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target: Drop lun_sep_lock for se_lun->lun_se_dev RCU usage
[karo-tx-linux.git] / drivers / target / target_core_pscsi.c
1 /*******************************************************************************
2  * Filename:  target_core_pscsi.c
3  *
4  * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
5  *
6  * (c) Copyright 2003-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25
26 #include <linux/string.h>
27 #include <linux/parser.h>
28 #include <linux/timer.h>
29 #include <linux/blkdev.h>
30 #include <linux/blk_types.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <linux/genhd.h>
34 #include <linux/cdrom.h>
35 #include <linux/ratelimit.h>
36 #include <linux/module.h>
37 #include <asm/unaligned.h>
38
39 #include <scsi/scsi.h>
40 #include <scsi/scsi_device.h>
41 #include <scsi/scsi_cmnd.h>
42 #include <scsi/scsi_host.h>
43 #include <scsi/scsi_tcq.h>
44
45 #include <target/target_core_base.h>
46 #include <target/target_core_backend.h>
47
48 #include "target_core_alua.h"
49 #include "target_core_internal.h"
50 #include "target_core_pscsi.h"
51
52 #define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
53
54 static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
55 {
56         return container_of(dev, struct pscsi_dev_virt, dev);
57 }
58
59 static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
60 static void pscsi_req_done(struct request *, int);
61
62 /*      pscsi_attach_hba():
63  *
64  *      pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
65  *      from the passed SCSI Host ID.
66  */
67 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
68 {
69         struct pscsi_hba_virt *phv;
70
71         phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
72         if (!phv) {
73                 pr_err("Unable to allocate struct pscsi_hba_virt\n");
74                 return -ENOMEM;
75         }
76         phv->phv_host_id = host_id;
77         phv->phv_mode = PHV_VIRTUAL_HOST_ID;
78
79         hba->hba_ptr = phv;
80
81         pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
82                 " Generic Target Core Stack %s\n", hba->hba_id,
83                 PSCSI_VERSION, TARGET_CORE_MOD_VERSION);
84         pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
85                hba->hba_id);
86
87         return 0;
88 }
89
90 static void pscsi_detach_hba(struct se_hba *hba)
91 {
92         struct pscsi_hba_virt *phv = hba->hba_ptr;
93         struct Scsi_Host *scsi_host = phv->phv_lld_host;
94
95         if (scsi_host) {
96                 scsi_host_put(scsi_host);
97
98                 pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
99                         " Generic Target Core\n", hba->hba_id,
100                         (scsi_host->hostt->name) ? (scsi_host->hostt->name) :
101                         "Unknown");
102         } else
103                 pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
104                         " from Generic Target Core\n", hba->hba_id);
105
106         kfree(phv);
107         hba->hba_ptr = NULL;
108 }
109
110 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
111 {
112         struct pscsi_hba_virt *phv = hba->hba_ptr;
113         struct Scsi_Host *sh = phv->phv_lld_host;
114         /*
115          * Release the struct Scsi_Host
116          */
117         if (!mode_flag) {
118                 if (!sh)
119                         return 0;
120
121                 phv->phv_lld_host = NULL;
122                 phv->phv_mode = PHV_VIRTUAL_HOST_ID;
123
124                 pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
125                         " %s\n", hba->hba_id, (sh->hostt->name) ?
126                         (sh->hostt->name) : "Unknown");
127
128                 scsi_host_put(sh);
129                 return 0;
130         }
131         /*
132          * Otherwise, locate struct Scsi_Host from the original passed
133          * pSCSI Host ID and enable for phba mode
134          */
135         sh = scsi_host_lookup(phv->phv_host_id);
136         if (!sh) {
137                 pr_err("pSCSI: Unable to locate SCSI Host for"
138                         " phv_host_id: %d\n", phv->phv_host_id);
139                 return -EINVAL;
140         }
141
142         phv->phv_lld_host = sh;
143         phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
144
145         pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
146                 hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
147
148         return 1;
149 }
150
151 static void pscsi_tape_read_blocksize(struct se_device *dev,
152                 struct scsi_device *sdev)
153 {
154         unsigned char cdb[MAX_COMMAND_SIZE], *buf;
155         int ret;
156
157         buf = kzalloc(12, GFP_KERNEL);
158         if (!buf)
159                 return;
160
161         memset(cdb, 0, MAX_COMMAND_SIZE);
162         cdb[0] = MODE_SENSE;
163         cdb[4] = 0x0c; /* 12 bytes */
164
165         ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
166                         HZ, 1, NULL);
167         if (ret)
168                 goto out_free;
169
170         /*
171          * If MODE_SENSE still returns zero, set the default value to 1024.
