/
st.c
4496 lines (3907 loc) · 122 KB
/
st.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
file Documentation/scsi/st.txt for more information.
History:
Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
Contribution and ideas from several people including (in alphabetical
order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
Michael Schaefer, J"org Weule, and Eric Youngdale.
Copyright 1992 - 2007 Kai Makisara
email Kai.Makisara@kolumbus.fi
Some small formal changes - aeb, 950809
Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
*/
static const char *verstr = "20070203";
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mtio.h>
#include <linux/cdrom.h>
#include <linux/ioctl.h>
#include <linux/fcntl.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/moduleparam.h>
#include <linux/cdev.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include <asm/dma.h>
#include <asm/system.h>
#include <scsi/scsi.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/sg.h>
/* The driver prints some debugging information on the console if DEBUG
is defined and non-zero. */
#define DEBUG 0
#if DEBUG
/* The message level for the debug messages is currently set to KERN_NOTICE
so that people can easily see the messages. Later when the debugging messages
in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
#define ST_DEB_MSG KERN_NOTICE
#define DEB(a) a
#define DEBC(a) if (debugging) { a ; }
#else
#define DEB(a)
#define DEBC(a)
#endif
#define ST_KILOBYTE 1024
#include "st_options.h"
#include "st.h"
static int buffer_kbs;
static int max_sg_segs;
static int try_direct_io = TRY_DIRECT_IO;
static int try_rdio = 1;
static int try_wdio = 1;
static int st_dev_max;
static int st_nr_dev;
static struct class *st_sysfs_class;
MODULE_AUTHOR("Kai Makisara");
MODULE_DESCRIPTION("SCSI tape (st) driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
/* Set 'perm' (4th argument) to 0 to disable module_param's definition
* of sysfs parameters (which module_param doesn't yet support).
* Sysfs parameters defined explicitly later.
*/
module_param_named(buffer_kbs, buffer_kbs, int, 0);
MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
module_param_named(max_sg_segs, max_sg_segs, int, 0);
MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
module_param_named(try_direct_io, try_direct_io, int, 0);
MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
/* Extra parameters for testing */
module_param_named(try_rdio, try_rdio, int, 0);
MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
module_param_named(try_wdio, try_wdio, int, 0);
MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
#ifndef MODULE
static int write_threshold_kbs; /* retained for compatibility */
static struct st_dev_parm {
char *name;
int *val;
} parms[] __initdata = {
{
"buffer_kbs", &buffer_kbs
},
{ /* Retained for compatibility with 2.4 */
"write_threshold_kbs", &write_threshold_kbs
},
{
"max_sg_segs", NULL
},
{
"try_direct_io", &try_direct_io
}
};
#endif
/* Restrict the number of modes so that names for all are assigned */
#if ST_NBR_MODES > 16
#error "Maximum number of modes is 16"
#endif
/* Bit reversed order to get same names for same minors with all
mode counts */
static const char *st_formats[] = {
"", "r", "k", "s", "l", "t", "o", "u",
"m", "v", "p", "x", "a", "y", "q", "z"};
/* The default definitions have been moved to st_options.h */
#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
/* The buffer size should fit into the 24 bits for length in the
6-byte SCSI read and write commands. */
#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
#endif
static int debugging = DEBUG;
#define MAX_RETRIES 0
#define MAX_WRITE_RETRIES 0
#define MAX_READY_RETRIES 0
#define NO_TAPE NOT_READY
#define ST_TIMEOUT (900 * HZ)
#define ST_LONG_TIMEOUT (14000 * HZ)
/* Remove mode bits and auto-rewind bit (7) */
#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
(iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
(d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
24 bits) */
#define SET_DENS_AND_BLK 0x10001
static DEFINE_RWLOCK(st_dev_arr_lock);
static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
static int st_max_sg_segs = ST_MAX_SG;
static struct scsi_tape **scsi_tapes = NULL;
static int modes_defined;
