
1519 if (unlikely(scsi_device_blocked(cmd->device))) {
1520 /*
1521 * in blocked state, the command is just put back on
1522 * the device queue. The suspend state has already
1523 * blocked the queue so future requests should not
1524 * occur until the device transitions out of the
1525 * suspend state.
1526 */
1527 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1528 "queuecommand : device blocked\n"));
1529 return SCSI_MLQUEUE_DEVICE_BUSY;
1530 }
1531
1532 /* Store the LUN value in cmnd, if needed. */
1533 if (cmd->device->lun_in_cdb)
1534 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
1535 (cmd->device->lun << 5 & 0xe0);
1536
1537 scsi_log_send(cmd);
1538
1539 /*
1540 * Before we queue this command, check if the command
1541 * length exceeds what the host adapter can handle.
1542 */
1543 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
1544 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1545 "queuecommand : command too long. "
1546 "cdb_size=%d host->max_cmd_len=%d\n",
1547 cmd->cmd_len, cmd->device->host->max_cmd_len));
1548 cmd->result = (DID_ABORT << 16);
1549 goto done;
1550 }
1551
1552 if (unlikely(host->shost_state == SHOST_DEL)) {
1553 cmd->result = (DID_NO_CONNECT << 16);
1554 goto done;
1555
1556 }
1557
1558 trace_scsi_dispatch_cmd_start(cmd);
1559 rtn = host->hostt->queuecommand(host, cmd);
1560 if (rtn) {
1561 trace_scsi_dispatch_cmd_error(cmd, rtn);
1562 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
1563 rtn != SCSI_MLQUEUE_TARGET_BUSY)
1564 rtn = SCSI_MLQUEUE_HOST_BUSY;
1565
1566 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1567 "queuecommand : request rejected\n"));
1568 }
1569
1570 return rtn;
1571 done:
1572 cmd->scsi_done(cmd);
1573 return 0;
1574}
1575
Bart Van Asschebe4c1862017-06-02 14:21:59 -07001576/* Size in bytes of the sg-list stored in the scsi-mq command-private data. */
Ming Lei3dccdf52019-04-28 15:39:32 +08001577static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost)
Bart Van Asschebe4c1862017-06-02 14:21:59 -07001578{
Ming Lei3dccdf52019-04-28 15:39:32 +08001579 return min_t(unsigned int, shost->sg_tablesize, SCSI_INLINE_SG_CNT) *
Bart Van Asschebe4c1862017-06-02 14:21:59 -07001580 sizeof(struct scatterlist);
1581}
1582
Christoph Hellwig785ba832018-11-09 14:42:37 +01001583static blk_status_t scsi_mq_prep_fn(struct request *req)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001584{
1585 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1586 struct scsi_device *sdev = req->q->queuedata;
1587 struct Scsi_Host *shost = sdev->host;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001588 struct scatterlist *sg;
1589
Bart Van Assche08f78432017-06-02 14:22:00 -07001590 scsi_init_command(sdev, cmd);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001591
Christoph Hellwigd2852032014-01-17 12:06:53 +01001592 cmd->request = req;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001593 cmd->tag = req->tag;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001594 cmd->prot_op = SCSI_PROT_NORMAL;
1595
Christoph Hellwigd2852032014-01-17 12:06:53 +01001596 sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
1597 cmd->sdb.table.sgl = sg;
1598
1599 if (scsi_host_get_prot(shost)) {
Christoph Hellwigd2852032014-01-17 12:06:53 +01001600 memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
1601
1602 cmd->prot_sdb->table.sgl =
1603 (struct scatterlist *)(cmd->prot_sdb + 1);
1604 }
1605
Christoph Hellwigfe052522014-09-22 15:59:31 +02001606 blk_mq_start_request(req);
1607
Bart Van Assche8fe8ffb2017-10-20 11:46:45 -07001608 return scsi_setup_cmnd(sdev, req);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001609}
1610
1611static void scsi_mq_done(struct scsi_cmnd *cmd)
1612{
Christoph Hellwig15f73f52020-06-11 08:44:47 +02001613 if (unlikely(blk_should_fake_timeout(cmd->request->q)))
1614 return;
Keith Buschf1342702018-11-26 09:54:29 -07001615 if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state)))
1616 return;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001617 trace_scsi_dispatch_cmd_done(cmd);
Christoph Hellwig15f73f52020-06-11 08:44:47 +02001618 blk_mq_complete_request(cmd->request);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001619}
1620
Ming Lei65c76362020-06-30 18:24:56 +08001621static void scsi_mq_put_budget(struct request_queue *q)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001622{
Christoph Hellwigd2852032014-01-17 12:06:53 +01001623 struct scsi_device *sdev = q->queuedata;
Ming Lei0df21c82017-10-14 17:22:32 +08001624
Ming Lei0df21c82017-10-14 17:22:32 +08001625 atomic_dec(&sdev->device_busy);
Ming Lei0df21c82017-10-14 17:22:32 +08001626}
1627
Ming Lei65c76362020-06-30 18:24:56 +08001628static bool scsi_mq_get_budget(struct request_queue *q)
Ming Lei0df21c82017-10-14 17:22:32 +08001629{
Ming Lei0df21c82017-10-14 17:22:32 +08001630 struct scsi_device *sdev = q->queuedata;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001631
Ming Leied5dd6a2020-09-10 15:50:56 +08001632 if (scsi_dev_queue_ready(q, sdev))
1633 return true;
1634
1635 atomic_inc(&sdev->restarts);
1636
1637 /*
1638 * Orders atomic_inc(&sdev->restarts) and atomic_read(&sdev->device_busy).
1639 * .restarts must be incremented before .device_busy is read because the
1640 * code in scsi_run_queue_async() depends on the order of these operations.
1641 */
1642 smp_mb__after_atomic();
1643
1644 /*
1645 * If all in-flight requests originated from this LUN are completed
1646 * before reading .device_busy, sdev->device_busy will be observed as
1647 * zero, then blk_mq_delay_run_hw_queues() will dispatch this request
1648 * soon. Otherwise, completion of one of these requests will observe
1649 * the .restarts flag, and the request queue will be run for handling
1650 * this request, see scsi_end_request().
1651 */
1652 if (unlikely(atomic_read(&sdev->device_busy) == 0 &&
1653 !scsi_device_blocked(sdev)))
1654 blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY);
1655 return false;
Ming Lei0df21c82017-10-14 17:22:32 +08001656}
1657
Christoph Hellwigd2852032014-01-17 12:06:53 +01001658static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
1659 const struct blk_mq_queue_data *bd)
1660{
1661 struct request *req = bd->rq;
1662 struct request_queue *q = req->q;
1663 struct scsi_device *sdev = q->queuedata;
1664 struct Scsi_Host *shost = sdev->host;
1665 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1666 blk_status_t ret;
1667 int reason;
1668
Christoph Hellwigc092d4e2018-11-09 14:42:36 +01001669 /*
1670 * If the device is not in running state we will reject some or all
1671 * commands.
1672 */
1673 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
1674 ret = scsi_prep_state_check(sdev, req);
1675 if (ret != BLK_STS_OK)
1676 goto out_put_budget;
1677 }
Christoph Hellwigd2852032014-01-17 12:06:53 +01001678
Christoph Hellwigfc17b652017-06-03 09:38:05 +02001679 ret = BLK_STS_RESOURCE;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001680 if (!scsi_target_queue_ready(shost, sdev))
Ming Lei826a70a2017-11-04 09:55:34 +08001681 goto out_put_budget;
Ming Lei6eb045e2019-10-25 14:58:55 +08001682 if (!scsi_host_queue_ready(q, shost, sdev, cmd))
Christoph Hellwigd2852032014-01-17 12:06:53 +01001683 goto out_dec_target_busy;
1684
Christoph Hellwige8064022016-10-20 15:12:13 +02001685 if (!(req->rq_flags & RQF_DONTPREP)) {
Christoph Hellwig785ba832018-11-09 14:42:37 +01001686 ret = scsi_mq_prep_fn(req);
Christoph Hellwigfc17b652017-06-03 09:38:05 +02001687 if (ret != BLK_STS_OK)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001688 goto out_dec_host_busy;
Christoph Hellwige8064022016-10-20 15:12:13 +02001689 req->rq_flags |= RQF_DONTPREP;
Christoph Hellwigfe052522014-09-22 15:59:31 +02001690 } else {
Bart Van Asschecd464d82019-01-15 16:50:03 -08001691 clear_bit(SCMD_STATE_COMPLETE, &cmd->state);
Christoph Hellwigfe052522014-09-22 15:59:31 +02001692 blk_mq_start_request(req);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001693 }
1694
Paolo Bonzini8930a6c2019-05-30 13:28:10 +02001695 cmd->flags &= SCMD_PRESERVED_FLAGS;
Christoph Hellwig125c99b2014-11-03 12:47:47 +01001696 if (sdev->simple_tags)
1697 cmd->flags |= SCMD_TAGGED;
Paolo Bonzini8930a6c2019-05-30 13:28:10 +02001698 if (bd->last)
1699 cmd->flags |= SCMD_LAST;
Christoph Hellwigb1dd2aa2014-10-19 17:13:58 +02001700
Christoph Hellwigd2852032014-01-17 12:06:53 +01001701 scsi_init_cmd_errh(cmd);
1702 cmd->scsi_done = scsi_mq_done;
1703
1704 reason = scsi_dispatch_cmd(cmd);
1705 if (reason) {
1706 scsi_set_blocked(cmd, reason);
Christoph Hellwigfc17b652017-06-03 09:38:05 +02001707 ret = BLK_STS_RESOURCE;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001708 goto out_dec_host_busy;
1709 }
1710
Christoph Hellwigfc17b652017-06-03 09:38:05 +02001711 return BLK_STS_OK;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001712
1713out_dec_host_busy:
Ming Lei6eb045e2019-10-25 14:58:55 +08001714 scsi_dec_host_busy(shost, cmd);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001715out_dec_target_busy:
1716 if (scsi_target(sdev)->can_queue > 0)
1717 atomic_dec(&scsi_target(sdev)->target_busy);
Ming Lei0df21c82017-10-14 17:22:32 +08001718out_put_budget:
Ming Lei65c76362020-06-30 18:24:56 +08001719 scsi_mq_put_budget(q);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001720 switch (ret) {
Christoph Hellwigfc17b652017-06-03 09:38:05 +02001721 case BLK_STS_OK:
1722 break;
1723 case BLK_STS_RESOURCE:
Keith Busch0512a752020-05-12 17:55:47 +09001724 case BLK_STS_ZONE_RESOURCE:
Ming Lei86ff7c22018-01-30 22:04:57 -05001725 if (atomic_read(&sdev->device_busy) ||
1726 scsi_device_blocked(sdev))
1727 ret = BLK_STS_DEV_RESOURCE;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001728 break;
Christoph Hellwigfc17b652017-06-03 09:38:05 +02001729 default:
Jaesoo Leebe549d42019-04-09 17:02:22 -07001730 if (unlikely(!scsi_device_online(sdev)))
1731 scsi_req(req)->result = DID_NO_CONNECT << 16;
1732 else
1733 scsi_req(req)->result = DID_ERROR << 16;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001734 /*
Jaesoo Leebe549d42019-04-09 17:02:22 -07001735 * Make sure to release all allocated resources when
Christoph Hellwigd2852032014-01-17 12:06:53 +01001736 * we hit an error, as we will never see this command
1737 * again.