172          */
173         sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
174         if (!sdev->sector_size)
175                 sdev->sector_size = 1024;
176 out_free:
177         kfree(buf);
178 }
179
180 static void
181 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
182 {
183         unsigned char *buf;
184
185         if (sdev->inquiry_len < INQUIRY_LEN)
186                 return;
187
188         buf = sdev->inquiry;
189         if (!buf)
190                 return;
191         /*
192          * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
193          */
194         memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
195         memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
196         memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
197 }
198
199 static int
200 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
201 {
202         unsigned char cdb[MAX_COMMAND_SIZE], *buf;
203         int ret;
204
205         buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
206         if (!buf)
207                 return -ENOMEM;
208
209         memset(cdb, 0, MAX_COMMAND_SIZE);
210         cdb[0] = INQUIRY;
211         cdb[1] = 0x01; /* Query VPD */
212         cdb[2] = 0x80; /* Unit Serial Number */
213         cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
214         cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);
215
216         ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
217                               INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
218         if (ret)
219                 goto out_free;
220
221         snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
222
223         wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
224
225         kfree(buf);
226         return 0;
227
228 out_free:
229         kfree(buf);
230         return -EPERM;
231 }
232
233 static void
234 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
235                 struct t10_wwn *wwn)
236 {
237         unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
238         int ident_len, page_len, off = 4, ret;
239         struct t10_vpd *vpd;
240
241         buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
242         if (!buf)
243                 return;
244
245         memset(cdb, 0, MAX_COMMAND_SIZE);
246         cdb[0] = INQUIRY;
247         cdb[1] = 0x01; /* Query VPD */
248         cdb[2] = 0x83; /* Device Identifier */
249         cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
250         cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);
251
252         ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
253                               INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
254                               NULL, HZ, 1, NULL);
255         if (ret)
256                 goto out;
257
258         page_len = (buf[2] << 8) | buf[3];
259         while (page_len > 0) {
260                 /* Grab a pointer to the Identification descriptor */
261                 page_83 = &buf[off];
262                 ident_len = page_83[3];
263                 if (!ident_len) {
264                         pr_err("page_83[3]: identifier"
265                                         " length zero!\n");
266                         break;
267                 }
268                 pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
269
270                 vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
271                 if (!vpd) {
272                         pr_err("Unable to allocate memory for"
273                                         " struct t10_vpd\n");
274                         goto out;
275                 }
276                 INIT_LIST_HEAD(&vpd->vpd_list);
277
278                 transport_set_vpd_proto_id(vpd, page_83);
279                 transport_set_vpd_assoc(vpd, page_83);
280
281                 if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
282                         off += (ident_len + 4);
283                         page_len -= (ident_len + 4);
284                         kfree(vpd);
285                         continue;
286                 }
287                 if (transport_set_vpd_ident(vpd, page_83) < 0) {
288                         off += (ident_len + 4);
289                         page_len -= (ident_len + 4);
290                         kfree(vpd);
291                         continue;
292                 }
293
294                 list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
295                 off += (ident_len + 4);
296                 page_len -= (ident_len + 4);
297         }
298
299 out:
300         kfree(buf);
301 }
302
303 static int pscsi_add_device_to_list(struct se_device *dev,
304                 struct scsi_device *sd)
305 {
306         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
307         struct request_queue *q = sd->request_queue;
308
309         pdv->pdv_sd = sd;
310
311         if (!sd->queue_depth) {
312                 sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
313
314                 pr_err("Set broken SCSI Device %d:%d:%llu"
315                         " queue_depth to %d\n", sd->channel, sd->id,
316                                 sd->lun, sd->queue_depth);
317         }
318
319         dev->dev_attrib.hw_block_size = sd->sector_size;
320         dev->dev_attrib.hw_max_sectors =
321                 min_t(int, sd->host->max_sectors, queue_max_hw_sectors(q));
322         dev->dev_attrib.hw_queue_depth = sd->queue_depth;
323
324         /*
325          * Setup our standard INQUIRY info into se_dev->t10_wwn
326          */
327         pscsi_set_inquiry_info(sd, &dev->t10_wwn);
328
329         /*
330          * Locate VPD WWN Information used for various purposes within
331          * the Storage Engine.