static struct st_buffer *new_tape_buffer(int, int, int);
static int enlarge_buffer(struct st_buffer *, int, int);
static void normalize_buffer(struct st_buffer *);
static int append_to_buffer(const char __user *, struct st_buffer *, int);
static int from_buffer(struct st_buffer *, char __user *, int);
static void move_buffer_data(struct st_buffer *, int);
static void buf_to_sg(struct st_buffer *, unsigned int);
static int sgl_map_user_pages(struct scatterlist *, const unsigned int,
unsigned long, size_t, int);
static int sgl_unmap_user_pages(struct scatterlist *, const unsigned int, int);
static int st_probe(struct device *);
static int st_remove(struct device *);
static int do_create_sysfs_files(void);
static void do_remove_sysfs_files(void);
static int do_create_class_files(struct scsi_tape *, int, int);
static struct scsi_driver st_template = {
.owner = THIS_MODULE,
.gendrv = {
.name = "st",
.probe = st_probe,
.remove = st_remove,
},
};
static int st_compression(struct scsi_tape *, int);
static int find_partition(struct scsi_tape *);
static int switch_partition(struct scsi_tape *);
static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
static void scsi_tape_release(struct kref *);
#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
static DEFINE_MUTEX(st_ref_mutex);
#include "osst_detect.h"
#ifndef SIGS_FROM_OSST
#define SIGS_FROM_OSST \
{"OnStream", "SC-", "", "osst"}, \
{"OnStream", "DI-", "", "osst"}, \
{"OnStream", "DP-", "", "osst"}, \
{"OnStream", "USB", "", "osst"}, \
{"OnStream", "FW-", "", "osst"}
#endif
static struct scsi_tape *scsi_tape_get(int dev)
{
struct scsi_tape *STp = NULL;
mutex_lock(&st_ref_mutex);
write_lock(&st_dev_arr_lock);
if (dev < st_dev_max && scsi_tapes != NULL)
STp = scsi_tapes[dev];
if (!STp) goto out;
kref_get(&STp->kref);
if (!STp->device)
goto out_put;
if (scsi_device_get(STp->device))
goto out_put;
goto out;
out_put:
kref_put(&STp->kref, scsi_tape_release);
STp = NULL;
out:
write_unlock(&st_dev_arr_lock);
mutex_unlock(&st_ref_mutex);
return STp;
}
static void scsi_tape_put(struct scsi_tape *STp)
{
struct scsi_device *sdev = STp->device;
mutex_lock(&st_ref_mutex);
kref_put(&STp->kref, scsi_tape_release);
scsi_device_put(sdev);
mutex_unlock(&st_ref_mutex);
}
struct st_reject_data {
char *vendor;
char *model;
char *rev;
char *driver_hint; /* Name of the correct driver, NULL if unknown */
};
static struct st_reject_data reject_list[] = {
/* {"XXX", "Yy-", "", NULL}, example */
SIGS_FROM_OSST,
{NULL, }};
/* If the device signature is on the list of incompatible drives, the
function returns a pointer to the name of the correct driver (if known) */
static char * st_incompatible(struct scsi_device* SDp)
{
struct st_reject_data *rp;
for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
!strncmp(rp->model, SDp->model, strlen(rp->model)) &&
!strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
if (rp->driver_hint)
return rp->driver_hint;
else
return "unknown";
}
return NULL;
}
static inline char *tape_name(struct scsi_tape *tape)
{
return tape->disk->disk_name;
}
static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
{
const u8 *ucp;
const u8 *sense = SRpnt->sense;
s->have_sense = scsi_normalize_sense(SRpnt->sense,
SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
s->flags = 0;
if (s->have_sense) {
s->deferred = 0;
s->remainder_valid =
scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
switch (sense[0] & 0x7f) {
case 0x71:
s->deferred = 1;
case 0x70:
s->fixed_format = 1;
s->flags = sense[2] & 0xe0;
break;
case 0x73:
s->deferred = 1;
case 0x72:
s->fixed_format = 0;
ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
s->flags = ucp ? (ucp[3] & 0xe0) : 0;
break;
}
}
}
/* Convert the result to success code */
static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
{
int result = SRpnt->result;
u8 scode;
DEB(const char *stp;)
char *name = tape_name(STp);
struct st_cmdstatus *cmdstatp;
if (!result)
return 0;
cmdstatp = &STp->buffer->cmdstat;
st_analyze_sense(SRpnt, cmdstatp);
if (cmdstatp->have_sense)
scode = STp->buffer->cmdstat.sense_hdr.sense_key;
else
scode = 0;
DEB(
if (debugging) {
printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x\n",
name, result,
SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
if (cmdstatp->have_sense)
__scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
} ) /* end DEB */
if (!debugging) { /* Abnormal conditions for tape */
if (!cmdstatp->have_sense)
printk(KERN_WARNING
"%s: Error %x (sugg. bt 0x%x, driver bt 0x%x, host bt 0x%x).\n",
name, result, suggestion(result),
driver_byte(result) & DRIVER_MASK, host_byte(result));
else if (cmdstatp->have_sense &&
scode != NO_SENSE &&
scode != RECOVERED_ERROR &&
/* scode != UNIT_ATTENTION && */
scode != BLANK_CHECK &&
scode != VOLUME_OVERFLOW &&
SRpnt->cmd[0] != MODE_SENSE &&
SRpnt->cmd[0] != TEST_UNIT_READY) {
__scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
}
}
if (cmdstatp->fixed_format &&
STp->cln_mode >= EXTENDED_SENSE_START) { /* Only fixed format sense */
if (STp->cln_sense_value)
STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
STp->cln_sense_mask) == STp->cln_sense_value);
else
STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
STp->cln_sense_mask) != 0);
}
if (cmdstatp->have_sense &&
cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
STp->pos_unknown |= STp->device->was_reset;
if (cmdstatp->have_sense &&
scode == RECOVERED_ERROR
#if ST_RECOVERED_WRITE_FATAL
&& SRpnt->cmd[0] != WRITE_6
&& SRpnt->cmd[0] != WRITE_FILEMARKS
#endif
) {
STp->recover_count++;
STp->recover_reg++;
DEB(
if (debugging) {
if (SRpnt->cmd[0] == READ_6)
stp = "read";
else if (SRpnt->cmd[0] == WRITE_6)
stp = "write";
else
stp = "ioctl";
printk(ST_DEB_MSG "%s: Recovered %s error (%d).\n", name, stp,
STp->recover_count);
} ) /* end DEB */
if (cmdstatp->flags == 0)
return 0;
}
return (-EIO);
}
/* Wakeup from interrupt */
static void st_sleep_done(void *data, char *sense, int result, int resid)
{
struct st_request *SRpnt = data;
struct scsi_tape *STp = SRpnt->stp;
memcpy(SRpnt->sense, sense, SCSI_SENSE_BUFFERSIZE);
(STp->buffer)->cmdstat.midlevel_result = SRpnt->result = result;
DEB( STp->write_pending = 0; )
if (SRpnt->waiting)
complete(SRpnt->waiting);
}
static struct st_request *st_allocate_request(void)
{
return kzalloc(sizeof(struct st_request), GFP_KERNEL);
}
static void st_release_request(struct st_request *streq)
{
kfree(streq);
}
/* Do the scsi command. Waits until command performed if do_wait is true.
Otherwise write_behind_check() is used to check that the command
has finished. */
static struct st_request *
st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
int bytes, int direction, int timeout, int retries, int do_wait)
{
struct completion *waiting;
/* if async, make sure there's no command outstanding */
if (!do_wait && ((STp->buffer)->last_SRpnt)) {
printk(KERN_ERR "%s: Async command already active.\n",
tape_name(STp));
if (signal_pending(current))
(STp->buffer)->syscall_result = (-EINTR);
else
(STp->buffer)->syscall_result = (-EBUSY);
return NULL;
}
if (SRpnt == NULL) {
SRpnt = st_allocate_request();
if (SRpnt == NULL) {
DEBC( printk(KERN_ERR "%s: Can't get SCSI request.\n",
tape_name(STp)); );
if (signal_pending(current))
(STp->buffer)->syscall_result = (-EINTR);
else
(STp->buffer)->syscall_result = (-EBUSY);
return NULL;
}
SRpnt->stp = STp;
}
/* If async IO, set last_SRpnt. This ptr tells write_behind_check
which IO is outstanding. It's nulled out when the IO completes. */
if (!do_wait)
(STp->buffer)->last_SRpnt = SRpnt;
waiting = &STp->wait;
init_completion(waiting);
SRpnt->waiting = waiting;
if (!STp->buffer->do_dio)
buf_to_sg(STp->buffer, bytes);
memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
STp->buffer->cmdstat.have_sense = 0;
STp->buffer->syscall_result = 0;
if (scsi_execute_async(STp->device, cmd, COMMAND_SIZE(cmd[0]), direction,
&((STp->buffer)->sg[0]), bytes, (STp->buffer)->sg_segs,
timeout, retries, SRpnt, st_sleep_done, GFP_KERNEL)) {
/* could not allocate the buffer or request was too large */
(STp->buffer)->syscall_result = (-EBUSY);
(STp->buffer)->last_SRpnt = NULL;
}
else if (do_wait) {
wait_for_completion(waiting);
SRpnt->waiting = NULL;
(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
}
return SRpnt;
}
/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
write has been correct but EOM early warning reached, -EIO if write ended in
error or zero if write successful. Asynchronous writes are used only in
variable block mode. */
static int write_behind_check(struct scsi_tape * STp)
{
int retval = 0;