1738 */
Christoph Hellwige8064022016-10-20 15:12:13 +02001739 if (req->rq_flags & RQF_DONTPREP)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001740 scsi_mq_uninit_cmd(cmd);
Ming Lei3f0dcfb2020-07-20 10:54:35 +08001741 scsi_run_queue_async(sdev);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001742 break;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001743 }
1744 return ret;
1745}
1746
Christoph Hellwig0152fb62014-09-13 16:40:13 -07001747static enum blk_eh_timer_return scsi_timeout(struct request *req,
1748 bool reserved)
1749{
1750 if (reserved)
1751 return BLK_EH_RESET_TIMER;
1752 return scsi_times_out(req);
1753}
1754
Bart Van Asschee7008ff2017-08-25 13:46:31 -07001755static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
1756 unsigned int hctx_idx, unsigned int numa_node)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001757{
Christoph Hellwigd6296d392017-05-01 10:19:08 -06001758 struct Scsi_Host *shost = set->driver_data;
Bart Van Assche8e688252017-06-02 14:21:52 -07001759 const bool unchecked_isa_dma = shost->unchecked_isa_dma;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001760 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
Bart Van Assche08f78432017-06-02 14:22:00 -07001761 struct scatterlist *sg;
Bart Van Assche65ca8462020-01-22 19:56:34 -08001762 int ret = 0;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001763
Bart Van Assche8e688252017-06-02 14:21:52 -07001764 if (unchecked_isa_dma)
1765 cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
1766 cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma,
1767 GFP_KERNEL, numa_node);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001768 if (!cmd->sense_buffer)
1769 return -ENOMEM;
Christoph Hellwig82ed4db2017-01-27 09:46:29 +01001770 cmd->req.sense = cmd->sense_buffer;
Bart Van Assche08f78432017-06-02 14:22:00 -07001771
1772 if (scsi_host_get_prot(shost)) {
1773 sg = (void *)cmd + sizeof(struct scsi_cmnd) +
1774 shost->hostt->cmd_size;
Ming Lei3dccdf52019-04-28 15:39:32 +08001775 cmd->prot_sdb = (void *)sg + scsi_mq_inline_sgl_size(shost);
Bart Van Assche08f78432017-06-02 14:22:00 -07001776 }
1777
Bart Van Assche65ca8462020-01-22 19:56:34 -08001778 if (shost->hostt->init_cmd_priv) {
1779 ret = shost->hostt->init_cmd_priv(shost, cmd);
1780 if (ret < 0)
1781 scsi_free_sense_buffer(unchecked_isa_dma,
1782 cmd->sense_buffer);
1783 }
1784
1785 return ret;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001786}
1787
Bart Van Asschee7008ff2017-08-25 13:46:31 -07001788static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq,
1789 unsigned int hctx_idx)
Christoph Hellwigd2852032014-01-17 12:06:53 +01001790{
Bart Van Assche65ca8462020-01-22 19:56:34 -08001791 struct Scsi_Host *shost = set->driver_data;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001792 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1793
Bart Van Assche65ca8462020-01-22 19:56:34 -08001794 if (shost->hostt->exit_cmd_priv)
1795 shost->hostt->exit_cmd_priv(shost, cmd);
Bart Van Assche8e688252017-06-02 14:21:52 -07001796 scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
1797 cmd->sense_buffer);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001798}
1799
Christoph Hellwig2d9c5c22016-11-01 08:12:48 -06001800static int scsi_map_queues(struct blk_mq_tag_set *set)
1801{
1802 struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set);
1803
1804 if (shost->hostt->map_queues)
1805 return shost->hostt->map_queues(shost);
Dongli Zhang99bbf482019-03-12 09:00:28 +08001806 return blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
Christoph Hellwig2d9c5c22016-11-01 08:12:48 -06001807}
1808
Christoph Hellwigd48777a62017-01-02 21:52:10 +03001809void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810{
Lin Ming6f381fa2012-04-12 13:50:38 +08001811 struct device *dev = shost->dma_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812
Jens Axboea8474ce2007-08-07 09:02:51 +02001813 /*
1814 * this limit is imposed by hardware restrictions
1815 */
Martin K. Petersen8a783622010-02-26 00:20:39 -05001816 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize,
Ming Lin65e86172016-04-04 14:48:10 -07001817 SG_MAX_SEGMENTS));
Jens Axboea8474ce2007-08-07 09:02:51 +02001818
Martin K. Petersen13f05c82010-09-10 20:50:10 +02001819 if (scsi_host_prot_dma(shost)) {
1820 shost->sg_prot_tablesize =
1821 min_not_zero(shost->sg_prot_tablesize,
1822 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS);
1823 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize);
1824 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
1825 }
1826
Christoph Hellwig1b5d9a62019-07-22 11:20:38 +02001827 if (dev->dma_mask) {
1828 shost->max_sectors = min_t(unsigned int, shost->max_sectors,
1829 dma_max_mapping_size(dev) >> SECTOR_SHIFT);
1830 }
Martin K. Petersen086fa5f2010-02-26 00:20:38 -05001831 blk_queue_max_hw_sectors(q, shost->max_sectors);
Christoph Hellwig21e07db2018-04-03 19:09:59 +02001832 if (shost->unchecked_isa_dma)
1833 blk_queue_bounce_limit(q, BLK_BOUNCE_ISA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001834 blk_queue_segment_boundary(q, shost->dma_boundary);
FUJITA Tomonori99c84db2008-02-04 22:28:17 -08001835 dma_set_seg_boundary(dev, shost->dma_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836
Christoph Hellwiga8cf59a2019-01-16 17:12:15 +01001837 blk_queue_max_segment_size(q, shost->max_segment_size);
Christoph Hellwig7ad388d2019-06-17 14:19:53 +02001838 blk_queue_virt_boundary(q, shost->virt_boundary_mask);
1839 dma_set_max_seg_size(dev, queue_max_segment_size(q));
James Bottomley465ff312008-01-01 10:00:10 -06001840
1841 /*
Huacai Chen90addc62017-11-21 14:23:38 +01001842 * Set a reasonable default alignment: The larger of 32-byte (dword),
1843 * which is a common minimum for HBAs, and the minimum DMA alignment,
1844 * which is set by the platform.
1845 *
1846 * Devices that require a bigger alignment can increase it later.