332          */
333         if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
334                 /*
335                  * If VPD Unit Serial returned GOOD status, try
336                  * VPD Device Identification page (0x83).
337                  */
338                 pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
339         }
340
341         /*
342          * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
343          */
344         if (sd->type == TYPE_TAPE)
345                 pscsi_tape_read_blocksize(dev, sd);
346         return 0;
347 }
348
349 static struct se_device *pscsi_alloc_device(struct se_hba *hba,
350                 const char *name)
351 {
352         struct pscsi_dev_virt *pdv;
353
354         pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
355         if (!pdv) {
356                 pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
357                 return NULL;
358         }
359
360         pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
361         return &pdv->dev;
362 }
363
364 /*
365  * Called with struct Scsi_Host->host_lock called.
366  */
367 static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
368         __releases(sh->host_lock)
369 {
370         struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
371         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
372         struct Scsi_Host *sh = sd->host;
373         struct block_device *bd;
374         int ret;
375
376         if (scsi_device_get(sd)) {
377                 pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
378                         sh->host_no, sd->channel, sd->id, sd->lun);
379                 spin_unlock_irq(sh->host_lock);
380                 return -EIO;
381         }
382         spin_unlock_irq(sh->host_lock);
383         /*
384          * Claim exclusive struct block_device access to struct scsi_device
385          * for TYPE_DISK using supplied udev_path
386          */
387         bd = blkdev_get_by_path(dev->udev_path,
388                                 FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
389         if (IS_ERR(bd)) {
390                 pr_err("pSCSI: blkdev_get_by_path() failed\n");
391                 scsi_device_put(sd);
392                 return PTR_ERR(bd);
393         }
394         pdv->pdv_bd = bd;
395
396         ret = pscsi_add_device_to_list(dev, sd);
397         if (ret) {
398                 blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
399                 scsi_device_put(sd);
400                 return ret;
401         }
402
403         pr_debug("CORE_PSCSI[%d] - Added TYPE_DISK for %d:%d:%d:%llu\n",
404                 phv->phv_host_id, sh->host_no, sd->channel, sd->id, sd->lun);
405         return 0;
406 }
407
408 /*
409  * Called with struct Scsi_Host->host_lock called.
410  */
411 static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
412         __releases(sh->host_lock)
413 {
414         struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
415         struct Scsi_Host *sh = sd->host;
416         int ret;
417
418         if (scsi_device_get(sd)) {
419                 pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
420                         sh->host_no, sd->channel, sd->id, sd->lun);
421                 spin_unlock_irq(sh->host_lock);
422                 return -EIO;
423         }
424         spin_unlock_irq(sh->host_lock);
425
426         ret = pscsi_add_device_to_list(dev, sd);
427         if (ret) {
428                 scsi_device_put(sd);
429                 return ret;
430         }
431         pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
432                 phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
433                 sd->channel, sd->id, sd->lun);
434
435         return 0;
436 }
437
438 /*
439  * Called with struct Scsi_Host->host_lock called.
440  */
441 static int pscsi_create_type_other(struct se_device *dev,
442                 struct scsi_device *sd)
443         __releases(sh->host_lock)
444 {
445         struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
446         struct Scsi_Host *sh = sd->host;
447         int ret;
448
449         spin_unlock_irq(sh->host_lock);
450         ret = pscsi_add_device_to_list(dev, sd);
451         if (ret)
452                 return ret;
453
454         pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
455                 phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
456                 sd->channel, sd->id, sd->lun);
457         return 0;
458 }
459
460 static int pscsi_configure_device(struct se_device *dev)
461 {
462         struct se_hba *hba = dev->se_hba;
463         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
464         struct scsi_device *sd;
465         struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
466         struct Scsi_Host *sh = phv->phv_lld_host;
467         int legacy_mode_enable = 0;
468         int ret;
469
470         if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
471             !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
472             !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
473                 pr_err("Missing scsi_channel_id=, scsi_target_id= and"
474                         " scsi_lun_id= parameters\n");
475                 return -EINVAL;
476         }
477
478         /*
479          * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
480          * struct Scsi_Host we will need to bring the TCM/pSCSI object online
481          */
482         if (!sh) {
483                 if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
484                         pr_err("pSCSI: Unable to locate struct"
485                                 " Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
486                         return -ENODEV;
487                 }
488                 /*
489                  * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
490                  * reference, we enforce that udev_path has been set
491                  */
492                 if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
493                         pr_err("pSCSI: udev_path attribute has not"
494                                 " been set before ENABLE=1\n");
495                         return -EINVAL;
496                 }
497                 /*
498                  * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
499                  * use the original TCM hba ID to reference Linux/SCSI Host No
500                  * and enable for PHV_LLD_SCSI_HOST_NO mode.