struct st_buffer *STbuffer;
struct st_partstat *STps;
struct st_cmdstatus *cmdstatp;
struct st_request *SRpnt;
STbuffer = STp->buffer;
if (!STbuffer->writing)
return 0;
DEB(
if (STp->write_pending)
STp->nbr_waits++;
else
STp->nbr_finished++;
) /* end DEB */
wait_for_completion(&(STp->wait));
SRpnt = STbuffer->last_SRpnt;
STbuffer->last_SRpnt = NULL;
SRpnt->waiting = NULL;
(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
st_release_request(SRpnt);
STbuffer->buffer_bytes -= STbuffer->writing;
STps = &(STp->ps[STp->partition]);
if (STps->drv_block >= 0) {
if (STp->block_size == 0)
STps->drv_block++;
else
STps->drv_block += STbuffer->writing / STp->block_size;
}
cmdstatp = &STbuffer->cmdstat;
if (STbuffer->syscall_result) {
retval = -EIO;
if (cmdstatp->have_sense && !cmdstatp->deferred &&
(cmdstatp->flags & SENSE_EOM) &&
(cmdstatp->sense_hdr.sense_key == NO_SENSE ||
cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
/* EOM at write-behind, has all data been written? */
if (!cmdstatp->remainder_valid ||
cmdstatp->uremainder64 == 0)
retval = -ENOSPC;
}
if (retval == -EIO)
STps->drv_block = -1;
}
STbuffer->writing = 0;
DEB(if (debugging && retval)
printk(ST_DEB_MSG "%s: Async write error %x, return value %d.\n",
tape_name(STp), STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
return retval;
}
/* Step over EOF if it has been inadvertently crossed (ioctl not used because
it messes up the block number). */
static int cross_eof(struct scsi_tape * STp, int forward)
{
struct st_request *SRpnt;
unsigned char cmd[MAX_COMMAND_SIZE];
cmd[0] = SPACE;
cmd[1] = 0x01; /* Space FileMarks */
if (forward) {
cmd[2] = cmd[3] = 0;
cmd[4] = 1;
} else
cmd[2] = cmd[3] = cmd[4] = 0xff; /* -1 filemarks */
cmd[5] = 0;
DEBC(printk(ST_DEB_MSG "%s: Stepping over filemark %s.\n",
tape_name(STp), forward ? "forward" : "backward"));
SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
STp->device->timeout, MAX_RETRIES, 1);
if (!SRpnt)
return (STp->buffer)->syscall_result;
st_release_request(SRpnt);
SRpnt = NULL;
if ((STp->buffer)->cmdstat.midlevel_result != 0)
printk(KERN_ERR "%s: Stepping over filemark %s failed.\n",
tape_name(STp), forward ? "forward" : "backward");
return (STp->buffer)->syscall_result;
}
/* Flush the write buffer (never need to write if variable blocksize). */
static int flush_write_buffer(struct scsi_tape * STp)
{
int offset, transfer, blks;
int result;
unsigned char cmd[MAX_COMMAND_SIZE];
struct st_request *SRpnt;
struct st_partstat *STps;
result = write_behind_check(STp);
if (result)
return result;
result = 0;
if (STp->dirty == 1) {
offset = (STp->buffer)->buffer_bytes;
transfer = ((offset + STp->block_size - 1) /
STp->block_size) * STp->block_size;
DEBC(printk(ST_DEB_MSG "%s: Flushing %d bytes.\n",
tape_name(STp), transfer));
memset((STp->buffer)->b_data + offset, 0, transfer - offset);
memset(cmd, 0, MAX_COMMAND_SIZE);
cmd[0] = WRITE_6;
cmd[1] = 1;
blks = transfer / STp->block_size;
cmd[2] = blks >> 16;
cmd[3] = blks >> 8;
cmd[4] = blks;
SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
STp->device->timeout, MAX_WRITE_RETRIES, 1);
if (!SRpnt)
return (STp->buffer)->syscall_result;
STps = &(STp->ps[STp->partition]);
if ((STp->buffer)->syscall_result != 0) {
struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
if (cmdstatp->have_sense && !cmdstatp->deferred &&
(cmdstatp->flags & SENSE_EOM) &&
(cmdstatp->sense_hdr.sense_key == NO_SENSE ||
cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
(!cmdstatp->remainder_valid ||
cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
STp->dirty = 0;
(STp->buffer)->buffer_bytes = 0;
if (STps->drv_block >= 0)
STps->drv_block += blks;
result = (-ENOSPC);
} else {
printk(KERN_ERR "%s: Error on flush.\n",
tape_name(STp));
STps->drv_block = (-1);
result = (-EIO);
}
} else {
if (STps->drv_block >= 0)
STps->drv_block += blks;
STp->dirty = 0;
(STp->buffer)->buffer_bytes = 0;
}
st_release_request(SRpnt);
SRpnt = NULL;
}
return result;
}
/* Flush the tape buffer. The tape will be positioned correctly unless
seek_next is true. */
static int flush_buffer(struct scsi_tape *STp, int seek_next)
{
int backspace, result;
struct st_buffer *STbuffer;
struct st_partstat *STps;
STbuffer = STp->buffer;
/*
* If there was a bus reset, block further access
* to this device.