James Bottomley465ff312008-01-01 10:00:10 -06001847 */
Huacai Chen90addc62017-11-21 14:23:38 +01001848 blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001849}
Christoph Hellwigd48777a62017-01-02 21:52:10 +03001850EXPORT_SYMBOL_GPL(__scsi_init_queue);
James Bottomley465ff312008-01-01 10:00:10 -06001851
Paolo Bonzini8930a6c2019-05-30 13:28:10 +02001852static const struct blk_mq_ops scsi_mq_ops_no_commit = {
1853 .get_budget = scsi_mq_get_budget,
1854 .put_budget = scsi_mq_put_budget,
1855 .queue_rq = scsi_queue_rq,
1856 .complete = scsi_softirq_done,
1857 .timeout = scsi_timeout,
1858#ifdef CONFIG_BLK_DEBUG_FS
1859 .show_rq = scsi_show_rq,
1860#endif
1861 .init_request = scsi_mq_init_request,
1862 .exit_request = scsi_mq_exit_request,
1863 .initialize_rq_fn = scsi_initialize_rq,
Steffen Maier82a9ac72019-08-07 16:49:47 +02001864 .cleanup_rq = scsi_cleanup_rq,
Paolo Bonzini8930a6c2019-05-30 13:28:10 +02001865 .busy = scsi_mq_lld_busy,
1866 .map_queues = scsi_map_queues,
1867};
1868
1869
1870static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx)
1871{
1872 struct request_queue *q = hctx->queue;
1873 struct scsi_device *sdev = q->queuedata;
1874 struct Scsi_Host *shost = sdev->host;
1875
1876 shost->hostt->commit_rqs(shost, hctx->queue_num);
1877}
1878
Eric Biggersf363b082017-03-30 13:39:16 -07001879static const struct blk_mq_ops scsi_mq_ops = {
Ming Lei0df21c82017-10-14 17:22:32 +08001880 .get_budget = scsi_mq_get_budget,
1881 .put_budget = scsi_mq_put_budget,
Christoph Hellwigd2852032014-01-17 12:06:53 +01001882 .queue_rq = scsi_queue_rq,
Paolo Bonzini8930a6c2019-05-30 13:28:10 +02001883 .commit_rqs = scsi_commit_rqs,
Christoph Hellwigd2852032014-01-17 12:06:53 +01001884 .complete = scsi_softirq_done,
Christoph Hellwig0152fb62014-09-13 16:40:13 -07001885 .timeout = scsi_timeout,
Bart Van Assche0eebd002017-04-26 13:47:57 -07001886#ifdef CONFIG_BLK_DEBUG_FS
1887 .show_rq = scsi_show_rq,
1888#endif
Bart Van Asschee7008ff2017-08-25 13:46:31 -07001889 .init_request = scsi_mq_init_request,
1890 .exit_request = scsi_mq_exit_request,
Bart Van Asscheca18d6f2017-06-20 11:15:41 -07001891 .initialize_rq_fn = scsi_initialize_rq,
Ming Leib7e9e1f2019-07-25 10:05:00 +08001892 .cleanup_rq = scsi_cleanup_rq,
Jens Axboe3a7ea2c42018-10-29 10:17:28 -06001893 .busy = scsi_mq_lld_busy,
Christoph Hellwig2d9c5c22016-11-01 08:12:48 -06001894 .map_queues = scsi_map_queues,
Christoph Hellwigd2852032014-01-17 12:06:53 +01001895};
1896
1897struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev)
1898{
1899 sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set);
1900 if (IS_ERR(sdev->request_queue))
1901 return NULL;
1902
1903 sdev->request_queue->queuedata = sdev;
1904 __scsi_init_queue(sdev->host, sdev->request_queue);
Christoph Hellwig17cb9602018-03-13 17:28:41 +01001905 blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, sdev->request_queue);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001906 return sdev->request_queue;
1907}
1908
1909int scsi_mq_setup_tags(struct Scsi_Host *shost)
1910{
Bart Van Asschebe4c1862017-06-02 14:21:59 -07001911 unsigned int cmd_size, sgl_size;
Ye Bin840e1b52020-05-18 15:47:32 +08001912 struct blk_mq_tag_set *tag_set = &shost->tag_set;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001913
Michael Schmitz9393c8de2019-11-05 15:49:10 +13001914 sgl_size = max_t(unsigned int, sizeof(struct scatterlist),
1915 scsi_mq_inline_sgl_size(shost));
Christoph Hellwigd2852032014-01-17 12:06:53 +01001916 cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size;
1917 if (scsi_host_get_prot(shost))
Ming Lei92524fa2019-04-28 15:39:31 +08001918 cmd_size += sizeof(struct scsi_data_buffer) +
1919 sizeof(struct scatterlist) * SCSI_INLINE_PROT_SG_CNT;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001920
Ye Bin840e1b52020-05-18 15:47:32 +08001921 memset(tag_set, 0, sizeof(*tag_set));
Paolo Bonzini8930a6c2019-05-30 13:28:10 +02001922 if (shost->hostt->commit_rqs)
Ye Bin840e1b52020-05-18 15:47:32 +08001923 tag_set->ops = &scsi_mq_ops;
Paolo Bonzini8930a6c2019-05-30 13:28:10 +02001924 else
Ye Bin840e1b52020-05-18 15:47:32 +08001925 tag_set->ops = &scsi_mq_ops_no_commit;
1926 tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1;
1927 tag_set->queue_depth = shost->can_queue;
1928 tag_set->cmd_size = cmd_size;
1929 tag_set->numa_node = NUMA_NO_NODE;
1930 tag_set->flags = BLK_MQ_F_SHOULD_MERGE;
1931 tag_set->flags |=
Shaohua Li24391c02015-01-23 14:18:00 -07001932 BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
Ye Bin840e1b52020-05-18 15:47:32 +08001933 tag_set->driver_data = shost;
Christoph Hellwigd2852032014-01-17 12:06:53 +01001934
Ye Bin840e1b52020-05-18 15:47:32 +08001935 return blk_mq_alloc_tag_set(tag_set);
Christoph Hellwigd2852032014-01-17 12:06:53 +01001936}
1937
1938void scsi_mq_destroy_tags(struct Scsi_Host *shost)
1939{
1940 blk_mq_free_tag_set(&shost->tag_set);
1941}
1942
Hannes Reinecke857de6e2017-02-17 09:02:45 +01001943/**
1944 * scsi_device_from_queue - return sdev associated with a request_queue
1945 * @q: The request queue to return the sdev from
1946 *
1947 * Return the sdev associated with a request queue or NULL if the
1948 * request_queue does not reference a SCSI device.
1949 */
1950struct scsi_device *scsi_device_from_queue(struct request_queue *q)
1951{
1952 struct scsi_device *sdev = NULL;
1953
Steffen Maier6b6fa7a2019-08-07 16:49:48 +02001954 if (q->mq_ops == &scsi_mq_ops_no_commit ||
1955 q->mq_ops == &scsi_mq_ops)
Hannes Reinecke857de6e2017-02-17 09:02:45 +01001956 sdev = q->queuedata;
1957 if (!sdev || !get_device(&sdev->sdev_gendev))
1958 sdev = NULL;
1959
1960 return sdev;
1961}
1962EXPORT_SYMBOL_GPL(scsi_device_from_queue);
1963
André Almeidaea941012020-04-19 02:01:48 -03001964/**
1965 * scsi_block_requests - Utility function used by low-level drivers to prevent
1966 * further commands from being queued to the device.
1967 * @shost: host in question
Linus Torvalds1da177e2005-04-16 15:20:36 -07001968 *
André Almeidaea941012020-04-19 02:01:48 -03001969 * There is no timer nor any other means by which the requests get unblocked
1970 * other than the low-level driver calling scsi_unblock_requests().
Linus Torvalds1da177e2005-04-16 15:20:36 -07001971 */
1972void scsi_block_requests(struct Scsi_Host *shost)
1973{
1974 shost->host_self_blocked = 1;
1975}
1976EXPORT_SYMBOL(scsi_block_requests);
1977
André Almeidaea941012020-04-19 02:01:48 -03001978/**
1979 * scsi_unblock_requests - Utility function used by low-level drivers to allow
1980 * further commands to be queued to the device.
1981 * @shost: host in question
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982 *
André Almeidaea941012020-04-19 02:01:48 -03001983 * There is no timer nor any other means by which the requests get unblocked
1984 * other than the low-level driver calling scsi_unblock_requests(). This is done
1985 * as an API function so that changes to the internals of the scsi mid-layer
1986 * won't require wholesale changes to drivers that use this feature.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001987 */
1988void scsi_unblock_requests(struct Scsi_Host *shost)
1989{
1990 shost->host_self_blocked = 0;
1991 scsi_run_host_queues(shost);
1992}
1993EXPORT_SYMBOL(scsi_unblock_requests);
1994
Linus Torvalds1da177e2005-04-16 15:20:36 -07001995void scsi_exit_queue(void)
1996{
Christoph Hellwig0a6ac4e2017-01-03 08:28:41 +03001997 kmem_cache_destroy(scsi_sense_cache);
1998 kmem_cache_destroy(scsi_sense_isadma_cache);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999}
James Bottomley5baba832006-03-18 14:10:35 -06002000
2001/**
2002 * scsi_mode_select - issue a mode select
2003 * @sdev: SCSI device to be queried
2004 * @pf: Page format bit (1 == standard, 0 == vendor specific)
2005 * @sp: Save page bit (0 == don't save, 1 == save)
2006 * @modepage: mode page being requested
2007 * @buffer: request buffer (may not be smaller than eight bytes)
2008 * @len: length of request buffer.
2009 * @timeout: command timeout
2010 * @retries: number of retries before failing
2011 * @data: returns a structure abstracting the mode header data
Rob Landleyeb448202007-11-03 13:30:39 -05002012 * @sshdr: place to put sense data (or NULL if no sense to be collected).
James Bottomley5baba832006-03-18 14:10:35 -06002013 * must be SCSI_SENSE_BUFFERSIZE big.