501                  */
502                 if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
503                         if (hba->dev_count) {
504                                 pr_err("pSCSI: Unable to set hba_mode"
505                                         " with active devices\n");
506                                 return -EEXIST;
507                         }
508
509                         if (pscsi_pmode_enable_hba(hba, 1) != 1)
510                                 return -ENODEV;
511
512                         legacy_mode_enable = 1;
513                         hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
514                         sh = phv->phv_lld_host;
515                 } else {
516                         sh = scsi_host_lookup(pdv->pdv_host_id);
517                         if (!sh) {
518                                 pr_err("pSCSI: Unable to locate"
519                                         " pdv_host_id: %d\n", pdv->pdv_host_id);
520                                 return -EINVAL;
521                         }
522                         pdv->pdv_lld_host = sh;
523                 }
524         } else {
525                 if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
526                         pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
527                                 " struct Scsi_Host exists\n");
528                         return -EEXIST;
529                 }
530         }
531
532         spin_lock_irq(sh->host_lock);
533         list_for_each_entry(sd, &sh->__devices, siblings) {
534                 if ((pdv->pdv_channel_id != sd->channel) ||
535                     (pdv->pdv_target_id != sd->id) ||
536                     (pdv->pdv_lun_id != sd->lun))
537                         continue;
538                 /*
539                  * Functions will release the held struct scsi_host->host_lock
540                  * before calling calling pscsi_add_device_to_list() to register
541                  * struct scsi_device with target_core_mod.
542                  */
543                 switch (sd->type) {
544                 case TYPE_DISK:
545                         ret = pscsi_create_type_disk(dev, sd);
546                         break;
547                 case TYPE_ROM:
548                         ret = pscsi_create_type_rom(dev, sd);
549                         break;
550                 default:
551                         ret = pscsi_create_type_other(dev, sd);
552                         break;
553                 }
554
555                 if (ret) {
556                         if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
557                                 scsi_host_put(sh);
558                         else if (legacy_mode_enable) {
559                                 pscsi_pmode_enable_hba(hba, 0);
560                                 hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
561                         }
562                         pdv->pdv_sd = NULL;
563                         return ret;
564                 }
565                 return 0;
566         }
567         spin_unlock_irq(sh->host_lock);
568
569         pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
570                 pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
571
572         if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
573                 scsi_host_put(sh);
574         else if (legacy_mode_enable) {
575                 pscsi_pmode_enable_hba(hba, 0);
576                 hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
577         }
578
579         return -ENODEV;
580 }
581
582 static void pscsi_dev_call_rcu(struct rcu_head *p)
583 {
584         struct se_device *dev = container_of(p, struct se_device, rcu_head);
585         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
586
587         kfree(pdv);
588 }
589
590 static void pscsi_free_device(struct se_device *dev)
591 {
592         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
593         struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
594         struct scsi_device *sd = pdv->pdv_sd;
595
596         if (sd) {
597                 /*
598                  * Release exclusive pSCSI internal struct block_device claim for
599                  * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
600                  */
601                 if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
602                         blkdev_put(pdv->pdv_bd,
603                                    FMODE_WRITE|FMODE_READ|FMODE_EXCL);
604                         pdv->pdv_bd = NULL;
605                 }
606                 /*
607                  * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
608                  * to struct Scsi_Host now.
609                  */
610                 if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
611                     (phv->phv_lld_host != NULL))
612                         scsi_host_put(phv->phv_lld_host);
613                 else if (pdv->pdv_lld_host)
614                         scsi_host_put(pdv->pdv_lld_host);
615
616                 if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
617                         scsi_device_put(sd);
618
619                 pdv->pdv_sd = NULL;
620         }
621         call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
622 }
623
624 static void pscsi_transport_complete(struct se_cmd *cmd, struct scatterlist *sg,
625                                      unsigned char *sense_buffer)
626 {
627         struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
628         struct scsi_device *sd = pdv->pdv_sd;
629         int result;
630         struct pscsi_plugin_task *pt = cmd->priv;
631         unsigned char *cdb;
632         /*
633          * Special case for REPORT_LUNs handling where pscsi_plugin_task has
634          * not been allocated because TCM is handling the emulation directly.