*/
if (STp->pos_unknown)
return (-EIO);
if (STp->ready != ST_READY)
return 0;
STps = &(STp->ps[STp->partition]);
if (STps->rw == ST_WRITING) /* Writing */
return flush_write_buffer(STp);
if (STp->block_size == 0)
return 0;
backspace = ((STp->buffer)->buffer_bytes +
(STp->buffer)->read_pointer) / STp->block_size -
((STp->buffer)->read_pointer + STp->block_size - 1) /
STp->block_size;
(STp->buffer)->buffer_bytes = 0;
(STp->buffer)->read_pointer = 0;
result = 0;
if (!seek_next) {
if (STps->eof == ST_FM_HIT) {
result = cross_eof(STp, 0); /* Back over the EOF hit */
if (!result)
STps->eof = ST_NOEOF;
else {
if (STps->drv_file >= 0)
STps->drv_file++;
STps->drv_block = 0;
}
}
if (!result && backspace > 0)
result = st_int_ioctl(STp, MTBSR, backspace);
} else if (STps->eof == ST_FM_HIT) {
if (STps->drv_file >= 0)
STps->drv_file++;
STps->drv_block = 0;
STps->eof = ST_NOEOF;
}
return result;
}
/* Set the mode parameters */
static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
{
int set_it = 0;
unsigned long arg;
char *name = tape_name(STp);
if (!STp->density_changed &&
STm->default_density >= 0 &&
STm->default_density != STp->density) {
arg = STm->default_density;
set_it = 1;
} else
arg = STp->density;
arg <<= MT_ST_DENSITY_SHIFT;
if (!STp->blksize_changed &&
STm->default_blksize >= 0 &&
STm->default_blksize != STp->block_size) {
arg |= STm->default_blksize;
set_it = 1;
} else
arg |= STp->block_size;
if (set_it &&
st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
printk(KERN_WARNING
"%s: Can't set default block size to %d bytes and density %x.\n",
name, STm->default_blksize, STm->default_density);
if (modes_defined)
return (-EINVAL);
}
return 0;
}
/* Lock or unlock the drive door. Don't use when st_request allocated. */
static int do_door_lock(struct scsi_tape * STp, int do_lock)
{
int retval, cmd;
DEB(char *name = tape_name(STp);)
cmd = do_lock ? SCSI_IOCTL_DOORLOCK : SCSI_IOCTL_DOORUNLOCK;
DEBC(printk(ST_DEB_MSG "%s: %socking drive door.\n", name,
do_lock ? "L" : "Unl"));
retval = scsi_ioctl(STp->device, cmd, NULL);
if (!retval) {
STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
}
else {
STp->door_locked = ST_LOCK_FAILS;
}
return retval;
}
/* Set the internal state after reset */
static void reset_state(struct scsi_tape *STp)
{
int i;
struct st_partstat *STps;
STp->pos_unknown = 0;
for (i = 0; i < ST_NBR_PARTITIONS; i++) {
STps = &(STp->ps[i]);
STps->rw = ST_IDLE;
STps->eof = ST_NOEOF;
STps->at_sm = 0;
STps->last_block_valid = 0;
STps->drv_block = -1;
STps->drv_file = -1;
}
if (STp->can_partitions) {
STp->partition = find_partition(STp);
if (STp->partition < 0)
STp->partition = 0;
STp->new_partition = STp->partition;
}
}
/* Test if the drive is ready. Returns either one of the codes below or a negative system
error code. */
#define CHKRES_READY 0
#define CHKRES_NEW_SESSION 1
#define CHKRES_NOT_READY 2
#define CHKRES_NO_TAPE 3
#define MAX_ATTENTIONS 10
static int test_ready(struct scsi_tape *STp, int do_wait)
{
int attentions, waits, max_wait, scode;
int retval = CHKRES_READY, new_session = 0;
unsigned char cmd[MAX_COMMAND_SIZE];
struct st_request *SRpnt = NULL;
struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
for (attentions=waits=0; ; ) {
memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