2014 *
2015 * Returns zero if successful; negative error number or scsi
2016 * status on error
2017 *
2018 */
2019int
2020scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
2021 unsigned char *buffer, int len, int timeout, int retries,
2022 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2023{
2024 unsigned char cmd[10];
2025 unsigned char *real_buffer;
2026 int ret;
2027
2028 memset(cmd, 0, sizeof(cmd));
2029 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
2030
2031 if (sdev->use_10_for_ms) {
2032 if (len > 65535)
2033 return -EINVAL;
2034 real_buffer = kmalloc(8 + len, GFP_KERNEL);
2035 if (!real_buffer)
2036 return -ENOMEM;
2037 memcpy(real_buffer + 8, buffer, len);
2038 len += 8;
2039 real_buffer[0] = 0;
2040 real_buffer[1] = 0;
2041 real_buffer[2] = data->medium_type;
2042 real_buffer[3] = data->device_specific;
2043 real_buffer[4] = data->longlba ? 0x01 : 0;
2044 real_buffer[5] = 0;
2045 real_buffer[6] = data->block_descriptor_length >> 8;
2046 real_buffer[7] = data->block_descriptor_length;
2047
2048 cmd[0] = MODE_SELECT_10;
2049 cmd[7] = len >> 8;
2050 cmd[8] = len;
2051 } else {
2052 if (len > 255 || data->block_descriptor_length > 255 ||
2053 data->longlba)
2054 return -EINVAL;
2055
2056 real_buffer = kmalloc(4 + len, GFP_KERNEL);
2057 if (!real_buffer)
2058 return -ENOMEM;
2059 memcpy(real_buffer + 4, buffer, len);
2060 len += 4;
2061 real_buffer[0] = 0;
2062 real_buffer[1] = data->medium_type;
2063 real_buffer[2] = data->device_specific;
2064 real_buffer[3] = data->block_descriptor_length;
James Bottomley5baba832006-03-18 14:10:35 -06002065
2066 cmd[0] = MODE_SELECT;
2067 cmd[4] = len;
2068 }
2069
2070 ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09002071 sshdr, timeout, retries, NULL);
James Bottomley5baba832006-03-18 14:10:35 -06002072 kfree(real_buffer);
2073 return ret;
2074}
2075EXPORT_SYMBOL_GPL(scsi_mode_select);
2076
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077/**
Rob Landleyeb448202007-11-03 13:30:39 -05002078 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
James Bottomley1cf72692005-08-28 11:27:01 -05002079 * @sdev: SCSI device to be queried
Linus Torvalds1da177e2005-04-16 15:20:36 -07002080 * @dbd: set if mode sense will allow block descriptors to be returned
2081 * @modepage: mode page being requested
2082 * @buffer: request buffer (may not be smaller than eight bytes)
2083 * @len: length of request buffer.
2084 * @timeout: command timeout
2085 * @retries: number of retries before failing
2086 * @data: returns a structure abstracting the mode header data
Rob Landleyeb448202007-11-03 13:30:39 -05002087 * @sshdr: place to put sense data (or NULL if no sense to be collected).
James Bottomley1cf72692005-08-28 11:27:01 -05002088 * must be SCSI_SENSE_BUFFERSIZE big.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002089 *
2090 * Returns zero if unsuccessful, or the header offset (either 4
2091 * or 8 depending on whether a six or ten byte command was
2092 * issued) if successful.
Rob Landleyeb448202007-11-03 13:30:39 -05002093 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002094int
James Bottomley1cf72692005-08-28 11:27:01 -05002095scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002096 unsigned char *buffer, int len, int timeout, int retries,
James Bottomley5baba832006-03-18 14:10:35 -06002097 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2098{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002099 unsigned char cmd[12];
2100 int use_10_for_ms;
2101 int header_length;
Hannes Reinecke0ae80ba2015-06-12 16:12:48 +02002102 int result, retry_count = retries;
James Bottomleyea73a9f2005-08-28 11:33:52 -05002103 struct scsi_sense_hdr my_sshdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002104
2105 memset(data, 0, sizeof(*data));
2106 memset(&cmd[0], 0, 12);
Can Guo0ec96912019-12-05 02:14:25 +00002107
2108 dbd = sdev->set_dbd_for_ms ? 8 : dbd;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */
2110 cmd[2] = modepage;
2111
James Bottomleyea73a9f2005-08-28 11:33:52 -05002112 /* caller might not be interested in sense, but we need it */
2113 if (!sshdr)
2114 sshdr = &my_sshdr;
2115
Linus Torvalds1da177e2005-04-16 15:20:36 -07002116 retry:
James Bottomley1cf72692005-08-28 11:27:01 -05002117 use_10_for_ms = sdev->use_10_for_ms;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002118
2119 if (use_10_for_ms) {
2120 if (len < 8)
2121 len = 8;
2122
2123 cmd[0] = MODE_SENSE_10;
2124 cmd[8] = len;
2125 header_length = 8;
2126 } else {
2127 if (len < 4)
2128 len = 4;
2129
2130 cmd[0] = MODE_SENSE;
2131 cmd[4] = len;
2132 header_length = 4;
2133 }
2134
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 memset(buffer, 0, len);
2136
James Bottomley1cf72692005-08-28 11:27:01 -05002137 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
FUJITA Tomonorif4f4e472008-12-04 14:24:39 +09002138 sshdr, timeout, retries, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002139
2140 /* This code looks awful: what it's doing is making sure an
2141 * ILLEGAL REQUEST sense return identifies the actual command
2142 * byte as the problem. MODE_SENSE commands can return
2143 * ILLEGAL REQUEST if the code page isn't supported */
2144
James Bottomley1cf72692005-08-28 11:27:01 -05002145 if (use_10_for_ms && !scsi_status_is_good(result) &&
Johannes Thumshirnc65be1a2018-06-25 13:20:58 +02002146 driver_byte(result) == DRIVER_SENSE) {
James Bottomleyea73a9f2005-08-28 11:33:52 -05002147 if (scsi_sense_valid(sshdr)) {
2148 if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
2149 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
Bean Huo4c7b4d62020-06-19 17:41:17 +02002150 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002151 * Invalid command operation code
2152 */
James Bottomley1cf72692005-08-28 11:27:01 -05002153 sdev->use_10_for_ms = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002154 goto retry;
2155 }
2156 }
2157 }
2158
Bean Huo4c7b4d62020-06-19 17:41:17 +02002159 if (scsi_status_is_good(result)) {
Al Viro6d73c852006-02-23 02:03:16 +01002160 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
2161 (modepage == 6 || modepage == 8))) {
2162 /* Initio breakage? */
2163 header_length = 0;
2164 data->length = 13;
2165 data->medium_type = 0;
2166 data->device_specific = 0;
2167 data->longlba = 0;
2168 data->block_descriptor_length = 0;
Bean Huo4c7b4d62020-06-19 17:41:17 +02002169 } else if (use_10_for_ms) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002170 data->length = buffer[0]*256 + buffer[1] + 2;
2171 data->medium_type = buffer[2];
2172 data->device_specific = buffer[3];
2173 data->longlba = buffer[4] & 0x01;
2174 data->block_descriptor_length = buffer[6]*256
2175 + buffer[7];
2176 } else {
2177 data->length = buffer[0] + 1;
2178 data->medium_type = buffer[1];
2179 data->device_specific = buffer[2];
2180 data->block_descriptor_length = buffer[3];
2181 }
Al Viro6d73c852006-02-23 02:03:16 +01002182 data->header_length = header_length;
Hannes Reinecke0ae80ba2015-06-12 16:12:48 +02002183 } else if ((status_byte(result) == CHECK_CONDITION) &&
2184 scsi_sense_valid(sshdr) &&
2185 sshdr->sense_key == UNIT_ATTENTION && retry_count) {
2186 retry_count--;
2187 goto retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002188 }
2189
James Bottomley1cf72692005-08-28 11:27:01 -05002190 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002191}
2192EXPORT_SYMBOL(scsi_mode_sense);
2193
James Bottomley001aac22007-12-02 19:10:40 +02002194/**
2195 * scsi_test_unit_ready - test if unit is ready
2196 * @sdev: scsi device to change the state of.
2197 * @timeout: command timeout
2198 * @retries: number of retries before failing
Christoph Hellwig74a78eb2017-02-14 20:15:57 +01002199 * @sshdr: outpout pointer for decoded sense information.
James Bottomley001aac22007-12-02 19:10:40 +02002200 *
2201 * Returns zero if unsuccessful or an error if TUR failed. For
Tejun Heo9f8a2c22010-12-08 20:57:40 +01002202 * removable media, UNIT_ATTENTION sets ->changed flag.
James Bottomley001aac22007-12-02 19:10:40 +02002203 **/
Linus Torvalds1da177e2005-04-16 15:20:36 -07002204int
James Bottomley001aac22007-12-02 19:10:40 +02002205scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
Christoph Hellwig74a78eb2017-02-14 20:15:57 +01002206 struct scsi_sense_hdr *sshdr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002207{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002208 char cmd[] = {
2209 TEST_UNIT_READY, 0, 0, 0, 0, 0,
2210 };
2211 int result;
James Bottomley001aac22007-12-02 19:10:40 +02002212
James Bottomley001aac22007-12-02 19:10:40 +02002213 /* try to eat the UNIT_ATTENTION if there are enough retries */
2214 do {
2215 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
Bart Van Assche9b91fd32018-02-12 10:57:52 -08002216 timeout, 1, NULL);
James Bottomley32c356d2008-08-20 00:58:13 +02002217 if (sdev->removable && scsi_sense_valid(sshdr) &&
2218 sshdr->sense_key == UNIT_ATTENTION)
2219 sdev->changed = 1;
2220 } while (scsi_sense_valid(sshdr) &&
2221 sshdr->sense_key == UNIT_ATTENTION && --retries);
James Bottomley001aac22007-12-02 19:10:40 +02002222
Linus Torvalds1da177e2005-04-16 15:20:36 -07002223 return result;
2224}
2225EXPORT_SYMBOL(scsi_test_unit_ready);
2226
2227/**
Rob Landleyeb448202007-11-03 13:30:39 -05002228 * scsi_device_set_state - Take the given device through the device state model.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002229 * @sdev: scsi device to change the state of.
2230 * @state: state to change to.
2231 *
Hannes Reinecke23cb27f2017-08-25 13:56:56 +02002232 * Returns zero if successful or an error if the requested
Linus Torvalds1da177e2005-04-16 15:20:36 -07002233 * transition is illegal.