635          */
636         if (!pt)
637                 return;
638
639         cdb = &pt->pscsi_cdb[0];
640         result = pt->pscsi_result;
641         /*
642          * Hack to make sure that Write-Protect modepage is set if R/O mode is
643          * forced.
644          */
645         if (!cmd->data_length)
646                 goto after_mode_sense;
647
648         if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
649              (status_byte(result) << 1) == SAM_STAT_GOOD) {
650                 bool read_only = target_lun_is_rdonly(cmd);
651
652                 if (read_only) {
653                         unsigned char *buf;
654
655                         buf = transport_kmap_data_sg(cmd);
656                         if (!buf)
657                                 ; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
658
659                         if (cdb[0] == MODE_SENSE_10) {
660                                 if (!(buf[3] & 0x80))
661                                         buf[3] |= 0x80;
662                         } else {
663                                 if (!(buf[2] & 0x80))
664                                         buf[2] |= 0x80;
665                         }
666
667                         transport_kunmap_data_sg(cmd);
668                 }
669         }
670 after_mode_sense:
671
672         if (sd->type != TYPE_TAPE || !cmd->data_length)
673                 goto after_mode_select;
674
675         /*
676          * Hack to correctly obtain the initiator requested blocksize for
677          * TYPE_TAPE.  Since this value is dependent upon each tape media,
678          * struct scsi_device->sector_size will not contain the correct value
679          * by default, so we go ahead and set it so
680          * TRANSPORT(dev)->get_blockdev() returns the correct value to the
681          * storage engine.
682          */
683         if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
684               (status_byte(result) << 1) == SAM_STAT_GOOD) {
685                 unsigned char *buf;
686                 u16 bdl;
687                 u32 blocksize;
688
689                 buf = sg_virt(&sg[0]);
690                 if (!buf) {
691                         pr_err("Unable to get buf for scatterlist\n");
692                         goto after_mode_select;
693                 }
694
695                 if (cdb[0] == MODE_SELECT)
696                         bdl = (buf[3]);
697                 else
698                         bdl = (buf[6] << 8) | (buf[7]);
699
700                 if (!bdl)
701                         goto after_mode_select;
702
703                 if (cdb[0] == MODE_SELECT)
704                         blocksize = (buf[9] << 16) | (buf[10] << 8) |
705                                         (buf[11]);
706                 else
707                         blocksize = (buf[13] << 16) | (buf[14] << 8) |
708                                         (buf[15]);
709
710                 sd->sector_size = blocksize;
711         }
712 after_mode_select:
713
714         if (sense_buffer && (status_byte(result) & CHECK_CONDITION)) {
715                 memcpy(sense_buffer, pt->pscsi_sense, TRANSPORT_SENSE_BUFFER);
716                 cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
717         }
718 }
719
720 enum {
721         Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
722         Opt_scsi_lun_id, Opt_err
723 };
724
725 static match_table_t tokens = {
726         {Opt_scsi_host_id, "scsi_host_id=%d"},
727         {Opt_scsi_channel_id, "scsi_channel_id=%d"},
728         {Opt_scsi_target_id, "scsi_target_id=%d"},
729         {Opt_scsi_lun_id, "scsi_lun_id=%d"},
730         {Opt_err, NULL}
731 };
732
733 static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
734                 const char *page, ssize_t count)
735 {
736         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
737         struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
738         char *orig, *ptr, *opts;
739         substring_t args[MAX_OPT_ARGS];
740         int ret = 0, arg, token;
741
742         opts = kstrdup(page, GFP_KERNEL);
743         if (!opts)
744                 return -ENOMEM;
745
746         orig = opts;
747
748         while ((ptr = strsep(&opts, ",\n")) != NULL) {
749                 if (!*ptr)
750                         continue;
751
752                 token = match_token(ptr, tokens, args);
753                 switch (token) {
754                 case Opt_scsi_host_id:
755                         if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
756                                 pr_err("PSCSI[%d]: Unable to accept"
757                                         " scsi_host_id while phv_mode =="
758                                         " PHV_LLD_SCSI_HOST_NO\n",
759                                         phv->phv_host_id);
760                                 ret = -EINVAL;
761                                 goto out;
762                         }
763                         ret = match_int(args, &arg);
764                         if (ret)
765                                 goto out;
766                         pdv->pdv_host_id = arg;
767                         pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
768                                 " %d\n", phv->phv_host_id, pdv->pdv_host_id);
769                         pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
770                         break;
771                 case Opt_scsi_channel_id:
772                         ret = match_int(args, &arg);