cmd[0] = TEST_UNIT_READY;
SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
STp->long_timeout, MAX_READY_RETRIES, 1);
if (!SRpnt) {
retval = (STp->buffer)->syscall_result;
break;
}
if (cmdstatp->have_sense) {
scode = cmdstatp->sense_hdr.sense_key;
if (scode == UNIT_ATTENTION) { /* New media? */
new_session = 1;
if (attentions < MAX_ATTENTIONS) {
attentions++;
continue;
}
else {
retval = (-EIO);
break;
}
}
if (scode == NOT_READY) {
if (waits < max_wait) {
if (msleep_interruptible(1000)) {
retval = (-EINTR);
break;
}
waits++;
continue;
}
else {
if ((STp->device)->scsi_level >= SCSI_2 &&
cmdstatp->sense_hdr.asc == 0x3a) /* Check ASC */
retval = CHKRES_NO_TAPE;
else
retval = CHKRES_NOT_READY;
break;
}
}
}
retval = (STp->buffer)->syscall_result;
if (!retval)
retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
break;
}
if (SRpnt != NULL)
st_release_request(SRpnt);
return retval;
}
/* See if the drive is ready and gather information about the tape. Return values:
< 0 negative error code from errno.h
0 drive ready
1 drive not ready (possibly no tape)
*/
static int check_tape(struct scsi_tape *STp, struct file *filp)
{
int i, retval, new_session = 0, do_wait;
unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
unsigned short st_flags = filp->f_flags;
struct st_request *SRpnt = NULL;
struct st_modedef *STm;
struct st_partstat *STps;
char *name = tape_name(STp);
struct inode *inode = filp->f_path.dentry->d_inode;
int mode = TAPE_MODE(inode);
STp->ready = ST_READY;
if (mode != STp->current_mode) {
DEBC(printk(ST_DEB_MSG "%s: Mode change from %d to %d.\n",
name, STp->current_mode, mode));
new_session = 1;
STp->current_mode = mode;
}
STm = &(STp->modes[STp->current_mode]);
saved_cleaning = STp->cleaning_req;
STp->cleaning_req = 0;
do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
retval = test_ready(STp, do_wait);
if (retval < 0)
goto err_out;
if (retval == CHKRES_NEW_SESSION) {
STp->pos_unknown = 0;
STp->partition = STp->new_partition = 0;
if (STp->can_partitions)
STp->nbr_partitions = 1; /* This guess will be updated later
if necessary */
for (i = 0; i < ST_NBR_PARTITIONS; i++) {
STps = &(STp->ps[i]);
STps->rw = ST_IDLE;
STps->eof = ST_NOEOF;
STps->at_sm = 0;
STps->last_block_valid = 0;
STps->drv_block = 0;
STps->drv_file = 0;
}
new_session = 1;
}
else {
STp->cleaning_req |= saved_cleaning;
if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
if (retval == CHKRES_NO_TAPE)
STp->ready = ST_NO_TAPE;
else
STp->ready = ST_NOT_READY;
STp->density = 0; /* Clear the erroneous "residue" */
STp->write_prot = 0;
STp->block_size = 0;
STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
STp->partition = STp->new_partition = 0;
STp->door_locked = ST_UNLOCKED;
return CHKRES_NOT_READY;
}
}
if (STp->omit_blklims)
STp->min_block = STp->max_block = (-1);
else {
memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
cmd[0] = READ_BLOCK_LIMITS;
SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
STp->device->timeout, MAX_READY_RETRIES, 1);
if (!SRpnt) {
retval = (STp->buffer)->syscall_result;
goto err_out;
}
if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
STp->max_block = ((STp->buffer)->b_data[1] << 16) |
((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
STp->min_block = ((STp->buffer)->b_data[4] << 8) |