Rob Landleyeb448202007-11-03 13:30:39 -05002234 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002235int
2236scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
2237{
2238 enum scsi_device_state oldstate = sdev->sdev_state;
2239
2240 if (state == oldstate)
2241 return 0;
2242
2243 switch (state) {
2244 case SDEV_CREATED:
James Bottomley6f4267e2008-08-22 16:53:31 -05002245 switch (oldstate) {
2246 case SDEV_CREATED_BLOCK:
2247 break;
2248 default:
2249 goto illegal;
2250 }
2251 break;
Bean Huo4c7b4d62020-06-19 17:41:17 +02002252
Linus Torvalds1da177e2005-04-16 15:20:36 -07002253 case SDEV_RUNNING:
2254 switch (oldstate) {
2255 case SDEV_CREATED:
2256 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002257 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002258 case SDEV_QUIESCE:
2259 case SDEV_BLOCK:
2260 break;
2261 default:
2262 goto illegal;
2263 }
2264 break;
2265
2266 case SDEV_QUIESCE:
2267 switch (oldstate) {
2268 case SDEV_RUNNING:
2269 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002270 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002271 break;
2272 default:
2273 goto illegal;
2274 }
2275 break;
2276
2277 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002278 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002279 switch (oldstate) {
2280 case SDEV_CREATED:
2281 case SDEV_RUNNING:
2282 case SDEV_QUIESCE:
2283 case SDEV_BLOCK:
2284 break;
2285 default:
2286 goto illegal;
2287 }
2288 break;
2289
2290 case SDEV_BLOCK:
2291 switch (oldstate) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002292 case SDEV_RUNNING:
James Bottomley6f4267e2008-08-22 16:53:31 -05002293 case SDEV_CREATED_BLOCK:
Dexuan Cui6cbb7ae2020-04-17 17:40:45 -07002294 case SDEV_QUIESCE:
Hannes Reineckea33e5bf2018-10-07 10:35:35 +02002295 case SDEV_OFFLINE:
James Bottomley6f4267e2008-08-22 16:53:31 -05002296 break;
2297 default:
2298 goto illegal;
2299 }
2300 break;
2301
2302 case SDEV_CREATED_BLOCK:
2303 switch (oldstate) {
2304 case SDEV_CREATED:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002305 break;
2306 default:
2307 goto illegal;
2308 }
2309 break;
2310
2311 case SDEV_CANCEL:
2312 switch (oldstate) {
2313 case SDEV_CREATED:
2314 case SDEV_RUNNING:
Alan Stern9ea72902006-06-23 14:25:34 -04002315 case SDEV_QUIESCE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002316 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002317 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002318 break;
2319 default:
2320 goto illegal;
2321 }
2322 break;
2323
2324 case SDEV_DEL:
2325 switch (oldstate) {
Brian King309bd272006-06-27 11:10:43 -05002326 case SDEV_CREATED:
2327 case SDEV_RUNNING:
2328 case SDEV_OFFLINE:
Mike Christie1b8d2622012-05-17 23:56:56 -05002329 case SDEV_TRANSPORT_OFFLINE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002330 case SDEV_CANCEL:
Bart Van Assche255ee932017-06-02 14:21:57 -07002331 case SDEV_BLOCK:
Bart Van Assche0516c082013-07-02 15:06:33 +02002332 case SDEV_CREATED_BLOCK:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002333 break;
2334 default:
2335 goto illegal;
2336 }
2337 break;
2338
2339 }
Ewan D. Milneb0962c52020-03-11 10:39:30 -04002340 sdev->offline_already = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002341 sdev->sdev_state = state;
2342 return 0;
2343
2344 illegal:
Hannes Reinecke91921e02014-06-25 16:39:59 +02002345 SCSI_LOG_ERROR_RECOVERY(1,
James Bottomley9ccfc752005-10-02 11:45:08 -05002346 sdev_printk(KERN_ERR, sdev,
Hannes Reinecke91921e02014-06-25 16:39:59 +02002347 "Illegal state transition %s->%s",
James Bottomley9ccfc752005-10-02 11:45:08 -05002348 scsi_device_state_name(oldstate),
2349 scsi_device_state_name(state))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002350 );
2351 return -EINVAL;
2352}
2353EXPORT_SYMBOL(scsi_device_set_state);
2354
2355/**
Jeff Garzika341cd02007-10-29 17:15:22 -04002356 * sdev_evt_emit - emit a single SCSI device uevent
2357 * @sdev: associated SCSI device
2358 * @evt: event to emit
2359 *
2360 * Send a single uevent (scsi_event) to the associated scsi_device.
2361 */
2362static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
2363{
2364 int idx = 0;
2365 char *envp[3];
2366
2367 switch (evt->evt_type) {
2368 case SDEV_EVT_MEDIA_CHANGE:
2369 envp[idx++] = "SDEV_MEDIA_CHANGE=1";
2370 break;
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002371 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
Hannes Reinecked3d32892016-02-19 09:17:16 +01002372 scsi_rescan_device(&sdev->sdev_gendev);
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002373 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
2374 break;
2375 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2376 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
2377 break;
2378 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2379 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED";
2380 break;
2381 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2382 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED";
2383 break;
2384 case SDEV_EVT_LUN_CHANGE_REPORTED:
2385 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
2386 break;
Hannes Reinecke14c3e672015-07-06 13:41:53 +02002387 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
2388 envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
2389 break;
Hannes Reineckecf3431b2017-10-17 09:11:24 +02002390 case SDEV_EVT_POWER_ON_RESET_OCCURRED:
2391 envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED";
2392 break;
Jeff Garzika341cd02007-10-29 17:15:22 -04002393 default:
2394 /* do nothing */
2395 break;
2396 }
2397
2398 envp[idx++] = NULL;
2399
2400 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
2401}
2402
2403/**
2404 * sdev_evt_thread - send a uevent for each scsi event
2405 * @work: work struct for scsi_device
2406 *
2407 * Dispatch queued events to their associated scsi_device kobjects
2408 * as uevents.
2409 */
2410void scsi_evt_thread(struct work_struct *work)
2411{
2412 struct scsi_device *sdev;
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002413 enum scsi_device_event evt_type;
Jeff Garzika341cd02007-10-29 17:15:22 -04002414 LIST_HEAD(event_list);
2415
2416 sdev = container_of(work, struct scsi_device, event_work);
2417
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002418 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++)
2419 if (test_and_clear_bit(evt_type, sdev->pending_events))
2420 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL);
2421
Jeff Garzika341cd02007-10-29 17:15:22 -04002422 while (1) {
2423 struct scsi_event *evt;
2424 struct list_head *this, *tmp;
2425 unsigned long flags;
2426
2427 spin_lock_irqsave(&sdev->list_lock, flags);
2428 list_splice_init(&sdev->event_list, &event_list);
2429 spin_unlock_irqrestore(&sdev->list_lock, flags);
2430
2431 if (list_empty(&event_list))
2432 break;
2433
2434 list_for_each_safe(this, tmp, &event_list) {
2435 evt = list_entry(this, struct scsi_event, node);
2436 list_del(&evt->node);
2437 scsi_evt_emit(sdev, evt);
2438 kfree(evt);
2439 }
2440 }
2441}
2442
2443/**
2444 * sdev_evt_send - send asserted event to uevent thread
2445 * @sdev: scsi_device event occurred on
2446 * @evt: event to send
2447 *
2448 * Assert scsi device event asynchronously.
2449 */
2450void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
2451{
2452 unsigned long flags;
2453
Kay Sievers4d1566e2008-03-19 13:04:47 +01002454#if 0
2455 /* FIXME: currently this check eliminates all media change events
2456 * for polled devices. Need to update to discriminate between AN
2457 * and polled events */
Jeff Garzika341cd02007-10-29 17:15:22 -04002458 if (!test_bit(evt->evt_type, sdev->supported_events)) {
2459 kfree(evt);
2460 return;
2461 }
Kay Sievers4d1566e2008-03-19 13:04:47 +01002462#endif
Jeff Garzika341cd02007-10-29 17:15:22 -04002463
2464 spin_lock_irqsave(&sdev->list_lock, flags);
2465 list_add_tail(&evt->node, &sdev->event_list);
2466 schedule_work(&sdev->event_work);
2467 spin_unlock_irqrestore(&sdev->list_lock, flags);
2468}
2469EXPORT_SYMBOL_GPL(sdev_evt_send);
2470
2471/**
2472 * sdev_evt_alloc - allocate a new scsi event
2473 * @evt_type: type of event to allocate
2474 * @gfpflags: GFP flags for allocation
2475 *
2476 * Allocates and returns a new scsi_event.
2477 */
2478struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
2479 gfp_t gfpflags)
2480{
2481 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
2482 if (!evt)
2483 return NULL;
2484
2485 evt->evt_type = evt_type;
2486 INIT_LIST_HEAD(&evt->node);
2487
2488 /* evt_type-specific initialization, if any */
2489 switch (evt_type) {
2490 case SDEV_EVT_MEDIA_CHANGE:
Ewan D. Milne279afdf2013-08-08 15:07:48 -04002491 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2492 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2493 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2494 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2495 case SDEV_EVT_LUN_CHANGE_REPORTED:
Hannes Reinecke14c3e672015-07-06 13:41:53 +02002496 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
Hannes Reineckecf3431b2017-10-17 09:11:24 +02002497 case SDEV_EVT_POWER_ON_RESET_OCCURRED:
Jeff Garzika341cd02007-10-29 17:15:22 -04002498 default:
2499 /* do nothing */
2500 break;
2501 }
2502
2503 return evt;
2504}
2505EXPORT_SYMBOL_GPL(sdev_evt_alloc);
2506
2507/**
2508 * sdev_evt_send_simple - send asserted event to uevent thread
2509 * @sdev: scsi_device event occurred on
2510 * @evt_type: type of event to send
2511 * @gfpflags: GFP flags for allocation
2512 *
2513 * Assert scsi device event asynchronously, given an event type.