773                         if (ret)
774                                 goto out;
775                         pdv->pdv_channel_id = arg;
776                         pr_debug("PSCSI[%d]: Referencing SCSI Channel"
777                                 " ID: %d\n",  phv->phv_host_id,
778                                 pdv->pdv_channel_id);
779                         pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
780                         break;
781                 case Opt_scsi_target_id:
782                         ret = match_int(args, &arg);
783                         if (ret)
784                                 goto out;
785                         pdv->pdv_target_id = arg;
786                         pr_debug("PSCSI[%d]: Referencing SCSI Target"
787                                 " ID: %d\n", phv->phv_host_id,
788                                 pdv->pdv_target_id);
789                         pdv->pdv_flags |= PDF_HAS_TARGET_ID;
790                         break;
791                 case Opt_scsi_lun_id:
792                         ret = match_int(args, &arg);
793                         if (ret)
794                                 goto out;
795                         pdv->pdv_lun_id = arg;
796                         pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
797                                 " %d\n", phv->phv_host_id, pdv->pdv_lun_id);
798                         pdv->pdv_flags |= PDF_HAS_LUN_ID;
799                         break;
800                 default:
801                         break;
802                 }
803         }
804
805 out:
806         kfree(orig);
807         return (!ret) ? count : ret;
808 }
809
810 static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
811 {
812         struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
813         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
814         struct scsi_device *sd = pdv->pdv_sd;
815         unsigned char host_id[16];
816         ssize_t bl;
817         int i;
818
819         if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
820                 snprintf(host_id, 16, "%d", pdv->pdv_host_id);
821         else
822                 snprintf(host_id, 16, "PHBA Mode");
823
824         bl = sprintf(b, "SCSI Device Bus Location:"
825                 " Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
826                 pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
827                 host_id);
828
829         if (sd) {
830                 bl += sprintf(b + bl, "        ");
831                 bl += sprintf(b + bl, "Vendor: ");
832                 for (i = 0; i < 8; i++) {
833                         if (ISPRINT(sd->vendor[i]))   /* printable character? */
834                                 bl += sprintf(b + bl, "%c", sd->vendor[i]);
835                         else
836                                 bl += sprintf(b + bl, " ");
837                 }
838                 bl += sprintf(b + bl, " Model: ");
839                 for (i = 0; i < 16; i++) {
840                         if (ISPRINT(sd->model[i]))   /* printable character ? */
841                                 bl += sprintf(b + bl, "%c", sd->model[i]);
842                         else
843                                 bl += sprintf(b + bl, " ");
844                 }
845                 bl += sprintf(b + bl, " Rev: ");
846                 for (i = 0; i < 4; i++) {
847                         if (ISPRINT(sd->rev[i]))   /* printable character ? */
848                                 bl += sprintf(b + bl, "%c", sd->rev[i]);
849                         else
850                                 bl += sprintf(b + bl, " ");
851                 }
852                 bl += sprintf(b + bl, "\n");
853         }
854         return bl;
855 }
856
857 static void pscsi_bi_endio(struct bio *bio, int error)
858 {
859         bio_put(bio);
860 }
861
862 static inline struct bio *pscsi_get_bio(int nr_vecs)
863 {
864         struct bio *bio;
865         /*
866          * Use bio_malloc() following the comment in for bio -> struct request
867          * in block/blk-core.c:blk_make_request()
868          */
869         bio = bio_kmalloc(GFP_KERNEL, nr_vecs);
870         if (!bio) {
871                 pr_err("PSCSI: bio_kmalloc() failed\n");
872                 return NULL;
873         }
874         bio->bi_end_io = pscsi_bi_endio;
875
876         return bio;
877 }
878
879 static sense_reason_t
880 pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
881                 enum dma_data_direction data_direction, struct bio **hbio)
882 {
883         struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
884         struct bio *bio = NULL, *tbio = NULL;
885         struct page *page;
886         struct scatterlist *sg;
887         u32 data_len = cmd->data_length, i, len, bytes, off;
888         int nr_pages = (cmd->data_length + sgl[0].offset +
889                         PAGE_SIZE - 1) >> PAGE_SHIFT;
890         int nr_vecs = 0, rc;
891         int rw = (data_direction == DMA_TO_DEVICE);
892
893         *hbio = NULL;
894
895         pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
896
897         for_each_sg(sgl, sg, sgl_nents, i) {
898                 page = sg_page(sg);
899                 off = sg->offset;
900                 len = sg->length;
901
902                 pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
903                         page, len, off);
904
905                 /*
906                  * We only have one page of data in each sg element,
907                  * we can not cross a page boundary.