2514 */
2515void sdev_evt_send_simple(struct scsi_device *sdev,
2516 enum scsi_device_event evt_type, gfp_t gfpflags)
2517{
2518 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
2519 if (!evt) {
2520 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
2521 evt_type);
2522 return;
2523 }
2524
2525 sdev_evt_send(sdev, evt);
2526}
2527EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
2528
2529/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07002530 * scsi_device_quiesce - Block user issued commands.
2531 * @sdev: scsi device to quiesce.
2532 *
2533 * This works by trying to transition to the SDEV_QUIESCE state
2534 * (which must be a legal transition). When the device is in this
2535 * state, only special requests will be accepted, all others will
2536 * be deferred. Since special requests may also be requeued requests,
Bean Huo4c7b4d62020-06-19 17:41:17 +02002537 * a successful return doesn't guarantee the device will be
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538 * totally quiescent.
2539 *
2540 * Must be called with user context, may sleep.
2541 *
2542 * Returns zero if unsuccessful or an error if not.
Rob Landleyeb448202007-11-03 13:30:39 -05002543 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002544int
2545scsi_device_quiesce(struct scsi_device *sdev)
2546{
Bart Van Assche3a0a5292017-11-09 10:49:58 -08002547 struct request_queue *q = sdev->request_queue;
Bart Van Assche0db6ca82017-06-02 14:21:55 -07002548 int err;
2549
Bart Van Assche3a0a5292017-11-09 10:49:58 -08002550 /*
2551 * It is allowed to call scsi_device_quiesce() multiple times from
2552 * the same context but concurrent scsi_device_quiesce() calls are
2553 * not allowed.
2554 */
2555 WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current);
2556
Bart Van Asschecd84a622018-09-26 14:01:04 -07002557 if (sdev->quiesced_by == current)
2558 return 0;
2559
2560 blk_set_pm_only(q);
Bart Van Assche3a0a5292017-11-09 10:49:58 -08002561
2562 blk_mq_freeze_queue(q);
2563 /*
Bart Van Asschecd84a622018-09-26 14:01:04 -07002564 * Ensure that the effect of blk_set_pm_only() will be visible
Bart Van Assche3a0a5292017-11-09 10:49:58 -08002565 * for percpu_ref_tryget() callers that occur after the queue
2566 * unfreeze even if the queue was already frozen before this function
2567 * was called. See also https://lwn.net/Articles/573497/.
2568 */
2569 synchronize_rcu();
2570 blk_mq_unfreeze_queue(q);
2571
Bart Van Assche0db6ca82017-06-02 14:21:55 -07002572 mutex_lock(&sdev->state_mutex);
2573 err = scsi_device_set_state(sdev, SDEV_QUIESCE);
Bart Van Assche3a0a5292017-11-09 10:49:58 -08002574 if (err == 0)
2575 sdev->quiesced_by = current;
2576 else
Bart Van Asschecd84a622018-09-26 14:01:04 -07002577 blk_clear_pm_only(q);
Bart Van Assche0db6ca82017-06-02 14:21:55 -07002578 mutex_unlock(&sdev->state_mutex);
2579
Bart Van Assche3a0a5292017-11-09 10:49:58 -08002580 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002581}
2582EXPORT_SYMBOL(scsi_device_quiesce);
2583
2584/**
2585 * scsi_device_resume - Restart user issued commands to a quiesced device.
2586 * @sdev: scsi device to resume.
2587 *
2588 * Moves the device from quiesced back to running and restarts the
2589 * queues.
2590 *
2591 * Must be called with user context, may sleep.
Rob Landleyeb448202007-11-03 13:30:39 -05002592 */
Dan Williamsa7a20d12012-03-22 17:05:11 -07002593void scsi_device_resume(struct scsi_device *sdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002594{
Dan Williamsa7a20d12012-03-22 17:05:11 -07002595 /* check if the device state was mutated prior to resume, and if
2596 * so assume the state is being managed elsewhere (for example
2597 * device deleted during suspend)
2598 */
Bart Van Assche0db6ca82017-06-02 14:21:55 -07002599 mutex_lock(&sdev->state_mutex);
Bart Van Assche17605af2019-03-15 16:27:58 -07002600 if (sdev->quiesced_by) {
2601 sdev->quiesced_by = NULL;
2602 blk_clear_pm_only(sdev->request_queue);
2603 }
Bart Van Assche3a0a5292017-11-09 10:49:58 -08002604 if (sdev->sdev_state == SDEV_QUIESCE)
2605 scsi_device_set_state(sdev, SDEV_RUNNING);
Bart Van Assche0db6ca82017-06-02 14:21:55 -07002606 mutex_unlock(&sdev->state_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002607}
2608EXPORT_SYMBOL(scsi_device_resume);
2609
2610static void
2611device_quiesce_fn(struct scsi_device *sdev, void *data)
2612{
2613 scsi_device_quiesce(sdev);
2614}
2615
2616void
2617scsi_target_quiesce(struct scsi_target *starget)
2618{
2619 starget_for_each_device(starget, NULL, device_quiesce_fn);
2620}
2621EXPORT_SYMBOL(scsi_target_quiesce);
2622
2623static void
2624device_resume_fn(struct scsi_device *sdev, void *data)
2625{
2626 scsi_device_resume(sdev);
2627}
2628
2629void
2630scsi_target_resume(struct scsi_target *starget)
2631{
2632 starget_for_each_device(starget, NULL, device_resume_fn);
2633}
2634EXPORT_SYMBOL(scsi_target_resume);
2635
2636/**
Bart Van Assche551eb592017-06-02 14:21:53 -07002637 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
2638 * @sdev: device to block
Linus Torvalds1da177e2005-04-16 15:20:36 -07002639 *
Bart Van Assche551eb592017-06-02 14:21:53 -07002640 * Pause SCSI command processing on the specified device. Does not sleep.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002641 *
Bart Van Assche551eb592017-06-02 14:21:53 -07002642 * Returns zero if successful or a negative error code upon failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002643 *
Bart Van Assche551eb592017-06-02 14:21:53 -07002644 * Notes:
2645 * This routine transitions the device to the SDEV_BLOCK state (which must be
2646 * a legal transition). When the device is in this state, command processing
2647 * is paused until the device leaves the SDEV_BLOCK state. See also
2648 * scsi_internal_device_unblock_nowait().
Rob Landleyeb448202007-11-03 13:30:39 -05002649 */
Bart Van Assche551eb592017-06-02 14:21:53 -07002650int scsi_internal_device_block_nowait(struct scsi_device *sdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002651{
Jens Axboe165125e2007-07-24 09:28:11 +02002652 struct request_queue *q = sdev->request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002653 int err = 0;
2654
2655 err = scsi_device_set_state(sdev, SDEV_BLOCK);
James Bottomley6f4267e2008-08-22 16:53:31 -05002656 if (err) {
2657 err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
2658
2659 if (err)
2660 return err;
2661 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002662
Bean Huo4c7b4d62020-06-19 17:41:17 +02002663 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002664 * The device has transitioned to SDEV_BLOCK. Stop the
2665 * block layer from calling the midlayer with this device's
Bean Huo4c7b4d62020-06-19 17:41:17 +02002666 * request queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002667 */
Jens Axboef664a3c2018-11-01 16:36:27 -06002668 blk_mq_quiesce_queue_nowait(q);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002669 return 0;
2670}
Bart Van Assche551eb592017-06-02 14:21:53 -07002671EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
2672
Linus Torvalds1da177e2005-04-16 15:20:36 -07002673/**
Bart Van Assche551eb592017-06-02 14:21:53 -07002674 * scsi_internal_device_block - try to transition to the SDEV_BLOCK state
2675 * @sdev: device to block
Linus Torvalds1da177e2005-04-16 15:20:36 -07002676 *
Bart Van Assche551eb592017-06-02 14:21:53 -07002677 * Pause SCSI command processing on the specified device and wait until all
2678 * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002679 *
Bart Van Assche551eb592017-06-02 14:21:53 -07002680 * Returns zero if successful or a negative error code upon failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002681 *
Bart Van Assche551eb592017-06-02 14:21:53 -07002682 * Note:
2683 * This routine transitions the device to the SDEV_BLOCK state (which must be
2684 * a legal transition). When the device is in this state, command processing
2685 * is paused until the device leaves the SDEV_BLOCK state. See also
2686 * scsi_internal_device_unblock().