908                  */
909                 if (off + len > PAGE_SIZE)
910                         goto fail;
911
912                 if (len > 0 && data_len > 0) {
913                         bytes = min_t(unsigned int, len, PAGE_SIZE - off);
914                         bytes = min(bytes, data_len);
915
916                         if (!bio) {
917                                 nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
918                                 nr_pages -= nr_vecs;
919                                 /*
920                                  * Calls bio_kmalloc() and sets bio->bi_end_io()
921                                  */
922                                 bio = pscsi_get_bio(nr_vecs);
923                                 if (!bio)
924                                         goto fail;
925
926                                 if (rw)
927                                         bio->bi_rw |= REQ_WRITE;
928
929                                 pr_debug("PSCSI: Allocated bio: %p,"
930                                         " dir: %s nr_vecs: %d\n", bio,
931                                         (rw) ? "rw" : "r", nr_vecs);
932                                 /*
933                                  * Set *hbio pointer to handle the case:
934                                  * nr_pages > BIO_MAX_PAGES, where additional
935                                  * bios need to be added to complete a given
936                                  * command.
937                                  */
938                                 if (!*hbio)
939                                         *hbio = tbio = bio;
940                                 else
941                                         tbio = tbio->bi_next = bio;
942                         }
943
944                         pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
945                                 " bio: %p page: %p len: %d off: %d\n", i, bio,
946                                 page, len, off);
947
948                         rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
949                                         bio, page, bytes, off);
950                         if (rc != bytes)
951                                 goto fail;
952
953                         pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
954                                 bio->bi_vcnt, nr_vecs);
955
956                         if (bio->bi_vcnt > nr_vecs) {
957                                 pr_debug("PSCSI: Reached bio->bi_vcnt max:"
958                                         " %d i: %d bio: %p, allocating another"
959                                         " bio\n", bio->bi_vcnt, i, bio);
960                                 /*
961                                  * Clear the pointer so that another bio will
962                                  * be allocated with pscsi_get_bio() above, the
963                                  * current bio has already been set *tbio and
964                                  * bio->bi_next.
965                                  */
966                                 bio = NULL;
967                         }
968
969                         data_len -= bytes;
970                 }
971         }
972
973         return 0;
974 fail:
975         while (*hbio) {
976                 bio = *hbio;
977                 *hbio = (*hbio)->bi_next;
978                 bio_endio(bio, 0);      /* XXX: should be error */
979         }
980         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
981 }
982
983 static sense_reason_t
984 pscsi_parse_cdb(struct se_cmd *cmd)
985 {
986         if (cmd->se_cmd_flags & SCF_BIDI)
987                 return TCM_UNSUPPORTED_SCSI_OPCODE;
988
989         return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
990 }
991
992 static sense_reason_t
993 pscsi_execute_cmd(struct se_cmd *cmd)
994 {
995         struct scatterlist *sgl = cmd->t_data_sg;
996         u32 sgl_nents = cmd->t_data_nents;
997         enum dma_data_direction data_direction = cmd->data_direction;
998         struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
999         struct pscsi_plugin_task *pt;
1000         struct request *req;
1001         struct bio *hbio;
1002         sense_reason_t ret;
1003
1004         /*
1005          * Dynamically alloc cdb space, since it may be larger than
1006          * TCM_MAX_COMMAND_SIZE
1007          */
1008         pt = kzalloc(sizeof(*pt) + scsi_command_size(cmd->t_task_cdb), GFP_KERNEL);
1009         if (!pt) {
1010                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1011         }
1012         cmd->priv = pt;
1013
1014         memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
1015                 scsi_command_size(cmd->t_task_cdb));
1016
1017         if (!sgl) {
1018                 req = blk_get_request(pdv->pdv_sd->request_queue,
1019                                 (data_direction == DMA_TO_DEVICE),
1020                                 GFP_KERNEL);
1021                 if (IS_ERR(req)) {
1022                         pr_err("PSCSI: blk_get_request() failed\n");
1023                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1024                         goto fail;
1025                 }
1026
1027                 blk_rq_set_block_pc(req);
1028         } else {
1029                 BUG_ON(!cmd->data_length);
1030
1031                 ret = pscsi_map_sg(cmd, sgl, sgl_nents, data_direction, &hbio);
1032                 if (ret)
1033                         goto fail;
1034
1035                 req = blk_make_request(pdv->pdv_sd->request_queue, hbio,
1036                                        GFP_KERNEL);
1037                 if (IS_ERR(req)) {
1038                         pr_err("pSCSI: blk_make_request() failed\n");
1039                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1040                         goto fail_free_bio;
1041                 }
1042         }
1043
1044         req->end_io = pscsi_req_done;
1045         req->end_io_data = cmd;
1046         req->cmd_len = scsi_command_size(pt->pscsi_cdb);
1047         req->cmd = &pt->pscsi_cdb[0];
1048         req->sense = &pt->pscsi_sense[0];
1049         req->sense_len = 0;
1050         if (pdv->pdv_sd->type == TYPE_DISK)
1051                 req->timeout = PS_TIMEOUT_DISK;
1052         else
1053                 req->timeout = PS_TIMEOUT_OTHER;
1054         req->retries = PS_RETRY;
1055
1056         blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, req,
1057                         (cmd->sam_task_attr == TCM_HEAD_TAG),
1058                         pscsi_req_done);
1059
1060         return 0;
1061
1062 fail_free_bio:
1063         while (hbio) {
1064                 struct bio *bio = hbio;
1065                 hbio = hbio->bi_next;
1066                 bio_endio(bio, 0);      /* XXX: should be error */
1067         }
1068         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1069 fail:
1070         kfree(pt);
1071         return ret;
1072 }
1073
1074 /*      pscsi_get_device_type():
1075  *
1076  *
1077  */
1078 static u32 pscsi_get_device_type(struct se_device *dev)
1079 {
1080         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1081         struct scsi_device *sd = pdv->pdv_sd;
1082
1083         return (sd) ? sd->type : TYPE_NO_LUN;
1084 }
1085
1086 static sector_t pscsi_get_blocks(struct se_device *dev)
1087 {
1088         struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1089
1090         if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1091                 return pdv->pdv_bd->bd_part->nr_sects;
1092
1093         dump_stack();
1094         return 0;
1095 }
1096
1097 static void pscsi_req_done(struct request *req, int uptodate)
1098 {
1099         struct se_cmd *cmd = req->end_io_data;
1100         struct pscsi_plugin_task *pt = cmd->priv;
1101
1102         pt->pscsi_result = req->errors;
1103         pt->pscsi_resid = req->resid_len;
1104
1105         cmd->scsi_status = status_byte(pt->pscsi_result) << 1;
1106         if (cmd->scsi_status) {
1107                 pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1108                         " 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1109                         pt->pscsi_result);
1110         }
1111
1112         switch (host_byte(pt->pscsi_result)) {
1113         case DID_OK:
1114                 target_complete_cmd(cmd, cmd->scsi_status);
1115                 break;
1116         default:
1117                 pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1118                         " 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1119                         pt->pscsi_result);
1120                 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1121                 break;
1122         }
1123
1124         __blk_put_request(req->q, req);
1125         kfree(pt);
1126 }
1127
1128 static const struct target_backend_ops pscsi_ops = {
1129         .name                   = "pscsi",
1130         .owner                  = THIS_MODULE,
1131         .transport_flags        = TRANSPORT_FLAG_PASSTHROUGH,
1132         .attach_hba             = pscsi_attach_hba,
1133         .detach_hba             = pscsi_detach_hba,
1134         .pmode_enable_hba       = pscsi_pmode_enable_hba,
1135         .alloc_device           = pscsi_alloc_device,
1136         .configure_device       = pscsi_configure_device,
1137         .free_device            = pscsi_free_device,
1138         .transport_complete     = pscsi_transport_complete,
1139         .parse_cdb              = pscsi_parse_cdb,
1140         .set_configfs_dev_params = pscsi_set_configfs_dev_params,
1141         .show_configfs_dev_params = pscsi_show_configfs_dev_params,
1142         .get_device_type        = pscsi_get_device_type,
1143         .get_blocks             = pscsi_get_blocks,
1144         .tb_dev_attrib_attrs    = passthrough_attrib_attrs,
1145 };
1146
1147 static int __init pscsi_module_init(void)
1148 {
1149         return transport_backend_register(&pscsi_ops);
1150 }
1151
1152 static void __exit pscsi_module_exit(void)
1153 {
1154         target_backend_unregister(&pscsi_ops);
1155 }
1156
1157 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1158 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1159 MODULE_LICENSE("GPL");
1160
1161 module_init(pscsi_module_init);
1162 module_exit(pscsi_module_exit);