Rob Landleyeb448202007-11-03 13:30:39 -05002687 */
Bart Van Assche551eb592017-06-02 14:21:53 -07002688static int scsi_internal_device_block(struct scsi_device *sdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002689{
Bart Van Assche551eb592017-06-02 14:21:53 -07002690 struct request_queue *q = sdev->request_queue;
2691 int err;
2692
Bart Van Assche0db6ca82017-06-02 14:21:55 -07002693 mutex_lock(&sdev->state_mutex);
Bart Van Assche551eb592017-06-02 14:21:53 -07002694 err = scsi_internal_device_block_nowait(sdev);
Jens Axboef664a3c2018-11-01 16:36:27 -06002695 if (err == 0)
2696 blk_mq_quiesce_queue(q);
Bart Van Assche0db6ca82017-06-02 14:21:55 -07002697 mutex_unlock(&sdev->state_mutex);
2698
Bart Van Assche551eb592017-06-02 14:21:53 -07002699 return err;
2700}
Bean Huo4c7b4d62020-06-19 17:41:17 +02002701
Bart Van Assche66483a42017-06-02 14:21:56 -07002702void scsi_start_queue(struct scsi_device *sdev)
2703{
2704 struct request_queue *q = sdev->request_queue;
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002705
Jens Axboef664a3c2018-11-01 16:36:27 -06002706 blk_mq_unquiesce_queue(q);
Bart Van Assche66483a42017-06-02 14:21:56 -07002707}
2708
Linus Torvalds1da177e2005-04-16 15:20:36 -07002709/**
Bart Van Assche43f75712017-06-02 14:21:54 -07002710 * scsi_internal_device_unblock_nowait - resume a device after a block request
Linus Torvalds1da177e2005-04-16 15:20:36 -07002711 * @sdev: device to resume
Bart Van Assche43f75712017-06-02 14:21:54 -07002712 * @new_state: state to set the device to after unblocking
Linus Torvalds1da177e2005-04-16 15:20:36 -07002713 *
Bart Van Assche43f75712017-06-02 14:21:54 -07002714 * Restart the device queue for a previously suspended SCSI device. Does not
2715 * sleep.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002716 *
Bart Van Assche43f75712017-06-02 14:21:54 -07002717 * Returns zero if successful or a negative error code upon failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002718 *
Bart Van Assche43f75712017-06-02 14:21:54 -07002719 * Notes:
2720 * This routine transitions the device to the SDEV_RUNNING state or to one of
2721 * the offline states (which must be a legal transition) allowing the midlayer
2722 * to goose the queue for this device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002723 */
Bart Van Assche43f75712017-06-02 14:21:54 -07002724int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
2725 enum scsi_device_state new_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002726{
Bart Van Assche09addb12019-08-01 15:38:12 -07002727 switch (new_state) {
2728 case SDEV_RUNNING:
2729 case SDEV_TRANSPORT_OFFLINE:
2730 break;
2731 default:
2732 return -EINVAL;
2733 }
2734
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002735 /*
2736 * Try to transition the scsi device to SDEV_RUNNING or one of the
2737 * offlined states and goose the device queue if successful.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002738 */
Hannes Reinecke8cd1ec72017-08-11 08:53:46 +02002739 switch (sdev->sdev_state) {
2740 case SDEV_BLOCK:
2741 case SDEV_TRANSPORT_OFFLINE:
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002742 sdev->sdev_state = new_state;
Hannes Reinecke8cd1ec72017-08-11 08:53:46 +02002743 break;
2744 case SDEV_CREATED_BLOCK:
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002745 if (new_state == SDEV_TRANSPORT_OFFLINE ||
2746 new_state == SDEV_OFFLINE)
2747 sdev->sdev_state = new_state;
2748 else
2749 sdev->sdev_state = SDEV_CREATED;
Hannes Reinecke8cd1ec72017-08-11 08:53:46 +02002750 break;
2751 case SDEV_CANCEL:
2752 case SDEV_OFFLINE:
2753 break;
2754 default:
Takahiro Yasui5c10e632009-04-29 12:13:02 -04002755 return -EINVAL;
Hannes Reinecke8cd1ec72017-08-11 08:53:46 +02002756 }
Bart Van Assche66483a42017-06-02 14:21:56 -07002757 scsi_start_queue(sdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002758
2759 return 0;
2760}
Bart Van Assche43f75712017-06-02 14:21:54 -07002761EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait);
2762
2763/**
2764 * scsi_internal_device_unblock - resume a device after a block request
2765 * @sdev: device to resume
2766 * @new_state: state to set the device to after unblocking
2767 *
2768 * Restart the device queue for a previously suspended SCSI device. May sleep.
2769 *
2770 * Returns zero if successful or a negative error code upon failure.
2771 *
2772 * Notes:
2773 * This routine transitions the device to the SDEV_RUNNING state or to one of
2774 * the offline states (which must be a legal transition) allowing the midlayer
2775 * to goose the queue for this device.
2776 */
2777static int scsi_internal_device_unblock(struct scsi_device *sdev,
2778 enum scsi_device_state new_state)
2779{
Bart Van Assche0db6ca82017-06-02 14:21:55 -07002780 int ret;
2781
2782 mutex_lock(&sdev->state_mutex);
2783 ret = scsi_internal_device_unblock_nowait(sdev, new_state);
2784 mutex_unlock(&sdev->state_mutex);
2785
2786 return ret;
Bart Van Assche43f75712017-06-02 14:21:54 -07002787}
Linus Torvalds1da177e2005-04-16 15:20:36 -07002788
2789static void
2790device_block(struct scsi_device *sdev, void *data)
2791{
Bart Van Assche94ef80a2019-08-01 15:38:13 -07002792 int ret;
2793
2794 ret = scsi_internal_device_block(sdev);
2795
2796 WARN_ONCE(ret, "scsi_internal_device_block(%s) failed: ret = %d\n",
2797 dev_name(&sdev->sdev_gendev), ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002798}
2799
2800static int
2801target_block(struct device *dev, void *data)
2802{
2803 if (scsi_is_target_device(dev))
2804 starget_for_each_device(to_scsi_target(dev), NULL,
2805 device_block);
2806 return 0;
2807}
2808
2809void
2810scsi_target_block(struct device *dev)
2811{
2812 if (scsi_is_target_device(dev))
2813 starget_for_each_device(to_scsi_target(dev), NULL,
2814 device_block);
2815 else
2816 device_for_each_child(dev, NULL, target_block);
2817}
2818EXPORT_SYMBOL_GPL(scsi_target_block);
2819
2820static void
2821device_unblock(struct scsi_device *sdev, void *data)
2822{
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002823 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002824}
2825
2826static int
2827target_unblock(struct device *dev, void *data)
2828{
2829 if (scsi_is_target_device(dev))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002830 starget_for_each_device(to_scsi_target(dev), data,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002831 device_unblock);
2832 return 0;
2833}
2834
2835void
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002836scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002837{
2838 if (scsi_is_target_device(dev))
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002839 starget_for_each_device(to_scsi_target(dev), &new_state,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002840 device_unblock);
2841 else
Mike Christie5d9fb5c2012-05-17 23:56:57 -05002842 device_for_each_child(dev, &new_state, target_unblock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002843}
2844EXPORT_SYMBOL_GPL(scsi_target_unblock);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002845
Hannes Reinecke2bb95582020-02-28 08:53:13 +01002846int
2847scsi_host_block(struct Scsi_Host *shost)
2848{
2849 struct scsi_device *sdev;
2850 int ret = 0;
2851
Ming Leif9836222020-04-23 10:07:13 +08002852 /*
2853 * Call scsi_internal_device_block_nowait so we can avoid
2854 * calling synchronize_rcu() for each LUN.
2855 */
Hannes Reinecke2bb95582020-02-28 08:53:13 +01002856 shost_for_each_device(sdev, shost) {
Ming Leif9836222020-04-23 10:07:13 +08002857 mutex_lock(&sdev->state_mutex);
2858 ret = scsi_internal_device_block_nowait(sdev);
2859 mutex_unlock(&sdev->state_mutex);
Ye Binf30785d2020-07-17 17:09:20 +08002860 if (ret) {
2861 scsi_device_put(sdev);
Hannes Reinecke2bb95582020-02-28 08:53:13 +01002862 break;
Ye Binf30785d2020-07-17 17:09:20 +08002863 }
Hannes Reinecke2bb95582020-02-28 08:53:13 +01002864 }
Ming Leif9836222020-04-23 10:07:13 +08002865
2866 /*
2867 * SCSI never enables blk-mq's BLK_MQ_F_BLOCKING flag so
2868 * calling synchronize_rcu() once is enough.
2869 */
2870 WARN_ON_ONCE(shost->tag_set.flags & BLK_MQ_F_BLOCKING);
2871
2872 if (!ret)
2873 synchronize_rcu();
2874
Hannes Reinecke2bb95582020-02-28 08:53:13 +01002875 return ret;
2876}
2877EXPORT_SYMBOL_GPL(scsi_host_block);
2878
2879int
2880scsi_host_unblock(struct Scsi_Host *shost, int new_state)
2881{
2882 struct scsi_device *sdev;
2883 int ret = 0;
2884
2885 shost_for_each_device(sdev, shost) {
2886 ret = scsi_internal_device_unblock(sdev, new_state);
Ye Bin4dea1702020-05-18 15:44:20 +08002887 if (ret) {
2888 scsi_device_put(sdev);
Hannes Reinecke2bb95582020-02-28 08:53:13 +01002889 break;
Ye Bin4dea1702020-05-18 15:44:20 +08002890 }
Hannes Reinecke2bb95582020-02-28 08:53:13 +01002891 }
2892 return ret;
2893}
2894EXPORT_SYMBOL_GPL(scsi_host_unblock);
2895
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002896/**
2897 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
Rob Landleyeb448202007-11-03 13:30:39 -05002898 * @sgl: scatter-gather list
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002899 * @sg_count: number of segments in sg
2900 * @offset: offset in bytes into sg, on return offset into the mapped area
2901 * @len: bytes to map, on return number of bytes mapped
2902 *
2903 * Returns virtual address of the start of the mapped page
2904 */
Jens Axboec6132da2007-10-16 11:08:49 +02002905void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002906 size_t *offset, size_t *len)
2907{
2908 int i;
2909 size_t sg_len = 0, len_complete = 0;
Jens Axboec6132da2007-10-16 11:08:49 +02002910 struct scatterlist *sg;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002911 struct page *page;
2912
Andrew Morton22cfefb2007-02-05 16:39:03 -08002913 WARN_ON(!irqs_disabled());
2914
Jens Axboec6132da2007-10-16 11:08:49 +02002915 for_each_sg(sgl, sg, sg_count, i) {
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002916 len_complete = sg_len; /* Complete sg-entries */
Jens Axboec6132da2007-10-16 11:08:49 +02002917 sg_len += sg->length;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002918 if (sg_len > *offset)
2919 break;
2920 }
2921
2922 if (unlikely(i == sg_count)) {
Andrew Morton169e1a22006-04-18 21:09:08 -07002923 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
2924 "elements %d\n",
Harvey Harrisoncadbd4a2008-07-03 23:47:27 -07002925 __func__, sg_len, *offset, sg_count);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002926 WARN_ON(1);
2927 return NULL;
2928 }
2929
2930 /* Offset starting from the beginning of first page in this sg-entry */
Jens Axboec6132da2007-10-16 11:08:49 +02002931 *offset = *offset - len_complete + sg->offset;
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002932
2933 /* Assumption: contiguous pages can be accessed as "page + i" */
Jens Axboe45711f12007-10-22 21:19:53 +02002934 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002935 *offset &= ~PAGE_MASK;
2936
2937 /* Bytes in this sg-entry from *offset to the end of the page */
2938 sg_len = PAGE_SIZE - *offset;
2939 if (*len > sg_len)
2940 *len = sg_len;
2941
Cong Wang77dfce02011-11-25 23:14:23 +08002942 return kmap_atomic(page);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002943}
2944EXPORT_SYMBOL(scsi_kmap_atomic_sg);
2945
2946/**
Rob Landleyeb448202007-11-03 13:30:39 -05002947 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002948 * @virt: virtual address to be unmapped
2949 */
2950void scsi_kunmap_atomic_sg(void *virt)
2951{
Cong Wang77dfce02011-11-25 23:14:23 +08002952 kunmap_atomic(virt);
Guennadi Liakhovetskicdb8c2a2006-04-02 21:57:43 +02002953}
2954EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
Aaron Lu6f4c8272013-01-23 15:09:32 +08002955
2956void sdev_disable_disk_events(struct scsi_device *sdev)
2957{
2958 atomic_inc(&sdev->disk_events_disable_depth);
2959}
2960EXPORT_SYMBOL(sdev_disable_disk_events);
2961
2962void sdev_enable_disk_events(struct scsi_device *sdev)
2963{
2964 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0))
2965 return;
2966 atomic_dec(&sdev->disk_events_disable_depth);
2967}
2968EXPORT_SYMBOL(sdev_enable_disk_events);
Hannes Reinecke9983bed2015-12-01 10:16:55 +01002969
2970/**
2971 * scsi_vpd_lun_id - return a unique device identification
2972 * @sdev: SCSI device
2973 * @id: buffer for the identification
2974 * @id_len: length of the buffer
2975 *
2976 * Copies a unique device identification into @id based
2977 * on the information in the VPD page 0x83 of the device.
2978 * The string will be formatted as a SCSI name string.
2979 *
2980 * Returns the length of the identification or error on failure.
2981 * If the identifier is longer than the supplied buffer the actual
2982 * identifier length is returned and the buffer is not zero-padded.
2983 */
2984int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
2985{
2986 u8 cur_id_type = 0xff;
2987 u8 cur_id_size = 0;
Bart Van Asscheccf1e002017-08-29 08:50:13 -07002988 const unsigned char *d, *cur_id_str;
2989 const struct scsi_vpd *vpd_pg83;
Hannes Reinecke9983bed2015-12-01 10:16:55 +01002990 int id_size = -EINVAL;
2991
2992 rcu_read_lock();
2993 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
2994 if (!vpd_pg83) {
2995 rcu_read_unlock();
2996 return -ENXIO;
2997 }
2998
2999 /*
3000 * Look for the correct descriptor.
3001 * Order of preference for lun descriptor:
3002 * - SCSI name string
3003 * - NAA IEEE Registered Extended
3004 * - EUI-64 based 16-byte
3005 * - EUI-64 based 12-byte
3006 * - NAA IEEE Registered
3007 * - NAA IEEE Extended
Hannes Reinecked2308232016-05-09 09:14:29 +02003008 * - T10 Vendor ID
Hannes Reinecke9983bed2015-12-01 10:16:55 +01003009 * as longer descriptors reduce the likelyhood
3010 * of identification clashes.
3011 */
3012
3013 /* The id string must be at least 20 bytes + terminating NULL byte */
3014 if (id_len < 21) {
3015 rcu_read_unlock();
3016 return -EINVAL;
3017 }
3018
3019 memset(id, 0, id_len);
Bart Van Asscheccf1e002017-08-29 08:50:13 -07003020 d = vpd_pg83->data + 4;
3021 while (d < vpd_pg83->data + vpd_pg83->len) {
Hannes Reinecke9983bed2015-12-01 10:16:55 +01003022 /* Skip designators not referring to the LUN */
3023 if ((d[1] & 0x30) != 0x00)
3024 goto next_desig;
3025
3026 switch (d[1] & 0xf) {
Hannes Reinecked2308232016-05-09 09:14:29 +02003027 case 0x1:
3028 /* T10 Vendor ID */
3029 if (cur_id_size > d[3])
3030 break;
3031 /* Prefer anything */
3032 if (cur_id_type > 0x01 && cur_id_type != 0xff)
3033 break;
3034 cur_id_size = d[3];
3035 if (cur_id_size + 4 > id_len)
3036 cur_id_size = id_len - 4;
3037 cur_id_str = d + 4;
3038 cur_id_type = d[1] & 0xf;
3039 id_size = snprintf(id, id_len, "t10.%*pE",
3040 cur_id_size, cur_id_str);
3041 break;
Hannes Reinecke9983bed2015-12-01 10:16:55 +01003042 case 0x2:
3043 /* EUI-64 */
3044 if (cur_id_size > d[3])
3045 break;
3046 /* Prefer NAA IEEE Registered Extended */
3047 if (cur_id_type == 0x3 &&
3048 cur_id_size == d[3])
3049 break;
3050 cur_id_size = d[3];
3051 cur_id_str = d + 4;
3052 cur_id_type = d[1] & 0xf;
3053 switch (cur_id_size) {
3054 case 8:
3055 id_size = snprintf(id, id_len,
3056 "eui.%8phN",
3057 cur_id_str);
3058 break;
3059 case 12:
3060 id_size = snprintf(id, id_len,
3061 "eui.%12phN",
3062 cur_id_str);
3063 break;
3064 case 16:
3065 id_size = snprintf(id, id_len,
3066 "eui.%16phN",
3067 cur_id_str);
3068 break;
3069 default:
3070 cur_id_size = 0;
3071 break;
3072 }
3073 break;
3074 case 0x3:
3075 /* NAA */
3076 if (cur_id_size > d[3])
3077 break;
3078 cur_id_size = d[3];
3079 cur_id_str = d + 4;
3080 cur_id_type = d[1] & 0xf;
3081 switch (cur_id_size) {
3082 case 8:
3083 id_size = snprintf(id, id_len,
3084 "naa.%8phN",
3085 cur_id_str);
3086 break;
3087 case 16:
3088 id_size = snprintf(id, id_len,
3089 "naa.%16phN",
3090 cur_id_str);
3091 break;
3092 default:
3093 cur_id_size = 0;
3094 break;
3095 }
3096 break;
3097 case 0x8:
3098 /* SCSI name string */
3099 if (cur_id_size + 4 > d[3])
3100 break;
3101 /* Prefer others for truncated descriptor */
3102 if (cur_id_size && d[3] > id_len)
3103 break;
3104 cur_id_size = id_size = d[3];
3105 cur_id_str = d + 4;
3106 cur_id_type = d[1] & 0xf;
3107 if (cur_id_size >= id_len)
3108 cur_id_size = id_len - 1;
3109 memcpy(id, cur_id_str, cur_id_size);
3110 /* Decrease priority for truncated descriptor */
3111 if (cur_id_size != id_size)
3112 cur_id_size = 6;
3113 break;
3114 default:
3115 break;
3116 }
3117next_desig:
3118 d += d[3] + 4;
3119 }
3120 rcu_read_unlock();
3121
3122 return id_size;
3123}
3124EXPORT_SYMBOL(scsi_vpd_lun_id);
Hannes Reineckea8aa3972015-12-01 10:16:57 +01003125
3126/*
3127 * scsi_vpd_tpg_id - return a target port group identifier
3128 * @sdev: SCSI device
3129 *
3130 * Returns the Target Port Group identifier from the information
3131 * froom VPD page 0x83 of the device.
3132 *
3133 * Returns the identifier or error on failure.
3134 */
3135int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id)
3136{
Bart Van Asscheccf1e002017-08-29 08:50:13 -07003137 const unsigned char *d;
3138 const struct scsi_vpd *vpd_pg83;
Hannes Reineckea8aa3972015-12-01 10:16:57 +01003139 int group_id = -EAGAIN, rel_port = -1;
3140
3141 rcu_read_lock();
3142 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3143 if (!vpd_pg83) {
3144 rcu_read_unlock();
3145 return -ENXIO;
3146 }
3147
Bart Van Asscheccf1e002017-08-29 08:50:13 -07003148 d = vpd_pg83->data + 4;
3149 while (d < vpd_pg83->data + vpd_pg83->len) {
Hannes Reineckea8aa3972015-12-01 10:16:57 +01003150 switch (d[1] & 0xf) {
3151 case 0x4:
3152 /* Relative target port */
3153 rel_port = get_unaligned_be16(&d[6]);
3154 break;
3155 case 0x5:
3156 /* Target port group */
3157 group_id = get_unaligned_be16(&d[6]);
3158 break;
3159 default:
3160 break;
3161 }
3162 d += d[3] + 4;
3163 }
3164 rcu_read_unlock();
3165
3166 if (group_id >= 0 && rel_id && rel_port != -1)
3167 *rel_id = rel_port;
3168
3169 return group_id;
3170}
3171EXPORT_SYMBOL(scsi_vpd_tpg_id);